net/mac80211/rx.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/jiffies.h>
  13 #include <linux/kernel.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/rcupdate.h>
  18 #include <net/mac80211.h>
  19 #include <net/ieee80211_radiotap.h>
  20
  21 #include "ieee80211_i.h"
  22 #include "driver-ops.h"
  23 #include "led.h"
  24 #include "mesh.h"
  25 #include "wep.h"
  26 #include "wpa.h"
  27 #include "tkip.h"
  28 #include "wme.h"
  29
  30 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
  31                                            struct tid_ampdu_rx *tid_agg_rx,
  32                                            struct sk_buff *skb,
  33                                            struct ieee80211_rx_status *status,
  34                                            u16 mpdu_seq_num,
  35                                            int bar_req);
  36 /*
  37  * monitor mode reception
  38  *
  39  * This function cleans up the SKB, i.e. it removes all the stuff
  40  * only useful for monitoring.
  41  */
  42 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  43                                            struct sk_buff *skb,
  44                                            int rtap_len)
  45 {
  46         skb_pull(skb, rtap_len);
  47
  48         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  49                 if (likely(skb->len > FCS_LEN))
  50                         skb_trim(skb, skb->len - FCS_LEN);
  51                 else {
  52                         /* driver bug */
  53                         WARN_ON(1);
  54                         dev_kfree_skb(skb);
  55                         skb = NULL;
  56                 }
  57         }
  58
  59         return skb;
  60 }
  61
  62 static inline int should_drop_frame(struct ieee80211_rx_status *status,
  63                                     struct sk_buff *skb,
  64                                     int present_fcs_len,
  65                                     int radiotap_len)
  66 {
  67         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  68
  69         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  70                 return 1;
  71         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
  72                 return 1;
  73         if (ieee80211_is_ctl(hdr->frame_control) &&
  74             !ieee80211_is_pspoll(hdr->frame_control) &&
  75             !ieee80211_is_back_req(hdr->frame_control))
  76                 return 1;
  77         return 0;
  78 }
  79
  80 static int
  81 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  82                           struct ieee80211_rx_status *status)
  83 {
  84         int len;
  85
  86         /* always present fields */
  87         len = sizeof(struct ieee80211_radiotap_header) + 9;
  88
  89         if (status->flag & RX_FLAG_TSFT)
  90                 len += 8;
  91         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  92                 len += 1;
  93         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
  94                 len += 1;
  95
  96         if (len & 1) /* padding for RX_FLAGS if necessary */
  97                 len++;
  98
  99         /* make sure radiotap starts at a naturally aligned address */
 100         if (len % 8)
 101                 len = roundup(len, 8);
 102
 103         return len;
 104 }
 105
 106 /*
 107  * ieee80211_add_rx_radiotap_header - add radiotap header
 108  *
 109  * add a radiotap header containing all the fields which the hardware provided.
 110  */
 111 static void
 112 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 113                                  struct sk_buff *skb,
 114                                  struct ieee80211_rx_status *status,
 115                                  struct ieee80211_rate *rate,
 116                                  int rtap_len)
 117 {
 118         struct ieee80211_radiotap_header *rthdr;
 119         unsigned char *pos;
 120
 121         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 122         memset(rthdr, 0, rtap_len);
 123
 124         /* radiotap header, set always present flags */
 125         rthdr->it_present =
 126                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 127                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 128                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 129                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 130         rthdr->it_len = cpu_to_le16(rtap_len);
 131
 132         pos = (unsigned char *)(rthdr+1);
 133
 134         /* the order of the following fields is important */
 135
 136         /* IEEE80211_RADIOTAP_TSFT */
 137         if (status->flag & RX_FLAG_TSFT) {
 138                 *(__le64 *)pos = cpu_to_le64(status->mactime);
 139                 rthdr->it_present |=
 140                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 141                 pos += 8;
 142         }
 143
 144         /* IEEE80211_RADIOTAP_FLAGS */
 145         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 146                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 147         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 148                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 149         if (status->flag & RX_FLAG_SHORTPRE)
 150                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 151         pos++;
 152
 153         /* IEEE80211_RADIOTAP_RATE */
 154         if (status->flag & RX_FLAG_HT) {
 155                 /*
 156                  * TODO: add following information into radiotap header once
 157                  * suitable fields are defined for it:
 158                  * - MCS index (status->rate_idx)
 159                  * - HT40 (status->flag & RX_FLAG_40MHZ)
 160                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
 161                  */
 162                 *pos = 0;
 163         } else {
 164                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 165                 *pos = rate->bitrate / 5;
 166         }
 167         pos++;
 168
 169         /* IEEE80211_RADIOTAP_CHANNEL */
 170         *(__le16 *)pos = cpu_to_le16(status->freq);
 171         pos += 2;
 172         if (status->band == IEEE80211_BAND_5GHZ)
 173                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
 174                                              IEEE80211_CHAN_5GHZ);
 175         else if (rate->flags & IEEE80211_RATE_ERP_G)
 176                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
 177                                              IEEE80211_CHAN_2GHZ);
 178         else
 179                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
 180                                              IEEE80211_CHAN_2GHZ);
 181         pos += 2;
 182
 183         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 184         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 185                 *pos = status->signal;
 186                 rthdr->it_present |=
 187                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 188                 pos++;
 189         }
 190
 191         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
 192         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
 193                 *pos = status->noise;
 194                 rthdr->it_present |=
 195                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
 196                 pos++;
 197         }
 198
 199         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 200
 201         /* IEEE80211_RADIOTAP_ANTENNA */
 202         *pos = status->antenna;
 203         pos++;
 204
 205         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 206
 207         /* IEEE80211_RADIOTAP_RX_FLAGS */
 208         /* ensure 2 byte alignment for the 2 byte field as required */
 209         if ((pos - (unsigned char *)rthdr) & 1)
 210                 pos++;
 211         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
 212                 *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADPLCP);
 213         pos += 2;
 214 }
 215
 216 /*
 217  * This function copies a received frame to all monitor interfaces and
 218  * returns a cleaned-up SKB that no longer includes the FCS nor the
 219  * radiotap header the driver might have added.
 220  */
 221 static struct sk_buff *
 222 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 223                      struct ieee80211_rx_status *status,
 224                      struct ieee80211_rate *rate)
 225 {
 226         struct ieee80211_sub_if_data *sdata;
 227         int needed_headroom = 0;
 228         struct sk_buff *skb, *skb2;
 229         struct net_device *prev_dev = NULL;
 230         int present_fcs_len = 0;
 231         int rtap_len = 0;
 232
 233         /*
 234          * First, we may need to make a copy of the skb because
 235          *  (1) we need to modify it for radiotap (if not present), and
 236          *  (2) the other RX handlers will modify the skb we got.
 237          *
 238          * We don't need to, of course, if we aren't going to return
 239          * the SKB because it has a bad FCS/PLCP checksum.
 240          */
 241         if (status->flag & RX_FLAG_RADIOTAP)
 242                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
 243         else
 244                 /* room for the radiotap header based on driver features */
 245                 needed_headroom = ieee80211_rx_radiotap_len(local, status);
 246
 247         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 248                 present_fcs_len = FCS_LEN;
 249
 250         if (!local->monitors) {
 251                 if (should_drop_frame(status, origskb, present_fcs_len,
 252                                       rtap_len)) {
 253                         dev_kfree_skb(origskb);
 254                         return NULL;
 255                 }
 256
 257                 return remove_monitor_info(local, origskb, rtap_len);
 258         }
 259
 260         if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
 261                 /* only need to expand headroom if necessary */
 262                 skb = origskb;
 263                 origskb = NULL;
 264
 265                 /*
 266                  * This shouldn't trigger often because most devices have an
 267                  * RX header they pull before we get here, and that should
 268                  * be big enough for our radiotap information. We should
 269                  * probably export the length to drivers so that we can have
 270                  * them allocate enough headroom to start with.
 271                  */
 272                 if (skb_headroom(skb) < needed_headroom &&
 273                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 274                         dev_kfree_skb(skb);
 275                         return NULL;
 276                 }
 277         } else {
 278                 /*
 279                  * Need to make a copy and possibly remove radiotap header
 280                  * and FCS from the original.
 281                  */
 282                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 283
 284                 origskb = remove_monitor_info(local, origskb, rtap_len);
 285
 286                 if (!skb)
 287                         return origskb;
 288         }
 289
 290         /* if necessary, prepend radiotap information */
 291         if (!(status->flag & RX_FLAG_RADIOTAP))
 292                 ieee80211_add_rx_radiotap_header(local, skb, status, rate,
 293                                                  needed_headroom);
 294
 295         skb_reset_mac_header(skb);
 296         skb->ip_summed = CHECKSUM_UNNECESSARY;
 297         skb->pkt_type = PACKET_OTHERHOST;
 298         skb->protocol = htons(ETH_P_802_2);
 299
 300         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 301                 if (!netif_running(sdata->dev))
 302                         continue;
 303
 304                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 305                         continue;
 306
 307                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 308                         continue;
 309
 310                 if (prev_dev) {
 311                         skb2 = skb_clone(skb, GFP_ATOMIC);
 312                         if (skb2) {
 313                                 skb2->dev = prev_dev;
 314                                 netif_rx(skb2);
 315                         }
 316                 }
 317
 318                 prev_dev = sdata->dev;
 319                 sdata->dev->stats.rx_packets++;
 320                 sdata->dev->stats.rx_bytes += skb->len;
 321         }
 322
 323         if (prev_dev) {
 324                 skb->dev = prev_dev;
 325                 netif_rx(skb);
 326         } else
 327                 dev_kfree_skb(skb);
 328
 329         return origskb;
 330 }
 331
 332
 333 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 334 {
 335         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 336         int tid;
 337
 338         /* does the frame have a qos control field? */
 339         if (ieee80211_is_data_qos(hdr->frame_control)) {
 340                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 341                 /* frame has qos control */
 342                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 343                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 344                         rx->flags |= IEEE80211_RX_AMSDU;
 345                 else
 346                         rx->flags &= ~IEEE80211_RX_AMSDU;
 347         } else {
 348                 /*
 349                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 350                  *
 351                  *      Sequence numbers for management frames, QoS data
 352                  *      frames with a broadcast/multicast address in the
 353                  *      Address 1 field, and all non-QoS data frames sent
 354                  *      by QoS STAs are assigned using an additional single
 355                  *      modulo-4096 counter, [...]
