xref: /freebsd/sys/net80211/ieee80211_radiotap.h (revision 4f29da19bd44f0e99f021510460a81bf754c21d2)
1 /* $FreeBSD$ */
2 /* $NetBSD: ieee80211_radiotap.h,v 1.10 2005/01/04 00:34:58 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 #ifndef _NET_IF_IEEE80211RADIOTAP_H_
33 #define _NET_IF_IEEE80211RADIOTAP_H_
34 
35 /* A generic radio capture format is desirable. There is one for
36  * Linux, but it is neither rigidly defined (there were not even
37  * units given for some fields) nor easily extensible.
38  *
39  * I suggest the following extensible radio capture format. It is
40  * based on a bitmap indicating which fields are present.
41  *
42  * I am trying to describe precisely what the application programmer
43  * should expect in the following, and for that reason I tell the
44  * units and origin of each measurement (where it applies), or else I
45  * use sufficiently weaselly language ("is a monotonically nondecreasing
46  * function of...") that I cannot set false expectations for lawyerly
47  * readers.
48  */
49 #if defined(__KERNEL__) || defined(_KERNEL)
50 #ifndef DLT_IEEE802_11_RADIO
51 #define	DLT_IEEE802_11_RADIO	127	/* 802.11 plus WLAN header */
52 #endif
53 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
54 
55 /* XXX tcpdump/libpcap do not tolerate variable-length headers,
56  * yet, so we pad every radiotap header to 64 bytes. Ugh.
57  */
58 #define IEEE80211_RADIOTAP_HDRLEN	64
59 
60 /* The radio capture header precedes the 802.11 header. */
61 struct ieee80211_radiotap_header {
62 	u_int8_t	it_version;	/* Version 0. Only increases
63 					 * for drastic changes,
64 					 * introduction of compatible
65 					 * new fields does not count.
66 					 */
67 	u_int8_t	it_pad;
68 	u_int16_t       it_len;         /* length of the whole
69 					 * header in bytes, including
70 					 * it_version, it_pad,
71 					 * it_len, and data fields.
72 					 */
73 	u_int32_t       it_present;     /* A bitmap telling which
74 					 * fields are present. Set bit 31
75 					 * (0x80000000) to extend the
76 					 * bitmap by another 32 bits.
77 					 * Additional extensions are made
78 					 * by setting bit 31.
79 					 */
80 } __attribute__((__packed__));
81 
82 /* Name                                 Data type       Units
83  * ----                                 ---------       -----
84  *
85  * IEEE80211_RADIOTAP_TSFT              u_int64_t       microseconds
86  *
87  *      Value in microseconds of the MAC's 64-bit 802.11 Time
88  *      Synchronization Function timer when the first bit of the
89  *      MPDU arrived at the MAC. For received frames, only.
90  *
91  * IEEE80211_RADIOTAP_CHANNEL           2 x u_int16_t   MHz, bitmap
92  *
93  *      Tx/Rx frequency in MHz, followed by flags (see below).
94  *
95  * IEEE80211_RADIOTAP_FHSS              u_int16_t       see below
96  *
97  *      For frequency-hopping radios, the hop set (first byte)
98  *      and pattern (second byte).
99  *
100  * IEEE80211_RADIOTAP_RATE              u_int8_t        500kb/s
101  *
102  *      Tx/Rx data rate
103  *
104  * IEEE80211_RADIOTAP_DBM_ANTSIGNAL     int8_t          decibels from
105  *                                                      one milliwatt (dBm)
106  *
107  *      RF signal power at the antenna, decibel difference from
108  *      one milliwatt.
109  *
110  * IEEE80211_RADIOTAP_DBM_ANTNOISE      int8_t          decibels from
111  *                                                      one milliwatt (dBm)
112  *
113  *      RF noise power at the antenna, decibel difference from one
114  *      milliwatt.
115  *
116  * IEEE80211_RADIOTAP_DB_ANTSIGNAL      u_int8_t        decibel (dB)
117  *
118  *      RF signal power at the antenna, decibel difference from an
119  *      arbitrary, fixed reference.
120  *
121  * IEEE80211_RADIOTAP_DB_ANTNOISE       u_int8_t        decibel (dB)
122  *
123  *      RF noise power at the antenna, decibel difference from an
124  *      arbitrary, fixed reference point.
125  *
126  * IEEE80211_RADIOTAP_LOCK_QUALITY      u_int16_t       unitless
127  *
128  *      Quality of Barker code lock. Unitless. Monotonically
129  *      nondecreasing with "better" lock strength. Called "Signal
130  *      Quality" in datasheets.  (Is there a standard way to measure
131  *      this?)
