net/mac80211/rx.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/jiffies.h>
  13 #include <linux/kernel.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/rcupdate.h>
  18 #include <net/mac80211.h>
  19 #include <net/ieee80211_radiotap.h>
  20
  21 #include "ieee80211_i.h"
  22 #include "driver-ops.h"
  23 #include "led.h"
  24 #include "mesh.h"
  25 #include "wep.h"
  26 #include "wpa.h"
  27 #include "tkip.h"
  28 #include "wme.h"
  29
  30 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
  31                                              struct tid_ampdu_rx *tid_agg_rx,
  32                                              u16 head_seq_num);
  33
  34 /*
  35  * monitor mode reception
  36  *
  37  * This function cleans up the SKB, i.e. it removes all the stuff
  38  * only useful for monitoring.
  39  */
  40 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  41                                            struct sk_buff *skb)
  42 {
  43         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  44                 if (likely(skb->len > FCS_LEN))
  45                         skb_trim(skb, skb->len - FCS_LEN);
  46                 else {
  47                         /* driver bug */
  48                         WARN_ON(1);
  49                         dev_kfree_skb(skb);
  50                         skb = NULL;
  51                 }
  52         }
  53
  54         return skb;
  55 }
  56
  57 static inline int should_drop_frame(struct sk_buff *skb,
  58                                     int present_fcs_len)
  59 {
  60         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  61         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  62
  63         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  64                 return 1;
  65         if (unlikely(skb->len < 16 + present_fcs_len))
  66                 return 1;
  67         if (ieee80211_is_ctl(hdr->frame_control) &&
  68             !ieee80211_is_pspoll(hdr->frame_control) &&
  69             !ieee80211_is_back_req(hdr->frame_control))
  70                 return 1;
  71         return 0;
  72 }
  73
  74 static int
  75 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  76                           struct ieee80211_rx_status *status)
  77 {
  78         int len;
  79
  80         /* always present fields */
  81         len = sizeof(struct ieee80211_radiotap_header) + 9;
  82
  83         if (status->flag & RX_FLAG_TSFT)
  84                 len += 8;
  85         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  86                 len += 1;
  87         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
  88                 len += 1;
  89
  90         if (len & 1) /* padding for RX_FLAGS if necessary */
  91                 len++;
  92
  93         return len;
  94 }
  95
  96 /*
  97  * ieee80211_add_rx_radiotap_header - add radiotap header
  98  *
  99  * add a radiotap header containing all the fields which the hardware provided.
 100  */
 101 static void
 102 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 103                                  struct sk_buff *skb,
 104                                  struct ieee80211_rate *rate,
 105                                  int rtap_len)
 106 {
 107         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 108         struct ieee80211_radiotap_header *rthdr;
 109         unsigned char *pos;
 110         u16 rx_flags = 0;
 111
 112         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 113         memset(rthdr, 0, rtap_len);
 114
 115         /* radiotap header, set always present flags */
 116         rthdr->it_present =
 117                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 118                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 119                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 120                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 121         rthdr->it_len = cpu_to_le16(rtap_len);
 122
 123         pos = (unsigned char *)(rthdr+1);
 124
 125         /* the order of the following fields is important */
 126
 127         /* IEEE80211_RADIOTAP_TSFT */
 128         if (status->flag & RX_FLAG_TSFT) {
 129                 put_unaligned_le64(status->mactime, pos);
 130                 rthdr->it_present |=
 131                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 132                 pos += 8;
 133         }
 134
 135         /* IEEE80211_RADIOTAP_FLAGS */
 136         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 137                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 138         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 139                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 140         if (status->flag & RX_FLAG_SHORTPRE)
 141                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 142         pos++;
 143
 144         /* IEEE80211_RADIOTAP_RATE */
 145         if (status->flag & RX_FLAG_HT) {
 146                 /*
 147                  * TODO: add following information into radiotap header once
 148                  * suitable fields are defined for it:
 149                  * - MCS index (status->rate_idx)
 150                  * - HT40 (status->flag & RX_FLAG_40MHZ)
 151                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
 152                  */
 153                 *pos = 0;
 154         } else {
 155                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 156                 *pos = rate->bitrate / 5;
 157         }
 158         pos++;
 159
 160         /* IEEE80211_RADIOTAP_CHANNEL */
 161         put_unaligned_le16(status->freq, pos);
 162         pos += 2;
 163         if (status->band == IEEE80211_BAND_5GHZ)
 164                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
 165                                    pos);
 166         else if (rate->flags & IEEE80211_RATE_ERP_G)
 167                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
 168                                    pos);
 169         else
 170                 put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
 171                                    pos);
 172         pos += 2;
 173
 174         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 175         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 176                 *pos = status->signal;
 177                 rthdr->it_present |=
 178                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 179                 pos++;
 180         }
 181
 182         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
 183         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
 184                 *pos = status->noise;
 185                 rthdr->it_present |=
 186                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
 187                 pos++;
 188         }
 189
 190         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 191
 192         /* IEEE80211_RADIOTAP_ANTENNA */
 193         *pos = status->antenna;
 194         pos++;
 195
 196         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 197
 198         /* IEEE80211_RADIOTAP_RX_FLAGS */
 199         /* ensure 2 byte alignment for the 2 byte field as required */
 200         if ((pos - (u8 *)rthdr) & 1)
 201                 pos++;
 202         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
 203                 rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
 204         put_unaligned_le16(rx_flags, pos);
 205         pos += 2;
 206 }
 207
 208 /*
 209  * This function copies a received frame to all monitor interfaces and
 210  * returns a cleaned-up SKB that no longer includes the FCS nor the
 211  * radiotap header the driver might have added.
 212  */
 213 static struct sk_buff *
 214 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 215                      struct ieee80211_rate *rate)
 216 {
 217         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
 218         struct ieee80211_sub_if_data *sdata;
 219         int needed_headroom = 0;
 220         struct sk_buff *skb, *skb2;
 221         struct net_device *prev_dev = NULL;
 222         int present_fcs_len = 0;
 223
 224         /*
 225          * First, we may need to make a copy of the skb because
 226          *  (1) we need to modify it for radiotap (if not present), and
 227          *  (2) the other RX handlers will modify the skb we got.
 228          *
 229          * We don't need to, of course, if we aren't going to return
 230          * the SKB because it has a bad FCS/PLCP checksum.
 231          */
 232
 233         /* room for the radiotap header based on driver features */
 234         needed_headroom = ieee80211_rx_radiotap_len(local, status);
 235
 236         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 237                 present_fcs_len = FCS_LEN;
 238
 239         if (!local->monitors) {
 240                 if (should_drop_frame(origskb, present_fcs_len)) {
 241                         dev_kfree_skb(origskb);
 242                         return NULL;
 243                 }
 244
 245                 return remove_monitor_info(local, origskb);
 246         }
 247
 248         if (should_drop_frame(origskb, present_fcs_len)) {
 249                 /* only need to expand headroom if necessary */
 250                 skb = origskb;
 251                 origskb = NULL;
 252
 253                 /*
 254                  * This shouldn't trigger often because most devices have an
 255                  * RX header they pull before we get here, and that should
 256                  * be big enough for our radiotap information. We should
 257                  * probably export the length to drivers so that we can have
 258                  * them allocate enough headroom to start with.
 259                  */
 260                 if (skb_headroom(skb) < needed_headroom &&
 261                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 262                         dev_kfree_skb(skb);
 263                         return NULL;
 264                 }
 265         } else {
 266                 /*
 267                  * Need to make a copy and possibly remove radiotap header
 268                  * and FCS from the original.
 269                  */
 270                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 271
 272                 origskb = remove_monitor_info(local, origskb);
 273
 274                 if (!skb)
 275                         return origskb;
 276         }
 277
 278         /* prepend radiotap information */
 279         ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
 280
 281         skb_reset_mac_header(skb);
 282         skb->ip_summed = CHECKSUM_UNNECESSARY;
 283         skb->pkt_type = PACKET_OTHERHOST;
 284         skb->protocol = htons(ETH_P_802_2);
 285
 286         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 287                 if (!netif_running(sdata->dev))
 288                         continue;
 289
 290                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 291                         continue;
 292
 293                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 294                         continue;
 295
 296                 if (prev_dev) {
 297                         skb2 = skb_clone(skb, GFP_ATOMIC);
 298                         if (skb2) {
 299                                 skb2->dev = prev_dev;
 300                                 netif_rx(skb2);
 301                         }
 302                 }
 303
 304                 prev_dev = sdata->dev;
 305                 sdata->dev->stats.rx_packets++;
 306                 sdata->dev->stats.rx_bytes += skb->len;
 307         }
 308
 309         if (prev_dev) {
 310                 skb->dev = prev_dev;
 311                 netif_rx(skb);
 312         } else
 313                 dev_kfree_skb(skb);
 314
 315         return origskb;
 316 }
 317
 318
 319 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 320 {
 321         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 322         int tid;
 323
 324         /* does the frame have a qos control field? */
 325         if (ieee80211_is_data_qos(hdr->frame_control)) {
 326                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 327                 /* frame has qos control */
 328                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 329                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 330                         rx->flags |= IEEE80211_RX_AMSDU;
 331                 else
 332                         rx->flags &= ~IEEE80211_RX_AMSDU;
 333         } else {
 334                 /*
 335                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 336                  *
 337                  *      Sequence numbers for management frames, QoS data
 338                  *      frames with a broadcast/multicast address in the
 339                  *      Address 1 field, and all non-QoS data frames sent
 340                  *      by QoS STAs are assigned using an additional single
 341                  *      modulo-4096 counter, [...]
 342                  *
 343                  * We also use that counter for non-QoS STAs.
 344                  */
 345                 tid = NUM_RX_DATA_QUEUES - 1;
 346         }
 347
 348         rx->queue = tid;
 349         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 350          * For now, set skb->priority to 0 for other cases. */
 351         rx->skb->priority = (tid > 7) ? 0 : tid;
 352 }
 353
 354 /**
 355  * DOC: Packet alignment
 356  *
 357  * Drivers always need to pass packets that are aligned to two-byte boundaries
 358  * to the stack.
