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 "led.h"
  23 #include "mesh.h"
  24 #include "wep.h"
  25 #include "wpa.h"
  26 #include "tkip.h"
  27 #include "wme.h"
  28
  29 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
  30                                            struct tid_ampdu_rx *tid_agg_rx,
  31                                            struct sk_buff *skb,
  32                                            u16 mpdu_seq_num,
  33                                            int bar_req);
  34 /*
  35  * monitor mode reception
  36  *
  37  * This function cleans up the SKB, i.e. it removes all the stuff
  38  * only useful for monitoring.
  39  */
  40 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  41                                            struct sk_buff *skb,
  42                                            int rtap_len)
  43 {
  44         skb_pull(skb, rtap_len);
  45
  46         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  47                 if (likely(skb->len > FCS_LEN))
  48                         skb_trim(skb, skb->len - FCS_LEN);
  49                 else {
  50                         /* driver bug */
  51                         WARN_ON(1);
  52                         dev_kfree_skb(skb);
  53                         skb = NULL;
  54                 }
  55         }
  56
  57         return skb;
  58 }
  59
  60 static inline int should_drop_frame(struct ieee80211_rx_status *status,
  61                                     struct sk_buff *skb,
  62                                     int present_fcs_len,
  63                                     int radiotap_len)
  64 {
  65         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  66
  67         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  68                 return 1;
  69         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
  70                 return 1;
  71         if (ieee80211_is_ctl(hdr->frame_control) &&
  72             !ieee80211_is_pspoll(hdr->frame_control) &&
  73             !ieee80211_is_back_req(hdr->frame_control))
  74                 return 1;
  75         return 0;
  76 }
  77
  78 static int
  79 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  80                           struct ieee80211_rx_status *status)
  81 {
  82         int len;
  83
  84         /* always present fields */
  85         len = sizeof(struct ieee80211_radiotap_header) + 9;
  86
  87         if (status->flag & RX_FLAG_TSFT)
  88                 len += 8;
  89         if (local->hw.flags & IEEE80211_HW_SIGNAL_DB ||
  90             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_rx_status *status,
 114                                  struct ieee80211_rate *rate,
 115                                  int rtap_len)
 116 {
 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_SHORTPRE)
 147                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 148         pos++;
 149
 150         /* IEEE80211_RADIOTAP_RATE */
 151         if (status->flag & RX_FLAG_HT) {
 152                 /*
 153                  * TODO: add following information into radiotap header once
 154                  * suitable fields are defined for it:
 155                  * - MCS index (status->rate_idx)
 156                  * - HT40 (status->flag & RX_FLAG_40MHZ)
 157                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
 158                  */
 159                 *pos = 0;
 160         } else {
 161                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 162                 *pos = rate->bitrate / 5;
 163         }
 164         pos++;
 165
 166         /* IEEE80211_RADIOTAP_CHANNEL */
 167         *(__le16 *)pos = cpu_to_le16(status->freq);
 168         pos += 2;
 169         if (status->band == IEEE80211_BAND_5GHZ)
 170                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
 171                                              IEEE80211_CHAN_5GHZ);
 172         else if (rate->flags & IEEE80211_RATE_ERP_G)
 173                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
 174                                              IEEE80211_CHAN_2GHZ);
 175         else
 176                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
 177                                              IEEE80211_CHAN_2GHZ);
 178         pos += 2;
 179
 180         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 181         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 182                 *pos = status->signal;
 183                 rthdr->it_present |=
 184                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 185                 pos++;
 186         }
 187
 188         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
 189         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
 190                 *pos = status->noise;
 191                 rthdr->it_present |=
 192                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
 193                 pos++;
 194         }
 195
 196         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 197
 198         /* IEEE80211_RADIOTAP_ANTENNA */
 199         *pos = status->antenna;
 200         pos++;
 201
 202         /* IEEE80211_RADIOTAP_DB_ANTSIGNAL */
 203         if (local->hw.flags & IEEE80211_HW_SIGNAL_DB) {
 204                 *pos = status->signal;
 205                 rthdr->it_present |=
 206                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL);
 207                 pos++;
 208         }
 209
 210         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 211
 212         /* IEEE80211_RADIOTAP_RX_FLAGS */
 213         /* ensure 2 byte alignment for the 2 byte field as required */
 214         if ((pos - (unsigned char *)rthdr) & 1)
 215                 pos++;
 216         /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
 217         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 218                 *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
 219         pos += 2;
 220 }
 221
 222 /*
 223  * This function copies a received frame to all monitor interfaces and
 224  * returns a cleaned-up SKB that no longer includes the FCS nor the
 225  * radiotap header the driver might have added.
 226  */
 227 static struct sk_buff *
 228 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 229                      struct ieee80211_rx_status *status,
 230                      struct ieee80211_rate *rate)
 231 {
 232         struct ieee80211_sub_if_data *sdata;
 233         int needed_headroom = 0;
 234         struct sk_buff *skb, *skb2;
 235         struct net_device *prev_dev = NULL;
 236         int present_fcs_len = 0;
 237         int rtap_len = 0;
 238
 239         /*
 240          * First, we may need to make a copy of the skb because
 241          *  (1) we need to modify it for radiotap (if not present), and
 242          *  (2) the other RX handlers will modify the skb we got.
 243          *
 244          * We don't need to, of course, if we aren't going to return
 245          * the SKB because it has a bad FCS/PLCP checksum.
 246          */
 247         if (status->flag & RX_FLAG_RADIOTAP)
 248                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
 249         else
 250                 /* room for the radiotap header based on driver features */
 251                 needed_headroom = ieee80211_rx_radiotap_len(local, status);
 252
 253         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 254                 present_fcs_len = FCS_LEN;
 255
 256         if (!local->monitors) {
 257                 if (should_drop_frame(status, origskb, present_fcs_len,
 258                                       rtap_len)) {
 259                         dev_kfree_skb(origskb);
 260                         return NULL;
 261                 }
 262
 263                 return remove_monitor_info(local, origskb, rtap_len);
 264         }
 265
 266         if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
 267                 /* only need to expand headroom if necessary */
 268                 skb = origskb;
 269                 origskb = NULL;
 270
 271                 /*
 272                  * This shouldn't trigger often because most devices have an
 273                  * RX header they pull before we get here, and that should
 274                  * be big enough for our radiotap information. We should
 275                  * probably export the length to drivers so that we can have
 276                  * them allocate enough headroom to start with.
 277                  */
 278                 if (skb_headroom(skb) < needed_headroom &&
 279                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 280                         dev_kfree_skb(skb);
 281                         return NULL;
 282                 }
 283         } else {
 284                 /*
 285                  * Need to make a copy and possibly remove radiotap header
 286                  * and FCS from the original.
 287                  */
 288                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 289
 290                 origskb = remove_monitor_info(local, origskb, rtap_len);
 291
 292                 if (!skb)
 293                         return origskb;
 294         }
 295
 296         /* if necessary, prepend radiotap information */
 297         if (!(status->flag & RX_FLAG_RADIOTAP))
 298                 ieee80211_add_rx_radiotap_header(local, skb, status, rate,
 299                                                  needed_headroom);
 300
 301         skb_reset_mac_header(skb);
 302         skb->ip_summed = CHECKSUM_UNNECESSARY;
 303         skb->pkt_type = PACKET_OTHERHOST;
 304         skb->protocol = htons(ETH_P_802_2);
 305
 306         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 307                 if (!netif_running(sdata->dev))
 308                         continue;
 309
 310                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 311                         continue;
 312
 313                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 314                         continue;
 315
 316                 if (prev_dev) {
 317                         skb2 = skb_clone(skb, GFP_ATOMIC);
 318                         if (skb2) {
 319                                 skb2->dev = prev_dev;
 320                                 netif_rx(skb2);
 321                         }
 322                 }
 323
 324                 prev_dev = sdata->dev;
 325                 sdata->dev->stats.rx_packets++;
 326                 sdata->dev->stats.rx_bytes += skb->len;
 327         }
 328
 329         if (prev_dev) {
 330                 skb->dev = prev_dev;
 331                 netif_rx(skb);
 332         } else
 333                 dev_kfree_skb(skb);
 334
 335         return origskb;
 336 }
 337
 338
 339 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 340 {
 341         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 342         int tid;
 343
 344         /* does the frame have a qos control field? */
 345         if (ieee80211_is_data_qos(hdr->frame_control)) {
 346                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 347                 /* frame has qos control */
 348                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 349                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 350                         rx->flags |= IEEE80211_RX_AMSDU;
 351                 else
 352                         rx->flags &= ~IEEE80211_RX_AMSDU;
 353         } else {
 354                 /*
 355                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 356                  *
 357                  *      Sequence numbers for management frames, QoS data
 358                  *      frames with a broadcast/multicast address in the
 359                  *      Address 1 field, and all non-QoS data frames sent
 360                  *      by QoS STAs are assigned using an additional single
 361                  *      modulo-4096 counter, [...]
 362                  *
 363                  * We also use that counter for non-QoS STAs.
 364                  */
 365                 tid = NUM_RX_DATA_QUEUES - 1;
 366         }
 367
 368         rx->queue = tid;
 369         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 370          * For now, set skb->priority to 0 for other cases. */
 371         rx->skb->priority = (tid > 7) ? 0 : tid;
 372 }
 373
 374 /**
 375  * DOC: Packet alignment
 376  *
 377  * Drivers always need to pass packets that are aligned to two-byte boundaries
 378  * to the stack.
 379  *
 380  * Additionally, should, if possible, align the payload data in a way that
 381  * guarantees that the contained IP header is aligned to a four-byte
 382  * boundary. In the case of regular frames, this simply means aligning the
 383  * payload to a four-byte boundary (because either the IP header is directly
 384  * contained, or IV/RFC1042 headers that have a length divisible by four are
 385  * in front of it).
