1 /*
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>
6 *
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.
10 *
11 *
12 * Transmit and frame generation functions.
13 */
14
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>
26
27 #include "ieee80211_i.h"
28 #include "led.h"
29 #include "mesh.h"
30 #include "wep.h"
31 #include "wpa.h"
32 #include "wme.h"
33 #include "rate.h"
34
35 #define IEEE80211_TX_OK 0
36 #define IEEE80211_TX_AGAIN 1
37 #define IEEE80211_TX_FRAG_AGAIN 2
38
39 /* misc utils */
40
ieee80211_duration(struct ieee80211_tx_data * tx,int group_addr,int next_frag_len)41 static __le16 ieee80211_duration(struct ieee80211_tx_data *tx, int group_addr,
42 int next_frag_len)
43 {
44 int rate, mrate, erp, dur, i;
45 struct ieee80211_rate *txrate;
46 struct ieee80211_local *local = tx->local;
47 struct ieee80211_supported_band *sband;
48 struct ieee80211_hdr *hdr;
49 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
50
51 /* assume HW handles this */
52 if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
53 return 0;
54
55 /* uh huh? */
56 if (WARN_ON_ONCE(info->control.rates[0].idx < 0))
57 return 0;
58
59 sband = local->hw.wiphy->bands[tx->channel->band];
60 txrate = &sband->bitrates[info->control.rates[0].idx];
61
62 erp = txrate->flags & IEEE80211_RATE_ERP_G;
63
64 /*
65 * data and mgmt (except PS Poll):
66 * - during CFP: 32768
67 * - during contention period:
68 * if addr1 is group address: 0
69 * if more fragments = 0 and addr1 is individual address: time to
70 * transmit one ACK plus SIFS
71 * if more fragments = 1 and addr1 is individual address: time to
72 * transmit next fragment plus 2 x ACK plus 3 x SIFS
73 *
74 * IEEE 802.11, 9.6:
75 * - control response frame (CTS or ACK) shall be transmitted using the
76 * same rate as the immediately previous frame in the frame exchange
77 * sequence, if this rate belongs to the PHY mandatory rates, or else
78 * at the highest possible rate belonging to the PHY rates in the
79 * BSSBasicRateSet
80 */
81 hdr = (struct ieee80211_hdr *)tx->skb->data;
82 if (ieee80211_is_ctl(hdr->frame_control)) {
83 /* TODO: These control frames are not currently sent by
84 * mac80211, but should they be implemented, this function
85 * needs to be updated to support duration field calculation.
86 *
87 * RTS: time needed to transmit pending data/mgmt frame plus
88 * one CTS frame plus one ACK frame plus 3 x SIFS
89 * CTS: duration of immediately previous RTS minus time
90 * required to transmit CTS and its SIFS
91 * ACK: 0 if immediately previous directed data/mgmt had
92 * more=0, with more=1 duration in ACK frame is duration
93 * from previous frame minus time needed to transmit ACK
94 * and its SIFS
95 * PS Poll: BIT(15) | BIT(14) | aid
96 */
97 return 0;
98 }
99
100 /* data/mgmt */
101 if (0 /* FIX: data/mgmt during CFP */)
102 return cpu_to_le16(32768);
103
104 if (group_addr) /* Group address as the destination - no ACK */
105 return 0;
106
107 /* Individual destination address:
108 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
109 * CTS and ACK frames shall be transmitted using the highest rate in
110 * basic rate set that is less than or equal to the rate of the
111 * immediately previous frame and that is using the same modulation
112 * (CCK or OFDM). If no basic rate set matches with these requirements,
113 * the highest mandatory rate of the PHY that is less than or equal to
114 * the rate of the previous frame is used.
115 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
116 */
117 rate = -1;
118 /* use lowest available if everything fails */
119 mrate = sband->bitrates[0].bitrate;
120 for (i = 0; i < sband->n_bitrates; i++) {
121 struct ieee80211_rate *r = &sband->bitrates[i];
122
123 if (r->bitrate > txrate->bitrate)
124 break;
125
126 if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
127 rate = r->bitrate;
128
129 switch (sband->band) {
130 case IEEE80211_BAND_2GHZ: {
131 u32 flag;
132 if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
133 flag = IEEE80211_RATE_MANDATORY_G;
134 else
135 flag = IEEE80211_RATE_MANDATORY_B;
136 if (r->flags & flag)
137 mrate = r->bitrate;
138 break;
139 }
140 case IEEE80211_BAND_5GHZ:
141 if (r->flags & IEEE80211_RATE_MANDATORY_A)
142 mrate = r->bitrate;
143 break;
144 case IEEE80211_NUM_BANDS:
145 WARN_ON(1);
146 break;
147 }
148 }
149 if (rate == -1) {
150 /* No matching basic rate found; use highest suitable mandatory
151 * PHY rate */
152 rate = mrate;
153 }
154
155 /* Time needed to transmit ACK
156 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
157 * to closest integer */
158
159 dur = ieee80211_frame_duration(local, 10, rate, erp,
160 tx->sdata->vif.bss_conf.use_short_preamble);
161
162 if (next_frag_len) {
163 /* Frame is fragmented: duration increases with time needed to
164 * transmit next fragment plus ACK and 2 x SIFS. */
165 dur *= 2; /* ACK + SIFS */
166 /* next fragment */
167 dur += ieee80211_frame_duration(local, next_frag_len,
168 txrate->bitrate, erp,
169 tx->sdata->vif.bss_conf.use_short_preamble);
170 }
171
172 return cpu_to_le16(dur);
173 }
174
is_ieee80211_device(struct ieee80211_local * local,struct net_device * dev)175 static int inline is_ieee80211_device(struct ieee80211_local *local,
176 struct net_device *dev)
177 {
178 return local == wdev_priv(dev->ieee80211_ptr);
179 }
180
181 /* tx handlers */
182
183 static ieee80211_tx_result debug_noinline
ieee80211_tx_h_check_assoc(struct ieee80211_tx_data * tx)184 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
185 {
186
187 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
188 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
189 u32 sta_flags;
190
191 if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
192 return TX_CONTINUE;
193
194 if (unlikely(tx->local->sw_scanning) &&
195 !ieee80211_is_probe_req(hdr->frame_control))
196 return TX_DROP;
197
198 if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
199 return TX_CONTINUE;
200
201 if (tx->flags & IEEE80211_TX_PS_BUFFERED)
202 return TX_CONTINUE;
203
204 sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
205
206 if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
207 if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
208 tx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
209 ieee80211_is_data(hdr->frame_control))) {
210 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
211 printk(KERN_DEBUG "%s: dropped data frame to not "
212 "associated station %pM\n",
213 tx->dev->name, hdr->addr1);
214 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
215 I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
216 return TX_DROP;
217 }
218 } else {
219 if (unlikely(ieee80211_is_data(hdr->frame_control) &&
220 tx->local->num_sta == 0 &&
221 tx->sdata->vif.type != NL80211_IFTYPE_ADHOC)) {
222 /*
223 * No associated STAs - no need to send multicast
224 * frames.
