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.
12 * Transmit and frame generation functions.
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/skbuff.h>
18 #include <linux/etherdevice.h>
19 #include <linux/bitmap.h>
20 #include <linux/rcupdate.h>
21 #include <net/net_namespace.h>
22 #include <net/ieee80211_radiotap.h>
23 #include <net/cfg80211.h>
24 #include <net/mac80211.h>
25 #include <asm/unaligned.h>
27 #include "ieee80211_i.h"
35 #define IEEE80211_TX_OK 0
36 #define IEEE80211_TX_AGAIN 1
37 #define IEEE80211_TX_FRAG_AGAIN 2
41 static inline void ieee80211_include_sequence(struct ieee80211_sub_if_data
*sdata
,
42 struct ieee80211_hdr
*hdr
)
44 /* Set the sequence number for this frame. */
45 hdr
->seq_ctrl
= cpu_to_le16(sdata
->sequence
);
47 /* Increase the sequence number. */
48 sdata
->sequence
= (sdata
->sequence
+ 0x10) & IEEE80211_SCTL_SEQ
;
51 #ifdef CONFIG_MAC80211_LOWTX_FRAME_DUMP
52 static void ieee80211_dump_frame(const char *ifname
, const char *title
,
53 const struct sk_buff
*skb
)
55 const struct ieee80211_hdr
*hdr
= (struct ieee80211_hdr
*) skb
->data
;
60 printk(KERN_DEBUG
"%s: %s (len=%d)", ifname
, title
, skb
->len
);
66 fc
= le16_to_cpu(hdr
->frame_control
);
67 hdrlen
= ieee80211_get_hdrlen(fc
);
68 if (hdrlen
> skb
->len
)
71 printk(" FC=0x%04x DUR=0x%04x",
72 fc
, le16_to_cpu(hdr
->duration_id
));
74 printk(" A1=%s", print_mac(mac
, hdr
->addr1
));
76 printk(" A2=%s", print_mac(mac
, hdr
->addr2
));
78 printk(" A3=%s", print_mac(mac
, hdr
->addr3
));
80 printk(" A4=%s", print_mac(mac
, hdr
->addr4
));
83 #else /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */
84 static inline void ieee80211_dump_frame(const char *ifname
, const char *title
,
88 #endif /* CONFIG_MAC80211_LOWTX_FRAME_DUMP */
90 static u16
ieee80211_duration(struct ieee80211_tx_data
*tx
, int group_addr
,
93 int rate
, mrate
, erp
, dur
, i
;
94 struct ieee80211_rate
*txrate
= tx
->rate
;
95 struct ieee80211_local
*local
= tx
->local
;
96 struct ieee80211_supported_band
*sband
;
98 sband
= local
->hw
.wiphy
->bands
[local
->hw
.conf
.channel
->band
];
101 if (tx
->sdata
->flags
& IEEE80211_SDATA_OPERATING_GMODE
)
102 erp
= txrate
->flags
& IEEE80211_RATE_ERP_G
;
105 * data and mgmt (except PS Poll):
106 * - during CFP: 32768
107 * - during contention period:
108 * if addr1 is group address: 0
109 * if more fragments = 0 and addr1 is individual address: time to
110 * transmit one ACK plus SIFS
111 * if more fragments = 1 and addr1 is individual address: time to
112 * transmit next fragment plus 2 x ACK plus 3 x SIFS
115 * - control response frame (CTS or ACK) shall be transmitted using the
116 * same rate as the immediately previous frame in the frame exchange
117 * sequence, if this rate belongs to the PHY mandatory rates, or else
118 * at the highest possible rate belonging to the PHY rates in the
122 if ((tx
->fc
& IEEE80211_FCTL_FTYPE
) == IEEE80211_FTYPE_CTL
) {
123 /* TODO: These control frames are not currently sent by
124 * 80211.o, but should they be implemented, this function
125 * needs to be updated to support duration field calculation.
127 * RTS: time needed to transmit pending data/mgmt frame plus
128 * one CTS frame plus one ACK frame plus 3 x SIFS
129 * CTS: duration of immediately previous RTS minus time
130 * required to transmit CTS and its SIFS
131 * ACK: 0 if immediately previous directed data/mgmt had
132 * more=0, with more=1 duration in ACK frame is duration
133 * from previous frame minus time needed to transmit ACK
135 * PS Poll: BIT(15) | BIT(14) | aid
141 if (0 /* FIX: data/mgmt during CFP */)
144 if (group_addr
) /* Group address as the destination - no ACK */
147 /* Individual destination address:
148 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
149 * CTS and ACK frames shall be transmitted using the highest rate in
150 * basic rate set that is less than or equal to the rate of the
151 * immediately previous frame and that is using the same modulation
152 * (CCK or OFDM). If no basic rate set matches with these requirements,
153 * the highest mandatory rate of the PHY that is less than or equal to
154 * the rate of the previous frame is used.
155 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
158 /* use lowest available if everything fails */
159 mrate
= sband
->bitrates
[0].bitrate
;
160 for (i
= 0; i
< sband
->n_bitrates
; i
++) {
161 struct ieee80211_rate
*r
= &sband
->bitrates
[i
];
163 if (r
->bitrate
> txrate
->bitrate
)
166 if (tx
->sdata
->basic_rates
& BIT(i
))
169 switch (sband
->band
) {
170 case IEEE80211_BAND_2GHZ
: {
172 if (tx
->sdata
->flags
& IEEE80211_SDATA_OPERATING_GMODE
)
173 flag
= IEEE80211_RATE_MANDATORY_G
;
175 flag
= IEEE80211_RATE_MANDATORY_B
;
180 case IEEE80211_BAND_5GHZ
:
181 if (r
->flags
& IEEE80211_RATE_MANDATORY_A
)
184 case IEEE80211_NUM_BANDS
:
190 /* No matching basic rate found; use highest suitable mandatory
195 /* Time needed to transmit ACK
196 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
197 * to closest integer */
199 dur
= ieee80211_frame_duration(local
, 10, rate
, erp
,
200 tx
->sdata
->bss_conf
.use_short_preamble
);
203 /* Frame is fragmented: duration increases with time needed to
204 * transmit next fragment plus ACK and 2 x SIFS. */
205 dur
*= 2; /* ACK + SIFS */
207 dur
+= ieee80211_frame_duration(local
, next_frag_len
,
208 txrate
->bitrate
, erp
,
209 tx
->sdata
->bss_conf
.use_short_preamble
);
215 static inline int __ieee80211_queue_stopped(const struct ieee80211_local
*local
,
218 return test_bit(IEEE80211_LINK_STATE_XOFF
, &local
->state
[queue
]);
221 static inline int __ieee80211_queue_pending(const struct ieee80211_local
*local
,
224 return test_bit(IEEE80211_LINK_STATE_PENDING
, &local
->state
[queue
]);
227 static int inline is_ieee80211_device(struct net_device
*dev
,
228 struct net_device
*master
)
230 return (wdev_priv(dev
->ieee80211_ptr
) ==
231 wdev_priv(master
->ieee80211_ptr
));
236 static ieee80211_tx_result
237 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data
*tx
)
239 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
240 struct sk_buff
*skb
= tx
->skb
;
241 struct ieee80211_hdr
*hdr
= (struct ieee80211_hdr
*) skb
->data
;
242 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
245 if (unlikely(tx
->flags
& IEEE80211_TX_INJECTED
))
248 if (unlikely(tx
->local
->sta_sw_scanning
) &&
249 ((tx
->fc
& IEEE80211_FCTL_FTYPE
) != IEEE80211_FTYPE_MGMT
||
250 (tx
->fc
& IEEE80211_FCTL_STYPE
) != IEEE80211_STYPE_PROBE_REQ
))
253 if (tx
->sdata
->vif
.type
== IEEE80211_IF_TYPE_MESH_POINT
)
256 if (tx
->flags
& IEEE80211_TX_PS_BUFFERED
)
259 sta_flags
= tx
->sta
? tx
->sta
->flags
: 0;
261 if (likely(tx
->flags
& IEEE80211_TX_UNICAST
)) {
262 if (unlikely(!(sta_flags
& WLAN_STA_ASSOC
) &&
263 tx
->sdata
->vif
.type
!= IEEE80211_IF_TYPE_IBSS
&&
264 (tx
->fc
& IEEE80211_FCTL_FTYPE
) == IEEE80211_FTYPE_DATA
)) {
265 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
266 DECLARE_MAC_BUF(mac
);
267 printk(KERN_DEBUG
"%s: dropped data frame to not "
268 "associated station %s\n",
269 tx
->dev
->name
, print_mac(mac
, hdr
->addr1
));
270 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
271 I802_DEBUG_INC(tx
->local
->tx_handlers_drop_not_assoc
);
275 if (unlikely((tx
->fc
& IEEE80211_FCTL_FTYPE
) == IEEE80211_FTYPE_DATA
&&
276 tx
->local
->num_sta
== 0 &&
277 tx
->sdata
->vif
.type
!= IEEE80211_IF_TYPE_IBSS
)) {
279 * No associated STAs - no need to send multicast
290 static ieee80211_tx_result
291 ieee80211_tx_h_sequence(struct ieee80211_tx_data
*tx
)
293 struct ieee80211_hdr
*hdr
= (struct ieee80211_hdr
*)tx
->skb
->data
;
295 if (ieee80211_get_hdrlen(le16_to_cpu(hdr
->frame_control
)) >= 24)
296 ieee80211_include_sequence(tx
->sdata
, hdr
);
301 /* This function is called whenever the AP is about to exceed the maximum limit
302 * of buffered frames for power saving STAs. This situation should not really
303 * happen often during normal operation, so dropping the oldest buffered packet
304 * from each queue should be OK to make some room for new frames. */
305 static void purge_old_ps_buffers(struct ieee80211_local
*local
)
307 int total
= 0, purged
= 0;
309 struct ieee80211_sub_if_data
*sdata
;
310 struct sta_info
*sta
;
313 * virtual interfaces are protected by RCU
317 list_for_each_entry_rcu(sdata
, &local
->interfaces
, list
) {
318 struct ieee80211_if_ap
*ap
;
319 if (sdata
->dev
== local
->mdev
||
320 sdata
->vif
.type
!= IEEE80211_IF_TYPE_AP
)
323 skb
= skb_dequeue(&ap
->ps_bc_buf
);
328 total
+= skb_queue_len(&ap
->ps_bc_buf
);
331 list_for_each_entry_rcu(sta
, &local
->sta_list
, list
) {
332 skb
= skb_dequeue(&sta
->ps_tx_buf
);
337 total
+= skb_queue_len(&sta
->ps_tx_buf
);
342 local
->total_ps_buffered
= total
;
343 printk(KERN_DEBUG
"%s: PS buffers full - purged %d frames\n",
344 wiphy_name(local
->hw
.wiphy
), purged
);
347 static ieee80211_tx_result
348 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data
*tx
)
351 * broadcast/multicast frame
353 * If any of the associated stations is in power save mode,
354 * the frame is buffered to be sent after DTIM beacon frame.