132  *
133  * IEEE80211_RADIOTAP_TX_ATTENUATION    u_int16_t       unitless
134  *
135  *      Transmit power expressed as unitless distance from max
136  *      power set at factory calibration.  0 is max power.
137  *      Monotonically nondecreasing with lower power levels.
138  *
139  * IEEE80211_RADIOTAP_DB_TX_ATTENUATION u_int16_t       decibels (dB)
140  *
141  *      Transmit power expressed as decibel distance from max power
142  *      set at factory calibration.  0 is max power.  Monotonically
143  *      nondecreasing with lower power levels.
144  *
145  * IEEE80211_RADIOTAP_DBM_TX_POWER      int8_t          decibels from
146  *                                                      one milliwatt (dBm)
147  *
148  *      Transmit power expressed as dBm (decibels from a 1 milliwatt
149  *      reference). This is the absolute power level measured at
150  *      the antenna port.
151  *
152  * IEEE80211_RADIOTAP_FLAGS             u_int8_t        bitmap
153  *
154  *      Properties of transmitted and received frames. See flags
155  *      defined below.
156  *
157  * IEEE80211_RADIOTAP_ANTENNA           u_int8_t        antenna index
158  *
159  *      Unitless indication of the Rx/Tx antenna for this packet.
160  *      The first antenna is antenna 0.
161  *
162  * IEEE80211_RADIOTAP_FCS           	u_int32_t       data
163  *
164  *	FCS from frame in network byte order.
165  */
166 enum ieee80211_radiotap_type {
167 	IEEE80211_RADIOTAP_TSFT = 0,
168 	IEEE80211_RADIOTAP_FLAGS = 1,
169 	IEEE80211_RADIOTAP_RATE = 2,
170 	IEEE80211_RADIOTAP_CHANNEL = 3,
171 	IEEE80211_RADIOTAP_FHSS = 4,
172 	IEEE80211_RADIOTAP_DBM_ANTSIGNAL = 5,
173 	IEEE80211_RADIOTAP_DBM_ANTNOISE = 6,
174 	IEEE80211_RADIOTAP_LOCK_QUALITY = 7,
175 	IEEE80211_RADIOTAP_TX_ATTENUATION = 8,
176 	IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9,
177 	IEEE80211_RADIOTAP_DBM_TX_POWER = 10,
178 	IEEE80211_RADIOTAP_ANTENNA = 11,
179 	IEEE80211_RADIOTAP_DB_ANTSIGNAL = 12,
180 	IEEE80211_RADIOTAP_DB_ANTNOISE = 13,
181 	IEEE80211_RADIOTAP_EXT = 31,
182 };
183 
184 #ifndef _KERNEL
185 /* Channel flags. */
186 #define	IEEE80211_CHAN_TURBO	0x0010	/* Turbo channel */
187 #define	IEEE80211_CHAN_CCK	0x0020	/* CCK channel */
188 #define	IEEE80211_CHAN_OFDM	0x0040	/* OFDM channel */
189 #define	IEEE80211_CHAN_2GHZ	0x0080	/* 2 GHz spectrum channel. */
190 #define	IEEE80211_CHAN_5GHZ	0x0100	/* 5 GHz spectrum channel */
191 #define	IEEE80211_CHAN_PASSIVE	0x0200	/* Only passive scan allowed */
192 #define	IEEE80211_CHAN_DYN	0x0400	/* Dynamic CCK-OFDM channel */
193 #define	IEEE80211_CHAN_GFSK	0x0800	/* GFSK channel (FHSS PHY) */
194 #endif /* !_KERNEL */
195 
196 /* For IEEE80211_RADIOTAP_FLAGS */
197 #define	IEEE80211_RADIOTAP_F_CFP	0x01	/* sent/received
198 						 * during CFP
199 						 */
200 #define	IEEE80211_RADIOTAP_F_SHORTPRE	0x02	/* sent/received
201 						 * with short
202 						 * preamble
203 						 */
204 #define	IEEE80211_RADIOTAP_F_WEP	0x04	/* sent/received
205 						 * with WEP encryption
206 						 */
207 #define	IEEE80211_RADIOTAP_F_FRAG	0x08	/* sent/received
208 						 * with fragmentation
209 						 */
210 #define	IEEE80211_RADIOTAP_F_FCS	0x10	/* frame includes FCS */
211 #define	IEEE80211_RADIOTAP_F_DATAPAD	0x20	/* frame has padding between
212 						 * 802.11 header and payload
213 						 * (to 32-bit boundary)
214 						 */
215 #define	IEEE80211_RADIOTAP_F_BADFCS	0x40	/* does not pass FCS check */
216 
217 #endif /* _NET_IF_IEEE80211RADIOTAP_H_ */
218