225 */
226 return TX_DROP;
227 }
228 return TX_CONTINUE;
229 }
230
231 return TX_CONTINUE;
232 }
233
234 /* This function is called whenever the AP is about to exceed the maximum limit
235 * of buffered frames for power saving STAs. This situation should not really
236 * happen often during normal operation, so dropping the oldest buffered packet
237 * from each queue should be OK to make some room for new frames. */
purge_old_ps_buffers(struct ieee80211_local * local)238 static void purge_old_ps_buffers(struct ieee80211_local *local)
239 {
240 int total = 0, purged = 0;
241 struct sk_buff *skb;
242 struct ieee80211_sub_if_data *sdata;
243 struct sta_info *sta;
244
245 /*
246 * virtual interfaces are protected by RCU
247 */
248 rcu_read_lock();
249
250 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
251 struct ieee80211_if_ap *ap;
252 if (sdata->vif.type != NL80211_IFTYPE_AP)
253 continue;
254 ap = &sdata->u.ap;
255 skb = skb_dequeue(&ap->ps_bc_buf);
256 if (skb) {
257 purged++;
258 dev_kfree_skb(skb);
259 }
260 total += skb_queue_len(&ap->ps_bc_buf);
261 }
262
263 list_for_each_entry_rcu(sta, &local->sta_list, list) {
264 skb = skb_dequeue(&sta->ps_tx_buf);
265 if (skb) {
266 purged++;
267 dev_kfree_skb(skb);
268 }
269 total += skb_queue_len(&sta->ps_tx_buf);
270 }
271
272 rcu_read_unlock();
273
274 local->total_ps_buffered = total;
275 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
276 printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n",
277 wiphy_name(local->hw.wiphy), purged);
278 #endif
279 }
280
281 static ieee80211_tx_result
ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data * tx)282 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
283 {
284 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
285 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
286
287 /*
288 * broadcast/multicast frame
289 *
290 * If any of the associated stations is in power save mode,
291 * the frame is buffered to be sent after DTIM beacon frame.
292 * This is done either by the hardware or us.
293 */
294
295 /* powersaving STAs only in AP/VLAN mode */
296 if (!tx->sdata->bss)
297 return TX_CONTINUE;
298
299 /* no buffering for ordered frames */
300 if (ieee80211_has_order(hdr->frame_control))
301 return TX_CONTINUE;
302
303 /* no stations in PS mode */
304 if (!atomic_read(&tx->sdata->bss->num_sta_ps))
305 return TX_CONTINUE;
306
307 /* buffered in mac80211 */
308 if (tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING) {
309 if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
310 purge_old_ps_buffers(tx->local);
311 if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >=
312 AP_MAX_BC_BUFFER) {
313 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
314 if (net_ratelimit()) {
315 printk(KERN_DEBUG "%s: BC TX buffer full - "
316 "dropping the oldest frame\n",
317 tx->dev->name);
318 }
319 #endif
320 dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
321 } else
322 tx->local->total_ps_buffered++;
323 skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
324 return TX_QUEUED;
325 }
326
327 /* buffered in hardware */
328 info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
329
330 return TX_CONTINUE;
331 }
332
333 static ieee80211_tx_result
ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data * tx)334 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
335 {
336 struct sta_info *sta = tx->sta;
337 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
338 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
339 u32 staflags;
340
341 if (unlikely(!sta || ieee80211_is_probe_resp(hdr->frame_control)))
342 return TX_CONTINUE;
343
344 staflags = get_sta_flags(sta);
345
346 if (unlikely((staflags & WLAN_STA_PS) &&
347 !(staflags & WLAN_STA_PSPOLL))) {
348 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
349 printk(KERN_DEBUG "STA %pM aid %d: PS buffer (entries "
350 "before %d)\n",
351 sta->sta.addr, sta->sta.aid,
352 skb_queue_len(&sta->ps_tx_buf));
353 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
354 if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
355 purge_old_ps_buffers(tx->local);
356 if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) {
357 struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf);
358 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
359 if (net_ratelimit()) {
360 printk(KERN_DEBUG "%s: STA %pM TX "
361 "buffer full - dropping oldest frame\n",
362 tx->dev->name, sta->sta.addr);
363 }
364 #endif
365 dev_kfree_skb(old);
366 } else
367 tx->local->total_ps_buffered++;
368
369 /* Queue frame to be sent after STA sends an PS Poll frame */
370 if (skb_queue_empty(&sta->ps_tx_buf))
371 sta_info_set_tim_bit(sta);
372
373 info->control.jiffies = jiffies;
374 skb_queue_tail(&sta->ps_tx_buf, tx->skb);
375 return TX_QUEUED;
376 }
377 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
378 else if (unlikely(test_sta_flags(sta, WLAN_STA_PS))) {
379 printk(KERN_DEBUG "%s: STA %pM in PS mode, but pspoll "
380 "set -> send frame\n", tx->dev->name,
381 sta->sta.addr);
382 }
383 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
384 clear_sta_flags(sta, WLAN_STA_PSPOLL);
