wlantest/rx_data.c

   1 /*
   2  * Received Data frame processing
   3  * Copyright (c) 2010, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "utils/includes.h"
  10 #include <linux/if_ether.h>
  11
  12 #include "utils/common.h"
  13 #include "common/defs.h"
  14 #include "common/ieee802_11_defs.h"
  15 #include "wlantest.h"
  16
  17 extern int wpa_debug_level;
  18
  19
  20 static const char * data_stype(u16 stype)
  21 {
  22         switch (stype) {
  23         case WLAN_FC_STYPE_DATA:
  24                 return "DATA";
  25         case WLAN_FC_STYPE_DATA_CFACK:
  26                 return "DATA-CFACK";
  27         case WLAN_FC_STYPE_DATA_CFPOLL:
  28                 return "DATA-CFPOLL";
  29         case WLAN_FC_STYPE_DATA_CFACKPOLL:
  30                 return "DATA-CFACKPOLL";
  31         case WLAN_FC_STYPE_NULLFUNC:
  32                 return "NULLFUNC";
  33         case WLAN_FC_STYPE_CFACK:
  34                 return "CFACK";
  35         case WLAN_FC_STYPE_CFPOLL:
  36                 return "CFPOLL";
  37         case WLAN_FC_STYPE_CFACKPOLL:
  38                 return "CFACKPOLL";
  39         case WLAN_FC_STYPE_QOS_DATA:
  40                 return "QOSDATA";
  41         case WLAN_FC_STYPE_QOS_DATA_CFACK:
  42                 return "QOSDATA-CFACK";
  43         case WLAN_FC_STYPE_QOS_DATA_CFPOLL:
  44                 return "QOSDATA-CFPOLL";
  45         case WLAN_FC_STYPE_QOS_DATA_CFACKPOLL:
  46                 return "QOSDATA-CFACKPOLL";
  47         case WLAN_FC_STYPE_QOS_NULL:
  48                 return "QOS-NULL";
  49         case WLAN_FC_STYPE_QOS_CFPOLL:
  50                 return "QOS-CFPOLL";
  51         case WLAN_FC_STYPE_QOS_CFACKPOLL:
  52                 return "QOS-CFACKPOLL";
  53         }
  54         return "??";
  55 }
  56
  57
  58 static void rx_data_eth(struct wlantest *wt, const u8 *bssid,
  59                         const u8 *sta_addr, const u8 *dst, const u8 *src,
  60                         u16 ethertype, const u8 *data, size_t len, int prot,
  61                         const u8 *peer_addr)
  62 {
  63         switch (ethertype) {
  64         case ETH_P_PAE:
  65                 rx_data_eapol(wt, dst, src, data, len, prot);
  66                 break;
  67         case ETH_P_IP:
  68                 rx_data_ip(wt, bssid, sta_addr, dst, src, data, len,
  69                            peer_addr);
  70                 break;
  71         case 0x890d:
  72                 rx_data_80211_encap(wt, bssid, sta_addr, dst, src, data, len);
  73                 break;
  74         }
  75 }
  76
  77
  78 static void rx_data_process(struct wlantest *wt, const u8 *bssid,
  79                             const u8 *sta_addr,
  80                             const u8 *dst, const u8 *src,
  81                             const u8 *data, size_t len, int prot,
  82                             const u8 *peer_addr)
  83 {
  84         if (len == 0)
  85                 return;
  86
  87         if (len >= 8 && os_memcmp(data, "\xaa\xaa\x03\x00\x00\x00", 6) == 0) {
  88                 rx_data_eth(wt, bssid, sta_addr, dst, src,
  89                             WPA_GET_BE16(data + 6), data + 8, len - 8, prot,
  90                             peer_addr);
  91                 return;
  92         }
  93
  94         wpa_hexdump(MSG_DEBUG, "Unrecognized LLC", data, len > 8 ? 8 : len);
  95 }
  96
  97
  98 static u8 * try_all_ptk(struct wlantest *wt, int pairwise_cipher,
  99                         const struct ieee80211_hdr *hdr,
 100                         const u8 *data, size_t data_len, size_t *decrypted_len)
 101 {
 102         struct wlantest_ptk *ptk;
 103         u8 *decrypted;
 104         int prev_level = wpa_debug_level;
 105
 106         wpa_debug_level = MSG_WARNING;
 107         dl_list_for_each(ptk, &wt->ptk, struct wlantest_ptk, list) {
 108                 decrypted = NULL;
 109                 if ((pairwise_cipher == WPA_CIPHER_CCMP ||
