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 #include <net/rtnetlink.h> 26 27 #include "ieee80211_i.h" 28 #include "ieee80211_rate.h" 29 #include "wme.h" 30 31 /* privid for wiphys to determine whether they belong to us or not */ 32 void *mac80211_wiphy_privid = &mac80211_wiphy_privid; 33 34 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */ 35 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */ 36 const unsigned char rfc1042_header[] = 37 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 }; 38 39 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */ 40 const unsigned char bridge_tunnel_header[] = 41 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 }; 42 43 44 static int rate_list_match(const int *rate_list, int rate) 45 { 46 int i; 47 48 if (!rate_list) 49 return 0; 50 51 for (i = 0; rate_list[i] >= 0; i++) 52 if (rate_list[i] == rate) 53 return 1; 54 55 return 0; 56 } 57 58 void ieee80211_prepare_rates(struct ieee80211_local *local, 59 struct ieee80211_hw_mode *mode) 60 { 61 int i; 62 63 for (i = 0; i < mode->num_rates; i++) { 64 struct ieee80211_rate *rate = &mode->rates[i]; 65 66 rate->flags &= ~(IEEE80211_RATE_SUPPORTED | 67 IEEE80211_RATE_BASIC); 68 69 if (local->supp_rates[mode->mode]) { 70 if (!rate_list_match(local->supp_rates[mode->mode], 71 rate->rate)) 72 continue; 73 } 74 75 rate->flags |= IEEE80211_RATE_SUPPORTED; 76 77 /* Use configured basic rate set if it is available. If not, 78 * use defaults that are sane for most cases. */ 79 if (local->basic_rates[mode->mode]) { 80 if (rate_list_match(local->basic_rates[mode->mode], 81 rate->rate)) 82 rate->flags |= IEEE80211_RATE_BASIC; 83 } else switch (mode->mode) { 84 case MODE_IEEE80211A: 85 if (rate->rate == 60 || rate->rate == 120 || 86 rate->rate == 240) 87 rate->flags |= IEEE80211_RATE_BASIC; 88 break; 89 case MODE_IEEE80211B: 90 if (rate->rate == 10 || rate->rate == 20) 91 rate->flags |= IEEE80211_RATE_BASIC; 92 break; 93 case MODE_IEEE80211G: 94 if (rate->rate == 10 || rate->rate == 20 || 95 rate->rate == 55 || rate->rate == 110) 96 rate->flags |= IEEE80211_RATE_BASIC; 97 break; 98 case NUM_IEEE80211_MODES: 99 /* not useful */ 100 break; 101 } 102 103 /* Set ERP and MANDATORY flags based on phymode */ 104 switch (mode->mode) { 105 case MODE_IEEE80211A: 106 if (rate->rate == 60 || rate->rate == 120 || 107 rate->rate == 240) 108 rate->flags |= IEEE80211_RATE_MANDATORY; 109 break; 110 case MODE_IEEE80211B: 111 if (rate->rate == 10) 112 rate->flags |= IEEE80211_RATE_MANDATORY; 113 break; 114 case MODE_IEEE80211G: 115 if (rate->rate == 10 || rate->rate == 20 || 116 rate->rate == 55 || rate->rate == 110 || 117 rate->rate == 60 || rate->rate == 120 || 118 rate->rate == 240) 119 rate->flags |= IEEE80211_RATE_MANDATORY; 120 break; 121 case NUM_IEEE80211_MODES: 122 /* not useful */ 123 break; 124 } 125 if (ieee80211_is_erp_rate(mode->mode, rate->rate)) 126 rate->flags |= IEEE80211_RATE_ERP; 127 } 128 } 129 130 u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len, 131 enum ieee80211_if_types type) 132 { 133 u16 fc; 134 135 /* drop ACK/CTS frames and incorrect hdr len (ctrl) */ 136 if (len < 16) 137 return NULL; 138 139 fc = le16_to_cpu(hdr->frame_control); 140 141 switch (fc & IEEE80211_FCTL_FTYPE) { 142 case IEEE80211_FTYPE_DATA: 143 if (len < 24) /* drop incorrect hdr len (data) */ 144 return NULL; 145 switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) { 