ieee80211_radiotap.h revision 1.24
1/* $FreeBSD: src/sys/net80211/ieee80211_radiotap.h,v 1.11 2007/12/13 01:23:40 sam Exp $ */ 2/* $NetBSD: ieee80211_radiotap.h,v 1.24 2011/02/25 10:45:57 tron 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 * 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#ifndef _NET80211_IEEE80211_RADIOTAP_H_ 30#define _NET80211_IEEE80211_RADIOTAP_H_ 31 32/* A generic radio capture format is desirable. It must be 33 * rigidly defined (e.g., units for fields should be given), 34 * and easily extensible. 35 * 36 * The following is an extensible radio capture format. It is 37 * based on a bitmap indicating which fields are present. 38 * 39 * I am trying to describe precisely what the application programmer 40 * should expect in the following, and for that reason I tell the 41 * units and origin of each measurement (where it applies), or else I 42 * use sufficiently weaselly language ("is a monotonically nondecreasing 43 * function of...") that I cannot set false expectations for lawyerly 44 * readers. 45 */ 46#if defined(__KERNEL__) || defined(_KERNEL) 47#ifndef DLT_IEEE802_11_RADIO 48#define DLT_IEEE802_11_RADIO 127 /* 802.11 plus WLAN header */ 49#endif 50#endif /* defined(__KERNEL__) || defined(_KERNEL) */ 51 52/* XXX tcpdump/libpcap do not tolerate variable-length headers, 53 * yet, so we pad every radiotap header to 64 bytes. Ugh. 54 */ 55#define IEEE80211_RADIOTAP_HDRLEN 64 56 57/* 58 * The radio capture header precedes the 802.11 header. 59 * 60 * Note well: all radiotap fields are little-endian. 61 */ 62struct ieee80211_radiotap_header { 63 uint8_t it_version; /* Version 0. Only increases 64 * for drastic changes, 65 * introduction of compatible 66 * new fields does not count. 67 */ 68 uint8_t it_pad; 69 uint16_t it_len; /* length of the whole 70 * header in bytes, including 71 * it_version, it_pad, 72 * it_len, and data fields. 73 */ 74 uint32_t it_present; /* A bitmap telling which 75 * fields are present. Set bit 31 76 * (0x80000000) to extend the 77 * bitmap by another 32 bits. 78 * Additional extensions are made 79 * by setting bit 31. 80 */ 81} __packed __aligned(8); 82 83/* 84 * Name Data type Units 85 * ---- --------- ----- 86 * 87 * IEEE80211_RADIOTAP_TSFT uint64_t microseconds 88 * 89 * Value in microseconds of the MAC's 64-bit 802.11 Time 90 * Synchronization Function timer when the first bit of the 91 * MPDU arrived at the MAC. For received frames, only. 92 * 93 * IEEE80211_RADIOTAP_CHANNEL 2 x uint16_t MHz, bitmap 94 * 95 * Tx/Rx frequency in MHz, followed by flags (see below). 96 * 97 * IEEE80211_RADIOTAP_FHSS uint16_t see below 98 * 99 * For frequency-hopping radios, the hop set (first byte) 100 * and pattern (second byte). 101 * 102 * IEEE80211_RADIOTAP_RATE uint8_t 500kb/s 103 * 104 * Tx/Rx data rate 105 * 106 * IEEE80211_RADIOTAP_DBM_ANTSIGNAL int8_t decibels from 107 * one milliwatt (dBm) 108 * 109 * RF signal power at the antenna, decibel difference from 110 * one milliwatt. 111 * 112 * IEEE80211_RADIOTAP_DBM_ANTNOISE int8_t decibels from 113 * one milliwatt (dBm) 114 * 115 * RF noise power at the antenna, decibel difference from one 116 * milliwatt. 117 * 118 * IEEE80211_RADIOTAP_DB_ANTSIGNAL uint8_t decibel (dB) 119 * 120 * RF signal power at the antenna, decibel difference from an 121 * arbitrary, fixed reference. 122 * 123 * IEEE80211_RADIOTAP_DB_ANTNOISE uint8_t decibel (dB) 124 * 125 * RF noise power at the antenna, decibel difference from an 126 * arbitrary, fixed reference point. 127 * 128 * IEEE80211_RADIOTAP_LOCK_QUALITY uint16_t unitless 129 * 130 * Quality of Barker code lock. Unitless. Monotonically 131 * nondecreasing with "better" lock strength. Called "Signal 132 * Quality" in datasheets. (Is there a standard way to measure 133 * this?) 134 * 135 * IEEE80211_RADIOTAP_TX_ATTENUATION uint16_t unitless 136 * 137 * Transmit power expressed as unitless distance from max 138 * power set at factory calibration. 0 is max power. 