 110                      pairwise_cipher == 0) && ptk->ptk_len == 48) {
 111                         decrypted = ccmp_decrypt(ptk->ptk.tk1, hdr, data,
 112                                                  data_len, decrypted_len);
 113                 }
 114                 if ((pairwise_cipher == WPA_CIPHER_TKIP ||
 115                      pairwise_cipher == 0) && ptk->ptk_len == 64) {
 116                         decrypted = tkip_decrypt(ptk->ptk.tk1, hdr, data,
 117                                                  data_len, decrypted_len);
 118                 }
 119                 if (decrypted) {
 120                         wpa_debug_level = prev_level;
 121                         add_note(wt, MSG_DEBUG, "Found PTK match from list of all known PTKs");
 122                         return decrypted;
 123                 }
 124         }
 125         wpa_debug_level = prev_level;
 126
 127         return NULL;
 128 }
 129
 130
 131 static void rx_data_bss_prot_group(struct wlantest *wt,
 132                                    const struct ieee80211_hdr *hdr,
 133                                    const u8 *qos, const u8 *dst, const u8 *src,
 134                                    const u8 *data, size_t len)
 135 {
 136         struct wlantest_bss *bss;
 137         int keyid;
 138         u8 *decrypted;
 139         size_t dlen;
 140         u8 pn[6];
 141
 142         bss = bss_get(wt, hdr->addr2);
 143         if (bss == NULL)
 144                 return;
 145         if (len < 4) {
 146                 add_note(wt, MSG_INFO, "Too short group addressed data frame");
 147                 return;
 148         }
 149
 150         if (bss->group_cipher & (WPA_CIPHER_TKIP | WPA_CIPHER_CCMP) &&
 151             !(data[3] & 0x20)) {
 152                 add_note(wt, MSG_INFO, "Expected TKIP/CCMP frame from "
 153                          MACSTR " did not have ExtIV bit set to 1",
 154                          MAC2STR(bss->bssid));
 155                 return;
 156         }
 157
 158         if (bss->group_cipher == WPA_CIPHER_TKIP) {
 159                 if (data[3] & 0x1f) {
 160                         add_note(wt, MSG_INFO, "TKIP frame from " MACSTR
 161                                  " used non-zero reserved bit",
 162                                  MAC2STR(bss->bssid));
 163                 }
 164                 if (data[1] != ((data[0] | 0x20) & 0x7f)) {
 165                         add_note(wt, MSG_INFO, "TKIP frame from " MACSTR
 166                                  " used incorrect WEPSeed[1] (was 0x%x, "
 167                                  "expected 0x%x)",
 168                                  MAC2STR(bss->bssid), data[1],
 169                                  (data[0] | 0x20) & 0x7f);
 170                 }
 171         } else if (bss->group_cipher == WPA_CIPHER_CCMP) {
 172                 if (data[2] != 0 || (data[3] & 0x1f) != 0) {
 173                         add_note(wt, MSG_INFO, "CCMP frame from " MACSTR
 174                                  " used non-zero reserved bit",
 175                                  MAC2STR(bss->bssid));
 176                 }
 177         }
 178
 179         keyid = data[3] >> 6;
 180         if (bss->gtk_len[keyid] == 0 && bss->group_cipher != WPA_CIPHER_WEP40)
 181         {
 182                 add_note(wt, MSG_MSGDUMP, "No GTK known to decrypt the frame "
 183                          "(A2=" MACSTR " KeyID=%d)",
 184                          MAC2STR(hdr->addr2), keyid);
 185                 return;
 186         }
 187
 188         if (bss->group_cipher == WPA_CIPHER_TKIP)
 189                 tkip_get_pn(pn, data);
 190         else if (bss->group_cipher == WPA_CIPHER_WEP40)
 191                 goto skip_replay_det;
 192         else
 193                 ccmp_get_pn(pn, data);
 194         if (os_memcmp(pn, bss->rsc[keyid], 6) <= 0) {
 195                 u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
