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/kernel.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/etherdevice.h>
  16 #include <linux/rcupdate.h>
  17 #include <net/mac80211.h>
  18 #include <net/ieee80211_radiotap.h>
  19
  20 #include "ieee80211_i.h"
  21 #include "ieee80211_led.h"
  22 #include "wep.h"
  23 #include "wpa.h"
  24 #include "tkip.h"
  25 #include "wme.h"
  26
  27 /*
  28  * monitor mode reception
  29  *
  30  * This function cleans up the SKB, i.e. it removes all the stuff
  31  * only useful for monitoring.
  32  */
  33 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  34                                            struct sk_buff *skb,
  35                                            int rtap_len)
  36 {
  37         skb_pull(skb, rtap_len);
  38
  39         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  40                 if (likely(skb->len > FCS_LEN))
  41                         skb_trim(skb, skb->len - FCS_LEN);
  42                 else {
  43                         /* driver bug */
  44                         WARN_ON(1);
  45                         dev_kfree_skb(skb);
  46                         skb = NULL;
  47                 }
  48         }
  49
  50         return skb;
  51 }
  52
  53 static inline int should_drop_frame(struct ieee80211_rx_status *status,
  54                                     struct sk_buff *skb,
  55                                     int present_fcs_len,
  56                                     int radiotap_len)
  57 {
  58         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
  59
  60         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  61                 return 1;
  62         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
  63                 return 1;
  64         if ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
  65                         cpu_to_le16(IEEE80211_FTYPE_CTL))
  66                 return 1;
  67         return 0;
  68 }
  69
  70 /*
  71  * This function copies a received frame to all monitor interfaces and
  72  * returns a cleaned-up SKB that no longer includes the FCS nor the
  73  * radiotap header the driver might have added.
  74  */
  75 static struct sk_buff *
  76 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
  77                      struct ieee80211_rx_status *status)
  78 {
  79         struct ieee80211_sub_if_data *sdata;
  80         struct ieee80211_rate *rate;
  81         int needed_headroom = 0;
  82         struct ieee80211_rtap_hdr {
  83                 struct ieee80211_radiotap_header hdr;
  84                 u8 flags;
  85                 u8 rate;
  86                 __le16 chan_freq;
  87                 __le16 chan_flags;
  88                 u8 antsignal;
  89                 u8 padding_for_rxflags;
  90                 __le16 rx_flags;
  91         } __attribute__ ((packed)) *rthdr;
  92         struct sk_buff *skb, *skb2;
  93         struct net_device *prev_dev = NULL;
  94         int present_fcs_len = 0;
  95         int rtap_len = 0;
  96
  97         /*
  98          * First, we may need to make a copy of the skb because
  99          *  (1) we need to modify it for radiotap (if not present), and
 100          *  (2) the other RX handlers will modify the skb we got.
 101          *
 102          * We don't need to, of course, if we aren't going to return
 103          * the SKB because it has a bad FCS/PLCP checksum.
 104          */
 105         if (status->flag & RX_FLAG_RADIOTAP)
 106                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
 107         else
 108                 needed_headroom = sizeof(*rthdr);
 109
 110         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 111                 present_fcs_len = FCS_LEN;
 112
 113         if (!local->monitors) {
 114                 if (should_drop_frame(status, origskb, present_fcs_len,
 115                                       rtap_len)) {
 116                         dev_kfree_skb(origskb);
 117                         return NULL;
 118                 }
 119
 120                 return remove_monitor_info(local, origskb, rtap_len);
 121         }
 122
 123         if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
 124                 /* only need to expand headroom if necessary */
 125                 skb = origskb;
 126                 origskb = NULL;
 127
 128                 /*
 129                  * This shouldn't trigger often because most devices have an
 130                  * RX header they pull before we get here, and that should
 131                  * be big enough for our radiotap information. We should
 132                  * probably export the length to drivers so that we can have
 133                  * them allocate enough headroom to start with.
 134                  */
 135                 if (skb_headroom(skb) < needed_headroom &&
 136                     pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC)) {
 137                         dev_kfree_skb(skb);
 138                         return NULL;
 139                 }
 140         } else {
 141                 /*
 142                  * Need to make a copy and possibly remove radiotap header
 143                  * and FCS from the original.
 144                  */
 145                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 146
 147                 origskb = remove_monitor_info(local, origskb, rtap_len);
 148
 149                 if (!skb)
 150                         return origskb;
 151         }
 152
 153         /* if necessary, prepend radiotap information */
 154         if (!(status->flag & RX_FLAG_RADIOTAP)) {
 155                 rthdr = (void *) skb_push(skb, sizeof(*rthdr));
 156                 memset(rthdr, 0, sizeof(*rthdr));
 157                 rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
 158                 rthdr->hdr.it_present =
 159                         cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 160                                     (1 << IEEE80211_RADIOTAP_RATE) |
 161                                     (1 << IEEE80211_RADIOTAP_CHANNEL) |
 162                                     (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL) |
 163                                     (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 164                 rthdr->flags = local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS ?
 165                                IEEE80211_RADIOTAP_F_FCS : 0;
 166
 167                 /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
 168                 rthdr->rx_flags = 0;
 169                 if (status->flag &
 170                     (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 171                         rthdr->rx_flags |=
 172                                 cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
 173
 174                 rate = ieee80211_get_rate(local, status->phymode,
 175                                           status->rate);
 176                 if (rate)
 177                         rthdr->rate = rate->rate / 5;
 178
 179                 rthdr->chan_freq = cpu_to_le16(status->freq);
 180
 181                 if (status->phymode == MODE_IEEE80211A)
 182                         rthdr->chan_flags =
 183                                 cpu_to_le16(IEEE80211_CHAN_OFDM |
 184                                             IEEE80211_CHAN_5GHZ);
 185                 else
 186                         rthdr->chan_flags =
 187                                 cpu_to_le16(IEEE80211_CHAN_DYN |
 188                                             IEEE80211_CHAN_2GHZ);
 189
 190                 rthdr->antsignal = status->ssi;
 191         }
 192
 193         skb_set_mac_header(skb, 0);
 194         skb->ip_summed = CHECKSUM_UNNECESSARY;
 195         skb->pkt_type = PACKET_OTHERHOST;
 196         skb->protocol = htons(ETH_P_802_2);
 197
 198         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 199                 if (!netif_running(sdata->dev))
 200                         continue;
 201
 202                 if (sdata->type != IEEE80211_IF_TYPE_MNTR)
 203                         continue;
 204
 205                 if (prev_dev) {
 206                         skb2 = skb_clone(skb, GFP_ATOMIC);
 207                         if (skb2) {
 208                                 skb2->dev = prev_dev;
 209                                 netif_rx(skb2);
 210                         }
 211                 }
 212
 213                 prev_dev = sdata->dev;
 214                 sdata->dev->stats.rx_packets++;
 215                 sdata->dev->stats.rx_bytes += skb->len;
 216         }
 217
 218         if (prev_dev) {
 219                 skb->dev = prev_dev;
 220                 netif_rx(skb);
 221         } else
 222                 dev_kfree_skb(skb);
 223
 224         return origskb;
 225 }
 226
 227
 228 /* pre-rx handlers
 229  *
 230  * these don't have dev/sdata fields in the rx data
 231  * The sta value should also not be used because it may
 232  * be NULL even though a STA (in IBSS mode) will be added.
