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-rw-r--r--sys/net80211/ieee80211_phy.c472
1 files changed, 472 insertions, 0 deletions
diff --git a/sys/net80211/ieee80211_phy.c b/sys/net80211/ieee80211_phy.c
new file mode 100644
index 0000000..e1c847f
--- /dev/null
+++ b/sys/net80211/ieee80211_phy.c
@@ -0,0 +1,472 @@
+/*-
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * IEEE 802.11 PHY-related support.
+ */
+
+#include "opt_inet.h"
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/systm.h>
+
+#include <sys/socket.h>
+
+#include <net/if.h>
+#include <net/if_media.h>
+
+#include <net80211/ieee80211_var.h>
+#include <net80211/ieee80211_phy.h>
+
+#ifdef notyet
+struct ieee80211_ds_plcp_hdr {
+ uint8_t i_signal;
+ uint8_t i_service;
+ uint16_t i_length;
+ uint16_t i_crc;
+} __packed;
+
+#endif /* notyet */
+
+/* shorthands to compact tables for readability */
+#define OFDM IEEE80211_T_OFDM
+#define CCK IEEE80211_T_CCK
+#define TURBO IEEE80211_T_TURBO
+#define PBCC (IEEE80211_T_HT+1) /* XXX */
+
+static struct ieee80211_rate_table ieee80211_11b_table = {
+ 4, /* number of rates, XXX no PBCC */
+ { 0 },
+ {
+/* short ctrl */
+/* Preamble dot11Rate Rate */
+/* 1 Mb */ { CCK, 1000, 0x00, (0x80| 2), 0 },
+/* 2 Mb */ { CCK, 2000, 0x04, (0x80| 4), 1 },
+/* 5.5 Mb */ { CCK, 5500, 0x04, (0x80|11), 1 },
+/* 11 Mb */ { CCK, 11000, 0x04, (0x80|22), 1 },
+/* 22 Mb */ { PBCC, 22000, 0x04, 44, 3 }
+ },
+};
+
+
+static struct ieee80211_rate_table ieee80211_11g_table = {
+ 12, /* number of rates */
+ { 0 },
+ {
+/* short ctrl */
+/* Preamble dot11Rate Rate */
+/* 1 Mb */ { CCK, 1000, 0x00, (0x80| 2), 0 },
+/* 2 Mb */ { CCK, 2000, 0x04, (0x80| 4), 1 },
+/* 5.5 Mb */ { CCK, 5500, 0x04, (0x80|11), 2 },
+/* 11 Mb */ { CCK, 11000, 0x04, (0x80|22), 3 },
+/* 6 Mb */ { OFDM, 6000, 0x00, 12, 4 },
+/* 9 Mb */ { OFDM, 9000, 0x00, 18, 4 },
+/* 12 Mb */ { OFDM, 12000, 0x00, 24, 6 },
+/* 18 Mb */ { OFDM, 18000, 0x00, 36, 6 },
+/* 24 Mb */ { OFDM, 24000, 0x00, 48, 8 },
+/* 36 Mb */ { OFDM, 36000, 0x00, 72, 8 },
+/* 48 Mb */ { OFDM, 48000, 0x00, 96, 8 },
+/* 54 Mb */ { OFDM, 54000, 0x00, 108, 8 }
+ },
+};
+
+static struct ieee80211_rate_table ieee80211_11a_table = {
+ 8, /* number of rates */
+ { 0 },
+ {
+/* short ctrl */
+/* Preamble dot11Rate Rate */
+/* 6 Mb */ { OFDM, 6000, 0x00, (0x80|12), 0 },
+/* 9 Mb */ { OFDM, 9000, 0x00, 18, 0 },
+/* 12 Mb */ { OFDM, 12000, 0x00, (0x80|24), 2 },
+/* 18 Mb */ { OFDM, 18000, 0x00, 36, 2 },
