1 /*- 2 * Copyright (c) 2007-2009 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 26 #include <sys/cdefs.h> 27 __FBSDID("$FreeBSD$"); 28 29 /* 30 * IEEE 802.11 PHY-related support. 31 */ 32 33 #include <sys/param.h> 34 35 #include <net/if_llc.h> 36 37 #include <net80211/_ieee80211.h> 38 #include <net80211/ieee80211.h> 39 40 #define IEEE80211_F_SHPREAMBLE 0x00040000 /* STATUS: use short preamble */ 41 42 #include <err.h> 43 #include <stdio.h> 44 #include <stdarg.h> 45 #include <stdlib.h> 46 #include <strings.h> 47 #include <unistd.h> 48 49 struct ieee80211_rate_table { 50 int rateCount; /* NB: for proper padding */ 51 uint8_t rateCodeToIndex[256]; /* back mapping */ 52 struct { 53 uint8_t phy; /* CCK/OFDM/TURBO */ 54 uint32_t rateKbps; /* transfer rate in kbs */ 55 uint8_t shortPreamble; /* mask for enabling short 56 * preamble in CCK rate code */ 57 uint8_t dot11Rate; /* value for supported rates 58 * info element of MLME */ 59 uint8_t ctlRateIndex; /* index of next lower basic 60 * rate; used for dur. calcs */ 61 uint16_t lpAckDuration; /* long preamble ACK dur. */ 62 uint16_t spAckDuration; /* short preamble ACK dur. */ 63 } info[32]; 64 }; 65 66 uint16_t 67 ieee80211_compute_duration(const struct ieee80211_rate_table *rt, 68 uint32_t frameLen, uint16_t rate, int isShortPreamble); 69 70 #define KASSERT(c, msg) do { \ 71 if (!(c)) { \ 72 printf msg; \ 73 putchar('\n'); \ 74 exit(-1); \ 75 } \ 76 } while (0) 77 78 static void 79 panic(const char *fmt, ...) 80 { 81 va_list ap; 82 83 va_start(ap, fmt); 84 vprintf(fmt, ap); 85 va_end(ap); 86 exit(-1); 87 } 88 89 /* shorthands to compact tables for readability */ 90 #define OFDM IEEE80211_T_OFDM 91 #define CCK IEEE80211_T_CCK 92 #define TURBO IEEE80211_T_TURBO 93 #define HALF IEEE80211_T_OFDM_HALF 94 #define QUART IEEE80211_T_OFDM_QUARTER 95 #define PBCC (IEEE80211_T_OFDM_QUARTER+1) /* XXX */ 96 #define B(r) (0x80 | r) 97 #define Mb(x) (x*1000) 98 99 static struct ieee80211_rate_table ieee80211_11b_table = { 100 .rateCount = 4, /* XXX no PBCC */ 101 .info = { 102 /* short ctrl */ 103 /* Preamble dot11Rate Rate */ 104 [0] = { .phy = CCK, 1000, 0x00, B(2), 0 },/* 1 Mb */ 105 [1] = { .phy = CCK, 2000, 0x04, B(4), 1 },/* 2 Mb */ 106 [2] = { .phy = CCK, 5500, 0x04, B(11), 1 },/* 5.5 Mb */ 107 [3] = { .phy = CCK, 11000, 0x04, B(22), 1 },/* 11 Mb */ 108 [4] = { .phy = PBCC, 22000, 0x04, 44, 3 } /* 22 Mb */ 109 }, 110 }; 111 112 static struct ieee80211_rate_table ieee80211_11g_table = { 113 .rateCount = 12, 114 .info = { 115 /* short ctrl */ 116 /* Preamble dot11Rate Rate */ 117 [0] = { .phy = CCK, 1000, 0x00, B(2), 0 }, 118 [1] = { .phy = CCK, 2000, 0x04, B(4), 1 }, 119 [2] = { .phy = CCK, 5500, 0x04, B(11), 2 }, 120 [3] = { .phy = CCK, 11000, 0x04, B(22), 3 }, 121 [4] = { .phy = OFDM, 6000, 0x00, 12, 4 }, 122 [5] = { .phy = OFDM, 9000, 0x00, 18, 4 }, 123 [6] = { .phy = OFDM, 12000, 0x00, 24, 6 }, 124 [7] = { .phy = OFDM, 18000, 0x00, 36, 6 }, 125 [8] = { .phy = OFDM, 24000, 0x00, 48, 8 }, 126 [9] = { .phy = OFDM, 36000, 0x00, 72, 8 }, 127 [10] = { .phy = OFDM, 48000, 0x00, 96, 8 }, 128 [11] = { .phy = OFDM, 54000, 0x00, 108, 8 } 129 }, 130 }; 131 132 static struct ieee80211_rate_table ieee80211_11a_table = { 133 .rateCount = 8, 134 .info = { 135 /* short ctrl */ 136 /* Preamble dot11Rate Rate */ 137 [0] = { .phy = OFDM, 6000, 0x00, B(12), 0 }, 138 [1] = { .phy = OFDM, 9000, 0x00, 18, 0 }, 139 [2] = { .phy = OFDM, 12000, 0x00, B(24), 2 }, 140 [3] = { .phy = OFDM, 18000, 0x00, 36, 2 }, 141 [4] = { .phy = OFDM, 24000, 0x00, B(48), 4 }, 142 [5] = { .phy = OFDM, 36000, 0x00, 72, 4 }, 143 [6] = { .phy = OFDM, 48000, 0x00, 96, 4 }, 144 [7] = { .phy = OFDM, 54000, 0x00, 108, 4 } 145 }, 146 }; 147 148 static struct ieee80211_rate_table ieee80211_half_table = { 149 .rateCount = 8, 150 .info = { 151 /* short ctrl */ 152 /* Preamble dot11Rate Rate */ 153 [0] = { .phy = HALF, 3000, 0x00, B(6), 0 }, 154 [1] = { .phy = HALF, 4500, 0x00, 9, 0 }, 155 [2] = { .phy = HALF, 6000, 0x00, B(12), 2 }, 156 [3] = { .phy = HALF, 9000, 0x00, 18, 2 }, 157 [4] = { .phy = HALF, 12000, 0x00, B(24), 4 }, 158 [5] = { .phy = HALF, 18000, 0x00, 36, 4 }, 159 [6] = { .phy = HALF, 24000, 0x00, 48, 4 }, 160 [7] = { .phy = HALF, 27000, 0x00, 54, 4 } 161 }, 162 }; 163 164 static struct ieee80211_rate_table ieee80211_quarter_table = { 165 .rateCount = 8, 166 .info = { 167 /* short ctrl */ 168 /* Preamble dot11Rate Rate */ 169 [0] = { .phy = QUART, 1500, 0x00, B(3), 0 }, 170 [1] = { .phy = QUART, 2250, 0x00, 4, 0 }, 171 [2] = { .phy = QUART, 3000, 0x00, B(9), 2 }, 172 [3] = { .phy = QUART, 4500, 0x00, 9, 2 }, 173 [4] = { .phy = QUART, 6000, 0x00, B(12), 4 }, 174 [5] = { .phy = QUART, 9000, 0x00, 18, 4 }, 175 [6] = { .phy = QUART, 12000, 0x00, 24, 4 }, 176 [7] = { .phy = QUART, 13500, 0x00, 27, 4 } 177 }, 178 }; 179 180 static struct ieee80211_rate_table ieee80211_turbog_table = { 181 .rateCount = 7, 182 .info = { 183 /* short ctrl */ 184 /* Preamble dot11Rate Rate */ 185 [0] = { .phy = TURBO, 12000, 0x00, B(12), 0 }, 186 [1] = { .phy = TURBO, 24000, 0x00, B(24), 1 }, 187 [2] = { .phy = TURBO, 36000, 0x00, 36, 1 }, 188 [3] = { .phy = TURBO, 48000, 0x00, B(48), 3 }, 189 [4] = { .phy = TURBO, 72000, 0x00, 72, 3 }, 190 [5] = { .phy = TURBO, 96000, 0x00, 96, 3 }, 191 [6] = { .phy = TURBO, 108000, 0x00, 108, 3 } 192 }, 193 }; 194 195 static struct ieee80211_rate_table ieee80211_turboa_table = { 196 .rateCount = 8, 197 .info = { 198 /* short ctrl */ 199 /* Preamble dot11Rate Rate */ 200 [0] = { .phy = TURBO, 12000, 0x00, B(12), 0 }, 201 [1] = { .phy = TURBO, 18000, 0x00, 18, 0 }, 202 [2] = { .phy = TURBO, 24000, 0x00, B(24), 2 }, 203 [3] = { .phy = TURBO, 36000, 0x00, 36, 2 }, 204 [4] = { .phy = TURBO, 48000, 0x00, B(48), 4 }, 205 [5] = { .phy = TURBO, 72000, 0x00, 72, 4 }, 206 [6] = { .phy = TURBO, 96000, 0x00, 96, 4 }, 207 [7] = { .phy = TURBO, 108000, 0x00, 108, 4 } 208 }, 209 }; 210 211 #undef Mb 212 #undef B 213 #undef OFDM 214 #undef CCK 215 #undef TURBO 216 #undef XR 217 218 /* 219 * Setup a rate table's reverse lookup table and fill in 220 * ack durations. The reverse lookup tables are assumed 221 * to be initialized to zero (or at least the first entry). 222 * We use this as a key that indicates whether or not 223 * we've previously setup the reverse lookup table. 224 * 225 * XXX not reentrant, but shouldn't matter 226 */ 227 static void 228 ieee80211_setup_ratetable(struct ieee80211_rate_table *rt) 229 { 230 #define WLAN_CTRL_FRAME_SIZE \ 231 (sizeof(struct ieee80211_frame_ack) + IEEE80211_CRC_LEN) 232 233 int i; 234 235 for (i = 0; i < nitems(rt->rateCodeToIndex); i++) 236 rt->rateCodeToIndex[i] = (uint8_t) -1; 237 for (i = 0; i < rt->rateCount; i++) { 238 uint8_t code = rt->info[i].dot11Rate; 239 uint8_t cix = rt->info[i].ctlRateIndex; 240 uint8_t ctl_rate = rt->info[cix].dot11Rate; 241 242 rt->rateCodeToIndex[code] = i; 243 if (code & IEEE80211_RATE_BASIC) { 244 /* 245 * Map w/o basic rate bit too. 246 */ 247 code &= IEEE80211_RATE_VAL; 248 rt->rateCodeToIndex[code] = i; 249 } 250 251 /* 252 * XXX for 11g the control rate to use for 5.5 and 11 Mb/s 253 * depends on whether they are marked as basic rates; 254 * the static tables are setup with an 11b-compatible 255 * 2Mb/s rate which will work but is suboptimal 256 * 257 * NB: Control rate is always less than or equal to the 258 * current rate, so control rate's reverse lookup entry 259 * has been installed and following call is safe. 260 */ 261 rt->info[i].lpAckDuration = ieee80211_compute_duration(rt, 262 WLAN_CTRL_FRAME_SIZE, ctl_rate, 0); 263 rt->info[i].spAckDuration = ieee80211_compute_duration(rt, 264 WLAN_CTRL_FRAME_SIZE, ctl_rate, IEEE80211_F_SHPREAMBLE); 265 } 266 267 #undef WLAN_CTRL_FRAME_SIZE 268 } 269 270 /* Setup all rate tables */ 271 static void 272 ieee80211_phy_init(void) 273 { 274 static struct ieee80211_rate_table * const ratetables[] = { 275 &ieee80211_half_table, 276 &ieee80211_quarter_table, 277 &ieee80211_11a_table, 278 &ieee80211_11g_table, 279 &ieee80211_turbog_table, 280 &ieee80211_turboa_table, 281 &ieee80211_turboa_table, 282 &ieee80211_11a_table, 283 &ieee80211_11g_table, 284 &ieee80211_11b_table 285 }; 286 unsigned int i; 287 288 for (i = 0; i < nitems(ratetables); ++i) 289 ieee80211_setup_ratetable(ratetables[i]); 290 291 } 292 #define CCK_SIFS_TIME 10 293 #define CCK_PREAMBLE_BITS 144 294 #define CCK_PLCP_BITS 48 295 296 #define OFDM_SIFS_TIME 16 297 #define OFDM_PREAMBLE_TIME 20 298 #define OFDM_PLCP_BITS 22 299 #define OFDM_SYMBOL_TIME 4 300 301 #define OFDM_HALF_SIFS_TIME 32 302 #define OFDM_HALF_PREAMBLE_TIME 40 303 #define OFDM_HALF_PLCP_BITS 