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/net_namespace.h>
24 #include <net/cfg80211.h>
26 #include "ieee80211_i.h"
27 #include "ieee80211_rate.h"
30 /* privid for wiphys to determine whether they belong to us or not */
31 void *mac80211_wiphy_privid = &mac80211_wiphy_privid;
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 };
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 };
42 /* No encapsulation header if EtherType < 0x600 (=length) */
43 static const unsigned char eapol_header[] =
44 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x88, 0x8e };
47 static int rate_list_match(const int *rate_list, int rate)
54 for (i = 0; rate_list[i] >= 0; i++)
55 if (rate_list[i] == rate)
61 void ieee80211_prepare_rates(struct ieee80211_local *local,
62 struct ieee80211_hw_mode *mode)
66 for (i = 0; i < mode->num_rates; i++) {
67 struct ieee80211_rate *rate = &mode->rates[i];
69 rate->flags &= ~(IEEE80211_RATE_SUPPORTED |
70 IEEE80211_RATE_BASIC);
72 if (local->supp_rates[mode->mode]) {
73 if (!rate_list_match(local->supp_rates[mode->mode],
78 rate->flags |= IEEE80211_RATE_SUPPORTED;
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],
85 rate->flags |= IEEE80211_RATE_BASIC;
86 } else switch (mode->mode) {
88 if (rate->rate == 60 || rate->rate == 120 ||
90 rate->flags |= IEEE80211_RATE_BASIC;
93 if (rate->rate == 10 || rate->rate == 20)
94 rate->flags |= IEEE80211_RATE_BASIC;
96 case MODE_ATHEROS_TURBO:
97 if (rate->rate == 120 || rate->rate == 240 ||
99 rate->flags |= IEEE80211_RATE_BASIC;
101 case MODE_IEEE80211G:
102 if (rate->rate == 10 || rate->rate == 20 ||
103 rate->rate == 55 || rate->rate == 110)
104 rate->flags |= IEEE80211_RATE_BASIC;
108 /* Set ERP and MANDATORY flags based on phymode */
109 switch (mode->mode) {
110 case MODE_IEEE80211A:
111 if (rate->rate == 60 || rate->rate == 120 ||
113 rate->flags |= IEEE80211_RATE_MANDATORY;
115 case MODE_IEEE80211B:
116 if (rate->rate == 10)
117 rate->flags |= IEEE80211_RATE_MANDATORY;
119 case MODE_ATHEROS_TURBO:
121 case MODE_IEEE80211G:
122 if (rate->rate == 10 || rate->rate == 20 ||
123 rate->rate == 55 || rate->rate == 110 ||
124 rate->rate == 60 || rate->rate == 120 ||
126 rate->flags |= IEEE80211_RATE_MANDATORY;
129 if (ieee80211_is_erp_rate(mode->mode, rate->rate))
130 rate->flags |= IEEE80211_RATE_ERP;
134 u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len)
141 fc = le16_to_cpu(hdr->frame_control);
143 switch (fc & IEEE80211_FCTL_FTYPE) {
144 case IEEE80211_FTYPE_DATA:
145 switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
146 case IEEE80211_FCTL_TODS:
148 case (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
150 case IEEE80211_FCTL_FROMDS:
156 case IEEE80211_FTYPE_MGMT:
158 case IEEE80211_FTYPE_CTL:
159 if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)
168 int ieee80211_get_hdrlen(u16 fc)
172 switch (fc & IEEE80211_FCTL_FTYPE) {
173 case IEEE80211_FTYPE_DATA:
174 if ((fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS))
175 hdrlen = 30; /* Addr4 */
177 * The QoS Control field is two bytes and its presence is
178 * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to
179 * hdrlen if that bit is set.
180 * This works by masking out the bit and shifting it to
181 * bit position 1 so the result has the value 0 or 2.
