net/mac80211/rx.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/jiffies.h>
  13 #include <linux/kernel.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/rcupdate.h>
  18 #include <net/mac80211.h>
  19 #include <net/ieee80211_radiotap.h>
  20
  21 #include "ieee80211_i.h"
  22 #include "led.h"
  23 #include "mesh.h"
  24 #include "wep.h"
  25 #include "wpa.h"
  26 #include "tkip.h"
  27 #include "wme.h"
  28
  29 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
  30                                 struct tid_ampdu_rx *tid_agg_rx,
  31                                 struct sk_buff *skb, u16 mpdu_seq_num,
  32                                 int bar_req);
  33 /*
  34  * monitor mode reception
  35  *
  36  * This function cleans up the SKB, i.e. it removes all the stuff
  37  * only useful for monitoring.
  38  */
  39 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  40                                            struct sk_buff *skb,
  41                                            int rtap_len)
  42 {
  43         skb_pull(skb, rtap_len);
  44
  45         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  46                 if (likely(skb->len > FCS_LEN))
  47                         skb_trim(skb, skb->len - FCS_LEN);
  48                 else {
  49                         /* driver bug */
  50                         WARN_ON(1);
  51                         dev_kfree_skb(skb);
  52                         skb = NULL;
  53                 }
  54         }
  55
  56         return skb;
  57 }
  58
  59 static inline int should_drop_frame(struct ieee80211_rx_status *status,
  60                                     struct sk_buff *skb,
  61                                     int present_fcs_len,
  62                                     int radiotap_len)
  63 {
  64         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  65
  66         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  67                 return 1;
  68         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
  69                 return 1;
  70         if (ieee80211_is_ctl(hdr->frame_control) &&
  71             !ieee80211_is_pspoll(hdr->frame_control) &&
  72             !ieee80211_is_back_req(hdr->frame_control))
  73                 return 1;
  74         return 0;
  75 }
  76
  77 static int
  78 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  79                           struct ieee80211_rx_status *status)
  80 {
  81         int len;
  82
  83         /* always present fields */
  84         len = sizeof(struct ieee80211_radiotap_header) + 9;
  85
  86         if (status->flag & RX_FLAG_TSFT)
  87                 len += 8;
  88         if (local->hw.flags & IEEE80211_HW_SIGNAL_DB ||
  89             local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  90                 len += 1;
  91         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
  92                 len += 1;
  93
  94         if (len & 1) /* padding for RX_FLAGS if necessary */
  95                 len++;
  96
  97         /* make sure radiotap starts at a naturally aligned address */
  98         if (len % 8)
  99                 len = roundup(len, 8);
 100
 101         return len;
 102 }
 103
 104 /**
 105  * ieee80211_add_rx_radiotap_header - add radiotap header
 106  *
 107  * add a radiotap header containing all the fields which the hardware provided.
 108  */
 109 static void
 110 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 111                                  struct sk_buff *skb,
 112                                  struct ieee80211_rx_status *status,
 113                                  struct ieee80211_rate *rate,
 114                                  int rtap_len)
 115 {
 116         struct ieee80211_radiotap_header *rthdr;
 117         unsigned char *pos;
 118
 119         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 120         memset(rthdr, 0, rtap_len);
 121
 122         /* radiotap header, set always present flags */
 123         rthdr->it_present =
 124                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 125                             (1 << IEEE80211_RADIOTAP_RATE) |
 126                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 127                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 128                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 129         rthdr->it_len = cpu_to_le16(rtap_len);
 130
 131         pos = (unsigned char *)(rthdr+1);
 132
 133         /* the order of the following fields is important */
 134
 135         /* IEEE80211_RADIOTAP_TSFT */
 136         if (status->flag & RX_FLAG_TSFT) {
 137                 *(__le64 *)pos = cpu_to_le64(status->mactime);
 138                 rthdr->it_present |=
 139                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 140                 pos += 8;
 141         }
 142
 143         /* IEEE80211_RADIOTAP_FLAGS */
 144         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 145                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 146         pos++;
 147
 148         /* IEEE80211_RADIOTAP_RATE */
 149         *pos = rate->bitrate / 5;
 150         pos++;
 151
 152         /* IEEE80211_RADIOTAP_CHANNEL */
 153         *(__le16 *)pos = cpu_to_le16(status->freq);
 154         pos += 2;
 155         if (status->band == IEEE80211_BAND_5GHZ)
 156                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
 157                                              IEEE80211_CHAN_5GHZ);
 158         else
 159                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_DYN |
 160                                              IEEE80211_CHAN_2GHZ);
 161         pos += 2;
 162
 163         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 164         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 165                 *pos = status->signal;
 166                 rthdr->it_present |=
 167                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 168                 pos++;
 169         }
 170
 171         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
 172         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
 173                 *pos = status->noise;
 174                 rthdr->it_present |=
 175                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
 176                 pos++;
 177         }
 178
 179         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 180
 181         /* IEEE80211_RADIOTAP_ANTENNA */
 182         *pos = status->antenna;
 183         pos++;
 184
 185         /* IEEE80211_RADIOTAP_DB_ANTSIGNAL */
 186         if (local->hw.flags & IEEE80211_HW_SIGNAL_DB) {
 187                 *pos = status->signal;
 188                 rthdr->it_present |=
 189                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL);
 190                 pos++;
 191         }
 192
 193         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 194
 195         /* IEEE80211_RADIOTAP_RX_FLAGS */
 196         /* ensure 2 byte alignment for the 2 byte field as required */
 197         if ((pos - (unsigned char *)rthdr) & 1)
 198                 pos++;
 199         /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
 200         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 201                 *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
 202         pos += 2;
 203 }
 204
 205 /*
 206  * This function copies a received frame to all monitor interfaces and
 207  * returns a cleaned-up SKB that no longer includes the FCS nor the
 208  * radiotap header the driver might have added.
 209  */
 210 static struct sk_buff *
 211 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 212                      struct ieee80211_rx_status *status,
 213                      struct ieee80211_rate *rate)
 214 {
 215         struct ieee80211_sub_if_data *sdata;
 216         int needed_headroom = 0;
 217         struct sk_buff *skb, *skb2;
 218         struct net_device *prev_dev = NULL;
 219         int present_fcs_len = 0;
 220         int rtap_len = 0;
 221
 222         /*
 223          * First, we may need to make a copy of the skb because
 224          *  (1) we need to modify it for radiotap (if not present), and
 225          *  (2) the other RX handlers will modify the skb we got.
 226          *
 227          * We don't need to, of course, if we aren't going to return
 228          * the SKB because it has a bad FCS/PLCP checksum.
 229          */
 230         if (status->flag & RX_FLAG_RADIOTAP)
 231                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
 232         else
 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(status, origskb, present_fcs_len,
 241                                       rtap_len)) {
 242                         dev_kfree_skb(origskb);
 243                         return NULL;
 244                 }
 245
 246                 return remove_monitor_info(local, origskb, rtap_len);
 247         }
 248
 249         if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
 250                 /* only need to expand headroom if necessary */
 251                 skb = origskb;
 252                 origskb = NULL;
 253
 254                 /*
 255                  * This shouldn't trigger often because most devices have an
 256                  * RX header they pull before we get here, and that should
 257                  * be big enough for our radiotap information. We should
 258                  * probably export the length to drivers so that we can have
 259                  * them allocate enough headroom to start with.
 260                  */
 261                 if (skb_headroom(skb) < needed_headroom &&
 262                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 263                         dev_kfree_skb(skb);
 264                         return NULL;
 265                 }
 266         } else {
 267                 /*
 268                  * Need to make a copy and possibly remove radiotap header
 269                  * and FCS from the original.