+/* 24 Mb */ { OFDM, 24000, 0x00, (0x80|48), 4 },
+/* 36 Mb */ { OFDM, 36000, 0x00, 72, 4 },
+/* 48 Mb */ { OFDM, 48000, 0x00, 96, 4 },
+/* 54 Mb */ { OFDM, 54000, 0x00, 108, 4 }
+ },
+};
+
+static struct ieee80211_rate_table ieee80211_half_table = {
+ 8, /* number of rates */
+ { 0 },
+ {
+/* short ctrl */
+/* Preamble dot11Rate Rate */
+/* 6 Mb */ { OFDM, 3000, 0x00, (0x80| 6), 0 },
+/* 9 Mb */ { OFDM, 4500, 0x00, 9, 0 },
+/* 12 Mb */ { OFDM, 6000, 0x00, (0x80|12), 2 },
+/* 18 Mb */ { OFDM, 9000, 0x00, 18, 2 },
+/* 24 Mb */ { OFDM, 12000, 0x00, (0x80|24), 4 },
+/* 36 Mb */ { OFDM, 18000, 0x00, 36, 4 },
+/* 48 Mb */ { OFDM, 24000, 0x00, 48, 4 },
+/* 54 Mb */ { OFDM, 27000, 0x00, 54, 4 }
+ },
+};
+
+static struct ieee80211_rate_table ieee80211_quarter_table = {
+ 8, /* number of rates */
+ { 0 },
+ {
+/* short ctrl */
+/* Preamble dot11Rate Rate */
+/* 6 Mb */ { OFDM, 1500, 0x00, (0x80| 3), 0 },
+/* 9 Mb */ { OFDM, 2250, 0x00, 4, 0 },
+/* 12 Mb */ { OFDM, 3000, 0x00, (0x80| 6), 2 },
+/* 18 Mb */ { OFDM, 4500, 0x00, 9, 2 },
+/* 24 Mb */ { OFDM, 6000, 0x00, (0x80|12), 4 },
+/* 36 Mb */ { OFDM, 9000, 0x00, 18, 4 },
+/* 48 Mb */ { OFDM, 12000, 0x00, 24, 4 },
+/* 54 Mb */ { OFDM, 13500, 0x00, 27, 4 }
+ },
+};
+
+static struct ieee80211_rate_table ieee80211_turbog_table = {
+ 7, /* number of rates */
+ { 0 },
+ {
+/* short ctrl */
+/* Preamble dot11Rate Rate */
+/* 6 Mb */ { TURBO, 6000, 0x00, (0x80|12), 0 },
+/* 12 Mb */ { TURBO, 12000, 0x00, (0x80|24), 1 },
+/* 18 Mb */ { TURBO, 18000, 0x00, 36, 1 },
+/* 24 Mb */ { TURBO, 24000, 0x00, (0x80|48), 3 },
+/* 36 Mb */ { TURBO, 36000, 0x00, 72, 3 },
+/* 48 Mb */ { TURBO, 48000, 0x00, 96, 3 },
+/* 54 Mb */ { TURBO, 54000, 0x00, 108, 3 }
+ },
+};
+
+static struct ieee80211_rate_table ieee80211_turboa_table = {
+ 8, /* number of rates */
+ { 0 },
+ {
+/* short ctrl */
+/* Preamble dot11Rate Rate */
+/* 6 Mb */ { TURBO, 6000, 0x00, (0x80|12), 0 },
+/* 9 Mb */ { TURBO, 9000, 0x00, 18, 0 },
+/* 12 Mb */ { TURBO, 12000, 0x00, (0x80|24), 2 },
+/* 18 Mb */ { TURBO, 18000, 0x00, 36, 2 },
+/* 24 Mb */ { TURBO, 24000, 0x00, (0x80|48), 4 },
+/* 36 Mb */ { TURBO, 36000, 0x00, 72, 4 },
+/* 48 Mb */ { TURBO, 48000, 0x00, 96, 4 },
+/* 54 Mb */ { TURBO, 54000, 0x00, 108, 4 }
+ },
+};
+
+#undef OFDM
+#undef CCK
+#undef TURBO
+#undef XR
+
+/*
+ * Setup a rate table's reverse lookup table and fill in
+ * ack durations. The reverse lookup tables are assumed
+ * to be initialized to zero (or at least the first entry).