385
386 return TX_CONTINUE;
387 }
388
389 static ieee80211_tx_result debug_noinline
ieee80211_tx_h_ps_buf(struct ieee80211_tx_data * tx)390 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
391 {
392 if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
393 return TX_CONTINUE;
394
395 if (tx->flags & IEEE80211_TX_UNICAST)
396 return ieee80211_tx_h_unicast_ps_buf(tx);
397 else
398 return ieee80211_tx_h_multicast_ps_buf(tx);
399 }
400
401 static ieee80211_tx_result debug_noinline
ieee80211_tx_h_select_key(struct ieee80211_tx_data * tx)402 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
403 {
404 struct ieee80211_key *key;
405 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
406 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
407
408 if (unlikely(tx->skb->do_not_encrypt))
409 tx->key = NULL;
410 else if (tx->sta && (key = rcu_dereference(tx->sta->key)))
411 tx->key = key;
412 else if ((key = rcu_dereference(tx->sdata->default_key)))
413 tx->key = key;
414 else if (tx->sdata->drop_unencrypted &&
415 (tx->skb->protocol != cpu_to_be16(ETH_P_PAE)) &&
416 !(info->flags & IEEE80211_TX_CTL_INJECTED)) {
417 I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
418 return TX_DROP;
419 } else
420 tx->key = NULL;
421
422 if (tx->key) {
423 tx->key->tx_rx_count++;
424 /* TODO: add threshold stuff again */
425
426 switch (tx->key->conf.alg) {
427 case ALG_WEP:
428 if (ieee80211_is_auth(hdr->frame_control))
429 break;
430 case ALG_TKIP:
431 case ALG_CCMP:
432 if (!ieee80211_is_data_present(hdr->frame_control))
433 tx->key = NULL;
434 break;
435 }
436 }
437
438 if (!tx->key || !(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
439 tx->skb->do_not_encrypt = 1;
440
441 return TX_CONTINUE;
442 }
443
444 static ieee80211_tx_result debug_noinline
ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data * tx)445 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
446 {
447 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
448 struct ieee80211_hdr *hdr = (void *)tx->skb->data;
449 struct ieee80211_supported_band *sband;
450 struct ieee80211_rate *rate;
451 int i, len;
452 bool inval = false, rts = false, short_preamble = false;
453 struct ieee80211_tx_rate_control txrc;
454
455 memset(&txrc, 0, sizeof(txrc));
456
457 sband = tx->local->hw.wiphy->bands[tx->channel->band];
458
459 len = min_t(int, tx->skb->len + FCS_LEN,
460 tx->local->fragmentation_threshold);
461
462 /* set up the tx rate control struct we give the RC algo */
463 txrc.hw = local_to_hw(tx->local);
464 txrc.sband = sband;
465 txrc.bss_conf = &tx->sdata->vif.bss_conf;
466 txrc.skb = tx->skb;
467 txrc.reported_rate.idx = -1;
468 txrc.max_rate_idx = tx->sdata->max_ratectrl_rateidx;
469
470 /* set up RTS protection if desired */
471 if (tx->local->rts_threshold < IEEE80211_MAX_RTS_THRESHOLD &&
472 len > tx->local->rts_threshold) {
473 txrc.rts = rts = true;
474 }
475
476 /*
477 * Use short preamble if the BSS can handle it, but not for
478 * management frames unless we know the receiver can handle
479 * that -- the management frame might be to a station that
480 * just wants a probe response.
481 */
482 if (tx->sdata->vif.bss_conf.use_short_preamble &&
483 (ieee80211_is_data(hdr->frame_control) ||
484 (tx->sta && test_sta_flags(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
485 txrc.short_preamble = short_preamble = true;
486
487
488 rate_control_get_rate(tx->sdata, tx->sta, &txrc);
489
490 if (unlikely(info->control.rates[0].idx < 0))
491 return TX_DROP;
492
493 if (txrc.reported_rate.idx < 0)
494 txrc.reported_rate = info->control.rates[0];
495
496 if (tx->sta)
497 tx->sta->last_tx_rate = txrc.reported_rate;
498
499 if (unlikely(!info->control.rates[0].count))
500 info->control.rates[0].count = 1;
501
502 if (is_multicast_ether_addr(hdr->addr1)) {
503 /*
504 * XXX: verify the rate is in the basic rateset
505 */
506 return TX_CONTINUE;
507 }
508
509 /*
510 * set up the RTS/CTS rate as the fastest basic rate
511 * that is not faster than the data rate
512 *
513 * XXX: Should this check all retry rates?
514 */
515 if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
516 s8 baserate = 0;
517
518 rate = &sband->bitrates[info->control.rates[0].idx];
519
520 for (i = 0; i < sband->n_bitrates; i++) {
521 /* must be a basic rate */
522 if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i)))
523 continue;
524 /* must not be faster than the data rate */
525 if (sband->bitrates[i].bitrate > rate->bitrate)
526 continue;
527 /* maximum */
528 if (sband->bitrates[baserate].bitrate <
529 sband->bitrates[i].bitrate)
530 baserate = i;
531 }
532
533 info->control.rts_cts_rate_idx = baserate;
534 }
535
536 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
537 /*
538 * make sure there's no valid rate following
539 * an invalid one, just in case drivers don't
540 * take the API seriously to stop at -1.
541 */
542 if (inval) {
543 info->control.rates[i].idx = -1;
544 continue;
545 }
546 if (info->control.rates[i].idx < 0) {
547 inval = true;
548 continue;
549 }
550
551 /*
552 * For now assume MCS is already set up correctly, this
553 * needs to be fixed.
