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 2007-2010  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/slab.h>
  14 #include <linux/kernel.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/rcupdate.h>
  19 #include <net/mac80211.h>
  20 #include <net/ieee80211_radiotap.h>
  21
  22 #include "ieee80211_i.h"
  23 #include "driver-ops.h"
  24 #include "led.h"
  25 #include "mesh.h"
  26 #include "wep.h"
  27 #include "wpa.h"
  28 #include "tkip.h"
  29 #include "wme.h"
  30
  31 /*
  32  * monitor mode reception
  33  *
  34  * This function cleans up the SKB, i.e. it removes all the stuff
  35  * only useful for monitoring.
  36  */
  37 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  38                                            struct sk_buff *skb)
  39 {
  40         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  41                 if (likely(skb->len > FCS_LEN))
  42                         __pskb_trim(skb, skb->len - FCS_LEN);
  43                 else {
  44                         /* driver bug */
  45                         WARN_ON(1);
  46                         dev_kfree_skb(skb);
  47                         skb = NULL;
  48                 }
  49         }
  50
  51         return skb;
  52 }
  53
  54 static inline int should_drop_frame(struct sk_buff *skb,
  55                                     int present_fcs_len)
  56 {
  57         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
  58         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  59
  60         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  61                 return 1;
  62         if (unlikely(skb->len < 16 + present_fcs_len))
  63                 return 1;
  64         if (ieee80211_is_ctl(hdr->frame_control) &&
  65             !ieee80211_is_pspoll(hdr->frame_control) &&
  66             !ieee80211_is_back_req(hdr->frame_control))
  67                 return 1;
  68         return 0;
  69 }
  70
  71 static int
  72 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  73                           struct ieee80211_rx_status *status)
  74 {
  75         int len;
  76
  77         /* always present fields */
  78         len = sizeof(struct ieee80211_radiotap_header) + 9;
  79
  80         if (status->flag & RX_FLAG_TSFT)
  81                 len += 8;
  82         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  83                 len += 1;
  84
  85         if (len & 1) /* padding for RX_FLAGS if necessary */
  86                 len++;
  87
  88         return len;
  89 }
  90
  91 /*
  92  * ieee80211_add_rx_radiotap_header - add radiotap header
  93  *
  94  * add a radiotap header containing all the fields which the hardware provided.
  95  */
  96 static void
  97 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
  98                                  struct sk_buff *skb,
  99                                  struct ieee80211_rate *rate,
 100                                  int rtap_len)
 101 {
 102         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 103         struct ieee80211_radiotap_header *rthdr;
 104         unsigned char *pos;
 105         u16 rx_flags = 0;
 106
 107         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 108         memset(rthdr, 0, rtap_len);
 109
 110         /* radiotap header, set always present flags */
 111         rthdr->it_present =
 112                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 113                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 114                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 115                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 116         rthdr->it_len = cpu_to_le16(rtap_len);
 117
 118         pos = (unsigned char *)(rthdr+1);
 119
 120         /* the order of the following fields is important */
 121
 122         /* IEEE80211_RADIOTAP_TSFT */
 123         if (status->flag & RX_FLAG_TSFT) {
 124                 put_unaligned_le64(status->mactime, pos);
 125                 rthdr->it_present |=
 126                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 127                 pos += 8;
 128         }
 129
 130         /* IEEE80211_RADIOTAP_FLAGS */
 131         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 132                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 133         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 134                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 135         if (status->flag & RX_FLAG_SHORTPRE)
 136                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 137         pos++;
 138
 139         /* IEEE80211_RADIOTAP_RATE */
 140         if (status->flag & RX_FLAG_HT) {
 141                 /*
 142                  * TODO: add following information into radiotap header once
 143                  * suitable fields are defined for it:
 144                  * - MCS index (status->rate_idx)
 145                  * - HT40 (status->flag & RX_FLAG_40MHZ)
 146                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
 147                  */
 148                 *pos = 0;
 149         } else {
 150                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 151                 *pos = rate->bitrate / 5;
 152         }
 153         pos++;
 154
 155         /* IEEE80211_RADIOTAP_CHANNEL */
 156         put_unaligned_le16(status->freq, pos);
 157         pos += 2;
 158         if (status->band == IEEE80211_BAND_5GHZ)
 159                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
 160                                    pos);
 161         else if (status->flag & RX_FLAG_HT)
 162                 put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
 163                                    pos);
 164         else if (rate->flags & IEEE80211_RATE_ERP_G)
 165                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
 166                                    pos);
 167         else
 168                 put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
 169                                    pos);
 170         pos += 2;
 171
 172         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 173         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 174                 *pos = status->signal;
 175                 rthdr->it_present |=
 176                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 177                 pos++;
 178         }
 179
 180         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 181
 182         /* IEEE80211_RADIOTAP_ANTENNA */
 183         *pos = status->antenna;
 184         pos++;
 185
 186         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 187
 188         /* IEEE80211_RADIOTAP_RX_FLAGS */
 189         /* ensure 2 byte alignment for the 2 byte field as required */
 190         if ((pos - (u8 *)rthdr) & 1)
 191                 pos++;
 192         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
 193                 rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
 194         put_unaligned_le16(rx_flags, pos);
 195         pos += 2;
 196 }
 197
 198 /*
 199  * This function copies a received frame to all monitor interfaces and
 200  * returns a cleaned-up SKB that no longer includes the FCS nor the
 201  * radiotap header the driver might have added.
 202  */
 203 static struct sk_buff *
 204 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 205                      struct ieee80211_rate *rate)
 206 {
 207         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
 208         struct ieee80211_sub_if_data *sdata;
 209         int needed_headroom = 0;
 210         struct sk_buff *skb, *skb2;
 211         struct net_device *prev_dev = NULL;
 212         int present_fcs_len = 0;
 213
 214         /*
 215          * First, we may need to make a copy of the skb because
 216          *  (1) we need to modify it for radiotap (if not present), and
 217          *  (2) the other RX handlers will modify the skb we got.
 218          *
 219          * We don't need to, of course, if we aren't going to return
 220          * the SKB because it has a bad FCS/PLCP checksum.
 221          */
 222
 223         /* room for the radiotap header based on driver features */
 224         needed_headroom = ieee80211_rx_radiotap_len(local, status);
 225
 226         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 227                 present_fcs_len = FCS_LEN;
 228
 229         /* make sure hdr->frame_control is on the linear part */
 230         if (!pskb_may_pull(origskb, 2)) {
 231                 dev_kfree_skb(origskb);
 232                 return NULL;
 233         }
 234
 235         if (!local->monitors) {
 236                 if (should_drop_frame(origskb, present_fcs_len)) {
 237                         dev_kfree_skb(origskb);
 238                         return NULL;
 239                 }
 240
 241                 return remove_monitor_info(local, origskb);
 242         }
 243
 244         if (should_drop_frame(origskb, present_fcs_len)) {
 245                 /* only need to expand headroom if necessary */
 246                 skb = origskb;
 247                 origskb = NULL;
 248
 249                 /*
 250                  * This shouldn't trigger often because most devices have an
 251                  * RX header they pull before we get here, and that should
 252                  * be big enough for our radiotap information. We should
 253                  * probably export the length to drivers so that we can have
 254                  * them allocate enough headroom to start with.
 255                  */
 256                 if (skb_headroom(skb) < needed_headroom &&
 257                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 258                         dev_kfree_skb(skb);
 259                         return NULL;
 260                 }
 261         } else {
 262                 /*
 263                  * Need to make a copy and possibly remove radiotap header
 264                  * and FCS from the original.
 265                  */
 266                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 267
 268                 origskb = remove_monitor_info(local, origskb);
 269
 270                 if (!skb)
 271                         return origskb;
 272         }
 273
 274         /* prepend radiotap information */
 275         ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
 276
 277         skb_reset_mac_header(skb);
 278         skb->ip_summed = CHECKSUM_UNNECESSARY;
 279         skb->pkt_type = PACKET_OTHERHOST;
 280         skb->protocol = htons(ETH_P_802_2);
 281
 282         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 283                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 284                         continue;
 285
 286                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 287                         continue;
 288
 289                 if (!ieee80211_sdata_running(sdata))
 290                         continue;
 291
 292                 if (prev_dev) {
 293                         skb2 = skb_clone(skb, GFP_ATOMIC);
 294                         if (skb2) {
 295                                 skb2->dev = prev_dev;
 296                                 netif_receive_skb(skb2);
 297                         }
 298                 }
 299
 300                 prev_dev = sdata->dev;
 301                 sdata->dev->stats.rx_packets++;
 302                 sdata->dev->stats.rx_bytes += skb->len;
 303         }
 304
 305         if (prev_dev) {
 306                 skb->dev = prev_dev;
 307                 netif_receive_skb(skb);
 308         } else
 309                 dev_kfree_skb(skb);
 310
 311         return origskb;
 312 }
 313
 314
 315 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 316 {
 317         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 318         int tid;
 319
 320         /* does the frame have a qos control field? */
 321         if (ieee80211_is_data_qos(hdr->frame_control)) {
 322                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 323                 /* frame has qos control */
 324                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 325                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 326                         rx->flags |= IEEE80211_RX_AMSDU;
 327                 else
 328                         rx->flags &= ~IEEE80211_RX_AMSDU;
 329         } else {
 330                 /*
 331                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 332                  *
 333                  *      Sequence numbers for management frames, QoS data
 334                  *      frames with a broadcast/multicast address in the
 335                  *      Address 1 field, and all non-QoS data frames sent
 336                  *      by QoS STAs are assigned using an additional single
 337                  *      modulo-4096 counter, [...]
 338                  *
 339                  * We also use that counter for non-QoS STAs.
 340                  */
 341                 tid = NUM_RX_DATA_QUEUES - 1;
 342         }
 343
 344         rx->queue = tid;
 345         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 346          * For now, set skb->priority to 0 for other cases. */
 347         rx->skb->priority = (tid > 7) ? 0 : tid;
 348 }
 349
 350 /**
 351  * DOC: Packet alignment
 352  *
 353  * Drivers always need to pass packets that are aligned to two-byte boundaries
 354  * to the stack.
 355  *
 356  * Additionally, should, if possible, align the payload data in a way that
 357  * guarantees that the contained IP header is aligned to a four-byte
 358  * boundary. In the case of regular frames, this simply means aligning the
 359  * payload to a four-byte boundary (because either the IP header is directly
 360  * contained, or IV/RFC1042 headers that have a length divisible by four are
 361  * in front of it).  If the payload data is not properly aligned and the
 362  * architecture doesn't support efficient unaligned operations, mac80211
 363  * will align the data.
