ieee80211_radiotap.h revision 1.1 
1/* $FreeBSD: src/sys/net80211/ieee80211_radiotap.h,v 1.1 2003/09/05 22:19:32 sam Exp $ */
2/*	$NetBSD: ieee80211_radiotap.h,v 1.1 2003/09/07 04:05:33 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#ifndef DLT_IEEE802_11_RADIO
50#define	DLT_IEEE802_11_RADIO	127	/* 802.11 plus WLAN header */
51#endif
52
53/* The radio capture header precedes the 802.11 header. */
54struct ieee80211_radiotap_header {
55	u_int8_t	it_version;	/* Version 0. Only increases
56					 * for drastic changes,
57					 * introduction of compatible
58					 * new LTVs does not count.
59					 */
60	u_int8_t	it_pad;
61	u_int16_t       it_len;         /* length of the whole
62					 * header in bytes, including
63					 * it_version, it_pad,
64					 * it_len, and LTVs.
65					 */
66	u_int32_t       it_present;     /* A bitmap telling which
67					 * fields are present. Set bit 31
68					 * (0x80000000) to extend the
69					 * bitmap by another 32 bits.
70					 * Additional extensions are made
71					 * by setting bit 31.
72					 */
73};
74
75/* Name                                 Data type       Units
76 * ----                                 ---------       -----
77 *
78 * IEEE80211_RADIOTAP_CHANNEL           u_int8_t	MHz
79 *
80 *      Tx/Rx channel number (for DSSS/OFDM/PBCC PHY)
81 *
82 * IEEE80211_RADIOTAP_FHSS              u_int16_t       see below
83 *
84 *      For frequency-hopping radios, the hop set (first byte)
85 *      and pattern (second byte).
86 *
87 * IEEE80211_RADIOTAP_RATE              u_int8_t	.5Mb/s
88 *
89 *      IEEE Tx/Rx data rate cookie (including basic rate flag)
90 *
91 * IEEE80211_RADIOTAP_DB_ANTSIGNAL      int16_t         decibel (dB)
92 *
93 *      RF signal power at the antenna, measured from a fixed,
94 *      arbitrary reference point.
95 *
96 * IEEE80211_RADIOTAP_DB_ANTNOISE       int16_t         decibel (dB)
97 *
98 *      RF noise power at the antenna in decibels from an arbitrary,
99 *      fixed reference point.
100 *
101 * IEEE80211_RADIOTAP_BARKER_CODE_LOCK  u_int16_t       unitless
102 *
103 *      Quality of Barker code lock. Unitless. Monotonically
104 *      nondecreasing with "better" lock strength. Called "Signal
105 *      Quality" in datasheets.  (Is there a standard way to measure
106 *      this?)
107 *
108 * IEEE80211_RADIOTAP_TX_ATTENUATION    u_int16_t       unitless
109 *
110 *      Transmit power expressed as unitless distance from max
111 *      power set at factory calibration.  0 is max power.
112 *      Monotonically nondecreasing with lower power levels.
113 *
114 * IEEE80211_RADIOTAP_DB_TX_ATTENUATION u_int16_t       decibels (dB)
115 *
116 *      Transmit power expressed as decibel distance from max power
117 *      set at factory calibration.  0 is max power.  Monotonically
118 *      nondecreasing with lower power levels.
119 *
120 * IEEE80211_RADIOTAP_DBM_TX_POWER      u_int16_t       decibels from
121 *                                                      milliwatt (dBm)
122 *
123 *      Transmit power expressed as dBm (decibels from a 1 milliwatt
124 *      reference). This is the absolute power level measured at
125 *      the antenna port.
126 *
127 * IEEE80211_RADIOTAP_TSFT              u_int64_t       microseconds
128 *
129 *      Value in microseconds of the MAC's 64-bit 802.11 Time
130 *      Synchronization Function timer when the first bit of the
131 *      MPDU arrived at the MAC. For received frames, only.
132 *      Little-endian byte order.
133 *
134 * IEEE80211_RADIOTAP_FLAGS             u_int16_t       bitmap
135 *
136 *      Properties of transmitted and received frames. See flags
137 *      defined below.
138 *
139 * IEEE80211_RADIOTAP_TIME              u_int32_t       microseconds
140 *
141 *      For radios that provide it: packet arrival time in
142 *      microseconds. Prism hardware will provide this, but it is
143 *      not known whether it marks the first or the last bit of
144 *      the frame. Nor is it known where that bit has arrived
145 *      (antenna, modem, MAC?) when the time is measured.
146 *
147 * IEEE80211_RADIOTAP_ANTENNA           u_int16_t       antenna index
148 *
149 *      Unitless indication of the Rx/Tx antenna for this packet.
150 *      The first antenna is antenna 0.
151 */
152enum ieee80211_radiotap_type {
153	IEEE80211_RADIOTAP_PAD = 0,
154	IEEE80211_RADIOTAP_FLAGS = 1,
155	IEEE80211_RADIOTAP_RATE = 2,
156	IEEE80211_RADIOTAP_CHANNEL = 3,
157	IEEE80211_RADIOTAP_FHSS = 4,
158	IEEE80211_RADIOTAP_DB_ANTSIGNAL = 5,
159	IEEE80211_RADIOTAP_DB_ANTNOISE = 6,
160	IEEE80211_RADIOTAP_LOCK_QUALITY = 7,
161	IEEE80211_RADIOTAP_TX_ATTENUATION = 8,
162	IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9,
163	IEEE80211_RADIOTAP_DBM_TX_POWER = 10,
164	IEEE80211_RADIOTAP_ANTENNA = 11,
165	IEEE80211_RADIOTAP_TSFT = 12,
166	IEEE80211_RADIOTAP_EXT = 31,
167	IEEE80211_RADIOTAP_TIME = 32
168};
169
170/* For IEEE80211_RADIOTAP_FLAGS */
171#define	IEEE80211_RADIOTAP_F_CFP	0x0001  /* sent/received
172						 * during CFP
173						 */
174#define	IEEE80211_RADIOTAP_F_SHORTPRE	0x0002  /* sent/received
175						 * with short
176						 * preamble
177						 */
178#define	IEEE80211_RADIOTAP_F_WEP	0x0004  /* sent/received
179						 * with WEP encryption
180						 */
181#define	IEEE80211_RADIOTAP_F_FRAG	0x0008  /* sent/received
182						 * with fragmentation
183						 */
184
185#endif /* _NET_IF_IEEE80211RADIOTAP_H_ */
186