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         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 319         int tid;
 320
 321         /* does the frame have a qos control field? */
 322         if (ieee80211_is_data_qos(hdr->frame_control)) {
 323                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 324                 /* frame has qos control */
 325                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 326                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 327                         status->rx_flags |= IEEE80211_RX_AMSDU;
 328         } else {
 329                 /*
 330                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 331                  *
 332                  *      Sequence numbers for management frames, QoS data
 333                  *      frames with a broadcast/multicast address in the
 334                  *      Address 1 field, and all non-QoS data frames sent
 335                  *      by QoS STAs are assigned using an additional single
 336                  *      modulo-4096 counter, [...]
 337                  *
 338                  * We also use that counter for non-QoS STAs.
 339                  */
 340                 tid = NUM_RX_DATA_QUEUES - 1;
 341         }
 342
 343         rx->queue = tid;
 344         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 345          * For now, set skb->priority to 0 for other cases. */
 346         rx->skb->priority = (tid > 7) ? 0 : tid;
 347 }
 348
 349 /**
 350  * DOC: Packet alignment
 351  *
 352  * Drivers always need to pass packets that are aligned to two-byte boundaries
 353  * to the stack.
 354  *
 355  * Additionally, should, if possible, align the payload data in a way that
 356  * guarantees that the contained IP header is aligned to a four-byte
 357  * boundary. In the case of regular frames, this simply means aligning the
 358  * payload to a four-byte boundary (because either the IP header is directly
 359  * contained, or IV/RFC1042 headers that have a length divisible by four are
 360  * in front of it).  If the payload data is not properly aligned and the
 361  * architecture doesn't support efficient unaligned operations, mac80211
 362  * will align the data.
 363  *
 364  * With A-MSDU frames, however, the payload data address must yield two modulo
 365  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 366  * push the IP header further back to a multiple of four again. Thankfully, the
 367  * specs were sane enough this time around to require padding each A-MSDU
 368  * subframe to a length that is a multiple of four.
 369  *
 370  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
 371  * the payload is not supported, the driver is required to move the 802.11
 372  * header to be directly in front of the payload in that case.
 373  */
 374 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 375 {
 376 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 377         WARN_ONCE((unsigned long)rx->skb->data & 1,
 378                   "unaligned packet at 0x%p\n", rx->skb->data);
 379 #endif
 380 }
 381
 382
 383 /* rx handlers */
 384
 385 static ieee80211_rx_result debug_noinline
 386 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 387 {
 388         struct ieee80211_local *local = rx->local;
 389         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 390         struct sk_buff *skb = rx->skb;
 391
 392         if (likely(!(status->rx_flags & IEEE80211_RX_IN_SCAN)))
 393                 return RX_CONTINUE;
 394
 395         if (test_bit(SCAN_HW_SCANNING, &local->scanning))
 396                 return ieee80211_scan_rx(rx->sdata, skb);
 397
 398         if (test_bit(SCAN_SW_SCANNING, &local->scanning)) {
 399                 /* drop all the other packets during a software scan anyway */
 400                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
 401                         dev_kfree_skb(skb);
 402                 return RX_QUEUED;
 403         }
 404
 405         /* scanning finished during invoking of handlers */
 406         I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 407         return RX_DROP_UNUSABLE;
 408 }
 409
 410
 411 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 412 {
 413         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 414
 415         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 416                 return 0;
 417
 418         return ieee80211_is_robust_mgmt_frame(hdr);
 419 }
 420
 421
 422 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 423 {
 424         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 425
 426         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 427                 return 0;
 428
 429         return ieee80211_is_robust_mgmt_frame(hdr);
 430 }
 431
 432
 433 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 434 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 435 {
 436         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 437         struct ieee80211_mmie *mmie;
 438
 439         if (skb->len < 24 + sizeof(*mmie) ||
 440             !is_multicast_ether_addr(hdr->da))
 441                 return -1;
 442
 443         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 444                 return -1; /* not a robust management frame */
 445
 446         mmie = (struct ieee80211_mmie *)
 447                 (skb->data + skb->len - sizeof(*mmie));
 448         if (mmie->element_id != WLAN_EID_MMIE ||
 449             mmie->length != sizeof(*mmie) - 2)
 450                 return -1;
 451
 452         return le16_to_cpu(mmie->key_id);
 453 }
 454
 455
 456 static ieee80211_rx_result
 457 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 458 {
 459         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 460         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 461         char *dev_addr = rx->sdata->vif.addr;
 462
 463         if (ieee80211_is_data(hdr->frame_control)) {
 464                 if (is_multicast_ether_addr(hdr->addr1)) {
 465                         if (ieee80211_has_tods(hdr->frame_control) ||
 466                                 !ieee80211_has_fromds(hdr->frame_control))
 467                                 return RX_DROP_MONITOR;
 468                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
 469                                 return RX_DROP_MONITOR;
 470                 } else {
 471                         if (!ieee80211_has_a4(hdr->frame_control))
 472                                 return RX_DROP_MONITOR;
 473                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
 474                                 return RX_DROP_MONITOR;
 475                 }
 476         }
 477
 478         /* If there is not an established peer link and this is not a peer link
 479          * establisment frame, beacon or probe, drop the frame.
 480          */
 481
 482         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 483                 struct ieee80211_mgmt *mgmt;
 484
 485                 if (!ieee80211_is_mgmt(hdr->frame_control))
 486                         return RX_DROP_MONITOR;
 487
 488                 if (ieee80211_is_action(hdr->frame_control)) {
 489                         mgmt = (struct ieee80211_mgmt *)hdr;
 490                         if (mgmt->u.action.category != WLAN_CATEGORY_MESH_PLINK)
 491                                 return RX_DROP_MONITOR;
 492                         return RX_CONTINUE;
 493                 }
 494
 495                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 496                     ieee80211_is_probe_resp(hdr->frame_control) ||
 497                     ieee80211_is_beacon(hdr->frame_control))
 498                         return RX_CONTINUE;
 499
 500                 return RX_DROP_MONITOR;
 501
 502         }
 503
 504 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 505
 506         if (ieee80211_is_data(hdr->frame_control) &&
 507             is_multicast_ether_addr(hdr->addr1) &&
 508             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
 509                 return RX_DROP_MONITOR;
 510 #undef msh_h_get
 511
 512         return RX_CONTINUE;
 513 }
 514
 515 #define SEQ_MODULO 0x1000
 516 #define SEQ_MASK   0xfff
 517
 518 static inline int seq_less(u16 sq1, u16 sq2)
 519 {
 520         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
 521 }
 522
 523 static inline u16 seq_inc(u16 sq)
 524 {
 525         return (sq + 1) & SEQ_MASK;
 526 }
 527
 528 static inline u16 seq_sub(u16 sq1, u16 sq2)
 529 {
 530         return (sq1 - sq2) & SEQ_MASK;
 531 }
 532
 533
 534 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
 535                                             struct tid_ampdu_rx *tid_agg_rx,
 536                                             int index,
 537                                             struct sk_buff_head *frames)
 538 {
 539         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
 540
 541         if (!skb)
 542                 goto no_frame;
 543
 544         /* release the frame from the reorder ring buffer */
 545         tid_agg_rx->stored_mpdu_num--;
 546         tid_agg_rx->reorder_buf[index] = NULL;
 547         __skb_queue_tail(frames, skb);
 548
 549 no_frame:
 550         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 551 }
 552
 553 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
 554                                              struct tid_ampdu_rx *tid_agg_rx,
 555                                              u16 head_seq_num,
 556                                              struct sk_buff_head *frames)
 557 {
 558         int index;
 559
 560         while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
 561                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 562                                                         tid_agg_rx->buf_size;
 563                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
 564         }
 565 }
 566
 567 /*
 568  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
 569  * the skb was added to the buffer longer than this time ago, the earlier
 570  * frames that have not yet been received are assumed to be lost and the skb
 571  * can be released for processing. This may also release other skb's from the
 572  * reorder buffer if there are no additional gaps between the frames.
 573  *
 574  * Callers must hold tid_agg_rx->reorder_lock.
 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, j;
 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 skipped = 1;
 594                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
 595                      j = (j + 1) % tid_agg_rx->buf_size) {
 596                         if (!tid_agg_rx->reorder_buf[j]) {
 597                                 skipped++;
 598                                 continue;
 599                         }
 600                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
 601                                         HT_RX_REORDER_BUF_TIMEOUT))
 602                                 goto set_release_timer;
 603
 604 #ifdef CONFIG_MAC80211_HT_DEBUG
 605                         if (net_ratelimit())
 606                                 wiphy_debug(hw->wiphy,
 607                                             "release an RX reorder frame due to timeout on earlier frames\n");
 608 #endif
 609                         ieee80211_release_reorder_frame(hw, tid_agg_rx,
 610                                                         j, frames);
 611
 612                         /*
 613                          * Increment the head seq# also for the skipped slots.
 614                          */
 615                         tid_agg_rx->head_seq_num =
 616                                 (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
 617                         skipped = 0;
 618                 }
 619         } else while (tid_agg_rx->reorder_buf[index]) {
 620                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
 621                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 622                                                         tid_agg_rx->buf_size;
 623         }
 624
 625         if (tid_agg_rx->stored_mpdu_num) {
 626                 j = index = seq_sub(tid_agg_rx->head_seq_num,
 627                                     tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 628
 629                 for (; j != (index - 1) % tid_agg_rx->buf_size;
 630                      j = (j + 1) % tid_agg_rx->buf_size) {
 631                         if (tid_agg_rx->reorder_buf[j])
 632                                 break;
 633                 }
 634
 635  set_release_timer:
 636
 637                 mod_timer(&tid_agg_rx->reorder_timer,
 638                           tid_agg_rx->reorder_time[j] +
 639                           HT_RX_REORDER_BUF_TIMEOUT);
 640         } else {
 641                 del_timer(&tid_agg_rx->reorder_timer);
 642         }
 643 }
 644
 645 /*
 646  * As this function belongs to the RX path it must be under
 647  * rcu_read_lock protection. It returns false if the frame
 648  * can be processed immediately, true if it was consumed.
