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: head/sys/net80211/ieee80211_phy.h 193072 2009-05-29 23:39:16Z sam $
  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 static __inline__ int
 108 ieee80211_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  */
 119 static __inline__ uint16_t
 120 ieee80211_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  */
 144 uint16_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  */
 149 uint8_t         ieee80211_plcp2rate(uint8_t, enum ieee80211_phytype);
 150 /*
 151  * Convert 802.11 rate code to PLCP signal.
 152  */
 153 uint8_t         ieee80211_rate2plcp(int, enum ieee80211_phytype);
 154 #endif  /* _KERNEL */
 155 #endif  /* !_NET80211_IEEE80211_PHY_H_ */