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      1 /* $FreeBSD: src/sys/net80211/ieee80211_radiotap.h,v 1.11 2007/12/13 01:23:40 sam Exp $ */
      2 /* $NetBSD: ieee80211_radiotap.h,v 1.25 2019/10/05 23:27:20 mrg Exp $ */
      3 
      4 /*-
      5  * Copyright (c) 2003, 2004 David Young.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY DAVID YOUNG ``AS IS'' AND ANY
     17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
     18  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
     19  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL DAVID
     20  * YOUNG BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     21  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
     22  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
     27  * OF SUCH DAMAGE.
     28  */
     29 #ifndef _NET80211_IEEE80211_RADIOTAP_H_
     30 #define _NET80211_IEEE80211_RADIOTAP_H_
     31 
     32 /* A generic radio capture format is desirable. It must be
     33  * rigidly defined (e.g., units for fields should be given),
     34  * and easily extensible.
     35  *
     36  * The following is an extensible radio capture format. It is
     37  * based on a bitmap indicating which fields are present.
     38  *
     39  * I am trying to describe precisely what the application programmer
     40  * should expect in the following, and for that reason I tell the
     41  * units and origin of each measurement (where it applies), or else I
     42  * use sufficiently weaselly language ("is a monotonically nondecreasing
     43  * function of...") that I cannot set false expectations for lawyerly
     44  * readers.
     45  */
     46 #if defined(__KERNEL__) || defined(_KERNEL)
     47 #ifndef DLT_IEEE802_11_RADIO
     48 #define	DLT_IEEE802_11_RADIO	127	/* 802.11 plus WLAN header */
     49 #endif
     50 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
     51 
     52 /* XXX tcpdump/libpcap do not tolerate variable-length headers,
     53  * yet, so we pad every radiotap header to 64 bytes. Ugh.
     54  */
     55 #define IEEE80211_RADIOTAP_HDRLEN	64
     56 
     57 /*
     58  * The radio capture header precedes the 802.11 header.
     59  *
     60  * Note well: all radiotap fields are little-endian.
     61  */
     62 struct ieee80211_radiotap_header {
     63 	uint8_t	it_version;		/* Version 0. Only increases
     64 					 * for drastic changes,
     65 					 * introduction of compatible
     66 					 * new fields does not count.
     67 					 */
     68 	uint8_t	it_pad;
     69 	uint16_t       it_len;		/* length of the whole
     70 					 * header in bytes, including
     71 					 * it_version, it_pad,
     72 					 * it_len, and data fields.
     73 					 */
     74 	uint32_t       it_present;	/* A bitmap telling which
     75 					 * fields are present. Set bit 31
     76 					 * (0x80000000) to extend the
     77 					 * bitmap by another 32 bits.
     78 					 * Additional extensions are made
     79 					 * by setting bit 31.
     80 					 */
     81 } __aligned(8);
     82 
     83 /*
     84  * Name                                 Data type       Units
     85  * ----                                 ---------       -----
     86  *
     87  * IEEE80211_RADIOTAP_TSFT              uint64_t        microseconds
     88  *
     89  *      Value in microseconds of the MAC's 64-bit 802.11 Time
     90  *      Synchronization Function timer when the first bit of the
     91  *      MPDU arrived at the MAC. For received frames, only.
     92  *
     93  * IEEE80211_RADIOTAP_CHANNEL           2 x uint16_t    MHz, bitmap
     94  *
     95  *      Tx/Rx frequency in MHz, followed by flags (see below).
     96  *
     97  * IEEE80211_RADIOTAP_FHSS              uint16_t        see below
     98  *
     99  *      For frequency-hopping radios, the hop set (first byte)
    100  *      and pattern (second byte).
    101  *
    102  * IEEE80211_RADIOTAP_RATE              uint8_t         500kb/s
    103  *
    104  *      Tx/Rx data rate
    105  *
    106  * IEEE80211_RADIOTAP_DBM_ANTSIGNAL     int8_t          decibels from
    107  *                                                      one milliwatt (dBm)
    108  *
    109  *      RF signal power at the antenna, decibel difference from
    110  *      one milliwatt.