 386  *
 387  * With A-MSDU frames, however, the payload data address must yield two modulo
 388  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 389  * push the IP header further back to a multiple of four again. Thankfully, the
 390  * specs were sane enough this time around to require padding each A-MSDU
 391  * subframe to a length that is a multiple of four.
 392  *
 393  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
 394  * the payload is not supported, the driver is required to move the 802.11
 395  * header to be directly in front of the payload in that case.
 396  */
 397 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 398 {
 399         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 400         int hdrlen;
 401
 402 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
 403         return;
 404 #endif
 405
 406         if (WARN_ONCE((unsigned long)rx->skb->data & 1,
 407                       "unaligned packet at 0x%p\n", rx->skb->data))
 408                 return;
 409
 410         if (!ieee80211_is_data_present(hdr->frame_control))
 411                 return;
 412
 413         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 414         if (rx->flags & IEEE80211_RX_AMSDU)
 415                 hdrlen += ETH_HLEN;
 416         WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
 417                   "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
 418 }
 419
 420
 421 /* rx handlers */
 422
 423 static ieee80211_rx_result debug_noinline
 424 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 425 {
 426         struct ieee80211_local *local = rx->local;
 427         struct sk_buff *skb = rx->skb;
 428
 429         if (unlikely(local->hw_scanning))
 430                 return ieee80211_scan_rx(rx->sdata, skb, rx->status);
 431
 432         if (unlikely(local->sw_scanning)) {
 433                 /* drop all the other packets during a software scan anyway */
 434                 if (ieee80211_scan_rx(rx->sdata, skb, rx->status)
 435                     != RX_QUEUED)
 436                         dev_kfree_skb(skb);
 437                 return RX_QUEUED;
 438         }
 439
 440         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
 441                 /* scanning finished during invoking of handlers */
 442                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 443                 return RX_DROP_UNUSABLE;
 444         }
 445
 446         return RX_CONTINUE;
 447 }
 448
 449
 450 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 451 {
 452         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 453
 454         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 455                 return 0;
 456
 457         return ieee80211_is_robust_mgmt_frame(hdr);
 458 }
 459
 460
 461 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 462 {
 463         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 464
 465         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 466                 return 0;
 467
 468         return ieee80211_is_robust_mgmt_frame(hdr);
 469 }
 470
 471
 472 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 473 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 474 {
 475         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 476         struct ieee80211_mmie *mmie;
 477
 478         if (skb->len < 24 + sizeof(*mmie) ||
 479             !is_multicast_ether_addr(hdr->da))
 480                 return -1;
 481
 482         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 483                 return -1; /* not a robust management frame */
 484
 485         mmie = (struct ieee80211_mmie *)
 486                 (skb->data + skb->len - sizeof(*mmie));
 487         if (mmie->element_id != WLAN_EID_MMIE ||
 488             mmie->length != sizeof(*mmie) - 2)
 489                 return -1;
 490
 491         return le16_to_cpu(mmie->key_id);
 492 }
 493
 494
 495 static ieee80211_rx_result
 496 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 497 {
 498         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 499         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 500
 501         if (ieee80211_is_data(hdr->frame_control)) {
 502                 if (!ieee80211_has_a4(hdr->frame_control))
 503                         return RX_DROP_MONITOR;
 504                 if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
 505                         return RX_DROP_MONITOR;
 506         }
 507
 508         /* If there is not an established peer link and this is not a peer link
 509          * establisment frame, beacon or probe, drop the frame.
 510          */
 511
 512         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 513                 struct ieee80211_mgmt *mgmt;
 514
 515                 if (!ieee80211_is_mgmt(hdr->frame_control))
 516                         return RX_DROP_MONITOR;
 517
 518                 if (ieee80211_is_action(hdr->frame_control)) {
 519                         mgmt = (struct ieee80211_mgmt *)hdr;
 520                         if (mgmt->u.action.category != PLINK_CATEGORY)
 521                                 return RX_DROP_MONITOR;
 522                         return RX_CONTINUE;
 523                 }
 524
 525                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 526                     ieee80211_is_probe_resp(hdr->frame_control) ||
 527                     ieee80211_is_beacon(hdr->frame_control))
 528                         return RX_CONTINUE;
 529
 530                 return RX_DROP_MONITOR;
 531
 532         }
 533
 534 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 535
 536         if (ieee80211_is_data(hdr->frame_control) &&
 537             is_multicast_ether_addr(hdr->addr1) &&
 538             mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->sdata))
 539                 return RX_DROP_MONITOR;
 540 #undef msh_h_get
 541
 542         return RX_CONTINUE;
 543 }
 544
 545
 546 static ieee80211_rx_result debug_noinline
 547 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 548 {
 549         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 550
 551         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 552         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 553                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 554                              rx->sta->last_seq_ctrl[rx->queue] ==
 555                              hdr->seq_ctrl)) {
 556                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
 557                                 rx->local->dot11FrameDuplicateCount++;
 558                                 rx->sta->num_duplicates++;
 559                         }
 560                         return RX_DROP_MONITOR;
 561                 } else
 562                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 563         }
 564
 565         if (unlikely(rx->skb->len < 16)) {
 566                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 567                 return RX_DROP_MONITOR;
 568         }
 569
 570         /* Drop disallowed frame classes based on STA auth/assoc state;
 571          * IEEE 802.11, Chap 5.5.
 572          *
 573          * mac80211 filters only based on association state, i.e. it drops
 574          * Class 3 frames from not associated stations. hostapd sends
 575          * deauth/disassoc frames when needed. In addition, hostapd is
 576          * responsible for filtering on both auth and assoc states.
 577          */
 578
 579         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 580                 return ieee80211_rx_mesh_check(rx);
 581
 582         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 583                       ieee80211_is_pspoll(hdr->frame_control)) &&
 584                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 585                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 586                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 587                      !ieee80211_has_tods(hdr->frame_control) &&
 588                      ieee80211_is_data(hdr->frame_control)) ||
 589                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
 590                         /* Drop IBSS frames and frames for other hosts
 591                          * silently. */
 592                         return RX_DROP_MONITOR;
 593                 }
 594
 595                 return RX_DROP_MONITOR;
 596         }
 597
 598         return RX_CONTINUE;
 599 }
 600
 601
 602 static ieee80211_rx_result debug_noinline
 603 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 604 {
 605         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 606         int keyidx;
 607         int hdrlen;
 608         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 609         struct ieee80211_key *stakey = NULL;
 610         int mmie_keyidx = -1;
 611
 612         /*
 613          * Key selection 101
 614          *
 615          * There are four types of keys:
 616          *  - GTK (group keys)
 617          *  - IGTK (group keys for management frames)
 618          *  - PTK (pairwise keys)
 619          *  - STK (station-to-station pairwise keys)
 620          *
 621          * When selecting a key, we have to distinguish between multicast
 622          * (including broadcast) and unicast frames, the latter can only
 623          * use PTKs and STKs while the former always use GTKs and IGTKs.
 624          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 625          * unicast frames can also use key indices like GTKs. Hence, if we
 626          * don't have a PTK/STK we check the key index for a WEP key.
 627          *
 628          * Note that in a regular BSS, multicast frames are sent by the
 629          * AP only, associated stations unicast the frame to the AP first
 630          * which then multicasts it on their behalf.
 631          *
 632          * There is also a slight problem in IBSS mode: GTKs are negotiated
 633          * with each station, that is something we don't currently handle.
 634          * The spec seems to expect that one negotiates the same key with
 635          * every station but there's no such requirement; VLANs could be
 636          * possible.
 637          */
 638
 639         if (!ieee80211_has_protected(hdr->frame_control)) {
 640                 if (!ieee80211_is_mgmt(hdr->frame_control) ||
 641                     rx->sta == NULL || !test_sta_flags(rx->sta, WLAN_STA_MFP))
 642                         return RX_CONTINUE;
 643                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 644                 if (mmie_keyidx < 0)
 645                         return RX_CONTINUE;
 646         }
 647
 648         /*
 649          * No point in finding a key and decrypting if the frame is neither
 650          * addressed to us nor a multicast frame.
 651          */
 652         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 653                 return RX_CONTINUE;
 654
 655         if (rx->sta)
 656                 stakey = rcu_dereference(rx->sta->key);
 657
 658         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 659                 rx->key = stakey;
 660         } else if (mmie_keyidx >= 0) {
 661                 /* Broadcast/multicast robust management frame / BIP */
 662                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 663                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 664                         return RX_CONTINUE;
 665
 666                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 667                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 668                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 669                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 670         } else {
 671                 /*
 672                  * The device doesn't give us the IV so we won't be
 673                  * able to look up the key. That's ok though, we
 674                  * don't need to decrypt the frame, we just won't
 675                  * be able to keep statistics accurate.
 676                  * Except for key threshold notifications, should
 677                  * we somehow allow the driver to tell us which key
 678                  * the hardware used if this flag is set?
 679                  */
 680                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 681                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 682                         return RX_CONTINUE;
 683
 684                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
 685
 686                 if (rx->skb->len < 8 + hdrlen)
 687                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 688
 689                 /*
 690                  * no need to call ieee80211_wep_get_keyidx,
 691                  * it verifies a bunch of things we've done already
 692                  */
 693                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 694
 695                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 696
 697                 /*
 698                  * RSNA-protected unicast frames should always be sent with
 699                  * pairwise or station-to-station keys, but for WEP we allow
 700                  * using a key index as well.