554 */
555 if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
556 WARN_ON(info->control.rates[i].idx > 76);
557 continue;
558 }
559
560 /* set up RTS protection if desired */
561 if (rts)
562 info->control.rates[i].flags |=
563 IEEE80211_TX_RC_USE_RTS_CTS;
564
565 /* RC is busted */
566 if (WARN_ON_ONCE(info->control.rates[i].idx >=
567 sband->n_bitrates)) {
568 info->control.rates[i].idx = -1;
569 continue;
570 }
571
572 rate = &sband->bitrates[info->control.rates[i].idx];
573
574 /* set up short preamble */
575 if (short_preamble &&
576 rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
577 info->control.rates[i].flags |=
578 IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
579
580 /* set up G protection */
581 if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
582 rate->flags & IEEE80211_RATE_ERP_G)
583 info->control.rates[i].flags |=
584 IEEE80211_TX_RC_USE_CTS_PROTECT;
585 }
586
587 return TX_CONTINUE;
588 }
589
590 static ieee80211_tx_result debug_noinline
ieee80211_tx_h_misc(struct ieee80211_tx_data * tx)591 ieee80211_tx_h_misc(struct ieee80211_tx_data *tx)
592 {
593 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
594
595 if (tx->sta)
596 info->control.sta = &tx->sta->sta;
597
598 return TX_CONTINUE;
599 }
600
601 static ieee80211_tx_result debug_noinline
ieee80211_tx_h_sequence(struct ieee80211_tx_data * tx)602 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
603 {
604 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
605 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
606 u16 *seq;
607 u8 *qc;
608 int tid;
609
610 /*
611 * Packet injection may want to control the sequence
612 * number, if we have no matching interface then we
613 * neither assign one ourselves nor ask the driver to.
614 */
615 if (unlikely(!info->control.vif))
616 return TX_CONTINUE;
617
618 if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
619 return TX_CONTINUE;
620
621 if (ieee80211_hdrlen(hdr->frame_control) < 24)
622 return TX_CONTINUE;
623
624 /*
625 * Anything but QoS data that has a sequence number field
626 * (is long enough) gets a sequence number from the global
627 * counter.
628 */
629 if (!ieee80211_is_data_qos(hdr->frame_control)) {
630 /* driver should assign sequence number */
631 info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
632 /* for pure STA mode without beacons, we can do it */
633 hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
634 tx->sdata->sequence_number += 0x10;
635 tx->sdata->sequence_number &= IEEE80211_SCTL_SEQ;
636 return TX_CONTINUE;
637 }
638
639 /*
640 * This should be true for injected/management frames only, for
641 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
642 * above since they are not QoS-data frames.
643 */
644 if (!tx->sta)
645 return TX_CONTINUE;
646
647 /* include per-STA, per-TID sequence counter */
648
649 qc = ieee80211_get_qos_ctl(hdr);
650 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
651 seq = &tx->sta->tid_seq[tid];
652
653 hdr->seq_ctrl = cpu_to_le16(*seq);
654
655 /* Increase the sequence number. */
656 *seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
657
658 return TX_CONTINUE;
659 }
660
661 static ieee80211_tx_result debug_noinline
ieee80211_tx_h_fragment(struct ieee80211_tx_data * tx)662 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
663 {
664 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
665 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
666 size_t hdrlen, per_fragm, num_fragm, payload_len, left;
667 struct sk_buff **frags, *first, *frag;
668 int i;
669 u16 seq;
670 u8 *pos;
671 int frag_threshold = tx->local->fragmentation_threshold;
672
673 if (!(tx->flags & IEEE80211_TX_FRAGMENTED))
674 return TX_CONTINUE;
675
676 /*
677 * Warn when submitting a fragmented A-MPDU frame and drop it.
678 * This scenario is handled in __ieee80211_tx_prepare but extra
679 * caution taken here as fragmented ampdu may cause Tx stop.
680 */
681 if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
682 return TX_DROP;
683
684 first = tx->skb;
685
686 hdrlen = ieee80211_hdrlen(hdr->frame_control);
687 payload_len = first->len - hdrlen;
688 per_fragm = frag_threshold - hdrlen - FCS_LEN;
689 num_fragm = DIV_ROUND_UP(payload_len, per_fragm);
690
691 frags = kzalloc(num_fragm * sizeof(struct sk_buff *), GFP_ATOMIC);
692 if (!frags)
693 goto fail;
694
695 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
696 seq = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_SEQ;
697 pos = first->data + hdrlen + per_fragm;
698 left = payload_len - per_fragm;
699 for (i = 0; i < num_fragm - 1; i++) {
700 struct ieee80211_hdr *fhdr;
701 size_t copylen;
702
703 if (left <= 0)
704 goto fail;
705
706 /* reserve enough extra head and tail room for possible
707 * encryption */
708 frag = frags[i] =
709 dev_alloc_skb(tx->local->tx_headroom +
710 frag_threshold +
711 IEEE80211_ENCRYPT_HEADROOM +
712 IEEE80211_ENCRYPT_TAILROOM);
713 if (!frag)
714 goto fail;
715
716 /* Make sure that all fragments use the same priority so
717 * that they end up using the same TX queue */
718 frag->priority = first->priority;
719
720 skb_reserve(frag, tx->local->tx_headroom +
721 IEEE80211_ENCRYPT_HEADROOM);
722
723 /* copy TX information */
724 info = IEEE80211_SKB_CB(frag);
725 memcpy(info, first->cb, sizeof(frag->cb));
726
727 /* copy/fill in 802.11 header */
728 fhdr = (struct ieee80211_hdr *) skb_put(frag, hdrlen);
729 memcpy(fhdr, first->data, hdrlen);
730 fhdr->seq_ctrl = cpu_to_le16(seq | ((i + 1) & IEEE80211_SCTL_FRAG));
731
732 if (i == num_fragm - 2) {
733 /* clear MOREFRAGS bit for the last fragment */
734 fhdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREFRAGS);
735 } else {
736 /*
737 * No multi-rate retries for fragmented frames, that
738 * would completely throw off the NAV at other STAs.
