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/cfg80211.h>
25 #include "ieee80211_i.h"
26 #include "ieee80211_rate.h"
29 /* privid for wiphys to determine whether they belong to us or not */
30 void *mac80211_wiphy_privid
= &mac80211_wiphy_privid
;
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 };
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 };
41 /* No encapsulation header if EtherType < 0x600 (=length) */
42 static const unsigned char eapol_header
[] =
43 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x88, 0x8e };
46 static int rate_list_match(const int *rate_list
, int rate
)
53 for (i
= 0; rate_list
[i
] >= 0; i
++)
54 if (rate_list
[i
] == rate
)
60 void ieee80211_prepare_rates(struct ieee80211_local
*local
,
61 struct ieee80211_hw_mode
*mode
)
65 for (i
= 0; i
< mode
->num_rates
; i
++) {
66 struct ieee80211_rate
*rate
= &mode
->rates
[i
];
68 rate
->flags
&= ~(IEEE80211_RATE_SUPPORTED
|
69 IEEE80211_RATE_BASIC
);
71 if (local
->supp_rates
[mode
->mode
]) {
72 if (!rate_list_match(local
->supp_rates
[mode
->mode
],
77 rate
->flags
|= IEEE80211_RATE_SUPPORTED
;
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
],
84 rate
->flags
|= IEEE80211_RATE_BASIC
;
85 } else switch (mode
->mode
) {
87 if (rate
->rate
== 60 || rate
->rate
== 120 ||
89 rate
->flags
|= IEEE80211_RATE_BASIC
;
92 if (rate
->rate
== 10 || rate
->rate
== 20)
93 rate
->flags
|= IEEE80211_RATE_BASIC
;
96 if (rate
->rate
== 10 || rate
->rate
== 20 ||
97 rate
->rate
== 55 || rate
->rate
== 110)
98 rate
->flags
|= IEEE80211_RATE_BASIC
;
100 case NUM_IEEE80211_MODES
:
105 /* Set ERP and MANDATORY flags based on phymode */
106 switch (mode
->mode
) {
107 case MODE_IEEE80211A
:
108 if (rate
->rate
== 60 || rate
->rate
== 120 ||
110 rate
->flags
|= IEEE80211_RATE_MANDATORY
;
112 case MODE_IEEE80211B
:
113 if (rate
->rate
== 10)
114 rate
->flags
|= IEEE80211_RATE_MANDATORY
;
116 case MODE_IEEE80211G
:
117 if (rate
->rate
== 10 || rate
->rate
== 20 ||
118 rate
->rate
== 55 || rate
->rate
== 110 ||
119 rate
->rate
== 60 || rate
->rate
== 120 ||
121 rate
->flags
|= IEEE80211_RATE_MANDATORY
;
123 case NUM_IEEE80211_MODES
:
127 if (ieee80211_is_erp_rate(mode
->mode
, rate
->rate
))
128 rate
->flags
|= IEEE80211_RATE_ERP
;
132 u8
*ieee80211_get_bssid(struct ieee80211_hdr
*hdr
, size_t len
)
139 fc
= le16_to_cpu(hdr
->frame_control
);
141 switch (fc
& IEEE80211_FCTL_FTYPE
) {
142 case IEEE80211_FTYPE_DATA
:
143 switch (fc
& (IEEE80211_FCTL_TODS
| IEEE80211_FCTL_FROMDS
)) {
144 case IEEE80211_FCTL_TODS
:
146 case (IEEE80211_FCTL_TODS
| IEEE80211_FCTL_FROMDS
):
148 case IEEE80211_FCTL_FROMDS
:
154 case IEEE80211_FTYPE_MGMT
:
156 case IEEE80211_FTYPE_CTL
:
157 if ((fc
& IEEE80211_FCTL_STYPE
) == IEEE80211_STYPE_PSPOLL
)
166 int ieee80211_get_hdrlen(u16 fc
)
170 switch (fc
& IEEE80211_FCTL_FTYPE
) {
171 case IEEE80211_FTYPE_DATA
:
172 if ((fc
& IEEE80211_FCTL_FROMDS
) && (fc
& IEEE80211_FCTL_TODS
))
173 hdrlen
= 30; /* Addr4 */
175 * The QoS Control field is two bytes and its presence is
176 * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to
177 * hdrlen if that bit is set.
178 * This works by masking out the bit and shifting it to
179 * bit position 1 so the result has the value 0 or 2.
