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>
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.
11 * utilities for mac80211
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/cfg80211.h>
25 #include "ieee80211_i.h"
26 #include "ieee80211_rate.h"
29 /* privid for wiphys to determine whether they belong to us or not */
30 void *mac80211_wiphy_privid = &mac80211_wiphy_privid;
32 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
33 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
34 const unsigned char rfc1042_header[] =
35 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
37 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
38 const unsigned char bridge_tunnel_header[] =
39 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
41 /* No encapsulation header if EtherType < 0x600 (=length) */
42 static const unsigned char eapol_header[] =
43 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x88, 0x8e };
46 static int rate_list_match(const int *rate_list, int rate)
53 for (i = 0; rate_list[i] >= 0; i++)
54 if (rate_list[i] == rate)
60 void ieee80211_prepare_rates(struct ieee80211_local *local,
61 struct ieee80211_hw_mode *mode)
65 for (i = 0; i < mode->num_rates; i++) {
66 struct ieee80211_rate *rate = &mode->rates[i];
68 rate->flags &= ~(IEEE80211_RATE_SUPPORTED |
69 IEEE80211_RATE_BASIC);
71 if (local->supp_rates[mode->mode]) {
72 if (!rate_list_match(local->supp_rates[mode->mode],
77 rate->flags |= IEEE80211_RATE_SUPPORTED;
79 /* Use configured basic rate set if it is available. If not,
80 * use defaults that are sane for most cases. */
81 if (local->basic_rates[mode->mode]) {
82 if (rate_list_match(local->basic_rates[mode->mode],
84 rate->flags |= IEEE80211_RATE_BASIC;
85 } else switch (mode->mode) {
87 if (rate->rate == 60 || rate->rate == 120 ||
89 rate->flags |= IEEE80211_RATE_BASIC;
92 if (rate->rate == 10 || rate->rate == 20)
93 rate->flags |= IEEE80211_RATE_BASIC;
95 case MODE_ATHEROS_TURBO:
96 if (rate->rate == 120 || rate->rate == 240 ||
98 rate->flags |= IEEE80211_RATE_BASIC;
100 case MODE_IEEE80211G:
101 if (rate->rate == 10 || rate->rate == 20 ||
102 rate->rate == 55 || rate->rate == 110)
103 rate->flags |= IEEE80211_RATE_BASIC;
107 /* Set ERP and MANDATORY flags based on phymode */
108 switch (mode->mode) {
109 case MODE_IEEE80211A:
110 if (rate->rate == 60 || rate->rate == 120 ||
112 rate->flags |= IEEE80211_RATE_MANDATORY;
114 case MODE_IEEE80211B:
115 if (rate->rate == 10)
116 rate->flags |= IEEE80211_RATE_MANDATORY;
118 case MODE_ATHEROS_TURBO:
120 case MODE_IEEE80211G:
121 if (rate->rate == 10 || rate->rate == 20 ||
122 rate->rate == 55 || rate->rate == 110 ||
123 rate->rate == 60 || rate->rate == 120 ||
125 rate->flags |= IEEE80211_RATE_MANDATORY;
128 if (ieee80211_is_erp_rate(mode->mode, rate->rate))
129 rate->flags |= IEEE80211_RATE_ERP;
133 u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len)
140 fc = le16_to_cpu(hdr->frame_control);
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:
147 case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
149 case IEEE80211_FCTL_FROMDS:
155 case IEEE80211_FTYPE_MGMT:
157 case IEEE80211_FTYPE_CTL:
158 if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)
167 int ieee80211_get_hdrlen(u16 fc)
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 */
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.
182 hdrlen += (fc & IEEE80211_STYPE_QOS_DATA)
183 >> (ilog2(IEEE80211_STYPE_QOS_DATA)-1);
185 case IEEE80211_FTYPE_CTL:
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)
195 if ((fc & 0xE0) == 0xC0)
204 EXPORT_SYMBOL(ieee80211_get_hdrlen);
206 int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
208 const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *) skb->data;
211 if (unlikely(skb->len < 10))
213 hdrlen = ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control));
214 if (unlikely(hdrlen > skb->len))
218 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
220 int ieee80211_is_eapol(const struct sk_buff *skb)
222 const struct ieee80211_hdr *hdr;
226 if (unlikely(skb->len < 10))
229 hdr = (const struct ieee80211_hdr *) skb->data;
230 fc = le16_to_cpu(hdr->frame_control);
232 if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
235 hdrlen = ieee80211_get_hdrlen(fc);
237 if (unlikely(skb->len >= hdrlen + sizeof(eapol_header) &&
238 memcmp(skb->data + hdrlen, eapol_header,
239 sizeof(eapol_header)) == 0))
245 void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx)
247 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
249 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
250 if (tx->u.tx.extra_frag) {
251 struct ieee80211_hdr *fhdr;
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);
261 int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
262 int rate, int erp, int short_preamble)
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
271 * rate is in 100 kbps, so divident is multiplied by 10 in the
272 * DIV_ROUND_UP() operations.
