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                         skb_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         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
  85                 len += 1;
  86
  87         if (len & 1) /* padding for RX_FLAGS if necessary */
  88                 len++;
  89
  90         return len;
  91 }
  92
  93 /*
  94  * ieee80211_add_rx_radiotap_header - add radiotap header
  95  *
  96  * add a radiotap header containing all the fields which the hardware provided.
  97  */
  98 static void
  99 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 100                                  struct sk_buff *skb,
 101                                  struct ieee80211_rate *rate,
 102                                  int rtap_len)
 103 {
 104         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 105         struct ieee80211_radiotap_header *rthdr;
 106         unsigned char *pos;
 107         u16 rx_flags = 0;
 108
 109         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 110         memset(rthdr, 0, rtap_len);
 111
 112         /* radiotap header, set always present flags */
 113         rthdr->it_present =
 114                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 115                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 116                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 117                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 118         rthdr->it_len = cpu_to_le16(rtap_len);
 119
 120         pos = (unsigned char *)(rthdr+1);
 121
 122         /* the order of the following fields is important */
 123
 124         /* IEEE80211_RADIOTAP_TSFT */
 125         if (status->flag & RX_FLAG_TSFT) {
 126                 put_unaligned_le64(status->mactime, pos);
 127                 rthdr->it_present |=
 128                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 129                 pos += 8;
 130         }
 131
 132         /* IEEE80211_RADIOTAP_FLAGS */
 133         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 134                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 135         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 136                 *pos |= IEEE80211_RADIOTAP_F_BADFCS;
 137         if (status->flag & RX_FLAG_SHORTPRE)
 138                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 139         pos++;
 140
 141         /* IEEE80211_RADIOTAP_RATE */
 142         if (status->flag & RX_FLAG_HT) {
 143                 /*
 144                  * TODO: add following information into radiotap header once
 145                  * suitable fields are defined for it:
 146                  * - MCS index (status->rate_idx)
 147                  * - HT40 (status->flag & RX_FLAG_40MHZ)
 148                  * - short-GI (status->flag & RX_FLAG_SHORT_GI)
 149                  */
 150                 *pos = 0;
 151         } else {
 152                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 153                 *pos = rate->bitrate / 5;
 154         }
 155         pos++;
 156
 157         /* IEEE80211_RADIOTAP_CHANNEL */
 158         put_unaligned_le16(status->freq, pos);
 159         pos += 2;
 160         if (status->band == IEEE80211_BAND_5GHZ)
 161                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
 162                                    pos);
 163         else if (status->flag & RX_FLAG_HT)
 164                 put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
 165                                    pos);
 166         else if (rate->flags & IEEE80211_RATE_ERP_G)
 167                 put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
 168                                    pos);
 169         else
 170                 put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
 171                                    pos);
 172         pos += 2;
 173
 174         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 175         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 176                 *pos = status->signal;
 177                 rthdr->it_present |=
 178                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 179                 pos++;
 180         }
 181
 182         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
 183         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
 184                 *pos = status->noise;
 185                 rthdr->it_present |=
 186                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
 187                 pos++;
 188         }
 189
 190         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 191
 192         /* IEEE80211_RADIOTAP_ANTENNA */
 193         *pos = status->antenna;
 194         pos++;
 195
 196         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 197
 198         /* IEEE80211_RADIOTAP_RX_FLAGS */
 199         /* ensure 2 byte alignment for the 2 byte field as required */
 200         if ((pos - (u8 *)rthdr) & 1)
 201                 pos++;
 202         if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
 203                 rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
 204         put_unaligned_le16(rx_flags, pos);
 205         pos += 2;
 206 }
 207
 208 /*
 209  * This function copies a received frame to all monitor interfaces and
 210  * returns a cleaned-up SKB that no longer includes the FCS nor the
 211  * radiotap header the driver might have added.
 212  */
 213 static struct sk_buff *
 214 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 215                      struct ieee80211_rate *rate)
 216 {
 217         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
 218         struct ieee80211_sub_if_data *sdata;
 219         int needed_headroom = 0;
 220         struct sk_buff *skb, *skb2;
 221         struct net_device *prev_dev = NULL;
 222         int present_fcs_len = 0;
 223
 224         /*
 225          * First, we may need to make a copy of the skb because
 226          *  (1) we need to modify it for radiotap (if not present), and
 227          *  (2) the other RX handlers will modify the skb we got.
 228          *
 229          * We don't need to, of course, if we aren't going to return
 230          * the SKB because it has a bad FCS/PLCP checksum.
 231          */
 232
 233         /* room for the radiotap header based on driver features */
 234         needed_headroom = ieee80211_rx_radiotap_len(local, status);
 235
 236         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 237                 present_fcs_len = FCS_LEN;
 238
 239         if (!local->monitors) {
 240                 if (should_drop_frame(origskb, present_fcs_len)) {
 241                         dev_kfree_skb(origskb);
 242                         return NULL;
 243                 }
 244
 245                 return remove_monitor_info(local, origskb);
 246         }
 247
 248         if (should_drop_frame(origskb, present_fcs_len)) {
 249                 /* only need to expand headroom if necessary */
 250                 skb = origskb;
 251                 origskb = NULL;
 252
 253                 /*
 254                  * This shouldn't trigger often because most devices have an
 255                  * RX header they pull before we get here, and that should
 256                  * be big enough for our radiotap information. We should
 257                  * probably export the length to drivers so that we can have
 258                  * them allocate enough headroom to start with.
 259                  */
 260                 if (skb_headroom(skb) < needed_headroom &&
 261                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 262                         dev_kfree_skb(skb);
 263                         return NULL;
 264                 }
 265         } else {
 266                 /*
 267                  * Need to make a copy and possibly remove radiotap header
 268                  * and FCS from the original.
 269                  */
 270                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 271
 272                 origskb = remove_monitor_info(local, origskb);
 273
 274                 if (!skb)
 275                         return origskb;
 276         }
 277
 278         /* prepend radiotap information */
 279         ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom);
 280
 281         skb_reset_mac_header(skb);
 282         skb->ip_summed = CHECKSUM_UNNECESSARY;
 283         skb->pkt_type = PACKET_OTHERHOST;
 284         skb->protocol = htons(ETH_P_802_2);
 285
 286         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 287                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 288                         continue;
 289
 290                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 291                         continue;
 292
 293                 if (!ieee80211_sdata_running(sdata))
 294                         continue;
 295
 296                 if (prev_dev) {
 297                         skb2 = skb_clone(skb, GFP_ATOMIC);
 298                         if (skb2) {
 299                                 skb2->dev = prev_dev;
 300                                 netif_rx(skb2);
 301                         }
 302                 }
 303
 304                 prev_dev = sdata->dev;
 305                 sdata->dev->stats.rx_packets++;
 306                 sdata->dev->stats.rx_bytes += skb->len;
 307         }
 308
 309         if (prev_dev) {
 310                 skb->dev = prev_dev;
 311                 netif_rx(skb);
 312         } else
 313                 dev_kfree_skb(skb);
 314
 315         return origskb;
 316 }
 317
 318
 319 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 320 {
 321         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 322         int tid;
 323
 324         /* does the frame have a qos control field? */
 325         if (ieee80211_is_data_qos(hdr->frame_control)) {
 326                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 327                 /* frame has qos control */
 328                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 329                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 330                         rx->flags |= IEEE80211_RX_AMSDU;
 331                 else
 332                         rx->flags &= ~IEEE80211_RX_AMSDU;
 333         } else {
 334                 /*
 335                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 336                  *
 337                  *      Sequence numbers for management frames, QoS data
 338                  *      frames with a broadcast/multicast address in the
 339                  *      Address 1 field, and all non-QoS data frames sent
 340                  *      by QoS STAs are assigned using an additional single
 341                  *      modulo-4096 counter, [...]
 342                  *
 343                  * We also use that counter for non-QoS STAs.
 344                  */
 345                 tid = NUM_RX_DATA_QUEUES - 1;
 346         }
 347
 348         rx->queue = tid;
 349         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 350          * For now, set skb->priority to 0 for other cases. */
 351         rx->skb->priority = (tid > 7) ? 0 : tid;
 352 }
 353
 354 /**
 355  * DOC: Packet alignment
 356  *
 357  * Drivers always need to pass packets that are aligned to two-byte boundaries
 358  * to the stack.
 359  *
 360  * Additionally, should, if possible, align the payload data in a way that
 361  * guarantees that the contained IP header is aligned to a four-byte
 362  * boundary. In the case of regular frames, this simply means aligning the
 363  * payload to a four-byte boundary (because either the IP header is directly
 364  * contained, or IV/RFC1042 headers that have a length divisible by four are
 365  * in front of it).  If the payload data is not properly aligned and the
 366  * architecture doesn't support efficient unaligned operations, mac80211
 367  * will align the data.
 368  *
 369  * With A-MSDU frames, however, the payload data address must yield two modulo
 370  * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 371  * push the IP header further back to a multiple of four again. Thankfully, the
 372  * specs were sane enough this time around to require padding each A-MSDU
 373  * subframe to a length that is a multiple of four.
 374  *
 375  * Padding like Atheros hardware adds which is inbetween the 802.11 header and
 376  * the payload is not supported, the driver is required to move the 802.11
 377  * header to be directly in front of the payload in that case.