181 hdrlen
+= (fc
& IEEE80211_STYPE_QOS_DATA
)
182 >> (ilog2(IEEE80211_STYPE_QOS_DATA
)-1);
184 case IEEE80211_FTYPE_CTL
:
186 * ACK and CTS are 10 bytes, all others 16. To see how
187 * to get this condition consider
188 * subtype mask: 0b0000000011110000 (0x00F0)
189 * ACK subtype: 0b0000000011010000 (0x00D0)
190 * CTS subtype: 0b0000000011000000 (0x00C0)
191 * bits that matter: ^^^ (0x00E0)
192 * value of those: 0b0000000011000000 (0x00C0)
194 if ((fc
& 0xE0) == 0xC0)
203 EXPORT_SYMBOL(ieee80211_get_hdrlen
);
205 int ieee80211_get_hdrlen_from_skb(const struct sk_buff
*skb
)
207 const struct ieee80211_hdr
*hdr
= (const struct ieee80211_hdr
*) skb
->data
;
210 if (unlikely(skb
->len
< 10))
212 hdrlen
= ieee80211_get_hdrlen(le16_to_cpu(hdr
->frame_control
));
213 if (unlikely(hdrlen
> skb
->len
))
217 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb
);
219 int ieee80211_is_eapol(const struct sk_buff
*skb
)
221 const struct ieee80211_hdr
*hdr
;
225 if (unlikely(skb
->len
< 10))
228 hdr
= (const struct ieee80211_hdr
*) skb
->data
;
229 fc
= le16_to_cpu(hdr
->frame_control
);
231 if (unlikely(!WLAN_FC_DATA_PRESENT(fc
)))
234 hdrlen
= ieee80211_get_hdrlen(fc
);
236 if (unlikely(skb
->len
>= hdrlen
+ sizeof(eapol_header
) &&
237 memcmp(skb
->data
+ hdrlen
, eapol_header
,
238 sizeof(eapol_header
)) == 0))
244 void ieee80211_tx_set_iswep(struct ieee80211_txrx_data
*tx
)
246 struct ieee80211_hdr
*hdr
= (struct ieee80211_hdr
*) tx
->skb
->data
;
248 hdr
->frame_control
|= cpu_to_le16(IEEE80211_FCTL_PROTECTED
);
249 if (tx
->u
.tx
.extra_frag
) {
250 struct ieee80211_hdr
*fhdr
;
252 for (i
= 0; i
< tx
->u
.tx
.num_extra_frag
; i
++) {
253 fhdr
= (struct ieee80211_hdr
*)
254 tx
->u
.tx
.extra_frag
[i
]->data
;
255 fhdr
->frame_control
|= cpu_to_le16(IEEE80211_FCTL_PROTECTED
);
260 int ieee80211_frame_duration(struct ieee80211_local
*local
, size_t len
,
261 int rate
, int erp
, int short_preamble
)
265 /* calculate duration (in microseconds, rounded up to next higher
266 * integer if it includes a fractional microsecond) to send frame of
267 * len bytes (does not include FCS) at the given rate. Duration will
270 * rate is in 100 kbps, so divident is multiplied by 10 in the
271 * DIV_ROUND_UP() operations.
274 if (local
->hw
.conf
.phymode
== MODE_IEEE80211A
|| erp
) {
278 * N_DBPS = DATARATE x 4
279 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
280 * (16 = SIGNAL time, 6 = tail bits)
281 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
284 * 802.11a - 17.5.2: aSIFSTime = 16 usec
285 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
286 * signal ext = 6 usec
288 dur
= 16; /* SIFS + signal ext */
289 dur
+= 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
290 dur
+= 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
291 dur
+= 4 * DIV_ROUND_UP((16 + 8 * (len
+ 4) + 6) * 10,
292 4 * rate
); /* T_SYM x N_SYM */
295 * 802.11b or 802.11g with 802.11b compatibility:
296 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
297 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
299 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4
300 * aSIFSTime = 10 usec
301 * aPreambleLength = 144 usec or 72 usec with short preamble
302 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble
304 dur
= 10; /* aSIFSTime = 10 usec */
305 dur
+= short_preamble
? (72 + 24) : (144 + 48);
307 dur
+= DIV_ROUND_UP(8 * (len
+ 4) * 10, rate
);
313 /* Exported duration function for driver use */
314 __le16
ieee80211_generic_frame_duration(struct ieee80211_hw
*hw
, int if_id
,
315 size_t frame_len
, int rate
)
317 struct ieee80211_local
*local
= hw_to_local(hw
);
318 struct net_device
*bdev
= dev_get_by_index(if_id
);
319 struct ieee80211_sub_if_data
*sdata
;
326 sdata
= IEEE80211_DEV_TO_SUB_IF(bdev
);
327 erp
= ieee80211_is_erp_rate(hw
->conf
.phymode
, rate
);
328 dur
= ieee80211_frame_duration(local
, frame_len
, rate
,
329 erp
, sdata