355 * This is done either by the hardware or us.
358 /* not AP/IBSS or ordered frame */
359 if (!tx
->sdata
->bss
|| (tx
->fc
& IEEE80211_FCTL_ORDER
))
362 /* no stations in PS mode */
363 if (!atomic_read(&tx
->sdata
->bss
->num_sta_ps
))
366 /* buffered in mac80211 */
367 if (tx
->local
->hw
.flags
& IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING
) {
368 if (tx
->local
->total_ps_buffered
>= TOTAL_MAX_TX_BUFFER
)
369 purge_old_ps_buffers(tx
->local
);
370 if (skb_queue_len(&tx
->sdata
->bss
->ps_bc_buf
) >=
372 if (net_ratelimit()) {
373 printk(KERN_DEBUG
"%s: BC TX buffer full - "
374 "dropping the oldest frame\n",
377 dev_kfree_skb(skb_dequeue(&tx
->sdata
->bss
->ps_bc_buf
));
379 tx
->local
->total_ps_buffered
++;
380 skb_queue_tail(&tx
->sdata
->bss
->ps_bc_buf
, tx
->skb
);
384 /* buffered in hardware */
385 tx
->control
->flags
|= IEEE80211_TXCTL_SEND_AFTER_DTIM
;
390 static ieee80211_tx_result
391 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data
*tx
)
393 struct sta_info
*sta
= tx
->sta
;
394 DECLARE_MAC_BUF(mac
);
397 ((tx
->fc
& IEEE80211_FCTL_FTYPE
) == IEEE80211_FTYPE_MGMT
&&
398 (tx
->fc
& IEEE80211_FCTL_STYPE
) == IEEE80211_STYPE_PROBE_RESP
)))
401 if (unlikely((sta
->flags
& WLAN_STA_PS
) &&
402 !(sta
->flags
& WLAN_STA_PSPOLL
))) {
403 struct ieee80211_tx_packet_data
*pkt_data
;
404 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
405 printk(KERN_DEBUG
"STA %s aid %d: PS buffer (entries "
407 print_mac(mac
, sta
->addr
), sta
->aid
,
408 skb_queue_len(&sta
->ps_tx_buf
));
409 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
410 if (tx
->local
->total_ps_buffered
>= TOTAL_MAX_TX_BUFFER
)
411 purge_old_ps_buffers(tx
->local
);
412 if (skb_queue_len(&sta
->ps_tx_buf
) >= STA_MAX_TX_BUFFER
) {
413 struct sk_buff
*old
= skb_dequeue(&sta
->ps_tx_buf
);
414 if (net_ratelimit()) {
415 printk(KERN_DEBUG
"%s: STA %s TX "
416 "buffer full - dropping oldest frame\n",
417 tx
->dev
->name
, print_mac(mac
, sta
->addr
));
421 tx
->local
->total_ps_buffered
++;
423 /* Queue frame to be sent after STA sends an PS Poll frame */
424 if (skb_queue_empty(&sta
->ps_tx_buf
))
425 sta_info_set_tim_bit(sta
);
427 pkt_data
= (struct ieee80211_tx_packet_data
*)tx
->skb
->cb
;
428 pkt_data
->jiffies
= jiffies
;
429 skb_queue_tail(&sta
->ps_tx_buf
, tx
->skb
);
432 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
433 else if (unlikely(sta
->flags
& WLAN_STA_PS
)) {
434 printk(KERN_DEBUG
"%s: STA %s in PS mode, but pspoll "
435 "set -> send frame\n", tx
->dev
->name
,
436 print_mac(mac
, sta
->addr
));
438 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
439 sta
->flags
&= ~WLAN_STA_PSPOLL
;
444 static ieee80211_tx_result
445 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data
*tx
)
447 if (unlikely(tx
->flags
& IEEE80211_TX_PS_BUFFERED
))
450 if (tx
->flags
& IEEE80211_TX_UNICAST
)
451 return ieee80211_tx_h_unicast_ps_buf(tx
);
453 return ieee80211_tx_h_multicast_ps_buf(tx
);
456 static ieee80211_tx_result
457 ieee80211_tx_h_select_key(struct ieee80211_tx_data
*tx
)
459 struct ieee80211_key
*key
;
462 if (unlikely(tx
->control
->flags
& IEEE80211_TXCTL_DO_NOT_ENCRYPT
))
464 else if (tx
->sta
&& (key
= rcu_dereference(tx
->sta
->key
)))
466 else if ((key
= rcu_dereference(tx
->sdata
->default_key
)))
468 else if (tx
->sdata
->drop_unencrypted
&&
469 !(tx
->control
->flags
& IEEE80211_TXCTL_EAPOL_FRAME
) &&
470 !(tx
->flags
& IEEE80211_TX_INJECTED
)) {
471 I802_DEBUG_INC(tx
->local
->tx_handlers_drop_unencrypted
);
479 tx
->key
->tx_rx_count
++;
480 /* TODO: add threshold stuff again */
482 switch (tx
->key
->conf
.alg
) {
484 ftype
= fc
& IEEE80211_FCTL_FTYPE
;
485 stype
= fc
& IEEE80211_FCTL_STYPE
;
487 if (ftype
== IEEE80211_FTYPE_MGMT
&&
488 stype
== IEEE80211_STYPE_AUTH
)
492 if (!WLAN_FC_DATA_PRESENT(fc
))
498 if (!tx
->key
|| !(tx
->key
->flags
& KEY_FLAG_UPLOADED_TO_HARDWARE
))
499 tx
->control
->flags
|= IEEE80211_TXCTL_DO_NOT_ENCRYPT
;
504 static ieee80211_tx_result
505 ieee80211_tx_h_fragment(struct ieee80211_tx_data
*tx
)
507 struct ieee80211_hdr
*hdr
= (struct ieee80211_hdr
*) tx
->skb
->data
;
508 size_t hdrlen
, per_fragm
, num_fragm
, payload_len
, left
;
509 struct sk_buff
**frags
, *first
, *frag
;
513 int frag_threshold
= tx
->local
->fragmentation_threshold
;
515 if (!(tx
->flags
& IEEE80211_TX_FRAGMENTED
))
520 hdrlen
= ieee80211_get_hdrlen(tx
->fc
);
521 payload_len
= first
->len
- hdrlen
;
522 per_fragm
= frag_threshold
- hdrlen
- FCS_LEN
;
523 num_fragm
= DIV_ROUND_UP(payload_len
, per_fragm
);
525 frags
= kzalloc(num_fragm
* sizeof(struct sk_buff
*), GFP_ATOMIC
);
529 hdr
->frame_control
|= cpu_to_le16(IEEE80211_FCTL_MOREFRAGS
);
530 seq
= le16_to_cpu(hdr
->seq_ctrl
) & IEEE80211_SCTL_SEQ
;
531 pos
= first
->data
+ hdrlen
+ per_fragm
;
532 left
= payload_len
- per_fragm
;
533 for (i
= 0; i
< num_fragm
