include/linux/ieee80211.h

   1 /*
   2  * IEEE 802.11 defines
   3  *
   4  * Copyright (c) 2001-2002, SSH Communications Security Corp and Jouni Malinen
   5  * <jkmaline@cc.hut.fi>
   6  * Copyright (c) 2002-2003, Jouni Malinen <jkmaline@cc.hut.fi>
   7  * Copyright (c) 2005, Devicescape Software, Inc.
   8  * Copyright (c) 2006, Michael Wu <flamingice@sourmilk.net>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #ifndef IEEE80211_H
  16 #define IEEE80211_H
  17
  18 #include <linux/types.h>
  19 #include <asm/byteorder.h>
  20
  21 #define FCS_LEN 4
  22
  23 #define IEEE80211_FCTL_VERS             0x0003
  24 #define IEEE80211_FCTL_FTYPE            0x000c
  25 #define IEEE80211_FCTL_STYPE            0x00f0
  26 #define IEEE80211_FCTL_TODS             0x0100
  27 #define IEEE80211_FCTL_FROMDS           0x0200
  28 #define IEEE80211_FCTL_MOREFRAGS        0x0400
  29 #define IEEE80211_FCTL_RETRY            0x0800
  30 #define IEEE80211_FCTL_PM               0x1000
  31 #define IEEE80211_FCTL_MOREDATA         0x2000
  32 #define IEEE80211_FCTL_PROTECTED        0x4000
  33 #define IEEE80211_FCTL_ORDER            0x8000
  34
  35 #define IEEE80211_SCTL_FRAG             0x000F
  36 #define IEEE80211_SCTL_SEQ              0xFFF0
  37
  38 #define IEEE80211_FTYPE_MGMT            0x0000
  39 #define IEEE80211_FTYPE_CTL             0x0004
  40 #define IEEE80211_FTYPE_DATA            0x0008
  41
  42 /* management */
  43 #define IEEE80211_STYPE_ASSOC_REQ       0x0000
  44 #define IEEE80211_STYPE_ASSOC_RESP      0x0010
  45 #define IEEE80211_STYPE_REASSOC_REQ     0x0020
  46 #define IEEE80211_STYPE_REASSOC_RESP    0x0030
  47 #define IEEE80211_STYPE_PROBE_REQ       0x0040
  48 #define IEEE80211_STYPE_PROBE_RESP      0x0050
  49 #define IEEE80211_STYPE_BEACON          0x0080
  50 #define IEEE80211_STYPE_ATIM            0x0090
  51 #define IEEE80211_STYPE_DISASSOC        0x00A0
  52 #define IEEE80211_STYPE_AUTH            0x00B0
  53 #define IEEE80211_STYPE_DEAUTH          0x00C0
  54 #define IEEE80211_STYPE_ACTION          0x00D0
  55
  56 /* control */
  57 #define IEEE80211_STYPE_BACK_REQ        0x0080
  58 #define IEEE80211_STYPE_BACK            0x0090
  59 #define IEEE80211_STYPE_PSPOLL          0x00A0
  60 #define IEEE80211_STYPE_RTS             0x00B0
  61 #define IEEE80211_STYPE_CTS             0x00C0
  62 #define IEEE80211_STYPE_ACK             0x00D0
  63 #define IEEE80211_STYPE_CFEND           0x00E0
  64 #define IEEE80211_STYPE_CFENDACK        0x00F0
  65
  66 /* data */
  67 #define IEEE80211_STYPE_DATA                    0x0000
  68 #define IEEE80211_STYPE_DATA_CFACK              0x0010
  69 #define IEEE80211_STYPE_DATA_CFPOLL             0x0020
  70 #define IEEE80211_STYPE_DATA_CFACKPOLL          0x0030
  71 #define IEEE80211_STYPE_NULLFUNC                0x0040
  72 #define IEEE80211_STYPE_CFACK                   0x0050
  73 #define IEEE80211_STYPE_CFPOLL                  0x0060
  74 #define IEEE80211_STYPE_CFACKPOLL               0x0070
  75 #define IEEE80211_STYPE_QOS_DATA                0x0080
  76 #define IEEE80211_STYPE_QOS_DATA_CFACK          0x0090