 356                  *
 357                  * We also use that counter for non-QoS STAs.
 358                  */
 359                 tid = NUM_RX_DATA_QUEUES - 1;
 360         }
 361
 362         rx->queue = tid;
 363         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 364          * For now, set skb->priority to 0 for other cases. */
 365         rx->skb->priority = (tid > 7) ? 0 : tid;
 366 }
 367
 368 /**
 369  * DOC: Packet alignment
 370  *
 371  * Drivers always need to pass packets that are aligned to two-byte boundaries
 372  * to the stack.
 373  *
 374  * Additionally, should, if possible, align the payload data in a way that
 375  * guarantees that the contained IP header is aligned to a four-byte
 376  * boundary. In the case of regular frames, this simply means aligning the
 377  * payload to a four-byte boundary (because either the IP header is directly
 378  * contained, or IV/RFC1042 headers that have a length divisible by four are
 379  * in front of it).
 380  *
 381  * With A-MSDU frames, however, the payload data address must yield two modulo
 382  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 383  * push the IP header further back to a multiple of four again. Thankfully, the
 384  * specs were sane enough this time around to require padding each A-MSDU
 385  * subframe to a length that is a multiple of four.
 386  *
 387  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
 388  * the payload is not supported, the driver is required to move the 802.11
 389  * header to be directly in front of the payload in that case.
 390  */
 391 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 392 {
 393         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 394         int hdrlen;
 395
 396 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
 397         return;
 398 #endif
 399
 400         if (WARN_ONCE((unsigned long)rx->skb->data & 1,
 401                       "unaligned packet at 0x%p\n", rx->skb->data))
 402                 return;
 403
 404         if (!ieee80211_is_data_present(hdr->frame_control))
 405                 return;
 406
 407         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 408         if (rx->flags & IEEE80211_RX_AMSDU)
 409                 hdrlen += ETH_HLEN;
 410         WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
 411                   "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
 412 }
 413
 414
 415 /* rx handlers */
 416
 417 static ieee80211_rx_result debug_noinline
 418 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 419 {
 420         struct ieee80211_local *local = rx->local;
 421         struct sk_buff *skb = rx->skb;
 422
 423         if (unlikely(local->hw_scanning))
 424                 return ieee80211_scan_rx(rx->sdata, skb, rx->status);
 425
 426         if (unlikely(local->sw_scanning)) {
 427                 /* drop all the other packets during a software scan anyway */
 428                 if (ieee80211_scan_rx(rx->sdata, skb, rx->status)
 429                     != RX_QUEUED)
 430                         dev_kfree_skb(skb);
 431                 return RX_QUEUED;
 432         }
 433
 434         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
 435                 /* scanning finished during invoking of handlers */
 436                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 437                 return RX_DROP_UNUSABLE;
 438         }
 439
 440         return RX_CONTINUE;
 441 }
 442
 443
 444 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 445 {
 446         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 447
 448         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 449                 return 0;
 450
 451         return ieee80211_is_robust_mgmt_frame(hdr);
 452 }
 453
 454
 455 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 456 {
 457         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 458
 459         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 460                 return 0;
 461
 462         return ieee80211_is_robust_mgmt_frame(hdr);
 463 }
 464
 465
 466 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 467 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 468 {
 469         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 470         struct ieee80211_mmie *mmie;
 471
 472         if (skb->len < 24 + sizeof(*mmie) ||
 473             !is_multicast_ether_addr(hdr->da))
 474                 return -1;
 475
 476         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 477                 return -1; /* not a robust management frame */
 478
 479         mmie = (struct ieee80211_mmie *)
 480                 (skb->data + skb->len - sizeof(*mmie));
 481         if (mmie->element_id != WLAN_EID_MMIE ||
 482             mmie->length != sizeof(*mmie) - 2)
 483                 return -1;
 484
 485         return le16_to_cpu(mmie->key_id);
 486 }
 487
 488
 489 static ieee80211_rx_result
 490 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 491 {
 492         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 493         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 494
 495         if (ieee80211_is_data(hdr->frame_control)) {
 496                 if (!ieee80211_has_a4(hdr->frame_control))
 497                         return RX_DROP_MONITOR;
 498                 if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
 499                         return RX_DROP_MONITOR;
 500         }
 501
 502         /* If there is not an established peer link and this is not a peer link
 503          * establisment frame, beacon or probe, drop the frame.
 504          */
 505
 506         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 507                 struct ieee80211_mgmt *mgmt;
 508
 509                 if (!ieee80211_is_mgmt(hdr->frame_control))
 510                         return RX_DROP_MONITOR;
 511
 512                 if (ieee80211_is_action(hdr->frame_control)) {
 513                         mgmt = (struct ieee80211_mgmt *)hdr;
 514                         if (mgmt->u.action.category != PLINK_CATEGORY)
 515                                 return RX_DROP_MONITOR;
 516                         return RX_CONTINUE;
 517                 }
 518
 519                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 520                     ieee80211_is_probe_resp(hdr->frame_control) ||
 521                     ieee80211_is_beacon(hdr->frame_control))
 522                         return RX_CONTINUE;
 523
 524                 return RX_DROP_MONITOR;
 525
 526         }
 527
 528 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 529
 530         if (ieee80211_is_data(hdr->frame_control) &&
 531             is_multicast_ether_addr(hdr->addr1) &&
 532             mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->sdata))
 533                 return RX_DROP_MONITOR;
 534 #undef msh_h_get
 535
 536         return RX_CONTINUE;
 537 }
 538
 539
 540 static ieee80211_rx_result debug_noinline
 541 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 542 {
 543         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 544
 545         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 546         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 547                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 548                              rx->sta->last_seq_ctrl[rx->queue] ==
 549                              hdr->seq_ctrl)) {
 550                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
 551                                 rx->local->dot11FrameDuplicateCount++;
 552                                 rx->sta->num_duplicates++;
 553                         }
 554                         return RX_DROP_MONITOR;
 555                 } else
 556                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 557         }
 558
 559         if (unlikely(rx->skb->len < 16)) {
 560                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 561                 return RX_DROP_MONITOR;
 562         }
 563
 564         /* Drop disallowed frame classes based on STA auth/assoc state;
 565          * IEEE 802.11, Chap 5.5.
 566          *
 567          * mac80211 filters only based on association state, i.e. it drops
 568          * Class 3 frames from not associated stations. hostapd sends
 569          * deauth/disassoc frames when needed. In addition, hostapd is
 570          * responsible for filtering on both auth and assoc states.
 571          */
 572
 573         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 574                 return ieee80211_rx_mesh_check(rx);
 575
 576         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 577                       ieee80211_is_pspoll(hdr->frame_control)) &&
 578                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 579                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 580                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 581                      !ieee80211_has_tods(hdr->frame_control) &&
 582                      ieee80211_is_data(hdr->frame_control)) ||
 583                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
 584                         /* Drop IBSS frames and frames for other hosts
 585                          * silently. */
 586                         return RX_DROP_MONITOR;
 587                 }
 588
 589                 return RX_DROP_MONITOR;
 590         }
 591
 592         return RX_CONTINUE;
 593 }
 594
 595
 596 static ieee80211_rx_result debug_noinline
 597 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 598 {
 599         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 600         int keyidx;
 601         int hdrlen;
 602         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 603         struct ieee80211_key *stakey = NULL;
 604         int mmie_keyidx = -1;
 605
 606         /*
 607          * Key selection 101
 608          *
 609          * There are four types of keys:
 610          *  - GTK (group keys)
 611          *  - IGTK (group keys for management frames)
 612          *  - PTK (pairwise keys)
 613          *  - STK (station-to-station pairwise keys)
 614          *
 615          * When selecting a key, we have to distinguish between multicast
 616          * (including broadcast) and unicast frames, the latter can only
 617          * use PTKs and STKs while the former always use GTKs and IGTKs.
 618          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 619          * unicast frames can also use key indices like GTKs. Hence, if we
 620          * don't have a PTK/STK we check the key index for a WEP key.
 621          *
 622          * Note that in a regular BSS, multicast frames are sent by the
 623          * AP only, associated stations unicast the frame to the AP first
 624          * which then multicasts it on their behalf.
 625          *
 626          * There is also a slight problem in IBSS mode: GTKs are negotiated
 627          * with each station, that is something we don't currently handle.
 628          * The spec seems to expect that one negotiates the same key with
 629          * every station but there's no such requirement; VLANs could be
 630          * possible.
 631          */
 632
 633         /*
 634          * No point in finding a key and decrypting if the frame is neither
 635          * addressed to us nor a multicast frame.
 636          */
 637         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 638                 return RX_CONTINUE;
 639
 640         if (rx->sta)
 641                 stakey = rcu_dereference(rx->sta->key);
 642
 643         if (!ieee80211_has_protected(hdr->frame_control))
 644                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 645
 646         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 647                 rx->key = stakey;
 648                 /* Skip decryption if the frame is not protected. */
 649                 if (!ieee80211_has_protected(hdr->frame_control))
 650                         return RX_CONTINUE;
 651         } else if (mmie_keyidx >= 0) {
 652                 /* Broadcast/multicast robust management frame / BIP */
 653                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 654                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 655                         return RX_CONTINUE;
 656
 657                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 658                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 659                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 660                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 661         } else if (!ieee80211_has_protected(hdr->frame_control)) {
 662                 /*
 663                  * The frame was not protected, so skip decryption. However, we
 664                  * need to set rx->key if there is a key that could have been
 665                  * used so that the frame may be dropped if encryption would
 666                  * have been expected.
