2 * Copyright (c) 2003, 2004 David Young. All rights reserved.
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31 * Modifications to fit into the linux IEEE 802.11 stack,
32 * Mike Kershaw (dragorn@kismetwireless.net)
35 #ifndef IEEE80211RADIOTAP_H
36 #define IEEE80211RADIOTAP_H
38 #include <linux/if_ether.h>
39 #include <linux/kernel.h>
40 #include <asm/unaligned.h>
42 /* Base version of the radiotap packet header data */
43 #define PKTHDR_RADIOTAP_VERSION 0
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.
49 * I suggest the following extensible radio capture format. It is
50 * based on a bitmap indicating which fields are present.
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
61 * The radio capture header precedes the 802.11 header.
62 * All data in the header is little endian on all platforms.
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.
71 __le16 it_len; /* length of the whole
72 * header in bytes, including
74 * it_len, and data fields.
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
85 /* Name Data type Units
86 * ---- --------- -----
88 * IEEE80211_RADIOTAP_TSFT __le64 microseconds
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.
94 * IEEE80211_RADIOTAP_CHANNEL 2 x __le16 MHz, bitmap
96 * Tx/Rx frequency in MHz, followed by flags (see below).
98 * IEEE80211_RADIOTAP_FHSS __le16 see below
100 * For frequency-hopping radios, the hop set (first byte)
101 * and pattern (second byte).
103 * IEEE80211_RADIOTAP_RATE u8 500kb/s
107 * IEEE80211_RADIOTAP_DBM_ANTSIGNAL s8 decibels from
108 * one milliwatt (dBm)
110 * RF signal power at the antenna, decibel difference from
113 * IEEE80211_RADIOTAP_DBM_ANTNOISE s8 decibels from
114 * one milliwatt (dBm)
116 * RF noise power at the antenna, decibel difference from one
119 * IEEE80211_RADIOTAP_DB_ANTSIGNAL u8 decibel (dB)
121 * RF signal power at the antenna, decibel difference from an
122 * arbitrary, fixed reference.
124 * IEEE80211_RADIOTAP_DB_ANTNOISE u8 decibel (dB)
126 * RF noise power at the antenna, decibel difference from an
127 * arbitrary, fixed reference point.
129 * IEEE80211_RADIOTAP_LOCK_QUALITY __le16 unitless
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
136 * IEEE80211_RADIOTAP_TX_ATTENUATION __le16 unitless
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.
142 * IEEE80211_RADIOTAP_DB_TX_ATTENUATION __le16 decibels (dB)
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.
148 * IEEE80211_RADIOTAP_DBM_TX_POWER s8 decibels from
149 * one milliwatt (dBm)
151 * Transmit power expressed as dBm (decibels from a 1 milliwatt
152 * reference). This is the absolute power level measured at
155 * IEEE80211_RADIOTAP_FLAGS u8 bitmap
157 * Properties of transmitted and received frames. See flags
160 * IEEE80211_RADIOTAP_ANTENNA u8 antenna index
162 * Unitless indication of the Rx/Tx antenna for this packet.
163 * The first antenna is antenna 0.
165 * IEEE80211_RADIOTAP_RX_FLAGS __le16 bitmap
167 * Properties of received frames. See flags defined below.
169 * IEEE80211_RADIOTAP_TX_FLAGS __le16 bitmap
171 * Properties of transmitted frames. See flags defined below.
173 * IEEE80211_RADIOTAP_RTS_RETRIES u8 data
175 * Number of rts retries a transmitted frame used.
177 * IEEE80211_RADIOTAP_DATA_RETRIES u8 data
179 * Number of unicast retries a transmitted frame used.
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
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) */
214 /* For IEEE80211_RADIOTAP_FLAGS */
215 #define IEEE80211_RADIOTAP_F_CFP 0x01 /* sent/received
218 #define IEEE80211_RADIOTAP_F_SHORTPRE 0x02 /* sent/received
222 #define IEEE80211_RADIOTAP_F_WEP 0x04 /* sent/received
223 * with WEP encryption
225 #define IEEE80211_RADIOTAP_F_FRAG 0x08 /* sent/received
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)
233 #define IEEE80211_RADIOTAP_F_BADFCS 0x40 /* bad FCS */
235 /* For IEEE80211_RADIOTAP_RX_FLAGS */
236 #define IEEE80211_RADIOTAP_F_RX_BADPLCP 0x0002 /* frame has bad PLCP */
238 /* For IEEE80211_RADIOTAP_TX_FLAGS */
239 #define IEEE80211_RADIOTAP_F_TX_FAIL 0x0001 /* failed due to excessive
241 #define IEEE80211_RADIOTAP_F_TX_CTS 0x0002 /* used cts 'protection' */
242 #define IEEE80211_RADIOTAP_F_TX_RTS 0x0004 /* used rts/cts handshake */
244 /* Ugly macro to convert literal channel numbers into their mhz equivalents
245 * There are certianly some conditions that will break this (like feeding it '30')
246 * but they shouldn't arise since nothing talks on channel 30. */
247 #define ieee80211chan2mhz(x) \
249 (((x) == 14) ? 2484 : ((x) * 5) + 2407) : \
253 static inline int ieee80211_get_radiotap_len(unsigned char *data)
255 struct ieee80211_radiotap_header *hdr =
256 (struct ieee80211_radiotap_header *)data;
258 return get_unaligned_le16(&hdr->it_len);
261 #endif /* IEEE80211_RADIOTAP_H */