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"
32 /* privid for wiphys to determine whether they belong to us or not */
33 void *mac80211_wiphy_privid
= &mac80211_wiphy_privid
;
35 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
36 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
37 const unsigned char rfc1042_header
[] =
38 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
40 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
41 const unsigned char bridge_tunnel_header
[] =
42 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
45 u8
*ieee80211_get_bssid(struct ieee80211_hdr
*hdr
, size_t len
,
46 enum ieee80211_if_types type
)
50 /* drop ACK/CTS frames and incorrect hdr len (ctrl) */
54 fc
= le16_to_cpu(hdr
->frame_control
);
56 switch (fc
& IEEE80211_FCTL_FTYPE
) {
57 case IEEE80211_FTYPE_DATA
:
58 if (len
< 24) /* drop incorrect hdr len (data) */
60 switch (fc
& (IEEE80211_FCTL_TODS
| IEEE80211_FCTL_FROMDS
)) {
61 case IEEE80211_FCTL_TODS
:
63 case (IEEE80211_FCTL_TODS
| IEEE80211_FCTL_FROMDS
):
65 case IEEE80211_FCTL_FROMDS
:
71 case IEEE80211_FTYPE_MGMT
:
72 if (len
< 24) /* drop incorrect hdr len (mgmt) */
75 case IEEE80211_FTYPE_CTL
:
76 if ((fc
& IEEE80211_FCTL_STYPE
) == IEEE80211_STYPE_PSPOLL
)
78 else if ((fc
& IEEE80211_FCTL_STYPE
) ==
79 IEEE80211_STYPE_BACK_REQ
) {
81 case IEEE80211_IF_TYPE_STA
:
83 case IEEE80211_IF_TYPE_AP
:
84 case IEEE80211_IF_TYPE_VLAN
:
97 int ieee80211_get_hdrlen(u16 fc
)
101 switch (fc
& IEEE80211_FCTL_FTYPE
) {
102 case IEEE80211_FTYPE_DATA
:
103 if ((fc
& IEEE80211_FCTL_FROMDS
) && (fc
& IEEE80211_FCTL_TODS
))
104 hdrlen
= 30; /* Addr4 */
106 * The QoS Control field is two bytes and its presence is
107 * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to
108 * hdrlen if that bit is set.
109 * This works by masking out the bit and shifting it to
110 * bit position 1 so the result has the value 0 or 2.
112 hdrlen
+= (fc
& IEEE80211_STYPE_QOS_DATA
)
113 >> (ilog2(IEEE80211_STYPE_QOS_DATA
)-1);
115 case IEEE80211_FTYPE_CTL
:
117 * ACK and CTS are 10 bytes, all others 16. To see how
118 * to get this condition consider
119 * subtype mask: 0b0000000011110000 (0x00F0)
120 * ACK subtype: 0b0000000011010000 (0x00D0)
121 * CTS subtype: 0b0000000011000000 (0x00C0)
122 * bits that matter: ^^^ (0x00E0)
123 * value of those: 0b0000000011000000 (0x00C0)
125 if ((fc
& 0xE0) == 0xC0)
134 EXPORT_SYMBOL(ieee80211_get_hdrlen
);
136 int ieee80211_get_hdrlen_from_skb(const struct sk_buff
*skb
)
138 const struct ieee80211_hdr
*hdr
= (const struct ieee80211_hdr
*) skb
->data
;
141 if (unlikely(skb
->len
< 10))
143 hdrlen
= ieee80211_get_hdrlen(le16_to_cpu(hdr
->frame_control
));
144 if (unlikely(hdrlen
> skb
->len
))
148 EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb
);
150 int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr
*meshhdr
)
152 int ae
= meshhdr
->flags
& IEEE80211S_FLAGS_AE
;
168 void ieee80211_tx_set_protected(struct ieee80211_tx_data
*tx
)
170 struct ieee80211_hdr
*hdr
= (struct ieee80211_hdr
*) tx
->skb
->data
;
172 hdr
->frame_control
|= cpu_to_le16(IEEE80211_FCTL_PROTECTED
);
173 if (tx
->extra_frag
) {
174 struct ieee80211_hdr
*fhdr
;
176 for (i
= 0; i
< tx
->num_extra_frag
; i
++) {
177 fhdr
= (struct ieee80211_hdr
*)
178 tx
->extra_frag
[i
]->data
;
179 fhdr
->frame_control
|= cpu_to_le16(IEEE80211_FCTL_PROTECTED
);
184 int ieee80211_frame_duration(struct ieee80211_local
*local
, size_t len
,
185 int rate
, int erp
, int short_preamble
)
189 /* calculate duration (in microseconds, rounded up to next higher
190 * integer if it includes a fractional microsecond) to send frame of
191 * len bytes (does not include FCS) at the given rate. Duration will
194 * rate is in 100 kbps, so divident is multiplied by 10 in the
195 * DIV_ROUND_UP() operations.