- 1; i
++) {
534 struct ieee80211_hdr
*fhdr
;
540 /* reserve enough extra head and tail room for possible
543 dev_alloc_skb(tx
->local
->tx_headroom
+
545 IEEE80211_ENCRYPT_HEADROOM
+
546 IEEE80211_ENCRYPT_TAILROOM
);
549 /* Make sure that all fragments use the same priority so
550 * that they end up using the same TX queue */
551 frag
->priority
= first
->priority
;
552 skb_reserve(frag
, tx
->local
->tx_headroom
+
553 IEEE80211_ENCRYPT_HEADROOM
);
554 fhdr
= (struct ieee80211_hdr
*) skb_put(frag
, hdrlen
);
555 memcpy(fhdr
, first
->data
, hdrlen
);
556 if (i
== num_fragm
- 2)
557 fhdr
->frame_control
&= cpu_to_le16(~IEEE80211_FCTL_MOREFRAGS
);
558 fhdr
->seq_ctrl
= cpu_to_le16(seq
| ((i
+ 1) & IEEE80211_SCTL_FRAG
));
559 copylen
= left
> per_fragm
? per_fragm
: left
;
560 memcpy(skb_put(frag
, copylen
), pos
, copylen
);
565 skb_trim(first
, hdrlen
+ per_fragm
);
567 tx
->num_extra_frag
= num_fragm
- 1;
568 tx
->extra_frag
= frags
;
573 printk(KERN_DEBUG
"%s: failed to fragment frame\n", tx
->dev
->name
);
575 for (i
= 0; i
< num_fragm
- 1; i
++)
577 dev_kfree_skb(frags
[i
]);
580 I802_DEBUG_INC(tx
->local
->tx_handlers_drop_fragment
);
584 static ieee80211_tx_result
585 ieee80211_tx_h_encrypt(struct ieee80211_tx_data
*tx
)
590 switch (tx
->key
->conf
.alg
) {
592 return ieee80211_crypto_wep_encrypt(tx
);
594 return ieee80211_crypto_tkip_encrypt(tx
);
596 return ieee80211_crypto_ccmp_encrypt(tx
);
604 static ieee80211_tx_result
605 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data
*tx
)
607 struct rate_selection rsel
;
608 struct ieee80211_supported_band
*sband
;
610 sband
= tx
->local
->hw
.wiphy
->bands
[tx
->local
->hw
.conf
.channel
->band
];
612 if (likely(!tx
->rate
)) {
613 rate_control_get_rate(tx
->dev
, sband
, tx
->skb
, &rsel
);
614 tx
->rate
= rsel
.rate
;
615 if (unlikely(rsel
.probe
)) {
616 tx
->control
->flags
|=
617 IEEE80211_TXCTL_RATE_CTRL_PROBE
;
618 tx
->flags
|= IEEE80211_TX_PROBE_LAST_FRAG
;
619 tx
->control
->alt_retry_rate
= tx
->rate
;
620 tx
->rate
= rsel
.probe
;
622 tx
->control
->alt_retry_rate
= NULL
;
627 tx
->control
->alt_retry_rate
= NULL
;
629 if (tx
->sdata
->bss_conf
.use_cts_prot
&&
630 (tx
->flags
& IEEE80211_TX_FRAGMENTED
) && rsel
.nonerp
) {
631 tx
->last_frag_rate
= tx
->rate
;
633 tx
->flags
&= ~IEEE80211_TX_PROBE_LAST_FRAG
;
635 tx
->flags
|= IEEE80211_TX_PROBE_LAST_FRAG
;
636 tx
->rate
= rsel
.nonerp
;
637 tx
->control
->tx_rate
= rsel
.nonerp
;
638 tx
->control
->flags
&= ~IEEE80211_TXCTL_RATE_CTRL_PROBE
;
640 tx
->last_frag_rate
= tx
->rate
;
641 tx
->control
->tx_rate
= tx
->rate
;
643 tx
->control
->tx_rate
= tx
->rate
;
648 static ieee80211_tx_result
649 ieee80211_tx_h_misc(struct ieee80211_tx_data
*tx
)
651 struct ieee80211_hdr
*hdr
= (struct ieee80211_hdr
*) tx
->skb
->data
;
652 u16 fc
= le16_to_cpu(hdr
->frame_control
);
654 struct ieee80211_tx_control
*control
= tx
->control
;
656 if (!control
->retry_limit
) {
657 if (!is_multicast_ether_addr(hdr
->addr1
)) {
658 if (tx
->skb
->len
+ FCS_LEN
> tx
->local
->rts_threshold
659 && tx
->local
->rts_threshold
<
660 IEEE80211_MAX_RTS_THRESHOLD
) {
662 IEEE80211_TXCTL_USE_RTS_CTS
;
664 IEEE80211_TXCTL_LONG_RETRY_LIMIT
;
665 control
->retry_limit
=
666 tx
->local
->long_retry_limit
;
668 control
->retry_limit
=
669 tx
->local
->short_retry_limit
;
672 control
->retry_limit
= 1;
676 if (tx
->flags
& IEEE80211_TX_FRAGMENTED
) {
677 /* Do not use multiple retry rates when sending fragmented
679 * TODO: The last fragment could still use multiple retry
681 control
->alt_retry_rate
= NULL
;
684 /* Use CTS protection for unicast frames sent using extended rates if
685 * there are associated non-ERP stations and RTS/CTS is not configured
687 if ((tx
->sdata
->flags
& IEEE80211_SDATA_OPERATING_GMODE
) &&
688 (tx
->rate
->flags
& IEEE80211_RATE_ERP_G
) &&
689 (tx
->flags
& IEEE80211_TX_UNICAST
) &&
690 tx
->sdata
->bss_conf
.use_cts_prot
&&
691 !(control
->flags
& IEEE80211_TXCTL_USE_RTS_CTS
))
692 control
->flags
|= IEEE80211_TXCTL_USE_CTS_PROTECT
;
694 /* Transmit data frames using short preambles if the driver supports
695 * short preambles at the selected rate and short preambles are
696 * available on the network at the current point in time. */
697 if (((fc
& IEEE80211_FCTL_FTYPE
) == IEEE80211_FTYPE_DATA
) &&
698 (tx
->rate
->flags
& IEEE80211_RATE_SHORT_PREAMBLE
) &&
699 tx
->sdata
->bss_conf
.use_short_preamble
&&
700 (!tx
->sta
|| (tx
->sta
->flags
& WLAN_STA_SHORT_PREAMBLE
))) {
701 tx
->control
->flags
|= IEEE80211_TXCTL_SHORT_PREAMBLE
;
704 /* Setup duration field for the first fragment of the frame. Duration
705 * for remaining fragments will be updated when they are being sent
706 * to low-level driver in ieee80211_tx(). */
707 dur
= ieee80211_duration(tx
, is_multicast_ether_addr(hdr
->addr1
),
708 (tx
->flags
& IEEE80211_TX_FRAGMENTED
) ?