 233  */
 234
 235 static ieee80211_txrx_result
 236 ieee80211_rx_h_parse_qos(struct ieee80211_txrx_data *rx)
 237 {
 238         u8 *data = rx->skb->data;
 239         int tid;
 240
 241         /* does the frame have a qos control field? */
 242         if (WLAN_FC_IS_QOS_DATA(rx->fc)) {
 243                 u8 *qc = data + ieee80211_get_hdrlen(rx->fc) - QOS_CONTROL_LEN;
 244                 /* frame has qos control */
 245                 tid = qc[0] & QOS_CONTROL_TID_MASK;
 246         } else {
 247                 if (unlikely((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT)) {
 248                         /* Separate TID for management frames */
 249                         tid = NUM_RX_DATA_QUEUES - 1;
 250                 } else {
 251                         /* no qos control present */
 252                         tid = 0; /* 802.1d - Best Effort */
 253                 }
 254         }
 255
 256         I802_DEBUG_INC(rx->local->wme_rx_queue[tid]);
 257         /* only a debug counter, sta might not be assigned properly yet */
 258         if (rx->sta)
 259                 I802_DEBUG_INC(rx->sta->wme_rx_queue[tid]);
 260
 261         rx->u.rx.queue = tid;
 262         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 263          * For now, set skb->priority to 0 for other cases. */
 264         rx->skb->priority = (tid > 7) ? 0 : tid;
 265
 266         return TXRX_CONTINUE;
 267 }
 268
 269 static ieee80211_txrx_result
 270 ieee80211_rx_h_load_stats(struct ieee80211_txrx_data *rx)
 271 {
 272         struct ieee80211_local *local = rx->local;
 273         struct sk_buff *skb = rx->skb;
 274         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 275         u32 load = 0, hdrtime;
 276         struct ieee80211_rate *rate;
 277         struct ieee80211_hw_mode *mode = local->hw.conf.mode;
 278         int i;
 279
 280         /* Estimate total channel use caused by this frame */
 281
 282         if (unlikely(mode->num_rates < 0))
 283                 return TXRX_CONTINUE;
 284
 285         rate = &mode->rates[0];
 286         for (i = 0; i < mode->num_rates; i++) {
 287                 if (mode->rates[i].val == rx->u.rx.status->rate) {
 288                         rate = &mode->rates[i];
 289                         break;
 290                 }
 291         }
 292
 293         /* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
 294          * 1 usec = 1/8 * (1080 / 10) = 13.5 */
 295
 296         if (mode->mode == MODE_IEEE80211A ||
 297             (mode->mode == MODE_IEEE80211G &&
 298              rate->flags & IEEE80211_RATE_ERP))
 299                 hdrtime = CHAN_UTIL_HDR_SHORT;
 300         else
 301                 hdrtime = CHAN_UTIL_HDR_LONG;
 302
 303         load = hdrtime;
 304         if (!is_multicast_ether_addr(hdr->addr1))
 305                 load += hdrtime;
 306
 307         load += skb->len * rate->rate_inv;
 308
 309         /* Divide channel_use by 8 to avoid wrapping around the counter */
 310         load >>= CHAN_UTIL_SHIFT;
 311         local->channel_use_raw += load;
 312         rx->u.rx.load = load;
 313
 314         return TXRX_CONTINUE;
 315 }
 316
 317 ieee80211_rx_handler ieee80211_rx_pre_handlers[] =
 318 {
 319         ieee80211_rx_h_parse_qos,
 320         ieee80211_rx_h_load_stats,
 321         NULL
 322 };
 323
 324 /* rx handlers */
 325
 326 static ieee80211_txrx_result
 327 ieee80211_rx_h_if_stats(struct ieee80211_txrx_data *rx)
 328 {
 329         if (rx->sta)
 330                 rx->sta->channel_use_raw += rx->u.rx.load;
 331         rx->sdata->channel_use_raw += rx->u.rx.load;
 332         return TXRX_CONTINUE;
 333 }
 334
 335 static ieee80211_txrx_result
 336 ieee80211_rx_h_passive_scan(struct ieee80211_txrx_data *rx)
 337 {
 338         struct ieee80211_local *local = rx->local;
 339         struct sk_buff *skb = rx->skb;
 340
 341         if (unlikely(local->sta_hw_scanning))
 342                 return ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status);
 343
 344         if (unlikely(local->sta_sw_scanning)) {
 345                 /* drop all the other packets during a software scan anyway */
 346                 if (ieee80211_sta_rx_scan(rx->dev, skb, rx->u.rx.status)
 347                     != TXRX_QUEUED)
 348                         dev_kfree_skb(skb);
 349                 return TXRX_QUEUED;
 350         }
 351
 352         if (unlikely(rx->flags & IEEE80211_TXRXD_RXIN_SCAN)) {
 353                 /* scanning finished during invoking of handlers */
 354                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 355                 return TXRX_DROP;
 356         }
 357
 358         return TXRX_CONTINUE;
 359 }
 360
 361 static ieee80211_txrx_result
 362 ieee80211_rx_h_check(struct ieee80211_txrx_data *rx)
 363 {
 364         struct ieee80211_hdr *hdr;
 365         hdr = (struct ieee80211_hdr *) rx->skb->data;
 366
 367         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 368         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 369                 if (unlikely(rx->fc & IEEE80211_FCTL_RETRY &&
 370                              rx->sta->last_seq_ctrl[rx->u.rx.queue] ==
 371                              hdr->seq_ctrl)) {
 372                         if (rx->flags & IEEE80211_TXRXD_RXRA_MATCH) {
 373                                 rx->local->dot11FrameDuplicateCount++;
 374                                 rx->sta->num_duplicates++;
 375                         }
 376                         return TXRX_DROP;
 377                 } else
 378                         rx->sta->last_seq_ctrl[rx->u.rx.queue] = hdr->seq_ctrl;
 379         }
 380
 381         if (unlikely(rx->skb->len < 16)) {
 382                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 383                 return TXRX_DROP;
 384         }
 385
 386         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
 387                 rx->skb->pkt_type = PACKET_OTHERHOST;
 388         else if (compare_ether_addr(rx->dev->dev_addr, hdr->addr1) == 0)
 389                 rx->skb->pkt_type = PACKET_HOST;
 390         else if (is_multicast_ether_addr(hdr->addr1)) {
 391                 if (is_broadcast_ether_addr(hdr->addr1))
 392                         rx->skb->pkt_type = PACKET_BROADCAST;
 393                 else
 394                         rx->skb->pkt_type = PACKET_MULTICAST;
 395         } else
 396                 rx->skb->pkt_type = PACKET_OTHERHOST;
 397
 398         /* Drop disallowed frame classes based on STA auth/assoc state;
 399          * IEEE 802.11, Chap 5.5.
 400          *
 401          * 80211.o does filtering only based on association state, i.e., it
 402          * drops Class 3 frames from not associated stations. hostapd sends
 403          * deauth/disassoc frames when needed. In addition, hostapd is
 404          * responsible for filtering on both auth and assoc states.