 364  *
 365  * With A-MSDU frames, however, the payload data address must yield two modulo
 366  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 367  * push the IP header further back to a multiple of four again. Thankfully, the
 368  * specs were sane enough this time around to require padding each A-MSDU
 369  * subframe to a length that is a multiple of four.
 370  *
 371  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
 372  * the payload is not supported, the driver is required to move the 802.11
 373  * header to be directly in front of the payload in that case.
 374  */
 375 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 376 {
 377 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 378         WARN_ONCE((unsigned long)rx->skb->data & 1,
 379                   "unaligned packet at 0x%p\n", rx->skb->data);
 380 #endif
 381 }
 382
 383
 384 /* rx handlers */
 385
 386 static ieee80211_rx_result debug_noinline
 387 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 388 {
 389         struct ieee80211_local *local = rx->local;
 390         struct sk_buff *skb = rx->skb;
 391
 392         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning)))
 393                 return ieee80211_scan_rx(rx->sdata, skb);
 394
 395         if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning) &&
 396                      (rx->flags & IEEE80211_RX_IN_SCAN))) {
 397                 /* drop all the other packets during a software scan anyway */
 398                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
 399                         dev_kfree_skb(skb);
 400                 return RX_QUEUED;
 401         }
 402
 403         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
 404                 /* scanning finished during invoking of handlers */
 405                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 406                 return RX_DROP_UNUSABLE;
 407         }
 408
 409         return RX_CONTINUE;
 410 }
 411
 412
 413 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 414 {
 415         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 416
 417         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 418                 return 0;
 419
 420         return ieee80211_is_robust_mgmt_frame(hdr);
 421 }
 422
 423
 424 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 425 {
 426         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 427
 428         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 429                 return 0;
 430
 431         return ieee80211_is_robust_mgmt_frame(hdr);
 432 }
 433
 434
 435 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 436 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 437 {
 438         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 439         struct ieee80211_mmie *mmie;
 440
 441         if (skb->len < 24 + sizeof(*mmie) ||
 442             !is_multicast_ether_addr(hdr->da))
 443                 return -1;
 444
 445         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 446                 return -1; /* not a robust management frame */
 447
 448         mmie = (struct ieee80211_mmie *)
 449                 (skb->data + skb->len - sizeof(*mmie));
 450         if (mmie->element_id != WLAN_EID_MMIE ||
 451             mmie->length != sizeof(*mmie) - 2)
 452                 return -1;
 453
 454         return le16_to_cpu(mmie->key_id);
 455 }
 456
 457
 458 static ieee80211_rx_result
 459 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 460 {
 461         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 462         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 463         char *dev_addr = rx->sdata->vif.addr;
 464
 465         if (ieee80211_is_data(hdr->frame_control)) {
 466                 if (is_multicast_ether_addr(hdr->addr1)) {
 467                         if (ieee80211_has_tods(hdr->frame_control) ||
 468                                 !ieee80211_has_fromds(hdr->frame_control))
 469                                 return RX_DROP_MONITOR;
 470                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
 471                                 return RX_DROP_MONITOR;
 472                 } else {
 473                         if (!ieee80211_has_a4(hdr->frame_control))
 474                                 return RX_DROP_MONITOR;
 475                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
 476                                 return RX_DROP_MONITOR;
 477                 }
 478         }
 479
 480         /* If there is not an established peer link and this is not a peer link
 481          * establisment frame, beacon or probe, drop the frame.
 482          */
 483
 484         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 485                 struct ieee80211_mgmt *mgmt;
 486
 487                 if (!ieee80211_is_mgmt(hdr->frame_control))
 488                         return RX_DROP_MONITOR;
 489
 490                 if (ieee80211_is_action(hdr->frame_control)) {
 491                         mgmt = (struct ieee80211_mgmt *)hdr;
 492                         if (mgmt->u.action.category != WLAN_CATEGORY_MESH_PLINK)
 493                                 return RX_DROP_MONITOR;
 494                         return RX_CONTINUE;
 495                 }
 496
 497                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 498                     ieee80211_is_probe_resp(hdr->frame_control) ||
 499                     ieee80211_is_beacon(hdr->frame_control))
 500                         return RX_CONTINUE;
 501
 502                 return RX_DROP_MONITOR;
 503
 504         }
 505
 506 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 507
 508         if (ieee80211_is_data(hdr->frame_control) &&
 509             is_multicast_ether_addr(hdr->addr1) &&
 510             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
 511                 return RX_DROP_MONITOR;
 512 #undef msh_h_get
 513
 514         return RX_CONTINUE;
 515 }
 516
 517 #define SEQ_MODULO 0x1000
 518 #define SEQ_MASK   0xfff
 519
 520 static inline int seq_less(u16 sq1, u16 sq2)
 521 {
 522         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
 523 }
 524
 525 static inline u16 seq_inc(u16 sq)
 526 {
 527         return (sq + 1) & SEQ_MASK;
 528 }
 529
 530 static inline u16 seq_sub(u16 sq1, u16 sq2)
 531 {
 532         return (sq1 - sq2) & SEQ_MASK;
 533 }
 534
 535
 536 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
 537                                             struct tid_ampdu_rx *tid_agg_rx,
 538                                             int index,
 539                                             struct sk_buff_head *frames)
 540 {
 541         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
 542
 543         if (!skb)
 544                 goto no_frame;
 545
 546         /* release the frame from the reorder ring buffer */
 547         tid_agg_rx->stored_mpdu_num--;
 548         tid_agg_rx->reorder_buf[index] = NULL;
 549         __skb_queue_tail(frames, skb);
 550
 551 no_frame:
 552         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 553 }
 554
 555 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
 556                                              struct tid_ampdu_rx *tid_agg_rx,
 557                                              u16 head_seq_num,
 558                                              struct sk_buff_head *frames)
 559 {
 560         int index;
 561
 562         while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
 563                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 564                                                         tid_agg_rx->buf_size;
 565                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
 566         }
 567 }
 568
 569 /*
 570  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
 571  * the skb was added to the buffer longer than this time ago, the earlier
 572  * frames that have not yet been received are assumed to be lost and the skb
 573  * can be released for processing. This may also release other skb's from the
 574  * reorder buffer if there are no additional gaps between the frames.
 575  */
 576 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
 577
 578 static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw,
 579                                           struct tid_ampdu_rx *tid_agg_rx,
 580                                           struct sk_buff_head *frames)
 581 {
 582         int index;
 583
 584         /* release the buffer until next missing frame */
 585         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 586                                                 tid_agg_rx->buf_size;
 587         if (!tid_agg_rx->reorder_buf[index] &&
 588             tid_agg_rx->stored_mpdu_num > 1) {
 589                 /*
 590                  * No buffers ready to be released, but check whether any
 591                  * frames in the reorder buffer have timed out.
 592                  */
 593                 int j;
 594                 int skipped = 1;
 595                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
 596                      j = (j + 1) % tid_agg_rx->buf_size) {
 597                         if (!tid_agg_rx->reorder_buf[j]) {
 598                                 skipped++;
 599                                 continue;
 600                         }
 601                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
 602                                         HT_RX_REORDER_BUF_TIMEOUT))
 603                                 break;
 604
 605 #ifdef CONFIG_MAC80211_HT_DEBUG
 606                         if (net_ratelimit())
 607                                 printk(KERN_DEBUG "%s: release an RX reorder "
 608                                        "frame due to timeout on earlier "
 609                                        "frames\n",
 610                                        wiphy_name(hw->wiphy));
 611 #endif
 612                         ieee80211_release_reorder_frame(hw, tid_agg_rx,
 613                                                         j, frames);
 614
 615                         /*
 616                          * Increment the head seq# also for the skipped slots.
 617                          */
 618                         tid_agg_rx->head_seq_num =
 619                                 (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
 620                         skipped = 0;
 621                 }
 622         } else while (tid_agg_rx->reorder_buf[index]) {
 623                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
 624                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 625                                                         tid_agg_rx->buf_size;
 626         }
 627 }
 628
 629 /*
 630  * As this function belongs to the RX path it must be under
 631  * rcu_read_lock protection. It returns false if the frame
 632  * can be processed immediately, true if it was consumed.
 633  */
 634 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
 635                                              struct tid_ampdu_rx *tid_agg_rx,
 636                                              struct sk_buff *skb,
 637                                              struct sk_buff_head *frames)
 638 {
 639         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 640         u16 sc = le16_to_cpu(hdr->seq_ctrl);
 641         u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
 642         u16 head_seq_num, buf_size;
 643         int index;
 644
 645         buf_size = tid_agg_rx->buf_size;
 646         head_seq_num = tid_agg_rx->head_seq_num;
 647
 648         /* frame with out of date sequence number */
 649         if (seq_less(mpdu_seq_num, head_seq_num)) {
 650                 dev_kfree_skb(skb);
 651                 return true;
 652         }
 653
 654         /*
 655          * If frame the sequence number exceeds our buffering window
 656          * size release some previous frames to make room for this one.
 657          */
 658         if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
 659                 head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
 660                 /* release stored frames up to new head to stack */
 661                 ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num,
 662                                                  frames);
 663         }
 664
 665         /* Now the new frame is always in the range of the reordering buffer */
 666
 667         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 668
 669         /* check if we already stored this frame */
 670         if (tid_agg_rx->reorder_buf[index]) {
 671                 dev_kfree_skb(skb);
 672                 return true;
 673         }
 674
 675         /*
 676          * If the current MPDU is in the right order and nothing else
 677          * is stored we can process it directly, no need to buffer it.
 678          */
 679         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
 680             tid_agg_rx->stored_mpdu_num == 0) {
 681                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 682                 return false;
 683         }
 684
 685         /* put the frame in the reordering buffer */
 686         tid_agg_rx->reorder_buf[index] = skb;
 687         tid_agg_rx->reorder_time[index] = jiffies;
 688         tid_agg_rx->stored_mpdu_num++;
 689         ieee80211_sta_reorder_release(hw, tid_agg_rx, frames);
 690
 691         return true;
 692 }
 693
 694 /*
 695  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
 696  * true if the MPDU was buffered, false if it should be processed.