  77 #define IEEE80211_STYPE_QOS_DATA_CFPOLL         0x00A0
  78 #define IEEE80211_STYPE_QOS_DATA_CFACKPOLL      0x00B0
  79 #define IEEE80211_STYPE_QOS_NULLFUNC            0x00C0
  80 #define IEEE80211_STYPE_QOS_CFACK               0x00D0
  81 #define IEEE80211_STYPE_QOS_CFPOLL              0x00E0
  82 #define IEEE80211_STYPE_QOS_CFACKPOLL           0x00F0
  83
  84
  85 /* miscellaneous IEEE 802.11 constants */
  86 #define IEEE80211_MAX_FRAG_THRESHOLD    2352
  87 #define IEEE80211_MAX_RTS_THRESHOLD     2353
  88 #define IEEE80211_MAX_AID               2007
  89 #define IEEE80211_MAX_TIM_LEN           251
  90 /* Maximum size for the MA-UNITDATA primitive, 802.11 standard section
  91    6.2.1.1.2.
  92
  93    802.11e clarifies the figure in section 7.1.2. The frame body is
  94    up to 2304 octets long (maximum MSDU size) plus any crypt overhead. */
  95 #define IEEE80211_MAX_DATA_LEN          2304
  96 /* 30 byte 4 addr hdr, 2 byte QoS, 2304 byte MSDU, 12 byte crypt, 4 byte FCS */
  97 #define IEEE80211_MAX_FRAME_LEN         2352
  98
  99 #define IEEE80211_MAX_SSID_LEN          32
 100
 101 struct ieee80211_hdr {
 102         __le16 frame_control;
 103         __le16 duration_id;
 104         u8 addr1[6];
 105         u8 addr2[6];
 106         u8 addr3[6];
 107         __le16 seq_ctrl;
 108         u8 addr4[6];
 109 } __attribute__ ((packed));
 110
 111
 112 struct ieee80211_mgmt {
 113         __le16 frame_control;
 114         __le16 duration;
 115         u8 da[6];
 116         u8 sa[6];
 117         u8 bssid[6];
 118         __le16 seq_ctrl;
 119         union {
 120                 struct {
 121                         __le16 auth_alg;
 122                         __le16 auth_transaction;
 123                         __le16 status_code;
 124                         /* possibly followed by Challenge text */
 125                         u8 variable[0];
 126                 } __attribute__ ((packed)) auth;
 127                 struct {
 128                         __le16 reason_code;
 129                 } __attribute__ ((packed)) deauth;
 130                 struct {
 131                         __le16 capab_info;
 132                         __le16 listen_interval;
 133                         /* followed by SSID and Supported rates */
 134                         u8 variable[0];
 135                 } __attribute__ ((packed)) assoc_req;
 136                 struct {
 137                         __le16 capab_info;
 138                         __le16 status_code;
 139                         __le16 aid;
 140                         /* followed by Supported rates */
 141                         u8 variable[0];
 142                 } __attribute__ ((packed)) assoc_resp, reassoc_resp;
 143                 struct {
 144                         __le16 capab_info;
 145                         __le16 listen_interval;
 146                         u8 current_ap[6];
 147                         /* followed by SSID and Supported rates */
 148                         u8 variable[0];
 149                 } __attribute__ ((packed)) reassoc_req;
 150                 struct {
 151                         __le16 reason_code;
