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 } __packed;
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 * IEEE80211_RADIOTAP_MCS u8, u8, u8 unitless
182 *
183 * Contains a bitmap of known fields/flags, the flags, and
184 * the MCS index.
185 *
186 */
187 enum ieee80211_radiotap_type {
188 IEEE80211_RADIOTAP_TSFT = 0,
189 IEEE80211_RADIOTAP_FLAGS = 1,
190 IEEE80211_RADIOTAP_RATE = 2,
191 IEEE80211_RADIOTAP_CHANNEL = 3,
192 IEEE80211_RADIOTAP_FHSS = 4,
193 IEEE80211_RADIOTAP_DBM_ANTSIGNAL = 5,
194 IEEE80211_RADIOTAP_DBM_ANTNOISE = 6,
195 IEEE80211_RADIOTAP_LOCK_QUALITY = 7,
196 IEEE80211_RADIOTAP_TX_ATTENUATION = 8,
197 IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9,
198 IEEE80211_RADIOTAP_DBM_TX_POWER = 10,
199 IEEE80211_RADIOTAP_ANTENNA = 11,
200 IEEE80211_RADIOTAP_DB_ANTSIGNAL = 12,
201 IEEE80211_RADIOTAP_DB_ANTNOISE = 13,
202 IEEE80211_RADIOTAP_RX_FLAGS = 14,
203 IEEE80211_RADIOTAP_TX_FLAGS = 15,
204 IEEE80211_RADIOTAP_RTS_RETRIES = 16,
205 IEEE80211_RADIOTAP_DATA_RETRIES = 17,
206
207 IEEE80211_RADIOTAP_MCS = 19,
208
209 /* valid in every it_present bitmap, even vendor namespaces */
210 IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE = 29,
211 IEEE80211_RADIOTAP_VENDOR_NAMESPACE = 30,
212 IEEE80211_RADIOTAP_EXT = 31
213 };
214
215 /* Channel flags. */
216 #define IEEE80211_CHAN_TURBO 0x0010 /* Turbo channel */
217 #define IEEE80211_CHAN_CCK 0x0020 /* CCK channel */
218 #define IEEE80211_CHAN_OFDM 0x0040 /* OFDM channel */
219 #define IEEE80211_CHAN_2GHZ 0x0080 /* 2 GHz spectrum channel. */
220 #define IEEE80211_CHAN_5GHZ 0x0100 /* 5 GHz spectrum channel */
221 #define IEEE80211_CHAN_PASSIVE 0x0200 /* Only passive scan allowed */
222 #define IEEE80211_CHAN_DYN 0x0400 /* Dynamic CCK-OFDM channel */
223 #define IEEE80211_CHAN_GFSK 0x0800 /* GFSK channel (FHSS PHY) */
224
225 /* For IEEE80211_RADIOTAP_FLAGS */
226 #define IEEE80211_RADIOTAP_F_CFP 0x01 /* sent/received
227 * during CFP
228 */
229 #define IEEE80211_RADIOTAP_F_SHORTPRE 0x02 /* sent/received
230 * with short
231 * preamble
232 */
233 #define IEEE80211_RADIOTAP_F_WEP 0x04 /* sent/received
234 * with WEP encryption
235 */
236 #define IEEE80211_RADIOTAP_F_FRAG 0x08 /* sent/received
237 * with fragmentation
238 */
239 #define IEEE80211_RADIOTAP_F_FCS 0x10 /* frame includes FCS */
240 #define IEEE80211_RADIOTAP_F_DATAPAD 0x20 /* frame has padding between
241 * 802.11 header and payload
242 * (to 32-bit boundary)
243 */
244 #define IEEE80211_RADIOTAP_F_BADFCS 0x40 /* bad FCS */
245
246 /* For IEEE80211_RADIOTAP_RX_FLAGS */
247 #define IEEE80211_RADIOTAP_F_RX_BADPLCP 0x0002 /* frame has bad PLCP */
248
249 /* For IEEE80211_RADIOTAP_TX_FLAGS */
250 #define IEEE80211_RADIOTAP_F_TX_FAIL 0x0001 /* failed due to excessive
251 * retries */
252 #define IEEE80211_RADIOTAP_F_TX_CTS 0x0002 /* used cts 'protection' */
253 #define IEEE80211_RADIOTAP_F_TX_RTS 0x0004 /* used rts/cts handshake */
254 #define IEEE80211_RADIOTAP_F_TX_NOACK 0x0008 /* don't expect an ack */
255
256
257 /* For IEEE80211_RADIOTAP_MCS */
258 #define IEEE80211_RADIOTAP_MCS_HAVE_BW 0x01
259 #define IEEE80211_RADIOTAP_MCS_HAVE_MCS 0x02
260 #define IEEE80211_RADIOTAP_MCS_HAVE_GI 0x04
261 #define IEEE80211_RADIOTAP_MCS_HAVE_FMT 0x08
262 #define IEEE80211_RADIOTAP_MCS_HAVE_FEC 0x10
263
264 #define IEEE80211_RADIOTAP_MCS_BW_MASK 0x03
265 #define IEEE80211_RADIOTAP_MCS_BW_20 0
266 #define IEEE80211_RADIOTAP_MCS_BW_40 1
267 #define IEEE80211_RADIOTAP_MCS_BW_20L 2
268 #define IEEE80211_RADIOTAP_MCS_BW_20U 3
269 #define IEEE80211_RADIOTAP_MCS_SGI 0x04
270 #define IEEE80211_RADIOTAP_MCS_FMT_GF 0x08
271 #define IEEE80211_RADIOTAP_MCS_FEC_LDPC 0x10
272
273
274 /* helpers */
ieee80211_get_radiotap_len(unsigned char * data)275 static inline int ieee80211_get_radiotap_len(unsigned char *data)
276 {
277 struct ieee80211_radiotap_header *hdr =
278 (struct ieee80211_radiotap_header *)data;
279
280 return get_unaligned_le16(&hdr->it_len);
281 }
282
283 #endif /* IEEE80211_RADIOTAP_H */
284