709 tx
->extra_frag
[0]->len
: 0);
710 hdr
->duration_id
= cpu_to_le16(dur
);
712 if ((control
->flags
& IEEE80211_TXCTL_USE_RTS_CTS
) ||
713 (control
->flags
& IEEE80211_TXCTL_USE_CTS_PROTECT
)) {
714 struct ieee80211_supported_band
*sband
;
715 struct ieee80211_rate
*rate
, *baserate
;
718 sband
= tx
->local
->hw
.wiphy
->bands
[
719 tx
->local
->hw
.conf
.channel
->band
];
721 /* Do not use multiple retry rates when using RTS/CTS */
722 control
->alt_retry_rate
= NULL
;
724 /* Use min(data rate, max base rate) as CTS/RTS rate */
728 for (idx
= 0; idx
< sband
->n_bitrates
; idx
++) {
729 if (sband
->bitrates
[idx
].bitrate
> rate
->bitrate
)
731 if (tx
->sdata
->basic_rates
& BIT(idx
) &&
733 (baserate
->bitrate
< sband
->bitrates
[idx
].bitrate
)))
734 baserate
= &sband
->bitrates
[idx
];
738 control
->rts_cts_rate
= baserate
;
740 control
->rts_cts_rate
= &sband
->bitrates
[0];
744 control
->aid
= tx
->sta
->aid
;
745 tx
->sta
->tx_packets
++;
746 tx
->sta
->tx_fragments
++;
747 tx
->sta
->tx_bytes
+= tx
->skb
->len
;
748 if (tx
->extra_frag
) {
750 tx
->sta
->tx_fragments
+= tx
->num_extra_frag
;
751 for (i
= 0; i
< tx
->num_extra_frag
; i
++) {
753 tx
->extra_frag
[i
]->len
;
761 static ieee80211_tx_result
762 ieee80211_tx_h_load_stats(struct ieee80211_tx_data
*tx
)
764 struct ieee80211_local
*local
= tx
->local
;
765 struct sk_buff
*skb
= tx
->skb
;
766 struct ieee80211_hdr
*hdr
= (struct ieee80211_hdr
*) skb
->data
;
767 u32 load
= 0, hdrtime
;
768 struct ieee80211_rate
*rate
= tx
->rate
;
770 /* TODO: this could be part of tx_status handling, so that the number
771 * of retries would be known; TX rate should in that case be stored
772 * somewhere with the packet */
774 /* Estimate total channel use caused by this frame */
776 /* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
777 * 1 usec = 1/8 * (1080 / 10) = 13.5 */
779 if (tx
->channel
->band
== IEEE80211_BAND_5GHZ
||
780 (tx
->channel
->band
== IEEE80211_BAND_2GHZ
&&
781 rate
->flags
& IEEE80211_RATE_ERP_G
))
782 hdrtime
= CHAN_UTIL_HDR_SHORT
;
784 hdrtime
= CHAN_UTIL_HDR_LONG
;
787 if (!is_multicast_ether_addr(hdr
->addr1
))
790 if (tx
->control
->flags
& IEEE80211_TXCTL_USE_RTS_CTS
)
792 else if (tx
->control
->flags
& IEEE80211_TXCTL_USE_CTS_PROTECT
)
795 /* TODO: optimise again */
796 load
+= skb
->len
* CHAN_UTIL_RATE_LCM
/ rate
->bitrate
;
798 if (tx
->extra_frag
) {
800 for (i
= 0; i
< tx
->num_extra_frag
; i
++) {
802 load
+= tx
->extra_frag
[i
]->len
*
807 /* Divide channel_use by 8 to avoid wrapping around the counter */
808 load
>>= CHAN_UTIL_SHIFT
;
809 local
->channel_use_raw
+= load
;
811 tx
->sta
->channel_use_raw
+= load
;
812 tx
->sdata
->channel_use_raw
+= load
;
818 typedef ieee80211_tx_result (*ieee80211_tx_handler
)(struct ieee80211_tx_data
*);
819 static ieee80211_tx_handler ieee80211_tx_handlers
[] =
821 ieee80211_tx_h_check_assoc
,
822 ieee80211_tx_h_sequence
,
823 ieee80211_tx_h_ps_buf
,
824 ieee80211_tx_h_select_key
,
825 ieee80211_tx_h_michael_mic_add
,
826 ieee80211_tx_h_fragment
,
827 ieee80211_tx_h_encrypt
,
828 ieee80211_tx_h_rate_ctrl
,
830 ieee80211_tx_h_load_stats
,
834 /* actual transmit path */
837 * deal with packet injection down monitor interface
838 * with Radiotap Header -- only called for monitor mode interface
840 static ieee80211_tx_result
841 __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data
*tx
,
845 * this is the moment to interpret and discard the radiotap header that
846 * must be at the start of the packet injected in Monitor mode
848 * Need to take some care with endian-ness since radiotap
849 * args are little-endian
852 struct ieee80211_radiotap_iterator iterator
;
853 struct ieee80211_radiotap_header
*rthdr
=
854 (struct ieee80211_radiotap_header
*) skb
->data
;
855 struct ieee80211_supported_band
*sband
;
856 int ret
= ieee80211_radiotap_iterator_init(&iterator
, rthdr
, skb
->len
);
857 struct ieee80211_tx_control
*control
= tx
->control
;
859 sband
= tx
->local
->hw
.wiphy
->bands
[tx
->local
->hw
.conf
.channel
->band
];
861 control
->flags
|= IEEE80211_TXCTL_DO_NOT_ENCRYPT
;
862 tx
->flags
|= IEEE80211_TX_INJECTED
;
863 tx
->flags
&= ~IEEE80211_TX_FRAGMENTED
;
866 * for every radiotap entry that is present
867 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
868 * entries present, or -EINVAL on error)
874 ret
= ieee80211_radiotap_iterator_next(&iterator
);
879 /* see if this argument is something we can use */
880 switch (iterator
.this_arg_index
) {
882 * You must take care when dereferencing iterator.this_arg
883 * for multibyte types... the pointer is not aligned. Use
884 * get_unaligned((type *)iterator.this_arg) to dereference
885 * iterator.this_arg for type "type" safely on all arches.
887 case IEEE80211_RADIOTAP_RATE
:
889 * radiotap rate u8 is in 500kbps units eg, 0x02=1Mbps
890 * ieee80211 rate int is in 100kbps units eg, 0x0a=1Mbps
892 target_rate
= (*iterator
.this_arg
) * 5;
893 for (i
= 0; i
< sband
->n_bitrates
; i
++) {
894 struct ieee80211_rate
*r
;
896 r
= &sband
->bitrates
[i
];
898 if (r
->bitrate
== target_rate
) {
905 case IEEE80211_RADIOTAP_ANTENNA
:
907 * radiotap uses 0 for 1st ant, mac80211 is 1 for
910 control
->antenna_sel_tx
= (*iterator
.this_arg
) + 1;
914 case IEEE80211_RADIOTAP_DBM_TX_POWER
:
915 control
->power_level
= *iterator
.this_arg
;
919 case IEEE80211_RADIOTAP_FLAGS
:
920 if (*iterator
.this_arg
& IEEE80211_RADIOTAP_F_FCS
) {
922 * this indicates that the skb we have been
923 * handed has the 32-bit FCS CRC at the end...
924 * we should react to that by snipping it off
925 * because it will be recomputed and added
928 if (skb
->len
< (iterator
.max_length
+ FCS_LEN
))
931 skb_trim(skb
, skb
->len
- FCS_LEN
);
933 if (*iterator
.this_arg
& IEEE80211_RADIOTAP_F_WEP
)
935 ~IEEE80211_TXCTL_DO_NOT_ENCRYPT
;
936 if (*iterator
.this_arg
& IEEE80211_RADIOTAP_F_FRAG
)
937 tx
->flags
|= IEEE80211_TX_FRAGMENTED
;
941 * Please update the file
942 * Documentation/networking/mac80211-injection.txt
943 * when parsing new fields here.
951 if (ret
!= -ENOENT
) /* ie, if we didn't simply run out of fields */
955 * remove the radiotap header
956 * iterator->max_length was sanity-checked against
957 * skb->len by iterator init
959 skb_pull(skb
, iterator
.max_length
);
967 static ieee80211_tx_result
968 __ieee80211_tx_prepare(struct ieee80211_tx_data
*tx
,
970 struct net_device
*dev
,
971 struct ieee80211_tx_control
*control
)
973 struct ieee80211_local
*local
= wdev_priv(dev
->ieee80211_ptr
);
974 struct ieee80211_hdr
*hdr
;
975 struct ieee80211_sub_if_data
*sdata
;
979 memset(tx
, 0, sizeof(*tx
));
981 tx
->dev
= dev
; /* use original interface */
983 tx
->sdata
= IEEE80211_DEV_TO_SUB_IF(dev
);
984 tx
->control
= control
;
986 * Set this flag (used below to indicate "automatic fragmentation"),
987 * it will be cleared/left by radiotap as desired.
989 tx
->flags
|= IEEE80211_TX_FRAGMENTED
;
991 /* process and remove the injection radiotap header */
992 sdata
= IEEE80211_DEV_TO_SUB_IF(dev
);
993 if (unlikely(sdata
->vif
.type
== IEEE80211_IF_TYPE_MNTR
)) {
994 if (__ieee80211_parse_tx_radiotap(tx
, skb
) == TX_DROP
)
998 * __ieee80211_parse_tx_radiotap has now removed
999 * the radiotap header that was present and pre-filled
1000 * 'tx' with tx control information.
