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 (((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
  71                         cpu_to_le16(IEEE80211_FTYPE_CTL)) &&
  72             ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
  73                         cpu_to_le16(IEEE80211_STYPE_PSPOLL)) &&
  74             ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
  75                         cpu_to_le16(IEEE80211_STYPE_BACK_REQ)))
  76                 return 1;
  77         return 0;
  78 }
  79
  80 /*
  81  * This function copies a received frame to all monitor interfaces and
  82  * returns a cleaned-up SKB that no longer includes the FCS nor the
  83  * radiotap header the driver might have added.
  84  */
  85 static struct sk_buff *
  86 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
  87                      struct ieee80211_rx_status *status,
  88                      struct ieee80211_rate *rate)
  89 {
  90         struct ieee80211_sub_if_data *sdata;
  91         int needed_headroom = 0;
  92         struct ieee80211_radiotap_header *rthdr;
  93         __le64 *rttsft = NULL;
  94         struct ieee80211_rtap_fixed_data {
  95                 u8 flags;
  96                 u8 rate;
  97                 __le16 chan_freq;
  98                 __le16 chan_flags;
  99                 u8 antsignal;
 100                 u8 padding_for_rxflags;
 101                 __le16 rx_flags;
 102         } __attribute__ ((packed)) *rtfixed;
 103         struct sk_buff *skb, *skb2;
 104         struct net_device *prev_dev = NULL;
 105         int present_fcs_len = 0;
 106         int rtap_len = 0;
 107
 108         /*
 109          * First, we may need to make a copy of the skb because
 110          *  (1) we need to modify it for radiotap (if not present), and
 111          *  (2) the other RX handlers will modify the skb we got.
 112          *
 113          * We don't need to, of course, if we aren't going to return
 114          * the SKB because it has a bad FCS/PLCP checksum.
 115          */
 116         if (status->flag & RX_FLAG_RADIOTAP)
 117                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
 118         else
 119                 /* room for radiotap header, always present fields and TSFT */
 120                 needed_headroom = sizeof(*rthdr) + sizeof(*rtfixed) + 8;
 121
 122         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 123                 present_fcs_len = FCS_LEN;
 124
 125         if (!local->monitors) {
 126                 if (should_drop_frame(status, origskb, present_fcs_len,
 127                                       rtap_len)) {
 128                         dev_kfree_skb(origskb);
 129                         return NULL;
 130                 }
 131
 132                 return remove_monitor_info(local, origskb, rtap_len);
 133         }
 134
 135         if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
 136                 /* only need to expand headroom if necessary */
 137                 skb = origskb;
 138                 origskb = NULL;
 139
 140                 /*
 141                  * This shouldn't trigger often because most devices have an
 142                  * RX header they pull before we get here, and that should
 143                  * be big enough for our radiotap information. We should
 144                  * probably export the length to drivers so that we can have
 145                  * them allocate enough headroom to start with.
 146                  */
 147                 if (skb_headroom(skb) < needed_headroom &&
 148                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 149                         dev_kfree_skb(skb);
 150                         return NULL;
 151                 }
 152         } else {
 153                 /*
 154                  * Need to make a copy and possibly remove radiotap header
 155                  * and FCS from the original.
 156                  */
 157                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 158
 159                 origskb = remove_monitor_info(local, origskb, rtap_len);
 160
 161                 if (!skb)
 162                         return origskb;
 163         }
 164
 165         /* if necessary, prepend radiotap information */
 166         if (!(status->flag & RX_FLAG_RADIOTAP)) {
 167                 rtfixed = (void *) skb_push(skb, sizeof(*rtfixed));
 168                 rtap_len = sizeof(*rthdr) + sizeof(*rtfixed);
 169                 if (status->flag & RX_FLAG_TSFT) {
 170                         rttsft = (void *) skb_push(skb, sizeof(*rttsft));
 171                         rtap_len += 8;
 172                 }
 173                 rthdr = (void *) skb_push(skb, sizeof(*rthdr));
 174                 memset(rthdr, 0, sizeof(*rthdr));
 175                 memset(rtfixed, 0, sizeof(*rtfixed));
 176                 rthdr->it_present =
 177                         cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 178                                     (1 << IEEE80211_RADIOTAP_RATE) |
 179                                     (1 << IEEE80211_RADIOTAP_CHANNEL) |
 180                                     (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL) |
 181                                     (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 182                 rtfixed->flags = 0;
 183                 if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 184                         rtfixed->flags |= IEEE80211_RADIOTAP_F_FCS;
 185
 186                 if (rttsft) {
 187                         *rttsft = cpu_to_le64(status->mactime);
 188                         rthdr->it_present |=
 189                                 cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 190                 }
 191
 192                 /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
 193                 rtfixed->rx_flags = 0;
 194                 if (status->flag &
 195                     (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 196                         rtfixed->rx_flags |=
 197                                 cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
 198
 199                 rtfixed->rate = rate->bitrate / 5;
 200
 201                 rtfixed->chan_freq = cpu_to_le16(status->freq);
 202
 203                 if (status->band == IEEE80211_BAND_5GHZ)
 204                         rtfixed->chan_flags =
 205                                 cpu_to_le16(IEEE80211_CHAN_OFDM |
 206                                             IEEE80211_CHAN_5GHZ);
 207                 else
 208                         rtfixed->chan_flags =
 209                                 cpu_to_le16(IEEE80211_CHAN_DYN |
 210                                             IEEE80211_CHAN_2GHZ);
 211
 212                 rtfixed->antsignal = status->ssi;
 213                 rthdr->it_len = cpu_to_le16(rtap_len);
 214         }
 215
 216         skb_reset_mac_header(skb);
 217         skb->ip_summed = CHECKSUM_UNNECESSARY;
 218         skb->pkt_type = PACKET_OTHERHOST;
 219         skb->protocol = htons(ETH_P_802_2);
 220
 221         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 222                 if (!netif_running(sdata->dev))
 223                         continue;
 224
 225                 if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR)
 226                         continue;
 227
 228                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 229                         continue;
 230
 231                 if (prev_dev) {
 232                         skb2 = skb_clone(skb, GFP_ATOMIC);
 233                         if (skb2) {
 234                                 skb2->dev = prev_dev;
 235                                 netif_rx(skb2);
 236                         }
 237                 }
 238
 239                 prev_dev = sdata->dev;
 240                 sdata->dev->stats.rx_packets++;
 241                 sdata->dev->stats.rx_bytes += skb->len;
 242         }
 243
 244         if (prev_dev) {
 245                 skb->dev = prev_dev;
 246                 netif_rx(skb);
 247         } else
 248                 dev_kfree_skb(skb);
 249
 250         return origskb;
 251 }
 252
 253
 254 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 255 {
 256         u8 *data = rx->skb->data;
 257         int tid;
 258
 259         /* does the frame have a qos control field? */
 260         if (WLAN_FC_IS_QOS_DATA(rx->fc)) {
 261                 u8 *qc = data + ieee80211_get_hdrlen(rx->fc) - QOS_CONTROL_LEN;
 262                 /* frame has qos control */
 263                 tid = qc[0] & QOS_CONTROL_TID_MASK;
 264                 if (qc[0] & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 265                         rx->flags |= IEEE80211_RX_AMSDU;
 266                 else
 267                         rx->flags &= ~IEEE80211_RX_AMSDU;
 268         } else {
 269                 if (unlikely((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT)) {
 270                         /* Separate TID for management frames */
 271                         tid = NUM_RX_DATA_QUEUES - 1;
 272                 } else {
 273                         /* no qos control present */
 274                         tid = 0; /* 802.1d - Best Effort */
 275                 }
 276         }
 277
 278         rx->queue = tid;
 279         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 280          * For now, set skb->priority to 0 for other cases. */
 281         rx->skb->priority = (tid > 7) ? 0 : tid;
 282 }
 283
 284 static void ieee80211_verify_ip_alignment(struct ieee80211_rx_data *rx)
 285 {
 286 #ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
 287         int hdrlen;
 288
 289         if (!WLAN_FC_DATA_PRESENT(rx->fc))
 290                 return;
 291
 292         /*
 293          * Drivers are required to align the payload data in a way that
 294          * guarantees that the contained IP header is aligned to a four-
 295          * byte boundary. In the case of regular frames, this simply means
 296          * aligning the payload to a four-byte boundary (because either
 297          * the IP header is directly contained, or IV/RFC1042 headers that
 298          * have a length divisible by four are in front of it.
 299          *
 300          * With A-MSDU frames, however, the payload data address must
 301          * yield two modulo four because there are 14-byte 802.3 headers
 302          * within the A-MSDU frames that push the IP header further back
 303          * to a multiple of four again. Thankfully, the specs were sane
 304          * enough this time around to require padding each A-MSDU subframe
 305          * to a length that is a multiple of four.
 306          *
 307          * Padding like atheros hardware adds which is inbetween the 802.11
 308          * header and the payload is not supported, the driver is required
 309          * to move the 802.11 header further back in that case.