 196                 add_note(wt, MSG_INFO, "CCMP/TKIP replay detected: A1=" MACSTR
 197                          " A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u",
 198                          MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
 199                          MAC2STR(hdr->addr3),
 200                          WLAN_GET_SEQ_SEQ(seq_ctrl),
 201                          WLAN_GET_SEQ_FRAG(seq_ctrl));
 202                 wpa_hexdump(MSG_INFO, "RX PN", pn, 6);
 203                 wpa_hexdump(MSG_INFO, "RSC", bss->rsc[keyid], 6);
 204         }
 205
 206 skip_replay_det:
 207         if (bss->group_cipher == WPA_CIPHER_TKIP)
 208                 decrypted = tkip_decrypt(bss->gtk[keyid], hdr, data, len,
 209                                          &dlen);
 210         else if (bss->group_cipher == WPA_CIPHER_WEP40)
 211                 decrypted = wep_decrypt(wt, hdr, data, len, &dlen);
 212         else
 213                 decrypted = ccmp_decrypt(bss->gtk[keyid], hdr, data, len,
 214                                          &dlen);
 215         if (decrypted) {
 216                 rx_data_process(wt, bss->bssid, NULL, dst, src, decrypted,
 217                                 dlen, 1, NULL);
 218                 os_memcpy(bss->rsc[keyid], pn, 6);
 219                 write_pcap_decrypted(wt, (const u8 *) hdr, 24 + (qos ? 2 : 0),
 220                                      decrypted, dlen);
 221         } else
 222                 add_note(wt, MSG_DEBUG, "Failed to decrypt frame");
 223         os_free(decrypted);
 224 }
 225
 226
 227 static void rx_data_bss_prot(struct wlantest *wt,
 228                              const struct ieee80211_hdr *hdr, const u8 *qos,
 229                              const u8 *dst, const u8 *src, const u8 *data,
 230                              size_t len)
 231 {
 232         struct wlantest_bss *bss;
 233         struct wlantest_sta *sta, *sta2;
 234         int keyid;
 235         u16 fc = le_to_host16(hdr->frame_control);
 236         u8 *decrypted;
 237         size_t dlen;
 238         int tid;
 239         u8 pn[6], *rsc;
 240         struct wlantest_tdls *tdls = NULL, *found;
 241         const u8 *tk = NULL;
 242         int ptk_iter_done = 0;
 243         int try_ptk_iter = 0;
 244
 245         if (hdr->addr1[0] & 0x01) {
 246                 rx_data_bss_prot_group(wt, hdr, qos, dst, src, data, len);
 247                 return;
 248         }
 249
 250         if (fc & WLAN_FC_TODS) {
 251                 bss = bss_get(wt, hdr->addr1);
 252                 if (bss == NULL)
 253                         return;
 254                 sta = sta_get(bss, hdr->addr2);
 255                 if (sta)
 256                         sta->counters[WLANTEST_STA_COUNTER_PROT_DATA_TX]++;
 257         } else if (fc & WLAN_FC_FROMDS) {
 258                 bss = bss_get(wt, hdr->addr2);
 259                 if (bss == NULL)
 260                         return;
 261                 sta = sta_get(bss, hdr->addr1);
 262         } else {
 263                 bss = bss_get(wt, hdr->addr3);
 264                 if (bss == NULL)
 265                         return;
 266                 sta = sta_find(bss, hdr->addr2);
 267                 sta2 = sta_find(bss, hdr->addr1);
 268                 if (sta == NULL || sta2 == NULL)
 269                         return;
 270                 found = NULL;
 271                 dl_list_for_each(tdls, &bss->tdls, struct wlantest_tdls, list)
 272                 {
 273                         if ((tdls->init == sta && tdls->resp == sta2) ||
 274                             (tdls->init == sta2 && tdls->resp == sta)) {
 275                                 found = tdls;
 276                                 if (tdls->link_up)
 277                                         break;
 278                         }
 279                 }
 280                 if (found) {
