1 /* 2 * Copyright 2002-2005, Instant802 Networks, Inc. 3 * Copyright 2005-2006, Devicescape Software, Inc. 4 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> 5 * Copyright 2007 Johannes Berg <johannes@sipsolutions.net> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * utilities for mac80211 12 */ 13 14 #include <net/mac80211.h> 15 #include <linux/netdevice.h> 16 #include <linux/types.h> 17 #include <linux/slab.h> 18 #include <linux/skbuff.h> 19 #include <linux/etherdevice.h> 20 #include <linux/if_arp.h> 21 #include <linux/wireless.h> 22 #include <linux/bitmap.h> 23 #include <net/net_namespace.h> 24 #include <net/cfg80211.h> 25 26 #include "ieee80211_i.h" 27 #include "ieee80211_rate.h" 28 #include "wme.h" 29 30 /* privid for wiphys to determine whether they belong to us or not */ 31 void *mac80211_wiphy_privid = &mac80211_wiphy_privid; 32 33 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */ 34 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */ 35 const unsigned char rfc1042_header[] = 36 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 }; 37 38 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */ 39 const unsigned char bridge_tunnel_header[] = 40 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 }; 41 42 /* No encapsulation header if EtherType < 0x600 (=length) */ 43 static const unsigned char eapol_header[] = 44 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x88, 0x8e }; 45 46 47 static int rate_list_match(const int *rate_list, int rate) 48 { 49 int i; 50 51 if (!rate_list) 52 return 0; 53 54 for (i = 0; rate_list[i] >= 0; i++) 55 if (rate_list[i] == rate) 56 return 1; 57 58 return 0; 59 } 60 61 void ieee80211_prepare_rates(struct ieee80211_local *local, 62 struct ieee80211_hw_mode *mode) 63 { 64 int i; 65 66 for (i = 0; i < mode->num_rates; i++) { 67 struct ieee80211_rate *rate = &mode->rates[i]; 68 69 rate->flags &= ~(IEEE80211_RATE_SUPPORTED | 70 IEEE80211_RATE_BASIC); 71 72 if (local->supp_rates[mode->mode]) { 73 if (!rate_list_match(local->supp_rates[mode->mode], 74 rate->rate)) 75 continue; 76 } 77 78 rate->flags |= IEEE80211_RATE_SUPPORTED; 79 80 /* Use configured basic rate set if it is available. If not, 81 * use defaults that are sane for most cases. */ 82 if (local->basic_rates[mode->mode]) { 83 if (rate_list_match(local->basic_rates[mode->mode], 84 rate->rate)) 85 rate->flags |= IEEE80211_RATE_BASIC; 86 } else switch (mode->mode) { 87 case MODE_IEEE80211A: 88 if (rate->rate == 60 || rate->rate == 120 || 89 rate->rate == 240) 90 rate->flags |= IEEE80211_RATE_BASIC; 91 break; 92 case MODE_IEEE80211B: 93 if (rate->rate == 10 || rate->rate == 20) 94 rate->flags |= IEEE80211_RATE_BASIC; 95 break; 96 case MODE_IEEE80211G: 97 if (rate->rate == 10 || rate->rate == 20 || 98 rate->rate == 55 || rate->rate == 110) 99 rate->flags |= IEEE80211_RATE_BASIC; 100 break; 101 case NUM_IEEE80211_MODES: 102 /* not useful */ 103 break; 104 } 105 106 /* Set ERP and MANDATORY flags based on phymode */ 107 switch (mode->mode) { 108 case MODE_IEEE80211A: 109 if (rate->rate == 60 || rate->rate == 120 || 110 rate->rate == 240) 111 rate->flags |= IEEE80211_RATE_MANDATORY; 112 break; 113 case MODE_IEEE80211B: 114 if (rate->rate == 10) 115 rate->flags |= IEEE80211_RATE_MANDATORY; 116 break; 117 case MODE_IEEE80211G: 118 if (rate->rate == 10 || rate->rate == 20 || 119 rate->rate == 55 || rate->rate == 110 || 120 rate->rate == 60 || rate->rate == 120 || 121 rate->rate == 240) 122 rate->flags |= IEEE80211_RATE_MANDATORY; 