 667                  */
 668                 struct ieee80211_key *key = NULL;
 669                 if (ieee80211_is_mgmt(hdr->frame_control) &&
 670                     is_multicast_ether_addr(hdr->addr1) &&
 671                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 672                         rx->key = key;
 673                 else if ((key = rcu_dereference(rx->sdata->default_key)))
 674                         rx->key = key;
 675                 return RX_CONTINUE;
 676         } else {
 677                 /*
 678                  * The device doesn't give us the IV so we won't be
 679                  * able to look up the key. That's ok though, we
 680                  * don't need to decrypt the frame, we just won't
 681                  * be able to keep statistics accurate.
 682                  * Except for key threshold notifications, should
 683                  * we somehow allow the driver to tell us which key
 684                  * the hardware used if this flag is set?
 685                  */
 686                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 687                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 688                         return RX_CONTINUE;
 689
 690                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
 691
 692                 if (rx->skb->len < 8 + hdrlen)
 693                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 694
 695                 /*
 696                  * no need to call ieee80211_wep_get_keyidx,
 697                  * it verifies a bunch of things we've done already
 698                  */
 699                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 700
 701                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 702
 703                 /*
 704                  * RSNA-protected unicast frames should always be sent with
 705                  * pairwise or station-to-station keys, but for WEP we allow
 706                  * using a key index as well.
 707                  */
 708                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 709                     !is_multicast_ether_addr(hdr->addr1))
 710                         rx->key = NULL;
 711         }
 712
 713         if (rx->key) {
 714                 rx->key->tx_rx_count++;
 715                 /* TODO: add threshold stuff again */
 716         } else {
 717                 return RX_DROP_MONITOR;
 718         }
 719
 720         /* Check for weak IVs if possible */
 721         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 722             ieee80211_is_data(hdr->frame_control) &&
 723             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
 724              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
 725             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 726                 rx->sta->wep_weak_iv_count++;
 727
 728         switch (rx->key->conf.alg) {
 729         case ALG_WEP:
 730                 result = ieee80211_crypto_wep_decrypt(rx);
 731                 break;
 732         case ALG_TKIP:
 733                 result = ieee80211_crypto_tkip_decrypt(rx);
 734                 break;
 735         case ALG_CCMP:
 736                 result = ieee80211_crypto_ccmp_decrypt(rx);
 737                 break;
 738         case ALG_AES_CMAC:
 739                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
 740                 break;
 741         }
 742
 743         /* either the frame has been decrypted or will be dropped */
 744         rx->status->flag |= RX_FLAG_DECRYPTED;
 745
 746         return result;
 747 }
 748
 749 static ieee80211_rx_result debug_noinline
 750 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
 751 {
 752         struct ieee80211_local *local;
 753         struct ieee80211_hdr *hdr;
 754         struct sk_buff *skb;
 755
 756         local = rx->local;
 757         skb = rx->skb;
 758         hdr = (struct ieee80211_hdr *) skb->data;
 759
 760         if (!local->pspolling)
 761                 return RX_CONTINUE;
 762
 763         if (!ieee80211_has_fromds(hdr->frame_control))
 764                 /* this is not from AP */
 765                 return RX_CONTINUE;
 766
 767         if (!ieee80211_is_data(hdr->frame_control))
 768                 return RX_CONTINUE;
 769
 770         if (!ieee80211_has_moredata(hdr->frame_control)) {
 771                 /* AP has no more frames buffered for us */
 772                 local->pspolling = false;
 773                 return RX_CONTINUE;
 774         }
 775
 776         /* more data bit is set, let's request a new frame from the AP */
 777         ieee80211_send_pspoll(local, rx->sdata);
 778
 779         return RX_CONTINUE;
 780 }
 781
 782 static void ap_sta_ps_start(struct sta_info *sta)
 783 {
 784         struct ieee80211_sub_if_data *sdata = sta->sdata;
 785         struct ieee80211_local *local = sdata->local;
 786
 787         atomic_inc(&sdata->bss->num_sta_ps);
 788         set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
 789         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_SLEEP, &sta->sta);
 790 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 791         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
 792                sdata->dev->name, sta->sta.addr, sta->sta.aid);
 793 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 794 }
 795
 796 static int ap_sta_ps_end(struct sta_info *sta)
 797 {
 798         struct ieee80211_sub_if_data *sdata = sta->sdata;
 799         struct ieee80211_local *local = sdata->local;
 800         int sent, buffered;
 801
 802         atomic_dec(&sdata->bss->num_sta_ps);
 803
 804         clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
 805         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_AWAKE, &sta->sta);
 806
 807         if (!skb_queue_empty(&sta->ps_tx_buf))
 808                 sta_info_clear_tim_bit(sta);
 809
 810 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 811         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
 812                sdata->dev->name, sta->sta.addr, sta->sta.aid);
 813 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 814
 815         /* Send all buffered frames to the station */
 816         sent = ieee80211_add_pending_skbs(local, &sta->tx_filtered);
 817         buffered = ieee80211_add_pending_skbs(local, &sta->ps_tx_buf);
 818         sent += buffered;
 819         local->total_ps_buffered -= buffered;
 820
 821 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 822         printk(KERN_DEBUG "%s: STA %pM aid %d sending %d filtered/%d PS frames "
 823                "since STA not sleeping anymore\n", sdata->dev->name,
 824                sta->sta.addr, sta->sta.aid, sent - buffered, buffered);
 825 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 826
 827         return sent;
 828 }
 829
 830 static ieee80211_rx_result debug_noinline
 831 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
 832 {
 833         struct sta_info *sta = rx->sta;
 834         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 835
 836         if (!sta)
 837                 return RX_CONTINUE;
 838
 839         /* Update last_rx only for IBSS packets which are for the current
 840          * BSSID to avoid keeping the current IBSS network alive in cases where
 841          * other STAs are using different BSSID. */
 842         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
 843                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
 844                                                 NL80211_IFTYPE_ADHOC);
 845                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
 846                         sta->last_rx = jiffies;
 847         } else
 848         if (!is_multicast_ether_addr(hdr->addr1) ||
 849             rx->sdata->vif.type == NL80211_IFTYPE_STATION) {
 850                 /* Update last_rx only for unicast frames in order to prevent
 851                  * the Probe Request frames (the only broadcast frames from a
 852                  * STA in infrastructure mode) from keeping a connection alive.
 853                  * Mesh beacons will update last_rx when if they are found to
 854                  * match the current local configuration when processed.
 855                  */
 856                 if (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
 857                     ieee80211_is_beacon(hdr->frame_control)) {
 858                         rx->sdata->u.mgd.last_beacon = jiffies;
 859                 } else
 860                         sta->last_rx = jiffies;
 861         }
 862
 863         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 864                 return RX_CONTINUE;
 865
 866         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
 867                 ieee80211_sta_rx_notify(rx->sdata, hdr);
 868
 869         sta->rx_fragments++;
 870         sta->rx_bytes += rx->skb->len;
 871         sta->last_signal = rx->status->signal;
 872         sta->last_qual = rx->status->qual;
 873         sta->last_noise = rx->status->noise;
 874
 875         /*
 876          * Change STA power saving mode only at the end of a frame
 877          * exchange sequence.
 878          */
 879         if (!ieee80211_has_morefrags(hdr->frame_control) &&
 880             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
 881              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
 882                 if (test_sta_flags(sta, WLAN_STA_PS)) {
 883                         /*
 884                          * Ignore doze->wake transitions that are
 885                          * indicated by non-data frames, the standard
 886                          * is unclear here, but for example going to
 887                          * PS mode and then scanning would cause a
 888                          * doze->wake transition for the probe request,
 889                          * and that is clearly undesirable.
 890                          */
 891                         if (ieee80211_is_data(hdr->frame_control) &&
 892                             !ieee80211_has_pm(hdr->frame_control))
 893                                 rx->sent_ps_buffered += ap_sta_ps_end(sta);
 894                 } else {
 895                         if (ieee80211_has_pm(hdr->frame_control))
 896                                 ap_sta_ps_start(sta);
 897                 }
 898         }
 899
 900         /* Drop data::nullfunc frames silently, since they are used only to
 901          * control station power saving mode. */
 902         if (ieee80211_is_nullfunc(hdr->frame_control)) {
 903                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
 904                 /* Update counter and free packet here to avoid counting this
 905                  * as a dropped packed. */
 906                 sta->rx_packets++;
 907                 dev_kfree_skb(rx->skb);
 908                 return RX_QUEUED;
 909         }
 910
 911         return RX_CONTINUE;
 912 } /* ieee80211_rx_h_sta_process */
 913
 914 static inline struct ieee80211_fragment_entry *
 915 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 916                          unsigned int frag, unsigned int seq, int rx_queue,
 917                          struct sk_buff **skb)
 918 {
 919         struct ieee80211_fragment_entry *entry;
 920         int idx;
 921
 922         idx = sdata->fragment_next;
 923         entry = &sdata->fragments[sdata->fragment_next++];
 924         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
 925                 sdata->fragment_next = 0;
 926
 927         if (!skb_queue_empty(&entry->skb_list)) {
 928 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 929                 struct ieee80211_hdr *hdr =
 930                         (struct ieee80211_hdr *) entry->skb_list.next->data;
 931                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
 932                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
 933                        "addr1=%pM addr2=%pM\n",
 934                        sdata->dev->name, idx,
 935                        jiffies - entry->first_frag_time, entry->seq,
 936                        entry->last_frag, hdr->addr1, hdr->addr2);
 937 #endif
 938                 __skb_queue_purge(&entry->skb_list);
 939         }
 940
 941         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
 942         *skb = NULL;
 943         entry->first_frag_time = jiffies;
 944         entry->seq = seq;
 945         entry->rx_queue = rx_queue;
 946         entry->last_frag = frag;
 947         entry->ccmp = 0;
 948         entry->extra_len = 0;
 949
 950         return entry;
 951 }
 952
 953 static inline struct ieee80211_fragment_entry *
 954 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
 955                           unsigned int frag, unsigned int seq,
 956                           int rx_queue, struct ieee80211_hdr *hdr)
 957 {
 958         struct ieee80211_fragment_entry *entry;
 959         int i, idx;
 960
 961         idx = sdata->fragment_next;
 962         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
 963                 struct ieee80211_hdr *f_hdr;
 964
 965                 idx--;
 966                 if (idx < 0)
 967                         idx = IEEE80211_FRAGMENT_MAX - 1;
 968
 969                 entry = &sdata->fragments[idx];
 970                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
 971                     entry->rx_queue != rx_queue ||
 972                     entry->last_frag + 1 != frag)
 973                         continue;
 974
 975                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
 976
 977                 /*
 978                  * Check ftype and addresses are equal, else check next fragment
 979                  */
 980                 if (((hdr->frame_control ^ f_hdr->frame_control) &
 981                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
 982                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
 983                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
 984                         continue;
 985
 986                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
 987                         __skb_queue_purge(&entry->skb_list);
 988                         continue;
 989                 }
 990                 return entry;
 991         }
 992
 993         return NULL;
 994 }
 995
 996 static ieee80211_rx_result debug_noinline
 997 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 998 {
 999         struct ieee80211_hdr *hdr;
1000         u16 sc;
1001         __le16 fc;
1002         unsigned int frag, seq;
1003         struct ieee80211_fragment_entry *entry;
1004         struct sk_buff *skb;
1005
1006         hdr = (struct ieee80211_hdr *)rx->skb->data;
1007         fc = hdr->frame_control;
1008         sc = le16_to_cpu(hdr->seq_ctrl);
1009         frag = sc & IEEE80211_SCTL_FRAG;
1010
1011         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1012                    (rx->skb)->len < 24 ||
1013                    is_multicast_ether_addr(hdr->addr1))) {
1014                 /* not fragmented */
1015                 goto out;
1016         }
1017         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1018
1019         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1020
1021         if (frag == 0) {
1022                 /* This is the first fragment of a new frame. */
1023                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1024                                                  rx->queue, &(rx->skb));
1025                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1026                     ieee80211_has_protected(fc)) {
1027                         /* Store CCMP PN so that we can verify that the next
1028                          * fragment has a sequential PN value. */
1029                         entry->ccmp = 1;
1030                         memcpy(entry->last_pn,
1031                                rx->key->u.ccmp.rx_pn[rx->queue],
1032                                CCMP_PN_LEN);
1033                 }
1034                 return RX_QUEUED;
1035         }
1036
1037         /* This is a fragment for a frame that should already be pending in
1038          * fragment cache. Add this fragment to the end of the pending entry.