 405          */
 406         if (unlikely(((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA ||
 407                       ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL &&
 408                        (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) &&
 409                      rx->sdata->type != IEEE80211_IF_TYPE_IBSS &&
 410                      (!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) {
 411                 if ((!(rx->fc & IEEE80211_FCTL_FROMDS) &&
 412                      !(rx->fc & IEEE80211_FCTL_TODS) &&
 413                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)
 414                     || !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
 415                         /* Drop IBSS frames and frames for other hosts
 416                          * silently. */
 417                         return TXRX_DROP;
 418                 }
 419
 420                 return TXRX_DROP;
 421         }
 422
 423         return TXRX_CONTINUE;
 424 }
 425
 426
 427 static ieee80211_txrx_result
 428 ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx)
 429 {
 430         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 431         int keyidx;
 432         int hdrlen;
 433         ieee80211_txrx_result result = TXRX_DROP;
 434         struct ieee80211_key *stakey = NULL;
 435
 436         /*
 437          * Key selection 101
 438          *
 439          * There are three types of keys:
 440          *  - GTK (group keys)
 441          *  - PTK (pairwise keys)
 442          *  - STK (station-to-station pairwise keys)
 443          *
 444          * When selecting a key, we have to distinguish between multicast
 445          * (including broadcast) and unicast frames, the latter can only
 446          * use PTKs and STKs while the former always use GTKs. Unless, of
 447          * course, actual WEP keys ("pre-RSNA") are used, then unicast
 448          * frames can also use key indizes like GTKs. Hence, if we don't
 449          * have a PTK/STK we check the key index for a WEP key.
 450          *
 451          * Note that in a regular BSS, multicast frames are sent by the
 452          * AP only, associated stations unicast the frame to the AP first
 453          * which then multicasts it on their behalf.
 454          *
 455          * There is also a slight problem in IBSS mode: GTKs are negotiated
 456          * with each station, that is something we don't currently handle.
 457          * The spec seems to expect that one negotiates the same key with
 458          * every station but there's no such requirement; VLANs could be
 459          * possible.
 460          */
 461
 462         if (!(rx->fc & IEEE80211_FCTL_PROTECTED))
 463                 return TXRX_CONTINUE;
 464
 465         /*
 466          * No point in finding a key and decrypting if the frame is neither
 467          * addressed to us nor a multicast frame.
 468          */
 469         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
 470                 return TXRX_CONTINUE;
 471
 472         if (rx->sta)
 473                 stakey = rcu_dereference(rx->sta->key);
 474
 475         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 476                 rx->key = stakey;
 477         } else {
 478                 /*
 479                  * The device doesn't give us the IV so we won't be
 480                  * able to look up the key. That's ok though, we
 481                  * don't need to decrypt the frame, we just won't
 482                  * be able to keep statistics accurate.
 483                  * Except for key threshold notifications, should
 484                  * we somehow allow the driver to tell us which key
 485                  * the hardware used if this flag is set?
 486                  */
 487                 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
 488                     (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
 489                         return TXRX_CONTINUE;
 490
 491                 hdrlen = ieee80211_get_hdrlen(rx->fc);
 492
 493                 if (rx->skb->len < 8 + hdrlen)
 494                         return TXRX_DROP; /* TODO: count this? */
 495
 496                 /*
 497                  * no need to call ieee80211_wep_get_keyidx,
 498                  * it verifies a bunch of things we've done already
 499                  */
 500                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 501
 502                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 503
 504                 /*
 505                  * RSNA-protected unicast frames should always be sent with
 506                  * pairwise or station-to-station keys, but for WEP we allow
 507                  * using a key index as well.
 508                  */
 509                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 510                     !is_multicast_ether_addr(hdr->addr1))
 511                         rx->key = NULL;
 512         }
 513
 514         if (rx->key) {
 515                 rx->key->tx_rx_count++;
 516                 /* TODO: add threshold stuff again */
 517         } else {
 518 #ifdef CONFIG_MAC80211_DEBUG
 519                 if (net_ratelimit())
 520                         printk(KERN_DEBUG "%s: RX protected frame,"
 521                                " but have no key\n", rx->dev->name);
 522 #endif /* CONFIG_MAC80211_DEBUG */
 523                 return TXRX_DROP;
 524         }
 525
 526         /* Check for weak IVs if possible */
 527         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 528             ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) &&
 529             (!(rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) ||
 530              !(rx->u.rx.status->flag & RX_FLAG_DECRYPTED)) &&
 531             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 532                 rx->sta->wep_weak_iv_count++;
 533
 534         switch (rx->key->conf.alg) {
 535         case ALG_WEP:
 536                 result = ieee80211_crypto_wep_decrypt(rx);
 537                 break;
 538         case ALG_TKIP:
 539                 result = ieee80211_crypto_tkip_decrypt(rx);
 540                 break;
 541         case ALG_CCMP:
 542                 result = ieee80211_crypto_ccmp_decrypt(rx);
 543                 break;
 544         }
 545
 546         /* either the frame has been decrypted or will be dropped */
 547         rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
 548
 549         return result;
 550 }
 551
 552 static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
 553 {
 554         struct ieee80211_sub_if_data *sdata;
 555         DECLARE_MAC_BUF(mac);
 556
 557         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 558
 559         if (sdata->bss)
 560                 atomic_inc(&sdata->bss->num_sta_ps);
 561         sta->flags |= WLAN_STA_PS;
 562         sta->pspoll = 0;
 563 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 564         printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
 565                dev->name, print_mac(mac, sta->addr), sta->aid);
 566 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 567 }
 568
 569 static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
 570 {
 571         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 572         struct sk_buff *skb;
 573         int sent = 0;
 574         struct ieee80211_sub_if_data *sdata;
 575         struct ieee80211_tx_packet_data *pkt_data;
 576         DECLARE_MAC_BUF(mac);
 577
 578         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
 579         if (sdata->bss)
 580                 atomic_dec(&sdata->bss->num_sta_ps);
 581         sta->flags &= ~(WLAN_STA_PS | WLAN_STA_TIM);
 582         sta->pspoll = 0;
 583         if (!skb_queue_empty(&sta->ps_tx_buf)) {
 584                 if (local->ops->set_tim)
 585                         local->ops->set_tim(local_to_hw(local), sta->aid, 0);
 586                 if (sdata->bss)
 587                         bss_tim_clear(local, sdata->bss, sta->aid);
 588         }
 589 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 590         printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
 591                dev->name, print_mac(mac, sta->addr), sta->aid);
 592 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 593         /* Send all buffered frames to the station */
 594         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 595                 pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 596                 sent++;
 597                 pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
 598                 dev_queue_xmit(skb);
 599         }
 600         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 601                 pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
 602                 local->total_ps_buffered--;
 603                 sent++;
 604 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 605                 printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
 606                        "since STA not sleeping anymore\n", dev->name,
 607                        print_mac(mac, sta->addr), sta->aid);
 608 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 609                 pkt_data->flags |= IEEE80211_TXPD_REQUEUE;
 610                 dev_queue_xmit(skb);
 611         }
 612
 613         return sent;
 614 }
 615
 616 static ieee80211_txrx_result
 617 ieee80211_rx_h_sta_process(struct ieee80211_txrx_data *rx)
 618 {
 619         struct sta_info *sta = rx->sta;
 620         struct net_device *dev = rx->dev;
 621         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
 622
 623         if (!sta)
 624                 return TXRX_CONTINUE;
 625
 626         /* Update last_rx only for IBSS packets which are for the current
 627          * BSSID to avoid keeping the current IBSS network alive in cases where
 628          * other STAs are using different BSSID. */
 629         if (rx->sdata->type == IEEE80211_IF_TYPE_IBSS) {
 630                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len);
 631                 if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
 632                         sta->last_rx = jiffies;
 633         } else
 634         if (!is_multicast_ether_addr(hdr->addr1) ||
 635             rx->sdata->type == IEEE80211_IF_TYPE_STA) {
 636                 /* Update last_rx only for unicast frames in order to prevent
 637                  * the Probe Request frames (the only broadcast frames from a
 638                  * STA in infrastructure mode) from keeping a connection alive.