 359  *
 360  * Additionally, should, if possible, align the payload data in a way that
 361  * guarantees that the contained IP header is aligned to a four-byte
 362  * boundary. In the case of regular frames, this simply means aligning the
 363  * payload to a four-byte boundary (because either the IP header is directly
 364  * contained, or IV/RFC1042 headers that have a length divisible by four are
 365  * in front of it).
 366  *
 367  * With A-MSDU frames, however, the payload data address must yield two modulo
 368  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 369  * push the IP header further back to a multiple of four again. Thankfully, the
 370  * specs were sane enough this time around to require padding each A-MSDU
 371  * subframe to a length that is a multiple of four.
 372  *
 373  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
 374  * the payload is not supported, the driver is required to move the 802.11
 375  * header to be directly in front of the payload in that case.
 376  */
 377 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 378 {
 379         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 380         int hdrlen;
 381
 382 #ifndef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
 383         return;
 384 #endif
 385
 386         if (WARN_ONCE((unsigned long)rx->skb->data & 1,
 387                       "unaligned packet at 0x%p\n", rx->skb->data))
 388                 return;
 389
 390         if (!ieee80211_is_data_present(hdr->frame_control))
 391                 return;
 392
 393         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 394         if (rx->flags & IEEE80211_RX_AMSDU)
 395                 hdrlen += ETH_HLEN;
 396         WARN_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3,
 397                   "unaligned IP payload at 0x%p\n", rx->skb->data + hdrlen);
 398 }
 399
 400
 401 /* rx handlers */
 402
 403 static ieee80211_rx_result debug_noinline
 404 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 405 {
 406         struct ieee80211_local *local = rx->local;
 407         struct sk_buff *skb = rx->skb;
 408
 409         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning)))
 410                 return ieee80211_scan_rx(rx->sdata, skb);
 411
 412         if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning) &&
 413                      (rx->flags & IEEE80211_RX_IN_SCAN))) {
 414                 /* drop all the other packets during a software scan anyway */
 415                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
 416                         dev_kfree_skb(skb);
 417                 return RX_QUEUED;
 418         }
 419
 420         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
 421                 /* scanning finished during invoking of handlers */
 422                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 423                 return RX_DROP_UNUSABLE;
 424         }
 425
 426         return RX_CONTINUE;
 427 }
 428
 429
 430 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 431 {
 432         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 433
 434         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 435                 return 0;
 436
 437         return ieee80211_is_robust_mgmt_frame(hdr);
 438 }
 439
 440
 441 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 442 {
 443         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 444
 445         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 446                 return 0;
 447
 448         return ieee80211_is_robust_mgmt_frame(hdr);
 449 }
 450
 451
 452 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 453 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 454 {
 455         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 456         struct ieee80211_mmie *mmie;
 457
 458         if (skb->len < 24 + sizeof(*mmie) ||
 459             !is_multicast_ether_addr(hdr->da))
 460                 return -1;
 461
 462         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 463                 return -1; /* not a robust management frame */
 464
 465         mmie = (struct ieee80211_mmie *)
 466                 (skb->data + skb->len - sizeof(*mmie));
 467         if (mmie->element_id != WLAN_EID_MMIE ||
 468             mmie->length != sizeof(*mmie) - 2)
 469                 return -1;
 470
 471         return le16_to_cpu(mmie->key_id);
 472 }
 473
 474
 475 static ieee80211_rx_result
 476 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 477 {
 478         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 479         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 480         char *dev_addr = rx->sdata->dev->dev_addr;
 481
 482         if (ieee80211_is_data(hdr->frame_control)) {
 483                 if (is_multicast_ether_addr(hdr->addr1)) {
 484                         if (ieee80211_has_tods(hdr->frame_control) ||
 485                                 !ieee80211_has_fromds(hdr->frame_control))
 486                                 return RX_DROP_MONITOR;
 487                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
 488                                 return RX_DROP_MONITOR;
 489                 } else {
 490                         if (!ieee80211_has_a4(hdr->frame_control))
 491                                 return RX_DROP_MONITOR;
 492                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
 493                                 return RX_DROP_MONITOR;
 494                 }
 495         }
 496
 497         /* If there is not an established peer link and this is not a peer link
 498          * establisment frame, beacon or probe, drop the frame.
 499          */
 500
 501         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 502                 struct ieee80211_mgmt *mgmt;
 503
 504                 if (!ieee80211_is_mgmt(hdr->frame_control))
 505                         return RX_DROP_MONITOR;
 506
 507                 if (ieee80211_is_action(hdr->frame_control)) {
 508                         mgmt = (struct ieee80211_mgmt *)hdr;
 509                         if (mgmt->u.action.category != MESH_PLINK_CATEGORY)
 510                                 return RX_DROP_MONITOR;
 511                         return RX_CONTINUE;
 512                 }
 513
 514                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 515                     ieee80211_is_probe_resp(hdr->frame_control) ||
 516                     ieee80211_is_beacon(hdr->frame_control))
 517                         return RX_CONTINUE;
 518
 519                 return RX_DROP_MONITOR;
 520
 521         }
 522
 523 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 524
 525         if (ieee80211_is_data(hdr->frame_control) &&
 526             is_multicast_ether_addr(hdr->addr1) &&
 527             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
 528                 return RX_DROP_MONITOR;
 529 #undef msh_h_get
 530
 531         return RX_CONTINUE;
 532 }
 533
 534
 535 static ieee80211_rx_result debug_noinline
 536 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 537 {
 538         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 539
 540         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 541         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 542                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 543                              rx->sta->last_seq_ctrl[rx->queue] ==
 544                              hdr->seq_ctrl)) {
 545                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
 546                                 rx->local->dot11FrameDuplicateCount++;
 547                                 rx->sta->num_duplicates++;
 548                         }
 549                         return RX_DROP_MONITOR;
 550                 } else
 551                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 552         }
 553
 554         if (unlikely(rx->skb->len < 16)) {
 555                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 556                 return RX_DROP_MONITOR;
 557         }
 558
 559         /* Drop disallowed frame classes based on STA auth/assoc state;
 560          * IEEE 802.11, Chap 5.5.
 561          *
 562          * mac80211 filters only based on association state, i.e. it drops
 563          * Class 3 frames from not associated stations. hostapd sends
 564          * deauth/disassoc frames when needed. In addition, hostapd is
 565          * responsible for filtering on both auth and assoc states.
 566          */
 567
 568         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 569                 return ieee80211_rx_mesh_check(rx);
 570
 571         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 572                       ieee80211_is_pspoll(hdr->frame_control)) &&
 573                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 574                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 575                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 576                      !ieee80211_has_tods(hdr->frame_control) &&
 577                      ieee80211_is_data(hdr->frame_control)) ||
 578                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
 579                         /* Drop IBSS frames and frames for other hosts
 580                          * silently. */
 581                         return RX_DROP_MONITOR;
 582                 }
 583
 584                 return RX_DROP_MONITOR;
 585         }
 586
 587         return RX_CONTINUE;
 588 }
 589
 590
 591 static ieee80211_rx_result debug_noinline
 592 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 593 {
 594         struct sk_buff *skb = rx->skb;
 595         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 596         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 597         int keyidx;
 598         int hdrlen;
 599         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 600         struct ieee80211_key *stakey = NULL;
 601         int mmie_keyidx = -1;
 602
 603         /*
 604          * Key selection 101
 605          *
 606          * There are four types of keys:
 607          *  - GTK (group keys)
 608          *  - IGTK (group keys for management frames)
 609          *  - PTK (pairwise keys)
 610          *  - STK (station-to-station pairwise keys)
 611          *
 612          * When selecting a key, we have to distinguish between multicast
 613          * (including broadcast) and unicast frames, the latter can only
 614          * use PTKs and STKs while the former always use GTKs and IGTKs.
 615          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 616          * unicast frames can also use key indices like GTKs. Hence, if we
 617          * don't have a PTK/STK we check the key index for a WEP key.
 618          *
 619          * Note that in a regular BSS, multicast frames are sent by the
 620          * AP only, associated stations unicast the frame to the AP first
 621          * which then multicasts it on their behalf.
 622          *
 623          * There is also a slight problem in IBSS mode: GTKs are negotiated
 624          * with each station, that is something we don't currently handle.
 625          * The spec seems to expect that one negotiates the same key with
 626          * every station but there's no such requirement; VLANs could be
 627          * possible.
 628          */
 629
 630         /*
 631          * No point in finding a key and decrypting if the frame is neither
 632          * addressed to us nor a multicast frame.
 633          */
 634         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 635                 return RX_CONTINUE;
 636
 637         if (rx->sta)
 638                 stakey = rcu_dereference(rx->sta->key);
 639
 640         if (!ieee80211_has_protected(hdr->frame_control))
 641                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 642
 643         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 644                 rx->key = stakey;
 645                 /* Skip decryption if the frame is not protected. */
 646                 if (!ieee80211_has_protected(hdr->frame_control))
 647                         return RX_CONTINUE;
 648         } else if (mmie_keyidx >= 0) {
 649                 /* Broadcast/multicast robust management frame / BIP */
 650                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 651                     (status->flag & RX_FLAG_IV_STRIPPED))
 652                         return RX_CONTINUE;
 653
 654                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 655                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 656                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 657                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 658         } else if (!ieee80211_has_protected(hdr->frame_control)) {
 659                 /*
 660                  * The frame was not protected, so skip decryption. However, we
 661                  * need to set rx->key if there is a key that could have been
 662                  * used so that the frame may be dropped if encryption would
 663                  * have been expected.
 664                  */
 665                 struct ieee80211_key *key = NULL;
 666                 if (ieee80211_is_mgmt(hdr->frame_control) &&
 667                     is_multicast_ether_addr(hdr->addr1) &&
 668                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 669                         rx->key = key;
 670                 else if ((key = rcu_dereference(rx->sdata->default_key)))
 671                         rx->key = key;
 672                 return RX_CONTINUE;
 673         } else {
 674                 /*
 675                  * The device doesn't give us the IV so we won't be
 676                  * able to look up the key. That's ok though, we
 677                  * don't need to decrypt the frame, we just won't
 678                  * be able to keep statistics accurate.