1039          */
1040         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1041         if (!entry) {
1042                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1043                 return RX_DROP_MONITOR;
1044         }
1045
1046         /* Verify that MPDUs within one MSDU have sequential PN values.
1047          * (IEEE 802.11i, 8.3.3.4.5) */
1048         if (entry->ccmp) {
1049                 int i;
1050                 u8 pn[CCMP_PN_LEN], *rpn;
1051                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1052                         return RX_DROP_UNUSABLE;
1053                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1054                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1055                         pn[i]++;
1056                         if (pn[i])
1057                                 break;
1058                 }
1059                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1060                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1061                         return RX_DROP_UNUSABLE;
1062                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1063         }
1064
1065         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1066         __skb_queue_tail(&entry->skb_list, rx->skb);
1067         entry->last_frag = frag;
1068         entry->extra_len += rx->skb->len;
1069         if (ieee80211_has_morefrags(fc)) {
1070                 rx->skb = NULL;
1071                 return RX_QUEUED;
1072         }
1073
1074         rx->skb = __skb_dequeue(&entry->skb_list);
1075         if (skb_tailroom(rx->skb) < entry->extra_len) {
1076                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1077                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1078                                               GFP_ATOMIC))) {
1079                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1080                         __skb_queue_purge(&entry->skb_list);
1081                         return RX_DROP_UNUSABLE;
1082                 }
1083         }
1084         while ((skb = __skb_dequeue(&entry->skb_list))) {
1085                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1086                 dev_kfree_skb(skb);
1087         }
1088
1089         /* Complete frame has been reassembled - process it now */
1090         rx->flags |= IEEE80211_RX_FRAGMENTED;
1091
1092  out:
1093         if (rx->sta)
1094                 rx->sta->rx_packets++;
1095         if (is_multicast_ether_addr(hdr->addr1))
1096                 rx->local->dot11MulticastReceivedFrameCount++;
1097         else
1098                 ieee80211_led_rx(rx->local);
1099         return RX_CONTINUE;
1100 }
1101
1102 static ieee80211_rx_result debug_noinline
1103 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1104 {
1105         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1106         struct sk_buff *skb;
1107         int no_pending_pkts;
1108         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1109
1110         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1111                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1112                 return RX_CONTINUE;
1113
1114         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1115             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1116                 return RX_DROP_UNUSABLE;
1117
1118         skb = skb_dequeue(&rx->sta->tx_filtered);
1119         if (!skb) {
1120                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
1121                 if (skb)
1122                         rx->local->total_ps_buffered--;
1123         }
1124         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
1125                 skb_queue_empty(&rx->sta->ps_tx_buf);
1126
1127         if (skb) {
1128                 struct ieee80211_hdr *hdr =
1129                         (struct ieee80211_hdr *) skb->data;
1130
1131                 /*
1132                  * Tell TX path to send one frame even though the STA may
1133                  * still remain is PS mode after this frame exchange.
1134                  */
1135                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1136
1137 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1138                 printk(KERN_DEBUG "STA %pM aid %d: PS Poll (entries after %d)\n",
1139                        rx->sta->sta.addr, rx->sta->sta.aid,
1140                        skb_queue_len(&rx->sta->ps_tx_buf));
1141 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1142
1143                 /* Use MoreData flag to indicate whether there are more
1144                  * buffered frames for this STA */
1145                 if (no_pending_pkts)
1146                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1147                 else
1148                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1149
1150                 dev_queue_xmit(skb);
1151
1152                 if (no_pending_pkts)
1153                         sta_info_clear_tim_bit(rx->sta);
1154 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1155         } else if (!rx->sent_ps_buffered) {
1156                 /*
1157                  * FIXME: This can be the result of a race condition between
1158                  *        us expiring a frame and the station polling for it.
1159                  *        Should we send it a null-func frame indicating we
1160                  *        have nothing buffered for it?
1161                  */
1162                 printk(KERN_DEBUG "%s: STA %pM sent PS Poll even "
1163                        "though there are no buffered frames for it\n",
1164                        rx->dev->name, rx->sta->sta.addr);
1165 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1166         }
1167
1168         /* Free PS Poll skb here instead of returning RX_DROP that would
1169          * count as an dropped frame. */
1170         dev_kfree_skb(rx->skb);
1171
1172         return RX_QUEUED;
1173 }
1174
1175 static ieee80211_rx_result debug_noinline
1176 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1177 {
1178         u8 *data = rx->skb->data;
1179         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1180
1181         if (!ieee80211_is_data_qos(hdr->frame_control))
1182                 return RX_CONTINUE;
1183
1184         /* remove the qos control field, update frame type and meta-data */
1185         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1186                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1187         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1188         /* change frame type to non QOS */
1189         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1190
1191         return RX_CONTINUE;
1192 }
1193
1194 static int
1195 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1196 {
1197         if (unlikely(!rx->sta ||
1198             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1199                 return -EACCES;
1200
1201         return 0;
1202 }
1203
1204 static int
1205 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1206 {
1207         /*
1208          * Pass through unencrypted frames if the hardware has
1209          * decrypted them already.
1210          */
1211         if (rx->status->flag & RX_FLAG_DECRYPTED)
1212                 return 0;
1213
1214         /* Drop unencrypted frames if key is set. */
1215         if (unlikely(!ieee80211_has_protected(fc) &&
1216                      !ieee80211_is_nullfunc(fc) &&
1217                      ieee80211_is_data(fc) &&
1218                      (rx->key || rx->sdata->drop_unencrypted)))
1219                 return -EACCES;
1220         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1221                 if (unlikely(ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1222                              rx->key))
1223                         return -EACCES;
1224                 /* BIP does not use Protected field, so need to check MMIE */
1225                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb)
1226                              && ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1227                              rx->key))
1228                         return -EACCES;
1229                 /*
1230                  * When using MFP, Action frames are not allowed prior to
1231                  * having configured keys.
1232                  */
1233                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1234                              ieee80211_is_robust_mgmt_frame(
1235                                      (struct ieee80211_hdr *) rx->skb->data)))
1236                         return -EACCES;
1237         }
1238
1239         return 0;
1240 }
1241
1242 static int
1243 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1244 {
1245         struct net_device *dev = rx->dev;
1246         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1247
1248         return ieee80211_data_to_8023(rx->skb, dev->dev_addr, sdata->vif.type);
1249 }
1250
1251 /*
1252  * requires that rx->skb is a frame with ethernet header
1253  */
1254 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1255 {
1256         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1257                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1258         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1259
1260         /*
1261          * Allow EAPOL frames to us/the PAE group address regardless
1262          * of whether the frame was encrypted or not.
1263          */
1264         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1265             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1266              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1267                 return true;
1268
1269         if (ieee80211_802_1x_port_control(rx) ||
1270             ieee80211_drop_unencrypted(rx, fc))
1271                 return false;
1272
1273         return true;
1274 }
1275
1276 /*
1277  * requires that rx->skb is a frame with ethernet header
1278  */
1279 static void
1280 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1281 {
1282         struct net_device *dev = rx->dev;
1283         struct ieee80211_local *local = rx->local;
1284         struct sk_buff *skb, *xmit_skb;
1285         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1286         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1287         struct sta_info *dsta;
1288
1289         skb = rx->skb;
1290         xmit_skb = NULL;
1291
1292         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1293              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1294             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1295             (rx->flags & IEEE80211_RX_RA_MATCH)) {
1296                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1297                         /*
1298                          * send multicast frames both to higher layers in
1299                          * local net stack and back to the wireless medium
1300                          */
1301                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1302                         if (!xmit_skb && net_ratelimit())
1303                                 printk(KERN_DEBUG "%s: failed to clone "
1304                                        "multicast frame\n", dev->name);
1305                 } else {
1306                         dsta = sta_info_get(local, skb->data);
1307                         if (dsta && dsta->sdata->dev == dev) {
1308                                 /*
1309                                  * The destination station is associated to
1310                                  * this AP (in this VLAN), so send the frame
1311                                  * directly to it and do not pass it to local
1312                                  * net stack.