 310          */
 311         hdrlen = ieee80211_get_hdrlen(rx->fc);
 312         if (rx->flags & IEEE80211_RX_AMSDU)
 313                 hdrlen += ETH_HLEN;
 314         WARN_ON_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3);
 315 #endif
 316 }
 317
 318
 319 static u32 ieee80211_rx_load_stats(struct ieee80211_local *local,
 320                                    struct sk_buff *skb,
 321                                    struct ieee80211_rx_status *status,
 322                                    struct ieee80211_rate *rate)
 323 {
 324         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 325         u32 load = 0, hdrtime;
 326
 327         /* Estimate total channel use caused by this frame */
 328
 329         /* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
 330          * 1 usec = 1/8 * (1080 / 10) = 13.5 */
 331
 332         if (status->band == IEEE80211_BAND_5GHZ ||
 333             (status->band == IEEE80211_BAND_5GHZ &&
 334              rate->flags & IEEE80211_RATE_ERP_G))
 335                 hdrtime = CHAN_UTIL_HDR_SHORT;
 336         else
 337                 hdrtime = CHAN_UTIL_HDR_LONG;
 338
 339         load = hdrtime;
 340         if (!is_multicast_ether_addr(hdr->addr1))
 341                 load += hdrtime;
 342
 343         /* TODO: optimise again */
 344         load += skb->len * CHAN_UTIL_RATE_LCM / rate->bitrate;
 345
 346         /* Divide channel_use by 8 to avoid wrapping around the counter */
 347         load >>= CHAN_UTIL_SHIFT;
 348
 349         return load;
 350 }
 351
 352 /* rx handlers */
 353
 354 static ieee80211_rx_result
 355 ieee80211_rx_h_if_stats(struct ieee80211_rx_data *rx)
 356 {
 357         if (rx->sta)
 358                 rx->sta->channel_use_raw += rx->load;
 359         rx->sdata->channel_use_raw += rx->load;
 360         return RX_CONTINUE;
 361 }
 362
 363 static ieee80211_rx_result
 364 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 365 {
 366         struct ieee80211_local *local = rx->local;
 367         struct sk_buff *skb = rx->skb;
 368
 369         if (unlikely(local->sta_hw_scanning))
 370                 return ieee80211_sta_rx_scan(rx->dev, skb, rx->status);
 371
 372         if (unlikely(local->sta_sw_scanning)) {
 373                 /* drop all the other packets during a software scan anyway */
 374                 if (ieee80211_sta_rx_scan(rx->dev, skb, rx->status)
 375                     != RX_QUEUED)
 376                         dev_kfree_skb(skb);
 377                 return RX_QUEUED;
 378         }
 379
 380         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
 381                 /* scanning finished during invoking of handlers */
 382                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 383                 return RX_DROP_UNUSABLE;
 384         }
 385
 386         return RX_CONTINUE;
 387 }
 388
 389 static ieee80211_rx_result
 390 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 391 {
 392         int hdrlen = ieee80211_get_hdrlen(rx->fc);
 393         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 394
 395 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 396
 397         if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) {
 398                 if (!((rx->fc & IEEE80211_FCTL_FROMDS) &&
 399                       (rx->fc & IEEE80211_FCTL_TODS)))
 400                         return RX_DROP_MONITOR;
 401                 if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
 402                         return RX_DROP_MONITOR;
 403         }
 404
 405         /* If there is not an established peer link and this is not a peer link
 406          * establisment frame, beacon or probe, drop the frame.
 407          */
 408
 409         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 410                 struct ieee80211_mgmt *mgmt;
 411
 412                 if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT)
 413                         return RX_DROP_MONITOR;
 414
 415                 switch (rx->fc & IEEE80211_FCTL_STYPE) {
 416                 case IEEE80211_STYPE_ACTION:
 417                         mgmt = (struct ieee80211_mgmt *)hdr;
 418                         if (mgmt->u.action.category != PLINK_CATEGORY)
 419                                 return RX_DROP_MONITOR;
 420                         /* fall through on else */
 421                 case IEEE80211_STYPE_PROBE_REQ:
 422                 case IEEE80211_STYPE_PROBE_RESP:
 423                 case IEEE80211_STYPE_BEACON:
 424                         return RX_CONTINUE;
 425                         break;
 426                 default:
 427                         return RX_DROP_MONITOR;
 428                 }
 429
 430          } else if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
 431                     is_multicast_ether_addr(hdr->addr1) &&
 432                     mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->dev))
 433                 return RX_DROP_MONITOR;
 434 #undef msh_h_get
 435
 436         return RX_CONTINUE;
 437 }
 438
 439
 440 static ieee80211_rx_result
 441 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 442 {
 443         struct ieee80211_hdr *hdr;
 444
 445         hdr = (struct ieee80211_hdr *) rx->skb->data;
 446
 447         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 448         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 449                 if (unlikely(rx->fc & IEEE80211_FCTL_RETRY &&
 450                              rx->sta->last_seq_ctrl[rx->queue] ==
 451                              hdr->seq_ctrl)) {
 452                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
 453                                 rx->local->dot11FrameDuplicateCount++;
 454                                 rx->sta->num_duplicates++;
 455                         }
 456                         return RX_DROP_MONITOR;
 457                 } else
 458                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 459         }
 460
 461         if (unlikely(rx->skb->len < 16)) {
 462                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 463                 return RX_DROP_MONITOR;
 464         }
 465
 466         /* Drop disallowed frame classes based on STA auth/assoc state;
 467          * IEEE 802.11, Chap 5.5.
 468          *
 469          * 80211.o does filtering only based on association state, i.e., it
 470          * drops Class 3 frames from not associated stations. hostapd sends
 471          * deauth/disassoc frames when needed. In addition, hostapd is
 472          * responsible for filtering on both auth and assoc states.
 473          */
 474
 475         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 476                 return ieee80211_rx_mesh_check(rx);
 477
 478         if (unlikely(((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA ||
 479                       ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL &&
 480                        (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) &&
 481                      rx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
 482                      (!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) {
 483                 if ((!(rx->fc & IEEE80211_FCTL_FROMDS) &&
 484                      !(rx->fc & IEEE80211_FCTL_TODS) &&
 485                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)
 486                     || !(rx->flags & IEEE80211_RX_RA_MATCH)) {
 487                         /* Drop IBSS frames and frames for other hosts
 488                          * silently. */
 489                         return RX_DROP_MONITOR;
 490                 }
 491
 492                 return RX_DROP_MONITOR;
 493         }
 494
 495         return RX_CONTINUE;
 496 }
 497
 498
 499 static ieee80211_rx_result
 500 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 501 {
 502         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 503         int keyidx;
 504         int hdrlen;
 505         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 506         struct ieee80211_key *stakey = NULL;
 507
 508         /*
 509          * Key selection 101
 510          *
 511          * There are three types of keys:
 512          *  - GTK (group keys)
 513          *  - PTK (pairwise keys)
 514          *  - STK (station-to-station pairwise keys)
 515          *
 516          * When selecting a key, we have to distinguish between multicast
 517          * (including broadcast) and unicast frames, the latter can only
 518          * use PTKs and STKs while the former always use GTKs. Unless, of
 519          * course, actual WEP keys ("pre-RSNA") are used, then unicast
 520          * frames can also use key indizes like GTKs. Hence, if we don't
 521          * have a PTK/STK we check the key index for a WEP key.
 522          *
 523          * Note that in a regular BSS, multicast frames are sent by the
 524          * AP only, associated stations unicast the frame to the AP first
 525          * which then multicasts it on their behalf.
 526          *
 527          * There is also a slight problem in IBSS mode: GTKs are negotiated
 528          * with each station, that is something we don't currently handle.
 529          * The spec seems to expect that one negotiates the same key with
 530          * every station but there's no such requirement; VLANs could be
 531          * possible.
 532          */
 533
 534         if (!(rx->fc & IEEE80211_FCTL_PROTECTED))
 535                 return RX_CONTINUE;
 536
 537         /*
 538          * No point in finding a key and decrypting if the frame is neither
 539          * addressed to us nor a multicast frame.
 540          */
 541         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 542                 return RX_CONTINUE;
 543
 544         if (rx->sta)
 545                 stakey = rcu_dereference(rx->sta->key);
 546
 547         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 548                 rx->key = stakey;
 549         } else {
 550                 /*
 551                  * The device doesn't give us the IV so we won't be
 552                  * able to look up the key. That's ok though, we
 553                  * don't need to decrypt the frame, we just won't
 554                  * be able to keep statistics accurate.
 555                  * Except for key threshold notifications, should
 556                  * we somehow allow the driver to tell us which key
 557                  * the hardware used if this flag is set?
 558                  */
 559                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 560                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 561                         return RX_CONTINUE;
 562
 563                 hdrlen = ieee80211_get_hdrlen(rx->fc);
 564
 565                 if (rx->skb->len < 8 + hdrlen)
 566                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 567
 568                 /*
 569                  * no need to call ieee80211_wep_get_keyidx,
 570                  * it verifies a bunch of things we've done already
 571                  */
 572                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 573
 574                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 575
 576                 /*
 577                  * RSNA-protected unicast frames should always be sent with
 578                  * pairwise or station-to-station keys, but for WEP we allow
 579                  * using a key index as well.