 679                  * Except for key threshold notifications, should
 680                  * we somehow allow the driver to tell us which key
 681                  * the hardware used if this flag is set?
 682                  */
 683                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 684                     (status->flag & RX_FLAG_IV_STRIPPED))
 685                         return RX_CONTINUE;
 686
 687                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
 688
 689                 if (rx->skb->len < 8 + hdrlen)
 690                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 691
 692                 /*
 693                  * no need to call ieee80211_wep_get_keyidx,
 694                  * it verifies a bunch of things we've done already
 695                  */
 696                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 697
 698                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 699
 700                 /*
 701                  * RSNA-protected unicast frames should always be sent with
 702                  * pairwise or station-to-station keys, but for WEP we allow
 703                  * using a key index as well.
 704                  */
 705                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 706                     !is_multicast_ether_addr(hdr->addr1))
 707                         rx->key = NULL;
 708         }
 709
 710         if (rx->key) {
 711                 rx->key->tx_rx_count++;
 712                 /* TODO: add threshold stuff again */
 713         } else {
 714                 return RX_DROP_MONITOR;
 715         }
 716
 717         /* Check for weak IVs if possible */
 718         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 719             ieee80211_is_data(hdr->frame_control) &&
 720             (!(status->flag & RX_FLAG_IV_STRIPPED) ||
 721              !(status->flag & RX_FLAG_DECRYPTED)) &&
 722             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 723                 rx->sta->wep_weak_iv_count++;
 724
 725         switch (rx->key->conf.alg) {
 726         case ALG_WEP:
 727                 result = ieee80211_crypto_wep_decrypt(rx);
 728                 break;
 729         case ALG_TKIP:
 730                 result = ieee80211_crypto_tkip_decrypt(rx);
 731                 break;
 732         case ALG_CCMP:
 733                 result = ieee80211_crypto_ccmp_decrypt(rx);
 734                 break;
 735         case ALG_AES_CMAC:
 736                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
 737                 break;
 738         }
 739
 740         /* either the frame has been decrypted or will be dropped */
 741         status->flag |= RX_FLAG_DECRYPTED;
 742
 743         return result;
 744 }
 745
 746 static ieee80211_rx_result debug_noinline
 747 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
 748 {
 749         struct ieee80211_local *local;
 750         struct ieee80211_hdr *hdr;
 751         struct sk_buff *skb;
 752
 753         local = rx->local;
 754         skb = rx->skb;
 755         hdr = (struct ieee80211_hdr *) skb->data;
 756
 757         if (!local->pspolling)
 758                 return RX_CONTINUE;
 759
 760         if (!ieee80211_has_fromds(hdr->frame_control))
 761                 /* this is not from AP */
 762                 return RX_CONTINUE;
 763
 764         if (!ieee80211_is_data(hdr->frame_control))
 765                 return RX_CONTINUE;
 766
 767         if (!ieee80211_has_moredata(hdr->frame_control)) {
 768                 /* AP has no more frames buffered for us */
 769                 local->pspolling = false;
 770                 return RX_CONTINUE;
 771         }
 772
 773         /* more data bit is set, let's request a new frame from the AP */
 774         ieee80211_send_pspoll(local, rx->sdata);
 775
 776         return RX_CONTINUE;
 777 }
 778
 779 static void ap_sta_ps_start(struct sta_info *sta)
 780 {
 781         struct ieee80211_sub_if_data *sdata = sta->sdata;
 782         struct ieee80211_local *local = sdata->local;
 783
 784         atomic_inc(&sdata->bss->num_sta_ps);
 785         set_sta_flags(sta, WLAN_STA_PS_STA);
 786         drv_sta_notify(local, &sdata->vif, STA_NOTIFY_SLEEP, &sta->sta);
 787 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 788         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
 789                sdata->dev->name, sta->sta.addr, sta->sta.aid);
 790 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 791 }
 792
 793 static void ap_sta_ps_end(struct sta_info *sta)
 794 {
 795         struct ieee80211_sub_if_data *sdata = sta->sdata;
 796
 797         atomic_dec(&sdata->bss->num_sta_ps);
 798
 799         clear_sta_flags(sta, WLAN_STA_PS_STA);
 800
 801 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 802         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
 803                sdata->dev->name, sta->sta.addr, sta->sta.aid);
 804 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 805
 806         if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
 807 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 808                 printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
 809                        sdata->dev->name, sta->sta.addr, sta->sta.aid);
 810 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 811                 return;
 812         }
 813
 814         ieee80211_sta_ps_deliver_wakeup(sta);
 815 }
 816
 817 static ieee80211_rx_result debug_noinline
 818 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
 819 {
 820         struct sta_info *sta = rx->sta;
 821         struct sk_buff *skb = rx->skb;
 822         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 823         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 824
 825         if (!sta)
 826                 return RX_CONTINUE;
 827
 828         /*
 829          * Update last_rx only for IBSS packets which are for the current
 830          * BSSID to avoid keeping the current IBSS network alive in cases
 831          * where other STAs start using different BSSID.
 832          */
 833         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
 834                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
 835                                                 NL80211_IFTYPE_ADHOC);
 836                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
 837                         sta->last_rx = jiffies;
 838         } else if (!is_multicast_ether_addr(hdr->addr1)) {
 839                 /*
 840                  * Mesh beacons will update last_rx when if they are found to
 841                  * match the current local configuration when processed.
 842                  */
 843                 sta->last_rx = jiffies;
 844         }
 845
 846         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 847                 return RX_CONTINUE;
 848
 849         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
 850                 ieee80211_sta_rx_notify(rx->sdata, hdr);
 851
 852         sta->rx_fragments++;
 853         sta->rx_bytes += rx->skb->len;
 854         sta->last_signal = status->signal;
 855         sta->last_noise = status->noise;
 856
 857         /*
 858          * Change STA power saving mode only at the end of a frame
 859          * exchange sequence.
 860          */
 861         if (!ieee80211_has_morefrags(hdr->frame_control) &&
 862             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
 863              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
 864                 if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
 865                         /*
 866                          * Ignore doze->wake transitions that are
 867                          * indicated by non-data frames, the standard
 868                          * is unclear here, but for example going to
 869                          * PS mode and then scanning would cause a
 870                          * doze->wake transition for the probe request,
 871                          * and that is clearly undesirable.
 872                          */
 873                         if (ieee80211_is_data(hdr->frame_control) &&
 874                             !ieee80211_has_pm(hdr->frame_control))
 875                                 ap_sta_ps_end(sta);
 876                 } else {
 877                         if (ieee80211_has_pm(hdr->frame_control))
 878                                 ap_sta_ps_start(sta);
 879                 }
 880         }
 881
 882         /*
 883          * Drop (qos-)data::nullfunc frames silently, since they
 884          * are used only to control station power saving mode.
 885          */
 886         if (ieee80211_is_nullfunc(hdr->frame_control) ||
 887             ieee80211_is_qos_nullfunc(hdr->frame_control)) {
 888                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
 889                 /*
 890                  * Update counter and free packet here to avoid
 891                  * counting this as a dropped packed.
 892                  */
 893                 sta->rx_packets++;
 894                 dev_kfree_skb(rx->skb);
 895                 return RX_QUEUED;
 896         }
 897
 898         return RX_CONTINUE;
 899 } /* ieee80211_rx_h_sta_process */
 900
 901 static inline struct ieee80211_fragment_entry *
 902 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 903                          unsigned int frag, unsigned int seq, int rx_queue,
 904                          struct sk_buff **skb)
 905 {
 906         struct ieee80211_fragment_entry *entry;
 907         int idx;
 908
 909         idx = sdata->fragment_next;
 910         entry = &sdata->fragments[sdata->fragment_next++];
 911         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
 912                 sdata->fragment_next = 0;
 913
 914         if (!skb_queue_empty(&entry->skb_list)) {
 915 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 916                 struct ieee80211_hdr *hdr =
 917                         (struct ieee80211_hdr *) entry->skb_list.next->data;
 918                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
 919                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
 920                        "addr1=%pM addr2=%pM\n",
 921                        sdata->dev->name, idx,
 922                        jiffies - entry->first_frag_time, entry->seq,
 923                        entry->last_frag, hdr->addr1, hdr->addr2);
 924 #endif
 925                 __skb_queue_purge(&entry->skb_list);
 926         }
 927
 928         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
 929         *skb = NULL;
 930         entry->first_frag_time = jiffies;
 931         entry->seq = seq;
 932         entry->rx_queue = rx_queue;
 933         entry->last_frag = frag;
 934         entry->ccmp = 0;
 935         entry->extra_len = 0;
 936
 937         return entry;
 938 }
 939
 940 static inline struct ieee80211_fragment_entry *
 941 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
 942                           unsigned int frag, unsigned int seq,
 943                           int rx_queue, struct ieee80211_hdr *hdr)
 944 {
 945         struct ieee80211_fragment_entry *entry;
 946         int i, idx;
 947
 948         idx = sdata->fragment_next;
 949         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
 950                 struct ieee80211_hdr *f_hdr;
 951
 952                 idx--;
 953                 if (idx < 0)
 954                         idx = IEEE80211_FRAGMENT_MAX - 1;
 955
 956                 entry = &sdata->fragments[idx];
 957                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
 958                     entry->rx_queue != rx_queue ||
 959                     entry->last_frag + 1 != frag)
 960                         continue;
 961
 962                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
 963
 964                 /*
 965                  * Check ftype and addresses are equal, else check next fragment
 966                  */
 967                 if (((hdr->frame_control ^ f_hdr->frame_control) &
 968                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
 969                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
 970                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
 971                         continue;
 972
 973                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
 974                         __skb_queue_purge(&entry->skb_list);
 975                         continue;
 976                 }
 977                 return entry;
 978         }
 979
 980         return NULL;
 981 }
 982
 983 static ieee80211_rx_result debug_noinline
 984 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 985 {
 986         struct ieee80211_hdr *hdr;
 987         u16 sc;
 988         __le16 fc;
 989         unsigned int frag, seq;
 990         struct ieee80211_fragment_entry *entry;
 991         struct sk_buff *skb;
 992
 993         hdr = (struct ieee80211_hdr *)rx->skb->data;
 994         fc = hdr->frame_control;
 995         sc = le16_to_cpu(hdr->seq_ctrl);
 996         frag = sc & IEEE80211_SCTL_FRAG;
 997
 998         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
 999                    (rx->skb)->len < 24 ||
1000                    is_multicast_ether_addr(hdr->addr1))) {
1001                 /* not fragmented */
1002                 goto out;
1003         }
1004         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1005
1006         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1007
1008         if (frag == 0) {
1009                 /* This is the first fragment of a new frame. */
1010                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1011                                                  rx->queue, &(rx->skb));
1012                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1013                     ieee80211_has_protected(fc)) {
1014                         /* Store CCMP PN so that we can verify that the next
1015                          * fragment has a sequential PN value. */
1016                         entry->ccmp = 1;
1017                         memcpy(entry->last_pn,
1018                                rx->key->u.ccmp.rx_pn[rx->queue],
1019                                CCMP_PN_LEN);
1020                 }
1021                 return RX_QUEUED;
1022         }
1023
1024         /* This is a fragment for a frame that should already be pending in
1025          * fragment cache. Add this fragment to the end of the pending entry.
