/*- * Copyright (c) 2007-2009 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: src/tools/tools/net80211/wlantxtime/wlantxtime.c,v 1.2 2009/02/19 05:36:07 sam Exp $ */ /* * IEEE 802.11 PHY-related support. */ #include #include #include #include #include #define IEEE80211_F_SHPREAMBLE 0x00040000 /* STATUS: use short preamble */ #include #include #include #include #include #include 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]; }; uint16_t ieee80211_compute_duration(const struct ieee80211_rate_table *rt, uint32_t frameLen, uint16_t rate, int isShortPreamble); #define KASSERT(c, msg) do { \ if (!(c)) { \ printf msg; \ putchar('\n'); \ exit(-1); \ } \ } while (0) static void panic(const char *fmt, ...) { va_list ap; va_start(ap, fmt); vprintf(fmt, ap); va_end(ap); exit(-1); } /* shorthands to compact tables for readability */ #define OFDM IEEE80211_T_OFDM #define CCK IEEE80211_T_CCK #define TURBO IEEE80211_T_TURBO #define HALF IEEE80211_T_OFDM_HALF #define QUART IEEE80211_T_OFDM_QUARTER #define PBCC (IEEE80211_T_OFDM_QUARTER+1) /* XXX */ #define B(r) (0x80 | r) #define Mb(x) (x*1000) static struct ieee80211_rate_table ieee80211_11b_table = { .rateCount = 4, /* XXX no PBCC */ .info = { /* short ctrl */ /* Preamble dot11Rate Rate */ [0] = { .phy = CCK, 1000, 0x00, B(2), 0 },/* 1 Mb */ [1] = { .phy = CCK, 2000, 0x04, B(4), 1 },/* 2 Mb */ [2] = { .phy = CCK, 5500, 0x04, B(11), 1 },/* 5.5 Mb */ [3] = { .phy = CCK, 11000, 0x04, B(22), 1 },/* 11 Mb */ [4] = { .phy = PBCC, 22000, 0x04, 44, 3 } /* 22 Mb */ }, }; static struct ieee80211_rate_table ieee80211_11g_table = { .rateCount = 12, .info = { /* short ctrl */ /* Preamble dot11Rate Rate */ [0] = { .phy = CCK, 1000, 0x00, B(2), 0 }, [1] = { .phy = CCK, 2000, 0x04, B(4), 1 }, [2] = { .phy = CCK, 5500, 0x04, B(11), 2 }, [3] = { .phy = CCK, 11000, 0x04, B(22), 3 }, [4] = { .phy = OFDM, 6000, 0x00, 12, 4 }, [5] = { .phy = OFDM, 9000, 0x00, 18, 4 }, [6] = { .phy = OFDM, 12000, 0x00, 24, 6 }, [7] = { .phy = OFDM, 18000, 0x00, 36, 6 }, [8] = { .phy = OFDM, 24000, 0x00, 48, 8 }, [9] = { .phy = OFDM, 36000, 0x00, 72, 8 }, [10] = { .phy = OFDM, 48000, 0x00, 96, 8 }, [11] = { .phy = OFDM, 54000, 0x00, 108, 8 } }, }; static struct ieee80211_rate_table ieee80211_11a_table = { .rateCount = 8, .info = { /* short ctrl */ /* Preamble dot11Rate Rate */ [0] = { .phy = OFDM, 6000, 0x00, B(12), 0 }, [1] = { .phy = OFDM, 9000, 0x00, 18, 0 }, [2] = { .phy = OFDM, 12000, 0x00, B(24), 2 }, [3] = { .phy = OFDM, 18000, 0x00, 36, 2 }, [4] = { .phy = OFDM, 24000, 0x00, B(48), 4 }, [5] = { .phy = OFDM, 36000, 0x00, 72, 4 }, [6] = { .phy = OFDM, 48000, 0x00, 96, 4 }, [7] = { .phy = OFDM, 54000, 0x00, 108, 4 } }, }; static struct ieee80211_rate_table ieee80211_half_table = { .rateCount = 8, .info = { /* short ctrl */ /* Preamble dot11Rate Rate */ [0] = { .phy = HALF, 3000, 0x00, B(6), 0 }, [1] = { .phy = HALF, 4500, 0x00, 9, 0 }, [2] = { .phy = HALF, 6000, 0x00, B(12), 2 }, [3] = { .phy = HALF, 9000, 0x00, 18, 2 }, [4] = { .phy = HALF, 12000, 0x00, B(24), 4 }, [5] = { .phy = HALF, 18000, 0x00, 36, 4 }, [6] = { .phy = HALF, 24000, 0x00, 48, 4 }, [7] = { .phy = HALF, 27000, 0x00, 54, 4 } }, }; static struct ieee80211_rate_table ieee80211_quarter_table = { .rateCount = 8, .info = { /* short ctrl */ /* Preamble dot11Rate Rate */ [0] = { .phy = QUART, 1500, 0x00, B(3), 0 }, [1] = { .phy = QUART, 2250, 0x00, 4, 0 }, [2] = { .phy = QUART, 3000, 0x00, B(9), 2 }, [3] = { .phy = QUART, 4500, 0x00, 9, 2 }, [4] = { .phy = QUART, 6000, 0x00, B(12), 4 }, [5] = { .phy = QUART, 9000, 0x00, 18, 4 }, [6] = { .phy = QUART, 12000, 0x00, 24, 4 }, [7] = { .phy = QUART, 13500, 0x00, 27, 4 } }, }; static struct ieee80211_rate_table ieee80211_turbog_table = { .rateCount = 7, .info = { /* short ctrl */ /* Preamble dot11Rate Rate */ [0] = { .phy = TURBO, 12000, 0x00, B(12), 0 }, [1] = { .phy = TURBO, 24000, 0x00, B(24), 1 }, [2] = { .phy = TURBO, 36000, 0x00, 36, 1 }, [3] = { .phy = TURBO, 48000, 0x00, B(48), 3 }, [4] = { .phy = TURBO, 72000, 0x00, 72, 3 }, [5] = { .phy = TURBO, 96000, 0x00, 96, 3 }, [6] = { .phy = TURBO, 108000, 0x00, 108, 3 } }, }; static struct ieee80211_rate_table ieee80211_turboa_table = { .rateCount = 8, .info = { /* short ctrl */ /* Preamble dot11Rate Rate */ [0] = { .phy = TURBO, 12000, 0x00, B(12), 0 }, [1] = { .phy = TURBO, 18000, 0x00, 18, 0 }, [2] = { .phy = TURBO, 24000, 0x00, B(24), 2 }, [3] = { .phy = TURBO, 36000, 0x00, 36, 2 }, [4] = { .phy = TURBO, 48000, 0x00, B(48), 4 }, [5] = { .phy = TURBO, 72000, 0x00, 72, 4 }, [6] = { .phy = TURBO, 96000, 0x00, 96, 4 }, [7] = { .phy = TURBO, 108000, 0x00, 108, 4 } }, }; #undef Mb #undef B #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 } #define CCK_SIFS_TIME 10 #define CCK_PREAMBLE_BITS 144 #define CCK_PLCP_BITS 48 #define OFDM_SIFS_TIME 16 #define OFDM_PREAMBLE_TIME 20 #define OFDM_PLCP_BITS 22 #define OFDM_SYMBOL_TIME 4 #define OFDM_HALF_SIFS_TIME 32 #define OFDM_HALF_PREAMBLE_TIME 40 #define OFDM_HALF_PLCP_BITS 22 #define OFDM_HALF_SYMBOL_TIME 8 #define OFDM_QUARTER_SIFS_TIME 64 #define OFDM_QUARTER_PREAMBLE_TIME 80 #define OFDM_QUARTER_PLCP_BITS 22 #define OFDM_QUARTER_SYMBOL_TIME 16 #define TURBO_SIFS_TIME 8 #define TURBO_PREAMBLE_TIME 14 #define TURBO_PLCP_BITS 22 #define TURBO_SYMBOL_TIME 4 #define HT_L_STF 8 #define HT_L_LTF 8 #define HT_L_SIG 4 #define HT_SIG 8 #define HT_STF 4 #define HT_LTF(n) ((n) * 4) /* * 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: 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; case IEEE80211_T_OFDM: 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; case IEEE80211_T_OFDM_HALF: bitsPerSymbol = (kbps * OFDM_HALF_SYMBOL_TIME) / 1000; KASSERT(bitsPerSymbol != 0, ("1/4 rate bps")); numBits = OFDM_PLCP_BITS + (frameLen << 3); numSymbols = howmany(numBits, bitsPerSymbol); txTime = OFDM_HALF_SIFS_TIME + OFDM_HALF_PREAMBLE_TIME + (numSymbols * OFDM_HALF_SYMBOL_TIME); break; case IEEE80211_T_OFDM_QUARTER: bitsPerSymbol = (kbps * OFDM_QUARTER_SYMBOL_TIME) / 1000; KASSERT(bitsPerSymbol != 0, ("1/2 rate bps")); numBits = OFDM_PLCP_BITS + (frameLen << 3); numSymbols = howmany(numBits, bitsPerSymbol); txTime = OFDM_QUARTER_SIFS_TIME + OFDM_QUARTER_PREAMBLE_TIME + (numSymbols * OFDM_QUARTER_SYMBOL_TIME); break; case IEEE80211_T_TURBO: /* 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; default: panic("%s: unknown phy %u (rate %u)\n", __func__, rt->info[rix].phy, rate); break; } return txTime; } uint32_t ieee80211_compute_duration_ht(const struct ieee80211_rate_table *rt, uint32_t frameLen, uint16_t rate, int streams, int isht40, int isShortGI) { static const uint16_t ht20_bps[16] = { 26, 52, 78, 104, 156, 208, 234, 260, 52, 104, 156, 208, 312, 416, 468, 520 }; static const uint16_t ht40_bps[16] = { 54, 108, 162, 216, 324, 432, 486, 540, 108, 216, 324, 432, 648, 864, 972, 1080, }; uint32_t bitsPerSymbol, numBits, numSymbols, txTime; KASSERT(rate & IEEE80211_RATE_MCS, ("not mcs %d", rate)); KASSERT((rate &~ IEEE80211_RATE_MCS) < 16, ("bad mcs 0x%x", rate)); if (isht40) bitsPerSymbol = ht40_bps[rate & 0xf]; else bitsPerSymbol = ht20_bps[rate & 0xf]; numBits = OFDM_PLCP_BITS + (frameLen << 3); numSymbols = howmany(numBits, bitsPerSymbol); if (isShortGI) txTime = ((numSymbols * 18) + 4) / 5; /* 3.6us */ else txTime = numSymbols * 4; /* 4us */ return txTime + HT_L_STF + HT_L_LTF + HT_L_SIG + HT_SIG + HT_STF + HT_LTF(streams); } static const struct ieee80211_rate_table * mode2table(const char *mode) { if (strcasecmp(mode, "half") == 0) return &ieee80211_half_table; else if (strcasecmp(mode, "quarter") == 0) return &ieee80211_quarter_table; else if (strcasecmp(mode, "hta") == 0) return &ieee80211_11a_table; /* XXX */ else if (strcasecmp(mode, "htg") == 0) return &ieee80211_11g_table; /* XXX */ else if (strcasecmp(mode, "108g") == 0) return &ieee80211_turbog_table; else if (strcasecmp(mode, "sturbo") == 0) return &ieee80211_turboa_table; else if (strcasecmp(mode, "turbo") == 0) return &ieee80211_turboa_table; else if (strcasecmp(mode, "11a") == 0) return &ieee80211_11a_table; else if (strcasecmp(mode, "11g") == 0) return &ieee80211_11g_table; else if (strcasecmp(mode, "11b") == 0) return &ieee80211_11b_table; else return NULL; } const char * srate(int rate) { static char buf[32]; if (rate & 1) snprintf(buf, sizeof(buf), "%u.5", rate/2); else snprintf(buf, sizeof(buf), "%u", rate/2); return buf; } static int checkpreamble(const struct ieee80211_rate_table *rt, uint8_t rix, int isShortPreamble, int