 649  */
 650 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
 651                                              struct tid_ampdu_rx *tid_agg_rx,
 652                                              struct sk_buff *skb,
 653                                              struct sk_buff_head *frames)
 654 {
 655         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 656         u16 sc = le16_to_cpu(hdr->seq_ctrl);
 657         u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
 658         u16 head_seq_num, buf_size;
 659         int index;
 660         bool ret = true;
 661
 662         buf_size = tid_agg_rx->buf_size;
 663         head_seq_num = tid_agg_rx->head_seq_num;
 664
 665         spin_lock(&tid_agg_rx->reorder_lock);
 666         /* frame with out of date sequence number */
 667         if (seq_less(mpdu_seq_num, head_seq_num)) {
 668                 dev_kfree_skb(skb);
 669                 goto out;
 670         }
 671
 672         /*
 673          * If frame the sequence number exceeds our buffering window
 674          * size release some previous frames to make room for this one.
 675          */
 676         if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
 677                 head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
 678                 /* release stored frames up to new head to stack */
 679                 ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num,
 680                                                  frames);
 681         }
 682
 683         /* Now the new frame is always in the range of the reordering buffer */
 684
 685         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 686
 687         /* check if we already stored this frame */
 688         if (tid_agg_rx->reorder_buf[index]) {
 689                 dev_kfree_skb(skb);
 690                 goto out;
 691         }
 692
 693         /*
 694          * If the current MPDU is in the right order and nothing else
 695          * is stored we can process it directly, no need to buffer it.
 696          */
 697         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
 698             tid_agg_rx->stored_mpdu_num == 0) {
 699                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 700                 ret = false;
 701                 goto out;
 702         }
 703
 704         /* put the frame in the reordering buffer */
 705         tid_agg_rx->reorder_buf[index] = skb;
 706         tid_agg_rx->reorder_time[index] = jiffies;
 707         tid_agg_rx->stored_mpdu_num++;
 708         ieee80211_sta_reorder_release(hw, tid_agg_rx, frames);
 709
 710  out:
 711         spin_unlock(&tid_agg_rx->reorder_lock);
 712         return ret;
 713 }
 714
 715 /*
 716  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
 717  * true if the MPDU was buffered, false if it should be processed.
 718  */
 719 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
 720                                        struct sk_buff_head *frames)
 721 {
 722         struct sk_buff *skb = rx->skb;
 723         struct ieee80211_local *local = rx->local;
 724         struct ieee80211_hw *hw = &local->hw;
 725         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 726         struct sta_info *sta = rx->sta;
 727         struct tid_ampdu_rx *tid_agg_rx;
 728         u16 sc;
 729         int tid;
 730
 731         if (!ieee80211_is_data_qos(hdr->frame_control))
 732                 goto dont_reorder;
 733
 734         /*
 735          * filter the QoS data rx stream according to
 736          * STA/TID and check if this STA/TID is on aggregation
 737          */
 738
 739         if (!sta)
 740                 goto dont_reorder;
 741
 742         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 743
 744         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 745         if (!tid_agg_rx)
 746                 goto dont_reorder;
 747
 748         /* qos null data frames are excluded */
 749         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
 750                 goto dont_reorder;
 751
 752         /* new, potentially un-ordered, ampdu frame - process it */
 753
 754         /* reset session timer */
 755         if (tid_agg_rx->timeout)
 756                 mod_timer(&tid_agg_rx->session_timer,
 757                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
 758
 759         /* if this mpdu is fragmented - terminate rx aggregation session */
 760         sc = le16_to_cpu(hdr->seq_ctrl);
 761         if (sc & IEEE80211_SCTL_FRAG) {
 762                 skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
 763                 skb_queue_tail(&rx->sdata->skb_queue, skb);
 764                 ieee80211_queue_work(&local->hw, &rx->sdata->work);
 765                 return;
 766         }
 767
 768         /*
 769          * No locking needed -- we will only ever process one
 770          * RX packet at a time, and thus own tid_agg_rx. All
 771          * other code manipulating it needs to (and does) make
 772          * sure that we cannot get to it any more before doing
 773          * anything with it.
 774          */
 775         if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, frames))
 776                 return;
 777
 778  dont_reorder:
 779         __skb_queue_tail(frames, skb);
 780 }
 781
 782 static ieee80211_rx_result debug_noinline
 783 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 784 {
 785         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 786         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 787
 788         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 789         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 790                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 791                              rx->sta->last_seq_ctrl[rx->queue] ==
 792                              hdr->seq_ctrl)) {
 793                         if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
 794                                 rx->local->dot11FrameDuplicateCount++;
 795                                 rx->sta->num_duplicates++;
 796                         }
 797                         return RX_DROP_MONITOR;
 798                 } else
 799                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 800         }
 801
 802         if (unlikely(rx->skb->len < 16)) {
 803                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 804                 return RX_DROP_MONITOR;
 805         }
 806
 807         /* Drop disallowed frame classes based on STA auth/assoc state;
 808          * IEEE 802.11, Chap 5.5.
 809          *
 810          * mac80211 filters only based on association state, i.e. it drops
 811          * Class 3 frames from not associated stations. hostapd sends
 812          * deauth/disassoc frames when needed. In addition, hostapd is
 813          * responsible for filtering on both auth and assoc states.
 814          */
 815
 816         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 817                 return ieee80211_rx_mesh_check(rx);
 818
 819         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 820                       ieee80211_is_pspoll(hdr->frame_control)) &&
 821                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 822                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 823                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 824                      !ieee80211_has_tods(hdr->frame_control) &&
 825                      ieee80211_is_data(hdr->frame_control)) ||
 826                     !(status->rx_flags & IEEE80211_RX_RA_MATCH)) {
 827                         /* Drop IBSS frames and frames for other hosts
 828                          * silently. */
 829                         return RX_DROP_MONITOR;
 830                 }
 831
 832                 return RX_DROP_MONITOR;
 833         }
 834
 835         return RX_CONTINUE;
 836 }
 837
 838
 839 static ieee80211_rx_result debug_noinline
 840 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 841 {
 842         struct sk_buff *skb = rx->skb;
 843         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 844         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 845         int keyidx;
 846         int hdrlen;
 847         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 848         struct ieee80211_key *stakey = NULL;
 849         int mmie_keyidx = -1;
 850         __le16 fc;
 851
 852         /*
 853          * Key selection 101
 854          *
 855          * There are four types of keys:
 856          *  - GTK (group keys)
 857          *  - IGTK (group keys for management frames)
 858          *  - PTK (pairwise keys)
 859          *  - STK (station-to-station pairwise keys)
 860          *
 861          * When selecting a key, we have to distinguish between multicast
 862          * (including broadcast) and unicast frames, the latter can only
 863          * use PTKs and STKs while the former always use GTKs and IGTKs.
 864          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 865          * unicast frames can also use key indices like GTKs. Hence, if we
 866          * don't have a PTK/STK we check the key index for a WEP key.
 867          *
 868          * Note that in a regular BSS, multicast frames are sent by the
 869          * AP only, associated stations unicast the frame to the AP first
 870          * which then multicasts it on their behalf.
 871          *
 872          * There is also a slight problem in IBSS mode: GTKs are negotiated
 873          * with each station, that is something we don't currently handle.
 874          * The spec seems to expect that one negotiates the same key with
 875          * every station but there's no such requirement; VLANs could be
 876          * possible.
 877          */
 878
 879         /*
 880          * No point in finding a key and decrypting if the frame is neither
 881          * addressed to us nor a multicast frame.
 882          */
 883         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
 884                 return RX_CONTINUE;
 885
 886         /* start without a key */
 887         rx->key = NULL;
 888
 889         if (rx->sta)
 890                 stakey = rcu_dereference(rx->sta->key);
 891
 892         fc = hdr->frame_control;
 893
 894         if (!ieee80211_has_protected(fc))
 895                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 896
 897         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 898                 rx->key = stakey;
 899                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 900                     (status->flag & RX_FLAG_IV_STRIPPED))
 901                         return RX_CONTINUE;
 902                 /* Skip decryption if the frame is not protected. */
 903                 if (!ieee80211_has_protected(fc))
 904                         return RX_CONTINUE;
 905         } else if (mmie_keyidx >= 0) {
 906                 /* Broadcast/multicast robust management frame / BIP */
 907                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 908                     (status->flag & RX_FLAG_IV_STRIPPED))
 909                         return RX_CONTINUE;
 910
 911                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 912                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 913                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 914                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 915         } else if (!ieee80211_has_protected(fc)) {
 916                 /*
 917                  * The frame was not protected, so skip decryption. However, we
 918                  * need to set rx->key if there is a key that could have been
 919                  * used so that the frame may be dropped if encryption would
 920                  * have been expected.
 921                  */
 922                 struct ieee80211_key *key = NULL;
 923                 if (ieee80211_is_mgmt(fc) &&
 924                     is_multicast_ether_addr(hdr->addr1) &&
 925                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 926                         rx->key = key;
 927                 else if ((key = rcu_dereference(rx->sdata->default_key)))
 928                         rx->key = key;
 929                 return RX_CONTINUE;
 930         } else {
 931                 u8 keyid;
 932                 /*
 933                  * The device doesn't give us the IV so we won't be
 934                  * able to look up the key. That's ok though, we
 935                  * don't need to decrypt the frame, we just won't
 936                  * be able to keep statistics accurate.
 937                  * Except for key threshold notifications, should
 938                  * we somehow allow the driver to tell us which key
 939                  * the hardware used if this flag is set?
 940                  */
 941                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 942                     (status->flag & RX_FLAG_IV_STRIPPED))
 943                         return RX_CONTINUE;
 944
 945                 hdrlen = ieee80211_hdrlen(fc);
 946
 947                 if (rx->skb->len < 8 + hdrlen)
 948                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 949
 950                 /*
 951                  * no need to call ieee80211_wep_get_keyidx,
 952                  * it verifies a bunch of things we've done already
 953                  */
 954                 skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
 955                 keyidx = keyid >> 6;
 956
 957                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 958
 959                 /*
 960                  * RSNA-protected unicast frames should always be sent with
 961                  * pairwise or station-to-station keys, but for WEP we allow
 962                  * using a key index as well.
