net/mac80211/rx.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/jiffies.h>
  13 #include <linux/kernel.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/rcupdate.h>
  18 #include <net/mac80211.h>
  19 #include <net/ieee80211_radiotap.h>
  20
  21 #include "ieee80211_i.h"
  22 #include "led.h"
  23 #include "mesh.h"
  24 #include "wep.h"
  25 #include "wpa.h"
  26 #include "tkip.h"
  27 #include "wme.h"
  28
  29 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
  30                                 struct tid_ampdu_rx *tid_agg_rx,
  31                                 struct sk_buff *skb, u16 mpdu_seq_num,
  32                                 int bar_req);
  33 /*
  34  * monitor mode reception
  35  *
  36  * This function cleans up the SKB, i.e. it removes all the stuff
  37  * only useful for monitoring.
  38  */
  39 static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
  40                                            struct sk_buff *skb,
  41                                            int rtap_len)
  42 {
  43         skb_pull(skb, rtap_len);
  44
  45         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
  46                 if (likely(skb->len > FCS_LEN))
  47                         skb_trim(skb, skb->len - FCS_LEN);
  48                 else {
  49                         /* driver bug */
  50                         WARN_ON(1);
  51                         dev_kfree_skb(skb);
  52                         skb = NULL;
  53                 }
  54         }
  55
  56         return skb;
  57 }
  58
  59 static inline int should_drop_frame(struct ieee80211_rx_status *status,
  60                                     struct sk_buff *skb,
  61                                     int present_fcs_len,
  62                                     int radiotap_len)
  63 {
  64         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  65
  66         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
  67                 return 1;
  68         if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
  69                 return 1;
  70         if (ieee80211_is_ctl(hdr->frame_control) &&
  71             !ieee80211_is_pspoll(hdr->frame_control) &&
  72             !ieee80211_is_back_req(hdr->frame_control))
  73                 return 1;
  74         return 0;
  75 }
  76
  77 static int
  78 ieee80211_rx_radiotap_len(struct ieee80211_local *local,
  79                           struct ieee80211_rx_status *status)
  80 {
  81         int len;
  82
  83         /* always present fields */
  84         len = sizeof(struct ieee80211_radiotap_header) + 9;
  85
  86         if (status->flag & RX_FLAG_TSFT)
  87                 len += 8;
  88         if (local->hw.flags & IEEE80211_HW_SIGNAL_DB ||
  89             local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
  90                 len += 1;
  91         if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
  92                 len += 1;
  93
  94         if (len & 1) /* padding for RX_FLAGS if necessary */
  95                 len++;
  96
  97         /* make sure radiotap starts at a naturally aligned address */
  98         if (len % 8)
  99                 len = roundup(len, 8);
 100
 101         return len;
 102 }
 103
 104 /**
 105  * ieee80211_add_rx_radiotap_header - add radiotap header
 106  *
 107  * add a radiotap header containing all the fields which the hardware provided.
 108  */
 109 static void
 110 ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 111                                  struct sk_buff *skb,
 112                                  struct ieee80211_rx_status *status,
 113                                  struct ieee80211_rate *rate,
 114                                  int rtap_len)
 115 {
 116         struct ieee80211_radiotap_header *rthdr;
 117         unsigned char *pos;
 118
 119         rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
 120         memset(rthdr, 0, rtap_len);
 121
 122         /* radiotap header, set always present flags */
 123         rthdr->it_present =
 124                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 125                             (1 << IEEE80211_RADIOTAP_RATE) |
 126                             (1 << IEEE80211_RADIOTAP_CHANNEL) |
 127                             (1 << IEEE80211_RADIOTAP_ANTENNA) |
 128                             (1 << IEEE80211_RADIOTAP_RX_FLAGS));
 129         rthdr->it_len = cpu_to_le16(rtap_len);
 130
 131         pos = (unsigned char *)(rthdr+1);
 132
 133         /* the order of the following fields is important */
 134
 135         /* IEEE80211_RADIOTAP_TSFT */
 136         if (status->flag & RX_FLAG_TSFT) {
 137                 *(__le64 *)pos = cpu_to_le64(status->mactime);
 138                 rthdr->it_present |=
 139                         cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
 140                 pos += 8;
 141         }
 142
 143         /* IEEE80211_RADIOTAP_FLAGS */
 144         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 145                 *pos |= IEEE80211_RADIOTAP_F_FCS;
 146         if (status->flag & RX_FLAG_SHORTPRE)
 147                 *pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
 148         pos++;
 149
 150         /* IEEE80211_RADIOTAP_RATE */
 151         *pos = rate->bitrate / 5;
 152         pos++;
 153
 154         /* IEEE80211_RADIOTAP_CHANNEL */
 155         *(__le16 *)pos = cpu_to_le16(status->freq);
 156         pos += 2;
 157         if (status->band == IEEE80211_BAND_5GHZ)
 158                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
 159                                              IEEE80211_CHAN_5GHZ);
 160         else if (rate->flags & IEEE80211_RATE_ERP_G)
 161                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
 162                                              IEEE80211_CHAN_2GHZ);
 163         else
 164                 *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK |
 165                                              IEEE80211_CHAN_2GHZ);
 166         pos += 2;
 167
 168         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
 169         if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
 170                 *pos = status->signal;
 171                 rthdr->it_present |=
 172                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
 173                 pos++;
 174         }
 175
 176         /* IEEE80211_RADIOTAP_DBM_ANTNOISE */
 177         if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
 178                 *pos = status->noise;
 179                 rthdr->it_present |=
 180                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
 181                 pos++;
 182         }
 183
 184         /* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
 185
 186         /* IEEE80211_RADIOTAP_ANTENNA */
 187         *pos = status->antenna;
 188         pos++;
 189
 190         /* IEEE80211_RADIOTAP_DB_ANTSIGNAL */
 191         if (local->hw.flags & IEEE80211_HW_SIGNAL_DB) {
 192                 *pos = status->signal;
 193                 rthdr->it_present |=
 194                         cpu_to_le32(1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL);
 195                 pos++;
 196         }
 197
 198         /* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
 199
 200         /* IEEE80211_RADIOTAP_RX_FLAGS */
 201         /* ensure 2 byte alignment for the 2 byte field as required */
 202         if ((pos - (unsigned char *)rthdr) & 1)
 203                 pos++;
 204         /* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
 205         if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
 206                 *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
 207         pos += 2;
 208 }
 209
 210 /*
 211  * This function copies a received frame to all monitor interfaces and
 212  * returns a cleaned-up SKB that no longer includes the FCS nor the
 213  * radiotap header the driver might have added.
 214  */
 215 static struct sk_buff *
 216 ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
 217                      struct ieee80211_rx_status *status,
 218                      struct ieee80211_rate *rate)
 219 {
 220         struct ieee80211_sub_if_data *sdata;
 221         int needed_headroom = 0;
 222         struct sk_buff *skb, *skb2;
 223         struct net_device *prev_dev = NULL;
 224         int present_fcs_len = 0;
 225         int rtap_len = 0;
 226
 227         /*
 228          * First, we may need to make a copy of the skb because
 229          *  (1) we need to modify it for radiotap (if not present), and
 230          *  (2) the other RX handlers will modify the skb we got.
 231          *
 232          * We don't need to, of course, if we aren't going to return
 233          * the SKB because it has a bad FCS/PLCP checksum.
 234          */
 235         if (status->flag & RX_FLAG_RADIOTAP)
 236                 rtap_len = ieee80211_get_radiotap_len(origskb->data);
 237         else
 238                 /* room for the radiotap header based on driver features */
 239                 needed_headroom = ieee80211_rx_radiotap_len(local, status);
 240
 241         if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
 242                 present_fcs_len = FCS_LEN;
 243
 244         if (!local->monitors) {
 245                 if (should_drop_frame(status, origskb, present_fcs_len,
 246                                       rtap_len)) {
 247                         dev_kfree_skb(origskb);
 248                         return NULL;
 249                 }
 250
 251                 return remove_monitor_info(local, origskb, rtap_len);
 252         }
 253
 254         if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
 255                 /* only need to expand headroom if necessary */
 256                 skb = origskb;
 257                 origskb = NULL;
 258
 259                 /*
 260                  * This shouldn't trigger often because most devices have an
 261                  * RX header they pull before we get here, and that should
 262                  * be big enough for our radiotap information. We should
 263                  * probably export the length to drivers so that we can have
 264                  * them allocate enough headroom to start with.
 265                  */
 266                 if (skb_headroom(skb) < needed_headroom &&
 267                     pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
 268                         dev_kfree_skb(skb);
 269                         return NULL;
 270                 }
 271         } else {
 272                 /*
 273                  * Need to make a copy and possibly remove radiotap header
 274                  * and FCS from the original.