 580                  */
 581                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 582                     !is_multicast_ether_addr(hdr->addr1))
 583                         rx->key = NULL;
 584         }
 585
 586         if (rx->key) {
 587                 rx->key->tx_rx_count++;
 588                 /* TODO: add threshold stuff again */
 589         } else {
 590 #ifdef CONFIG_MAC80211_DEBUG
 591                 if (net_ratelimit())
 592                         printk(KERN_DEBUG "%s: RX protected frame,"
 593                                " but have no key\n", rx->dev->name);
 594 #endif /* CONFIG_MAC80211_DEBUG */
 595                 return RX_DROP_MONITOR;
 596         }
 597
 598         /* Check for weak IVs if possible */
 599         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 600             ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
 601             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
 602              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
 603             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 604                 rx->sta->wep_weak_iv_count++;
 605
 606         switch (rx->key->conf.alg) {
 607         case ALG_WEP:
 608                 result = ieee80211_crypto_wep_decrypt(rx);
 609                 break;
 610         case ALG_TKIP:
 611                 result = ieee80211_crypto_tkip_decrypt(rx);
 612                 break;
 613         case ALG_CCMP:
 614                 result = ieee80211_crypto_ccmp_decrypt(rx);
 615                 break;
 616         }
 617
 618         /* either the frame has been decrypted or will be dropped */
 619         rx->status->flag |= RX_FLAG_DECRYPTED;
 620
 621         return result;
 622 }
 623
 624 static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
 625 {
 626         struct ieee80211_sub_if_data *sdata;
 627         DECLARE_MAC_BUF(mac);
 628
 629         sdata = sta->sdata;
 630
 631         if (sdata->bss)
 632                 atomic_inc(&sdata->bss->num_sta_ps);
 633         sta->flags |= WLAN_STA_PS;
 634         sta->flags &= ~WLAN_STA_PSPOLL;
 635 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 636         printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
 637                dev->name, print_mac(mac, sta->addr), sta->aid);
 638 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 639 }
 640
 641 static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
 642 {
 643         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 644         struct sk_buff *skb;
 645         int sent = 0;
 646         struct ieee80211_sub_if_data *sdata;
 647         struct ieee80211_tx_packet_data *pkt_data;
 648         DECLARE_MAC_BUF(mac);
 649
 650         sdata = sta->sdata;
 651
 652         if (sdata->bss)
 653                 atomic_dec(&sdata->bss->num_sta_ps);
 654
 655         sta->flags &= ~(WLAN_STA_PS | WLAN_STA_PSPOLL);
 656
 657         if (!skb_queue_empty(&sta->ps_tx_buf))
 658                 sta_info_clear_tim_bit(sta);
 659
 660 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 661         printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
 662                dev->name, print_mac(mac, sta->addr), sta->aid);
 663 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 664
 665         /* Send all buffered frames to the station */
 666         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 667                 pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 668                 sent++;
 669                 pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
 670                 dev_queue_xmit(skb);
 671         }
 672         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 673                 pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 674                 local->total_ps_buffered--;
 675                 sent++;
 676 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 677                 printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
 678                        "since STA not sleeping anymore\n", dev->name,
 679                        print_mac(mac, sta->addr), sta->aid);
 680 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 681                 pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
 682                 dev_queue_xmit(skb);
 683         }
 684
 685         return sent;
 686 }
 687
 688 static ieee80211_rx_result
 689 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
 690 {
 691         struct sta_info *sta = rx->sta;
 692         struct net_device *dev = rx->dev;
 693         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 694
 695         if (!sta)
 696                 return RX_CONTINUE;
 697
 698         /* Update last_rx only for IBSS packets which are for the current
 699          * BSSID to avoid keeping the current IBSS network alive in cases where
 700          * other STAs are using different BSSID. */
 701         if (rx->sdata->vif.type == IEEE80211_IF_TYPE_IBSS) {
 702                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
 703                                                 IEEE80211_IF_TYPE_IBSS);
 704                 if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
 705                         sta->last_rx = jiffies;
 706         } else
 707         if (!is_multicast_ether_addr(hdr->addr1) ||
 708             rx->sdata->vif.type == IEEE80211_IF_TYPE_STA) {
 709                 /* Update last_rx only for unicast frames in order to prevent
 710                  * the Probe Request frames (the only broadcast frames from a
 711                  * STA in infrastructure mode) from keeping a connection alive.
 712                  * Mesh beacons will update last_rx when if they are found to
 713                  * match the current local configuration when processed.
 714                  */
 715                 sta->last_rx = jiffies;
 716         }
 717
 718         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 719                 return RX_CONTINUE;
 720
 721         sta->rx_fragments++;
 722         sta->rx_bytes += rx->skb->len;
 723         sta->last_rssi = rx->status->ssi;
 724         sta->last_signal = rx->status->signal;
 725         sta->last_noise = rx->status->noise;
 726
 727         if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) {
 728                 /* Change STA power saving mode only in the end of a frame
 729                  * exchange sequence */
 730                 if ((sta->flags & WLAN_STA_PS) && !(rx->fc & IEEE80211_FCTL_PM))
 731                         rx->sent_ps_buffered += ap_sta_ps_end(dev, sta);
 732                 else if (!(sta->flags & WLAN_STA_PS) &&
 733                          (rx->fc & IEEE80211_FCTL_PM))
 734                         ap_sta_ps_start(dev, sta);
 735         }
 736
 737         /* Drop data::nullfunc frames silently, since they are used only to
 738          * control station power saving mode. */
 739         if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
 740             (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_NULLFUNC) {
 741                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
 742                 /* Update counter and free packet here to avoid counting this
 743                  * as a dropped packed. */
 744                 sta->rx_packets++;
 745                 dev_kfree_skb(rx->skb);
 746                 return RX_QUEUED;
 747         }
 748
 749         return RX_CONTINUE;
 750 } /* ieee80211_rx_h_sta_process */
 751
 752 static inline struct ieee80211_fragment_entry *
 753 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 754                          unsigned int frag, unsigned int seq, int rx_queue,
 755                          struct sk_buff **skb)
 756 {
 757         struct ieee80211_fragment_entry *entry;
 758         int idx;
 759
 760         idx = sdata->fragment_next;
 761         entry = &sdata->fragments[sdata->fragment_next++];
 762         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
 763                 sdata->fragment_next = 0;
 764
 765         if (!skb_queue_empty(&entry->skb_list)) {
 766 #ifdef CONFIG_MAC80211_DEBUG
 767                 struct ieee80211_hdr *hdr =
 768                         (struct ieee80211_hdr *) entry->skb_list.next->data;
 769                 DECLARE_MAC_BUF(mac);
 770                 DECLARE_MAC_BUF(mac2);
 771                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
 772                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
 773                        "addr1=%s addr2=%s\n",
 774                        sdata->dev->name, idx,
 775                        jiffies - entry->first_frag_time, entry->seq,
 776                        entry->last_frag, print_mac(mac, hdr->addr1),
 777                        print_mac(mac2, hdr->addr2));
 778 #endif /* CONFIG_MAC80211_DEBUG */
 779                 __skb_queue_purge(&entry->skb_list);
 780         }
 781
 782         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
 783         *skb = NULL;
 784         entry->first_frag_time = jiffies;
 785         entry->seq = seq;
 786         entry->rx_queue = rx_queue;
 787         entry->last_frag = frag;
 788         entry->ccmp = 0;
 789         entry->extra_len = 0;
 790
 791         return entry;
 792 }
 793
 794 static inline struct ieee80211_fragment_entry *
 795 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
 796                           u16 fc, unsigned int frag, unsigned int seq,
 797                           int rx_queue, struct ieee80211_hdr *hdr)
 798 {
 799         struct ieee80211_fragment_entry *entry;
 800         int i, idx;
 801
 802         idx = sdata->fragment_next;
 803         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
 804                 struct ieee80211_hdr *f_hdr;
 805                 u16 f_fc;
 806
 807                 idx--;
 808                 if (idx < 0)
 809                         idx = IEEE80211_FRAGMENT_MAX - 1;
 810
 811                 entry = &sdata->fragments[idx];
 812                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
 813                     entry->rx_queue != rx_queue ||
 814                     entry->last_frag + 1 != frag)
 815                         continue;
 816
 817                 f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data;
 818                 f_fc = le16_to_cpu(f_hdr->frame_control);
 819
 820                 if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
 821                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
 822                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
 823                         continue;
 824
 825                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
 826                         __skb_queue_purge(&entry->skb_list);
 827                         continue;
 828                 }
 829                 return entry;
 830         }
 831
 832         return NULL;
 833 }
 834
 835 static ieee80211_rx_result
 836 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 837 {
 838         struct ieee80211_hdr *hdr;
 839         u16 sc;
 840         unsigned int frag, seq;
 841         struct ieee80211_fragment_entry *entry;
 842         struct sk_buff *skb;
 843         DECLARE_MAC_BUF(mac);
 844
 845         hdr = (struct ieee80211_hdr *) rx->skb->data;
 846         sc = le16_to_cpu(hdr->seq_ctrl);
 847         frag = sc & IEEE80211_SCTL_FRAG;
 848
 849         if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
 850                    (rx->skb)->len < 24 ||
 851                    is_multicast_ether_addr(hdr->addr1))) {
 852                 /* not fragmented */
 853                 goto out;
 854         }
 855         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
 856
 857         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
 858
 859         if (frag == 0) {
 860                 /* This is the first fragment of a new frame. */
 861                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
 862                                                  rx->queue, &(rx->skb));
 863                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
 864                     (rx->fc & IEEE80211_FCTL_PROTECTED)) {
 865                         /* Store CCMP PN so that we can verify that the next
 866                          * fragment has a sequential PN value. */
 867                         entry->ccmp = 1;
 868                         memcpy(entry->last_pn,
 869                                rx->key->u.ccmp.rx_pn[rx->queue],
 870                                CCMP_PN_LEN);
 871                 }
 872                 return RX_QUEUED;
 873         }
 874
 875         /* This is a fragment for a frame that should already be pending in
 876          * fragment cache. Add this fragment to the end of the pending entry.