 963                  */
 964                 if (rx->key && rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
 965                     rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
 966                     !is_multicast_ether_addr(hdr->addr1))
 967                         rx->key = NULL;
 968         }
 969
 970         if (rx->key) {
 971                 rx->key->tx_rx_count++;
 972                 /* TODO: add threshold stuff again */
 973         } else {
 974                 return RX_DROP_MONITOR;
 975         }
 976
 977         if (skb_linearize(rx->skb))
 978                 return RX_DROP_UNUSABLE;
 979         /* the hdr variable is invalid now! */
 980
 981         switch (rx->key->conf.cipher) {
 982         case WLAN_CIPHER_SUITE_WEP40:
 983         case WLAN_CIPHER_SUITE_WEP104:
 984                 /* Check for weak IVs if possible */
 985                 if (rx->sta && ieee80211_is_data(fc) &&
 986                     (!(status->flag & RX_FLAG_IV_STRIPPED) ||
 987                      !(status->flag & RX_FLAG_DECRYPTED)) &&
 988                     ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 989                         rx->sta->wep_weak_iv_count++;
 990
 991                 result = ieee80211_crypto_wep_decrypt(rx);
 992                 break;
 993         case WLAN_CIPHER_SUITE_TKIP:
 994                 result = ieee80211_crypto_tkip_decrypt(rx);
 995                 break;
 996         case WLAN_CIPHER_SUITE_CCMP:
 997                 result = ieee80211_crypto_ccmp_decrypt(rx);
 998                 break;
 999         case WLAN_CIPHER_SUITE_AES_CMAC:
1000                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
1001                 break;
1002         default:
1003                 /*
1004                  * We can reach here only with HW-only algorithms
1005                  * but why didn't it decrypt the frame?!
1006                  */
1007                 return RX_DROP_UNUSABLE;
1008         }
1009
1010         /* either the frame has been decrypted or will be dropped */
1011         status->flag |= RX_FLAG_DECRYPTED;
1012
1013         return result;
1014 }
1015
1016 static ieee80211_rx_result debug_noinline
1017 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
1018 {
1019         struct ieee80211_local *local;
1020         struct ieee80211_hdr *hdr;
1021         struct sk_buff *skb;
1022
1023         local = rx->local;
1024         skb = rx->skb;
1025         hdr = (struct ieee80211_hdr *) skb->data;
1026
1027         if (!local->pspolling)
1028                 return RX_CONTINUE;
1029
1030         if (!ieee80211_has_fromds(hdr->frame_control))
1031                 /* this is not from AP */
1032                 return RX_CONTINUE;
1033
1034         if (!ieee80211_is_data(hdr->frame_control))
1035                 return RX_CONTINUE;
1036
1037         if (!ieee80211_has_moredata(hdr->frame_control)) {
1038                 /* AP has no more frames buffered for us */
1039                 local->pspolling = false;
1040                 return RX_CONTINUE;
1041         }
1042
1043         /* more data bit is set, let's request a new frame from the AP */
1044         ieee80211_send_pspoll(local, rx->sdata);
1045
1046         return RX_CONTINUE;
1047 }
1048
1049 static void ap_sta_ps_start(struct sta_info *sta)
1050 {
1051         struct ieee80211_sub_if_data *sdata = sta->sdata;
1052         struct ieee80211_local *local = sdata->local;
1053
1054         atomic_inc(&sdata->bss->num_sta_ps);
1055         set_sta_flags(sta, WLAN_STA_PS_STA);
1056         drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1057 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1058         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1059                sdata->name, sta->sta.addr, sta->sta.aid);
1060 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1061 }
1062
1063 static void ap_sta_ps_end(struct sta_info *sta)
1064 {
1065         struct ieee80211_sub_if_data *sdata = sta->sdata;
1066
1067         atomic_dec(&sdata->bss->num_sta_ps);
1068
1069         clear_sta_flags(sta, WLAN_STA_PS_STA);
1070
1071 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1072         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1073                sdata->name, sta->sta.addr, sta->sta.aid);
1074 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1075
1076         if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
1077 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1078                 printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1079                        sdata->name, sta->sta.addr, sta->sta.aid);
1080 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1081                 return;
1082         }
1083
1084         ieee80211_sta_ps_deliver_wakeup(sta);
1085 }
1086
1087 static ieee80211_rx_result debug_noinline
1088 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1089 {
1090         struct sta_info *sta = rx->sta;
1091         struct sk_buff *skb = rx->skb;
1092         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1093         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1094
1095         if (!sta)
1096                 return RX_CONTINUE;
1097
1098         /*
1099          * Update last_rx only for IBSS packets which are for the current
1100          * BSSID to avoid keeping the current IBSS network alive in cases
1101          * where other STAs start using different BSSID.
1102          */
1103         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1104                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1105                                                 NL80211_IFTYPE_ADHOC);
1106                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
1107                         sta->last_rx = jiffies;
1108         } else if (!is_multicast_ether_addr(hdr->addr1)) {
1109                 /*
1110                  * Mesh beacons will update last_rx when if they are found to
1111                  * match the current local configuration when processed.
1112                  */
1113                 sta->last_rx = jiffies;
1114         }
1115
1116         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1117                 return RX_CONTINUE;
1118
1119         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1120                 ieee80211_sta_rx_notify(rx->sdata, hdr);
1121
1122         sta->rx_fragments++;
1123         sta->rx_bytes += rx->skb->len;
1124         sta->last_signal = status->signal;
1125
1126         /*
1127          * Change STA power saving mode only at the end of a frame
1128          * exchange sequence.
1129          */
1130         if (!ieee80211_has_morefrags(hdr->frame_control) &&
1131             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1132              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1133                 if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
1134                         /*
1135                          * Ignore doze->wake transitions that are
1136                          * indicated by non-data frames, the standard
1137                          * is unclear here, but for example going to
1138                          * PS mode and then scanning would cause a
1139                          * doze->wake transition for the probe request,
1140                          * and that is clearly undesirable.
1141                          */
1142                         if (ieee80211_is_data(hdr->frame_control) &&
1143                             !ieee80211_has_pm(hdr->frame_control))
1144                                 ap_sta_ps_end(sta);
1145                 } else {
1146                         if (ieee80211_has_pm(hdr->frame_control))
1147                                 ap_sta_ps_start(sta);
1148                 }
1149         }
1150
1151         /*
1152          * Drop (qos-)data::nullfunc frames silently, since they
1153          * are used only to control station power saving mode.
1154          */
1155         if (ieee80211_is_nullfunc(hdr->frame_control) ||
1156             ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1157                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1158
1159                 /*
1160                  * If we receive a 4-addr nullfunc frame from a STA
1161                  * that was not moved to a 4-addr STA vlan yet, drop
1162                  * the frame to the monitor interface, to make sure
1163                  * that hostapd sees it
1164                  */
1165                 if (ieee80211_has_a4(hdr->frame_control) &&
1166                     (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1167                      (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1168                       !rx->sdata->u.vlan.sta)))
1169                         return RX_DROP_MONITOR;
1170                 /*
1171                  * Update counter and free packet here to avoid
1172                  * counting this as a dropped packed.
1173                  */
1174                 sta->rx_packets++;
1175                 dev_kfree_skb(rx->skb);
1176                 return RX_QUEUED;
1177         }
1178
1179         return RX_CONTINUE;
1180 } /* ieee80211_rx_h_sta_process */
1181
1182 static inline struct ieee80211_fragment_entry *
1183 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1184                          unsigned int frag, unsigned int seq, int rx_queue,
1185                          struct sk_buff **skb)
1186 {
1187         struct ieee80211_fragment_entry *entry;
1188         int idx;
1189
1190         idx = sdata->fragment_next;
1191         entry = &sdata->fragments[sdata->fragment_next++];
1192         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1193                 sdata->fragment_next = 0;
1194
1195         if (!skb_queue_empty(&entry->skb_list)) {
1196 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1197                 struct ieee80211_hdr *hdr =
1198                         (struct ieee80211_hdr *) entry->skb_list.next->data;
1199                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1200                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1201                        "addr1=%pM addr2=%pM\n",
1202                        sdata->name, idx,
1203                        jiffies - entry->first_frag_time, entry->seq,
1204                        entry->last_frag, hdr->addr1, hdr->addr2);
1205 #endif
1206                 __skb_queue_purge(&entry->skb_list);
1207         }
1208
1209         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1210         *skb = NULL;
1211         entry->first_frag_time = jiffies;
1212         entry->seq = seq;
1213         entry->rx_queue = rx_queue;
1214         entry->last_frag = frag;
1215         entry->ccmp = 0;
1216         entry->extra_len = 0;
1217
1218         return entry;
1219 }
1220
1221 static inline struct ieee80211_fragment_entry *
1222 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1223                           unsigned int frag, unsigned int seq,
1224                           int rx_queue, struct ieee80211_hdr *hdr)
1225 {
1226         struct ieee80211_fragment_entry *entry;
1227         int i, idx;
1228
1229         idx = sdata->fragment_next;
1230         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1231                 struct ieee80211_hdr *f_hdr;
1232
1233                 idx--;
1234                 if (idx < 0)
1235                         idx = IEEE80211_FRAGMENT_MAX - 1;
1236
1237                 entry = &sdata->fragments[idx];
1238                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1239                     entry->rx_queue != rx_queue ||
1240                     entry->last_frag + 1 != frag)
1241                         continue;
1242
1243                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1244
1245                 /*
1246                  * Check ftype and addresses are equal, else check next fragment
1247                  */
1248                 if (((hdr->frame_control ^ f_hdr->frame_control) &
1249                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1250                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1251                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1252                         continue;
1253
1254                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1255                         __skb_queue_purge(&entry->skb_list);
1256                         continue;
1257                 }
1258                 return entry;
1259         }
1260
1261         return NULL;
1262 }
1263
1264 static ieee80211_rx_result debug_noinline
1265 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1266 {
1267         struct ieee80211_hdr *hdr;
1268         u16 sc;
1269         __le16 fc;
1270         unsigned int frag, seq;
1271         struct ieee80211_fragment_entry *entry;
1272         struct sk_buff *skb;
1273         struct ieee80211_rx_status *status;
1274
1275         hdr = (struct ieee80211_hdr *)rx->skb->data;
1276         fc = hdr->frame_control;
1277         sc = le16_to_cpu(hdr->seq_ctrl);
1278         frag = sc & IEEE80211_SCTL_FRAG;
1279
1280         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1281                    (rx->skb)->len < 24 ||
1282                    is_multicast_ether_addr(hdr->addr1))) {
1283                 /* not fragmented */
1284                 goto out;
1285         }
1286         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1287
1288         if (skb_linearize(rx->skb))
1289                 return RX_DROP_UNUSABLE;
1290
1291         /*
1292          *  skb_linearize() might change the skb->data and
1293          *  previously cached variables (in this case, hdr) need to
1294          *  be refreshed with the new data.
