include/net/ieee80211_radiotap.h

   1 /*
   2  * Copyright (c) 2003, 2004 David Young.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  * 3. The name of David Young may not be used to endorse or promote
  13  *    products derived from this software without specific prior
  14  *    written permission.
  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
  30 /*
  31  * Modifications to fit into the linux IEEE 802.11 stack,
  32  * Mike Kershaw (dragorn@kismetwireless.net)
  33  */
  34
  35 #ifndef IEEE80211RADIOTAP_H
  36 #define IEEE80211RADIOTAP_H
  37
  38 #include <linux/if_ether.h>
  39 #include <linux/kernel.h>
  40 #include <asm/unaligned.h>
  41
  42 /* Base version of the radiotap packet header data */
  43 #define PKTHDR_RADIOTAP_VERSION         0
  44
  45 /* A generic radio capture format is desirable. There is one for
  46  * Linux, but it is neither rigidly defined (there were not even
  47  * units given for some fields) nor easily extensible.
  48  *
  49  * I suggest the following extensible radio capture format. It is
  50  * based on a bitmap indicating which fields are present.
  51  *
  52  * I am trying to describe precisely what the application programmer
  53  * should expect in the following, and for that reason I tell the
  54  * units and origin of each measurement (where it applies), or else I
  55  * use sufficiently weaselly language ("is a monotonically nondecreasing
  56  * function of...") that I cannot set false expectations for lawyerly
  57  * readers.
  58  */
  59
  60 /*
  61  * The radio capture header precedes the 802.11 header.
  62  * All data in the header is little endian on all platforms.
  63  */
  64 struct ieee80211_radiotap_header {
  65         u8 it_version;          /* Version 0. Only increases
  66                                  * for drastic changes,
  67                                  * introduction of compatible
  68                                  * new fields does not count.
  69                                  */
  70         u8 it_pad;
  71         __le16 it_len;          /* length of the whole
  72                                  * header in bytes, including
  73                                  * it_version, it_pad,
  74                                  * it_len, and data fields.
  75                                  */
  76         __le32 it_present;      /* A bitmap telling which
  77                                  * fields are present. Set bit 31
  78                                  * (0x80000000) to extend the
  79                                  * bitmap by another 32 bits.
  80                                  * Additional extensions are made
  81                                  * by setting bit 31.
  82                                  */
  83 };
  84
  85 /* Name                                 Data type    Units
  86  * ----                                 ---------    -----
  87  *
  88  * IEEE80211_RADIOTAP_TSFT              __le64       microseconds
  89  *
  90  *      Value in microseconds of the MAC's 64-bit 802.11 Time
  91  *      Synchronization Function timer when the first bit of the
  92  *      MPDU arrived at the MAC. For received frames, only.
  93  *
  94  * IEEE80211_RADIOTAP_CHANNEL           2 x __le16   MHz, bitmap
  95  *
  96  *      Tx/Rx frequency in MHz, followed by flags (see below).
  97  *
  98  * IEEE80211_RADIOTAP_FHSS              __le16       see below
  99  *
 100  *      For frequency-hopping radios, the hop set (first byte)
 101  *      and pattern (second byte).
 102  *
 103  * IEEE80211_RADIOTAP_RATE              u8           500kb/s
 104  *
 105  *      Tx/Rx data rate
 106  *
 107  * IEEE80211_RADIOTAP_DBM_ANTSIGNAL     s8           decibels from
 108  *                                                   one milliwatt (dBm)
 109  *
 110  *      RF signal power at the antenna, decibel difference from
 111  *      one milliwatt.
 112  *
 113  * IEEE80211_RADIOTAP_DBM_ANTNOISE      s8           decibels from
 114  *                                                   one milliwatt (dBm)
 115  *
 116  *      RF noise power at the antenna, decibel difference from one
 117  *      milliwatt.
 118  *
 119  * IEEE80211_RADIOTAP_DB_ANTSIGNAL      u8           decibel (dB)
 120  *
 121  *      RF signal power at the antenna, decibel difference from an
 122  *      arbitrary, fixed reference.
 123  *
 124  * IEEE80211_RADIOTAP_DB_ANTNOISE       u8           decibel (dB)
 125  *
 126  *      RF noise power at the antenna, decibel difference from an
 127  *      arbitrary, fixed reference point.
 128  *
 129  * IEEE80211_RADIOTAP_LOCK_QUALITY      __le16       unitless
 130  *
 131  *      Quality of Barker code lock. Unitless. Monotonically
 132  *      nondecreasing with "better" lock strength. Called "Signal
 133  *      Quality" in datasheets.  (Is there a standard way to measure
 134  *      this?)
 135  *
 136  * IEEE80211_RADIOTAP_TX_ATTENUATION    __le16       unitless
 137  *
 138  *      Transmit power expressed as unitless distance from max
 139  *      power set at factory calibration.  0 is max power.
 140  *      Monotonically nondecreasing with lower power levels.
 141  *
 142  * IEEE80211_RADIOTAP_DB_TX_ATTENUATION __le16       decibels (dB)
 143  *
 144  *      Transmit power expressed as decibel distance from max power
 145  *      set at factory calibration.  0 is max power.  Monotonically
 146  *      nondecreasing with lower power levels.
