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>
25 #include <net/rtnetlink.h>
27 #include "ieee80211_i.h"
28 #include "ieee80211_rate.h"
31 /* privid for wiphys to determine whether they belong to us or not */
32 void *mac80211_wiphy_privid = &mac80211_wiphy_privid;
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 };
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 };
43 /* No encapsulation header if EtherType < 0x600 (=length) */
44 static const unsigned char eapol_header[] =
45 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x88, 0x8e };
48 static int rate_list_match(const int *rate_list, int rate)
55 for (i = 0; rate_list[i] >= 0; i++)
56 if (rate_list[i] == rate)
62 void ieee80211_prepare_rates(struct ieee80211_local *local,
63 struct ieee80211_hw_mode *mode)
67 for (i = 0; i < mode->num_rates; i++) {
68 struct ieee80211_rate *rate = &mode->rates[i];
70 rate->flags &= ~(IEEE80211_RATE_SUPPORTED |
71 IEEE80211_RATE_BASIC);
73 if (local->supp_rates[mode->mode]) {
74 if (!rate_list_match(local->supp_rates[mode->mode],
79 rate->flags |= IEEE80211_RATE_SUPPORTED;
81 /* Use configured basic rate set if it is available. If not,
82 * use defaults that are sane for most cases. */
83 if (local->basic_rates[mode->mode]) {
84 if (rate_list_match(local->basic_rates[mode->mode],
86 rate->flags |= IEEE80211_RATE_BASIC;
87 } else switch (mode->mode) {
89 if (rate->rate == 60 || rate->rate == 120 ||
91 rate->flags |= IEEE80211_RATE_BASIC;
94 if (rate->rate == 10 || rate->rate == 20)
95 rate->flags |= IEEE80211_RATE_BASIC;
98 if (rate->rate == 10 || rate->rate == 20 ||
99 rate->rate == 55 || rate->rate == 110)
100 rate->flags |= IEEE80211_RATE_BASIC;
102 case NUM_IEEE80211_MODES:
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_IEEE80211G:
119 if (rate->rate == 10 || rate->rate == 20 ||
120 rate->rate == 55 || rate->rate == 110 ||
121 rate->rate == 60 || rate->rate == 120 ||
123 rate->flags |= IEEE80211_RATE_MANDATORY;
125 case NUM_IEEE80211_MODES:
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, int hdrlen)
223 if (unlikely(skb->len < 10))
226 if (unlikely(skb->len >= hdrlen + sizeof(eapol_header) &&
227 memcmp(skb->data + hdrlen, eapol_header,
228 sizeof(eapol_header)) == 0))
234 void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx)
236 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
238 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
239 if (tx->u.tx.extra_frag) {
240 struct ieee80211_hdr *fhdr;
242 for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
243 fhdr = (struct ieee80211_hdr *)
244 tx->u.tx.extra_frag[i]->data;
245 fhdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
250 int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
251 int rate, int erp, int short_preamble)
255 /* calculate duration (in microseconds, rounded up to next higher
256 * integer if it includes a fractional microsecond) to send frame of
257 * len bytes (does not include FCS) at the given rate. Duration will
260 * rate is in 100 kbps, so divident is multiplied by 10 in the
261 * DIV_ROUND_UP() operations.
264 if (local->hw.conf.phymode == MODE_IEEE80211A || erp) {
268 * N_DBPS = DATARATE x 4
269 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
270 * (16 = SIGNAL time, 6 = tail bits)
271 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
274 * 802.11a - 17.5.2: aSIFSTime = 16 usec
275 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
276 * signal ext = 6 usec
278 dur = 16; /* SIFS + signal ext */
279 dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
280 dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
281 dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
282 4 * rate); /* T_SYM x N_SYM */
285 * 802.11b or 802.11g with 802.11b compatibility:
286 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
287 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
289 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4
290 * aSIFSTime = 10 usec
291 * aPreambleLength = 144 usec or 72 usec with short preamble
292 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble
294 dur = 10; /* aSIFSTime = 10 usec */
295 dur += short_preamble ? (72 + 24) : (144 + 48);
297 dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
303 /* Exported duration function for driver use */
304 __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw, int if_id,
305 size_t frame_len, int rate)
307 struct ieee80211_local *local = hw_to_local(hw);
308 struct net_device *bdev = dev_get_by_index(&init_net, if_id);
309 struct ieee80211_sub_if_data *sdata;
316 sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
317 erp = ieee80211_is_erp_rate(hw->conf.phymode, rate);