1295          */
1296         hdr = (struct ieee80211_hdr *)rx->skb->data;
1297         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1298
1299         if (frag == 0) {
1300                 /* This is the first fragment of a new frame. */
1301                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1302                                                  rx->queue, &(rx->skb));
1303                 if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
1304                     ieee80211_has_protected(fc)) {
1305                         int queue = ieee80211_is_mgmt(fc) ?
1306                                 NUM_RX_DATA_QUEUES : rx->queue;
1307                         /* Store CCMP PN so that we can verify that the next
1308                          * fragment has a sequential PN value. */
1309                         entry->ccmp = 1;
1310                         memcpy(entry->last_pn,
1311                                rx->key->u.ccmp.rx_pn[queue],
1312                                CCMP_PN_LEN);
1313                 }
1314                 return RX_QUEUED;
1315         }
1316
1317         /* This is a fragment for a frame that should already be pending in
1318          * fragment cache. Add this fragment to the end of the pending entry.
1319          */
1320         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1321         if (!entry) {
1322                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1323                 return RX_DROP_MONITOR;
1324         }
1325
1326         /* Verify that MPDUs within one MSDU have sequential PN values.
1327          * (IEEE 802.11i, 8.3.3.4.5) */
1328         if (entry->ccmp) {
1329                 int i;
1330                 u8 pn[CCMP_PN_LEN], *rpn;
1331                 int queue;
1332                 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
1333                         return RX_DROP_UNUSABLE;
1334                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1335                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1336                         pn[i]++;
1337                         if (pn[i])
1338                                 break;
1339                 }
1340                 queue = ieee80211_is_mgmt(fc) ?
1341                         NUM_RX_DATA_QUEUES : rx->queue;
1342                 rpn = rx->key->u.ccmp.rx_pn[queue];
1343                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1344                         return RX_DROP_UNUSABLE;
1345                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1346         }
1347
1348         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1349         __skb_queue_tail(&entry->skb_list, rx->skb);
1350         entry->last_frag = frag;
1351         entry->extra_len += rx->skb->len;
1352         if (ieee80211_has_morefrags(fc)) {
1353                 rx->skb = NULL;
1354                 return RX_QUEUED;
1355         }
1356
1357         rx->skb = __skb_dequeue(&entry->skb_list);
1358         if (skb_tailroom(rx->skb) < entry->extra_len) {
1359                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1360                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1361                                               GFP_ATOMIC))) {
1362                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1363                         __skb_queue_purge(&entry->skb_list);
1364                         return RX_DROP_UNUSABLE;
1365                 }
1366         }
1367         while ((skb = __skb_dequeue(&entry->skb_list))) {
1368                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1369                 dev_kfree_skb(skb);
1370         }
1371
1372         /* Complete frame has been reassembled - process it now */
1373         status = IEEE80211_SKB_RXCB(rx->skb);
1374         status->rx_flags |= IEEE80211_RX_FRAGMENTED;
1375
1376  out:
1377         if (rx->sta)
1378                 rx->sta->rx_packets++;
1379         if (is_multicast_ether_addr(hdr->addr1))
1380                 rx->local->dot11MulticastReceivedFrameCount++;
1381         else
1382                 ieee80211_led_rx(rx->local);
1383         return RX_CONTINUE;
1384 }
1385
1386 static ieee80211_rx_result debug_noinline
1387 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1388 {
1389         struct ieee80211_sub_if_data *sdata = rx->sdata;
1390         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1391         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1392
1393         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1394                    !(status->rx_flags & IEEE80211_RX_RA_MATCH)))
1395                 return RX_CONTINUE;
1396
1397         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1398             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1399                 return RX_DROP_UNUSABLE;
1400
1401         if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1402                 ieee80211_sta_ps_deliver_poll_response(rx->sta);
1403         else
1404                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1405
1406         /* Free PS Poll skb here instead of returning RX_DROP that would
1407          * count as an dropped frame. */
1408         dev_kfree_skb(rx->skb);
1409
1410         return RX_QUEUED;
1411 }
1412
1413 static ieee80211_rx_result debug_noinline
1414 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1415 {
1416         u8 *data = rx->skb->data;
1417         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1418
1419         if (!ieee80211_is_data_qos(hdr->frame_control))
1420                 return RX_CONTINUE;
1421
1422         /* remove the qos control field, update frame type and meta-data */
1423         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1424                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1425         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1426         /* change frame type to non QOS */
1427         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1428
1429         return RX_CONTINUE;
1430 }
1431
1432 static int
1433 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1434 {
1435         if (unlikely(!rx->sta ||
1436             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1437                 return -EACCES;
1438
1439         return 0;
1440 }
1441
1442 static int
1443 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1444 {
1445         struct sk_buff *skb = rx->skb;
1446         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1447
1448         /*
1449          * Pass through unencrypted frames if the hardware has
1450          * decrypted them already.
1451          */
1452         if (status->flag & RX_FLAG_DECRYPTED)
1453                 return 0;
1454
1455         /* Drop unencrypted frames if key is set. */
1456         if (unlikely(!ieee80211_has_protected(fc) &&
1457                      !ieee80211_is_nullfunc(fc) &&
1458                      ieee80211_is_data(fc) &&
1459                      (rx->key || rx->sdata->drop_unencrypted)))
1460                 return -EACCES;
1461
1462         return 0;
1463 }
1464
1465 static int
1466 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1467 {
1468         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1469         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1470         __le16 fc = hdr->frame_control;
1471
1472         /*
1473          * Pass through unencrypted frames if the hardware has
1474          * decrypted them already.
1475          */
1476         if (status->flag & RX_FLAG_DECRYPTED)
1477                 return 0;
1478
1479         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1480                 if (unlikely(!ieee80211_has_protected(fc) &&
1481                              ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1482                              rx->key))
1483                         return -EACCES;
1484                 /* BIP does not use Protected field, so need to check MMIE */
1485                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1486                              ieee80211_get_mmie_keyidx(rx->skb) < 0))
1487                         return -EACCES;
1488                 /*
1489                  * When using MFP, Action frames are not allowed prior to
1490                  * having configured keys.
1491                  */
1492                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1493                              ieee80211_is_robust_mgmt_frame(
1494                                      (struct ieee80211_hdr *) rx->skb->data)))
1495                         return -EACCES;
1496         }
1497
1498         return 0;
1499 }
1500
1501 static int
1502 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1503 {
1504         struct ieee80211_sub_if_data *sdata = rx->sdata;
1505         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1506
1507         if (ieee80211_has_a4(hdr->frame_control) &&
1508             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1509                 return -1;
1510
1511         if (is_multicast_ether_addr(hdr->addr1) &&
1512             ((sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta) ||
1513              (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.use_4addr)))
1514                 return -1;
1515
1516         return ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1517 }
1518
1519 /*
1520  * requires that rx->skb is a frame with ethernet header
1521  */
1522 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1523 {
1524         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1525                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1526         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1527
1528         /*
1529          * Allow EAPOL frames to us/the PAE group address regardless
1530          * of whether the frame was encrypted or not.
1531          */
1532         if (ehdr->h_proto == rx->sdata->control_port_protocol &&
1533             (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1534              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1535                 return true;
1536
1537         if (ieee80211_802_1x_port_control(rx) ||
1538             ieee80211_drop_unencrypted(rx, fc))
1539                 return false;
1540
1541         return true;
1542 }
1543
1544 /*
1545  * requires that rx->skb is a frame with ethernet header
1546  */
1547 static void
1548 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1549 {
1550         struct ieee80211_sub_if_data *sdata = rx->sdata;
1551         struct net_device *dev = sdata->dev;
1552         struct sk_buff *skb, *xmit_skb;
1553         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1554         struct sta_info *dsta;
1555         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1556
1557         skb = rx->skb;
1558         xmit_skb = NULL;
1559
1560         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1561              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1562             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1563             (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
1564             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1565                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1566                         /*
1567                          * send multicast frames both to higher layers in
1568                          * local net stack and back to the wireless medium
1569                          */
1570                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1571                         if (!xmit_skb && net_ratelimit())
1572                                 printk(KERN_DEBUG "%s: failed to clone "
1573                                        "multicast frame\n", dev->name);
1574                 } else {
1575                         dsta = sta_info_get(sdata, skb->data);
1576                         if (dsta) {
1577                                 /*
1578                                  * The destination station is associated to
1579                                  * this AP (in this VLAN), so send the frame
1580                                  * directly to it and do not pass it to local
1581                                  * net stack.
1582                                  */
1583                                 xmit_skb = skb;
1584                                 skb = NULL;
1585                         }
1586                 }
1587         }
1588
1589         if (skb) {
1590                 int align __maybe_unused;
1591
1592 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1593                 /*
1594                  * 'align' will only take the values 0 or 2 here
1595                  * since all frames are required to be aligned
1596                  * to 2-byte boundaries when being passed to
1597                  * mac80211. That also explains the __skb_push()
1598                  * below.
