1/*- 2 * Copyright (c) 2007-2008 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 "opt_inet.h" 34 35#include <sys/param.h> 36#include <sys/kernel.h> 37#include <sys/systm.h> 38#include <sys/malloc.h> 39 40#include <sys/socket.h> 41 42#include <net/if.h> 43#include <net/if_media.h> 44 45#include <net/ethernet.h> 46#include <net/route.h> 47 48#include <net80211/ieee80211_var.h> 49#include <net80211/ieee80211_phy.h> 50 51#ifdef notyet 52struct ieee80211_ds_plcp_hdr { 53 uint8_t i_signal; 54 uint8_t i_service; 55 uint16_t i_length; 56 uint16_t i_crc; 57} __packed; 58 59#endif /* notyet */ 60 61/* shorthands to compact tables for readability */ 62#define OFDM IEEE80211_T_OFDM 63#define CCK IEEE80211_T_CCK 64#define TURBO IEEE80211_T_TURBO 65#define HALF IEEE80211_T_OFDM_HALF 66#define QUART IEEE80211_T_OFDM_QUARTER 67#define HT IEEE80211_T_HT 68/* XXX the 11n and the basic rate flag are unfortunately overlapping. Grr. */ 69#define N(r) (IEEE80211_RATE_MCS | r) 70#define PBCC (IEEE80211_T_OFDM_QUARTER+1) /* XXX */ 71#define B(r) (IEEE80211_RATE_BASIC | r) 72#define Mb(x) (x*1000) 73 74static struct ieee80211_rate_table ieee80211_11b_table = { 75 .rateCount = 4, /* XXX no PBCC */ 76 .info = { 77/* short ctrl */ 78/* Preamble dot11Rate Rate */ 79 [0] = { .phy = CCK, 1000, 0x00, B(2), 0 },/* 1 Mb */ 80 [1] = { .phy = CCK, 2000, 0x04, B(4), 1 },/* 2 Mb */ 81 [2] = { .phy = CCK, 5500, 0x04, B(11), 1 },/* 5.5 Mb */ 82 [3] = { .phy = CCK, 11000, 0x04, B(22), 1 },/* 11 Mb */ 83 [4] = { .phy = PBCC, 22000, 0x04, 44, 3 } /* 22 Mb */ 84 }, 85}; 86 87static struct ieee80211_rate_table ieee80211_11g_table = { 88 .rateCount = 12, 89 .info = { 90/* short ctrl */ 91/* Preamble dot11Rate Rate */ 92 [0] = { .phy = CCK, 1000, 0x00, B(2), 0 }, 93 [1] = { .phy = CCK, 2000, 0x04, B(4), 1 }, 94 [2] = { .phy = CCK, 5500, 0x04, B(11), 2 }, 95 [3] = { .phy = CCK, 11000, 0x04, B(22), 3 }, 96 [4] = { .phy = OFDM, 6000, 0x00, 12, 4 }, 97 [5] = { .phy = OFDM, 9000, 0x00, 18, 4 }, 98 [6] = { .phy = OFDM, 12000, 0x00, 24, 6 }, 99 [7] = { .phy = OFDM, 18000, 0x00, 36, 6 }, 100 [8] = { .phy = OFDM, 24000, 0x00, 48, 8 }, 101 [9] = { .phy = OFDM, 36000, 0x00, 72, 8 }, 102 [10] = { .phy = OFDM, 48000, 0x00, 96, 8 }, 103 [11] = { .phy = OFDM, 54000, 0x00, 108, 8 } 104 }, 105}; 106 107static struct ieee80211_rate_table ieee80211_11a_table = { 108 .rateCount = 8, 109 .info = { 110/* short ctrl */ 111/* Preamble dot11Rate Rate */ 112 [0] = { .phy = OFDM, 6000, 0x00, B(12), 0 }, 113 [1] = { .phy = OFDM, 9000, 0x00, 18, 0 }, 114 [2] = { .phy = OFDM, 12000, 0x00, B(24), 2 }, 115 [3] = { .phy = OFDM, 18000, 0x00, 36, 2 }, 116 [4] = { .phy = OFDM, 24000, 0x00, B(48), 4 }, 117 [5] = { .phy = OFDM, 36000, 