 701                  */
 702                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 703                     !is_multicast_ether_addr(hdr->addr1))
 704                         rx->key = NULL;
 705         }
 706
 707         if (rx->key) {
 708                 rx->key->tx_rx_count++;
 709                 /* TODO: add threshold stuff again */
 710         } else {
 711                 return RX_DROP_MONITOR;
 712         }
 713
 714         /* Check for weak IVs if possible */
 715         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 716             ieee80211_is_data(hdr->frame_control) &&
 717             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
 718              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
 719             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 720                 rx->sta->wep_weak_iv_count++;
 721
 722         switch (rx->key->conf.alg) {
 723         case ALG_WEP:
 724                 result = ieee80211_crypto_wep_decrypt(rx);
 725                 break;
 726         case ALG_TKIP:
 727                 result = ieee80211_crypto_tkip_decrypt(rx);
 728                 break;
 729         case ALG_CCMP:
 730                 result = ieee80211_crypto_ccmp_decrypt(rx);
 731                 break;
 732         case ALG_AES_CMAC:
 733                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
 734                 break;
 735         }
 736
 737         /* either the frame has been decrypted or will be dropped */
 738         rx->status->flag |= RX_FLAG_DECRYPTED;
 739
 740         return result;
 741 }
 742
 743 static void ap_sta_ps_start(struct sta_info *sta)
 744 {
 745         struct ieee80211_sub_if_data *sdata = sta->sdata;
 746         struct ieee80211_local *local = sdata->local;
 747
 748         atomic_inc(&sdata->bss->num_sta_ps);
 749         set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
 750         if (local->ops->sta_notify)
 751                 local->ops->sta_notify(local_to_hw(local), &sdata->vif,
 752                                         STA_NOTIFY_SLEEP, &sta->sta);
 753 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 754         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
 755                sdata->dev->name, sta->sta.addr, sta->sta.aid);
 756 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 757 }
 758
 759 static int ap_sta_ps_end(struct sta_info *sta)
 760 {
 761         struct ieee80211_sub_if_data *sdata = sta->sdata;
 762         struct ieee80211_local *local = sdata->local;
 763         struct sk_buff *skb;
 764         int sent = 0;
 765
 766         atomic_dec(&sdata->bss->num_sta_ps);
 767
 768         clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
 769         if (local->ops->sta_notify)
 770                 local->ops->sta_notify(local_to_hw(local), &sdata->vif,
 771                                         STA_NOTIFY_AWAKE, &sta->sta);
 772
 773         if (!skb_queue_empty(&sta->ps_tx_buf))
 774                 sta_info_clear_tim_bit(sta);
 775
 776 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 777         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
 778                sdata->dev->name, sta->sta.addr, sta->sta.aid);
 779 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 780
 781         /* Send all buffered frames to the station */
 782         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 783                 sent++;
 784                 skb->requeue = 1;
 785                 dev_queue_xmit(skb);
 786         }
 787         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 788                 local->total_ps_buffered--;
 789                 sent++;
 790 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 791                 printk(KERN_DEBUG "%s: STA %pM aid %d send PS frame "
 792                        "since STA not sleeping anymore\n", sdata->dev->name,
 793                        sta->sta.addr, sta->sta.aid);
 794 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 795                 skb->requeue = 1;
 796                 dev_queue_xmit(skb);
 797         }
 798
 799         return sent;
 800 }
 801
 802 static ieee80211_rx_result debug_noinline
 803 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
 804 {
 805         struct sta_info *sta = rx->sta;
 806         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 807
 808         if (!sta)
 809                 return RX_CONTINUE;
 810
 811         /* Update last_rx only for IBSS packets which are for the current
 812          * BSSID to avoid keeping the current IBSS network alive in cases where
 813          * other STAs are using different BSSID. */
 814         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
 815                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
 816                                                 NL80211_IFTYPE_ADHOC);
 817                 if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
 818                         sta->last_rx = jiffies;
 819         } else
 820         if (!is_multicast_ether_addr(hdr->addr1) ||
 821             rx->sdata->vif.type == NL80211_IFTYPE_STATION) {
 822                 /* Update last_rx only for unicast frames in order to prevent
 823                  * the Probe Request frames (the only broadcast frames from a
 824                  * STA in infrastructure mode) from keeping a connection alive.
 825                  * Mesh beacons will update last_rx when if they are found to
 826                  * match the current local configuration when processed.
 827                  */
 828                 sta->last_rx = jiffies;
 829         }
 830
 831         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 832                 return RX_CONTINUE;
 833
 834         sta->rx_fragments++;
 835         sta->rx_bytes += rx->skb->len;
 836         sta->last_signal = rx->status->signal;
 837         sta->last_qual = rx->status->qual;
 838         sta->last_noise = rx->status->noise;
 839
 840         /*
 841          * Change STA power saving mode only at the end of a frame
 842          * exchange sequence.
 843          */
 844         if (!ieee80211_has_morefrags(hdr->frame_control) &&
 845             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
 846              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
 847                 if (test_sta_flags(sta, WLAN_STA_PS)) {
 848                         /*
 849                          * Ignore doze->wake transitions that are
 850                          * indicated by non-data frames, the standard
 851                          * is unclear here, but for example going to
 852                          * PS mode and then scanning would cause a
 853                          * doze->wake transition for the probe request,
 854                          * and that is clearly undesirable.
 855                          */
 856                         if (ieee80211_is_data(hdr->frame_control) &&
 857                             !ieee80211_has_pm(hdr->frame_control))
 858                                 rx->sent_ps_buffered += ap_sta_ps_end(sta);
 859                 } else {
 860                         if (ieee80211_has_pm(hdr->frame_control))
 861                                 ap_sta_ps_start(sta);
 862                 }
 863         }
 864
 865         /* Drop data::nullfunc frames silently, since they are used only to
 866          * control station power saving mode. */
 867         if (ieee80211_is_nullfunc(hdr->frame_control)) {
 868                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
 869                 /* Update counter and free packet here to avoid counting this
 870                  * as a dropped packed. */
 871                 sta->rx_packets++;
 872                 dev_kfree_skb(rx->skb);
 873                 return RX_QUEUED;
 874         }
 875
 876         return RX_CONTINUE;
 877 } /* ieee80211_rx_h_sta_process */
 878
 879 static inline struct ieee80211_fragment_entry *
 880 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 881                          unsigned int frag, unsigned int seq, int rx_queue,
 882                          struct sk_buff **skb)
 883 {
 884         struct ieee80211_fragment_entry *entry;
 885         int idx;
 886
 887         idx = sdata->fragment_next;
 888         entry = &sdata->fragments[sdata->fragment_next++];
 889         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
 890                 sdata->fragment_next = 0;
 891
 892         if (!skb_queue_empty(&entry->skb_list)) {
 893 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 894                 struct ieee80211_hdr *hdr =
 895                         (struct ieee80211_hdr *) entry->skb_list.next->data;
 896                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
 897                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
 898                        "addr1=%pM addr2=%pM\n",
 899                        sdata->dev->name, idx,
 900                        jiffies - entry->first_frag_time, entry->seq,
 901                        entry->last_frag, hdr->addr1, hdr->addr2);
 902 #endif
 903                 __skb_queue_purge(&entry->skb_list);
 904         }
 905
 906         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
 907         *skb = NULL;
 908         entry->first_frag_time = jiffies;
 909         entry->seq = seq;
 910         entry->rx_queue = rx_queue;
 911         entry->last_frag = frag;
 912         entry->ccmp = 0;
 913         entry->extra_len = 0;
 914
 915         return entry;
 916 }
 917
 918 static inline struct ieee80211_fragment_entry *
 919 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
 920                           unsigned int frag, unsigned int seq,
 921                           int rx_queue, struct ieee80211_hdr *hdr)
 922 {
 923         struct ieee80211_fragment_entry *entry;
 924         int i, idx;
 925
 926         idx = sdata->fragment_next;
 927         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
 928                 struct ieee80211_hdr *f_hdr;
 929
 930                 idx--;
 931                 if (idx < 0)
 932                         idx = IEEE80211_FRAGMENT_MAX - 1;
 933
 934                 entry = &sdata->fragments[idx];
 935                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
 936                     entry->rx_queue != rx_queue ||
 937                     entry->last_frag + 1 != frag)
 938                         continue;
 939
 940                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
 941
 942                 /*
 943                  * Check ftype and addresses are equal, else check next fragment
 944                  */
 945                 if (((hdr->frame_control ^ f_hdr->frame_control) &
 946                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
 947                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
 948                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
 949                         continue;
 950
 951                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
 952                         __skb_queue_purge(&entry->skb_list);
 953                         continue;
 954                 }
 955                 return entry;
 956         }
 957
 958         return NULL;
 959 }
 960
 961 static ieee80211_rx_result debug_noinline
 962 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 963 {
 964         struct ieee80211_hdr *hdr;
 965         u16 sc;
 966         __le16 fc;
 967         unsigned int frag, seq;
 968         struct ieee80211_fragment_entry *entry;
 969         struct sk_buff *skb;
 970
 971         hdr = (struct ieee80211_hdr *)rx->skb->data;
 972         fc = hdr->frame_control;
 973         sc = le16_to_cpu(hdr->seq_ctrl);
 974         frag = sc & IEEE80211_SCTL_FRAG;
 975
 976         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
 977                    (rx->skb)->len < 24 ||
 978                    is_multicast_ether_addr(hdr->addr1))) {
 979                 /* not fragmented */
 980                 goto out;
 981         }
 982         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
 983
 984         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
 985
 986         if (frag == 0) {
 987                 /* This is the first fragment of a new frame. */
 988                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
 989                                                  rx->queue, &(rx->skb));
 990                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
 991                     ieee80211_has_protected(fc)) {
 992                         /* Store CCMP PN so that we can verify that the next
 993                          * fragment has a sequential PN value. */
 994                         entry->ccmp = 1;
 995                         memcpy(entry->last_pn,
 996                                rx->key->u.ccmp.rx_pn[rx->queue],
 997                                CCMP_PN_LEN);
 998                 }
 999                 return RX_QUEUED;
1000         }
1001
1002         /* This is a fragment for a frame that should already be pending in
1003          * fragment cache. Add this fragment to the end of the pending entry.