1599                  */
1600                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1601                 if (align) {
1602                         if (WARN_ON(skb_headroom(skb) < 3)) {
1603                                 dev_kfree_skb(skb);
1604                                 skb = NULL;
1605                         } else {
1606                                 u8 *data = skb->data;
1607                                 size_t len = skb_headlen(skb);
1608                                 skb->data -= align;
1609                                 memmove(skb->data, data, len);
1610                                 skb_set_tail_pointer(skb, len);
1611                         }
1612                 }
1613 #endif
1614
1615                 if (skb) {
1616                         /* deliver to local stack */
1617                         skb->protocol = eth_type_trans(skb, dev);
1618                         memset(skb->cb, 0, sizeof(skb->cb));
1619                         netif_receive_skb(skb);
1620                 }
1621         }
1622
1623         if (xmit_skb) {
1624                 /* send to wireless media */
1625                 xmit_skb->protocol = htons(ETH_P_802_3);
1626                 skb_reset_network_header(xmit_skb);
1627                 skb_reset_mac_header(xmit_skb);
1628                 dev_queue_xmit(xmit_skb);
1629         }
1630 }
1631
1632 static ieee80211_rx_result debug_noinline
1633 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1634 {
1635         struct net_device *dev = rx->sdata->dev;
1636         struct sk_buff *skb = rx->skb;
1637         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1638         __le16 fc = hdr->frame_control;
1639         struct sk_buff_head frame_list;
1640         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1641
1642         if (unlikely(!ieee80211_is_data(fc)))
1643                 return RX_CONTINUE;
1644
1645         if (unlikely(!ieee80211_is_data_present(fc)))
1646                 return RX_DROP_MONITOR;
1647
1648         if (!(status->rx_flags & IEEE80211_RX_AMSDU))
1649                 return RX_CONTINUE;
1650
1651         if (ieee80211_has_a4(hdr->frame_control) &&
1652             rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1653             !rx->sdata->u.vlan.sta)
1654                 return RX_DROP_UNUSABLE;
1655
1656         if (is_multicast_ether_addr(hdr->addr1) &&
1657             ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1658               rx->sdata->u.vlan.sta) ||
1659              (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1660               rx->sdata->u.mgd.use_4addr)))
1661                 return RX_DROP_UNUSABLE;
1662
1663         skb->dev = dev;
1664         __skb_queue_head_init(&frame_list);
1665
1666         if (skb_linearize(skb))
1667                 return RX_DROP_UNUSABLE;
1668
1669         ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1670                                  rx->sdata->vif.type,
1671                                  rx->local->hw.extra_tx_headroom);
1672
1673         while (!skb_queue_empty(&frame_list)) {
1674                 rx->skb = __skb_dequeue(&frame_list);
1675
1676                 if (!ieee80211_frame_allowed(rx, fc)) {
1677                         dev_kfree_skb(rx->skb);
1678                         continue;
1679                 }
1680                 dev->stats.rx_packets++;
1681                 dev->stats.rx_bytes += rx->skb->len;
1682
1683                 ieee80211_deliver_skb(rx);
1684         }
1685
1686         return RX_QUEUED;
1687 }
1688
1689 #ifdef CONFIG_MAC80211_MESH
1690 static ieee80211_rx_result
1691 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1692 {
1693         struct ieee80211_hdr *hdr;
1694         struct ieee80211s_hdr *mesh_hdr;
1695         unsigned int hdrlen;
1696         struct sk_buff *skb = rx->skb, *fwd_skb;
1697         struct ieee80211_local *local = rx->local;
1698         struct ieee80211_sub_if_data *sdata = rx->sdata;
1699         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1700
1701         hdr = (struct ieee80211_hdr *) skb->data;
1702         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1703         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1704
1705         if (!ieee80211_is_data(hdr->frame_control))
1706                 return RX_CONTINUE;
1707
1708         if (!mesh_hdr->ttl)
1709                 /* illegal frame */
1710                 return RX_DROP_MONITOR;
1711
1712         if (mesh_hdr->flags & MESH_FLAGS_AE) {
1713                 struct mesh_path *mppath;
1714                 char *proxied_addr;
1715                 char *mpp_addr;
1716
1717                 if (is_multicast_ether_addr(hdr->addr1)) {
1718                         mpp_addr = hdr->addr3;
1719                         proxied_addr = mesh_hdr->eaddr1;
1720                 } else {
1721                         mpp_addr = hdr->addr4;
1722                         proxied_addr = mesh_hdr->eaddr2;
1723                 }
1724
1725                 rcu_read_lock();
1726                 mppath = mpp_path_lookup(proxied_addr, sdata);
1727                 if (!mppath) {
1728                         mpp_path_add(proxied_addr, mpp_addr, sdata);
1729                 } else {
1730                         spin_lock_bh(&mppath->state_lock);
1731                         if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1732                                 memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1733                         spin_unlock_bh(&mppath->state_lock);
1734                 }
1735                 rcu_read_unlock();
1736         }
1737
1738         /* Frame has reached destination.  Don't forward */
1739         if (!is_multicast_ether_addr(hdr->addr1) &&
1740             compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1741                 return RX_CONTINUE;
1742
1743         mesh_hdr->ttl--;
1744
1745         if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
1746                 if (!mesh_hdr->ttl)
1747                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1748                                                      dropped_frames_ttl);
1749                 else {
1750                         struct ieee80211_hdr *fwd_hdr;
1751                         struct ieee80211_tx_info *info;
1752
1753                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1754
1755                         if (!fwd_skb && net_ratelimit())
1756                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1757                                                    sdata->name);
1758
1759                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1760                         memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1761                         info = IEEE80211_SKB_CB(fwd_skb);
1762                         memset(info, 0, sizeof(*info));
1763                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1764                         info->control.vif = &rx->sdata->vif;
1765                         skb_set_queue_mapping(skb,
1766                                 ieee80211_select_queue(rx->sdata, fwd_skb));
1767                         ieee80211_set_qos_hdr(local, skb);
1768                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1769                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1770                                                                 fwded_mcast);
1771                         else {
1772                                 int err;
1773                                 /*
1774                                  * Save TA to addr1 to send TA a path error if a
1775                                  * suitable next hop is not found
1776                                  */
1777                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1778                                                 ETH_ALEN);
1779                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1780                                 /* Failed to immediately resolve next hop:
1781                                  * fwded frame was dropped or will be added
1782                                  * later to the pending skb queue.  */
1783                                 if (err)
1784                                         return RX_DROP_MONITOR;
1785
1786                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1787                                                                 fwded_unicast);
1788                         }
1789                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1790                                                      fwded_frames);
1791                         ieee80211_add_pending_skb(local, fwd_skb);
1792                 }
1793         }
1794
1795         if (is_multicast_ether_addr(hdr->addr1) ||
1796             sdata->dev->flags & IFF_PROMISC)
1797                 return RX_CONTINUE;
1798         else
1799                 return RX_DROP_MONITOR;
1800 }
1801 #endif
1802
1803 static ieee80211_rx_result debug_noinline
1804 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1805 {
1806         struct ieee80211_sub_if_data *sdata = rx->sdata;
1807         struct ieee80211_local *local = rx->local;
1808         struct net_device *dev = sdata->dev;
1809         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1810         __le16 fc = hdr->frame_control;
1811         int err;
1812
1813         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1814                 return RX_CONTINUE;
1815
1816         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1817                 return RX_DROP_MONITOR;
1818
1819         /*
1820          * Allow the cooked monitor interface of an AP to see 4-addr frames so
1821          * that a 4-addr station can be detected and moved into a separate VLAN
1822          */
1823         if (ieee80211_has_a4(hdr->frame_control) &&
1824             sdata->vif.type == NL80211_IFTYPE_AP)
1825                 return RX_DROP_MONITOR;
1826
1827         err = __ieee80211_data_to_8023(rx);
1828         if (unlikely(err))
1829                 return RX_DROP_UNUSABLE;
1830
1831         if (!ieee80211_frame_allowed(rx, fc))
1832                 return RX_DROP_MONITOR;
1833
1834         rx->skb->dev = dev;
1835
1836         dev->stats.rx_packets++;
1837         dev->stats.rx_bytes += rx->skb->len;
1838
1839         if (ieee80211_is_data(hdr->frame_control) &&
1840             !is_multicast_ether_addr(hdr->addr1) &&
1841             local->hw.conf.dynamic_ps_timeout > 0 && local->ps_sdata) {
1842                         mod_timer(&local->dynamic_ps_timer, jiffies +
1843                          msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1844         }
1845
1846         ieee80211_deliver_skb(rx);
1847
1848         return RX_QUEUED;
1849 }
1850
1851 static ieee80211_rx_result debug_noinline
1852 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
1853 {
1854         struct ieee80211_local *local = rx->local;
1855         struct ieee80211_hw *hw = &local->hw;
1856         struct sk_buff *skb = rx->skb;
1857         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1858         struct tid_ampdu_rx *tid_agg_rx;
1859         u16 start_seq_num;
1860         u16 tid;
1861
1862         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1863                 return RX_CONTINUE;
1864
1865         if (ieee80211_is_back_req(bar->frame_control)) {
1866                 struct {
1867                         __le16 control, start_seq_num;
1868                 } __packed bar_data;
1869
1870                 if (!rx->sta)
1871                         return RX_DROP_MONITOR;
1872
1873                 if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
1874                                   &bar_data, sizeof(bar_data)))
1875                         return RX_DROP_MONITOR;
1876
1877                 tid = le16_to_cpu(bar_data.control) >> 12;
1878
1879                 tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
1880                 if (!tid_agg_rx)
1881                         return RX_DROP_MONITOR;
1882
1883                 start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
1884
1885                 /* reset session timer */
1886                 if (tid_agg_rx->timeout)
1887                         mod_timer(&tid_agg_rx->session_timer,
1888                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1889
1890                 /* release stored frames up to start of BAR */
1891                 ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num,
1892                                                  frames);
1893                 kfree_skb(skb);
1894                 return RX_QUEUED;
1895         }
1896
1897         /*
1898          * After this point, we only want management frames,
1899          * so we can drop all remaining control frames to
1900          * cooked monitor interfaces.