 152                 } __attribute__ ((packed)) disassoc;
 153                 struct {
 154                         __le64 timestamp;
 155                         __le16 beacon_int;
 156                         __le16 capab_info;
 157                         /* followed by some of SSID, Supported rates,
 158                          * FH Params, DS Params, CF Params, IBSS Params, TIM */
 159                         u8 variable[0];
 160                 } __attribute__ ((packed)) beacon;
 161                 struct {
 162                         /* only variable items: SSID, Supported rates */
 163                         u8 variable[0];
 164                 } __attribute__ ((packed)) probe_req;
 165                 struct {
 166                         __le64 timestamp;
 167                         __le16 beacon_int;
 168                         __le16 capab_info;
 169                         /* followed by some of SSID, Supported rates,
 170                          * FH Params, DS Params, CF Params, IBSS Params */
 171                         u8 variable[0];
 172                 } __attribute__ ((packed)) probe_resp;
 173                 struct {
 174                         u8 category;
 175                         union {
 176                                 struct {
 177                                         u8 action_code;
 178                                         u8 dialog_token;
 179                                         u8 status_code;
 180                                         u8 variable[0];
 181                                 } __attribute__ ((packed)) wme_action;
 182                                 struct{
 183                                         u8 action_code;
 184                                         u8 element_id;
 185                                         u8 length;
 186                                         u8 switch_mode;
 187                                         u8 new_chan;
 188                                         u8 switch_count;
 189                                 } __attribute__((packed)) chan_switch;
 190                                 struct{
 191                                         u8 action_code;
 192                                         u8 dialog_token;
 193                                         __le16 capab;
 194                                         __le16 timeout;
 195                                         __le16 start_seq_num;
 196                                 } __attribute__((packed)) addba_req;
 197                                 struct{
 198                                         u8 action_code;
 199                                         u8 dialog_token;
 200                                         __le16 status;
 201                                         __le16 capab;
 202                                         __le16 timeout;
 203                                 } __attribute__((packed)) addba_resp;
 204                                 struct{
 205                                         u8 action_code;
 206                                         __le16 params;
