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
;
95 case MODE_ATHEROS_TURBO
:
96 if (rate
->rate
== 120 || rate
->rate
== 240 ||
98 rate
->flags
|= IEEE80211_RATE_BASIC
;
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
;
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_ATHEROS_TURBO
:
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 ||
125 rate
->flags
|= IEEE80211_RATE_MANDATORY
;
128 if (ieee80211_is_erp_rate(mode
->mode
, rate
->rate
))
129 rate
->flags
|= IEEE80211_RATE_ERP
;
133 u8
*ieee80211_get_bssid(struct ieee80211_hdr
*hdr
, size_t len
)
140 fc
= le16_to_cpu(hdr
->frame_control
);
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
:
147 case (IEEE80211_FCTL_TODS
| IEEE80211_FCTL_FROMDS
):
149 case IEEE80211_FCTL_FROMDS
:
155 case IEEE80211_FTYPE_MGMT
:
157 case IEEE80211_FTYPE_CTL
:
158 if ((fc
& IEEE80211_FCTL_STYPE
) == IEEE80211_STYPE_PSPOLL
)
167 int ieee80211_get_hdrlen(u16 fc
)
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 */
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.
182 hdrlen
+= (fc
& IEEE80211_STYPE_QOS_DATA
)
183 >> (ilog2(IEEE80211_STYPE_QOS_DATA
)-1);
185 case IEEE80211_FTYPE_CTL
:
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)
195 if ((fc
& 0xE0) == 0xC0)
204 EXPORT_SYMBOL(ieee80211_get_hdrlen
);
206 int ieee80211_get_hdrlen_from_skb(const struct sk_buff
*skb
)
208 const struct ieee80211_hdr
*hdr
= (const struct ieee80211_hdr
*) skb
->data
;
211 if (unlikely(skb
->len
< 10))
213 hdrlen
= ieee80211_get_hdrlen(le16_to_cpu(hdr
->frame_control
));
214 if (unlikely(hdrlen
> skb
->len
))
218 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb
);
220 int ieee80211_is_eapol(const struct sk_buff
*skb
)
222 const struct ieee80211_hdr
*hdr
;
226 if (unlikely(skb
->len
< 10))
229 hdr
= (const struct ieee80211_hdr
*) skb
->data
;
230 fc
= le16_to_cpu(hdr
->frame_control
);
232 if (unlikely(!WLAN_FC_DATA_PRESENT(fc
)))
235 hdrlen
= ieee80211_get_hdrlen(fc
);
237 if (unlikely(skb
->len
>= hdrlen
+ sizeof(eapol_header
) &&
238 memcmp(skb
->data
+ hdrlen
, eapol_header
,
239 sizeof(eapol_header
)) == 0))
245 void ieee80211_tx_set_iswep(struct ieee80211_txrx_data
*tx
)
247 struct ieee80211_hdr
*hdr
= (struct ieee80211_hdr
*) tx
->skb
->data
;
249 hdr
->frame_control
|= cpu_to_le16(IEEE80211_FCTL_PROTECTED
);
250 if (tx
->u
.tx
.extra_frag
) {
251 struct ieee80211_hdr
*fhdr
;
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
);
261 int ieee80211_frame_duration(struct ieee80211_local
*local
, size_t len
,
262 int rate
, int erp
, int short_preamble
)
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
271 * rate is in 100 kbps, so divident is multiplied by 10 in the
272 * DIV_ROUND_UP() operations.
275 if (local
->hw
.conf
.phymode
== MODE_IEEE80211A
|| erp
||
276 local
->hw
.conf
.phymode
== MODE_ATHEROS_TURBO
) {
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
286 * 802.11a - 17.5.2: aSIFSTime = 16 usec
287 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
288 * signal ext = 6 usec
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 */
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.