1901          */
1902         return RX_DROP_MONITOR;
1903 }
1904
1905 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1906                                            struct ieee80211_mgmt *mgmt,
1907                                            size_t len)
1908 {
1909         struct ieee80211_local *local = sdata->local;
1910         struct sk_buff *skb;
1911         struct ieee80211_mgmt *resp;
1912
1913         if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
1914                 /* Not to own unicast address */
1915                 return;
1916         }
1917
1918         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1919             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1920                 /* Not from the current AP or not associated yet. */
1921                 return;
1922         }
1923
1924         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1925                 /* Too short SA Query request frame */
1926                 return;
1927         }
1928
1929         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1930         if (skb == NULL)
1931                 return;
1932
1933         skb_reserve(skb, local->hw.extra_tx_headroom);
1934         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1935         memset(resp, 0, 24);
1936         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1937         memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
1938         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1939         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1940                                           IEEE80211_STYPE_ACTION);
1941         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1942         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1943         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1944         memcpy(resp->u.action.u.sa_query.trans_id,
1945                mgmt->u.action.u.sa_query.trans_id,
1946                WLAN_SA_QUERY_TR_ID_LEN);
1947
1948         ieee80211_tx_skb(sdata, skb);
1949 }
1950
1951 static ieee80211_rx_result debug_noinline
1952 ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
1953 {
1954         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1955         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1956
1957         /*
1958          * From here on, look only at management frames.
1959          * Data and control frames are already handled,
1960          * and unknown (reserved) frames are useless.
1961          */
1962         if (rx->skb->len < 24)
1963                 return RX_DROP_MONITOR;
1964
1965         if (!ieee80211_is_mgmt(mgmt->frame_control))
1966                 return RX_DROP_MONITOR;
1967
1968         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1969                 return RX_DROP_MONITOR;
1970
1971         if (ieee80211_drop_unencrypted_mgmt(rx))
1972                 return RX_DROP_UNUSABLE;
1973
1974         return RX_CONTINUE;
1975 }
1976
1977 static ieee80211_rx_result debug_noinline
1978 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1979 {
1980         struct ieee80211_local *local = rx->local;
1981         struct ieee80211_sub_if_data *sdata = rx->sdata;
1982         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1983         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
1984         int len = rx->skb->len;
1985
1986         if (!ieee80211_is_action(mgmt->frame_control))
1987                 return RX_CONTINUE;
1988
1989         /* drop too small frames */
1990         if (len < IEEE80211_MIN_ACTION_SIZE)
1991                 return RX_DROP_UNUSABLE;
1992
1993         if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
1994                 return RX_DROP_UNUSABLE;
1995
1996         if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
1997                 return RX_DROP_UNUSABLE;
1998
1999         switch (mgmt->u.action.category) {
2000         case WLAN_CATEGORY_BACK:
2001                 /*
2002                  * The aggregation code is not prepared to handle
2003                  * anything but STA/AP due to the BSSID handling;
2004                  * IBSS could work in the code but isn't supported
2005                  * by drivers or the standard.
2006                  */
2007                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
2008                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
2009                     sdata->vif.type != NL80211_IFTYPE_AP)
2010                         break;
2011
2012                 /* verify action_code is present */
2013                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2014                         break;
2015
2016                 switch (mgmt->u.action.u.addba_req.action_code) {
2017                 case WLAN_ACTION_ADDBA_REQ:
2018                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2019                                    sizeof(mgmt->u.action.u.addba_req)))
2020                                 goto invalid;
2021                         break;
2022                 case WLAN_ACTION_ADDBA_RESP:
2023                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2024                                    sizeof(mgmt->u.action.u.addba_resp)))
2025                                 goto invalid;
2026                         break;
2027                 case WLAN_ACTION_DELBA:
2028                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2029                                    sizeof(mgmt->u.action.u.delba)))
2030                                 goto invalid;
2031                         break;
2032                 default:
2033                         goto invalid;
2034                 }
2035
2036                 goto queue;
2037         case WLAN_CATEGORY_SPECTRUM_MGMT:
2038                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
2039                         break;
2040
2041                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2042                         break;
2043
2044                 /* verify action_code is present */
2045                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
2046                         break;
2047
2048                 switch (mgmt->u.action.u.measurement.action_code) {
2049                 case WLAN_ACTION_SPCT_MSR_REQ:
2050                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2051                                    sizeof(mgmt->u.action.u.measurement)))
2052                                 break;
2053                         ieee80211_process_measurement_req(sdata, mgmt, len);
2054                         goto handled;
2055                 case WLAN_ACTION_SPCT_CHL_SWITCH:
2056                         if (len < (IEEE80211_MIN_ACTION_SIZE +
2057                                    sizeof(mgmt->u.action.u.chan_switch)))
2058                                 break;
2059
2060                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2061                                 break;
2062
2063                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
2064                                 break;
2065
2066                         goto queue;
2067                 }
2068                 break;
2069         case WLAN_CATEGORY_SA_QUERY:
2070                 if (len < (IEEE80211_MIN_ACTION_SIZE +
2071                            sizeof(mgmt->u.action.u.sa_query)))
2072                         break;
2073
2074                 switch (mgmt->u.action.u.sa_query.action) {
2075                 case WLAN_ACTION_SA_QUERY_REQUEST:
2076                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
2077                                 break;
2078                         ieee80211_process_sa_query_req(sdata, mgmt, len);
2079                         goto handled;
2080                 }
2081                 break;
2082         case WLAN_CATEGORY_MESH_PLINK:
2083         case WLAN_CATEGORY_MESH_PATH_SEL:
2084                 if (!ieee80211_vif_is_mesh(&sdata->vif))
2085                         break;
2086                 goto queue;
2087         }
2088
2089         return RX_CONTINUE;
2090
2091  invalid:
2092         status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
2093         /* will return in the next handlers */
2094         return RX_CONTINUE;
2095
2096  handled:
2097         if (rx->sta)
2098                 rx->sta->rx_packets++;
2099         dev_kfree_skb(rx->skb);
2100         return RX_QUEUED;
2101
2102  queue:
2103         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2104         skb_queue_tail(&sdata->skb_queue, rx->skb);
2105         ieee80211_queue_work(&local->hw, &sdata->work);
2106         if (rx->sta)
2107                 rx->sta->rx_packets++;
2108         return RX_QUEUED;
2109 }
2110
2111 static ieee80211_rx_result debug_noinline
2112 ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
2113 {
2114         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2115
2116         /* skip known-bad action frames and return them in the next handler */
2117         if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
2118                 return RX_CONTINUE;
2119
2120         /*
2121          * Getting here means the kernel doesn't know how to handle
2122          * it, but maybe userspace does ... include returned frames
2123          * so userspace can register for those to know whether ones
2124          * it transmitted were processed or returned.
2125          */
2126
2127         if (cfg80211_rx_mgmt(rx->sdata->dev, status->freq,
2128                              rx->skb->data, rx->skb->len,
2129                              GFP_ATOMIC)) {
2130                 if (rx->sta)
2131                         rx->sta->rx_packets++;
2132                 dev_kfree_skb(rx->skb);
2133                 return RX_QUEUED;
2134         }
2135
2136
2137         return RX_CONTINUE;
2138 }
2139
2140 static ieee80211_rx_result debug_noinline
2141 ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
2142 {
2143         struct ieee80211_local *local = rx->local;
2144         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
2145         struct sk_buff *nskb;
2146         struct ieee80211_sub_if_data *sdata = rx->sdata;
2147         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
2148
2149         if (!ieee80211_is_action(mgmt->frame_control))
2150                 return RX_CONTINUE;
2151
2152         /*
2153          * For AP mode, hostapd is responsible for handling any action
2154          * frames that we didn't handle, including returning unknown
2155          * ones. For all other modes we will return them to the sender,
2156          * setting the 0x80 bit in the action category, as required by
2157          * 802.11-2007 7.3.1.11.
2158          * Newer versions of hostapd shall also use the management frame
2159          * registration mechanisms, but older ones still use cooked
2160          * monitor interfaces so push all frames there.
2161          */
2162         if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
2163             (sdata->vif.type == NL80211_IFTYPE_AP ||
2164              sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
2165                 return RX_DROP_MONITOR;
2166
2167         /* do not return rejected action frames */
2168         if (mgmt->u.action.category & 0x80)
2169                 return RX_DROP_UNUSABLE;
2170
2171         nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2172                                GFP_ATOMIC);
2173         if (nskb) {
2174                 struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
2175
2176                 nmgmt->u.action.category |= 0x80;
2177                 memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
2178                 memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2179
2180                 memset(nskb->cb, 0, sizeof(nskb->cb));
2181
2182                 ieee80211_tx_skb(rx->sdata, nskb);
2183         }
2184         dev_kfree_skb(rx->skb);
2185         return RX_QUEUED;
2186 }
2187
2188 static ieee80211_rx_result debug_noinline
2189 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2190 {
2191         struct ieee80211_sub_if_data *sdata = rx->sdata;
2192         ieee80211_rx_result rxs;
2193         struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
2194         __le16 stype;
2195
2196         rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2197         if (rxs != RX_CONTINUE)
2198                 return rxs;
2199
2200         stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
2201
2202         if (!ieee80211_vif_is_mesh(&sdata->vif) &&
2203             sdata->vif.type != NL80211_IFTYPE_ADHOC &&
2204             sdata->vif.type != NL80211_IFTYPE_STATION)
2205                 return RX_DROP_MONITOR;
2206
2207         switch (stype) {
2208         case cpu_to_le16(IEEE80211_STYPE_BEACON):
2209         case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
2210                 /* process for all: mesh, mlme, ibss */
2211                 break;
2212         case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
2213         case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
2214                 /* process only for station */
2215                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
2216                         return RX_DROP_MONITOR;
2217                 break;
2218         case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
2219         case cpu_to_le16(IEEE80211_STYPE_AUTH):
2220                 /* process only for ibss */
2221                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
2222                         return RX_DROP_MONITOR;
2223                 break;
2224         default:
2225                 return RX_DROP_MONITOR;
2226         }
2227
2228         /* queue up frame and kick off work to process it */
2229         rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
2230         skb_queue_tail(&sdata->skb_queue, rx->skb);
2231         ieee80211_queue_work(&rx->local->hw, &sdata->work);
2232         if (rx->sta)
2233                 rx->sta->rx_packets++;
2234
2235         return RX_QUEUED;
2236 }
2237
2238 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
2239                                             struct ieee80211_rx_data *rx)
2240 {
2241         int keyidx;
2242         unsigned int hdrlen;
2243
2244         hdrlen = ieee80211_hdrlen(hdr->frame_control);
2245         if (rx->skb->len >= hdrlen + 4)
2246                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
2247         else
2248                 keyidx = -1;
2249
2250         if (!rx->sta) {
2251                 /*
2252                  * Some hardware seem to generate incorrect Michael MIC
2253                  * reports; ignore them to avoid triggering countermeasures.