1026          */
1027         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1028         if (!entry) {
1029                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1030                 return RX_DROP_MONITOR;
1031         }
1032
1033         /* Verify that MPDUs within one MSDU have sequential PN values.
1034          * (IEEE 802.11i, 8.3.3.4.5) */
1035         if (entry->ccmp) {
1036                 int i;
1037                 u8 pn[CCMP_PN_LEN], *rpn;
1038                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1039                         return RX_DROP_UNUSABLE;
1040                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1041                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1042                         pn[i]++;
1043                         if (pn[i])
1044                                 break;
1045                 }
1046                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1047                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1048                         return RX_DROP_UNUSABLE;
1049                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1050         }
1051
1052         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1053         __skb_queue_tail(&entry->skb_list, rx->skb);
1054         entry->last_frag = frag;
1055         entry->extra_len += rx->skb->len;
1056         if (ieee80211_has_morefrags(fc)) {
1057                 rx->skb = NULL;
1058                 return RX_QUEUED;
1059         }
1060
1061         rx->skb = __skb_dequeue(&entry->skb_list);
1062         if (skb_tailroom(rx->skb) < entry->extra_len) {
1063                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1064                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1065                                               GFP_ATOMIC))) {
1066                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1067                         __skb_queue_purge(&entry->skb_list);
1068                         return RX_DROP_UNUSABLE;
1069                 }
1070         }
1071         while ((skb = __skb_dequeue(&entry->skb_list))) {
1072                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1073                 dev_kfree_skb(skb);
1074         }
1075
1076         /* Complete frame has been reassembled - process it now */
1077         rx->flags |= IEEE80211_RX_FRAGMENTED;
1078
1079  out:
1080         if (rx->sta)
1081                 rx->sta->rx_packets++;
1082         if (is_multicast_ether_addr(hdr->addr1))
1083                 rx->local->dot11MulticastReceivedFrameCount++;
1084         else
1085                 ieee80211_led_rx(rx->local);
1086         return RX_CONTINUE;
1087 }
1088
1089 static ieee80211_rx_result debug_noinline
1090 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1091 {
1092         struct ieee80211_sub_if_data *sdata = rx->sdata;
1093         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1094
1095         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1096                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1097                 return RX_CONTINUE;
1098
1099         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1100             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1101                 return RX_DROP_UNUSABLE;
1102
1103         if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1104                 ieee80211_sta_ps_deliver_poll_response(rx->sta);
1105         else
1106                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1107
1108         /* Free PS Poll skb here instead of returning RX_DROP that would
1109          * count as an dropped frame. */
1110         dev_kfree_skb(rx->skb);
1111
1112         return RX_QUEUED;
1113 }
1114
1115 static ieee80211_rx_result debug_noinline
1116 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1117 {
1118         u8 *data = rx->skb->data;
1119         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1120
1121         if (!ieee80211_is_data_qos(hdr->frame_control))
1122                 return RX_CONTINUE;
1123
1124         /* remove the qos control field, update frame type and meta-data */
1125         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1126                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1127         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1128         /* change frame type to non QOS */
1129         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1130
1131         return RX_CONTINUE;
1132 }
1133
1134 static int
1135 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1136 {
1137         if (unlikely(!rx->sta ||
1138             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1139                 return -EACCES;
1140
1141         return 0;
1142 }
1143
1144 static int
1145 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1146 {
1147         struct sk_buff *skb = rx->skb;
1148         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1149
1150         /*
1151          * Pass through unencrypted frames if the hardware has
1152          * decrypted them already.
1153          */
1154         if (status->flag & RX_FLAG_DECRYPTED)
1155                 return 0;
1156
1157         /* Drop unencrypted frames if key is set. */
1158         if (unlikely(!ieee80211_has_protected(fc) &&
1159                      !ieee80211_is_nullfunc(fc) &&
1160                      ieee80211_is_data(fc) &&
1161                      (rx->key || rx->sdata->drop_unencrypted)))
1162                 return -EACCES;
1163         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1164                 if (unlikely(ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1165                              rx->key))
1166                         return -EACCES;
1167                 /* BIP does not use Protected field, so need to check MMIE */
1168                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb)
1169                              && ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1170                              rx->key))
1171                         return -EACCES;
1172                 /*
1173                  * When using MFP, Action frames are not allowed prior to
1174                  * having configured keys.
1175                  */
1176                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1177                              ieee80211_is_robust_mgmt_frame(
1178                                      (struct ieee80211_hdr *) rx->skb->data)))
1179                         return -EACCES;
1180         }
1181
1182         return 0;
1183 }
1184
1185 static int
1186 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1187 {
1188         struct ieee80211_sub_if_data *sdata = rx->sdata;
1189         struct net_device *dev = sdata->dev;
1190         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1191
1192         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->use_4addr &&
1193             ieee80211_has_a4(hdr->frame_control))
1194                 return -1;
1195         if (sdata->use_4addr && is_multicast_ether_addr(hdr->addr1))
1196                 return -1;
1197
1198         return ieee80211_data_to_8023(rx->skb, dev->dev_addr, sdata->vif.type);
1199 }
1200
1201 /*
1202  * requires that rx->skb is a frame with ethernet header
1203  */
1204 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1205 {
1206         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1207                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1208         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1209
1210         /*
1211          * Allow EAPOL frames to us/the PAE group address regardless
1212          * of whether the frame was encrypted or not.
1213          */
1214         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1215             (compare_ether_addr(ehdr->h_dest, rx->sdata->dev->dev_addr) == 0 ||
1216              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1217                 return true;
1218
1219         if (ieee80211_802_1x_port_control(rx) ||
1220             ieee80211_drop_unencrypted(rx, fc))
1221                 return false;
1222
1223         return true;
1224 }
1225
1226 /*
1227  * requires that rx->skb is a frame with ethernet header
1228  */
1229 static void
1230 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1231 {
1232         struct ieee80211_sub_if_data *sdata = rx->sdata;
1233         struct net_device *dev = sdata->dev;
1234         struct ieee80211_local *local = rx->local;
1235         struct sk_buff *skb, *xmit_skb;
1236         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1237         struct sta_info *dsta;
1238
1239         skb = rx->skb;
1240         xmit_skb = NULL;
1241
1242         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1243              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1244             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1245             (rx->flags & IEEE80211_RX_RA_MATCH) && !rx->sdata->use_4addr) {
1246                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1247                         /*
1248                          * send multicast frames both to higher layers in
1249                          * local net stack and back to the wireless medium
1250                          */
1251                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1252                         if (!xmit_skb && net_ratelimit())
1253                                 printk(KERN_DEBUG "%s: failed to clone "
1254                                        "multicast frame\n", dev->name);
1255                 } else {
1256                         dsta = sta_info_get(local, skb->data);
1257                         if (dsta && dsta->sdata->dev == dev) {
1258                                 /*
1259                                  * The destination station is associated to
1260                                  * this AP (in this VLAN), so send the frame
1261                                  * directly to it and do not pass it to local
1262                                  * net stack.
1263                                  */
1264                                 xmit_skb = skb;
1265                                 skb = NULL;
1266                         }
1267                 }
1268         }
1269
1270         if (skb) {
1271                 int align __maybe_unused;
1272
1273 #if defined(CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT) || !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
1274                 /*
1275                  * 'align' will only take the values 0 or 2 here
1276                  * since all frames are required to be aligned
1277                  * to 2-byte boundaries when being passed to
1278                  * mac80211. That also explains the __skb_push()
1279                  * below.