 378  */
 379 static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
 380 {
 381 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 382         WARN_ONCE((unsigned long)rx->skb->data & 1,
 383                   "unaligned packet at 0x%p\n", rx->skb->data);
 384 #endif
 385 }
 386
 387
 388 /* rx handlers */
 389
 390 static ieee80211_rx_result debug_noinline
 391 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 392 {
 393         struct ieee80211_local *local = rx->local;
 394         struct sk_buff *skb = rx->skb;
 395
 396         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning)))
 397                 return ieee80211_scan_rx(rx->sdata, skb);
 398
 399         if (unlikely(test_bit(SCAN_SW_SCANNING, &local->scanning) &&
 400                      (rx->flags & IEEE80211_RX_IN_SCAN))) {
 401                 /* drop all the other packets during a software scan anyway */
 402                 if (ieee80211_scan_rx(rx->sdata, skb) != RX_QUEUED)
 403                         dev_kfree_skb(skb);
 404                 return RX_QUEUED;
 405         }
 406
 407         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
 408                 /* scanning finished during invoking of handlers */
 409                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 410                 return RX_DROP_UNUSABLE;
 411         }
 412
 413         return RX_CONTINUE;
 414 }
 415
 416
 417 static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
 418 {
 419         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 420
 421         if (skb->len < 24 || is_multicast_ether_addr(hdr->addr1))
 422                 return 0;
 423
 424         return ieee80211_is_robust_mgmt_frame(hdr);
 425 }
 426
 427
 428 static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
 429 {
 430         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 431
 432         if (skb->len < 24 || !is_multicast_ether_addr(hdr->addr1))
 433                 return 0;
 434
 435         return ieee80211_is_robust_mgmt_frame(hdr);
 436 }
 437
 438
 439 /* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
 440 static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
 441 {
 442         struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
 443         struct ieee80211_mmie *mmie;
 444
 445         if (skb->len < 24 + sizeof(*mmie) ||
 446             !is_multicast_ether_addr(hdr->da))
 447                 return -1;
 448
 449         if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *) hdr))
 450                 return -1; /* not a robust management frame */
 451
 452         mmie = (struct ieee80211_mmie *)
 453                 (skb->data + skb->len - sizeof(*mmie));
 454         if (mmie->element_id != WLAN_EID_MMIE ||
 455             mmie->length != sizeof(*mmie) - 2)
 456                 return -1;
 457
 458         return le16_to_cpu(mmie->key_id);
 459 }
 460
 461
 462 static ieee80211_rx_result
 463 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 464 {
 465         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 466         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 467         char *dev_addr = rx->sdata->vif.addr;
 468
 469         if (ieee80211_is_data(hdr->frame_control)) {
 470                 if (is_multicast_ether_addr(hdr->addr1)) {
 471                         if (ieee80211_has_tods(hdr->frame_control) ||
 472                                 !ieee80211_has_fromds(hdr->frame_control))
 473                                 return RX_DROP_MONITOR;
 474                         if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)
 475                                 return RX_DROP_MONITOR;
 476                 } else {
 477                         if (!ieee80211_has_a4(hdr->frame_control))
 478                                 return RX_DROP_MONITOR;
 479                         if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)
 480                                 return RX_DROP_MONITOR;
 481                 }
 482         }
 483
 484         /* If there is not an established peer link and this is not a peer link
 485          * establisment frame, beacon or probe, drop the frame.
 486          */
 487
 488         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 489                 struct ieee80211_mgmt *mgmt;
 490
 491                 if (!ieee80211_is_mgmt(hdr->frame_control))
 492                         return RX_DROP_MONITOR;
 493
 494                 if (ieee80211_is_action(hdr->frame_control)) {
 495                         mgmt = (struct ieee80211_mgmt *)hdr;
 496                         if (mgmt->u.action.category != MESH_PLINK_CATEGORY)
 497                                 return RX_DROP_MONITOR;
 498                         return RX_CONTINUE;
 499                 }
 500
 501                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 502                     ieee80211_is_probe_resp(hdr->frame_control) ||
 503                     ieee80211_is_beacon(hdr->frame_control))
 504                         return RX_CONTINUE;
 505
 506                 return RX_DROP_MONITOR;
 507
 508         }
 509
 510 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 511
 512         if (ieee80211_is_data(hdr->frame_control) &&
 513             is_multicast_ether_addr(hdr->addr1) &&
 514             mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))
 515                 return RX_DROP_MONITOR;
 516 #undef msh_h_get
 517
 518         return RX_CONTINUE;
 519 }
 520
 521 #define SEQ_MODULO 0x1000
 522 #define SEQ_MASK   0xfff
 523
 524 static inline int seq_less(u16 sq1, u16 sq2)
 525 {
 526         return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
 527 }
 528
 529 static inline u16 seq_inc(u16 sq)
 530 {
 531         return (sq + 1) & SEQ_MASK;
 532 }
 533
 534 static inline u16 seq_sub(u16 sq1, u16 sq2)
 535 {
 536         return (sq1 - sq2) & SEQ_MASK;
 537 }
 538
 539
 540 static void ieee80211_release_reorder_frame(struct ieee80211_hw *hw,
 541                                             struct tid_ampdu_rx *tid_agg_rx,
 542                                             int index,
 543                                             struct sk_buff_head *frames)
 544 {
 545         struct ieee80211_supported_band *sband;
 546         struct ieee80211_rate *rate = NULL;
 547         struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
 548         struct ieee80211_rx_status *status;
 549
 550         if (!skb)
 551                 goto no_frame;
 552
 553         status = IEEE80211_SKB_RXCB(skb);
 554
 555         /* release the reordered frames to stack */
 556         sband = hw->wiphy->bands[status->band];
 557         if (!(status->flag & RX_FLAG_HT))
 558                 rate = &sband->bitrates[status->rate_idx];
 559         tid_agg_rx->stored_mpdu_num--;
 560         tid_agg_rx->reorder_buf[index] = NULL;
 561         __skb_queue_tail(frames, skb);
 562
 563 no_frame:
 564         tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 565 }
 566
 567 static void ieee80211_release_reorder_frames(struct ieee80211_hw *hw,
 568                                              struct tid_ampdu_rx *tid_agg_rx,
 569                                              u16 head_seq_num,
 570                                              struct sk_buff_head *frames)
 571 {
 572         int index;
 573
 574         while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
 575                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 576                                                         tid_agg_rx->buf_size;
 577                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
 578         }
 579 }
 580
 581 /*
 582  * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
 583  * the skb was added to the buffer longer than this time ago, the earlier
 584  * frames that have not yet been received are assumed to be lost and the skb
 585  * can be released for processing. This may also release other skb's from the
 586  * reorder buffer if there are no additional gaps between the frames.
 587  */
 588 #define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
 589
 590 /*
 591  * As this function belongs to the RX path it must be under
 592  * rcu_read_lock protection. It returns false if the frame
 593  * can be processed immediately, true if it was consumed.
 594  */
 595 static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
 596                                              struct tid_ampdu_rx *tid_agg_rx,
 597                                              struct sk_buff *skb,
 598                                              struct sk_buff_head *frames)
 599 {
 600         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 601         u16 sc = le16_to_cpu(hdr->seq_ctrl);
 602         u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
 603         u16 head_seq_num, buf_size;
 604         int index;
 605
 606         buf_size = tid_agg_rx->buf_size;
 607         head_seq_num = tid_agg_rx->head_seq_num;
 608
 609         /* frame with out of date sequence number */
 610         if (seq_less(mpdu_seq_num, head_seq_num)) {
 611                 dev_kfree_skb(skb);
 612                 return true;
 613         }
 614
 615         /*
 616          * If frame the sequence number exceeds our buffering window
 617          * size release some previous frames to make room for this one.
 618          */
 619         if (!seq_less(mpdu_seq_num, head_seq_num + buf_size)) {
 620                 head_seq_num = seq_inc(seq_sub(mpdu_seq_num, buf_size));
 621                 /* release stored frames up to new head to stack */
 622                 ieee80211_release_reorder_frames(hw, tid_agg_rx, head_seq_num,
 623                                                  frames);
 624         }
 625
 626         /* Now the new frame is always in the range of the reordering buffer */
 627
 628         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn) % tid_agg_rx->buf_size;
 629
 630         /* check if we already stored this frame */
 631         if (tid_agg_rx->reorder_buf[index]) {
 632                 dev_kfree_skb(skb);
 633                 return true;
 634         }
 635
 636         /*
 637          * If the current MPDU is in the right order and nothing else
 638          * is stored we can process it directly, no need to buffer it.
 639          */
 640         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
 641             tid_agg_rx->stored_mpdu_num == 0) {
 642                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
 643                 return false;
 644         }
 645
 646         /* put the frame in the reordering buffer */
 647         tid_agg_rx->reorder_buf[index] = skb;
 648         tid_agg_rx->reorder_time[index] = jiffies;
 649         tid_agg_rx->stored_mpdu_num++;
 650         /* release the buffer until next missing frame */
 651         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 652                                                 tid_agg_rx->buf_size;
 653         if (!tid_agg_rx->reorder_buf[index] &&
 654             tid_agg_rx->stored_mpdu_num > 1) {
 655                 /*
 656                  * No buffers ready to be released, but check whether any
 657                  * frames in the reorder buffer have timed out.
 658                  */
 659                 int j;
 660                 int skipped = 1;
 661                 for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
 662                      j = (j + 1) % tid_agg_rx->buf_size) {
 663                         if (!tid_agg_rx->reorder_buf[j]) {
 664                                 skipped++;
 665                                 continue;
 666                         }
 667                         if (!time_after(jiffies, tid_agg_rx->reorder_time[j] +
 668                                         HT_RX_REORDER_BUF_TIMEOUT))
 669                                 break;
 670
 671 #ifdef CONFIG_MAC80211_HT_DEBUG
 672                         if (net_ratelimit())
 673                                 printk(KERN_DEBUG "%s: release an RX reorder "
 674                                        "frame due to timeout on earlier "
 675                                        "frames\n",
 676                                        wiphy_name(hw->wiphy));
 677 #endif
 678                         ieee80211_release_reorder_frame(hw, tid_agg_rx,
 679                                                         j, frames);
 680
 681                         /*
 682                          * Increment the head seq# also for the skipped slots.
 683                          */
 684                         tid_agg_rx->head_seq_num =
 685                                 (tid_agg_rx->head_seq_num + skipped) & SEQ_MASK;
 686                         skipped = 0;
 687                 }
 688         } else while (tid_agg_rx->reorder_buf[index]) {
 689                 ieee80211_release_reorder_frame(hw, tid_agg_rx, index, frames);
 690                 index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn) %
 691                                                         tid_agg_rx->buf_size;
 692         }
 693
 694         return true;
 695 }
 696
 697 /*
 698  * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
 699  * true if the MPDU was buffered, false if it should be processed.