1004          */
1005         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1006         if (!entry) {
1007                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1008                 return RX_DROP_MONITOR;
1009         }
1010
1011         /* Verify that MPDUs within one MSDU have sequential PN values.
1012          * (IEEE 802.11i, 8.3.3.4.5) */
1013         if (entry->ccmp) {
1014                 int i;
1015                 u8 pn[CCMP_PN_LEN], *rpn;
1016                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1017                         return RX_DROP_UNUSABLE;
1018                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1019                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1020                         pn[i]++;
1021                         if (pn[i])
1022                                 break;
1023                 }
1024                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1025                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1026                         return RX_DROP_UNUSABLE;
1027                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1028         }
1029
1030         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1031         __skb_queue_tail(&entry->skb_list, rx->skb);
1032         entry->last_frag = frag;
1033         entry->extra_len += rx->skb->len;
1034         if (ieee80211_has_morefrags(fc)) {
1035                 rx->skb = NULL;
1036                 return RX_QUEUED;
1037         }
1038
1039         rx->skb = __skb_dequeue(&entry->skb_list);
1040         if (skb_tailroom(rx->skb) < entry->extra_len) {
1041                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1042                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1043                                               GFP_ATOMIC))) {
1044                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1045                         __skb_queue_purge(&entry->skb_list);
1046                         return RX_DROP_UNUSABLE;
1047                 }
1048         }
1049         while ((skb = __skb_dequeue(&entry->skb_list))) {
1050                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1051                 dev_kfree_skb(skb);
1052         }
1053
1054         /* Complete frame has been reassembled - process it now */
1055         rx->flags |= IEEE80211_RX_FRAGMENTED;
1056
1057  out:
1058         if (rx->sta)
1059                 rx->sta->rx_packets++;
1060         if (is_multicast_ether_addr(hdr->addr1))
1061                 rx->local->dot11MulticastReceivedFrameCount++;
1062         else
1063                 ieee80211_led_rx(rx->local);
1064         return RX_CONTINUE;
1065 }
1066
1067 static ieee80211_rx_result debug_noinline
1068 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1069 {
1070         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1071         struct sk_buff *skb;
1072         int no_pending_pkts;
1073         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1074
1075         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1076                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1077                 return RX_CONTINUE;
1078
1079         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1080             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1081                 return RX_DROP_UNUSABLE;
1082
1083         skb = skb_dequeue(&rx->sta->tx_filtered);
1084         if (!skb) {
1085                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
1086                 if (skb)
1087                         rx->local->total_ps_buffered--;
1088         }
1089         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
1090                 skb_queue_empty(&rx->sta->ps_tx_buf);
1091
1092         if (skb) {
1093                 struct ieee80211_hdr *hdr =
1094                         (struct ieee80211_hdr *) skb->data;
1095
1096                 /*
1097                  * Tell TX path to send one frame even though the STA may
1098                  * still remain is PS mode after this frame exchange.
1099                  */
1100                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1101
1102 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1103                 printk(KERN_DEBUG "STA %pM aid %d: PS Poll (entries after %d)\n",
1104                        rx->sta->sta.addr, rx->sta->sta.aid,
1105                        skb_queue_len(&rx->sta->ps_tx_buf));
1106 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1107
1108                 /* Use MoreData flag to indicate whether there are more
1109                  * buffered frames for this STA */
1110                 if (no_pending_pkts)
1111                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1112                 else
1113                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1114
1115                 dev_queue_xmit(skb);
1116
1117                 if (no_pending_pkts)
1118                         sta_info_clear_tim_bit(rx->sta);
1119 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1120         } else if (!rx->sent_ps_buffered) {
1121                 /*
1122                  * FIXME: This can be the result of a race condition between
1123                  *        us expiring a frame and the station polling for it.
1124                  *        Should we send it a null-func frame indicating we
1125                  *        have nothing buffered for it?
1126                  */
1127                 printk(KERN_DEBUG "%s: STA %pM sent PS Poll even "
1128                        "though there are no buffered frames for it\n",
1129                        rx->dev->name, rx->sta->sta.addr);
1130 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1131         }
1132
1133         /* Free PS Poll skb here instead of returning RX_DROP that would
1134          * count as an dropped frame. */
1135         dev_kfree_skb(rx->skb);
1136
1137         return RX_QUEUED;
1138 }
1139
1140 static ieee80211_rx_result debug_noinline
1141 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1142 {
1143         u8 *data = rx->skb->data;
1144         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1145
1146         if (!ieee80211_is_data_qos(hdr->frame_control))
1147                 return RX_CONTINUE;
1148
1149         /* remove the qos control field, update frame type and meta-data */
1150         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1151                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1152         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1153         /* change frame type to non QOS */
1154         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1155
1156         return RX_CONTINUE;
1157 }
1158
1159 static int
1160 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1161 {
1162         if (unlikely(!rx->sta ||
1163             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1164                 return -EACCES;
1165
1166         return 0;
1167 }
1168
1169 static int
1170 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1171 {
1172         /*
1173          * Pass through unencrypted frames if the hardware has
1174          * decrypted them already.
1175          */
1176         if (rx->status->flag & RX_FLAG_DECRYPTED)
1177                 return 0;
1178
1179         /* Drop unencrypted frames if key is set. */
1180         if (unlikely(!ieee80211_has_protected(fc) &&
1181                      !ieee80211_is_nullfunc(fc) &&
1182                      (!ieee80211_is_mgmt(fc) ||
1183                       (ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1184                        rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP))) &&
1185                      (rx->key || rx->sdata->drop_unencrypted)))
1186                 return -EACCES;
1187         /* BIP does not use Protected field, so need to check MMIE */
1188         if (unlikely(rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP) &&
1189                      ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1190                      ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1191                      (rx->key || rx->sdata->drop_unencrypted)))
1192                 return -EACCES;
1193
1194         return 0;
1195 }
1196
1197 static int
1198 ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1199 {
1200         struct net_device *dev = rx->dev;
1201         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1202         u16 hdrlen, ethertype;
1203         u8 *payload;
1204         u8 dst[ETH_ALEN];
1205         u8 src[ETH_ALEN] __aligned(2);
1206         struct sk_buff *skb = rx->skb;
1207         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1208
1209         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1210                 return -1;
1211
1212         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1213
1214         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
1215          * header
1216          * IEEE 802.11 address fields:
1217          * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1218          *   0     0   DA    SA    BSSID n/a
1219          *   0     1   DA    BSSID SA    n/a
1220          *   1     0   BSSID SA    DA    n/a
1221          *   1     1   RA    TA    DA    SA
1222          */
1223         memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
1224         memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
1225
1226         switch (hdr->frame_control &
1227                 cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1228         case __constant_cpu_to_le16(IEEE80211_FCTL_TODS):
1229                 if (unlikely(sdata->vif.type != NL80211_IFTYPE_AP &&
1230                              sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1231                         return -1;
1232                 break;
1233         case __constant_cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1234                 if (unlikely(sdata->vif.type != NL80211_IFTYPE_WDS &&
1235                              sdata->vif.type != NL80211_IFTYPE_MESH_POINT))
1236                         return -1;
1237                 if (ieee80211_vif_is_mesh(&sdata->vif)) {
1238                         struct ieee80211s_hdr *meshdr = (struct ieee80211s_hdr *)
1239                                 (skb->data + hdrlen);
1240                         hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
1241                         if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
1242                                 memcpy(dst, meshdr->eaddr1, ETH_ALEN);
1243                                 memcpy(src, meshdr->eaddr2, ETH_ALEN);
1244                         }
1245                 }
1246                 break;
1247         case __constant_cpu_to_le16(IEEE80211_FCTL_FROMDS):
1248                 if (sdata->vif.type != NL80211_IFTYPE_STATION ||
1249                     (is_multicast_ether_addr(dst) &&
1250                      !compare_ether_addr(src, dev->dev_addr)))
1251                         return -1;
1252                 break;
1253         case __constant_cpu_to_le16(0):
1254                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1255                         return -1;
1256                 break;
1257         }
1258
1259         if (unlikely(skb->len - hdrlen < 8))
1260                 return -1;
1261
1262         payload = skb->data + hdrlen;
1263         ethertype = (payload[6] << 8) | payload[7];
1264
1265         if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1266                     ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1267                    compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1268                 /* remove RFC1042 or Bridge-Tunnel encapsulation and
1269                  * replace EtherType */
1270                 skb_pull(skb, hdrlen + 6);
1271                 memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1272                 memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1273         } else {
1274                 struct ethhdr *ehdr;
1275                 __be16 len;
1276
1277                 skb_pull(skb, hdrlen);
1278                 len = htons(skb->len);
1279                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1280                 memcpy(ehdr->h_dest, dst, ETH_ALEN);
1281                 memcpy(ehdr->h_source, src, ETH_ALEN);
1282                 ehdr->h_proto = len;
1283         }
1284         return 0;
1285 }
1286
1287 /*
1288  * requires that rx->skb is a frame with ethernet header
1289  */
1290 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1291 {
1292         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1293                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1294         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1295
1296         /*
1297          * Allow EAPOL frames to us/the PAE group address regardless
1298          * of whether the frame was encrypted or not.
