net/mac80211/rx.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/jiffies.h>
  13 #include <linux/kernel.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/rcupdate.h>
  18 #include <net/mac80211.h>
  19 #include <net/ieee80211_radiotap.h>
  20
  21 #include "ieee80211_i.h"
  22 #include "driver-ops.h"
  23 #include "led.h"
  24 #include "mesh.h"
  25 #include "wep.h"
  26 #include "wpa.h"
  27 #include "tkip.h"
  28 #include "wme.h"
  29
  30 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
  31                                            struct tid_ampdu_rx *tid_agg_rx,
  32                                            struct sk_buff *skb,
  33                                            u16 mpdu_seq_num,
  34                                            int bar_req);
  35 /*
  36  * monitor mode reception
  37  *
  38  * This function cleans up the SKB, i.e. it removes all the stuff
  39  * only useful for monitoring.
  40  */
  41 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  42                                            struct sk_buff *skb,
  43                                            int rtap_len)
  44 {
  45         skb_pull(skb, rtap_len);
  46
  47         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  48                 if (likely(skb->len > FCS_LEN))
  49                         skb_trim(skb, skb->len - FCS_LEN);
  50                 else {
  51                         /* driver bug */
  52                         WARN_ON(1);
  53                         dev_kfree_skb(skb);
  54                         skb = NULL;
  55                 }
  56         }
  57
  58         return skb;
  59 }
  60
  61 static inline int should_drop_frame(struct sk_buff *skb,
  62                                     int present_fcs_len,
  63                                     int radiotap_len)
  64 {
  65         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  66         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  67
  68         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  69                 return 1;
  70         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
  71                 return 1;
  72         if (ieee80211_is_ctl(hdr->frame_control) &&
  73             !ieee80211_is_pspoll(hdr->frame_control) &&
  74             !ieee80211_is_back_req(hdr->frame_control))
  75                 return 1;
  76         return 0;
  77 }
  78
  79 static int
  80 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  81                           struct ieee80211_rx_status *status)
  82 {
  83         int len;
  84
  85         /* always present fields */
  86         len = sizeof(struct ieee80211_radiotap_header) + 9;
  87
  88         if (status->flag & RX_FLAG_TSFT)
  89                 len += 8;
  90         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  91                 len += 1;
  92         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
  93                 len += 1;
  94
  95         if (len & 1) /* padding for RX_FLAGS if necessary */
  96                 len++;
  97
  98         /* make sure radiotap starts at a naturally aligned address */
  99         if (len % 8)
 100                 len = roundup(len, 8);
 101
 102         return len;
 103 }
 104
 105 /*
 106  * ieee80211_add_rx_radiotap_header - add radiotap header
 107  *
 108  * add a radiotap header containing all the fields which the hardware provided.
 109  */
 110 static void
 111 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 112                                  struct sk_buff *skb,
 113                                  struct ieee80211_rate *rate,
 114                                  int rtap_len)
 115 {
 116         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 117         struct ieee80211_radiotap_header *rthdr;
 118         unsigned char *pos;
 119
 120         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 121         memset(rthdr, 0, rtap_len);
 122
 123         /* radiotap header, set always present flags */
 124         rthdr->it_present =
 125                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 126                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 127                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 128                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 129         rthdr->it_len = cpu_to_le16(rtap_len);
 130
 131         pos = (unsigned char *)(rthdr+1);
 132
 133         /* the order of the following fields is important */
 134
 135         /* IEEE80211_RADIOTAP_TSFT */
 136         if (status->flag & RX_FLAG_TSFT) {
 137                 *(__le64 *)pos = cpu_to_le64(status->mactime);
 138                 rthdr->it_present |=
 139                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 140                 pos += 8;
 141         }
 142
 143         /* IEEE80211_RADIOTAP_FLAGS */
 144         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 145                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 146         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 147                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 148         if (status->flag & RX_FLAG_SHORTPRE)
 149                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 150         pos++;
 151
 152         /* IEEE80211_RADIOTAP_RATE */
 153         if (status->flag & RX_FLAG_HT) {
 154                 /*
 155                  * TODO: add following information into radiotap header once
 156                  * suitable fields are defined for it:
 157                  * - MCS index (status->rate_idx)
 158                  * - HT40 (status->flag & RX_FLAG_40MHZ)
 159                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
 160                  */
 161                 *pos = 0;
 162         } else {
 163                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 164                 *pos = rate->bitrate / 5;
 165         }
 166         pos++;
 167
 168         /* IEEE80211_RADIOTAP_CHANNEL */
 169         *(__le16 *)pos = cpu_to_le16(status->freq);
 170         pos += 2;
 171         if (status->band == IEEE80211_BAND_5GHZ)
 172                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
 173                                              IEEE80211_CHAN_5GHZ);
 174         else if (rate->flags & IEEE80211_RATE_ERP_G)
 175                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
 176                                              IEEE80211_CHAN_2GHZ);
 177         else
 178                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
 179                                              IEEE80211_CHAN_2GHZ);
 180         pos += 2;
 181
 182         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 183         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 184                 *pos = status->signal;
 185                 rthdr->it_present |=
 186                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 187                 pos++;
 188         }
 189
 190         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
 191         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
 192                 *pos = status->noise;
 193                 rthdr->it_present |=
 194                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
 195                 pos++;
 196         }
 197
 198         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 199
 200         /* IEEE80211_RADIOTAP_ANTENNA */
 201         *pos = status->antenna;
 202         pos++;
 203
 204         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 205
 206         /* IEEE80211_RADIOTAP_RX_FLAGS */
 207         /* ensure 2 byte alignment for the 2 byte field as required */
 208         if ((pos - (unsigned char *)rthdr) & 1)
 209                 pos++;
 210         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
 211                 *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADPLCP);
 212         pos += 2;
 213 }
 214
 215 /*
 216  * This function copies a received frame to all monitor interfaces and
 217  * returns a cleaned-up SKB that no longer includes the FCS nor the
 218  * radiotap header the driver might have added.
 219  */
 220 static struct sk_buff *
 221 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 222                      struct ieee80211_rate *rate)
 223 {
 224         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
 225         struct ieee80211_sub_if_data *sdata;
 226         int needed_headroom = 0;
 227         struct sk_buff *skb, *skb2;
 228         struct net_device *prev_dev = NULL;
 229         int present_fcs_len = 0;
 230         int rtap_len = 0;
 231
 232         /*
 233          * First, we may need to make a copy of the skb because
 234          *  (1) we need to modify it for radiotap (if not present), and
 235          *  (2) the other RX handlers will modify the skb we got.
 236          *
 237          * We don't need to, of course, if we aren't going to return
 238          * the SKB because it has a bad FCS/PLCP checksum.
 239          */
 240         if (status->flag & RX_FLAG_RADIOTAP)
 241                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
 242         else
 243                 /* room for the radiotap header based on driver features */
 244                 needed_headroom = ieee80211_rx_radiotap_len(local, status);
 245
 246         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 247                 present_fcs_len = FCS_LEN;
 248
 249         if (!local->monitors) {
 250                 if (should_drop_frame(origskb, present_fcs_len, rtap_len)) {
 251                         dev_kfree_skb(origskb);
 252                         return NULL;
 253                 }
 254
 255                 return remove_monitor_info(local, origskb, rtap_len);
 256         }
 257
 258         if (should_drop_frame(origskb, present_fcs_len, rtap_len)) {
 259                 /* only need to expand headroom if necessary */
 260                 skb = origskb;
 261                 origskb = NULL;
 262
 263                 /*
 264                  * This shouldn't trigger often because most devices have an
 265                  * RX header they pull before we get here, and that should
 266                  * be big enough for our radiotap information. We should
 267                  * probably export the length to drivers so that we can have
 268                  * them allocate enough headroom to start with.
 269                  */
 270                 if (skb_headroom(skb) < needed_headroom &&
 271                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 272                         dev_kfree_skb(skb);
 273                         return NULL;
 274                 }
 275         } else {
 276                 /*
 277                  * Need to make a copy and possibly remove radiotap header
 278                  * and FCS from the original.
 279                  */
 280                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 281
 282                 origskb = remove_monitor_info(local, origskb, rtap_len);
 283
 284                 if (!skb)
 285                         return origskb;
 286         }
 287
 288         /* if necessary, prepend radiotap information */
 289         if (!(status->flag & RX_FLAG_RADIOTAP))
 290                 ieee80211_add_rx_radiotap_header(local, skb, rate,
 291                                                  needed_headroom);
 292
 293         skb_reset_mac_header(skb);
 294         skb->ip_summed = CHECKSUM_UNNECESSARY;
 295         skb->pkt_type = PACKET_OTHERHOST;
 296         skb->protocol = htons(ETH_P_802_2);
 297
 298         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 299                 if (!netif_running(sdata->dev))
 300                         continue;
 301
 302                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 303                         continue;
 304
 305                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 306                         continue;
 307
 308                 if (prev_dev) {
 309                         skb2 = skb_clone(skb, GFP_ATOMIC);
 310                         if (skb2) {
 311                                 skb2->dev = prev_dev;
 312                                 netif_rx(skb2);
 313                         }
 314                 }
 315
 316                 prev_dev = sdata->dev;
 317                 sdata->dev->stats.rx_packets++;
 318                 sdata->dev->stats.rx_bytes += skb->len;
 319         }
 320
 321         if (prev_dev) {
 322                 skb->dev = prev_dev;
 323                 netif_rx(skb);
 324         } else
 325                 dev_kfree_skb(skb);
 326
 327         return origskb;
 328 }
 329
 330
 331 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 332 {
 333         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 334         int tid;
 335
 336         /* does the frame have a qos control field? */
 337         if (ieee80211_is_data_qos(hdr->frame_control)) {
 338                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 339                 /* frame has qos control */
 340                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 341                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 342                         rx->flags |= IEEE80211_RX_AMSDU;
 343                 else
 344                         rx->flags &= ~IEEE80211_RX_AMSDU;
 345         } else {
 346                 /*
 347                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 348                  *
 349                  *      Sequence numbers for management frames, QoS data
 350                  *      frames with a broadcast/multicast address in the
 351                  *      Address 1 field, and all non-QoS data frames sent
 352                  *      by QoS STAs are assigned using an additional single
 353                  *      modulo-4096 counter, [...]
