include/net/ieee80211_radiotap.h

   1 /* $FreeBSD: src/sys/net80211/ieee80211_radiotap.h,v 1.5 2005/01/22 20:12:05 sam Exp $ */
   2 /* $NetBSD: ieee80211_radiotap.h,v 1.11 2005/06/22 06:16:02 dyoung 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  * 3. The name of David Young may not be used to endorse or promote
  16  *    products derived from this software without specific prior
  17  *    written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY DAVID YOUNG ``AS IS'' AND ANY
  20  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL DAVID
  23  * YOUNG BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  25  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  27  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  30  * OF SUCH DAMAGE.
  31  */
  32
  33 /*
  34  * Modifications to fit into the linux IEEE 802.11 stack,
  35  * Mike Kershaw (dragorn@kismetwireless.net)
  36  */
  37
  38 #ifndef IEEE80211RADIOTAP_H
  39 #define IEEE80211RADIOTAP_H
  40
  41 #include <linux/if_ether.h>
  42 #include <linux/kernel.h>
  43 #include <asm/unaligned.h>
  44
  45 /* Radiotap header version (from official NetBSD feed) */
  46 #define IEEE80211RADIOTAP_VERSION       "1.5"
  47 /* Base version of the radiotap packet header data */
  48 #define PKTHDR_RADIOTAP_VERSION         0
  49
  50 /* A generic radio capture format is desirable. There is one for
  51  * Linux, but it is neither rigidly defined (there were not even
  52  * units given for some fields) nor easily extensible.
  53  *
  54  * I suggest the following extensible radio capture format. It is
  55  * based on a bitmap indicating which fields are present.
  56  *
  57  * I am trying to describe precisely what the application programmer
  58  * should expect in the following, and for that reason I tell the
  59  * units and origin of each measurement (where it applies), or else I
  60  * use sufficiently weaselly language ("is a monotonically nondecreasing
  61  * function of...") that I cannot set false expectations for lawyerly
  62  * readers.
  63  */
  64
  65 /* XXX tcpdump/libpcap do not tolerate variable-length headers,
  66  * yet, so we pad every radiotap header to 64 bytes. Ugh.
  67  */
  68 #define IEEE80211_RADIOTAP_HDRLEN       64
  69
  70 /* The radio capture header precedes the 802.11 header.
  71  * All data in the header is little endian on all platforms.
  72  */
  73 struct ieee80211_radiotap_header {
  74         u8 it_version;          /* Version 0. Only increases
  75                                  * for drastic changes,
  76                                  * introduction of compatible
  77                                  * new fields does not count.
  78                                  */
  79         u8 it_pad;
  80         __le16 it_len;          /* length of the whole
  81                                  * header in bytes, including
  82                                  * it_version, it_pad,
  83                                  * it_len, and data fields.
  84                                  */
  85         __le32 it_present;      /* A bitmap telling which
  86                                  * fields are present. Set bit 31
  87                                  * (0x80000000) to extend the
  88                                  * bitmap by another 32 bits.
  89                                  * Additional extensions are made
  90                                  * by setting bit 31.
  91                                  */
  92 };
  93
  94 /* Name                                 Data type    Units
  95  * ----                                 ---------    -----
  96  *
  97  * IEEE80211_RADIOTAP_TSFT              __le64       microseconds
  98  *
  99  *      Value in microseconds of the MAC's 64-bit 802.11 Time
 100  *      Synchronization Function timer when the first bit of the
 101  *      MPDU arrived at the MAC. For received frames, only.
 102  *
 103  * IEEE80211_RADIOTAP_CHANNEL           2 x __le16   MHz, bitmap
 104  *
 105  *      Tx/Rx frequency in MHz, followed by flags (see below).
 106  *
 107  * IEEE80211_RADIOTAP_FHSS              __le16       see below
 108  *
 109  *      For frequency-hopping radios, the hop set (first byte)
 110  *      and pattern (second byte).
 111  *
 112  * IEEE80211_RADIOTAP_RATE              u8           500kb/s
 113  *
 114  *      Tx/Rx data rate
 115  *
 116  * IEEE80211_RADIOTAP_DBM_ANTSIGNAL     s8           decibels from
 117  *                                                   one milliwatt (dBm)
 118  *
 119  *      RF signal power at the antenna, decibel difference from
 120  *      one milliwatt.
 121  *
 122  * IEEE80211_RADIOTAP_DBM_ANTNOISE      s8           decibels from
 123  *                                                   one milliwatt (dBm)
 124  *
 125  *      RF noise power at the antenna, decibel difference from one
 126  *      milliwatt.
 127  *
 128  * IEEE80211_RADIOTAP_DB_ANTSIGNAL      u8           decibel (dB)
 129  *
 130  *      RF signal power at the antenna, decibel difference from an
 131  *      arbitrary, fixed reference.
 132  *
 133  * IEEE80211_RADIOTAP_DB_ANTNOISE       u8           decibel (dB)
 134  *
 135  *      RF noise power at the antenna, decibel difference from an
 136  *      arbitrary, fixed reference point.
 137  *
 138  * IEEE80211_RADIOTAP_LOCK_QUALITY      __le16       unitless
 139  *
 140  *      Quality of Barker code lock. Unitless. Monotonically
 141  *      nondecreasing with "better" lock strength. Called "Signal
 142  *      Quality" in datasheets.  (Is there a standard way to measure
 143  *      this?)