1299          */
1300         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1301             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1302              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1303                 return true;
1304
1305         if (ieee80211_802_1x_port_control(rx) ||
1306             ieee80211_drop_unencrypted(rx, fc))
1307                 return false;
1308
1309         return true;
1310 }
1311
1312 /*
1313  * requires that rx->skb is a frame with ethernet header
1314  */
1315 static void
1316 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1317 {
1318         struct net_device *dev = rx->dev;
1319         struct ieee80211_local *local = rx->local;
1320         struct sk_buff *skb, *xmit_skb;
1321         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1322         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1323         struct sta_info *dsta;
1324
1325         skb = rx->skb;
1326         xmit_skb = NULL;
1327
1328         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1329              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1330             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1331             (rx->flags & IEEE80211_RX_RA_MATCH)) {
1332                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1333                         /*
1334                          * send multicast frames both to higher layers in
1335                          * local net stack and back to the wireless medium
1336                          */
1337                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1338                         if (!xmit_skb && net_ratelimit())
1339                                 printk(KERN_DEBUG "%s: failed to clone "
1340                                        "multicast frame\n", dev->name);
1341                 } else {
1342                         dsta = sta_info_get(local, skb->data);
1343                         if (dsta && dsta->sdata->dev == dev) {
1344                                 /*
1345                                  * The destination station is associated to
1346                                  * this AP (in this VLAN), so send the frame
1347                                  * directly to it and do not pass it to local
1348                                  * net stack.
1349                                  */
1350                                 xmit_skb = skb;
1351                                 skb = NULL;
1352                         }
1353                 }
1354         }
1355
1356         if (skb) {
1357                 int align __maybe_unused;
1358
1359 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1360                 /*
1361                  * 'align' will only take the values 0 or 2 here
1362                  * since all frames are required to be aligned
1363                  * to 2-byte boundaries when being passed to
1364                  * mac80211. That also explains the __skb_push()
1365                  * below.
1366                  */
1367                 align = (unsigned long)skb->data & 4;
1368                 if (align) {
1369                         if (WARN_ON(skb_headroom(skb) < 3)) {
1370                                 dev_kfree_skb(skb);
1371                                 skb = NULL;
1372                         } else {
1373                                 u8 *data = skb->data;
1374                                 size_t len = skb->len;
1375                                 u8 *new = __skb_push(skb, align);
1376                                 memmove(new, data, len);
1377                                 __skb_trim(skb, len);
1378                         }
1379                 }
1380 #endif
1381
1382                 if (skb) {
1383                         /* deliver to local stack */
1384                         skb->protocol = eth_type_trans(skb, dev);
1385                         memset(skb->cb, 0, sizeof(skb->cb));
1386                         netif_rx(skb);
1387                 }
1388         }
1389
1390         if (xmit_skb) {
1391                 /* send to wireless media */
1392                 xmit_skb->protocol = htons(ETH_P_802_3);
1393                 skb_reset_network_header(xmit_skb);
1394                 skb_reset_mac_header(xmit_skb);
1395                 dev_queue_xmit(xmit_skb);
1396         }
1397 }
1398
1399 static ieee80211_rx_result debug_noinline
1400 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1401 {
1402         struct net_device *dev = rx->dev;
1403         struct ieee80211_local *local = rx->local;
1404         u16 ethertype;
1405         u8 *payload;
1406         struct sk_buff *skb = rx->skb, *frame = NULL;
1407         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1408         __le16 fc = hdr->frame_control;
1409         const struct ethhdr *eth;
1410         int remaining, err;
1411         u8 dst[ETH_ALEN];
1412         u8 src[ETH_ALEN];
1413
1414         if (unlikely(!ieee80211_is_data(fc)))
1415                 return RX_CONTINUE;
1416
1417         if (unlikely(!ieee80211_is_data_present(fc)))
1418                 return RX_DROP_MONITOR;
1419
1420         if (!(rx->flags & IEEE80211_RX_AMSDU))
1421                 return RX_CONTINUE;
1422
1423         err = ieee80211_data_to_8023(rx);
1424         if (unlikely(err))
1425                 return RX_DROP_UNUSABLE;
1426
1427         skb->dev = dev;
1428
1429         dev->stats.rx_packets++;
1430         dev->stats.rx_bytes += skb->len;
1431
1432         /* skip the wrapping header */
1433         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1434         if (!eth)
1435                 return RX_DROP_UNUSABLE;
1436
1437         while (skb != frame) {
1438                 u8 padding;
1439                 __be16 len = eth->h_proto;
1440                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1441
1442                 remaining = skb->len;
1443                 memcpy(dst, eth->h_dest, ETH_ALEN);
1444                 memcpy(src, eth->h_source, ETH_ALEN);
1445
1446                 padding = ((4 - subframe_len) & 0x3);
1447                 /* the last MSDU has no padding */
1448                 if (subframe_len > remaining)
1449                         return RX_DROP_UNUSABLE;
1450
1451                 skb_pull(skb, sizeof(struct ethhdr));
1452                 /* if last subframe reuse skb */
1453                 if (remaining <= subframe_len + padding)
1454                         frame = skb;
1455                 else {
1456                         /*
1457                          * Allocate and reserve two bytes more for payload
1458                          * alignment since sizeof(struct ethhdr) is 14.
1459                          */
1460                         frame = dev_alloc_skb(
1461                                 ALIGN(local->hw.extra_tx_headroom, 4) +
1462                                 subframe_len + 2);
1463
1464                         if (frame == NULL)
1465                                 return RX_DROP_UNUSABLE;
1466
1467                         skb_reserve(frame,
1468                                     ALIGN(local->hw.extra_tx_headroom, 4) +
1469                                     sizeof(struct ethhdr) + 2);
1470                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1471                                 ntohs(len));
1472
1473                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1474                                                         padding);
1475                         if (!eth) {
1476                                 dev_kfree_skb(frame);
1477                                 return RX_DROP_UNUSABLE;
1478                         }
1479                 }
1480
1481                 skb_reset_network_header(frame);
1482                 frame->dev = dev;
1483                 frame->priority = skb->priority;
1484                 rx->skb = frame;
1485
1486                 payload = frame->data;
1487                 ethertype = (payload[6] << 8) | payload[7];
1488
1489                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1490                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1491                            compare_ether_addr(payload,
1492                                               bridge_tunnel_header) == 0)) {
1493                         /* remove RFC1042 or Bridge-Tunnel
1494                          * encapsulation and replace EtherType */
1495                         skb_pull(frame, 6);
1496                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1497                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1498                 } else {
1499                         memcpy(skb_push(frame, sizeof(__be16)),
1500                                &len, sizeof(__be16));
1501                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1502                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1503                 }
1504
1505                 if (!ieee80211_frame_allowed(rx, fc)) {
1506                         if (skb == frame) /* last frame */
1507                                 return RX_DROP_UNUSABLE;
1508                         dev_kfree_skb(frame);
1509                         continue;
1510                 }
1511
1512                 ieee80211_deliver_skb(rx);
1513         }
1514
1515         return RX_QUEUED;
1516 }
1517
1518 #ifdef CONFIG_MAC80211_MESH
1519 static ieee80211_rx_result
1520 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1521 {
1522         struct ieee80211_hdr *hdr;
1523         struct ieee80211s_hdr *mesh_hdr;
1524         unsigned int hdrlen;
1525         struct sk_buff *skb = rx->skb, *fwd_skb;
1526
1527         hdr = (struct ieee80211_hdr *) skb->data;
1528         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1529         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1530
1531         if (!ieee80211_is_data(hdr->frame_control))
1532                 return RX_CONTINUE;
1533
1534         if (!mesh_hdr->ttl)
1535                 /* illegal frame */
1536                 return RX_DROP_MONITOR;
1537
1538         if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6){
1539                 struct ieee80211_sub_if_data *sdata;
1540                 struct mesh_path *mppath;
1541
1542                 sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1543                 rcu_read_lock();
1544                 mppath = mpp_path_lookup(mesh_hdr->eaddr2, sdata);
1545                 if (!mppath) {
1546                         mpp_path_add(mesh_hdr->eaddr2, hdr->addr4, sdata);
1547                 } else {
1548                         spin_lock_bh(&mppath->state_lock);
1549                         mppath->exp_time = jiffies;
1550                         if (compare_ether_addr(mppath->mpp, hdr->addr4) != 0)
1551                                 memcpy(mppath->mpp, hdr->addr4, ETH_ALEN);
1552                         spin_unlock_bh(&mppath->state_lock);
1553                 }
1554                 rcu_read_unlock();
1555         }
1556
1557         if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1558                 return RX_CONTINUE;
1559
1560         mesh_hdr->ttl--;
1561
1562         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1563                 if (!mesh_hdr->ttl)
1564                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1565                                                      dropped_frames_ttl);
1566                 else {
1567                         struct ieee80211_hdr *fwd_hdr;
1568                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1569
1570                         if (!fwd_skb && net_ratelimit())
1571                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1572                                                    rx->dev->name);
1573
1574                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1575                         /*
1576                          * Save TA to addr1 to send TA a path error if a
1577                          * suitable next hop is not found
1578                          */
1579                         memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1580                         memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1581                         fwd_skb->dev = rx->local->mdev;
1582                         fwd_skb->iif = rx->dev->ifindex;
1583                         dev_queue_xmit(fwd_skb);
1584                 }
1585         }
1586
1587         if (is_multicast_ether_addr(hdr->addr3) ||
1588             rx->dev->flags & IFF_PROMISC)
1589                 return RX_CONTINUE;