1313                                  */
1314                                 xmit_skb = skb;
1315                                 skb = NULL;
1316                         }
1317                 }
1318         }
1319
1320         if (skb) {
1321                 int align __maybe_unused;
1322
1323 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1324                 /*
1325                  * 'align' will only take the values 0 or 2 here
1326                  * since all frames are required to be aligned
1327                  * to 2-byte boundaries when being passed to
1328                  * mac80211. That also explains the __skb_push()
1329                  * below.
1330                  */
1331                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1332                 if (align) {
1333                         if (WARN_ON(skb_headroom(skb) < 3)) {
1334                                 dev_kfree_skb(skb);
1335                                 skb = NULL;
1336                         } else {
1337                                 u8 *data = skb->data;
1338                                 size_t len = skb->len;
1339                                 u8 *new = __skb_push(skb, align);
1340                                 memmove(new, data, len);
1341                                 __skb_trim(skb, len);
1342                         }
1343                 }
1344 #endif
1345
1346                 if (skb) {
1347                         /* deliver to local stack */
1348                         skb->protocol = eth_type_trans(skb, dev);
1349                         memset(skb->cb, 0, sizeof(skb->cb));
1350                         netif_rx(skb);
1351                 }
1352         }
1353
1354         if (xmit_skb) {
1355                 /* send to wireless media */
1356                 xmit_skb->protocol = htons(ETH_P_802_3);
1357                 skb_reset_network_header(xmit_skb);
1358                 skb_reset_mac_header(xmit_skb);
1359                 dev_queue_xmit(xmit_skb);
1360         }
1361 }
1362
1363 static ieee80211_rx_result debug_noinline
1364 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1365 {
1366         struct net_device *dev = rx->dev;
1367         struct ieee80211_local *local = rx->local;
1368         u16 ethertype;
1369         u8 *payload;
1370         struct sk_buff *skb = rx->skb, *frame = NULL;
1371         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1372         __le16 fc = hdr->frame_control;
1373         const struct ethhdr *eth;
1374         int remaining, err;
1375         u8 dst[ETH_ALEN];
1376         u8 src[ETH_ALEN];
1377
1378         if (unlikely(!ieee80211_is_data(fc)))
1379                 return RX_CONTINUE;
1380
1381         if (unlikely(!ieee80211_is_data_present(fc)))
1382                 return RX_DROP_MONITOR;
1383
1384         if (!(rx->flags & IEEE80211_RX_AMSDU))
1385                 return RX_CONTINUE;
1386
1387         err = __ieee80211_data_to_8023(rx);
1388         if (unlikely(err))
1389                 return RX_DROP_UNUSABLE;
1390
1391         skb->dev = dev;
1392
1393         dev->stats.rx_packets++;
1394         dev->stats.rx_bytes += skb->len;
1395
1396         /* skip the wrapping header */
1397         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1398         if (!eth)
1399                 return RX_DROP_UNUSABLE;
1400
1401         while (skb != frame) {
1402                 u8 padding;
1403                 __be16 len = eth->h_proto;
1404                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1405
1406                 remaining = skb->len;
1407                 memcpy(dst, eth->h_dest, ETH_ALEN);
1408                 memcpy(src, eth->h_source, ETH_ALEN);
1409
1410                 padding = ((4 - subframe_len) & 0x3);
1411                 /* the last MSDU has no padding */
1412                 if (subframe_len > remaining)
1413                         return RX_DROP_UNUSABLE;
1414
1415                 skb_pull(skb, sizeof(struct ethhdr));
1416                 /* if last subframe reuse skb */
1417                 if (remaining <= subframe_len + padding)
1418                         frame = skb;
1419                 else {
1420                         /*
1421                          * Allocate and reserve two bytes more for payload
1422                          * alignment since sizeof(struct ethhdr) is 14.
1423                          */
1424                         frame = dev_alloc_skb(
1425                                 ALIGN(local->hw.extra_tx_headroom, 4) +
1426                                 subframe_len + 2);
1427
1428                         if (frame == NULL)
1429                                 return RX_DROP_UNUSABLE;
1430
1431                         skb_reserve(frame,
1432                                     ALIGN(local->hw.extra_tx_headroom, 4) +
1433                                     sizeof(struct ethhdr) + 2);
1434                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1435                                 ntohs(len));
1436
1437                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1438                                                         padding);
1439                         if (!eth) {
1440                                 dev_kfree_skb(frame);
1441                                 return RX_DROP_UNUSABLE;
1442                         }
1443                 }
1444
1445                 skb_reset_network_header(frame);
1446                 frame->dev = dev;
1447                 frame->priority = skb->priority;
1448                 rx->skb = frame;
1449
1450                 payload = frame->data;
1451                 ethertype = (payload[6] << 8) | payload[7];
1452
1453                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1454                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1455                            compare_ether_addr(payload,
1456                                               bridge_tunnel_header) == 0)) {
1457                         /* remove RFC1042 or Bridge-Tunnel
1458                          * encapsulation and replace EtherType */
1459                         skb_pull(frame, 6);
1460                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1461                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1462                 } else {
1463                         memcpy(skb_push(frame, sizeof(__be16)),
1464                                &len, sizeof(__be16));
1465                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1466                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1467                 }
1468
1469                 if (!ieee80211_frame_allowed(rx, fc)) {
1470                         if (skb == frame) /* last frame */
1471                                 return RX_DROP_UNUSABLE;
1472                         dev_kfree_skb(frame);
1473                         continue;
1474                 }
1475
1476                 ieee80211_deliver_skb(rx);
1477         }
1478
1479         return RX_QUEUED;
1480 }
1481
1482 #ifdef CONFIG_MAC80211_MESH
1483 static ieee80211_rx_result
1484 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1485 {
1486         struct ieee80211_hdr *hdr;
1487         struct ieee80211s_hdr *mesh_hdr;
1488         unsigned int hdrlen;
1489         struct sk_buff *skb = rx->skb, *fwd_skb;
1490
1491         hdr = (struct ieee80211_hdr *) skb->data;
1492         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1493         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1494
1495         if (!ieee80211_is_data(hdr->frame_control))
1496                 return RX_CONTINUE;
1497
1498         if (!mesh_hdr->ttl)
1499                 /* illegal frame */
1500                 return RX_DROP_MONITOR;
1501
1502         if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6){
1503                 struct ieee80211_sub_if_data *sdata;
1504                 struct mesh_path *mppath;
1505
1506                 sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1507                 rcu_read_lock();
1508                 mppath = mpp_path_lookup(mesh_hdr->eaddr2, sdata);
1509                 if (!mppath) {
1510                         mpp_path_add(mesh_hdr->eaddr2, hdr->addr4, sdata);
1511                 } else {
1512                         spin_lock_bh(&mppath->state_lock);
1513                         mppath->exp_time = jiffies;
1514                         if (compare_ether_addr(mppath->mpp, hdr->addr4) != 0)
1515                                 memcpy(mppath->mpp, hdr->addr4, ETH_ALEN);
1516                         spin_unlock_bh(&mppath->state_lock);
1517                 }
1518                 rcu_read_unlock();
1519         }
1520
1521         if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1522                 return RX_CONTINUE;
1523
1524         mesh_hdr->ttl--;
1525
1526         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1527                 if (!mesh_hdr->ttl)
1528                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1529                                                      dropped_frames_ttl);
1530                 else {
1531                         struct ieee80211_hdr *fwd_hdr;
1532                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1533
1534                         if (!fwd_skb && net_ratelimit())
1535                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1536                                                    rx->dev->name);
1537
1538                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1539                         /*
1540                          * Save TA to addr1 to send TA a path error if a
1541                          * suitable next hop is not found
1542                          */
1543                         memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1544                         memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1545                         fwd_skb->dev = rx->local->mdev;
1546                         fwd_skb->iif = rx->dev->ifindex;
1547                         dev_queue_xmit(fwd_skb);
1548                 }
1549         }
1550
1551         if (is_multicast_ether_addr(hdr->addr3) ||
1552             rx->dev->flags & IFF_PROMISC)
1553                 return RX_CONTINUE;
1554         else
1555                 return RX_DROP_MONITOR;
1556 }
1557 #endif
1558
1559 static ieee80211_rx_result debug_noinline
1560 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1561 {
1562         struct net_device *dev = rx->dev;
1563         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1564         __le16 fc = hdr->frame_control;
1565         int err;
1566
1567         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1568                 return RX_CONTINUE;
1569
1570         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1571                 return RX_DROP_MONITOR;
1572
1573         err = __ieee80211_data_to_8023(rx);
1574         if (unlikely(err))
1575                 return RX_DROP_UNUSABLE;
1576
1577         if (!ieee80211_frame_allowed(rx, fc))
1578                 return RX_DROP_MONITOR;
1579
1580         rx->skb->dev = dev;
1581
1582         dev->stats.rx_packets++;
1583         dev->stats.rx_bytes += rx->skb->len;
1584
1585         ieee80211_deliver_skb(rx);
1586
1587         return RX_QUEUED;
1588 }
1589
1590 static ieee80211_rx_result debug_noinline
1591 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1592 {
1593         struct ieee80211_local *local = rx->local;
1594         struct ieee80211_hw *hw = &local->hw;
1595         struct sk_buff *skb = rx->skb;
1596         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1597         struct tid_ampdu_rx *tid_agg_rx;
1598         u16 start_seq_num;
1599         u16 tid;
1600
1601         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1602                 return RX_CONTINUE;
1603
1604         if (ieee80211_is_back_req(bar->frame_control)) {
1605                 if (!rx->sta)
1606                         return RX_CONTINUE;
1607                 tid = le16_to_cpu(bar->control) >> 12;
1608                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1609                                         != HT_AGG_STATE_OPERATIONAL)
1610                         return RX_CONTINUE;
1611                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1612
1613                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1614
1615                 /* reset session timer */
1616                 if (tid_agg_rx->timeout)
1617                         mod_timer(&tid_agg_rx->session_timer,
1618                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1619
1620                 /* manage reordering buffer according to requested */
1621                 /* sequence number */
1622                 rcu_read_lock();
1623                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL, NULL,
1624                                                  start_seq_num, 1);
1625                 rcu_read_unlock();
1626                 return RX_DROP_UNUSABLE;
1627         }
1628
1629         return RX_CONTINUE;
1630 }
1631
1632 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1633                                            struct ieee80211_mgmt *mgmt,
1634                                            size_t len)
1635 {
1636         struct ieee80211_local *local = sdata->local;
1637         struct sk_buff *skb;
1638         struct ieee80211_mgmt *resp;
1639
1640         if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1641                 /* Not to own unicast address */
1642                 return;
1643         }
1644
1645         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1646             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1647                 /* Not from the current AP. */
1648                 return;
1649         }
1650
1651         if (sdata->u.mgd.state == IEEE80211_STA_MLME_ASSOCIATE) {
1652                 /* Association in progress; ignore SA Query */
1653                 return;
1654         }
1655
1656         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1657                 /* Too short SA Query request frame */
1658                 return;
1659         }
1660
1661         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1662         if (skb == NULL)
1663                 return;
1664
1665         skb_reserve(skb, local->hw.extra_tx_headroom);
1666         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1667         memset(resp, 0, 24);
1668         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1669         memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1670         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1671         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1672                                           IEEE80211_STYPE_ACTION);
1673         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1674         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1675         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1676         memcpy(resp->u.action.u.sa_query.trans_id,
1677                mgmt->u.action.u.sa_query.trans_id,
1678                WLAN_SA_QUERY_TR_ID_LEN);
1679
1680         ieee80211_tx_skb(sdata, skb, 1);
1681 }
1682
1683 static ieee80211_rx_result debug_noinline
1684 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1685 {
1686         struct ieee80211_local *local = rx->local;
1687         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1688         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1689         struct ieee80211_bss *bss;
1690         int len = rx->skb->len;
1691
1692         if (!ieee80211_is_action(mgmt->frame_control))
1693                 return RX_CONTINUE;
1694
1695         if (!rx->sta)
1696                 return RX_DROP_MONITOR;
1697
1698         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1699                 return RX_DROP_MONITOR;
1700
1701         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1702                 return RX_DROP_MONITOR;
1703
1704         /* all categories we currently handle have action_code */
1705         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1706                 return RX_DROP_MONITOR;
1707
1708         switch (mgmt->u.action.category) {
1709         case WLAN_CATEGORY_BACK:
1710                 /*
1711                  * The aggregation code is not prepared to handle
1712                  * anything but STA/AP due to the BSSID handling;
1713                  * IBSS could work in the code but isn't supported
1714                  * by drivers or the standard.