2254                  */
2255                 return;
2256         }
2257
2258         if (!ieee80211_has_protected(hdr->frame_control))
2259                 return;
2260
2261         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
2262                 /*
2263                  * APs with pairwise keys should never receive Michael MIC
2264                  * errors for non-zero keyidx because these are reserved for
2265                  * group keys and only the AP is sending real multicast
2266                  * frames in the BSS.
2267                  */
2268                 return;
2269         }
2270
2271         if (!ieee80211_is_data(hdr->frame_control) &&
2272             !ieee80211_is_auth(hdr->frame_control))
2273                 return;
2274
2275         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
2276                                         GFP_ATOMIC);
2277 }
2278
2279 /* TODO: use IEEE80211_RX_FRAGMENTED */
2280 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2281                                         struct ieee80211_rate *rate)
2282 {
2283         struct ieee80211_sub_if_data *sdata;
2284         struct ieee80211_local *local = rx->local;
2285         struct ieee80211_rtap_hdr {
2286                 struct ieee80211_radiotap_header hdr;
2287                 u8 flags;
2288                 u8 rate_or_pad;
2289                 __le16 chan_freq;
2290                 __le16 chan_flags;
2291         } __packed *rthdr;
2292         struct sk_buff *skb = rx->skb, *skb2;
2293         struct net_device *prev_dev = NULL;
2294         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2295
2296         /*
2297          * If cooked monitor has been processed already, then
2298          * don't do it again. If not, set the flag.
2299          */
2300         if (rx->flags & IEEE80211_RX_CMNTR)
2301                 goto out_free_skb;
2302         rx->flags |= IEEE80211_RX_CMNTR;
2303
2304         if (skb_headroom(skb) < sizeof(*rthdr) &&
2305             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2306                 goto out_free_skb;
2307
2308         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2309         memset(rthdr, 0, sizeof(*rthdr));
2310         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2311         rthdr->hdr.it_present =
2312                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2313                             (1 << IEEE80211_RADIOTAP_CHANNEL));
2314
2315         if (rate) {
2316                 rthdr->rate_or_pad = rate->bitrate / 5;
2317                 rthdr->hdr.it_present |=
2318                         cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2319         }
2320         rthdr->chan_freq = cpu_to_le16(status->freq);
2321
2322         if (status->band == IEEE80211_BAND_5GHZ)
2323                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2324                                                 IEEE80211_CHAN_5GHZ);
2325         else
2326                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2327                                                 IEEE80211_CHAN_2GHZ);
2328
2329         skb_set_mac_header(skb, 0);
2330         skb->ip_summed = CHECKSUM_UNNECESSARY;
2331         skb->pkt_type = PACKET_OTHERHOST;
2332         skb->protocol = htons(ETH_P_802_2);
2333
2334         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2335                 if (!ieee80211_sdata_running(sdata))
2336                         continue;
2337
2338                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2339                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2340                         continue;
2341
2342                 if (prev_dev) {
2343                         skb2 = skb_clone(skb, GFP_ATOMIC);
2344                         if (skb2) {
2345                                 skb2->dev = prev_dev;
2346                                 netif_receive_skb(skb2);
2347                         }
2348                 }
2349
2350                 prev_dev = sdata->dev;
2351                 sdata->dev->stats.rx_packets++;
2352                 sdata->dev->stats.rx_bytes += skb->len;
2353         }
2354
2355         if (prev_dev) {
2356                 skb->dev = prev_dev;
2357                 netif_receive_skb(skb);
2358                 return;
2359         }
2360
2361  out_free_skb:
2362         dev_kfree_skb(skb);
2363 }
2364
2365 static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
2366                                          ieee80211_rx_result res)
2367 {
2368         switch (res) {
2369         case RX_DROP_MONITOR:
2370                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2371                 if (rx->sta)
2372                         rx->sta->rx_dropped++;
2373                 /* fall through */
2374         case RX_CONTINUE: {
2375                 struct ieee80211_rate *rate = NULL;
2376                 struct ieee80211_supported_band *sband;
2377                 struct ieee80211_rx_status *status;
2378
2379                 status = IEEE80211_SKB_RXCB((rx->skb));
2380
2381                 sband = rx->local->hw.wiphy->bands[status->band];
2382                 if (!(status->flag & RX_FLAG_HT))
2383                         rate = &sband->bitrates[status->rate_idx];
2384
2385                 ieee80211_rx_cooked_monitor(rx, rate);
2386                 break;
2387                 }
2388         case RX_DROP_UNUSABLE:
2389                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
2390                 if (rx->sta)
2391                         rx->sta->rx_dropped++;
2392                 dev_kfree_skb(rx->skb);
2393                 break;
2394         case RX_QUEUED:
2395                 I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
2396                 break;
2397         }
2398 }
2399
2400 static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
2401                                   struct sk_buff_head *frames)
2402 {
2403         ieee80211_rx_result res = RX_DROP_MONITOR;
2404         struct sk_buff *skb;
2405
2406 #define CALL_RXH(rxh)                   \
2407         do {                            \
2408                 res = rxh(rx);          \
2409                 if (res != RX_CONTINUE) \
2410                         goto rxh_next;  \
2411         } while (0);
2412
2413         while ((skb = __skb_dequeue(frames))) {
2414                 /*
2415                  * all the other fields are valid across frames
2416                  * that belong to an aMPDU since they are on the
2417                  * same TID from the same station
2418                  */
2419                 rx->skb = skb;
2420                 rx->flags = 0;
2421
2422                 CALL_RXH(ieee80211_rx_h_decrypt)
2423                 CALL_RXH(ieee80211_rx_h_check_more_data)
2424                 CALL_RXH(ieee80211_rx_h_sta_process)
2425                 CALL_RXH(ieee80211_rx_h_defragment)
2426                 CALL_RXH(ieee80211_rx_h_ps_poll)
2427                 CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2428                 /* must be after MMIC verify so header is counted in MPDU mic */
2429                 CALL_RXH(ieee80211_rx_h_remove_qos_control)
2430                 CALL_RXH(ieee80211_rx_h_amsdu)
2431 #ifdef CONFIG_MAC80211_MESH
2432                 if (ieee80211_vif_is_mesh(&rx->sdata->vif))
2433                         CALL_RXH(ieee80211_rx_h_mesh_fwding);
2434 #endif
2435                 CALL_RXH(ieee80211_rx_h_data)
2436
2437                 /* special treatment -- needs the queue */
2438                 res = ieee80211_rx_h_ctrl(rx, frames);
2439                 if (res != RX_CONTINUE)
2440                         goto rxh_next;
2441
2442                 CALL_RXH(ieee80211_rx_h_mgmt_check)
2443                 CALL_RXH(ieee80211_rx_h_action)
2444                 CALL_RXH(ieee80211_rx_h_userspace_mgmt)
2445                 CALL_RXH(ieee80211_rx_h_action_return)
2446                 CALL_RXH(ieee80211_rx_h_mgmt)
2447
2448  rxh_next:
2449                 ieee80211_rx_handlers_result(rx, res);
2450
2451 #undef CALL_RXH
2452         }
2453 }
2454
2455 static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
2456 {
2457         struct sk_buff_head reorder_release;
2458         ieee80211_rx_result res = RX_DROP_MONITOR;
2459
2460         __skb_queue_head_init(&reorder_release);
2461
2462 #define CALL_RXH(rxh)                   \
2463         do {                            \
2464                 res = rxh(rx);          \
2465                 if (res != RX_CONTINUE) \
2466                         goto rxh_next;  \
2467         } while (0);
2468
2469         CALL_RXH(ieee80211_rx_h_passive_scan)
2470         CALL_RXH(ieee80211_rx_h_check)
2471
2472         ieee80211_rx_reorder_ampdu(rx, &reorder_release);
2473
2474         ieee80211_rx_handlers(rx, &reorder_release);
2475         return;
2476
2477  rxh_next:
2478         ieee80211_rx_handlers_result(rx, res);
2479
2480 #undef CALL_RXH
2481 }
2482
2483 /*
2484  * This function makes calls into the RX path. Therefore the
2485  * caller must hold the sta_info->lock and everything has to
2486  * be under rcu_read_lock protection as well.