1590         else
1591                 return RX_DROP_MONITOR;
1592 }
1593 #endif
1594
1595 static ieee80211_rx_result debug_noinline
1596 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1597 {
1598         struct net_device *dev = rx->dev;
1599         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1600         __le16 fc = hdr->frame_control;
1601         int err;
1602
1603         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1604                 return RX_CONTINUE;
1605
1606         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1607                 return RX_DROP_MONITOR;
1608
1609         err = ieee80211_data_to_8023(rx);
1610         if (unlikely(err))
1611                 return RX_DROP_UNUSABLE;
1612
1613         if (!ieee80211_frame_allowed(rx, fc))
1614                 return RX_DROP_MONITOR;
1615
1616         rx->skb->dev = dev;
1617
1618         dev->stats.rx_packets++;
1619         dev->stats.rx_bytes += rx->skb->len;
1620
1621         ieee80211_deliver_skb(rx);
1622
1623         return RX_QUEUED;
1624 }
1625
1626 static ieee80211_rx_result debug_noinline
1627 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1628 {
1629         struct ieee80211_local *local = rx->local;
1630         struct ieee80211_hw *hw = &local->hw;
1631         struct sk_buff *skb = rx->skb;
1632         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1633         struct tid_ampdu_rx *tid_agg_rx;
1634         u16 start_seq_num;
1635         u16 tid;
1636
1637         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1638                 return RX_CONTINUE;
1639
1640         if (ieee80211_is_back_req(bar->frame_control)) {
1641                 if (!rx->sta)
1642                         return RX_CONTINUE;
1643                 tid = le16_to_cpu(bar->control) >> 12;
1644                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1645                                         != HT_AGG_STATE_OPERATIONAL)
1646                         return RX_CONTINUE;
1647                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1648
1649                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1650
1651                 /* reset session timer */
1652                 if (tid_agg_rx->timeout) {
1653                         unsigned long expires =
1654                                 jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1655                         mod_timer(&tid_agg_rx->session_timer, expires);
1656                 }
1657
1658                 /* manage reordering buffer according to requested */
1659                 /* sequence number */
1660                 rcu_read_lock();
1661                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1662                                                  start_seq_num, 1);
1663                 rcu_read_unlock();
1664                 return RX_DROP_UNUSABLE;
1665         }
1666
1667         return RX_CONTINUE;
1668 }
1669
1670 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1671                                            struct ieee80211_mgmt *mgmt,
1672                                            size_t len)
1673 {
1674         struct ieee80211_local *local = sdata->local;
1675         struct sk_buff *skb;
1676         struct ieee80211_mgmt *resp;
1677
1678         if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1679                 /* Not to own unicast address */
1680                 return;
1681         }
1682
1683         if (compare_ether_addr(mgmt->sa, sdata->u.sta.bssid) != 0 ||
1684             compare_ether_addr(mgmt->bssid, sdata->u.sta.bssid) != 0) {
1685                 /* Not from the current AP. */
1686                 return;
1687         }
1688
1689         if (sdata->u.sta.state == IEEE80211_STA_MLME_ASSOCIATE) {
1690                 /* Association in progress; ignore SA Query */
1691                 return;
1692         }
1693
1694         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1695                 /* Too short SA Query request frame */
1696                 return;
1697         }
1698
1699         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1700         if (skb == NULL)
1701                 return;
1702
1703         skb_reserve(skb, local->hw.extra_tx_headroom);
1704         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1705         memset(resp, 0, 24);
1706         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1707         memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1708         memcpy(resp->bssid, sdata->u.sta.bssid, ETH_ALEN);
1709         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1710                                           IEEE80211_STYPE_ACTION);
1711         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1712         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1713         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1714         memcpy(resp->u.action.u.sa_query.trans_id,
1715                mgmt->u.action.u.sa_query.trans_id,
1716                WLAN_SA_QUERY_TR_ID_LEN);
1717
1718         ieee80211_tx_skb(sdata, skb, 1);
1719 }
1720
1721 static ieee80211_rx_result debug_noinline
1722 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1723 {
1724         struct ieee80211_local *local = rx->local;
1725         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1726         struct ieee80211_if_sta *ifsta = &sdata->u.sta;
1727         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1728         struct ieee80211_bss *bss;
1729         int len = rx->skb->len;
1730
1731         if (!ieee80211_is_action(mgmt->frame_control))
1732                 return RX_CONTINUE;
1733
1734         if (!rx->sta)
1735                 return RX_DROP_MONITOR;
1736
1737         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1738                 return RX_DROP_MONITOR;
1739
1740         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1741                 return RX_DROP_MONITOR;
1742
1743         /* all categories we currently handle have action_code */
1744         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1745                 return RX_DROP_MONITOR;
1746
1747         switch (mgmt->u.action.category) {
1748         case WLAN_CATEGORY_BACK:
1749                 switch (mgmt->u.action.u.addba_req.action_code) {
1750                 case WLAN_ACTION_ADDBA_REQ:
1751                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1752                                    sizeof(mgmt->u.action.u.addba_req)))
1753                                 return RX_DROP_MONITOR;
1754                         ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1755                         break;
1756                 case WLAN_ACTION_ADDBA_RESP:
1757                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1758                                    sizeof(mgmt->u.action.u.addba_resp)))
1759                                 return RX_DROP_MONITOR;
1760                         ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1761                         break;
1762                 case WLAN_ACTION_DELBA:
1763                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1764                                    sizeof(mgmt->u.action.u.delba)))
1765                                 return RX_DROP_MONITOR;
1766                         ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1767                         break;
1768                 }
1769                 break;
1770         case WLAN_CATEGORY_SPECTRUM_MGMT:
1771                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1772                         return RX_DROP_MONITOR;
1773                 switch (mgmt->u.action.u.measurement.action_code) {
1774                 case WLAN_ACTION_SPCT_MSR_REQ:
1775                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1776                                    sizeof(mgmt->u.action.u.measurement)))
1777                                 return RX_DROP_MONITOR;
1778                         ieee80211_process_measurement_req(sdata, mgmt, len);
1779                         break;
1780                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1781                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1782                                    sizeof(mgmt->u.action.u.chan_switch)))
1783                                 return RX_DROP_MONITOR;
1784
1785                         if (memcmp(mgmt->bssid, ifsta->bssid, ETH_ALEN) != 0)
1786                                 return RX_DROP_MONITOR;
1787
1788                         bss = ieee80211_rx_bss_get(local, ifsta->bssid,
1789                                            local->hw.conf.channel->center_freq,
1790                                            ifsta->ssid, ifsta->ssid_len);
1791                         if (!bss)
1792                                 return RX_DROP_MONITOR;
1793
1794                         ieee80211_process_chanswitch(sdata,
1795                                      &mgmt->u.action.u.chan_switch.sw_elem, bss);
1796                         ieee80211_rx_bss_put(local, bss);
1797                         break;
1798                 }
1799                 break;
1800         case WLAN_CATEGORY_SA_QUERY:
1801                 if (len < (IEEE80211_MIN_ACTION_SIZE +
1802                            sizeof(mgmt->u.action.u.sa_query)))
1803                         return RX_DROP_MONITOR;
1804                 switch (mgmt->u.action.u.sa_query.action) {
1805                 case WLAN_ACTION_SA_QUERY_REQUEST:
1806                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1807                                 return RX_DROP_MONITOR;
1808                         ieee80211_process_sa_query_req(sdata, mgmt, len);
1809                         break;
1810                 case WLAN_ACTION_SA_QUERY_RESPONSE:
1811                         /*
1812                          * SA Query response is currently only used in AP mode
1813                          * and it is processed in user space.
1814                          */
1815                         return RX_CONTINUE;
1816                 }
1817                 break;
1818         default:
1819                 return RX_CONTINUE;
1820         }
1821
1822         rx->sta->rx_packets++;
1823         dev_kfree_skb(rx->skb);
1824         return RX_QUEUED;
1825 }
1826
1827 static ieee80211_rx_result debug_noinline
1828 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1829 {
1830         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1831         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1832
1833         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1834                 return RX_DROP_MONITOR;
1835
1836         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1837                 return RX_DROP_MONITOR;
1838
1839         if (ieee80211_vif_is_mesh(&sdata->vif))
1840                 return ieee80211_mesh_rx_mgmt(sdata, rx->skb, rx->status);
1841
1842         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1843             sdata->vif.type != NL80211_IFTYPE_ADHOC)
1844                 return RX_DROP_MONITOR;
1845
1846         if (sdata->flags & IEEE80211_SDATA_USERSPACE_MLME)
1847                 return RX_DROP_MONITOR;
1848
1849         ieee80211_sta_rx_mgmt(sdata, rx->skb, rx->status);
1850         return RX_QUEUED;
1851 }
1852
1853 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1854                                             struct ieee80211_hdr *hdr,
1855                                             struct ieee80211_rx_data *rx)
1856 {
1857         int keyidx;
1858         unsigned int hdrlen;
1859
1860         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1861         if (rx->skb->len >= hdrlen + 4)
1862                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1863         else
1864                 keyidx = -1;
1865
1866         if (!rx->sta) {
1867                 /*
1868                  * Some hardware seem to generate incorrect Michael MIC
1869                  * reports; ignore them to avoid triggering countermeasures.
1870                  */
1871                 goto ignore;
1872         }
1873
1874         if (!ieee80211_has_protected(hdr->frame_control))
1875                 goto ignore;
1876
1877         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1878                 /*
1879                  * APs with pairwise keys should never receive Michael MIC
1880                  * errors for non-zero keyidx because these are reserved for
1881                  * group keys and only the AP is sending real multicast
1882                  * frames in the BSS.