 877          */
 878         entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq,
 879                                           rx->queue, hdr);
 880         if (!entry) {
 881                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
 882                 return RX_DROP_MONITOR;
 883         }
 884
 885         /* Verify that MPDUs within one MSDU have sequential PN values.
 886          * (IEEE 802.11i, 8.3.3.4.5) */
 887         if (entry->ccmp) {
 888                 int i;
 889                 u8 pn[CCMP_PN_LEN], *rpn;
 890                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
 891                         return RX_DROP_UNUSABLE;
 892                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
 893                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
 894                         pn[i]++;
 895                         if (pn[i])
 896                                 break;
 897                 }
 898                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
 899                 if (memcmp(pn, rpn, CCMP_PN_LEN) != 0) {
 900                         if (net_ratelimit())
 901                                 printk(KERN_DEBUG "%s: defrag: CCMP PN not "
 902                                        "sequential A2=%s"
 903                                        " PN=%02x%02x%02x%02x%02x%02x "
 904                                        "(expected %02x%02x%02x%02x%02x%02x)\n",
 905                                        rx->dev->name, print_mac(mac, hdr->addr2),
 906                                        rpn[0], rpn[1], rpn[2], rpn[3], rpn[4],
 907                                        rpn[5], pn[0], pn[1], pn[2], pn[3],
 908                                        pn[4], pn[5]);
 909                         return RX_DROP_UNUSABLE;
 910                 }
 911                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
 912         }
 913
 914         skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
 915         __skb_queue_tail(&entry->skb_list, rx->skb);
 916         entry->last_frag = frag;
 917         entry->extra_len += rx->skb->len;
 918         if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
 919                 rx->skb = NULL;
 920                 return RX_QUEUED;
 921         }
 922
 923         rx->skb = __skb_dequeue(&entry->skb_list);
 924         if (skb_tailroom(rx->skb) < entry->extra_len) {
 925                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
 926                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
 927                                               GFP_ATOMIC))) {
 928                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
 929                         __skb_queue_purge(&entry->skb_list);
 930                         return RX_DROP_UNUSABLE;
 931                 }
 932         }
 933         while ((skb = __skb_dequeue(&entry->skb_list))) {
 934                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
 935                 dev_kfree_skb(skb);
 936         }
 937
 938         /* Complete frame has been reassembled - process it now */
 939         rx->flags |= IEEE80211_RX_FRAGMENTED;
 940
 941  out:
 942         if (rx->sta)
 943                 rx->sta->rx_packets++;
 944         if (is_multicast_ether_addr(hdr->addr1))
 945                 rx->local->dot11MulticastReceivedFrameCount++;
 946         else
 947                 ieee80211_led_rx(rx->local);
 948         return RX_CONTINUE;
 949 }
 950
 951 static ieee80211_rx_result
 952 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
 953 {
 954         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
 955         struct sk_buff *skb;
 956         int no_pending_pkts;
 957         DECLARE_MAC_BUF(mac);
 958
 959         if (likely(!rx->sta ||
 960                    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
 961                    (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
 962                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
 963                 return RX_CONTINUE;
 964
 965         if ((sdata->vif.type != IEEE80211_IF_TYPE_AP) &&
 966             (sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
 967                 return RX_DROP_UNUSABLE;
 968
 969         skb = skb_dequeue(&rx->sta->tx_filtered);
 970         if (!skb) {
 971                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
 972                 if (skb)
 973                         rx->local->total_ps_buffered--;
 974         }
 975         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
 976                 skb_queue_empty(&rx->sta->ps_tx_buf);
 977
 978         if (skb) {
 979                 struct ieee80211_hdr *hdr =
 980                         (struct ieee80211_hdr *) skb->data;
 981
 982                 /*
 983                  * Tell TX path to send one frame even though the STA may
 984                  * still remain is PS mode after this frame exchange.
 985                  */
 986                 rx->sta->flags |= WLAN_STA_PSPOLL;
 987
 988 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 989                 printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
 990                        print_mac(mac, rx->sta->addr), rx->sta->aid,
 991                        skb_queue_len(&rx->sta->ps_tx_buf));
 992 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 993
 994                 /* Use MoreData flag to indicate whether there are more
 995                  * buffered frames for this STA */
 996                 if (no_pending_pkts)
 997                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 998                 else
 999                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1000
1001                 dev_queue_xmit(skb);
1002
1003                 if (no_pending_pkts)
1004                         sta_info_clear_tim_bit(rx->sta);
1005 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1006         } else if (!rx->sent_ps_buffered) {
1007                 /*
1008                  * FIXME: This can be the result of a race condition between
1009                  *        us expiring a frame and the station polling for it.
1010                  *        Should we send it a null-func frame indicating we
1011                  *        have nothing buffered for it?
1012                  */
1013                 printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
1014                        "though there is no buffered frames for it\n",
1015                        rx->dev->name, print_mac(mac, rx->sta->addr));
1016 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1017         }
1018
1019         /* Free PS Poll skb here instead of returning RX_DROP that would
1020          * count as an dropped frame. */
1021         dev_kfree_skb(rx->skb);
1022
1023         return RX_QUEUED;
1024 }
1025
1026 static ieee80211_rx_result
1027 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1028 {
1029         u16 fc = rx->fc;
1030         u8 *data = rx->skb->data;
1031         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) data;
1032
1033         if (!WLAN_FC_IS_QOS_DATA(fc))
1034                 return RX_CONTINUE;
1035
1036         /* remove the qos control field, update frame type and meta-data */
1037         memmove(data + 2, data, ieee80211_get_hdrlen(fc) - 2);
1038         hdr = (struct ieee80211_hdr *) skb_pull(rx->skb, 2);
1039         /* change frame type to non QOS */
1040         rx->fc = fc &= ~IEEE80211_STYPE_QOS_DATA;
1041         hdr->frame_control = cpu_to_le16(fc);
1042
1043         return RX_CONTINUE;
1044 }
1045
1046 static int
1047 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1048 {
1049         if (unlikely(!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED))) {
1050 #ifdef CONFIG_MAC80211_DEBUG
1051                 if (net_ratelimit())
1052                         printk(KERN_DEBUG "%s: dropped frame "
1053                                "(unauthorized port)\n", rx->dev->name);
1054 #endif /* CONFIG_MAC80211_DEBUG */
1055                 return -EACCES;
1056         }
1057
1058         return 0;
1059 }
1060
1061 static int
1062 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx)
1063 {
1064         /*
1065          * Pass through unencrypted frames if the hardware has
1066          * decrypted them already.
1067          */
1068         if (rx->status->flag & RX_FLAG_DECRYPTED)
1069                 return 0;
1070
1071         /* Drop unencrypted frames if key is set. */
1072         if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
1073                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
1074                      (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
1075                      (rx->key || rx->sdata->drop_unencrypted)))
1076                 return -EACCES;
1077
1078         return 0;
1079 }
1080
1081 static int
1082 ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1083 {
1084         struct net_device *dev = rx->dev;
1085         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1086         u16 fc, hdrlen, ethertype;
1087         u8 *payload;
1088         u8 dst[ETH_ALEN];
1089         u8 src[ETH_ALEN];
1090         struct sk_buff *skb = rx->skb;
1091         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1092         DECLARE_MAC_BUF(mac);
1093         DECLARE_MAC_BUF(mac2);
1094         DECLARE_MAC_BUF(mac3);
1095         DECLARE_MAC_BUF(mac4);
1096
1097         fc = rx->fc;
1098
1099         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1100                 return -1;
1101
1102         hdrlen = ieee80211_get_hdrlen(fc);
1103
1104         if (ieee80211_vif_is_mesh(&sdata->vif)) {
1105                 int meshhdrlen = ieee80211_get_mesh_hdrlen(
1106                                 (struct ieee80211s_hdr *) (skb->data + hdrlen));
1107                 /* Copy on cb:
1108                  *  - mesh header: to be used for mesh forwarding
1109                  * decision. It will also be used as mesh header template at
1110                  * tx.c:ieee80211_subif_start_xmit() if interface
1111                  * type is mesh and skb->pkt_type == PACKET_OTHERHOST
1112                  *  - ta: to be used if a RERR needs to be sent.