123 break; 124 case NUM_IEEE80211_MODES: 125 /* not useful */ 126 break; 127 } 128 if (ieee80211_is_erp_rate(mode->mode, rate->rate)) 129 rate->flags |= IEEE80211_RATE_ERP; 130 } 131 } 132 133 u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len) 134 { 135 u16 fc; 136 137 if (len < 24) 138 return NULL; 139 140 fc = le16_to_cpu(hdr->frame_control); 141 142 switch (fc & IEEE80211_FCTL_FTYPE) { 143 case IEEE80211_FTYPE_DATA: 144 switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) { 145 case IEEE80211_FCTL_TODS: 146 return hdr->addr1; 147 case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS): 148 return NULL; 149 case IEEE80211_FCTL_FROMDS: 150 return hdr->addr2; 151 case 0: 152 return hdr->addr3; 153 } 154 break; 155 case IEEE80211_FTYPE_MGMT: 156 return hdr->addr3; 157 case IEEE80211_FTYPE_CTL: 158 if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL) 159 return hdr->addr1; 160 else 161 return NULL; 162 } 163 164 return NULL; 165 } 166 167 int ieee80211_get_hdrlen(u16 fc) 168 { 169 int hdrlen = 24; 170 171 switch (fc & IEEE80211_FCTL_FTYPE) { 172 case IEEE80211_FTYPE_DATA: 173 if ((fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS)) 174 hdrlen = 30; /* Addr4 */ 175 /* 176 * The QoS Control field is two bytes and its presence is 177 * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to 178 * hdrlen if that bit is set. 179 * This works by masking out the bit and shifting it to 180 * bit position 1 so the result has the value 0 or 2. 181 */ 182 hdrlen += (fc & IEEE80211_STYPE_QOS_DATA) 183 >> (ilog2(IEEE80211_STYPE_QOS_DATA)-1); 184 break; 185 case IEEE80211_FTYPE_CTL: 186 /* 187 * ACK and CTS are 10 bytes, all others 16. To see how 188 * to get this condition consider 189 * subtype mask: 0b0000000011110000 (0x00F0) 190 * ACK subtype: 0b0000000011010000 (0x00D0) 191 * CTS subtype: 0b0000000011000000 (0x00C0) 192 * bits that matter: ^^^ (0x00E0) 193 * value of those: 0b0000000011000000 (0x00C0) 194 */ 195 if ((fc & 0xE0) == 0xC0) 196 hdrlen = 10; 197 else 198 hdrlen = 16; 199 break; 200 } 201 202 return hdrlen; 203 } 204 EXPORT_SYMBOL(ieee80211_get_hdrlen); 205 206 int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb) 207 { 208 const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *) skb->data; 209 int hdrlen; 210 211 if (unlikely(skb->len < 10)) 212 return 0; 213 hdrlen = ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control)); 214 if (unlikely(hdrlen > skb->len)) 215 return 0; 216 return hdrlen; 217 } 218 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb); 219 220 int ieee80211_is_eapol(const struct sk_buff *skb) 221 { 222 const struct ieee80211_hdr *hdr; 223 u16 fc; 224 int hdrlen; 225 226 if (unlikely(skb->len < 10)) 227 return 0; 228 229 hdr = (const struct ieee80211_hdr *) skb->data; 230 fc = le16_to_cpu(hdr->frame_control); 231 232 if (unlikely(!WLAN_FC_DATA_PRESENT(fc))) 233 return 0; 234 235 hdrlen = ieee80211_get_hdrlen(fc); 236 237 if (unlikely(skb->len >= hdrlen + sizeof(eapol_header) && 238 memcmp(skb->data + hdrlen, eapol_header, 239 sizeof(eapol_header)) == 0)) 240 return 1; 241 242 return 0; 243 } 244 245 void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx) 246 { 247 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data; 248 249 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); 250 if (tx->u.tx.extra_frag) { 251 struct ieee80211_hdr *fhdr; 252 int i; 253 for (i = 0; i < tx->u.tx.num_extra_frag; i++) { 254 fhdr = (struct ieee80211_hdr *) 