 354                  *
 355                  * We also use that counter for non-QoS STAs.
 356                  */
 357                 tid = NUM_RX_DATA_QUEUES - 1;
 358         }
 359
 360         rx->queue = tid;
 361         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 362          * For now, set skb->priority to 0 for other cases. */
 363         rx->skb->priority = (tid > 7) ? 0 : tid;
 364 }
 365
 366 /**
 367  * DOC: Packet alignment
 368  *
 369  * Drivers always need to pass packets that are aligned to two-byte boundaries
 370  * to the stack.
 371  *
 372  * Additionally, should, if possible, align the payload data in a way that
 373  * guarantees that the contained IP header is aligned to a four-byte
 374  * boundary. In the case of regular frames, this simply means aligning the
 375  * payload to a four-byte boundary (because either the IP header is directly
 376  * contained, or IV/RFC1042 headers that have a length divisible by four are
 377  * in front of it).
 378  *
 379  * With A-MSDU frames, however, the payload data address must yield two modulo
 380  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 381  * push the IP header further back to a multiple of four again. Thankfully, the
 382  * specs were sane enough this time around to require padding each A-MSDU
 383  * subframe to a length that is a multiple of four.
 384  *
 385  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
 386  * the payload is not supported, the driver is required to move the 802.11
 387  * header to be directly in front of the payload in that case.
 388  */
 389 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 390 {
 391         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 392         int hdrlen;
 393
 394 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
 395         return;
 396 #endif
 397
 398         if (WARN_ONCE((unsigned long)rx->skb->data & 1,
 399                       "unaligned packet at 0x%p\n", rx->skb->data))
 400                 return;
 401
 402         if (!ieee80211_is_data_present(hdr->frame_control))
 403                 return;
 404
 405         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 406         if (rx->flags & IEEE80211_RX_AMSDU)
 407                 hdrlen += ETH_HLEN;
 408         WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
 409                   "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
 410 }
 411
 412
 413 /* rx handlers */
 414
 415 static ieee80211_rx_result debug_noinline
 416 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 417 {
 418         struct ieee80211_local *local = rx->local;
 419         struct sk_buff *skb = rx->skb;
 420
 421         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning)))
 422                 return ieee80211_scan_rx(rx->sdata, skb);
 423
 424         if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning) &&
 425                      (rx->flags & IEEE80211_RX_IN_SCAN))) {
 426                 /* drop all the other packets during a software scan anyway */
 427                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
 428                         dev_kfree_skb(skb);
 429                 return RX_QUEUED;
 430         }
 431
 432         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
 433                 /* scanning finished during invoking of handlers */
 434                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 435                 return RX_DROP_UNUSABLE;
 436         }
 437
 438         return RX_CONTINUE;
 439 }
 440
 441
 442 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 443 {
 444         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 445
 446         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 447                 return 0;
 448
 449         return ieee80211_is_robust_mgmt_frame(hdr);
 450 }
 451
 452
 453 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 454 {
 455         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 456
 457         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 458                 return 0;
 459
 460         return ieee80211_is_robust_mgmt_frame(hdr);
 461 }
 462
 463
 464 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 465 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 466 {
 467         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 468         struct ieee80211_mmie *mmie;
 469
 470         if (skb->len < 24 + sizeof(*mmie) ||
 471             !is_multicast_ether_addr(hdr->da))
 472                 return -1;
 473
 474         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 475                 return -1; /* not a robust management frame */
 476
 477         mmie = (struct ieee80211_mmie *)
 478                 (skb->data + skb->len - sizeof(*mmie));
 479         if (mmie->element_id != WLAN_EID_MMIE ||
 480             mmie->length != sizeof(*mmie) - 2)
 481                 return -1;
 482
 483         return le16_to_cpu(mmie->key_id);
 484 }
 485
 486
 487 static ieee80211_rx_result
 488 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 489 {
 490         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 491         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 492         char *dev_addr = rx->dev->dev_addr;
 493
 494         if (ieee80211_is_data(hdr->frame_control)) {
 495                 if (is_multicast_ether_addr(hdr->addr1)) {
 496                         if (ieee80211_has_tods(hdr->frame_control) ||
 497                                 !ieee80211_has_fromds(hdr->frame_control))
 498                                 return RX_DROP_MONITOR;
 499                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
 500                                 return RX_DROP_MONITOR;
 501                 } else {
 502                         if (!ieee80211_has_a4(hdr->frame_control))
 503                                 return RX_DROP_MONITOR;
 504                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
 505                                 return RX_DROP_MONITOR;
 506                 }
 507         }
 508
 509         /* If there is not an established peer link and this is not a peer link
 510          * establisment frame, beacon or probe, drop the frame.
 511          */
 512
 513         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 514                 struct ieee80211_mgmt *mgmt;
 515
 516                 if (!ieee80211_is_mgmt(hdr->frame_control))
 517                         return RX_DROP_MONITOR;
 518
 519                 if (ieee80211_is_action(hdr->frame_control)) {
 520                         mgmt = (struct ieee80211_mgmt *)hdr;
 521                         if (mgmt->u.action.category != PLINK_CATEGORY)
 522                                 return RX_DROP_MONITOR;
 523                         return RX_CONTINUE;
 524                 }
 525
 526                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 527                     ieee80211_is_probe_resp(hdr->frame_control) ||
 528                     ieee80211_is_beacon(hdr->frame_control))
 529                         return RX_CONTINUE;
 530
 531                 return RX_DROP_MONITOR;
 532
 533         }
 534
 535 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 536
 537         if (ieee80211_is_data(hdr->frame_control) &&
 538             is_multicast_ether_addr(hdr->addr1) &&
 539             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
 540                 return RX_DROP_MONITOR;
 541 #undef msh_h_get
 542
 543         return RX_CONTINUE;
 544 }
 545
 546
 547 static ieee80211_rx_result debug_noinline
 548 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 549 {
 550         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 551
 552         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 553         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 554                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 555                              rx->sta->last_seq_ctrl[rx->queue] ==
 556                              hdr->seq_ctrl)) {
 557                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
 558                                 rx->local->dot11FrameDuplicateCount++;
 559                                 rx->sta->num_duplicates++;
 560                         }
 561                         return RX_DROP_MONITOR;
 562                 } else
 563                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 564         }
 565
 566         if (unlikely(rx->skb->len < 16)) {
 567                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 568                 return RX_DROP_MONITOR;
 569         }
 570
 571         /* Drop disallowed frame classes based on STA auth/assoc state;
 572          * IEEE 802.11, Chap 5.5.
 573          *
 574          * mac80211 filters only based on association state, i.e. it drops
 575          * Class 3 frames from not associated stations. hostapd sends
 576          * deauth/disassoc frames when needed. In addition, hostapd is
 577          * responsible for filtering on both auth and assoc states.
 578          */
 579
 580         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 581                 return ieee80211_rx_mesh_check(rx);
 582
 583         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 584                       ieee80211_is_pspoll(hdr->frame_control)) &&
 585                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 586                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 587                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 588                      !ieee80211_has_tods(hdr->frame_control) &&
 589                      ieee80211_is_data(hdr->frame_control)) ||
 590                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
 591                         /* Drop IBSS frames and frames for other hosts
 592                          * silently. */
 593                         return RX_DROP_MONITOR;
 594                 }
 595
 596                 return RX_DROP_MONITOR;
 597         }
 598
 599         return RX_CONTINUE;
 600 }
 601
 602
 603 static ieee80211_rx_result debug_noinline
 604 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 605 {
 606         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 607         int keyidx;
 608         int hdrlen;
 609         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 610         struct ieee80211_key *stakey = NULL;
 611         int mmie_keyidx = -1;
 612
 613         /*
 614          * Key selection 101
 615          *
 616          * There are four types of keys:
 617          *  - GTK (group keys)
 618          *  - IGTK (group keys for management frames)
 619          *  - PTK (pairwise keys)
 620          *  - STK (station-to-station pairwise keys)
 621          *
 622          * When selecting a key, we have to distinguish between multicast
 623          * (including broadcast) and unicast frames, the latter can only
 624          * use PTKs and STKs while the former always use GTKs and IGTKs.
 625          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 626          * unicast frames can also use key indices like GTKs. Hence, if we
 627          * don't have a PTK/STK we check the key index for a WEP key.
 628          *
 629          * Note that in a regular BSS, multicast frames are sent by the
 630          * AP only, associated stations unicast the frame to the AP first
 631          * which then multicasts it on their behalf.
 632          *
 633          * There is also a slight problem in IBSS mode: GTKs are negotiated
 634          * with each station, that is something we don't currently handle.
 635          * The spec seems to expect that one negotiates the same key with
 636          * every station but there's no such requirement; VLANs could be
 637          * possible.
 638          */
 639
 640         /*
 641          * No point in finding a key and decrypting if the frame is neither
 642          * addressed to us nor a multicast frame.
 643          */
 644         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 645                 return RX_CONTINUE;
 646
 647         if (rx->sta)
 648                 stakey = rcu_dereference(rx->sta->key);
 649
 650         if (!ieee80211_has_protected(hdr->frame_control))
 651                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 652
 653         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 654                 rx->key = stakey;
 655                 /* Skip decryption if the frame is not protected. */
 656                 if (!ieee80211_has_protected(hdr->frame_control))
 657                         return RX_CONTINUE;
 658         } else if (mmie_keyidx >= 0) {
 659                 /* Broadcast/multicast robust management frame / BIP */
 660                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 661                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 662                         return RX_CONTINUE;
 663
 664                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 665                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 666                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 667                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 668         } else if (!ieee80211_has_protected(hdr->frame_control)) {
 669                 /*
 670                  * The frame was not protected, so skip decryption. However, we
 671                  * need to set rx->key if there is a key that could have been
 672                  * used so that the frame may be dropped if encryption would
 673                  * have been expected.