    111  *
    112  * IEEE80211_RADIOTAP_DBM_ANTNOISE      int8_t          decibels from
    113  *                                                      one milliwatt (dBm)
    114  *
    115  *      RF noise power at the antenna, decibel difference from one
    116  *      milliwatt.
    117  *
    118  * IEEE80211_RADIOTAP_DB_ANTSIGNAL      uint8_t         decibel (dB)
    119  *
    120  *      RF signal power at the antenna, decibel difference from an
    121  *      arbitrary, fixed reference.
    122  *
    123  * IEEE80211_RADIOTAP_DB_ANTNOISE       uint8_t         decibel (dB)
    124  *
    125  *      RF noise power at the antenna, decibel difference from an
    126  *      arbitrary, fixed reference point.
    127  *
    128  * IEEE80211_RADIOTAP_LOCK_QUALITY      uint16_t        unitless
    129  *
    130  *      Quality of Barker code lock. Unitless. Monotonically
    131  *      nondecreasing with "better" lock strength. Called "Signal
    132  *      Quality" in datasheets.  (Is there a standard way to measure
    133  *      this?)
    134  *
    135  * IEEE80211_RADIOTAP_TX_ATTENUATION    uint16_t        unitless
    136  *
    137  *      Transmit power expressed as unitless distance from max
    138  *      power set at factory calibration.  0 is max power.
    139  *      Monotonically nondecreasing with lower power levels.
    140  *
    141  * IEEE80211_RADIOTAP_DB_TX_ATTENUATION uint16_t        decibels (dB)
    142  *
    143  *      Transmit power expressed as decibel distance from max power
    144  *      set at factory calibration.  0 is max power.  Monotonically
    145  *      nondecreasing with lower power levels.
    146  *
    147  * IEEE80211_RADIOTAP_DBM_TX_POWER      int8_t          decibels from
    148  *                                                      one milliwatt (dBm)
    149  *
    150  *      Transmit power expressed as dBm (decibels from a 1 milliwatt
    151  *      reference). This is the absolute power level measured at
    152  *      the antenna port.
    153  *
    154  * IEEE80211_RADIOTAP_FLAGS             uint8_t         bitmap
    155  *
    156  *      Properties of transmitted and received frames. See flags
    157  *      defined below.
    158  *
    159  * IEEE80211_RADIOTAP_ANTENNA           uint8_t         antenna index
    160  *
    161  *      Unitless indication of the Rx/Tx antenna for this packet.
    162  *      The first antenna is antenna 0.
    163  *
    164  * IEEE80211_RADIOTAP_RX_FLAGS          uint16_t        bitmap
    165  *
    166  *     Properties of received frames. See flags defined below.
    167  *
    168  * IEEE80211_RADIOTAP_TX_FLAGS          uint16_t        bitmap
    169  *
    170  *     Properties of transmitted frames. See flags defined below.
    171  *
    172  * IEEE80211_RADIOTAP_RTS_RETRIES       uint8_t         data
    173  *
    174  *     Number of rts retries a transmitted frame used.
    175  *
    176  * IEEE80211_RADIOTAP_DATA_RETRIES      uint8_t         data
    177  *
    178  *     Number of unicast retries a transmitted frame used.
    179  *
    180  * IEEE80211_RADIOTAP_XCHANNEL          uint32_t        bitmap
    181  *                                      uint16_t        MHz
    182  *                                      uint8_t         channel number
    183  *                                      int8_t          .5 dBm
    184  *
    185  *      Extended channel specification: flags (see below) followed by
    186  *      frequency in MHz, the corresponding IEEE channel number, and
    187  *      finally the maximum regulatory transmit power cap in .5 dBm
    188  *      units.  This property supersedes IEEE80211_RADIOTAP_CHANNEL
    189  *      and only one of the two should be present.