 275                  */
 276                 skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
 277
 278                 origskb = remove_monitor_info(local, origskb, rtap_len);
 279
 280                 if (!skb)
 281                         return origskb;
 282         }
 283
 284         /* if necessary, prepend radiotap information */
 285         if (!(status->flag & RX_FLAG_RADIOTAP))
 286                 ieee80211_add_rx_radiotap_header(local, skb, status, rate,
 287                                                  needed_headroom);
 288
 289         skb_reset_mac_header(skb);
 290         skb->ip_summed = CHECKSUM_UNNECESSARY;
 291         skb->pkt_type = PACKET_OTHERHOST;
 292         skb->protocol = htons(ETH_P_802_2);
 293
 294         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 295                 if (!netif_running(sdata->dev))
 296                         continue;
 297
 298                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 299                         continue;
 300
 301                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
 302                         continue;
 303
 304                 if (prev_dev) {
 305                         skb2 = skb_clone(skb, GFP_ATOMIC);
 306                         if (skb2) {
 307                                 skb2->dev = prev_dev;
 308                                 netif_rx(skb2);
 309                         }
 310                 }
 311
 312                 prev_dev = sdata->dev;
 313                 sdata->dev->stats.rx_packets++;
 314                 sdata->dev->stats.rx_bytes += skb->len;
 315         }
 316
 317         if (prev_dev) {
 318                 skb->dev = prev_dev;
 319                 netif_rx(skb);
 320         } else
 321                 dev_kfree_skb(skb);
 322
 323         return origskb;
 324 }
 325
 326
 327 static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
 328 {
 329         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 330         int tid;
 331
 332         /* does the frame have a qos control field? */
 333         if (ieee80211_is_data_qos(hdr->frame_control)) {
 334                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 335                 /* frame has qos control */
 336                 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 337                 if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
 338                         rx->flags |= IEEE80211_RX_AMSDU;
 339                 else
 340                         rx->flags &= ~IEEE80211_RX_AMSDU;
 341         } else {
 342                 /*
 343                  * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
 344                  *
 345                  *      Sequence numbers for management frames, QoS data
 346                  *      frames with a broadcast/multicast address in the
 347                  *      Address 1 field, and all non-QoS data frames sent
 348                  *      by QoS STAs are assigned using an additional single
 349                  *      modulo-4096 counter, [...]
 350                  *
 351                  * We also use that counter for non-QoS STAs.
 352                  */
 353                 tid = NUM_RX_DATA_QUEUES - 1;
 354         }
 355
 356         rx->queue = tid;
 357         /* Set skb->priority to 1d tag if highest order bit of TID is not set.
 358          * For now, set skb->priority to 0 for other cases. */
 359         rx->skb->priority = (tid > 7) ? 0 : tid;
 360 }
 361
 362 static void ieee80211_verify_ip_alignment(struct ieee80211_rx_data *rx)
 363 {
 364 #ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
 365         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 366         int hdrlen;
 367
 368         if (!ieee80211_is_data_present(hdr->frame_control))
 369                 return;
 370
 371         /*
 372          * Drivers are required to align the payload data in a way that
 373          * guarantees that the contained IP header is aligned to a four-
 374          * byte boundary. In the case of regular frames, this simply means
 375          * aligning the payload to a four-byte boundary (because either
 376          * the IP header is directly contained, or IV/RFC1042 headers that
 377          * have a length divisible by four are in front of it.
 378          *
 379          * With A-MSDU frames, however, the payload data address must
 380          * yield two modulo four because there are 14-byte 802.3 headers
 381          * within the A-MSDU frames that push the IP header further back
 382          * to a multiple of four again. Thankfully, the specs were sane
 383          * enough this time around to require padding each A-MSDU subframe
 384          * to a length that is a multiple of four.
 385          *
 386          * Padding like atheros hardware adds which is inbetween the 802.11
 387          * header and the payload is not supported, the driver is required
 388          * to move the 802.11 header further back in that case.
 389          */
 390         hdrlen = ieee80211_hdrlen(hdr->frame_control);
 391         if (rx->flags & IEEE80211_RX_AMSDU)
 392                 hdrlen += ETH_HLEN;
 393         WARN_ON_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3);
 394 #endif
 395 }
 396
 397
 398 /* rx handlers */
 399
 400 static ieee80211_rx_result debug_noinline
 401 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 402 {
 403         struct ieee80211_local *local = rx->local;
 404         struct sk_buff *skb = rx->skb;
 405
 406         if (unlikely(local->hw_scanning))
 407                 return ieee80211_scan_rx(rx->sdata, skb, rx->status);
 408
 409         if (unlikely(local->sw_scanning)) {
 410                 /* drop all the other packets during a software scan anyway */
 411                 if (ieee80211_scan_rx(rx->sdata, skb, rx->status)
 412                     != RX_QUEUED)
 413                         dev_kfree_skb(skb);
 414                 return RX_QUEUED;
 415         }
 416
 417         if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
 418                 /* scanning finished during invoking of handlers */
 419                 I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
 420                 return RX_DROP_UNUSABLE;
 421         }
 422
 423         return RX_CONTINUE;
 424 }
 425
 426 static ieee80211_rx_result
 427 ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
 428 {
 429         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 430         unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
 431
 432         if (ieee80211_is_data(hdr->frame_control)) {
 433                 if (!ieee80211_has_a4(hdr->frame_control))
 434                         return RX_DROP_MONITOR;
 435                 if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
 436                         return RX_DROP_MONITOR;
 437         }
 438
 439         /* If there is not an established peer link and this is not a peer link
 440          * establisment frame, beacon or probe, drop the frame.
 441          */
 442
 443         if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
 444                 struct ieee80211_mgmt *mgmt;
 445
 446                 if (!ieee80211_is_mgmt(hdr->frame_control))
 447                         return RX_DROP_MONITOR;
 448
 449                 if (ieee80211_is_action(hdr->frame_control)) {
 450                         mgmt = (struct ieee80211_mgmt *)hdr;
 451                         if (mgmt->u.action.category != PLINK_CATEGORY)
 452                                 return RX_DROP_MONITOR;
 453                         return RX_CONTINUE;
 454                 }
 455
 456                 if (ieee80211_is_probe_req(hdr->frame_control) ||
 457                     ieee80211_is_probe_resp(hdr->frame_control) ||
 458                     ieee80211_is_beacon(hdr->frame_control))
 459                         return RX_CONTINUE;
 460
 461                 return RX_DROP_MONITOR;
 462
 463         }
 464
 465 #define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
 466
 467         if (ieee80211_is_data(hdr->frame_control) &&
 468             is_multicast_ether_addr(hdr->addr1) &&
 469             mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->sdata))
 470                 return RX_DROP_MONITOR;
 471 #undef msh_h_get
 472
 473         return RX_CONTINUE;
 474 }
 475
 476
 477 static ieee80211_rx_result debug_noinline
 478 ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
 479 {
 480         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 481
 482         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
 483         if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
 484                 if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
 485                              rx->sta->last_seq_ctrl[rx->queue] ==
 486                              hdr->seq_ctrl)) {
 487                         if (rx->flags & IEEE80211_RX_RA_MATCH) {
 488                                 rx->local->dot11FrameDuplicateCount++;
 489                                 rx->sta->num_duplicates++;
 490                         }
 491                         return RX_DROP_MONITOR;
 492                 } else
 493                         rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
 494         }
 495
 496         if (unlikely(rx->skb->len < 16)) {
 497                 I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
 498                 return RX_DROP_MONITOR;
 499         }
 500
 501         /* Drop disallowed frame classes based on STA auth/assoc state;
 502          * IEEE 802.11, Chap 5.5.
 503          *
 504          * mac80211 filters only based on association state, i.e. it drops
 505          * Class 3 frames from not associated stations. hostapd sends
 506          * deauth/disassoc frames when needed. In addition, hostapd is
 507          * responsible for filtering on both auth and assoc states.
 508          */
 509
 510         if (ieee80211_vif_is_mesh(&rx->sdata->vif))
 511                 return ieee80211_rx_mesh_check(rx);
 512
 513         if (unlikely((ieee80211_is_data(hdr->frame_control) ||
 514                       ieee80211_is_pspoll(hdr->frame_control)) &&
 515                      rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 516                      (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
 517                 if ((!ieee80211_has_fromds(hdr->frame_control) &&
 518                      !ieee80211_has_tods(hdr->frame_control) &&
 519                      ieee80211_is_data(hdr->frame_control)) ||
 520                     !(rx->flags & IEEE80211_RX_RA_MATCH)) {
 521                         /* Drop IBSS frames and frames for other hosts
 522                          * silently. */
 523                         return RX_DROP_MONITOR;
 524                 }
 525
 526                 return RX_DROP_MONITOR;
 527         }
 528
 529         return RX_CONTINUE;
 530 }
 531
 532
 533 static ieee80211_rx_result debug_noinline
 534 ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 535 {
 536         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 537         int keyidx;
 538         int hdrlen;
 539         ieee80211_rx_result result = RX_DROP_UNUSABLE;
 540         struct ieee80211_key *stakey = NULL;
 541
 542         /*
 543          * Key selection 101
 544          *
 545          * There are three types of keys:
 546          *  - GTK (group keys)
 547          *  - PTK (pairwise keys)
 548          *  - STK (station-to-station pairwise keys)
 549          *
 550          * When selecting a key, we have to distinguish between multicast
 551          * (including broadcast) and unicast frames, the latter can only
 552          * use PTKs and STKs while the former always use GTKs. Unless, of
 553          * course, actual WEP keys ("pre-RSNA") are used, then unicast
 554          * frames can also use key indizes like GTKs. Hence, if we don't
 555          * have a PTK/STK we check the key index for a WEP key.
 556          *
 557          * Note that in a regular BSS, multicast frames are sent by the
 558          * AP only, associated stations unicast the frame to the AP first
 559          * which then multicasts it on their behalf.
 560          *
 561          * There is also a slight problem in IBSS mode: GTKs are negotiated
 562          * with each station, that is something we don't currently handle.
 563          * The spec seems to expect that one negotiates the same key with
 564          * every station but there's no such requirement; VLANs could be
 565          * possible.
 566          */
 567
 568         if (!ieee80211_has_protected(hdr->frame_control))
 569                 return RX_CONTINUE;
 570
 571         /*
 572          * No point in finding a key and decrypting if the frame is neither
 573          * addressed to us nor a multicast frame.
 574          */
 575         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 576                 return RX_CONTINUE;
 577
 578         if (rx->sta)
 579                 stakey = rcu_dereference(rx->sta->key);
 580
 581         if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
 582                 rx->key = stakey;
 583         } else {
 584                 /*
 585                  * The device doesn't give us the IV so we won't be
 586                  * able to look up the key. That's ok though, we
 587                  * don't need to decrypt the frame, we just won't
 588                  * be able to keep statistics accurate.