 639                  */
 640                 sta->last_rx = jiffies;
 641         }
 642
 643         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
 644                 return TXRX_CONTINUE;
 645
 646         sta->rx_fragments++;
 647         sta->rx_bytes += rx->skb->len;
 648         sta->last_rssi = rx->u.rx.status->ssi;
 649         sta->last_signal = rx->u.rx.status->signal;
 650         sta->last_noise = rx->u.rx.status->noise;
 651
 652         if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) {
 653                 /* Change STA power saving mode only in the end of a frame
 654                  * exchange sequence */
 655                 if ((sta->flags & WLAN_STA_PS) && !(rx->fc & IEEE80211_FCTL_PM))
 656                         rx->u.rx.sent_ps_buffered += ap_sta_ps_end(dev, sta);
 657                 else if (!(sta->flags & WLAN_STA_PS) &&
 658                          (rx->fc & IEEE80211_FCTL_PM))
 659                         ap_sta_ps_start(dev, sta);
 660         }
 661
 662         /* Drop data::nullfunc frames silently, since they are used only to
 663          * control station power saving mode. */
 664         if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
 665             (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_NULLFUNC) {
 666                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
 667                 /* Update counter and free packet here to avoid counting this
 668                  * as a dropped packed. */
 669                 sta->rx_packets++;
 670                 dev_kfree_skb(rx->skb);
 671                 return TXRX_QUEUED;
 672         }
 673
 674         return TXRX_CONTINUE;
 675 } /* ieee80211_rx_h_sta_process */
 676
 677 static inline struct ieee80211_fragment_entry *
 678 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 679                          unsigned int frag, unsigned int seq, int rx_queue,
 680                          struct sk_buff **skb)
 681 {
 682         struct ieee80211_fragment_entry *entry;
 683         int idx;
 684
 685         idx = sdata->fragment_next;
 686         entry = &sdata->fragments[sdata->fragment_next++];
 687         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
 688                 sdata->fragment_next = 0;
 689
 690         if (!skb_queue_empty(&entry->skb_list)) {
 691 #ifdef CONFIG_MAC80211_DEBUG
 692                 struct ieee80211_hdr *hdr =
 693                         (struct ieee80211_hdr *) entry->skb_list.next->data;
 694                 DECLARE_MAC_BUF(mac);
 695                 DECLARE_MAC_BUF(mac2);
 696                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
 697                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
 698                        "addr1=%s addr2=%s\n",
 699                        sdata->dev->name, idx,
 700                        jiffies - entry->first_frag_time, entry->seq,
 701                        entry->last_frag, print_mac(mac, hdr->addr1),
 702                        print_mac(mac2, hdr->addr2));
 703 #endif /* CONFIG_MAC80211_DEBUG */
 704                 __skb_queue_purge(&entry->skb_list);
 705         }
 706
 707         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
 708         *skb = NULL;
 709         entry->first_frag_time = jiffies;
 710         entry->seq = seq;
 711         entry->rx_queue = rx_queue;
 712         entry->last_frag = frag;
 713         entry->ccmp = 0;
 714         entry->extra_len = 0;
 715
 716         return entry;
 717 }
 718
 719 static inline struct ieee80211_fragment_entry *
 720 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
 721                           u16 fc, unsigned int frag, unsigned int seq,
 722                           int rx_queue, struct ieee80211_hdr *hdr)
 723 {
 724         struct ieee80211_fragment_entry *entry;
 725         int i, idx;
 726
 727         idx = sdata->fragment_next;
 728         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
 729                 struct ieee80211_hdr *f_hdr;
 730                 u16 f_fc;
 731
 732                 idx--;
 733                 if (idx < 0)
 734                         idx = IEEE80211_FRAGMENT_MAX - 1;
 735
 736                 entry = &sdata->fragments[idx];
 737                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
 738                     entry->rx_queue != rx_queue ||
 739                     entry->last_frag + 1 != frag)
 740                         continue;
 741
 742                 f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data;
 743                 f_fc = le16_to_cpu(f_hdr->frame_control);
 744
 745                 if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
 746                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
 747                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
 748                         continue;
 749
 750                 if (entry->first_frag_time + 2 * HZ < jiffies) {
 751                         __skb_queue_purge(&entry->skb_list);
 752                         continue;
 753                 }
 754                 return entry;
 755         }
 756
 757         return NULL;
 758 }
 759
 760 static ieee80211_txrx_result
 761 ieee80211_rx_h_defragment(struct ieee80211_txrx_data *rx)
 762 {
 763         struct ieee80211_hdr *hdr;
 764         u16 sc;
 765         unsigned int frag, seq;
 766         struct ieee80211_fragment_entry *entry;
 767         struct sk_buff *skb;
 768         DECLARE_MAC_BUF(mac);
 769
 770         hdr = (struct ieee80211_hdr *) rx->skb->data;
 771         sc = le16_to_cpu(hdr->seq_ctrl);
 772         frag = sc & IEEE80211_SCTL_FRAG;
 773
 774         if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
 775                    (rx->skb)->len < 24 ||
 776                    is_multicast_ether_addr(hdr->addr1))) {
 777                 /* not fragmented */
 778                 goto out;
 779         }
 780         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
 781
 782         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
 783
 784         if (frag == 0) {
 785                 /* This is the first fragment of a new frame. */
 786                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
 787                                                  rx->u.rx.queue, &(rx->skb));
 788                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
 789                     (rx->fc & IEEE80211_FCTL_PROTECTED)) {
 790                         /* Store CCMP PN so that we can verify that the next
 791                          * fragment has a sequential PN value. */
 792                         entry->ccmp = 1;
 793                         memcpy(entry->last_pn,
 794                                rx->key->u.ccmp.rx_pn[rx->u.rx.queue],
 795                                CCMP_PN_LEN);
 796                 }
 797                 return TXRX_QUEUED;
 798         }
 799
 800         /* This is a fragment for a frame that should already be pending in
 801          * fragment cache. Add this fragment to the end of the pending entry.
 802          */
 803         entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq,
 804                                           rx->u.rx.queue, hdr);
 805         if (!entry) {
 806                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
 807                 return TXRX_DROP;
 808         }
 809
 810         /* Verify that MPDUs within one MSDU have sequential PN values.