1280                  */
1281                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1282                 if (align) {
1283                         if (WARN_ON(skb_headroom(skb) < 3)) {
1284                                 dev_kfree_skb(skb);
1285                                 skb = NULL;
1286                         } else {
1287                                 u8 *data = skb->data;
1288                                 size_t len = skb_headlen(skb);
1289                                 skb->data -= align;
1290                                 memmove(skb->data, data, len);
1291                                 skb_set_tail_pointer(skb, len);
1292                         }
1293                 }
1294 #endif
1295
1296                 if (skb) {
1297                         /* deliver to local stack */
1298                         skb->protocol = eth_type_trans(skb, dev);
1299                         memset(skb->cb, 0, sizeof(skb->cb));
1300                         netif_rx(skb);
1301                 }
1302         }
1303
1304         if (xmit_skb) {
1305                 /* send to wireless media */
1306                 xmit_skb->protocol = htons(ETH_P_802_3);
1307                 skb_reset_network_header(xmit_skb);
1308                 skb_reset_mac_header(xmit_skb);
1309                 dev_queue_xmit(xmit_skb);
1310         }
1311 }
1312
1313 static ieee80211_rx_result debug_noinline
1314 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1315 {
1316         struct net_device *dev = rx->sdata->dev;
1317         struct ieee80211_local *local = rx->local;
1318         u16 ethertype;
1319         u8 *payload;
1320         struct sk_buff *skb = rx->skb, *frame = NULL;
1321         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1322         __le16 fc = hdr->frame_control;
1323         const struct ethhdr *eth;
1324         int remaining, err;
1325         u8 dst[ETH_ALEN];
1326         u8 src[ETH_ALEN];
1327
1328         if (unlikely(!ieee80211_is_data(fc)))
1329                 return RX_CONTINUE;
1330
1331         if (unlikely(!ieee80211_is_data_present(fc)))
1332                 return RX_DROP_MONITOR;
1333
1334         if (!(rx->flags & IEEE80211_RX_AMSDU))
1335                 return RX_CONTINUE;
1336
1337         err = __ieee80211_data_to_8023(rx);
1338         if (unlikely(err))
1339                 return RX_DROP_UNUSABLE;
1340
1341         skb->dev = dev;
1342
1343         dev->stats.rx_packets++;
1344         dev->stats.rx_bytes += skb->len;
1345
1346         /* skip the wrapping header */
1347         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1348         if (!eth)
1349                 return RX_DROP_UNUSABLE;
1350
1351         while (skb != frame) {
1352                 u8 padding;
1353                 __be16 len = eth->h_proto;
1354                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1355
1356                 remaining = skb->len;
1357                 memcpy(dst, eth->h_dest, ETH_ALEN);
1358                 memcpy(src, eth->h_source, ETH_ALEN);
1359
1360                 padding = ((4 - subframe_len) & 0x3);
1361                 /* the last MSDU has no padding */
1362                 if (subframe_len > remaining)
1363                         return RX_DROP_UNUSABLE;
1364
1365                 skb_pull(skb, sizeof(struct ethhdr));
1366                 /* if last subframe reuse skb */
1367                 if (remaining <= subframe_len + padding)
1368                         frame = skb;
1369                 else {
1370                         /*
1371                          * Allocate and reserve two bytes more for payload
1372                          * alignment since sizeof(struct ethhdr) is 14.
1373                          */
1374                         frame = dev_alloc_skb(
1375                                 ALIGN(local->hw.extra_tx_headroom, 4) +
1376                                 subframe_len + 2);
1377
1378                         if (frame == NULL)
1379                                 return RX_DROP_UNUSABLE;
1380
1381                         skb_reserve(frame,
1382                                     ALIGN(local->hw.extra_tx_headroom, 4) +
1383                                     sizeof(struct ethhdr) + 2);
1384                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1385                                 ntohs(len));
1386
1387                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1388                                                         padding);
1389                         if (!eth) {
1390                                 dev_kfree_skb(frame);
1391                                 return RX_DROP_UNUSABLE;
1392                         }
1393                 }
1394
1395                 skb_reset_network_header(frame);
1396                 frame->dev = dev;
1397                 frame->priority = skb->priority;
1398                 rx->skb = frame;
1399
1400                 payload = frame->data;
1401                 ethertype = (payload[6] << 8) | payload[7];
1402
1403                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1404                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1405                            compare_ether_addr(payload,
1406                                               bridge_tunnel_header) == 0)) {
1407                         /* remove RFC1042 or Bridge-Tunnel
1408                          * encapsulation and replace EtherType */
1409                         skb_pull(frame, 6);
1410                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1411                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1412                 } else {
1413                         memcpy(skb_push(frame, sizeof(__be16)),
1414                                &len, sizeof(__be16));
1415                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1416                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1417                 }
1418
1419                 if (!ieee80211_frame_allowed(rx, fc)) {
1420                         if (skb == frame) /* last frame */
1421                                 return RX_DROP_UNUSABLE;
1422                         dev_kfree_skb(frame);
1423                         continue;
1424                 }
1425
1426                 ieee80211_deliver_skb(rx);
1427         }
1428
1429         return RX_QUEUED;
1430 }
1431
1432 #ifdef CONFIG_MAC80211_MESH
1433 static ieee80211_rx_result
1434 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1435 {
1436         struct ieee80211_hdr *hdr;
1437         struct ieee80211s_hdr *mesh_hdr;
1438         unsigned int hdrlen;
1439         struct sk_buff *skb = rx->skb, *fwd_skb;
1440         struct ieee80211_local *local = rx->local;
1441         struct ieee80211_sub_if_data *sdata = rx->sdata;
1442
1443         hdr = (struct ieee80211_hdr *) skb->data;
1444         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1445         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1446
1447         if (!ieee80211_is_data(hdr->frame_control))
1448                 return RX_CONTINUE;
1449
1450         if (!mesh_hdr->ttl)
1451                 /* illegal frame */
1452                 return RX_DROP_MONITOR;
1453
1454         if (mesh_hdr->flags & MESH_FLAGS_AE) {
1455                 struct mesh_path *mppath;
1456                 char *proxied_addr;
1457                 char *mpp_addr;
1458
1459                 if (is_multicast_ether_addr(hdr->addr1)) {
1460                         mpp_addr = hdr->addr3;
1461                         proxied_addr = mesh_hdr->eaddr1;
1462                 } else {
1463                         mpp_addr = hdr->addr4;
1464                         proxied_addr = mesh_hdr->eaddr2;
1465                 }
1466
1467                 rcu_read_lock();
1468                 mppath = mpp_path_lookup(proxied_addr, sdata);
1469                 if (!mppath) {
1470                         mpp_path_add(proxied_addr, mpp_addr, sdata);
1471                 } else {
1472                         spin_lock_bh(&mppath->state_lock);
1473                         mppath->exp_time = jiffies;
1474                         if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1475                                 memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1476                         spin_unlock_bh(&mppath->state_lock);
1477                 }
1478                 rcu_read_unlock();
1479         }
1480
1481         /* Frame has reached destination.  Don't forward */
1482         if (!is_multicast_ether_addr(hdr->addr1) &&
1483             compare_ether_addr(sdata->dev->dev_addr, hdr->addr3) == 0)
1484                 return RX_CONTINUE;
1485
1486         mesh_hdr->ttl--;
1487
1488         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1489                 if (!mesh_hdr->ttl)
1490                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1491                                                      dropped_frames_ttl);
1492                 else {
1493                         struct ieee80211_hdr *fwd_hdr;
1494                         struct ieee80211_tx_info *info;
1495
1496                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1497
1498                         if (!fwd_skb && net_ratelimit())
1499                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1500                                                    sdata->dev->name);
1501
1502                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1503                         memcpy(fwd_hdr->addr2, sdata->dev->dev_addr, ETH_ALEN);
1504                         info = IEEE80211_SKB_CB(fwd_skb);
1505                         memset(info, 0, sizeof(*info));
1506                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1507                         info->control.vif = &rx->sdata->vif;
1508                         ieee80211_select_queue(local, fwd_skb);
1509                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1510                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1511                                                                 fwded_mcast);
1512                         else {
1513                                 int err;
1514                                 /*
1515                                  * Save TA to addr1 to send TA a path error if a
1516                                  * suitable next hop is not found
1517                                  */
1518                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1519                                                 ETH_ALEN);
1520                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1521                                 /* Failed to immediately resolve next hop:
1522                                  * fwded frame was dropped or will be added
1523                                  * later to the pending skb queue.  */
1524                                 if (err)
1525                                         return RX_DROP_MONITOR;
1526
1527                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1528                                                                 fwded_unicast);
1529                         }
1530                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1531                                                      fwded_frames);
1532                         ieee80211_add_pending_skb(local, fwd_skb);
1533                 }
1534         }
1535
1536         if (is_multicast_ether_addr(hdr->addr1) ||
1537             sdata->dev->flags & IFF_PROMISC)
1538                 return RX_CONTINUE;
1539         else
1540                 return RX_DROP_MONITOR;
1541 }
1542 #endif
1543
1544 static ieee80211_rx_result debug_noinline
1545 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1546 {
1547         struct ieee80211_sub_if_data *sdata = rx->sdata;
1548         struct net_device *dev = sdata->dev;
1549         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1550         __le16 fc = hdr->frame_control;
1551         int err;
1552
1553         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1554                 return RX_CONTINUE;
1555
1556         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1557                 return RX_DROP_MONITOR;
1558
1559         /*
1560          * Allow the cooked monitor interface of an AP to see 4-addr frames so
1561          * that a 4-addr station can be detected and moved into a separate VLAN
1562          */
1563         if (ieee80211_has_a4(hdr->frame_control) &&
1564             sdata->vif.type == NL80211_IFTYPE_AP)
1565                 return RX_DROP_MONITOR;
1566
1567         err = __ieee80211_data_to_8023(rx);
1568         if (unlikely(err))
1569                 return RX_DROP_UNUSABLE;
1570
1571         if (!ieee80211_frame_allowed(rx, fc))
1572                 return RX_DROP_MONITOR;
1573
1574         rx->skb->dev = dev;
1575
1576         dev->stats.rx_packets++;
1577         dev->stats.rx_bytes += rx->skb->len;
1578
1579         ieee80211_deliver_skb(rx);
1580
1581         return RX_QUEUED;
1582 }
1583
1584 static ieee80211_rx_result debug_noinline
1585 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1586 {
1587         struct ieee80211_local *local = rx->local;
1588         struct ieee80211_hw *hw = &local->hw;
1589         struct sk_buff *skb = rx->skb;
1590         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1591         struct tid_ampdu_rx *tid_agg_rx;
1592         u16 start_seq_num;
1593         u16 tid;
1594
1595         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1596                 return RX_CONTINUE;
1597
1598         if (ieee80211_is_back_req(bar->frame_control)) {
1599                 if (!rx->sta)
1600                         return RX_DROP_MONITOR;
1601                 tid = le16_to_cpu(bar->control) >> 12;
1602                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1603                                         != HT_AGG_STATE_OPERATIONAL)
1604                         return RX_DROP_MONITOR;
1605                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1606
1607                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1608
1609                 /* reset session timer */
1610                 if (tid_agg_rx->timeout)
1611                         mod_timer(&tid_agg_rx->session_timer,
1612                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1613
1614                 /* release stored frames up to start of BAR */
1615                 ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num);
1616                 kfree_skb(skb);
1617                 return RX_QUEUED;
1618         }
1619
1620         return RX_CONTINUE;
1621 }
1622
1623 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1624                                            struct ieee80211_mgmt *mgmt,
1625                                            size_t len)
1626 {
1627         struct ieee80211_local *local = sdata->local;
1628         struct sk_buff *skb;
1629         struct ieee80211_mgmt *resp;
1630
1631         if (compare_ether_addr(mgmt->da, sdata->dev->dev_addr) != 0) {
1632                 /* Not to own unicast address */
1633                 return;
1634         }
1635
1636         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1637             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1638                 /* Not from the current AP or not associated yet. */
1639                 return;
1640         }
1641
1642         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1643                 /* Too short SA Query request frame */
1644                 return;
1645         }
1646
1647         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1648         if (skb == NULL)
1649                 return;
1650
1651         skb_reserve(skb, local->hw.extra_tx_headroom);
1652         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1653         memset(resp, 0, 24);
1654         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1655         memcpy(resp->sa, sdata->dev->dev_addr, ETH_ALEN);
1656         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1657         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1658                                           IEEE80211_STYPE_ACTION);
1659         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1660         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1661         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1662         memcpy(resp->u.action.u.sa_query.trans_id,
1663                mgmt->u.action.u.sa_query.trans_id,
1664                WLAN_SA_QUERY_TR_ID_LEN);
1665
1666         ieee80211_tx_skb(sdata, skb, 1);
1667 }
1668
1669 static ieee80211_rx_result debug_noinline
1670 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1671 {
1672         struct ieee80211_local *local = rx->local;
1673         struct ieee80211_sub_if_data *sdata = rx->sdata;
1674         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1675         int len = rx->skb->len;
1676
1677         if (!ieee80211_is_action(mgmt->frame_control))
1678                 return RX_CONTINUE;
1679
1680         if (!rx->sta)
1681                 return RX_DROP_MONITOR;
1682
1683         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1684                 return RX_DROP_MONITOR;
1685
1686         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1687                 return RX_DROP_MONITOR;
1688
1689         /* all categories we currently handle have action_code */
1690         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1691                 return RX_DROP_MONITOR;
1692
1693         switch (mgmt->u.action.category) {
1694         case WLAN_CATEGORY_BACK:
1695                 /*
1696                  * The aggregation code is not prepared to handle
1697                  * anything but STA/AP due to the BSSID handling;
1698                  * IBSS could work in the code but isn't supported
1699                  * by drivers or the standard.
