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 
44 /* Radiotap header version (from official NetBSD feed) */
45 #define IEEE80211RADIOTAP_VERSION	"1.5"
46 /* Base version of the radiotap packet header data */
47 #define PKTHDR_RADIOTAP_VERSION		0
48 
49 /* A generic radio capture format is desirable. There is one for
50  * Linux, but it is neither rigidly defined (there were not even
51  * units given for some fields) nor easily extensible.
52  *
53  * I suggest the following extensible radio capture format. It is
54  * based on a bitmap indicating which fields are present.
55  *
56  * I am trying to describe precisely what the application programmer
57  * should expect in the following, and for that reason I tell the
58  * units and origin of each measurement (where it applies), or else I
59  * use sufficiently weaselly language ("is a monotonically nondecreasing
60  * function of...") that I cannot set false expectations for lawyerly
61  * readers.
62  */
63 
64 /* XXX tcpdump/libpcap do not tolerate variable-length headers,
65  * yet, so we pad every radiotap header to 64 bytes. Ugh.
66  */
67 #define IEEE80211_RADIOTAP_HDRLEN	64
68 
69 /* The radio capture header precedes the 802.11 header. */
70 struct ieee80211_radiotap_header {
71 	u8 it_version;		/* Version 0. Only increases
72 				 * for drastic changes,
73 				 * introduction of compatible
74 				 * new fields does not count.
75 				 */
76 	u8 it_pad;
77 	u16 it_len;		/* length of the whole
78 				 * header in bytes, including
79 				 * it_version, it_pad,
80 				 * it_len, and data fields.
81 				 */
82 	u32 it_present;		/* A bitmap telling which
83 				 * fields are present. Set bit 31
84 				 * (0x80000000) to extend the
85 				 * bitmap by another 32 bits.
86 				 * Additional extensions are made
87 				 * by setting bit 31.
88 				 */
89 };
90 
91 /* Name                                 Data type       Units
92  * ----                                 ---------       -----
93  *
94  * IEEE80211_RADIOTAP_TSFT              u64       microseconds
95  *
96  *      Value in microseconds of the MAC's 64-bit 802.11 Time
97  *      Synchronization Function timer when the first bit of the
98  *      MPDU arrived at the MAC. For received frames, only.
99  *
100  * IEEE80211_RADIOTAP_CHANNEL           2 x u16   MHz, bitmap
101  *
102  *      Tx/Rx frequency in MHz, followed by flags (see below).
103  *
104  * IEEE80211_RADIOTAP_FHSS              u16       see below
105  *
106  *      For frequency-hopping radios, the hop set (first byte)
107  *      and pattern (second byte).
108  *
109  * IEEE80211_RADIOTAP_RATE              u8        500kb/s
110  *
111  *      Tx/Rx data rate
112  *
113  * IEEE80211_RADIOTAP_DBM_ANTSIGNAL     int8_t          decibels from
114  *                                                      one milliwatt (dBm)
115  *
116  *      RF signal power at the antenna, decibel difference from
117  *      one milliwatt.
118  *
119  * IEEE80211_RADIOTAP_DBM_ANTNOISE      int8_t          decibels from
120  *                                                      one milliwatt (dBm)
121  *
122  *      RF noise power at the antenna, decibel difference from one
123  *      milliwatt.
124  *
125  * IEEE80211_RADIOTAP_DB_ANTSIGNAL      u8        decibel (dB)
126  *
127  *      RF signal power at the antenna, decibel difference from an
128  *      arbitrary, fixed reference.
129  *
130  * IEEE80211_RADIOTAP_DB_ANTNOISE       u8        decibel (dB)
131  *
132  *      RF noise power at the antenna, decibel difference from an
133  *      arbitrary, fixed reference point.
134  *
135  * IEEE80211_RADIOTAP_LOCK_QUALITY      u16       unitless
136  *
137  *      Quality of Barker code lock. Unitless. Monotonically
138  *      nondecreasing with "better" lock strength. Called "Signal
139  *      Quality" in datasheets.  (Is there a standard way to measure
140  *      this?)
141  *
142  * IEEE80211_RADIOTAP_TX_ATTENUATION    u16       unitless
143  *
144  *      Transmit power expressed as unitless distance from max
145  *      power set at factory calibration.  0 is max power.
146  *      Monotonically nondecreasing with lower power levels.
147  *
148  * IEEE80211_RADIOTAP_DB_TX_ATTENUATION u16       decibels (dB)
149  *
150  *      Transmit power expressed as decibel distance from max power
151  *      set at factory calibration.  0 is max power.  Monotonically
152  *      nondecreasing with lower power levels.