 811          * (IEEE 802.11i, 8.3.3.4.5) */
 812         if (entry->ccmp) {
 813                 int i;
 814                 u8 pn[CCMP_PN_LEN], *rpn;
 815                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
 816                         return TXRX_DROP;
 817                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
 818                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
 819                         pn[i]++;
 820                         if (pn[i])
 821                                 break;
 822                 }
 823                 rpn = rx->key->u.ccmp.rx_pn[rx->u.rx.queue];
 824                 if (memcmp(pn, rpn, CCMP_PN_LEN) != 0) {
 825                         if (net_ratelimit())
 826                                 printk(KERN_DEBUG "%s: defrag: CCMP PN not "
 827                                        "sequential A2=%s"
 828                                        " PN=%02x%02x%02x%02x%02x%02x "
 829                                        "(expected %02x%02x%02x%02x%02x%02x)\n",
 830                                        rx->dev->name, print_mac(mac, hdr->addr2),
 831                                        rpn[0], rpn[1], rpn[2], rpn[3], rpn[4],
 832                                        rpn[5], pn[0], pn[1], pn[2], pn[3],
 833                                        pn[4], pn[5]);
 834                         return TXRX_DROP;
 835                 }
 836                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
 837         }
 838
 839         skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
 840         __skb_queue_tail(&entry->skb_list, rx->skb);
 841         entry->last_frag = frag;
 842         entry->extra_len += rx->skb->len;
 843         if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
 844                 rx->skb = NULL;
 845                 return TXRX_QUEUED;
 846         }
 847
 848         rx->skb = __skb_dequeue(&entry->skb_list);
 849         if (skb_tailroom(rx->skb) < entry->extra_len) {
 850                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
 851                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
 852                                               GFP_ATOMIC))) {
 853                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
 854                         __skb_queue_purge(&entry->skb_list);
 855                         return TXRX_DROP;
 856                 }
 857         }
 858         while ((skb = __skb_dequeue(&entry->skb_list))) {
 859                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
 860                 dev_kfree_skb(skb);
 861         }
 862
 863         /* Complete frame has been reassembled - process it now */
 864         rx->flags |= IEEE80211_TXRXD_FRAGMENTED;
 865
 866  out:
 867         if (rx->sta)
 868                 rx->sta->rx_packets++;
 869         if (is_multicast_ether_addr(hdr->addr1))
 870                 rx->local->dot11MulticastReceivedFrameCount++;
 871         else
 872                 ieee80211_led_rx(rx->local);
 873         return TXRX_CONTINUE;
 874 }
 875
 876 static ieee80211_txrx_result
 877 ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
 878 {
 879         struct sk_buff *skb;
 880         int no_pending_pkts;
 881         DECLARE_MAC_BUF(mac);
 882
 883         if (likely(!rx->sta ||
 884                    (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
 885                    (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
 886                    !(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)))
 887                 return TXRX_CONTINUE;
 888
 889         skb = skb_dequeue(&rx->sta->tx_filtered);
 890         if (!skb) {
 891                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
 892                 if (skb)
 893                         rx->local->total_ps_buffered--;
 894         }
 895         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
 896                 skb_queue_empty(&rx->sta->ps_tx_buf);
 897
 898         if (skb) {
 899                 struct ieee80211_hdr *hdr =
 900                         (struct ieee80211_hdr *) skb->data;
 901
 902                 /* tell TX path to send one frame even though the STA may
 903                  * still remain is PS mode after this frame exchange */
 904                 rx->sta->pspoll = 1;
 905
 906 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 907                 printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
 908                        print_mac(mac, rx->sta->addr), rx->sta->aid,
 909                        skb_queue_len(&rx->sta->ps_tx_buf));
 910 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 911
 912                 /* Use MoreData flag to indicate whether there are more
 913                  * buffered frames for this STA */
 914                 if (no_pending_pkts) {
 915                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 916                         rx->sta->flags &= ~WLAN_STA_TIM;
 917                 } else
 918                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 919
 920                 dev_queue_xmit(skb);
 921
 922                 if (no_pending_pkts) {
 923                         if (rx->local->ops->set_tim)
 924                                 rx->local->ops->set_tim(local_to_hw(rx->local),
 925                                                        rx->sta->aid, 0);
 926                         if (rx->sdata->bss)
 927                                 bss_tim_clear(rx->local, rx->sdata->bss, rx->sta->aid);
 928                 }
 929 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 930         } else if (!rx->u.rx.sent_ps_buffered) {
 931                 printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
 932                        "though there is no buffered frames for it\n",
 933                        rx->dev->name, print_mac(mac, rx->sta->addr));
 934 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 935
 936         }
 937
 938         /* Free PS Poll skb here instead of returning TXRX_DROP that would
 939          * count as an dropped frame. */
 940         dev_kfree_skb(rx->skb);
 941
 942         return TXRX_QUEUED;
 943 }
 944
 945 static ieee80211_txrx_result
 946 ieee80211_rx_h_remove_qos_control(struct ieee80211_txrx_data *rx)
 947 {
 948         u16 fc = rx->fc;
 949         u8 *data = rx->skb->data;
 950         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) data;
 951
 952         if (!WLAN_FC_IS_QOS_DATA(fc))
 953                 return TXRX_CONTINUE;
 954
 955         /* remove the qos control field, update frame type and meta-data */
 956         memmove(data + 2, data, ieee80211_get_hdrlen(fc) - 2);
 957         hdr = (struct ieee80211_hdr *) skb_pull(rx->skb, 2);
 958         /* change frame type to non QOS */
 959         rx->fc = fc &= ~IEEE80211_STYPE_QOS_DATA;
 960         hdr->frame_control = cpu_to_le16(fc);
 961
 962         return TXRX_CONTINUE;
 963 }
 964
 965 static ieee80211_txrx_result
 966 ieee80211_rx_h_802_1x_pae(struct ieee80211_txrx_data *rx)
 967 {
 968         if (rx->sdata->eapol && ieee80211_is_eapol(rx->skb) &&
 969             rx->sdata->type != IEEE80211_IF_TYPE_STA &&
 970             (rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
 971                 return TXRX_CONTINUE;
 972
 973         if (unlikely(rx->sdata->ieee802_1x &&
 974                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
 975                      (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
 976                      (!rx->sta || !(rx->sta->flags & WLAN_STA_AUTHORIZED)) &&
 977                      !ieee80211_is_eapol(rx->skb))) {
 978 #ifdef CONFIG_MAC80211_DEBUG
 979                 struct ieee80211_hdr *hdr =
 980                         (struct ieee80211_hdr *) rx->skb->data;
 981                 DECLARE_MAC_BUF(mac);
 982                 printk(KERN_DEBUG "%s: dropped frame from %s"
 983                        " (unauthorized port)\n", rx->dev->name,
 984                        print_mac(mac, hdr->addr2));
 985 #endif /* CONFIG_MAC80211_DEBUG */
 986                 return TXRX_DROP;
 987         }
 988
 989         return TXRX_CONTINUE;
 990 }
 991
 992 static ieee80211_txrx_result
 993 ieee80211_rx_h_drop_unencrypted(struct ieee80211_txrx_data *rx)
 994 {
 995         /*
 996          * Pass through unencrypted frames if the hardware has
 997          * decrypted them already.