 589                  * Except for key threshold notifications, should
 590                  * we somehow allow the driver to tell us which key
 591                  * the hardware used if this flag is set?
 592                  */
 593                 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
 594                     (rx->status->flag & RX_FLAG_IV_STRIPPED))
 595                         return RX_CONTINUE;
 596
 597                 hdrlen = ieee80211_hdrlen(hdr->frame_control);
 598
 599                 if (rx->skb->len < 8 + hdrlen)
 600                         return RX_DROP_UNUSABLE; /* TODO: count this? */
 601
 602                 /*
 603                  * no need to call ieee80211_wep_get_keyidx,
 604                  * it verifies a bunch of things we've done already
 605                  */
 606                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
 607
 608                 rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
 609
 610                 /*
 611                  * RSNA-protected unicast frames should always be sent with
 612                  * pairwise or station-to-station keys, but for WEP we allow
 613                  * using a key index as well.
 614                  */
 615                 if (rx->key && rx->key->conf.alg != ALG_WEP &&
 616                     !is_multicast_ether_addr(hdr->addr1))
 617                         rx->key = NULL;
 618         }
 619
 620         if (rx->key) {
 621                 rx->key->tx_rx_count++;
 622                 /* TODO: add threshold stuff again */
 623         } else {
 624                 return RX_DROP_MONITOR;
 625         }
 626
 627         /* Check for weak IVs if possible */
 628         if (rx->sta && rx->key->conf.alg == ALG_WEP &&
 629             ieee80211_is_data(hdr->frame_control) &&
 630             (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
 631              !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
 632             ieee80211_wep_is_weak_iv(rx->skb, rx->key))
 633                 rx->sta->wep_weak_iv_count++;
 634
 635         switch (rx->key->conf.alg) {
 636         case ALG_WEP:
 637                 result = ieee80211_crypto_wep_decrypt(rx);
 638                 break;
 639         case ALG_TKIP:
 640                 result = ieee80211_crypto_tkip_decrypt(rx);
 641                 break;
 642         case ALG_CCMP:
 643                 result = ieee80211_crypto_ccmp_decrypt(rx);
 644                 break;
 645         }
 646
 647         /* either the frame has been decrypted or will be dropped */
 648         rx->status->flag |= RX_FLAG_DECRYPTED;
 649
 650         return result;
 651 }
 652
 653 static void ap_sta_ps_start(struct sta_info *sta)
 654 {
 655         struct ieee80211_sub_if_data *sdata = sta->sdata;
 656         DECLARE_MAC_BUF(mac);
 657
 658         atomic_inc(&sdata->bss->num_sta_ps);
 659         set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
 660 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 661         printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
 662                sdata->dev->name, print_mac(mac, sta->sta.addr), sta->sta.aid);
 663 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 664 }
 665
 666 static int ap_sta_ps_end(struct sta_info *sta)
 667 {
 668         struct ieee80211_sub_if_data *sdata = sta->sdata;
 669         struct ieee80211_local *local = sdata->local;
 670         struct sk_buff *skb;
 671         int sent = 0;
 672         struct ieee80211_tx_info *info;
 673         DECLARE_MAC_BUF(mac);
 674
 675         atomic_dec(&sdata->bss->num_sta_ps);
 676
 677         clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
 678
 679         if (!skb_queue_empty(&sta->ps_tx_buf))
 680                 sta_info_clear_tim_bit(sta);
 681
 682 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 683         printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
 684                sdata->dev->name, print_mac(mac, sta->sta.addr), sta->sta.aid);
 685 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 686
 687         /* Send all buffered frames to the station */
 688         while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
 689                 info = IEEE80211_SKB_CB(skb);
 690                 sent++;
 691                 info->flags |= IEEE80211_TX_CTL_REQUEUE;
 692                 dev_queue_xmit(skb);
 693         }
 694         while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
 695                 info = IEEE80211_SKB_CB(skb);
 696                 local->total_ps_buffered--;
 697                 sent++;
 698 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 699                 printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
 700                        "since STA not sleeping anymore\n", sdata->dev->name,
 701                        print_mac(mac, sta->sta.addr), sta->sta.aid);
 702 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 703                 info->flags |= IEEE80211_TX_CTL_REQUEUE;
 704                 dev_queue_xmit(skb);
 705         }
 706
 707         return sent;
 708 }
 709
 710 static ieee80211_rx_result debug_noinline
 711 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
 712 {
 713         struct sta_info *sta = rx->sta;
 714         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 715
 716         if (!sta)
 717                 return RX_CONTINUE;
 718
 719         /* Update last_rx only for IBSS packets which are for the current
 720          * BSSID to avoid keeping the current IBSS network alive in cases where
 721          * other STAs are using different BSSID. */
 722         if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
 723                 u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
 724                                                 NL80211_IFTYPE_ADHOC);
 725                 if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
 726                         sta->last_rx = jiffies;
 727         } else
 728         if (!is_multicast_ether_addr(hdr->addr1) ||
 729             rx->sdata->vif.type == NL80211_IFTYPE_STATION) {
 730                 /* Update last_rx only for unicast frames in order to prevent
 731                  * the Probe Request frames (the only broadcast frames from a
 732                  * STA in infrastructure mode) from keeping a connection alive.
 733                  * Mesh beacons will update last_rx when if they are found to
 734                  * match the current local configuration when processed.
 735                  */
 736                 sta->last_rx = jiffies;
 737         }
 738
 739         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
 740                 return RX_CONTINUE;
 741
 742         sta->rx_fragments++;
 743         sta->rx_bytes += rx->skb->len;
 744         sta->last_signal = rx->status->signal;
 745         sta->last_qual = rx->status->qual;
 746         sta->last_noise = rx->status->noise;
 747
 748         if (!ieee80211_has_morefrags(hdr->frame_control) &&
 749             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
 750              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)) {
 751                 /* Change STA power saving mode only in the end of a frame
 752                  * exchange sequence */
 753                 if (test_sta_flags(sta, WLAN_STA_PS) &&
 754                     !ieee80211_has_pm(hdr->frame_control))
 755                         rx->sent_ps_buffered += ap_sta_ps_end(sta);
 756                 else if (!test_sta_flags(sta, WLAN_STA_PS) &&
 757                          ieee80211_has_pm(hdr->frame_control))
 758                         ap_sta_ps_start(sta);
 759         }
 760
 761         /* Drop data::nullfunc frames silently, since they are used only to
 762          * control station power saving mode. */
 763         if (ieee80211_is_nullfunc(hdr->frame_control)) {
 764                 I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
 765                 /* Update counter and free packet here to avoid counting this
 766                  * as a dropped packed. */
 767                 sta->rx_packets++;
 768                 dev_kfree_skb(rx->skb);
 769                 return RX_QUEUED;
 770         }
 771
 772         return RX_CONTINUE;
 773 } /* ieee80211_rx_h_sta_process */
 774
 775 static inline struct ieee80211_fragment_entry *
 776 ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
 777                          unsigned int frag, unsigned int seq, int rx_queue,
 778                          struct sk_buff **skb)
 779 {
 780         struct ieee80211_fragment_entry *entry;
 781         int idx;
 782
 783         idx = sdata->fragment_next;
 784         entry = &sdata->fragments[sdata->fragment_next++];
 785         if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
 786                 sdata->fragment_next = 0;
 787
 788         if (!skb_queue_empty(&entry->skb_list)) {
 789 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 790                 struct ieee80211_hdr *hdr =
 791                         (struct ieee80211_hdr *) entry->skb_list.next->data;
 792                 DECLARE_MAC_BUF(mac);
 793                 DECLARE_MAC_BUF(mac2);
 794                 printk(KERN_DEBUG "%s: RX reassembly removed oldest "
 795                        "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
 796                        "addr1=%s addr2=%s\n",
 797                        sdata->dev->name, idx,
 798                        jiffies - entry->first_frag_time, entry->seq,
 799                        entry->last_frag, print_mac(mac, hdr->addr1),
 800                        print_mac(mac2, hdr->addr2));
 801 #endif
 802                 __skb_queue_purge(&entry->skb_list);
 803         }
 804
 805         __skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
 806         *skb = NULL;
 807         entry->first_frag_time = jiffies;
 808         entry->seq = seq;
 809         entry->rx_queue = rx_queue;
 810         entry->last_frag = frag;
 811         entry->ccmp = 0;
 812         entry->extra_len = 0;
 813
 814         return entry;
 815 }
 816
 817 static inline struct ieee80211_fragment_entry *
 818 ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
 819                           unsigned int frag, unsigned int seq,
 820                           int rx_queue, struct ieee80211_hdr *hdr)
 821 {
 822         struct ieee80211_fragment_entry *entry;
 823         int i, idx;
 824
 825         idx = sdata->fragment_next;
 826         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
 827                 struct ieee80211_hdr *f_hdr;
 828
 829                 idx--;
 830                 if (idx < 0)
 831                         idx = IEEE80211_FRAGMENT_MAX - 1;
 832
 833                 entry = &sdata->fragments[idx];
 834                 if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
 835                     entry->rx_queue != rx_queue ||
 836                     entry->last_frag + 1 != frag)
 837                         continue;
 838
 839                 f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
 840
 841                 /*
 842                  * Check ftype and addresses are equal, else check next fragment
 843                  */
 844                 if (((hdr->frame_control ^ f_hdr->frame_control) &
 845                      cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
 846                     compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
 847                     compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
 848                         continue;
 849
 850                 if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
 851                         __skb_queue_purge(&entry->skb_list);
 852                         continue;
 853                 }
 854                 return entry;
 855         }
 856
 857         return NULL;
 858 }
 859
 860 static ieee80211_rx_result debug_noinline
 861 ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 862 {
 863         struct ieee80211_hdr *hdr;
 864         u16 sc;
 865         __le16 fc;
 866         unsigned int frag, seq;
 867         struct ieee80211_fragment_entry *entry;
 868         struct sk_buff *skb;
 869         DECLARE_MAC_BUF(mac);
 870
 871         hdr = (struct ieee80211_hdr *)rx->skb->data;
 872         fc = hdr->frame_control;
 873         sc = le16_to_cpu(hdr->seq_ctrl);
 874         frag = sc & IEEE80211_SCTL_FRAG;
 875
 876         if (likely((!ieee80211_has_morefrags(fc) && frag == 0) ||
 877                    (rx->skb)->len < 24 ||
 878                    is_multicast_ether_addr(hdr->addr1))) {
 879                 /* not fragmented */
 880                 goto out;
 881         }
 882         I802_DEBUG_INC(rx->local->rx_handlers_fragments);
 883
 884         seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
 885
 886         if (frag == 0) {
 887                 /* This is the first fragment of a new frame. */
 888                 entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
 889                                                  rx->queue, &(rx->skb));
 890                 if (rx->key && rx->key->conf.alg == ALG_CCMP &&
 891                     ieee80211_has_protected(fc)) {
 892                         /* Store CCMP PN so that we can verify that the next
 893                          * fragment has a sequential PN value. */
 894                         entry->ccmp = 1;
 895                         memcpy(entry->last_pn,
 896                                rx->key->u.ccmp.rx_pn[rx->queue],
 897                                CCMP_PN_LEN);
 898                 }
 899                 return RX_QUEUED;
 900         }
 901
 902         /* This is a fragment for a frame that should already be pending in
 903          * fragment cache. Add this fragment to the end of the pending entry.