+ * We use this as a key that indicates whether or not
+ * we've previously setup the reverse lookup table.
+ *
+ * XXX not reentrant, but shouldn't matter
+ */
+static void
+ieee80211_setup_ratetable(struct ieee80211_rate_table *rt)
+{
+#define N(a) (sizeof(a)/sizeof(a[0]))
+#define WLAN_CTRL_FRAME_SIZE \
+ (sizeof(struct ieee80211_frame_ack) + IEEE80211_CRC_LEN)
+
+ int i;
+
+ for (i = 0; i < N(rt->rateCodeToIndex); i++)
+ rt->rateCodeToIndex[i] = (uint8_t) -1;
+ for (i = 0; i < rt->rateCount; i++) {
+ uint8_t code = rt->info[i].dot11Rate;
+ uint8_t cix = rt->info[i].ctlRateIndex;
+ uint8_t ctl_rate = rt->info[cix].dot11Rate;
+
+ rt->rateCodeToIndex[code] = i;
+ if (code & IEEE80211_RATE_BASIC) {
+ /*
+ * Map w/o basic rate bit too.
+ */
+ code &= IEEE80211_RATE_VAL;
+ rt->rateCodeToIndex[code] = i;
+ }
+
+ /*
+ * XXX for 11g the control rate to use for 5.5 and 11 Mb/s
+ * depends on whether they are marked as basic rates;
+ * the static tables are setup with an 11b-compatible
+ * 2Mb/s rate which will work but is suboptimal
+ *
+ * NB: Control rate is always less than or equal to the
+ * current rate, so control rate's reverse lookup entry
+ * has been installed and following call is safe.
+ */
+ rt->info[i].lpAckDuration = ieee80211_compute_duration(rt,
+ WLAN_CTRL_FRAME_SIZE, ctl_rate, 0);
+ rt->info[i].spAckDuration = ieee80211_compute_duration(rt,
+ WLAN_CTRL_FRAME_SIZE, ctl_rate, IEEE80211_F_SHPREAMBLE);
+ }
+
+#undef WLAN_CTRL_FRAME_SIZE
+#undef N
+}
+
+/* Setup all rate tables */
+static void
+ieee80211_phy_init(void)
+{
+#define N(arr) (int)(sizeof(arr) / sizeof(arr[0]))
+ static struct ieee80211_rate_table * const ratetables[] = {
+ &ieee80211_half_table,
+ &ieee80211_quarter_table,
+ &ieee80211_11a_table,
+ &ieee80211_11g_table,
+ &ieee80211_turbog_table,
+ &ieee80211_turboa_table,
+ &ieee80211_turboa_table,
+ &ieee80211_11a_table,
+ &ieee80211_11g_table,
+ &ieee80211_11b_table
+ };
+ int i;
+
+ for (i = 0; i < N(ratetables); ++i)
+ ieee80211_setup_ratetable(ratetables[i]);
+
+#undef N
+}
+SYSINIT(wlan_phy, SI_SUB_DRIVERS, SI_ORDER_FIRST, ieee80211_phy_init, NULL);
+
+const struct ieee80211_rate_table *
+ieee80211_get_ratetable(struct ieee80211_channel *c)
+{
+ const struct ieee80211_rate_table *rt;
+
+ /* XXX HT */
+ if (IEEE80211_IS_CHAN_HALF(c))
+ rt = &ieee80211_half_table;
+ else if (IEEE80211_IS_CHAN_QUARTER(c))
+ rt = &ieee80211_quarter_table;
+ else if (IEEE80211_IS_CHAN_HTA(c))
+ rt = &ieee80211_11a_table; /* XXX */
+ else if (IEEE80211_IS_CHAN_HTG(c))
+ rt = &ieee80211_11g_table; /* XXX */
+ else if (IEEE80211_IS_CHAN_108G(c))
+ rt = &ieee80211_turbog_table;
+ else if (IEEE80211_IS_CHAN_ST(c))
+ rt = &ieee80211_turboa_table;
+ else if (IEEE80211_IS_CHAN_TURBO(c))
+ rt = &ieee80211_turboa_table;
+ else if (IEEE80211_IS_CHAN_A(c))
+ rt = &ieee80211_11a_table;
+ else if (IEEE80211_IS_CHAN_ANYG(c))
+ rt = &ieee80211_11g_table;
+ else if (IEEE80211_IS_CHAN_B(c))
+ rt = &ieee80211_11b_table;
+ else {
+ /* NB: should not get here */
+ panic("%s: no rate table for channel; freq %u flags 0x%x\n",
+ __func__, c->ic_freq, c->ic_flags);
+ }
+ return rt;
+}
+
+/*
+ * Convert PLCP signal/rate field to 802.11 rate (.5Mbits/s)
+ *
+ * Note we do no parameter checking; this routine is mainly
+ * used to derive an 802.11 rate for constructing radiotap
+ * header data for rx frames.