1715                  */
1716                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1717                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1718                     sdata->vif.type != NL80211_IFTYPE_AP)
1719                         return RX_DROP_MONITOR;
1720
1721                 switch (mgmt->u.action.u.addba_req.action_code) {
1722                 case WLAN_ACTION_ADDBA_REQ:
1723                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1724                                    sizeof(mgmt->u.action.u.addba_req)))
1725                                 return RX_DROP_MONITOR;
1726                         ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1727                         break;
1728                 case WLAN_ACTION_ADDBA_RESP:
1729                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1730                                    sizeof(mgmt->u.action.u.addba_resp)))
1731                                 return RX_DROP_MONITOR;
1732                         ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1733                         break;
1734                 case WLAN_ACTION_DELBA:
1735                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1736                                    sizeof(mgmt->u.action.u.delba)))
1737                                 return RX_DROP_MONITOR;
1738                         ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1739                         break;
1740                 }
1741                 break;
1742         case WLAN_CATEGORY_SPECTRUM_MGMT:
1743                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1744                         return RX_DROP_MONITOR;
1745
1746                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
1747                         return RX_DROP_MONITOR;
1748
1749                 switch (mgmt->u.action.u.measurement.action_code) {
1750                 case WLAN_ACTION_SPCT_MSR_REQ:
1751                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1752                                    sizeof(mgmt->u.action.u.measurement)))
1753                                 return RX_DROP_MONITOR;
1754                         ieee80211_process_measurement_req(sdata, mgmt, len);
1755                         break;
1756                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1757                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1758                                    sizeof(mgmt->u.action.u.chan_switch)))
1759                                 return RX_DROP_MONITOR;
1760
1761                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1762                                 return RX_DROP_MONITOR;
1763
1764                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1765                                 return RX_DROP_MONITOR;
1766
1767                         bss = ieee80211_rx_bss_get(local, sdata->u.mgd.bssid,
1768                                            local->hw.conf.channel->center_freq,
1769                                            sdata->u.mgd.ssid,
1770                                            sdata->u.mgd.ssid_len);
1771                         if (!bss)
1772                                 return RX_DROP_MONITOR;
1773
1774                         ieee80211_sta_process_chanswitch(sdata,
1775                                      &mgmt->u.action.u.chan_switch.sw_elem, bss);
1776                         ieee80211_rx_bss_put(local, bss);
1777                         break;
1778                 }
1779                 break;
1780         case WLAN_CATEGORY_SA_QUERY:
1781                 if (len < (IEEE80211_MIN_ACTION_SIZE +
1782                            sizeof(mgmt->u.action.u.sa_query)))
1783                         return RX_DROP_MONITOR;
1784                 switch (mgmt->u.action.u.sa_query.action) {
1785                 case WLAN_ACTION_SA_QUERY_REQUEST:
1786                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1787                                 return RX_DROP_MONITOR;
1788                         ieee80211_process_sa_query_req(sdata, mgmt, len);
1789                         break;
1790                 case WLAN_ACTION_SA_QUERY_RESPONSE:
1791                         /*
1792                          * SA Query response is currently only used in AP mode
1793                          * and it is processed in user space.
1794                          */
1795                         return RX_CONTINUE;
1796                 }
1797                 break;
1798         default:
1799                 return RX_CONTINUE;
1800         }
1801
1802         rx->sta->rx_packets++;
1803         dev_kfree_skb(rx->skb);
1804         return RX_QUEUED;
1805 }
1806
1807 static ieee80211_rx_result debug_noinline
1808 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1809 {
1810         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1811         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1812
1813         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1814                 return RX_DROP_MONITOR;
1815
1816         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1817                 return RX_DROP_MONITOR;
1818
1819         if (ieee80211_vif_is_mesh(&sdata->vif))
1820                 return ieee80211_mesh_rx_mgmt(sdata, rx->skb, rx->status);
1821
1822         if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
1823                 return ieee80211_ibss_rx_mgmt(sdata, rx->skb, rx->status);
1824
1825         if (sdata->vif.type == NL80211_IFTYPE_STATION)
1826                 return ieee80211_sta_rx_mgmt(sdata, rx->skb, rx->status);
1827
1828         return RX_DROP_MONITOR;
1829 }
1830
1831 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1832                                             struct ieee80211_hdr *hdr,
1833                                             struct ieee80211_rx_data *rx)
1834 {
1835         int keyidx;
1836         unsigned int hdrlen;
1837
1838         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1839         if (rx->skb->len >= hdrlen + 4)
1840                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1841         else
1842                 keyidx = -1;
1843
1844         if (!rx->sta) {
1845                 /*
1846                  * Some hardware seem to generate incorrect Michael MIC
1847                  * reports; ignore them to avoid triggering countermeasures.
1848                  */
1849                 goto ignore;
1850         }
1851
1852         if (!ieee80211_has_protected(hdr->frame_control))
1853                 goto ignore;
1854
1855         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1856                 /*
1857                  * APs with pairwise keys should never receive Michael MIC
1858                  * errors for non-zero keyidx because these are reserved for
1859                  * group keys and only the AP is sending real multicast
1860                  * frames in the BSS.