255 tx->u.tx.extra_frag[i]->data; 256 fhdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); 257 } 258 } 259 } 260 261 int ieee80211_frame_duration(struct ieee80211_local *local, size_t len, 262 int rate, int erp, int short_preamble) 263 { 264 int dur; 265 266 /* calculate duration (in microseconds, rounded up to next higher 267 * integer if it includes a fractional microsecond) to send frame of 268 * len bytes (does not include FCS) at the given rate. Duration will 269 * also include SIFS. 270 * 271 * rate is in 100 kbps, so divident is multiplied by 10 in the 272 * DIV_ROUND_UP() operations. 273 */ 274 275 if (local->hw.conf.phymode == MODE_IEEE80211A || erp) { 276 /* 277 * OFDM: 278 * 279 * N_DBPS = DATARATE x 4 280 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS) 281 * (16 = SIGNAL time, 6 = tail bits) 282 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext 283 * 284 * T_SYM = 4 usec 285 * 802.11a - 17.5.2: aSIFSTime = 16 usec 286 * 802.11g - 19.8.4: aSIFSTime = 10 usec + 287 * signal ext = 6 usec 288 */ 289 dur = 16; /* SIFS + signal ext */ 290 dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */ 291 dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */ 292 dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10, 293 4 * rate); /* T_SYM x N_SYM */ 294 } else { 295 /* 296 * 802.11b or 802.11g with 802.11b compatibility: 297 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime + 298 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0. 299 * 300 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4 301 * aSIFSTime = 10 usec 302 * aPreambleLength = 144 usec or 72 usec with short preamble 303 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble 304 */ 305 dur = 10; /* aSIFSTime = 10 usec */ 306 dur += short_preamble ? (72 + 24) : (144 + 48); 307 308 dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate); 309 } 310 311 return dur; 312 } 313 314 /* Exported duration function for driver use */ 315 __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw, int if_id, 316 size_t frame_len, int rate) 317 { 318 struct ieee80211_local *local = hw_to_local(hw); 319 struct net_device *bdev = dev_get_by_index(&init_net, if_id); 320 struct ieee80211_sub_if_data *sdata; 321 u16 dur; 322 int erp; 323 324 if (unlikely(!bdev)) 325 return 0; 326 327 sdata = IEEE80211_DEV_TO_SUB_IF(bdev); 328 erp = ieee80211_is_erp_rate(hw->conf.phymode, rate); 329 dur = ieee80211_frame_duration(local, frame_len, rate, 330 erp, sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE); 331 332 dev_put(bdev); 333 return cpu_to_le16(dur); 334 } 335 EXPORT_SYMBOL(ieee80211_generic_frame_duration); 336 337 __le16 ieee80211_rts_duration(struct ieee80211_hw *hw, int if_id, 338 size_t frame_len, 339 const struct ieee80211_tx_control *frame_txctl) 340 { 341 struct ieee80211_local *local = hw_to_local(hw); 342 struct ieee80211_rate *rate; 343 struct net_device *bdev = dev_get_by_index(&init_net, if_id); 344 struct ieee80211_sub_if_data *sdata; 345 int short_preamble; 346 int erp; 347 u16 dur; 348 349 if (unlikely(!bdev)) 350 return 0; 351 352 sdata = IEEE80211_DEV_TO_SUB_IF(bdev); 353 short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE; 354 355 rate = frame_txctl->rts_rate; 356 erp = !!