Experimental bpf capture format for 802.11 devices. The link layer

type belongs in net/bpf.h but we keep it here for the moment.

P:
Submittep by:
Obtained from:	David Young <dyoung@pobox.com>

1 files changed, 185 insertions, 0 deletions

diff --git a/sys/net80211/ieee80211_radiotap.h b/sys/net80211/ieee80211_radiotap.h
new file mode 100644
index 0000000..d263d53
--- /dev/null
+++ b/sys/net80211/ieee80211_radiotap.h
@@ -0,0 +1,185 @@
+/* $FreeBSD$ */
+/*	$NetBSD: $	*/
+
+/*-
+ * Copyright (c) 2003, 2004 David Young.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of David Young may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY DAVID YOUNG ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL DAVID
+ * YOUNG BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ */
+#ifndef _NET_IF_IEEE80211RADIOTAP_H_
+#define _NET_IF_IEEE80211RADIOTAP_H_
+
+/* A generic radio capture format is desirable. There is one for
+ * Linux, but it is neither rigidly defined (there were not even
+ * units given for some fields) nor easily extensible.
+ *
+ * I suggest the following extensible radio capture format. It is
+ * based on a bitmap indicating which fields are present.
+ *
+ * I am trying to describe precisely what the application programmer
+ * should expect in the following, and for that reason I tell the
+ * units and origin of each measurement (where it applies), or else I
+ * use sufficiently weaselly language ("is a monotonically nondecreasing
+ * function of...") that I cannot set false expectations for lawyerly
+ * readers.
+ */
+#ifndef DLT_IEEE802_11_RADIO
+#define	DLT_IEEE802_11_RADIO	127	/* 802.11 plus WLAN header */
+#endif
+
+/* The radio capture header precedes the 802.11 header. */
+struct ieee80211_radiotap_header {
+	u_int8_t	it_version;	/* Version 0. Only increases
+					 * for drastic changes,
+					 * introduction of compatible
+					 * new LTVs does not count.
+					 */
+	u_int8_t	it_pad;
+	u_int16_t       it_len;         /* length of the whole
+					 * header in bytes, including
+					 * it_version, it_pad,
+					 * it_len, and LTVs.
+					 */
+	u_int32_t       it_present;     /* A bitmap telling which
+					 * fields are present. Set bit 31
+					 * (0x80000000) to extend the
+					 * bitmap by another 32 bits.
+					 * Additional extensions are made
+					 * by setting bit 31.
+					 */
+};
+
+/* Name                                 Data type       Units
+ * ----                                 ---------       -----
+ *
+ * IEEE80211_RADIOTAP_CHANNEL           u_int8_t	MHz
+ *
+ *      Tx/Rx channel number (for DSSS/OFDM/PBCC PHY)
+ *
+ * IEEE80211_RADIOTAP_FHSS              u_int16_t       see below
+ *
+ *      For frequency-hopping radios, the hop set (first byte)
+ *      and pattern (second byte).
+ *
+ * IEEE80211_RADIOTAP_RATE              u_int8_t	.5Mb/s
+ *
+ *      IEEE Tx/Rx data rate cookie (including basic rate flag)
+ *
+ * IEEE80211_RADIOTAP_DB_ANTSIGNAL      int16_t         decibel (dB)
+ *              
+ *      RF signal power at the antenna, measured from a fixed,
+ *      arbitrary reference point.
+ *
+ * IEEE80211_RADIOTAP_DB_ANTNOISE       int16_t         decibel (dB)
+ *
+ *      RF noise power at the antenna in decibels from an arbitrary,
