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 #include <sys/types.h> 35 36 #include <net/if_llc.h> 37 38 #include <net80211/_ieee80211.h> 39 #include <net80211/ieee80211.h> 40 41 #define IEEE80211_F_SHPREAMBLE 0x00040000 /* STATUS: use short preamble */ 42 43 #include <err.h> 44 #include <stdio.h> 45 #include <stdarg.h> 46 #include <stdlib.h> 47 #include <strings.h> 48 #include <unistd.h> 49 50 struct ieee80211_rate_table { 51 int rateCount; /* NB: for proper padding */ 52 uint8_t rateCodeToIndex[256]; /* back mapping */ 53 struct { 54 uint8_t phy; /* CCK/OFDM/TURBO */ 55 uint32_t rateKbps; /* transfer rate in kbs */ 56 uint8_t shortPreamble; /* mask for enabling short 57 * preamble in CCK rate code */ 58 uint8_t dot11Rate; /* value for supported rates 59 * info element of MLME */ 60 uint8_t ctlRateIndex; /* index of next lower basic 61 * rate; used for dur. calcs */ 62 uint16_t lpAckDuration; /* long preamble ACK dur. */ 63 uint16_t spAckDuration; /* short preamble ACK dur. */ 64 } info[32]; 65 }; 66 67 uint16_t 68 ieee80211_compute_duration(const struct ieee80211_rate_table *rt, 69 uint32_t frameLen, uint16_t rate, int isShortPreamble); 70 71 #define KASSERT(c, msg) do { \ 72 if (!(c)) { \ 73 printf msg; \ 74 putchar('\n'); \ 75 exit(-1); \ 76 } \ 77 } while (0) 78 79 static void 80 panic(const char *fmt, ...) 81 { 82 va_list ap; 83 84 va_start(ap, fmt); 85 vprintf(fmt, ap); 86 va_end(ap); 87 exit(-1); 88 } 89 90 /* shorthands to compact tables for readability */ 91 #define OFDM IEEE80211_T_OFDM 92 #define CCK IEEE80211_T_CCK 93 #define TURBO IEEE80211_T_TURBO 94 #define HALF IEEE80211_T_OFDM_HALF 95 #define QUART IEEE80211_T_OFDM_QUARTER 96 #define PBCC (IEEE80211_T_OFDM_QUARTER+1) /* XXX */ 97 #define B(r) (0x80 | r) 98 #define Mb(x) (x*1000) 99 100 static struct ieee80211_rate_table ieee80211_11b_table = { 101 .rateCount = 4, /* XXX no PBCC */ 102 .info = { 103 /* short ctrl */ 104 /* Preamble dot11Rate Rate */ 105 [0] = { .phy = CCK, 1000, 0x00, B(2), 0 },/* 1 Mb */ 106 [1] = { .phy = CCK, 2000, 0x04, B(4), 1 },/* 2 Mb */ 107 [2] = { .phy = CCK, 5500, 0x04, B(11), 1 },/* 5.5 Mb */ 108 [3] = { .phy = CCK, 11000, 0x04, B(22), 1 },/* 11 Mb */ 109 [4] = { .phy = PBCC, 22000, 0x04, 44, 3 } /* 22 Mb */ 110 }, 111 }; 112 113 static struct ieee80211_rate_table ieee80211_11g_table = { 114 .rateCount = 12, 115 .info = { 116 /* short ctrl */ 117 /* Preamble dot11Rate Rate */ 118 [0] = { .phy = CCK, 1000, 0x00, B(2), 0 }, 119 [1] = { .phy = CCK, 2000, 0x04, B(4), 1 }, 120 [2] = { .phy = CCK, 5500, 0x04, B(11), 2 }, 121 [3] = { .phy = CCK, 11000, 0x04, B(22), 3 }, 122 [4] = { .phy = OFDM, 6000, 0x00, 12, 4 }, 123 [5] = { .phy = OFDM, 9000, 0x00, 18, 4 }, 124 [6] = { .phy = OFDM, 12000, 0x00, 24, 6 }, 125 [7] = { .phy = OFDM, 18000, 0x00, 36, 6 }, 126 [8] = { .phy = OFDM, 24000, 0x00, 48, 8 }, 127 [9] = { .phy = OFDM, 36000, 0x00, 72, 8 }, 128 [10] = { .phy = OFDM, 48000, 0x00, 96, 8 }, 129 [11] = { .phy = OFDM, 54000, 0x00, 108, 8 } 130 }, 131 }; 132 133 static struct ieee80211_rate_table ieee80211_11a_table = { 134 .rateCount = 8, 135 .info = { 136 /* short ctrl */ 137 /* Preamble dot11Rate Rate */ 138 [0] = { .phy = OFDM, 6000, 0x00, B(12), 0 }, 139 [1] = { .phy = OFDM, 9000, 0x00, 18, 0 }, 140 [2] = { .phy = OFDM, 12000, 0x00, B(24), 2 }, 141 [3] = { .phy = OFDM, 18000, 0x00, 36, 2 }, 142 [4] = { .phy = OFDM, 24000, 0x00, B(48), 4 }, 143 [5] = { .phy = OFDM, 36000, 0x00, 72, 4 }, 144 [6] = { .phy = OFDM, 48000, 0x00, 96, 4 }, 145 [7] = { .phy = OFDM, 54000, 0x00, 108, 4 } 146 }, 147 }; 148 149 static struct ieee80211_rate_table ieee80211_half_table = { 150 .rateCount = 8, 151 .info = { 152 /* short ctrl */ 153 /* Preamble dot11Rate Rate */ 154 [0] = { .phy = HALF, 3000, 0x00, B(6), 0 }, 155 [1] = { .phy = HALF, 4500, 0x00, 9, 0 }, 156 [2] = { .phy = HALF, 6000, 0x00, B(12), 2 }, 157 [3] = { .phy = HALF, 9000, 0x00, 18, 2 }, 158 [4] = { .phy = HALF, 12000, 0x00, B(24), 4 }, 159 [5] = { .phy = HALF, 18000, 0x00, 36, 4 }, 160 [6] = { .phy = HALF, 24000, 0x00, 48, 4 }, 161 [7] = { .phy = HALF, 27000, 0x00, 54, 4 } 162 }, 163 }; 164 165 static struct ieee80211_rate_table ieee80211_quarter_table = { 166 .rateCount = 8, 167 .info = { 168 /* short ctrl */ 169 /* Preamble dot11Rate Rate */ 170 [0] = { .phy = QUART, 1500, 0x00, B(3), 0 }, 171 [1] = { .phy = QUART, 2250, 0x00, 4, 0 }, 172 [2] = { .phy = QUART, 3000, 0x00, B(9), 2 }, 173 [3] = { .phy = QUART, 4500, 0x00, 9, 2 }, 174 [4] = { .phy = QUART, 6000, 0x00, B(12), 4 }, 175 [5] = { .phy = QUART, 9000, 0x00, 18, 4 }, 176 [6] = { .phy = QUART, 12000, 0x00, 24, 4 }, 177 [7] = { .phy = QUART, 13500, 0x00, 27, 4 } 178 }, 179 }; 180 181 static struct ieee80211_rate_table ieee80211_turbog_table = { 182 .rateCount = 7, 183 .info = { 184 /* short ctrl */ 185 /* Preamble dot11Rate Rate */ 186 [0] = { .phy = TURBO, 12000, 0x00, B(12), 0 }, 187 [1] = { .phy = TURBO, 24000, 0x00, B(24), 1 }, 188 [2] = { .phy = TURBO, 36000, 0x00, 36, 1 }, 189 [3] = { .phy = TURBO, 48000, 0x00, B(48), 3 }, 190 [4] = { .phy = TURBO, 72000, 0x00, 72, 3 }, 191 [5] = { .phy = TURBO, 96000, 0x00, 96, 3 }, 192 [6] = { .phy = TURBO, 108000, 0x00, 108, 3 } 193 }, 194 }; 195 196 static struct ieee80211_rate_table ieee80211_turboa_table = { 197 .rateCount = 8, 198 .info = { 199 /* short ctrl */ 200 /* Preamble dot11Rate Rate */ 201 [0] = { .phy = TURBO, 12000, 0x00, B(12), 0 }, 202 [1] = { .phy = TURBO, 18000, 0x00, 18, 0 }, 203 [2] = { .phy = TURBO, 24000, 0x00, B(24), 2 }, 204 [3] = { .phy = TURBO, 36000, 0x00, 36, 2 }, 205 [4] = { .phy = TURBO, 48000, 0x00, B(48), 4 }, 206 [5] = { .phy = TURBO, 72000, 0x00, 72, 4 }, 207 [6] = { .phy = TURBO, 96000, 0x00, 96, 4 }, 208 [7] = { .phy = TURBO, 108000, 0x00, 108, 4 } 209 }, 210 }; 211 212 #undef Mb 213 #undef B 214 #undef OFDM 215 #undef CCK 216 #undef TURBO 217 #undef XR 218 219 /* 220 * Setup a rate table's reverse lookup table and fill in 221 * ack durations. The reverse lookup tables are assumed 222 * to be initialized to zero (or at least the first entry). 