(rate->flags & IEEE80211_RATE_ERP); 357 358 /* CTS duration */ 359 dur = ieee80211_frame_duration(local, 10, rate->rate, 360 erp, short_preamble); 361 /* Data frame duration */ 362 dur += ieee80211_frame_duration(local, frame_len, rate->rate, 363 erp, short_preamble); 364 /* ACK duration */ 365 dur += ieee80211_frame_duration(local, 10, rate->rate, 366 erp, short_preamble); 367 368 dev_put(bdev); 369 return cpu_to_le16(dur); 370 } 371 EXPORT_SYMBOL(ieee80211_rts_duration); 372 373 __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw, int if_id, 374 size_t frame_len, 375 const struct ieee80211_tx_control *frame_txctl) 376 { 377 struct ieee80211_local *local = hw_to_local(hw); 378 struct ieee80211_rate *rate; 379 struct net_device *bdev = dev_get_by_index(&init_net, if_id); 380 struct ieee80211_sub_if_data *sdata; 381 int short_preamble; 382 int erp; 383 u16 dur; 384 385 if (unlikely(!bdev)) 386 return 0; 387 388 sdata = IEEE80211_DEV_TO_SUB_IF(bdev); 389 short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE; 390 391 rate = frame_txctl->rts_rate; 392 erp = !!(rate->flags & IEEE80211_RATE_ERP); 393 394 /* Data frame duration */ 395 dur = ieee80211_frame_duration(local, frame_len, rate->rate, 396 erp, short_preamble); 397 if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) { 398 /* ACK duration */ 399 dur += ieee80211_frame_duration(local, 10, rate->rate, 400 erp, short_preamble); 401 } 402 403 dev_put(bdev); 404 return cpu_to_le16(dur); 405 } 406 EXPORT_SYMBOL(ieee80211_ctstoself_duration); 407 408 struct ieee80211_rate * 409 ieee80211_get_rate(struct ieee80211_local *local, int phymode, int hw_rate) 410 { 411 struct ieee80211_hw_mode *mode; 412 int r; 413 414 list_for_each_entry(mode, &local->modes_list, list) { 415 if (mode->mode != phymode) 416 continue; 417 for (r = 0; r < mode->num_rates; r++) { 418 struct ieee80211_rate *rate = &mode->rates[r]; 419 if (rate->val == hw_rate || 420 (rate->flags & IEEE80211_RATE_PREAMBLE2 && 421 rate->val2 == hw_rate)) 422 return rate; 423 } 424 } 425 426 return NULL; 427 } 428 429 void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue) 430 { 431 struct ieee80211_local *local = hw_to_local(hw); 432 433 if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF, 434 &local->state[queue])) { 435 if (test_bit(IEEE80211_LINK_STATE_PENDING, 436 &local->state[queue])) 437 tasklet_schedule(&local->tx_pending_tasklet); 438 else 439 if (!ieee80211_qdisc_installed(local->mdev)) { 440 if (queue == 0) 441 netif_wake_queue(local->mdev); 442 } else 443 __netif_schedule(local->mdev); 444 } 445 } 446 EXPORT_SYMBOL(ieee80211_wake_queue); 447 448 void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue) 449 { 450 struct ieee80211_local *local = hw_to_local(hw); 451 452 if (!ieee80211_qdisc_installed(local->mdev) && queue == 0) 453 netif_stop_queue(local->mdev); 454 set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]); 455 } 456 EXPORT_SYMBOL(ieee80211_stop_queue); 457 458 void ieee80211_start_queues(struct ieee80211_hw *hw) 459 { 460 struct ieee80211_local *local = hw_to_local(hw); 461 int i; 462 463 for (i = 0; i < local->hw.queues; i++) 464 clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[i]); 465 if (!ieee80211_qdisc_installed(local->mdev)) 466 netif_start_queue(local->mdev); 467 } 468 EXPORT_SYMBOL(ieee80211_start_queues); 469 470 void ieee80211_stop_queues(struct ieee80211_hw *hw) 471 { 472 int i; 473 474 for (i = 0; i < hw->queues; i++) 475 ieee80211_stop_queue(hw, i); 476 } 477 EXPORT_SYMBOL(ieee80211_stop_queues); 478 479 void ieee80211_wake_queues(struct ieee80211_hw *hw) 480 { 481 int i; 482 483 for (i = 0; i < hw->queues; i++) 484 ieee80211_wake_queue(hw, i); 485 } 486 EXPORT_SYMBOL(ieee80211_wake_queues); 487