sys/netproto/802_11/ieee80211_phy.h

   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
  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
 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
 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
 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
 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
 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_ */