153  *
154  * IEEE80211_RADIOTAP_DBM_TX_POWER      int8_t          decibels from
155  *                                                      one milliwatt (dBm)
156  *
157  *      Transmit power expressed as dBm (decibels from a 1 milliwatt
158  *      reference). This is the absolute power level measured at
159  *      the antenna port.
160  *
161  * IEEE80211_RADIOTAP_FLAGS             u8        bitmap
162  *
163  *      Properties of transmitted and received frames. See flags
164  *      defined below.
165  *
166  * IEEE80211_RADIOTAP_ANTENNA           u8        antenna index
167  *
168  *      Unitless indication of the Rx/Tx antenna for this packet.
169  *      The first antenna is antenna 0.
170  *
171  * IEEE80211_RADIOTAP_FCS           	u32       data
172  *
173  *	FCS from frame in network byte order.
174  */
175 enum ieee80211_radiotap_type {
176 	IEEE80211_RADIOTAP_TSFT = 0,
177 	IEEE80211_RADIOTAP_FLAGS = 1,
178 	IEEE80211_RADIOTAP_RATE = 2,
179 	IEEE80211_RADIOTAP_CHANNEL = 3,
180 	IEEE80211_RADIOTAP_FHSS = 4,
181 	IEEE80211_RADIOTAP_DBM_ANTSIGNAL = 5,
182 	IEEE80211_RADIOTAP_DBM_ANTNOISE = 6,
183 	IEEE80211_RADIOTAP_LOCK_QUALITY = 7,
184 	IEEE80211_RADIOTAP_TX_ATTENUATION = 8,
185 	IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9,
186 	IEEE80211_RADIOTAP_DBM_TX_POWER = 10,
187 	IEEE80211_RADIOTAP_ANTENNA = 11,
188 	IEEE80211_RADIOTAP_DB_ANTSIGNAL = 12,
189 	IEEE80211_RADIOTAP_DB_ANTNOISE = 13,
190 	IEEE80211_RADIOTAP_EXT = 31,
191 };
192 
193 /* Channel flags. */
194 #define	IEEE80211_CHAN_TURBO	0x0010	/* Turbo channel */
195 #define	IEEE80211_CHAN_CCK	0x0020	/* CCK channel */
196 #define	IEEE80211_CHAN_OFDM	0x0040	/* OFDM channel */
197 #define	IEEE80211_CHAN_2GHZ	0x0080	/* 2 GHz spectrum channel. */
198 #define	IEEE80211_CHAN_5GHZ	0x0100	/* 5 GHz spectrum channel */
199 #define	IEEE80211_CHAN_PASSIVE	0x0200	/* Only passive scan allowed */
200 #define	IEEE80211_CHAN_DYN	0x0400	/* Dynamic CCK-OFDM channel */
201 #define	IEEE80211_CHAN_GFSK	0x0800	/* GFSK channel (FHSS PHY) */
202 
203 /* For IEEE80211_RADIOTAP_FLAGS */
204 #define	IEEE80211_RADIOTAP_F_CFP	0x01	/* sent/received
205 						 * during CFP
206 						 */
207 #define	IEEE80211_RADIOTAP_F_SHORTPRE	0x02	/* sent/received
208 						 * with short
209 						 * preamble
210 						 */
211 #define	IEEE80211_RADIOTAP_F_WEP	0x04	/* sent/received
212 						 * with WEP encryption
213 						 */
214 #define	IEEE80211_RADIOTAP_F_FRAG	0x08	/* sent/received
215 						 * with fragmentation
216 						 */
217 #define	IEEE80211_RADIOTAP_F_FCS	0x10	/* frame includes FCS */
218 #define	IEEE80211_RADIOTAP_F_DATAPAD	0x20	/* frame has padding between
219 						 * 802.11 header and payload
220 						 * (to 32-bit boundary)
221 						 */
222 
223 /* Ugly macro to convert literal channel numbers into their mhz equivalents
224  * There are certianly some conditions that will break this (like feeding it '30')
225  * but they shouldn't arise since nothing talks on channel 30. */
226 #define ieee80211chan2mhz(x) \
227 	(((x) <= 14) ? \
228 	(((x) == 14) ? 2484 : ((x) * 5) + 2407) : \
229 	((x) + 1000) * 5)
230 
231 #endif				/* IEEE80211_RADIOTAP_H */
232