 697  */
 698 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
 699                                        struct sk_buff_head *frames)
 700 {
 701         struct sk_buff *skb = rx->skb;
 702         struct ieee80211_local *local = rx->local;
 703         struct ieee80211_hw *hw = &local->hw;
 704         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 705         struct sta_info *sta = rx->sta;
 706         struct tid_ampdu_rx *tid_agg_rx;
 707         u16 sc;
 708         int tid;
 709
 710         if (!ieee80211_is_data_qos(hdr->frame_control))
 711                 goto dont_reorder;
 712
 713         /*
 714          * filter the QoS data rx stream according to
 715          * STA/TID and check if this STA/TID is on aggregation
 716          */
 717
 718         if (!sta)
 719                 goto dont_reorder;
 720
 721         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 722
 723         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 724         if (!tid_agg_rx)
 725                 goto dont_reorder;
 726
 727         /* qos null data frames are excluded */
 728         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
 729                 goto dont_reorder;
 730
 731         /* new, potentially un-ordered, ampdu frame - process it */
 732
 733         /* reset session timer */
 734         if (tid_agg_rx->timeout)
 735                 mod_timer(&tid_agg_rx->session_timer,
 736                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
 737
 738         /* if this mpdu is fragmented - terminate rx aggregation session */
 739         sc = le16_to_cpu(hdr->seq_ctrl);
 740         if (sc & IEEE80211_SCTL_FRAG) {
 741                 skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
 742                 skb_queue_tail(&rx->sdata->skb_queue, skb);
 743                 ieee80211_queue_work(&local->hw, &rx->sdata->work);
 744                 return;
 745         }
 746
 747         /*
 748          * No locking needed -- we will only ever process one
 749          * RX packet at a time, and thus own tid_agg_rx. All
 750          * other code manipulating it needs to (and does) make
 751          * sure that we cannot get to it any more before doing
 752          * anything with it.
 753          */
 754         if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, frames))
 755                 return;
 756
 757  dont_reorder:
 758         __skb_queue_tail(frames, skb);
 759 }
 760
 761 static ieee80211_rx_result debug_noinline
 762 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 763 {
 764         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 765
 766         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 767         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 768                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 769                              rx->sta->last_seq_ctrl[rx->queue] ==
 770                              hdr->seq_ctrl)) {
 771                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
 772                                 rx->local->dot11FrameDuplicateCount++;
 773                                 rx->sta->num_duplicates++;
 774                         }
 775                         return RX_DROP_MONITOR;
 776                 } else
 777                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 778         }
 779
 780         if (unlikely(rx->skb->len < 16)) {
 781                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 782                 return RX_DROP_MONITOR;
 783         }
 784
 785         /* Drop disallowed frame classes based on STA auth/assoc state;
 786          * IEEE 802.11, Chap 5.5.
 787          *
 788          * mac80211 filters only based on association state, i.e. it drops
 789          * Class 3 frames from not associated stations. hostapd sends
 790          * deauth/disassoc frames when needed. In addition, hostapd is
 791          * responsible for filtering on both auth and assoc states.
 792          */
 793
 794         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 795                 return ieee80211_rx_mesh_check(rx);
 796
 797         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 798                       ieee80211_is_pspoll(hdr->frame_control)) &&
 799                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 800                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 801                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 802                      !ieee80211_has_tods(hdr->frame_control) &&
 803                      ieee80211_is_data(hdr->frame_control)) ||
 804                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
 805                         /* Drop IBSS frames and frames for other hosts
 806                          * silently. */
 807                         return RX_DROP_MONITOR;
 808                 }
 809
 810                 return RX_DROP_MONITOR;
 811         }
 812
 813         return RX_CONTINUE;
 814 }
 815
 816
 817 static ieee80211_rx_result debug_noinline
 818 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 819 {
 820         struct sk_buff *skb = rx->skb;
 821         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 822         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 823         int keyidx;
 824         int hdrlen;
 825         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 826         struct ieee80211_key *stakey = NULL;
 827         int mmie_keyidx = -1;
 828         __le16 fc;
 829
 830         /*
 831          * Key selection 101
 832          *
 833          * There are four types of keys:
 834          *  - GTK (group keys)
 835          *  - IGTK (group keys for management frames)
 836          *  - PTK (pairwise keys)
 837          *  - STK (station-to-station pairwise keys)
 838          *
 839          * When selecting a key, we have to distinguish between multicast
 840          * (including broadcast) and unicast frames, the latter can only
 841          * use PTKs and STKs while the former always use GTKs and IGTKs.
 842          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 843          * unicast frames can also use key indices like GTKs. Hence, if we
 844          * don't have a PTK/STK we check the key index for a WEP key.
 845          *
 846          * Note that in a regular BSS, multicast frames are sent by the
 847          * AP only, associated stations unicast the frame to the AP first
 848          * which then multicasts it on their behalf.
 849          *
 850          * There is also a slight problem in IBSS mode: GTKs are negotiated
 851          * with each station, that is something we don't currently handle.
 852          * The spec seems to expect that one negotiates the same key with
 853          * every station but there's no such requirement; VLANs could be
 854          * possible.
 855          */
 856
 857         /*
 858          * No point in finding a key and decrypting if the frame is neither
 859          * addressed to us nor a multicast frame.
 860          */
 861         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 862                 return RX_CONTINUE;
 863
 864         /* start without a key */
 865         rx->key = NULL;
 866
 867         if (rx->sta)
 868                 stakey = rcu_dereference(rx->sta->key);
 869
 870         fc = hdr->frame_control;
 871
 872         if (!ieee80211_has_protected(fc))
 873                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 874
 875         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 876                 rx->key = stakey;
 877                 /* Skip decryption if the frame is not protected. */
 878                 if (!ieee80211_has_protected(fc))
 879                         return RX_CONTINUE;
 880         } else if (mmie_keyidx >= 0) {
 881                 /* Broadcast/multicast robust management frame / BIP */
 882                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 883                     (status->flag & RX_FLAG_IV_STRIPPED))
 884                         return RX_CONTINUE;
 885
 886                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 887                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 888                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 889                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 890         } else if (!ieee80211_has_protected(fc)) {
 891                 /*
 892                  * The frame was not protected, so skip decryption. However, we
 893                  * need to set rx->key if there is a key that could have been
 894                  * used so that the frame may be dropped if encryption would
 895                  * have been expected.
 896                  */
 897                 struct ieee80211_key *key = NULL;
 898                 if (ieee80211_is_mgmt(fc) &&
 899                     is_multicast_ether_addr(hdr->addr1) &&
 900                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 901                         rx->key = key;
 902                 else if ((key = rcu_dereference(rx->sdata->default_key)))
 903                         rx->key = key;
 904                 return RX_CONTINUE;
 905         } else {
 906                 u8 keyid;
 907                 /*
 908                  * The device doesn't give us the IV so we won't be
 909                  * able to look up the key. That's ok though, we
 910                  * don't need to decrypt the frame, we just won't
 911                  * be able to keep statistics accurate.
 912                  * Except for key threshold notifications, should
 913                  * we somehow allow the driver to tell us which key
 914                  * the hardware used if this flag is set?
 915                  */
 916                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 917                     (status->flag & RX_FLAG_IV_STRIPPED))
 918                         return RX_CONTINUE;
 919
 920                 hdrlen = ieee80211_hdrlen(fc);
 921
 922                 if (rx->skb->len < 8 + hdrlen)
 923                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 924
 925                 /*
 926                  * no need to call ieee80211_wep_get_keyidx,
 927                  * it verifies a bunch of things we've done already
 928                  */
 929                 skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
 930                 keyidx = keyid >> 6;
 931
 932                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 933
 934                 /*
 935                  * RSNA-protected unicast frames should always be sent with
 936                  * pairwise or station-to-station keys, but for WEP we allow
 937                  * using a key index as well.
 938                  */
 939                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 940                     !is_multicast_ether_addr(hdr->addr1))
 941                         rx->key = NULL;
 942         }
 943
 944         if (rx->key) {
 945                 rx->key->tx_rx_count++;
 946                 /* TODO: add threshold stuff again */
 947         } else {
 948                 return RX_DROP_MONITOR;
 949         }
 950
 951         if (skb_linearize(rx->skb))
 952                 return RX_DROP_UNUSABLE;
 953         /* the hdr variable is invalid now! */
 954
 955         switch (rx->key->conf.alg) {
 956         case ALG_WEP:
 957                 /* Check for weak IVs if possible */
 958                 if (rx->sta && ieee80211_is_data(fc) &&
 959                     (!(status->flag & RX_FLAG_IV_STRIPPED) ||
 960                      !(status->flag & RX_FLAG_DECRYPTED)) &&
 961                     ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 962                         rx->sta->wep_weak_iv_count++;
 963
 964                 result = ieee80211_crypto_wep_decrypt(rx);
 965                 break;
 966         case ALG_TKIP:
 967                 result = ieee80211_crypto_tkip_decrypt(rx);
 968                 break;
 969         case ALG_CCMP:
 970                 result = ieee80211_crypto_ccmp_decrypt(rx);
 971                 break;
 972         case ALG_AES_CMAC:
 973                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
 974                 break;
 975         }
 976
 977         /* either the frame has been decrypted or will be dropped */
 978         status->flag |= RX_FLAG_DECRYPTED;
 979
 980         return result;
 981 }
 982
 983 static ieee80211_rx_result debug_noinline
 984 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
 985 {
 986         struct ieee80211_local *local;
 987         struct ieee80211_hdr *hdr;
 988         struct sk_buff *skb;
 989
 990         local = rx->local;
 991         skb = rx->skb;
 992         hdr = (struct ieee80211_hdr *) skb->data;
 993
 994         if (!local->pspolling)
 995                 return RX_CONTINUE;
 996
 997         if (!ieee80211_has_fromds(hdr->frame_control))
 998                 /* this is not from AP */
 999                 return RX_CONTINUE;
1000
1001         if (!ieee80211_is_data(hdr->frame_control))
1002                 return RX_CONTINUE;
1003
1004         if (!ieee80211_has_moredata(hdr->frame_control)) {
1005                 /* AP has no more frames buffered for us */
1006                 local->pspolling = false;
1007                 return RX_CONTINUE;
1008         }
1009
1010         /* more data bit is set, let's request a new frame from the AP */
1011         ieee80211_send_pspoll(local, rx->sdata);
1012
1013         return RX_CONTINUE;
1014 }
1015
1016 static void ap_sta_ps_start(struct sta_info *sta)
1017 {
1018         struct ieee80211_sub_if_data *sdata = sta->sdata;
1019         struct ieee80211_local *local = sdata->local;
1020
1021         atomic_inc(&sdata->bss->num_sta_ps);
1022         set_sta_flags(sta, WLAN_STA_PS_STA);
1023         drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1024 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1025         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1026                sdata->name, sta->sta.addr, sta->sta.aid);
1027 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1028 }
1029
1030 static void ap_sta_ps_end(struct sta_info *sta)
1031 {
1032         struct ieee80211_sub_if_data *sdata = sta->sdata;
1033
1034         atomic_dec(&sdata->bss->num_sta_ps);
1035
1036         clear_sta_flags(sta, WLAN_STA_PS_STA);
1037
1038 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1039         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1040                sdata->name, sta->sta.addr, sta->sta.aid);
1041 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1042
1043         if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
1044 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1045                 printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1046                        sdata->name, sta->sta.addr, sta->sta.aid);
1047 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1048                 return;
1049         }
1050
1051         ieee80211_sta_ps_deliver_wakeup(sta);
1052 }
1053
1054 static ieee80211_rx_result debug_noinline
1055 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1056 {
1057         struct sta_info *sta = rx->sta;
1058         struct sk_buff *skb = rx->skb;
1059         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1060         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1061
1062         if (!sta)
1063                 return RX_CONTINUE;
1064
1065         /*
1066          * Update last_rx only for IBSS packets which are for the current
1067          * BSSID to avoid keeping the current IBSS network alive in cases
1068          * where other STAs start using different BSSID.
