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c2d1560a JB |
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/cfg80211.h> | |
24 | ||
25 | #include "ieee80211_i.h" | |
26 | #include "ieee80211_rate.h" | |
27 | #include "wme.h" | |
28 | ||
29 | /* privid for wiphys to determine whether they belong to us or not */ | |
30 | void *mac80211_wiphy_privid = &mac80211_wiphy_privid; | |
31 | ||
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 }; | |
36 | ||
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 }; | |
40 | ||
41 | /* No encapsulation header if EtherType < 0x600 (=length) */ | |
42 | static const unsigned char eapol_header[] = | |
43 | { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x88, 0x8e }; | |
44 | ||
45 | ||
46 | static int rate_list_match(const int *rate_list, int rate) | |
47 | { | |
48 | int i; | |
49 | ||
50 | if (!rate_list) | |
51 | return 0; | |
52 | ||
53 | for (i = 0; rate_list[i] >= 0; i++) | |
54 | if (rate_list[i] == rate) | |
55 | return 1; | |
56 | ||
57 | return 0; | |
58 | } | |
59 | ||
60 | void ieee80211_prepare_rates(struct ieee80211_local *local, | |
61 | struct ieee80211_hw_mode *mode) | |
62 | { | |
63 | int i; | |
64 | ||
65 | for (i = 0; i < mode->num_rates; i++) { | |
66 | struct ieee80211_rate *rate = &mode->rates[i]; | |
67 | ||
68 | rate->flags &= ~(IEEE80211_RATE_SUPPORTED | | |
69 | IEEE80211_RATE_BASIC); | |
70 | ||
71 | if (local->supp_rates[mode->mode]) { | |
72 | if (!rate_list_match(local->supp_rates[mode->mode], | |
73 | rate->rate)) | |
74 | continue; | |
75 | } | |
76 | ||
77 | rate->flags |= IEEE80211_RATE_SUPPORTED; | |
78 | ||
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], | |
83 | rate->rate)) | |
84 | rate->flags |= IEEE80211_RATE_BASIC; | |
85 | } else switch (mode->mode) { | |
86 | case MODE_IEEE80211A: | |
87 | if (rate->rate == 60 || rate->rate == 120 || | |
88 | rate->rate == 240) | |
89 | rate->flags |= IEEE80211_RATE_BASIC; | |
90 | break; | |
91 | case MODE_IEEE80211B: | |
92 | if (rate->rate == 10 || rate->rate == 20) | |
93 | rate->flags |= IEEE80211_RATE_BASIC; | |
94 | break; | |
95 | case MODE_ATHEROS_TURBO: | |
96 | if (rate->rate == 120 || rate->rate == 240 || | |
97 | rate->rate == 480) | |
98 | rate->flags |= IEEE80211_RATE_BASIC; | |
99 | break; | |
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; | |
104 | break; | |
105 | } | |
106 | ||
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 || | |
111 | rate->rate == 240) | |
112 | rate->flags |= IEEE80211_RATE_MANDATORY; | |
113 | break; | |
114 | case MODE_IEEE80211B: | |
115 | if (rate->rate == 10) | |
116 | rate->flags |= IEEE80211_RATE_MANDATORY; | |
117 | break; | |
118 | case MODE_ATHEROS_TURBO: | |
119 | break; | |
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 || | |
124 | rate->rate == 240) | |
125 | rate->flags |= IEEE80211_RATE_MANDATORY; | |
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 | local->hw.conf.phymode == MODE_ATHEROS_TURBO) { | |
277 | /* | |
278 | * OFDM: | |
279 | * | |
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 | |
284 | * | |
285 | * T_SYM = 4 usec | |
286 | * 802.11a - 17.5.2: aSIFSTime = 16 usec | |
287 | * 802.11g - 19.8.4: aSIFSTime = 10 usec + | |
288 | * signal ext = 6 usec | |
289 | */ | |
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 */ | |
296 | } else { | |
297 | /* | |
