summaryrefslogtreecommitdiff
path: root/src/transport/ieee80211_radiotap.h
blob: 1a79cf214d813d4f6b91df41acc1dc360a624809 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
/*
 * Copyright (c) 2003, 2004 David Young.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of David Young may not be used to endorse or promote
 *    products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY DAVID YOUNG ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL DAVID
 * YOUNG BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 */

/*
 * Modifications to fit into the linux IEEE 802.11 stack,
 * Mike Kershaw (dragorn@kismetwireless.net)
 */

#ifndef IEEE80211RADIOTAP_H
#define IEEE80211RADIOTAP_H

#include <linux/if_ether.h>
#include <linux/kernel.h>
// #include <asm/unaligned.h>

/* Base version of the radiotap packet header data */
#define PKTHDR_RADIOTAP_VERSION         0

/* A generic radio capture format is desirable. There is one for
 * Linux, but it is neither rigidly defined (there were not even
 * units given for some fields) nor easily extensible.
 *
 * I suggest the following extensible radio capture format. It is
 * based on a bitmap indicating which fields are present.
 *
 * I am trying to describe precisely what the application programmer
 * should expect in the following, and for that reason I tell the
 * units and origin of each measurement (where it applies), or else I
 * use sufficiently weaselly language ("is a monotonically nondecreasing
 * function of...") that I cannot set false expectations for lawyerly
 * readers.
 */

/*
 * The radio capture header precedes the 802.11 header.
 * All data in the header is little endian on all platforms.
 */
struct ieee80211_radiotap_header
{
  u8 it_version;                /* Version 0. Only increases
                                 * for drastic changes,
                                 * introduction of compatible
                                 * new fields does not count.
                                 */
  u8 it_pad;
  __le16 it_len;                /* length of the whole
                                 * header in bytes, including
                                 * it_version, it_pad,
                                 * it_len, and data fields.
                                 */
  __le32 it_present;            /* A bitmap telling which
                                 * fields are present. Set bit 31
                                 * (0x80000000) to extend the
                                 * bitmap by another 32 bits.
                                 * Additional extensions are made
                                 * by setting bit 31.
                                 */
} __packed;

/* Name                                 Data type    Units
 * ----                                 ---------    -----
 *
 * IEEE80211_RADIOTAP_TSFT              __le64       microseconds
 *
 *      Value in microseconds of the MAC's 64-bit 802.11 Time
 *      Synchronization Function timer when the first bit of the
 *      MPDU arrived at the MAC. For received frames, only.
 *
 * IEEE80211_RADIOTAP_CHANNEL           2 x __le16   MHz, bitmap
 *
 *      Tx/Rx frequency in MHz, followed by flags (see below).
 *
 * IEEE80211_RADIOTAP_FHSS              __le16       see below
 *
 *      For frequency-hopping radios, the hop set (first byte)
 *      and pattern (second byte).
 *
 * IEEE80211_RADIOTAP_RATE              u8           500kb/s
 *
 *      Tx/Rx data rate
 *
 * IEEE80211_RADIOTAP_DBM_ANTSIGNAL     s8           decibels from
 *                                                   one milliwatt (dBm)
 *
 *      RF signal power at the antenna, decibel difference from
 *      one milliwatt.
 *
 * IEEE80211_RADIOTAP_DBM_ANTNOISE      s8           decibels from
 *                                                   one milliwatt (dBm)
 *
 *      RF noise power at the antenna, decibel difference from one
 *      milliwatt.
 *
 * IEEE80211_RADIOTAP_DB_ANTSIGNAL      u8           decibel (dB)
 *
 *      RF signal power at the antenna, decibel difference from an
 *      arbitrary, fixed reference.
 *
 * IEEE80211_RADIOTAP_DB_ANTNOISE       u8           decibel (dB)
 *
 *      RF noise power at the antenna, decibel difference from an
 *      arbitrary, fixed reference point.
 *
 * IEEE80211_RADIOTAP_LOCK_QUALITY      __le16       unitless
 *
 *      Quality of Barker code lock. Unitless. Monotonically
 *      nondecreasing with "better" lock strength. Called "Signal
 *      Quality" in datasheets.  (Is there a standard way to measure
 *      this?)
 *
 * IEEE80211_RADIOTAP_TX_ATTENUATION    __le16       unitless
 *
 *      Transmit power expressed as unitless distance from max
 *      power set at factory calibration.  0 is max power.
 *      Monotonically nondecreasing with lower power levels.
 *
 * IEEE80211_RADIOTAP_DB_TX_ATTENUATION __le16       decibels (dB)
 *
 *      Transmit power expressed as decibel distance from max power
 *      set at factory calibration.  0 is max power.  Monotonically
 *      nondecreasing with lower power levels.
 *
 * IEEE80211_RADIOTAP_DBM_TX_POWER      s8           decibels from
 *                                                   one milliwatt (dBm)
 *
 *      Transmit power expressed as dBm (decibels from a 1 milliwatt
 *      reference). This is the absolute power level measured at
 *      the antenna port.
 *
 * IEEE80211_RADIOTAP_FLAGS             u8           bitmap
 *
 *      Properties of transmitted and received frames. See flags
 *      defined below.
 *
 * IEEE80211_RADIOTAP_ANTENNA           u8           antenna index
 *
 *      Unitless indication of the Rx/Tx antenna for this packet.
 *      The first antenna is antenna 0.
 *
 * IEEE80211_RADIOTAP_RX_FLAGS          __le16       bitmap
 *
 *     Properties of received frames. See flags defined below.
 *
 * IEEE80211_RADIOTAP_TX_FLAGS          __le16       bitmap
 *
 *     Properties of transmitted frames. See flags defined below.
 *
 * IEEE80211_RADIOTAP_RTS_RETRIES       u8           data
 *
 *     Number of rts retries a transmitted frame used.
 *
 * IEEE80211_RADIOTAP_DATA_RETRIES      u8           data
 *
 *     Number of unicast retries a transmitted frame used.
 *
 */
enum ieee80211_radiotap_type
{
  IEEE80211_RADIOTAP_TSFT = 0,
  IEEE80211_RADIOTAP_FLAGS = 1,
  IEEE80211_RADIOTAP_RATE = 2,
  IEEE80211_RADIOTAP_CHANNEL = 3,
  IEEE80211_RADIOTAP_FHSS = 4,
  IEEE80211_RADIOTAP_DBM_ANTSIGNAL = 5,
  IEEE80211_RADIOTAP_DBM_ANTNOISE = 6,
  IEEE80211_RADIOTAP_LOCK_QUALITY = 7,
  IEEE80211_RADIOTAP_TX_ATTENUATION = 8,
  IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9,
  IEEE80211_RADIOTAP_DBM_TX_POWER = 10,
  IEEE80211_RADIOTAP_ANTENNA = 11,
  IEEE80211_RADIOTAP_DB_ANTSIGNAL = 12,
  IEEE80211_RADIOTAP_DB_ANTNOISE = 13,
  IEEE80211_RADIOTAP_RX_FLAGS = 14,
  IEEE80211_RADIOTAP_TX_FLAGS = 15,
  IEEE80211_RADIOTAP_RTS_RETRIES = 16,
  IEEE80211_RADIOTAP_DATA_RETRIES = 17,