0x00, 72, 4 }, 118 [6] = { .phy = OFDM, 48000, 0x00, 96, 4 }, 119 [7] = { .phy = OFDM, 54000, 0x00, 108, 4 } 120 }, 121}; 122 123static struct ieee80211_rate_table ieee80211_half_table = { 124 .rateCount = 8, 125 .info = { 126/* short ctrl */ 127/* Preamble dot11Rate Rate */ 128 [0] = { .phy = HALF, 3000, 0x00, B(6), 0 }, 129 [1] = { .phy = HALF, 4500, 0x00, 9, 0 }, 130 [2] = { .phy = HALF, 6000, 0x00, B(12), 2 }, 131 [3] = { .phy = HALF, 9000, 0x00, 18, 2 }, 132 [4] = { .phy = HALF, 12000, 0x00, B(24), 4 }, 133 [5] = { .phy = HALF, 18000, 0x00, 36, 4 }, 134 [6] = { .phy = HALF, 24000, 0x00, 48, 4 }, 135 [7] = { .phy = HALF, 27000, 0x00, 54, 4 } 136 }, 137}; 138 139static struct ieee80211_rate_table ieee80211_quarter_table = { 140 .rateCount = 8, 141 .info = { 142/* short ctrl */ 143/* Preamble dot11Rate Rate */ 144 [0] = { .phy = QUART, 1500, 0x00, B(3), 0 }, 145 [1] = { .phy = QUART, 2250, 0x00, 4, 0 }, 146 [2] = { .phy = QUART, 3000, 0x00, B(9), 2 }, 147 [3] = { .phy = QUART, 4500, 0x00, 9, 2 }, 148 [4] = { .phy = QUART, 6000, 0x00, B(12), 4 }, 149 [5] = { .phy = QUART, 9000, 0x00, 18, 4 }, 150 [6] = { .phy = QUART, 12000, 0x00, 24, 4 }, 151 [7] = { .phy = QUART, 13500, 0x00, 27, 4 } 152 }, 153}; 154 155static struct ieee80211_rate_table ieee80211_turbog_table = { 156 .rateCount = 7, 157 .info = { 158/* short ctrl */ 159/* Preamble dot11Rate Rate */ 160 [0] = { .phy = TURBO, 12000, 0x00, B(12), 0 }, 161 [1] = { .phy = TURBO, 24000, 0x00, B(24), 1 }, 162 [2] = { .phy = TURBO, 36000, 0x00, 36, 1 }, 163 [3] = { .phy = TURBO, 48000, 0x00, B(48), 3 }, 164 [4] = { .phy = TURBO, 72000, 0x00, 72, 3 }, 165 [5] = { .phy = TURBO, 96000, 0x00, 96, 3 }, 166 [6] = { .phy = TURBO, 108000, 0x00, 108, 3 } 167 }, 168}; 169 170static struct ieee80211_rate_table ieee80211_turboa_table = { 171 .rateCount = 8, 172 .info = { 173/* short ctrl */ 174/* Preamble dot11Rate Rate */ 175 [0] = { .phy = TURBO, 12000, 0x00, B(12), 0 }, 176 [1] = { .phy = TURBO, 18000, 0x00, 18, 0 }, 177 [2] = { .phy = TURBO, 24000, 0x00, B(24), 2 }, 178 [3] = { .phy = TURBO, 36000, 0x00, 36, 2 }, 179 [4] = { .phy = TURBO, 48000, 0x00, B(48), 4 }, 180 [5] = { .phy = TURBO, 72000, 0x00, 72, 4 }, 181 [6] = { .phy = TURBO, 96000, 0x00, 96, 4 }, 182 [7] = { .phy = TURBO, 108000, 0x00, 108, 4 } 183 }, 184}; 185 186static struct ieee80211_rate_table ieee80211_11ng_table = { 187 .rateCount = 36, 188 .info = { 189/* short ctrl */ 190/* Preamble dot11Rate Rate */ 191 [0] = { .phy = CCK, 1000, 0x00, B(2), 0 }, 192 [1] = { .phy = CCK, 2000, 0x04, B(4), 1 }, 193 [2] = { .phy = CCK, 5500, 0x04, B(11), 2 }, 194 [3] = { .phy = CCK, 11000, 0x04, B(22), 3 }, 195 [4] = { .phy = OFDM, 6000, 0x00, 12, 4 }, 196 [5] = { .phy = OFDM, 9000, 0x00, 18, 4 }, 197 [6] = { .phy = OFDM, 12000, 0x00, 24, 6 }, 198 [7] = { .phy = OFDM, 18000, 0x00, 36, 6 }, 199 [8] = { .phy = OFDM, 24000, 0x00, 48, 8 }, 200 [9] = { .phy = OFDM, 36000, 0x00, 72, 8 }, 201 [10] = { .phy = OFDM, 48000, 0x00, 96, 8 }, 202 [11] = { .phy = OFDM, 54000, 0x00, 108, 8 }, 203 204 [12] = { .phy = HT, 6500, 0x00, N(0), 4 }, 205 [13] = { .phy = HT, 13000, 0x00, N(1), 6 }, 206 [14] = { .phy = HT, 19500, 0x00, N(2), 6 }, 207 [15] = { .phy = HT, 26000, 0x00, N(3), 8 }, 208 [16] = { .phy = HT, 39000, 0x00, N(4), 8 }, 209 [17] = { .phy = HT, 52000, 0x00, N(5), 8 }, 210 [18] = { .phy = HT, 58500, 0x00, N(6), 8 }, 211 [19] = { .phy = HT, 65000, 0x00, N(7), 8 }, 212 213 [20] = { .phy = HT, 13000, 0x00, N(8), 4 }, 214 [21] = { .phy = HT, 26000, 0x00, N(9), 6 }, 215 [22] = { .phy = HT, 39000, 0x00, N(10), 6 }, 216 [23] = { .phy = HT, 52000, 0x00, N(11), 8 }, 217 [24] = { .phy = HT, 78000, 0x00, N(12), 8 }, 218 [25] = { .phy = HT, 104000, 0x00, N(13), 8 }, 219 [26] = { .phy = HT, 117000, 0x00, N(14), 8 }, 220 [27] = { .phy = HT, 130000, 0x00, N(15), 8 }, 221 222 [28] = { .phy = HT, 19500, 0x00, N(16), 4 }, 223 [29] = { .phy = HT, 39000, 0x00, N(17), 6 }, 224 [30] = { .phy = HT, 58500, 0x00, N(18), 6 }, 225 [31] = { .phy = HT, 78000, 0x00, N(19), 8 }, 226 [32] = { .phy = HT, 117000, 0x00, N(20), 8 }, 227 [33] = { .phy = HT, 156000, 0x00, N(21), 8 }, 228 [34] = { .phy = HT, 175500, 0x00, N(22), 8 }, 229 [35] = { .phy = HT, 195000, 0x00, N(23), 8 }, 230 231 }, 232}; 233 234static struct ieee80211_rate_table ieee80211_11na_table = { 235 .rateCount = 32, 236 .info = { 237/* short ctrl */ 238/* Preamble dot11Rate Rate */ 239 [0] = { .phy = OFDM, 6000, 0x00, B(12), 0 }, 240 [1] = { .phy = OFDM, 9000, 0x00, 18, 0 }, 241 [2] = { .phy = OFDM, 12000, 0x00, B(24), 2 }, 242 [3] = { .phy = OFDM, 18000, 0x00, 36, 2 }, 243 [4] = { .phy = OFDM, 24000, 0x00, B(48), 4 }, 244 [5] = { .phy = OFDM, 36000, 0x00, 72, 4 }, 245 [6] = { .phy = OFDM, 48000, 0x00, 96, 4 }, 246 [7] = { .phy = OFDM, 54000, 0x00, 108, 4 }, 247 248 [8] = { .phy = HT, 6500, 0x00, N(0), 0 }, 249 [9] = { .phy = HT, 13000, 0x00, N(1), 2 }, 250 [10] = { .phy = HT, 19500, 0x00, N(2), 2 }, 251 [11] = { .phy = HT, 26000, 0x00, N(3), 4 }, 252 [12] = { .phy = HT, 39000, 0x00, N(4), 4 }, 253 [13] = { .phy = HT, 52000, 0x00, N(5), 4 }, 254 [14] = { .phy = HT, 58500, 0x00, N(6), 4 }, 255 [15] = { .phy = HT, 65000, 0x00, N(7), 4 }, 256 257 [16] = { .phy = HT, 13000, 0x00, N(8), 0 }, 258 [17] = { .phy = HT, 26000, 0x00, N(9), 2 }, 259 [18] = { .phy = HT, 39000, 0x00, N(10), 2 }, 260 [19] = { .phy = HT, 52000, 0x00, N(11), 4 }, 261 [20] = { .phy = HT, 78000, 0x00, N(12), 4 }, 262 [21] = { .phy = HT, 104000, 0x00, N(13), 4 }, 263 [22] = { .phy = HT, 117000, 0x00, N(14), 4 }, 264 [23] = { .phy = HT, 130000, 0x00, N(15), 4 }, 265 266 [24] = { .phy = HT, 19500, 0x00, N(16), 0 }, 267 [25] = { .phy = HT, 39000, 0x00, N(17), 2 }, 268 [26] = { .phy = HT, 58500, 0x00, N(18), 2 }, 269 [27] = { .phy = HT, 78000, 0x00, N(19), 4 }, 270 [28] = { .phy = HT, 117000, 0x00, N(20), 4 }, 271 [29] = { .phy = HT, 156000, 0x00, N(21), 4 }, 272 [30] = { .phy = HT, 175500, 0x00, N(22), 4 }, 273 [31] = { .phy = HT, 195000, 0x00, N(23), 4 }, 274 275 }, 276}; 277 278#undef Mb 279#undef B 280#undef OFDM 281#undef HALF 282#undef QUART 283#undef CCK 284#undef TURBO 285#undef XR 286#undef HT 287#undef N 288 289/* 290 * Setup a rate table's reverse lookup table and fill in 291 * ack durations. The reverse lookup tables are assumed 292 * to be initialized to zero (or at least the first entry). 293 * We use this as a key that indicates whether or not 294 * we've previously setup the reverse lookup table. 295 * 296 * XXX not reentrant, but shouldn't matter 297 */ 298static void 299ieee80211_setup_ratetable(struct ieee80211_rate_table *rt) 300{ 301#define WLAN_CTRL_FRAME_SIZE \ 302 (sizeof(struct ieee80211_frame_ack) + IEEE80211_CRC_LEN) 303 304 int i; 305 306 for (i = 0; i < nitems(rt->rateCodeToIndex); i++) 307 rt->rateCodeToIndex[i] = (uint8_t) -1; 308 for (i = 0; i < rt->rateCount; i++) { 309 uint8_t code = rt->info[i].dot11Rate; 310 uint8_t cix = rt->info[i].ctlRateIndex; 311 uint8_t ctl_rate = rt->info[cix].dot11Rate; 312 313 /* 314 * Map without the basic rate bit. 315 * 316 * It's up to the caller to ensure that the basic 317 * rate bit is stripped here. 318 * 319 * For HT, use the MCS rate bit. 320 */ 321 code &= IEEE80211_RATE_VAL; 322 if (rt->info[i].phy == IEEE80211_T_HT) { 323 code |= IEEE80211_RATE_MCS; 324 } 325 326 /* XXX assume the control rate is non-MCS? */ 327 ctl_rate &= IEEE80211_RATE_VAL; 328 rt->rateCodeToIndex[code] = i; 329 330 /* 331 * XXX for 11g the control rate to use for 5.5 and 11 Mb/s 332 * depends on whether they are marked as basic rates; 333 * the static tables are setup with an 11b-compatible 334 * 2Mb/s rate which will work but is suboptimal 335 * 336 * NB: Control rate is always less than or equal to the 337 * current rate, so control rate's reverse lookup entry 338 * has been installed and following call is safe. 339 */ 340 rt->info[i].lpAckDuration = ieee80211_compute_duration(rt, 341 WLAN_CTRL_FRAME_SIZE, ctl_rate, 0); 342 rt->info[i].spAckDuration = ieee80211_compute_duration(rt, 343 WLAN_CTRL_FRAME_SIZE, ctl_rate, IEEE80211_F_SHPREAMBLE); 344 } 345 346#undef WLAN_CTRL_FRAME_SIZE 347} 348 349/* Setup all rate tables */ 350static