1113                  */
1114                 memcpy(skb->cb, skb->data + hdrlen, meshhdrlen);
1115                 memcpy(MESH_PREQ(skb), hdr->addr2, ETH_ALEN);
1116                 hdrlen += meshhdrlen;
1117         }
1118
1119         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
1120          * header
1121          * IEEE 802.11 address fields:
1122          * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1123          *   0     0   DA    SA    BSSID n/a
1124          *   0     1   DA    BSSID SA    n/a
1125          *   1     0   BSSID SA    DA    n/a
1126          *   1     1   RA    TA    DA    SA
1127          */
1128
1129         switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1130         case IEEE80211_FCTL_TODS:
1131                 /* BSSID SA DA */
1132                 memcpy(dst, hdr->addr3, ETH_ALEN);
1133                 memcpy(src, hdr->addr2, ETH_ALEN);
1134
1135                 if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_AP &&
1136                              sdata->vif.type != IEEE80211_IF_TYPE_VLAN)) {
1137                         if (net_ratelimit())
1138                                 printk(KERN_DEBUG "%s: dropped ToDS frame "
1139                                        "(BSSID=%s SA=%s DA=%s)\n",
1140                                        dev->name,
1141                                        print_mac(mac, hdr->addr1),
1142                                        print_mac(mac2, hdr->addr2),
1143                                        print_mac(mac3, hdr->addr3));
1144                         return -1;
1145                 }
1146                 break;
1147         case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1148                 /* RA TA DA SA */
1149                 memcpy(dst, hdr->addr3, ETH_ALEN);
1150                 memcpy(src, hdr->addr4, ETH_ALEN);
1151
1152                  if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_WDS &&
1153                              sdata->vif.type != IEEE80211_IF_TYPE_MESH_POINT)) {
1154                          if (net_ratelimit())
1155                                  printk(KERN_DEBUG "%s: dropped FromDS&ToDS "
1156                                        "frame (RA=%s TA=%s DA=%s SA=%s)\n",
1157                                        rx->dev->name,
1158                                        print_mac(mac, hdr->addr1),
1159                                        print_mac(mac2, hdr->addr2),
1160                                        print_mac(mac3, hdr->addr3),
1161                                        print_mac(mac4, hdr->addr4));
1162                         return -1;
1163                 }
1164                 break;
1165         case IEEE80211_FCTL_FROMDS:
1166                 /* DA BSSID SA */
1167                 memcpy(dst, hdr->addr1, ETH_ALEN);
1168                 memcpy(src, hdr->addr3, ETH_ALEN);
1169
1170                 if (sdata->vif.type != IEEE80211_IF_TYPE_STA ||
1171                     (is_multicast_ether_addr(dst) &&
1172                      !compare_ether_addr(src, dev->dev_addr)))
1173                         return -1;
1174                 break;
1175         case 0:
1176                 /* DA SA BSSID */
1177                 memcpy(dst, hdr->addr1, ETH_ALEN);
1178                 memcpy(src, hdr->addr2, ETH_ALEN);
1179
1180                 if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS) {
1181                         if (net_ratelimit()) {
1182                                 printk(KERN_DEBUG "%s: dropped IBSS frame "
1183                                        "(DA=%s SA=%s BSSID=%s)\n",
1184                                        dev->name,
1185                                        print_mac(mac, hdr->addr1),
1186                                        print_mac(mac2, hdr->addr2),
1187                                        print_mac(mac3, hdr->addr3));
1188                         }
1189                         return -1;
1190                 }
1191                 break;
1192         }
1193
1194         if (unlikely(skb->len - hdrlen < 8)) {
1195                 if (net_ratelimit()) {
1196                         printk(KERN_DEBUG "%s: RX too short data frame "
1197                                "payload\n", dev->name);
1198                 }
1199                 return -1;
1200         }
1201
1202         payload = skb->data + hdrlen;
1203         ethertype = (payload[6] << 8) | payload[7];
1204
1205         if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1206                     ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1207                    compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1208                 /* remove RFC1042 or Bridge-Tunnel encapsulation and
1209                  * replace EtherType */
1210                 skb_pull(skb, hdrlen + 6);
1211                 memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1212                 memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1213         } else {
1214                 struct ethhdr *ehdr;
1215                 __be16 len;
1216
1217                 skb_pull(skb, hdrlen);
1218                 len = htons(skb->len);
1219                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1220                 memcpy(ehdr->h_dest, dst, ETH_ALEN);
1221                 memcpy(ehdr->h_source, src, ETH_ALEN);
1222                 ehdr->h_proto = len;
1223         }
1224         return 0;
1225 }
1226
1227 /*
1228  * requires that rx->skb is a frame with ethernet header
1229  */
1230 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx)
1231 {
1232         static const u8 pae_group_addr[ETH_ALEN]
1233                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1234         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1235
1236         /*
1237          * Allow EAPOL frames to us/the PAE group address regardless
1238          * of whether the frame was encrypted or not.
1239          */
1240         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1241             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1242              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1243                 return true;
1244
1245         if (ieee80211_802_1x_port_control(rx) ||
1246             ieee80211_drop_unencrypted(rx))
1247                 return false;
1248
1249         return true;
1250 }
1251
1252 /*
1253  * requires that rx->skb is a frame with ethernet header
1254  */
1255 static void
1256 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1257 {
1258         struct net_device *dev = rx->dev;
1259         struct ieee80211_local *local = rx->local;
1260         struct sk_buff *skb, *xmit_skb;
1261         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1262         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1263         struct sta_info *dsta;
1264
1265         skb = rx->skb;
1266         xmit_skb = NULL;
1267
1268         if (local->bridge_packets && (sdata->vif.type == IEEE80211_IF_TYPE_AP ||
1269                                       sdata->vif.type == IEEE80211_IF_TYPE_VLAN) &&
1270             (rx->flags & IEEE80211_RX_RA_MATCH)) {
1271                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1272                         /*
1273                          * send multicast frames both to higher layers in
1274                          * local net stack and back to the wireless medium
1275                          */
1276                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1277                         if (!xmit_skb && net_ratelimit())
1278                                 printk(KERN_DEBUG "%s: failed to clone "
1279                                        "multicast frame\n", dev->name);
1280                 } else {
1281                         dsta = sta_info_get(local, skb->data);
1282                         if (dsta && dsta->sdata->dev == dev) {
1283                                 /*
1284                                  * The destination station is associated to
1285                                  * this AP (in this VLAN), so send the frame
1286                                  * directly to it and do not pass it to local
1287                                  * net stack.
1288                                  */
1289                                 xmit_skb = skb;
1290                                 skb = NULL;
1291                         }
1292                 }
1293         }
1294
1295         /* Mesh forwarding */
1296         if (ieee80211_vif_is_mesh(&sdata->vif)) {
1297                 u8 *mesh_ttl = &((struct ieee80211s_hdr *)skb->cb)->ttl;
1298                 (*mesh_ttl)--;
1299
1300                 if (is_multicast_ether_addr(skb->data)) {
1301                         if (*mesh_ttl > 0) {
1302                                 xmit_skb = skb_copy(skb, GFP_ATOMIC);
1303                                 if (!xmit_skb && net_ratelimit())
1304                                         printk(KERN_DEBUG "%s: failed to clone "
1305                                                "multicast frame\n", dev->name);
1306                                 else
1307                                         xmit_skb->pkt_type = PACKET_OTHERHOST;
1308                         } else
1309                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.sta,
1310                                                              dropped_frames_ttl);
1311                 } else if (skb->pkt_type != PACKET_OTHERHOST &&
1312                         compare_ether_addr(dev->dev_addr, skb->data) != 0) {
1313                         if (*mesh_ttl == 0) {
1314                                 IEEE80211_IFSTA_MESH_CTR_INC(&sdata->u.sta,
1315                                                              dropped_frames_ttl);
1316                                 dev_kfree_skb(skb);
1317                                 skb = NULL;
1318                         } else {
1319                                 xmit_skb = skb;
1320                                 xmit_skb->pkt_type = PACKET_OTHERHOST;
1321                                 if (!(dev->flags & IFF_PROMISC))
1322                                         skb  = NULL;
1323                         }
1324                 }
1325         }
1326
1327         if (skb) {
1328                 /* deliver to local stack */
1329                 skb->protocol = eth_type_trans(skb, dev);
1330                 memset(skb->cb, 0, sizeof(skb->cb));
1331                 netif_rx(skb);
1332         }
1333
1334         if (xmit_skb) {
1335                 /* send to wireless media */
1336                 xmit_skb->protocol = htons(ETH_P_802_3);
1337                 skb_reset_network_header(xmit_skb);
1338                 skb_reset_mac_header(xmit_skb);
1339                 dev_queue_xmit(xmit_skb);
1340         }
1341 }
1342
1343 static ieee80211_rx_result
1344 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1345 {
1346         struct net_device *dev = rx->dev;
1347         struct ieee80211_local *local = rx->local;
1348         u16 fc, ethertype;
1349         u8 *payload;
1350         struct sk_buff *skb = rx->skb, *frame = NULL;
1351         const struct ethhdr *eth;
1352         int remaining, err;
1353         u8 dst[ETH_ALEN];
1354         u8 src[ETH_ALEN];
1355         DECLARE_MAC_BUF(mac);
1356
1357         fc = rx->fc;
1358         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1359                 return RX_CONTINUE;
1360
1361         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1362                 return RX_DROP_MONITOR;
1363
1364         if (!(rx->flags & IEEE80211_RX_AMSDU))
1365                 return RX_CONTINUE;
1366
1367         err = ieee80211_data_to_8023(rx);
1368         if (unlikely(err))
1369                 return RX_DROP_UNUSABLE;
1370
1371         skb->dev = dev;
1372
1373         dev->stats.rx_packets++;
1374         dev->stats.rx_bytes += skb->len;
1375
1376         /* skip the wrapping header */
1377         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1378         if (!eth)
1379                 return RX_DROP_UNUSABLE;
1380
1381         while (skb != frame) {
1382                 u8 padding;
1383                 __be16 len = eth->h_proto;
1384                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1385
1386                 remaining = skb->len;
1387                 memcpy(dst, eth->h_dest, ETH_ALEN);
1388                 memcpy(src, eth->h_source, ETH_ALEN);
1389