1069          */
1070         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1071                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1072                                                 NL80211_IFTYPE_ADHOC);
1073                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
1074                         sta->last_rx = jiffies;
1075         } else if (!is_multicast_ether_addr(hdr->addr1)) {
1076                 /*
1077                  * Mesh beacons will update last_rx when if they are found to
1078                  * match the current local configuration when processed.
1079                  */
1080                 sta->last_rx = jiffies;
1081         }
1082
1083         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1084                 return RX_CONTINUE;
1085
1086         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1087                 ieee80211_sta_rx_notify(rx->sdata, hdr);
1088
1089         sta->rx_fragments++;
1090         sta->rx_bytes += rx->skb->len;
1091         sta->last_signal = status->signal;
1092
1093         /*
1094          * Change STA power saving mode only at the end of a frame
1095          * exchange sequence.
1096          */
1097         if (!ieee80211_has_morefrags(hdr->frame_control) &&
1098             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1099              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1100                 if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
1101                         /*
1102                          * Ignore doze->wake transitions that are
1103                          * indicated by non-data frames, the standard
1104                          * is unclear here, but for example going to
1105                          * PS mode and then scanning would cause a
1106                          * doze->wake transition for the probe request,
1107                          * and that is clearly undesirable.
1108                          */
1109                         if (ieee80211_is_data(hdr->frame_control) &&
1110                             !ieee80211_has_pm(hdr->frame_control))
1111                                 ap_sta_ps_end(sta);
1112                 } else {
1113                         if (ieee80211_has_pm(hdr->frame_control))
1114                                 ap_sta_ps_start(sta);
1115                 }
1116         }
1117
1118         /*
1119          * Drop (qos-)data::nullfunc frames silently, since they
1120          * are used only to control station power saving mode.
1121          */
1122         if (ieee80211_is_nullfunc(hdr->frame_control) ||
1123             ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1124                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1125
1126                 /*
1127                  * If we receive a 4-addr nullfunc frame from a STA
1128                  * that was not moved to a 4-addr STA vlan yet, drop
1129                  * the frame to the monitor interface, to make sure
1130                  * that hostapd sees it
1131                  */
1132                 if (ieee80211_has_a4(hdr->frame_control) &&
1133                     (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1134                      (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1135                       !rx->sdata->u.vlan.sta)))
1136                         return RX_DROP_MONITOR;
1137                 /*
1138                  * Update counter and free packet here to avoid
1139                  * counting this as a dropped packed.
1140                  */
1141                 sta->rx_packets++;
1142                 dev_kfree_skb(rx->skb);
1143                 return RX_QUEUED;
1144         }
1145
1146         return RX_CONTINUE;
1147 } /* ieee80211_rx_h_sta_process */
1148
1149 static inline struct ieee80211_fragment_entry *
1150 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1151                          unsigned int frag, unsigned int seq, int rx_queue,
1152                          struct sk_buff **skb)
1153 {
1154         struct ieee80211_fragment_entry *entry;
1155         int idx;
1156
1157         idx = sdata->fragment_next;
1158         entry = &sdata->fragments[sdata->fragment_next++];
1159         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1160                 sdata->fragment_next = 0;
1161
1162         if (!skb_queue_empty(&entry->skb_list)) {
1163 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1164                 struct ieee80211_hdr *hdr =
1165                         (struct ieee80211_hdr *) entry->skb_list.next->data;
1166                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1167                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1168                        "addr1=%pM addr2=%pM\n",
1169                        sdata->name, idx,
1170                        jiffies - entry->first_frag_time, entry->seq,
1171                        entry->last_frag, hdr->addr1, hdr->addr2);
1172 #endif
1173                 __skb_queue_purge(&entry->skb_list);
1174         }
1175
1176         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1177         *skb = NULL;
1178         entry->first_frag_time = jiffies;
1179         entry->seq = seq;
1180         entry->rx_queue = rx_queue;
1181         entry->last_frag = frag;
1182         entry->ccmp = 0;
1183         entry->extra_len = 0;
1184
1185         return entry;
1186 }
1187
1188 static inline struct ieee80211_fragment_entry *
1189 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1190                           unsigned int frag, unsigned int seq,
1191                           int rx_queue, struct ieee80211_hdr *hdr)
1192 {
1193         struct ieee80211_fragment_entry *entry;
1194         int i, idx;
1195
1196         idx = sdata->fragment_next;
1197         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1198                 struct ieee80211_hdr *f_hdr;
1199
1200                 idx--;
1201                 if (idx < 0)
1202                         idx = IEEE80211_FRAGMENT_MAX - 1;
1203
1204                 entry = &sdata->fragments[idx];
1205                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1206                     entry->rx_queue != rx_queue ||
1207                     entry->last_frag + 1 != frag)
1208                         continue;
1209
1210                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1211
1212                 /*
1213                  * Check ftype and addresses are equal, else check next fragment
1214                  */
1215                 if (((hdr->frame_control ^ f_hdr->frame_control) &
1216                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1217                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1218                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1219                         continue;
1220
1221                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1222                         __skb_queue_purge(&entry->skb_list);
1223                         continue;
1224                 }
1225                 return entry;
1226         }
1227
1228         return NULL;
1229 }
1230
1231 static ieee80211_rx_result debug_noinline
1232 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1233 {
1234         struct ieee80211_hdr *hdr;
1235         u16 sc;
1236         __le16 fc;
1237         unsigned int frag, seq;
1238         struct ieee80211_fragment_entry *entry;
1239         struct sk_buff *skb;
1240
1241         hdr = (struct ieee80211_hdr *)rx->skb->data;
1242         fc = hdr->frame_control;
1243         sc = le16_to_cpu(hdr->seq_ctrl);
1244         frag = sc & IEEE80211_SCTL_FRAG;
1245
1246         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1247                    (rx->skb)->len < 24 ||
1248                    is_multicast_ether_addr(hdr->addr1))) {
1249                 /* not fragmented */
1250                 goto out;
1251         }
1252         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1253
1254         if (skb_linearize(rx->skb))
1255                 return RX_DROP_UNUSABLE;
1256
1257         /*
1258          *  skb_linearize() might change the skb->data and
1259          *  previously cached variables (in this case, hdr) need to
1260          *  be refreshed with the new data.
1261          */
1262         hdr = (struct ieee80211_hdr *)rx->skb->data;
1263         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1264
1265         if (frag == 0) {
1266                 /* This is the first fragment of a new frame. */
1267                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1268                                                  rx->queue, &(rx->skb));
1269                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1270                     ieee80211_has_protected(fc)) {
1271                         int queue = ieee80211_is_mgmt(fc) ?
1272                                 NUM_RX_DATA_QUEUES : rx->queue;
1273                         /* Store CCMP PN so that we can verify that the next
1274                          * fragment has a sequential PN value. */
1275                         entry->ccmp = 1;
1276                         memcpy(entry->last_pn,
1277                                rx->key->u.ccmp.rx_pn[queue],
1278                                CCMP_PN_LEN);
1279                 }
1280                 return RX_QUEUED;
1281         }
1282
1283         /* This is a fragment for a frame that should already be pending in
1284          * fragment cache. Add this fragment to the end of the pending entry.
1285          */
1286         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1287         if (!entry) {
1288                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1289                 return RX_DROP_MONITOR;
1290         }
1291
1292         /* Verify that MPDUs within one MSDU have sequential PN values.
1293          * (IEEE 802.11i, 8.3.3.4.5) */
1294         if (entry->ccmp) {
1295                 int i;
1296                 u8 pn[CCMP_PN_LEN], *rpn;
1297                 int queue;
1298                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1299                         return RX_DROP_UNUSABLE;
1300                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1301                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1302                         pn[i]++;
1303                         if (pn[i])
1304                                 break;
1305                 }
1306                 queue = ieee80211_is_mgmt(fc) ?
1307                         NUM_RX_DATA_QUEUES : rx->queue;
1308                 rpn = rx->key->u.ccmp.rx_pn[queue];
1309                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1310                         return RX_DROP_UNUSABLE;
1311                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1312         }
1313
1314         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1315         __skb_queue_tail(&entry->skb_list, rx->skb);
1316         entry->last_frag = frag;
1317         entry->extra_len += rx->skb->len;
1318         if (ieee80211_has_morefrags(fc)) {
1319                 rx->skb = NULL;
1320                 return RX_QUEUED;
1321         }
1322
1323         rx->skb = __skb_dequeue(&entry->skb_list);
1324         if (skb_tailroom(rx->skb) < entry->extra_len) {
1325                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1326                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1327                                               GFP_ATOMIC))) {
1328                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1329                         __skb_queue_purge(&entry->skb_list);
1330                         return RX_DROP_UNUSABLE;
1331                 }
1332         }
1333         while ((skb = __skb_dequeue(&entry->skb_list))) {
1334                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1335                 dev_kfree_skb(skb);
1336         }
1337
1338         /* Complete frame has been reassembled - process it now */
1339         rx->flags |= IEEE80211_RX_FRAGMENTED;
1340
1341  out:
1342         if (rx->sta)
1343                 rx->sta->rx_packets++;
1344         if (is_multicast_ether_addr(hdr->addr1))
1345                 rx->local->dot11MulticastReceivedFrameCount++;
1346         else
1347                 ieee80211_led_rx(rx->local);
1348         return RX_CONTINUE;
1349 }
1350
1351 static ieee80211_rx_result debug_noinline
1352 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1353 {
1354         struct ieee80211_sub_if_data *sdata = rx->sdata;
1355         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1356
1357         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1358                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1359                 return RX_CONTINUE;
1360
1361         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1362             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1363                 return RX_DROP_UNUSABLE;
1364
1365         if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1366                 ieee80211_sta_ps_deliver_poll_response(rx->sta);
1367         else
1368                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1369
1370         /* Free PS Poll skb here instead of returning RX_DROP that would
1371          * count as an dropped frame. */
1372         dev_kfree_skb(rx->skb);
1373
1374         return RX_QUEUED;
1375 }
1376
1377 static ieee80211_rx_result debug_noinline
1378 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1379 {
1380         u8 *data = rx->skb->data;
1381         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1382
1383         if (!ieee80211_is_data_qos(hdr->frame_control))
1384                 return RX_CONTINUE;
1385
1386         /* remove the qos control field, update frame type and meta-data */
1387         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1388                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1389         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1390         /* change frame type to non QOS */
1391         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1392
1393         return RX_CONTINUE;
1394 }
1395
1396 static int
1397 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1398 {
1399         if (unlikely(!rx->sta ||
1400             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1401                 return -EACCES;
1402
1403         return 0;
1404 }
1405
1406 static int
1407 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1408 {
1409         struct sk_buff *skb = rx->skb;
1410         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1411
1412         /*
1413          * Pass through unencrypted frames if the hardware has
1414          * decrypted them already.