739 */
740 info->control.rates[1].idx = -1;
741 info->control.rates[2].idx = -1;
742 info->control.rates[3].idx = -1;
743 info->control.rates[4].idx = -1;
744 BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
745 info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
746 }
747
748 /* copy data */
749 copylen = left > per_fragm ? per_fragm : left;
750 memcpy(skb_put(frag, copylen), pos, copylen);
751
752 skb_copy_queue_mapping(frag, first);
753
754 frag->do_not_encrypt = first->do_not_encrypt;
755 frag->dev = first->dev;
756 frag->iif = first->iif;
757
758 pos += copylen;
759 left -= copylen;
760 }
761 skb_trim(first, hdrlen + per_fragm);
762
763 tx->num_extra_frag = num_fragm - 1;
764 tx->extra_frag = frags;
765
766 return TX_CONTINUE;
767
768 fail:
769 if (frags) {
770 for (i = 0; i < num_fragm - 1; i++)
771 if (frags[i])
772 dev_kfree_skb(frags[i]);
773 kfree(frags);
774 }
775 I802_DEBUG_INC(tx->local->tx_handlers_drop_fragment);
776 return TX_DROP;
777 }
778
779 static ieee80211_tx_result debug_noinline
ieee80211_tx_h_encrypt(struct ieee80211_tx_data * tx)780 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
781 {
782 if (!tx->key)
783 return TX_CONTINUE;
784
785 switch (tx->key->conf.alg) {
786 case ALG_WEP:
787 return ieee80211_crypto_wep_encrypt(tx);
788 case ALG_TKIP:
789 return ieee80211_crypto_tkip_encrypt(tx);
790 case ALG_CCMP:
791 return ieee80211_crypto_ccmp_encrypt(tx);
792 }
793
794 /* not reached */
795 WARN_ON(1);
796 return TX_DROP;
797 }
798
799 static ieee80211_tx_result debug_noinline
ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data * tx)800 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
801 {
802 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
803 int next_len, i;
804 int group_addr = is_multicast_ether_addr(hdr->addr1);
805
806 if (!(tx->flags & IEEE80211_TX_FRAGMENTED)) {
807 hdr->duration_id = ieee80211_duration(tx, group_addr, 0);
808 return TX_CONTINUE;
809 }
810
811 hdr->duration_id = ieee80211_duration(tx, group_addr,
812 tx->extra_frag[0]->len);
813
814 for (i = 0; i < tx->num_extra_frag; i++) {
815 if (i + 1 < tx->num_extra_frag)
816 next_len = tx->extra_frag[i + 1]->len;
817 else
818 next_len = 0;
819
820 hdr = (struct ieee80211_hdr *)tx->extra_frag[i]->data;
821 hdr->duration_id = ieee80211_duration(tx, 0, next_len);
822 }
823
824 return TX_CONTINUE;
825 }
826
827 static ieee80211_tx_result debug_noinline
ieee80211_tx_h_stats(struct ieee80211_tx_data * tx)828 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
829 {
830 int i;
831
832 if (!tx->sta)
833 return TX_CONTINUE;
834
835 tx->sta->tx_packets++;
836 tx->sta->tx_fragments++;
837 tx->sta->tx_bytes += tx->skb->len;
838 if (tx->extra_frag) {
839 tx->sta->tx_fragments += tx->num_extra_frag;
840 for (i = 0; i < tx->num_extra_frag; i++)
841 tx->sta->tx_bytes += tx->extra_frag[i]->len;
842 }
843
844 return TX_CONTINUE;
845 }
846
847
848 /* actual transmit path */
849
850 /*
851 * deal with packet injection down monitor interface
852 * with Radiotap Header -- only called for monitor mode interface
853 */
854 static ieee80211_tx_result
__ieee80211_parse_tx_radiotap(struct ieee80211_tx_data * tx,struct sk_buff * skb)855 __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
856 struct sk_buff *skb)
857 {
858 /*
859 * this is the moment to interpret and discard the radiotap header that
860 * must be at the start of the packet injected in Monitor mode
861 *
862 * Need to take some care with endian-ness since radiotap
863 * args are little-endian
864 */
865
866 struct ieee80211_radiotap_iterator iterator;
867 struct ieee80211_radiotap_header *rthdr =
868 (struct ieee80211_radiotap_header *) skb->data;
869 struct ieee80211_supported_band *sband;
870 int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);
871
872 sband = tx->local->hw.wiphy->bands[tx->channel->band];
873
874 skb->do_not_encrypt = 1;
875 tx->flags &= ~IEEE80211_TX_FRAGMENTED;
876
877 /*
878 * for every radiotap entry that is present
879 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
880 * entries present, or -EINVAL on error)
881 */
882
883 while (!ret) {
884 ret = ieee80211_radiotap_iterator_next(&iterator);
885
886 if (ret)
887 continue;
888
889 /* see if this argument is something we can use */
890 switch (iterator.this_arg_index) {
891 /*
892 * You must take care when dereferencing iterator.this_arg
893 * for multibyte types... the pointer is not aligned. Use
894 * get_unaligned((type *)iterator.this_arg) to dereference
895 * iterator.this_arg for type "type" safely on all arches.
896 */
897 case IEEE80211_RADIOTAP_FLAGS:
898 if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
899 /*
900 * this indicates that the skb we have been
901 * handed has the 32-bit FCS CRC at the end...
902 * we should react to that by snipping it off
903 * because it will be recomputed and added
904 * on transmission
905 */
906 if (skb->len < (iterator.max_length + FCS_LEN))
907 return TX_DROP;
908
909 skb_trim(skb, skb->len - FCS_LEN);
910 }
911 if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
912 tx->skb->do_not_encrypt = 0;
913 if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
914 tx->flags |= IEEE80211_TX_FRAGMENTED;
915 break;
916
917 /*
918 * Please update the file
919 * Documentation/networking/mac80211-injection.txt
920 * when parsing new fields here.
921 */
922
923 default:
924 break;
925 }
926 }
927
928 if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
929 return TX_DROP;
930
931 /*
932 * remove the radiotap header
933 * iterator->max_length was sanity-checked against
934 * skb->len by iterator init
935 */
936 skb_pull(skb, iterator.max_length);
937
938 return TX_CONTINUE;
939 }
940
941 /*
942 * initialises @tx
943 */
944 static ieee80211_tx_result
__ieee80211_tx_prepare(struct ieee80211_tx_data * tx,struct sk_buff * skb,struct net_device * dev)945 __ieee80211_tx_prepare(struct ieee80211_tx_data *tx,
946 struct sk_buff *skb,
947 struct net_device *dev)
948 {
949 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
950 struct ieee80211_hdr *hdr;
951 struct ieee80211_sub_if_data *sdata;
952 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
953
954 int hdrlen, tid;
955 u8 *qc, *state;
956
957 memset(tx, 0, sizeof(*tx));
958 tx->skb = skb;
959 tx->dev = dev; /* use original interface */
960 tx->local = local;
961 tx->sdata = IEEE80211_DEV_TO_SUB_IF(dev);
962 tx->channel = local->hw.conf.channel;
963 /*
964 * Set this flag (used below to indicate "automatic fragmentation"),
965 * it will be cleared/left by radiotap as desired.
