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 39#include <sys/socket.h> 40 41#include <net/if.h> 42#include <net/if_media.h> 43 44#include <net80211/ieee80211_var.h> 45#include <net80211/ieee80211_phy.h> 46 47#ifdef notyet 48struct ieee80211_ds_plcp_hdr { 49 uint8_t i_signal; 50 uint8_t i_service; 51 uint16_t i_length; 52 uint16_t i_crc; 53} __packed; 54 55#endif /* notyet */ 56 57/* shorthands to compact tables for readability */ 58#define OFDM IEEE80211_T_OFDM 59#define CCK IEEE80211_T_CCK 60#define TURBO IEEE80211_T_TURBO 61#define HALF IEEE80211_T_OFDM_HALF 62#define QUART IEEE80211_T_OFDM_QUARTER 63#define PBCC (IEEE80211_T_OFDM_QUARTER+1) /* XXX */ 64#define B(r) (0x80 | r) 65#define Mb(x) (x*1000) 66 67static struct ieee80211_rate_table ieee80211_11b_table = { 68 .rateCount = 4, /* XXX no PBCC */ 69 .info = { 70/* short ctrl */ 71/* Preamble dot11Rate Rate */ 72 [0] = { .phy = CCK, 1000, 0x00, B(2), 0 },/* 1 Mb */ 73 [1] = { .phy = CCK, 2000, 0x04, B(4), 1 },/* 2 Mb */ 74 [2] = { .phy = CCK, 5500, 0x04, B(11), 1 },/* 5.5 Mb */ 75 [3] = { .phy = CCK, 11000, 0x04, B(22), 1 },/* 11 Mb */ 76 [4] = { .phy = PBCC, 22000, 0x04, 44, 3 } /* 22 Mb */ 77 }, 78}; 79 80static struct ieee80211_rate_table ieee80211_11g_table = { 81 .rateCount = 12, 82 .info = { 83/* short ctrl */ 84/* Preamble dot11Rate Rate */ 85 [0] = { .phy = CCK, 1000, 0x00, B(2), 0 }, 86 [1] = { .phy = CCK, 2000, 0x04, B(4), 1 }, 87 [2] = { .phy = CCK, 5500, 0x04, B(11), 2 }, 88 [3] = { .phy = CCK, 11000, 0x04, B(22), 3 }, 89 [4] = { .phy = OFDM, 6000, 0x00, 12, 4 }, 90 [5] = { .phy = OFDM, 9000, 0x00, 18, 4 }, 91 [6] = { .phy = OFDM, 12000, 0x00, 24, 6 }, 92 [7] = { .phy = OFDM, 18000, 0x00, 36, 6 }, 93 [8] = { .phy = OFDM, 24000, 0x00, 48, 8 }, 94 [9] = { .phy = OFDM, 36000, 0x00, 72, 8 }, 95 [10] = { .phy = OFDM, 48000, 0x00, 96, 8 }, 96 [11] = { .phy = OFDM, 54000, 0x00, 108, 8 } 97 }, 98}; 99 100static struct ieee80211_rate_table ieee80211_11a_table = { 101 .rateCount = 8, 102 .info = { 103/* short ctrl */ 104/* Preamble dot11Rate Rate */ 105 [0] = { .phy = OFDM, 6000, 0x00, B(12), 0 }, 106 [1] = { .phy = OFDM, 9000, 0x00, 18, 0 }, 107 [2] = { .phy = OFDM, 12000, 0x00, B(24), 2 }, 108 [3] = { .phy = OFDM, 18000, 0x00, 36, 2 }, 109 [4] = { .phy = OFDM, 24000, 0x00, B(48), 4 }, 110 [5] = { .phy = OFDM, 36000, 0x00, 72, 4 }, 111 [6] = { .phy = OFDM, 48000, 0x00, 96, 4 }, 112 [7] = { .phy = OFDM, 54000, 0x00, 108, 4 } 113 }, 114}; 115 116static struct ieee80211_rate_table ieee80211_half_table = { 117 .rateCount = 8, 118 .info = { 119/* short ctrl */ 120/* Preamble dot11Rate Rate */ 121 [0] = { .phy = HALF, 3000, 0x00, B(6), 