  /* valid in every it_present bitmap, even vendor namespaces */
  IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE = 29,
  IEEE80211_RADIOTAP_VENDOR_NAMESPACE = 30,
  IEEE80211_RADIOTAP_EXT = 31
};

/* Channel flags. */
#define IEEE80211_CHAN_TURBO    0x0010  /* Turbo channel */
#define IEEE80211_CHAN_CCK      0x0020  /* CCK channel */
#define IEEE80211_CHAN_OFDM     0x0040  /* OFDM channel */
#define IEEE80211_CHAN_2GHZ     0x0080  /* 2 GHz spectrum channel. */
#define IEEE80211_CHAN_5GHZ     0x0100  /* 5 GHz spectrum channel */
#define IEEE80211_CHAN_PASSIVE  0x0200  /* Only passive scan allowed */
#define IEEE80211_CHAN_DYN      0x0400  /* Dynamic CCK-OFDM channel */
#define IEEE80211_CHAN_GFSK     0x0800  /* GFSK channel (FHSS PHY) */

/* For IEEE80211_RADIOTAP_FLAGS */
#define IEEE80211_RADIOTAP_F_CFP        0x01    /* sent/received
                                                 * during CFP
                                                 */
#define IEEE80211_RADIOTAP_F_SHORTPRE   0x02    /* sent/received
                                                 * with short
                                                 * preamble
                                                 */
#define IEEE80211_RADIOTAP_F_WEP        0x04    /* sent/received
                                                 * with WEP encryption
                                                 */
#define IEEE80211_RADIOTAP_F_FRAG       0x08    /* sent/received
                                                 * with fragmentation
                                                 */
#define IEEE80211_RADIOTAP_F_FCS        0x10    /* frame includes FCS */
#define IEEE80211_RADIOTAP_F_DATAPAD    0x20    /* frame has padding between
                                                 * 802.11 header and payload
                                                 * (to 32-bit boundary)
                                                 */
#define IEEE80211_RADIOTAP_F_BADFCS     0x40    /* bad FCS */

/* For IEEE80211_RADIOTAP_RX_FLAGS */
#define IEEE80211_RADIOTAP_F_RX_BADPLCP 0x0002  /* frame has bad PLCP */

/* For IEEE80211_RADIOTAP_TX_FLAGS */
#define IEEE80211_RADIOTAP_F_TX_FAIL    0x0001  /* failed due to excessive
                                                 * retries */
#define IEEE80211_RADIOTAP_F_TX_CTS     0x0002  /* used cts 'protection' */
#define IEEE80211_RADIOTAP_F_TX_RTS     0x0004  /* used rts/cts handshake */

/* Ugly macro to convert literal channel numbers into their mhz equivalents
 * There are certianly some conditions that will break this (like feeding it '30')
 * but they shouldn't arise since nothing talks on channel 30. */
#define ieee80211chan2mhz(x) \
  (((x) <= 14) ? \
   (((x) == 14) ? 2484 : ((x) * 5) + 2407) : \
   ((x) + 1000) * 5)

/* helpers */
static inline u16
get_unaligned_le16 (const u8 *p)
{
  return p[0] | p[1] << 8;
}


static inline int
ieee80211_get_radiotap_len (unsigned char *data)
{
  struct ieee80211_radiotap_header *hdr =
    (struct ieee80211_radiotap_header *) data;

  return get_unaligned_le16 ((const u8 *) &hdr->it_len);
}


#endif /* IEEE80211_RADIOTAP_H */