 144  *
 145  * IEEE80211_RADIOTAP_TX_ATTENUATION    __le16       unitless
 146  *
 147  *      Transmit power expressed as unitless distance from max
 148  *      power set at factory calibration.  0 is max power.
 149  *      Monotonically nondecreasing with lower power levels.
 150  *
 151  * IEEE80211_RADIOTAP_DB_TX_ATTENUATION __le16       decibels (dB)
 152  *
 153  *      Transmit power expressed as decibel distance from max power
 154  *      set at factory calibration.  0 is max power.  Monotonically
 155  *      nondecreasing with lower power levels.
 156  *
 157  * IEEE80211_RADIOTAP_DBM_TX_POWER      s8           decibels from
 158  *                                                   one milliwatt (dBm)
 159  *
 160  *      Transmit power expressed as dBm (decibels from a 1 milliwatt
 161  *      reference). This is the absolute power level measured at
 162  *      the antenna port.
 163  *
 164  * IEEE80211_RADIOTAP_FLAGS             u8           bitmap
 165  *
 166  *      Properties of transmitted and received frames. See flags
 167  *      defined below.
 168  *
 169  * IEEE80211_RADIOTAP_ANTENNA           u8           antenna index
 170  *
 171  *      Unitless indication of the Rx/Tx antenna for this packet.
 172  *      The first antenna is antenna 0.
 173  *
 174  * IEEE80211_RADIOTAP_RX_FLAGS          __le16       bitmap
 175  *
 176  *     Properties of received frames. See flags defined below.
 177  *
 178  * IEEE80211_RADIOTAP_TX_FLAGS          __le16       bitmap
 179  *
 180  *     Properties of transmitted frames. See flags defined below.
 181  *
 182  * IEEE80211_RADIOTAP_RTS_RETRIES       u8           data
 183  *
 184  *     Number of rts retries a transmitted frame used.
 185  *
 186  * IEEE80211_RADIOTAP_DATA_RETRIES      u8           data
 187  *
 188  *     Number of unicast retries a transmitted frame used.
 189  *
 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_EXT = 31
 211 };
 212
 213 /* Channel flags. */
 214 #define IEEE80211_CHAN_TURBO    0x0010  /* Turbo channel */
 215 #define IEEE80211_CHAN_CCK      0x0020  /* CCK channel */
 216 #define IEEE80211_CHAN_OFDM     0x0040  /* OFDM channel */
 217 #define IEEE80211_CHAN_2GHZ     0x0080  /* 2 GHz spectrum channel. */
 218 #define IEEE80211_CHAN_5GHZ     0x0100  /* 5 GHz spectrum channel */
 219 #define IEEE80211_CHAN_PASSIVE  0x0200  /* Only passive scan allowed */
 220 #define IEEE80211_CHAN_DYN      0x0400  /* Dynamic CCK-OFDM channel */
 221 #define IEEE80211_CHAN_GFSK     0x0800  /* GFSK channel (FHSS PHY) */
 222
 223 /* For IEEE80211_RADIOTAP_FLAGS */
 224 #define IEEE80211_RADIOTAP_F_CFP        0x01    /* sent/received
 225                                                  * during CFP
 226                                                  */
 227 #define IEEE80211_RADIOTAP_F_SHORTPRE   0x02    /* sent/received
 228                                                  * with short
 229                                                  * preamble
 230                                                  */
 231 #define IEEE80211_RADIOTAP_F_WEP        0x04    /* sent/received
 232                                                  * with WEP encryption
 233                                                  */
 234 #define IEEE80211_RADIOTAP_F_FRAG       0x08    /* sent/received
 235                                                  * with fragmentation
 236                                                  */
 237 #define IEEE80211_RADIOTAP_F_FCS        0x10    /* frame includes FCS */
 238 #define IEEE80211_RADIOTAP_F_DATAPAD    0x20    /* frame has padding between
 239                                                  * 802.11 header and payload
 240                                                  * (to 32-bit boundary)
 241                                                  */
 242 /* For IEEE80211_RADIOTAP_RX_FLAGS */
 243 #define IEEE80211_RADIOTAP_F_RX_BADFCS  0x0001  /* frame failed crc check */
 244
 245 /* For IEEE80211_RADIOTAP_TX_FLAGS */
 246 #define IEEE80211_RADIOTAP_F_TX_FAIL    0x0001  /* failed due to excessive
 247                                                  * retries */
 248 #define IEEE80211_RADIOTAP_F_TX_CTS     0x0002  /* used cts 'protection' */
 249 #define IEEE80211_RADIOTAP_F_TX_RTS     0x0004  /* used rts/cts handshake */
 250
 251 /* Ugly macro to convert literal channel numbers into their mhz equivalents
 252  * There are certianly some conditions that will break this (like feeding it '30')
 253  * but they shouldn't arise since nothing talks on channel 30. */
 254 #define ieee80211chan2mhz(x) \
 255         (((x) <= 14) ? \
 256         (((x) == 14) ? 2484 : ((x) * 5) + 2407) : \
 257         ((x) + 1000) * 5)
 258
 259 /* helpers */
 260 static inline int ieee80211_get_radiotap_len(unsigned char *data)
 261 {
 262         struct ieee80211_radiotap_header *hdr =
 263                 (struct ieee80211_radiotap_header *)data;
 264
 265         return get_unaligned_le16(&hdr->it_len);
 266 }
 267
 268 #endif                          /* IEEE80211_RADIOTAP_H */