1700                  */
1701                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1702                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1703                     sdata->vif.type != NL80211_IFTYPE_AP)
1704                         return RX_DROP_MONITOR;
1705
1706                 switch (mgmt->u.action.u.addba_req.action_code) {
1707                 case WLAN_ACTION_ADDBA_REQ:
1708                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1709                                    sizeof(mgmt->u.action.u.addba_req)))
1710                                 return RX_DROP_MONITOR;
1711                         ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1712                         break;
1713                 case WLAN_ACTION_ADDBA_RESP:
1714                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1715                                    sizeof(mgmt->u.action.u.addba_resp)))
1716                                 return RX_DROP_MONITOR;
1717                         ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1718                         break;
1719                 case WLAN_ACTION_DELBA:
1720                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1721                                    sizeof(mgmt->u.action.u.delba)))
1722                                 return RX_DROP_MONITOR;
1723                         ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1724                         break;
1725                 }
1726                 break;
1727         case WLAN_CATEGORY_SPECTRUM_MGMT:
1728                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1729                         return RX_DROP_MONITOR;
1730
1731                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
1732                         return RX_DROP_MONITOR;
1733
1734                 switch (mgmt->u.action.u.measurement.action_code) {
1735                 case WLAN_ACTION_SPCT_MSR_REQ:
1736                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1737                                    sizeof(mgmt->u.action.u.measurement)))
1738                                 return RX_DROP_MONITOR;
1739                         ieee80211_process_measurement_req(sdata, mgmt, len);
1740                         break;
1741                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1742                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1743                                    sizeof(mgmt->u.action.u.chan_switch)))
1744                                 return RX_DROP_MONITOR;
1745
1746                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1747                                 return RX_DROP_MONITOR;
1748
1749                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1750                                 return RX_DROP_MONITOR;
1751
1752                         return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1753                 }
1754                 break;
1755         case WLAN_CATEGORY_SA_QUERY:
1756                 if (len < (IEEE80211_MIN_ACTION_SIZE +
1757                            sizeof(mgmt->u.action.u.sa_query)))
1758                         return RX_DROP_MONITOR;
1759                 switch (mgmt->u.action.u.sa_query.action) {
1760                 case WLAN_ACTION_SA_QUERY_REQUEST:
1761                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1762                                 return RX_DROP_MONITOR;
1763                         ieee80211_process_sa_query_req(sdata, mgmt, len);
1764                         break;
1765                 case WLAN_ACTION_SA_QUERY_RESPONSE:
1766                         /*
1767                          * SA Query response is currently only used in AP mode
1768                          * and it is processed in user space.
1769                          */
1770                         return RX_CONTINUE;
1771                 }
1772                 break;
1773         default:
1774                 return RX_CONTINUE;
1775         }
1776
1777         rx->sta->rx_packets++;
1778         dev_kfree_skb(rx->skb);
1779         return RX_QUEUED;
1780 }
1781
1782 static ieee80211_rx_result debug_noinline
1783 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1784 {
1785         struct ieee80211_sub_if_data *sdata = rx->sdata;
1786         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1787
1788         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1789                 return RX_DROP_MONITOR;
1790
1791         if (ieee80211_drop_unencrypted(rx, mgmt->frame_control))
1792                 return RX_DROP_MONITOR;
1793
1794         if (ieee80211_vif_is_mesh(&sdata->vif))
1795                 return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
1796
1797         if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
1798                 return ieee80211_ibss_rx_mgmt(sdata, rx->skb);
1799
1800         if (sdata->vif.type == NL80211_IFTYPE_STATION)
1801                 return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1802
1803         return RX_DROP_MONITOR;
1804 }
1805
1806 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
1807                                             struct ieee80211_rx_data *rx)
1808 {
1809         int keyidx;
1810         unsigned int hdrlen;
1811
1812         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1813         if (rx->skb->len >= hdrlen + 4)
1814                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1815         else
1816                 keyidx = -1;
1817
1818         if (!rx->sta) {
1819                 /*
1820                  * Some hardware seem to generate incorrect Michael MIC
1821                  * reports; ignore them to avoid triggering countermeasures.
1822                  */
1823                 return;
1824         }
1825
1826         if (!ieee80211_has_protected(hdr->frame_control))
1827                 return;
1828
1829         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1830                 /*
1831                  * APs with pairwise keys should never receive Michael MIC
1832                  * errors for non-zero keyidx because these are reserved for
1833                  * group keys and only the AP is sending real multicast
1834                  * frames in the BSS.