0 }, 122 [1] = { .phy = HALF, 4500, 0x00, 9, 0 }, 123 [2] = { .phy = HALF, 6000, 0x00, B(12), 2 }, 124 [3] = { .phy = HALF, 9000, 0x00, 18, 2 }, 125 [4] = { .phy = HALF, 12000, 0x00, B(24), 4 }, 126 [5] = { .phy = HALF, 18000, 0x00, 36, 4 }, 127 [6] = { .phy = HALF, 24000, 0x00, 48, 4 }, 128 [7] = { .phy = HALF, 27000, 0x00, 54, 4 } 129 }, 130}; 131 132static struct ieee80211_rate_table ieee80211_quarter_table = { 133 .rateCount = 8, 134 .info = { 135/* short ctrl */ 136/* Preamble dot11Rate Rate */ 137 [0] = { .phy = QUART, 1500, 0x00, B(3), 0 }, 138 [1] = { .phy = QUART, 2250, 0x00, 4, 0 }, 139 [2] = { .phy = QUART, 3000, 0x00, B(9), 2 }, 140 [3] = { .phy = QUART, 4500, 0x00, 9, 2 }, 141 [4] = { .phy = QUART, 6000, 0x00, B(12), 4 }, 142 [5] = { .phy = QUART, 9000, 0x00, 18, 4 }, 143 [6] = { .phy = QUART, 12000, 0x00, 24, 4 }, 144 [7] = { .phy = QUART, 13500, 0x00, 27, 4 } 145 }, 146}; 147 148static struct ieee80211_rate_table ieee80211_turbog_table = { 149 .rateCount = 7, 150 .info = { 151/* short ctrl */ 152/* Preamble dot11Rate Rate */ 153 [0] = { .phy = TURBO, 12000, 0x00, B(12), 0 }, 154 [1] = { .phy = TURBO, 24000, 0x00, B(24), 1 }, 155 [2] = { .phy = TURBO, 36000, 0x00, 36, 1 }, 156 [3] = { .phy = TURBO, 48000, 0x00, B(48), 3 }, 157 [4] = { .phy = TURBO, 72000, 0x00, 72, 3 }, 158 [5] = { .phy = TURBO, 96000, 0x00, 96, 3 }, 159 [6] = { .phy = TURBO, 108000, 0x00, 108, 3 } 160 }, 161}; 162 163static struct ieee80211_rate_table ieee80211_turboa_table = { 164 .rateCount = 8, 165 .info = { 166/* short ctrl */ 167/* Preamble dot11Rate Rate */ 168 [0] = { .phy = TURBO, 12000, 0x00, B(12), 0 }, 169 [1] = { .phy = TURBO, 18000, 0x00, 18, 0 }, 170 [2] = { .phy = TURBO, 24000, 0x00, B(24), 2 }, 171 [3] = { .phy = TURBO, 36000, 0x00, 36, 2 }, 172 [4] = { .phy = TURBO, 48000, 0x00, B(48), 4 }, 173 [5] = { .phy = TURBO, 72000, 0x00, 72, 4 }, 174 [6] = { .phy = TURBO, 96000, 0x00, 96, 4 }, 175 [7] = { .phy = TURBO, 108000, 0x00, 108, 4 } 176 }, 177}; 178 179#undef Mb 180#undef B 181#undef OFDM 182#undef HALF 183#undef QUART 184#undef CCK 185#undef TURBO 186#undef XR 187 188/* 189 * Setup a rate table's reverse lookup table and fill in 190 * ack durations. The reverse lookup tables are assumed 191 * to be initialized to zero (or at least the first entry). 192 * We use this as a key that indicates whether or not 193 * we've previously setup the reverse lookup table. 