1415          */
1416         if (status->flag & RX_FLAG_DECRYPTED)
1417                 return 0;
1418
1419         /* Drop unencrypted frames if key is set. */
1420         if (unlikely(!ieee80211_has_protected(fc) &&
1421                      !ieee80211_is_nullfunc(fc) &&
1422                      ieee80211_is_data(fc) &&
1423                      (rx->key || rx->sdata->drop_unencrypted)))
1424                 return -EACCES;
1425
1426         return 0;
1427 }
1428
1429 static int
1430 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1431 {
1432         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1433         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1434         __le16 fc = hdr->frame_control;
1435
1436         /*
1437          * Pass through unencrypted frames if the hardware has
1438          * decrypted them already.
1439          */
1440         if (status->flag & RX_FLAG_DECRYPTED)
1441                 return 0;
1442
1443         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1444                 if (unlikely(!ieee80211_has_protected(fc) &&
1445                              ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1446                              rx->key))
1447                         return -EACCES;
1448                 /* BIP does not use Protected field, so need to check MMIE */
1449                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1450                              ieee80211_get_mmie_keyidx(rx->skb) < 0))
1451                         return -EACCES;
1452                 /*
1453                  * When using MFP, Action frames are not allowed prior to
1454                  * having configured keys.
1455                  */
1456                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1457                              ieee80211_is_robust_mgmt_frame(
1458                                      (struct ieee80211_hdr *) rx->skb->data)))
1459                         return -EACCES;
1460         }
1461
1462         return 0;
1463 }
1464
1465 static int
1466 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1467 {
1468         struct ieee80211_sub_if_data *sdata = rx->sdata;
1469         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1470
1471         if (ieee80211_has_a4(hdr->frame_control) &&
1472             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1473                 return -1;
1474
1475         if (is_multicast_ether_addr(hdr->addr1) &&
1476             ((sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta) ||
1477              (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.use_4addr)))
1478                 return -1;
1479
1480         return ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1481 }
1482
1483 /*
1484  * requires that rx->skb is a frame with ethernet header
1485  */
1486 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1487 {
1488         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1489                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1490         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1491
1492         /*
1493          * Allow EAPOL frames to us/the PAE group address regardless
1494          * of whether the frame was encrypted or not.
1495          */
1496         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1497             (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1498              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1499                 return true;
1500
1501         if (ieee80211_802_1x_port_control(rx) ||
1502             ieee80211_drop_unencrypted(rx, fc))
1503                 return false;
1504
1505         return true;
1506 }
1507
1508 /*
1509  * requires that rx->skb is a frame with ethernet header
1510  */
1511 static void
1512 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1513 {
1514         struct ieee80211_sub_if_data *sdata = rx->sdata;
1515         struct net_device *dev = sdata->dev;
1516         struct sk_buff *skb, *xmit_skb;
1517         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1518         struct sta_info *dsta;
1519
1520         skb = rx->skb;
1521         xmit_skb = NULL;
1522
1523         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1524              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1525             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1526             (rx->flags & IEEE80211_RX_RA_MATCH) &&
1527             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1528                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1529                         /*
1530                          * send multicast frames both to higher layers in
1531                          * local net stack and back to the wireless medium
1532                          */
1533                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1534                         if (!xmit_skb && net_ratelimit())
1535                                 printk(KERN_DEBUG "%s: failed to clone "
1536                                        "multicast frame\n", dev->name);
1537                 } else {
1538                         dsta = sta_info_get(sdata, skb->data);
1539                         if (dsta) {
1540                                 /*
1541                                  * The destination station is associated to
1542                                  * this AP (in this VLAN), so send the frame
1543                                  * directly to it and do not pass it to local
1544                                  * net stack.
1545                                  */
1546                                 xmit_skb = skb;
1547                                 skb = NULL;
1548                         }
1549                 }
1550         }
1551
1552         if (skb) {
1553                 int align __maybe_unused;
1554
1555 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1556                 /*
1557                  * 'align' will only take the values 0 or 2 here
1558                  * since all frames are required to be aligned
1559                  * to 2-byte boundaries when being passed to
1560                  * mac80211. That also explains the __skb_push()
1561                  * below.
1562                  */
1563                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1564                 if (align) {
1565                         if (WARN_ON(skb_headroom(skb) < 3)) {
1566                                 dev_kfree_skb(skb);
1567                                 skb = NULL;
1568                         } else {
1569                                 u8 *data = skb->data;
1570                                 size_t len = skb_headlen(skb);
1571                                 skb->data -= align;
1572                                 memmove(skb->data, data, len);
1573                                 skb_set_tail_pointer(skb, len);
1574                         }
1575                 }
1576 #endif
1577
1578                 if (skb) {
1579                         /* deliver to local stack */
1580                         skb->protocol = eth_type_trans(skb, dev);
1581                         memset(skb->cb, 0, sizeof(skb->cb));
1582                         netif_receive_skb(skb);
1583                 }
1584         }
1585
1586         if (xmit_skb) {
1587                 /* send to wireless media */
1588                 xmit_skb->protocol = htons(ETH_P_802_3);
1589                 skb_reset_network_header(xmit_skb);
1590                 skb_reset_mac_header(xmit_skb);
1591                 dev_queue_xmit(xmit_skb);
1592         }
1593 }
1594
1595 static ieee80211_rx_result debug_noinline
1596 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1597 {
1598         struct net_device *dev = rx->sdata->dev;
1599         struct sk_buff *skb = rx->skb;
1600         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1601         __le16 fc = hdr->frame_control;
1602         struct sk_buff_head frame_list;
1603
1604         if (unlikely(!ieee80211_is_data(fc)))
1605                 return RX_CONTINUE;
1606
1607         if (unlikely(!ieee80211_is_data_present(fc)))
1608                 return RX_DROP_MONITOR;
1609
1610         if (!(rx->flags & IEEE80211_RX_AMSDU))
1611                 return RX_CONTINUE;
1612
1613         if (ieee80211_has_a4(hdr->frame_control) &&
1614             rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1615             !rx->sdata->u.vlan.sta)
1616                 return RX_DROP_UNUSABLE;
1617
1618         if (is_multicast_ether_addr(hdr->addr1) &&
1619             ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1620               rx->sdata->u.vlan.sta) ||
1621              (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1622               rx->sdata->u.mgd.use_4addr)))
1623                 return RX_DROP_UNUSABLE;
1624
1625         skb->dev = dev;
1626         __skb_queue_head_init(&frame_list);
1627
1628         if (skb_linearize(skb))
1629                 return RX_DROP_UNUSABLE;
1630
1631         ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1632                                  rx->sdata->vif.type,
1633                                  rx->local->hw.extra_tx_headroom);
1634
1635         while (!skb_queue_empty(&frame_list)) {
1636                 rx->skb = __skb_dequeue(&frame_list);
1637
1638                 if (!ieee80211_frame_allowed(rx, fc)) {
1639                         dev_kfree_skb(rx->skb);
1640                         continue;
1641                 }
1642                 dev->stats.rx_packets++;
1643                 dev->stats.rx_bytes += rx->skb->len;
1644
1645                 ieee80211_deliver_skb(rx);
1646         }
1647
1648         return RX_QUEUED;
1649 }
1650
1651 #ifdef CONFIG_MAC80211_MESH
1652 static ieee80211_rx_result
1653 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1654 {
1655         struct ieee80211_hdr *hdr;
1656         struct ieee80211s_hdr *mesh_hdr;
1657         unsigned int hdrlen;
1658         struct sk_buff *skb = rx->skb, *fwd_skb;
1659         struct ieee80211_local *local = rx->local;
1660         struct ieee80211_sub_if_data *sdata = rx->sdata;
1661
1662         hdr = (struct ieee80211_hdr *) skb->data;
1663         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1664         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1665
1666         if (!ieee80211_is_data(hdr->frame_control))
1667                 return RX_CONTINUE;
1668
1669         if (!mesh_hdr->ttl)
1670                 /* illegal frame */
1671                 return RX_DROP_MONITOR;
1672
1673         if (mesh_hdr->flags & MESH_FLAGS_AE) {
1674                 struct mesh_path *mppath;
1675                 char *proxied_addr;
1676                 char *mpp_addr;
1677
1678                 if (is_multicast_ether_addr(hdr->addr1)) {
1679                         mpp_addr = hdr->addr3;
1680                         proxied_addr = mesh_hdr->eaddr1;
1681                 } else {
1682                         mpp_addr = hdr->addr4;
1683                         proxied_addr = mesh_hdr->eaddr2;
1684                 }
1685
1686                 rcu_read_lock();
1687                 mppath = mpp_path_lookup(proxied_addr, sdata);
1688                 if (!mppath) {
1689                         mpp_path_add(proxied_addr, mpp_addr, sdata);
1690                 } else {
1691                         spin_lock_bh(&mppath->state_lock);
1692                         if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1693                                 memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1694                         spin_unlock_bh(&mppath->state_lock);
1695                 }
1696                 rcu_read_unlock();
1697         }
1698
1699         /* Frame has reached destination.  Don't forward */
1700         if (!is_multicast_ether_addr(hdr->addr1) &&
1701             compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1702                 return RX_CONTINUE;
1703
1704         mesh_hdr->ttl--;
1705
1706         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1707                 if (!mesh_hdr->ttl)
1708                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1709                                                      dropped_frames_ttl);
1710                 else {
1711                         struct ieee80211_hdr *fwd_hdr;
1712                         struct ieee80211_tx_info *info;
1713
1714                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1715
1716                         if (!fwd_skb && net_ratelimit())
1717                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1718                                                    sdata->name);
1719
1720                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1721                         memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1722                         info = IEEE80211_SKB_CB(fwd_skb);
1723                         memset(info, 0, sizeof(*info));
1724                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1725                         info->control.vif = &rx->sdata->vif;
1726                         skb_set_queue_mapping(skb,
1727                                 ieee80211_select_queue(rx->sdata, fwd_skb));
1728                         ieee80211_set_qos_hdr(local, skb);
1729                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1730                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1731                                                                 fwded_mcast);
1732                         else {