318 dur = ieee80211_frame_duration(local, frame_len, rate,
319 erp, sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE);
322 return cpu_to_le16(dur);
324 EXPORT_SYMBOL(ieee80211_generic_frame_duration);
326 __le16 ieee80211_rts_duration(struct ieee80211_hw *hw, int if_id,
328 const struct ieee80211_tx_control *frame_txctl)
330 struct ieee80211_local *local = hw_to_local(hw);
331 struct ieee80211_rate *rate;
332 struct net_device *bdev = dev_get_by_index(&init_net, if_id);
333 struct ieee80211_sub_if_data *sdata;
341 sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
342 short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE;
344 rate = frame_txctl->rts_rate;
345 erp = !!(rate->flags & IEEE80211_RATE_ERP);
348 dur = ieee80211_frame_duration(local, 10, rate->rate,
349 erp, short_preamble);
350 /* Data frame duration */
351 dur += ieee80211_frame_duration(local, frame_len, rate->rate,
352 erp, short_preamble);
354 dur += ieee80211_frame_duration(local, 10, rate->rate,
355 erp, short_preamble);
358 return cpu_to_le16(dur);
360 EXPORT_SYMBOL(ieee80211_rts_duration);
362 __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw, int if_id,
364 const struct ieee80211_tx_control *frame_txctl)
366 struct ieee80211_local *local = hw_to_local(hw);
367 struct ieee80211_rate *rate;
368 struct net_device *bdev = dev_get_by_index(&init_net, if_id);
369 struct ieee80211_sub_if_data *sdata;
377 sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
378 short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE;
380 rate = frame_txctl->rts_rate;
381 erp = !!(rate->flags & IEEE80211_RATE_ERP);
383 /* Data frame duration */
384 dur = ieee80211_frame_duration(local, frame_len, rate->rate,
385 erp, short_preamble);
386 if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) {
388 dur += ieee80211_frame_duration(local, 10, rate->rate,
389 erp, short_preamble);
393 return cpu_to_le16(dur);
395 EXPORT_SYMBOL(ieee80211_ctstoself_duration);
397 struct ieee80211_rate *
398 ieee80211_get_rate(struct ieee80211_local *local, int phymode, int hw_rate)
400 struct ieee80211_hw_mode *mode;
403 list_for_each_entry(mode, &local->modes_list, list) {
404 if (mode->mode != phymode)
406 for (r = 0; r < mode->num_rates; r++) {
407 struct ieee80211_rate *rate = &mode->rates[r];
408 if (rate->val == hw_rate ||
409 (rate->flags & IEEE80211_RATE_PREAMBLE2 &&
410 rate->val2 == hw_rate))
418 void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
420 struct ieee80211_local *local = hw_to_local(hw);
422 if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF,
423 &local->state[queue])) {
424 if (test_bit(IEEE80211_LINK_STATE_PENDING,
425 &local->state[queue]))
426 tasklet_schedule(&local->tx_pending_tasklet);
428 if (!ieee80211_qdisc_installed(local->mdev)) {
430 netif_wake_queue(local->mdev);
432 __netif_schedule(local->mdev);
435 EXPORT_SYMBOL(ieee80211_wake_queue);
437 void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
439 struct ieee80211_local *local = hw_to_local(hw);
441 if (!ieee80211_qdisc_installed(local->mdev) && queue == 0)
442 netif_stop_queue(local->mdev);
443 set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
445 EXPORT_SYMBOL(ieee80211_stop_queue);
447 void ieee80211_start_queues(struct ieee80211_hw *hw)
449 struct ieee80211_local *local = hw_to_local(hw);
452 for (i = 0; i < local->hw.queues; i++)
453 clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[i]);
454 if (!ieee80211_qdisc_installed(local->mdev))
455 netif_start_queue(local->mdev);
457 EXPORT_SYMBOL(ieee80211_start_queues);
459 void ieee80211_stop_queues(struct ieee80211_hw *hw)
463 for (i = 0; i < hw->queues; i++)
464 ieee80211_stop_queue(hw, i);
466 EXPORT_SYMBOL(ieee80211_stop_queues);
468 void ieee80211_wake_queues(struct ieee80211_hw *hw)
472 for (i = 0; i < hw->queues; i++)
473 ieee80211_wake_queue(hw, i);
475 EXPORT_SYMBOL(ieee80211_wake_queues);
477 void ieee80211_iterate_active_interfaces(struct ieee80211_hw *hw,
478 void (*iterator)(void *data, u8 *mac,
482 struct ieee80211_local *local = hw_to_local(hw);
483 struct ieee80211_sub_if_data *sdata;
487 /* we hold the RTNL here so can safely walk the list */
488 list_for_each_entry(sdata, &local->interfaces, list) {
489 switch (sdata->type) {
490 case IEEE80211_IF_TYPE_INVALID:
491 case IEEE80211_IF_TYPE_MNTR:
492 case IEEE80211_IF_TYPE_VLAN:
494 case IEEE80211_IF_TYPE_AP:
495 case IEEE80211_IF_TYPE_STA:
496 case IEEE80211_IF_TYPE_IBSS:
497 case IEEE80211_IF_TYPE_WDS:
500 if (sdata->dev == local->mdev)
502 if (netif_running(sdata->dev))
503 iterator(data, sdata->dev->dev_addr,
504 sdata->dev->ifindex);
507 EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);