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: src/sys/net80211/ieee80211_phy.h,v 1.2 2008/05/12 00:32:51 sam Exp $
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
61 struct ieee80211_channel;
62
63 struct 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
80 const struct ieee80211_rate_table *ieee80211_get_ratetable(
81 struct ieee80211_channel *);
82
83 static __inline__ uint8_t
84 ieee80211_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
91 static __inline__ uint8_t
92 ieee80211_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
99 static __inline__ enum ieee80211_phytype
100 ieee80211_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
107 /*
108 * Calculate ACK field for
109 * o non-fragment data frames
110 * o management frames
111 * sent using rate, phy and short preamble setting.
112 */
113 static __inline__ uint16_t
114 ieee80211_ack_duration(const struct ieee80211_rate_table *rt,
115 uint8_t rate, int isShortPreamble)
116 {
117 uint8_t rix = rt->rateCodeToIndex[rate];
118
119 KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate));
120 if (isShortPreamble) {
121 KASSERT(rt->info[rix].spAckDuration != 0,
122 ("shpreamble ack dur is not computed!\n"));
123 return rt->info[rix].spAckDuration;
124 } else {
125 KASSERT(rt->info[rix].lpAckDuration != 0,
126 ("lgpreamble ack dur is not computed!\n"));
127 return rt->info[rix].lpAckDuration;
128 }
129 }
130
131 /*
132 * Compute the time to transmit a frame of length frameLen bytes
133 * using the specified 802.11 rate code, phy, and short preamble
134 * setting.
135 *
136 * NB: SIFS is included.
137 */
138 uint16_t ieee80211_compute_duration(const struct ieee80211_rate_table *,
139 uint32_t frameLen, uint16_t rate, int isShortPreamble);
140 /*
141 * Convert PLCP signal/rate field to 802.11 rate code (.5Mbits/s)
142 */
143 uint8_t ieee80211_plcp2rate(uint8_t, enum ieee80211_phytype);
144 /*
145 * Convert 802.11 rate code to PLCP signal.
146 */
147 uint8_t ieee80211_rate2plcp(int, enum ieee80211_phytype);
148 #endif /* _KERNEL */
149 #endif /* !_NET80211_IEEE80211_PHY_H_ */
150
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