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Initial commit
[wrt350n-kernel.git] / net / mac80211 / util.c
blob5e631ce98d7e6656c807329e8a9d9b8ac73ad599
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);
WRT350N Kernel Patches