 147  *
 148  * IEEE80211_RADIOTAP_DBM_TX_POWER      s8           decibels from
 149  *                                                   one milliwatt (dBm)
 150  *
 151  *      Transmit power expressed as dBm (decibels from a 1 milliwatt
 152  *      reference). This is the absolute power level measured at
 153  *      the antenna port.
 154  *
 155  * IEEE80211_RADIOTAP_FLAGS             u8           bitmap
 156  *
 157  *      Properties of transmitted and received frames. See flags
 158  *      defined below.
 159  *
 160  * IEEE80211_RADIOTAP_ANTENNA           u8           antenna index
 161  *
 162  *      Unitless indication of the Rx/Tx antenna for this packet.
 163  *      The first antenna is antenna 0.
 164  *
 165  * IEEE80211_RADIOTAP_RX_FLAGS          __le16       bitmap
 166  *
 167  *     Properties of received frames. See flags defined below.
 168  *
 169  * IEEE80211_RADIOTAP_TX_FLAGS          __le16       bitmap
 170  *
 171  *     Properties of transmitted frames. See flags defined below.
 172  *
 173  * IEEE80211_RADIOTAP_RTS_RETRIES       u8           data
 174  *
 175  *     Number of rts retries a transmitted frame used.
 176  *
 177  * IEEE80211_RADIOTAP_DATA_RETRIES      u8           data
 178  *
 179  *     Number of unicast retries a transmitted frame used.
 180  *
 181  */
 182 enum ieee80211_radiotap_type {
 183         IEEE80211_RADIOTAP_TSFT = 0,
 184         IEEE80211_RADIOTAP_FLAGS = 1,
 185         IEEE80211_RADIOTAP_RATE = 2,
 186         IEEE80211_RADIOTAP_CHANNEL = 3,
 187         IEEE80211_RADIOTAP_FHSS = 4,
 188         IEEE80211_RADIOTAP_DBM_ANTSIGNAL = 5,
 189         IEEE80211_RADIOTAP_DBM_ANTNOISE = 6,
 190         IEEE80211_RADIOTAP_LOCK_QUALITY = 7,
 191         IEEE80211_RADIOTAP_TX_ATTENUATION = 8,
 192         IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9,
 193         IEEE80211_RADIOTAP_DBM_TX_POWER = 10,
 194         IEEE80211_RADIOTAP_ANTENNA = 11,
 195         IEEE80211_RADIOTAP_DB_ANTSIGNAL = 12,
 196         IEEE80211_RADIOTAP_DB_ANTNOISE = 13,
 197         IEEE80211_RADIOTAP_RX_FLAGS = 14,
 198         IEEE80211_RADIOTAP_TX_FLAGS = 15,
 199         IEEE80211_RADIOTAP_RTS_RETRIES = 16,
 200         IEEE80211_RADIOTAP_DATA_RETRIES = 17,
 201         IEEE80211_RADIOTAP_EXT = 31
 202 };
 203
 204 /* Channel flags. */
 205 #define IEEE80211_CHAN_TURBO    0x0010  /* Turbo channel */
 206 #define IEEE80211_CHAN_CCK      0x0020  /* CCK channel */
 207 #define IEEE80211_CHAN_OFDM     0x0040  /* OFDM channel */
 208 #define IEEE80211_CHAN_2GHZ     0x0080  /* 2 GHz spectrum channel. */
 209 #define IEEE80211_CHAN_5GHZ     0x0100  /* 5 GHz spectrum channel */
 210 #define IEEE80211_CHAN_PASSIVE  0x0200  /* Only passive scan allowed */
 211 #define IEEE80211_CHAN_DYN      0x0400  /* Dynamic CCK-OFDM channel */
 212 #define IEEE80211_CHAN_GFSK     0x0800  /* GFSK channel (FHSS PHY) */
 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 /* For IEEE80211_RADIOTAP_RX_FLAGS */
 234 #define IEEE80211_RADIOTAP_F_RX_BADFCS  0x0001  /* frame failed crc check */
 235
 236 /* For IEEE80211_RADIOTAP_TX_FLAGS */
 237 #define IEEE80211_RADIOTAP_F_TX_FAIL    0x0001  /* failed due to excessive
 238                                                  * retries */
 239 #define IEEE80211_RADIOTAP_F_TX_CTS     0x0002  /* used cts 'protection' */
 240 #define IEEE80211_RADIOTAP_F_TX_RTS     0x0004  /* used rts/cts handshake */
 241
 242 /* Ugly macro to convert literal channel numbers into their mhz equivalents
 243  * There are certianly some conditions that will break this (like feeding it '30')
 244  * but they shouldn't arise since nothing talks on channel 30. */
 245 #define ieee80211chan2mhz(x) \
 246         (((x) <= 14) ? \
 247         (((x) == 14) ? 2484 : ((x) * 5) + 2407) : \
 248         ((x) + 1000) * 5)
 249
 250 /* helpers */
 251 static inline int ieee80211_get_radiotap_len(unsigned char *data)
 252 {
 253         struct ieee80211_radiotap_header *hdr =
 254                 (struct ieee80211_radiotap_header *)data;
 255
 256         return get_unaligned_le16(&hdr->it_len);
 257 }
 258
 259 #endif                          /* IEEE80211_RADIOTAP_H */