 674                  */
 675                 struct ieee80211_key *key = NULL;
 676                 if (ieee80211_is_mgmt(hdr->frame_control) &&
 677                     is_multicast_ether_addr(hdr->addr1) &&
 678                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 679                         rx->key = key;
 680                 else if ((key = rcu_dereference(rx->sdata->default_key)))
 681                         rx->key = key;
 682                 return RX_CONTINUE;
 683         } else {
 684                 /*
 685                  * The device doesn't give us the IV so we won't be
 686                  * able to look up the key. That's ok though, we
 687                  * don't need to decrypt the frame, we just won't
 688                  * be able to keep statistics accurate.
 689                  * Except for key threshold notifications, should
 690                  * we somehow allow the driver to tell us which key
 691                  * the hardware used if this flag is set?
 692                  */
 693                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 694                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 695                         return RX_CONTINUE;
 696
 697                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
 698
 699                 if (rx->skb->len < 8 + hdrlen)
 700                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 701
 702                 /*
 703                  * no need to call ieee80211_wep_get_keyidx,
 704                  * it verifies a bunch of things we've done already
 705                  */
 706                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 707
 708                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 709
 710                 /*
 711                  * RSNA-protected unicast frames should always be sent with
 712                  * pairwise or station-to-station keys, but for WEP we allow
 713                  * using a key index as well.
 714                  */
 715                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 716                     !is_multicast_ether_addr(hdr->addr1))
 717                         rx->key = NULL;
 718         }
 719
 720         if (rx->key) {
 721                 rx->key->tx_rx_count++;
 722                 /* TODO: add threshold stuff again */
 723         } else {
 724                 return RX_DROP_MONITOR;
 725         }
 726
 727         /* Check for weak IVs if possible */
 728         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 729             ieee80211_is_data(hdr->frame_control) &&
 730             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
 731              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
 732             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 733                 rx->sta->wep_weak_iv_count++;
 734
 735         switch (rx->key->conf.alg) {
 736         case ALG_WEP:
 737                 result = ieee80211_crypto_wep_decrypt(rx);
 738                 break;
 739         case ALG_TKIP:
 740                 result = ieee80211_crypto_tkip_decrypt(rx);
 741                 break;
 742         case ALG_CCMP:
 743                 result = ieee80211_crypto_ccmp_decrypt(rx);
 744                 break;
 745         case ALG_AES_CMAC:
 746                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
 747                 break;
 748         }
 749
 750         /* either the frame has been decrypted or will be dropped */
 751         rx->status->flag |= RX_FLAG_DECRYPTED;
 752
 753         return result;
 754 }
 755
 756 static ieee80211_rx_result debug_noinline
 757 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
 758 {
 759         struct ieee80211_local *local;
 760         struct ieee80211_hdr *hdr;
 761         struct sk_buff *skb;
 762
 763         local = rx->local;
 764         skb = rx->skb;
 765         hdr = (struct ieee80211_hdr *) skb->data;
 766
 767         if (!local->pspolling)
 768                 return RX_CONTINUE;
 769
 770         if (!ieee80211_has_fromds(hdr->frame_control))
 771                 /* this is not from AP */
 772                 return RX_CONTINUE;
 773
 774         if (!ieee80211_is_data(hdr->frame_control))
 775                 return RX_CONTINUE;
 776
 777         if (!ieee80211_has_moredata(hdr->frame_control)) {
 778                 /* AP has no more frames buffered for us */
 779                 local->pspolling = false;
 780                 return RX_CONTINUE;
 781         }
 782
 783         /* more data bit is set, let's request a new frame from the AP */
 784         ieee80211_send_pspoll(local, rx->sdata);
 785
 786         return RX_CONTINUE;
 787 }
 788
 789 static void ap_sta_ps_start(struct sta_info *sta)
 790 {
 791         struct ieee80211_sub_if_data *sdata = sta->sdata;
 792         struct ieee80211_local *local = sdata->local;
 793
 794         atomic_inc(&sdata->bss->num_sta_ps);
 795         set_sta_flags(sta, WLAN_STA_PS);
 796         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_SLEEP, &sta->sta);
 797 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 798         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
 799                sdata->dev->name, sta->sta.addr, sta->sta.aid);
 800 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 801 }
 802
 803 static int ap_sta_ps_end(struct sta_info *sta)
 804 {
 805         struct ieee80211_sub_if_data *sdata = sta->sdata;
 806         struct ieee80211_local *local = sdata->local;
 807         int sent, buffered;
 808
 809         atomic_dec(&sdata->bss->num_sta_ps);
 810
 811         clear_sta_flags(sta, WLAN_STA_PS);
 812         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_AWAKE, &sta->sta);
 813
 814         if (!skb_queue_empty(&sta->ps_tx_buf))
 815                 sta_info_clear_tim_bit(sta);
 816
 817 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 818         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
 819                sdata->dev->name, sta->sta.addr, sta->sta.aid);
 820 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 821
 822         /* Send all buffered frames to the station */
 823         sent = ieee80211_add_pending_skbs(local, &sta->tx_filtered);
 824         buffered = ieee80211_add_pending_skbs(local, &sta->ps_tx_buf);
 825         sent += buffered;
 826         local->total_ps_buffered -= buffered;
 827
 828 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 829         printk(KERN_DEBUG "%s: STA %pM aid %d sending %d filtered/%d PS frames "
 830                "since STA not sleeping anymore\n", sdata->dev->name,
 831                sta->sta.addr, sta->sta.aid, sent - buffered, buffered);
 832 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 833
 834         return sent;
 835 }
 836
 837 static ieee80211_rx_result debug_noinline
 838 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
 839 {
 840         struct sta_info *sta = rx->sta;
 841         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 842
 843         if (!sta)
 844                 return RX_CONTINUE;
 845
 846         /*
 847          * Update last_rx only for IBSS packets which are for the current
 848          * BSSID to avoid keeping the current IBSS network alive in cases
 849          * where other STAs start using different BSSID.
 850          */
 851         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
 852                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
 853                                                 NL80211_IFTYPE_ADHOC);
 854                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
 855                         sta->last_rx = jiffies;
 856         } else if (!is_multicast_ether_addr(hdr->addr1)) {
 857                 /*
 858                  * Mesh beacons will update last_rx when if they are found to
 859                  * match the current local configuration when processed.
 860                  */
 861                 sta->last_rx = jiffies;
 862         }
 863
 864         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 865                 return RX_CONTINUE;
 866
 867         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
 868                 ieee80211_sta_rx_notify(rx->sdata, hdr);
 869
 870         sta->rx_fragments++;
 871         sta->rx_bytes += rx->skb->len;
 872         sta->last_signal = rx->status->signal;
 873         sta->last_qual = rx->status->qual;
 874         sta->last_noise = rx->status->noise;
 875
 876         /*
 877          * Change STA power saving mode only at the end of a frame
 878          * exchange sequence.
 879          */
 880         if (!ieee80211_has_morefrags(hdr->frame_control) &&
 881             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
 882              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
 883                 if (test_sta_flags(sta, WLAN_STA_PS)) {
 884                         /*
 885                          * Ignore doze->wake transitions that are
 886                          * indicated by non-data frames, the standard
 887                          * is unclear here, but for example going to
 888                          * PS mode and then scanning would cause a
 889                          * doze->wake transition for the probe request,
 890                          * and that is clearly undesirable.
 891                          */
 892                         if (ieee80211_is_data(hdr->frame_control) &&
 893                             !ieee80211_has_pm(hdr->frame_control))
 894                                 rx->sent_ps_buffered += ap_sta_ps_end(sta);
 895                 } else {
 896                         if (ieee80211_has_pm(hdr->frame_control))
 897                                 ap_sta_ps_start(sta);
 898                 }
 899         }
 900
 901         /* Drop data::nullfunc frames silently, since they are used only to
 902          * control station power saving mode. */
 903         if (ieee80211_is_nullfunc(hdr->frame_control)) {
 904                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
 905                 /* Update counter and free packet here to avoid counting this
 906                  * as a dropped packed. */
 907                 sta->rx_packets++;
 908                 dev_kfree_skb(rx->skb);
 909                 return RX_QUEUED;
 910         }
 911
 912         return RX_CONTINUE;
 913 } /* ieee80211_rx_h_sta_process */
 914
 915 static inline struct ieee80211_fragment_entry *
 916 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 917                          unsigned int frag, unsigned int seq, int rx_queue,
 918                          struct sk_buff **skb)
 919 {
 920         struct ieee80211_fragment_entry *entry;
 921         int idx;
 922
 923         idx = sdata->fragment_next;
 924         entry = &sdata->fragments[sdata->fragment_next++];
 925         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
 926                 sdata->fragment_next = 0;
 927
 928         if (!skb_queue_empty(&entry->skb_list)) {
 929 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 930                 struct ieee80211_hdr *hdr =
 931                         (struct ieee80211_hdr *) entry->skb_list.next->data;
 932                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
 933                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
 934                        "addr1=%pM addr2=%pM\n",
 935                        sdata->dev->name, idx,
 936                        jiffies - entry->first_frag_time, entry->seq,
 937                        entry->last_frag, hdr->addr1, hdr->addr2);
 938 #endif
 939                 __skb_queue_purge(&entry->skb_list);
 940         }
 941
 942         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
 943         *skb = NULL;
 944         entry->first_frag_time = jiffies;
 945         entry->seq = seq;
 946         entry->rx_queue = rx_queue;
 947         entry->last_frag = frag;
 948         entry->ccmp = 0;
 949         entry->extra_len = 0;
 950
 951         return entry;
 952 }
 953
 954 static inline struct ieee80211_fragment_entry *
 955 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
 956                           unsigned int frag, unsigned int seq,
 957                           int rx_queue, struct ieee80211_hdr *hdr)
 958 {
 959         struct ieee80211_fragment_entry *entry;
 960         int i, idx;
 961
 962         idx = sdata->fragment_next;
 963         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
 964                 struct ieee80211_hdr *f_hdr;
 965
 966                 idx--;
 967                 if (idx < 0)
 968                         idx = IEEE80211_FRAGMENT_MAX - 1;
 969
 970                 entry = &sdata->fragments[idx];
 971                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
 972                     entry->rx_queue != rx_queue ||
 973                     entry->last_frag + 1 != frag)
 974                         continue;
 975
 976                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
 977
 978                 /*
 979                  * Check ftype and addresses are equal, else check next fragment
 980                  */
 981                 if (((hdr->frame_control ^ f_hdr->frame_control) &
 982                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
 983                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
 984                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
 985                         continue;
 986
 987                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
 988                         __skb_queue_purge(&entry->skb_list);
 989                         continue;
 990                 }
 991                 return entry;
 992         }
 993
 994         return NULL;
 995 }
 996
 997 static ieee80211_rx_result debug_noinline
 998 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 999 {
1000         struct ieee80211_hdr *hdr;
1001         u16 sc;
1002         __le16 fc;
1003         unsigned int frag, seq;
1004         struct ieee80211_fragment_entry *entry;
1005         struct sk_buff *skb;
1006
1007         hdr = (struct ieee80211_hdr *)rx->skb->data;
1008         fc = hdr->frame_control;
1009         sc = le16_to_cpu(hdr->seq_ctrl);
1010         frag = sc & IEEE80211_SCTL_FRAG;
1011
1012         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1013                    (rx->skb)->len < 24 ||
1014                    is_multicast_ether_addr(hdr->addr1))) {
1015                 /* not fragmented */
1016                 goto out;
1017         }
1018         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1019
1020         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1021
1022         if (frag == 0) {
1023                 /* This is the first fragment of a new frame. */
1024                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1025                                                  rx->queue, &(rx->skb));
1026                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1027                     ieee80211_has_protected(fc)) {
1028                         /* Store CCMP PN so that we can verify that the next
1029                          * fragment has a sequential PN value. */
1030                         entry->ccmp = 1;
1031                         memcpy(entry->last_pn,
1032                                rx->key->u.ccmp.rx_pn[rx->queue],
1033                                CCMP_PN_LEN);
1034                 }
1035                 return RX_QUEUED;
1036         }
1037
1038         /* This is a fragment for a frame that should already be pending in
1039          * fragment cache. Add this fragment to the end of the pending entry.