 700  */
 701 static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
 702                                        struct sk_buff_head *frames)
 703 {
 704         struct sk_buff *skb = rx->skb;
 705         struct ieee80211_local *local = rx->local;
 706         struct ieee80211_hw *hw = &local->hw;
 707         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 708         struct sta_info *sta = rx->sta;
 709         struct tid_ampdu_rx *tid_agg_rx;
 710         u16 sc;
 711         int tid;
 712
 713         if (!ieee80211_is_data_qos(hdr->frame_control))
 714                 goto dont_reorder;
 715
 716         /*
 717          * filter the QoS data rx stream according to
 718          * STA/TID and check if this STA/TID is on aggregation
 719          */
 720
 721         if (!sta)
 722                 goto dont_reorder;
 723
 724         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 725
 726         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
 727                 goto dont_reorder;
 728
 729         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
 730
 731         /* qos null data frames are excluded */
 732         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
 733                 goto dont_reorder;
 734
 735         /* new, potentially un-ordered, ampdu frame - process it */
 736
 737         /* reset session timer */
 738         if (tid_agg_rx->timeout)
 739                 mod_timer(&tid_agg_rx->session_timer,
 740                           TU_TO_EXP_TIME(tid_agg_rx->timeout));
 741
 742         /* if this mpdu is fragmented - terminate rx aggregation session */
 743         sc = le16_to_cpu(hdr->seq_ctrl);
 744         if (sc & IEEE80211_SCTL_FRAG) {
 745                 ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
 746                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
 747                 dev_kfree_skb(skb);
 748                 return;
 749         }
 750
 751         if (ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb, frames))
 752                 return;
 753
 754  dont_reorder:
 755         __skb_queue_tail(frames, skb);
 756 }
 757
 758 static ieee80211_rx_result debug_noinline
 759 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 760 {
 761         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 762
 763         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 764         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 765                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 766                              rx->sta->last_seq_ctrl[rx->queue] ==
 767                              hdr->seq_ctrl)) {
 768                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
 769                                 rx->local->dot11FrameDuplicateCount++;
 770                                 rx->sta->num_duplicates++;
 771                         }
 772                         return RX_DROP_MONITOR;
 773                 } else
 774                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 775         }
 776
 777         if (unlikely(rx->skb->len < 16)) {
 778                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 779                 return RX_DROP_MONITOR;
 780         }
 781
 782         /* Drop disallowed frame classes based on STA auth/assoc state;
 783          * IEEE 802.11, Chap 5.5.
 784          *
 785          * mac80211 filters only based on association state, i.e. it drops
 786          * Class 3 frames from not associated stations. hostapd sends
 787          * deauth/disassoc frames when needed. In addition, hostapd is
 788          * responsible for filtering on both auth and assoc states.
 789          */
 790
 791         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 792                 return ieee80211_rx_mesh_check(rx);
 793
 794         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 795                       ieee80211_is_pspoll(hdr->frame_control)) &&
 796                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 797                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 798                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 799                      !ieee80211_has_tods(hdr->frame_control) &&
 800                      ieee80211_is_data(hdr->frame_control)) ||
 801                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
 802                         /* Drop IBSS frames and frames for other hosts
 803                          * silently. */
 804                         return RX_DROP_MONITOR;
 805                 }
 806
 807                 return RX_DROP_MONITOR;
 808         }
 809
 810         return RX_CONTINUE;
 811 }
 812
 813
 814 static ieee80211_rx_result debug_noinline
 815 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 816 {
 817         struct sk_buff *skb = rx->skb;
 818         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 819         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 820         int keyidx;
 821         int hdrlen;
 822         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 823         struct ieee80211_key *stakey = NULL;
 824         int mmie_keyidx = -1;
 825
 826         /*
 827          * Key selection 101
 828          *
 829          * There are four types of keys:
 830          *  - GTK (group keys)
 831          *  - IGTK (group keys for management frames)
 832          *  - PTK (pairwise keys)
 833          *  - STK (station-to-station pairwise keys)
 834          *
 835          * When selecting a key, we have to distinguish between multicast
 836          * (including broadcast) and unicast frames, the latter can only
 837          * use PTKs and STKs while the former always use GTKs and IGTKs.
 838          * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
 839          * unicast frames can also use key indices like GTKs. Hence, if we
 840          * don't have a PTK/STK we check the key index for a WEP key.
 841          *
 842          * Note that in a regular BSS, multicast frames are sent by the
 843          * AP only, associated stations unicast the frame to the AP first
 844          * which then multicasts it on their behalf.
 845          *
 846          * There is also a slight problem in IBSS mode: GTKs are negotiated
 847          * with each station, that is something we don't currently handle.
 848          * The spec seems to expect that one negotiates the same key with
 849          * every station but there's no such requirement; VLANs could be
 850          * possible.
 851          */
 852
 853         /*
 854          * No point in finding a key and decrypting if the frame is neither
 855          * addressed to us nor a multicast frame.
 856          */
 857         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 858                 return RX_CONTINUE;
 859
 860         /* start without a key */
 861         rx->key = NULL;
 862
 863         if (rx->sta)
 864                 stakey = rcu_dereference(rx->sta->key);
 865
 866         if (!ieee80211_has_protected(hdr->frame_control))
 867                 mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
 868
 869         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 870                 rx->key = stakey;
 871                 /* Skip decryption if the frame is not protected. */
 872                 if (!ieee80211_has_protected(hdr->frame_control))
 873                         return RX_CONTINUE;
 874         } else if (mmie_keyidx >= 0) {
 875                 /* Broadcast/multicast robust management frame / BIP */
 876                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 877                     (status->flag & RX_FLAG_IV_STRIPPED))
 878                         return RX_CONTINUE;
 879
 880                 if (mmie_keyidx < NUM_DEFAULT_KEYS ||
 881                     mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
 882                         return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 883                 rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
 884         } else if (!ieee80211_has_protected(hdr->frame_control)) {
 885                 /*
 886                  * The frame was not protected, so skip decryption. However, we
 887                  * need to set rx->key if there is a key that could have been
 888                  * used so that the frame may be dropped if encryption would
 889                  * have been expected.
 890                  */
 891                 struct ieee80211_key *key = NULL;
 892                 if (ieee80211_is_mgmt(hdr->frame_control) &&
 893                     is_multicast_ether_addr(hdr->addr1) &&
 894                     (key = rcu_dereference(rx->sdata->default_mgmt_key)))
 895                         rx->key = key;
 896                 else if ((key = rcu_dereference(rx->sdata->default_key)))
 897                         rx->key = key;
 898                 return RX_CONTINUE;
 899         } else {
 900                 /*
 901                  * The device doesn't give us the IV so we won't be
 902                  * able to look up the key. That's ok though, we
 903                  * don't need to decrypt the frame, we just won't
 904                  * be able to keep statistics accurate.
 905                  * Except for key threshold notifications, should
 906                  * we somehow allow the driver to tell us which key
 907                  * the hardware used if this flag is set?
 908                  */
 909                 if ((status->flag & RX_FLAG_DECRYPTED) &&
 910                     (status->flag & RX_FLAG_IV_STRIPPED))
 911                         return RX_CONTINUE;
 912
 913                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
 914
 915                 if (rx->skb->len < 8 + hdrlen)
 916                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 917
 918                 /*
 919                  * no need to call ieee80211_wep_get_keyidx,
 920                  * it verifies a bunch of things we've done already
 921                  */
 922                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 923
 924                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 925
 926                 /*
 927                  * RSNA-protected unicast frames should always be sent with
 928                  * pairwise or station-to-station keys, but for WEP we allow
 929                  * using a key index as well.
 930                  */
 931                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 932                     !is_multicast_ether_addr(hdr->addr1))
 933                         rx->key = NULL;
 934         }
 935
 936         if (rx->key) {
 937                 rx->key->tx_rx_count++;
 938                 /* TODO: add threshold stuff again */
 939         } else {
 940                 return RX_DROP_MONITOR;
 941         }
 942
 943         /* Check for weak IVs if possible */
 944         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 945             ieee80211_is_data(hdr->frame_control) &&
 946             (!(status->flag & RX_FLAG_IV_STRIPPED) ||
 947              !(status->flag & RX_FLAG_DECRYPTED)) &&
 948             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 949                 rx->sta->wep_weak_iv_count++;
 950
 951         switch (rx->key->conf.alg) {
 952         case ALG_WEP:
 953                 result = ieee80211_crypto_wep_decrypt(rx);
 954                 break;
 955         case ALG_TKIP:
 956                 result = ieee80211_crypto_tkip_decrypt(rx);
 957                 break;
 958         case ALG_CCMP:
 959                 result = ieee80211_crypto_ccmp_decrypt(rx);
 960                 break;
 961         case ALG_AES_CMAC:
 962                 result = ieee80211_crypto_aes_cmac_decrypt(rx);
 963                 break;
 964         }
 965
 966         /* either the frame has been decrypted or will be dropped */
 967         status->flag |= RX_FLAG_DECRYPTED;
 968
 969         return result;
 970 }
 971
 972 static ieee80211_rx_result debug_noinline
 973 ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
 974 {
 975         struct ieee80211_local *local;
 976         struct ieee80211_hdr *hdr;
 977         struct sk_buff *skb;
 978
 979         local = rx->local;
 980         skb = rx->skb;
 981         hdr = (struct ieee80211_hdr *) skb->data;
 982
 983         if (!local->pspolling)
 984                 return RX_CONTINUE;
 985
 986         if (!ieee80211_has_fromds(hdr->frame_control))
 987                 /* this is not from AP */
 988                 return RX_CONTINUE;
 989
 990         if (!ieee80211_is_data(hdr->frame_control))
 991                 return RX_CONTINUE;
 992
 993         if (!ieee80211_has_moredata(hdr->frame_control)) {
 994                 /* AP has no more frames buffered for us */
 995                 local->pspolling = false;
 996                 return RX_CONTINUE;
 997         }
 998
 999         /* more data bit is set, let's request a new frame from the AP */
1000         ieee80211_send_pspoll(local, rx->sdata);
1001
1002         return RX_CONTINUE;
1003 }
1004
1005 static void ap_sta_ps_start(struct sta_info *sta)
1006 {
1007         struct ieee80211_sub_if_data *sdata = sta->sdata;
1008         struct ieee80211_local *local = sdata->local;
1009
1010         atomic_inc(&sdata->bss->num_sta_ps);
1011         set_sta_flags(sta, WLAN_STA_PS_STA);
1012         drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
1013 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1014         printk(KERN_DEBUG "%s: STA %pM aid %d enters power save mode\n",
1015                sdata->name, sta->sta.addr, sta->sta.aid);
1016 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1017 }
1018
1019 static void ap_sta_ps_end(struct sta_info *sta)
1020 {
1021         struct ieee80211_sub_if_data *sdata = sta->sdata;
1022
1023         atomic_dec(&sdata->bss->num_sta_ps);
1024
1025         clear_sta_flags(sta, WLAN_STA_PS_STA);
1026
1027 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1028         printk(KERN_DEBUG "%s: STA %pM aid %d exits power save mode\n",
1029                sdata->name, sta->sta.addr, sta->sta.aid);
1030 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1031
1032         if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) {
1033 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1034                 printk(KERN_DEBUG "%s: STA %pM aid %d driver-ps-blocked\n",
1035                        sdata->name, sta->sta.addr, sta->sta.aid);
1036 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1037                 return;
1038         }
1039
1040         ieee80211_sta_ps_deliver_wakeup(sta);
1041 }
1042
1043 static ieee80211_rx_result debug_noinline
1044 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
1045 {
1046         struct sta_info *sta = rx->sta;
1047         struct sk_buff *skb = rx->skb;
1048         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1049         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1050
1051         if (!sta)
1052                 return RX_CONTINUE;
1053
1054         /*
1055          * Update last_rx only for IBSS packets which are for the current
1056          * BSSID to avoid keeping the current IBSS network alive in cases
1057          * where other STAs start using different BSSID.