 270                  */
 271                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 272
 273                 origskb = remove_monitor_info(local, origskb, rtap_len);
 274
 275                 if (!skb)
 276                         return origskb;
 277         }
 278
 279         /* if necessary, prepend radiotap information */
 280         if (!(status->flag & RX_FLAG_RADIOTAP))
 281                 ieee80211_add_rx_radiotap_header(local, skb, status, rate,
 282                                                  needed_headroom);
 283
 284         skb_reset_mac_header(skb);
 285         skb->ip_summed = CHECKSUM_UNNECESSARY;
 286         skb->pkt_type = PACKET_OTHERHOST;
 287         skb->protocol = htons(ETH_P_802_2);
 288
 289         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 290                 if (!netif_running(sdata->dev))
 291                         continue;
 292
 293                 if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR)
 294                         continue;
 295
 296                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 297                         continue;
 298
 299                 if (prev_dev) {
 300                         skb2 = skb_clone(skb, GFP_ATOMIC);
 301                         if (skb2) {
 302                                 skb2->dev = prev_dev;
 303                                 netif_rx(skb2);
 304                         }
 305                 }
 306
 307                 prev_dev = sdata->dev;
 308                 sdata->dev->stats.rx_packets++;
 309                 sdata->dev->stats.rx_bytes += skb->len;
 310         }
 311
 312         if (prev_dev) {
 313                 skb->dev = prev_dev;
 314                 netif_rx(skb);
 315         } else
 316                 dev_kfree_skb(skb);
 317
 318         return origskb;
 319 }
 320
 321
 322 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 323 {
 324         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 325         int tid;
 326
 327         /* does the frame have a qos control field? */
 328         if (ieee80211_is_data_qos(hdr->frame_control)) {
 329                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 330                 /* frame has qos control */
 331                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 332                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 333                         rx->flags |= IEEE80211_RX_AMSDU;
 334                 else
 335                         rx->flags &= ~IEEE80211_RX_AMSDU;
 336         } else {
 337                 /*
 338                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 339                  *
 340                  *      Sequence numbers for management frames, QoS data
 341                  *      frames with a broadcast/multicast address in the
 342                  *      Address 1 field, and all non-QoS data frames sent
 343                  *      by QoS STAs are assigned using an additional single
 344                  *      modulo-4096 counter, [...]
 345                  *
 346                  * We also use that counter for non-QoS STAs.
 347                  */
 348                 tid = NUM_RX_DATA_QUEUES - 1;
 349         }
 350
 351         rx->queue = tid;
 352         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 353          * For now, set skb->priority to 0 for other cases. */
 354         rx->skb->priority = (tid > 7) ? 0 : tid;
 355 }
 356
 357 static void ieee80211_verify_ip_alignment(struct ieee80211_rx_data *rx)
 358 {
 359 #ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
 360         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 361         int hdrlen;
 362
 363         if (!ieee80211_is_data_present(hdr->frame_control))
 364                 return;
 365
 366         /*
 367          * Drivers are required to align the payload data in a way that
 368          * guarantees that the contained IP header is aligned to a four-
 369          * byte boundary. In the case of regular frames, this simply means
 370          * aligning the payload to a four-byte boundary (because either
 371          * the IP header is directly contained, or IV/RFC1042 headers that
 372          * have a length divisible by four are in front of it.
 373          *
 374          * With A-MSDU frames, however, the payload data address must
 375          * yield two modulo four because there are 14-byte 802.3 headers
 376          * within the A-MSDU frames that push the IP header further back
 377          * to a multiple of four again. Thankfully, the specs were sane
 378          * enough this time around to require padding each A-MSDU subframe
 379          * to a length that is a multiple of four.
 380          *
 381          * Padding like atheros hardware adds which is inbetween the 802.11
 382          * header and the payload is not supported, the driver is required
 383          * to move the 802.11 header further back in that case.
 384          */
 385         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 386         if (rx->flags & IEEE80211_RX_AMSDU)
 387                 hdrlen += ETH_HLEN;
 388         WARN_ON_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3);
 389 #endif
 390 }
 391
 392
 393 /* rx handlers */
 394
 395 static ieee80211_rx_result debug_noinline
 396 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 397 {
 398         struct ieee80211_local *local = rx->local;
 399         struct sk_buff *skb = rx->skb;
 400
 401         if (unlikely(local->sta_hw_scanning))
 402                 return ieee80211_sta_rx_scan(rx->dev, skb, rx->status);
 403
 404         if (unlikely(local->sta_sw_scanning)) {
 405                 /* drop all the other packets during a software scan anyway */
 406                 if (ieee80211_sta_rx_scan(rx->dev, skb, rx->status)
 407                     != RX_QUEUED)
 408                         dev_kfree_skb(skb);
 409                 return RX_QUEUED;
 410         }
 411
 412         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
 413                 /* scanning finished during invoking of handlers */
 414                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 415                 return RX_DROP_UNUSABLE;
 416         }
 417
 418         return RX_CONTINUE;
 419 }
 420
 421 static ieee80211_rx_result
 422 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 423 {
 424         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 425         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 426
 427         if (ieee80211_is_data(hdr->frame_control)) {
 428                 if (!ieee80211_has_a4(hdr->frame_control))
 429                         return RX_DROP_MONITOR;
 430                 if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
 431                         return RX_DROP_MONITOR;
 432         }
 433
 434         /* If there is not an established peer link and this is not a peer link
 435          * establisment frame, beacon or probe, drop the frame.
 436          */
 437
 438         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 439                 struct ieee80211_mgmt *mgmt;
 440
 441                 if (!ieee80211_is_mgmt(hdr->frame_control))
 442                         return RX_DROP_MONITOR;
 443
 444                 if (ieee80211_is_action(hdr->frame_control)) {
 445                         mgmt = (struct ieee80211_mgmt *)hdr;
 446                         if (mgmt->u.action.category != PLINK_CATEGORY)
 447                                 return RX_DROP_MONITOR;
 448                         return RX_CONTINUE;
 449                 }
 450
 451                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 452                     ieee80211_is_probe_resp(hdr->frame_control) ||
 453                     ieee80211_is_beacon(hdr->frame_control))
 454                         return RX_CONTINUE;
 455
 456                 return RX_DROP_MONITOR;
 457
 458         }
 459
 460 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 461
 462         if (ieee80211_is_data(hdr->frame_control) &&
 463             is_multicast_ether_addr(hdr->addr1) &&
 464             mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->dev))
 465                 return RX_DROP_MONITOR;
 466 #undef msh_h_get
 467
 468         return RX_CONTINUE;
 469 }
 470
 471
 472 static ieee80211_rx_result debug_noinline
 473 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 474 {
 475         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 476
 477         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 478         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 479                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 480                              rx->sta->last_seq_ctrl[rx->queue] ==
 481                              hdr->seq_ctrl)) {
 482                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
 483                                 rx->local->dot11FrameDuplicateCount++;
 484                                 rx->sta->num_duplicates++;
 485                         }
 486                         return RX_DROP_MONITOR;
 487                 } else
 488                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 489         }
 490
 491         if (unlikely(rx->skb->len < 16)) {
 492                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 493                 return RX_DROP_MONITOR;
 494         }
 495
 496         /* Drop disallowed frame classes based on STA auth/assoc state;
 497          * IEEE 802.11, Chap 5.5.
 498          *
 499          * 80211.o does filtering only based on association state, i.e., it
 500          * drops Class 3 frames from not associated stations. hostapd sends
 501          * deauth/disassoc frames when needed. In addition, hostapd is
 502          * responsible for filtering on both auth and assoc states.
 503          */
 504
 505         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 506                 return ieee80211_rx_mesh_check(rx);
 507
 508         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 509                       ieee80211_is_pspoll(hdr->frame_control)) &&
 510                      rx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
 511                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 512                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 513                      !ieee80211_has_tods(hdr->frame_control) &&
 514                      ieee80211_is_data(hdr->frame_control)) ||
 515                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
 516                         /* Drop IBSS frames and frames for other hosts
 517                          * silently. */
 518                         return RX_DROP_MONITOR;
 519                 }
 520
 521                 return RX_DROP_MONITOR;
 522         }
 523
 524         return RX_CONTINUE;
 525 }
 526
 527
 528 static ieee80211_rx_result debug_noinline
 529 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 530 {
 531         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 532         int keyidx;
 533         int hdrlen;
 534         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 535         struct ieee80211_key *stakey = NULL;
 536
 537         /*
 538          * Key selection 101
 539          *
 540          * There are three types of keys:
 541          *  - GTK (group keys)
 542          *  - PTK (pairwise keys)
 543          *  - STK (station-to-station pairwise keys)
 544          *
 545          * When selecting a key, we have to distinguish between multicast
 546          * (including broadcast) and unicast frames, the latter can only
 547          * use PTKs and STKs while the former always use GTKs. Unless, of
 548          * course, actual WEP keys ("pre-RSNA") are used, then unicast
 549          * frames can also use key indizes like GTKs. Hence, if we don't
 550          * have a PTK/STK we check the key index for a WEP key.
 551          *
 552          * Note that in a regular BSS, multicast frames are sent by the
 553          * AP only, associated stations unicast the frame to the AP first
 554          * which then multicasts it on their behalf.
 555          *
 556          * There is also a slight problem in IBSS mode: GTKs are negotiated
 557          * with each station, that is something we don't currently handle.
 558          * The spec seems to expect that one negotiates the same key with
 559          * every station but there's no such requirement; VLANs could be
 560          * possible.
 561          */
 562
 563         if (!ieee80211_has_protected(hdr->frame_control))
 564                 return RX_CONTINUE;
 565
 566         /*
 567          * No point in finding a key and decrypting if the frame is neither
 568          * addressed to us nor a multicast frame.