 904          */
 905         entry = ieee80211_reassemble_find(rx->sdata, frag, seq, rx->queue, hdr);
 906         if (!entry) {
 907                 I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
 908                 return RX_DROP_MONITOR;
 909         }
 910
 911         /* Verify that MPDUs within one MSDU have sequential PN values.
 912          * (IEEE 802.11i, 8.3.3.4.5) */
 913         if (entry->ccmp) {
 914                 int i;
 915                 u8 pn[CCMP_PN_LEN], *rpn;
 916                 if (!rx->key || rx->key->conf.alg != ALG_CCMP)
 917                         return RX_DROP_UNUSABLE;
 918                 memcpy(pn, entry->last_pn, CCMP_PN_LEN);
 919                 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
 920                         pn[i]++;
 921                         if (pn[i])
 922                                 break;
 923                 }
 924                 rpn = rx->key->u.ccmp.rx_pn[rx->queue];
 925                 if (memcmp(pn, rpn, CCMP_PN_LEN))
 926                         return RX_DROP_UNUSABLE;
 927                 memcpy(entry->last_pn, pn, CCMP_PN_LEN);
 928         }
 929
 930         skb_pull(rx->skb, ieee80211_hdrlen(fc));
 931         __skb_queue_tail(&entry->skb_list, rx->skb);
 932         entry->last_frag = frag;
 933         entry->extra_len += rx->skb->len;
 934         if (ieee80211_has_morefrags(fc)) {
 935                 rx->skb = NULL;
 936                 return RX_QUEUED;
 937         }
 938
 939         rx->skb = __skb_dequeue(&entry->skb_list);
 940         if (skb_tailroom(rx->skb) < entry->extra_len) {
 941                 I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
 942                 if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
 943                                               GFP_ATOMIC))) {
 944                         I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
 945                         __skb_queue_purge(&entry->skb_list);
 946                         return RX_DROP_UNUSABLE;
 947                 }
 948         }
 949         while ((skb = __skb_dequeue(&entry->skb_list))) {
 950                 memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
 951                 dev_kfree_skb(skb);
 952         }
 953
 954         /* Complete frame has been reassembled - process it now */
 955         rx->flags |= IEEE80211_RX_FRAGMENTED;
 956
 957  out:
 958         if (rx->sta)
 959                 rx->sta->rx_packets++;
 960         if (is_multicast_ether_addr(hdr->addr1))
 961                 rx->local->dot11MulticastReceivedFrameCount++;
 962         else
 963                 ieee80211_led_rx(rx->local);
 964         return RX_CONTINUE;
 965 }
 966
 967 static ieee80211_rx_result debug_noinline
 968 ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
 969 {
 970         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
 971         struct sk_buff *skb;
 972         int no_pending_pkts;
 973         DECLARE_MAC_BUF(mac);
 974         __le16 fc = ((struct ieee80211_hdr *)rx->skb->data)->frame_control;
 975
 976         if (likely(!rx->sta || !ieee80211_is_pspoll(fc) ||
 977                    !(rx->flags & IEEE80211_RX_RA_MATCH)))
 978                 return RX_CONTINUE;
 979
 980         if ((sdata->vif.type != NL80211_IFTYPE_AP) &&
 981             (sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
 982                 return RX_DROP_UNUSABLE;
 983
 984         skb = skb_dequeue(&rx->sta->tx_filtered);
 985         if (!skb) {
 986                 skb = skb_dequeue(&rx->sta->ps_tx_buf);
 987                 if (skb)
 988                         rx->local->total_ps_buffered--;
 989         }
 990         no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
 991                 skb_queue_empty(&rx->sta->ps_tx_buf);
 992
 993         if (skb) {
 994                 struct ieee80211_hdr *hdr =
 995                         (struct ieee80211_hdr *) skb->data;
 996
 997                 /*
 998                  * Tell TX path to send one frame even though the STA may
 999                  * still remain is PS mode after this frame exchange.
1000                  */
1001                 set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1002
1003 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1004                 printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
1005                        print_mac(mac, rx->sta->sta.addr), rx->sta->sta.aid,
1006                        skb_queue_len(&rx->sta->ps_tx_buf));
1007 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1008
1009                 /* Use MoreData flag to indicate whether there are more
1010                  * buffered frames for this STA */
1011                 if (no_pending_pkts)
1012                         hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1013                 else
1014                         hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1015
1016                 dev_queue_xmit(skb);
1017
1018                 if (no_pending_pkts)
1019                         sta_info_clear_tim_bit(rx->sta);
1020 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1021         } else if (!rx->sent_ps_buffered) {
1022                 /*
1023                  * FIXME: This can be the result of a race condition between
1024                  *        us expiring a frame and the station polling for it.
1025                  *        Should we send it a null-func frame indicating we
1026                  *        have nothing buffered for it?
1027                  */
1028                 printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
1029                        "though there are no buffered frames for it\n",
1030                        rx->dev->name, print_mac(mac, rx->sta->sta.addr));
1031 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
1032         }
1033
1034         /* Free PS Poll skb here instead of returning RX_DROP that would
1035          * count as an dropped frame. */
1036         dev_kfree_skb(rx->skb);
1037
1038         return RX_QUEUED;
1039 }
1040
1041 static ieee80211_rx_result debug_noinline
1042 ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1043 {
1044         u8 *data = rx->skb->data;
1045         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1046
1047         if (!ieee80211_is_data_qos(hdr->frame_control))
1048                 return RX_CONTINUE;
1049
1050         /* remove the qos control field, update frame type and meta-data */
1051         memmove(data + IEEE80211_QOS_CTL_LEN, data,
1052                 ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
1053         hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1054         /* change frame type to non QOS */
1055         hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1056
1057         return RX_CONTINUE;
1058 }
1059
1060 static int
1061 ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1062 {
1063         if (unlikely(!rx->sta ||
1064             !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1065                 return -EACCES;
1066
1067         return 0;
1068 }
1069
1070 static int
1071 ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
1072 {
1073         /*
1074          * Pass through unencrypted frames if the hardware has
1075          * decrypted them already.
1076          */
1077         if (rx->status->flag & RX_FLAG_DECRYPTED)
1078                 return 0;
1079
1080         /* Drop unencrypted frames if key is set. */
1081         if (unlikely(!ieee80211_has_protected(fc) &&
1082                      !ieee80211_is_nullfunc(fc) &&
1083                      (rx->key || rx->sdata->drop_unencrypted)))
1084                 return -EACCES;
1085
1086         return 0;
1087 }
1088
1089 static int
1090 ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1091 {
1092         struct net_device *dev = rx->dev;
1093         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
1094         u16 hdrlen, ethertype;
1095         u8 *payload;
1096         u8 dst[ETH_ALEN];
1097         u8 src[ETH_ALEN] __aligned(2);
1098         struct sk_buff *skb = rx->skb;
1099         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1100         DECLARE_MAC_BUF(mac);
1101         DECLARE_MAC_BUF(mac2);
1102         DECLARE_MAC_BUF(mac3);
1103         DECLARE_MAC_BUF(mac4);
1104
1105         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1106                 return -1;
1107
1108         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1109
1110         if (ieee80211_vif_is_mesh(&sdata->vif))
1111                 hdrlen += ieee80211_get_mesh_hdrlen(
1112                                 (struct ieee80211s_hdr *) (skb->data + hdrlen));
1113
1114         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
1115          * header
1116          * IEEE 802.11 address fields:
1117          * ToDS FromDS Addr1 Addr2 Addr3 Addr4
1118          *   0     0   DA    SA    BSSID n/a
1119          *   0     1   DA    BSSID SA    n/a
1120          *   1     0   BSSID SA    DA    n/a
1121          *   1     1   RA    TA    DA    SA
1122          */
1123         memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
1124         memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
1125
1126         switch (hdr->frame_control &
1127                 cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
1128         case __constant_cpu_to_le16(IEEE80211_FCTL_TODS):
1129                 if (unlikely(sdata->vif.type != NL80211_IFTYPE_AP &&
1130                              sdata->vif.type != NL80211_IFTYPE_AP_VLAN))
1131                         return -1;
1132                 break;
1133         case __constant_cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
1134                 if (unlikely(sdata->vif.type != NL80211_IFTYPE_WDS &&
1135                              sdata->vif.type != NL80211_IFTYPE_MESH_POINT))
1136                         return -1;
1137                 break;
1138         case __constant_cpu_to_le16(IEEE80211_FCTL_FROMDS):
1139                 if (sdata->vif.type != NL80211_IFTYPE_STATION ||
1140                     (is_multicast_ether_addr(dst) &&
1141                      !compare_ether_addr(src, dev->dev_addr)))
1142                         return -1;
1143                 break;
1144         case __constant_cpu_to_le16(0):
1145                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1146                         return -1;
1147                 break;
1148         }
1149
1150         if (unlikely(skb->len - hdrlen < 8))
1151                 return -1;
1152
1153         payload = skb->data + hdrlen;
1154         ethertype = (payload[6] << 8) | payload[7];
1155
1156         if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1157                     ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1158                    compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
1159                 /* remove RFC1042 or Bridge-Tunnel encapsulation and
1160                  * replace EtherType */
1161                 skb_pull(skb, hdrlen + 6);
1162                 memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1163                 memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1164         } else {
1165                 struct ethhdr *ehdr;
1166                 __be16 len;
1167
1168                 skb_pull(skb, hdrlen);
1169                 len = htons(skb->len);
1170                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
1171                 memcpy(ehdr->h_dest, dst, ETH_ALEN);
1172                 memcpy(ehdr->h_source, src, ETH_ALEN);
1173                 ehdr->h_proto = len;
1174         }
1175         return 0;
1176 }
1177
1178 /*
1179  * requires that rx->skb is a frame with ethernet header
1180  */
1181 static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
1182 {
1183         static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
1184                 = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
1185         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1186
1187         /*
1188          * Allow EAPOL frames to us/the PAE group address regardless
1189          * of whether the frame was encrypted or not.