194 * 195 * XXX not reentrant, but shouldn't matter 196 */ 197static void 198ieee80211_setup_ratetable(struct ieee80211_rate_table *rt) 199{ 200#define N(a) (sizeof(a)/sizeof(a[0])) 201#define WLAN_CTRL_FRAME_SIZE \ 202 (sizeof(struct ieee80211_frame_ack) + IEEE80211_CRC_LEN) 203 204 int i; 205 206 for (i = 0; i < N(rt->rateCodeToIndex); i++) 207 rt->rateCodeToIndex[i] = (uint8_t) -1; 208 for (i = 0; i < rt->rateCount; i++) { 209 uint8_t code = rt->info[i].dot11Rate; 210 uint8_t cix = rt->info[i].ctlRateIndex; 211 uint8_t ctl_rate = rt->info[cix].dot11Rate; 212 213 rt->rateCodeToIndex[code] = i; 214 if (code & IEEE80211_RATE_BASIC) { 215 /* 216 * Map w/o basic rate bit too. 217 */ 218 code &= IEEE80211_RATE_VAL; 219 rt->rateCodeToIndex[code] = i; 220 } 221 222 /* 223 * XXX for 11g the control rate to use for 5.5 and 11 Mb/s 224 * depends on whether they are marked as basic rates; 225 * the static tables are setup with an 11b-compatible 226 * 2Mb/s rate which will work but is suboptimal 227 * 228 * NB: Control rate is always less than or equal to the 229 * current rate, so control rate's reverse lookup entry 230 * has been installed and following call is safe. 231 */ 232 rt->info[i].lpAckDuration = ieee80211_compute_duration(rt, 233 WLAN_CTRL_FRAME_SIZE, ctl_rate, 0); 234 rt->info[i].spAckDuration = ieee80211_compute_duration(rt, 235 WLAN_CTRL_FRAME_SIZE, ctl_rate, IEEE80211_F_SHPREAMBLE); 236 } 237 238#undef WLAN_CTRL_FRAME_SIZE 239#undef N 240} 241 242/* Setup all rate tables */ 243static void 244ieee80211_phy_init(void) 245{ 246#define N(arr) (int)(sizeof(arr) / sizeof(arr[0])) 247 static struct ieee80211_rate_table * const ratetables[] = { 248 &ieee80211_half_table, 249 &ieee80211_quarter_table, 250 &ieee80211_11a_table, 251 &ieee80211_11g_table, 252 &ieee80211_turbog_table, 253 &ieee80211_turboa_table, 254 &ieee80211_turboa_table, 255 &ieee80211_11a_table, 256 &ieee80211_11g_table, 257 &ieee80211_11b_table 258 }; 259 int i; 260 261 for (i = 0; i < N(ratetables); ++i) 262 ieee80211_setup_ratetable(ratetables[i]); 263 264#undef N 265} 266SYSINIT(wlan_phy, SI_SUB_DRIVERS, SI_ORDER_FIRST, ieee80211_phy_init, NULL); 267 268const struct ieee80211_rate_table * 269ieee80211_get_ratetable(struct ieee80211_channel *c) 270{ 271 const struct ieee80211_rate_table *rt; 272 273 /* XXX HT */ 274 if (IEEE80211_IS_CHAN_HALF(c)) 275 rt = &ieee80211_half_table; 276 else if (IEEE80211_IS_CHAN_QUARTER(c)) 277 rt = &ieee80211_quarter_table; 278 else if (IEEE80211_IS_CHAN_HTA(c)) 279 rt = &ieee80211_11a_table; /* XXX */ 280 else if (IEEE80211_IS_CHAN_HTG(c)) 281 rt = &ieee80211_11g_table; /* XXX */ 282 else if (IEEE80211_IS_CHAN_108G(c)) 283 rt = &ieee80211_turbog_table; 284 else if (IEEE80211_IS_CHAN_ST(c)) 285 rt = &ieee80211_turboa_table; 286 else if (IEEE80211_IS_CHAN_TURBO(c)) 287 rt = &ieee80211_turboa_table; 288 else if (IEEE80211_IS_CHAN_A(c)) 