146 case IEEE80211_FCTL_TODS: 147 return hdr->addr1; 148 case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS): 149 return NULL; 150 case IEEE80211_FCTL_FROMDS: 151 return hdr->addr2; 152 case 0: 153 return hdr->addr3; 154 } 155 break; 156 case IEEE80211_FTYPE_MGMT: 157 if (len < 24) /* drop incorrect hdr len (mgmt) */ 158 return NULL; 159 return hdr->addr3; 160 case IEEE80211_FTYPE_CTL: 161 if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL) 162 return hdr->addr1; 163 else if ((fc & IEEE80211_FCTL_STYPE) == 164 IEEE80211_STYPE_BACK_REQ) { 165 switch (type) { 166 case IEEE80211_IF_TYPE_STA: 167 return hdr->addr2; 168 case IEEE80211_IF_TYPE_AP: 169 case IEEE80211_IF_TYPE_VLAN: 170 return hdr->addr1; 171 default: 172 return NULL; 173 } 174 } 175 else 176 return NULL; 177 } 178 179 return NULL; 180 } 181 182 int ieee80211_get_hdrlen(u16 fc) 183 { 184 int hdrlen = 24; 185 186 switch (fc & IEEE80211_FCTL_FTYPE) { 187 case IEEE80211_FTYPE_DATA: 188 if ((fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS)) 189 hdrlen = 30; /* Addr4 */ 190 /* 191 * The QoS Control field is two bytes and its presence is 192 * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to 193 * hdrlen if that bit is set. 194 * This works by masking out the bit and shifting it to 195 * bit position 1 so the result has the value 0 or 2. 196 */ 197 hdrlen += (fc & IEEE80211_STYPE_QOS_DATA) 198 >> (ilog2(IEEE80211_STYPE_QOS_DATA)-1); 199 break; 200 case IEEE80211_FTYPE_CTL: 201 /* 202 * ACK and CTS are 10 bytes, all others 16. To see how 203 * to get this condition consider 204 * subtype mask: 0b0000000011110000 (0x00F0) 205 * ACK subtype: 0b0000000011010000 (0x00D0) 206 * CTS subtype: 0b0000000011000000 (0x00C0) 207 * bits that matter: ^^^ (0x00E0) 208 * value of those: 0b0000000011000000 (0x00C0) 209 */ 210 if ((fc & 0xE0) == 0xC0) 211 hdrlen = 10; 212 else 213 hdrlen = 16; 214 break; 215 } 216 217 return hdrlen; 218 } 219 EXPORT_SYMBOL(ieee80211_get_hdrlen); 220 221 int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb) 222 { 223 const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *) skb->data; 224 int hdrlen; 225 226 if (unlikely(skb->len < 10)) 227 return 0; 228 hdrlen = ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control)); 229 if (unlikely(hdrlen > skb->len)) 230 return 0; 231 return hdrlen; 232 } 233 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb); 234 235 void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx) 236 { 237 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data; 238 239 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); 240 if (tx->u.tx.extra_frag) { 241 struct ieee80211_hdr *fhdr; 242 int i; 243 for (i = 0; i < tx->u.tx.num_extra_frag; i++) { 244 fhdr = (struct ieee80211_hdr *) 245 tx->u.tx.extra_frag[i]->data; 246 fhdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); 247 } 248 } 249 } 250 251 int ieee80211_frame_duration(struct ieee80211_local *local, size_t len, 252 int rate, int erp, int short_preamble) 253 { 254 int dur; 255 256 /* calculate duration (in microseconds, rounded up to next higher 257 * integer if it includes a fractional microsecond) to send frame of 258 * len bytes (does not include FCS) at the given rate. Duration will 259 * also include SIFS. 260 * 261 * rate is in 100 kbps, so divident is multiplied by 10 in the 262 * DIV_ROUND_UP() operations. 