1/*-
2 * Copyright (c) 2007-2008 Sam Leffler, Errno Consulting
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 * $FreeBSD$
26 */
27
28#ifndef _NET80211_IEEE80211_PHY_H_
29#define _NET80211_IEEE80211_PHY_H_
30
31#ifdef _KERNEL
32/*
33 * IEEE 802.11 PHY-related definitions.
34 */
35
36/*
37 * Contention window (slots).
38 */
39#define IEEE80211_CW_MAX	1023	/* aCWmax */
40#define IEEE80211_CW_MIN_0	31	/* DS/CCK aCWmin, ERP aCWmin(0) */
41#define IEEE80211_CW_MIN_1	15	/* OFDM aCWmin, ERP aCWmin(1) */
42
43/*
44 * SIFS (microseconds).
45 */
46#define IEEE80211_DUR_SIFS	10	/* DS/CCK/ERP SIFS */
47#define IEEE80211_DUR_OFDM_SIFS	16	/* OFDM SIFS */
48
49/*
50 * Slot time (microseconds).
51 */
52#define IEEE80211_DUR_SLOT	20	/* DS/CCK slottime, ERP long slottime */
53#define IEEE80211_DUR_SHSLOT	9	/* ERP short slottime */
54#define IEEE80211_DUR_OFDM_SLOT	9	/* OFDM slottime */
55
56/*
57 * DIFS (microseconds).
58 */
59#define IEEE80211_DUR_DIFS(sifs, slot)	((sifs) + 2 * (slot))
60
61struct ieee80211_channel;
62
63struct ieee80211_rate_table {
64	int		rateCount;		/* NB: for proper padding */
65	uint8_t		rateCodeToIndex[256];	/* back mapping */
66	struct {
67		uint8_t		phy;		/* CCK/OFDM/TURBO */
68		uint32_t	rateKbps;	/* transfer rate in kbs */
69		uint8_t		shortPreamble;	/* mask for enabling short
70						 * preamble in CCK rate code */
71		uint8_t		dot11Rate;	/* value for supported rates
72						 * info element of MLME */
73		uint8_t		ctlRateIndex;	/* index of next lower basic
74						 * rate; used for dur. calcs */
75		uint16_t	lpAckDuration;	/* long preamble ACK dur. */
76		uint16_t	spAckDuration;	/* short preamble ACK dur. */
77	} info[32];
78};
79
80const struct ieee80211_rate_table *ieee80211_get_ratetable(
81			struct ieee80211_channel *);
82
83static __inline__ uint8_t
84ieee80211_ack_rate(const struct ieee80211_rate_table *rt, uint8_t rate)
85{
86	uint8_t cix = rt->info[rt->rateCodeToIndex[rate]].ctlRateIndex;
87	KASSERT(cix != (uint8_t)-1, ("rate %d has no info", rate));
88	return rt->info[cix].dot11Rate;
89}
90
91static __inline__ uint8_t
92ieee80211_ctl_rate(const struct ieee80211_rate_table *rt, uint8_t rate)
93{
94	uint8_t cix = rt->info[rt->rateCodeToIndex[rate]].ctlRateIndex;
95	KASSERT(cix != (uint8_t)-1, ("rate %d has no info", rate));
96	return rt->info[cix].dot11Rate;
97}
98
99static __inline__ enum ieee80211_phytype
100ieee80211_rate2phytype(const struct ieee80211_rate_table *rt, uint8_t rate)
101{
102	uint8_t rix = rt->rateCodeToIndex[rate];
103	KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate));
104	return rt->info[rix].phy;
105}
106
107static __inline__ int
108ieee80211_isratevalid(const struct ieee80211_rate_table *rt, uint8_t rate)
109{
110	return rt->rateCodeToIndex[rate] != (uint8_t)-1;
111}
112
113/*
114 * Calculate ACK field for
115 * o  non-fragment data frames
116 * o  management frames
117 * sent using rate, phy and short preamble setting.
118 */
119static __inline__ uint16_t
120ieee80211_ack_duration(const struct ieee80211_rate_table *rt,
121    uint8_t rate, int isShortPreamble)
122{
123	uint8_t rix = rt->rateCodeToIndex[rate];
124
125	KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate));
126	if (isShortPreamble) {
127		KASSERT(rt->info[rix].spAckDuration != 0,
128			("shpreamble ack dur is not computed!\n"));
129		return rt->info[rix].spAckDuration;
130	} else {
131		KASSERT(rt->info[rix].lpAckDuration != 0,
132			("lgpreamble ack dur is not computed!\n"));
133		return rt->info[rix].lpAckDuration;
134	}
135}
136
137/*
138 * Compute the time to transmit a frame of length frameLen bytes
139 * using the specified 802.11 rate code, phy, and short preamble
140 * setting.
141 *
142 * NB: SIFS is included.
143 */
144uint16_t	ieee80211_compute_duration(const struct ieee80211_rate_table *,
145			uint32_t frameLen, uint16_t rate, int isShortPreamble);
146/*
147 * Convert PLCP signal/rate field to 802.11 rate code (.5Mbits/s)
148 */
149uint8_t		ieee80211_plcp2rate(uint8_t, enum ieee80211_phytype);
150/*
151 * Convert 802.11 rate code to PLCP signal.
152 */
153uint8_t		ieee80211_rate2plcp(int, enum ieee80211_phytype);
154#endif	/* _KERNEL */
155#endif	/* !_NET80211_IEEE80211_PHY_H_ */
156