223 * We use this as a key that indicates whether or not 224 * we've previously setup the reverse lookup table. 225 * 226 * XXX not reentrant, but shouldn't matter 227 */ 228 static void 229 ieee80211_setup_ratetable(struct ieee80211_rate_table *rt) 230 { 231 #define N(a) (sizeof(a)/sizeof(a[0])) 232 #define WLAN_CTRL_FRAME_SIZE \ 233 (sizeof(struct ieee80211_frame_ack) + IEEE80211_CRC_LEN) 234 235 int i; 236 237 for (i = 0; i < N(rt->rateCodeToIndex); i++) 238 rt->rateCodeToIndex[i] = (uint8_t) -1; 239 for (i = 0; i < rt->rateCount; i++) { 240 uint8_t code = rt->info[i].dot11Rate; 241 uint8_t cix = rt->info[i].ctlRateIndex; 242 uint8_t ctl_rate = rt->info[cix].dot11Rate; 243 244 rt->rateCodeToIndex[code] = i; 245 if (code & IEEE80211_RATE_BASIC) { 246 /* 247 * Map w/o basic rate bit too. 248 */ 249 code &= IEEE80211_RATE_VAL; 250 rt->rateCodeToIndex[code] = i; 251 } 252 253 /* 254 * XXX for 11g the control rate to use for 5.5 and 11 Mb/s 255 * depends on whether they are marked as basic rates; 256 * the static tables are setup with an 11b-compatible 257 * 2Mb/s rate which will work but is suboptimal 258 * 259 * NB: Control rate is always less than or equal to the 260 * current rate, so control rate's reverse lookup entry 261 * has been installed and following call is safe. 262 */ 263 rt->info[i].lpAckDuration = ieee80211_compute_duration(rt, 264 WLAN_CTRL_FRAME_SIZE, ctl_rate, 0); 265 rt->info[i].spAckDuration = ieee80211_compute_duration(rt, 266 WLAN_CTRL_FRAME_SIZE, ctl_rate, IEEE80211_F_SHPREAMBLE); 267 } 268 269 #undef WLAN_CTRL_FRAME_SIZE 270 #undef N 271 } 272 273 /* Setup all rate tables */ 274 static void 275 ieee80211_phy_init(void) 276 { 277 #define N(arr) (int)(sizeof(arr) / sizeof(arr[0])) 278 static struct ieee80211_rate_table * const ratetables[] = { 279 &ieee80211_half_table, 280 &ieee80211_quarter_table, 281 &ieee80211_11a_table, 282 &ieee80211_11g_table, 283 &ieee80211_turbog_table, 284 &ieee80211_turboa_table, 285 &ieee80211_turboa_table, 286 &ieee80211_11a_table, 287 &ieee80211_11g_table, 288 &ieee80211_11b_table 289 }; 290 int i; 291 292 for (i = 0; i < N(ratetables); ++i) 293 ieee80211_setup_ratetable(ratetables[i]); 294 295 #undef N 296 } 297 #define CCK_SIFS_TIME 10 298 #define CCK_PREAMBLE_BITS 144 299 #define CCK_PLCP_BITS 48 300 301 #define OFDM_SIFS_TIME 16 302 #define OFDM_PREAMBLE_TIME 20 303 #define OFDM_PLCP_BITS 22 304 #define OFDM_SYMBOL_TIME 4 305 306 #define OFDM_HALF_SIFS_TIME 32 307 #define OFDM_HALF_PREAMBLE_TIME 40 308 #define OFDM_HALF_PLCP_BITS 22 309 #define