2487  */
2488 void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
2489 {
2490         struct sk_buff_head frames;
2491         struct ieee80211_rx_data rx = {
2492                 .sta = sta,
2493                 .sdata = sta->sdata,
2494                 .local = sta->local,
2495                 .queue = tid,
2496         };
2497         struct tid_ampdu_rx *tid_agg_rx;
2498
2499         tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
2500         if (!tid_agg_rx)
2501                 return;
2502
2503         __skb_queue_head_init(&frames);
2504
2505         spin_lock(&tid_agg_rx->reorder_lock);
2506         ieee80211_sta_reorder_release(&sta->local->hw, tid_agg_rx, &frames);
2507         spin_unlock(&tid_agg_rx->reorder_lock);
2508
2509         ieee80211_rx_handlers(&rx, &frames);
2510 }
2511
2512 /* main receive path */
2513
2514 static int prepare_for_handlers(struct ieee80211_rx_data *rx,
2515                                 struct ieee80211_hdr *hdr)
2516 {
2517         struct ieee80211_sub_if_data *sdata = rx->sdata;
2518         struct sk_buff *skb = rx->skb;
2519         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2520         u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2521         int multicast = is_multicast_ether_addr(hdr->addr1);
2522
2523         switch (sdata->vif.type) {
2524         case NL80211_IFTYPE_STATION:
2525                 if (!bssid && !sdata->u.mgd.use_4addr)
2526                         return 0;
2527                 if (!multicast &&
2528                     compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2529                         if (!(sdata->dev->flags & IFF_PROMISC))
2530                                 return 0;
2531                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2532                 }
2533                 break;
2534         case NL80211_IFTYPE_ADHOC:
2535                 if (!bssid)
2536                         return 0;
2537                 if (ieee80211_is_beacon(hdr->frame_control)) {
2538                         return 1;
2539                 }
2540                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2541                         if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
2542                                 return 0;
2543                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2544                 } else if (!multicast &&
2545                            compare_ether_addr(sdata->vif.addr,
2546                                               hdr->addr1) != 0) {
2547                         if (!(sdata->dev->flags & IFF_PROMISC))
2548                                 return 0;
2549                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2550                 } else if (!rx->sta) {
2551                         int rate_idx;
2552                         if (status->flag & RX_FLAG_HT)
2553                                 rate_idx = 0; /* TODO: HT rates */
2554                         else
2555                                 rate_idx = status->rate_idx;
2556                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
2557                                         hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
2558                 }
2559                 break;
2560         case NL80211_IFTYPE_MESH_POINT:
2561                 if (!multicast &&
2562                     compare_ether_addr(sdata->vif.addr,
2563                                        hdr->addr1) != 0) {
2564                         if (!(sdata->dev->flags & IFF_PROMISC))
2565                                 return 0;
2566
2567                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2568                 }
2569                 break;
2570         case NL80211_IFTYPE_AP_VLAN:
2571         case NL80211_IFTYPE_AP:
2572                 if (!bssid) {
2573                         if (compare_ether_addr(sdata->vif.addr,
2574                                                hdr->addr1))
2575                                 return 0;
2576                 } else if (!ieee80211_bssid_match(bssid,
2577                                         sdata->vif.addr)) {
2578                         if (!(status->rx_flags & IEEE80211_RX_IN_SCAN))
2579                                 return 0;
2580                         status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
2581                 }
2582                 break;
2583         case NL80211_IFTYPE_WDS:
2584                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2585                         return 0;
2586                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2587                         return 0;
2588                 break;
2589         default:
2590                 /* should never get here */
2591                 WARN_ON(1);
2592                 break;
2593         }
2594
2595         return 1;
2596 }
2597
2598 /*
2599  * This function returns whether or not the SKB
2600  * was destined for RX processing or not, which,
2601  * if consume is true, is equivalent to whether
2602  * or not the skb was consumed.
2603  */
2604 static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
2605                                             struct sk_buff *skb, bool consume)
2606 {
2607         struct ieee80211_local *local = rx->local;
2608         struct ieee80211_sub_if_data *sdata = rx->sdata;
2609         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2610         struct ieee80211_hdr *hdr = (void *)skb->data;
2611         int prepares;
2612
2613         rx->skb = skb;
2614         status->rx_flags |= IEEE80211_RX_RA_MATCH;
2615         prepares = prepare_for_handlers(rx, hdr);
2616
2617         if (!prepares)
2618                 return false;
2619
2620         if (status->flag & RX_FLAG_MMIC_ERROR) {
2621                 if (status->rx_flags & IEEE80211_RX_RA_MATCH)
2622                         ieee80211_rx_michael_mic_report(hdr, rx);
2623                 return false;
2624         }
2625
2626         if (!consume) {
2627                 skb = skb_copy(skb, GFP_ATOMIC);
2628                 if (!skb) {
2629                         if (net_ratelimit())
2630                                 wiphy_debug(local->hw.wiphy,
2631                                         "failed to copy multicast frame for %s\n",
2632                                         sdata->name);
2633                         return true;
2634                 }
2635
2636                 rx->skb = skb;
2637         }
2638
2639         ieee80211_invoke_rx_handlers(rx);
2640         return true;
2641 }
2642
2643 /*
2644  * This is the actual Rx frames handler. as it blongs to Rx path it must
2645  * be called with rcu_read_lock protection.
2646  */
2647 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2648                                          struct sk_buff *skb)
2649 {
2650         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2651         struct ieee80211_local *local = hw_to_local(hw);
2652         struct ieee80211_sub_if_data *sdata;
2653         struct ieee80211_hdr *hdr;
2654         __le16 fc;
2655         struct ieee80211_rx_data rx;
2656         struct ieee80211_sub_if_data *prev;
2657         struct sta_info *sta, *tmp, *prev_sta;
2658         int err = 0;
2659
2660         fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
2661         memset(&rx, 0, sizeof(rx));
2662         rx.skb = skb;
2663         rx.local = local;
2664
2665         if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
2666                 local->dot11ReceivedFragmentCount++;
2667
2668         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2669                      test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2670                 status->rx_flags |= IEEE80211_RX_IN_SCAN;
2671
2672         if (ieee80211_is_mgmt(fc))
2673                 err = skb_linearize(skb);
2674         else
2675                 err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
2676
2677         if (err) {
2678                 dev_kfree_skb(skb);
2679                 return;
2680         }
2681
2682         hdr = (struct ieee80211_hdr *)skb->data;
2683         ieee80211_parse_qos(&rx);
2684         ieee80211_verify_alignment(&rx);
2685
2686         if (ieee80211_is_data(fc)) {
2687                 prev_sta = NULL;
2688
2689                 for_each_sta_info(local, hdr->addr2, sta, tmp) {
2690                         if (!prev_sta) {
2691                                 prev_sta = sta;
2692                                 continue;
2693                         }
2694
2695                         rx.sta = prev_sta;
2696                         rx.sdata = prev_sta->sdata;
2697                         ieee80211_prepare_and_rx_handle(&rx, skb, false);
2698
2699                         prev_sta = sta;
2700                 }
2701
2702                 if (prev_sta) {
2703                         rx.sta = prev_sta;
2704                         rx.sdata = prev_sta->sdata;
2705
2706                         if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2707                                 return;
2708                 }
2709         }
2710
2711         prev = NULL;
2712
2713         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2714                 if (!ieee80211_sdata_running(sdata))
2715                         continue;
2716
2717                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2718                     sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2719                         continue;
2720
2721                 /*
2722                  * frame is destined for this interface, but if it's
2723                  * not also for the previous one we handle that after
2724                  * the loop to avoid copying the SKB once too much
2725                  */
2726
2727                 if (!prev) {
2728                         prev = sdata;
2729                         continue;
2730                 }
2731
2732                 rx.sta = sta_info_get_bss(prev, hdr->addr2);
2733                 rx.sdata = prev;
2734                 ieee80211_prepare_and_rx_handle(&rx, skb, false);
2735
2736                 prev = sdata;
2737         }
2738
2739         if (prev) {
2740                 rx.sta = sta_info_get_bss(prev, hdr->addr2);
2741                 rx.sdata = prev;
2742
2743                 if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
2744                         return;
2745         }
2746
2747         dev_kfree_skb(skb);
2748 }
2749
2750 /*
2751  * This is the receive path handler. It is called by a low level driver when an
2752  * 802.11 MPDU is received from the hardware.
2753  */
2754 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2755 {
2756         struct ieee80211_local *local = hw_to_local(hw);
2757         struct ieee80211_rate *rate = NULL;
2758         struct ieee80211_supported_band *sband;
2759         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2760
2761         WARN_ON_ONCE(softirq_count() == 0);
2762
2763         if (WARN_ON(status->band < 0 ||
2764                     status->band >= IEEE80211_NUM_BANDS))
2765                 goto drop;
2766
2767         sband = local->hw.wiphy->bands[status->band];
2768         if (WARN_ON(!sband))
2769                 goto drop;
2770
2771         /*
2772          * If we're suspending, it is possible although not too likely
2773          * that we'd be receiving frames after having already partially
2774          * quiesced the stack. We can't process such frames then since
2775          * that might, for example, cause stations to be added or other
2776          * driver callbacks be invoked.
2777          */
2778         if (unlikely(local->quiescing || local->suspended))
2779                 goto drop;
2780
2781         /*
2782          * The same happens when we're not even started,
2783          * but that's worth a warning.
2784          */
2785         if (WARN_ON(!local->started))
2786                 goto drop;
2787
2788         if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
2789                 /*
2790                  * Validate the rate, unless a PLCP error means that
2791                  * we probably can't have a valid rate here anyway.
2792                  */
2793
2794                 if (status->flag & RX_FLAG_HT) {
2795                         /*
2796                          * rate_idx is MCS index, which can be [0-76]
2797                          * as documented on:
2798                          *
2799                          * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2800                          *
2801                          * Anything else would be some sort of driver or
2802                          * hardware error. The driver should catch hardware
2803                          * errors.
2804                          */
2805                         if (WARN((status->rate_idx < 0 ||
2806                                  status->rate_idx > 76),
2807                                  "Rate marked as an HT rate but passed "
2808                                  "status->rate_idx is not "
2809                                  "an MCS index [0-76]: %d (0x%02x)\n",
2810                                  status->rate_idx,
2811                                  status->rate_idx))
2812                                 goto drop;
2813                 } else {
2814                         if (WARN_ON(status->rate_idx < 0 ||
2815                                     status->rate_idx >= sband->n_bitrates))
2816                                 goto drop;
2817                         rate = &sband->bitrates[status->rate_idx];
2818                 }
2819         }
2820
2821         status->rx_flags = 0;
2822
2823         /*
2824          * key references and virtual interfaces are protected using RCU
2825          * and this requires that we are in a read-side RCU section during
2826          * receive processing
2827          */
2828         rcu_read_lock();
2829
2830         /*
2831          * Frames with failed FCS/PLCP checksum are not returned,
2832          * all other frames are returned without radiotap header
2833          * if it was previously present.
2834          * Also, frames with less than 16 bytes are dropped.
2835          */
2836         skb = ieee80211_rx_monitor(local, skb, rate);
2837         if (!skb) {
2838                 rcu_read_unlock();
2839                 return;
2840         }
2841
2842         __ieee80211_rx_handle_packet(hw, skb);
2843
2844         rcu_read_unlock();
2845
2846         return;
2847  drop:
2848         kfree_skb(skb);
2849 }
2850 EXPORT_SYMBOL(ieee80211_rx);
2851
2852 /* This is a version of the rx handler that can be called from hard irq
2853  * context. Post the skb on the queue and schedule the tasklet */
2854 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2855 {
2856         struct ieee80211_local *local = hw_to_local(hw);
2857
2858         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2859
2860         skb->pkt_type = IEEE80211_RX_MSG;
2861         skb_queue_tail(&local->skb_queue, skb);
2862         tasklet_schedule(&local->tasklet);
2863 }
2864 EXPORT_SYMBOL(ieee80211_rx_irqsafe);