22 304 #define OFDM_HALF_SYMBOL_TIME 8 305 306 #define OFDM_QUARTER_SIFS_TIME 64 307 #define OFDM_QUARTER_PREAMBLE_TIME 80 308 #define OFDM_QUARTER_PLCP_BITS 22 309 #define OFDM_QUARTER_SYMBOL_TIME 16 310 311 #define TURBO_SIFS_TIME 8 312 #define TURBO_PREAMBLE_TIME 14 313 #define TURBO_PLCP_BITS 22 314 #define TURBO_SYMBOL_TIME 4 315 316 #define HT_L_STF 8 317 #define HT_L_LTF 8 318 #define HT_L_SIG 4 319 #define HT_SIG 8 320 #define HT_STF 4 321 #define HT_LTF(n) ((n) * 4) 322 323 /* 324 * Compute the time to transmit a frame of length frameLen bytes 325 * using the specified rate, phy, and short preamble setting. 326 * SIFS is included. 327 */ 328 uint16_t 329 ieee80211_compute_duration(const struct ieee80211_rate_table *rt, 330 uint32_t frameLen, uint16_t rate, int isShortPreamble) 331 { 332 uint8_t rix = rt->rateCodeToIndex[rate]; 333 uint32_t bitsPerSymbol, numBits, numSymbols, phyTime, txTime; 334 uint32_t kbps; 335 336 KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate)); 337 kbps = rt->info[rix].rateKbps; 338 if (kbps == 0) /* XXX bandaid for channel changes */ 339 return 0; 340 341 switch (rt->info[rix].phy) { 342 case IEEE80211_T_CCK: 343 phyTime = CCK_PREAMBLE_BITS + CCK_PLCP_BITS; 344 if (isShortPreamble && rt->info[rix].shortPreamble) 345 phyTime >>= 1; 346 numBits = frameLen << 3; 347 txTime = CCK_SIFS_TIME + phyTime 348 + ((numBits * 1000)/kbps); 349 break; 350 case IEEE80211_T_OFDM: 351 bitsPerSymbol = (kbps * OFDM_SYMBOL_TIME) / 1000; 352 KASSERT(bitsPerSymbol != 0, ("full rate bps")); 353 354 numBits = OFDM_PLCP_BITS + (frameLen << 3); 355 numSymbols = howmany(numBits, bitsPerSymbol); 356 txTime = OFDM_SIFS_TIME 357 + OFDM_PREAMBLE_TIME 358 + (numSymbols * OFDM_SYMBOL_TIME); 359 break; 360 case IEEE80211_T_OFDM_HALF: 361 bitsPerSymbol = (kbps * OFDM_HALF_SYMBOL_TIME) / 1000; 362 KASSERT(bitsPerSymbol != 0, ("1/4 rate bps")); 363 364 numBits = OFDM_PLCP_BITS + (frameLen << 3); 365 numSymbols = howmany(numBits, bitsPerSymbol); 366 txTime = OFDM_HALF_SIFS_TIME 367 + OFDM_HALF_PREAMBLE_TIME 368 + (numSymbols * OFDM_HALF_SYMBOL_TIME); 369 break; 370 case IEEE80211_T_OFDM_QUARTER: 371 bitsPerSymbol = (kbps * OFDM_QUARTER_SYMBOL_TIME) / 1000; 372 KASSERT(bitsPerSymbol != 0, ("1/2 rate bps")); 373 374 numBits = OFDM_PLCP_BITS + (frameLen << 3); 375 numSymbols = howmany(numBits, bitsPerSymbol); 376 txTime = OFDM_QUARTER_SIFS_TIME 377 + OFDM_QUARTER_PREAMBLE_TIME 378 + (numSymbols * OFDM_QUARTER_SYMBOL_TIME); 379 break; 380 case IEEE80211_T_TURBO: 381 /* we still save OFDM rates in kbps - so double them */ 382 bitsPerSymbol = ((kbps << 1) * TURBO_SYMBOL_TIME) / 1000; 383 KASSERT(bitsPerSymbol != 0, ("turbo bps")); 384 385 numBits = TURBO_PLCP_BITS + (frameLen << 3); 386 numSymbols = howmany(numBits, bitsPerSymbol); 387 txTime = TURBO_SIFS_TIME + TURBO_PREAMBLE_TIME 388 + (numSymbols * TURBO_SYMBOL_TIME); 