 998          */
 999         if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED)
1000                 return TXRX_CONTINUE;
1001
1002         /* Drop unencrypted frames if key is set. */
1003         if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
1004                      (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
1005                      (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
1006                      (rx->key || rx->sdata->drop_unencrypted) &&
1007                      (rx->sdata->eapol == 0 || !ieee80211_is_eapol(rx->skb)))) {
1008                 if (net_ratelimit())
1009                         printk(KERN_DEBUG "%s: RX non-WEP frame, but expected "
1010                                "encryption\n", rx->dev->name);
1011                 return TXRX_DROP;
1012         }
1013         return TXRX_CONTINUE;
1014 }
1015
1016 static ieee80211_txrx_result
1017 ieee80211_rx_h_data(struct ieee80211_txrx_data *rx)
1018 {
1019         struct net_device *dev = rx->dev;
1020         struct ieee80211_local *local = rx->local;
1021         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1022         u16 fc, hdrlen, ethertype;
1023         u8 *payload;
1024         u8 dst[ETH_ALEN];
1025         u8 src[ETH_ALEN];
1026         struct sk_buff *skb = rx->skb, *skb2;
1027         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1028         DECLARE_MAC_BUF(mac);
1029         DECLARE_MAC_BUF(mac2);
1030         DECLARE_MAC_BUF(mac3);
1031         DECLARE_MAC_BUF(mac4);
1032
1033         fc = rx->fc;
1034         if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA))
1035                 return TXRX_CONTINUE;
1036
1037         if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
1038                 return TXRX_DROP;
1039
1040         hdrlen = ieee80211_get_hdrlen(fc);
1041
1042         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
1043          * header
1044          * IEEE 802.11 address fields:
1045          * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1046          *   0     0   DA    SA    BSSID n/a
1047          *   0     1   DA    BSSID SA    n/a
1048          *   1     0   BSSID SA    DA    n/a
1049          *   1     1   RA    TA    DA    SA
1050          */
1051
1052         switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1053         case IEEE80211_FCTL_TODS:
1054                 /* BSSID SA DA */
1055                 memcpy(dst, hdr->addr3, ETH_ALEN);
1056                 memcpy(src, hdr->addr2, ETH_ALEN);
1057
1058                 if (unlikely(sdata->type != IEEE80211_IF_TYPE_AP &&
1059                              sdata->type != IEEE80211_IF_TYPE_VLAN)) {
1060                         if (net_ratelimit())
1061                                 printk(KERN_DEBUG "%s: dropped ToDS frame "
1062                                        "(BSSID=%s SA=%s DA=%s)\n",
1063                                        dev->name,
1064                                        print_mac(mac, hdr->addr1),
1065                                        print_mac(mac2, hdr->addr2),
1066                                        print_mac(mac3, hdr->addr3));
1067                         return TXRX_DROP;
1068                 }
1069                 break;
1070         case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1071                 /* RA TA DA SA */
1072                 memcpy(dst, hdr->addr3, ETH_ALEN);
1073                 memcpy(src, hdr->addr4, ETH_ALEN);
1074
1075                 if (unlikely(sdata->type != IEEE80211_IF_TYPE_WDS)) {
1076                         if (net_ratelimit())
1077                                 printk(KERN_DEBUG "%s: dropped FromDS&ToDS "
1078                                        "frame (RA=%s TA=%s DA=%s SA=%s)\n",
1079                                        rx->dev->name,
1080                                        print_mac(mac, hdr->addr1),
1081                                        print_mac(mac2, hdr->addr2),
1082                                        print_mac(mac3, hdr->addr3),
1083                                        print_mac(mac4, hdr->addr4));
1084                         return TXRX_DROP;
1085                 }
1086                 break;
1087         case IEEE80211_FCTL_FROMDS:
1088                 /* DA BSSID SA */
1089                 memcpy(dst, hdr->addr1, ETH_ALEN);
1090                 memcpy(src, hdr->addr3, ETH_ALEN);
1091
1092                 if (sdata->type != IEEE80211_IF_TYPE_STA ||
1093                     (is_multicast_ether_addr(dst) &&
1094                      !compare_ether_addr(src, dev->dev_addr)))
1095                         return TXRX_DROP;
1096                 break;
1097         case 0:
1098                 /* DA SA BSSID */
1099                 memcpy(dst, hdr->addr1, ETH_ALEN);
1100                 memcpy(src, hdr->addr2, ETH_ALEN);
1101
1102                 if (sdata->type != IEEE80211_IF_TYPE_IBSS) {
1103                         if (net_ratelimit()) {
1104                                 printk(KERN_DEBUG "%s: dropped IBSS frame "
1105                                        "(DA=%s SA=%s BSSID=%s)\n",
1106                                        dev->name,
1107                                        print_mac(mac, hdr->addr1),
1108                                        print_mac(mac2, hdr->addr2),
1109                                        print_mac(mac3, hdr->addr3));
1110                         }
1111                         return TXRX_DROP;
1112                 }
1113                 break;
1114         }
1115
1116         payload = skb->data + hdrlen;
1117
1118         if (unlikely(skb->len - hdrlen < 8)) {
1119                 if (net_ratelimit()) {
1120                         printk(KERN_DEBUG "%s: RX too short data frame "
1121                                "payload\n", dev->name);
1122                 }
1123                 return TXRX_DROP;
1124         }
1125
1126         ethertype = (payload[6] << 8) | payload[7];
1127
1128         if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1129                     ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1130                    compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1131                 /* remove RFC1042 or Bridge-Tunnel encapsulation and
1132                  * replace EtherType */
1133                 skb_pull(skb, hdrlen + 6);
1134                 memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1135                 memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1136         } else {
1137                 struct ethhdr *ehdr;
1138                 __be16 len;
1139                 skb_pull(skb, hdrlen);
1140                 len = htons(skb->len);
1141                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1142                 memcpy(ehdr->h_dest, dst, ETH_ALEN);
1143                 memcpy(ehdr->h_source, src, ETH_ALEN);
1144                 ehdr->h_proto = len;
1145         }
1146         skb->dev = dev;
1147
1148         skb2 = NULL;
1149
1150         dev->stats.rx_packets++;
1151         dev->stats.rx_bytes += skb->len;
1152
1153         if (local->bridge_packets && (sdata->type == IEEE80211_IF_TYPE_AP
1154             || sdata->type == IEEE80211_IF_TYPE_VLAN) &&
1155             (rx->flags & IEEE80211_TXRXD_RXRA_MATCH)) {
1156                 if (is_multicast_ether_addr(skb->data)) {
1157                         /* send multicast frames both to higher layers in
1158                          * local net stack and back to the wireless media */
1159                         skb2 = skb_copy(skb, GFP_ATOMIC);
1160                         if (!skb2 && net_ratelimit())
1161                                 printk(KERN_DEBUG "%s: failed to clone "
1162                                        "multicast frame\n", dev->name);
1163                 } else {
1164                         struct sta_info *dsta;
1165                         dsta = sta_info_get(local, skb->data);
1166                         if (dsta && !dsta->dev) {
1167                                 if (net_ratelimit())
1168                                         printk(KERN_DEBUG "Station with null "
1169                                                "dev structure!\n");
1170                         } else if (dsta && dsta->dev == dev) {
1171                                 /* Destination station is associated to this
1172                                  * AP, so send the frame directly to it and
1173                                  * do not pass the frame to local net stack.