1883                  */
1884                 goto ignore;
1885         }
1886
1887         if (!ieee80211_is_data(hdr->frame_control) &&
1888             !ieee80211_is_auth(hdr->frame_control))
1889                 goto ignore;
1890
1891         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr);
1892  ignore:
1893         dev_kfree_skb(rx->skb);
1894         rx->skb = NULL;
1895 }
1896
1897 /* TODO: use IEEE80211_RX_FRAGMENTED */
1898 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1899 {
1900         struct ieee80211_sub_if_data *sdata;
1901         struct ieee80211_local *local = rx->local;
1902         struct ieee80211_rtap_hdr {
1903                 struct ieee80211_radiotap_header hdr;
1904                 u8 flags;
1905                 u8 rate;
1906                 __le16 chan_freq;
1907                 __le16 chan_flags;
1908         } __attribute__ ((packed)) *rthdr;
1909         struct sk_buff *skb = rx->skb, *skb2;
1910         struct net_device *prev_dev = NULL;
1911         struct ieee80211_rx_status *status = rx->status;
1912
1913         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1914                 goto out_free_skb;
1915
1916         if (skb_headroom(skb) < sizeof(*rthdr) &&
1917             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1918                 goto out_free_skb;
1919
1920         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1921         memset(rthdr, 0, sizeof(*rthdr));
1922         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1923         rthdr->hdr.it_present =
1924                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1925                             (1 << IEEE80211_RADIOTAP_RATE) |
1926                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1927
1928         rthdr->rate = rx->rate->bitrate / 5;
1929         rthdr->chan_freq = cpu_to_le16(status->freq);
1930
1931         if (status->band == IEEE80211_BAND_5GHZ)
1932                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1933                                                 IEEE80211_CHAN_5GHZ);
1934         else
1935                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1936                                                 IEEE80211_CHAN_2GHZ);
1937
1938         skb_set_mac_header(skb, 0);
1939         skb->ip_summed = CHECKSUM_UNNECESSARY;
1940         skb->pkt_type = PACKET_OTHERHOST;
1941         skb->protocol = htons(ETH_P_802_2);
1942
1943         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1944                 if (!netif_running(sdata->dev))
1945                         continue;
1946
1947                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1948                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1949                         continue;
1950
1951                 if (prev_dev) {
1952                         skb2 = skb_clone(skb, GFP_ATOMIC);
1953                         if (skb2) {
1954                                 skb2->dev = prev_dev;
1955                                 netif_rx(skb2);
1956                         }
1957                 }
1958
1959                 prev_dev = sdata->dev;
1960                 sdata->dev->stats.rx_packets++;
1961                 sdata->dev->stats.rx_bytes += skb->len;
1962         }
1963
1964         if (prev_dev) {
1965                 skb->dev = prev_dev;
1966                 netif_rx(skb);
1967                 skb = NULL;
1968         } else
1969                 goto out_free_skb;
1970
1971         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1972         return;
1973
1974  out_free_skb:
1975         dev_kfree_skb(skb);
1976 }
1977
1978
1979 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1980                                          struct ieee80211_rx_data *rx,
1981                                          struct sk_buff *skb)
1982 {
1983         ieee80211_rx_result res = RX_DROP_MONITOR;
1984
1985         rx->skb = skb;
1986         rx->sdata = sdata;
1987         rx->dev = sdata->dev;
1988
1989 #define CALL_RXH(rxh)                   \
1990         do {                            \
1991                 res = rxh(rx);          \
1992                 if (res != RX_CONTINUE) \
1993                         goto rxh_done;  \
1994         } while (0);
1995
1996         CALL_RXH(ieee80211_rx_h_passive_scan)
1997         CALL_RXH(ieee80211_rx_h_check)
1998         CALL_RXH(ieee80211_rx_h_decrypt)
1999         CALL_RXH(ieee80211_rx_h_sta_process)
2000         CALL_RXH(ieee80211_rx_h_defragment)
2001         CALL_RXH(ieee80211_rx_h_ps_poll)
2002         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2003         /* must be after MMIC verify so header is counted in MPDU mic */
2004         CALL_RXH(ieee80211_rx_h_remove_qos_control)
2005         CALL_RXH(ieee80211_rx_h_amsdu)
2006 #ifdef CONFIG_MAC80211_MESH
2007         if (ieee80211_vif_is_mesh(&sdata->vif))
2008                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
2009 #endif
2010         CALL_RXH(ieee80211_rx_h_data)
2011         CALL_RXH(ieee80211_rx_h_ctrl)
2012         CALL_RXH(ieee80211_rx_h_action)
2013         CALL_RXH(ieee80211_rx_h_mgmt)
2014
2015 #undef CALL_RXH
2016
2017  rxh_done:
2018         switch (res) {
2019         case RX_DROP_MONITOR:
2020                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2021                 if (rx->sta)
2022                         rx->sta->rx_dropped++;
2023                 /* fall through */
2024         case RX_CONTINUE:
2025                 ieee80211_rx_cooked_monitor(rx);
2026                 break;
2027         case RX_DROP_UNUSABLE:
2028                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2029                 if (rx->sta)
2030                         rx->sta->rx_dropped++;
2031                 dev_kfree_skb(rx->skb);
2032                 break;
2033         case RX_QUEUED:
2034                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2035                 break;
2036         }
2037 }
2038
2039 /* main receive path */
2040
2041 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2042                                 u8 *bssid, struct ieee80211_rx_data *rx,
2043                                 struct ieee80211_hdr *hdr)
2044 {
2045         int multicast = is_multicast_ether_addr(hdr->addr1);
2046
2047         switch (sdata->vif.type) {
2048         case NL80211_IFTYPE_STATION:
2049                 if (!bssid)
2050                         return 0;
2051                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
2052                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2053                                 return 0;
2054                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2055                 } else if (!multicast &&
2056                            compare_ether_addr(sdata->dev->dev_addr,
2057                                               hdr->addr1) != 0) {
2058                         if (!(sdata->dev->flags & IFF_PROMISC))
2059                                 return 0;
2060                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2061                 }
2062                 break;
2063         case NL80211_IFTYPE_ADHOC:
2064                 if (!bssid)
2065                         return 0;
2066                 if (ieee80211_is_beacon(hdr->frame_control)) {
2067                         return 1;
2068                 }
2069                 else if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
2070                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2071                                 return 0;
2072                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2073                 } else if (!multicast &&
2074                            compare_ether_addr(sdata->dev->dev_addr,
2075                                               hdr->addr1) != 0) {
2076                         if (!(sdata->dev->flags & IFF_PROMISC))
2077                                 return 0;
2078                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2079                 } else if (!rx->sta) {
2080                         int rate_idx;
2081                         if (rx->status->flag & RX_FLAG_HT)
2082                                 rate_idx = 0; /* TODO: HT rates */
2083                         else
2084                                 rate_idx = rx->status->rate_idx;
2085                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2086                                 BIT(rate_idx));
2087                 }
2088                 break;
2089         case NL80211_IFTYPE_MESH_POINT:
2090                 if (!multicast &&
2091                     compare_ether_addr(sdata->dev->dev_addr,
2092                                        hdr->addr1) != 0) {
2093                         if (!(sdata->dev->flags & IFF_PROMISC))
2094                                 return 0;
2095
2096                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2097                 }
2098                 break;
2099         case NL80211_IFTYPE_AP_VLAN:
2100         case NL80211_IFTYPE_AP:
2101                 if (!bssid) {
2102                         if (compare_ether_addr(sdata->dev->dev_addr,
2103                                                hdr->addr1))
2104                                 return 0;
2105                 } else if (!ieee80211_bssid_match(bssid,
2106                                         sdata->dev->dev_addr)) {
2107                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2108                                 return 0;
2109                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2110                 }
2111                 break;
2112         case NL80211_IFTYPE_WDS:
2113                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2114                         return 0;
2115                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2116                         return 0;
2117                 break;
2118         case NL80211_IFTYPE_MONITOR:
2119                 /* take everything */
2120                 break;
2121         case NL80211_IFTYPE_UNSPECIFIED:
2122         case __NL80211_IFTYPE_AFTER_LAST:
2123                 /* should never get here */
2124                 WARN_ON(1);
2125                 break;
2126         }
2127
2128         return 1;
2129 }
2130
2131 /*
2132  * This is the actual Rx frames handler. as it blongs to Rx path it must
2133  * be called with rcu_read_lock protection.
2134  */
2135 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2136                                          struct sk_buff *skb,
2137                                          struct ieee80211_rx_status *status,
2138                                          struct ieee80211_rate *rate)
2139 {
2140         struct ieee80211_local *local = hw_to_local(hw);
2141         struct ieee80211_sub_if_data *sdata;
2142         struct ieee80211_hdr *hdr;
2143         struct ieee80211_rx_data rx;
2144         int prepares;
2145         struct ieee80211_sub_if_data *prev = NULL;
2146         struct sk_buff *skb_new;
2147         u8 *bssid;
2148
2149         hdr = (struct ieee80211_hdr *)skb->data;
2150         memset(&rx, 0, sizeof(rx));
2151         rx.skb = skb;
2152         rx.local = local;
2153
2154         rx.status = status;
2155         rx.rate = rate;
2156
2157         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2158                 local->dot11ReceivedFragmentCount++;
2159
2160         rx.sta = sta_info_get(local, hdr->addr2);
2161         if (rx.sta) {
2162                 rx.sdata = rx.sta->sdata;
2163                 rx.dev = rx.sta->sdata->dev;
2164         }
2165
2166         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
2167                 ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
2168                 return;
2169         }
2170
2171         if (unlikely(local->sw_scanning || local->hw_scanning))
2172                 rx.flags |= IEEE80211_RX_IN_SCAN;
2173
2174         ieee80211_parse_qos(&rx);
2175         ieee80211_verify_alignment(&rx);
2176
2177         skb = rx.skb;
2178
2179         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2180                 if (!netif_running(sdata->dev))
2181                         continue;
2182
2183                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
2184                         continue;
2185
2186                 bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2187                 rx.flags |= IEEE80211_RX_RA_MATCH;
2188                 prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
2189
2190                 if (!prepares)
2191                         continue;
2192
2193                 /*
2194                  * frame is destined for this interface, but if it's not
2195                  * also for the previous one we handle that after the
2196                  * loop to avoid copying the SKB once too much
2197                  */
2198
2199                 if (!prev) {
2200                         prev = sdata;
2201                         continue;
2202                 }
2203
2204                 /*
2205                  * frame was destined for the previous interface
2206                  * so invoke RX handlers for it
2207                  */
2208
2209                 skb_new = skb_copy(skb, GFP_ATOMIC);
2210                 if (!skb_new) {
2211                         if (net_ratelimit())
2212                                 printk(KERN_DEBUG "%s: failed to copy "
2213                                        "multicast frame for %s\n",
2214                                        wiphy_name(local->hw.wiphy),
2215                                        prev->dev->name);
2216                         continue;
2217                 }
2218                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
2219                 prev = sdata;
2220         }
2221         if (prev)
2222                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
2223         else
2224                 dev_kfree_skb(skb);
2225 }
2226
2227 #define SEQ_MODULO 0x1000
2228 #define SEQ_MASK   0xfff
2229
2230 static inline int seq_less(u16 sq1, u16 sq2)
2231 {
2232         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
2233 }
2234
2235 static inline u16 seq_inc(u16 sq)
2236 {
2237         return (sq + 1) & SEQ_MASK;
2238 }
2239
2240 static inline u16 seq_sub(u16 sq1, u16 sq2)
2241 {
2242         return (sq1 - sq2) & SEQ_MASK;
2243 }
2244
2245
2246 /*
2247  * As it function blongs to Rx path it must be called with
2248  * the proper rcu_read_lock protection for its flow.