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. | |
301 | * | |
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 | |
306 | */ | |
307 | dur = 10; /* aSIFSTime = 10 usec */ | |
308 | dur += short_preamble ? (72 + 24) : (144 + 48); | |
309 | ||
310 | dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate); | |
311 | } | |
312 | ||
313 | return dur; | |
314 | } | |
315 | ||
316 | /* Exported duration function for driver use */ | |
7e9ed188 | 317 | __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw, int if_id, |
c2d1560a JB |
318 | size_t frame_len, int rate) |
319 | { | |
320 | struct ieee80211_local *local = hw_to_local(hw); | |
7e9ed188 DD |
321 | struct net_device *bdev = dev_get_by_index(if_id); |
322 | struct ieee80211_sub_if_data *sdata; | |
c2d1560a JB |
323 | u16 dur; |
324 | int erp; | |
325 | ||
7e9ed188 DD |
326 | if (unlikely(!bdev)) |
327 | return 0; | |
328 | ||
329 | sdata = IEEE80211_DEV_TO_SUB_IF(bdev); | |
c2d1560a JB |
330 | erp = ieee80211_is_erp_rate(hw->conf.phymode, rate); |
331 | dur = ieee80211_frame_duration(local, frame_len, rate, | |
13262ffd | 332 | erp, sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE); |
c2d1560a | 333 | |
7e9ed188 | 334 | dev_put(bdev); |
c2d1560a JB |
335 | return cpu_to_le16(dur); |
336 | } | |
337 | EXPORT_SYMBOL(ieee80211_generic_frame_duration); | |
338 | ||
7e9ed188 | 339 | __le16 ieee80211_rts_duration(struct ieee80211_hw *hw, int if_id, |
c2d1560a JB |
340 | size_t frame_len, |
341 | const struct ieee80211_tx_control *frame_txctl) | |
342 | { | |
343 | struct ieee80211_local *local = hw_to_local(hw); | |
344 | struct ieee80211_rate *rate; | |
7e9ed188 DD |
345 | struct net_device *bdev = dev_get_by_index(if_id); |
346 | struct ieee80211_sub_if_data *sdata; | |
347 | int short_preamble; | |
c2d1560a JB |
348 | int erp; |
349 | u16 dur; | |
350 | ||
7e9ed188 DD |
351 | if (unlikely(!bdev)) |
352 | return 0; | |
353 | ||
354 | sdata = IEEE80211_DEV_TO_SUB_IF(bdev); | |
13262ffd | 355 | short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE; |
7e9ed188 | 356 | |
c2d1560a JB |
357 | rate = frame_txctl->rts_rate; |
358 | erp = !!(rate->flags & IEEE80211_RATE_ERP); | |
359 | ||
360 | /* CTS duration */ | |
361 | dur = ieee80211_frame_duration(local, 10, rate->rate, | |
362 | erp, short_preamble); | |
363 | /* Data frame duration */ | |
364 | dur += ieee80211_frame_duration(local, frame_len, rate->rate, | |
365 | erp, short_preamble); | |
366 | /* ACK duration */ | |
367 | dur += ieee80211_frame_duration(local, 10, rate->rate, | |
368 | erp, short_preamble); | |
369 | ||
7e9ed188 | 370 | dev_put(bdev); |
c2d1560a JB |
371 | return cpu_to_le16(dur); |
372 | } | |
373 | EXPORT_SYMBOL(ieee80211_rts_duration); | |
374 | ||
7e9ed188 | 375 | __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw, int if_id, |
c2d1560a JB |
376 | size_t frame_len, |
377 | const struct ieee80211_tx_control *frame_txctl) | |
378 | { | |
379 | struct ieee80211_local *local = hw_to_local(hw); | |
380 | struct ieee80211_rate *rate; | |
7e9ed188 DD |
381 | struct net_device *bdev = dev_get_by_index(if_id); |
382 | struct ieee80211_sub_if_data *sdata; | |
383 | int short_preamble; | |
c2d1560a JB |
384 | int erp; |
385 | u16 dur; | |
386 | ||
7e9ed188 DD |
387 | if (unlikely(!bdev)) |
388 | return 0; | |
389 | ||
390 | sdata = IEEE80211_DEV_TO_SUB_IF(bdev); | |