1058          */
1059         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1060                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
1061                                                 NL80211_IFTYPE_ADHOC);
1062                 if (compare_ether_addr(bssid, rx->sdata->u.ibss.bssid) == 0)
1063                         sta->last_rx = jiffies;
1064         } else if (!is_multicast_ether_addr(hdr->addr1)) {
1065                 /*
1066                  * Mesh beacons will update last_rx when if they are found to
1067                  * match the current local configuration when processed.
1068                  */
1069                 sta->last_rx = jiffies;
1070         }
1071
1072         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1073                 return RX_CONTINUE;
1074
1075         if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
1076                 ieee80211_sta_rx_notify(rx->sdata, hdr);
1077
1078         sta->rx_fragments++;
1079         sta->rx_bytes += rx->skb->len;
1080         sta->last_signal = status->signal;
1081         sta->last_noise = status->noise;
1082
1083         /*
1084          * Change STA power saving mode only at the end of a frame
1085          * exchange sequence.
1086          */
1087         if (!ieee80211_has_morefrags(hdr->frame_control) &&
1088             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1089              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
1090                 if (test_sta_flags(sta, WLAN_STA_PS_STA)) {
1091                         /*
1092                          * Ignore doze->wake transitions that are
1093                          * indicated by non-data frames, the standard
1094                          * is unclear here, but for example going to
1095                          * PS mode and then scanning would cause a
1096                          * doze->wake transition for the probe request,
1097                          * and that is clearly undesirable.
1098                          */
1099                         if (ieee80211_is_data(hdr->frame_control) &&
1100                             !ieee80211_has_pm(hdr->frame_control))
1101                                 ap_sta_ps_end(sta);
1102                 } else {
1103                         if (ieee80211_has_pm(hdr->frame_control))
1104                                 ap_sta_ps_start(sta);
1105                 }
1106         }
1107
1108         /*
1109          * Drop (qos-)data::nullfunc frames silently, since they
1110          * are used only to control station power saving mode.
1111          */
1112         if (ieee80211_is_nullfunc(hdr->frame_control) ||
1113             ieee80211_is_qos_nullfunc(hdr->frame_control)) {
1114                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
1115
1116                 /*
1117                  * If we receive a 4-addr nullfunc frame from a STA
1118                  * that was not moved to a 4-addr STA vlan yet, drop
1119                  * the frame to the monitor interface, to make sure
1120                  * that hostapd sees it
1121                  */
1122                 if (ieee80211_has_a4(hdr->frame_control) &&
1123                     (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
1124                      (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1125                       !rx->sdata->u.vlan.sta)))
1126                         return RX_DROP_MONITOR;
1127                 /*
1128                  * Update counter and free packet here to avoid
1129                  * counting this as a dropped packed.
1130                  */
1131                 sta->rx_packets++;
1132                 dev_kfree_skb(rx->skb);
1133                 return RX_QUEUED;
1134         }
1135
1136         return RX_CONTINUE;
1137 } /* ieee80211_rx_h_sta_process */
1138
1139 static inline struct ieee80211_fragment_entry *
1140 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
1141                          unsigned int frag, unsigned int seq, int rx_queue,
1142                          struct sk_buff **skb)
1143 {
1144         struct ieee80211_fragment_entry *entry;
1145         int idx;
1146
1147         idx = sdata->fragment_next;
1148         entry = &sdata->fragments[sdata->fragment_next++];
1149         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
1150                 sdata->fragment_next = 0;
1151
1152         if (!skb_queue_empty(&entry->skb_list)) {
1153 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1154                 struct ieee80211_hdr *hdr =
1155                         (struct ieee80211_hdr *) entry->skb_list.next->data;
1156                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
1157                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
1158                        "addr1=%pM addr2=%pM\n",
1159                        sdata->name, idx,
1160                        jiffies - entry->first_frag_time, entry->seq,
1161                        entry->last_frag, hdr->addr1, hdr->addr2);
1162 #endif
1163                 __skb_queue_purge(&entry->skb_list);
1164         }
1165
1166         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
1167         *skb = NULL;
1168         entry->first_frag_time = jiffies;
1169         entry->seq = seq;
1170         entry->rx_queue = rx_queue;
1171         entry->last_frag = frag;
1172         entry->ccmp = 0;
1173         entry->extra_len = 0;
1174
1175         return entry;
1176 }
1177
1178 static inline struct ieee80211_fragment_entry *
1179 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
1180                           unsigned int frag, unsigned int seq,
1181                           int rx_queue, struct ieee80211_hdr *hdr)
1182 {
1183         struct ieee80211_fragment_entry *entry;
1184         int i, idx;
1185
1186         idx = sdata->fragment_next;
1187         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
1188                 struct ieee80211_hdr *f_hdr;
1189
1190                 idx--;
1191                 if (idx < 0)
1192                         idx = IEEE80211_FRAGMENT_MAX - 1;
1193
1194                 entry = &sdata->fragments[idx];
1195                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
1196                     entry->rx_queue != rx_queue ||
1197                     entry->last_frag + 1 != frag)
1198                         continue;
1199
1200                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
1201
1202                 /*
1203                  * Check ftype and addresses are equal, else check next fragment
1204                  */
1205                 if (((hdr->frame_control ^ f_hdr->frame_control) &
1206                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
1207                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
1208                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
1209                         continue;
1210
1211                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
1212                         __skb_queue_purge(&entry->skb_list);
1213                         continue;
1214                 }
1215                 return entry;
1216         }
1217
1218         return NULL;
1219 }
1220
1221 static ieee80211_rx_result debug_noinline
1222 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
1223 {
1224         struct ieee80211_hdr *hdr;
1225         u16 sc;
1226         __le16 fc;
1227         unsigned int frag, seq;
1228         struct ieee80211_fragment_entry *entry;
1229         struct sk_buff *skb;
1230
1231         hdr = (struct ieee80211_hdr *)rx->skb->data;
1232         fc = hdr->frame_control;
1233         sc = le16_to_cpu(hdr->seq_ctrl);
1234         frag = sc & IEEE80211_SCTL_FRAG;
1235
1236         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
1237                    (rx->skb)->len < 24 ||
1238                    is_multicast_ether_addr(hdr->addr1))) {
1239                 /* not fragmented */
1240                 goto out;
1241         }
1242         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
1243
1244         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
1245
1246         if (frag == 0) {
1247                 /* This is the first fragment of a new frame. */
1248                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
1249                                                  rx->queue, &(rx->skb));
1250                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
1251                     ieee80211_has_protected(fc)) {
1252                         /* Store CCMP PN so that we can verify that the next
1253                          * fragment has a sequential PN value. */
1254                         entry->ccmp = 1;
1255                         memcpy(entry->last_pn,
1256                                rx->key->u.ccmp.rx_pn[rx->queue],
1257                                CCMP_PN_LEN);
1258                 }
1259                 return RX_QUEUED;
1260         }
1261
1262         /* This is a fragment for a frame that should already be pending in
1263          * fragment cache. Add this fragment to the end of the pending entry.
1264          */
1265         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
1266         if (!entry) {
1267                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1268                 return RX_DROP_MONITOR;
1269         }
1270
1271         /* Verify that MPDUs within one MSDU have sequential PN values.
1272          * (IEEE 802.11i, 8.3.3.4.5) */
1273         if (entry->ccmp) {
1274                 int i;
1275                 u8 pn[CCMP_PN_LEN], *rpn;
1276                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
1277                         return RX_DROP_UNUSABLE;
1278                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
1279                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
1280                         pn[i]++;
1281                         if (pn[i])
1282                                 break;
1283                 }
1284                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
1285                 if (memcmp(pn, rpn, CCMP_PN_LEN))
1286                         return RX_DROP_UNUSABLE;
1287                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
1288         }
1289
1290         skb_pull(rx->skb, ieee80211_hdrlen(fc));
1291         __skb_queue_tail(&entry->skb_list, rx->skb);
1292         entry->last_frag = frag;
1293         entry->extra_len += rx->skb->len;
1294         if (ieee80211_has_morefrags(fc)) {
1295                 rx->skb = NULL;
1296                 return RX_QUEUED;
1297         }
1298
1299         rx->skb = __skb_dequeue(&entry->skb_list);
1300         if (skb_tailroom(rx->skb) < entry->extra_len) {
1301                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
1302                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
1303                                               GFP_ATOMIC))) {
1304                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
1305                         __skb_queue_purge(&entry->skb_list);
1306                         return RX_DROP_UNUSABLE;
1307                 }
1308         }
1309         while ((skb = __skb_dequeue(&entry->skb_list))) {
1310                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
1311                 dev_kfree_skb(skb);
1312         }
1313
1314         /* Complete frame has been reassembled - process it now */
1315         rx->flags |= IEEE80211_RX_FRAGMENTED;
1316
1317  out:
1318         if (rx->sta)
1319                 rx->sta->rx_packets++;
1320         if (is_multicast_ether_addr(hdr->addr1))
1321                 rx->local->dot11MulticastReceivedFrameCount++;
1322         else
1323                 ieee80211_led_rx(rx->local);
1324         return RX_CONTINUE;
1325 }
1326
1327 static ieee80211_rx_result debug_noinline
1328 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
1329 {
1330         struct ieee80211_sub_if_data *sdata = rx->sdata;
1331         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
1332
1333         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
1334                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
1335                 return RX_CONTINUE;
1336
1337         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
1338             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1339                 return RX_DROP_UNUSABLE;
1340
1341         if (!test_sta_flags(rx->sta, WLAN_STA_PS_DRIVER))
1342                 ieee80211_sta_ps_deliver_poll_response(rx->sta);
1343         else
1344                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1345
1346         /* Free PS Poll skb here instead of returning RX_DROP that would
1347          * count as an dropped frame. */
1348         dev_kfree_skb(rx->skb);
1349
1350         return RX_QUEUED;
1351 }
1352
1353 static ieee80211_rx_result debug_noinline
1354 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1355 {
1356         u8 *data = rx->skb->data;
1357         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1358
1359         if (!ieee80211_is_data_qos(hdr->frame_control))
1360                 return RX_CONTINUE;
1361
1362         /* remove the qos control field, update frame type and meta-data */
1363         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1364                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1365         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1366         /* change frame type to non QOS */
1367         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1368
1369         return RX_CONTINUE;
1370 }
1371
1372 static int
1373 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1374 {
1375         if (unlikely(!rx->sta ||
1376             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1377                 return -EACCES;
1378
1379         return 0;
1380 }
1381
1382 static int
1383 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1384 {
1385         struct sk_buff *skb = rx->skb;
1386         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1387
1388         /*
1389          * Pass through unencrypted frames if the hardware has
1390          * decrypted them already.