1861                  */
1862                 goto ignore;
1863         }
1864
1865         if (!ieee80211_is_data(hdr->frame_control) &&
1866             !ieee80211_is_auth(hdr->frame_control))
1867                 goto ignore;
1868
1869         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL);
1870  ignore:
1871         dev_kfree_skb(rx->skb);
1872         rx->skb = NULL;
1873 }
1874
1875 /* TODO: use IEEE80211_RX_FRAGMENTED */
1876 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1877 {
1878         struct ieee80211_sub_if_data *sdata;
1879         struct ieee80211_local *local = rx->local;
1880         struct ieee80211_rtap_hdr {
1881                 struct ieee80211_radiotap_header hdr;
1882                 u8 flags;
1883                 u8 rate;
1884                 __le16 chan_freq;
1885                 __le16 chan_flags;
1886         } __attribute__ ((packed)) *rthdr;
1887         struct sk_buff *skb = rx->skb, *skb2;
1888         struct net_device *prev_dev = NULL;
1889         struct ieee80211_rx_status *status = rx->status;
1890
1891         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1892                 goto out_free_skb;
1893
1894         if (skb_headroom(skb) < sizeof(*rthdr) &&
1895             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1896                 goto out_free_skb;
1897
1898         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1899         memset(rthdr, 0, sizeof(*rthdr));
1900         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1901         rthdr->hdr.it_present =
1902                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1903                             (1 << IEEE80211_RADIOTAP_RATE) |
1904                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1905
1906         rthdr->rate = rx->rate->bitrate / 5;
1907         rthdr->chan_freq = cpu_to_le16(status->freq);
1908
1909         if (status->band == IEEE80211_BAND_5GHZ)
1910                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1911                                                 IEEE80211_CHAN_5GHZ);
1912         else
1913                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1914                                                 IEEE80211_CHAN_2GHZ);
1915
1916         skb_set_mac_header(skb, 0);
1917         skb->ip_summed = CHECKSUM_UNNECESSARY;
1918         skb->pkt_type = PACKET_OTHERHOST;
1919         skb->protocol = htons(ETH_P_802_2);
1920
1921         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1922                 if (!netif_running(sdata->dev))
1923                         continue;
1924
1925                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1926                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1927                         continue;
1928
1929                 if (prev_dev) {
1930                         skb2 = skb_clone(skb, GFP_ATOMIC);
1931                         if (skb2) {
1932                                 skb2->dev = prev_dev;
1933                                 netif_rx(skb2);
1934                         }
1935                 }
1936
1937                 prev_dev = sdata->dev;
1938                 sdata->dev->stats.rx_packets++;
1939                 sdata->dev->stats.rx_bytes += skb->len;
1940         }
1941
1942         if (prev_dev) {
1943                 skb->dev = prev_dev;
1944                 netif_rx(skb);
1945                 skb = NULL;
1946         } else
1947                 goto out_free_skb;
1948
1949         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1950         return;
1951
1952  out_free_skb:
1953         dev_kfree_skb(skb);
1954 }
1955
1956
1957 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1958                                          struct ieee80211_rx_data *rx,
1959                                          struct sk_buff *skb)
1960 {
1961         ieee80211_rx_result res = RX_DROP_MONITOR;
1962
1963         rx->skb = skb;
1964         rx->sdata = sdata;
1965         rx->dev = sdata->dev;
1966
1967 #define CALL_RXH(rxh)                   \
1968         do {                            \
1969                 res = rxh(rx);          \
1970                 if (res != RX_CONTINUE) \
1971                         goto rxh_done;  \
1972         } while (0);
1973
1974         CALL_RXH(ieee80211_rx_h_passive_scan)
1975         CALL_RXH(ieee80211_rx_h_check)
1976         CALL_RXH(ieee80211_rx_h_decrypt)
1977         CALL_RXH(ieee80211_rx_h_check_more_data)
1978         CALL_RXH(ieee80211_rx_h_sta_process)
1979         CALL_RXH(ieee80211_rx_h_defragment)
1980         CALL_RXH(ieee80211_rx_h_ps_poll)
1981         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1982         /* must be after MMIC verify so header is counted in MPDU mic */
1983         CALL_RXH(ieee80211_rx_h_remove_qos_control)
1984         CALL_RXH(ieee80211_rx_h_amsdu)
1985 #ifdef CONFIG_MAC80211_MESH
1986         if (ieee80211_vif_is_mesh(&sdata->vif))
1987                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
1988 #endif
1989         CALL_RXH(ieee80211_rx_h_data)
1990         CALL_RXH(ieee80211_rx_h_ctrl)
1991         CALL_RXH(ieee80211_rx_h_action)
1992         CALL_RXH(ieee80211_rx_h_mgmt)
1993
1994 #undef CALL_RXH
1995
1996  rxh_done:
1997         switch (res) {
1998         case RX_DROP_MONITOR:
1999                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2000                 if (rx->sta)
2001                         rx->sta->rx_dropped++;
2002                 /* fall through */
2003         case RX_CONTINUE:
2004                 ieee80211_rx_cooked_monitor(rx);
2005                 break;
2006         case RX_DROP_UNUSABLE:
2007                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2008                 if (rx->sta)
2009                         rx->sta->rx_dropped++;
2010                 dev_kfree_skb(rx->skb);
2011                 break;
2012         case RX_QUEUED:
2013                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2014                 break;
2015         }
2016 }
2017
2018 /* main receive path */
2019
2020 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2021                                 struct ieee80211_rx_data *rx,
2022                                 struct ieee80211_hdr *hdr)
2023 {
2024         u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len, sdata->vif.type);
2025         int multicast = is_multicast_ether_addr(hdr->addr1);
2026
2027         switch (sdata->vif.type) {
2028         case NL80211_IFTYPE_STATION:
2029                 if (!bssid)
2030                         return 0;
2031                 if (!ieee80211_bssid_match(bssid, sdata->u.mgd.bssid)) {
2032                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2033                                 return 0;
2034                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2035                 } else if (!multicast &&
2036                            compare_ether_addr(sdata->dev->dev_addr,
2037                                               hdr->addr1) != 0) {
2038                         if (!(sdata->dev->flags & IFF_PROMISC))
2039                                 return 0;
2040                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2041                 }
2042                 break;
2043         case NL80211_IFTYPE_ADHOC:
2044                 if (!bssid)
2045                         return 0;
2046                 if (ieee80211_is_beacon(hdr->frame_control)) {
2047                         return 1;
2048                 }
2049                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2050                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2051                                 return 0;
2052                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2053                 } else if (!multicast &&
2054                            compare_ether_addr(sdata->dev->dev_addr,
2055                                               hdr->addr1) != 0) {
2056                         if (!(sdata->dev->flags & IFF_PROMISC))
2057                                 return 0;
2058                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2059                 } else if (!rx->sta) {
2060                         int rate_idx;
2061                         if (rx->status->flag & RX_FLAG_HT)
2062                                 rate_idx = 0; /* TODO: HT rates */
2063                         else
2064                                 rate_idx = rx->status->rate_idx;
2065                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2066                                 BIT(rate_idx));
2067                 }
2068                 break;
2069         case NL80211_IFTYPE_MESH_POINT:
2070                 if (!multicast &&
2071                     compare_ether_addr(sdata->dev->dev_addr,
2072                                        hdr->addr1) != 0) {
2073                         if (!(sdata->dev->flags & IFF_PROMISC))
2074                                 return 0;
2075
2076                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2077                 }
2078                 break;
2079         case NL80211_IFTYPE_AP_VLAN:
2080         case NL80211_IFTYPE_AP:
2081                 if (!bssid) {
2082                         if (compare_ether_addr(sdata->dev->dev_addr,
2083                                                hdr->addr1))
2084                                 return 0;
2085                 } else if (!ieee80211_bssid_match(bssid,
2086                                         sdata->dev->dev_addr)) {
2087                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2088                                 return 0;
2089                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2090                 }
2091                 break;
2092         case NL80211_IFTYPE_WDS:
2093                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2094                         return 0;
2095                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2096                         return 0;
2097                 break;
2098         case NL80211_IFTYPE_MONITOR:
2099                 /* take everything */
2100                 break;
2101         case NL80211_IFTYPE_UNSPECIFIED:
2102         case __NL80211_IFTYPE_AFTER_LAST:
2103                 /* should never get here */
2104                 WARN_ON(1);
2105                 break;
2106         }
2107
2108         return 1;
2109 }
2110
2111 /*
2112  * This is the actual Rx frames handler. as it blongs to Rx path it must
2113  * be called with rcu_read_lock protection.
2114  */
2115 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2116                                          struct sk_buff *skb,
2117                                          struct ieee80211_rx_status *status,
2118                                          struct ieee80211_rate *rate)
2119 {
2120         struct ieee80211_local *local = hw_to_local(hw);
2121         struct ieee80211_sub_if_data *sdata;
2122         struct ieee80211_hdr *hdr;
2123         struct ieee80211_rx_data rx;
2124         int prepares;
2125         struct ieee80211_sub_if_data *prev = NULL;
2126         struct sk_buff *skb_new;
2127
2128         hdr = (struct ieee80211_hdr *)skb->data;
2129         memset(&rx, 0, sizeof(rx));
2130         rx.skb = skb;
2131         rx.local = local;
2132
2133         rx.status = status;
2134         rx.rate = rate;
2135
2136         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2137                 local->dot11ReceivedFragmentCount++;
2138
2139         rx.sta = sta_info_get(local, hdr->addr2);
2140         if (rx.sta) {
2141                 rx.sdata = rx.sta->sdata;
2142                 rx.dev = rx.sta->sdata->dev;
2143         }
2144
2145         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
2146                 ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
2147                 return;
2148         }
2149
2150         if (unlikely(local->sw_scanning || local->hw_scanning))
2151                 rx.flags |= IEEE80211_RX_IN_SCAN;
2152
2153         ieee80211_parse_qos(&rx);
2154         ieee80211_verify_alignment(&rx);
2155
2156         skb = rx.skb;
2157
2158         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2159                 if (!netif_running(sdata->dev))
2160                         continue;
2161
2162                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
2163                         continue;
2164
2165                 rx.flags |= IEEE80211_RX_RA_MATCH;
2166                 prepares = prepare_for_handlers(sdata, &rx, hdr);
2167
2168                 if (!prepares)
2169                         continue;
2170
2171                 /*
2172                  * frame is destined for this interface, but if it's not
2173                  * also for the previous one we handle that after the
2174                  * loop to avoid copying the SKB once too much
2175                  */
2176
2177                 if (!prev) {
2178                         prev = sdata;
2179                         continue;
2180                 }
2181
2182                 /*
2183                  * frame was destined for the previous interface
2184                  * so invoke RX handlers for it
2185                  */
2186
2187                 skb_new = skb_copy(skb, GFP_ATOMIC);
2188                 if (!skb_new) {
2189                         if (net_ratelimit())
2190                                 printk(KERN_DEBUG "%s: failed to copy "
2191                                        "multicast frame for %s\n",
2192                                        wiphy_name(local->hw.wiphy),
2193                                        prev->dev->name);
2194                         continue;
2195                 }
2196                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
2197                 prev = sdata;
2198         }
2199         if (prev)
2200                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
2201         else
2202                 dev_kfree_skb(skb);
2203 }
2204
2205 #define SEQ_MODULO 0x1000
2206 #define SEQ_MASK   0xfff
2207
2208 static inline int seq_less(u16 sq1, u16 sq2)
2209 {
2210         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
2211 }
2212
2213 static inline u16 seq_inc(u16 sq)
2214 {
2215         return (sq + 1) & SEQ_MASK;
2216 }
2217
2218 static inline u16 seq_sub(u16 sq1, u16 sq2)
2219 {
2220         return (sq1 - sq2) & SEQ_MASK;
2221 }
2222
2223
2224 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
2225                                             struct tid_ampdu_rx *tid_agg_rx,
2226                                             int index)
2227 {
2228         struct ieee80211_supported_band *sband;
2229         struct ieee80211_rate *rate;
2230         struct ieee80211_rx_status status;
2231
2232         if (!tid_agg_rx->reorder_buf[index])
2233                 goto no_frame;
2234
2235         /* release the reordered frames to stack */
2236         memcpy(&status, tid_agg_rx->reorder_buf[index]->cb, sizeof(status));
2237         sband = hw->wiphy->bands[status.band];
2238         if (status.flag & RX_FLAG_HT)
2239                 rate = sband->bitrates; /* TODO: HT rates */
2240         else
2241                 rate = &sband->bitrates[status.rate_idx];
2242         __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
2243                                      &status, rate);
2244         tid_agg_rx->stored_mpdu_num--;
2245         tid_agg_rx->reorder_buf[index] = NULL;
2246
2247 no_frame:
2248         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2249 }
2250
2251
2252 /*
2253  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
2254  * the skb was added to the buffer longer than this time ago, the earlier
2255  * frames that have not yet been received are assumed to be lost and the skb
2256  * can be released for processing. This may also release other skb's from the
2257  * reorder buffer if there are no additional gaps between the frames.