1040          */
1041         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1042         if (!entry) {
1043                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1044                 return RX_DROP_MONITOR;
1045         }
1046
1047         /* Verify that MPDUs within one MSDU have sequential PN values.
1048          * (IEEE 802.11i, 8.3.3.4.5) */
1049         if (entry->ccmp) {
1050                 int i;
1051                 u8 pn[CCMP_PN_LEN], *rpn;
1052                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1053                         return RX_DROP_UNUSABLE;
1054                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1055                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1056                         pn[i]++;
1057                         if (pn[i])
1058                                 break;
1059                 }
1060                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1061                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1062                         return RX_DROP_UNUSABLE;
1063                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1064         }
1065
1066         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1067         __skb_queue_tail(&entry->skb_list, rx->skb);
1068         entry->last_frag = frag;
1069         entry->extra_len += rx->skb->len;
1070         if (ieee80211_has_morefrags(fc)) {
1071                 rx->skb = NULL;
1072                 return RX_QUEUED;
1073         }
1074
1075         rx->skb = __skb_dequeue(&entry->skb_list);
1076         if (skb_tailroom(rx->skb) < entry->extra_len) {
1077                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1078                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1079                                               GFP_ATOMIC))) {
1080                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1081                         __skb_queue_purge(&entry->skb_list);
1082                         return RX_DROP_UNUSABLE;
1083                 }
1084         }
1085         while ((skb = __skb_dequeue(&entry->skb_list))) {
1086                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1087                 dev_kfree_skb(skb);
1088         }
1089
1090         /* Complete frame has been reassembled - process it now */
1091         rx->flags |= IEEE80211_RX_FRAGMENTED;
1092
1093  out:
1094         if (rx->sta)
1095                 rx->sta->rx_packets++;
1096         if (is_multicast_ether_addr(hdr->addr1))
1097                 rx->local->dot11MulticastReceivedFrameCount++;
1098         else
1099                 ieee80211_led_rx(rx->local);
1100         return RX_CONTINUE;
1101 }
1102
1103 static ieee80211_rx_result debug_noinline
1104 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1105 {
1106         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1107         struct sk_buff *skb;
1108         int no_pending_pkts;
1109         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1110
1111         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1112                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1113                 return RX_CONTINUE;
1114
1115         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1116             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1117                 return RX_DROP_UNUSABLE;
1118
1119         skb = skb_dequeue(&rx->sta->tx_filtered);
1120         if (!skb) {
1121                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
1122                 if (skb)
1123                         rx->local->total_ps_buffered--;
1124         }
1125         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
1126                 skb_queue_empty(&rx->sta->ps_tx_buf);
1127
1128         if (skb) {
1129                 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1130                 struct ieee80211_hdr *hdr =
1131                         (struct ieee80211_hdr *) skb->data;
1132
1133                 /*
1134                  * Tell TX path to send this frame even though the STA may
1135                  * still remain is PS mode after this frame exchange.
1136                  */
1137                 info->flags |= IEEE80211_TX_CTL_PSPOLL_RESPONSE;
1138
1139 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1140                 printk(KERN_DEBUG "STA %pM aid %d: PS Poll (entries after %d)\n",
1141                        rx->sta->sta.addr, rx->sta->sta.aid,
1142                        skb_queue_len(&rx->sta->ps_tx_buf));
1143 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1144
1145                 /* Use MoreData flag to indicate whether there are more
1146                  * buffered frames for this STA */
1147                 if (no_pending_pkts)
1148                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1149                 else
1150                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1151
1152                 ieee80211_add_pending_skb(rx->local, skb);
1153
1154                 if (no_pending_pkts)
1155                         sta_info_clear_tim_bit(rx->sta);
1156 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1157         } else if (!rx->sent_ps_buffered) {
1158                 /*
1159                  * FIXME: This can be the result of a race condition between
1160                  *        us expiring a frame and the station polling for it.
1161                  *        Should we send it a null-func frame indicating we
1162                  *        have nothing buffered for it?
1163                  */
1164                 printk(KERN_DEBUG "%s: STA %pM sent PS Poll even "
1165                        "though there are no buffered frames for it\n",
1166                        rx->dev->name, rx->sta->sta.addr);
1167 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1168         }
1169
1170         /* Free PS Poll skb here instead of returning RX_DROP that would
1171          * count as an dropped frame. */
1172         dev_kfree_skb(rx->skb);
1173
1174         return RX_QUEUED;
1175 }
1176
1177 static ieee80211_rx_result debug_noinline
1178 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1179 {
1180         u8 *data = rx->skb->data;
1181         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1182
1183         if (!ieee80211_is_data_qos(hdr->frame_control))
1184                 return RX_CONTINUE;
1185
1186         /* remove the qos control field, update frame type and meta-data */
1187         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1188                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1189         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1190         /* change frame type to non QOS */
1191         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1192
1193         return RX_CONTINUE;
1194 }
1195
1196 static int
1197 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1198 {
1199         if (unlikely(!rx->sta ||
1200             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1201                 return -EACCES;
1202
1203         return 0;
1204 }
1205
1206 static int
1207 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1208 {
1209         /*
1210          * Pass through unencrypted frames if the hardware has
1211          * decrypted them already.
1212          */
1213         if (rx->status->flag & RX_FLAG_DECRYPTED)
1214                 return 0;
1215
1216         /* Drop unencrypted frames if key is set. */
1217         if (unlikely(!ieee80211_has_protected(fc) &&
1218                      !ieee80211_is_nullfunc(fc) &&
1219                      ieee80211_is_data(fc) &&
1220                      (rx->key || rx->sdata->drop_unencrypted)))
1221                 return -EACCES;
1222         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1223                 if (unlikely(ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1224                              rx->key))
1225                         return -EACCES;
1226                 /* BIP does not use Protected field, so need to check MMIE */
1227                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb)
1228                              && ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1229                              rx->key))
1230                         return -EACCES;
1231                 /*
1232                  * When using MFP, Action frames are not allowed prior to
1233                  * having configured keys.
1234                  */
1235                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1236                              ieee80211_is_robust_mgmt_frame(
1237                                      (struct ieee80211_hdr *) rx->skb->data)))
1238                         return -EACCES;
1239         }
1240
1241         return 0;
1242 }
1243
1244 static int
1245 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1246 {
1247         struct net_device *dev = rx->dev;
1248         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1249
1250         return ieee80211_data_to_8023(rx->skb, dev->dev_addr, sdata->vif.type);
1251 }
1252
1253 /*
1254  * requires that rx->skb is a frame with ethernet header
1255  */
1256 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1257 {
1258         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1259                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1260         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1261
1262         /*
1263          * Allow EAPOL frames to us/the PAE group address regardless
1264          * of whether the frame was encrypted or not.
1265          */
1266         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1267             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1268              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1269                 return true;
1270
1271         if (ieee80211_802_1x_port_control(rx) ||
1272             ieee80211_drop_unencrypted(rx, fc))
1273                 return false;
1274
1275         return true;
1276 }
1277
1278 /*
1279  * requires that rx->skb is a frame with ethernet header
1280  */
1281 static void
1282 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1283 {
1284         struct net_device *dev = rx->dev;
1285         struct ieee80211_local *local = rx->local;
1286         struct sk_buff *skb, *xmit_skb;
1287         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1288         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1289         struct sta_info *dsta;
1290
1291         skb = rx->skb;
1292         xmit_skb = NULL;
1293
1294         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1295              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1296             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1297             (rx->flags & IEEE80211_RX_RA_MATCH)) {
1298                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1299                         /*
1300                          * send multicast frames both to higher layers in
1301                          * local net stack and back to the wireless medium
1302                          */
1303                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1304                         if (!xmit_skb && net_ratelimit())
1305                                 printk(KERN_DEBUG "%s: failed to clone "
1306                                        "multicast frame\n", dev->name);
1307                 } else {
1308                         dsta = sta_info_get(local, skb->data);
1309                         if (dsta && dsta->sdata->dev == dev) {
1310                                 /*
1311                                  * The destination station is associated to
1312                                  * this AP (in this VLAN), so send the frame
1313                                  * directly to it and do not pass it to local
1314                                  * net stack.