+ *
+ * XXX might be a candidate for inline
+ */
+uint8_t
+ieee80211_plcp2rate(uint8_t plcp, int ofdm)
+{
+ if (ofdm) {
+ static const uint8_t ofdm_plcp2rate[16] = {
+ [0xb] = 12,
+ [0xf] = 18,
+ [0xa] = 24,
+ [0xe] = 36,
+ [0x9] = 48,
+ [0xd] = 72,
+ [0x8] = 96,
+ [0xc] = 108
+ };
+ return ofdm_plcp2rate[plcp & 0xf];
+ } else {
+ static const uint8_t cck_plcp2rate[16] = {
+ [0xa] = 2, /* 0x0a */
+ [0x4] = 4, /* 0x14 */
+ [0x7] = 11, /* 0x37 */
+ [0xe] = 22, /* 0x6e */
+ [0xc] = 44, /* 0xdc , actually PBCC */
+ };
+ return cck_plcp2rate[plcp & 0xf];
+ }
+}
+
+/*
+ * Covert 802.11 rate to PLCP signal.
+ */
+uint8_t
+ieee80211_rate2plcp(int rate)
+{
+ switch (rate) {
+ /* CCK rates (returned values are device-dependent) */
+ case 2: return 0x0;
+ case 4: return 0x1;
+ case 11: return 0x2;
+ case 22: return 0x3;
+
+ /* OFDM rates (cf IEEE Std 802.11a-1999, pp. 14 Table 80) */
+ case 12: return 0xb;
+ case 18: return 0xf;
+ case 24: return 0xa;
+ case 36: return 0xe;
+ case 48: return 0x9;
+ case 72: return 0xd;
+ case 96: return 0x8;
+ case 108: return 0xc;
+ }
+ return 0xff; /* XXX unsupported/unknown rate */
+}
+/*
+ * Compute the time to transmit a frame of length frameLen bytes
+ * using the specified rate, phy, and short preamble setting.
+ * SIFS is included.