289 rt = &ieee80211_11a_table; 290 else if (IEEE80211_IS_CHAN_ANYG(c)) 291 rt = &ieee80211_11g_table; 292 else if (IEEE80211_IS_CHAN_B(c)) 293 rt = &ieee80211_11b_table; 294 else { 295 /* NB: should not get here */ 296 panic("%s: no rate table for channel; freq %u flags 0x%x\n", 297 __func__, c->ic_freq, c->ic_flags); 298 } 299 return rt; 300} 301 302/* 303 * Convert PLCP signal/rate field to 802.11 rate (.5Mbits/s) 304 * 305 * Note we do no parameter checking; this routine is mainly 306 * used to derive an 802.11 rate for constructing radiotap 307 * header data for rx frames. 308 * 309 * XXX might be a candidate for inline 310 */ 311uint8_t 312ieee80211_plcp2rate(uint8_t plcp, enum ieee80211_phytype type) 313{ 314 if (type == IEEE80211_T_OFDM) { 315 static const uint8_t ofdm_plcp2rate[16] = { 316 [0xb] = 12, 317 [0xf] = 18, 318 [0xa] = 24, 319 [0xe] = 36, 320 [0x9] = 48, 321 [0xd] = 72, 322 [0x8] = 96, 323 [0xc] = 108 324 }; 325 return ofdm_plcp2rate[plcp & 0xf]; 326 } 327 if (type == IEEE80211_T_CCK) { 328 static const uint8_t cck_plcp2rate[16] = { 329 [0xa] = 2, /* 0x0a */ 330 [0x4] = 4, /* 0x14 */ 331 [0x7] = 11, /* 0x37 */ 332 [0xe] = 22, /* 0x6e */ 333 [0xc] = 44, /* 0xdc , actually PBCC */ 334 }; 335 return cck_plcp2rate[plcp & 0xf]; 336 } 337 return 0; 338} 339 340/* 341 * Covert 802.11 rate to PLCP signal. 342 */ 343uint8_t 344ieee80211_rate2plcp(int rate, enum ieee80211_phytype type) 345{ 346 /* XXX ignore type for now since rates are unique */ 347 switch (rate) { 348 /* OFDM rates (cf IEEE Std 802.11a-1999, pp. 14 Table 80) */ 349 case 12: return 0xb; 350 case 18: return 0xf; 351 case 24: return 0xa; 352 case 36: return 0xe; 353 case 48: return 0x9; 354 case 72: return 0xd; 355 case 96: return 0x8; 356 case 108: return 0xc; 357 /* CCK rates (IEEE Std 802.11b-1999 page 15, subclause 18.2.3.3) */ 358 case 2: return 10; 359 case 4: return 20; 360 case 11: return 55; 361 case 22: return 110; 362 /* IEEE Std 802.11g-2003 page 19, subclause 19.3.2.1 */ 363 case 44: return 220; 364 } 365 return 0; /* XXX unsupported/unknown rate */ 366} 367 368#define CCK_SIFS_TIME 10 369#define CCK_PREAMBLE_BITS 144 370#define CCK_PLCP_BITS 48 371 372#define OFDM_SIFS_TIME 16 373#define OFDM_PREAMBLE_TIME 20 374#define OFDM_PLCP_BITS 22 375#define OFDM_SYMBOL_TIME 4 376 377#define OFDM_HALF_SIFS_TIME 32 378#define OFDM_HALF_PREAMBLE_TIME 40 379#define OFDM_HALF_PLCP_BITS 22 380#define OFDM_HALF_SYMBOL_TIME 8 381 382#define OFDM_QUARTER_SIFS_TIME 64 383#define OFDM_QUARTER_PREAMBLE_TIME 80 384#define OFDM_QUARTER_PLCP_BITS 22 385#define OFDM_QUARTER_SYMBOL_TIME 16 386 387#define TURBO_SIFS_TIME 8 388#define TURBO_PREAMBLE_TIME 14 389#define TURBO_PLCP_BITS 22 390#define TURBO_SYMBOL_TIME 4 391 392/* 393 * Compute the time to transmit a frame of length frameLen bytes 394 * using the specified rate, phy, and short preamble setting. 