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 u8
*ieee80211_get_bssid(struct ieee80211_hdr
*hdr
, size_t len
,
45 enum ieee80211_if_types type
)
49 /* drop ACK/CTS frames and incorrect hdr len (ctrl) */
53 fc
= le16_to_cpu(hdr
->frame_control
);
55 switch (fc
& IEEE80211_FCTL_FTYPE
) {
56 case IEEE80211_FTYPE_DATA
:
57 if (len
< 24) /* drop incorrect hdr len (data) */
59 switch (fc
& (IEEE80211_FCTL_TODS
| IEEE80211_FCTL_FROMDS
)) {
60 case IEEE80211_FCTL_TODS
:
62 case (IEEE80211_FCTL_TODS
| IEEE80211_FCTL_FROMDS
):
64 case IEEE80211_FCTL_FROMDS
:
70 case IEEE80211_FTYPE_MGMT
:
71 if (len
< 24) /* drop incorrect hdr len (mgmt) */
74 case IEEE80211_FTYPE_CTL
:
75 if ((fc
& IEEE80211_FCTL_STYPE
) == IEEE80211_STYPE_PSPOLL
)
77 else if ((fc
& IEEE80211_FCTL_STYPE
) ==
78 IEEE80211_STYPE_BACK_REQ
) {
80 case IEEE80211_IF_TYPE_STA
:
82 case IEEE80211_IF_TYPE_AP
:
83 case IEEE80211_IF_TYPE_VLAN
:
96 int ieee80211_get_hdrlen(u16 fc
)
100 switch (fc
& IEEE80211_FCTL_FTYPE
) {
101 case IEEE80211_FTYPE_DATA
:
102 if ((fc
& IEEE80211_FCTL_FROMDS
) && (fc
& IEEE80211_FCTL_TODS
))
103 hdrlen
= 30; /* Addr4 */
105 * The QoS Control field is two bytes and its presence is
106 * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to
107 * hdrlen if that bit is set.
108 * This works by masking out the bit and shifting it to
109 * bit position 1 so the result has the value 0 or 2.
111 hdrlen
+= (fc
& IEEE80211_STYPE_QOS_DATA
)
112 >> (ilog2(IEEE80211_STYPE_QOS_DATA
)-1);
114 case IEEE80211_FTYPE_CTL
:
116 * ACK and CTS are 10 bytes, all others 16. To see how
117 * to get this condition consider
118 * subtype mask: 0b0000000011110000 (0x00F0)
119 * ACK subtype: 0b0000000011010000 (0x00D0)
120 * CTS subtype: 0b0000000011000000 (0x00C0)
121 * bits that matter: ^^^ (0x00E0)
122 * value of those: 0b0000000011000000 (0x00C0)
124 if ((fc
& 0xE0) == 0xC0)
133 EXPORT_SYMBOL(ieee80211_get_hdrlen
);
135 int ieee80211_get_hdrlen_from_skb(const struct sk_buff
*skb
)
137 const struct ieee80211_hdr
*hdr
= (const struct ieee80211_hdr
*) skb
->data
;
140 if (unlikely(skb
->len
< 10))
142 hdrlen
= ieee80211_get_hdrlen(le16_to_cpu(hdr
->frame_control
));
143 if (unlikely(hdrlen
> skb
->len
))
147 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb
);
149 void ieee80211_tx_set_iswep(struct ieee80211_txrx_data
*tx
)
151 struct ieee80211_hdr
*hdr
= (struct ieee80211_hdr
*) tx
->skb
->data
;
153 hdr
->frame_control
|= cpu_to_le16(IEEE80211_FCTL_PROTECTED
);
154 if (tx
->u
.tx
.extra_frag
) {
155 struct ieee80211_hdr
*fhdr
;
157 for (i
= 0; i
< tx
->u
.tx
.num_extra_frag
; i
++) {
158 fhdr
= (struct ieee80211_hdr
*)
159 tx
->u
.tx
.extra_frag
[i
]->data
;
160 fhdr
->frame_control
|= cpu_to_le16(IEEE80211_FCTL_PROTECTED
);
165 int ieee80211_frame_duration(struct ieee80211_local
*local
, size_t len
,
166 int rate
, int erp
, int short_preamble
)
170 /* calculate duration (in microseconds, rounded up to next higher
171 * integer if it includes a fractional microsecond) to send frame of
172 * len bytes (does not include FCS) at the given rate. Duration will
175 * rate is in 100 kbps, so divident is multiplied by 10 in the
176 * DIV_ROUND_UP() operations.