1315                                  */
1316                                 xmit_skb = skb;
1317                                 skb = NULL;
1318                         }
1319                 }
1320         }
1321
1322         if (skb) {
1323                 int align __maybe_unused;
1324
1325 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1326                 /*
1327                  * 'align' will only take the values 0 or 2 here
1328                  * since all frames are required to be aligned
1329                  * to 2-byte boundaries when being passed to
1330                  * mac80211. That also explains the __skb_push()
1331                  * below.
1332                  */
1333                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1334                 if (align) {
1335                         if (WARN_ON(skb_headroom(skb) < 3)) {
1336                                 dev_kfree_skb(skb);
1337                                 skb = NULL;
1338                         } else {
1339                                 u8 *data = skb->data;
1340                                 size_t len = skb->len;
1341                                 u8 *new = __skb_push(skb, align);
1342                                 memmove(new, data, len);
1343                                 __skb_trim(skb, len);
1344                         }
1345                 }
1346 #endif
1347
1348                 if (skb) {
1349                         /* deliver to local stack */
1350                         skb->protocol = eth_type_trans(skb, dev);
1351                         memset(skb->cb, 0, sizeof(skb->cb));
1352                         netif_rx(skb);
1353                 }
1354         }
1355
1356         if (xmit_skb) {
1357                 /* send to wireless media */
1358                 xmit_skb->protocol = htons(ETH_P_802_3);
1359                 skb_reset_network_header(xmit_skb);
1360                 skb_reset_mac_header(xmit_skb);
1361                 dev_queue_xmit(xmit_skb);
1362         }
1363 }
1364
1365 static ieee80211_rx_result debug_noinline
1366 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1367 {
1368         struct net_device *dev = rx->dev;
1369         struct ieee80211_local *local = rx->local;
1370         u16 ethertype;
1371         u8 *payload;
1372         struct sk_buff *skb = rx->skb, *frame = NULL;
1373         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1374         __le16 fc = hdr->frame_control;
1375         const struct ethhdr *eth;
1376         int remaining, err;
1377         u8 dst[ETH_ALEN];
1378         u8 src[ETH_ALEN];
1379
1380         if (unlikely(!ieee80211_is_data(fc)))
1381                 return RX_CONTINUE;
1382
1383         if (unlikely(!ieee80211_is_data_present(fc)))
1384                 return RX_DROP_MONITOR;
1385
1386         if (!(rx->flags & IEEE80211_RX_AMSDU))
1387                 return RX_CONTINUE;
1388
1389         err = __ieee80211_data_to_8023(rx);
1390         if (unlikely(err))
1391                 return RX_DROP_UNUSABLE;
1392
1393         skb->dev = dev;
1394
1395         dev->stats.rx_packets++;
1396         dev->stats.rx_bytes += skb->len;
1397
1398         /* skip the wrapping header */
1399         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1400         if (!eth)
1401                 return RX_DROP_UNUSABLE;
1402
1403         while (skb != frame) {
1404                 u8 padding;
1405                 __be16 len = eth->h_proto;
1406                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1407
1408                 remaining = skb->len;
1409                 memcpy(dst, eth->h_dest, ETH_ALEN);
1410                 memcpy(src, eth->h_source, ETH_ALEN);
1411
1412                 padding = ((4 - subframe_len) & 0x3);
1413                 /* the last MSDU has no padding */
1414                 if (subframe_len > remaining)
1415                         return RX_DROP_UNUSABLE;
1416
1417                 skb_pull(skb, sizeof(struct ethhdr));
1418                 /* if last subframe reuse skb */
1419                 if (remaining <= subframe_len + padding)
1420                         frame = skb;
1421                 else {
1422                         /*
1423                          * Allocate and reserve two bytes more for payload
1424                          * alignment since sizeof(struct ethhdr) is 14.
1425                          */
1426                         frame = dev_alloc_skb(
1427                                 ALIGN(local->hw.extra_tx_headroom, 4) +
1428                                 subframe_len + 2);
1429
1430                         if (frame == NULL)
1431                                 return RX_DROP_UNUSABLE;
1432
1433                         skb_reserve(frame,
1434                                     ALIGN(local->hw.extra_tx_headroom, 4) +
1435                                     sizeof(struct ethhdr) + 2);
1436                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1437                                 ntohs(len));
1438
1439                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1440                                                         padding);
1441                         if (!eth) {
1442                                 dev_kfree_skb(frame);
1443                                 return RX_DROP_UNUSABLE;
1444                         }
1445                 }
1446
1447                 skb_reset_network_header(frame);
1448                 frame->dev = dev;
1449                 frame->priority = skb->priority;
1450                 rx->skb = frame;
1451
1452                 payload = frame->data;
1453                 ethertype = (payload[6] << 8) | payload[7];
1454
1455                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1456                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1457                            compare_ether_addr(payload,
1458                                               bridge_tunnel_header) == 0)) {
1459                         /* remove RFC1042 or Bridge-Tunnel
1460                          * encapsulation and replace EtherType */
1461                         skb_pull(frame, 6);
1462                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1463                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1464                 } else {
1465                         memcpy(skb_push(frame, sizeof(__be16)),
1466                                &len, sizeof(__be16));
1467                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1468                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1469                 }
1470
1471                 if (!ieee80211_frame_allowed(rx, fc)) {
1472                         if (skb == frame) /* last frame */
1473                                 return RX_DROP_UNUSABLE;
1474                         dev_kfree_skb(frame);
1475                         continue;
1476                 }
1477
1478                 ieee80211_deliver_skb(rx);
1479         }
1480
1481         return RX_QUEUED;
1482 }
1483
1484 #ifdef CONFIG_MAC80211_MESH
1485 static ieee80211_rx_result
1486 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1487 {
1488         struct ieee80211_hdr *hdr;
1489         struct ieee80211s_hdr *mesh_hdr;
1490         unsigned int hdrlen;
1491         struct sk_buff *skb = rx->skb, *fwd_skb;
1492         struct ieee80211_local *local = rx->local;
1493         struct ieee80211_sub_if_data *sdata;
1494
1495         hdr = (struct ieee80211_hdr *) skb->data;
1496         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1497         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1498         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1499
1500         if (!ieee80211_is_data(hdr->frame_control))
1501                 return RX_CONTINUE;
1502
1503         if (!mesh_hdr->ttl)
1504                 /* illegal frame */
1505                 return RX_DROP_MONITOR;
1506
1507         if (!is_multicast_ether_addr(hdr->addr1) &&
1508                         (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6)) {
1509                 struct mesh_path *mppath;
1510
1511                 rcu_read_lock();
1512                 mppath = mpp_path_lookup(mesh_hdr->eaddr2, sdata);
1513                 if (!mppath) {
1514                         mpp_path_add(mesh_hdr->eaddr2, hdr->addr4, sdata);
1515                 } else {
1516                         spin_lock_bh(&mppath->state_lock);
1517                         mppath->exp_time = jiffies;
1518                         if (compare_ether_addr(mppath->mpp, hdr->addr4) != 0)
1519                                 memcpy(mppath->mpp, hdr->addr4, ETH_ALEN);
1520                         spin_unlock_bh(&mppath->state_lock);
1521                 }
1522                 rcu_read_unlock();
1523         }
1524
1525         /* Frame has reached destination.  Don't forward */
1526         if (!is_multicast_ether_addr(hdr->addr1) &&
1527                         compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1528                 return RX_CONTINUE;
1529
1530         mesh_hdr->ttl--;
1531
1532         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1533                 if (!mesh_hdr->ttl)
1534                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1535                                                      dropped_frames_ttl);
1536                 else {
1537                         struct ieee80211_hdr *fwd_hdr;
1538                         struct ieee80211_tx_info *info;
1539
1540                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1541
1542                         if (!fwd_skb && net_ratelimit())
1543                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1544                                                    rx->dev->name);
1545
1546                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1547                         memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1548                         info = IEEE80211_SKB_CB(fwd_skb);
1549                         memset(info, 0, sizeof(*info));
1550                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1551                         info->control.vif = &rx->sdata->vif;
1552                         ieee80211_select_queue(local, fwd_skb);
1553                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1554                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1555                                                                 fwded_mcast);
1556                         else {
1557                                 int err;
1558                                 /*
1559                                  * Save TA to addr1 to send TA a path error if a
1560                                  * suitable next hop is not found
1561                                  */
1562                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1563                                                 ETH_ALEN);
1564                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1565                                 /* Failed to immediately resolve next hop:
1566                                  * fwded frame was dropped or will be added
1567                                  * later to the pending skb queue.  */
1568                                 if (err)
1569                                         return RX_DROP_MONITOR;
1570
1571                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1572                                                                 fwded_unicast);
1573                         }
1574                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1575                                                      fwded_frames);
1576                         ieee80211_add_pending_skb(local, fwd_skb);
1577                 }
1578         }
1579
1580         if (is_multicast_ether_addr(hdr->addr1) ||
1581             rx->dev->flags & IFF_PROMISC)
1582                 return RX_CONTINUE;
1583         else
1584                 return RX_DROP_MONITOR;
1585 }
1586 #endif
1587
1588 static ieee80211_rx_result debug_noinline
1589 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1590 {
1591         struct net_device *dev = rx->dev;