1835                  */
1836                 return;
1837         }
1838
1839         if (!ieee80211_is_data(hdr->frame_control) &&
1840             !ieee80211_is_auth(hdr->frame_control))
1841                 return;
1842
1843         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
1844                                         GFP_ATOMIC);
1845 }
1846
1847 /* TODO: use IEEE80211_RX_FRAGMENTED */
1848 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1849 {
1850         struct ieee80211_sub_if_data *sdata;
1851         struct ieee80211_local *local = rx->local;
1852         struct ieee80211_rtap_hdr {
1853                 struct ieee80211_radiotap_header hdr;
1854                 u8 flags;
1855                 u8 rate;
1856                 __le16 chan_freq;
1857                 __le16 chan_flags;
1858         } __attribute__ ((packed)) *rthdr;
1859         struct sk_buff *skb = rx->skb, *skb2;
1860         struct net_device *prev_dev = NULL;
1861         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1862
1863         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1864                 goto out_free_skb;
1865
1866         if (skb_headroom(skb) < sizeof(*rthdr) &&
1867             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1868                 goto out_free_skb;
1869
1870         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1871         memset(rthdr, 0, sizeof(*rthdr));
1872         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1873         rthdr->hdr.it_present =
1874                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1875                             (1 << IEEE80211_RADIOTAP_RATE) |
1876                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1877
1878         rthdr->rate = rx->rate->bitrate / 5;
1879         rthdr->chan_freq = cpu_to_le16(status->freq);
1880
1881         if (status->band == IEEE80211_BAND_5GHZ)
1882                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1883                                                 IEEE80211_CHAN_5GHZ);
1884         else
1885                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1886                                                 IEEE80211_CHAN_2GHZ);
1887
1888         skb_set_mac_header(skb, 0);
1889         skb->ip_summed = CHECKSUM_UNNECESSARY;
1890         skb->pkt_type = PACKET_OTHERHOST;
1891         skb->protocol = htons(ETH_P_802_2);
1892
1893         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1894                 if (!netif_running(sdata->dev))
1895                         continue;
1896
1897                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1898                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1899                         continue;
1900
1901                 if (prev_dev) {
1902                         skb2 = skb_clone(skb, GFP_ATOMIC);
1903                         if (skb2) {
1904                                 skb2->dev = prev_dev;
1905                                 netif_rx(skb2);
1906                         }
1907                 }
1908
1909                 prev_dev = sdata->dev;
1910                 sdata->dev->stats.rx_packets++;
1911                 sdata->dev->stats.rx_bytes += skb->len;
1912         }
1913
1914         if (prev_dev) {
1915                 skb->dev = prev_dev;
1916                 netif_rx(skb);
1917                 skb = NULL;
1918         } else
1919                 goto out_free_skb;
1920
1921         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1922         return;
1923
1924  out_free_skb:
1925         dev_kfree_skb(skb);
1926 }
1927
1928
1929 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1930                                          struct ieee80211_rx_data *rx,
1931                                          struct sk_buff *skb)
1932 {
1933         ieee80211_rx_result res = RX_DROP_MONITOR;
1934
1935         rx->skb = skb;
1936         rx->sdata = sdata;
1937
1938 #define CALL_RXH(rxh)                   \
1939         do {                            \
1940                 res = rxh(rx);          \
1941                 if (res != RX_CONTINUE) \
1942                         goto rxh_done;  \
1943         } while (0);
1944
1945         CALL_RXH(ieee80211_rx_h_passive_scan)
1946         CALL_RXH(ieee80211_rx_h_check)
1947         CALL_RXH(ieee80211_rx_h_decrypt)
1948         CALL_RXH(ieee80211_rx_h_check_more_data)
1949         CALL_RXH(ieee80211_rx_h_sta_process)
1950         CALL_RXH(ieee80211_rx_h_defragment)
1951         CALL_RXH(ieee80211_rx_h_ps_poll)
1952         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1953         /* must be after MMIC verify so header is counted in MPDU mic */
1954         CALL_RXH(ieee80211_rx_h_remove_qos_control)
1955         CALL_RXH(ieee80211_rx_h_amsdu)
1956 #ifdef CONFIG_MAC80211_MESH
1957         if (ieee80211_vif_is_mesh(&sdata->vif))
1958                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
1959 #endif
1960         CALL_RXH(ieee80211_rx_h_data)
1961         CALL_RXH(ieee80211_rx_h_ctrl)
1962         CALL_RXH(ieee80211_rx_h_action)
1963         CALL_RXH(ieee80211_rx_h_mgmt)
1964
1965 #undef CALL_RXH
1966
1967  rxh_done:
1968         switch (res) {
1969         case RX_DROP_MONITOR:
1970                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1971                 if (rx->sta)
1972                         rx->sta->rx_dropped++;
1973                 /* fall through */
1974         case RX_CONTINUE:
1975                 ieee80211_rx_cooked_monitor(rx);
1976                 break;
1977         case RX_DROP_UNUSABLE:
1978                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1979                 if (rx->sta)
1980                         rx->sta->rx_dropped++;
1981                 dev_kfree_skb(rx->skb);
1982                 break;
1983         case RX_QUEUED:
1984                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
1985                 break;
1986         }
1987 }
1988
1989 /* main receive path */
1990
1991 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1992                                 struct ieee80211_rx_data *rx,
1993                                 struct ieee80211_hdr *hdr)
1994 {
1995         struct sk_buff *skb = rx->skb;
1996         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1997         u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
1998         int multicast = is_multicast_ether_addr(hdr->addr1);
1999
2000         switch (sdata->vif.type) {
2001         case NL80211_IFTYPE_STATION:
2002                 if (!bssid && !sdata->use_4addr)
2003                         return 0;
2004                 if (!multicast &&
2005                     compare_ether_addr(sdata->dev->dev_addr, hdr->addr1) != 0) {
2006                         if (!(sdata->dev->flags & IFF_PROMISC))
2007                                 return 0;
2008                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2009                 }
2010                 break;
2011         case NL80211_IFTYPE_ADHOC:
2012                 if (!bssid)
2013                         return 0;
2014                 if (ieee80211_is_beacon(hdr->frame_control)) {
2015                         return 1;
2016                 }
2017                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2018                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2019                                 return 0;
2020                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2021                 } else if (!multicast &&
2022                            compare_ether_addr(sdata->dev->dev_addr,
2023                                               hdr->addr1) != 0) {
2024                         if (!(sdata->dev->flags & IFF_PROMISC))
2025                                 return 0;
2026                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2027                 } else if (!rx->sta) {
2028                         int rate_idx;
2029                         if (status->flag & RX_FLAG_HT)
2030                                 rate_idx = 0; /* TODO: HT rates */
2031                         else
2032                                 rate_idx = status->rate_idx;
2033                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid, hdr->addr2,
2034                                 BIT(rate_idx));
2035                 }
2036                 break;
2037         case NL80211_IFTYPE_MESH_POINT:
2038                 if (!multicast &&
2039                     compare_ether_addr(sdata->dev->dev_addr,
2040                                        hdr->addr1) != 0) {
2041                         if (!(sdata->dev->flags & IFF_PROMISC))
2042                                 return 0;
2043
2044                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2045                 }
2046                 break;
2047         case NL80211_IFTYPE_AP_VLAN:
2048         case NL80211_IFTYPE_AP:
2049                 if (!bssid) {
2050                         if (compare_ether_addr(sdata->dev->dev_addr,
2051                                                hdr->addr1))
2052                                 return 0;
2053                 } else if (!ieee80211_bssid_match(bssid,
2054                                         sdata->dev->dev_addr)) {
2055                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2056                                 return 0;
2057                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2058                 }
2059                 break;
2060         case NL80211_IFTYPE_WDS:
2061                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2062                         return 0;
2063                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2064                         return 0;
2065                 break;
2066         case NL80211_IFTYPE_MONITOR:
2067         case NL80211_IFTYPE_UNSPECIFIED:
2068         case __NL80211_IFTYPE_AFTER_LAST:
2069                 /* should never get here */
2070                 WARN_ON(1);
2071                 break;
2072         }
2073
2074         return 1;
2075 }
2076
2077 /*
2078  * This is the actual Rx frames handler. as it blongs to Rx path it must
2079  * be called with rcu_read_lock protection.
2080  */
2081 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2082                                          struct sk_buff *skb,
2083                                          struct ieee80211_rate *rate)
2084 {
2085         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2086         struct ieee80211_local *local = hw_to_local(hw);
2087         struct ieee80211_sub_if_data *sdata;
2088         struct ieee80211_hdr *hdr;
2089         struct ieee80211_rx_data rx;
2090         int prepares;
2091         struct ieee80211_sub_if_data *prev = NULL;
2092         struct sk_buff *skb_new;
2093
2094         hdr = (struct ieee80211_hdr *)skb->data;
2095         memset(&rx, 0, sizeof(rx));
2096         rx.skb = skb;
2097         rx.local = local;
2098         rx.rate = rate;
2099
2100         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2101                 local->dot11ReceivedFragmentCount++;
2102
2103         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2104                      test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2105                 rx.flags |= IEEE80211_RX_IN_SCAN;
2106
2107         ieee80211_parse_qos(&rx);
2108         ieee80211_verify_alignment(&rx);
2109
2110         rx.sta = sta_info_get(local, hdr->addr2);
2111         if (rx.sta)
2112                 rx.sdata = rx.sta->sdata;
2113
2114         if (rx.sdata && ieee80211_is_data(hdr->frame_control)) {
2115                 rx.flags |= IEEE80211_RX_RA_MATCH;
2116                 prepares = prepare_for_handlers(rx.sdata, &rx, hdr);
2117                 if (prepares) {
2118                         if (status->flag & RX_FLAG_MMIC_ERROR) {
2119                                 if (rx.flags & IEEE80211_RX_RA_MATCH)
2120                                         ieee80211_rx_michael_mic_report(hdr, &rx);
2121                         } else
2122                                 prev = rx.sdata;
2123                 }
2124         } else list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2125                 if (!netif_running(sdata->dev))
2126                         continue;
2127
2128                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2129                     sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2130                         continue;
2131
2132                 rx.flags |= IEEE80211_RX_RA_MATCH;
2133                 prepares = prepare_for_handlers(sdata, &rx, hdr);
2134
2135                 if (!prepares)
2136                         continue;
2137
2138                 if (status->flag & RX_FLAG_MMIC_ERROR) {
2139                         rx.sdata = sdata;
2140                         if (rx.flags & IEEE80211_RX_RA_MATCH)
2141                                 ieee80211_rx_michael_mic_report(hdr, &rx);
2142                         continue;
2143                 }
2144
2145                 /*
2146                  * frame is destined for this interface, but if it's not
2147                  * also for the previous one we handle that after the
2148                  * loop to avoid copying the SKB once too much
2149                  */
2150
2151                 if (!prev) {
2152                         prev = sdata;
2153                         continue;
2154                 }
2155
2156                 /*
2157                  * frame was destined for the previous interface
2158                  * so invoke RX handlers for it
2159                  */
2160
2161                 skb_new = skb_copy(skb, GFP_ATOMIC);
2162                 if (!skb_new) {
2163                         if (net_ratelimit())
2164                                 printk(KERN_DEBUG "%s: failed to copy "
2165                                        "multicast frame for %s\n",
2166                                        wiphy_name(local->hw.wiphy),
2167                                        prev->dev->name);
2168                         continue;
2169                 }
2170                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
2171                 prev = sdata;
2172         }
2173         if (prev)
2174                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
2175         else
2176                 dev_kfree_skb(skb);
2177 }
2178
2179 #define SEQ_MODULO 0x1000
2180 #define SEQ_MASK   0xfff
2181
2182 static inline int seq_less(u16 sq1, u16 sq2)
2183 {
2184         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
2185 }
2186
2187 static inline u16 seq_inc(u16 sq)
2188 {
2189         return (sq + 1) & SEQ_MASK;
2190 }
2191
2192 static inline u16 seq_sub(u16 sq1, u16 sq2)
2193 {
2194         return (sq1 - sq2) & SEQ_MASK;
2195 }
2196
2197
2198 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
2199                                             struct tid_ampdu_rx *tid_agg_rx,
2200                                             int index)
2201 {
2202         struct ieee80211_supported_band *sband;
2203         struct ieee80211_rate *rate;
2204         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
2205         struct ieee80211_rx_status *status;
2206
2207         if (!skb)
2208                 goto no_frame;
2209
2210         status = IEEE80211_SKB_RXCB(skb);
2211
2212         /* release the reordered frames to stack */
2213         sband = hw->wiphy->bands[status->band];
2214         if (status->flag & RX_FLAG_HT)
2215                 rate = sband->bitrates; /* TODO: HT rates */
2216         else
2217                 rate = &sband->bitrates[status->rate_idx];
2218         __ieee80211_rx_handle_packet(hw, skb, rate);
2219         tid_agg_rx->stored_mpdu_num--;
2220         tid_agg_rx->reorder_buf[index] = NULL;
2221
2222 no_frame:
2223         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2224 }
2225
2226 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
2227                                              struct tid_ampdu_rx *tid_agg_rx,
2228                                              u16 head_seq_num)
2229 {
2230         int index;
2231
2232         while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2233                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
2234                                                         tid_agg_rx->buf_size;
2235                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
2236         }
2237 }
2238
2239 /*
2240  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
2241  * the skb was added to the buffer longer than this time ago, the earlier
2242  * frames that have not yet been received are assumed to be lost and the skb
2243  * can be released for processing. This may also release other skb's from the
2244  * reorder buffer if there are no additional gaps between the frames.