verbose) { if (isShortPreamble) { if (rt->info[rix].phy != IEEE80211_T_CCK) { if (verbose) warnx("short preamble not meaningful, ignored"); isShortPreamble = 0; } else if (!rt->info[rix].shortPreamble) { if (verbose) warnx("short preamble not meaningful with " "rate %s, ignored", srate(rt->info[rix].dot11Rate &~ IEEE80211_RATE_BASIC)); isShortPreamble = 0; } } return isShortPreamble; } static void usage(const char *progname) { fprintf(stderr, "usage: %s [-a] [-l framelen] [-m mode] [-r rate] [-s]\n", progname); fprintf(stderr, "-a display calculations for all possible rates\n"); fprintf(stderr, "-l framelen length in bytes of 802.11 payload (default 1536)\n"); fprintf(stderr, "-m 11a calculate for 11a channel\n"); fprintf(stderr, "-m 11b calculate for 11b channel\n"); fprintf(stderr, "-m 11g calculate for 11g channel (default)\n"); fprintf(stderr, "-m half calculate for 1/2 width channel\n"); fprintf(stderr, "-m quarter calculate for 1/4 width channel\n"); fprintf(stderr, "-m 108g calculate for dynamic turbo 11g channel\n"); fprintf(stderr, "-m sturbo calculate for static turbo channel\n"); fprintf(stderr, "-m turbo calculate for dynamic turbo 11a channel\n"); fprintf(stderr, "-r rate IEEE rate code (default 54)\n"); fprintf(stderr, "-s short preamble (default long)\n"); exit(0); } int main(int argc, char *argv[]) { const struct ieee80211_rate_table *rt; const char *mode; uint32_t frameLen; uint16_t rate; uint16_t time; uint8_t rix; int ch, allrates, isShortPreamble, isShort; float frate; ieee80211_phy_init(); mode = "11g"; isShortPreamble = 0; frameLen = 1500 + sizeof(struct ieee80211_frame) + LLC_SNAPFRAMELEN + IEEE80211_CRC_LEN ; rate = 2*54; allrates = 0; while ((ch = getopt(argc, argv, "al:m:r:s")) != -1) { switch (ch) { case 'a': allrates = 1; break; case 'l': frameLen = strtoul(optarg, NULL, 0); break; case 'm': mode = optarg; break; case 'r': frate = atof(optarg); rate = (int) 2*frate; break; case 's': isShortPreamble = 1; break; default: usage(argv[0]); break; } } rt = mode2table(mode); if (rt == NULL) errx(-1, "unknown mode %s", mode); if (!allrates) { rix = rt->rateCodeToIndex[rate]; if (rix == (uint8_t) -1) errx(-1, "rate %s not valid for mode %s", srate(rate), mode); isShort = checkpreamble(rt, rix, isShortPreamble, 1); time = ieee80211_compute_duration(rt, frameLen, rate, isShort); printf("%u usec to send %u bytes @ %s Mb/s, %s preamble\n", time, frameLen, srate(rate), isShort ? "short" : "long"); } else { for (rix = 0; rix < rt->rateCount; rix++) { rate = rt->info[rix].dot11Rate &~ IEEE80211_RATE_BASIC; isShort = checkpreamble(rt, rix, isShortPreamble, 0); time = ieee80211_compute_duration(rt, frameLen, rate, isShort); printf("%u usec to send %u bytes @ %s Mb/s, %s preamble\n", time, frameLen, srate(rate), isShort ? "short" : "long"); } } return 0; }