1004 hdr
= (struct ieee80211_hdr
*) skb
->data
;
1006 tx
->sta
= sta_info_get(local
, hdr
->addr1
);
1007 tx
->fc
= le16_to_cpu(hdr
->frame_control
);
1009 if (is_multicast_ether_addr(hdr
->addr1
)) {
1010 tx
->flags
&= ~IEEE80211_TX_UNICAST
;
1011 control
->flags
|= IEEE80211_TXCTL_NO_ACK
;
1013 tx
->flags
|= IEEE80211_TX_UNICAST
;
1014 control
->flags
&= ~IEEE80211_TXCTL_NO_ACK
;
1017 if (tx
->flags
& IEEE80211_TX_FRAGMENTED
) {
1018 if ((tx
->flags
& IEEE80211_TX_UNICAST
) &&
1019 skb
->len
+ FCS_LEN
> local
->fragmentation_threshold
&&
1020 !local
->ops
->set_frag_threshold
)
1021 tx
->flags
|= IEEE80211_TX_FRAGMENTED
;
1023 tx
->flags
&= ~IEEE80211_TX_FRAGMENTED
;
1027 control
->flags
|= IEEE80211_TXCTL_CLEAR_PS_FILT
;
1028 else if (tx
->sta
->flags
& WLAN_STA_CLEAR_PS_FILT
) {
1029 control
->flags
|= IEEE80211_TXCTL_CLEAR_PS_FILT
;
1030 tx
->sta
->flags
&= ~WLAN_STA_CLEAR_PS_FILT
;
1033 hdrlen
= ieee80211_get_hdrlen(tx
->fc
);
1034 if (skb
->len
> hdrlen
+ sizeof(rfc1042_header
) + 2) {
1035 u8
*pos
= &skb
->data
[hdrlen
+ sizeof(rfc1042_header
)];
1036 tx
->ethertype
= (pos
[0] << 8) | pos
[1];
1038 control
->flags
|= IEEE80211_TXCTL_FIRST_FRAGMENT
;
1044 * NB: @tx is uninitialised when passed in here
1046 static int ieee80211_tx_prepare(struct ieee80211_tx_data
*tx
,
1047 struct sk_buff
*skb
,
1048 struct net_device
*mdev
,
1049 struct ieee80211_tx_control
*control
)
1051 struct ieee80211_tx_packet_data
*pkt_data
;
1052 struct net_device
*dev
;
1054 pkt_data
= (struct ieee80211_tx_packet_data
*)skb
->cb
;
1055 dev
= dev_get_by_index(&init_net
, pkt_data
->ifindex
);
1056 if (unlikely(dev
&& !is_ieee80211_device(dev
, mdev
))) {
1062 /* initialises tx with control */
1063 __ieee80211_tx_prepare(tx
, skb
, dev
, control
);
1068 static int __ieee80211_tx(struct ieee80211_local
*local
, struct sk_buff
*skb
,
1069 struct ieee80211_tx_data
*tx
)
1071 struct ieee80211_tx_control
*control
= tx
->control
;
1074 if (!ieee80211_qdisc_installed(local
->mdev
) &&
1075 __ieee80211_queue_stopped(local
, 0)) {
1076 netif_stop_queue(local
->mdev
);
1077 return IEEE80211_TX_AGAIN
;
1080 ieee80211_dump_frame(wiphy_name(local
->hw
.wiphy
),
1081 "TX to low-level driver", skb
);
1082 ret
= local
->ops
->tx(local_to_hw(local
), skb
, control
);
1084 return IEEE80211_TX_AGAIN
;
1085 local
->mdev
->trans_start
= jiffies
;
1086 ieee80211_led_tx(local
, 1);
1088 if (tx
->extra_frag
) {
1089 control
->flags
&= ~(IEEE80211_TXCTL_USE_RTS_CTS
|
1090 IEEE80211_TXCTL_USE_CTS_PROTECT
|
1091 IEEE80211_TXCTL_CLEAR_PS_FILT
|
1092 IEEE80211_TXCTL_FIRST_FRAGMENT
);
1093 for (i
= 0; i
< tx
->num_extra_frag
; i
++) {
1094 if (!tx
->extra_frag
[i
])
1096 if (__ieee80211_queue_stopped(local
, control
->queue
))
1097 return IEEE80211_TX_FRAG_AGAIN
;
1098 if (i
== tx
->num_extra_frag
) {
1099 control
->tx_rate
= tx
->last_frag_rate
;
1101 if (tx
->flags
& IEEE80211_TX_PROBE_LAST_FRAG
)
1103 IEEE80211_TXCTL_RATE_CTRL_PROBE
;
1106 ~IEEE80211_TXCTL_RATE_CTRL_PROBE
;
1109 ieee80211_dump_frame(wiphy_name(local
->hw
.wiphy
),
1110 "TX to low-level driver",
1112 ret
= local
->ops
->tx(local_to_hw(local
),
1116 return IEEE80211_TX_FRAG_AGAIN
;
1117 local
->mdev
->trans_start
= jiffies
;
1118 ieee80211_led_tx(local
, 1);
1119 tx
->extra_frag
[i
] = NULL
;
1121 kfree(tx
->extra_frag
);
1122 tx
->extra_frag
= NULL
;
1124 return IEEE80211_TX_OK
;
1127 static int ieee80211_tx(struct net_device
*dev
, struct sk_buff
*skb
,
1128 struct ieee80211_tx_control
*control
)
1130 struct ieee80211_local
*local
= wdev_priv(dev
->ieee80211_ptr
);
1131 struct sta_info
*sta
;
1132 ieee80211_tx_handler
*handler
;
1133 struct ieee80211_tx_data tx
;
1134 ieee80211_tx_result res
= TX_DROP
, res_prepare
;
1137 WARN_ON(__ieee80211_queue_pending(local
, control
->queue
));
1139 if (unlikely(skb
->len
< 10)) {
1146 /* initialises tx */
1147 res_prepare
= __ieee80211_tx_prepare(&tx
, skb
, dev
, control
);
1149 if (res_prepare
== TX_DROP
) {
1156 tx
.channel
= local
->hw
.conf
.channel
;
1158 for (handler
= ieee80211_tx_handlers
; *handler
!= NULL
;
1160 res
= (*handler
)(&tx
);
1161 if (res
!= TX_CONTINUE
)
1165 skb
= tx
.skb
; /* handlers are allowed to change skb */
1167 if (unlikely(res
== TX_DROP
)) {
1168 I802_DEBUG_INC(local
->tx_handlers_drop
);
1172 if (unlikely(res
== TX_QUEUED
)) {
1173 I802_DEBUG_INC(local
->tx_handlers_queued
);
1178 if (tx
.extra_frag
) {
1179 for (i
= 0; i
< tx
.num_extra_frag
; i
++) {
1181 struct ieee80211_hdr
*hdr
=
1182 (struct ieee80211_hdr
*)
1183 tx
.extra_frag
[i
]->data
;
1185 if (i
+ 1 < tx
.num_extra_frag
) {
1186 next_len
= tx
.extra_frag
[i
+ 1]->len
;
1189 tx
.rate
= tx
.last_frag_rate
;
1191 dur
= ieee80211_duration(&tx
, 0, next_len
);
1192 hdr
->duration_id
= cpu_to_le16(dur
);
1197 ret
= __ieee80211_tx(local
, skb
, &tx
);
1199 struct ieee80211_tx_stored_packet
*store
=
1200 &local
->pending_packet
[control
->queue
];
1202 if (ret
== IEEE80211_TX_FRAG_AGAIN
)
1204 set_bit(IEEE80211_LINK_STATE_PENDING
,
1205 &local
->state
[control
->queue
]);
1207 /* When the driver gets out of buffers during sending of
1208 * fragments and calls ieee80211_stop_queue, there is
1209 * a small window between IEEE80211_LINK_STATE_XOFF and
1210 * IEEE80211_LINK_STATE_PENDING flags are set. If a buffer
1211 * gets available in that window (i.e. driver calls
1212 * ieee80211_wake_queue), we would end up with ieee80211_tx
1213 * called with IEEE80211_LINK_STATE_PENDING. Prevent this by
1214 * continuing transmitting here when that situation is
1215 * possible to have happened. */
1216 if (!__ieee80211_queue_stopped(local
, control
->queue
)) {
1217 clear_bit(IEEE80211_LINK_STATE_PENDING
,
1218 &local
->state
[control
->queue
]);
1221 memcpy(&store
->control
, control
,
1222 sizeof(struct ieee80211_tx_control
));
1224 store
->extra_frag
= tx
.extra_frag
;
1225 store
->num_extra_frag
= tx
.num_extra_frag
;
1226 store
->last_frag_rate
= tx
.last_frag_rate
;
1227 store
->last_frag_rate_ctrl_probe
=
1228 !!(tx
.flags
& IEEE80211_TX_PROBE_LAST_FRAG
);
1236 for (i
= 0; i
< tx
.num_extra_frag
; i
++)
1237 if (tx
.extra_frag
[i
])
1238 dev_kfree_skb(tx
.extra_frag
[i
]);
1239 kfree(tx
.extra_frag
);
1244 /* device xmit handlers */
1246 int ieee80211_master_start_xmit(struct sk_buff
*skb
,
1247 struct net_device
*dev
)
1249 struct ieee80211_tx_control control
;
1250 struct ieee80211_tx_packet_data
*pkt_data
;
1251 struct net_device
*odev
= NULL
;
1252 struct ieee80211_sub_if_data
*osdata
;
1257 * copy control out of the skb so other people can use skb->cb
1259 pkt_data
= (struct ieee80211_tx_packet_data
*)skb
->cb
;
1260 memset(&control
, 0, sizeof(struct ieee80211_tx_control
));
1262 if (pkt_data
->ifindex
)
1263 odev
= dev_get_by_index(&init_net
, pkt_data
->ifindex
);
1264 if (unlikely(odev
&& !is_ieee80211_device(odev
, dev
))) {
1268 if (unlikely(!odev
)) {
1269 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1270 printk(KERN_DEBUG
"%s: Discarded packet with nonexistent "
1271 "originating device\n", dev
->name
);