1391          */
1392         if (status->flag & RX_FLAG_DECRYPTED)
1393                 return 0;
1394
1395         /* Drop unencrypted frames if key is set. */
1396         if (unlikely(!ieee80211_has_protected(fc) &&
1397                      !ieee80211_is_nullfunc(fc) &&
1398                      ieee80211_is_data(fc) &&
1399                      (rx->key || rx->sdata->drop_unencrypted)))
1400                 return -EACCES;
1401
1402         return 0;
1403 }
1404
1405 static int
1406 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
1407 {
1408         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1409         __le16 fc = hdr->frame_control;
1410         int res;
1411
1412         res = ieee80211_drop_unencrypted(rx, fc);
1413         if (unlikely(res))
1414                 return res;
1415
1416         if (rx->sta && test_sta_flags(rx->sta, WLAN_STA_MFP)) {
1417                 if (unlikely(ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
1418                              rx->key))
1419                         return -EACCES;
1420                 /* BIP does not use Protected field, so need to check MMIE */
1421                 if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
1422                              ieee80211_get_mmie_keyidx(rx->skb) < 0 &&
1423                              rx->key))
1424                         return -EACCES;
1425                 /*
1426                  * When using MFP, Action frames are not allowed prior to
1427                  * having configured keys.
1428                  */
1429                 if (unlikely(ieee80211_is_action(fc) && !rx->key &&
1430                              ieee80211_is_robust_mgmt_frame(
1431                                      (struct ieee80211_hdr *) rx->skb->data)))
1432                         return -EACCES;
1433         }
1434
1435         return 0;
1436 }
1437
1438 static int
1439 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1440 {
1441         struct ieee80211_sub_if_data *sdata = rx->sdata;
1442         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1443
1444         if (ieee80211_has_a4(hdr->frame_control) &&
1445             sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
1446                 return -1;
1447
1448         if (is_multicast_ether_addr(hdr->addr1) &&
1449             ((sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta) ||
1450              (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.use_4addr)))
1451                 return -1;
1452
1453         return ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
1454 }
1455
1456 /*
1457  * requires that rx->skb is a frame with ethernet header
1458  */
1459 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1460 {
1461         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1462                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1463         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1464
1465         /*
1466          * Allow EAPOL frames to us/the PAE group address regardless
1467          * of whether the frame was encrypted or not.
1468          */
1469         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1470             (compare_ether_addr(ehdr->h_dest, rx->sdata->vif.addr) == 0 ||
1471              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1472                 return true;
1473
1474         if (ieee80211_802_1x_port_control(rx) ||
1475             ieee80211_drop_unencrypted(rx, fc))
1476                 return false;
1477
1478         return true;
1479 }
1480
1481 /*
1482  * requires that rx->skb is a frame with ethernet header
1483  */
1484 static void
1485 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1486 {
1487         struct ieee80211_sub_if_data *sdata = rx->sdata;
1488         struct net_device *dev = sdata->dev;
1489         struct sk_buff *skb, *xmit_skb;
1490         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1491         struct sta_info *dsta;
1492
1493         skb = rx->skb;
1494         xmit_skb = NULL;
1495
1496         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1497              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1498             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1499             (rx->flags & IEEE80211_RX_RA_MATCH) &&
1500             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
1501                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1502                         /*
1503                          * send multicast frames both to higher layers in
1504                          * local net stack and back to the wireless medium
1505                          */
1506                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1507                         if (!xmit_skb && net_ratelimit())
1508                                 printk(KERN_DEBUG "%s: failed to clone "
1509                                        "multicast frame\n", dev->name);
1510                 } else {
1511                         dsta = sta_info_get(sdata, skb->data);
1512                         if (dsta) {
1513                                 /*
1514                                  * The destination station is associated to
1515                                  * this AP (in this VLAN), so send the frame
1516                                  * directly to it and do not pass it to local
1517                                  * net stack.
1518                                  */
1519                                 xmit_skb = skb;
1520                                 skb = NULL;
1521                         }
1522                 }
1523         }
1524
1525         if (skb) {
1526                 int align __maybe_unused;
1527
1528 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
1529                 /*
1530                  * 'align' will only take the values 0 or 2 here
1531                  * since all frames are required to be aligned
1532                  * to 2-byte boundaries when being passed to
1533                  * mac80211. That also explains the __skb_push()
1534                  * below.
1535                  */
1536                 align = ((unsigned long)(skb->data + sizeof(struct ethhdr))) & 3;
1537                 if (align) {
1538                         if (WARN_ON(skb_headroom(skb) < 3)) {
1539                                 dev_kfree_skb(skb);
1540                                 skb = NULL;
1541                         } else {
1542                                 u8 *data = skb->data;
1543                                 size_t len = skb_headlen(skb);
1544                                 skb->data -= align;
1545                                 memmove(skb->data, data, len);
1546                                 skb_set_tail_pointer(skb, len);
1547                         }
1548                 }
1549 #endif
1550
1551                 if (skb) {
1552                         /* deliver to local stack */
1553                         skb->protocol = eth_type_trans(skb, dev);
1554                         memset(skb->cb, 0, sizeof(skb->cb));
1555                         netif_rx(skb);
1556                 }
1557         }
1558
1559         if (xmit_skb) {
1560                 /* send to wireless media */
1561                 xmit_skb->protocol = htons(ETH_P_802_3);
1562                 skb_reset_network_header(xmit_skb);
1563                 skb_reset_mac_header(xmit_skb);
1564                 dev_queue_xmit(xmit_skb);
1565         }
1566 }
1567
1568 static ieee80211_rx_result debug_noinline
1569 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1570 {
1571         struct net_device *dev = rx->sdata->dev;
1572         struct sk_buff *skb = rx->skb;
1573         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1574         __le16 fc = hdr->frame_control;
1575         struct sk_buff_head frame_list;
1576
1577         if (unlikely(!ieee80211_is_data(fc)))
1578                 return RX_CONTINUE;
1579
1580         if (unlikely(!ieee80211_is_data_present(fc)))
1581                 return RX_DROP_MONITOR;
1582
1583         if (!(rx->flags & IEEE80211_RX_AMSDU))
1584                 return RX_CONTINUE;
1585
1586         if (ieee80211_has_a4(hdr->frame_control) &&
1587             rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1588             !rx->sdata->u.vlan.sta)
1589                 return RX_DROP_UNUSABLE;
1590
1591         if (is_multicast_ether_addr(hdr->addr1) &&
1592             ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1593               rx->sdata->u.vlan.sta) ||
1594              (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1595               rx->sdata->u.mgd.use_4addr)))
1596                 return RX_DROP_UNUSABLE;
1597
1598         skb->dev = dev;
1599         __skb_queue_head_init(&frame_list);
1600
1601         ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
1602                                  rx->sdata->vif.type,
1603                                  rx->local->hw.extra_tx_headroom);
1604
1605         while (!skb_queue_empty(&frame_list)) {
1606                 rx->skb = __skb_dequeue(&frame_list);
1607
1608                 if (!ieee80211_frame_allowed(rx, fc)) {
1609                         dev_kfree_skb(rx->skb);
1610                         continue;
1611                 }
1612                 dev->stats.rx_packets++;
1613                 dev->stats.rx_bytes += rx->skb->len;
1614
1615                 ieee80211_deliver_skb(rx);
1616         }
1617
1618         return RX_QUEUED;
1619 }
1620
1621 #ifdef CONFIG_MAC80211_MESH
1622 static ieee80211_rx_result
1623 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1624 {
1625         struct ieee80211_hdr *hdr;
1626         struct ieee80211s_hdr *mesh_hdr;
1627         unsigned int hdrlen;
1628         struct sk_buff *skb = rx->skb, *fwd_skb;
1629         struct ieee80211_local *local = rx->local;
1630         struct ieee80211_sub_if_data *sdata = rx->sdata;
1631
1632         hdr = (struct ieee80211_hdr *) skb->data;
1633         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1634         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1635
1636         if (!ieee80211_is_data(hdr->frame_control))
1637                 return RX_CONTINUE;
1638
1639         if (!mesh_hdr->ttl)
1640                 /* illegal frame */
1641                 return RX_DROP_MONITOR;
1642
1643         if (mesh_hdr->flags & MESH_FLAGS_AE) {
1644                 struct mesh_path *mppath;
1645                 char *proxied_addr;
1646                 char *mpp_addr;
1647
1648                 if (is_multicast_ether_addr(hdr->addr1)) {
1649                         mpp_addr = hdr->addr3;
1650                         proxied_addr = mesh_hdr->eaddr1;
1651                 } else {
1652                         mpp_addr = hdr->addr4;
1653                         proxied_addr = mesh_hdr->eaddr2;
1654                 }
1655
1656                 rcu_read_lock();
1657                 mppath = mpp_path_lookup(proxied_addr, sdata);
1658                 if (!mppath) {
1659                         mpp_path_add(proxied_addr, mpp_addr, sdata);
1660                 } else {
1661                         spin_lock_bh(&mppath->state_lock);
1662                         if (compare_ether_addr(mppath->mpp, mpp_addr) != 0)
1663                                 memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
1664                         spin_unlock_bh(&mppath->state_lock);
1665                 }
1666                 rcu_read_unlock();
1667         }
1668
1669         /* Frame has reached destination.  Don't forward */
1670         if (!is_multicast_ether_addr(hdr->addr1) &&
1671             compare_ether_addr(sdata->vif.addr, hdr->addr3) == 0)
1672                 return RX_CONTINUE;
1673
1674         mesh_hdr->ttl--;
1675
1676         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1677                 if (!mesh_hdr->ttl)
1678                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1679                                                      dropped_frames_ttl);
1680                 else {
1681                         struct ieee80211_hdr *fwd_hdr;
1682                         struct ieee80211_tx_info *info;
1683
1684                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1685
1686                         if (!fwd_skb && net_ratelimit())
1687                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1688                                                    sdata->name);
1689
1690                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1691                         memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
1692                         info = IEEE80211_SKB_CB(fwd_skb);
1693                         memset(info, 0, sizeof(*info));
1694                         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1695                         info->control.vif = &rx->sdata->vif;
1696                         skb_set_queue_mapping(skb,
1697                                 ieee80211_select_queue(rx->sdata, fwd_skb));
1698                         ieee80211_set_qos_hdr(local, skb);
1699                         if (is_multicast_ether_addr(fwd_hdr->addr1))