966 */
967 tx->flags |= IEEE80211_TX_FRAGMENTED;
968
969 /* process and remove the injection radiotap header */
970 sdata = IEEE80211_DEV_TO_SUB_IF(dev);
971 if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) {
972 if (__ieee80211_parse_tx_radiotap(tx, skb) == TX_DROP)
973 return TX_DROP;
974
975 /*
976 * __ieee80211_parse_tx_radiotap has now removed
977 * the radiotap header that was present and pre-filled
978 * 'tx' with tx control information.
979 */
980 }
981
982 hdr = (struct ieee80211_hdr *) skb->data;
983
984 tx->sta = sta_info_get(local, hdr->addr1);
985
986 if (tx->sta && ieee80211_is_data_qos(hdr->frame_control)) {
987 qc = ieee80211_get_qos_ctl(hdr);
988 tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
989
990 state = &tx->sta->ampdu_mlme.tid_state_tx[tid];
991 if (*state == HT_AGG_STATE_OPERATIONAL)
992 info->flags |= IEEE80211_TX_CTL_AMPDU;
993 }
994
995 if (is_multicast_ether_addr(hdr->addr1)) {
996 tx->flags &= ~IEEE80211_TX_UNICAST;
997 info->flags |= IEEE80211_TX_CTL_NO_ACK;
998 } else {
999 tx->flags |= IEEE80211_TX_UNICAST;
1000 info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
1001 }
1002
1003 if (tx->flags & IEEE80211_TX_FRAGMENTED) {
1004 if ((tx->flags & IEEE80211_TX_UNICAST) &&
1005 skb->len + FCS_LEN > local->fragmentation_threshold &&
1006 !(info->flags & IEEE80211_TX_CTL_AMPDU))
1007 tx->flags |= IEEE80211_TX_FRAGMENTED;
1008 else
1009 tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1010 }
1011
1012 if (!tx->sta)
1013 info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1014 else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1015 info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1016
1017 hdrlen = ieee80211_hdrlen(hdr->frame_control);
1018 if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
1019 u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
1020 tx->ethertype = (pos[0] << 8) | pos[1];
1021 }
1022 info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1023
1024 return TX_CONTINUE;
1025 }
1026
1027 /*
1028 * NB: @tx is uninitialised when passed in here
1029 */
ieee80211_tx_prepare(struct ieee80211_local * local,struct ieee80211_tx_data * tx,struct sk_buff * skb)1030 static int ieee80211_tx_prepare(struct ieee80211_local *local,
1031 struct ieee80211_tx_data *tx,
1032 struct sk_buff *skb)
1033 {
1034 struct net_device *dev;
1035
1036 dev = dev_get_by_index(&init_net, skb->iif);
1037 if (unlikely(dev && !is_ieee80211_device(local, dev))) {
1038 dev_put(dev);
1039 dev = NULL;
1040 }
1041 if (unlikely(!dev))
1042 return -ENODEV;
1043 /* initialises tx with control */
1044 __ieee80211_tx_prepare(tx, skb, dev);
1045 dev_put(dev);
1046 return 0;
1047 }
1048
__ieee80211_tx(struct ieee80211_local * local,struct sk_buff * skb,struct ieee80211_tx_data * tx)1049 static int __ieee80211_tx(struct ieee80211_local *local, struct sk_buff *skb,
1050 struct ieee80211_tx_data *tx)
1051 {
1052 struct ieee80211_tx_info *info;
1053 int ret, i;
1054
1055 if (skb) {
1056 if (netif_subqueue_stopped(local->mdev, skb))
1057 return IEEE80211_TX_AGAIN;
1058 info = IEEE80211_SKB_CB(skb);
1059
1060 ret = local->ops->tx(local_to_hw(local), skb);
1061 if (ret)
1062 return IEEE80211_TX_AGAIN;
1063 local->mdev->trans_start = jiffies;
1064 ieee80211_led_tx(local, 1);
1065 }
1066 if (tx->extra_frag) {
1067 for (i = 0; i < tx->num_extra_frag; i++) {
1068 if (!tx->extra_frag[i])
1069 continue;
1070 info = IEEE80211_SKB_CB(tx->extra_frag[i]);
1071 info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
1072 IEEE80211_TX_CTL_FIRST_FRAGMENT);
1073 if (netif_subqueue_stopped(local->mdev,
1074 tx->extra_frag[i]))
1075 return IEEE80211_TX_FRAG_AGAIN;
1076
1077 ret = local->ops->tx(local_to_hw(local),
1078 tx->extra_frag[i]);
1079 if (ret)
1080 return IEEE80211_TX_FRAG_AGAIN;
1081 local->mdev->trans_start = jiffies;
1082 ieee80211_led_tx(local, 1);
1083 tx->extra_frag[i] = NULL;
1084 }
1085 kfree(tx->extra_frag);
1086 tx->extra_frag = NULL;
1087 }
1088 return IEEE80211_TX_OK;
1089 }
1090
1091 /*
1092 * Invoke TX handlers, return 0 on success and non-zero if the
1093 * frame was dropped or queued.
