1 /* $FreeBSD$ */ 2 /* $NetBSD: $ */ 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. */ 54 struct 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 */ 152 enum 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