13262ffd | 391 | short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE; |
7e9ed188 | 392 | |
c2d1560a JB |
393 | rate = frame_txctl->rts_rate; |
394 | erp = !!(rate->flags & IEEE80211_RATE_ERP); | |
395 | ||
396 | /* Data frame duration */ | |
397 | dur = ieee80211_frame_duration(local, frame_len, rate->rate, | |
398 | erp, short_preamble); | |
399 | if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) { | |
400 | /* ACK duration */ | |
401 | dur += ieee80211_frame_duration(local, 10, rate->rate, | |
402 | erp, short_preamble); | |
403 | } | |
404 | ||
7e9ed188 | 405 | dev_put(bdev); |
c2d1560a JB |
406 | return cpu_to_le16(dur); |
407 | } | |
408 | EXPORT_SYMBOL(ieee80211_ctstoself_duration); | |
409 | ||
410 | struct ieee80211_rate * | |
411 | ieee80211_get_rate(struct ieee80211_local *local, int phymode, int hw_rate) | |
412 | { | |
413 | struct ieee80211_hw_mode *mode; | |
414 | int r; | |
415 | ||
416 | list_for_each_entry(mode, &local->modes_list, list) { | |
417 | if (mode->mode != phymode) | |
418 | continue; | |
419 | for (r = 0; r < mode->num_rates; r++) { | |
420 | struct ieee80211_rate *rate = &mode->rates[r]; | |
421 | if (rate->val == hw_rate || | |
422 | (rate->flags & IEEE80211_RATE_PREAMBLE2 && | |
423 | rate->val2 == hw_rate)) | |
424 | return rate; | |
425 | } | |
426 | } | |
427 | ||
428 | return NULL; | |
429 | } | |
430 | ||
431 | void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue) | |
432 | { | |
433 | struct ieee80211_local *local = hw_to_local(hw); | |
434 | ||
435 | if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF, | |
436 | &local->state[queue])) { | |
437 | if (test_bit(IEEE80211_LINK_STATE_PENDING, | |
438 | &local->state[queue])) | |
439 | tasklet_schedule(&local->tx_pending_tasklet); | |
440 | else | |
441 | if (!ieee80211_qdisc_installed(local->mdev)) { | |
442 | if (queue == 0) | |
443 | netif_wake_queue(local->mdev); | |
444 | } else | |
445 | __netif_schedule(local->mdev); | |
446 | } | |
447 | } | |
448 | EXPORT_SYMBOL(ieee80211_wake_queue); | |
449 | ||
450 | void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue) | |
451 | { | |
452 | struct ieee80211_local *local = hw_to_local(hw); | |
453 | ||
454 | if (!ieee80211_qdisc_installed(local->mdev) && queue == 0) | |
455 | netif_stop_queue(local->mdev); | |
456 | set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]); | |
457 | } | |
458 | EXPORT_SYMBOL(ieee80211_stop_queue); | |
459 | ||
460 | void ieee80211_start_queues(struct ieee80211_hw *hw) | |
461 | { | |
462 | struct ieee80211_local *local = hw_to_local(hw); | |
463 | int i; | |
464 | ||
465 | for (i = 0; i < local->hw.queues; i++) | |
466 | clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[i]); | |
467 | if (!ieee80211_qdisc_installed(local->mdev)) | |
468 | netif_start_queue(local->mdev); | |
469 | } | |
470 | EXPORT_SYMBOL(ieee80211_start_queues); | |
471 | ||
472 | void ieee80211_stop_queues(struct ieee80211_hw *hw) | |
473 | { | |
474 | int i; | |
475 | ||
476 | for (i = 0; i < hw->queues; i++) | |
477 | ieee80211_stop_queue(hw, i); | |
478 | } | |
479 | EXPORT_SYMBOL(ieee80211_stop_queues); | |
480 | ||
481 | void ieee80211_wake_queues(struct ieee80211_hw *hw) | |
482 | { | |
483 | int i; | |
484 | ||
485 | for (i = 0; i < hw->queues; i++) | |
486 | ieee80211_wake_queue(hw, i); | |
487 | } | |
488 | EXPORT_SYMBOL(ieee80211_wake_queues); |