139 * Monotonically nondecreasing with lower power levels. 140 * 141 * IEEE80211_RADIOTAP_DB_TX_ATTENUATION uint16_t decibels (dB) 142 * 143 * Transmit power expressed as decibel distance from max power 144 * set at factory calibration. 0 is max power. Monotonically 145 * nondecreasing with lower power levels. 146 * 147 * IEEE80211_RADIOTAP_DBM_TX_POWER int8_t decibels from 148 * one milliwatt (dBm) 149 * 150 * Transmit power expressed as dBm (decibels from a 1 milliwatt 151 * reference). This is the absolute power level measured at 152 * the antenna port. 153 * 154 * IEEE80211_RADIOTAP_FLAGS uint8_t bitmap 155 * 156 * Properties of transmitted and received frames. See flags 157 * defined below. 158 * 159 * IEEE80211_RADIOTAP_ANTENNA uint8_t antenna index 160 * 161 * Unitless indication of the Rx/Tx antenna for this packet. 162 * The first antenna is antenna 0. 163 * 164 * IEEE80211_RADIOTAP_RX_FLAGS uint16_t bitmap 165 * 166 * Properties of received frames. See flags defined below. 167 * 168 * IEEE80211_RADIOTAP_TX_FLAGS uint16_t bitmap 169 * 170 * Properties of transmitted frames. See flags defined below. 171 * 172 * IEEE80211_RADIOTAP_RTS_RETRIES uint8_t data 173 * 174 * Number of rts retries a transmitted frame used. 175 * 176 * IEEE80211_RADIOTAP_DATA_RETRIES uint8_t data 177 * 178 * Number of unicast retries a transmitted frame used. 179 * 180 * IEEE80211_RADIOTAP_XCHANNEL uint32_t bitmap 181 * uint16_t MHz 182 * uint8_t channel number 183 * int8_t .5 dBm 184 * 185 * Extended channel specification: flags (see below) followed by 186 * frequency in MHz, the corresponding IEEE channel number, and 187 * finally the maximum regulatory transmit power cap in .5 dBm 188 * units. This property supersedes IEEE80211_RADIOTAP_CHANNEL 189 * and only one of the two should be present. 190 */ 191enum ieee80211_radiotap_type { 192 IEEE80211_RADIOTAP_TSFT = 0, 193 IEEE80211_RADIOTAP_FLAGS = 1, 194 IEEE80211_RADIOTAP_RATE = 2, 195 IEEE80211_RADIOTAP_CHANNEL = 3, 196 IEEE80211_RADIOTAP_FHSS = 4, 197 IEEE80211_RADIOTAP_DBM_ANTSIGNAL = 5, 198 IEEE80211_RADIOTAP_DBM_ANTNOISE = 6, 199 IEEE80211_RADIOTAP_LOCK_QUALITY = 7, 200 IEEE80211_RADIOTAP_TX_ATTENUATION = 8, 201 IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9, 202 IEEE80211_RADIOTAP_DBM_TX_POWER = 10, 203 IEEE80211_RADIOTAP_ANTENNA = 11, 204 IEEE80211_RADIOTAP_DB_ANTSIGNAL = 12, 205 IEEE80211_RADIOTAP_DB_ANTNOISE = 13, 206 IEEE80211_RADIOTAP_RX_FLAGS = 14, 207 IEEE80211_RADIOTAP_TX_FLAGS = 15, 208 IEEE80211_RADIOTAP_RTS_RETRIES = 16, 209 IEEE80211_RADIOTAP_DATA_RETRIES = 17, 210 IEEE80211_RADIOTAP_XCHANNEL = 18, 211 IEEE80211_RADIOTAP_EXT = 31 212}; 213 214/* For IEEE80211_RADIOTAP_FLAGS */ 215#define IEEE80211_RADIOTAP_F_CFP 0x01 /* sent/received 216 * during CFP 217 */ 218#define IEEE80211_RADIOTAP_F_SHORTPRE 0x02 /* sent/received 219 * with short 220 * preamble 221 */ 222#define IEEE80211_RADIOTAP_F_WEP 0x04 /* sent/received 223 * with WEP encryption 224 */ 225#define IEEE80211_RADIOTAP_F_FRAG 0x08 /* sent/received 226 * with fragmentation 227 */ 228#define IEEE80211_RADIOTAP_F_FCS 0x10 /* frame includes FCS */ 229#define IEEE80211_RADIOTAP_F_DATAPAD 0x20 /* frame has padding between 230 * 802.11 header and payload 231 * (to 32-bit boundary) 232 */ 233#define IEEE80211_RADIOTAP_F_BADFCS 0x40 /* does not pass FCS check */ 234#define IEEE80211_RADIOTAP_F_SHORTGI 0x80 /* HT short GI */ 235 236/* For IEEE80211_RADIOTAP_RX_FLAGS */ 237#define IEEE80211_RADIOTAP_F_RX_BADFCS 0x0001 /* Frame failed CRC check. 238 * 239 * Deprecated: use the flag 240 * IEEE80211_RADIOTAP_F_BADFCS in 241 * the IEEE80211_RADIOTAP_FLAGS 242 * field, instead. 243 */ 244 245/* For IEEE80211_RADIOTAP_TX_FLAGS */ 246#define IEEE80211_RADIOTAP_F_TX_FAIL 0x0001 /* failed due to excessive 247 * retries 248 */ 249#define IEEE80211_RADIOTAP_F_TX_CTS 0x0002 /* used cts 'protection' */ 250#define IEEE80211_RADIOTAP_F_TX_RTS 0x0004 /* used rts/cts handshake */ 251 252#endif /* !_NET80211_IEEE80211_RADIOTAP_H_ */ 253