 569          */
 570         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 571                 return RX_CONTINUE;
 572
 573         if (rx->sta)
 574                 stakey = rcu_dereference(rx->sta->key);
 575
 576         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 577                 rx->key = stakey;
 578         } else {
 579                 /*
 580                  * The device doesn't give us the IV so we won't be
 581                  * able to look up the key. That's ok though, we
 582                  * don't need to decrypt the frame, we just won't
 583                  * be able to keep statistics accurate.
 584                  * Except for key threshold notifications, should
 585                  * we somehow allow the driver to tell us which key
 586                  * the hardware used if this flag is set?
 587                  */
 588                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 589                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 590                         return RX_CONTINUE;
 591
 592                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
 593
 594                 if (rx->skb->len < 8 + hdrlen)
 595                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 596
 597                 /*
 598                  * no need to call ieee80211_wep_get_keyidx,
 599                  * it verifies a bunch of things we've done already
 600                  */
 601                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 602
 603                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 604
 605                 /*
 606                  * RSNA-protected unicast frames should always be sent with
 607                  * pairwise or station-to-station keys, but for WEP we allow
 608                  * using a key index as well.
 609                  */
 610                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 611                     !is_multicast_ether_addr(hdr->addr1))
 612                         rx->key = NULL;
 613         }
 614
 615         if (rx->key) {
 616                 rx->key->tx_rx_count++;
 617                 /* TODO: add threshold stuff again */
 618         } else {
 619                 return RX_DROP_MONITOR;
 620         }
 621
 622         /* Check for weak IVs if possible */
 623         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 624             ieee80211_is_data(hdr->frame_control) &&
 625             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
 626              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
 627             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 628                 rx->sta->wep_weak_iv_count++;
 629
 630         switch (rx->key->conf.alg) {
 631         case ALG_WEP:
 632                 result = ieee80211_crypto_wep_decrypt(rx);
 633                 break;
 634         case ALG_TKIP:
 635                 result = ieee80211_crypto_tkip_decrypt(rx);
 636                 break;
 637         case ALG_CCMP:
 638                 result = ieee80211_crypto_ccmp_decrypt(rx);
 639                 break;
 640         }
 641
 642         /* either the frame has been decrypted or will be dropped */
 643         rx->status->flag |= RX_FLAG_DECRYPTED;
 644
 645         return result;
 646 }
 647
 648 static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
 649 {
 650         struct ieee80211_sub_if_data *sdata;
 651         DECLARE_MAC_BUF(mac);
 652
 653         sdata = sta->sdata;
 654
 655         atomic_inc(&sdata->bss->num_sta_ps);
 656         set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
 657 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 658         printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
 659                dev->name, print_mac(mac, sta->addr), sta->aid);
 660 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 661 }
 662
 663 static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
 664 {
 665         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 666         struct sk_buff *skb;
 667         int sent = 0;
 668         struct ieee80211_sub_if_data *sdata;
 669         struct ieee80211_tx_info *info;
 670         DECLARE_MAC_BUF(mac);
 671
 672         sdata = sta->sdata;
 673
 674         atomic_dec(&sdata->bss->num_sta_ps);
 675
 676         clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
 677
 678         if (!skb_queue_empty(&sta->ps_tx_buf))
 679                 sta_info_clear_tim_bit(sta);
 680
 681 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 682         printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
 683                dev->name, print_mac(mac, sta->addr), sta->aid);
 684 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 685
 686         /* Send all buffered frames to the station */
 687         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 688                 info = IEEE80211_SKB_CB(skb);
 689                 sent++;
 690                 info->flags |= IEEE80211_TX_CTL_REQUEUE;
 691                 dev_queue_xmit(skb);
 692         }
 693         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 694                 info = IEEE80211_SKB_CB(skb);
 695                 local->total_ps_buffered--;
 696                 sent++;
 697 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 698                 printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
 699                        "since STA not sleeping anymore\n", dev->name,
 700                        print_mac(mac, sta->addr), sta->aid);
 701 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 702                 info->flags |= IEEE80211_TX_CTL_REQUEUE;
 703                 dev_queue_xmit(skb);
 704         }
 705
 706         return sent;
 707 }
 708
 709 static ieee80211_rx_result debug_noinline
 710 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
 711 {
 712         struct sta_info *sta = rx->sta;
 713         struct net_device *dev = rx->dev;
 714         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 715
 716         if (!sta)
 717                 return RX_CONTINUE;
 718
 719         /* Update last_rx only for IBSS packets which are for the current
 720          * BSSID to avoid keeping the current IBSS network alive in cases where
 721          * other STAs are using different BSSID. */
 722         if (rx->sdata->vif.type == IEEE80211_IF_TYPE_IBSS) {
 723                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
 724                                                 IEEE80211_IF_TYPE_IBSS);
 725                 if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
 726                         sta->last_rx = jiffies;
 727         } else
 728         if (!is_multicast_ether_addr(hdr->addr1) ||
 729             rx->sdata->vif.type == IEEE80211_IF_TYPE_STA) {
 730                 /* Update last_rx only for unicast frames in order to prevent
 731                  * the Probe Request frames (the only broadcast frames from a
 732                  * STA in infrastructure mode) from keeping a connection alive.
 733                  * Mesh beacons will update last_rx when if they are found to
 734                  * match the current local configuration when processed.
 735                  */
 736                 sta->last_rx = jiffies;
 737         }
 738
 739         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 740                 return RX_CONTINUE;
 741
 742         sta->rx_fragments++;
 743         sta->rx_bytes += rx->skb->len;
 744         sta->last_signal = rx->status->signal;
 745         sta->last_qual = rx->status->qual;
 746         sta->last_noise = rx->status->noise;
 747
 748         if (!ieee80211_has_morefrags(hdr->frame_control) &&
 749             (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP ||
 750              rx->sdata->vif.type == IEEE80211_IF_TYPE_VLAN)) {
 751                 /* Change STA power saving mode only in the end of a frame
 752                  * exchange sequence */
 753                 if (test_sta_flags(sta, WLAN_STA_PS) &&
 754                     !ieee80211_has_pm(hdr->frame_control))
 755                         rx->sent_ps_buffered += ap_sta_ps_end(dev, sta);
 756                 else if (!test_sta_flags(sta, WLAN_STA_PS) &&
 757                          ieee80211_has_pm(hdr->frame_control))
 758                         ap_sta_ps_start(dev, sta);
 759         }
 760
 761         /* Drop data::nullfunc frames silently, since they are used only to
 762          * control station power saving mode. */
 763         if (ieee80211_is_nullfunc(hdr->frame_control)) {
 764                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
 765                 /* Update counter and free packet here to avoid counting this
 766                  * as a dropped packed. */
 767                 sta->rx_packets++;
 768                 dev_kfree_skb(rx->skb);
 769                 return RX_QUEUED;
 770         }
 771
 772         return RX_CONTINUE;
 773 } /* ieee80211_rx_h_sta_process */
 774
 775 static inline struct ieee80211_fragment_entry *
 776 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 777                          unsigned int frag, unsigned int seq, int rx_queue,
 778                          struct sk_buff **skb)
 779 {
 780         struct ieee80211_fragment_entry *entry;
 781         int idx;
 782
 783         idx = sdata->fragment_next;
 784         entry = &sdata->fragments[sdata->fragment_next++];
 785         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
 786                 sdata->fragment_next = 0;
 787
 788         if (!skb_queue_empty(&entry->skb_list)) {
 789 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 790                 struct ieee80211_hdr *hdr =
 791                         (struct ieee80211_hdr *) entry->skb_list.next->data;
 792                 DECLARE_MAC_BUF(mac);
 793                 DECLARE_MAC_BUF(mac2);
 794                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
 795                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
 796                        "addr1=%s addr2=%s\n",
 797                        sdata->dev->name, idx,
 798                        jiffies - entry->first_frag_time, entry->seq,
 799                        entry->last_frag, print_mac(mac, hdr->addr1),
 800                        print_mac(mac2, hdr->addr2));
 801 #endif
 802                 __skb_queue_purge(&entry->skb_list);
 803         }
 804
 805         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
 806         *skb = NULL;
 807         entry->first_frag_time = jiffies;
 808         entry->seq = seq;
 809         entry->rx_queue = rx_queue;
 810         entry->last_frag = frag;
 811         entry->ccmp = 0;
 812         entry->extra_len = 0;
 813
 814         return entry;
 815 }
 816
 817 static inline struct ieee80211_fragment_entry *
 818 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
 819                           u16 fc, unsigned int frag, unsigned int seq,
 820                           int rx_queue, struct ieee80211_hdr *hdr)
 821 {
 822         struct ieee80211_fragment_entry *entry;
 823         int i, idx;
 824
 825         idx = sdata->fragment_next;
 826         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
 827                 struct ieee80211_hdr *f_hdr;
 828                 u16 f_fc;
 829
 830                 idx--;
 831                 if (idx < 0)
 832                         idx = IEEE80211_FRAGMENT_MAX - 1;
 833
 834                 entry = &sdata->fragments[idx];
 835                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
 836                     entry->rx_queue != rx_queue ||
 837                     entry->last_frag + 1 != frag)
 838                         continue;
 839
 840                 f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data;
 841                 f_fc = le16_to_cpu(f_hdr->frame_control);
 842
 843                 if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
 844                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
 845                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
 846                         continue;
 847
 848                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
 849                         __skb_queue_purge(&entry->skb_list);
 850                         continue;
 851                 }
 852                 return entry;
 853         }
 854
 855         return NULL;
 856 }
 857
 858 static ieee80211_rx_result debug_noinline
 859 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 860 {
 861         struct ieee80211_hdr *hdr;
 862         u16 sc;
 863         unsigned int frag, seq;
 864         struct ieee80211_fragment_entry *entry;
 865         struct sk_buff *skb;
 866         DECLARE_MAC_BUF(mac);
 867
 868         hdr = (struct ieee80211_hdr *) rx->skb->data;
 869         sc = le16_to_cpu(hdr->seq_ctrl);
 870         frag = sc & IEEE80211_SCTL_FRAG;
 871
 872         if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
 873                    (rx->skb)->len < 24 ||
 874                    is_multicast_ether_addr(hdr->addr1))) {
 875                 /* not fragmented */
 876                 goto out;
 877         }
 878         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
 879
 880         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
 881
 882         if (frag == 0) {
 883                 /* This is the first fragment of a new frame. */
 884                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
 885                                                  rx->queue, &(rx->skb));
 886                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
 887                     (rx->fc & IEEE80211_FCTL_PROTECTED)) {
 888                         /* Store CCMP PN so that we can verify that the next
 889                          * fragment has a sequential PN value. */
 890                         entry->ccmp = 1;
 891                         memcpy(entry->last_pn,
 892                                rx->key->u.ccmp.rx_pn[rx->queue],
 893                                CCMP_PN_LEN);
 894                 }
 895                 return RX_QUEUED;
 896         }
 897
 898         /* This is a fragment for a frame that should already be pending in
 899          * fragment cache. Add this fragment to the end of the pending entry.