 281                         if (!found->link_up)
 282                                 add_note(wt, MSG_DEBUG,
 283                                          "TDLS: Link not up, but Data "
 284                                          "frame seen");
 285                         tk = found->tpk.tk;
 286                         tdls = found;
 287                 }
 288         }
 289         if ((sta == NULL ||
 290              (!sta->ptk_set && sta->pairwise_cipher != WPA_CIPHER_WEP40)) &&
 291             tk == NULL) {
 292                 add_note(wt, MSG_MSGDUMP, "No PTK known to decrypt the frame");
 293                 if (dl_list_empty(&wt->ptk))
 294                         return;
 295                 try_ptk_iter = 1;
 296         }
 297
 298         if (len < 4) {
 299                 add_note(wt, MSG_INFO, "Too short encrypted data frame");
 300                 return;
 301         }
 302
 303         if (sta == NULL)
 304                 return;
 305         if (sta->pairwise_cipher & (WPA_CIPHER_TKIP | WPA_CIPHER_CCMP) &&
 306             !(data[3] & 0x20)) {
 307                 add_note(wt, MSG_INFO, "Expected TKIP/CCMP frame from "
 308                          MACSTR " did not have ExtIV bit set to 1",
 309                          MAC2STR(src));
 310                 return;
 311         }
 312
 313         if (tk == NULL && sta->pairwise_cipher == WPA_CIPHER_TKIP) {
 314                 if (data[3] & 0x1f) {
 315                         add_note(wt, MSG_INFO, "TKIP frame from " MACSTR
 316                                  " used non-zero reserved bit",
 317                                  MAC2STR(hdr->addr2));
 318                 }
 319                 if (data[1] != ((data[0] | 0x20) & 0x7f)) {
 320                         add_note(wt, MSG_INFO, "TKIP frame from " MACSTR
 321                                  " used incorrect WEPSeed[1] (was 0x%x, "
 322                                  "expected 0x%x)",
 323                                  MAC2STR(hdr->addr2), data[1],
 324                                  (data[0] | 0x20) & 0x7f);
 325                 }
 326         } else if (tk || sta->pairwise_cipher == WPA_CIPHER_CCMP) {
 327                 if (data[2] != 0 || (data[3] & 0x1f) != 0) {
 328                         add_note(wt, MSG_INFO, "CCMP frame from " MACSTR
 329                                  " used non-zero reserved bit",
 330                                  MAC2STR(hdr->addr2));
 331                 }
 332         }
 333
 334         keyid = data[3] >> 6;
 335         if (keyid != 0) {
 336                 add_note(wt, MSG_INFO, "Unexpected non-zero KeyID %d in "
 337                          "individually addressed Data frame from " MACSTR,
 338                          keyid, MAC2STR(hdr->addr2));
 339         }
 340
 341         if (qos) {
 342                 tid = qos[0] & 0x0f;
 343                 if (fc & WLAN_FC_TODS)
 344                         sta->tx_tid[tid]++;
 345                 else
 346                         sta->rx_tid[tid]++;
 347         } else {
 348                 tid = 0;
 349                 if (fc & WLAN_FC_TODS)
 350                         sta->tx_tid[16]++;
 351                 else
 352                         sta->rx_tid[16]++;
 353         }
 354         if (tk) {
 355                 if (os_memcmp(hdr->addr2, tdls->init->addr, ETH_ALEN) == 0)
 356                         rsc = tdls->rsc_init[tid];
 357                 else
 358                         rsc = tdls->rsc_resp[tid];
 359         } else if (fc & WLAN_FC_TODS)
 360                 rsc = sta->rsc_tods[tid];
 361         else
 362                 rsc = sta->rsc_fromds[tid];
 363
 364
 365         if (tk == NULL && sta->pairwise_cipher == WPA_CIPHER_TKIP)
 366                 tkip_get_pn(pn, data);
 367         else if (sta->pairwise_cipher == WPA_CIPHER_WEP40)
 368                 goto skip_replay_det;
 369         else
 370                 ccmp_get_pn(pn, data);