1174                                  */
1175                                 skb2 = skb;
1176                                 skb = NULL;
1177                         }
1178                         if (dsta)
1179                                 sta_info_put(dsta);
1180                 }
1181         }
1182
1183         if (skb) {
1184                 /* deliver to local stack */
1185                 skb->protocol = eth_type_trans(skb, dev);
1186                 memset(skb->cb, 0, sizeof(skb->cb));
1187                 netif_rx(skb);
1188         }
1189
1190         if (skb2) {
1191                 /* send to wireless media */
1192                 skb2->protocol = __constant_htons(ETH_P_802_3);
1193                 skb_set_network_header(skb2, 0);
1194                 skb_set_mac_header(skb2, 0);
1195                 dev_queue_xmit(skb2);
1196         }
1197
1198         return TXRX_QUEUED;
1199 }
1200
1201 static ieee80211_txrx_result
1202 ieee80211_rx_h_mgmt(struct ieee80211_txrx_data *rx)
1203 {
1204         struct ieee80211_sub_if_data *sdata;
1205
1206         if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
1207                 return TXRX_DROP;
1208
1209         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1210         if ((sdata->type == IEEE80211_IF_TYPE_STA ||
1211              sdata->type == IEEE80211_IF_TYPE_IBSS) &&
1212             !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
1213                 ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->u.rx.status);
1214         else
1215                 return TXRX_DROP;
1216
1217         return TXRX_QUEUED;
1218 }
1219
1220 static inline ieee80211_txrx_result __ieee80211_invoke_rx_handlers(
1221                                 struct ieee80211_local *local,
1222                                 ieee80211_rx_handler *handlers,
1223                                 struct ieee80211_txrx_data *rx,
1224                                 struct sta_info *sta)
1225 {
1226         ieee80211_rx_handler *handler;
1227         ieee80211_txrx_result res = TXRX_DROP;
1228
1229         for (handler = handlers; *handler != NULL; handler++) {
1230                 res = (*handler)(rx);
1231
1232                 switch (res) {
1233                 case TXRX_CONTINUE:
1234                         continue;
1235                 case TXRX_DROP:
1236                         I802_DEBUG_INC(local->rx_handlers_drop);
1237                         if (sta)
1238                                 sta->rx_dropped++;
1239                         break;
1240                 case TXRX_QUEUED:
1241                         I802_DEBUG_INC(local->rx_handlers_queued);
1242                         break;
1243                 }
1244                 break;
1245         }
1246
1247         if (res == TXRX_DROP)
1248                 dev_kfree_skb(rx->skb);
1249         return res;
1250 }
1251
1252 static inline void ieee80211_invoke_rx_handlers(struct ieee80211_local *local,
1253                                                 ieee80211_rx_handler *handlers,
1254                                                 struct ieee80211_txrx_data *rx,
1255                                                 struct sta_info *sta)
1256 {
1257         if (__ieee80211_invoke_rx_handlers(local, handlers, rx, sta) ==
1258             TXRX_CONTINUE)
1259                 dev_kfree_skb(rx->skb);
1260 }
1261
1262 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1263                                             struct ieee80211_hdr *hdr,
1264                                             struct sta_info *sta,
1265                                             struct ieee80211_txrx_data *rx)
1266 {
1267         int keyidx, hdrlen;
1268         DECLARE_MAC_BUF(mac);
1269         DECLARE_MAC_BUF(mac2);
1270
1271         hdrlen = ieee80211_get_hdrlen_from_skb(rx->skb);
1272         if (rx->skb->len >= hdrlen + 4)
1273                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1274         else
1275                 keyidx = -1;
1276
1277         if (net_ratelimit())
1278                 printk(KERN_DEBUG "%s: TKIP hwaccel reported Michael MIC "
1279                        "failure from %s to %s keyidx=%d\n",
1280                        dev->name, print_mac(mac, hdr->addr2),
1281                        print_mac(mac2, hdr->addr1), keyidx);
1282
1283         if (!sta) {
1284                 /*
1285                  * Some hardware seem to generate incorrect Michael MIC
1286                  * reports; ignore them to avoid triggering countermeasures.
1287                  */
1288                 if (net_ratelimit())
1289                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1290                                "error for unknown address %s\n",
1291                                dev->name, print_mac(mac, hdr->addr2));
1292                 goto ignore;
1293         }
1294
1295         if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) {
1296                 if (net_ratelimit())
1297                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1298                                "error for a frame with no PROTECTED flag (src "
1299                                "%s)\n", dev->name, print_mac(mac, hdr->addr2));
1300                 goto ignore;
1301         }
1302
1303         if (rx->sdata->type == IEEE80211_IF_TYPE_AP && keyidx) {
1304                 /*
1305                  * APs with pairwise keys should never receive Michael MIC
1306                  * errors for non-zero keyidx because these are reserved for
1307                  * group keys and only the AP is sending real multicast
1308                  * frames in the BSS.
1309                  */
1310                 if (net_ratelimit())
1311                         printk(KERN_DEBUG "%s: ignored Michael MIC error for "
1312                                "a frame with non-zero keyidx (%d)"
1313                                " (src %s)\n", dev->name, keyidx,
1314                                print_mac(mac, hdr->addr2));
1315                 goto ignore;
1316         }
1317
1318         if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
1319             ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
1320              (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_AUTH)) {
1321                 if (net_ratelimit())
1322                         printk(KERN_DEBUG "%s: ignored spurious Michael MIC "
1323                                "error for a frame that cannot be encrypted "
1324                                "(fc=0x%04x) (src %s)\n",
1325                                dev->name, rx->fc, print_mac(mac, hdr->addr2));
1326                 goto ignore;
1327         }
1328
1329         mac80211_ev_michael_mic_failure(rx->dev, keyidx, hdr);
1330  ignore:
1331         dev_kfree_skb(rx->skb);
1332         rx->skb = NULL;
1333 }
1334
1335 ieee80211_rx_handler ieee80211_rx_handlers[] =
1336 {
1337         ieee80211_rx_h_if_stats,
1338         ieee80211_rx_h_passive_scan,
1339         ieee80211_rx_h_check,
1340         ieee80211_rx_h_decrypt,
1341         ieee80211_rx_h_sta_process,
1342         ieee80211_rx_h_defragment,
1343         ieee80211_rx_h_ps_poll,
1344         ieee80211_rx_h_michael_mic_verify,
1345         /* this must be after decryption - so header is counted in MPDU mic
1346          * must be before pae and data, so QOS_DATA format frames
1347          * are not passed to user space by these functions
1348          */
1349         ieee80211_rx_h_remove_qos_control,
1350         ieee80211_rx_h_802_1x_pae,
1351         ieee80211_rx_h_drop_unencrypted,
1352         ieee80211_rx_h_data,
1353         ieee80211_rx_h_mgmt,
1354         NULL
1355 };
1356
1357 /* main receive path */
1358
1359 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1360                                 u8 *bssid, struct ieee80211_txrx_data *rx,
1361                                 struct ieee80211_hdr *hdr)
1362 {
1363         int multicast = is_multicast_ether_addr(hdr->addr1);
1364
1365         switch (sdata->type) {
1366         case IEEE80211_IF_TYPE_STA:
1367                 if (!bssid)
1368                         return 0;
1369                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1370                         if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1371                                 return 0;
1372                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1373                 } else if (!multicast &&
1374                            compare_ether_addr(sdata->dev->dev_addr,
1375                                               hdr->addr1) != 0) {
1376                         if (!(sdata->dev->flags & IFF_PROMISC))
1377                                 return 0;
1378                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1379                 }
1380                 break;
1381         case IEEE80211_IF_TYPE_IBSS:
1382                 if (!bssid)
1383                         return 0;
1384                 if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1385                         if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1386                                 return 0;
1387                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1388                 } else if (!multicast &&
1389                            compare_ether_addr(sdata->dev->dev_addr,
1390                                               hdr->addr1) != 0) {
1391                         if (!(sdata->dev->flags & IFF_PROMISC))
1392                                 return 0;
1393                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1394                 } else if (!rx->sta)
1395                         rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
1396                                                          bssid, hdr->addr2);
1397                 break;
1398         case IEEE80211_IF_TYPE_VLAN:
1399         case IEEE80211_IF_TYPE_AP:
1400                 if (!bssid) {
1401                         if (compare_ether_addr(sdata->dev->dev_addr,
1402                                                hdr->addr1))
1403                                 return 0;
1404                 } else if (!ieee80211_bssid_match(bssid,
1405                                         sdata->dev->dev_addr)) {
1406                         if (!(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1407                                 return 0;
1408                         rx->flags &= ~IEEE80211_TXRXD_RXRA_MATCH;
1409                 }
1410                 if (sdata->dev == sdata->local->mdev &&
1411                     !(rx->flags & IEEE80211_TXRXD_RXIN_SCAN))
1412                         /* do not receive anything via
1413                          * master device when not scanning */
1414                         return 0;
1415                 break;
1416         case IEEE80211_IF_TYPE_WDS:
1417                 if (bssid ||
1418                     (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
1419                         return 0;
1420                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1421                         return 0;
1422                 break;
1423         case IEEE80211_IF_TYPE_MNTR:
1424                 /* take everything */
1425                 break;
1426         case IEEE80211_IF_TYPE_INVALID:
1427                 /* should never get here */
1428                 WARN_ON(1);
1429                 break;
1430         }
1431
1432         return 1;
1433 }
1434
1435 /*
1436  * This is the receive path handler. It is called by a low level driver when an
1437  * 802.11 MPDU is received from the hardware.