198 if (local
->hw
.conf
.channel
->band
== IEEE80211_BAND_5GHZ
|| erp
) {
202 * N_DBPS = DATARATE x 4
203 * N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
204 * (16 = SIGNAL time, 6 = tail bits)
205 * TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
208 * 802.11a - 17.5.2: aSIFSTime = 16 usec
209 * 802.11g - 19.8.4: aSIFSTime = 10 usec +
210 * signal ext = 6 usec
212 dur
= 16; /* SIFS + signal ext */
213 dur
+= 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
214 dur
+= 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
215 dur
+= 4 * DIV_ROUND_UP((16 + 8 * (len
+ 4) + 6) * 10,
216 4 * rate
); /* T_SYM x N_SYM */
219 * 802.11b or 802.11g with 802.11b compatibility:
220 * 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
221 * Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
223 * 802.11 (DS): 15.3.3, 802.11b: 18.3.4
224 * aSIFSTime = 10 usec
225 * aPreambleLength = 144 usec or 72 usec with short preamble
226 * aPLCPHeaderLength = 48 usec or 24 usec with short preamble
228 dur
= 10; /* aSIFSTime = 10 usec */
229 dur
+= short_preamble
? (72 + 24) : (144 + 48);
231 dur
+= DIV_ROUND_UP(8 * (len
+ 4) * 10, rate
);
237 /* Exported duration function for driver use */
238 __le16
ieee80211_generic_frame_duration(struct ieee80211_hw
*hw
,
239 struct ieee80211_vif
*vif
,
241 struct ieee80211_rate
*rate
)
243 struct ieee80211_local
*local
= hw_to_local(hw
);
244 struct ieee80211_sub_if_data
*sdata
= vif_to_sdata(vif
);
249 if (sdata
->flags
& IEEE80211_SDATA_OPERATING_GMODE
)
250 erp
= rate
->flags
& IEEE80211_RATE_ERP_G
;
252 dur
= ieee80211_frame_duration(local
, frame_len
, rate
->bitrate
, erp
,
253 sdata
->bss_conf
.use_short_preamble
);
255 return cpu_to_le16(dur
);
257 EXPORT_SYMBOL(ieee80211_generic_frame_duration
);
259 __le16
ieee80211_rts_duration(struct ieee80211_hw
*hw
,
260 struct ieee80211_vif
*vif
, size_t frame_len
,
261 const struct ieee80211_tx_info
*frame_txctl
)
263 struct ieee80211_local
*local
= hw_to_local(hw
);
264 struct ieee80211_rate
*rate
;
265 struct ieee80211_sub_if_data
*sdata
= vif_to_sdata(vif
);
269 struct ieee80211_supported_band
*sband
;
271 sband
= local
->hw
.wiphy
->bands
[local
->hw
.conf
.channel
->band
];
273 short_preamble
= sdata
->bss_conf
.use_short_preamble
;
275 rate
= &sband
->bitrates
[frame_txctl
->control
.rts_cts_rate_idx
];
278 if (sdata
->flags
& IEEE80211_SDATA_OPERATING_GMODE
)
279 erp
= rate
->flags
& IEEE80211_RATE_ERP_G
;
282 dur
= ieee80211_frame_duration(local
, 10, rate
->bitrate
,
283 erp
, short_preamble
);
284 /* Data frame duration */
285 dur
+= ieee80211_frame_duration(local
, frame_len
, rate
->bitrate
,
286 erp
, short_preamble
);
288 dur
+= ieee80211_frame_duration(local
, 10, rate
->bitrate
,
289 erp
, short_preamble
);
291 return cpu_to_le16(dur
);
293 EXPORT_SYMBOL(ieee80211_rts_duration
);
295 __le16
ieee80211_ctstoself_duration(struct ieee80211_hw
*hw
,
296 struct ieee80211_vif
*vif
,