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
307 dur
= 10; /* aSIFSTime = 10 usec */
308 dur
+= short_preamble
? (72 + 24) : (144 + 48);
310 dur
+= DIV_ROUND_UP(8 * (len
+ 4) * 10, rate
);
316 /* Exported duration function for driver use */
317 __le16
ieee80211_generic_frame_duration(struct ieee80211_hw
*hw
,
318 size_t frame_len
, int rate
)
320 struct ieee80211_local
*local
= hw_to_local(hw
);
324 erp
= ieee80211_is_erp_rate(hw
->conf
.phymode
, rate
);
325 dur
= ieee80211_frame_duration(local
, frame_len
, rate
,
326 erp
, local
->short_preamble
);
328 return cpu_to_le16(dur
);
330 EXPORT_SYMBOL(ieee80211_generic_frame_duration
);
332 __le16
ieee80211_rts_duration(struct ieee80211_hw
*hw
,
334 const struct ieee80211_tx_control
*frame_txctl
)
336 struct ieee80211_local
*local
= hw_to_local(hw
);
337 struct ieee80211_rate
*rate
;
338 int short_preamble
= local
->short_preamble
;
342 rate
= frame_txctl
->rts_rate
;
343 erp
= !!(rate
->flags
& IEEE80211_RATE_ERP
);
346 dur
= ieee80211_frame_duration(local
, 10, rate
->rate
,
347 erp
, short_preamble
);
348 /* Data frame duration */
349 dur
+= ieee80211_frame_duration(local
, frame_len
, rate
->rate
,
350 erp
, short_preamble
);
352 dur
+= ieee80211_frame_duration(local
, 10, rate
->rate
,
353 erp
, short_preamble
);
355 return cpu_to_le16(dur
);
357 EXPORT_SYMBOL(ieee80211_rts_duration
);
359 __le16
ieee80211_ctstoself_duration(struct ieee80211_hw
*hw
,
361 const struct ieee80211_tx_control
*frame_txctl
)
363 struct ieee80211_local
*local
= hw_to_local(hw
);
364 struct ieee80211_rate
*rate
;
365 int short_preamble
= local
->short_preamble
;
369 rate
= frame_txctl
->rts_rate
;
370 erp
= !!(rate
->flags
& IEEE80211_RATE_ERP
);
372 /* Data frame duration */
373 dur
= ieee80211_frame_duration(local
, frame_len
, rate
->rate
,
374 erp
, short_preamble
);
375 if (!(frame_txctl
->flags
& IEEE80211_TXCTL_NO_ACK
)) {
377 dur
+= ieee80211_frame_duration(local
, 10, rate
->rate
,
378 erp
, short_preamble
);
381 return cpu_to_le16(dur
);
383 EXPORT_SYMBOL(ieee80211_ctstoself_duration
);
385 struct ieee80211_rate
*
386 ieee80211_get_rate(struct ieee80211_local
*local
, int phymode
, int hw_rate
)
388 struct ieee80211_hw_mode
*mode
;
391 list_for_each_entry(mode
, &local
->modes_list
, list
) {
392 if (mode
->mode
!= phymode
)
394 for (r
= 0; r
< mode
->num_rates
; r
++) {
395 struct ieee80211_rate
*rate
= &mode
->rates
[r
];
396 if (rate
->val
== hw_rate
||
397 (rate
->flags
& IEEE80211_RATE_PREAMBLE2
&&
398 rate
->val2
== hw_rate
))
406 void ieee80211_wake_queue(struct ieee80211_hw
*hw
, int queue
)
408 struct ieee80211_local
*local
= hw_to_local(hw
);
410 if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF
,
411 &local
->state
[queue
])) {
412 if (test_bit(IEEE80211_LINK_STATE_PENDING
,
413 &local
->state
[queue
]))
414 tasklet_schedule(&local
->tx_pending_tasklet
);
416 if (!ieee80211_qdisc_installed(local
->mdev
)) {
418 netif_wake_queue(local
->mdev
);
420 __netif_schedule(local
->mdev
);
423 EXPORT_SYMBOL(ieee80211_wake_queue
);
425 void ieee80211_stop_queue(struct ieee80211_hw
*hw
, int queue
)
427 struct ieee80211_local
*local
= hw_to_local(hw
);
429 if (!ieee80211_qdisc_installed(local
->mdev
) && queue
== 0)
430 netif_stop_queue(local
->mdev
);
431 set_bit(IEEE80211_LINK_STATE_XOFF
, &local
->state
[queue
]);
433 EXPORT_SYMBOL(ieee80211_stop_queue
);
435 void ieee80211_start_queues(struct ieee80211_hw
*hw
)
437 struct ieee80211_local
*local
= hw_to_local(hw
);
440 for (i
= 0; i
< local
->hw
.queues
; i
++)
441 clear_bit(IEEE80211_LINK_STATE_XOFF
, &local
->state
[i
]);
442 if (!ieee80211_qdisc_installed(local
->mdev
))
443 netif_start_queue(local
->mdev
);
445 EXPORT_SYMBOL(ieee80211_start_queues
);
447 void ieee80211_stop_queues(struct ieee80211_hw
*hw
)
451 for (i
= 0; i
< hw
->queues
; i
++)
452 ieee80211_stop_queue(hw
, i
);
454 EXPORT_SYMBOL(ieee80211_stop_queues
);
456 void ieee80211_wake_queues(struct ieee80211_hw
*hw
)
460 for (i
= 0; i
< hw
->queues
; i
++)
461 ieee80211_wake_queue(hw
, i
);
463 EXPORT_SYMBOL(ieee80211_wake_queues
);