 900          */
 901         entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq,
 902                                           rx->queue, hdr);
 903         if (!entry) {
 904                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
 905                 return RX_DROP_MONITOR;
 906         }
 907
 908         /* Verify that MPDUs within one MSDU have sequential PN values.
 909          * (IEEE 802.11i, 8.3.3.4.5) */
 910         if (entry->ccmp) {
 911                 int i;
 912                 u8 pn[CCMP_PN_LEN], *rpn;
 913                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
 914                         return RX_DROP_UNUSABLE;
 915                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
 916                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
 917                         pn[i]++;
 918                         if (pn[i])
 919                                 break;
 920                 }
 921                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
 922                 if (memcmp(pn, rpn, CCMP_PN_LEN))
 923                         return RX_DROP_UNUSABLE;
 924                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
 925         }
 926
 927         skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
 928         __skb_queue_tail(&entry->skb_list, rx->skb);
 929         entry->last_frag = frag;
 930         entry->extra_len += rx->skb->len;
 931         if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
 932                 rx->skb = NULL;
 933                 return RX_QUEUED;
 934         }
 935
 936         rx->skb = __skb_dequeue(&entry->skb_list);
 937         if (skb_tailroom(rx->skb) < entry->extra_len) {
 938                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
 939                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
 940                                               GFP_ATOMIC))) {
 941                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
 942                         __skb_queue_purge(&entry->skb_list);
 943                         return RX_DROP_UNUSABLE;
 944                 }
 945         }
 946         while ((skb = __skb_dequeue(&entry->skb_list))) {
 947                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
 948                 dev_kfree_skb(skb);
 949         }
 950
 951         /* Complete frame has been reassembled - process it now */
 952         rx->flags |= IEEE80211_RX_FRAGMENTED;
 953
 954  out:
 955         if (rx->sta)
 956                 rx->sta->rx_packets++;
 957         if (is_multicast_ether_addr(hdr->addr1))
 958                 rx->local->dot11MulticastReceivedFrameCount++;
 959         else
 960                 ieee80211_led_rx(rx->local);
 961         return RX_CONTINUE;
 962 }
 963
 964 static ieee80211_rx_result debug_noinline
 965 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
 966 {
 967         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
 968         struct sk_buff *skb;
 969         int no_pending_pkts;
 970         DECLARE_MAC_BUF(mac);
 971
 972         if (likely(!rx->sta ||
 973                    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
 974                    (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
 975                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
 976                 return RX_CONTINUE;
 977
 978         if ((sdata->vif.type != IEEE80211_IF_TYPE_AP) &&
 979             (sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
 980                 return RX_DROP_UNUSABLE;
 981
 982         skb = skb_dequeue(&rx->sta->tx_filtered);
 983         if (!skb) {
 984                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
 985                 if (skb)
 986                         rx->local->total_ps_buffered--;
 987         }
 988         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
 989                 skb_queue_empty(&rx->sta->ps_tx_buf);
 990
 991         if (skb) {
 992                 struct ieee80211_hdr *hdr =
 993                         (struct ieee80211_hdr *) skb->data;
 994
 995                 /*
 996                  * Tell TX path to send one frame even though the STA may
 997                  * still remain is PS mode after this frame exchange.
 998                  */
 999                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1000
1001 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1002                 printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
1003                        print_mac(mac, rx->sta->addr), rx->sta->aid,
1004                        skb_queue_len(&rx->sta->ps_tx_buf));
1005 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1006
1007                 /* Use MoreData flag to indicate whether there are more
1008                  * buffered frames for this STA */
1009                 if (no_pending_pkts)
1010                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1011                 else
1012                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1013
1014                 dev_queue_xmit(skb);
1015
1016                 if (no_pending_pkts)
1017                         sta_info_clear_tim_bit(rx->sta);
1018 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1019         } else if (!rx->sent_ps_buffered) {
1020                 /*
1021                  * FIXME: This can be the result of a race condition between
1022                  *        us expiring a frame and the station polling for it.
1023                  *        Should we send it a null-func frame indicating we
1024                  *        have nothing buffered for it?
1025                  */
1026                 printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
1027                        "though there are no buffered frames for it\n",
1028                        rx->dev->name, print_mac(mac, rx->sta->addr));
1029 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1030         }
1031
1032         /* Free PS Poll skb here instead of returning RX_DROP that would
1033          * count as an dropped frame. */
1034         dev_kfree_skb(rx->skb);
1035
1036         return RX_QUEUED;
1037 }
1038
1039 static ieee80211_rx_result debug_noinline
1040 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1041 {
1042         u8 *data = rx->skb->data;
1043         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1044
1045         if (!ieee80211_is_data_qos(hdr->frame_control))
1046                 return RX_CONTINUE;
1047
1048         /* remove the qos control field, update frame type and meta-data */
1049         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1050                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1051         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1052         /* change frame type to non QOS */
1053         rx->fc &= ~IEEE80211_STYPE_QOS_DATA;
1054         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1055
1056         return RX_CONTINUE;
1057 }
1058
1059 static int
1060 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1061 {
1062         if (unlikely(!rx->sta ||
1063             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1064                 return -EACCES;
1065
1066         return 0;
1067 }
1068
1069 static int
1070 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx)
1071 {
1072         /*
1073          * Pass through unencrypted frames if the hardware has
1074          * decrypted them already.
