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 };
44 static int rate_list_match(const int *rate_list, int rate)
51 for (i = 0; rate_list[i] >= 0; i++)
52 if (rate_list[i] == rate)
58 void ieee80211_prepare_rates(struct ieee80211_local *local,
59 struct ieee80211_hw_mode *mode)
63 for (i = 0; i < mode->num_rates; i++) {
64 struct ieee80211_rate *rate = &mode->rates[i];
66 rate->flags &= ~(IEEE80211_RATE_SUPPORTED |
67 IEEE80211_RATE_BASIC);
69 if (local->supp_rates[mode->mode]) {
70 if (!rate_list_match(local->supp_rates[mode->mode],
75 rate->flags |= IEEE80211_RATE_SUPPORTED;
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],
82 rate->flags |= IEEE80211_RATE_BASIC;
83 } else switch (mode->mode) {
85 if (rate->rate == 60 || rate->rate == 120 ||
87 rate->flags |= IEEE80211_RATE_BASIC;
90 if (rate->rate == 10 || rate->rate == 20)
91 rate->flags |= IEEE80211_RATE_BASIC;
94 if (rate->rate == 10 || rate->rate == 20 ||
95 rate->rate == 55 || rate->rate == 110)
96 rate->flags |= IEEE80211_RATE_BASIC;
98 case NUM_IEEE80211_MODES:
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 ||
108 rate->flags |= IEEE80211_RATE_MANDATORY;
110 case MODE_IEEE80211B:
111 if (rate->rate == 10)
112 rate->flags |= IEEE80211_RATE_MANDATORY;
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 ||
119 rate->flags |= IEEE80211_RATE_MANDATORY;
121 case NUM_IEEE80211_MODES:
125 if (ieee80211_is_erp_rate(mode->mode, rate->rate))
126 rate->flags |= IEEE80211_RATE_ERP;
130 u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
131 enum ieee80211_if_types type)
135 /* drop ACK/CTS frames and incorrect hdr len (ctrl) */
139 fc = le16_to_cpu(hdr->frame_control);
141 switch (fc & IEEE80211_FCTL_FTYPE) {
142 case IEEE80211_FTYPE_DATA:
143 if (len < 24) /* drop incorrect hdr len (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:
157 if (len < 24) /* drop incorrect hdr len (mgmt) */
160 case IEEE80211_FTYPE_CTL:
161 if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)
163 else if ((fc & IEEE80211_FCTL_STYPE) ==
164 IEEE80211_STYPE_BACK_REQ) {
166 case IEEE80211_IF_TYPE_STA:
168 case IEEE80211_IF_TYPE_AP:
169 case IEEE80211_IF_TYPE_VLAN:
182 int ieee80211_get_hdrlen(u16 fc)
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 */
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.
197 hdrlen += (fc & IEEE80211_STYPE_QOS_DATA)
198 >> (ilog2(IEEE80211_STYPE_QOS_DATA)-1);
200 case IEEE80211_FTYPE_CTL:
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)
210 if ((fc & 0xE0) == 0xC0)
219 EXPORT_SYMBOL(ieee80211_get_hdrlen);
221 int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
223 const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *) skb->data;
226 if (unlikely(skb->len < 10))
228 hdrlen = ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control));
229 if (unlikely(hdrlen > skb->len))
233 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
235 void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx)
237 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
239 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
240 if (tx->u.tx.extra_frag) {
241 struct ieee80211_hdr *fhdr;
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);
251 int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
252 int rate, int erp, int short_preamble)
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
261 * rate is in 100 kbps, so divident is multiplied by 10 in the
262 * DIV_ROUND_UP() operations.
265 if (local->hw.conf.phymode == MODE_IEEE80211A || erp) {
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
275 * 802.11a - 17.5.2: aSIFSTime = 16 usec
276 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
277 * signal ext = 6 usec
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 */
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.