void 351ieee80211_phy_init(void) 352{ 353 static struct ieee80211_rate_table * const ratetables[] = { 354 &ieee80211_half_table, 355 &ieee80211_quarter_table, 356 &ieee80211_11na_table, 357 &ieee80211_11ng_table, 358 &ieee80211_turbog_table, 359 &ieee80211_turboa_table, 360 &ieee80211_11a_table, 361 &ieee80211_11g_table, 362 &ieee80211_11b_table 363 }; 364 int i; 365 366 for (i = 0; i < nitems(ratetables); ++i) 367 ieee80211_setup_ratetable(ratetables[i]); 368 369} 370SYSINIT(wlan_phy, SI_SUB_DRIVERS, SI_ORDER_FIRST, ieee80211_phy_init, NULL); 371 372const struct ieee80211_rate_table * 373ieee80211_get_ratetable(struct ieee80211_channel *c) 374{ 375 const struct ieee80211_rate_table *rt; 376 377 /* XXX HT */ 378 if (IEEE80211_IS_CHAN_HALF(c)) 379 rt = &ieee80211_half_table; 380 else if (IEEE80211_IS_CHAN_QUARTER(c)) 381 rt = &ieee80211_quarter_table; 382 else if (IEEE80211_IS_CHAN_HTA(c)) 383 rt = &ieee80211_11na_table; 384 else if (IEEE80211_IS_CHAN_HTG(c)) 385 rt = &ieee80211_11ng_table; 386 else if (IEEE80211_IS_CHAN_108G(c)) 387 rt = &ieee80211_turbog_table; 388 else if (IEEE80211_IS_CHAN_ST(c)) 389 rt = &ieee80211_turboa_table; 390 else if (IEEE80211_IS_CHAN_TURBO(c)) 391 rt = &ieee80211_turboa_table; 392 else if (IEEE80211_IS_CHAN_A(c)) 393 rt = &ieee80211_11a_table; 394 else if (IEEE80211_IS_CHAN_ANYG(c)) 395 rt = &ieee80211_11g_table; 396 else if (IEEE80211_IS_CHAN_B(c)) 397 rt = &ieee80211_11b_table; 398 else { 399 /* NB: should not get here */ 400 panic("%s: no rate table for channel; freq %u flags 0x%x\n", 401 __func__, c->ic_freq, c->ic_flags); 402 } 403 return rt; 404} 405 406/* 407 * Convert PLCP signal/rate field to 802.11 rate (.5Mbits/s) 408 * 409 * Note we do no parameter checking; this routine is mainly 410 * used to derive an 802.11 rate for constructing radiotap 411 * header data for rx frames. 412 * 413 * XXX might be a candidate for inline 414 */ 415uint8_t 416ieee80211_plcp2rate(uint8_t plcp, enum ieee80211_phytype type) 417{ 418 if (type == IEEE80211_T_OFDM) { 419 static const uint8_t ofdm_plcp2rate[16] = { 420 [0xb] = 12, 421 [0xf] = 18, 422 [0xa] = 24, 423 [0xe] = 36, 424 [0x9] = 48, 425 [0xd] = 72, 426 [0x8] = 96, 427 [0xc] = 108 428 }; 429 return ofdm_plcp2rate[plcp & 0xf]; 430 } 431 if (type == IEEE80211_T_CCK) { 432 static const uint8_t cck_plcp2rate[16] = { 433 [0xa] = 2, /* 0x0a */ 434 [0x4] = 4, /* 0x14 */ 435 [0x7] = 11, /* 0x37 */ 436 [0xe] = 22, /* 0x6e */ 437 [0xc] = 44, /* 0xdc , actually PBCC */ 438 }; 439 return cck_plcp2rate[plcp & 0xf]; 440 } 441 return 0; 442} 443 444/* 445 * Covert 802.11 rate to PLCP signal. 