1700                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1701                                                                 fwded_mcast);
1702                         else {
1703                                 int err;
1704                                 /*
1705                                  * Save TA to addr1 to send TA a path error if a
1706                                  * suitable next hop is not found
1707                                  */
1708                                 memcpy(fwd_hdr->addr1, fwd_hdr->addr2,
1709                                                 ETH_ALEN);
1710                                 err = mesh_nexthop_lookup(fwd_skb, sdata);
1711                                 /* Failed to immediately resolve next hop:
1712                                  * fwded frame was dropped or will be added
1713                                  * later to the pending skb queue.  */
1714                                 if (err)
1715                                         return RX_DROP_MONITOR;
1716
1717                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1718                                                                 fwded_unicast);
1719                         }
1720                         IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.mesh,
1721                                                      fwded_frames);
1722                         ieee80211_add_pending_skb(local, fwd_skb);
1723                 }
1724         }
1725
1726         if (is_multicast_ether_addr(hdr->addr1) ||
1727             sdata->dev->flags & IFF_PROMISC)
1728                 return RX_CONTINUE;
1729         else
1730                 return RX_DROP_MONITOR;
1731 }
1732 #endif
1733
1734 static ieee80211_rx_result debug_noinline
1735 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1736 {
1737         struct ieee80211_sub_if_data *sdata = rx->sdata;
1738         struct ieee80211_local *local = rx->local;
1739         struct net_device *dev = sdata->dev;
1740         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1741         __le16 fc = hdr->frame_control;
1742         int err;
1743
1744         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1745                 return RX_CONTINUE;
1746
1747         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1748                 return RX_DROP_MONITOR;
1749
1750         /*
1751          * Allow the cooked monitor interface of an AP to see 4-addr frames so
1752          * that a 4-addr station can be detected and moved into a separate VLAN
1753          */
1754         if (ieee80211_has_a4(hdr->frame_control) &&
1755             sdata->vif.type == NL80211_IFTYPE_AP)
1756                 return RX_DROP_MONITOR;
1757
1758         err = __ieee80211_data_to_8023(rx);
1759         if (unlikely(err))
1760                 return RX_DROP_UNUSABLE;
1761
1762         if (!ieee80211_frame_allowed(rx, fc))
1763                 return RX_DROP_MONITOR;
1764
1765         rx->skb->dev = dev;
1766
1767         dev->stats.rx_packets++;
1768         dev->stats.rx_bytes += rx->skb->len;
1769
1770         if (ieee80211_is_data(hdr->frame_control) &&
1771             !is_multicast_ether_addr(hdr->addr1) &&
1772             local->hw.conf.dynamic_ps_timeout > 0 && local->ps_sdata) {
1773                         mod_timer(&local->dynamic_ps_timer, jiffies +
1774                          msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1775         }
1776
1777         ieee80211_deliver_skb(rx);
1778
1779         return RX_QUEUED;
1780 }
1781
1782 static ieee80211_rx_result debug_noinline
1783 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
1784 {
1785         struct ieee80211_local *local = rx->local;
1786         struct ieee80211_hw *hw = &local->hw;
1787         struct sk_buff *skb = rx->skb;
1788         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1789         struct tid_ampdu_rx *tid_agg_rx;
1790         u16 start_seq_num;
1791         u16 tid;
1792
1793         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1794                 return RX_CONTINUE;
1795
1796         if (ieee80211_is_back_req(bar->frame_control)) {
1797                 if (!rx->sta)
1798                         return RX_DROP_MONITOR;
1799                 tid = le16_to_cpu(bar->control) >> 12;
1800                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1801                                         != HT_AGG_STATE_OPERATIONAL)
1802                         return RX_DROP_MONITOR;
1803                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1804
1805                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1806
1807                 /* reset session timer */
1808                 if (tid_agg_rx->timeout)
1809                         mod_timer(&tid_agg_rx->session_timer,
1810                                   TU_TO_EXP_TIME(tid_agg_rx->timeout));
1811
1812                 /* release stored frames up to start of BAR */
1813                 ieee80211_release_reorder_frames(hw, tid_agg_rx, start_seq_num,
1814                                                  frames);
1815                 kfree_skb(skb);
1816                 return RX_QUEUED;
1817         }
1818
1819         return RX_CONTINUE;
1820 }
1821
1822 static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
1823                                            struct ieee80211_mgmt *mgmt,
1824                                            size_t len)
1825 {
1826         struct ieee80211_local *local = sdata->local;
1827         struct sk_buff *skb;
1828         struct ieee80211_mgmt *resp;
1829
1830         if (compare_ether_addr(mgmt->da, sdata->vif.addr) != 0) {
1831                 /* Not to own unicast address */
1832                 return;
1833         }
1834
1835         if (compare_ether_addr(mgmt->sa, sdata->u.mgd.bssid) != 0 ||
1836             compare_ether_addr(mgmt->bssid, sdata->u.mgd.bssid) != 0) {
1837                 /* Not from the current AP or not associated yet. */
1838                 return;
1839         }
1840
1841         if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
1842                 /* Too short SA Query request frame */
1843                 return;
1844         }
1845
1846         skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
1847         if (skb == NULL)
1848                 return;
1849
1850         skb_reserve(skb, local->hw.extra_tx_headroom);
1851         resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
1852         memset(resp, 0, 24);
1853         memcpy(resp->da, mgmt->sa, ETH_ALEN);
1854         memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
1855         memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
1856         resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1857                                           IEEE80211_STYPE_ACTION);
1858         skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
1859         resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
1860         resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
1861         memcpy(resp->u.action.u.sa_query.trans_id,
1862                mgmt->u.action.u.sa_query.trans_id,
1863                WLAN_SA_QUERY_TR_ID_LEN);
1864
1865         ieee80211_tx_skb(sdata, skb);
1866 }
1867
1868 static ieee80211_rx_result debug_noinline
1869 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1870 {
1871         struct ieee80211_local *local = rx->local;
1872         struct ieee80211_sub_if_data *sdata = rx->sdata;
1873         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1874         struct sk_buff *nskb;
1875         struct ieee80211_rx_status *status;
1876         int len = rx->skb->len;
1877
1878         if (!ieee80211_is_action(mgmt->frame_control))
1879                 return RX_CONTINUE;
1880
1881         /* drop too small frames */
1882         if (len < IEEE80211_MIN_ACTION_SIZE)
1883                 return RX_DROP_UNUSABLE;
1884
1885         if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC)
1886                 return RX_DROP_UNUSABLE;
1887
1888         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1889                 return RX_DROP_UNUSABLE;
1890
1891         if (ieee80211_drop_unencrypted_mgmt(rx))
1892                 return RX_DROP_UNUSABLE;
1893
1894         switch (mgmt->u.action.category) {
1895         case WLAN_CATEGORY_BACK:
1896                 /*
1897                  * The aggregation code is not prepared to handle
1898                  * anything but STA/AP due to the BSSID handling;
1899                  * IBSS could work in the code but isn't supported
1900                  * by drivers or the standard.
1901                  */
1902                 if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1903                     sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
1904                     sdata->vif.type != NL80211_IFTYPE_AP)
1905                         break;
1906
1907                 /* verify action_code is present */
1908                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1909                         break;
1910
1911                 switch (mgmt->u.action.u.addba_req.action_code) {
1912                 case WLAN_ACTION_ADDBA_REQ:
1913                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1914                                    sizeof(mgmt->u.action.u.addba_req)))
1915                                 return RX_DROP_MONITOR;
1916                         ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1917                         goto handled;
1918                 case WLAN_ACTION_ADDBA_RESP:
1919                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1920                                    sizeof(mgmt->u.action.u.addba_resp)))
1921                                 break;
1922                         ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1923                         goto handled;
1924                 case WLAN_ACTION_DELBA:
1925                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1926                                    sizeof(mgmt->u.action.u.delba)))
1927                                 break;
1928                         ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1929                         goto handled;
1930                 }
1931                 break;
1932         case WLAN_CATEGORY_SPECTRUM_MGMT:
1933                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1934                         break;
1935
1936                 if (sdata->vif.type != NL80211_IFTYPE_STATION)
1937                         break;
1938
1939                 /* verify action_code is present */
1940                 if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1941                         break;
1942
1943                 switch (mgmt->u.action.u.measurement.action_code) {
1944                 case WLAN_ACTION_SPCT_MSR_REQ:
1945                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1946                                    sizeof(mgmt->u.action.u.measurement)))
1947                                 break;
1948                         ieee80211_process_measurement_req(sdata, mgmt, len);
1949                         goto handled;
1950                 case WLAN_ACTION_SPCT_CHL_SWITCH:
1951                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1952                                    sizeof(mgmt->u.action.u.chan_switch)))
1953                                 break;
1954
1955                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1956                                 break;
1957
1958                         if (memcmp(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN))
1959                                 break;
1960
1961                         return ieee80211_sta_rx_mgmt(sdata, rx->skb);
1962                 }
1963                 break;
1964         case WLAN_CATEGORY_SA_QUERY:
1965                 if (len < (IEEE80211_MIN_ACTION_SIZE +
1966                            sizeof(mgmt->u.action.u.sa_query)))
1967                         break;
1968
1969                 switch (mgmt->u.action.u.sa_query.action) {
1970                 case WLAN_ACTION_SA_QUERY_REQUEST:
1971                         if (sdata->vif.type != NL80211_IFTYPE_STATION)
1972                                 break;
1973                         ieee80211_process_sa_query_req(sdata, mgmt, len);
1974                         goto handled;
1975                 }
1976                 break;
1977         case MESH_PLINK_CATEGORY:
1978         case MESH_PATH_SEL_CATEGORY:
1979                 if (ieee80211_vif_is_mesh(&sdata->vif))
1980                         return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
1981                 break;
1982         }
1983
1984         /*
1985          * For AP mode, hostapd is responsible for handling any action
1986          * frames that we didn't handle, including returning unknown
1987          * ones. For all other modes we will return them to the sender,
1988          * setting the 0x80 bit in the action category, as required by
1989          * 802.11-2007 7.3.1.11.