263 */ 264 265 if (local->hw.conf.phymode == MODE_IEEE80211A || erp) { 266 /* 267 * OFDM: 268 * 269 * N_DBPS = DATARATE x 4 270 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS) 271 * (16 = SIGNAL time, 6 = tail bits) 272 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext 273 * 274 * T_SYM = 4 usec 275 * 802.11a - 17.5.2: aSIFSTime = 16 usec 276 * 802.11g - 19.8.4: aSIFSTime = 10 usec + 277 * signal ext = 6 usec 278 */ 279 dur = 16; /* SIFS + signal ext */ 280 dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */ 281 dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */ 282 dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10, 283 4 * rate); /* T_SYM x N_SYM */ 284 } else { 285 /* 286 * 802.11b or 802.11g with 802.11b compatibility: 287 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime + 288 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0. 289 * 290 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4 291 * aSIFSTime = 10 usec 292 * aPreambleLength = 144 usec or 72 usec with short preamble 293 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble 294 */ 295 dur = 10; /* aSIFSTime = 10 usec */ 296 dur += short_preamble ? (72 + 24) : (144 + 48); 297 298 dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate); 299 } 300 301 return dur; 302 } 303 304 /* Exported duration function for driver use */ 305 __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw, 306 struct ieee80211_vif *vif, 307 size_t frame_len, int rate) 308 { 309 struct ieee80211_local *local = hw_to_local(hw); 310 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 311 u16 dur; 312 int erp; 313 314 erp = ieee80211_is_erp_rate(hw->conf.phymode, rate); 315 dur = ieee80211_frame_duration(local, frame_len, rate, erp, 316 sdata->bss_conf.use_short_preamble); 317 318 return cpu_to_le16(dur); 319 } 320 EXPORT_SYMBOL(ieee80211_generic_frame_duration); 321 322 __le16 ieee80211_rts_duration(struct ieee80211_hw *hw, 323 struct ieee80211_vif *vif, size_t frame_len, 324 const struct ieee80211_tx_control *frame_txctl) 325 { 326 struct ieee80211_local *local = hw_to_local(hw); 327 struct ieee80211_rate *rate; 328 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 329 bool short_preamble; 330 int erp; 331 u16 dur; 332 333 short_preamble = sdata->bss_conf.use_short_preamble; 334 335 rate = frame_txctl->rts_rate; 336 erp = !!(rate->flags & IEEE80211_RATE_ERP); 337 338 /* CTS duration */ 339 dur = ieee80211_frame_duration(local, 10, rate->rate, 340 erp, short_preamble); 341 /* Data frame duration */ 342 dur += ieee80211_frame_duration(local, frame_len, rate->rate, 343 erp, short_preamble); 344 /* ACK duration */ 345 dur += ieee80211_frame_duration(local, 10, rate->rate, 346 erp, short_preamble); 347 348 return cpu_to_le16(dur); 349 } 350 EXPORT_SYMBOL(ieee80211_rts_duration); 351 352 __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw, 353 struct ieee80211_vif *vif, 354 size_t frame_len, 355 const struct ieee80211_tx_control *frame_txctl) 356 { 357 struct ieee80211_local *local = hw_to_local(hw); 358 struct ieee80211_rate *rate; 359 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); 360 bool short_preamble; 361 int erp; 362 u16 dur; 363 364 short_preamble = sdata->bss_conf.use_short_preamble; 365 366 rate = frame_txctl->rts_rate; 367 erp = !!