1190          */
1191         if (ehdr->h_proto == htons(ETH_P_PAE) &&
1192             (compare_ether_addr(ehdr->h_dest, rx->dev->dev_addr) == 0 ||
1193              compare_ether_addr(ehdr->h_dest, pae_group_addr) == 0))
1194                 return true;
1195
1196         if (ieee80211_802_1x_port_control(rx) ||
1197             ieee80211_drop_unencrypted(rx, fc))
1198                 return false;
1199
1200         return true;
1201 }
1202
1203 /*
1204  * requires that rx->skb is a frame with ethernet header
1205  */
1206 static void
1207 ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
1208 {
1209         struct net_device *dev = rx->dev;
1210         struct ieee80211_local *local = rx->local;
1211         struct sk_buff *skb, *xmit_skb;
1212         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1213         struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
1214         struct sta_info *dsta;
1215
1216         skb = rx->skb;
1217         xmit_skb = NULL;
1218
1219         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
1220              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
1221             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
1222             (rx->flags & IEEE80211_RX_RA_MATCH)) {
1223                 if (is_multicast_ether_addr(ehdr->h_dest)) {
1224                         /*
1225                          * send multicast frames both to higher layers in
1226                          * local net stack and back to the wireless medium
1227                          */
1228                         xmit_skb = skb_copy(skb, GFP_ATOMIC);
1229                         if (!xmit_skb && net_ratelimit())
1230                                 printk(KERN_DEBUG "%s: failed to clone "
1231                                        "multicast frame\n", dev->name);
1232                 } else {
1233                         dsta = sta_info_get(local, skb->data);
1234                         if (dsta && dsta->sdata->dev == dev) {
1235                                 /*
1236                                  * The destination station is associated to
1237                                  * this AP (in this VLAN), so send the frame
1238                                  * directly to it and do not pass it to local
1239                                  * net stack.
1240                                  */
1241                                 xmit_skb = skb;
1242                                 skb = NULL;
1243                         }
1244                 }
1245         }
1246
1247         if (skb) {
1248                 /* deliver to local stack */
1249                 skb->protocol = eth_type_trans(skb, dev);
1250                 memset(skb->cb, 0, sizeof(skb->cb));
1251                 netif_rx(skb);
1252         }
1253
1254         if (xmit_skb) {
1255                 /* send to wireless media */
1256                 xmit_skb->protocol = htons(ETH_P_802_3);
1257                 skb_reset_network_header(xmit_skb);
1258                 skb_reset_mac_header(xmit_skb);
1259                 dev_queue_xmit(xmit_skb);
1260         }
1261 }
1262
1263 static ieee80211_rx_result debug_noinline
1264 ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
1265 {
1266         struct net_device *dev = rx->dev;
1267         struct ieee80211_local *local = rx->local;
1268         u16 ethertype;
1269         u8 *payload;
1270         struct sk_buff *skb = rx->skb, *frame = NULL;
1271         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1272         __le16 fc = hdr->frame_control;
1273         const struct ethhdr *eth;
1274         int remaining, err;
1275         u8 dst[ETH_ALEN];
1276         u8 src[ETH_ALEN];
1277         DECLARE_MAC_BUF(mac);
1278
1279         if (unlikely(!ieee80211_is_data(fc)))
1280                 return RX_CONTINUE;
1281
1282         if (unlikely(!ieee80211_is_data_present(fc)))
1283                 return RX_DROP_MONITOR;
1284
1285         if (!(rx->flags & IEEE80211_RX_AMSDU))
1286                 return RX_CONTINUE;
1287
1288         err = ieee80211_data_to_8023(rx);
1289         if (unlikely(err))
1290                 return RX_DROP_UNUSABLE;
1291
1292         skb->dev = dev;
1293
1294         dev->stats.rx_packets++;
1295         dev->stats.rx_bytes += skb->len;
1296
1297         /* skip the wrapping header */
1298         eth = (struct ethhdr *) skb_pull(skb, sizeof(struct ethhdr));
1299         if (!eth)
1300                 return RX_DROP_UNUSABLE;
1301
1302         while (skb != frame) {
1303                 u8 padding;
1304                 __be16 len = eth->h_proto;
1305                 unsigned int subframe_len = sizeof(struct ethhdr) + ntohs(len);
1306
1307                 remaining = skb->len;
1308                 memcpy(dst, eth->h_dest, ETH_ALEN);
1309                 memcpy(src, eth->h_source, ETH_ALEN);
1310
1311                 padding = ((4 - subframe_len) & 0x3);
1312                 /* the last MSDU has no padding */
1313                 if (subframe_len > remaining)
1314                         return RX_DROP_UNUSABLE;
1315
1316                 skb_pull(skb, sizeof(struct ethhdr));
1317                 /* if last subframe reuse skb */
1318                 if (remaining <= subframe_len + padding)
1319                         frame = skb;
1320                 else {
1321                         frame = dev_alloc_skb(local->hw.extra_tx_headroom +
1322                                               subframe_len);
1323
1324                         if (frame == NULL)
1325                                 return RX_DROP_UNUSABLE;
1326
1327                         skb_reserve(frame, local->hw.extra_tx_headroom +
1328                                     sizeof(struct ethhdr));
1329                         memcpy(skb_put(frame, ntohs(len)), skb->data,
1330                                 ntohs(len));
1331
1332                         eth = (struct ethhdr *) skb_pull(skb, ntohs(len) +
1333                                                         padding);
1334                         if (!eth) {
1335                                 dev_kfree_skb(frame);
1336                                 return RX_DROP_UNUSABLE;
1337                         }
1338                 }
1339
1340                 skb_reset_network_header(frame);
1341                 frame->dev = dev;
1342                 frame->priority = skb->priority;
1343                 rx->skb = frame;
1344
1345                 payload = frame->data;
1346                 ethertype = (payload[6] << 8) | payload[7];
1347
1348                 if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
1349                             ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1350                            compare_ether_addr(payload,
1351                                               bridge_tunnel_header) == 0)) {
1352                         /* remove RFC1042 or Bridge-Tunnel
1353                          * encapsulation and replace EtherType */
1354                         skb_pull(frame, 6);
1355                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1356                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1357                 } else {
1358                         memcpy(skb_push(frame, sizeof(__be16)),
1359                                &len, sizeof(__be16));
1360                         memcpy(skb_push(frame, ETH_ALEN), src, ETH_ALEN);
1361                         memcpy(skb_push(frame, ETH_ALEN), dst, ETH_ALEN);
1362                 }
1363
1364                 if (!ieee80211_frame_allowed(rx, fc)) {
1365                         if (skb == frame) /* last frame */
1366                                 return RX_DROP_UNUSABLE;
1367                         dev_kfree_skb(frame);
1368                         continue;
1369                 }
1370
1371                 ieee80211_deliver_skb(rx);
1372         }
1373
1374         return RX_QUEUED;
1375 }
1376
1377 static ieee80211_rx_result debug_noinline
1378 ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
1379 {
1380         struct ieee80211_hdr *hdr;
1381         struct ieee80211s_hdr *mesh_hdr;
1382         unsigned int hdrlen;
1383         struct sk_buff *skb = rx->skb, *fwd_skb;
1384
1385         hdr = (struct ieee80211_hdr *) skb->data;
1386         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1387         mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
1388
1389         if (!ieee80211_is_data(hdr->frame_control))
1390                 return RX_CONTINUE;
1391
1392         if (!mesh_hdr->ttl)
1393                 /* illegal frame */
1394                 return RX_DROP_MONITOR;
1395
1396         if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)
1397                 return RX_CONTINUE;
1398
1399         mesh_hdr->ttl--;
1400
1401         if (rx->flags & IEEE80211_RX_RA_MATCH) {
1402                 if (!mesh_hdr->ttl)
1403                         IEEE80211_IFSTA_MESH_CTR_INC(&rx->sdata->u.mesh,
1404                                                      dropped_frames_ttl);
1405                 else {
1406                         struct ieee80211_hdr *fwd_hdr;
1407                         fwd_skb = skb_copy(skb, GFP_ATOMIC);
1408
1409                         if (!fwd_skb && net_ratelimit())
1410                                 printk(KERN_DEBUG "%s: failed to clone mesh frame\n",