2258  */
2259 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
2260
2261 /*
2262  * As it function blongs to Rx path it must be called with
2263  * the proper rcu_read_lock protection for its flow.
2264  */
2265 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2266                                            struct tid_ampdu_rx *tid_agg_rx,
2267                                            struct sk_buff *skb,
2268                                            struct ieee80211_rx_status *rxstatus,
2269                                            u16 mpdu_seq_num,
2270                                            int bar_req)
2271 {
2272         u16 head_seq_num, buf_size;
2273         int index;
2274
2275         buf_size = tid_agg_rx->buf_size;
2276         head_seq_num = tid_agg_rx->head_seq_num;
2277
2278         /* frame with out of date sequence number */
2279         if (seq_less(mpdu_seq_num, head_seq_num)) {
2280                 dev_kfree_skb(skb);
2281                 return 1;
2282         }
2283
2284         /* if frame sequence number exceeds our buffering window size or
2285          * block Ack Request arrived - release stored frames */
2286         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
2287                 /* new head to the ordering buffer */
2288                 if (bar_req)
2289                         head_seq_num = mpdu_seq_num;
2290                 else
2291                         head_seq_num =
2292                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
2293                 /* release stored frames up to new head to stack */
2294                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2295                         index = seq_sub(tid_agg_rx->head_seq_num,
2296                                 tid_agg_rx->ssn)
2297                                 % tid_agg_rx->buf_size;
2298                         ieee80211_release_reorder_frame(hw, tid_agg_rx,
2299                                                         index);
2300                 }
2301                 if (bar_req)
2302                         return 1;
2303         }
2304
2305         /* now the new frame is always in the range of the reordering */
2306         /* buffer window */
2307         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2308                                 % tid_agg_rx->buf_size;
2309         /* check if we already stored this frame */
2310         if (tid_agg_rx->reorder_buf[index]) {
2311                 dev_kfree_skb(skb);
2312                 return 1;
2313         }
2314
2315         /* if arrived mpdu is in the right order and nothing else stored */
2316         /* release it immediately */
2317         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2318                         tid_agg_rx->stored_mpdu_num == 0) {
2319                 tid_agg_rx->head_seq_num =
2320                         seq_inc(tid_agg_rx->head_seq_num);
2321                 return 0;
2322         }
2323
2324         /* put the frame in the reordering buffer */
2325         tid_agg_rx->reorder_buf[index] = skb;
2326         tid_agg_rx->reorder_time[index] = jiffies;
2327         memcpy(tid_agg_rx->reorder_buf[index]->cb, rxstatus,
2328                sizeof(*rxstatus));
2329         tid_agg_rx->stored_mpdu_num++;
2330         /* release the buffer until next missing frame */
2331         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2332                                                 % tid_agg_rx->buf_size;
2333         if (!tid_agg_rx->reorder_buf[index] &&
2334             tid_agg_rx->stored_mpdu_num > 1) {
2335                 /*
2336                  * No buffers ready to be released, but check whether any
2337                  * frames in the reorder buffer have timed out.
2338                  */
2339                 int j;
2340                 int skipped = 1;
2341                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
2342                      j = (j + 1) % tid_agg_rx->buf_size) {
2343                         if (tid_agg_rx->reorder_buf[j] == NULL) {
2344                                 skipped++;
2345                                 continue;
2346                         }
2347                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
2348                                         HZ / 10))
2349                                 break;
2350
2351 #ifdef CONFIG_MAC80211_HT_DEBUG
2352                         if (net_ratelimit())
2353                                 printk(KERN_DEBUG "%s: release an RX reorder "
2354                                        "frame due to timeout on earlier "
2355                                        "frames\n",
2356                                        wiphy_name(hw->wiphy));
2357 #endif
2358                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
2359
2360                         /*
2361                          * Increment the head seq# also for the skipped slots.
2362                          */
2363                         tid_agg_rx->head_seq_num =
2364                                 (tid_agg_rx->head_seq_num + skipped) &
2365                                 SEQ_MASK;
2366                         skipped = 0;
2367                 }
2368         } else while (tid_agg_rx->reorder_buf[index]) {
2369                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
2370                 index = seq_sub(tid_agg_rx->head_seq_num,
2371                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2372         }
2373         return 1;
2374 }
2375
2376 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2377                                      struct sk_buff *skb,
2378                                      struct ieee80211_rx_status *status)
2379 {
2380         struct ieee80211_hw *hw = &local->hw;
2381         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2382         struct sta_info *sta;
2383         struct tid_ampdu_rx *tid_agg_rx;
2384         u16 sc;
2385         u16 mpdu_seq_num;
2386         u8 ret = 0;
2387         int tid;
2388
2389         sta = sta_info_get(local, hdr->addr2);
2390         if (!sta)
2391                 return ret;
2392
2393         /* filter the QoS data rx stream according to
2394          * STA/TID and check if this STA/TID is on aggregation */
2395         if (!ieee80211_is_data_qos(hdr->frame_control))
2396                 goto end_reorder;
2397
2398         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2399
2400         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2401                 goto end_reorder;
2402
2403         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2404
2405         /* qos null data frames are excluded */
2406         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2407                 goto end_reorder;
2408
2409         /* new un-ordered ampdu frame - process it */
2410
2411         /* reset session timer */
2412         if (tid_agg_rx->timeout)
2413                 mod_timer(&tid_agg_rx->session_timer,
2414                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
2415
2416         /* if this mpdu is fragmented - terminate rx aggregation session */
2417         sc = le16_to_cpu(hdr->seq_ctrl);
2418         if (sc & IEEE80211_SCTL_FRAG) {
2419                 ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2420                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2421                 ret = 1;
2422                 goto end_reorder;
2423         }
2424
2425         /* according to mpdu sequence number deal with reordering buffer */
2426         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2427         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, status,
2428                                                 mpdu_seq_num, 0);
2429  end_reorder:
2430         return ret;
2431 }
2432
2433 /*
2434  * This is the receive path handler. It is called by a low level driver when an
2435  * 802.11 MPDU is received from the hardware.
2436  */
2437 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2438                     struct ieee80211_rx_status *status)
2439 {
2440         struct ieee80211_local *local = hw_to_local(hw);
2441         struct ieee80211_rate *rate = NULL;
2442         struct ieee80211_supported_band *sband;
2443
2444         if (status->band < 0 ||
2445             status->band >= IEEE80211_NUM_BANDS) {
2446                 WARN_ON(1);
2447                 return;
2448         }
2449
2450         sband = local->hw.wiphy->bands[status->band];
2451         if (!sband) {
2452                 WARN_ON(1);
2453                 return;
2454         }
2455
2456         if (status->flag & RX_FLAG_HT) {
2457                 /* rate_idx is MCS index */
2458                 if (WARN_ON(status->rate_idx < 0 ||
2459                             status->rate_idx >= 76))
2460                         return;
2461                 /* HT rates are not in the table - use the highest legacy rate
2462                  * for now since other parts of mac80211 may not yet be fully
2463                  * MCS aware. */
2464                 rate = &sband->bitrates[sband->n_bitrates - 1];
2465         } else {
2466                 if (WARN_ON(status->rate_idx < 0 ||
2467                             status->rate_idx >= sband->n_bitrates))
2468                         return;
2469                 rate = &sband->bitrates[status->rate_idx];
2470         }
2471
2472         /*
2473          * key references and virtual interfaces are protected using RCU
2474          * and this requires that we are in a read-side RCU section during
2475          * receive processing
2476          */
2477         rcu_read_lock();
2478
2479         /*
2480          * Frames with failed FCS/PLCP checksum are not returned,
2481          * all other frames are returned without radiotap header
2482          * if it was previously present.
2483          * Also, frames with less than 16 bytes are dropped.
2484          */
2485         skb = ieee80211_rx_monitor(local, skb, status, rate);
2486         if (!skb) {
2487                 rcu_read_unlock();
2488                 return;
2489         }
2490
2491         /*
2492          * In theory, the block ack reordering should happen after duplicate
2493          * removal (ieee80211_rx_h_check(), which is an RX handler). As such,
2494          * the call to ieee80211_rx_reorder_ampdu() should really be moved to
2495          * happen as a new RX handler between ieee80211_rx_h_check and
2496          * ieee80211_rx_h_decrypt. This cleanup may eventually happen, but for
2497          * the time being, the call can be here since RX reorder buf processing
2498          * will implicitly skip duplicates. We could, in theory at least,
2499          * process frames that ieee80211_rx_h_passive_scan would drop (e.g.,
2500          * frames from other than operational channel), but that should not
2501          * happen in normal networks.
2502          */
2503         if (!ieee80211_rx_reorder_ampdu(local, skb, status))
2504                 __ieee80211_rx_handle_packet(hw, skb, status, rate);
2505
2506         rcu_read_unlock();
2507 }
2508 EXPORT_SYMBOL(__ieee80211_rx);
2509
2510 /* This is a version of the rx handler that can be called from hard irq
2511  * context. Post the skb on the queue and schedule the tasklet */
2512 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2513                           struct ieee80211_rx_status *status)
2514 {
2515         struct ieee80211_local *local = hw_to_local(hw);
2516
2517         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2518
2519         skb->dev = local->mdev;
2520         /* copy status into skb->cb for use by tasklet */
2521         memcpy(skb->cb, status, sizeof(*status));
2522         skb->pkt_type = IEEE80211_RX_MSG;
2523         skb_queue_tail(&local->skb_queue, skb);
2524         tasklet_schedule(&local->tasklet);
2525 }
2526 EXPORT_SYMBOL(ieee80211_rx_irqsafe);