    190  */
    191 enum ieee80211_radiotap_type {
    192 	IEEE80211_RADIOTAP_TSFT = 0,
    193 	IEEE80211_RADIOTAP_FLAGS = 1,
    194 	IEEE80211_RADIOTAP_RATE = 2,
    195 	IEEE80211_RADIOTAP_CHANNEL = 3,
    196 	IEEE80211_RADIOTAP_FHSS = 4,
    197 	IEEE80211_RADIOTAP_DBM_ANTSIGNAL = 5,
    198 	IEEE80211_RADIOTAP_DBM_ANTNOISE = 6,
    199 	IEEE80211_RADIOTAP_LOCK_QUALITY = 7,
    200 	IEEE80211_RADIOTAP_TX_ATTENUATION = 8,
    201 	IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9,
    202 	IEEE80211_RADIOTAP_DBM_TX_POWER = 10,
    203 	IEEE80211_RADIOTAP_ANTENNA = 11,
    204 	IEEE80211_RADIOTAP_DB_ANTSIGNAL = 12,
    205 	IEEE80211_RADIOTAP_DB_ANTNOISE = 13,
    206 	IEEE80211_RADIOTAP_RX_FLAGS = 14,
    207 	IEEE80211_RADIOTAP_TX_FLAGS = 15,
    208 	IEEE80211_RADIOTAP_RTS_RETRIES = 16,
    209 	IEEE80211_RADIOTAP_DATA_RETRIES = 17,
    210 	IEEE80211_RADIOTAP_XCHANNEL = 18,
    211 	IEEE80211_RADIOTAP_EXT = 31
    212 };
    213 
    214 /* For IEEE80211_RADIOTAP_FLAGS */
    215 #define	IEEE80211_RADIOTAP_F_CFP	0x01	/* sent/received
    216 						 * during CFP
    217 						 */
    218 #define	IEEE80211_RADIOTAP_F_SHORTPRE	0x02	/* sent/received
    219 						 * with short
    220 						 * preamble
    221 						 */
    222 #define	IEEE80211_RADIOTAP_F_WEP	0x04	/* sent/received
    223 						 * with WEP encryption
    224 						 */
    225 #define	IEEE80211_RADIOTAP_F_FRAG	0x08	/* sent/received
    226 						 * with fragmentation
    227 						 */
    228 #define	IEEE80211_RADIOTAP_F_FCS	0x10	/* frame includes FCS */
    229 #define	IEEE80211_RADIOTAP_F_DATAPAD	0x20	/* frame has padding between
    230 						 * 802.11 header and payload
    231 						 * (to 32-bit boundary)
    232 						 */
    233 #define	IEEE80211_RADIOTAP_F_BADFCS	0x40	/* does not pass FCS check */
    234 #define IEEE80211_RADIOTAP_F_SHORTGI	0x80	/* HT short GI */
    235 
    236 /* For IEEE80211_RADIOTAP_RX_FLAGS */
    237 #define IEEE80211_RADIOTAP_F_RX_BADFCS 0x0001  /* Frame failed CRC check.
    238 						*
    239 						* Deprecated: use the flag
    240 						* IEEE80211_RADIOTAP_F_BADFCS in
    241 						* the IEEE80211_RADIOTAP_FLAGS
    242 						* field, instead.
    243 						*/
    244 
    245 /* For IEEE80211_RADIOTAP_TX_FLAGS */
    246 #define IEEE80211_RADIOTAP_F_TX_FAIL   0x0001  /* failed due to excessive
    247 						* retries
    248 						*/
    249 #define IEEE80211_RADIOTAP_F_TX_CTS    0x0002  /* used cts 'protection' */
    250 #define IEEE80211_RADIOTAP_F_TX_RTS    0x0004  /* used rts/cts handshake */
    251 
    252 #endif /* !_NET80211_IEEE80211_RADIOTAP_H_ */
    253