1390                 padding = ((4 - subframe_len) & 0x3);
1391                 /* the last MSDU has no padding */
1392                 if (subframe_len > remaining) {
1393                         printk(KERN_DEBUG "%s: wrong buffer size", dev->name);
1394                         return RX_DROP_UNUSABLE;
1395                 }
1396
1397                 skb_pull(skb, sizeof(struct ethhdr));
1398                 /* if last subframe reuse skb */
1399                 if (remaining <= subframe_len + padding)
1400                         frame = skb;
1401                 else {
1402                         frame = dev_alloc_skb(local->hw.extra_tx_headroom +
1403                                               subframe_len);
1404
1405                         if (frame == NULL)
1406                                 return RX_DROP_UNUSABLE;
1407
1408                         skb_reserve(frame, local->hw.extra_tx_headroom +
1409                                     sizeof(struct ethhdr));
1410                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1411                                 ntohs(len));
1412
1413                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1414                                                         padding);
1415                         if (!eth) {
1416                                 printk(KERN_DEBUG "%s: wrong buffer size ",
1417                                        dev->name);
1418                                 dev_kfree_skb(frame);
1419                                 return RX_DROP_UNUSABLE;
1420                         }
1421                 }
1422
1423                 skb_reset_network_header(frame);
1424                 frame->dev = dev;
1425                 frame->priority = skb->priority;
1426                 rx->skb = frame;
1427
1428                 payload = frame->data;
1429                 ethertype = (payload[6] << 8) | payload[7];
1430
1431                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1432                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1433                            compare_ether_addr(payload,
1434                                               bridge_tunnel_header) == 0)) {
1435                         /* remove RFC1042 or Bridge-Tunnel
1436                          * encapsulation and replace EtherType */
1437                         skb_pull(frame, 6);
1438                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1439                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1440                 } else {
1441                         memcpy(skb_push(frame, sizeof(__be16)),
1442                                &len, sizeof(__be16));
1443                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1444                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1445                 }
1446
1447                 if (!ieee80211_frame_allowed(rx)) {
1448                         if (skb == frame) /* last frame */
1449                                 return RX_DROP_UNUSABLE;
1450                         dev_kfree_skb(frame);
1451                         continue;
1452                 }
1453
1454                 ieee80211_deliver_skb(rx);
1455         }
1456
1457         return RX_QUEUED;
1458 }
1459
1460 static ieee80211_rx_result
1461 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1462 {
1463         struct net_device *dev = rx->dev;
1464         u16 fc;
1465         int err;
1466
1467         fc = rx->fc;
1468         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1469                 return RX_CONTINUE;
1470
1471         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1472                 return RX_DROP_MONITOR;
1473
1474         err = ieee80211_data_to_8023(rx);
1475         if (unlikely(err))
1476                 return RX_DROP_UNUSABLE;
1477
1478         if (!ieee80211_frame_allowed(rx))
1479                 return RX_DROP_MONITOR;
1480
1481         rx->skb->dev = dev;
1482
1483         dev->stats.rx_packets++;
1484         dev->stats.rx_bytes += rx->skb->len;
1485
1486         ieee80211_deliver_skb(rx);
1487
1488         return RX_QUEUED;
1489 }
1490
1491 static ieee80211_rx_result
1492 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1493 {
1494         struct ieee80211_local *local = rx->local;
1495         struct ieee80211_hw *hw = &local->hw;
1496         struct sk_buff *skb = rx->skb;
1497         struct ieee80211_bar *bar = (struct ieee80211_bar *) skb->data;
1498         struct tid_ampdu_rx *tid_agg_rx;
1499         u16 start_seq_num;
1500         u16 tid;
1501
1502         if (likely((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL))
1503                 return RX_CONTINUE;
1504
1505         if ((rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BACK_REQ) {
1506                 if (!rx->sta)
1507                         return RX_CONTINUE;
1508                 tid = le16_to_cpu(bar->control) >> 12;
1509                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1510                                         != HT_AGG_STATE_OPERATIONAL)
1511                         return RX_CONTINUE;
1512                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1513
1514                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1515
1516                 /* reset session timer */
1517                 if (tid_agg_rx->timeout) {
1518                         unsigned long expires =
1519                                 jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1520                         mod_timer(&tid_agg_rx->session_timer, expires);
1521                 }
1522
1523                 /* manage reordering buffer according to requested */
1524                 /* sequence number */
1525                 rcu_read_lock();
1526                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1527                                                  start_seq_num, 1);
1528                 rcu_read_unlock();
1529                 return RX_DROP_UNUSABLE;
1530         }
1531
1532         return RX_CONTINUE;
1533 }
1534
1535 static ieee80211_rx_result
1536 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1537 {
1538         struct ieee80211_sub_if_data *sdata;
1539
1540         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1541                 return RX_DROP_MONITOR;
1542
1543         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1544         if ((sdata->vif.type == IEEE80211_IF_TYPE_STA ||
1545              sdata->vif.type == IEEE80211_IF_TYPE_IBSS ||
1546              sdata->vif.type == IEEE80211_IF_TYPE_MESH_POINT) &&
1547             !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
1548                 ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->status);
1549         else
1550                 return RX_DROP_MONITOR;
1551
1552         return RX_QUEUED;
1553 }
1554
1555 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1556                                             struct ieee80211_hdr *hdr,
1557                                             struct ieee80211_rx_data *rx)
1558 {
1559         int keyidx, hdrlen;
1560         DECLARE_MAC_BUF(mac);
1561         DECLARE_MAC_BUF(mac2);
1562
1563         hdrlen = ieee80211_get_hdrlen_from_skb(rx->skb);
1564         if (rx->skb->len >= hdrlen + 4)
1565                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1566         else
1567                 keyidx = -1;
1568
1569         if (net_ratelimit())
1570                 printk(KERN_DEBUG "%s: TKIP hwaccel reported Michael MIC "
1571                        "failure from %s to %s keyidx=%d\n",
1572                        dev->name, print_mac(mac, hdr->addr2),
1573                        print_mac(mac2, hdr->addr1), keyidx);
1574
1575         if (!rx->sta) {
1576                 /*
1577                  * Some hardware seem to generate incorrect Michael MIC
1578                  * reports; ignore them to avoid triggering countermeasures.
1579                  */
1580                 if (net_ratelimit())
1581                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1582                                "error for unknown address %s\n",
1583                                dev->name, print_mac(mac, hdr->addr2));
1584                 goto ignore;
1585         }
1586
1587         if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) {
1588                 if (net_ratelimit())
1589                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1590                                "error for a frame with no PROTECTED flag (src "
1591                                "%s)\n", dev->name, print_mac(mac, hdr->addr2));
1592                 goto ignore;
1593         }
1594
1595         if (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP && keyidx) {
1596                 /*
1597                  * APs with pairwise keys should never receive Michael MIC
1598                  * errors for non-zero keyidx because these are reserved for
1599                  * group keys and only the AP is sending real multicast
1600                  * frames in the BSS.
1601                  */
1602                 if (net_ratelimit())
1603                         printk(KERN_DEBUG "%s: ignored Michael MIC error for "
1604                                "a frame with non-zero keyidx (%d)"
1605                                " (src %s)\n", dev->name, keyidx,
1606                                print_mac(mac, hdr->addr2));
1607                 goto ignore;
1608         }
1609
1610         if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
1611             ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
1612              (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)) {
1613                 if (net_ratelimit())
1614                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1615                                "error for a frame that cannot be encrypted "
1616                                "(fc=0x%04x) (src %s)\n",
1617                                dev->name, rx->fc, print_mac(mac, hdr->addr2));
1618                 goto ignore;
1619         }
1620
1621         mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
1622  ignore:
1623         dev_kfree_skb(rx->skb);
1624         rx->skb = NULL;
1625 }
1626
1627 /* TODO: use IEEE80211_RX_FRAGMENTED */
1628 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1629 {
1630         struct ieee80211_sub_if_data *sdata;
1631         struct ieee80211_local *local = rx->local;
1632         struct ieee80211_rtap_hdr {
1633                 struct ieee80211_radiotap_header hdr;
1634                 u8 flags;
1635                 u8 rate;
1636                 __le16 chan_freq;
1637                 __le16 chan_flags;
1638         } __attribute__ ((packed)) *rthdr;
1639         struct sk_buff *skb = rx->skb, *skb2;
1640         struct net_device *prev_dev = NULL;
1641         struct ieee80211_rx_status *status = rx->status;
1642
1643         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1644                 goto out_free_skb;
1645
1646         if (skb_headroom(skb) < sizeof(*rthdr) &&
1647             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1648                 goto out_free_skb;
1649
1650         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1651         memset(rthdr, 0, sizeof(*rthdr));
1652         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1653         rthdr->hdr.it_present =
1654                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1655                             (1 << IEEE80211_RADIOTAP_RATE) |
1656                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1657
1658         rthdr->rate = rx->rate->bitrate / 5;
1659         rthdr->chan_freq = cpu_to_le16(status->freq);
1660
1661         if (status->band == IEEE80211_BAND_5GHZ)
1662                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1663                                                 IEEE80211_CHAN_5GHZ);
1664         else
1665                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1666                                                 IEEE80211_CHAN_2GHZ);
1667
1668         skb_set_mac_header(skb, 0);
1669         skb->ip_summed = CHECKSUM_UNNECESSARY;
1670         skb->pkt_type = PACKET_OTHERHOST;
1671         skb->protocol = htons(ETH_P_802_2);
1672
1673         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1674                 if (!netif_running(sdata->dev))
1675                         continue;
1676