1733                                 int err;
1734                                 /*
1735                                  * Save TA to addr1 to send TA a path error if a
1736                                  * suitable next hop is not found
1737                                  */
1738                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1739                                                 ETH_ALEN);
1740                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1741                                 /* Failed to immediately resolve next hop:
1742                                  * fwded frame was dropped or will be added
1743                                  * later to the pending skb queue.  */
1744                                 if (err)
1745                                         return RX_DROP_MONITOR;
1746
1747                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1748                                                                 fwded_unicast);
1749                         }
1750                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1751                                                      fwded_frames);
1752                         ieee80211_add_pending_skb(local, fwd_skb);
1753                 }
1754         }
1755
1756         if (is_multicast_ether_addr(hdr->addr1) ||
1757             sdata->dev->flags & IFF_PROMISC)
1758                 return RX_CONTINUE;
1759         else
1760                 return RX_DROP_MONITOR;
1761 }
1762 #endif
1763
1764 static ieee80211_rx_result debug_noinline
1765 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1766 {
1767         struct ieee80211_sub_if_data *sdata = rx->sdata;
1768         struct ieee80211_local *local = rx->local;
1769         struct net_device *dev = sdata->dev;
1770         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1771         __le16 fc = hdr->frame_control;
1772         int err;
1773
1774         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1775                 return RX_CONTINUE;
1776
1777         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1778                 return RX_DROP_MONITOR;
1779
1780         /*
1781          * Allow the cooked monitor interface of an AP to see 4-addr frames so
1782          * that a 4-addr station can be detected and moved into a separate VLAN
1783          */
1784         if (ieee80211_has_a4(hdr->frame_control) &&
1785             sdata->vif.type == NL80211_IFTYPE_AP)
1786                 return RX_DROP_MONITOR;
1787
1788         err = __ieee80211_data_to_8023(rx);
1789         if (unlikely(err))
1790                 return RX_DROP_UNUSABLE;
1791
1792         if (!ieee80211_frame_allowed(rx, fc))
1793                 return RX_DROP_MONITOR;
1794
1795         rx->skb->dev = dev;
1796
1797         dev->stats.rx_packets++;
1798         dev->stats.rx_bytes += rx->skb->len;
1799
1800         if (ieee80211_is_data(hdr->frame_control) &&
1801             !is_multicast_ether_addr(hdr->addr1) &&
1802             local->hw.conf.dynamic_ps_timeout > 0 && local->ps_sdata) {
1803                         mod_timer(&local->dynamic_ps_timer, jiffies +
1804                          msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1805         }
1806
1807         ieee80211_deliver_skb(rx);
1808
1809         return RX_QUEUED;
1810 }
1811
1812 static ieee80211_rx_result debug_noinline
1813 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
1814 {
1815         struct ieee80211_local *local = rx->local;
1816         struct ieee80211_hw *hw = &local->hw;
1817         struct sk_buff *skb = rx->skb;
1818         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1819         struct tid_ampdu_rx *tid_agg_rx;
1820         u16 start_seq_num;
1821         u16 tid;
1822
1823         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1824                 return RX_CONTINUE;
1825
1826         if (ieee80211_is_back_req(bar->frame_control)) {
1827                 struct {
1828                         __le16 control, start_seq_num;
1829                 } __packed bar_data;
1830
1831                 if (!rx->sta)
1832                         return RX_DROP_MONITOR;
1833
1834                 if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
1835                                   &bar_data, sizeof(bar_data)))
1836                         return RX_DROP_MONITOR;
1837
1838                 tid = le16_to_cpu(bar_data.control) >> 12;
1839
1840                 tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
1841                 if (!tid_agg_rx)
1842                         return RX_DROP_MONITOR;
1843
1844                 start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
1845
1846                 /* reset session timer */
1847                 if (tid_agg_rx->timeout)
1848                         mod_timer(&tid_agg_rx->session_timer,
1849                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1850
1851                 /* release stored frames up to start of BAR */
1852                 ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num,
1853                                                  frames);
1854                 kfree_skb(skb);
1855                 return RX_QUEUED;
1856         }
1857
1858         /*
1859          * After this point, we only want management frames,
1860          * so we can drop all remaining control frames to
1861          * cooked monitor interfaces.
1862          */
1863         return RX_DROP_MONITOR;
1864 }
1865
1866 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1867                                            struct ieee80211_mgmt *mgmt,
1868                                            size_t len)
1869 {
1870         struct ieee80211_local *local = sdata->local;
1871         struct sk_buff *skb;
1872         struct ieee80211_mgmt *resp;
1873
1874         if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
1875                 /* Not to own unicast address */
1876                 return;
1877         }
1878
1879         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1880             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1881                 /* Not from the current AP or not associated yet. */
1882                 return;
1883         }
1884
1885         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1886                 /* Too short SA Query request frame */
1887                 return;
1888         }
1889
1890         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1891         if (skb == NULL)
1892                 return;
1893
1894         skb_reserve(skb, local->hw.extra_tx_headroom);
1895         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1896         memset(resp, 0, 24);
1897         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1898         memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
1899         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1900         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1901                                           IEEE80211_STYPE_ACTION);
1902         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1903         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1904         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1905         memcpy(resp->u.action.u.sa_query.trans_id,
1906                mgmt->u.action.u.sa_query.trans_id,
1907                WLAN_SA_QUERY_TR_ID_LEN);
1908
1909         ieee80211_tx_skb(sdata, skb);
1910 }
1911
1912 static ieee80211_rx_result debug_noinline
1913 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1914 {
1915         struct ieee80211_local *local = rx->local;
1916         struct ieee80211_sub_if_data *sdata = rx->sdata;
1917         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1918         struct sk_buff *nskb;
1919         struct ieee80211_rx_status *status;
1920         int len = rx->skb->len;
1921
1922         if (!ieee80211_is_action(mgmt->frame_control))
1923                 return RX_CONTINUE;
1924
1925         /* drop too small frames */
1926         if (len < IEEE80211_MIN_ACTION_SIZE)
1927                 return RX_DROP_UNUSABLE;
1928
1929         if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
1930                 return RX_DROP_UNUSABLE;
1931
1932         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1933                 return RX_DROP_UNUSABLE;
1934
1935         if (ieee80211_drop_unencrypted_mgmt(rx))
1936                 return RX_DROP_UNUSABLE;
1937
1938         switch (mgmt->u.action.category) {
1939         case WLAN_CATEGORY_BACK:
1940                 /*
1941                  * The aggregation code is not prepared to handle
1942                  * anything but STA/AP due to the BSSID handling;
1943                  * IBSS could work in the code but isn't supported
1944                  * by drivers or the standard.
1945                  */
1946                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1947                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1948                     sdata->vif.type != NL80211_IFTYPE_AP)
1949                         break;
1950
1951                 /* verify action_code is present */
1952                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1953                         break;
1954
1955                 switch (mgmt->u.action.u.addba_req.action_code) {
1956                 case WLAN_ACTION_ADDBA_REQ:
1957                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1958                                    sizeof(mgmt->u.action.u.addba_req)))
1959                                 goto invalid;
1960                         break;
1961                 case WLAN_ACTION_ADDBA_RESP:
1962                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1963                                    sizeof(mgmt->u.action.u.addba_resp)))
1964                                 goto invalid;
1965                         break;
1966                 case WLAN_ACTION_DELBA:
1967                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1968                                    sizeof(mgmt->u.action.u.delba)))
1969                                 goto invalid;
1970                         break;
1971                 default:
1972                         goto invalid;
1973                 }
1974
1975                 goto queue;
1976         case WLAN_CATEGORY_SPECTRUM_MGMT:
1977                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1978                         break;
1979
1980                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
1981                         break;
1982
1983                 /* verify action_code is present */
1984                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1985                         break;
1986
1987                 switch (mgmt->u.action.u.measurement.action_code) {
1988                 case WLAN_ACTION_SPCT_MSR_REQ:
1989                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1990                                    sizeof(mgmt->u.action.u.measurement)))
1991                                 break;
1992                         ieee80211_process_measurement_req(sdata, mgmt, len);
1993                         goto handled;
1994                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1995                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1996                                    sizeof(mgmt->u.action.u.chan_switch)))
1997                                 break;
1998
1999                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2000                                 break;
2001
2002                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
2003                                 break;
2004
2005                         goto queue;
2006                 }
2007                 break;
2008         case WLAN_CATEGORY_SA_QUERY:
2009                 if (len < (IEEE80211_MIN_ACTION_SIZE +
2010                            sizeof(mgmt->u.action.u.sa_query)))
2011                         break;
2012
2013                 switch (mgmt->u.action.u.sa_query.action) {
2014                 case WLAN_ACTION_SA_QUERY_REQUEST:
2015                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2016                                 break;
2017                         ieee80211_process_sa_query_req(sdata, mgmt, len);
2018                         goto handled;
2019                 }
2020                 break;
2021         case WLAN_CATEGORY_MESH_PLINK:
2022         case WLAN_CATEGORY_MESH_PATH_SEL:
2023                 if (!ieee80211_vif_is_mesh(&sdata->vif))
2024                         break;
2025                 goto queue;
2026         }
2027
2028  invalid:
2029         /*
2030          * For AP mode, hostapd is responsible for handling any action
2031          * frames that we didn't handle, including returning unknown
2032          * ones. For all other modes we will return them to the sender,
2033          * setting the 0x80 bit in the action category, as required by
2034          * 802.11-2007 7.3.1.11.
2035          */
2036         if (sdata->vif.type == NL80211_IFTYPE_AP ||
2037             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2038                 return RX_DROP_MONITOR;
2039
2040         /*
2041          * Getting here means the kernel doesn't know how to handle
2042          * it, but maybe userspace does ... include returned frames
2043          * so userspace can register for those to know whether ones
2044          * it transmitted were processed or returned.