1592         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1593         __le16 fc = hdr->frame_control;
1594         int err;
1595
1596         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1597                 return RX_CONTINUE;
1598
1599         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1600                 return RX_DROP_MONITOR;
1601
1602         err = __ieee80211_data_to_8023(rx);
1603         if (unlikely(err))
1604                 return RX_DROP_UNUSABLE;
1605
1606         if (!ieee80211_frame_allowed(rx, fc))
1607                 return RX_DROP_MONITOR;
1608
1609         rx->skb->dev = dev;
1610
1611         dev->stats.rx_packets++;
1612         dev->stats.rx_bytes += rx->skb->len;
1613
1614         ieee80211_deliver_skb(rx);
1615
1616         return RX_QUEUED;
1617 }
1618
1619 static ieee80211_rx_result debug_noinline
1620 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1621 {
1622         struct ieee80211_local *local = rx->local;
1623         struct ieee80211_hw *hw = &local->hw;
1624         struct sk_buff *skb = rx->skb;
1625         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1626         struct tid_ampdu_rx *tid_agg_rx;
1627         u16 start_seq_num;
1628         u16 tid;
1629
1630         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1631                 return RX_CONTINUE;
1632
1633         if (ieee80211_is_back_req(bar->frame_control)) {
1634                 if (!rx->sta)
1635                         return RX_CONTINUE;
1636                 tid = le16_to_cpu(bar->control) >> 12;
1637                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1638                                         != HT_AGG_STATE_OPERATIONAL)
1639                         return RX_CONTINUE;
1640                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1641
1642                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1643
1644                 /* reset session timer */
1645                 if (tid_agg_rx->timeout)
1646                         mod_timer(&tid_agg_rx->session_timer,
1647                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1648
1649                 /* manage reordering buffer according to requested */
1650                 /* sequence number */
1651                 rcu_read_lock();
1652                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1653                                                  start_seq_num, 1);
1654                 rcu_read_unlock();
1655                 return RX_DROP_UNUSABLE;
1656         }
1657
1658         return RX_CONTINUE;
1659 }
1660
1661 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1662                                            struct ieee80211_mgmt *mgmt,
1663                                            size_t len)
1664 {
1665         struct ieee80211_local *local = sdata->local;
1666         struct sk_buff *skb;
1667         struct ieee80211_mgmt *resp;
1668
1669         if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1670                 /* Not to own unicast address */
1671                 return;
1672         }
1673
1674         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1675             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1676                 /* Not from the current AP or not associated yet. */
1677                 return;
1678         }
1679
1680         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1681                 /* Too short SA Query request frame */
1682                 return;
1683         }
1684
1685         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1686         if (skb == NULL)
1687                 return;
1688
1689         skb_reserve(skb, local->hw.extra_tx_headroom);
1690         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1691         memset(resp, 0, 24);
1692         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1693         memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1694         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1695         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1696                                           IEEE80211_STYPE_ACTION);
1697         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1698         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1699         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1700         memcpy(resp->u.action.u.sa_query.trans_id,
1701                mgmt->u.action.u.sa_query.trans_id,
1702                WLAN_SA_QUERY_TR_ID_LEN);
1703
1704         ieee80211_tx_skb(sdata, skb, 1);
1705 }
1706
1707 static ieee80211_rx_result debug_noinline
1708 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1709 {
1710         struct ieee80211_local *local = rx->local;
1711         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1712         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1713         int len = rx->skb->len;
1714
1715         if (!ieee80211_is_action(mgmt->frame_control))
1716                 return RX_CONTINUE;
1717
1718         if (!rx->sta)
1719                 return RX_DROP_MONITOR;
1720
1721         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1722                 return RX_DROP_MONITOR;
1723
1724         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1725                 return RX_DROP_MONITOR;
1726
1727         /* all categories we currently handle have action_code */
1728         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1729                 return RX_DROP_MONITOR;
1730
1731         switch (mgmt->u.action.category) {
1732         case WLAN_CATEGORY_BACK:
1733                 /*
1734                  * The aggregation code is not prepared to handle
1735                  * anything but STA/AP due to the BSSID handling;
1736                  * IBSS could work in the code but isn't supported
1737                  * by drivers or the standard.
1738                  */
1739                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1740                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1741                     sdata->vif.type != NL80211_IFTYPE_AP)
1742                         return RX_DROP_MONITOR;
1743
1744                 switch (mgmt->u.action.u.addba_req.action_code) {
1745                 case WLAN_ACTION_ADDBA_REQ:
1746                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1747                                    sizeof(mgmt->u.action.u.addba_req)))
1748                                 return RX_DROP_MONITOR;
1749                         ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1750                         break;
1751                 case WLAN_ACTION_ADDBA_RESP:
1752                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1753                                    sizeof(mgmt->u.action.u.addba_resp)))
1754                                 return RX_DROP_MONITOR;
1755                         ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1756                         break;
1757                 case WLAN_ACTION_DELBA:
1758                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1759                                    sizeof(mgmt->u.action.u.delba)))
1760                                 return RX_DROP_MONITOR;
1761                         ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1762                         break;
1763                 }
1764                 break;
1765         case WLAN_CATEGORY_SPECTRUM_MGMT:
1766                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1767                         return RX_DROP_MONITOR;
1768
1769                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
1770                         return RX_DROP_MONITOR;
1771
1772                 switch (mgmt->u.action.u.measurement.action_code) {
1773                 case WLAN_ACTION_SPCT_MSR_REQ:
1774                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1775                                    sizeof(mgmt->u.action.u.measurement)))
1776                                 return RX_DROP_MONITOR;
1777                         ieee80211_process_measurement_req(sdata, mgmt, len);
1778                         break;
1779                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1780                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1781                                    sizeof(mgmt->u.action.u.chan_switch)))
1782                                 return RX_DROP_MONITOR;
1783
1784                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1785                                 return RX_DROP_MONITOR;
1786
1787                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1788                                 return RX_DROP_MONITOR;
1789
1790                         return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1791                 }
1792                 break;
1793         case WLAN_CATEGORY_SA_QUERY:
1794                 if (len < (IEEE80211_MIN_ACTION_SIZE +
1795                            sizeof(mgmt->u.action.u.sa_query)))
1796                         return RX_DROP_MONITOR;
1797                 switch (mgmt->u.action.u.sa_query.action) {
1798                 case WLAN_ACTION_SA_QUERY_REQUEST:
1799                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1800                                 return RX_DROP_MONITOR;
1801                         ieee80211_process_sa_query_req(sdata, mgmt, len);
1802                         break;
1803                 case WLAN_ACTION_SA_QUERY_RESPONSE:
1804                         /*
1805                          * SA Query response is currently only used in AP mode
1806                          * and it is processed in user space.
1807                          */
1808                         return RX_CONTINUE;
1809                 }
1810                 break;
1811         default:
1812                 return RX_CONTINUE;
1813         }
1814
1815         rx->sta->rx_packets++;
1816         dev_kfree_skb(rx->skb);
1817         return RX_QUEUED;
1818 }
1819
1820 static ieee80211_rx_result debug_noinline
1821 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1822 {
1823         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1824         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1825
1826         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1827                 return RX_DROP_MONITOR;
1828
1829         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1830                 return RX_DROP_MONITOR;
1831
1832         if (ieee80211_vif_is_mesh(&sdata->vif))
1833                 return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
1834
1835         if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
1836                 return ieee80211_ibss_rx_mgmt(sdata, rx->skb);
1837
1838         if (sdata->vif.type == NL80211_IFTYPE_STATION)
1839                 return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1840
1841         return RX_DROP_MONITOR;
1842 }
1843
1844 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
1845                                             struct ieee80211_rx_data *rx)
1846 {
1847         int keyidx;
1848         unsigned int hdrlen;
1849
1850         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1851         if (rx->skb->len >= hdrlen + 4)
1852                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1853         else
1854                 keyidx = -1;
1855
1856         if (!rx->sta) {
1857                 /*
1858                  * Some hardware seem to generate incorrect Michael MIC
1859                  * reports; ignore them to avoid triggering countermeasures.
1860                  */
1861                 goto ignore;
1862         }
1863
1864         if (!ieee80211_has_protected(hdr->frame_control))
1865                 goto ignore;
1866
1867         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1868                 /*
1869                  * APs with pairwise keys should never receive Michael MIC
1870                  * errors for non-zero keyidx because these are reserved for
1871                  * group keys and only the AP is sending real multicast
1872                  * frames in the BSS.