1677                 if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR ||
1678                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1679                         continue;
1680
1681                 if (prev_dev) {
1682                         skb2 = skb_clone(skb, GFP_ATOMIC);
1683                         if (skb2) {
1684                                 skb2->dev = prev_dev;
1685                                 netif_rx(skb2);
1686                         }
1687                 }
1688
1689                 prev_dev = sdata->dev;
1690                 sdata->dev->stats.rx_packets++;
1691                 sdata->dev->stats.rx_bytes += skb->len;
1692         }
1693
1694         if (prev_dev) {
1695                 skb->dev = prev_dev;
1696                 netif_rx(skb);
1697                 skb = NULL;
1698         } else
1699                 goto out_free_skb;
1700
1701         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1702         return;
1703
1704  out_free_skb:
1705         dev_kfree_skb(skb);
1706 }
1707
1708 typedef ieee80211_rx_result (*ieee80211_rx_handler)(struct ieee80211_rx_data *);
1709 static ieee80211_rx_handler ieee80211_rx_handlers[] =
1710 {
1711         ieee80211_rx_h_if_stats,
1712         ieee80211_rx_h_passive_scan,
1713         ieee80211_rx_h_check,
1714         ieee80211_rx_h_decrypt,
1715         ieee80211_rx_h_sta_process,
1716         ieee80211_rx_h_defragment,
1717         ieee80211_rx_h_ps_poll,
1718         ieee80211_rx_h_michael_mic_verify,
1719         /* this must be after decryption - so header is counted in MPDU mic
1720          * must be before pae and data, so QOS_DATA format frames
1721          * are not passed to user space by these functions
1722          */
1723         ieee80211_rx_h_remove_qos_control,
1724         ieee80211_rx_h_amsdu,
1725         ieee80211_rx_h_data,
1726         ieee80211_rx_h_ctrl,
1727         ieee80211_rx_h_mgmt,
1728         NULL
1729 };
1730
1731 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1732                                          struct ieee80211_rx_data *rx,
1733                                          struct sk_buff *skb)
1734 {
1735         ieee80211_rx_handler *handler;
1736         ieee80211_rx_result res = RX_DROP_MONITOR;
1737
1738         rx->skb = skb;
1739         rx->sdata = sdata;
1740         rx->dev = sdata->dev;
1741
1742         for (handler = ieee80211_rx_handlers; *handler != NULL; handler++) {
1743                 res = (*handler)(rx);
1744
1745                 switch (res) {
1746                 case RX_CONTINUE:
1747                         continue;
1748                 case RX_DROP_UNUSABLE:
1749                 case RX_DROP_MONITOR:
1750                         I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1751                         if (rx->sta)
1752                                 rx->sta->rx_dropped++;
1753                         break;
1754                 case RX_QUEUED:
1755                         I802_DEBUG_INC(sdata->local->rx_handlers_queued);
1756                         break;
1757                 }
1758                 break;
1759         }
1760
1761         switch (res) {
1762         case RX_CONTINUE:
1763         case RX_DROP_MONITOR:
1764                 ieee80211_rx_cooked_monitor(rx);
1765                 break;
1766         case RX_DROP_UNUSABLE:
1767                 dev_kfree_skb(rx->skb);
1768                 break;
1769         }
1770 }
1771
1772 /* main receive path */
1773
1774 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1775                                 u8 *bssid, struct ieee80211_rx_data *rx,
1776                                 struct ieee80211_hdr *hdr)
1777 {
1778         int multicast = is_multicast_ether_addr(hdr->addr1);
1779
1780         switch (sdata->vif.type) {
1781         case IEEE80211_IF_TYPE_STA:
1782                 if (!bssid)
1783                         return 0;
1784                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1785                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1786                                 return 0;
1787                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1788                 } else if (!multicast &&
1789                            compare_ether_addr(sdata->dev->dev_addr,
1790                                               hdr->addr1) != 0) {
1791                         if (!(sdata->dev->flags & IFF_PROMISC))
1792                                 return 0;
1793                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1794                 }
1795                 break;
1796         case IEEE80211_IF_TYPE_IBSS:
1797                 if (!bssid)
1798                         return 0;
1799                 if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT &&
1800                     (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
1801                         return 1;
1802                 else if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1803                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1804                                 return 0;
1805                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1806                 } else if (!multicast &&
1807                            compare_ether_addr(sdata->dev->dev_addr,
1808                                               hdr->addr1) != 0) {
1809                         if (!(sdata->dev->flags & IFF_PROMISC))
1810                                 return 0;
1811                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1812                 } else if (!rx->sta)
1813                         rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
1814                                                          bssid, hdr->addr2);
1815                 break;
1816         case IEEE80211_IF_TYPE_MESH_POINT:
1817                 if (!multicast &&
1818                     compare_ether_addr(sdata->dev->dev_addr,
1819                                        hdr->addr1) != 0) {
1820                         if (!(sdata->dev->flags & IFF_PROMISC))
1821                                 return 0;
1822
1823                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1824                 }
1825                 break;
1826         case IEEE80211_IF_TYPE_VLAN:
1827         case IEEE80211_IF_TYPE_AP:
1828                 if (!bssid) {
1829                         if (compare_ether_addr(sdata->dev->dev_addr,
1830                                                hdr->addr1))
1831                                 return 0;
1832                 } else if (!ieee80211_bssid_match(bssid,
1833                                         sdata->dev->dev_addr)) {
1834                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1835                                 return 0;
1836                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1837                 }
1838                 if (sdata->dev == sdata->local->mdev &&
1839                     !(rx->flags & IEEE80211_RX_IN_SCAN))
1840                         /* do not receive anything via
1841                          * master device when not scanning */
1842                         return 0;
1843                 break;
1844         case IEEE80211_IF_TYPE_WDS:
1845                 if (bssid ||
1846                     (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
1847                         return 0;
1848                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1849                         return 0;
1850                 break;
1851         case IEEE80211_IF_TYPE_MNTR:
1852                 /* take everything */
1853                 break;
1854         case IEEE80211_IF_TYPE_INVALID:
1855                 /* should never get here */
1856                 WARN_ON(1);
1857                 break;
1858         }
1859
1860         return 1;
1861 }
1862
1863 /*
1864  * This is the actual Rx frames handler. as it blongs to Rx path it must
1865  * be called with rcu_read_lock protection.
1866  */
1867 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
1868                                          struct sk_buff *skb,
1869                                          struct ieee80211_rx_status *status,
1870                                          u32 load,
1871                                          struct ieee80211_rate *rate)
1872 {
1873         struct ieee80211_local *local = hw_to_local(hw);
1874         struct ieee80211_sub_if_data *sdata;
1875         struct ieee80211_hdr *hdr;
1876         struct ieee80211_rx_data rx;
1877         u16 type;
1878         int prepares;
1879         struct ieee80211_sub_if_data *prev = NULL;
1880         struct sk_buff *skb_new;
1881         u8 *bssid;
1882
1883         hdr = (struct ieee80211_hdr *) skb->data;
1884         memset(&rx, 0, sizeof(rx));
1885         rx.skb = skb;
1886         rx.local = local;
1887
1888         rx.status = status;
1889         rx.load = load;
1890         rx.rate = rate;
1891         rx.fc = le16_to_cpu(hdr->frame_control);
1892         type = rx.fc & IEEE80211_FCTL_FTYPE;
1893
1894         if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
1895                 local->dot11ReceivedFragmentCount++;
1896
1897         rx.sta = sta_info_get(local, hdr->addr2);
1898         if (rx.sta) {
1899                 rx.sdata = rx.sta->sdata;
1900                 rx.dev = rx.sta->sdata->dev;
1901         }
1902
1903         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1904                 ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
1905                 return;
1906         }
1907
1908         if (unlikely(local->sta_sw_scanning || local->sta_hw_scanning))
1909                 rx.flags |= IEEE80211_RX_IN_SCAN;
1910
1911         ieee80211_parse_qos(&rx);
1912         ieee80211_verify_ip_alignment(&rx);
1913
1914         skb = rx.skb;
1915
1916         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1917                 if (!netif_running(sdata->dev))
1918                         continue;
1919
1920                 if (sdata->vif.type == IEEE80211_IF_TYPE_MNTR)
1921                         continue;
1922
1923                 bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
1924                 rx.flags |= IEEE80211_RX_RA_MATCH;
1925                 prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
1926
1927                 if (!prepares)
1928                         continue;
1929
1930                 /*
1931                  * frame is destined for this interface, but if it's not
1932                  * also for the previous one we handle that after the
1933                  * loop to avoid copying the SKB once too much
1934                  */
1935
1936                 if (!prev) {
1937                         prev = sdata;
1938                         continue;
1939                 }
1940
1941                 /*
1942                  * frame was destined for the previous interface
1943                  * so invoke RX handlers for it
1944                  */
1945
1946                 skb_new = skb_copy(skb, GFP_ATOMIC);
1947                 if (!skb_new) {
1948                         if (net_ratelimit())
1949                                 printk(KERN_DEBUG "%s: failed to copy "
1950                                        "multicast frame for %s",
1951                                        wiphy_name(local->hw.wiphy),
1952                                        prev->dev->name);
1953                         continue;
1954                 }
1955                 rx.fc = le16_to_cpu(hdr->frame_control);
1956                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
1957                 prev = sdata;
1958         }
1959         if (prev) {
1960                 rx.fc = le16_to_cpu(hdr->frame_control);
1961                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
1962         } else
1963                 dev_kfree_skb(skb);
1964 }
1965
1966 #define SEQ_MODULO 0x1000
1967 #define SEQ_MASK   0xfff
1968
1969 static inline int seq_less(u16 sq1, u16 sq2)
1970 {
1971         return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1));
1972 }
1973
1974 static inline u16 seq_inc(u16 sq)
1975 {
1976         return ((sq + 1) & SEQ_MASK);
1977 }
1978
1979 static inline u16 seq_sub(u16 sq1, u16 sq2)
1980 {
1981         return ((sq1 - sq2) & SEQ_MASK);
1982 }
1983
1984
1985 /*
1986  * As it function blongs to Rx path it must be called with
1987  * the proper rcu_read_lock protection for its flow.