2249  */
2250 static u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2251                                            struct tid_ampdu_rx *tid_agg_rx,
2252                                            struct sk_buff *skb,
2253                                            u16 mpdu_seq_num,
2254                                            int bar_req)
2255 {
2256         struct ieee80211_local *local = hw_to_local(hw);
2257         struct ieee80211_rx_status status;
2258         u16 head_seq_num, buf_size;
2259         int index;
2260         struct ieee80211_supported_band *sband;
2261         struct ieee80211_rate *rate;
2262
2263         buf_size = tid_agg_rx->buf_size;
2264         head_seq_num = tid_agg_rx->head_seq_num;
2265
2266         /* frame with out of date sequence number */
2267         if (seq_less(mpdu_seq_num, head_seq_num)) {
2268                 dev_kfree_skb(skb);
2269                 return 1;
2270         }
2271
2272         /* if frame sequence number exceeds our buffering window size or
2273          * block Ack Request arrived - release stored frames */
2274         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
2275                 /* new head to the ordering buffer */
2276                 if (bar_req)
2277                         head_seq_num = mpdu_seq_num;
2278                 else
2279                         head_seq_num =
2280                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
2281                 /* release stored frames up to new head to stack */
2282                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2283                         index = seq_sub(tid_agg_rx->head_seq_num,
2284                                 tid_agg_rx->ssn)
2285                                 % tid_agg_rx->buf_size;
2286
2287                         if (tid_agg_rx->reorder_buf[index]) {
2288                                 /* release the reordered frames to stack */
2289                                 memcpy(&status,
2290                                         tid_agg_rx->reorder_buf[index]->cb,
2291                                         sizeof(status));
2292                                 sband = local->hw.wiphy->bands[status.band];
2293                                 if (status.flag & RX_FLAG_HT) {
2294                                         /* TODO: HT rates */
2295                                         rate = sband->bitrates;
2296                                 } else {
2297                                         rate = &sband->bitrates
2298                                                 [status.rate_idx];
2299                                 }
2300                                 __ieee80211_rx_handle_packet(hw,
2301                                         tid_agg_rx->reorder_buf[index],
2302                                         &status, rate);
2303                                 tid_agg_rx->stored_mpdu_num--;
2304                                 tid_agg_rx->reorder_buf[index] = NULL;
2305                         }
2306                         tid_agg_rx->head_seq_num =
2307                                 seq_inc(tid_agg_rx->head_seq_num);
2308                 }
2309                 if (bar_req)
2310                         return 1;
2311         }
2312
2313         /* now the new frame is always in the range of the reordering */
2314         /* buffer window */
2315         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2316                                 % tid_agg_rx->buf_size;
2317         /* check if we already stored this frame */
2318         if (tid_agg_rx->reorder_buf[index]) {
2319                 dev_kfree_skb(skb);
2320                 return 1;
2321         }
2322
2323         /* if arrived mpdu is in the right order and nothing else stored */
2324         /* release it immediately */
2325         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2326                         tid_agg_rx->stored_mpdu_num == 0) {
2327                 tid_agg_rx->head_seq_num =
2328                         seq_inc(tid_agg_rx->head_seq_num);
2329                 return 0;
2330         }
2331
2332         /* put the frame in the reordering buffer */
2333         tid_agg_rx->reorder_buf[index] = skb;
2334         tid_agg_rx->stored_mpdu_num++;
2335         /* release the buffer until next missing frame */
2336         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2337                                                 % tid_agg_rx->buf_size;
2338         while (tid_agg_rx->reorder_buf[index]) {
2339                 /* release the reordered frame back to stack */
2340                 memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
2341                         sizeof(status));
2342                 sband = local->hw.wiphy->bands[status.band];
2343                 if (status.flag & RX_FLAG_HT)
2344                         rate = sband->bitrates; /* TODO: HT rates */
2345                 else
2346                         rate = &sband->bitrates[status.rate_idx];
2347                 __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
2348                                              &status, rate);
2349                 tid_agg_rx->stored_mpdu_num--;
2350                 tid_agg_rx->reorder_buf[index] = NULL;
2351                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2352                 index = seq_sub(tid_agg_rx->head_seq_num,
2353                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2354         }
2355         return 1;
2356 }
2357
2358 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2359                                      struct sk_buff *skb)
2360 {
2361         struct ieee80211_hw *hw = &local->hw;
2362         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2363         struct sta_info *sta;
2364         struct tid_ampdu_rx *tid_agg_rx;
2365         u16 sc;
2366         u16 mpdu_seq_num;
2367         u8 ret = 0;
2368         int tid;
2369
2370         sta = sta_info_get(local, hdr->addr2);
2371         if (!sta)
2372                 return ret;
2373
2374         /* filter the QoS data rx stream according to
2375          * STA/TID and check if this STA/TID is on aggregation */
2376         if (!ieee80211_is_data_qos(hdr->frame_control))
2377                 goto end_reorder;
2378
2379         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2380
2381         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2382                 goto end_reorder;
2383
2384         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2385
2386         /* qos null data frames are excluded */
2387         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2388                 goto end_reorder;
2389
2390         /* new un-ordered ampdu frame - process it */
2391
2392         /* reset session timer */
2393         if (tid_agg_rx->timeout) {
2394                 unsigned long expires =
2395                         jiffies + (tid_agg_rx->timeout / 1000) * HZ;
2396                 mod_timer(&tid_agg_rx->session_timer, expires);
2397         }
2398
2399         /* if this mpdu is fragmented - terminate rx aggregation session */
2400         sc = le16_to_cpu(hdr->seq_ctrl);
2401         if (sc & IEEE80211_SCTL_FRAG) {
2402                 ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2403                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2404                 ret = 1;
2405                 goto end_reorder;
2406         }
2407
2408         /* according to mpdu sequence number deal with reordering buffer */
2409         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2410         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2411                                                 mpdu_seq_num, 0);
2412  end_reorder:
2413         return ret;
2414 }
2415
2416 /*
2417  * This is the receive path handler. It is called by a low level driver when an
2418  * 802.11 MPDU is received from the hardware.
2419  */
2420 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2421                     struct ieee80211_rx_status *status)
2422 {
2423         struct ieee80211_local *local = hw_to_local(hw);
2424         struct ieee80211_rate *rate = NULL;
2425         struct ieee80211_supported_band *sband;
2426
2427         if (status->band < 0 ||
2428             status->band >= IEEE80211_NUM_BANDS) {
2429                 WARN_ON(1);
2430                 return;
2431         }
2432
2433         sband = local->hw.wiphy->bands[status->band];
2434         if (!sband) {
2435                 WARN_ON(1);
2436                 return;
2437         }
2438
2439         if (status->flag & RX_FLAG_HT) {
2440                 /* rate_idx is MCS index */
2441                 if (WARN_ON(status->rate_idx < 0 ||
2442                             status->rate_idx >= 76))
2443                         return;
2444                 /* HT rates are not in the table - use the highest legacy rate
2445                  * for now since other parts of mac80211 may not yet be fully
2446                  * MCS aware. */
2447                 rate = &sband->bitrates[sband->n_bitrates - 1];
2448         } else {
2449                 if (WARN_ON(status->rate_idx < 0 ||
2450                             status->rate_idx >= sband->n_bitrates))
2451                         return;
2452                 rate = &sband->bitrates[status->rate_idx];
2453         }
2454
2455         /*
2456          * key references and virtual interfaces are protected using RCU
2457          * and this requires that we are in a read-side RCU section during
2458          * receive processing
2459          */
2460         rcu_read_lock();
2461
2462         /*
2463          * Frames with failed FCS/PLCP checksum are not returned,
2464          * all other frames are returned without radiotap header
2465          * if it was previously present.
2466          * Also, frames with less than 16 bytes are dropped.
2467          */
2468         skb = ieee80211_rx_monitor(local, skb, status, rate);
2469         if (!skb) {
2470                 rcu_read_unlock();
2471                 return;
2472         }
2473
2474         if (!ieee80211_rx_reorder_ampdu(local, skb))
2475                 __ieee80211_rx_handle_packet(hw, skb, status, rate);
2476
2477         rcu_read_unlock();
2478 }
2479 EXPORT_SYMBOL(__ieee80211_rx);
2480
2481 /* This is a version of the rx handler that can be called from hard irq
2482  * context. Post the skb on the queue and schedule the tasklet */
2483 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2484                           struct ieee80211_rx_status *status)
2485 {
2486         struct ieee80211_local *local = hw_to_local(hw);
2487
2488         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2489
2490         skb->dev = local->mdev;
2491         /* copy status into skb->cb for use by tasklet */
2492         memcpy(skb->cb, status, sizeof(*status));
2493         skb->pkt_type = IEEE80211_RX_MSG;
2494         skb_queue_tail(&local->skb_queue, skb);
2495         tasklet_schedule(&local->tasklet);
2496 }
2497 EXPORT_SYMBOL(ieee80211_rx_irqsafe);