179 if (local
->hw
.conf
.channel
->band
== IEEE80211_BAND_5GHZ
|| erp
) {
183 * N_DBPS = DATARATE x 4
184 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
185 * (16 = SIGNAL time, 6 = tail bits)
186 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
189 * 802.11a - 17.5.2: aSIFSTime = 16 usec
190 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
191 * signal ext = 6 usec
193 dur
= 16; /* SIFS + signal ext */
194 dur
+= 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
195 dur
+= 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
196 dur
+= 4 * DIV_ROUND_UP((16 + 8 * (len
+ 4) + 6) * 10,
197 4 * rate
); /* T_SYM x N_SYM */
200 * 802.11b or 802.11g with 802.11b compatibility:
201 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
202 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
204 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4
205 * aSIFSTime = 10 usec
206 * aPreambleLength = 144 usec or 72 usec with short preamble
207 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble
209 dur
= 10; /* aSIFSTime = 10 usec */
210 dur
+= short_preamble
? (72 + 24) : (144 + 48);
212 dur
+= DIV_ROUND_UP(8 * (len
+ 4) * 10, rate
);
218 /* Exported duration function for driver use */
219 __le16
ieee80211_generic_frame_duration(struct ieee80211_hw
*hw
,
220 struct ieee80211_vif
*vif
,
222 struct ieee80211_rate
*rate
)
224 struct ieee80211_local
*local
= hw_to_local(hw
);
225 struct ieee80211_sub_if_data
*sdata
= vif_to_sdata(vif
);
230 if (sdata
->flags
& IEEE80211_SDATA_OPERATING_GMODE
)
231 erp
= rate
->flags
& IEEE80211_RATE_ERP_G
;
233 dur
= ieee80211_frame_duration(local
, frame_len
, rate
->bitrate
, erp
,
234 sdata
->bss_conf
.use_short_preamble
);
236 return cpu_to_le16(dur
);
238 EXPORT_SYMBOL(ieee80211_generic_frame_duration
);
240 __le16
ieee80211_rts_duration(struct ieee80211_hw
*hw
,
241 struct ieee80211_vif
*vif
, size_t frame_len
,
242 const struct ieee80211_tx_control
*frame_txctl
)
244 struct ieee80211_local
*local
= hw_to_local(hw
);
245 struct ieee80211_rate
*rate
;
246 struct ieee80211_sub_if_data
*sdata
= vif_to_sdata(vif
);
251 short_preamble
= sdata
->bss_conf
.use_short_preamble
;
253 rate
= frame_txctl
->rts_cts_rate
;
256 if (sdata
->flags
& IEEE80211_SDATA_OPERATING_GMODE
)
257 erp
= rate
->flags
& IEEE80211_RATE_ERP_G
;
260 dur
= ieee80211_frame_duration(local
, 10, rate
->bitrate
,
261 erp
, short_preamble
);
262 /* Data frame duration */
263 dur
+= ieee80211_frame_duration(local
, frame_len
, rate
->bitrate
,
264 erp
, short_preamble
);
266 dur
+= ieee80211_frame_duration(local
, 10, rate
->bitrate
,
267 erp
, short_preamble
);
269 return cpu_to_le16(dur
);
271 EXPORT_SYMBOL(ieee80211_rts_duration
);
273 __le16
ieee80211_ctstoself_duration(struct ieee80211_hw
*hw
,
274 struct ieee80211_vif
*vif
,
276 const struct ieee80211_tx_control
*frame_txctl
)
278 struct ieee80211_local
*local
= hw_to_local(hw
);
279 struct ieee80211_rate
*rate
;