1075          */
1076         if (rx->status->flag & RX_FLAG_DECRYPTED)
1077                 return 0;
1078
1079         /* Drop unencrypted frames if key is set. */
1080         if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
1081                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
1082                      (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
1083                      (rx->key || rx->sdata->drop_unencrypted)))
1084                 return -EACCES;
1085
1086         return 0;
1087 }
1088
1089 static int
1090 ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1091 {
1092         struct net_device *dev = rx->dev;
1093         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1094         u16 fc, hdrlen, ethertype;
1095         u8 *payload;
1096         u8 dst[ETH_ALEN];
1097         u8 src[ETH_ALEN] __aligned(2);
1098         struct sk_buff *skb = rx->skb;
1099         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1100         DECLARE_MAC_BUF(mac);
1101         DECLARE_MAC_BUF(mac2);
1102         DECLARE_MAC_BUF(mac3);
1103         DECLARE_MAC_BUF(mac4);
1104
1105         fc = rx->fc;
1106
1107         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1108                 return -1;
1109
1110         hdrlen = ieee80211_get_hdrlen(fc);
1111
1112         if (ieee80211_vif_is_mesh(&sdata->vif))
1113                 hdrlen += ieee80211_get_mesh_hdrlen(
1114                                 (struct ieee80211s_hdr *) (skb->data + hdrlen));
1115
1116         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
1117          * header
1118          * IEEE 802.11 address fields:
1119          * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1120          *   0     0   DA    SA    BSSID n/a
1121          *   0     1   DA    BSSID SA    n/a
1122          *   1     0   BSSID SA    DA    n/a
1123          *   1     1   RA    TA    DA    SA
1124          */
1125
1126         switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1127         case IEEE80211_FCTL_TODS:
1128                 /* BSSID SA DA */
1129                 memcpy(dst, hdr->addr3, ETH_ALEN);
1130                 memcpy(src, hdr->addr2, ETH_ALEN);
1131
1132                 if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_AP &&
1133                              sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
1134                         return -1;
1135                 break;
1136         case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1137                 /* RA TA DA SA */
1138                 memcpy(dst, hdr->addr3, ETH_ALEN);
1139                 memcpy(src, hdr->addr4, ETH_ALEN);
1140
1141                  if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_WDS &&
1142                              sdata->vif.type != IEEE80211_IF_TYPE_MESH_POINT))
1143                         return -1;
1144                 break;
1145         case IEEE80211_FCTL_FROMDS:
1146                 /* DA BSSID SA */
1147                 memcpy(dst, hdr->addr1, ETH_ALEN);
1148                 memcpy(src, hdr->addr3, ETH_ALEN);
1149
1150                 if (sdata->vif.type != IEEE80211_IF_TYPE_STA ||
1151                     (is_multicast_ether_addr(dst) &&
1152                      !compare_ether_addr(src, dev->dev_addr)))
1153                         return -1;
1154                 break;
1155         case 0:
1156                 /* DA SA BSSID */
1157                 memcpy(dst, hdr->addr1, ETH_ALEN);
1158                 memcpy(src, hdr->addr2, ETH_ALEN);
1159
1160                 if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS)
1161                         return -1;
1162                 break;
1163         }
1164
1165         if (unlikely(skb->len - hdrlen < 8))
1166                 return -1;
1167
1168         payload = skb->data + hdrlen;
1169         ethertype = (payload[6] << 8) | payload[7];
1170
1171         if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1172                     ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1173                    compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1174                 /* remove RFC1042 or Bridge-Tunnel encapsulation and
1175                  * replace EtherType */
1176                 skb_pull(skb, hdrlen + 6);
1177                 memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1178                 memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1179         } else {
1180                 struct ethhdr *ehdr;
1181                 __be16 len;
1182
1183                 skb_pull(skb, hdrlen);
1184                 len = htons(skb->len);
1185                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1186                 memcpy(ehdr->h_dest, dst, ETH_ALEN);
1187                 memcpy(ehdr->h_source, src, ETH_ALEN);
1188                 ehdr->h_proto = len;
1189         }
1190         return 0;
1191 }
1192
1193 /*
1194  * requires that rx->skb is a frame with ethernet header
1195  */
1196 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx)
1197 {
1198         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1199                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1200         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1201
1202         /*
1203          * Allow EAPOL frames to us/the PAE group address regardless
1204          * of whether the frame was encrypted or not.
1205          */
1206         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1207             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1208              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1209                 return true;
1210
1211         if (ieee80211_802_1x_port_control(rx) ||
1212             ieee80211_drop_unencrypted(rx))
1213                 return false;
1214
1215         return true;
1216 }
1217
1218 /*
1219  * requires that rx->skb is a frame with ethernet header
1220  */
1221 static void
1222 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1223 {
1224         struct net_device *dev = rx->dev;
1225         struct ieee80211_local *local = rx->local;
1226         struct sk_buff *skb, *xmit_skb;
1227         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1228         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1229         struct sta_info *dsta;
1230
1231         skb = rx->skb;
1232         xmit_skb = NULL;
1233
1234         if (local->bridge_packets && (sdata->vif.type == IEEE80211_IF_TYPE_AP ||
1235                                       sdata->vif.type == IEEE80211_IF_TYPE_VLAN) &&
1236             (rx->flags & IEEE80211_RX_RA_MATCH)) {
1237                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1238                         /*
1239                          * send multicast frames both to higher layers in
1240                          * local net stack and back to the wireless medium
1241                          */
1242                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1243                         if (!xmit_skb && net_ratelimit())
1244                                 printk(KERN_DEBUG "%s: failed to clone "
1245                                        "multicast frame\n", dev->name);
1246                 } else {
1247                         dsta = sta_info_get(local, skb->data);
1248                         if (dsta && dsta->sdata->dev == dev) {
1249                                 /*
1250                                  * The destination station is associated to
1251                                  * this AP (in this VLAN), so send the frame
1252                                  * directly to it and do not pass it to local
1253                                  * net stack.
1254                                  */
1255                                 xmit_skb = skb;
1256                                 skb = NULL;
1257                         }
1258                 }
1259         }
1260
1261         if (skb) {
1262                 /* deliver to local stack */
1263                 skb->protocol = eth_type_trans(skb, dev);
1264                 memset(skb->cb, 0, sizeof(skb->cb));
1265                 netif_rx(skb);
1266         }
1267
1268         if (xmit_skb) {
1269                 /* send to wireless media */
1270                 xmit_skb->protocol = htons(ETH_P_802_3);
1271                 skb_reset_network_header(xmit_skb);
1272                 skb_reset_mac_header(xmit_skb);
1273                 dev_queue_xmit(xmit_skb);
1274         }
1275 }
1276
1277 static ieee80211_rx_result debug_noinline
1278 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1279 {
1280         struct net_device *dev = rx->dev;
1281         struct ieee80211_local *local = rx->local;
1282         u16 fc, ethertype;
1283         u8 *payload;
1284         struct sk_buff *skb = rx->skb, *frame = NULL;
1285         const struct ethhdr *eth;
1286         int remaining, err;
1287         u8 dst[ETH_ALEN];
1288         u8 src[ETH_ALEN];
1289         DECLARE_MAC_BUF(mac);
1290
1291         fc = rx->fc;
1292         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1293                 return RX_CONTINUE;
1294
1295         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1296                 return RX_DROP_MONITOR;
1297
1298         if (!(rx->flags & IEEE80211_RX_AMSDU))
1299                 return RX_CONTINUE;
1300
1301         err = ieee80211_data_to_8023(rx);
1302         if (unlikely(err))
1303                 return RX_DROP_UNUSABLE;
1304
1305         skb->dev = dev;
1306
1307         dev->stats.rx_packets++;
1308         dev->stats.rx_bytes += skb->len;
1309
1310         /* skip the wrapping header */
1311         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1312         if (!eth)
1313                 return RX_DROP_UNUSABLE;
1314
1315         while (skb != frame) {
1316                 u8 padding;
1317                 __be16 len = eth->h_proto;
1318                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1319
1320                 remaining = skb->len;
1321                 memcpy(dst, eth->h_dest, ETH_ALEN);
1322                 memcpy(src, eth->h_source, ETH_ALEN);
1323
1324                 padding = ((4 - subframe_len) & 0x3);
1325                 /* the last MSDU has no padding */
1326                 if (subframe_len > remaining)
1327                         return RX_DROP_UNUSABLE;
1328
1329                 skb_pull(skb, sizeof(struct ethhdr));
1330                 /* if last subframe reuse skb */
1331                 if (remaining <= subframe_len + padding)
1332                         frame = skb;
1333                 else {
1334                         frame = dev_alloc_skb(local->hw.extra_tx_headroom +
1335                                               subframe_len);
1336
1337                         if (frame == NULL)
1338                                 return RX_DROP_UNUSABLE;
1339
1340                         skb_reserve(frame, local->hw.extra_tx_headroom +
1341                                     sizeof(struct ethhdr));
1342                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1343                                 ntohs(len));
1344
1345                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1346                                                         padding);
1347                         if (!eth) {
1348                                 dev_kfree_skb(frame);
1349                                 return RX_DROP_UNUSABLE;
1350                         }
1351                 }
1352
1353                 skb_reset_network_header(frame);
1354                 frame->dev = dev;
1355                 frame->priority = skb->priority;
1356                 rx->skb = frame;
1357
1358                 payload = frame->data;
1359                 ethertype = (payload[6] << 8) | payload[7];