 207                                         __le16 reason_code;
 208                                 } __attribute__((packed)) delba;
 209                         } u;
 210                 } __attribute__ ((packed)) action;
 211         } u;
 212 } __attribute__ ((packed));
 213
 214
 215 /* Control frames */
 216 struct ieee80211_rts {
 217         __le16 frame_control;
 218         __le16 duration;
 219         u8 ra[6];
 220         u8 ta[6];
 221 } __attribute__ ((packed));
 222
 223 struct ieee80211_cts {
 224         __le16 frame_control;
 225         __le16 duration;
 226         u8 ra[6];
 227 } __attribute__ ((packed));
 228
 229 /**
 230  * struct ieee80211_bar - HT Block Ack Request
 231  *
 232  * This structure refers to "HT BlockAckReq" as
 233  * described in 802.11n draft section 7.2.1.7.1
 234  */
 235 struct ieee80211_bar {
 236         __le16 frame_control;
 237         __le16 duration;
 238         __u8 ra[6];
 239         __u8 ta[6];
 240         __u16 control;
 241         __u16 start_seq_num;
 242 } __attribute__((packed));
 243
 244 /**
 245  * struct ieee80211_ht_cap - HT capabilities
 246  *
 247  * This structure refers to "HT capabilities element" as
 248  * described in 802.11n draft section 7.3.2.52
 249  */
 250 struct ieee80211_ht_cap {
 251         __le16 cap_info;
 252         u8 ampdu_params_info;
 253         u8 supp_mcs_set[16];
 254         __le16 extended_ht_cap_info;
 255         __le32 tx_BF_cap_info;
 256         u8 antenna_selection_info;
 257 } __attribute__ ((packed));
 258
 259 /**
 260  * struct ieee80211_ht_cap - HT additional information
 261  *
 262  * This structure refers to "HT information element" as
 263  * described in 802.11n draft section 7.3.2.53
 264  */
 265 struct ieee80211_ht_addt_info {
 266         u8 control_chan;
 267         u8 ht_param;
 268         __le16 operation_mode;
 269         __le16 stbc_param;
 270         u8 basic_set[16];
 271 } __attribute__ ((packed));
 272
 273 /* 802.11n HT capabilities masks */
 274 #define IEEE80211_HT_CAP_SUP_WIDTH              0x0002
 275 #define IEEE80211_HT_CAP_MIMO_PS                0x000C
 276 #define IEEE80211_HT_CAP_GRN_FLD                0x0010
 277 #define IEEE80211_HT_CAP_SGI_20                 0x0020
 278 #define IEEE80211_HT_CAP_SGI_40                 0x0040
 279 #define IEEE80211_HT_CAP_DELAY_BA               0x0400
 280 #define IEEE80211_HT_CAP_MAX_AMSDU              0x0800
 281 #define IEEE80211_HT_CAP_AMPDU_FACTOR           0x03
 282 #define IEEE80211_HT_CAP_AMPDU_DENSITY          0x1C
 283 /* 802.11n HT IE masks */
 284 #define IEEE80211_HT_IE_CHA_SEC_OFFSET          0x03
 285 #define IEEE80211_HT_IE_CHA_WIDTH               0x04
 286 #define IEEE80211_HT_IE_HT_PROTECTION           0x0003
 287 #define IEEE80211_HT_IE_NON_GF_STA_PRSNT        0x0004
 288 #define IEEE80211_HT_IE_NON_HT_STA_PRSNT        0x0010
 289
 290 /* Authentication algorithms */
 291 #define WLAN_AUTH_OPEN 0
 292 #define WLAN_AUTH_SHARED_KEY 1
 293 #define WLAN_AUTH_FAST_BSS_TRANSITION 2
 294 #define WLAN_AUTH_LEAP 128
 295
 296 #define WLAN_AUTH_CHALLENGE_LEN 128
 297
 298 #define WLAN_CAPABILITY_ESS             (1<<0)