389 break; 390 default: 391 panic("%s: unknown phy %u (rate %u)\n", __func__, 392 rt->info[rix].phy, rate); 393 break; 394 } 395 return txTime; 396 } 397 398 uint32_t 399 ieee80211_compute_duration_ht(const struct ieee80211_rate_table *rt, 400 uint32_t frameLen, uint16_t rate, 401 int streams, int isht40, int isShortGI) 402 { 403 static const uint16_t ht20_bps[16] = { 404 26, 52, 78, 104, 156, 208, 234, 260, 405 52, 104, 156, 208, 312, 416, 468, 520 406 }; 407 static const uint16_t ht40_bps[16] = { 408 54, 108, 162, 216, 324, 432, 486, 540, 409 108, 216, 324, 432, 648, 864, 972, 1080, 410 }; 411 uint32_t bitsPerSymbol, numBits, numSymbols, txTime; 412 413 KASSERT(rate & IEEE80211_RATE_MCS, ("not mcs %d", rate)); 414 KASSERT((rate &~ IEEE80211_RATE_MCS) < 16, ("bad mcs 0x%x", rate)); 415 416 if (isht40) 417 bitsPerSymbol = ht40_bps[rate & 0xf]; 418 else 419 bitsPerSymbol = ht20_bps[rate & 0xf]; 420 numBits = OFDM_PLCP_BITS + (frameLen << 3); 421 numSymbols = howmany(numBits, bitsPerSymbol); 422 if (isShortGI) 423 txTime = ((numSymbols * 18) + 4) / 5; /* 3.6us */ 424 else 425 txTime = numSymbols * 4; /* 4us */ 426 return txTime + HT_L_STF + HT_L_LTF + 427 HT_L_SIG + HT_SIG + HT_STF + HT_LTF(streams); 428 } 429 430 static const struct ieee80211_rate_table * 431 mode2table(const char *mode) 432 { 433 if (strcasecmp(mode, "half") == 0) 434 return &ieee80211_half_table; 435 else if (strcasecmp(mode, "quarter") == 0) 436 return &ieee80211_quarter_table; 437 else if (strcasecmp(mode, "hta") == 0) 438 return &ieee80211_11a_table; /* XXX */ 439 else if (strcasecmp(mode, "htg") == 0) 440 return &ieee80211_11g_table; /* XXX */ 441 else if (strcasecmp(mode, "108g") == 0) 442 return &ieee80211_turbog_table; 443 else if (strcasecmp(mode, "sturbo") == 0) 444 return &ieee80211_turboa_table; 445 else if (strcasecmp(mode, "turbo") == 0) 446 return &ieee80211_turboa_table; 447 else if (strcasecmp(mode, "11a") == 0) 448 return &ieee80211_11a_table; 449 else if (strcasecmp(mode, "11g") == 0) 450 return &ieee80211_11g_table; 451 else if (strcasecmp(mode, "11b") == 0) 452 return &ieee80211_11b_table; 453 else 454 return NULL; 455 } 456 457 const char * 458 srate(int rate) 459 { 460 static char buf[32]; 461 if (rate & 1) 462 snprintf(buf, sizeof(buf), "%u.5", rate/2); 463 else 464 snprintf(buf, sizeof(buf), "%u", rate/2); 465 return buf; 466 } 467 468 static int 469 checkpreamble(const struct ieee80211_rate_table *rt, uint8_t rix, 470 int isShortPreamble, int verbose) 471 { 472 if (isShortPreamble) { 473 if (rt->info[rix].phy != IEEE80211_T_CCK) { 474 if (verbose) 475 warnx("short preamble not meaningful, ignored"); 476 isShortPreamble = 0; 477 } else if (!rt->info[rix].shortPreamble) { 478 if (verbose) 479 warnx("short preamble not meaningful with " 480 "rate %s, ignored", 481 srate(rt->info[rix].dot11Rate &~ IEEE80211_RATE_BASIC)); 482 