+ *      fixed reference point.
+ *
+ * IEEE80211_RADIOTAP_BARKER_CODE_LOCK  u_int16_t       unitless
+ *
+ *      Quality of Barker code lock. Unitless. Monotonically
+ *      nondecreasing with "better" lock strength. Called "Signal
+ *      Quality" in datasheets.  (Is there a standard way to measure
+ *      this?)
+ *
+ * IEEE80211_RADIOTAP_TX_ATTENUATION    u_int16_t       unitless
+ *
+ *      Transmit power expressed as unitless distance from max
+ *      power set at factory calibration.  0 is max power.
+ *      Monotonically nondecreasing with lower power levels.
+ *
+ * IEEE80211_RADIOTAP_DB_TX_ATTENUATION u_int16_t       decibels (dB)
+ *
+ *      Transmit power expressed as decibel distance from max power
+ *      set at factory calibration.  0 is max power.  Monotonically
+ *      nondecreasing with lower power levels.
+ *
+ * IEEE80211_RADIOTAP_DBM_TX_POWER      u_int16_t       decibels from
+ *                                                      milliwatt (dBm)
+ *
+ *      Transmit power expressed as dBm (decibels from a 1 milliwatt
+ *      reference). This is the absolute power level measured at
+ *      the antenna port.
+ *
+ * IEEE80211_RADIOTAP_TSFT              u_int64_t       microseconds
+ *
+ *      Value in microseconds of the MAC's 64-bit 802.11 Time
+ *      Synchronization Function timer when the first bit of the
+ *      MPDU arrived at the MAC. For received frames, only.
+ *      Little-endian byte order.
+ *
+ * IEEE80211_RADIOTAP_FLAGS             u_int16_t       bitmap
+ *
+ *      Properties of transmitted and received frames. See flags
+ *      defined below.
+ *
+ * IEEE80211_RADIOTAP_TIME              u_int32_t       microseconds
+ *
+ *      For radios that provide it: packet arrival time in
+ *      microseconds. Prism hardware will provide this, but it is
+ *      not known whether it marks the first or the last bit of
+ *      the frame. Nor is it known where that bit has arrived
+ *      (antenna, modem, MAC?) when the time is measured.
+ *
+ * IEEE80211_RADIOTAP_ANTENNA           u_int16_t       antenna index
+ *
+ *      Unitless indication of the Rx/Tx antenna for this packet.
+ *      The first antenna is antenna 0.
+ */
+enum ieee80211_radiotap_type {
+	IEEE80211_RADIOTAP_PAD = 0,
+	IEEE80211_RADIOTAP_FLAGS = 1,
+	IEEE80211_RADIOTAP_RATE = 2,
+	IEEE80211_RADIOTAP_CHANNEL = 3,
+	IEEE80211_RADIOTAP_FHSS = 4,
+	IEEE80211_RADIOTAP_DB_ANTSIGNAL = 5,
+	IEEE80211_RADIOTAP_DB_ANTNOISE = 6,
+	IEEE80211_RADIOTAP_LOCK_QUALITY = 7,
+	IEEE80211_RADIOTAP_TX_ATTENUATION = 8,
+	IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9,
+	IEEE80211_RADIOTAP_DBM_TX_POWER = 10,
+	IEEE80211_RADIOTAP_ANTENNA = 11,
+	IEEE80211_RADIOTAP_TSFT = 12,
+	IEEE80211_RADIOTAP_EXT = 31,
+	IEEE80211_RADIOTAP_TIME = 32
+};
+
+/* For IEEE80211_RADIOTAP_FLAGS */
+#define	IEEE80211_RADIOTAP_F_CFP	0x0001  /* sent/received
+						 * during CFP
+						 */
+#define	IEEE80211_RADIOTAP_F_SHORTPRE	0x0002  /* sent/received
+						 * with short
+						 * preamble
+						 */
+#define	IEEE80211_RADIOTAP_F_WEP	0x0004  /* sent/received
+						 * with WEP encryption
+						 */
+#define	IEEE80211_RADIOTAP_F_FRAG	0x0008  /* sent/received
+						 * with fragmentation
+						 */
+
+#endif /* _NET_IF_IEEE80211RADIOTAP_H_ */