 299 #define WLAN_CAPABILITY_IBSS            (1<<1)
 300 #define WLAN_CAPABILITY_CF_POLLABLE     (1<<2)
 301 #define WLAN_CAPABILITY_CF_POLL_REQUEST (1<<3)
 302 #define WLAN_CAPABILITY_PRIVACY         (1<<4)
 303 #define WLAN_CAPABILITY_SHORT_PREAMBLE  (1<<5)
 304 #define WLAN_CAPABILITY_PBCC            (1<<6)
 305 #define WLAN_CAPABILITY_CHANNEL_AGILITY (1<<7)
 306 /* 802.11h */
 307 #define WLAN_CAPABILITY_SPECTRUM_MGMT   (1<<8)
 308 #define WLAN_CAPABILITY_QOS             (1<<9)
 309 #define WLAN_CAPABILITY_SHORT_SLOT_TIME (1<<10)
 310 #define WLAN_CAPABILITY_DSSS_OFDM       (1<<13)
 311
 312 /* 802.11g ERP information element */
 313 #define WLAN_ERP_NON_ERP_PRESENT (1<<0)
 314 #define WLAN_ERP_USE_PROTECTION (1<<1)
 315 #define WLAN_ERP_BARKER_PREAMBLE (1<<2)
 316
 317 /* WLAN_ERP_BARKER_PREAMBLE values */
 318 enum {
 319         WLAN_ERP_PREAMBLE_SHORT = 0,
 320         WLAN_ERP_PREAMBLE_LONG = 1,
 321 };
 322
 323 /* Status codes */
 324 enum ieee80211_statuscode {
 325         WLAN_STATUS_SUCCESS = 0,
 326         WLAN_STATUS_UNSPECIFIED_FAILURE = 1,
 327         WLAN_STATUS_CAPS_UNSUPPORTED = 10,
 328         WLAN_STATUS_REASSOC_NO_ASSOC = 11,
 329         WLAN_STATUS_ASSOC_DENIED_UNSPEC = 12,
 330         WLAN_STATUS_NOT_SUPPORTED_AUTH_ALG = 13,
 331         WLAN_STATUS_UNKNOWN_AUTH_TRANSACTION = 14,
 332         WLAN_STATUS_CHALLENGE_FAIL = 15,
 333         WLAN_STATUS_AUTH_TIMEOUT = 16,
 334         WLAN_STATUS_AP_UNABLE_TO_HANDLE_NEW_STA = 17,
 335         WLAN_STATUS_ASSOC_DENIED_RATES = 18,
 336         /* 802.11b */
 337         WLAN_STATUS_ASSOC_DENIED_NOSHORTPREAMBLE = 19,
 338         WLAN_STATUS_ASSOC_DENIED_NOPBCC = 20,
 339         WLAN_STATUS_ASSOC_DENIED_NOAGILITY = 21,
 340         /* 802.11h */
 341         WLAN_STATUS_ASSOC_DENIED_NOSPECTRUM = 22,
 342         WLAN_STATUS_ASSOC_REJECTED_BAD_POWER = 23,
 343         WLAN_STATUS_ASSOC_REJECTED_BAD_SUPP_CHAN = 24,
 344         /* 802.11g */
 345         WLAN_STATUS_ASSOC_DENIED_NOSHORTTIME = 25,
 346         WLAN_STATUS_ASSOC_DENIED_NODSSSOFDM = 26,
 347         /* 802.11i */
 348         WLAN_STATUS_INVALID_IE = 40,
 349         WLAN_STATUS_INVALID_GROUP_CIPHER = 41,
 350         WLAN_STATUS_INVALID_PAIRWISE_CIPHER = 42,
 351         WLAN_STATUS_INVALID_AKMP = 43,
 352         WLAN_STATUS_UNSUPP_RSN_VERSION = 44,
 353         WLAN_STATUS_INVALID_RSN_IE_CAP = 45,
 354         WLAN_STATUS_CIPHER_SUITE_REJECTED = 46,
 355         /* 802.11e */
 356         WLAN_STATUS_UNSPECIFIED_QOS = 32,
 357         WLAN_STATUS_ASSOC_DENIED_NOBANDWIDTH = 33,
 358         WLAN_STATUS_ASSOC_DENIED_LOWACK = 34,
 359         WLAN_STATUS_ASSOC_DENIED_UNSUPP_QOS = 35,
 360         WLAN_STATUS_REQUEST_DECLINED = 37,
 361         WLAN_STATUS_INVALID_QOS_PARAM = 38,
 362         WLAN_STATUS_CHANGE_TSPEC = 39,
 363         WLAN_STATUS_WAIT_TS_DELAY = 47,
 364         WLAN_STATUS_NO_DIRECT_LINK = 48,
 365         WLAN_STATUS_STA_NOT_PRESENT = 49,
 366         WLAN_STATUS_STA_NOT_QSTA = 50,
 367 };
 368
 369
 370 /* Reason codes */
 371 enum ieee80211_reasoncode {
 372         WLAN_REASON_UNSPECIFIED = 1,
 373         WLAN_REASON_PREV_AUTH_NOT_VALID = 2,