1276 osdata
= IEEE80211_DEV_TO_SUB_IF(odev
);
1278 headroom
= osdata
->local
->tx_headroom
+ IEEE80211_ENCRYPT_HEADROOM
;
1279 if (skb_headroom(skb
) < headroom
) {
1280 if (pskb_expand_head(skb
, headroom
, 0, GFP_ATOMIC
)) {
1287 control
.vif
= &osdata
->vif
;
1288 control
.type
= osdata
->vif
.type
;
1289 if (pkt_data
->flags
& IEEE80211_TXPD_REQ_TX_STATUS
)
1290 control
.flags
|= IEEE80211_TXCTL_REQ_TX_STATUS
;
1291 if (pkt_data
->flags
& IEEE80211_TXPD_DO_NOT_ENCRYPT
)
1292 control
.flags
|= IEEE80211_TXCTL_DO_NOT_ENCRYPT
;
1293 if (pkt_data
->flags
& IEEE80211_TXPD_REQUEUE
)
1294 control
.flags
|= IEEE80211_TXCTL_REQUEUE
;
1295 if (pkt_data
->flags
& IEEE80211_TXPD_EAPOL_FRAME
)
1296 control
.flags
|= IEEE80211_TXCTL_EAPOL_FRAME
;
1297 if (pkt_data
->flags
& IEEE80211_TXPD_AMPDU
)
1298 control
.flags
|= IEEE80211_TXCTL_AMPDU
;
1299 control
.queue
= pkt_data
->queue
;
1301 ret
= ieee80211_tx(odev
, skb
, &control
);
1307 int ieee80211_monitor_start_xmit(struct sk_buff
*skb
,
1308 struct net_device
*dev
)
1310 struct ieee80211_local
*local
= wdev_priv(dev
->ieee80211_ptr
);
1311 struct ieee80211_tx_packet_data
*pkt_data
;
1312 struct ieee80211_radiotap_header
*prthdr
=
1313 (struct ieee80211_radiotap_header
*)skb
->data
;
1316 /* check for not even having the fixed radiotap header part */
1317 if (unlikely(skb
->len
< sizeof(struct ieee80211_radiotap_header
)))
1318 goto fail
; /* too short to be possibly valid */
1320 /* is it a header version we can trust to find length from? */
1321 if (unlikely(prthdr
->it_version
))
1322 goto fail
; /* only version 0 is supported */
1324 /* then there must be a radiotap header with a length we can use */
1325 len_rthdr
= ieee80211_get_radiotap_len(skb
->data
);
1327 /* does the skb contain enough to deliver on the alleged length? */
1328 if (unlikely(skb
->len
< len_rthdr
))
1329 goto fail
; /* skb too short for claimed rt header extent */
1331 skb
->dev
= local
->mdev
;
1333 pkt_data
= (struct ieee80211_tx_packet_data
*)skb
->cb
;
1334 memset(pkt_data
, 0, sizeof(*pkt_data
));
1335 /* needed because we set skb device to master */
1336 pkt_data
->ifindex
= dev
->ifindex
;
1338 pkt_data
->flags
|= IEEE80211_TXPD_DO_NOT_ENCRYPT
;
1341 * fix up the pointers accounting for the radiotap
1342 * header still being in there. We are being given
1343 * a precooked IEEE80211 header so no need for
1346 skb_set_mac_header(skb
, len_rthdr
);
1348 * these are just fixed to the end of the rt area since we
1349 * don't have any better information and at this point, nobody cares
1351 skb_set_network_header(skb
, len_rthdr
);
1352 skb_set_transport_header(skb
, len_rthdr
);
1354 /* pass the radiotap header up to the next stage intact */
1355 dev_queue_xmit(skb
);
1356 return NETDEV_TX_OK
;
1360 return NETDEV_TX_OK
; /* meaning, we dealt with the skb */
1364 * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1365 * subinterfaces (wlan#, WDS, and VLAN interfaces)
1366 * @skb: packet to be sent
1367 * @dev: incoming interface
1369 * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1370 * not be freed, and caller is responsible for either retrying later or freeing
1373 * This function takes in an Ethernet header and encapsulates it with suitable
1374 * IEEE 802.11 header based on which interface the packet is coming in. The
1375 * encapsulated packet will then be passed to master interface, wlan#.11, for
1376 * transmission (through low-level driver).
1378 int ieee80211_subif_start_xmit(struct sk_buff
*skb
,
1379 struct net_device
*dev
)
1381 struct ieee80211_local
*local
= wdev_priv(dev
->ieee80211_ptr
);
1382 struct ieee80211_tx_packet_data
*pkt_data
;
1383 struct ieee80211_sub_if_data
*sdata
;
1384 int ret
= 1, head_need
;
1385 u16 ethertype
, hdrlen
, meshhdrlen
= 0, fc
;
1386 struct ieee80211_hdr hdr
;
1387 struct ieee80211s_hdr mesh_hdr
;
1388 const u8
*encaps_data
;
1389 int encaps_len
, skip_header_bytes
;
1391 struct sta_info
*sta
;
1394 sdata
= IEEE80211_DEV_TO_SUB_IF(dev
);
1395 if (unlikely(skb
->len
< ETH_HLEN
)) {
1396 printk(KERN_DEBUG
"%s: short skb (len=%d)\n",
1397 dev
->name
, skb
->len
);
1402 nh_pos
= skb_network_header(skb
) - skb
->data
;
1403 h_pos
= skb_transport_header(skb
) - skb
->data
;
1405 /* convert Ethernet header to proper 802.11 header (based on
1406 * operation mode) */
1407 ethertype
= (skb
->data
[12] << 8) | skb
->data
[13];
1408 fc
= IEEE80211_FTYPE_DATA
| IEEE80211_STYPE_DATA
;
1410 switch (sdata
->vif
.type
) {
1411 case IEEE80211_IF_TYPE_AP
:
1412 case IEEE80211_IF_TYPE_VLAN
:
1413 fc
|= IEEE80211_FCTL_FROMDS
;
1415 memcpy(hdr
.addr1
, skb
->data
, ETH_ALEN
);
1416 memcpy(hdr
.addr2
, dev
->dev_addr
, ETH_ALEN
);
1417 memcpy(hdr
.addr3
, skb
->data
+ ETH_ALEN
, ETH_ALEN
);
1420 case IEEE80211_IF_TYPE_WDS
:
1421 fc
|= IEEE80211_FCTL_FROMDS
| IEEE80211_FCTL_TODS
;
1423 memcpy(hdr
.addr1
, sdata
->u
.wds
.remote_addr
, ETH_ALEN
);
1424 memcpy(hdr
.addr2
, dev
->dev_addr
, ETH_ALEN
);
1425 memcpy(hdr
.addr3
, skb
->data
, ETH_ALEN
);
1426 memcpy(hdr
.addr4
, skb
->data
+ ETH_ALEN
, ETH_ALEN
);
1429 #ifdef CONFIG_MAC80211_MESH
1430 case IEEE80211_IF_TYPE_MESH_POINT
:
1431 fc
|= IEEE80211_FCTL_FROMDS
| IEEE80211_FCTL_TODS
;
1433 if (is_multicast_ether_addr(skb
->data
))
1434 memcpy(hdr
.addr1
, skb
->data
, ETH_ALEN
);
1435 else if (mesh_nexthop_lookup(hdr
.addr1
, skb
, dev
))
1437 memcpy(hdr
.addr2
, dev
->dev_addr
, ETH_ALEN
);
1438 memcpy(hdr
.addr3
, skb
->data
, ETH_ALEN
);
1439 memcpy(hdr
.addr4
, skb
->data
+ ETH_ALEN
, ETH_ALEN
);
1440 if (skb
->pkt_type
== PACKET_OTHERHOST
) {
1441 /* Forwarded frame, keep mesh ttl and seqnum */
1442 struct ieee80211s_hdr
*prev_meshhdr
;
1443 prev_meshhdr
= ((struct ieee80211s_hdr
*)skb
->cb
);
1444 meshhdrlen
= ieee80211_get_mesh_hdrlen(prev_meshhdr
);
1445 memcpy(&mesh_hdr
, prev_meshhdr
, meshhdrlen
);
1446 sdata
->u
.sta
.mshstats
.fwded_frames
++;
1448 if (!sdata
->u
.sta
.mshcfg
.dot11MeshTTL
) {
1449 /* Do not send frames with mesh_ttl == 0 */
1450 sdata
->u
.sta
.mshstats
.dropped_frames_ttl
++;
1454 meshhdrlen
= ieee80211_new_mesh_header(&mesh_hdr
,
1460 case IEEE80211_IF_TYPE_STA
:
1461 fc
|= IEEE80211_FCTL_TODS
;
1463 memcpy(hdr
.addr1
, sdata
->u
.sta
.bssid
, ETH_ALEN
);
1464 memcpy(hdr
.addr2
, skb
->data
+ ETH_ALEN
, ETH_ALEN
);
1465 memcpy(hdr
.addr3
, skb
->data
, ETH_ALEN
);
1468 case IEEE80211_IF_TYPE_IBSS
:
1470 memcpy(hdr
.addr1
, skb
->data
, ETH_ALEN
);
1471 memcpy(hdr
.addr2
, skb
->data
+ ETH_ALEN
, ETH_ALEN
);
1472 memcpy(hdr
.addr3
, sdata
->u
.sta
.bssid
, ETH_ALEN
);
1481 * There's no need to try to look up the destination
1482 * if it is a multicast address (which can only happen
1485 if (!is_multicast_ether_addr(hdr
.addr1
)) {
1487 sta
= sta_info_get(local
, hdr
.addr1
);
1489 sta_flags
= sta
->flags
;
1493 /* receiver is QoS enabled, use a QoS type frame */
1494 if (sta_flags
& WLAN_STA_WME
) {
1495 fc
|= IEEE80211_STYPE_QOS_DATA
;
1500 * Drop unicast frames to unauthorised stations unless they are
1501 * EAPOL frames from the local station.