446 */ 447uint8_t 448ieee80211_rate2plcp(int rate, enum ieee80211_phytype type) 449{ 450 /* XXX ignore type for now since rates are unique */ 451 switch (rate) { 452 /* OFDM rates (cf IEEE Std 802.11a-1999, pp. 14 Table 80) */ 453 case 12: return 0xb; 454 case 18: return 0xf; 455 case 24: return 0xa; 456 case 36: return 0xe; 457 case 48: return 0x9; 458 case 72: return 0xd; 459 case 96: return 0x8; 460 case 108: return 0xc; 461 /* CCK rates (IEEE Std 802.11b-1999 page 15, subclause 18.2.3.3) */ 462 case 2: return 10; 463 case 4: return 20; 464 case 11: return 55; 465 case 22: return 110; 466 /* IEEE Std 802.11g-2003 page 19, subclause 19.3.2.1 */ 467 case 44: return 220; 468 } 469 return 0; /* XXX unsupported/unknown rate */ 470} 471 472#define CCK_SIFS_TIME 10 473#define CCK_PREAMBLE_BITS 144 474#define CCK_PLCP_BITS 48 475 476#define OFDM_SIFS_TIME 16 477#define OFDM_PREAMBLE_TIME 20 478#define OFDM_PLCP_BITS 22 479#define OFDM_SYMBOL_TIME 4 480 481#define OFDM_HALF_SIFS_TIME 32 482#define OFDM_HALF_PREAMBLE_TIME 40 483#define OFDM_HALF_PLCP_BITS 22 484#define OFDM_HALF_SYMBOL_TIME 8 485 486#define OFDM_QUARTER_SIFS_TIME 64 487#define OFDM_QUARTER_PREAMBLE_TIME 80 488#define OFDM_QUARTER_PLCP_BITS 22 489#define OFDM_QUARTER_SYMBOL_TIME 16 490 491#define TURBO_SIFS_TIME 8 492#define TURBO_PREAMBLE_TIME 14 493#define TURBO_PLCP_BITS 22 494#define TURBO_SYMBOL_TIME 4 495 496/* 497 * Compute the time to transmit a frame of length frameLen bytes 498 * using the specified rate, phy, and short preamble setting. 499 * SIFS is included. 500 */ 501uint16_t 502ieee80211_compute_duration(const struct ieee80211_rate_table *rt, 503 uint32_t frameLen, uint16_t rate, int isShortPreamble) 504{ 505 uint8_t rix = rt->rateCodeToIndex[rate]; 506 uint32_t bitsPerSymbol, numBits, numSymbols, phyTime, txTime; 507 uint32_t kbps; 508 509 KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate)); 510 kbps = rt->info[rix].rateKbps; 511 if (kbps == 0) /* XXX bandaid for channel changes */ 512 return 0; 513 514 switch (rt->info[rix].phy) { 515 case IEEE80211_T_CCK: 516 phyTime = CCK_PREAMBLE_BITS + CCK_PLCP_BITS; 517 if (isShortPreamble && rt->info[rix].shortPreamble) 518 phyTime >>= 1; 519 numBits = frameLen << 3; 520 txTime = CCK_SIFS_TIME + phyTime 521 + ((numBits * 1000)/kbps); 522 break; 523 case IEEE80211_T_OFDM: 524 bitsPerSymbol = (kbps * OFDM_SYMBOL_TIME) / 1000; 525 KASSERT(bitsPerSymbol != 0, ("full rate bps")); 526 527 numBits = OFDM_PLCP_BITS + (frameLen << 3); 528 numSymbols = howmany(numBits, bitsPerSymbol); 529 txTime = OFDM_SIFS_TIME 530 + OFDM_PREAMBLE_TIME 531 + (numSymbols * OFDM_SYMBOL_TIME); 532 break; 533 case IEEE80211_T_OFDM_HALF: 534 bitsPerSymbol = (kbps * OFDM_HALF_SYMBOL_TIME) / 1000; 535 KASSERT(bitsPerSymbol != 0, ("1/4 rate bps")); 536 537 numBits = OFDM_PLCP_BITS + (frameLen << 3); 538 numSymbols = howmany(numBits, bitsPerSymbol); 539 txTime = OFDM_HALF_SIFS_TIME 540 + OFDM_HALF_PREAMBLE_TIME 541 + (numSymbols * OFDM_HALF_SYMBOL_TIME); 542 break; 543 case IEEE80211_T_OFDM_QUARTER: 544 bitsPerSymbol = (kbps * OFDM_QUARTER_SYMBOL_TIME) / 1000; 545 KASSERT(bitsPerSymbol != 0, ("1/2 rate bps")); 546 547 numBits = OFDM_PLCP_BITS + (frameLen << 3); 548 numSymbols = howmany(numBits, bitsPerSymbol); 549 txTime = OFDM_QUARTER_SIFS_TIME 550 + OFDM_QUARTER_PREAMBLE_TIME 551 + (numSymbols * OFDM_QUARTER_SYMBOL_TIME); 552 break; 553 case IEEE80211_T_TURBO: 554 /* we still save OFDM rates in kbps - so double them */ 555 bitsPerSymbol = ((kbps << 1) * TURBO_SYMBOL_TIME) / 1000; 556 KASSERT(bitsPerSymbol != 0, ("turbo bps")); 557 558 numBits = TURBO_PLCP_BITS + (frameLen << 3); 559 numSymbols = howmany(numBits, bitsPerSymbol); 560 txTime = TURBO_SIFS_TIME + TURBO_PREAMBLE_TIME 561 + (numSymbols * TURBO_SYMBOL_TIME); 562 break; 563 default: 564 panic("%s: unknown phy %u (rate %u)\n", __func__, 565 rt->info[rix].phy, rate); 566 } 567 return txTime; 568} 569 570static const uint16_t ht20_bps[32] = { 571 26, 52, 78, 104, 156, 208, 234, 260, 572 52, 104, 156, 208, 312, 416, 468, 520, 573 78, 156, 234, 312, 468, 624, 702, 780, 574 104, 208, 312, 416, 624, 832, 936, 1040 575}; 576static const uint16_t ht40_bps[32] = { 577 54, 108, 162, 216, 324, 432, 486, 540, 578 108, 216, 324, 432, 648, 864, 972, 1080, 579 162, 324, 486, 648, 972, 1296, 1458, 1620, 580 216, 432, 648, 864, 1296, 1728, 1944, 2160 581}; 582 583 584#define OFDM_PLCP_BITS 22 585#define HT_L_STF 8 586#define HT_L_LTF 8 587#define HT_L_SIG 4 588#define HT_SIG 8 589#define HT_STF 4 590#define HT_LTF(n) ((n) * 4) 591 592/* 593 * Calculate the transmit duration of an 11n frame. 594 */ 595uint32_t 596ieee80211_compute_duration_ht(uint32_t frameLen, uint16_t rate, 597 int streams, int isht40, int isShortGI) 598{ 599 uint32_t bitsPerSymbol, numBits, numSymbols, txTime; 600 601 KASSERT(rate & IEEE80211_RATE_MCS, ("not mcs %d", rate)); 602 KASSERT((rate &~ IEEE80211_RATE_MCS) < 31, ("bad mcs 0x%x", rate)); 603 604 if (isht40) 605 bitsPerSymbol = ht40_bps[rate & 0x1f]; 606 else 607 bitsPerSymbol = ht20_bps[rate & 0x1f]; 608 numBits = OFDM_PLCP_BITS + (frameLen << 3); 609 numSymbols = howmany(numBits, bitsPerSymbol); 610 if (isShortGI) 611 txTime = ((numSymbols * 18) + 4) / 5; /* 3.6us */ 612 else 613 txTime = numSymbols * 4; /* 4us */ 614 return txTime + HT_L_STF + HT_L_LTF + 615 HT_L_SIG + HT_SIG + HT_STF + HT_LTF(streams); 616} 617 618#undef HT_LTF 619#undef HT_STF 620#undef HT_SIG 621#undef HT_L_SIG 622#undef HT_L_LTF 623#undef HT_L_STF 624#undef OFDM_PLCP_BITS 625