298 const struct ieee80211_tx_info
*frame_txctl
)
300 struct ieee80211_local
*local
= hw_to_local(hw
);
301 struct ieee80211_rate
*rate
;
302 struct ieee80211_sub_if_data
*sdata
= vif_to_sdata(vif
);
306 struct ieee80211_supported_band
*sband
;
308 sband
= local
->hw
.wiphy
->bands
[local
->hw
.conf
.channel
->band
];
310 short_preamble
= sdata
->bss_conf
.use_short_preamble
;
312 rate
= &sband
->bitrates
[frame_txctl
->control
.rts_cts_rate_idx
];
314 if (sdata
->flags
& IEEE80211_SDATA_OPERATING_GMODE
)
315 erp
= rate
->flags
& IEEE80211_RATE_ERP_G
;
317 /* Data frame duration */
318 dur
= ieee80211_frame_duration(local
, frame_len
, rate
->bitrate
,
319 erp
, short_preamble
);
320 if (!(frame_txctl
->flags
& IEEE80211_TX_CTL_NO_ACK
)) {
322 dur
+= ieee80211_frame_duration(local
, 10, rate
->bitrate
,
323 erp
, short_preamble
);
326 return cpu_to_le16(dur
);
328 EXPORT_SYMBOL(ieee80211_ctstoself_duration
);
330 void ieee80211_wake_queue(struct ieee80211_hw
*hw
, int queue
)
332 struct ieee80211_local
*local
= hw_to_local(hw
);
334 if (test_and_clear_bit(IEEE80211_LINK_STATE_XOFF
,
335 &local
->state
[queue
])) {
336 if (test_bit(IEEE80211_LINK_STATE_PENDING
,
337 &local
->state
[queue
]))
338 tasklet_schedule(&local
->tx_pending_tasklet
);
340 if (!ieee80211_qdisc_installed(local
->mdev
)) {
342 netif_wake_queue(local
->mdev
);
344 __netif_schedule(local
->mdev
);
347 EXPORT_SYMBOL(ieee80211_wake_queue
);
349 void ieee80211_stop_queue(struct ieee80211_hw
*hw
, int queue
)
351 struct ieee80211_local
*local
= hw_to_local(hw
);
353 if (!ieee80211_qdisc_installed(local
->mdev
) && queue
== 0)
354 netif_stop_queue(local
->mdev
);
355 set_bit(IEEE80211_LINK_STATE_XOFF
, &local
->state
[queue
]);
357 EXPORT_SYMBOL(ieee80211_stop_queue
);
359 void ieee80211_stop_queues(struct ieee80211_hw
*hw
)
363 for (i
= 0; i
< hw
->queues
+ hw
->ampdu_queues
; i
++)
364 ieee80211_stop_queue(hw
, i
);
366 EXPORT_SYMBOL(ieee80211_stop_queues
);
368 void ieee80211_wake_queues(struct ieee80211_hw
*hw
)
372 for (i
= 0; i
< hw
->queues
+ hw
->ampdu_queues
; i
++)
373 ieee80211_wake_queue(hw
, i
);
375 EXPORT_SYMBOL(ieee80211_wake_queues
);
377 void ieee80211_iterate_active_interfaces(
378 struct ieee80211_hw
*hw
,
379 void (*iterator
)(void *data
, u8
*mac
,
380 struct ieee80211_vif
*vif
),
383 struct ieee80211_local
*local
= hw_to_local(hw
);
384 struct ieee80211_sub_if_data
*sdata
;
388 list_for_each_entry_rcu(sdata
, &local
->interfaces
, list
) {
389 switch (sdata
->vif
.type
) {
390 case IEEE80211_IF_TYPE_INVALID
:
391 case IEEE80211_IF_TYPE_MNTR
:
392 case IEEE80211_IF_TYPE_VLAN
:
394 case IEEE80211_IF_TYPE_AP
:
395 case IEEE80211_IF_TYPE_STA
:
396 case IEEE80211_IF_TYPE_IBSS
:
397 case IEEE80211_IF_TYPE_WDS
:
398 case IEEE80211_IF_TYPE_MESH_POINT
:
401 if (sdata
->dev
== local
->mdev
)
403 if (netif_running(sdata
->dev
))
404 iterator(data
, sdata
->dev
->dev_addr
,
410 EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces
);