183 hdrlen += (fc & IEEE80211_STYPE_QOS_DATA)
184 >> (ilog2(IEEE80211_STYPE_QOS_DATA)-1);
186 case IEEE80211_FTYPE_CTL:
188 * ACK and CTS are 10 bytes, all others 16. To see how
189 * to get this condition consider
190 * subtype mask: 0b0000000011110000 (0x00F0)
191 * ACK subtype: 0b0000000011010000 (0x00D0)
192 * CTS subtype: 0b0000000011000000 (0x00C0)
193 * bits that matter: ^^^ (0x00E0)
194 * value of those: 0b0000000011000000 (0x00C0)
196 if ((fc & 0xE0) == 0xC0)
205 EXPORT_SYMBOL(ieee80211_get_hdrlen);
207 int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
209 const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *) skb->data;
212 if (unlikely(skb->len < 10))
214 hdrlen = ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control));
215 if (unlikely(hdrlen > skb->len))
219 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
221 int ieee80211_is_eapol(const struct sk_buff *skb)
223 const struct ieee80211_hdr *hdr;
227 if (unlikely(skb->len < 10))
230 hdr = (const struct ieee80211_hdr *) skb->data;
231 fc = le16_to_cpu(hdr->frame_control);
233 if (unlikely(!WLAN_FC_DATA_PRESENT(fc)))
236 hdrlen = ieee80211_get_hdrlen(fc);
238 if (unlikely(skb->len >= hdrlen + sizeof(eapol_header) &&
239 memcmp(skb->data + hdrlen, eapol_header,
240 sizeof(eapol_header)) == 0))
246 void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx)
248 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
250 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
251 if (tx->u.tx.extra_frag) {
252 struct ieee80211_hdr *fhdr;
254 for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
255 fhdr = (struct ieee80211_hdr *)
256 tx->u.tx.extra_frag[i]->data;
257 fhdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
262 int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
263 int rate, int erp, int short_preamble)
267 /* calculate duration (in microseconds, rounded up to next higher
268 * integer if it includes a fractional microsecond) to send frame of
269 * len bytes (does not include FCS) at the given rate. Duration will
272 * rate is in 100 kbps, so divident is multiplied by 10 in the
273 * DIV_ROUND_UP() operations.
276 if (local->hw.conf.phymode == MODE_IEEE80211A || erp ||
277 local->hw.conf.phymode == MODE_ATHEROS_TURBO) {
281 * N_DBPS = DATARATE x 4
282 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
283 * (16 = SIGNAL time, 6 = tail bits)
284 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
287 * 802.11a - 17.5.2: aSIFSTime = 16 usec
288 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
289 * signal ext = 6 usec
291 /* FIX: Atheros Turbo may have different (shorter) duration? */
292 dur = 16; /* SIFS + signal ext */
293 dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
294 dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
295 dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
296 4 * rate); /* T_SYM x N_SYM */
299 * 802.11b or 802.11g with 802.11b compatibility:
300 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
301 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
303 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4
304 * aSIFSTime = 10 usec
305 * aPreambleLength = 144 usec or 72 usec with short preamble
306 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble
308 dur = 10; /* aSIFSTime = 10 usec */
309 dur += short_preamble ? (72 + 24) : (144 + 48);
311 dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
317 /* Exported duration function for driver use */
318 __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw, int if_id,
319 size_t frame_len, int rate)
321 struct ieee80211_local *local = hw_to_local(hw);
322 struct net_device *bdev = dev_get_by_index(&init_net, if_id);
323 struct ieee80211_sub_if_data *sdata;
330 sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
331 erp = ieee80211_is_erp_rate(hw->conf.phymode, rate);