395 * SIFS is included. 396 */ 397uint16_t 398ieee80211_compute_duration(const struct ieee80211_rate_table *rt, 399 uint32_t frameLen, uint16_t rate, int isShortPreamble) 400{ 401 uint8_t rix = rt->rateCodeToIndex[rate]; 402 uint32_t bitsPerSymbol, numBits, numSymbols, phyTime, txTime; 403 uint32_t kbps; 404 405 KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate)); 406 kbps = rt->info[rix].rateKbps; 407 if (kbps == 0) /* XXX bandaid for channel changes */ 408 return 0; 409 410 switch (rt->info[rix].phy) { 411 case IEEE80211_T_CCK: 412 phyTime = CCK_PREAMBLE_BITS + CCK_PLCP_BITS; 413 if (isShortPreamble && rt->info[rix].shortPreamble) 414 phyTime >>= 1; 415 numBits = frameLen << 3; 416 txTime = CCK_SIFS_TIME + phyTime 417 + ((numBits * 1000)/kbps); 418 break; 419 case IEEE80211_T_OFDM: 420 bitsPerSymbol = (kbps * OFDM_SYMBOL_TIME) / 1000; 421 KASSERT(bitsPerSymbol != 0, ("full rate bps")); 422 423 numBits = OFDM_PLCP_BITS + (frameLen << 3); 424 numSymbols = howmany(numBits, bitsPerSymbol); 425 txTime = OFDM_SIFS_TIME 426 + OFDM_PREAMBLE_TIME 427 + (numSymbols * OFDM_SYMBOL_TIME); 428 break; 429 case IEEE80211_T_OFDM_HALF: 430 bitsPerSymbol = (kbps * OFDM_HALF_SYMBOL_TIME) / 1000; 431 KASSERT(bitsPerSymbol != 0, ("1/4 rate bps")); 432 433 numBits = OFDM_PLCP_BITS + (frameLen << 3); 434 numSymbols = howmany(numBits, bitsPerSymbol); 435 txTime = OFDM_HALF_SIFS_TIME 436 + OFDM_HALF_PREAMBLE_TIME 437 + (numSymbols * OFDM_HALF_SYMBOL_TIME); 438 break; 439 case IEEE80211_T_OFDM_QUARTER: 440 bitsPerSymbol = (kbps * OFDM_QUARTER_SYMBOL_TIME) / 1000; 441 KASSERT(bitsPerSymbol != 0, ("1/2 rate bps")); 442 443 numBits = OFDM_PLCP_BITS + (frameLen << 3); 444 numSymbols = howmany(numBits, bitsPerSymbol); 445 txTime = OFDM_QUARTER_SIFS_TIME 446 + OFDM_QUARTER_PREAMBLE_TIME 447 + (numSymbols * OFDM_QUARTER_SYMBOL_TIME); 448 break; 449 case IEEE80211_T_TURBO: 450 /* we still save OFDM rates in kbps - so double them */ 451 bitsPerSymbol = ((kbps << 1) * TURBO_SYMBOL_TIME) / 1000; 452 KASSERT(bitsPerSymbol != 0, ("turbo bps")); 453 454 numBits = TURBO_PLCP_BITS + (frameLen << 3); 455 numSymbols = howmany(numBits, bitsPerSymbol); 456 txTime = TURBO_SIFS_TIME + TURBO_PREAMBLE_TIME 457 + (numSymbols * TURBO_SYMBOL_TIME); 458 break; 459 default: 460 panic("%s: unknown phy %u (rate %u)\n", __func__, 461 rt->info[rix].phy, rate); 462 break; 463 } 464 return txTime; 465} 466