1360
1361                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1362                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1363                            compare_ether_addr(payload,
1364                                               bridge_tunnel_header) == 0)) {
1365                         /* remove RFC1042 or Bridge-Tunnel
1366                          * encapsulation and replace EtherType */
1367                         skb_pull(frame, 6);
1368                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1369                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1370                 } else {
1371                         memcpy(skb_push(frame, sizeof(__be16)),
1372                                &len, sizeof(__be16));
1373                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1374                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1375                 }
1376
1377                 if (!ieee80211_frame_allowed(rx)) {
1378                         if (skb == frame) /* last frame */
1379                                 return RX_DROP_UNUSABLE;
1380                         dev_kfree_skb(frame);
1381                         continue;
1382                 }
1383
1384                 ieee80211_deliver_skb(rx);
1385         }
1386
1387         return RX_QUEUED;
1388 }
1389
1390 static ieee80211_rx_result debug_noinline
1391 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1392 {
1393         struct ieee80211_hdr *hdr;
1394         struct ieee80211s_hdr *mesh_hdr;
1395         unsigned int hdrlen;
1396         struct sk_buff *skb = rx->skb, *fwd_skb;
1397
1398         hdr = (struct ieee80211_hdr *) skb->data;
1399         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1400         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1401
1402         if (!ieee80211_is_data(hdr->frame_control))
1403                 return RX_CONTINUE;
1404
1405         if (!mesh_hdr->ttl)
1406                 /* illegal frame */
1407                 return RX_DROP_MONITOR;
1408
1409         if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1410                 return RX_CONTINUE;
1411
1412         mesh_hdr->ttl--;
1413
1414         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1415                 if (!mesh_hdr->ttl)
1416                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.sta,
1417                                                      dropped_frames_ttl);
1418                 else {
1419                         struct ieee80211_hdr *fwd_hdr;
1420                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1421
1422                         if (!fwd_skb && net_ratelimit())
1423                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1424                                                    rx->dev->name);
1425
1426                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1427                         /*
1428                          * Save TA to addr1 to send TA a path error if a
1429                          * suitable next hop is not found
1430                          */
1431                         memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1432                         memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1433                         fwd_skb->dev = rx->local->mdev;
1434                         fwd_skb->iif = rx->dev->ifindex;
1435                         dev_queue_xmit(fwd_skb);
1436                 }
1437         }
1438
1439         if (is_multicast_ether_addr(hdr->addr3) ||
1440             rx->dev->flags & IFF_PROMISC)
1441                 return RX_CONTINUE;
1442         else
1443                 return RX_DROP_MONITOR;
1444 }
1445
1446
1447 static ieee80211_rx_result debug_noinline
1448 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1449 {
1450         struct net_device *dev = rx->dev;
1451         u16 fc;
1452         int err;
1453
1454         fc = rx->fc;
1455         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1456                 return RX_CONTINUE;
1457
1458         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1459                 return RX_DROP_MONITOR;
1460
1461         err = ieee80211_data_to_8023(rx);
1462         if (unlikely(err))
1463                 return RX_DROP_UNUSABLE;
1464
1465         if (!ieee80211_frame_allowed(rx))
1466                 return RX_DROP_MONITOR;
1467
1468         rx->skb->dev = dev;
1469
1470         dev->stats.rx_packets++;
1471         dev->stats.rx_bytes += rx->skb->len;
1472
1473         ieee80211_deliver_skb(rx);
1474
1475         return RX_QUEUED;
1476 }
1477
1478 static ieee80211_rx_result debug_noinline
1479 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1480 {
1481         struct ieee80211_local *local = rx->local;
1482         struct ieee80211_hw *hw = &local->hw;
1483         struct sk_buff *skb = rx->skb;
1484         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1485         struct tid_ampdu_rx *tid_agg_rx;
1486         u16 start_seq_num;
1487         u16 tid;
1488
1489         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1490                 return RX_CONTINUE;
1491
1492         if (ieee80211_is_back_req(bar->frame_control)) {
1493                 if (!rx->sta)
1494                         return RX_CONTINUE;
1495                 tid = le16_to_cpu(bar->control) >> 12;
1496                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1497                                         != HT_AGG_STATE_OPERATIONAL)
1498                         return RX_CONTINUE;
1499                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1500
1501                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1502
1503                 /* reset session timer */
1504                 if (tid_agg_rx->timeout) {
1505                         unsigned long expires =
1506                                 jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1507                         mod_timer(&tid_agg_rx->session_timer, expires);
1508                 }
1509
1510                 /* manage reordering buffer according to requested */
1511                 /* sequence number */
1512                 rcu_read_lock();
1513                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1514                                                  start_seq_num, 1);
1515                 rcu_read_unlock();
1516                 return RX_DROP_UNUSABLE;
1517         }
1518
1519         return RX_CONTINUE;
1520 }
1521
1522 static ieee80211_rx_result debug_noinline
1523 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1524 {
1525         struct ieee80211_sub_if_data *sdata;
1526
1527         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1528                 return RX_DROP_MONITOR;
1529
1530         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1531         if ((sdata->vif.type == IEEE80211_IF_TYPE_STA ||
1532              sdata->vif.type == IEEE80211_IF_TYPE_IBSS ||
1533              sdata->vif.type == IEEE80211_IF_TYPE_MESH_POINT) &&
1534             !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
1535                 ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->status);
1536         else
1537                 return RX_DROP_MONITOR;
1538
1539         return RX_QUEUED;
1540 }
1541
1542 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1543                                             struct ieee80211_hdr *hdr,
1544                                             struct ieee80211_rx_data *rx)
1545 {
1546         int keyidx;
1547         unsigned int hdrlen;
1548         DECLARE_MAC_BUF(mac);
1549         DECLARE_MAC_BUF(mac2);
1550
1551         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1552         if (rx->skb->len >= hdrlen + 4)
1553                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1554         else
1555                 keyidx = -1;
1556
1557         if (!rx->sta) {
1558                 /*
1559                  * Some hardware seem to generate incorrect Michael MIC
1560                  * reports; ignore them to avoid triggering countermeasures.
1561                  */
1562                 goto ignore;
1563         }
1564
1565         if (!ieee80211_has_protected(hdr->frame_control))
1566                 goto ignore;
1567
1568         if (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP && keyidx) {
1569                 /*
1570                  * APs with pairwise keys should never receive Michael MIC
1571                  * errors for non-zero keyidx because these are reserved for
1572                  * group keys and only the AP is sending real multicast
1573                  * frames in the BSS.
1574                  */
1575                 goto ignore;
1576         }
1577
1578         if (!ieee80211_is_data(hdr->frame_control) &&
1579             !ieee80211_is_auth(hdr->frame_control))
1580                 goto ignore;
1581
1582         mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
1583  ignore:
1584         dev_kfree_skb(rx->skb);
1585         rx->skb = NULL;
1586 }
1587
1588 /* TODO: use IEEE80211_RX_FRAGMENTED */
1589 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1590 {
1591         struct ieee80211_sub_if_data *sdata;
1592         struct ieee80211_local *local = rx->local;
1593         struct ieee80211_rtap_hdr {
1594                 struct ieee80211_radiotap_header hdr;
1595                 u8 flags;
1596                 u8 rate;
1597                 __le16 chan_freq;
1598                 __le16 chan_flags;
1599         } __attribute__ ((packed)) *rthdr;
1600         struct sk_buff *skb = rx->skb, *skb2;
1601         struct net_device *prev_dev = NULL;
1602         struct ieee80211_rx_status *status = rx->status;
1603
1604         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1605                 goto out_free_skb;
1606
1607         if (skb_headroom(skb) < sizeof(*rthdr) &&
1608             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1609                 goto out_free_skb;
1610
1611         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1612         memset(rthdr, 0, sizeof(*rthdr));
1613         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1614         rthdr->hdr.it_present =
1615                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1616                             (1 << IEEE80211_RADIOTAP_RATE) |
1617                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1618
1619         rthdr->rate = rx->rate->bitrate / 5;
1620         rthdr->chan_freq = cpu_to_le16(status->freq);
1621
1622         if (status->band == IEEE80211_BAND_5GHZ)
1623                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1624                                                 IEEE80211_CHAN_5GHZ);
1625         else
1626                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1627                                                 IEEE80211_CHAN_2GHZ);
1628
1629         skb_set_mac_header(skb, 0);
1630         skb->ip_summed = CHECKSUM_UNNECESSARY;
1631         skb->pkt_type = PACKET_OTHERHOST;
1632         skb->protocol = htons(ETH_P_802_2);
1633
1634         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1635                 if (!netif_running(sdata->dev))
1636                         continue;
1637
1638                 if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR ||
1639                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1640                         continue;
1641
1642                 if (prev_dev) {
1643                         skb2 = skb_clone(skb, GFP_ATOMIC);
1644                         if (skb2) {
1645                                 skb2->dev = prev_dev;
1646                                 netif_rx(skb2);