1988  */
1989 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
1990                                 struct tid_ampdu_rx *tid_agg_rx,
1991                                 struct sk_buff *skb, u16 mpdu_seq_num,
1992                                 int bar_req)
1993 {
1994         struct ieee80211_local *local = hw_to_local(hw);
1995         struct ieee80211_rx_status status;
1996         u16 head_seq_num, buf_size;
1997         int index;
1998         u32 pkt_load;
1999         struct ieee80211_supported_band *sband;
2000         struct ieee80211_rate *rate;
2001
2002         buf_size = tid_agg_rx->buf_size;
2003         head_seq_num = tid_agg_rx->head_seq_num;
2004
2005         /* frame with out of date sequence number */
2006         if (seq_less(mpdu_seq_num, head_seq_num)) {
2007                 dev_kfree_skb(skb);
2008                 return 1;
2009         }
2010
2011         /* if frame sequence number exceeds our buffering window size or
2012          * block Ack Request arrived - release stored frames */
2013         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
2014                 /* new head to the ordering buffer */
2015                 if (bar_req)
2016                         head_seq_num = mpdu_seq_num;
2017                 else
2018                         head_seq_num =
2019                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
2020                 /* release stored frames up to new head to stack */
2021                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2022                         index = seq_sub(tid_agg_rx->head_seq_num,
2023                                 tid_agg_rx->ssn)
2024                                 % tid_agg_rx->buf_size;
2025
2026                         if (tid_agg_rx->reorder_buf[index]) {
2027                                 /* release the reordered frames to stack */
2028                                 memcpy(&status,
2029                                         tid_agg_rx->reorder_buf[index]->cb,
2030                                         sizeof(status));
2031                                 sband = local->hw.wiphy->bands[status.band];
2032                                 rate = &sband->bitrates[status.rate_idx];
2033                                 pkt_load = ieee80211_rx_load_stats(local,
2034                                                 tid_agg_rx->reorder_buf[index],
2035                                                 &status, rate);
2036                                 __ieee80211_rx_handle_packet(hw,
2037                                         tid_agg_rx->reorder_buf[index],
2038                                         &status, pkt_load, rate);
2039                                 tid_agg_rx->stored_mpdu_num--;
2040                                 tid_agg_rx->reorder_buf[index] = NULL;
2041                         }
2042                         tid_agg_rx->head_seq_num =
2043                                 seq_inc(tid_agg_rx->head_seq_num);
2044                 }
2045                 if (bar_req)
2046                         return 1;
2047         }
2048
2049         /* now the new frame is always in the range of the reordering */
2050         /* buffer window */
2051         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2052                                 % tid_agg_rx->buf_size;
2053         /* check if we already stored this frame */
2054         if (tid_agg_rx->reorder_buf[index]) {
2055                 dev_kfree_skb(skb);
2056                 return 1;
2057         }
2058
2059         /* if arrived mpdu is in the right order and nothing else stored */
2060         /* release it immediately */
2061         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2062                         tid_agg_rx->stored_mpdu_num == 0) {
2063                 tid_agg_rx->head_seq_num =
2064                         seq_inc(tid_agg_rx->head_seq_num);
2065                 return 0;
2066         }
2067
2068         /* put the frame in the reordering buffer */
2069         tid_agg_rx->reorder_buf[index] = skb;
2070         tid_agg_rx->stored_mpdu_num++;
2071         /* release the buffer until next missing frame */
2072         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2073                                                 % tid_agg_rx->buf_size;
2074         while (tid_agg_rx->reorder_buf[index]) {
2075                 /* release the reordered frame back to stack */
2076                 memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
2077                         sizeof(status));
2078                 sband = local->hw.wiphy->bands[status.band];
2079                 rate = &sband->bitrates[status.rate_idx];
2080                 pkt_load = ieee80211_rx_load_stats(local,
2081                                         tid_agg_rx->reorder_buf[index],
2082                                         &status, rate);
2083                 __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
2084                                              &status, pkt_load, rate);
2085                 tid_agg_rx->stored_mpdu_num--;
2086                 tid_agg_rx->reorder_buf[index] = NULL;
2087                 tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
2088                 index = seq_sub(tid_agg_rx->head_seq_num,
2089                         tid_agg_rx->ssn) % tid_agg_rx->buf_size;
2090         }
2091         return 1;
2092 }
2093
2094 static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
2095                                      struct sk_buff *skb)
2096 {
2097         struct ieee80211_hw *hw = &local->hw;
2098         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
2099         struct sta_info *sta;
2100         struct tid_ampdu_rx *tid_agg_rx;
2101         u16 fc, sc;
2102         u16 mpdu_seq_num;
2103         u8 ret = 0, *qc;
2104         int tid;
2105
2106         sta = sta_info_get(local, hdr->addr2);
2107         if (!sta)
2108                 return ret;
2109
2110         fc = le16_to_cpu(hdr->frame_control);
2111
2112         /* filter the QoS data rx stream according to
2113          * STA/TID and check if this STA/TID is on aggregation */
2114         if (!WLAN_FC_IS_QOS_DATA(fc))
2115                 goto end_reorder;
2116
2117         qc = skb->data + ieee80211_get_hdrlen(fc) - QOS_CONTROL_LEN;
2118         tid = qc[0] & QOS_CONTROL_TID_MASK;
2119
2120         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2121                 goto end_reorder;
2122
2123         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2124
2125         /* null data frames are excluded */
2126         if (unlikely(fc & IEEE80211_STYPE_NULLFUNC))
2127                 goto end_reorder;
2128
2129         /* new un-ordered ampdu frame - process it */
2130
2131         /* reset session timer */
2132         if (tid_agg_rx->timeout) {
2133                 unsigned long expires =
2134                         jiffies + (tid_agg_rx->timeout / 1000) * HZ;
2135                 mod_timer(&tid_agg_rx->session_timer, expires);
2136         }
2137
2138         /* if this mpdu is fragmented - terminate rx aggregation session */
2139         sc = le16_to_cpu(hdr->seq_ctrl);
2140         if (sc & IEEE80211_SCTL_FRAG) {
2141                 ieee80211_sta_stop_rx_ba_session(sta->sdata->dev, sta->addr,
2142                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2143                 ret = 1;
2144                 goto end_reorder;
2145         }
2146
2147         /* according to mpdu sequence number deal with reordering buffer */
2148         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2149         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2150                                                 mpdu_seq_num, 0);
2151  end_reorder:
2152         return ret;
2153 }
2154
2155 /*
2156  * This is the receive path handler. It is called by a low level driver when an
2157  * 802.11 MPDU is received from the hardware.
2158  */
2159 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2160                     struct ieee80211_rx_status *status)
2161 {
2162         struct ieee80211_local *local = hw_to_local(hw);
2163         u32 pkt_load;
2164         struct ieee80211_rate *rate = NULL;
2165         struct ieee80211_supported_band *sband;
2166
2167         if (status->band < 0 ||
2168             status->band >= IEEE80211_NUM_BANDS) {
2169                 WARN_ON(1);
2170                 return;
2171         }
2172
2173         sband = local->hw.wiphy->bands[status->band];
2174
2175         if (!sband ||
2176             status->rate_idx < 0 ||
2177             status->rate_idx >= sband->n_bitrates) {
2178                 WARN_ON(1);
2179                 return;
2180         }
2181
2182         rate = &sband->bitrates[status->rate_idx];
2183
2184         /*
2185          * key references and virtual interfaces are protected using RCU
2186          * and this requires that we are in a read-side RCU section during
2187          * receive processing
2188          */
2189         rcu_read_lock();
2190
2191         /*
2192          * Frames with failed FCS/PLCP checksum are not returned,
2193          * all other frames are returned without radiotap header
2194          * if it was previously present.
2195          * Also, frames with less than 16 bytes are dropped.
2196          */
2197         skb = ieee80211_rx_monitor(local, skb, status, rate);
2198         if (!skb) {
2199                 rcu_read_unlock();
2200                 return;
2201         }
2202
2203         pkt_load = ieee80211_rx_load_stats(local, skb, status, rate);
2204         local->channel_use_raw += pkt_load;
2205
2206         if (!ieee80211_rx_reorder_ampdu(local, skb))
2207                 __ieee80211_rx_handle_packet(hw, skb, status, pkt_load, rate);
2208
2209         rcu_read_unlock();
2210 }
2211 EXPORT_SYMBOL(__ieee80211_rx);
2212
2213 /* This is a version of the rx handler that can be called from hard irq
2214  * context. Post the skb on the queue and schedule the tasklet */
2215 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2216                           struct ieee80211_rx_status *status)
2217 {
2218         struct ieee80211_local *local = hw_to_local(hw);
2219
2220         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2221
2222         skb->dev = local->mdev;
2223         /* copy status into skb->cb for use by tasklet */
2224         memcpy(skb->cb, status, sizeof(*status));
2225         skb->pkt_type = IEEE80211_RX_MSG;
2226         skb_queue_tail(&local->skb_queue, skb);
2227         tasklet_schedule(&local->tasklet);
2228 }
2229 EXPORT_SYMBOL(ieee80211_rx_irqsafe);