1873                  */
1874                 goto ignore;
1875         }
1876
1877         if (!ieee80211_is_data(hdr->frame_control) &&
1878             !ieee80211_is_auth(hdr->frame_control))
1879                 goto ignore;
1880
1881         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
1882                                         GFP_ATOMIC);
1883  ignore:
1884         dev_kfree_skb(rx->skb);
1885         rx->skb = NULL;
1886 }
1887
1888 /* TODO: use IEEE80211_RX_FRAGMENTED */
1889 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1890 {
1891         struct ieee80211_sub_if_data *sdata;
1892         struct ieee80211_local *local = rx->local;
1893         struct ieee80211_rtap_hdr {
1894                 struct ieee80211_radiotap_header hdr;
1895                 u8 flags;
1896                 u8 rate;
1897                 __le16 chan_freq;
1898                 __le16 chan_flags;
1899         } __attribute__ ((packed)) *rthdr;
1900         struct sk_buff *skb = rx->skb, *skb2;
1901         struct net_device *prev_dev = NULL;
1902         struct ieee80211_rx_status *status = rx->status;
1903
1904         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1905                 goto out_free_skb;
1906
1907         if (skb_headroom(skb) < sizeof(*rthdr) &&
1908             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1909                 goto out_free_skb;
1910
1911         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1912         memset(rthdr, 0, sizeof(*rthdr));
1913         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1914         rthdr->hdr.it_present =
1915                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1916                             (1 << IEEE80211_RADIOTAP_RATE) |
1917                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1918
1919         rthdr->rate = rx->rate->bitrate / 5;
1920         rthdr->chan_freq = cpu_to_le16(status->freq);
1921
1922         if (status->band == IEEE80211_BAND_5GHZ)
1923                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1924                                                 IEEE80211_CHAN_5GHZ);
1925         else
1926                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1927                                                 IEEE80211_CHAN_2GHZ);
1928
1929         skb_set_mac_header(skb, 0);
1930         skb->ip_summed = CHECKSUM_UNNECESSARY;
1931         skb->pkt_type = PACKET_OTHERHOST;
1932         skb->protocol = htons(ETH_P_802_2);
1933
1934         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1935                 if (!netif_running(sdata->dev))
1936                         continue;
1937
1938                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1939                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1940                         continue;
1941
1942                 if (prev_dev) {
1943                         skb2 = skb_clone(skb, GFP_ATOMIC);
1944                         if (skb2) {
1945                                 skb2->dev = prev_dev;
1946                                 netif_rx(skb2);
1947                         }
1948                 }
1949
1950                 prev_dev = sdata->dev;
1951                 sdata->dev->stats.rx_packets++;
1952                 sdata->dev->stats.rx_bytes += skb->len;
1953         }
1954
1955         if (prev_dev) {
1956                 skb->dev = prev_dev;
1957                 netif_rx(skb);
1958                 skb = NULL;
1959         } else
1960                 goto out_free_skb;
1961
1962         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1963         return;
1964
1965  out_free_skb:
1966         dev_kfree_skb(skb);
1967 }
1968
1969
1970 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1971                                          struct ieee80211_rx_data *rx,
1972                                          struct sk_buff *skb)
1973 {
1974         ieee80211_rx_result res = RX_DROP_MONITOR;
1975
1976         rx->skb = skb;
1977         rx->sdata = sdata;
1978         rx->dev = sdata->dev;
1979
1980 #define CALL_RXH(rxh)                   \
1981         do {                            \
1982                 res = rxh(rx);          \
1983                 if (res != RX_CONTINUE) \
1984                         goto rxh_done;  \
1985         } while (0);
1986
1987         CALL_RXH(ieee80211_rx_h_passive_scan)
1988         CALL_RXH(ieee80211_rx_h_check)
1989         CALL_RXH(ieee80211_rx_h_decrypt)
1990         CALL_RXH(ieee80211_rx_h_check_more_data)
1991         CALL_RXH(ieee80211_rx_h_sta_process)
1992         CALL_RXH(ieee80211_rx_h_defragment)
1993         CALL_RXH(ieee80211_rx_h_ps_poll)
1994         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1995         /* must be after MMIC verify so header is counted in MPDU mic */
1996         CALL_RXH(ieee80211_rx_h_remove_qos_control)
1997         CALL_RXH(ieee80211_rx_h_amsdu)
1998 #ifdef CONFIG_MAC80211_MESH
1999         if (ieee80211_vif_is_mesh(&sdata->vif))
2000                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
2001 #endif
2002         CALL_RXH(ieee80211_rx_h_data)
2003         CALL_RXH(ieee80211_rx_h_ctrl)
2004         CALL_RXH(ieee80211_rx_h_action)
2005         CALL_RXH(ieee80211_rx_h_mgmt)
2006
2007 #undef CALL_RXH
2008
2009  rxh_done:
2010         switch (res) {
2011         case RX_DROP_MONITOR:
2012                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2013                 if (rx->sta)
2014                         rx->sta->rx_dropped++;
2015                 /* fall through */
2016         case RX_CONTINUE:
2017                 ieee80211_rx_cooked_monitor(rx);
2018                 break;
2019         case RX_DROP_UNUSABLE:
2020                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2021                 if (rx->sta)
2022                         rx->sta->rx_dropped++;
2023                 dev_kfree_skb(rx->skb);
2024                 break;
2025         case RX_QUEUED:
2026                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2027                 break;
2028         }
2029 }
2030
2031 /* main receive path */
2032
2033 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2034                                 struct ieee80211_rx_data *rx,
2035                                 struct ieee80211_hdr *hdr)
2036 {
2037         u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len, sdata->vif.type);
2038         int multicast = is_multicast_ether_addr(hdr->addr1);
2039
2040         switch (sdata->vif.type) {
2041         case NL80211_IFTYPE_STATION:
2042                 if (!bssid)
2043                         return 0;
2044                 if (!multicast &&
2045                     compare_ether_addr(sdata->dev->dev_addr, hdr->addr1) != 0) {
2046                         if (!(sdata->dev->flags & IFF_PROMISC))
2047                                 return 0;
2048                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2049                 }
2050                 break;
2051         case NL80211_IFTYPE_ADHOC:
2052                 if (!bssid)
2053                         return 0;
2054                 if (ieee80211_is_beacon(hdr->frame_control)) {
2055                         return 1;
2056                 }
2057                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2058                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2059                                 return 0;
2060                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2061                 } else if (!multicast &&
2062                            compare_ether_addr(sdata->dev->dev_addr,
2063                                               hdr->addr1) != 0) {
2064                         if (!(sdata->dev->flags & IFF_PROMISC))
2065                                 return 0;
2066                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2067                 } else if (!rx->sta) {
2068                         int rate_idx;
2069                         if (rx->status->flag & RX_FLAG_HT)
2070                                 rate_idx = 0; /* TODO: HT rates */
2071                         else
2072                                 rate_idx = rx->status->rate_idx;
2073                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2074                                 BIT(rate_idx));
2075                 }
2076                 break;
2077         case NL80211_IFTYPE_MESH_POINT:
2078                 if (!multicast &&
2079                     compare_ether_addr(sdata->dev->dev_addr,
2080                                        hdr->addr1) != 0) {
2081                         if (!(sdata->dev->flags & IFF_PROMISC))
2082                                 return 0;
2083
2084                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2085                 }
2086                 break;
2087         case NL80211_IFTYPE_AP_VLAN:
2088         case NL80211_IFTYPE_AP:
2089                 if (!bssid) {
2090                         if (compare_ether_addr(sdata->dev->dev_addr,
2091                                                hdr->addr1))
2092                                 return 0;
2093                 } else if (!ieee80211_bssid_match(bssid,
2094                                         sdata->dev->dev_addr)) {
2095                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2096                                 return 0;
2097                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2098                 }
2099                 break;
2100         case NL80211_IFTYPE_WDS:
2101                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2102                         return 0;
2103                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2104                         return 0;
2105                 break;
2106         case NL80211_IFTYPE_MONITOR:
2107                 /* take everything */
2108                 break;
2109         case NL80211_IFTYPE_UNSPECIFIED:
2110         case __NL80211_IFTYPE_AFTER_LAST:
2111                 /* should never get here */
2112                 WARN_ON(1);
2113                 break;
2114         }
2115
2116         return 1;
2117 }
2118
2119 /*
2120  * This is the actual Rx frames handler. as it blongs to Rx path it must
2121  * be called with rcu_read_lock protection.
2122  */
2123 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2124                                          struct sk_buff *skb,
2125                                          struct ieee80211_rate *rate)
2126 {
2127         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2128         struct ieee80211_local *local = hw_to_local(hw);
2129         struct ieee80211_sub_if_data *sdata;
2130         struct ieee80211_hdr *hdr;
2131         struct ieee80211_rx_data rx;
2132         int prepares;
2133         struct ieee80211_sub_if_data *prev = NULL;
2134         struct sk_buff *skb_new;
2135
2136         hdr = (struct ieee80211_hdr *)skb->data;
2137         memset(&rx, 0, sizeof(rx));
2138         rx.skb = skb;
2139         rx.local = local;
2140
2141         rx.status = status;
2142         rx.rate = rate;
2143
2144         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2145                 local->dot11ReceivedFragmentCount++;
2146
2147         rx.sta = sta_info_get(local, hdr->addr2);
2148         if (rx.sta) {
2149                 rx.sdata = rx.sta->sdata;
2150                 rx.dev = rx.sta->sdata->dev;
2151         }
2152
2153         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
2154                 ieee80211_rx_michael_mic_report(hdr, &rx);
2155                 return;
2156         }
2157
2158         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2159                      test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2160                 rx.flags |= IEEE80211_RX_IN_SCAN;
2161
2162         ieee80211_parse_qos(&rx);
2163         ieee80211_verify_alignment(&rx);
2164
2165         skb = rx.skb;
2166
2167         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2168                 if (!netif_running(sdata->dev))
2169                         continue;
2170
2171                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
2172                         continue;
2173
2174                 rx.flags |= IEEE80211_RX_RA_MATCH;
2175                 prepares = prepare_for_handlers(sdata, &rx, hdr);
2176
2177                 if (!prepares)
2178                         continue;
2179
2180                 /*
2181                  * frame is destined for this interface, but if it's not
2182                  * also for the previous one we handle that after the
2183                  * loop to avoid copying the SKB once too much
2184                  */
2185
2186                 if (!prev) {
2187                         prev = sdata;
2188                         continue;
2189                 }
2190
2191                 /*
2192                  * frame was destined for the previous interface
2193                  * so invoke RX handlers for it
2194                  */
2195
2196                 skb_new = skb_copy(skb, GFP_ATOMIC);
2197                 if (!skb_new) {
2198                         if (net_ratelimit())
2199                                 printk(KERN_DEBUG "%s: failed to copy "
2200                                        "multicast frame for %s\n",
2201                                        wiphy_name(local->hw.wiphy),
2202                                        prev->dev->name);
2203                         continue;
2204                 }
2205                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
2206                 prev = sdata;
2207         }
2208         if (prev)
2209                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
2210         else
2211                 dev_kfree_skb(skb);
2212 }
2213
2214 #define SEQ_MODULO 0x1000
2215 #define SEQ_MASK   0xfff
2216
2217 static inline int seq_less(u16 sq1, u16 sq2)
2218 {
2219         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
2220 }
2221
2222 static inline u16 seq_inc(u16 sq)
2223 {
2224         return (sq + 1) & SEQ_MASK;
2225 }
2226
2227 static inline u16 seq_sub(u16 sq1, u16 sq2)
2228 {
2229         return (sq1 - sq2) & SEQ_MASK;
2230 }
2231
2232
2233 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
2234                                             struct tid_ampdu_rx *tid_agg_rx,
2235                                             int index)
2236 {
2237         struct ieee80211_supported_band *sband;
2238         struct ieee80211_rate *rate;
2239         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
2240         struct ieee80211_rx_status *status;
2241
2242         if (!skb)
2243                 goto no_frame;
2244
2245         status = IEEE80211_SKB_RXCB(skb);
2246
2247         /* release the reordered frames to stack */
2248         sband = hw->wiphy->bands[status->band];
2249         if (status->flag & RX_FLAG_HT)
2250                 rate = sband->bitrates; /* TODO: HT rates */
2251         else
2252                 rate = &sband->bitrates[status->rate_idx];
2253         __ieee80211_rx_handle_packet(hw, skb, rate);
2254         tid_agg_rx->stored_mpdu_num--;
2255         tid_agg_rx->reorder_buf[index] = NULL;
2256
2257 no_frame:
2258         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2259 }
2260
2261
2262 /*
2263  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
2264  * the skb was added to the buffer longer than this time ago, the earlier
2265  * frames that have not yet been received are assumed to be lost and the skb
2266  * can be released for processing. This may also release other skb's from the
2267  * reorder buffer if there are no additional gaps between the frames.