1503 if (unlikely(!is_multicast_ether_addr(hdr
.addr1
) &&
1504 !(sta_flags
& WLAN_STA_AUTHORIZED
) &&
1505 !(ethertype
== ETH_P_PAE
&&
1506 compare_ether_addr(dev
->dev_addr
,
1507 skb
->data
+ ETH_ALEN
) == 0))) {
1508 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1509 DECLARE_MAC_BUF(mac
);
1511 if (net_ratelimit())
1512 printk(KERN_DEBUG
"%s: dropped frame to %s"
1513 " (unauthorized port)\n", dev
->name
,
1514 print_mac(mac
, hdr
.addr1
));
1517 I802_DEBUG_INC(local
->tx_handlers_drop_unauth_port
);
1523 hdr
.frame_control
= cpu_to_le16(fc
);
1524 hdr
.duration_id
= 0;
1527 skip_header_bytes
= ETH_HLEN
;
1528 if (ethertype
== ETH_P_AARP
|| ethertype
== ETH_P_IPX
) {
1529 encaps_data
= bridge_tunnel_header
;
1530 encaps_len
= sizeof(bridge_tunnel_header
);
1531 skip_header_bytes
-= 2;
1532 } else if (ethertype
>= 0x600) {
1533 encaps_data
= rfc1042_header
;
1534 encaps_len
= sizeof(rfc1042_header
);
1535 skip_header_bytes
-= 2;
1541 skb_pull(skb
, skip_header_bytes
);
1542 nh_pos
-= skip_header_bytes
;
1543 h_pos
-= skip_header_bytes
;
1545 /* TODO: implement support for fragments so that there is no need to
1546 * reallocate and copy payload; it might be enough to support one
1547 * extra fragment that would be copied in the beginning of the frame
1548 * data.. anyway, it would be nice to include this into skb structure
1551 * There are few options for this:
1552 * use skb->cb as an extra space for 802.11 header
1553 * allocate new buffer if not enough headroom
1554 * make sure that there is enough headroom in every skb by increasing
1555 * build in headroom in __dev_alloc_skb() (linux/skbuff.h) and
1556 * alloc_skb() (net/core/skbuff.c)
1558 head_need
= hdrlen
+ encaps_len
+ meshhdrlen
+ local
->tx_headroom
;
1559 head_need
-= skb_headroom(skb
);
1561 /* We are going to modify skb data, so make a copy of it if happens to
1562 * be cloned. This could happen, e.g., with Linux bridge code passing
1563 * us broadcast frames. */
1565 if (head_need
> 0 || skb_header_cloned(skb
)) {
1567 printk(KERN_DEBUG
"%s: need to reallocate buffer for %d bytes "
1568 "of headroom\n", dev
->name
, head_need
);
1571 if (skb_header_cloned(skb
))
1572 I802_DEBUG_INC(local
->tx_expand_skb_head_cloned
);
1574 I802_DEBUG_INC(local
->tx_expand_skb_head
);
1575 /* Since we have to reallocate the buffer, make sure that there
1576 * is enough room for possible WEP IV/ICV and TKIP (8 bytes
1577 * before payload and 12 after). */
1578 if (pskb_expand_head(skb
, (head_need
> 0 ? head_need
+ 8 : 8),
1580 printk(KERN_DEBUG
"%s: failed to reallocate TX buffer"
1587 memcpy(skb_push(skb
, encaps_len
), encaps_data
, encaps_len
);
1588 nh_pos
+= encaps_len
;
1589 h_pos
+= encaps_len
;
1592 if (meshhdrlen
> 0) {
1593 memcpy(skb_push(skb
, meshhdrlen
), &mesh_hdr
, meshhdrlen
);
1594 nh_pos
+= meshhdrlen
;
1595 h_pos
+= meshhdrlen
;
1598 if (fc
& IEEE80211_STYPE_QOS_DATA
) {
1599 __le16
*qos_control
;
1601 qos_control
= (__le16
*) skb_push(skb
, 2);
1602 memcpy(skb_push(skb
, hdrlen
- 2), &hdr
, hdrlen
- 2);
1604 * Maybe we could actually set some fields here, for now just
1605 * initialise to zero to indicate no special operation.
1609 memcpy(skb_push(skb
, hdrlen
), &hdr
, hdrlen
);
1614 pkt_data
= (struct ieee80211_tx_packet_data
*)skb
->cb
;
1615 memset(pkt_data
, 0, sizeof(struct ieee80211_tx_packet_data
));
1616 pkt_data
->ifindex
= dev
->ifindex
;
1617 if (ethertype
== ETH_P_PAE
)
1618 pkt_data
->flags
|= IEEE80211_TXPD_EAPOL_FRAME
;
1620 skb
->dev
= local
->mdev
;
1621 dev
->stats
.tx_packets
++;
1622 dev
->stats
.tx_bytes
+= skb
->len
;
1624 /* Update skb pointers to various headers since this modified frame
1625 * is going to go through Linux networking code that may potentially
1626 * need things like pointer to IP header. */
1627 skb_set_mac_header(skb
, 0);
1628 skb_set_network_header(skb
, nh_pos
);
1629 skb_set_transport_header(skb
, h_pos
);
1631 dev
->trans_start
= jiffies
;
1632 dev_queue_xmit(skb
);
1643 /* helper functions for pending packets for when queues are stopped */
1645 void ieee80211_clear_tx_pending(struct ieee80211_local
*local
)
1648 struct ieee80211_tx_stored_packet
*store
;
1650 for (i
= 0; i
< local
->hw
.queues
; i
++) {
1651 if (!__ieee80211_queue_pending(local
, i
))
1653 store
= &local
->pending_packet
[i
];
1654 kfree_skb(store
->skb
);
1655 for (j
= 0; j
< store
->num_extra_frag
; j
++)
1656 kfree_skb(store
->extra_frag
[j
]);
1657 kfree(store
->extra_frag
);
1658 clear_bit(IEEE80211_LINK_STATE_PENDING
, &local
->state
[i
]);
1662 void ieee80211_tx_pending(unsigned long data
)
1664 struct ieee80211_local
*local
= (struct ieee80211_local
*)data
;
1665 struct net_device
*dev
= local
->mdev
;
1666 struct ieee80211_tx_stored_packet
*store
;
1667 struct ieee80211_tx_data tx
;
1668 int i
, ret
, reschedule
= 0;
1670 netif_tx_lock_bh(dev
);
1671 for (i
= 0; i
< local
->hw
.queues
; i
++) {
1672 if (__ieee80211_queue_stopped(local
, i
))
1674 if (!__ieee80211_queue_pending(local
, i
)) {
1678 store
= &local
->pending_packet
[i
];
1679 tx
.control
= &store
->control
;
1680 tx
.extra_frag
= store
->extra_frag
;
1681 tx
.num_extra_frag
= store
->num_extra_frag
;
1682 tx
.last_frag_rate
= store
->last_frag_rate
;
1684 if (store
->last_frag_rate_ctrl_probe
)
1685 tx
.flags
|= IEEE80211_TX_PROBE_LAST_FRAG
;
1686 ret
= __ieee80211_tx(local
, store
->skb
, &tx
);
1688 if (ret
== IEEE80211_TX_FRAG_AGAIN
)
1691 clear_bit(IEEE80211_LINK_STATE_PENDING
,
1696 netif_tx_unlock_bh(dev
);
1698 if (!ieee80211_qdisc_installed(dev
)) {
1699 if (!__ieee80211_queue_stopped(local
, 0))
1700 netif_wake_queue(dev
);
1702 netif_schedule(dev
);
1706 /* functions for drivers to get certain frames */
1708 static void ieee80211_beacon_add_tim(struct ieee80211_local
*local
,
1709 struct ieee80211_if_ap
*bss
,
1710 struct sk_buff
*skb
,
1711 struct beacon_data
*beacon
)
1715 int i
, have_bits
= 0, n1
, n2
;
1717 /* Generate bitmap for TIM only if there are any STAs in power save
1719 if (atomic_read(&bss
->num_sta_ps
) > 0)
1720 /* in the hope that this is faster than
1721 * checking byte-for-byte */
1722 have_bits
= !bitmap_empty((unsigned long*)bss
->tim
,
1723 IEEE80211_MAX_AID
+1);
1725 if (bss
->dtim_count
== 0)
1726 bss
->dtim_count
= beacon
->dtim_period
- 1;
1730 tim
= pos
= (u8
*) skb_put(skb
, 6);
1731 *pos
++ = WLAN_EID_TIM
;
1733 *pos
++ = bss
->dtim_count
;
1734 *pos
++ = beacon
->dtim_period
;
1736 if (bss
->dtim_count
== 0 && !skb_queue_empty(&bss
->ps_bc_buf
))
1740 /* Find largest even number N1 so that bits numbered 1 through
1741 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
1742 * (N2 + 1) x 8 through 2007 are 0. */
1744 for (i
= 0; i
< IEEE80211_MAX_TIM_LEN
; i
++) {
1751 for (i
= IEEE80211_MAX_TIM_LEN
- 1; i
>= n1
; i
--) {
1758 /* Bitmap control */
1760 /* Part Virt Bitmap */
1761 memcpy(pos
, bss
->tim
+ n1
, n2
- n1
+ 1);
1763 tim
[1] = n2
- n1
+ 4;
1764 skb_put(skb
, n2
- n1
);
1766 *pos
++ = aid0
; /* Bitmap control */
1767 *pos
++ = 0; /* Part Virt Bitmap */
1771 struct sk_buff
*ieee80211_beacon_get(struct ieee80211_hw
*hw
,
1772 struct ieee80211_vif
*vif
,
1773 struct ieee80211_tx_control
*control
)
1775 struct ieee80211_local
*local
= hw_to_local(hw
);
1776 struct sk_buff
*skb
;
1777 struct net_device
*bdev
;
1778 struct ieee80211_sub_if_data
*sdata
= NULL
;
1779 struct ieee80211_if_ap
*ap
= NULL
;
1780 struct rate_selection rsel
;
1781 struct beacon_data
*beacon
;
1782 struct ieee80211_supported_band
*sband
;
1783 struct ieee80211_mgmt
*mgmt
;
1788 sband
= local
->hw
.wiphy
->bands
[local
->hw
.conf
.channel
->band
];
1792 sdata
= vif_to_sdata(vif
);
1795 if (sdata
->vif
.type
== IEEE80211_IF_TYPE_AP
) {
1797 beacon
= rcu_dereference(ap
->beacon
);
1800 * headroom, head length,
1801 * tail length and maximum TIM length
1803 skb
= dev_alloc_skb(local
->tx_headroom
+
1805 beacon
->tail_len
+ 256);
1809 skb_reserve(skb
, local
->tx_headroom
);
1810 memcpy(skb_put(skb
, beacon
->head_len
), beacon
->head
,
1813 ieee80211_include_sequence(sdata
,
1814 (struct ieee80211_hdr
*)skb
->data
);
1817 * Not very nice, but we want to allow the driver to call
1818 * ieee80211_beacon_get() as a response to the set_tim()
1819 * callback. That, however, is already invoked under the
1820 * sta_lock to guarantee consistent and race-free update
1821 * of the tim bitmap in mac80211 and the driver.