isShortPreamble = 0; 483 } 484 } 485 return isShortPreamble; 486 } 487 488 static void 489 usage(const char *progname) 490 { 491 fprintf(stderr, "usage: %s [-a] [-l framelen] [-m mode] [-r rate] [-s]\n", 492 progname); 493 fprintf(stderr, "-a display calculations for all possible rates\n"); 494 fprintf(stderr, "-l framelen length in bytes of 802.11 payload (default 1536)\n"); 495 fprintf(stderr, "-m 11a calculate for 11a channel\n"); 496 fprintf(stderr, "-m 11b calculate for 11b channel\n"); 497 fprintf(stderr, "-m 11g calculate for 11g channel (default)\n"); 498 fprintf(stderr, "-m half calculate for 1/2 width channel\n"); 499 fprintf(stderr, "-m quarter calculate for 1/4 width channel\n"); 500 fprintf(stderr, "-m 108g calculate for dynamic turbo 11g channel\n"); 501 fprintf(stderr, "-m sturbo calculate for static turbo channel\n"); 502 fprintf(stderr, "-m turbo calculate for dynamic turbo 11a channel\n"); 503 fprintf(stderr, "-r rate IEEE rate code (default 54)\n"); 504 fprintf(stderr, "-s short preamble (default long)\n"); 505 exit(0); 506 } 507 508 int 509 main(int argc, char *argv[]) 510 { 511 const struct ieee80211_rate_table *rt; 512 const char *mode; 513 uint32_t frameLen; 514 uint16_t rate; 515 uint16_t time; 516 uint8_t rix; 517 int ch, allrates, isShortPreamble, isShort; 518 float frate; 519 520 ieee80211_phy_init(); 521 522 mode = "11g"; 523 isShortPreamble = 0; 524 frameLen = 1500 525 + sizeof(struct ieee80211_frame) 526 + LLC_SNAPFRAMELEN 527 + IEEE80211_CRC_LEN 528 ; 529 rate = 2*54; 530 allrates = 0; 531 while ((ch = getopt(argc, argv, "al:m:r:s")) != -1) { 532 switch (ch) { 533 case 'a': 534 allrates = 1; 535 break; 536 case 'l': 537 frameLen = strtoul(optarg, NULL, 0); 538 break; 539 case 'm': 540 mode = optarg; 541 break; 542 case 'r': 543 frate = atof(optarg); 544 rate = (int) 2*frate; 545 break; 546 case 's': 547 isShortPreamble = 1; 548 break; 549 default: 550 usage(argv[0]); 551 break; 552 } 553 } 554 rt = mode2table(mode); 555 if (rt == NULL) 556 errx(-1, "unknown mode %s", mode); 557 if (!allrates) { 558 rix = rt->rateCodeToIndex[rate]; 559 if (rix == (uint8_t) -1) 560 errx(-1, "rate %s not valid for mode %s", srate(rate), mode); 561 isShort = checkpreamble(rt, rix, isShortPreamble, 1); 562 563 time = ieee80211_compute_duration(rt, frameLen, rate, isShort); 564 printf("%u usec to send %u bytes @ %s Mb/s, %s preamble\n", 565 time, frameLen, srate(rate), 566 isShort ? "short" : "long"); 567 } else { 568 for (rix = 0; rix < rt->rateCount; rix++) { 569 rate = rt->info[rix].dot11Rate &~ IEEE80211_RATE_BASIC; 570 isShort = checkpreamble(rt, rix, isShortPreamble, 0); 571 time = ieee80211_compute_duration(rt, frameLen, rate, 572 isShort); 573 printf("%u usec to send %u bytes @ %s Mb/s, %s preamble\n", 574 time, frameLen, srate(rate), 575 isShort ? "short" : "long"); 576 } 577 } 578 return 0; 579 } 580