275 if (local->hw.conf.phymode == MODE_IEEE80211A || erp ||
276 local->hw.conf.phymode == MODE_ATHEROS_TURBO) {
280 * N_DBPS = DATARATE x 4
281 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
282 * (16 = SIGNAL time, 6 = tail bits)
283 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
286 * 802.11a - 17.5.2: aSIFSTime = 16 usec
287 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
288 * signal ext = 6 usec
290 /* FIX: Atheros Turbo may have different (shorter) duration? */
291 dur = 16; /* SIFS + signal ext */
292 dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
293 dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
294 dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
295 4 * rate); /* T_SYM x N_SYM */
298 * 802.11b or 802.11g with 802.11b compatibility:
299 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
300 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
302 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4
303 * aSIFSTime = 10 usec
304 * aPreambleLength = 144 usec or 72 usec with short preamble
305 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble
307 dur = 10; /* aSIFSTime = 10 usec */
308 dur += short_preamble ? (72 + 24) : (144 + 48);
310 dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
316 /* Exported duration function for driver use */
317 __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
318 size_t frame_len, int rate)
320 struct ieee80211_local *local = hw_to_local(hw);
324 erp = ieee80211_is_erp_rate(hw->conf.phymode, rate);
325 dur = ieee80211_frame_duration(local, frame_len, rate,
326 erp, local->short_preamble);
328 return cpu_to_le16(dur);
330 EXPORT_SYMBOL(ieee80211_generic_frame_duration);
332 __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
334 const struct ieee80211_tx_control *frame_txctl)
336 struct ieee80211_local *local = hw_to_local(hw);
337 struct ieee80211_rate *rate;
338 int short_preamble = local->short_preamble;
342 rate = frame_txctl->rts_rate;
343 erp = !!(rate->flags & IEEE80211_RATE_ERP);
346 dur = ieee80211_frame_duration(local, 10, rate->rate,
347 erp, short_preamble);
348 /* Data frame duration */
349 dur += ieee80211_frame_duration(local, frame_len, rate->rate,
350 erp, short_preamble);
352 dur += ieee80211_frame_duration(local, 10, rate->rate,
353 erp, short_preamble);
355 return cpu_to_le16(dur);
357 EXPORT_SYMBOL(ieee80211_rts_duration);
359 __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
361 const struct ieee80211_tx_control *frame_txctl)
363 struct ieee80211_local *local = hw_to_local(hw);
364 struct ieee80211_rate *rate;
365 int short_preamble = local->short_preamble;
369 rate = frame_txctl->rts_rate;
370 erp = !!(rate->flags & IEEE80211_RATE_ERP);
372 /* Data frame duration */
373 dur = ieee80211_frame_duration(local, frame_len, rate->rate,
374 erp, short_preamble);
375 if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) {
377 dur += ieee80211_frame_duration(local, 10, rate->rate,
378 erp, short_preamble);
381 return cpu_to_le16(dur);
383 EXPORT_SYMBOL(ieee80211_ctstoself_duration);
385 struct ieee80211_rate *
386 ieee80211_get_rate(struct ieee80211_local *local, int phymode, int hw_rate)
388 struct ieee80211_hw_mode *mode;
391 list_for_each_entry(mode, &local->modes_list, list) {
392 if (mode->mode != phymode)
394 for (r = 0; r < mode->num_rates; r++) {
395 struct ieee80211_rate *rate = &mode->rates[r];
396 if (rate->val == hw_rate ||
397 (rate->flags & IEEE80211_RATE_PREAMBLE2 &&
398 rate->val2 == hw_rate))
406 void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
408 struct ieee80211_local *local = hw_to_local(hw);
410 if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF,
411 &local->state[queue])) {
412 if (test_bit(IEEE80211_LINK_STATE_PENDING,
413 &local->state[queue]))
414 tasklet_schedule(&local->tx_pending_tasklet);
416 if (!ieee80211_qdisc_installed(local->mdev)) {
418 netif_wake_queue(local->mdev);
420 __netif_schedule(local->mdev);
423 EXPORT_SYMBOL(ieee80211_wake_queue);
425 void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
427 struct ieee80211_local *local = hw_to_local(hw);
429 if (!ieee80211_qdisc_installed(local->mdev) && queue == 0)
430 netif_stop_queue(local->mdev);
431 set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
433 EXPORT_SYMBOL(ieee80211_stop_queue);
435 void ieee80211_start_queues(struct ieee80211_hw *hw)
437 struct ieee80211_local *local = hw_to_local(hw);
440 for (i = 0; i < local->hw.queues; i++)
441 clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[i]);
442 if (!ieee80211_qdisc_installed(local->mdev))
443 netif_start_queue(local->mdev);
445 EXPORT_SYMBOL(ieee80211_start_queues);
447 void ieee80211_stop_queues(struct ieee80211_hw *hw)
451 for (i = 0; i < hw->queues; i++)
452 ieee80211_stop_queue(hw, i);
454 EXPORT_SYMBOL(ieee80211_stop_queues);
456 void ieee80211_wake_queues(struct ieee80211_hw *hw)
460 for (i = 0; i < hw->queues; i++)
461 ieee80211_wake_queue(hw, i);
463 EXPORT_SYMBOL(ieee80211_wake_queues);