OFDM_HALF_SYMBOL_TIME 8 310 311 #define OFDM_QUARTER_SIFS_TIME 64 312 #define OFDM_QUARTER_PREAMBLE_TIME 80 313 #define OFDM_QUARTER_PLCP_BITS 22 314 #define OFDM_QUARTER_SYMBOL_TIME 16 315 316 #define TURBO_SIFS_TIME 8 317 #define TURBO_PREAMBLE_TIME 14 318 #define TURBO_PLCP_BITS 22 319 #define TURBO_SYMBOL_TIME 4 320 321 #define HT_L_STF 8 322 #define HT_L_LTF 8 323 #define HT_L_SIG 4 324 #define HT_SIG 8 325 #define HT_STF 4 326 #define HT_LTF(n) ((n) * 4) 327 328 /* 329 * Compute the time to transmit a frame of length frameLen bytes 330 * using the specified rate, phy, and short preamble setting. 331 * SIFS is included. 332 */ 333 uint16_t 334 ieee80211_compute_duration(const struct ieee80211_rate_table *rt, 335 uint32_t frameLen, uint16_t rate, int isShortPreamble) 336 { 337 uint8_t rix = rt->rateCodeToIndex[rate]; 338 uint32_t bitsPerSymbol, numBits, numSymbols, phyTime, txTime; 339 uint32_t kbps; 340 341 KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate)); 342 kbps = rt->info[rix].rateKbps; 343 if (kbps == 0) /* XXX bandaid for channel changes */ 344 return 0; 345 346 switch (rt->info[rix].phy) { 347 case IEEE80211_T_CCK: 348 phyTime = CCK_PREAMBLE_BITS + CCK_PLCP_BITS; 349 if (isShortPreamble && rt->info[rix].shortPreamble) 350 phyTime >>= 1; 351 numBits = frameLen << 3; 352 txTime = CCK_SIFS_TIME + phyTime 353 + ((numBits * 1000)/kbps); 354 break; 355 case IEEE80211_T_OFDM: 356 bitsPerSymbol = (kbps * OFDM_SYMBOL_TIME) / 1000; 357 KASSERT(bitsPerSymbol != 0, ("full rate bps")); 358 359 numBits = OFDM_PLCP_BITS + (frameLen << 3); 360 numSymbols = howmany(numBits, bitsPerSymbol); 361 txTime = OFDM_SIFS_TIME 362 + OFDM_PREAMBLE_TIME 363 + (numSymbols * OFDM_SYMBOL_TIME); 364 break; 365 case IEEE80211_T_OFDM_HALF: 366 bitsPerSymbol = (kbps * OFDM_HALF_SYMBOL_TIME) / 1000; 367 KASSERT(bitsPerSymbol != 0, ("1/4 rate bps")); 368 369 numBits = OFDM_PLCP_BITS + (frameLen << 3); 370 numSymbols = howmany(numBits, bitsPerSymbol); 371 txTime = OFDM_HALF_SIFS_TIME 372 + OFDM_HALF_PREAMBLE_TIME 373 + (numSymbols * OFDM_HALF_SYMBOL_TIME); 374 break; 375 case IEEE80211_T_OFDM_QUARTER: 376 bitsPerSymbol = (kbps * OFDM_QUARTER_SYMBOL_TIME) / 1000; 377 KASSERT(bitsPerSymbol != 0, ("1/2 rate bps")); 378 379 numBits = OFDM_PLCP_BITS + (frameLen << 3); 380 numSymbols = howmany(numBits, bitsPerSymbol); 381 txTime = OFDM_QUARTER_SIFS_TIME 382 + OFDM_QUARTER_PREAMBLE_TIME 383 + (numSymbols * OFDM_QUARTER_SYMBOL_TIME); 384 break; 385 case IEEE80211_T_TURBO: 386 /* we still save OFDM rates in kbps - so double them */ 387 bitsPerSymbol = ((kbps << 1) * TURBO_SYMBOL_TIME) / 1000; 388 KASSERT(bitsPerSymbol != 0, ("turbo bps")); 389 390 numBits = TURBO_PLCP_BITS + (frameLen << 3); 391 numSymbols = howmany(numBits, bitsPerSymbol); 392 txTime = TURBO_SIFS_TIME + TURBO_PREAMBLE_TIME 393 + (numSymbols * TURBO_SYMBOL_TIME); 394 break; 