 374         WLAN_REASON_DEAUTH_LEAVING = 3,
 375         WLAN_REASON_DISASSOC_DUE_TO_INACTIVITY = 4,
 376         WLAN_REASON_DISASSOC_AP_BUSY = 5,
 377         WLAN_REASON_CLASS2_FRAME_FROM_NONAUTH_STA = 6,
 378         WLAN_REASON_CLASS3_FRAME_FROM_NONASSOC_STA = 7,
 379         WLAN_REASON_DISASSOC_STA_HAS_LEFT = 8,
 380         WLAN_REASON_STA_REQ_ASSOC_WITHOUT_AUTH = 9,
 381         /* 802.11h */
 382         WLAN_REASON_DISASSOC_BAD_POWER = 10,
 383         WLAN_REASON_DISASSOC_BAD_SUPP_CHAN = 11,
 384         /* 802.11i */
 385         WLAN_REASON_INVALID_IE = 13,
 386         WLAN_REASON_MIC_FAILURE = 14,
 387         WLAN_REASON_4WAY_HANDSHAKE_TIMEOUT = 15,
 388         WLAN_REASON_GROUP_KEY_HANDSHAKE_TIMEOUT = 16,
 389         WLAN_REASON_IE_DIFFERENT = 17,
 390         WLAN_REASON_INVALID_GROUP_CIPHER = 18,
 391         WLAN_REASON_INVALID_PAIRWISE_CIPHER = 19,
 392         WLAN_REASON_INVALID_AKMP = 20,
 393         WLAN_REASON_UNSUPP_RSN_VERSION = 21,
 394         WLAN_REASON_INVALID_RSN_IE_CAP = 22,
 395         WLAN_REASON_IEEE8021X_FAILED = 23,
 396         WLAN_REASON_CIPHER_SUITE_REJECTED = 24,
 397         /* 802.11e */
 398         WLAN_REASON_DISASSOC_UNSPECIFIED_QOS = 32,
 399         WLAN_REASON_DISASSOC_QAP_NO_BANDWIDTH = 33,
 400         WLAN_REASON_DISASSOC_LOW_ACK = 34,
 401         WLAN_REASON_DISASSOC_QAP_EXCEED_TXOP = 35,
 402         WLAN_REASON_QSTA_LEAVE_QBSS = 36,
 403         WLAN_REASON_QSTA_NOT_USE = 37,
 404         WLAN_REASON_QSTA_REQUIRE_SETUP = 38,
 405         WLAN_REASON_QSTA_TIMEOUT = 39,
 406         WLAN_REASON_QSTA_CIPHER_NOT_SUPP = 45,
 407 };
 408
 409
 410 /* Information Element IDs */
 411 enum ieee80211_eid {
 412         WLAN_EID_SSID = 0,
 413         WLAN_EID_SUPP_RATES = 1,
 414         WLAN_EID_FH_PARAMS = 2,
 415         WLAN_EID_DS_PARAMS = 3,
 416         WLAN_EID_CF_PARAMS = 4,
 417         WLAN_EID_TIM = 5,
 418         WLAN_EID_IBSS_PARAMS = 6,
 419         WLAN_EID_CHALLENGE = 16,
 420         /* 802.11d */
 421         WLAN_EID_COUNTRY = 7,
 422         WLAN_EID_HP_PARAMS = 8,
 423         WLAN_EID_HP_TABLE = 9,
 424         WLAN_EID_REQUEST = 10,
 425         /* 802.11e */
 426         WLAN_EID_QBSS_LOAD = 11,
 427         WLAN_EID_EDCA_PARAM_SET = 12,
 428         WLAN_EID_TSPEC = 13,
 429         WLAN_EID_TCLAS = 14,
 430         WLAN_EID_SCHEDULE = 15,
 431         WLAN_EID_TS_DELAY = 43,
 432         WLAN_EID_TCLAS_PROCESSING = 44,
 433         WLAN_EID_QOS_CAPA = 46,
 434         /* 802.11h */
 435         WLAN_EID_PWR_CONSTRAINT = 32,
 436         WLAN_EID_PWR_CAPABILITY = 33,
 437         WLAN_EID_TPC_REQUEST = 34,
 438         WLAN_EID_TPC_REPORT = 35,
 439         WLAN_EID_SUPPORTED_CHANNELS = 36,
 440         WLAN_EID_CHANNEL_SWITCH = 37,
 441         WLAN_EID_MEASURE_REQUEST = 38,
 442         WLAN_EID_MEASURE_REPORT = 39,
 443         WLAN_EID_QUIET = 40,
 444         WLAN_EID_IBSS_DFS = 41,
 445         /* 802.11g */
 446         WLAN_EID_ERP_INFO = 42,
 447         WLAN_EID_EXT_SUPP_RATES = 50,
 448         /* 802.11n */
 449         WLAN_EID_HT_CAPABILITY = 45,
 450         WLAN_EID_HT_EXTRA_INFO = 61,