1990          */
1991         if (sdata->vif.type == NL80211_IFTYPE_AP ||
1992             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
1993                 return RX_DROP_MONITOR;
1994
1995         /*
1996          * Getting here means the kernel doesn't know how to handle
1997          * it, but maybe userspace does ... include returned frames
1998          * so userspace can register for those to know whether ones
1999          * it transmitted were processed or returned.
2000          */
2001         status = IEEE80211_SKB_RXCB(rx->skb);
2002
2003         if (sdata->vif.type == NL80211_IFTYPE_STATION &&
2004             cfg80211_rx_action(rx->sdata->dev, status->freq,
2005                                rx->skb->data, rx->skb->len,
2006                                GFP_ATOMIC))
2007                 goto handled;
2008
2009         /* do not return rejected action frames */
2010         if (mgmt->u.action.category & 0x80)
2011                 return RX_DROP_UNUSABLE;
2012
2013         nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
2014                                GFP_ATOMIC);
2015         if (nskb) {
2016                 struct ieee80211_mgmt *mgmt = (void *)nskb->data;
2017
2018                 mgmt->u.action.category |= 0x80;
2019                 memcpy(mgmt->da, mgmt->sa, ETH_ALEN);
2020                 memcpy(mgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
2021
2022                 memset(nskb->cb, 0, sizeof(nskb->cb));
2023
2024                 ieee80211_tx_skb(rx->sdata, nskb);
2025         }
2026
2027  handled:
2028         if (rx->sta)
2029                 rx->sta->rx_packets++;
2030         dev_kfree_skb(rx->skb);
2031         return RX_QUEUED;
2032 }
2033
2034 static ieee80211_rx_result debug_noinline
2035 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
2036 {
2037         struct ieee80211_sub_if_data *sdata = rx->sdata;
2038         ieee80211_rx_result rxs;
2039
2040         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
2041                 return RX_DROP_MONITOR;
2042
2043         if (ieee80211_drop_unencrypted_mgmt(rx))
2044                 return RX_DROP_UNUSABLE;
2045
2046         rxs = ieee80211_work_rx_mgmt(rx->sdata, rx->skb);
2047         if (rxs != RX_CONTINUE)
2048                 return rxs;
2049
2050         if (ieee80211_vif_is_mesh(&sdata->vif))
2051                 return ieee80211_mesh_rx_mgmt(sdata, rx->skb);
2052
2053         if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
2054                 return ieee80211_ibss_rx_mgmt(sdata, rx->skb);
2055
2056         if (sdata->vif.type == NL80211_IFTYPE_STATION)
2057                 return ieee80211_sta_rx_mgmt(sdata, rx->skb);
2058
2059         return RX_DROP_MONITOR;
2060 }
2061
2062 static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
2063                                             struct ieee80211_rx_data *rx)
2064 {
2065         int keyidx;
2066         unsigned int hdrlen;
2067
2068         hdrlen = ieee80211_hdrlen(hdr->frame_control);
2069         if (rx->skb->len >= hdrlen + 4)
2070                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
2071         else
2072                 keyidx = -1;
2073
2074         if (!rx->sta) {
2075                 /*
2076                  * Some hardware seem to generate incorrect Michael MIC
2077                  * reports; ignore them to avoid triggering countermeasures.
2078                  */
2079                 return;
2080         }
2081
2082         if (!ieee80211_has_protected(hdr->frame_control))
2083                 return;
2084
2085         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
2086                 /*
2087                  * APs with pairwise keys should never receive Michael MIC
2088                  * errors for non-zero keyidx because these are reserved for
2089                  * group keys and only the AP is sending real multicast
2090                  * frames in the BSS.
2091                  */
2092                 return;
2093         }
2094
2095         if (!ieee80211_is_data(hdr->frame_control) &&
2096             !ieee80211_is_auth(hdr->frame_control))
2097                 return;
2098
2099         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
2100                                         GFP_ATOMIC);
2101 }
2102
2103 /* TODO: use IEEE80211_RX_FRAGMENTED */
2104 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
2105                                         struct ieee80211_rate *rate)
2106 {
2107         struct ieee80211_sub_if_data *sdata;
2108         struct ieee80211_local *local = rx->local;
2109         struct ieee80211_rtap_hdr {
2110                 struct ieee80211_radiotap_header hdr;
2111                 u8 flags;
2112                 u8 rate_or_pad;
2113                 __le16 chan_freq;
2114                 __le16 chan_flags;
2115         } __attribute__ ((packed)) *rthdr;
2116         struct sk_buff *skb = rx->skb, *skb2;
2117         struct net_device *prev_dev = NULL;
2118         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2119
2120         if (status->flag & RX_FLAG_INTERNAL_CMTR)
2121                 goto out_free_skb;
2122
2123         if (skb_headroom(skb) < sizeof(*rthdr) &&
2124             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
2125                 goto out_free_skb;
2126
2127         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
2128         memset(rthdr, 0, sizeof(*rthdr));
2129         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
2130         rthdr->hdr.it_present =
2131                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
2132                             (1 << IEEE80211_RADIOTAP_CHANNEL));
2133
2134         if (rate) {
2135                 rthdr->rate_or_pad = rate->bitrate / 5;
2136                 rthdr->hdr.it_present |=
2137                         cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
2138         }
2139         rthdr->chan_freq = cpu_to_le16(status->freq);
2140
2141         if (status->band == IEEE80211_BAND_5GHZ)
2142                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
2143                                                 IEEE80211_CHAN_5GHZ);
2144         else
2145                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
2146                                                 IEEE80211_CHAN_2GHZ);
2147
2148         skb_set_mac_header(skb, 0);
2149         skb->ip_summed = CHECKSUM_UNNECESSARY;
2150         skb->pkt_type = PACKET_OTHERHOST;
2151         skb->protocol = htons(ETH_P_802_2);
2152
2153         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2154                 if (!ieee80211_sdata_running(sdata))
2155                         continue;
2156
2157                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
2158                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
2159                         continue;
2160
2161                 if (prev_dev) {
2162                         skb2 = skb_clone(skb, GFP_ATOMIC);
2163                         if (skb2) {
2164                                 skb2->dev = prev_dev;
2165                                 netif_rx(skb2);
2166                         }
2167                 }
2168
2169                 prev_dev = sdata->dev;
2170                 sdata->dev->stats.rx_packets++;
2171                 sdata->dev->stats.rx_bytes += skb->len;
2172         }
2173
2174         if (prev_dev) {
2175                 skb->dev = prev_dev;
2176                 netif_rx(skb);
2177                 skb = NULL;
2178         } else
2179                 goto out_free_skb;
2180
2181         status->flag |= RX_FLAG_INTERNAL_CMTR;
2182         return;
2183
2184  out_free_skb:
2185         dev_kfree_skb(skb);
2186 }
2187
2188
2189 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
2190                                          struct ieee80211_rx_data *rx,
2191                                          struct sk_buff *skb,
2192                                          struct ieee80211_rate *rate)
2193 {
2194         struct sk_buff_head reorder_release;
2195         ieee80211_rx_result res = RX_DROP_MONITOR;
2196
2197         __skb_queue_head_init(&reorder_release);
2198
2199         rx->skb = skb;
2200         rx->sdata = sdata;
2201
2202 #define CALL_RXH(rxh)                   \
2203         do {                            \
2204                 res = rxh(rx);          \
2205                 if (res != RX_CONTINUE) \
2206                         goto rxh_next;  \
2207         } while (0);
2208
2209         /*
2210          * NB: the rxh_next label works even if we jump
2211          *     to it from here because then the list will
2212          *     be empty, which is a trivial check
2213          */
2214         CALL_RXH(ieee80211_rx_h_passive_scan)
2215         CALL_RXH(ieee80211_rx_h_check)
2216
2217         ieee80211_rx_reorder_ampdu(rx, &reorder_release);
2218
2219         while ((skb = __skb_dequeue(&reorder_release))) {
2220                 /*
2221                  * all the other fields are valid across frames
2222                  * that belong to an aMPDU since they are on the
2223                  * same TID from the same station
2224                  */
2225                 rx->skb = skb;
2226
2227                 CALL_RXH(ieee80211_rx_h_decrypt)
2228                 CALL_RXH(ieee80211_rx_h_check_more_data)
2229                 CALL_RXH(ieee80211_rx_h_sta_process)
2230                 CALL_RXH(ieee80211_rx_h_defragment)
2231                 CALL_RXH(ieee80211_rx_h_ps_poll)
2232                 CALL_RXH(ieee80211_rx_h_michael_mic_verify)
2233                 /* must be after MMIC verify so header is counted in MPDU mic */
2234                 CALL_RXH(ieee80211_rx_h_remove_qos_control)
2235                 CALL_RXH(ieee80211_rx_h_amsdu)
2236 #ifdef CONFIG_MAC80211_MESH
2237                 if (ieee80211_vif_is_mesh(&sdata->vif))
2238                         CALL_RXH(ieee80211_rx_h_mesh_fwding);
2239 #endif
2240                 CALL_RXH(ieee80211_rx_h_data)
2241
2242                 /* special treatment -- needs the queue */
2243                 res = ieee80211_rx_h_ctrl(rx, &reorder_release);
2244                 if (res != RX_CONTINUE)
2245                         goto rxh_next;
2246
2247                 CALL_RXH(ieee80211_rx_h_action)
2248                 CALL_RXH(ieee80211_rx_h_mgmt)
2249
2250 #undef CALL_RXH
2251
2252  rxh_next:
2253                 switch (res) {
2254                 case RX_DROP_MONITOR:
2255                         I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2256                         if (rx->sta)
2257                                 rx->sta->rx_dropped++;
2258                         /* fall through */
2259                 case RX_CONTINUE:
2260                         ieee80211_rx_cooked_monitor(rx, rate);
2261                         break;
2262                 case RX_DROP_UNUSABLE:
2263                         I802_DEBUG_INC(sdata->local->rx_handlers_drop);
2264                         if (rx->sta)
2265                                 rx->sta->rx_dropped++;
2266                         dev_kfree_skb(rx->skb);
2267                         break;
2268                 case RX_QUEUED:
2269                         I802_DEBUG_INC(sdata->local->rx_handlers_queued);
2270                         break;
2271                 }
2272         }
2273 }
2274
2275 /* main receive path */
2276
2277 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
2278                                 struct ieee80211_rx_data *rx,
2279                                 struct ieee80211_hdr *hdr)
2280 {
2281         struct sk_buff *skb = rx->skb;
2282         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2283         u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
2284         int multicast = is_multicast_ether_addr(hdr->addr1);
2285
2286         switch (sdata->vif.type) {
2287         case NL80211_IFTYPE_STATION:
2288                 if (!bssid && !sdata->u.mgd.use_4addr)
2289                         return 0;
2290                 if (!multicast &&
2291                     compare_ether_addr(sdata->vif.addr, hdr->addr1) != 0) {
2292                         if (!(sdata->dev->flags & IFF_PROMISC))
2293                                 return 0;
2294                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2295                 }
2296                 break;
2297         case NL80211_IFTYPE_ADHOC:
2298                 if (!bssid)
2299                         return 0;
2300                 if (ieee80211_is_beacon(hdr->frame_control)) {
2301                         return 1;
2302                 }
2303                 else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
2304                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2305                                 return 0;
2306                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2307                 } else if (!multicast &&
2308                            compare_ether_addr(sdata->vif.addr,
2309                                               hdr->addr1) != 0) {
2310                         if (!(sdata->dev->flags & IFF_PROMISC))
2311                                 return 0;
2312                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2313                 } else if (!rx->sta) {
2314                         int rate_idx;
2315                         if (status->flag & RX_FLAG_HT)
2316                                 rate_idx = 0; /* TODO: HT rates */
2317                         else
2318                                 rate_idx = status->rate_idx;
2319                         rx->sta = ieee80211_ibss_add_sta(sdata, bssid,
2320                                         hdr->addr2, BIT(rate_idx), GFP_ATOMIC);
2321                 }
2322                 break;
2323         case NL80211_IFTYPE_MESH_POINT:
2324                 if (!multicast &&
2325                     compare_ether_addr(sdata->vif.addr,
2326                                        hdr->addr1) != 0) {
2327                         if (!(sdata->dev->flags & IFF_PROMISC))
2328                                 return 0;
2329
2330                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2331                 }
2332                 break;
2333         case NL80211_IFTYPE_AP_VLAN:
2334         case NL80211_IFTYPE_AP:
2335                 if (!bssid) {
2336                         if (compare_ether_addr(sdata->vif.addr,
2337                                                hdr->addr1))
2338                                 return 0;
2339                 } else if (!ieee80211_bssid_match(bssid,
2340                                         sdata->vif.addr)) {
2341                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
2342                                 return 0;
2343                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
2344                 }
2345                 break;
2346         case NL80211_IFTYPE_WDS:
2347                 if (bssid || !ieee80211_is_data(hdr->frame_control))
2348                         return 0;
2349                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
2350                         return 0;
2351                 break;
2352         case NL80211_IFTYPE_MONITOR:
2353         case NL80211_IFTYPE_UNSPECIFIED:
2354         case __NL80211_IFTYPE_AFTER_LAST:
2355                 /* should never get here */
2356                 WARN_ON(1);
2357                 break;
2358         }
2359
2360         return 1;
2361 }
2362
2363 /*
2364  * This is the actual Rx frames handler. as it blongs to Rx path it must
2365  * be called with rcu_read_lock protection.