1411                                                    rx->dev->name);
1412
1413                         fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
1414                         /*
1415                          * Save TA to addr1 to send TA a path error if a
1416                          * suitable next hop is not found
1417                          */
1418                         memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);
1419                         memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);
1420                         fwd_skb->dev = rx->local->mdev;
1421                         fwd_skb->iif = rx->dev->ifindex;
1422                         dev_queue_xmit(fwd_skb);
1423                 }
1424         }
1425
1426         if (is_multicast_ether_addr(hdr->addr3) ||
1427             rx->dev->flags & IFF_PROMISC)
1428                 return RX_CONTINUE;
1429         else
1430                 return RX_DROP_MONITOR;
1431 }
1432
1433
1434 static ieee80211_rx_result debug_noinline
1435 ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
1436 {
1437         struct net_device *dev = rx->dev;
1438         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
1439         __le16 fc = hdr->frame_control;
1440         int err;
1441
1442         if (unlikely(!ieee80211_is_data(hdr->frame_control)))
1443                 return RX_CONTINUE;
1444
1445         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
1446                 return RX_DROP_MONITOR;
1447
1448         err = ieee80211_data_to_8023(rx);
1449         if (unlikely(err))
1450                 return RX_DROP_UNUSABLE;
1451
1452         if (!ieee80211_frame_allowed(rx, fc))
1453                 return RX_DROP_MONITOR;
1454
1455         rx->skb->dev = dev;
1456
1457         dev->stats.rx_packets++;
1458         dev->stats.rx_bytes += rx->skb->len;
1459
1460         ieee80211_deliver_skb(rx);
1461
1462         return RX_QUEUED;
1463 }
1464
1465 static ieee80211_rx_result debug_noinline
1466 ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
1467 {
1468         struct ieee80211_local *local = rx->local;
1469         struct ieee80211_hw *hw = &local->hw;
1470         struct sk_buff *skb = rx->skb;
1471         struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
1472         struct tid_ampdu_rx *tid_agg_rx;
1473         u16 start_seq_num;
1474         u16 tid;
1475
1476         if (likely(!ieee80211_is_ctl(bar->frame_control)))
1477                 return RX_CONTINUE;
1478
1479         if (ieee80211_is_back_req(bar->frame_control)) {
1480                 if (!rx->sta)
1481                         return RX_CONTINUE;
1482                 tid = le16_to_cpu(bar->control) >> 12;
1483                 if (rx->sta->ampdu_mlme.tid_state_rx[tid]
1484                                         != HT_AGG_STATE_OPERATIONAL)
1485                         return RX_CONTINUE;
1486                 tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
1487
1488                 start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
1489
1490                 /* reset session timer */
1491                 if (tid_agg_rx->timeout) {
1492                         unsigned long expires =
1493                                 jiffies + (tid_agg_rx->timeout / 1000) * HZ;
1494                         mod_timer(&tid_agg_rx->session_timer, expires);
1495                 }
1496
1497                 /* manage reordering buffer according to requested */
1498                 /* sequence number */
1499                 rcu_read_lock();
1500                 ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, NULL,
1501                                                  start_seq_num, 1);
1502                 rcu_read_unlock();
1503                 return RX_DROP_UNUSABLE;
1504         }
1505
1506         return RX_CONTINUE;
1507 }
1508
1509 static ieee80211_rx_result debug_noinline
1510 ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
1511 {
1512         struct ieee80211_local *local = rx->local;
1513         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1514         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
1515         int len = rx->skb->len;
1516
1517         if (!ieee80211_is_action(mgmt->frame_control))
1518                 return RX_CONTINUE;
1519
1520         if (!rx->sta)
1521                 return RX_DROP_MONITOR;
1522
1523         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1524                 return RX_DROP_MONITOR;
1525
1526         /* all categories we currently handle have action_code */
1527         if (len < IEEE80211_MIN_ACTION_SIZE + 1)
1528                 return RX_DROP_MONITOR;
1529
1530         /*
1531          * FIXME: revisit this, I'm sure we should handle most
1532          *        of these frames in other modes as well!
1533          */
1534         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1535             sdata->vif.type != NL80211_IFTYPE_ADHOC)
1536                 return RX_DROP_MONITOR;
1537
1538         switch (mgmt->u.action.category) {
1539         case WLAN_CATEGORY_BACK:
1540                 switch (mgmt->u.action.u.addba_req.action_code) {
1541                 case WLAN_ACTION_ADDBA_REQ:
1542                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1543                                    sizeof(mgmt->u.action.u.addba_req)))
1544                                 return RX_DROP_MONITOR;
1545                         ieee80211_process_addba_request(local, rx->sta, mgmt, len);
1546                         break;
1547                 case WLAN_ACTION_ADDBA_RESP:
1548                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1549                                    sizeof(mgmt->u.action.u.addba_resp)))
1550                                 return RX_DROP_MONITOR;
1551                         ieee80211_process_addba_resp(local, rx->sta, mgmt, len);
1552                         break;
1553                 case WLAN_ACTION_DELBA:
1554                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1555                                    sizeof(mgmt->u.action.u.delba)))
1556                                 return RX_DROP_MONITOR;
1557                         ieee80211_process_delba(sdata, rx->sta, mgmt, len);
1558                         break;
1559                 }
1560                 break;
1561         case WLAN_CATEGORY_SPECTRUM_MGMT:
1562                 if (local->hw.conf.channel->band != IEEE80211_BAND_5GHZ)
1563                         return RX_DROP_MONITOR;
1564                 switch (mgmt->u.action.u.measurement.action_code) {
1565                 case WLAN_ACTION_SPCT_MSR_REQ:
1566                         if (len < (IEEE80211_MIN_ACTION_SIZE +
1567                                    sizeof(mgmt->u.action.u.measurement)))
1568                                 return RX_DROP_MONITOR;
1569                         ieee80211_process_measurement_req(sdata, mgmt, len);
1570                         break;
1571                 }
1572                 break;
1573         default:
1574                 return RX_CONTINUE;
1575         }
1576
1577         rx->sta->rx_packets++;
1578         dev_kfree_skb(rx->skb);
1579         return RX_QUEUED;
1580 }
1581
1582 static ieee80211_rx_result debug_noinline
1583 ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
1584 {
1585         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
1586
1587         if (!(rx->flags & IEEE80211_RX_RA_MATCH))
1588                 return RX_DROP_MONITOR;
1589
1590         if (ieee80211_vif_is_mesh(&sdata->vif))
1591                 return ieee80211_mesh_rx_mgmt(sdata, rx->skb, rx->status);
1592
1593         if (sdata->vif.type != NL80211_IFTYPE_STATION &&
1594             sdata->vif.type != NL80211_IFTYPE_ADHOC)
1595                 return RX_DROP_MONITOR;
1596
1597         if (sdata->flags & IEEE80211_SDATA_USERSPACE_MLME)
1598                 return RX_DROP_MONITOR;
1599
1600         ieee80211_sta_rx_mgmt(sdata, rx->skb, rx->status);
1601         return RX_QUEUED;
1602 }
1603
1604 static void ieee80211_rx_michael_mic_report(struct net_device *dev,
1605                                             struct ieee80211_hdr *hdr,
1606                                             struct ieee80211_rx_data *rx)
1607 {
1608         int keyidx;
1609         unsigned int hdrlen;
1610         DECLARE_MAC_BUF(mac);
1611         DECLARE_MAC_BUF(mac2);
1612
1613         hdrlen = ieee80211_hdrlen(hdr->frame_control);
1614         if (rx->skb->len >= hdrlen + 4)
1615                 keyidx = rx->skb->data[hdrlen + 3] >> 6;
1616         else
1617                 keyidx = -1;
1618
1619         if (!rx->sta) {
1620                 /*
1621                  * Some hardware seem to generate incorrect Michael MIC
1622                  * reports; ignore them to avoid triggering countermeasures.
1623                  */
1624                 goto ignore;
1625         }
1626
1627         if (!ieee80211_has_protected(hdr->frame_control))
1628                 goto ignore;
1629
1630         if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
1631                 /*
1632                  * APs with pairwise keys should never receive Michael MIC
1633                  * errors for non-zero keyidx because these are reserved for
1634                  * group keys and only the AP is sending real multicast
1635                  * frames in the BSS.