->flags
& IEEE80211_SDATA_SHORT_PREAMBLE
);
332 return cpu_to_le16(dur
);
334 EXPORT_SYMBOL(ieee80211_generic_frame_duration
);
336 __le16
ieee80211_rts_duration(struct ieee80211_hw
*hw
, int if_id
,
338 const struct ieee80211_tx_control
*frame_txctl
)
340 struct ieee80211_local
*local
= hw_to_local(hw
);
341 struct ieee80211_rate
*rate
;
342 struct net_device
*bdev
= dev_get_by_index(if_id
);
343 struct ieee80211_sub_if_data
*sdata
;
351 sdata
= IEEE80211_DEV_TO_SUB_IF(bdev
);
352 short_preamble
= sdata
->flags
& IEEE80211_SDATA_SHORT_PREAMBLE
;
354 rate
= frame_txctl
->rts_rate
;
355 erp
= !!(rate
->flags
& IEEE80211_RATE_ERP
);
358 dur
= ieee80211_frame_duration(local
, 10, rate
->rate
,
359 erp
, short_preamble
);
360 /* Data frame duration */
361 dur
+= ieee80211_frame_duration(local
, frame_len
, rate
->rate
,
362 erp
, short_preamble
);
364 dur
+= ieee80211_frame_duration(local
, 10, rate
->rate
,
365 erp
, short_preamble
);
368 return cpu_to_le16(dur
);
370 EXPORT_SYMBOL(ieee80211_rts_duration
);
372 __le16
ieee80211_ctstoself_duration(struct ieee80211_hw
*hw
, int if_id
,
374 const struct ieee80211_tx_control
*frame_txctl
)
376 struct ieee80211_local
*local
= hw_to_local(hw
);
377 struct ieee80211_rate
*rate
;
378 struct net_device
*bdev
= dev_get_by_index(if_id
);
379 struct ieee80211_sub_if_data
*sdata
;
387 sdata
= IEEE80211_DEV_TO_SUB_IF(bdev
);
388 short_preamble
= sdata
->flags
& IEEE80211_SDATA_SHORT_PREAMBLE
;
390 rate
= frame_txctl
->rts_rate
;
391 erp
= !!(rate
->flags
& IEEE80211_RATE_ERP
);
393 /* Data frame duration */
394 dur
= ieee80211_frame_duration(local
, frame_len
, rate
->rate
,
395 erp
, short_preamble
);
396 if (!(frame_txctl
->flags
& IEEE80211_TXCTL_NO_ACK
)) {
398 dur
+= ieee80211_frame_duration(local
, 10, rate
->rate
,
399 erp
, short_preamble
);
403 return cpu_to_le16(dur
);
405 EXPORT_SYMBOL(ieee80211_ctstoself_duration
);
407 struct ieee80211_rate
*
408 ieee80211_get_rate(struct ieee80211_local
*local
, int phymode
, int hw_rate
)
410 struct ieee80211_hw_mode
*mode
;
413 list_for_each_entry(mode
, &local
->modes_list
, list
) {
414 if (mode
->mode
!= phymode
)
416 for (r
= 0; r
< mode
->num_rates
; r
++) {
417 struct ieee80211_rate
*rate
= &mode
->rates
[r
];
418 if (rate
->val
== hw_rate
||
419 (rate
->flags
& IEEE80211_RATE_PREAMBLE2
&&
420 rate
->val2
== hw_rate
))
428 void ieee80211_wake_queue(struct ieee80211_hw
*hw
, int queue
)
430 struct ieee80211_local
*local
= hw_to_local(hw
);
432 if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF
,
433 &local
->state
[queue
])) {
434 if (test_bit(IEEE80211_LINK_STATE_PENDING
,
435 &local
->state
[queue
]))
436 tasklet_schedule(&local
->tx_pending_tasklet
);
438 if (!ieee80211_qdisc_installed(local
->mdev
)) {
440 netif_wake_queue(local
->mdev
);
442 __netif_schedule(local
->mdev
);
445 EXPORT_SYMBOL(ieee80211_wake_queue
);
447 void ieee80211_stop_queue(struct ieee80211_hw
*hw
, int queue
)
449 struct ieee80211_local
*local
= hw_to_local(hw
);
451 if (!ieee80211_qdisc_installed(local
->mdev
) && queue
== 0)
452 netif_stop_queue(local
->mdev
);
453 set_bit(IEEE80211_LINK_STATE_XOFF
, &local
->state
[queue
]);
455 EXPORT_SYMBOL(ieee80211_stop_queue
);
457 void ieee80211_start_queues(struct ieee80211_hw
*hw
)
459 struct ieee80211_local
*local
= hw_to_local(hw
);
462 for (i
= 0; i
< local
->hw
.queues
; i
++)
463 clear_bit(IEEE80211_LINK_STATE_XOFF
, &local
->state
[i
]);
464 if (!ieee80211_qdisc_installed(local
->mdev
))
465 netif_start_queue(local
->mdev
);
467 EXPORT_SYMBOL(ieee80211_start_queues
);
469 void ieee80211_stop_queues(struct ieee80211_hw
*hw
)
473 for (i
= 0; i
< hw
->queues
; i
++)
474 ieee80211_stop_queue(hw
, i
);
476 EXPORT_SYMBOL(ieee80211_stop_queues
);
478 void ieee80211_wake_queues(struct ieee80211_hw
*hw
)
482 for (i
= 0; i
< hw
->queues
; i
++)
483 ieee80211_wake_queue(hw
, i
);
485 EXPORT_SYMBOL(ieee80211_wake_queues
);