2366  */
2367 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
2368                                          struct sk_buff *skb,
2369                                          struct ieee80211_rate *rate)
2370 {
2371         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2372         struct ieee80211_local *local = hw_to_local(hw);
2373         struct ieee80211_sub_if_data *sdata;
2374         struct ieee80211_hdr *hdr;
2375         struct ieee80211_rx_data rx;
2376         int prepares;
2377         struct ieee80211_sub_if_data *prev = NULL;
2378         struct sk_buff *skb_new;
2379         struct sta_info *sta, *tmp;
2380         bool found_sta = false;
2381
2382         hdr = (struct ieee80211_hdr *)skb->data;
2383         memset(&rx, 0, sizeof(rx));
2384         rx.skb = skb;
2385         rx.local = local;
2386
2387         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
2388                 local->dot11ReceivedFragmentCount++;
2389
2390         if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
2391                      test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
2392                 rx.flags |= IEEE80211_RX_IN_SCAN;
2393
2394         ieee80211_parse_qos(&rx);
2395         ieee80211_verify_alignment(&rx);
2396
2397         if (ieee80211_is_data(hdr->frame_control)) {
2398                 for_each_sta_info(local, hdr->addr2, sta, tmp) {
2399                         rx.sta = sta;
2400                         found_sta = true;
2401                         rx.sdata = sta->sdata;
2402
2403                         rx.flags |= IEEE80211_RX_RA_MATCH;
2404                         prepares = prepare_for_handlers(rx.sdata, &rx, hdr);
2405                         if (prepares) {
2406                                 if (status->flag & RX_FLAG_MMIC_ERROR) {
2407                                         if (rx.flags & IEEE80211_RX_RA_MATCH)
2408                                                 ieee80211_rx_michael_mic_report(hdr, &rx);
2409                                 } else
2410                                         prev = rx.sdata;
2411                         }
2412                 }
2413         }
2414         if (!found_sta) {
2415                 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
2416                         if (!ieee80211_sdata_running(sdata))
2417                                 continue;
2418
2419                         if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
2420                             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2421                                 continue;
2422
2423                         /*
2424                          * frame is destined for this interface, but if it's
2425                          * not also for the previous one we handle that after
2426                          * the loop to avoid copying the SKB once too much
2427                          */
2428
2429                         if (!prev) {
2430                                 prev = sdata;
2431                                 continue;
2432                         }
2433
2434                         rx.sta = sta_info_get_bss(prev, hdr->addr2);
2435
2436                         rx.flags |= IEEE80211_RX_RA_MATCH;
2437                         prepares = prepare_for_handlers(prev, &rx, hdr);
2438
2439                         if (!prepares)
2440                                 goto next;
2441
2442                         if (status->flag & RX_FLAG_MMIC_ERROR) {
2443                                 rx.sdata = prev;
2444                                 if (rx.flags & IEEE80211_RX_RA_MATCH)
2445                                         ieee80211_rx_michael_mic_report(hdr,
2446                                                                         &rx);
2447                                 goto next;
2448                         }
2449
2450                         /*
2451                          * frame was destined for the previous interface
2452                          * so invoke RX handlers for it
2453                          */
2454
2455                         skb_new = skb_copy(skb, GFP_ATOMIC);
2456                         if (!skb_new) {
2457                                 if (net_ratelimit())
2458                                         printk(KERN_DEBUG "%s: failed to copy "
2459                                                "multicast frame for %s\n",
2460                                                wiphy_name(local->hw.wiphy),
2461                                                prev->name);
2462                                 goto next;
2463                         }
2464                         ieee80211_invoke_rx_handlers(prev, &rx, skb_new, rate);
2465 next:
2466                         prev = sdata;
2467                 }
2468
2469                 if (prev) {
2470                         rx.sta = sta_info_get_bss(prev, hdr->addr2);
2471
2472                         rx.flags |= IEEE80211_RX_RA_MATCH;
2473                         prepares = prepare_for_handlers(prev, &rx, hdr);
2474
2475                         if (!prepares)
2476                                 prev = NULL;
2477                 }
2478         }
2479         if (prev)
2480                 ieee80211_invoke_rx_handlers(prev, &rx, skb, rate);
2481         else
2482                 dev_kfree_skb(skb);
2483 }
2484
2485 /*
2486  * This is the receive path handler. It is called by a low level driver when an
2487  * 802.11 MPDU is received from the hardware.
2488  */
2489 void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
2490 {
2491         struct ieee80211_local *local = hw_to_local(hw);
2492         struct ieee80211_rate *rate = NULL;
2493         struct ieee80211_supported_band *sband;
2494         struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
2495
2496         WARN_ON_ONCE(softirq_count() == 0);
2497
2498         if (WARN_ON(status->band < 0 ||
2499                     status->band >= IEEE80211_NUM_BANDS))
2500                 goto drop;
2501
2502         sband = local->hw.wiphy->bands[status->band];
2503         if (WARN_ON(!sband))
2504                 goto drop;
2505
2506         /*
2507          * If we're suspending, it is possible although not too likely
2508          * that we'd be receiving frames after having already partially
2509          * quiesced the stack. We can't process such frames then since
2510          * that might, for example, cause stations to be added or other
2511          * driver callbacks be invoked.
2512          */
2513         if (unlikely(local->quiescing || local->suspended))
2514                 goto drop;
2515
2516         /*
2517          * The same happens when we're not even started,
2518          * but that's worth a warning.
2519          */
2520         if (WARN_ON(!local->started))
2521                 goto drop;
2522
2523         if (status->flag & RX_FLAG_HT) {
2524                 /*
2525                  * rate_idx is MCS index, which can be [0-76] as documented on:
2526                  *
2527                  * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
2528                  *
2529                  * Anything else would be some sort of driver or hardware error.
2530                  * The driver should catch hardware errors.
2531                  */
2532                 if (WARN((status->rate_idx < 0 ||
2533                          status->rate_idx > 76),
2534                          "Rate marked as an HT rate but passed "
2535                          "status->rate_idx is not "
2536                          "an MCS index [0-76]: %d (0x%02x)\n",
2537                          status->rate_idx,
2538                          status->rate_idx))
2539                         goto drop;
2540         } else {
2541                 if (WARN_ON(status->rate_idx < 0 ||
2542                             status->rate_idx >= sband->n_bitrates))
2543                         goto drop;
2544                 rate = &sband->bitrates[status->rate_idx];
2545         }
2546
2547         /*
2548          * key references and virtual interfaces are protected using RCU
2549          * and this requires that we are in a read-side RCU section during
2550          * receive processing
2551          */
2552         rcu_read_lock();
2553
2554         /*
2555          * Frames with failed FCS/PLCP checksum are not returned,
2556          * all other frames are returned without radiotap header
2557          * if it was previously present.
2558          * Also, frames with less than 16 bytes are dropped.
2559          */
2560         skb = ieee80211_rx_monitor(local, skb, rate);
2561         if (!skb) {
2562                 rcu_read_unlock();
2563                 return;
2564         }
2565
2566         __ieee80211_rx_handle_packet(hw, skb, rate);
2567
2568         rcu_read_unlock();
2569
2570         return;
2571  drop:
2572         kfree_skb(skb);
2573 }
2574 EXPORT_SYMBOL(ieee80211_rx);
2575
2576 /* This is a version of the rx handler that can be called from hard irq
2577  * context. Post the skb on the queue and schedule the tasklet */
2578 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
2579 {
2580         struct ieee80211_local *local = hw_to_local(hw);
2581
2582         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2583
2584         skb->pkt_type = IEEE80211_RX_MSG;
2585         skb_queue_tail(&local->skb_queue, skb);
2586         tasklet_schedule(&local->tasklet);
2587 }
2588 EXPORT_SYMBOL(ieee80211_rx_irqsafe);