1636                  */
1637                 goto ignore;
1638         }
1639
1640         if (!ieee80211_is_data(hdr->frame_control) &&
1641             !ieee80211_is_auth(hdr->frame_control))
1642                 goto ignore;
1643
1644         mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr);
1645  ignore:
1646         dev_kfree_skb(rx->skb);
1647         rx->skb = NULL;
1648 }
1649
1650 /* TODO: use IEEE80211_RX_FRAGMENTED */
1651 static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
1652 {
1653         struct ieee80211_sub_if_data *sdata;
1654         struct ieee80211_local *local = rx->local;
1655         struct ieee80211_rtap_hdr {
1656                 struct ieee80211_radiotap_header hdr;
1657                 u8 flags;
1658                 u8 rate;
1659                 __le16 chan_freq;
1660                 __le16 chan_flags;
1661         } __attribute__ ((packed)) *rthdr;
1662         struct sk_buff *skb = rx->skb, *skb2;
1663         struct net_device *prev_dev = NULL;
1664         struct ieee80211_rx_status *status = rx->status;
1665
1666         if (rx->flags & IEEE80211_RX_CMNTR_REPORTED)
1667                 goto out_free_skb;
1668
1669         if (skb_headroom(skb) < sizeof(*rthdr) &&
1670             pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC))
1671                 goto out_free_skb;
1672
1673         rthdr = (void *)skb_push(skb, sizeof(*rthdr));
1674         memset(rthdr, 0, sizeof(*rthdr));
1675         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
1676         rthdr->hdr.it_present =
1677                 cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
1678                             (1 << IEEE80211_RADIOTAP_RATE) |
1679                             (1 << IEEE80211_RADIOTAP_CHANNEL));
1680
1681         rthdr->rate = rx->rate->bitrate / 5;
1682         rthdr->chan_freq = cpu_to_le16(status->freq);
1683
1684         if (status->band == IEEE80211_BAND_5GHZ)
1685                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_OFDM |
1686                                                 IEEE80211_CHAN_5GHZ);
1687         else
1688                 rthdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_DYN |
1689                                                 IEEE80211_CHAN_2GHZ);
1690
1691         skb_set_mac_header(skb, 0);
1692         skb->ip_summed = CHECKSUM_UNNECESSARY;
1693         skb->pkt_type = PACKET_OTHERHOST;
1694         skb->protocol = htons(ETH_P_802_2);
1695
1696         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1697                 if (!netif_running(sdata->dev))
1698                         continue;
1699
1700                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
1701                     !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
1702                         continue;
1703
1704                 if (prev_dev) {
1705                         skb2 = skb_clone(skb, GFP_ATOMIC);
1706                         if (skb2) {
1707                                 skb2->dev = prev_dev;
1708                                 netif_rx(skb2);
1709                         }
1710                 }
1711
1712                 prev_dev = sdata->dev;
1713                 sdata->dev->stats.rx_packets++;
1714                 sdata->dev->stats.rx_bytes += skb->len;
1715         }
1716
1717         if (prev_dev) {
1718                 skb->dev = prev_dev;
1719                 netif_rx(skb);
1720                 skb = NULL;
1721         } else
1722                 goto out_free_skb;
1723
1724         rx->flags |= IEEE80211_RX_CMNTR_REPORTED;
1725         return;
1726
1727  out_free_skb:
1728         dev_kfree_skb(skb);
1729 }
1730
1731
1732 static void ieee80211_invoke_rx_handlers(struct ieee80211_sub_if_data *sdata,
1733                                          struct ieee80211_rx_data *rx,
1734                                          struct sk_buff *skb)
1735 {
1736         ieee80211_rx_result res = RX_DROP_MONITOR;
1737
1738         rx->skb = skb;
1739         rx->sdata = sdata;
1740         rx->dev = sdata->dev;
1741
1742 #define CALL_RXH(rxh)                   \
1743         do {                            \
1744                 res = rxh(rx);          \
1745                 if (res != RX_CONTINUE) \
1746                         goto rxh_done;  \
1747         } while (0);
1748
1749         CALL_RXH(ieee80211_rx_h_passive_scan)
1750         CALL_RXH(ieee80211_rx_h_check)
1751         CALL_RXH(ieee80211_rx_h_decrypt)
1752         CALL_RXH(ieee80211_rx_h_sta_process)
1753         CALL_RXH(ieee80211_rx_h_defragment)
1754         CALL_RXH(ieee80211_rx_h_ps_poll)
1755         CALL_RXH(ieee80211_rx_h_michael_mic_verify)
1756         /* must be after MMIC verify so header is counted in MPDU mic */
1757         CALL_RXH(ieee80211_rx_h_remove_qos_control)
1758         CALL_RXH(ieee80211_rx_h_amsdu)
1759         if (ieee80211_vif_is_mesh(&sdata->vif))
1760                 CALL_RXH(ieee80211_rx_h_mesh_fwding);
1761         CALL_RXH(ieee80211_rx_h_data)
1762         CALL_RXH(ieee80211_rx_h_ctrl)
1763         CALL_RXH(ieee80211_rx_h_action)
1764         CALL_RXH(ieee80211_rx_h_mgmt)
1765
1766 #undef CALL_RXH
1767
1768  rxh_done:
1769         switch (res) {
1770         case RX_DROP_MONITOR:
1771                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1772                 if (rx->sta)
1773                         rx->sta->rx_dropped++;
1774                 /* fall through */
1775         case RX_CONTINUE:
1776                 ieee80211_rx_cooked_monitor(rx);
1777                 break;
1778         case RX_DROP_UNUSABLE:
1779                 I802_DEBUG_INC(sdata->local->rx_handlers_drop);
1780                 if (rx->sta)
1781                         rx->sta->rx_dropped++;
1782                 dev_kfree_skb(rx->skb);
1783                 break;
1784         case RX_QUEUED:
1785                 I802_DEBUG_INC(sdata->local->rx_handlers_queued);
1786                 break;
1787         }
1788 }
1789
1790 /* main receive path */
1791
1792 static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
1793                                 u8 *bssid, struct ieee80211_rx_data *rx,
1794                                 struct ieee80211_hdr *hdr)
1795 {
1796         int multicast = is_multicast_ether_addr(hdr->addr1);
1797
1798         switch (sdata->vif.type) {
1799         case NL80211_IFTYPE_STATION:
1800                 if (!bssid)
1801                         return 0;
1802                 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                 }
1813                 break;
1814         case NL80211_IFTYPE_ADHOC:
1815                 if (!bssid)
1816                         return 0;
1817                 if (ieee80211_is_beacon(hdr->frame_control)) {
1818                         return 1;
1819                 }
1820                 else if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
1821                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1822                                 return 0;
1823                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1824                 } else if (!multicast &&
1825                            compare_ether_addr(sdata->dev->dev_addr,
1826                                               hdr->addr1) != 0) {
1827                         if (!(sdata->dev->flags & IFF_PROMISC))
1828                                 return 0;
1829                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1830                 } else if (!rx->sta)
1831                         rx->sta = ieee80211_ibss_add_sta(sdata, rx->skb,
1832                                                 bssid, hdr->addr2,
1833                                                 BIT(rx->status->rate_idx));
1834                 break;
1835         case NL80211_IFTYPE_MESH_POINT:
1836                 if (!multicast &&
1837                     compare_ether_addr(sdata->dev->dev_addr,
1838                                        hdr->addr1) != 0) {
1839                         if (!(sdata->dev->flags & IFF_PROMISC))
1840                                 return 0;
1841
1842                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1843                 }
1844                 break;
1845         case NL80211_IFTYPE_AP_VLAN:
1846         case NL80211_IFTYPE_AP:
1847                 if (!bssid) {
1848                         if (compare_ether_addr(sdata->dev->dev_addr,
1849                                                hdr->addr1))
1850                                 return 0;
1851                 } else if (!ieee80211_bssid_match(bssid,
1852                                         sdata->dev->dev_addr)) {
1853                         if (!(rx->flags & IEEE80211_RX_IN_SCAN))
1854                                 return 0;
1855                         rx->flags &= ~IEEE80211_RX_RA_MATCH;
1856                 }
1857                 break;
1858         case NL80211_IFTYPE_WDS:
1859                 if (bssid || !ieee80211_is_data(hdr->frame_control))
1860                         return 0;
1861                 if (compare_ether_addr(sdata->u.wds.remote_addr, hdr->addr2))
1862                         return 0;
1863                 break;
1864         case NL80211_IFTYPE_MONITOR:
1865                 /* take everything */
1866                 break;
1867         case NL80211_IFTYPE_UNSPECIFIED:
1868         case __NL80211_IFTYPE_AFTER_LAST:
1869                 /* should never get here */
1870                 WARN_ON(1);
1871                 break;
1872         }
1873
1874         return 1;
1875 }
1876
1877 /*
1878  * This is the actual Rx frames handler. as it blongs to Rx path it must
1879  * be called with rcu_read_lock protection.
1880  */
1881 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
1882                                          struct sk_buff *skb,
1883                                          struct ieee80211_rx_status *status,
1884                                          struct ieee80211_rate *rate)
1885 {
1886         struct ieee80211_local *local = hw_to_local(hw);
1887         struct ieee80211_sub_if_data *sdata;
1888         struct ieee80211_hdr *hdr;
1889         struct ieee80211_rx_data rx;
1890         int prepares;
1891         struct ieee80211_sub_if_data *prev = NULL;
1892         struct sk_buff *skb_new;
1893         u8 *bssid;
1894
1895         hdr = (struct ieee80211_hdr *)skb->data;
1896         memset(&rx, 0, sizeof(rx));
1897         rx.skb = skb;
1898         rx.local = local;
1899
1900         rx.status = status;
1901         rx.rate = rate;
1902
1903         if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
1904                 local->dot11ReceivedFragmentCount++;
1905
1906         rx.sta = sta_info_get(local, hdr->addr2);
1907         if (rx.sta) {
1908                 rx.sdata = rx.sta->sdata;
1909                 rx.dev = rx.sta->sdata->dev;
1910         }
1911
1912         if ((status->flag & RX_FLAG_MMIC_ERROR)) {
1913                 ieee80211_rx_michael_mic_report(local->mdev, hdr, &rx);
1914                 return;
1915         }
1916
1917         if (unlikely(local->sw_scanning || local->hw_scanning))
1918                 rx.flags |= IEEE80211_RX_IN_SCAN;
1919
1920         ieee80211_parse_qos(&rx);
1921         ieee80211_verify_ip_alignment(&rx);
1922
1923         skb = rx.skb;
1924
1925         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
1926                 if (!netif_running(sdata->dev))
1927                         continue;
1928
1929                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR)
1930                         continue;
1931
1932                 bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
1933                 rx.flags |= IEEE80211_RX_RA_MATCH;
1934                 prepares = prepare_for_handlers(sdata, bssid, &rx, hdr);
1935
1936                 if (!prepares)
1937                         continue;
1938
1939                 /*
1940                  * frame is destined for this interface, but if it's not
1941                  * also for the previous one we handle that after the
1942                  * loop to avoid copying the SKB once too much
1943                  */
1944
1945                 if (!prev) {
1946                         prev = sdata;
1947                         continue;
1948                 }
1949
1950                 /*
1951                  * frame was destined for the previous interface
1952                  * so invoke RX handlers for it
1953                  */
1954
1955                 skb_new = skb_copy(skb, GFP_ATOMIC);
1956                 if (!skb_new) {
1957                         if (net_ratelimit())
1958                                 printk(KERN_DEBUG "%s: failed to copy "
1959                                        "multicast frame for %s\n",
1960                                        wiphy_name(local->hw.wiphy),
1961                                        prev->dev->name);
1962                         continue;
1963                 }
1964                 ieee80211_invoke_rx_handlers(prev, &rx, skb_new);
1965                 prev = sdata;
1966         }
1967         if (prev)
1968                 ieee80211_invoke_rx_handlers(prev, &rx, skb);
1969         else
1970                 dev_kfree_skb(skb);
1971 }
1972
1973 #define SEQ_MODULO 0x1000
1974 #define SEQ_MASK   0xfff
1975
1976 static inline int seq_less(u16 sq1, u16 sq2)
1977 {
1978         return (((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1));
1979 }
1980
1981 static inline u16 seq_inc(u16 sq)
1982 {
1983         return ((sq + 1) & SEQ_MASK);
1984 }
1985
1986 static inline u16 seq_sub(u16 sq1, u16 sq2)
1987 {
1988         return ((sq1 - sq2) & SEQ_MASK);
1989 }
1990
1991
1992 /*
1993  * As it function blongs to Rx path it must be called with
1994  * the proper rcu_read_lock protection for its flow.