332 dur = ieee80211_frame_duration(local, frame_len, rate,
333 erp, sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE);
336 return cpu_to_le16(dur);
338 EXPORT_SYMBOL(ieee80211_generic_frame_duration);
340 __le16 ieee80211_rts_duration(struct ieee80211_hw *hw, int if_id,
342 const struct ieee80211_tx_control *frame_txctl)
344 struct ieee80211_local *local = hw_to_local(hw);
345 struct ieee80211_rate *rate;
346 struct net_device *bdev = dev_get_by_index(&init_net, if_id);
347 struct ieee80211_sub_if_data *sdata;
355 sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
356 short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE;
358 rate = frame_txctl->rts_rate;
359 erp = !!(rate->flags & IEEE80211_RATE_ERP);
362 dur = ieee80211_frame_duration(local, 10, rate->rate,
363 erp, short_preamble);
364 /* Data frame duration */
365 dur += ieee80211_frame_duration(local, frame_len, rate->rate,
366 erp, short_preamble);
368 dur += ieee80211_frame_duration(local, 10, rate->rate,
369 erp, short_preamble);
372 return cpu_to_le16(dur);
374 EXPORT_SYMBOL(ieee80211_rts_duration);
376 __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw, int if_id,
378 const struct ieee80211_tx_control *frame_txctl)
380 struct ieee80211_local *local = hw_to_local(hw);
381 struct ieee80211_rate *rate;
382 struct net_device *bdev = dev_get_by_index(&init_net, if_id);
383 struct ieee80211_sub_if_data *sdata;
391 sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
392 short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE;
394 rate = frame_txctl->rts_rate;
395 erp = !!(rate->flags & IEEE80211_RATE_ERP);
397 /* Data frame duration */
398 dur = ieee80211_frame_duration(local, frame_len, rate->rate,
399 erp, short_preamble);
400 if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) {
402 dur += ieee80211_frame_duration(local, 10, rate->rate,
403 erp, short_preamble);
407 return cpu_to_le16(dur);
409 EXPORT_SYMBOL(ieee80211_ctstoself_duration);
411 struct ieee80211_rate *
412 ieee80211_get_rate(struct ieee80211_local *local, int phymode, int hw_rate)
414 struct ieee80211_hw_mode *mode;
417 list_for_each_entry(mode, &local->modes_list, list) {
418 if (mode->mode != phymode)
420 for (r = 0; r < mode->num_rates; r++) {
421 struct ieee80211_rate *rate = &mode->rates[r];
422 if (rate->val == hw_rate ||
423 (rate->flags & IEEE80211_RATE_PREAMBLE2 &&
424 rate->val2 == hw_rate))
432 void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
434 struct ieee80211_local *local = hw_to_local(hw);
436 if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF,
437 &local->state[queue])) {
438 if (test_bit(IEEE80211_LINK_STATE_PENDING,
439 &local->state[queue]))
440 tasklet_schedule(&local->tx_pending_tasklet);
442 if (!ieee80211_qdisc_installed(local->mdev)) {
444 netif_wake_queue(local->mdev);
446 __netif_schedule(local->mdev);
449 EXPORT_SYMBOL(ieee80211_wake_queue);
451 void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
453 struct ieee80211_local *local = hw_to_local(hw);
455 if (!ieee80211_qdisc_installed(local->mdev) && queue == 0)
456 netif_stop_queue(local->mdev);
457 set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
459 EXPORT_SYMBOL(ieee80211_stop_queue);
461 void ieee80211_start_queues(struct ieee80211_hw *hw)
463 struct ieee80211_local *local = hw_to_local(hw);
466 for (i = 0; i < local->hw.queues; i++)
467 clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[i]);
468 if (!ieee80211_qdisc_installed(local->mdev))
469 netif_start_queue(local->mdev);
471 EXPORT_SYMBOL(ieee80211_start_queues);
473 void ieee80211_stop_queues(struct ieee80211_hw *hw)
477 for (i = 0; i < hw->queues; i++)
478 ieee80211_stop_queue(hw, i);
480 EXPORT_SYMBOL(ieee80211_stop_queues);
482 void ieee80211_wake_queues(struct ieee80211_hw *hw)
486 for (i = 0; i < hw->queues; i++)
487 ieee80211_wake_queue(hw, i);
489 EXPORT_SYMBOL(ieee80211_wake_queues);