395 default: 396 panic("%s: unknown phy %u (rate %u)\n", __func__, 397 rt->info[rix].phy, rate); 398 break; 399 } 400 return txTime; 401 } 402 403 uint32_t 404 ieee80211_compute_duration_ht(const struct ieee80211_rate_table *rt, 405 uint32_t frameLen, uint16_t rate, 406 int streams, int isht40, int isShortGI) 407 { 408 static const uint16_t ht20_bps[16] = { 409 26, 52, 78, 104, 156, 208, 234, 260, 410 52, 104, 156, 208, 312, 416, 468, 520 411 }; 412 static const uint16_t ht40_bps[16] = { 413 54, 108, 162, 216, 324, 432, 486, 540, 414 108, 216, 324, 432, 648, 864, 972, 1080, 415 }; 416 uint32_t bitsPerSymbol, numBits, numSymbols, txTime; 417 418 KASSERT(rate & IEEE80211_RATE_MCS, ("not mcs %d", rate)); 419 KASSERT((rate &~ IEEE80211_RATE_MCS) < 16, ("bad mcs 0x%x", rate)); 420 421 if (isht40) 422 bitsPerSymbol = ht40_bps[rate & 0xf]; 423 else 424 bitsPerSymbol = ht20_bps[rate & 0xf]; 425 numBits = OFDM_PLCP_BITS + (frameLen << 3); 426 numSymbols = howmany(numBits, bitsPerSymbol); 427 if (isShortGI) 428 txTime = ((numSymbols * 18) + 4) / 5; /* 3.6us */ 429 else 430 txTime = numSymbols * 4; /* 4us */ 431 return txTime + HT_L_STF + HT_L_LTF + 432 HT_L_SIG + HT_SIG + HT_STF + HT_LTF(streams); 433 } 434 435 static const struct ieee80211_rate_table * 436 mode2table(const char *mode) 437 { 438 if (strcasecmp(mode, "half") == 0) 439 return &ieee80211_half_table; 440 else if (strcasecmp(mode, "quarter") == 0) 441 return &ieee80211_quarter_table; 442 else if (strcasecmp(mode, "hta") == 0) 443 return &ieee80211_11a_table; /* XXX */ 444 else if (strcasecmp(mode, "htg") == 0) 445 return &ieee80211_11g_table; /* XXX */ 446 else if (strcasecmp(mode, "108g") == 0) 447 return &ieee80211_turbog_table; 448 else if (strcasecmp(mode, "sturbo") == 0) 449 return &ieee80211_turboa_table; 450 else if (strcasecmp(mode, "turbo") == 0) 451 return &ieee80211_turboa_table; 452 else if (strcasecmp(mode, "11a") == 0) 453 return &ieee80211_11a_table; 454 else if (strcasecmp(mode, "11g") == 0) 455 return &ieee80211_11g_table; 456 else if (strcasecmp(mode, "11b") == 0) 457 return &ieee80211_11b_table; 458 else 459 return NULL; 460 } 461 462 const char * 463 srate(int rate) 464 { 465 static char buf[32]; 466 if (rate & 1) 467 snprintf(buf, sizeof(buf), "%u.5", rate/2); 468 else 469 snprintf(buf, sizeof(buf), "%u", rate/2); 470 return buf; 471 } 472 473 static int 474 checkpreamble(const struct ieee80211_rate_table *rt, uint8_t rix, 475 int isShortPreamble, int verbose) 476 { 477 if (isShortPreamble) { 478 if (rt->info[rix].phy != IEEE80211_T_CCK) { 479 if (verbose) 480 warnx("short preamble not meaningful, ignored"); 481 isShortPreamble = 0; 482 } else if (!rt->info[rix].shortPreamble) { 483 if (verbose) 484 warnx("short preamble not meaningful with " 485 "rate %s, ignored", 486 srate(rt->info[rix].dot11Rate &~ IEEE80211_RATE_BASIC)); 487 