1823 if (local
->tim_in_locked_section
) {
1824 ieee80211_beacon_add_tim(local
, ap
, skb
, beacon
);
1826 unsigned long flags
;
1828 spin_lock_irqsave(&local
->sta_lock
, flags
);
1829 ieee80211_beacon_add_tim(local
, ap
, skb
, beacon
);
1830 spin_unlock_irqrestore(&local
->sta_lock
, flags
);
1834 memcpy(skb_put(skb
, beacon
->tail_len
),
1835 beacon
->tail
, beacon
->tail_len
);
1837 num_beacons
= &ap
->num_beacons
;
1841 } else if (ieee80211_vif_is_mesh(&sdata
->vif
)) {
1842 /* headroom, head length, tail length and maximum TIM length */
1843 skb
= dev_alloc_skb(local
->tx_headroom
+ 400);
1847 skb_reserve(skb
, local
->hw
.extra_tx_headroom
);
1848 mgmt
= (struct ieee80211_mgmt
*)
1849 skb_put(skb
, 24 + sizeof(mgmt
->u
.beacon
));
1850 memset(mgmt
, 0, 24 + sizeof(mgmt
->u
.beacon
));
1851 mgmt
->frame_control
= IEEE80211_FC(IEEE80211_FTYPE_MGMT
,
1852 IEEE80211_STYPE_BEACON
);
1853 memset(mgmt
->da
, 0xff, ETH_ALEN
);
1854 memcpy(mgmt
->sa
, sdata
->dev
->dev_addr
, ETH_ALEN
);
1855 /* BSSID is left zeroed, wildcard value */
1856 mgmt
->u
.beacon
.beacon_int
=
1857 cpu_to_le16(local
->hw
.conf
.beacon_int
);
1858 mgmt
->u
.beacon
.capab_info
= 0x0; /* 0x0 for MPs */
1860 pos
= skb_put(skb
, 2);
1861 *pos
++ = WLAN_EID_SSID
;
1864 mesh_mgmt_ies_add(skb
, sdata
->dev
);
1866 num_beacons
= &sdata
->u
.sta
.num_beacons
;
1872 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1873 if (net_ratelimit())
1874 printk(KERN_DEBUG
"no beacon data avail for %s\n",
1876 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
1882 rate_control_get_rate(local
->mdev
, sband
, skb
, &rsel
);
1884 if (net_ratelimit()) {
1885 printk(KERN_DEBUG
"%s: ieee80211_beacon_get: "
1887 wiphy_name(local
->hw
.wiphy
));
1895 control
->tx_rate
= rsel
.rate
;
1896 if (sdata
->bss_conf
.use_short_preamble
&&
1897 rsel
.rate
->flags
& IEEE80211_RATE_SHORT_PREAMBLE
)
1898 control
->flags
|= IEEE80211_TXCTL_SHORT_PREAMBLE
;
1899 control
->antenna_sel_tx
= local
->hw
.conf
.antenna_sel_tx
;
1900 control
->flags
|= IEEE80211_TXCTL_NO_ACK
;
1901 control
->flags
|= IEEE80211_TXCTL_DO_NOT_ENCRYPT
;
1902 control
->retry_limit
= 1;
1903 control
->flags
|= IEEE80211_TXCTL_CLEAR_PS_FILT
;
1910 EXPORT_SYMBOL(ieee80211_beacon_get
);
1912 void ieee80211_rts_get(struct ieee80211_hw
*hw
, struct ieee80211_vif
*vif
,
1913 const void *frame
, size_t frame_len
,
1914 const struct ieee80211_tx_control
*frame_txctl
,
1915 struct ieee80211_rts
*rts
)
1917 const struct ieee80211_hdr
*hdr
= frame
;
1920 fctl
= IEEE80211_FTYPE_CTL
| IEEE80211_STYPE_RTS
;
1921 rts
->frame_control
= cpu_to_le16(fctl
);
1922 rts
->duration
= ieee80211_rts_duration(hw
, vif
, frame_len
,
1924 memcpy(rts
->ra
, hdr
->addr1
, sizeof(rts
->ra
));
1925 memcpy(rts
->ta
, hdr
->addr2
, sizeof(rts
->ta
));
1927 EXPORT_SYMBOL(ieee80211_rts_get
);
1929 void ieee80211_ctstoself_get(struct ieee80211_hw
*hw
, struct ieee80211_vif
*vif
,
1930 const void *frame
, size_t frame_len
,
1931 const struct ieee80211_tx_control
*frame_txctl
,
1932 struct ieee80211_cts
*cts
)
1934 const struct ieee80211_hdr
*hdr
= frame
;
1937 fctl
= IEEE80211_FTYPE_CTL
| IEEE80211_STYPE_CTS
;
1938 cts
->frame_control
= cpu_to_le16(fctl
);
1939 cts
->duration
= ieee80211_ctstoself_duration(hw
, vif
,
1940 frame_len
, frame_txctl
);
1941 memcpy(cts
->ra
, hdr
->addr1
, sizeof(cts
->ra
));
1943 EXPORT_SYMBOL(ieee80211_ctstoself_get
);
1946 ieee80211_get_buffered_bc(struct ieee80211_hw
*hw
,
1947 struct ieee80211_vif
*vif
,
1948 struct ieee80211_tx_control
*control
)
1950 struct ieee80211_local
*local
= hw_to_local(hw
);
1951 struct sk_buff
*skb
;
1952 struct sta_info
*sta
;
1953 ieee80211_tx_handler
*handler
;
1954 struct ieee80211_tx_data tx
;
1955 ieee80211_tx_result res
= TX_DROP
;
1956 struct net_device
*bdev
;
1957 struct ieee80211_sub_if_data
*sdata
;
1958 struct ieee80211_if_ap
*bss
= NULL
;
1959 struct beacon_data
*beacon
;
1961 sdata
= vif_to_sdata(vif
);
1969 beacon
= rcu_dereference(bss
->beacon
);
1971 if (sdata
->vif
.type
!= IEEE80211_IF_TYPE_AP
|| !beacon
||
1977 if (bss
->dtim_count
!= 0)
1978 return NULL
; /* send buffered bc/mc only after DTIM beacon */
1979 memset(control
, 0, sizeof(*control
));
1981 skb
= skb_dequeue(&bss
->ps_bc_buf
);
1984 local
->total_ps_buffered
--;
1986 if (!skb_queue_empty(&bss
->ps_bc_buf
) && skb
->len
>= 2) {
1987 struct ieee80211_hdr
*hdr
=
1988 (struct ieee80211_hdr
*) skb
->data
;
1989 /* more buffered multicast/broadcast frames ==> set
1990 * MoreData flag in IEEE 802.11 header to inform PS
1992 hdr
->frame_control
|=
1993 cpu_to_le16(IEEE80211_FCTL_MOREDATA
);
1996 if (!ieee80211_tx_prepare(&tx
, skb
, local
->mdev
, control
))
1998 dev_kfree_skb_any(skb
);
2001 tx
.flags
|= IEEE80211_TX_PS_BUFFERED
;
2002 tx
.channel
= local
->hw
.conf
.channel
;
2004 for (handler
= ieee80211_tx_handlers
; *handler
!= NULL
; handler
++) {
2005 res
= (*handler
)(&tx
);
2006 if (res
== TX_DROP
|| res
== TX_QUEUED
)
2009 skb
= tx
.skb
; /* handlers are allowed to change skb */
2011 if (res
== TX_DROP
) {
2012 I802_DEBUG_INC(local
->tx_handlers_drop
);
2015 } else if (res
== TX_QUEUED
) {
2016 I802_DEBUG_INC(local
->tx_handlers_queued
);
2024 EXPORT_SYMBOL(ieee80211_get_buffered_bc
);