 451         /* 802.11i */
 452         WLAN_EID_RSN = 48,
 453         WLAN_EID_WPA = 221,
 454         WLAN_EID_GENERIC = 221,
 455         WLAN_EID_VENDOR_SPECIFIC = 221,
 456         WLAN_EID_QOS_PARAMETER = 222
 457 };
 458
 459 /* Action category code */
 460 enum ieee80211_category {
 461         WLAN_CATEGORY_SPECTRUM_MGMT = 0,
 462         WLAN_CATEGORY_QOS = 1,
 463         WLAN_CATEGORY_DLS = 2,
 464         WLAN_CATEGORY_BACK = 3,
 465         WLAN_CATEGORY_WMM = 17,
 466 };
 467
 468 /* BACK action code */
 469 enum ieee80211_back_actioncode {
 470         WLAN_ACTION_ADDBA_REQ = 0,
 471         WLAN_ACTION_ADDBA_RESP = 1,
 472         WLAN_ACTION_DELBA = 2,
 473 };
 474
 475 /* A-MSDU 802.11n */
 476 #define IEEE80211_QOS_CONTROL_A_MSDU_PRESENT 0x0080
 477
 478 /* cipher suite selectors */
 479 #define WLAN_CIPHER_SUITE_USE_GROUP     0x000FAC00
 480 #define WLAN_CIPHER_SUITE_WEP40         0x000FAC01
 481 #define WLAN_CIPHER_SUITE_TKIP          0x000FAC02
 482 /* reserved:                            0x000FAC03 */
 483 #define WLAN_CIPHER_SUITE_CCMP          0x000FAC04
 484 #define WLAN_CIPHER_SUITE_WEP104        0x000FAC05
 485
 486 #define WLAN_MAX_KEY_LEN                32
 487
 488 /**
 489  * ieee80211_get_SA - get pointer to SA
 490  *
 491  * Given an 802.11 frame, this function returns the offset
 492  * to the source address (SA). It does not verify that the
 493  * header is long enough to contain the address, and the
 494  * header must be long enough to contain the frame control
 495  * field.
 496  *
 497  * @hdr: the frame
 498  */
 499 static inline u8 *ieee80211_get_SA(struct ieee80211_hdr *hdr)
 500 {
 501         u8 *raw = (u8 *) hdr;
 502         u8 tofrom = (*(raw+1)) & 3; /* get the TODS and FROMDS bits */
 503
 504         switch (tofrom) {
 505                 case 2:
 506                         return hdr->addr3;
 507                 case 3:
 508                         return hdr->addr4;
 509         }
 510         return hdr->addr2;
 511 }
 512
 513 /**
 514  * ieee80211_get_DA - get pointer to DA
 515  *
 516  * Given an 802.11 frame, this function returns the offset
 517  * to the destination address (DA). It does not verify that
 518  * the header is long enough to contain the address, and the
 519  * header must be long enough to contain the frame control
 520  * field.
 521  *
 522  * @hdr: the frame
 523  */
 524 static inline u8 *ieee80211_get_DA(struct ieee80211_hdr *hdr)
 525 {
 526         u8 *raw = (u8 *) hdr;
 527         u8 to_ds = (*(raw+1)) & 1; /* get the TODS bit */
 528
 529         if (to_ds)
 530                 return hdr->addr3;
 531         return hdr->addr1;
 532 }
 533
 534 /**
 535  * ieee80211_get_morefrag - determine whether the MOREFRAGS bit is set
 536  *
 537  * This function determines whether the "more fragments" bit is set
 538  * in the frame.
 539  *
 540  * @hdr: the frame
 541  */
 542 static inline int ieee80211_get_morefrag(struct ieee80211_hdr *hdr)
 543 {
 544         return (le16_to_cpu(hdr->frame_control) &
 545                 IEEE80211_FCTL_MOREFRAGS) != 0;
 546 }
 547
 548 #endif /* IEEE80211_H */