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
295 dur = 10; /* aSIFSTime = 10 usec */
296 dur += short_preamble ? (72 + 24) : (144 + 48);
298 dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
304 /* Exported duration function for driver use */
305 __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw, int if_id,
306 size_t frame_len, int rate)
308 struct ieee80211_local *local = hw_to_local(hw);
309 struct net_device *bdev = dev_get_by_index(&init_net, if_id);
310 struct ieee80211_sub_if_data *sdata;
317 sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
318 erp = ieee80211_is_erp_rate(hw->conf.phymode, rate);
319 dur = ieee80211_frame_duration(local, frame_len, rate,
320 erp, sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE);
323 return cpu_to_le16(dur);
325 EXPORT_SYMBOL(ieee80211_generic_frame_duration);
327 __le16 ieee80211_rts_duration(struct ieee80211_hw *hw, int if_id,
329 const struct ieee80211_tx_control *frame_txctl)
331 struct ieee80211_local *local = hw_to_local(hw);
332 struct ieee80211_rate *rate;
333 struct net_device *bdev = dev_get_by_index(&init_net, if_id);
334 struct ieee80211_sub_if_data *sdata;
342 sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
343 short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE;
345 rate = frame_txctl->rts_rate;
346 erp = !!(rate->flags & IEEE80211_RATE_ERP);
349 dur = ieee80211_frame_duration(local, 10, rate->rate,
350 erp, short_preamble);
351 /* Data frame duration */
352 dur += ieee80211_frame_duration(local, frame_len, rate->rate,
353 erp, short_preamble);
355 dur += ieee80211_frame_duration(local, 10, rate->rate,
356 erp, short_preamble);
359 return cpu_to_le16(dur);
361 EXPORT_SYMBOL(ieee80211_rts_duration);
363 __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw, int if_id,
365 const struct ieee80211_tx_control *frame_txctl)
367 struct ieee80211_local *local = hw_to_local(hw);
368 struct ieee80211_rate *rate;
369 struct net_device *bdev = dev_get_by_index(&init_net, if_id);
370 struct ieee80211_sub_if_data *sdata;
378 sdata = IEEE80211_DEV_TO_SUB_IF(bdev);
379 short_preamble = sdata->flags & IEEE80211_SDATA_SHORT_PREAMBLE;
381 rate = frame_txctl->rts_rate;
382 erp = !!(rate->flags & IEEE80211_RATE_ERP);
384 /* Data frame duration */
385 dur = ieee80211_frame_duration(local, frame_len, rate->rate,
386 erp, short_preamble);
387 if (!(frame_txctl->flags & IEEE80211_TXCTL_NO_ACK)) {
389 dur += ieee80211_frame_duration(local, 10, rate->rate,
390 erp, short_preamble);
394 return cpu_to_le16(dur);
396 EXPORT_SYMBOL(ieee80211_ctstoself_duration);
398 struct ieee80211_rate *
399 ieee80211_get_rate(struct ieee80211_local *local, int phymode, int hw_rate)
401 struct ieee80211_hw_mode *mode;
404 list_for_each_entry(mode, &local->modes_list, list) {
405 if (mode->mode != phymode)
407 for (r = 0; r < mode->num_rates; r++) {
408 struct ieee80211_rate *rate = &mode->rates[r];
409 if (rate->val == hw_rate ||
410 (rate->flags & IEEE80211_RATE_PREAMBLE2 &&
411 rate->val2 == hw_rate))
419 void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
421 struct ieee80211_local *local = hw_to_local(hw);
423 if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF,
424 &local->state[queue])) {
425 if (test_bit(IEEE80211_LINK_STATE_PENDING,
426 &local->state[queue]))
427 tasklet_schedule(&local->tx_pending_tasklet);
429 if (!ieee80211_qdisc_installed(local->mdev)) {
431 netif_wake_queue(local->mdev);
433 __netif_schedule(local->mdev);
436 EXPORT_SYMBOL(ieee80211_wake_queue);
438 void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
440 struct ieee80211_local *local = hw_to_local(hw);
442 if (!ieee80211_qdisc_installed(local->mdev) && queue == 0)
443 netif_stop_queue(local->mdev);
444 set_bit(IEEE80211_LINK_STATE_XOFF, &local->state[queue]);
446 EXPORT_SYMBOL(ieee80211_stop_queue);
448 void ieee80211_start_queues(struct ieee80211_hw *hw)
450 struct ieee80211_local *local = hw_to_local(hw);
453 for (i = 0; i < local->hw.queues; i++)
454 clear_bit(IEEE80211_LINK_STATE_XOFF, &local->state[i]);
455 if (!ieee80211_qdisc_installed(local->mdev))
456 netif_start_queue(local->mdev);
458 EXPORT_SYMBOL(ieee80211_start_queues);
460 void ieee80211_stop_queues(struct ieee80211_hw *hw)
464 for (i = 0; i < hw->queues; i++)
465 ieee80211_stop_queue(hw, i);
467 EXPORT_SYMBOL(ieee80211_stop_queues);
469 void ieee80211_wake_queues(struct ieee80211_hw *hw)
473 for (i = 0; i < hw->queues; i++)
474 ieee80211_wake_queue(hw, i);
476 EXPORT_SYMBOL(ieee80211_wake_queues);
478 void ieee80211_iterate_active_interfaces(struct ieee80211_hw *hw,
479 void (*iterator)(void *data, u8 *mac,
483 struct ieee80211_local *local = hw_to_local(hw);
484 struct ieee80211_sub_if_data *sdata;
488 list_for_each_entry_rcu(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);
509 EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);