2045          */
2046         status = IEEE80211_SKB_RXCB(rx->skb);
2047
2048         if (cfg80211_rx_action(rx->sdata->dev, status->freq,
2049                                rx->skb->data, rx->skb->len,
2050                                GFP_ATOMIC))
2051                 goto handled;
2052
2053         /* do not return rejected action frames */
2054         if (mgmt->u.action.category & 0x80)
2055                 return RX_DROP_UNUSABLE;
2056
2057         nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2058                                GFP_ATOMIC);
2059         if (nskb) {
2060                 struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2061
2062                 nmgmt->u.action.category |= 0x80;
2063                 memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2064                 memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2065
2066                 memset(nskb->cb, 0, sizeof(nskb->cb));
2067
2068                 ieee80211_tx_skb(rx->sdata, nskb);
2069         }
2070
2071  handled:
2072         if (rx->sta)
2073                 rx->sta->rx_packets++;
2074         dev_kfree_skb(rx->skb);
2075         return RX_QUEUED;
2076
2077  queue:
2078         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2079         skb_queue_tail(&sdata->skb_queue, rx->skb);
2080         ieee80211_queue_work(&local->hw, &sdata->work);
2081         if (rx->sta)
2082                 rx->sta->rx_packets++;
2083         return RX_QUEUED;
2084 }
2085
2086 static ieee80211_rx_result debug_noinline
2087 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2088 {
2089         struct ieee80211_sub_if_data *sdata = rx->sdata;
2090         ieee80211_rx_result rxs;
2091         struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2092         __le16 stype;
2093
2094         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
2095                 return RX_DROP_MONITOR;
2096
2097         if (rx->skb->len < 24)
2098                 return RX_DROP_MONITOR;
2099
2100         if (ieee80211_drop_unencrypted_mgmt(rx))
2101                 return RX_DROP_UNUSABLE;
2102
2103         rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2104         if (rxs != RX_CONTINUE)
2105                 return rxs;
2106
2107         stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2108
2109         if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2110             sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2111             sdata->vif.type != NL80211_IFTYPE_STATION)
2112                 return RX_DROP_MONITOR;
2113
2114         switch (stype) {
2115         case cpu_to_le16(IEEE80211_STYPE_BEACON):
2116         case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2117                 /* process for all: mesh, mlme, ibss */
2118                 break;
2119         case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2120         case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2121                 /* process only for station */
2122                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2123                         return RX_DROP_MONITOR;
2124                 break;
2125         case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2126         case cpu_to_le16(IEEE80211_STYPE_AUTH):
2127                 /* process only for ibss */
2128                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2129                         return RX_DROP_MONITOR;
2130                 break;
2131         default:
2132                 return RX_DROP_MONITOR;
2133         }
2134
2135         /* queue up frame and kick off work to process it */
2136         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2137         skb_queue_tail(&sdata->skb_queue, rx->skb);
2138         ieee80211_queue_work(&rx->local->hw, &sdata->work);
2139         if (rx->sta)
2140                 rx->sta->rx_packets++;
2141
2142         return RX_QUEUED;
2143 }
2144
2145 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
2146                                             struct ieee80211_rx_data *rx)
2147 {
2148         int keyidx;
2149         unsigned int hdrlen;
2150
2151         hdrlen = ieee80211_hdrlen(hdr->frame_control);
2152         if (rx->skb->len >= hdrlen + 4)
2153                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
2154         else
2155                 keyidx = -1;
2156
2157         if (!rx->sta) {
2158                 /*
2159                  * Some hardware seem to generate incorrect Michael MIC
2160                  * reports; ignore them to avoid triggering countermeasures.
2161                  */
2162                 return;
2163         }
2164
2165         if (!ieee80211_has_protected(hdr->frame_control))
2166                 return;
2167
2168         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
2169                 /*
2170                  * APs with pairwise keys should never receive Michael MIC
2171                  * errors for non-zero keyidx because these are reserved for
2172                  * group keys and only the AP is sending real multicast
2173                  * frames in the BSS.
2174                  */
2175                 return;
2176         }
2177
2178         if (!ieee80211_is_data(hdr->frame_control) &&
2179             !ieee80211_is_auth(hdr->frame_control))
2180                 return;
2181
2182         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
2183                                         GFP_ATOMIC);
2184 }
2185
2186 /* TODO: use IEEE80211_RX_FRAGMENTED */
2187 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2188                                         struct ieee80211_rate *rate)
2189 {
2190         struct ieee80211_sub_if_data *sdata;
2191         struct ieee80211_local *local = rx->local;
2192         struct ieee80211_rtap_hdr {
2193                 struct ieee80211_radiotap_header hdr;
2194                 u8 flags;
2195                 u8 rate_or_pad;
2196                 __le16 chan_freq;
2197                 __le16 chan_flags;
2198         } __packed *rthdr;
2199         struct sk_buff *skb = rx->skb, *skb2;
2200         struct net_device *prev_dev = NULL;
2201         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2202
2203         if (status->flag & RX_FLAG_INTERNAL_CMTR)
2204                 goto out_free_skb;
2205
2206         if (skb_headroom(skb) < sizeof(*rthdr) &&
2207             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2208                 goto out_free_skb;
2209
2210         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2211         memset(rthdr, 0, sizeof(*rthdr));
2212         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2213         rthdr->hdr.it_present =
2214                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2215                             (1 << IEEE80211_RADIOTAP_CHANNEL));
2216
2217         if (rate) {
2218                 rthdr->rate_or_pad = rate->bitrate / 5;
2219                 rthdr->hdr.it_present |=
2220                         cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2221         }
2222         rthdr->chan_freq = cpu_to_le16(status->freq);
2223
2224         if (status->band == IEEE80211_BAND_5GHZ)
2225                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2226                                                 IEEE80211_CHAN_5GHZ);
2227         else
2228                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2229                                                 IEEE80211_CHAN_2GHZ);
2230
2231         skb_set_mac_header(skb, 0);
2232         skb->ip_summed = CHECKSUM_UNNECESSARY;
2233         skb->pkt_type = PACKET_OTHERHOST;
2234         skb->protocol = htons(ETH_P_802_2);
2235
2236         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2237                 if (!ieee80211_sdata_running(sdata))
2238                         continue;
2239
2240                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2241                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2242                         continue;
2243
2244                 if (prev_dev) {
2245                         skb2 = skb_clone(skb, GFP_ATOMIC);
2246                         if (skb2) {
2247                                 skb2->dev = prev_dev;
2248                                 netif_receive_skb(skb2);
2249                         }
2250                 }
2251
2252                 prev_dev = sdata->dev;
2253                 sdata->dev->stats.rx_packets++;
2254                 sdata->dev->stats.rx_bytes += skb->len;
2255         }
2256
2257         if (prev_dev) {
2258                 skb->dev = prev_dev;
2259                 netif_receive_skb(skb);
2260                 skb = NULL;
2261         } else
2262                 goto out_free_skb;
2263
2264         status->flag |= RX_FLAG_INTERNAL_CMTR;
2265         return;
2266
2267  out_free_skb:
2268         dev_kfree_skb(skb);
2269 }
2270
2271 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2272                                          ieee80211_rx_result res)
2273 {
2274         switch (res) {
2275         case RX_DROP_MONITOR:
2276                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2277                 if (rx->sta)
2278                         rx->sta->rx_dropped++;
2279                 /* fall through */
2280         case RX_CONTINUE: {
2281                 struct ieee80211_rate *rate = NULL;
2282                 struct ieee80211_supported_band *sband;
2283                 struct ieee80211_rx_status *status;
2284
2285                 status = IEEE80211_SKB_RXCB((rx->skb));
2286
2287                 sband = rx->local->hw.wiphy->bands[status->band];
2288                 if (!(status->flag & RX_FLAG_HT))
2289                         rate = &sband->bitrates[status->rate_idx];
2290
2291                 ieee80211_rx_cooked_monitor(rx, rate);
2292                 break;
2293                 }
2294         case RX_DROP_UNUSABLE:
2295                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2296                 if (rx->sta)
2297                         rx->sta->rx_dropped++;
2298                 dev_kfree_skb(rx->skb);
2299                 break;
2300         case RX_QUEUED:
2301                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2302                 break;
2303         }
2304 }
2305
2306 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
2307                                   struct sk_buff_head *frames)
2308 {
2309         ieee80211_rx_result res = RX_DROP_MONITOR;
2310         struct sk_buff *skb;
2311
2312 #define CALL_RXH(rxh)                   \
2313         do {                            \
2314                 res = rxh(rx);          \
2315                 if (res != RX_CONTINUE) \
2316                         goto rxh_next;  \
2317         } while (0);
2318
2319         while ((skb = __skb_dequeue(frames))) {
2320                 /*
2321                  * all the other fields are valid across frames
2322                  * that belong to an aMPDU since they are on the
2323                  * same TID from the same station
2324                  */
2325                 rx->skb = skb;
2326
2327                 CALL_RXH(ieee80211_rx_h_decrypt)
2328                 CALL_RXH(ieee80211_rx_h_check_more_data)
2329                 CALL_RXH(ieee80211_rx_h_sta_process)
2330                 CALL_RXH(ieee80211_rx_h_defragment)
2331                 CALL_RXH(ieee80211_rx_h_ps_poll)
2332                 CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2333                 /* must be after MMIC verify so header is counted in MPDU mic */
2334                 CALL_RXH(ieee80211_rx_h_remove_qos_control)
2335                 CALL_RXH(ieee80211_rx_h_amsdu)
2336 #ifdef CONFIG_MAC80211_MESH
2337                 if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2338                         CALL_RXH(ieee80211_rx_h_mesh_fwding);
2339 #endif
2340                 CALL_RXH(ieee80211_rx_h_data)
2341
2342                 /* special treatment -- needs the queue */
2343                 res = ieee80211_rx_h_ctrl(rx, frames);
2344                 if (res != RX_CONTINUE)
2345                         goto rxh_next;
2346
2347                 CALL_RXH(ieee80211_rx_h_action)
2348                 CALL_RXH(ieee80211_rx_h_mgmt)
2349
2350  rxh_next:
2351                 ieee80211_rx_handlers_result(rx, res);
2352
2353 #undef CALL_RXH
2354         }
2355 }
2356
2357 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
2358                                          struct ieee80211_rx_data *rx,
2359                                          struct sk_buff *skb)
2360 {
2361         struct sk_buff_head reorder_release;
2362         ieee80211_rx_result res = RX_DROP_MONITOR;
2363
2364         __skb_queue_head_init(&reorder_release);
2365
2366         rx->skb = skb;
2367         rx->sdata = sdata;
2368
2369 #define CALL_RXH(rxh)                   \
2370         do {                            \
2371                 res = rxh(rx);          \
2372                 if (res != RX_CONTINUE) \
2373                         goto rxh_next;  \
2374         } while (0);
2375
2376         CALL_RXH(ieee80211_rx_h_passive_scan)
2377         CALL_RXH(ieee80211_rx_h_check)
2378
2379         ieee80211_rx_reorder_ampdu(rx, &reorder_release);
2380
2381         ieee80211_rx_handlers(rx, &reorder_release);
2382         return;
2383
2384  rxh_next:
2385         ieee80211_rx_handlers_result(rx, res);
2386
2387 #undef CALL_RXH
2388 }
2389
2390 /* main receive path */
2391
2392 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2393                                 struct ieee80211_rx_data *rx,
2394                                 struct ieee80211_hdr *hdr)
2395 {
2396         struct sk_buff *skb = rx->skb;
2397         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2398         u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2399         int multicast = is_multicast_ether_addr(hdr->addr1);
2400
2401         switch (sdata->vif.type) {
2402         case NL80211_IFTYPE_STATION:
2403                 if (!bssid && !sdata->u.mgd.use_4addr)
2404                         return 0;
2405                 if (!multicast &&
2406                     compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2407                         if (!(sdata->dev->flags & IFF_PROMISC))
2408                                 return 0;
2409                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2410                 }
2411                 break;
2412         case NL80211_IFTYPE_ADHOC:
2413                 if (!bssid)
2414                         return 0;
2415                 if (ieee80211_is_beacon(hdr->frame_control)) {
2416                         return 1;
2417                 }
2418                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2419                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2420                                 return 0;
2421                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2422                 } else if (!multicast &&
2423                            compare_ether_addr(sdata->vif.addr,
2424                                               hdr->addr1) != 0) {
2425                         if (!(sdata->dev->flags & IFF_PROMISC))
2426                                 return 0;
2427                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2428                 } else if (!rx->sta) {
2429                         int rate_idx;
2430                         if (status->flag & RX_FLAG_HT)
2431                                 rate_idx = 0; /* TODO: HT rates */
2432                         else
2433                                 rate_idx = status->rate_idx;
2434                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
2435                                         hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
2436                 }
2437                 break;
2438         case NL80211_IFTYPE_MESH_POINT:
2439                 if (!multicast &&
2440                     compare_ether_addr(sdata->vif.addr,
2441                                        hdr->addr1) != 0) {
2442                         if (!(sdata->dev->flags & IFF_PROMISC))
2443                                 return 0;
2444
2445                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2446                 }
2447                 break;
2448         case NL80211_IFTYPE_AP_VLAN:
2449         case NL80211_IFTYPE_AP:
2450                 if (!bssid) {
2451                         if (compare_ether_addr(sdata->vif.addr,
2452                                                hdr->addr1))
2453                                 return 0;
2454                 } else if (!ieee80211_bssid_match(bssid,
2455                                         sdata->vif.addr)) {
2456                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2457                                 return 0;
2458                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2459                 }
2460                 break;
2461         case NL80211_IFTYPE_WDS:
2462                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2463                         return 0;
2464                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2465                         return 0;
2466                 break;
2467         case NL80211_IFTYPE_MONITOR:
2468         case NL80211_IFTYPE_UNSPECIFIED:
2469         case __NL80211_IFTYPE_AFTER_LAST:
2470                 /* should never get here */
2471                 WARN_ON(1);
2472                 break;
2473         }
2474
2475         return 1;
2476 }
2477
2478 /*
2479  * This is the actual Rx frames handler. as it blongs to Rx path it must
2480  * be called with rcu_read_lock protection.