280 struct ieee80211_sub_if_data
*sdata
= vif_to_sdata(vif
);
285 short_preamble
= sdata
->bss_conf
.use_short_preamble
;
287 rate
= frame_txctl
->rts_cts_rate
;
289 if (sdata
->flags
& IEEE80211_SDATA_OPERATING_GMODE
)
290 erp
= rate
->flags
& IEEE80211_RATE_ERP_G
;
292 /* Data frame duration */
293 dur
= ieee80211_frame_duration(local
, frame_len
, rate
->bitrate
,
294 erp
, short_preamble
);
295 if (!(frame_txctl
->flags
& IEEE80211_TXCTL_NO_ACK
)) {
297 dur
+= ieee80211_frame_duration(local
, 10, rate
->bitrate
,
298 erp
, short_preamble
);
301 return cpu_to_le16(dur
);
303 EXPORT_SYMBOL(ieee80211_ctstoself_duration
);
305 void ieee80211_wake_queue(struct ieee80211_hw
*hw
, int queue
)
307 struct ieee80211_local
*local
= hw_to_local(hw
);
309 if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF
,
310 &local
->state
[queue
])) {
311 if (test_bit(IEEE80211_LINK_STATE_PENDING
,
312 &local
->state
[queue
]))
313 tasklet_schedule(&local
->tx_pending_tasklet
);
315 if (!ieee80211_qdisc_installed(local
->mdev
)) {
317 netif_wake_queue(local
->mdev
);
319 __netif_schedule(local
->mdev
);
322 EXPORT_SYMBOL(ieee80211_wake_queue
);
324 void ieee80211_stop_queue(struct ieee80211_hw
*hw
, int queue
)
326 struct ieee80211_local
*local
= hw_to_local(hw
);
328 if (!ieee80211_qdisc_installed(local
->mdev
) && queue
== 0)
329 netif_stop_queue(local
->mdev
);
330 set_bit(IEEE80211_LINK_STATE_XOFF
, &local
->state
[queue
]);
332 EXPORT_SYMBOL(ieee80211_stop_queue
);
334 void ieee80211_start_queues(struct ieee80211_hw
*hw
)
336 struct ieee80211_local
*local
= hw_to_local(hw
);
339 for (i
= 0; i
< local
->hw
.queues
; i
++)
340 clear_bit(IEEE80211_LINK_STATE_XOFF
, &local
->state
[i
]);
341 if (!ieee80211_qdisc_installed(local
->mdev
))
342 netif_start_queue(local
->mdev
);
344 EXPORT_SYMBOL(ieee80211_start_queues
);
346 void ieee80211_stop_queues(struct ieee80211_hw
*hw
)
350 for (i
= 0; i
< hw
->queues
; i
++)
351 ieee80211_stop_queue(hw
, i
);
353 EXPORT_SYMBOL(ieee80211_stop_queues
);
355 void ieee80211_wake_queues(struct ieee80211_hw
*hw
)
359 for (i
= 0; i
< hw
->queues
; i
++)
360 ieee80211_wake_queue(hw
, i
);
362 EXPORT_SYMBOL(ieee80211_wake_queues
);
364 void ieee80211_iterate_active_interfaces(
365 struct ieee80211_hw
*hw
,
366 void (*iterator
)(void *data
, u8
*mac
,
367 struct ieee80211_vif
*vif
),
370 struct ieee80211_local
*local
= hw_to_local(hw
);
371 struct ieee80211_sub_if_data
*sdata
;
375 list_for_each_entry_rcu(sdata
, &local
->interfaces
, list
) {
376 switch (sdata
->vif
.type
) {
377 case IEEE80211_IF_TYPE_INVALID
:
378 case IEEE80211_IF_TYPE_MNTR
:
379 case IEEE80211_IF_TYPE_VLAN
:
381 case IEEE80211_IF_TYPE_AP
:
382 case IEEE80211_IF_TYPE_STA
:
383 case IEEE80211_IF_TYPE_IBSS
:
384 case IEEE80211_IF_TYPE_WDS
:
387 if (sdata
->dev
== local
->mdev
)
389 if (netif_running(sdata
->dev
))
390 iterator(data
, sdata
->dev
->dev_addr
,
396 EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces
);