2245  */
2246 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
2247
2248 /*
2249  * As this function belongs to the RX path it must be under
2250  * rcu_read_lock protection. It returns false if the frame
2251  * can be processed immediately, true if it was consumed.
2252  */
2253 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
2254                                              struct tid_ampdu_rx *tid_agg_rx,
2255                                              struct sk_buff *skb)
2256 {
2257         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2258         u16 sc = le16_to_cpu(hdr->seq_ctrl);
2259         u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2260         u16 head_seq_num, buf_size;
2261         int index;
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 true;
2270         }
2271
2272         /*
2273          * If frame the sequence number exceeds our buffering window
2274          * size release some previous frames to make room for this one.
2275          */
2276         if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
2277                 head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
2278                 /* release stored frames up to new head to stack */
2279                 ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num);
2280         }
2281
2282         /* Now the new frame is always in the range of the reordering buffer */
2283
2284         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2285
2286         /* check if we already stored this frame */
2287         if (tid_agg_rx->reorder_buf[index]) {
2288                 dev_kfree_skb(skb);
2289                 return true;
2290         }
2291
2292         /*
2293          * If the current MPDU is in the right order and nothing else
2294          * is stored we can process it directly, no need to buffer it.
2295          */
2296         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2297             tid_agg_rx->stored_mpdu_num == 0) {
2298                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2299                 return false;
2300         }
2301
2302         /* put the frame in the reordering buffer */
2303         tid_agg_rx->reorder_buf[index] = skb;
2304         tid_agg_rx->reorder_time[index] = jiffies;
2305         tid_agg_rx->stored_mpdu_num++;
2306         /* release the buffer until next missing frame */
2307         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
2308                                                 tid_agg_rx->buf_size;
2309         if (!tid_agg_rx->reorder_buf[index] &&
2310             tid_agg_rx->stored_mpdu_num > 1) {
2311                 /*
2312                  * No buffers ready to be released, but check whether any
2313                  * frames in the reorder buffer have timed out.
2314                  */
2315                 int j;
2316                 int skipped = 1;
2317                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
2318                      j = (j + 1) % tid_agg_rx->buf_size) {
2319                         if (!tid_agg_rx->reorder_buf[j]) {
2320                                 skipped++;
2321                                 continue;
2322                         }
2323                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
2324                                         HT_RX_REORDER_BUF_TIMEOUT))
2325                                 break;
2326
2327 #ifdef CONFIG_MAC80211_HT_DEBUG
2328                         if (net_ratelimit())
2329                                 printk(KERN_DEBUG "%s: release an RX reorder "
2330                                        "frame due to timeout on earlier "
2331                                        "frames\n",
2332                                        wiphy_name(hw->wiphy));
2333 #endif
2334                         ieee80211_release_reorder_frame(hw, tid_agg_rx, j);
2335
2336                         /*
2337                          * Increment the head seq# also for the skipped slots.
2338                          */
2339                         tid_agg_rx->head_seq_num =
2340                                 (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
2341                         skipped = 0;
2342                 }
2343         } else while (tid_agg_rx->reorder_buf[index]) {
2344                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index);
2345                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
2346                                                         tid_agg_rx->buf_size;
2347         }
2348
2349         return true;
2350 }
2351
2352 /*
2353  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
2354  * true if the MPDU was buffered, false if it should be processed.
2355  */
2356 static bool ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2357                                        struct sk_buff *skb)
2358 {
2359         struct ieee80211_hw *hw = &local->hw;
2360         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2361         struct sta_info *sta;
2362         struct tid_ampdu_rx *tid_agg_rx;
2363         u16 sc;
2364         int tid;
2365
2366         if (!ieee80211_is_data_qos(hdr->frame_control))
2367                 return false;
2368
2369         /*
2370          * filter the QoS data rx stream according to
2371          * STA/TID and check if this STA/TID is on aggregation
2372          */
2373
2374         sta = sta_info_get(local, hdr->addr2);
2375         if (!sta)
2376                 return false;
2377
2378         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2379
2380         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2381                 return false;
2382
2383         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2384
2385         /* qos null data frames are excluded */
2386         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2387                 return false;
2388
2389         /* new, potentially un-ordered, ampdu frame - process it */
2390
2391         /* reset session timer */
2392         if (tid_agg_rx->timeout)
2393                 mod_timer(&tid_agg_rx->session_timer,
2394                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
2395
2396         /* if this mpdu is fragmented - terminate rx aggregation session */
2397         sc = le16_to_cpu(hdr->seq_ctrl);
2398         if (sc & IEEE80211_SCTL_FRAG) {
2399                 ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2400                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2401                 dev_kfree_skb(skb);
2402                 return true;
2403         }
2404
2405         return ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb);
2406 }
2407
2408 /*
2409  * This is the receive path handler. It is called by a low level driver when an
2410  * 802.11 MPDU is received from the hardware.
2411  */
2412 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2413 {
2414         struct ieee80211_local *local = hw_to_local(hw);
2415         struct ieee80211_rate *rate = NULL;
2416         struct ieee80211_supported_band *sband;
2417         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2418
2419         WARN_ON_ONCE(softirq_count() == 0);
2420
2421         if (WARN_ON(status->band < 0 ||
2422                     status->band >= IEEE80211_NUM_BANDS))
2423                 goto drop;
2424
2425         sband = local->hw.wiphy->bands[status->band];
2426         if (WARN_ON(!sband))
2427                 goto drop;
2428
2429         /*
2430          * If we're suspending, it is possible although not too likely
2431          * that we'd be receiving frames after having already partially
2432          * quiesced the stack. We can't process such frames then since
2433          * that might, for example, cause stations to be added or other
2434          * driver callbacks be invoked.
2435          */
2436         if (unlikely(local->quiescing || local->suspended))
2437                 goto drop;
2438
2439         /*
2440          * The same happens when we're not even started,
2441          * but that's worth a warning.
2442          */
2443         if (WARN_ON(!local->started))
2444                 goto drop;
2445
2446         if (status->flag & RX_FLAG_HT) {
2447                 /*
2448                  * rate_idx is MCS index, which can be [0-76] as documented on:
2449                  *
2450                  * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2451                  *
2452                  * Anything else would be some sort of driver or hardware error.
2453                  * The driver should catch hardware errors.
2454                  */
2455                 if (WARN((status->rate_idx < 0 ||
2456                          status->rate_idx > 76),
2457                          "Rate marked as an HT rate but passed "
2458                          "status->rate_idx is not "
2459                          "an MCS index [0-76]: %d (0x%02x)\n",
2460                          status->rate_idx,
2461                          status->rate_idx))
2462                         goto drop;
2463                 /* HT rates are not in the table - use the highest legacy rate
2464                  * for now since other parts of mac80211 may not yet be fully
2465                  * MCS aware. */
2466                 rate = &sband->bitrates[sband->n_bitrates - 1];
2467         } else {
2468                 if (WARN_ON(status->rate_idx < 0 ||
2469                             status->rate_idx >= sband->n_bitrates))
2470                         goto drop;
2471                 rate = &sband->bitrates[status->rate_idx];
2472         }
2473
2474         /*
2475          * key references and virtual interfaces are protected using RCU
2476          * and this requires that we are in a read-side RCU section during
2477          * receive processing
2478          */
2479         rcu_read_lock();
2480
2481         /*
2482          * Frames with failed FCS/PLCP checksum are not returned,
2483          * all other frames are returned without radiotap header
2484          * if it was previously present.
2485          * Also, frames with less than 16 bytes are dropped.
2486          */
2487         skb = ieee80211_rx_monitor(local, skb, rate);
2488         if (!skb) {
2489                 rcu_read_unlock();
2490                 return;
2491         }
2492
2493         /*
2494          * In theory, the block ack reordering should happen after duplicate
2495          * removal (ieee80211_rx_h_check(), which is an RX handler). As such,
2496          * the call to ieee80211_rx_reorder_ampdu() should really be moved to
2497          * happen as a new RX handler between ieee80211_rx_h_check and
2498          * ieee80211_rx_h_decrypt. This cleanup may eventually happen, but for
2499          * the time being, the call can be here since RX reorder buf processing
2500          * will implicitly skip duplicates. We could, in theory at least,
2501          * process frames that ieee80211_rx_h_passive_scan would drop (e.g.,
2502          * frames from other than operational channel), but that should not
2503          * happen in normal networks.
2504          */
2505         if (!ieee80211_rx_reorder_ampdu(local, skb))
2506                 __ieee80211_rx_handle_packet(hw, skb, rate);
2507
2508         rcu_read_unlock();
2509
2510         return;
2511  drop:
2512         kfree_skb(skb);
2513 }
2514 EXPORT_SYMBOL(ieee80211_rx);
2515
2516 /* This is a version of the rx handler that can be called from hard irq
2517  * context. Post the skb on the queue and schedule the tasklet */
2518 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2519 {
2520         struct ieee80211_local *local = hw_to_local(hw);
2521
2522         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2523
2524         skb->pkt_type = IEEE80211_RX_MSG;
2525         skb_queue_tail(&local->skb_queue, skb);
2526         tasklet_schedule(&local->tasklet);
2527 }
2528 EXPORT_SYMBOL(ieee80211_rx_irqsafe);