(rate->flags & IEEE80211_RATE_ERP); 368 369 /* Data frame duration */ 370 dur = ieee80211_frame_duration(local, frame_len, rate->rate, 371 erp, short_preamble); 372 if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) { 373 /* ACK duration */ 374 dur += ieee80211_frame_duration(local, 10, rate->rate, 375 erp, short_preamble); 376 } 377 378 return cpu_to_le16(dur); 379 } 380 EXPORT_SYMBOL(ieee80211_ctstoself_duration); 381 382 struct ieee80211_rate * 383 ieee80211_get_rate(struct ieee80211_local *local, int phymode, int hw_rate) 384 { 385 struct ieee80211_hw_mode *mode; 386 int r; 387 388 list_for_each_entry(mode, &local->modes_list, list) { 389 if (mode->mode != phymode) 390 continue; 391 for (r = 0; r < mode->num_rates; r++) { 392 struct ieee80211_rate *rate = &mode->rates[r]; 393 if (rate->val == hw_rate || 394 (rate->flags & IEEE80211_RATE_PREAMBLE2 && 395 rate->val2 == hw_rate)) 396 return rate; 397 } 398 } 399 400 return NULL; 401 } 402 403 void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue) 404 { 405 struct ieee80211_local *local = hw_to_local(hw); 406 407 if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF, 408 &local->state[queue])) { 409 if (test_bit(IEEE80211_LINK_STATE_PENDING, 410 &local->state[queue])) 411 tasklet_schedule(&local->tx_pending_tasklet); 412 else 413 if (!ieee80211_qdisc_installed(local->mdev)) { 414 if (queue == 0) 415 netif_wake_queue(local->mdev); 416 } else 417 __netif_schedule(local->mdev); 418 } 419 } 420 EXPORT_SYMBOL(ieee80211_wake_queue); 421 422 void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue) 423 { 424 struct ieee80211_local *local = hw_to_local(hw); 425 426 if (!ieee80211_qdisc_installed(local->mdev) && queue == 0) 427 netif_stop_queue(local->mdev); 428 set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]); 429 } 430 EXPORT_SYMBOL(ieee80211_stop_queue); 431 432 void ieee80211_start_queues(struct ieee80211_hw *hw) 433 { 434 struct ieee80211_local *local = hw_to_local(hw); 435 int i; 436 437 for (i = 0; i < local->hw.queues; i++) 438 clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[i]); 439 if (!ieee80211_qdisc_installed(local->mdev)) 440 netif_start_queue(local->mdev); 441 } 442 EXPORT_SYMBOL(ieee80211_start_queues); 443 444 void ieee80211_stop_queues(struct ieee80211_hw *hw) 445 { 446 int i; 447 448 for (i = 0; i < hw->queues; i++) 449 ieee80211_stop_queue(hw, i); 450 } 451 EXPORT_SYMBOL(ieee80211_stop_queues); 452 453 void ieee80211_wake_queues(struct ieee80211_hw *hw) 454 { 455 int i; 456 457 for (i = 0; i < hw->queues; i++) 458 ieee80211_wake_queue(hw, i); 459 } 460 EXPORT_SYMBOL(ieee80211_wake_queues); 461 462 void ieee80211_iterate_active_interfaces( 463 struct ieee80211_hw *hw, 464 void (*iterator)(void *data, u8 *mac, 465 struct ieee80211_vif *vif), 466 void *data) 467 { 468 struct ieee80211_local *local = hw_to_local(hw); 469 struct ieee80211_sub_if_data *sdata; 470 471 rcu_read_lock(); 472 473 list_for_each_entry_rcu(sdata, &local->interfaces, list) { 474 switch (sdata->vif.type) { 475 case IEEE80211_IF_TYPE_INVALID: 476 case IEEE80211_IF_TYPE_MNTR: 477 case IEEE80211_IF_TYPE_VLAN: 478 continue; 479 case IEEE80211_IF_TYPE_AP: 480 case IEEE80211_IF_TYPE_STA: 481 case IEEE80211_IF_TYPE_IBSS: 482 case IEEE80211_IF_TYPE_WDS: 483 break; 484 } 485 if (sdata->dev == local->mdev) 486 continue; 487 if (netif_running(sdata->dev)) 488 iterator(data, sdata->dev->dev_addr, 489 &sdata->vif); 490 } 491 492 rcu_read_unlock(); 493 } 494 EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces); 495