1995  */
1996 u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
1997                                 struct tid_ampdu_rx *tid_agg_rx,
1998                                 struct sk_buff *skb, u16 mpdu_seq_num,
1999                                 int bar_req)
2000 {
2001         struct ieee80211_local *local = hw_to_local(hw);
2002         struct ieee80211_rx_status status;
2003         u16 head_seq_num, buf_size;
2004         int index;
2005         struct ieee80211_supported_band *sband;
2006         struct ieee80211_rate *rate;
2007
2008         buf_size = tid_agg_rx->buf_size;
2009         head_seq_num = tid_agg_rx->head_seq_num;
2010
2011         /* frame with out of date sequence number */
2012         if (seq_less(mpdu_seq_num, head_seq_num)) {
2013                 dev_kfree_skb(skb);
2014                 return 1;
2015         }
2016
2017         /* if frame sequence number exceeds our buffering window size or
2018          * block Ack Request arrived - release stored frames */
2019         if ((!seq_less(mpdu_seq_num, head_seq_num + buf_size)) || (bar_req)) {
2020                 /* new head to the ordering buffer */
2021                 if (bar_req)
2022                         head_seq_num = mpdu_seq_num;
2023                 else
2024                         head_seq_num =
2025                                 seq_inc(seq_sub(mpdu_seq_num, buf_size));
2026                 /* release stored frames up to new head to stack */
2027                 while (seq_less(tid_agg_rx->head_seq_num, head_seq_num)) {
2028                         index = seq_sub(tid_agg_rx->head_seq_num,
2029                                 tid_agg_rx->ssn)
2030                                 % tid_agg_rx->buf_size;
2031
2032                         if (tid_agg_rx->reorder_buf[index]) {
2033                                 /* release the reordered frames to stack */
2034                                 memcpy(&status,
2035                                         tid_agg_rx->reorder_buf[index]->cb,
2036                                         sizeof(status));
2037                                 sband = local->hw.wiphy->bands[status.band];
2038                                 rate = &sband->bitrates[status.rate_idx];
2039                                 __ieee80211_rx_handle_packet(hw,
2040                                         tid_agg_rx->reorder_buf[index],
2041                                         &status, rate);
2042                                 tid_agg_rx->stored_mpdu_num--;
2043                                 tid_agg_rx->reorder_buf[index] = NULL;
2044                         }
2045                         tid_agg_rx->head_seq_num =
2046                                 seq_inc(tid_agg_rx->head_seq_num);
2047                 }
2048                 if (bar_req)
2049                         return 1;
2050         }
2051
2052         /* now the new frame is always in the range of the reordering */
2053         /* buffer window */
2054         index = seq_sub(mpdu_seq_num, tid_agg_rx->ssn)
2055                                 % tid_agg_rx->buf_size;
2056         /* check if we already stored this frame */
2057         if (tid_agg_rx->reorder_buf[index]) {
2058                 dev_kfree_skb(skb);
2059                 return 1;
2060         }
2061
2062         /* if arrived mpdu is in the right order and nothing else stored */
2063         /* release it immediately */
2064         if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
2065                         tid_agg_rx->stored_mpdu_num == 0) {
2066                 tid_agg_rx->head_seq_num =
2067                         seq_inc(tid_agg_rx->head_seq_num);
2068                 return 0;
2069         }
2070
2071         /* put the frame in the reordering buffer */
2072         tid_agg_rx->reorder_buf[index] = skb;
2073         tid_agg_rx->stored_mpdu_num++;
2074         /* release the buffer until next missing frame */
2075         index = seq_sub(tid_agg_rx->head_seq_num, tid_agg_rx->ssn)
2076                                                 % tid_agg_rx->buf_size;
2077         while (tid_agg_rx->reorder_buf[index]) {
2078                 /* release the reordered frame back to stack */
2079                 memcpy(&status, tid_agg_rx->reorder_buf[index]->cb,
2080                         sizeof(status));
2081                 sband = local->hw.wiphy->bands[status.band];
2082                 rate = &sband->bitrates[status.rate_idx];
2083                 __ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
2084                                              &status, 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 sc;
2102         u16 mpdu_seq_num;
2103         u8 ret = 0;
2104         int tid;
2105
2106         sta = sta_info_get(local, hdr->addr2);
2107         if (!sta)
2108                 return ret;
2109
2110         /* filter the QoS data rx stream according to
2111          * STA/TID and check if this STA/TID is on aggregation */
2112         if (!ieee80211_is_data_qos(hdr->frame_control))
2113                 goto end_reorder;
2114
2115         tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
2116
2117         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
2118                 goto end_reorder;
2119
2120         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
2121
2122         /* qos null data frames are excluded */
2123         if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
2124                 goto end_reorder;
2125
2126         /* new un-ordered ampdu frame - process it */
2127
2128         /* reset session timer */
2129         if (tid_agg_rx->timeout) {
2130                 unsigned long expires =
2131                         jiffies + (tid_agg_rx->timeout / 1000) * HZ;
2132                 mod_timer(&tid_agg_rx->session_timer, expires);
2133         }
2134
2135         /* if this mpdu is fragmented - terminate rx aggregation session */
2136         sc = le16_to_cpu(hdr->seq_ctrl);
2137         if (sc & IEEE80211_SCTL_FRAG) {
2138                 ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
2139                         tid, 0, WLAN_REASON_QSTA_REQUIRE_SETUP);
2140                 ret = 1;
2141                 goto end_reorder;
2142         }
2143
2144         /* according to mpdu sequence number deal with reordering buffer */
2145         mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
2146         ret = ieee80211_sta_manage_reorder_buf(hw, tid_agg_rx, skb,
2147                                                 mpdu_seq_num, 0);
2148  end_reorder:
2149         return ret;
2150 }
2151
2152 /*
2153  * This is the receive path handler. It is called by a low level driver when an
2154  * 802.11 MPDU is received from the hardware.
2155  */
2156 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
2157                     struct ieee80211_rx_status *status)
2158 {
2159         struct ieee80211_local *local = hw_to_local(hw);
2160         struct ieee80211_rate *rate = NULL;
2161         struct ieee80211_supported_band *sband;
2162
2163         if (status->band < 0 ||
2164             status->band >= IEEE80211_NUM_BANDS) {
2165                 WARN_ON(1);
2166                 return;
2167         }
2168
2169         sband = local->hw.wiphy->bands[status->band];
2170
2171         if (!sband ||
2172             status->rate_idx < 0 ||
2173             status->rate_idx >= sband->n_bitrates) {
2174                 WARN_ON(1);
2175                 return;
2176         }
2177
2178         rate = &sband->bitrates[status->rate_idx];
2179
2180         /*
2181          * key references and virtual interfaces are protected using RCU
2182          * and this requires that we are in a read-side RCU section during
2183          * receive processing
2184          */
2185         rcu_read_lock();
2186
2187         /*
2188          * Frames with failed FCS/PLCP checksum are not returned,
2189          * all other frames are returned without radiotap header
2190          * if it was previously present.
2191          * Also, frames with less than 16 bytes are dropped.
2192          */
2193         skb = ieee80211_rx_monitor(local, skb, status, rate);
2194         if (!skb) {
2195                 rcu_read_unlock();
2196                 return;
2197         }
2198
2199         if (!ieee80211_rx_reorder_ampdu(local, skb))
2200                 __ieee80211_rx_handle_packet(hw, skb, status, rate);
2201
2202         rcu_read_unlock();
2203 }
2204 EXPORT_SYMBOL(__ieee80211_rx);
2205
2206 /* This is a version of the rx handler that can be called from hard irq
2207  * context. Post the skb on the queue and schedule the tasklet */
2208 void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb,
2209                           struct ieee80211_rx_status *status)
2210 {
2211         struct ieee80211_local *local = hw_to_local(hw);
2212
2213         BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
2214
2215         skb->dev = local->mdev;
2216         /* copy status into skb->cb for use by tasklet */
2217         memcpy(skb->cb, status, sizeof(*status));
2218         skb->pkt_type = IEEE80211_RX_MSG;
2219         skb_queue_tail(&local->skb_queue, skb);
2220         tasklet_schedule(&local->tasklet);
2221 }
2222 EXPORT_SYMBOL(ieee80211_rx_irqsafe);