+ */
+uint16_t
+ieee80211_compute_duration(const struct ieee80211_rate_table *rt,
+ uint32_t frameLen, uint16_t rate, int isShortPreamble)
+{
+ uint8_t rix = rt->rateCodeToIndex[rate];
+ uint32_t bitsPerSymbol, numBits, numSymbols, phyTime, txTime;
+ uint32_t kbps;
+
+ KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate));
+ kbps = rt->info[rix].rateKbps;
+ if (kbps == 0) /* XXX bandaid for channel changes */
+ return 0;
+
+ switch (rt->info[rix].phy) {
+ case IEEE80211_T_CCK:
+#define CCK_SIFS_TIME 10
+#define CCK_PREAMBLE_BITS 144
+#define CCK_PLCP_BITS 48
+ phyTime = CCK_PREAMBLE_BITS + CCK_PLCP_BITS;
+ if (isShortPreamble && rt->info[rix].shortPreamble)
+ phyTime >>= 1;
+ numBits = frameLen << 3;
+ txTime = CCK_SIFS_TIME + phyTime
+ + ((numBits * 1000)/kbps);
+ break;
+#undef CCK_SIFS_TIME
+#undef CCK_PREAMBLE_BITS
+#undef CCK_PLCP_BITS
+
+ case IEEE80211_T_OFDM:
+#define OFDM_SIFS_TIME 16
+#define OFDM_PREAMBLE_TIME 20
+#define OFDM_PLCP_BITS 22
+#define OFDM_SYMBOL_TIME 4
+
+#define OFDM_SIFS_TIME_HALF 32
+#define OFDM_PREAMBLE_TIME_HALF 40
+#define OFDM_PLCP_BITS_HALF 22
+#define OFDM_SYMBOL_TIME_HALF 8
+
+#define OFDM_SIFS_TIME_QUARTER 64
+#define OFDM_PREAMBLE_TIME_QUARTER 80
+#define OFDM_PLCP_BITS_QUARTER 22
+#define OFDM_SYMBOL_TIME_QUARTER 16
+ if (rt == &ieee80211_half_table) {
+ bitsPerSymbol = (kbps * OFDM_SYMBOL_TIME_QUARTER) / 1000;
+ KASSERT(bitsPerSymbol != 0, ("1/2 rate bps"));
+
+ numBits = OFDM_PLCP_BITS + (frameLen << 3);
+ numSymbols = howmany(numBits, bitsPerSymbol);
+ txTime = OFDM_SIFS_TIME_QUARTER
+ + OFDM_PREAMBLE_TIME_QUARTER
+ + (numSymbols * OFDM_SYMBOL_TIME_QUARTER);
+ } else if (rt == &ieee80211_quarter_table) {
+ bitsPerSymbol = (kbps * OFDM_SYMBOL_TIME_HALF) / 1000;
+ KASSERT(bitsPerSymbol != 0, ("1/4 rate bps"));
+
+ numBits = OFDM_PLCP_BITS + (frameLen << 3);
+ numSymbols = howmany(numBits, bitsPerSymbol);
+ txTime = OFDM_SIFS_TIME_HALF
+ + OFDM_PREAMBLE_TIME_HALF
+ + (numSymbols * OFDM_SYMBOL_TIME_HALF);
+ } else { /* full rate channel */
+ bitsPerSymbol = (kbps * OFDM_SYMBOL_TIME) / 1000;
+ KASSERT(bitsPerSymbol != 0, ("full rate bps"));
+
+ numBits = OFDM_PLCP_BITS + (frameLen << 3);
+ numSymbols = howmany(numBits, bitsPerSymbol);
+ txTime = OFDM_SIFS_TIME
+ + OFDM_PREAMBLE_TIME
+ + (numSymbols * OFDM_SYMBOL_TIME);
+ }
+ break;
+
+#undef OFDM_SIFS_TIME
+#undef OFDM_PREAMBLE_TIME
+#undef OFDM_PLCP_BITS
+#undef OFDM_SYMBOL_TIME
+
+ case IEEE80211_T_TURBO:
+#define TURBO_SIFS_TIME 8
+#define TURBO_PREAMBLE_TIME 14
+#define TURBO_PLCP_BITS 22
+#define TURBO_SYMBOL_TIME 4
+ /* we still save OFDM rates in kbps - so double them */
+ bitsPerSymbol = ((kbps << 1) * TURBO_SYMBOL_TIME) / 1000;
+ KASSERT(bitsPerSymbol != 0, ("turbo bps"));
+
+ numBits = TURBO_PLCP_BITS + (frameLen << 3);
+ numSymbols = howmany(numBits, bitsPerSymbol);
+ txTime = TURBO_SIFS_TIME + TURBO_PREAMBLE_TIME
+ + (numSymbols * TURBO_SYMBOL_TIME);
+ break;
+#undef TURBO_SIFS_TIME
+#undef TURBO_PREAMBLE_TIME
+#undef TURBO_PLCP_BITS
+#undef TURBO_SYMBOL_TIME
+
+ default:
+ panic("%s: unknown phy %u (rate %u)\n", __func__,
+ rt->info[rix].phy, rate);
+ break;
+ }
+ return txTime;
+}
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