1438  */
1439 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
1440                     struct ieee80211_rx_status *status)
1441 {
1442         struct ieee80211_local *local = hw_to_local(hw);
1443         struct ieee80211_sub_if_data *sdata;
1444         struct sta_info *sta;
1445         struct ieee80211_hdr *hdr;
1446         struct ieee80211_txrx_data rx;
1447         u16 type;
1448         int prepres;
1449         struct ieee80211_sub_if_data *prev = NULL;
1450         struct sk_buff *skb_new;
1451         u8 *bssid;
1452         int hdrlen;
1453
1454         /*
1455          * key references and virtual interfaces are protected using RCU
1456          * and this requires that we are in a read-side RCU section during
1457          * receive processing
1458          */
1459         rcu_read_lock();
1460
1461         /*
1462          * Frames with failed FCS/PLCP checksum are not returned,
1463          * all other frames are returned without radiotap header
1464          * if it was previously present.
1465          * Also, frames with less than 16 bytes are dropped.
1466          */
1467         skb = ieee80211_rx_monitor(local, skb, status);
1468         if (!skb) {
1469                 rcu_read_unlock();
1470                 return;
1471         }
1472
1473         hdr = (struct ieee80211_hdr *) skb->data;
1474         memset(&rx, 0, sizeof(rx));
1475         rx.skb = skb;
1476         rx.local = local;
1477
1478         rx.u.rx.status = status;
1479         rx.fc = le16_to_cpu(hdr->frame_control);
1480         type = rx.fc & IEEE80211_FCTL_FTYPE;
1481
1482         /*
1483          * Drivers are required to align the payload data to a four-byte
1484          * boundary, so the last two bits of the address where it starts
1485          * may not be set. The header is required to be directly before
1486          * the payload data, padding like atheros hardware adds which is
1487          * inbetween the 802.11 header and the payload is not supported,
1488          * the driver is required to move the 802.11 header further back
1489          * in that case.
1490          */
1491         hdrlen = ieee80211_get_hdrlen(rx.fc);
1492         WARN_ON_ONCE(((unsigned long)(skb->data + hdrlen)) & 3);
1493
1494         if (type == IEEE80211_FTYPE_DATA || type == IEEE80211_FTYPE_MGMT)
1495                 local->dot11ReceivedFragmentCount++;
1496
1497         sta = rx.sta = sta_info_get(local, hdr->addr2);
1498         if (sta) {
1499                 rx.dev = rx.sta->dev;
1500                 rx.sdata = IEEE80211_DEV_TO_SUB_IF(rx.dev);
1501         }
1502
1503         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1504                 ieee80211_rx_michael_mic_report(local->mdev, hdr, sta, &rx);
1505                 goto end;
1506         }
1507
1508         if (unlikely(local->sta_sw_scanning || local->sta_hw_scanning))
1509                 rx.flags |= IEEE80211_TXRXD_RXIN_SCAN;
1510
1511         if (__ieee80211_invoke_rx_handlers(local, local->rx_pre_handlers, &rx,
1512                                            sta) != TXRX_CONTINUE)
1513                 goto end;
1514         skb = rx.skb;
1515
1516         if (sta && !(sta->flags & (WLAN_STA_WDS | WLAN_STA_ASSOC_AP)) &&
1517             !atomic_read(&local->iff_promiscs) &&
1518             !is_multicast_ether_addr(hdr->addr1)) {
1519                 rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1520                 ieee80211_invoke_rx_handlers(local, local->rx_handlers, &rx,
1521                                              rx.sta);
1522                 sta_info_put(sta);
1523                 rcu_read_unlock();
1524                 return;
1525         }
1526
1527         bssid = ieee80211_get_bssid(hdr, skb->len);
1528
1529         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1530                 if (!netif_running(sdata->dev))
1531                         continue;
1532
1533                 if (sdata->type == IEEE80211_IF_TYPE_MNTR)
1534                         continue;
1535
1536                 rx.flags |= IEEE80211_TXRXD_RXRA_MATCH;
1537                 prepres = prepare_for_handlers(sdata, bssid, &rx, hdr);
1538                 /* prepare_for_handlers can change sta */
1539                 sta = rx.sta;
1540
1541                 if (!prepres)
1542                         continue;
1543
1544                 /*
1545                  * frame is destined for this interface, but if it's not
1546                  * also for the previous one we handle that after the
1547                  * loop to avoid copying the SKB once too much
1548                  */
1549
1550                 if (!prev) {
1551                         prev = sdata;
1552                         continue;
1553                 }
1554
1555                 /*
1556                  * frame was destined for the previous interface
1557                  * so invoke RX handlers for it
1558                  */
1559
1560                 skb_new = skb_copy(skb, GFP_ATOMIC);
1561                 if (!skb_new) {
1562                         if (net_ratelimit())
1563                                 printk(KERN_DEBUG "%s: failed to copy "
1564                                        "multicast frame for %s",
1565                                        wiphy_name(local->hw.wiphy),
1566                                        prev->dev->name);
1567                         continue;
1568                 }
1569                 rx.skb = skb_new;
1570                 rx.dev = prev->dev;
1571                 rx.sdata = prev;
1572                 ieee80211_invoke_rx_handlers(local, local->rx_handlers,
1573                                              &rx, sta);
1574                 prev = sdata;
1575         }
1576         if (prev) {
1577                 rx.skb = skb;
1578                 rx.dev = prev->dev;
1579                 rx.sdata = prev;
1580                 ieee80211_invoke_rx_handlers(local, local->rx_handlers,
1581                                              &rx, sta);
1582         } else
1583                 dev_kfree_skb(skb);
1584
1585  end:
1586         rcu_read_unlock();
1587
1588         if (sta)
1589                 sta_info_put(sta);
1590 }
1591 EXPORT_SYMBOL(__ieee80211_rx);
1592
1593 /* This is a version of the rx handler that can be called from hard irq
1594  * context. Post the skb on the queue and schedule the tasklet */
1595 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
1596                           struct ieee80211_rx_status *status)
1597 {
1598         struct ieee80211_local *local = hw_to_local(hw);
1599
1600         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
1601
1602         skb->dev = local->mdev;
1603         /* copy status into skb->cb for use by tasklet */
1604         memcpy(skb->cb, status, sizeof(*status));
1605         skb->pkt_type = IEEE80211_RX_MSG;
1606         skb_queue_tail(&local->skb_queue, skb);
1607         tasklet_schedule(&local->tasklet);
1608 }
1609 EXPORT_SYMBOL(ieee80211_rx_irqsafe);