1647                         }
1648                 }
1649
1650                 prev_dev = sdata->dev;
1651                 sdata->dev->stats.rx_packets++;
1652                 sdata->dev->stats.rx_bytes += skb->len;
1653         }
1654
1655         if (prev_dev) {
1656                 skb->dev = prev_dev;
1657                 netif_rx(skb);
1658                 skb = NULL;
1659         } else
1660                 goto out_free_skb;
1661
1662         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1663         return;
1664
1665  out_free_skb:
1666         dev_kfree_skb(skb);
1667 }
1668
1669
1670 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1671                                          struct ieee80211_rx_data *rx,
1672                                          struct sk_buff *skb)
1673 {
1674         ieee80211_rx_result res = RX_DROP_MONITOR;
1675
1676         rx->skb = skb;
1677         rx->sdata = sdata;
1678         rx->dev = sdata->dev;
1679
1680 #define CALL_RXH(rxh)                   \
1681         do {                            \
1682                 res = rxh(rx);          \
1683                 if (res != RX_CONTINUE) \
1684                         goto rxh_done;  \
1685         } while (0);
1686
1687         CALL_RXH(ieee80211_rx_h_passive_scan)
1688         CALL_RXH(ieee80211_rx_h_check)
1689         CALL_RXH(ieee80211_rx_h_decrypt)
1690         CALL_RXH(ieee80211_rx_h_sta_process)
1691         CALL_RXH(ieee80211_rx_h_defragment)
1692         CALL_RXH(ieee80211_rx_h_ps_poll)
1693         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1694         /* must be after MMIC verify so header is counted in MPDU mic */
1695         CALL_RXH(ieee80211_rx_h_remove_qos_control)
1696         CALL_RXH(ieee80211_rx_h_amsdu)
1697         if (ieee80211_vif_is_mesh(&sdata->vif))
1698                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
1699         CALL_RXH(ieee80211_rx_h_data)
1700         CALL_RXH(ieee80211_rx_h_ctrl)
1701         CALL_RXH(ieee80211_rx_h_mgmt)
1702
1703 #undef CALL_RXH
1704
1705  rxh_done:
1706         switch (res) {
1707         case RX_DROP_MONITOR:
1708                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1709                 if (rx->sta)
1710                         rx->sta->rx_dropped++;
1711                 /* fall through */
1712         case RX_CONTINUE:
1713                 ieee80211_rx_cooked_monitor(rx);
1714                 break;
1715         case RX_DROP_UNUSABLE:
1716                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1717                 if (rx->sta)
1718                         rx->sta->rx_dropped++;
1719                 dev_kfree_skb(rx->skb);
1720                 break;
1721         case RX_QUEUED:
1722                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
1723                 break;
1724         }
1725 }
1726
1727 /* main receive path */
1728
1729 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1730                                 u8 *bssid, struct ieee80211_rx_data *rx,
1731                                 struct ieee80211_hdr *hdr)
1732 {
1733         int multicast = is_multicast_ether_addr(hdr->addr1);
1734
1735         switch (sdata->vif.type) {
1736         case IEEE80211_IF_TYPE_STA:
1737                 if (!bssid)
1738                         return 0;
1739                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1740                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1741                                 return 0;
1742                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1743                 } else if (!multicast &&
1744                            compare_ether_addr(sdata->dev->dev_addr,
1745                                               hdr->addr1) != 0) {
1746                         if (!(sdata->dev->flags & IFF_PROMISC))
1747                                 return 0;
1748                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1749                 }
1750                 break;
1751         case IEEE80211_IF_TYPE_IBSS:
1752                 if (!bssid)
1753                         return 0;
1754                 if (ieee80211_is_beacon(hdr->frame_control)) {
1755                         if (!rx->sta)
1756                                 rx->sta = ieee80211_ibss_add_sta(sdata->dev,
1757                                                 rx->skb, bssid, hdr->addr2,
1758                                                 BIT(rx->status->rate_idx));
1759                         return 1;
1760                 }
1761                 else if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1762                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1763                                 return 0;
1764                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1765                 } else if (!multicast &&
1766                            compare_ether_addr(sdata->dev->dev_addr,
1767                                               hdr->addr1) != 0) {
1768                         if (!(sdata->dev->flags & IFF_PROMISC))
1769                                 return 0;
1770                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1771                 } else if (!rx->sta)
1772                         rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
1773                                                 bssid, hdr->addr2,
1774                                                 BIT(rx->status->rate_idx));
1775                 break;
1776         case IEEE80211_IF_TYPE_MESH_POINT:
1777                 if (!multicast &&
1778                     compare_ether_addr(sdata->dev->dev_addr,
1779                                        hdr->addr1) != 0) {
1780                         if (!(sdata->dev->flags & IFF_PROMISC))
1781                                 return 0;
1782
1783                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1784                 }
1785                 break;
1786         case IEEE80211_IF_TYPE_VLAN:
1787         case IEEE80211_IF_TYPE_AP:
1788                 if (!bssid) {
1789                         if (compare_ether_addr(sdata->dev->dev_addr,
1790                                                hdr->addr1))
1791                                 return 0;
1792                 } else if (!ieee80211_bssid_match(bssid,
1793                                         sdata->dev->dev_addr)) {
1794                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1795                                 return 0;
1796                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1797                 }
1798                 break;
1799         case IEEE80211_IF_TYPE_WDS:
1800                 if (bssid || !ieee80211_is_data(hdr->frame_control))
1801                         return 0;
1802                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1803                         return 0;
1804                 break;
1805         case IEEE80211_IF_TYPE_MNTR:
1806                 /* take everything */
1807                 break;
1808         case IEEE80211_IF_TYPE_INVALID:
1809                 /* should never get here */
1810                 WARN_ON(1);
1811                 break;
1812         }
1813
1814         return 1;
1815 }
1816
1817 /*
1818  * This is the actual Rx frames handler. as it blongs to Rx path it must
1819  * be called with rcu_read_lock protection.
1820  */
1821 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
1822                                          struct sk_buff *skb,
1823                                          struct ieee80211_rx_status *status,
1824                                          struct ieee80211_rate *rate)
1825 {
1826         struct ieee80211_local *local = hw_to_local(hw);
1827         struct ieee80211_sub_if_data *sdata;
1828         struct ieee80211_hdr *hdr;
1829         struct ieee80211_rx_data rx;
1830         u16 type;
1831         int prepares;
1832         struct ieee80211_sub_if_data *prev = NULL;
1833         struct sk_buff *skb_new;
1834         u8 *bssid;
1835
1836         hdr = (struct ieee80211_hdr *) skb->data;
1837         memset(&rx, 0, sizeof(rx));
1838         rx.skb = skb;
1839         rx.local = local;
1840
1841         rx.status = status;
1842         rx.rate = rate;
1843         rx.fc = le16_to_cpu(hdr->frame_control);
1844         type = rx.fc & IEEE80211_FCTL_FTYPE;
1845
1846         if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
1847                 local->dot11ReceivedFragmentCount++;
1848
1849         rx.sta = sta_info_get(local, hdr->addr2);
1850         if (rx.sta) {
1851                 rx.sdata = rx.sta->sdata;
1852                 rx.dev = rx.sta->sdata->dev;
1853         }
1854
1855         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1856                 ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
1857                 return;
1858         }
1859
1860         if (unlikely(local->sta_sw_scanning || local->sta_hw_scanning))
1861                 rx.flags |= IEEE80211_RX_IN_SCAN;
1862
1863         ieee80211_parse_qos(&rx);
1864         ieee80211_verify_ip_alignment(&rx);
1865
1866         skb = rx.skb;
1867
1868         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1869                 if (!netif_running(sdata->dev))
1870                         continue;
1871
1872                 if (sdata->vif.type == IEEE80211_IF_TYPE_MNTR)
1873                         continue;
1874
1875                 bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
1876                 rx.flags |= IEEE80211_RX_RA_MATCH;
1877                 prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
1878
1879                 if (!prepares)
1880                         continue;
1881
1882                 /*
1883                  * frame is destined for this interface, but if it's not
1884                  * also for the previous one we handle that after the
1885                  * loop to avoid copying the SKB once too much
1886                  */
1887
1888                 if (!prev) {
1889                         prev = sdata;
1890                         continue;
1891                 }
1892
1893                 /*
1894                  * frame was destined for the previous interface
1895                  * so invoke RX handlers for it
1896                  */
1897
1898                 skb_new = skb_copy(skb, GFP_ATOMIC);
1899                 if (!skb_new) {
1900                         if (net_ratelimit())
1901                                 printk(KERN_DEBUG "%s: failed to copy "
1902                                        "multicast frame for %s\n",
1903                                        wiphy_name(local->hw.wiphy),
1904                                        prev->dev->name);
1905                         continue;
1906                 }
1907                 rx.fc = le16_to_cpu(hdr->frame_control);
1908                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
1909                 prev = sdata;
1910         }
1911         if (prev) {
1912                 rx.fc = le16_to_cpu(hdr->frame_control);
1913                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
1914         } else
1915                 dev_kfree_skb(skb);
1916 }
1917
1918 #define SEQ_MODULO 0x1000
1919 #define SEQ_MASK   0xfff
1920
1921 static inline int seq_less(u16 sq1, u16 sq2)
1922 {
1923         return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1));
1924 }
1925
1926 static inline u16 seq_inc(u16 sq)
1927 {
1928         return ((sq + 1) & SEQ_MASK);
1929 }
1930
1931 static inline u16 seq_sub(u16 sq1, u16 sq2)
1932 {
1933         return ((sq1 - sq2) & SEQ_MASK);
1934 }
1935
1936
1937 /*
1938  * As it function blongs to Rx path it must be called with
1939  * the proper rcu_read_lock protection for its flow.