 371         if (os_memcmp(pn, rsc, 6) <= 0) {
 372                 u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
 373                 add_note(wt, MSG_INFO, "CCMP/TKIP replay detected: A1=" MACSTR
 374                          " A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u",
 375                          MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
 376                          MAC2STR(hdr->addr3),
 377                          WLAN_GET_SEQ_SEQ(seq_ctrl),
 378                          WLAN_GET_SEQ_FRAG(seq_ctrl));
 379                 wpa_hexdump(MSG_INFO, "RX PN", pn, 6);
 380                 wpa_hexdump(MSG_INFO, "RSC", rsc, 6);
 381         }
 382
 383 skip_replay_det:
 384         if (tk)
 385                 decrypted = ccmp_decrypt(tk, hdr, data, len, &dlen);
 386         else if (sta->pairwise_cipher == WPA_CIPHER_TKIP)
 387                 decrypted = tkip_decrypt(sta->ptk.tk1, hdr, data, len, &dlen);
 388         else if (sta->pairwise_cipher == WPA_CIPHER_WEP40)
 389                 decrypted = wep_decrypt(wt, hdr, data, len, &dlen);
 390         else if (sta->ptk_set)
 391                 decrypted = ccmp_decrypt(sta->ptk.tk1, hdr, data, len, &dlen);
 392         else {
 393                 decrypted = try_all_ptk(wt, sta->pairwise_cipher, hdr, data,
 394                                         len, &dlen);
 395                 ptk_iter_done = 1;
 396         }
 397         if (!decrypted && !ptk_iter_done) {
 398                 decrypted = try_all_ptk(wt, sta->pairwise_cipher, hdr, data,
 399                                         len, &dlen);
 400                 if (decrypted) {
 401                         add_note(wt, MSG_DEBUG, "Current PTK did not work, but found a match from all known PTKs");
 402                 }
 403         }
 404         if (decrypted) {
 405                 u16 fc = le_to_host16(hdr->frame_control);
 406                 const u8 *peer_addr = NULL;
 407                 if (!(fc & (WLAN_FC_FROMDS | WLAN_FC_TODS)))
 408                         peer_addr = hdr->addr1;
 409                 os_memcpy(rsc, pn, 6);
 410                 rx_data_process(wt, bss->bssid, sta->addr, dst, src, decrypted,
 411                                 dlen, 1, peer_addr);
 412                 write_pcap_decrypted(wt, (const u8 *) hdr, 24 + (qos ? 2 : 0),
 413                                      decrypted, dlen);
 414         } else if (!try_ptk_iter)
 415                 add_note(wt, MSG_DEBUG, "Failed to decrypt frame");
 416         os_free(decrypted);
 417 }
 418
 419
 420 static void rx_data_bss(struct wlantest *wt, const struct ieee80211_hdr *hdr,
 421                         const u8 *qos, const u8 *dst, const u8 *src,
 422                         const u8 *data, size_t len)
 423 {
 424         u16 fc = le_to_host16(hdr->frame_control);
 425         int prot = !!(fc & WLAN_FC_ISWEP);
 426
 427         if (qos) {
 428                 u8 ack = (qos[0] & 0x60) >> 5;
 429                 wpa_printf(MSG_MSGDUMP, "BSS DATA: " MACSTR " -> " MACSTR
 430                            " len=%u%s tid=%u%s%s",
 431                            MAC2STR(src), MAC2STR(dst), (unsigned int) len,
 432                            prot ? " Prot" : "", qos[0] & 0x0f,
 433                            (qos[0] & 0x10) ? " EOSP" : "",
 434                            ack == 0 ? "" :
 435                            (ack == 1 ? " NoAck" :
 436                             (ack == 2 ? " NoExpAck" : " BA")));
 437         } else {
 438                 wpa_printf(MSG_MSGDUMP, "BSS DATA: " MACSTR " -> " MACSTR
 439                            " len=%u%s",
 440                            MAC2STR(src), MAC2STR(dst), (unsigned int) len,
 441                            prot ? " Prot" : "");
 442         }
 443
 444         if (prot)
 445                 rx_data_bss_prot(wt, hdr, qos, dst, src, data, len);
 446         else {
