freebsd-dev/sys/net80211/ieee80211_phy.h
2009-05-29 23:39:16 +00:00

156 lines
5.0 KiB
C

/*-
* Copyright (c) 2007-2008 Sam Leffler, Errno Consulting
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _NET80211_IEEE80211_PHY_H_
#define _NET80211_IEEE80211_PHY_H_
#ifdef _KERNEL
/*
* IEEE 802.11 PHY-related definitions.
*/
/*
* Contention window (slots).
*/
#define IEEE80211_CW_MAX 1023 /* aCWmax */
#define IEEE80211_CW_MIN_0 31 /* DS/CCK aCWmin, ERP aCWmin(0) */
#define IEEE80211_CW_MIN_1 15 /* OFDM aCWmin, ERP aCWmin(1) */
/*
* SIFS (microseconds).
*/
#define IEEE80211_DUR_SIFS 10 /* DS/CCK/ERP SIFS */
#define IEEE80211_DUR_OFDM_SIFS 16 /* OFDM SIFS */
/*
* Slot time (microseconds).
*/
#define IEEE80211_DUR_SLOT 20 /* DS/CCK slottime, ERP long slottime */
#define IEEE80211_DUR_SHSLOT 9 /* ERP short slottime */
#define IEEE80211_DUR_OFDM_SLOT 9 /* OFDM slottime */
/*
* DIFS (microseconds).
*/
#define IEEE80211_DUR_DIFS(sifs, slot) ((sifs) + 2 * (slot))
struct ieee80211_channel;
struct ieee80211_rate_table {
int rateCount; /* NB: for proper padding */
uint8_t rateCodeToIndex[256]; /* back mapping */
struct {
uint8_t phy; /* CCK/OFDM/TURBO */
uint32_t rateKbps; /* transfer rate in kbs */
uint8_t shortPreamble; /* mask for enabling short
* preamble in CCK rate code */
uint8_t dot11Rate; /* value for supported rates
* info element of MLME */
uint8_t ctlRateIndex; /* index of next lower basic
* rate; used for dur. calcs */
uint16_t lpAckDuration; /* long preamble ACK dur. */
uint16_t spAckDuration; /* short preamble ACK dur. */
} info[32];
};
const struct ieee80211_rate_table *ieee80211_get_ratetable(
struct ieee80211_channel *);
static __inline__ uint8_t
ieee80211_ack_rate(const struct ieee80211_rate_table *rt, uint8_t rate)
{
uint8_t cix = rt->info[rt->rateCodeToIndex[rate]].ctlRateIndex;
KASSERT(cix != (uint8_t)-1, ("rate %d has no info", rate));
return rt->info[cix].dot11Rate;
}
static __inline__ uint8_t
ieee80211_ctl_rate(const struct ieee80211_rate_table *rt, uint8_t rate)
{
uint8_t cix = rt->info[rt->rateCodeToIndex[rate]].ctlRateIndex;
KASSERT(cix != (uint8_t)-1, ("rate %d has no info", rate));
return rt->info[cix].dot11Rate;
}
static __inline__ enum ieee80211_phytype
ieee80211_rate2phytype(const struct ieee80211_rate_table *rt, uint8_t rate)
{
uint8_t rix = rt->rateCodeToIndex[rate];
KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate));
return rt->info[rix].phy;
}
static __inline__ int
ieee80211_isratevalid(const struct ieee80211_rate_table *rt, uint8_t rate)
{
return rt->rateCodeToIndex[rate] != (uint8_t)-1;
}
/*
* Calculate ACK field for
* o non-fragment data frames
* o management frames
* sent using rate, phy and short preamble setting.
*/
static __inline__ uint16_t
ieee80211_ack_duration(const struct ieee80211_rate_table *rt,
uint8_t rate, int isShortPreamble)
{
uint8_t rix = rt->rateCodeToIndex[rate];
KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate));
if (isShortPreamble) {
KASSERT(rt->info[rix].spAckDuration != 0,
("shpreamble ack dur is not computed!\n"));
return rt->info[rix].spAckDuration;
} else {
KASSERT(rt->info[rix].lpAckDuration != 0,
("lgpreamble ack dur is not computed!\n"));
return rt->info[rix].lpAckDuration;
}
}
/*
* Compute the time to transmit a frame of length frameLen bytes
* using the specified 802.11 rate code, phy, and short preamble
* setting.
*
* NB: SIFS is included.
*/
uint16_t ieee80211_compute_duration(const struct ieee80211_rate_table *,
uint32_t frameLen, uint16_t rate, int isShortPreamble);
/*
* Convert PLCP signal/rate field to 802.11 rate code (.5Mbits/s)
*/
uint8_t ieee80211_plcp2rate(uint8_t, enum ieee80211_phytype);
/*
* Convert 802.11 rate code to PLCP signal.
*/
uint8_t ieee80211_rate2plcp(int, enum ieee80211_phytype);
#endif /* _KERNEL */
#endif /* !_NET80211_IEEE80211_PHY_H_ */