1094 */
invoke_tx_handlers(struct ieee80211_tx_data * tx)1095 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1096 {
1097 struct sk_buff *skb = tx->skb;
1098 ieee80211_tx_result res = TX_DROP;
1099 int i;
1100
1101 #define CALL_TXH(txh) \
1102 res = txh(tx); \
1103 if (res != TX_CONTINUE) \
1104 goto txh_done;
1105
1106 CALL_TXH(ieee80211_tx_h_check_assoc)
1107 CALL_TXH(ieee80211_tx_h_ps_buf)
1108 CALL_TXH(ieee80211_tx_h_select_key)
1109 CALL_TXH(ieee80211_tx_h_michael_mic_add)
1110 CALL_TXH(ieee80211_tx_h_rate_ctrl)
1111 CALL_TXH(ieee80211_tx_h_misc)
1112 CALL_TXH(ieee80211_tx_h_sequence)
1113 CALL_TXH(ieee80211_tx_h_fragment)
1114 /* handlers after fragment must be aware of tx info fragmentation! */
1115 CALL_TXH(ieee80211_tx_h_encrypt)
1116 CALL_TXH(ieee80211_tx_h_calculate_duration)
1117 CALL_TXH(ieee80211_tx_h_stats)
1118 #undef CALL_TXH
1119
1120 txh_done:
1121 if (unlikely(res == TX_DROP)) {
1122 I802_DEBUG_INC(tx->local->tx_handlers_drop);
1123 dev_kfree_skb(skb);
1124 for (i = 0; i < tx->num_extra_frag; i++)
1125 if (tx->extra_frag[i])
1126 dev_kfree_skb(tx->extra_frag[i]);
1127 kfree(tx->extra_frag);
1128 return -1;
1129 } else if (unlikely(res == TX_QUEUED)) {
1130 I802_DEBUG_INC(tx->local->tx_handlers_queued);
1131 return -1;
1132 }
1133
1134 return 0;
1135 }
1136
ieee80211_tx(struct net_device * dev,struct sk_buff * skb)1137 static int ieee80211_tx(struct net_device *dev, struct sk_buff *skb)
1138 {
1139 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1140 struct sta_info *sta;
1141 struct ieee80211_tx_data tx;
1142 ieee80211_tx_result res_prepare;
1143 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1144 int ret, i;
1145 u16 queue;
1146
1147 queue = skb_get_queue_mapping(skb);
1148
1149 WARN_ON(test_bit(queue, local->queues_pending));
1150
1151 if (unlikely(skb->len < 10)) {
1152 dev_kfree_skb(skb);
1153 return 0;
1154 }
1155
1156 rcu_read_lock();
1157
1158 /* initialises tx */
1159 res_prepare = __ieee80211_tx_prepare(&tx, skb, dev);
1160
1161 if (res_prepare == TX_DROP) {
1162 dev_kfree_skb(skb);
1163 rcu_read_unlock();
1164 return 0;
1165 }
1166
1167 sta = tx.sta;
1168 tx.channel = local->hw.conf.channel;
1169 info->band = tx.channel->band;
1170
1171 if (invoke_tx_handlers(&tx))
1172 goto out;
1173
1174 retry:
1175 ret = __ieee80211_tx(local, skb, &tx);
1176 if (ret) {
1177 struct ieee80211_tx_stored_packet *store;
1178
1179 /*
1180 * Since there are no fragmented frames on A-MPDU
1181 * queues, there's no reason for a driver to reject
1182 * a frame there, warn and drop it.
1183 */
1184 if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
1185 goto drop;
1186
1187 store = &local->pending_packet[queue];
1188
1189 if (ret == IEEE80211_TX_FRAG_AGAIN)
1190 skb = NULL;
1191
1192 set_bit(queue, local->queues_pending);
1193 smp_mb();
1194 /*
1195 * When the driver gets out of buffers during sending of
1196 * fragments and calls ieee80211_stop_queue, the netif
1197 * subqueue is stopped. There is, however, a small window
1198 * in which the PENDING bit is not yet set. If a buffer
1199 * gets available in that window (i.e. driver calls
1200 * ieee80211_wake_queue), we would end up with ieee80211_tx
1201 * called with the PENDING bit still set. Prevent this by
1202 * continuing transmitting here when that situation is
1203 * possible to have happened.
1204 */
1205 if (!__netif_subqueue_stopped(local->mdev, queue)) {
1206 clear_bit(queue, local->queues_pending);
1207 goto retry;
1208 }
1209 store->skb = skb;
1210 store->extra_frag = tx.extra_frag;
1211 store->num_extra_frag = tx.num_extra_frag;
1212 }
1213 out:
1214 rcu_read_unlock();
1215 return 0;
1216
1217 drop:
1218 if (skb)
1219 dev_kfree_skb(skb);
1220 for (i = 0; i < tx.num_extra_frag; i++)
1221 if (tx.extra_frag[i])
1222 dev_kfree_skb(tx.extra_frag[i]);
1223 kfree(tx.extra_frag);
1224 rcu_read_unlock();
1225 return 0;
1226 }
1227
1228 /* device xmit handlers */
1229
ieee80211_skb_resize(struct ieee80211_local * local,struct sk_buff * skb,int head_need,bool may_encrypt)1230 static int ieee80211_skb_resize(struct ieee80211_local *local,
1231 struct sk_buff *skb,
1232 int head_need, bool may_encrypt)
1233 {
1234 int tail_need = 0;
1235
1236 /*
1237 * This could be optimised, devices that do full hardware
1238 * crypto (including TKIP MMIC) need no tailroom... But we
1239 * have no drivers for such devices currently.