1940  */
1941 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
1942                                 struct tid_ampdu_rx *tid_agg_rx,
1943                                 struct sk_buff *skb, u16 mpdu_seq_num,
1944                                 int bar_req)
1945 {
1946         struct ieee80211_local *local = hw_to_local(hw);
1947         struct ieee80211_rx_status status;
1948         u16 head_seq_num, buf_size;
1949         int index;
1950         struct ieee80211_supported_band *sband;
1951         struct ieee80211_rate *rate;
1952
1953         buf_size = tid_agg_rx->buf_size;
1954         head_seq_num = tid_agg_rx->head_seq_num;
1955
1956         /* frame with out of date sequence number */
1957         if (seq_less(mpdu_seq_num, head_seq_num)) {
1958                 dev_kfree_skb(skb);
1959                 return 1;
1960         }
1961
1962         /* if frame sequence number exceeds our buffering window size or
1963          * block Ack Request arrived - release stored frames */
1964         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
1965                 /* new head to the ordering buffer */
1966                 if (bar_req)
1967                         head_seq_num = mpdu_seq_num;
1968                 else
1969                         head_seq_num =
1970                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
1971                 /* release stored frames up to new head to stack */
1972                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
1973                         index = seq_sub(tid_agg_rx->head_seq_num,
1974                                 tid_agg_rx->ssn)
1975                                 % tid_agg_rx->buf_size;
1976
1977                         if (tid_agg_rx->reorder_buf[index]) {
1978                                 /* release the reordered frames to stack */
1979                                 memcpy(&status,
1980                                         tid_agg_rx->reorder_buf[index]->cb,
1981                                         sizeof(status));
1982                                 sband = local->hw.wiphy->bands[status.band];
1983                                 rate = &sband->bitrates[status.rate_idx];
1984                                 __ieee80211_rx_handle_packet(hw,
1985                                         tid_agg_rx->reorder_buf[index],
1986                                         &status, rate);
1987                                 tid_agg_rx->stored_mpdu_num--;
1988                                 tid_agg_rx->reorder_buf[index] = NULL;
1989                         }
1990                         tid_agg_rx->head_seq_num =
1991                                 seq_inc(tid_agg_rx->head_seq_num);
1992                 }
1993                 if (bar_req)
1994                         return 1;
1995         }
1996
1997         /* now the new frame is always in the range of the reordering */
1998         /* buffer window */
1999         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2000                                 % tid_agg_rx->buf_size;
2001         /* check if we already stored this frame */
2002         if (tid_agg_rx->reorder_buf[index]) {
2003                 dev_kfree_skb(skb);
2004                 return 1;
2005         }
2006
2007         /* if arrived mpdu is in the right order and nothing else stored */
2008         /* release it immediately */
2009         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2010                         tid_agg_rx->stored_mpdu_num == 0) {
2011                 tid_agg_rx->head_seq_num =
2012                         seq_inc(tid_agg_rx->head_seq_num);
2013                 return 0;
2014         }
2015
2016         /* put the frame in the reordering buffer */
2017         tid_agg_rx->reorder_buf[index] = skb;
2018         tid_agg_rx->stored_mpdu_num++;
2019         /* release the buffer until next missing frame */
2020         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2021                                                 % tid_agg_rx->buf_size;
2022         while (tid_agg_rx->reorder_buf[index]) {
2023                 /* release the reordered frame back to stack */
2024                 memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
2025                         sizeof(status));
2026                 sband = local->hw.wiphy->bands[status.band];
2027                 rate = &sband->bitrates[status.rate_idx];
2028                 __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
2029                                              &status, rate);
2030                 tid_agg_rx->stored_mpdu_num--;
2031                 tid_agg_rx->reorder_buf[index] = NULL;
2032                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2033                 index = seq_sub(tid_agg_rx->head_seq_num,
2034                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2035         }
2036         return 1;
2037 }
2038
2039 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2040                                      struct sk_buff *skb)
2041 {
2042         struct ieee80211_hw *hw = &local->hw;
2043         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2044         struct sta_info *sta;
2045         struct tid_ampdu_rx *tid_agg_rx;
2046         u16 sc;
2047         u16 mpdu_seq_num;
2048         u8 ret = 0;
2049         int tid;
2050
2051         sta = sta_info_get(local, hdr->addr2);
2052         if (!sta)
2053                 return ret;
2054
2055         /* filter the QoS data rx stream according to
2056          * STA/TID and check if this STA/TID is on aggregation */
2057         if (!ieee80211_is_data_qos(hdr->frame_control))
2058                 goto end_reorder;
2059
2060         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2061
2062         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2063                 goto end_reorder;
2064
2065         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2066
2067         /* qos null data frames are excluded */
2068         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2069                 goto end_reorder;
2070
2071         /* new un-ordered ampdu frame - process it */
2072
2073         /* reset session timer */
2074         if (tid_agg_rx->timeout) {
2075                 unsigned long expires =
2076                         jiffies + (tid_agg_rx->timeout / 1000) * HZ;
2077                 mod_timer(&tid_agg_rx->session_timer, expires);
2078         }
2079
2080         /* if this mpdu is fragmented - terminate rx aggregation session */
2081         sc = le16_to_cpu(hdr->seq_ctrl);
2082         if (sc & IEEE80211_SCTL_FRAG) {
2083                 ieee80211_sta_stop_rx_ba_session(sta->sdata->dev, sta->addr,
2084                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2085                 ret = 1;
2086                 goto end_reorder;
2087         }
2088
2089         /* according to mpdu sequence number deal with reordering buffer */
2090         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2091         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2092                                                 mpdu_seq_num, 0);
2093  end_reorder:
2094         return ret;
2095 }
2096
2097 /*
2098  * This is the receive path handler. It is called by a low level driver when an
2099  * 802.11 MPDU is received from the hardware.
2100  */
2101 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2102                     struct ieee80211_rx_status *status)
2103 {
2104         struct ieee80211_local *local = hw_to_local(hw);
2105         struct ieee80211_rate *rate = NULL;
2106         struct ieee80211_supported_band *sband;
2107
2108         if (status->band < 0 ||
2109             status->band >= IEEE80211_NUM_BANDS) {
2110                 WARN_ON(1);
2111                 return;
2112         }
2113
2114         sband = local->hw.wiphy->bands[status->band];
2115
2116         if (!sband ||
2117             status->rate_idx < 0 ||
2118             status->rate_idx >= sband->n_bitrates) {
2119                 WARN_ON(1);
2120                 return;
2121         }
2122
2123         rate = &sband->bitrates[status->rate_idx];
2124
2125         /*
2126          * key references and virtual interfaces are protected using RCU
2127          * and this requires that we are in a read-side RCU section during
2128          * receive processing
2129          */
2130         rcu_read_lock();
2131
2132         /*
2133          * Frames with failed FCS/PLCP checksum are not returned,
2134          * all other frames are returned without radiotap header
2135          * if it was previously present.
2136          * Also, frames with less than 16 bytes are dropped.
2137          */
2138         skb = ieee80211_rx_monitor(local, skb, status, rate);
2139         if (!skb) {
2140                 rcu_read_unlock();
2141                 return;
2142         }
2143
2144         if (!ieee80211_rx_reorder_ampdu(local, skb))
2145                 __ieee80211_rx_handle_packet(hw, skb, status, rate);
2146
2147         rcu_read_unlock();
2148 }
2149 EXPORT_SYMBOL(__ieee80211_rx);
2150
2151 /* This is a version of the rx handler that can be called from hard irq
2152  * context. Post the skb on the queue and schedule the tasklet */
2153 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2154                           struct ieee80211_rx_status *status)
2155 {
2156         struct ieee80211_local *local = hw_to_local(hw);
2157
2158         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2159
2160         skb->dev = local->mdev;
2161         /* copy status into skb->cb for use by tasklet */
2162         memcpy(skb->cb, status, sizeof(*status));
2163         skb->pkt_type = IEEE80211_RX_MSG;
2164         skb_queue_tail(&local->skb_queue, skb);
2165         tasklet_schedule(&local->tasklet);
2166 }
2167 EXPORT_SYMBOL(ieee80211_rx_irqsafe);