2481  */
2482 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2483                                          struct sk_buff *skb)
2484 {
2485         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2486         struct ieee80211_local *local = hw_to_local(hw);
2487         struct ieee80211_sub_if_data *sdata;
2488         struct ieee80211_hdr *hdr;
2489         __le16 fc;
2490         struct ieee80211_rx_data rx;
2491         int prepares;
2492         struct ieee80211_sub_if_data *prev = NULL;
2493         struct sk_buff *skb_new;
2494         struct sta_info *sta, *tmp;
2495         bool found_sta = false;
2496         int err = 0;
2497
2498         fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
2499         memset(&rx, 0, sizeof(rx));
2500         rx.skb = skb;
2501         rx.local = local;
2502
2503         if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
2504                 local->dot11ReceivedFragmentCount++;
2505
2506         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2507                      test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2508                 rx.flags |= IEEE80211_RX_IN_SCAN;
2509
2510         if (ieee80211_is_mgmt(fc))
2511                 err = skb_linearize(skb);
2512         else
2513                 err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
2514
2515         if (err) {
2516                 dev_kfree_skb(skb);
2517                 return;
2518         }
2519
2520         hdr = (struct ieee80211_hdr *)skb->data;
2521         ieee80211_parse_qos(&rx);
2522         ieee80211_verify_alignment(&rx);
2523
2524         if (ieee80211_is_data(fc)) {
2525                 for_each_sta_info(local, hdr->addr2, sta, tmp) {
2526                         rx.sta = sta;
2527                         found_sta = true;
2528                         rx.sdata = sta->sdata;
2529
2530                         rx.flags |= IEEE80211_RX_RA_MATCH;
2531                         prepares = prepare_for_handlers(rx.sdata, &rx, hdr);
2532                         if (prepares) {
2533                                 if (status->flag & RX_FLAG_MMIC_ERROR) {
2534                                         if (rx.flags & IEEE80211_RX_RA_MATCH)
2535                                                 ieee80211_rx_michael_mic_report(hdr, &rx);
2536                                 } else
2537                                         prev = rx.sdata;
2538                         }
2539                 }
2540         }
2541         if (!found_sta) {
2542                 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2543                         if (!ieee80211_sdata_running(sdata))
2544                                 continue;
2545
2546                         if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2547                             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2548                                 continue;
2549
2550                         /*
2551                          * frame is destined for this interface, but if it's
2552                          * not also for the previous one we handle that after
2553                          * the loop to avoid copying the SKB once too much
2554                          */
2555
2556                         if (!prev) {
2557                                 prev = sdata;
2558                                 continue;
2559                         }
2560
2561                         rx.sta = sta_info_get_bss(prev, hdr->addr2);
2562
2563                         rx.flags |= IEEE80211_RX_RA_MATCH;
2564                         prepares = prepare_for_handlers(prev, &rx, hdr);
2565
2566                         if (!prepares)
2567                                 goto next;
2568
2569                         if (status->flag & RX_FLAG_MMIC_ERROR) {
2570                                 rx.sdata = prev;
2571                                 if (rx.flags & IEEE80211_RX_RA_MATCH)
2572                                         ieee80211_rx_michael_mic_report(hdr,
2573                                                                         &rx);
2574                                 goto next;
2575                         }
2576
2577                         /*
2578                          * frame was destined for the previous interface
2579                          * so invoke RX handlers for it
2580                          */
2581
2582                         skb_new = skb_copy(skb, GFP_ATOMIC);
2583                         if (!skb_new) {
2584                                 if (net_ratelimit())
2585                                         printk(KERN_DEBUG "%s: failed to copy "
2586                                                "multicast frame for %s\n",
2587                                                wiphy_name(local->hw.wiphy),
2588                                                prev->name);
2589                                 goto next;
2590                         }
2591                         ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
2592 next:
2593                         prev = sdata;
2594                 }
2595
2596                 if (prev) {
2597                         rx.sta = sta_info_get_bss(prev, hdr->addr2);
2598
2599                         rx.flags |= IEEE80211_RX_RA_MATCH;
2600                         prepares = prepare_for_handlers(prev, &rx, hdr);
2601
2602                         if (!prepares)
2603                                 prev = NULL;
2604                 }
2605         }
2606         if (prev)
2607                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
2608         else
2609                 dev_kfree_skb(skb);
2610 }
2611
2612 /*
2613  * This is the receive path handler. It is called by a low level driver when an
2614  * 802.11 MPDU is received from the hardware.
2615  */
2616 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2617 {
2618         struct ieee80211_local *local = hw_to_local(hw);
2619         struct ieee80211_rate *rate = NULL;
2620         struct ieee80211_supported_band *sband;
2621         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2622
2623         WARN_ON_ONCE(softirq_count() == 0);
2624
2625         if (WARN_ON(status->band < 0 ||
2626                     status->band >= IEEE80211_NUM_BANDS))
2627                 goto drop;
2628
2629         sband = local->hw.wiphy->bands[status->band];
2630         if (WARN_ON(!sband))
2631                 goto drop;
2632
2633         /*
2634          * If we're suspending, it is possible although not too likely
2635          * that we'd be receiving frames after having already partially
2636          * quiesced the stack. We can't process such frames then since
2637          * that might, for example, cause stations to be added or other
2638          * driver callbacks be invoked.
2639          */
2640         if (unlikely(local->quiescing || local->suspended))
2641                 goto drop;
2642
2643         /*
2644          * The same happens when we're not even started,
2645          * but that's worth a warning.
2646          */
2647         if (WARN_ON(!local->started))
2648                 goto drop;
2649
2650         if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
2651                 /*
2652                  * Validate the rate, unless a PLCP error means that
2653                  * we probably can't have a valid rate here anyway.
2654                  */
2655
2656                 if (status->flag & RX_FLAG_HT) {
2657                         /*
2658                          * rate_idx is MCS index, which can be [0-76]
2659                          * as documented on:
2660                          *
2661                          * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2662                          *
2663                          * Anything else would be some sort of driver or
2664                          * hardware error. The driver should catch hardware
2665                          * errors.
2666                          */
2667                         if (WARN((status->rate_idx < 0 ||
2668                                  status->rate_idx > 76),
2669                                  "Rate marked as an HT rate but passed "
2670                                  "status->rate_idx is not "
2671                                  "an MCS index [0-76]: %d (0x%02x)\n",
2672                                  status->rate_idx,
2673                                  status->rate_idx))
2674                                 goto drop;
2675                 } else {
2676                         if (WARN_ON(status->rate_idx < 0 ||
2677                                     status->rate_idx >= sband->n_bitrates))
2678                                 goto drop;
2679                         rate = &sband->bitrates[status->rate_idx];
2680                 }
2681         }
2682
2683         /*
2684          * key references and virtual interfaces are protected using RCU
2685          * and this requires that we are in a read-side RCU section during
2686          * receive processing
2687          */
2688         rcu_read_lock();
2689
2690         /*
2691          * Frames with failed FCS/PLCP checksum are not returned,
2692          * all other frames are returned without radiotap header
2693          * if it was previously present.
2694          * Also, frames with less than 16 bytes are dropped.
2695          */
2696         skb = ieee80211_rx_monitor(local, skb, rate);
2697         if (!skb) {
2698                 rcu_read_unlock();
2699                 return;
2700         }
2701
2702         __ieee80211_rx_handle_packet(hw, skb);
2703
2704         rcu_read_unlock();
2705
2706         return;
2707  drop:
2708         kfree_skb(skb);
2709 }
2710 EXPORT_SYMBOL(ieee80211_rx);
2711
2712 /* This is a version of the rx handler that can be called from hard irq
2713  * context. Post the skb on the queue and schedule the tasklet */
2714 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2715 {
2716         struct ieee80211_local *local = hw_to_local(hw);
2717
2718         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2719
2720         skb->pkt_type = IEEE80211_RX_MSG;
2721         skb_queue_tail(&local->skb_queue, skb);
2722         tasklet_schedule(&local->tasklet);
2723 }
2724 EXPORT_SYMBOL(ieee80211_rx_irqsafe);