 447                 const u8 *bssid, *sta_addr, *peer_addr;
 448                 struct wlantest_bss *bss;
 449
 450                 if (fc & WLAN_FC_TODS) {
 451                         bssid = hdr->addr1;
 452                         sta_addr = hdr->addr2;
 453                         peer_addr = NULL;
 454                 } else if (fc & WLAN_FC_FROMDS) {
 455                         bssid = hdr->addr2;
 456                         sta_addr = hdr->addr1;
 457                         peer_addr = NULL;
 458                 } else {
 459                         bssid = hdr->addr3;
 460                         sta_addr = hdr->addr2;
 461                         peer_addr = hdr->addr1;
 462                 }
 463
 464                 bss = bss_get(wt, bssid);
 465                 if (bss) {
 466                         struct wlantest_sta *sta = sta_get(bss, sta_addr);
 467
 468                         if (sta) {
 469                                 if (qos) {
 470                                         int tid = qos[0] & 0x0f;
 471                                         if (fc & WLAN_FC_TODS)
 472                                                 sta->tx_tid[tid]++;
 473                                         else
 474                                                 sta->rx_tid[tid]++;
 475                                 } else {
 476                                         if (fc & WLAN_FC_TODS)
 477                                                 sta->tx_tid[16]++;
 478                                         else
 479                                                 sta->rx_tid[16]++;
 480                                 }
 481                         }
 482                 }
 483
 484                 rx_data_process(wt, bssid, sta_addr, dst, src, data, len, 0,
 485                                 peer_addr);
 486         }
 487 }
 488
 489
 490 static struct wlantest_tdls * get_tdls(struct wlantest *wt, const u8 *bssid,
 491                                        const u8 *sta1_addr,
 492                                        const u8 *sta2_addr)
 493 {
 494         struct wlantest_bss *bss;
 495         struct wlantest_sta *sta1, *sta2;
 496         struct wlantest_tdls *tdls, *found = NULL;
 497
 498         bss = bss_find(wt, bssid);
 499         if (bss == NULL)
 500                 return NULL;
 501         sta1 = sta_find(bss, sta1_addr);
 502         if (sta1 == NULL)
 503                 return NULL;
 504         sta2 = sta_find(bss, sta2_addr);
 505         if (sta2 == NULL)
 506                 return NULL;
 507
 508         dl_list_for_each(tdls, &bss->tdls, struct wlantest_tdls, list) {
 509                 if ((tdls->init == sta1 && tdls->resp == sta2) ||
 510                     (tdls->init == sta2 && tdls->resp == sta1)) {
 511                         found = tdls;
 512                         if (tdls->link_up)
 513                                 break;
 514                 }
 515         }
 516
 517         return found;
 518 }
 519
 520
 521 static void add_direct_link(struct wlantest *wt, const u8 *bssid,
 522                             const u8 *sta1_addr, const u8 *sta2_addr)
 523 {
 524         struct wlantest_tdls *tdls;
 525
 526         tdls = get_tdls(wt, bssid, sta1_addr, sta2_addr);
 527         if (tdls == NULL)
 528                 return;
 529
 530         if (tdls->link_up)
 531                 tdls->counters[WLANTEST_TDLS_COUNTER_VALID_DIRECT_LINK]++;
 532         else
 533                 tdls->counters[WLANTEST_TDLS_COUNTER_INVALID_DIRECT_LINK]++;
 534 }
 535
 536
 537 static void add_ap_path(struct wlantest *wt, const u8 *bssid,
 538                         const u8 *sta1_addr, const u8 *sta2_addr)
 539 {
 540         struct wlantest_tdls *tdls;
 541
 542         tdls = get_tdls(wt, bssid, sta1_addr, sta2_addr);
 543         if (tdls == NULL)
 544                 return;
 545
 546         if (tdls->link_up)
 547                 tdls->counters[WLANTEST_TDLS_COUNTER_INVALID_AP_PATH]++;
