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 #define IEEE80211_GET_SLOTTIME(ic) \
57 ((ic->ic_flags & IEEE80211_F_SHSLOT) ? \
58 IEEE80211_DUR_SHSLOT : IEEE80211_DUR_SLOT)
59
60 /*
61 * DIFS (microseconds).
62 */
63 #define IEEE80211_DUR_DIFS(sifs, slot) ((sifs) + 2 * (slot))
64
65 struct ieee80211_channel;
66
67 #define IEEE80211_RATE_TABLE_SIZE 128
68
69 struct ieee80211_rate_table {
70 int rateCount; /* NB: for proper padding */
71 uint8_t rateCodeToIndex[256]; /* back mapping */
72 struct {
73 uint8_t phy; /* CCK/OFDM/TURBO */
74 uint32_t rateKbps; /* transfer rate in kbs */
75 uint8_t shortPreamble; /* mask for enabling short
76 * preamble in CCK rate code */
77 uint8_t dot11Rate; /* value for supported rates
78 * info element of MLME */
79 uint8_t ctlRateIndex; /* index of next lower basic
80 * rate; used for dur. calcs */
81 uint16_t lpAckDuration; /* long preamble ACK dur. */
82 uint16_t spAckDuration; /* short preamble ACK dur. */
83 } info[IEEE80211_RATE_TABLE_SIZE];
84 };
85
86 const struct ieee80211_rate_table *ieee80211_get_ratetable(
87 struct ieee80211_channel *);
88
89 static __inline__ uint8_t
ieee80211_ack_rate(const struct ieee80211_rate_table * rt,uint8_t rate)90 ieee80211_ack_rate(const struct ieee80211_rate_table *rt, uint8_t rate)
91 {
92 /*
93 * XXX Assert this is for a legacy rate; not for an MCS rate.
94 * If the caller wishes to use it for a basic rate, they should
95 * clear the high bit first.
96 */
97 KASSERT(! (rate & 0x80), ("rate %d is basic/mcs?", rate));
98
99 uint8_t cix = rt->info[rt->rateCodeToIndex[rate & IEEE80211_RATE_VAL]].ctlRateIndex;
100 KASSERT(cix != (uint8_t)-1, ("rate %d has no info", rate));
101 return rt->info[cix].dot11Rate;
102 }
103
104 static __inline__ uint8_t
ieee80211_ctl_rate(const struct ieee80211_rate_table * rt,uint8_t rate)105 ieee80211_ctl_rate(const struct ieee80211_rate_table *rt, uint8_t rate)
106 {
107 /*
108 * XXX Assert this is for a legacy rate; not for an MCS rate.
109 * If the caller wishes to use it for a basic rate, they should
110 * clear the high bit first.
111 */
112 KASSERT(! (rate & 0x80), ("rate %d is basic/mcs?", rate));
113
114 uint8_t cix = rt->info[rt->rateCodeToIndex[rate & IEEE80211_RATE_VAL]].ctlRateIndex;
115 KASSERT(cix != (uint8_t)-1, ("rate %d has no info", rate));
116 return rt->info[cix].dot11Rate;
117 }
118
119 static __inline__ enum ieee80211_phytype
ieee80211_rate2phytype(const struct ieee80211_rate_table * rt,uint8_t rate)120 ieee80211_rate2phytype(const struct ieee80211_rate_table *rt, uint8_t rate)
121 {
122 /*
123 * XXX Assert this is for a legacy rate; not for an MCS rate.
124 * If the caller wishes to use it for a basic rate, they should
125 * clear the high bit first.
126 */
127 KASSERT(! (rate & 0x80), ("rate %d is basic/mcs?", rate));
128
129 uint8_t rix = rt->rateCodeToIndex[rate & IEEE80211_RATE_VAL];
130 KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate));
131 return rt->info[rix].phy;
132 }
133
134 static __inline__ int
ieee80211_isratevalid(const struct ieee80211_rate_table * rt,uint8_t rate)135 ieee80211_isratevalid(const struct ieee80211_rate_table *rt, uint8_t rate)
136 {
137 /*
138 * XXX Assert this is for a legacy rate; not for an MCS rate.
139 * If the caller wishes to use it for a basic rate, they should
140 * clear the high bit first.
141 */
142 KASSERT(! (rate & 0x80), ("rate %d is basic/mcs?", rate));
143
144 return rt->rateCodeToIndex[rate] != (uint8_t)-1;
145 }
146
147 /*
148 * Calculate ACK field for
149 * o non-fragment data frames
150 * o management frames
151 * sent using rate, phy and short preamble setting.
152 */
153 static __inline__ uint16_t
ieee80211_ack_duration(const struct ieee80211_rate_table * rt,uint8_t rate,int isShortPreamble)154 ieee80211_ack_duration(const struct ieee80211_rate_table *rt,
155 uint8_t rate, int isShortPreamble)
156 {
157 uint8_t rix = rt->rateCodeToIndex[rate];
158
159 KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate));
160 if (isShortPreamble) {
161 KASSERT(rt->info[rix].spAckDuration != 0,
162 ("shpreamble ack dur is not computed!\n"));
163 return rt->info[rix].spAckDuration;
164 } else {
165 KASSERT(rt->info[rix].lpAckDuration != 0,
166 ("lgpreamble ack dur is not computed!\n"));
167 return rt->info[rix].lpAckDuration;
168 }
169 }
170
171 static __inline__ uint8_t
ieee80211_legacy_rate_lookup(const struct ieee80211_rate_table * rt,uint8_t rate)172 ieee80211_legacy_rate_lookup(const struct ieee80211_rate_table *rt,
173 uint8_t rate)
174 {
175
176 return (rt->rateCodeToIndex[rate & IEEE80211_RATE_VAL]);
177 }
178
179 /*
180 * Compute the time to transmit a frame of length frameLen bytes
181 * using the specified 802.11 rate code, phy, and short preamble
182 * setting.
183 *
184 * NB: SIFS is included.
185 */
186 uint16_t ieee80211_compute_duration(const struct ieee80211_rate_table *,
187 uint32_t frameLen, uint16_t rate, int isShortPreamble);
188 /*
189 * Convert PLCP signal/rate field to 802.11 rate code (.5Mbits/s)
190 */
191 uint8_t ieee80211_plcp2rate(uint8_t, enum ieee80211_phytype);
192 /*
193 * Convert 802.11 rate code to PLCP signal.
194 */
195 uint8_t ieee80211_rate2plcp(int, enum ieee80211_phytype);
196
197 /*
198 * 802.11n rate manipulation.
199 */
200
201 #define IEEE80211_HT_RC_2_MCS(_rc) ((_rc) & 0x1f)
202 #define IEEE80211_HT_RC_2_STREAMS(_rc) ((((_rc) & 0x78) >> 3) + 1)
203 #define IEEE80211_IS_HT_RATE(_rc) ( (_rc) & IEEE80211_RATE_MCS)
204
205 uint32_t ieee80211_compute_duration_ht(uint32_t frameLen,
206 uint16_t rate, int streams, int isht40,
207 int isShortGI);
208
209 #endif /* _KERNEL */
210 #endif /* !_NET80211_IEEE80211_PHY_H_ */
211