isShortPreamble = 0; 488 } 489 } 490 return isShortPreamble; 491 } 492 493 static void 494 usage(const char *progname) 495 { 496 fprintf(stderr, "usage: %s [-a] [-l framelen] [-m mode] [-r rate] [-s]\n", 497 progname); 498 fprintf(stderr, "-a display calculations for all possible rates\n"); 499 fprintf(stderr, "-l framelen length in bytes of 802.11 payload (default 1536)\n"); 500 fprintf(stderr, "-m 11a calculate for 11a channel\n"); 501 fprintf(stderr, "-m 11b calculate for 11b channel\n"); 502 fprintf(stderr, "-m 11g calculate for 11g channel (default)\n"); 503 fprintf(stderr, "-m half calculate for 1/2 width channel\n"); 504 fprintf(stderr, "-m quarter calculate for 1/4 width channel\n"); 505 fprintf(stderr, "-m 108g calculate for dynamic turbo 11g channel\n"); 506 fprintf(stderr, "-m sturbo calculate for static turbo channel\n"); 507 fprintf(stderr, "-m turbo calculate for dynamic turbo 11a channel\n"); 508 fprintf(stderr, "-r rate IEEE rate code (default 54)\n"); 509 fprintf(stderr, "-s short preamble (default long)\n"); 510 exit(0); 511 } 512 513 int 514 main(int argc, char *argv[]) 515 { 516 const struct ieee80211_rate_table *rt; 517 const char *mode; 518 uint32_t frameLen; 519 uint16_t rate; 520 uint16_t time; 521 uint8_t rix; 522 int ch, allrates, isShortPreamble, isShort; 523 float frate; 524 525 ieee80211_phy_init(); 526 527 mode = "11g"; 528 isShortPreamble = 0; 529 frameLen = 1500 530 + sizeof(struct ieee80211_frame) 531 + LLC_SNAPFRAMELEN 532 + IEEE80211_CRC_LEN 533 ; 534 rate = 2*54; 535 allrates = 0; 536 while ((ch = getopt(argc, argv, "al:m:r:s")) != -1) { 537 switch (ch) { 538 case 'a': 539 allrates = 1; 540 break; 541 case 'l': 542 frameLen = strtoul(optarg, NULL, 0); 543 break; 544 case 'm': 545 mode = optarg; 546 break; 547 case 'r': 548 frate = atof(optarg); 549 rate = (int) 2*frate; 550 break; 551 case 's': 552 isShortPreamble = 1; 553 break; 554 default: 555 usage(argv[0]); 556 break; 557 } 558 } 559 rt = mode2table(mode); 560 if (rt == NULL) 561 errx(-1, "unknown mode %s", mode); 562 if (!allrates) { 563 rix = rt->rateCodeToIndex[rate]; 564 if (rix == (uint8_t) -1) 565 errx(-1, "rate %s not valid for mode %s", srate(rate), mode); 566 isShort = checkpreamble(rt, rix, isShortPreamble, 1); 567 568 time = ieee80211_compute_duration(rt, frameLen, rate, isShort); 569 printf("%u usec to send %u bytes @ %s Mb/s, %s preamble\n", 570 time, frameLen, srate(rate), 571 isShort ? "short" : "long"); 572 } else { 573 for (rix = 0; rix < rt->rateCount; rix++) { 574 rate = rt->info[rix].dot11Rate &~ IEEE80211_RATE_BASIC; 575 isShort = checkpreamble(rt, rix, isShortPreamble, 0); 576 time = ieee80211_compute_duration(rt, frameLen, rate, 577 isShort); 578 printf("%u usec to send %u bytes @ %s Mb/s, %s preamble\n", 579 time, frameLen, srate(rate), 580 isShort ? "short" : "long"); 581 } 582 } 583 return 0; 584 } 585