 548         else
 549                 tdls->counters[WLANTEST_TDLS_COUNTER_VALID_AP_PATH]++;
 550 }
 551
 552
 553 void rx_data(struct wlantest *wt, const u8 *data, size_t len)
 554 {
 555         const struct ieee80211_hdr *hdr;
 556         u16 fc, stype;
 557         size_t hdrlen;
 558         const u8 *qos = NULL;
 559
 560         if (len < 24)
 561                 return;
 562
 563         hdr = (const struct ieee80211_hdr *) data;
 564         fc = le_to_host16(hdr->frame_control);
 565         stype = WLAN_FC_GET_STYPE(fc);
 566         hdrlen = 24;
 567         if ((fc & (WLAN_FC_TODS | WLAN_FC_FROMDS)) ==
 568             (WLAN_FC_TODS | WLAN_FC_FROMDS))
 569                 hdrlen += ETH_ALEN;
 570         if (stype & 0x08) {
 571                 qos = data + hdrlen;
 572                 hdrlen += 2;
 573         }
 574         if (len < hdrlen)
 575                 return;
 576         wt->rx_data++;
 577
 578         switch (fc & (WLAN_FC_TODS | WLAN_FC_FROMDS)) {
 579         case 0:
 580                 wpa_printf(MSG_EXCESSIVE, "DATA %s%s%s IBSS DA=" MACSTR " SA="
 581                            MACSTR " BSSID=" MACSTR,
 582                            data_stype(WLAN_FC_GET_STYPE(fc)),
 583                            fc & WLAN_FC_PWRMGT ? " PwrMgt" : "",
 584                            fc & WLAN_FC_ISWEP ? " Prot" : "",
 585                            MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
 586                            MAC2STR(hdr->addr3));
 587                 add_direct_link(wt, hdr->addr3, hdr->addr1, hdr->addr2);
 588                 rx_data_bss(wt, hdr, qos, hdr->addr1, hdr->addr2,
 589                             data + hdrlen, len - hdrlen);
 590                 break;
 591         case WLAN_FC_FROMDS:
 592                 wpa_printf(MSG_EXCESSIVE, "DATA %s%s%s FromDS DA=" MACSTR
 593                            " BSSID=" MACSTR " SA=" MACSTR,
 594                            data_stype(WLAN_FC_GET_STYPE(fc)),
 595                            fc & WLAN_FC_PWRMGT ? " PwrMgt" : "",
 596                            fc & WLAN_FC_ISWEP ? " Prot" : "",
 597                            MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
 598                            MAC2STR(hdr->addr3));
 599                 add_ap_path(wt, hdr->addr2, hdr->addr1, hdr->addr3);
 600                 rx_data_bss(wt, hdr, qos, hdr->addr1, hdr->addr3,
 601                             data + hdrlen, len - hdrlen);
 602                 break;
 603         case WLAN_FC_TODS:
 604                 wpa_printf(MSG_EXCESSIVE, "DATA %s%s%s ToDS BSSID=" MACSTR
 605                            " SA=" MACSTR " DA=" MACSTR,
 606                            data_stype(WLAN_FC_GET_STYPE(fc)),
 607                            fc & WLAN_FC_PWRMGT ? " PwrMgt" : "",
 608                            fc & WLAN_FC_ISWEP ? " Prot" : "",
 609                            MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
 610                            MAC2STR(hdr->addr3));
 611                 add_ap_path(wt, hdr->addr1, hdr->addr3, hdr->addr2);
 612                 rx_data_bss(wt, hdr, qos, hdr->addr3, hdr->addr2,
 613                             data + hdrlen, len - hdrlen);
 614                 break;
 615         case WLAN_FC_TODS | WLAN_FC_FROMDS:
 616                 wpa_printf(MSG_EXCESSIVE, "DATA %s%s%s WDS RA=" MACSTR " TA="
 617                            MACSTR " DA=" MACSTR " SA=" MACSTR,
 618                            data_stype(WLAN_FC_GET_STYPE(fc)),
 619                            fc & WLAN_FC_PWRMGT ? " PwrMgt" : "",
 620                            fc & WLAN_FC_ISWEP ? " Prot" : "",
 621                            MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
 622                            MAC2STR(hdr->addr3),
 623                            MAC2STR((const u8 *) (hdr + 1)));
 624                 break;
 625         }
 626 }