2268  */
2269 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
2270
2271 /*
2272  * As it function blongs to Rx path it must be called with
2273  * the proper rcu_read_lock protection for its flow.
2274  */
2275 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2276                                            struct tid_ampdu_rx *tid_agg_rx,
2277                                            struct sk_buff *skb,
2278                                            u16 mpdu_seq_num,
2279                                            int bar_req)
2280 {
2281         u16 head_seq_num, buf_size;
2282         int index;
2283
2284         buf_size = tid_agg_rx->buf_size;
2285         head_seq_num = tid_agg_rx->head_seq_num;
2286
2287         /* frame with out of date sequence number */
2288         if (seq_less(mpdu_seq_num, head_seq_num)) {
2289                 dev_kfree_skb(skb);
2290                 return 1;
2291         }
2292
2293         /* if frame sequence number exceeds our buffering window size or
2294          * block Ack Request arrived - release stored frames */
2295         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
2296                 /* new head to the ordering buffer */
2297                 if (bar_req)
2298                         head_seq_num = mpdu_seq_num;
2299                 else
2300                         head_seq_num =
2301                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
2302                 /* release stored frames up to new head to stack */
2303                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2304                         index = seq_sub(tid_agg_rx->head_seq_num,
2305                                 tid_agg_rx->ssn)
2306                                 % tid_agg_rx->buf_size;
2307                         ieee80211_release_reorder_frame(hw, tid_agg_rx,
2308                                                         index);
2309                 }
2310                 if (bar_req)
2311                         return 1;
2312         }
2313
2314         /* now the new frame is always in the range of the reordering */
2315         /* buffer window */
2316         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2317                                 % tid_agg_rx->buf_size;
2318         /* check if we already stored this frame */
2319         if (tid_agg_rx->reorder_buf[index]) {
2320                 dev_kfree_skb(skb);
2321                 return 1;
2322         }
2323
2324         /* if arrived mpdu is in the right order and nothing else stored */
2325         /* release it immediately */
2326         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2327                         tid_agg_rx->stored_mpdu_num == 0) {
2328                 tid_agg_rx->head_seq_num =
2329                         seq_inc(tid_agg_rx->head_seq_num);
2330                 return 0;
2331         }
2332
2333         /* put the frame in the reordering buffer */
2334         tid_agg_rx->reorder_buf[index] = skb;
2335         tid_agg_rx->reorder_time[index] = jiffies;
2336         tid_agg_rx->stored_mpdu_num++;
2337         /* release the buffer until next missing frame */
2338         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2339                                                 % tid_agg_rx->buf_size;
2340         if (!tid_agg_rx->reorder_buf[index] &&
2341             tid_agg_rx->stored_mpdu_num > 1) {
2342                 /*
2343                  * No buffers ready to be released, but check whether any
2344                  * frames in the reorder buffer have timed out.
2345                  */
2346                 int j;
2347                 int skipped = 1;
2348                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
2349                      j = (j + 1) % tid_agg_rx->buf_size) {
2350                         if (tid_agg_rx->reorder_buf[j] == NULL) {
2351                                 skipped++;
2352                                 continue;
2353                         }
2354                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
2355                                         HZ / 10))
2356                                 break;
2357
2358 #ifdef CONFIG_MAC80211_HT_DEBUG
2359                         if (net_ratelimit())
2360                                 printk(KERN_DEBUG "%s: release an RX reorder "
2361                                        "frame due to timeout on earlier "
2362                                        "frames\n",
2363                                        wiphy_name(hw->wiphy));
2364 #endif
2365                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
2366
2367                         /*
2368                          * Increment the head seq# also for the skipped slots.
2369                          */
2370                         tid_agg_rx->head_seq_num =
2371                                 (tid_agg_rx->head_seq_num + skipped) &
2372                                 SEQ_MASK;
2373                         skipped = 0;
2374                 }
2375         } else while (tid_agg_rx->reorder_buf[index]) {
2376                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
2377                 index = seq_sub(tid_agg_rx->head_seq_num,
2378                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2379         }
2380         return 1;
2381 }
2382
2383 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2384                                      struct sk_buff *skb)
2385 {
2386         struct ieee80211_hw *hw = &local->hw;
2387         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2388         struct sta_info *sta;
2389         struct tid_ampdu_rx *tid_agg_rx;
2390         u16 sc;
2391         u16 mpdu_seq_num;
2392         u8 ret = 0;
2393         int tid;
2394
2395         sta = sta_info_get(local, hdr->addr2);
2396         if (!sta)
2397                 return ret;
2398
2399         /* filter the QoS data rx stream according to
2400          * STA/TID and check if this STA/TID is on aggregation */
2401         if (!ieee80211_is_data_qos(hdr->frame_control))
2402                 goto end_reorder;
2403
2404         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2405
2406         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2407                 goto end_reorder;
2408
2409         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2410
2411         /* qos null data frames are excluded */
2412         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2413                 goto end_reorder;
2414
2415         /* new un-ordered ampdu frame - process it */
2416
2417         /* reset session timer */
2418         if (tid_agg_rx->timeout)
2419                 mod_timer(&tid_agg_rx->session_timer,
2420                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
2421
2422         /* if this mpdu is fragmented - terminate rx aggregation session */
2423         sc = le16_to_cpu(hdr->seq_ctrl);
2424         if (sc & IEEE80211_SCTL_FRAG) {
2425                 ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2426                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2427                 ret = 1;
2428                 goto end_reorder;
2429         }
2430
2431         /* according to mpdu sequence number deal with reordering buffer */
2432         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2433         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2434                                                 mpdu_seq_num, 0);
2435  end_reorder:
2436         return ret;
2437 }
2438
2439 /*
2440  * This is the receive path handler. It is called by a low level driver when an
2441  * 802.11 MPDU is received from the hardware.
2442  */
2443 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2444 {
2445         struct ieee80211_local *local = hw_to_local(hw);
2446         struct ieee80211_rate *rate = NULL;
2447         struct ieee80211_supported_band *sband;
2448         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2449
2450         if (status->band < 0 ||
2451             status->band >= IEEE80211_NUM_BANDS) {
2452                 WARN_ON(1);
2453                 return;
2454         }
2455
2456         sband = local->hw.wiphy->bands[status->band];
2457         if (!sband) {
2458                 WARN_ON(1);
2459                 return;
2460         }
2461
2462         /*
2463          * If we're suspending, it is possible although not too likely
2464          * that we'd be receiving frames after having already partially
2465          * quiesced the stack. We can't process such frames then since
2466          * that might, for example, cause stations to be added or other
2467          * driver callbacks be invoked.
2468          */
2469         if (unlikely(local->quiescing || local->suspended)) {
2470                 kfree_skb(skb);
2471                 return;
2472         }
2473
2474         if (status->flag & RX_FLAG_HT) {
2475                 /* rate_idx is MCS index */
2476                 if (WARN_ON(status->rate_idx < 0 ||
2477                             status->rate_idx >= 76))
2478                         return;
2479                 /* HT rates are not in the table - use the highest legacy rate
2480                  * for now since other parts of mac80211 may not yet be fully
2481                  * MCS aware. */
2482                 rate = &sband->bitrates[sband->n_bitrates - 1];
2483         } else {
2484                 if (WARN_ON(status->rate_idx < 0 ||
2485                             status->rate_idx >= sband->n_bitrates))
2486                         return;
2487                 rate = &sband->bitrates[status->rate_idx];
2488         }
2489
2490         /*
2491          * key references and virtual interfaces are protected using RCU
2492          * and this requires that we are in a read-side RCU section during
2493          * receive processing
2494          */
2495         rcu_read_lock();
2496
2497         /*
2498          * Frames with failed FCS/PLCP checksum are not returned,
2499          * all other frames are returned without radiotap header
2500          * if it was previously present.
2501          * Also, frames with less than 16 bytes are dropped.
2502          */
2503         skb = ieee80211_rx_monitor(local, skb, rate);
2504         if (!skb) {
2505                 rcu_read_unlock();
2506                 return;
2507         }
2508
2509         /*
2510          * In theory, the block ack reordering should happen after duplicate
2511          * removal (ieee80211_rx_h_check(), which is an RX handler). As such,
2512          * the call to ieee80211_rx_reorder_ampdu() should really be moved to
2513          * happen as a new RX handler between ieee80211_rx_h_check and
2514          * ieee80211_rx_h_decrypt. This cleanup may eventually happen, but for
2515          * the time being, the call can be here since RX reorder buf processing
2516          * will implicitly skip duplicates. We could, in theory at least,
2517          * process frames that ieee80211_rx_h_passive_scan would drop (e.g.,
2518          * frames from other than operational channel), but that should not
2519          * happen in normal networks.
2520          */
2521         if (!ieee80211_rx_reorder_ampdu(local, skb))
2522                 __ieee80211_rx_handle_packet(hw, skb, rate);
2523
2524         rcu_read_unlock();
2525 }
2526 EXPORT_SYMBOL(__ieee80211_rx);
2527
2528 /* This is a version of the rx handler that can be called from hard irq
2529  * context. Post the skb on the queue and schedule the tasklet */
2530 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2531 {
2532         struct ieee80211_local *local = hw_to_local(hw);
2533
2534         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2535
2536         skb->pkt_type = IEEE80211_RX_MSG;
2537         skb_queue_tail(&local->skb_queue, skb);
2538         tasklet_schedule(&local->tasklet);
2539 }
2540 EXPORT_SYMBOL(ieee80211_rx_irqsafe);