1240 */
1241 if (may_encrypt) {
1242 tail_need = IEEE80211_ENCRYPT_TAILROOM;
1243 tail_need -= skb_tailroom(skb);
1244 tail_need = max_t(int, tail_need, 0);
1245 }
1246
1247 if (head_need || tail_need) {
1248 /* Sorry. Can't account for this any more */
1249 skb_orphan(skb);
1250 }
1251
1252 if (skb_header_cloned(skb))
1253 I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1254 else
1255 I802_DEBUG_INC(local->tx_expand_skb_head);
1256
1257 if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1258 printk(KERN_DEBUG "%s: failed to reallocate TX buffer\n",
1259 wiphy_name(local->hw.wiphy));
1260 return -ENOMEM;
1261 }
1262
1263 /* update truesize too */
1264 skb->truesize += head_need + tail_need;
1265
1266 return 0;
1267 }
1268
ieee80211_master_start_xmit(struct sk_buff * skb,struct net_device * dev)1269 int ieee80211_master_start_xmit(struct sk_buff *skb, struct net_device *dev)
1270 {
1271 struct ieee80211_master_priv *mpriv = netdev_priv(dev);
1272 struct ieee80211_local *local = mpriv->local;
1273 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1274 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1275 struct net_device *odev = NULL;
1276 struct ieee80211_sub_if_data *osdata;
1277 int headroom;
1278 bool may_encrypt;
1279 enum {
1280 NOT_MONITOR,
1281 FOUND_SDATA,
1282 UNKNOWN_ADDRESS,
1283 } monitor_iface = NOT_MONITOR;
1284 int ret;
1285
1286 if (skb->iif)
1287 odev = dev_get_by_index(&init_net, skb->iif);
1288 if (unlikely(odev && !is_ieee80211_device(local, odev))) {
1289 dev_put(odev);
1290 odev = NULL;
1291 }
1292 if (unlikely(!odev)) {
1293 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1294 printk(KERN_DEBUG "%s: Discarded packet with nonexistent "
1295 "originating device\n", dev->name);
1296 #endif
1297 dev_kfree_skb(skb);
1298 return 0;
1299 }
1300
1301 memset(info, 0, sizeof(*info));
1302
1303 info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
1304
1305 osdata = IEEE80211_DEV_TO_SUB_IF(odev);
1306
1307 if (ieee80211_vif_is_mesh(&osdata->vif) &&
1308 ieee80211_is_data(hdr->frame_control)) {
1309 if (is_multicast_ether_addr(hdr->addr3))
1310 memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
1311 else
1312 if (mesh_nexthop_lookup(skb, osdata)) {
1313 dev_put(odev);
1314 return 0;
1315 }
1316 if (memcmp(odev->dev_addr, hdr->addr4, ETH_ALEN) != 0)
1317 IEEE80211_IFSTA_MESH_CTR_INC(&osdata->u.mesh,
1318 fwded_frames);
1319 } else if (unlikely(osdata->vif.type == NL80211_IFTYPE_MONITOR)) {
1320 struct ieee80211_sub_if_data *sdata;
1321 int hdrlen;
1322 u16 len_rthdr;
1323
1324 info->flags |= IEEE80211_TX_CTL_INJECTED;
1325 monitor_iface = UNKNOWN_ADDRESS;
1326
1327 len_rthdr = ieee80211_get_radiotap_len(skb->data);
1328 hdr = (struct ieee80211_hdr *)skb->data + len_rthdr;
1329 hdrlen = ieee80211_hdrlen(hdr->frame_control);
1330
1331 /* check the header is complete in the frame */
1332 if (likely(skb->len >= len_rthdr + hdrlen)) {
1333 /*
1334 * We process outgoing injected frames that have a
1335 * local address we handle as though they are our
1336 * own frames.
1337 * This code here isn't entirely correct, the local
1338 * MAC address is not necessarily enough to find
1339 * the interface to use; for that proper VLAN/WDS
1340 * support we will need a different mechanism.
1341 */
1342
1343 rcu_read_lock();
1344 list_for_each_entry_rcu(sdata, &local->interfaces,
1345 list) {
1346 if (!netif_running(sdata->dev))
1347 continue;
1348 if (sdata->vif.type != NL80211_IFTYPE_AP)
1349 continue;
1350 if (compare_ether_addr(sdata->dev->dev_addr,
1351 hdr->addr2)) {
1352 dev_hold(sdata->dev);
1353 dev_put(odev);
1354 osdata = sdata;
1355 odev = osdata->dev;
1356 skb->iif = sdata->dev->ifindex;
1357 monitor_iface = FOUND_SDATA;
1358 break;
1359 }
1360 }
1361 rcu_read_unlock();
1362 }
1363 }
1364
1365 may_encrypt = !skb->do_not_encrypt;
1366
1367 headroom = osdata->local->tx_headroom;
1368 if (may_encrypt)
1369 headroom += IEEE80211_ENCRYPT_HEADROOM;
1370 headroom -= skb_headroom(skb);
1371 headroom = max_t(int, 0, headroom);
1372
1373 if (ieee80211_skb_resize(osdata->local, skb, headroom, may_encrypt)) {
1374 dev_kfree_skb(skb);
1375 dev_put(odev);
1376 return 0;
1377 }
1378
1379 if (osdata->vif.type == NL80211_IFTYPE_AP_VLAN)
1380 osdata = container_of(osdata->bss,
1381 struct ieee80211_sub_if_data,
1382 u.ap);
1383 if (likely(monitor_iface != UNKNOWN_ADDRESS))
1384 info->control.vif = &osdata->vif;
1385 ret = ieee80211_tx(odev, skb);
1386 dev_put(odev);
1387
1388 return ret;
1389 }
1390
ieee80211_monitor_start_xmit(struct sk_buff * skb,struct net_device * dev)1391 int ieee80211_monitor_start_xmit(struct sk_buff *skb,
1392 struct net_device *dev)
1393 {
1394 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1395 struct ieee80211_radiotap_header *prthdr =
1396 (struct ieee80211_radiotap_header *)skb->data;
1397 u16 len_rthdr;
1398
1399 /* check for not even having the fixed radiotap header part */
1400 if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
1401 goto fail; /* too short to be possibly valid */
1402
1403 /* is it a header version we can trust to find length from? */
1404 if (unlikely(prthdr->it_version))
1405 goto fail; /* only version 0 is supported */
1406
1407 /* then there must be a radiotap header with a length we can use */
1408 len_rthdr = ieee80211_get_radiotap_len(skb->data);
1409
1410 /* does the skb contain enough to deliver on the alleged length? */
1411 if (unlikely(skb->len < len_rthdr))
1412 goto fail; /* skb too short for claimed rt header extent */
1413
1414 skb->dev = local->mdev;
1415
1416 /* needed because we set skb device to master */
1417 skb->iif = dev->ifindex;
1418
1419 /* sometimes we do encrypt injected frames, will be fixed
1420 * up in radiotap parser if not wanted */
1421 skb->do_not_encrypt = 0;
1422
1423 /*
1424 * fix up the pointers accounting for the radiotap
1425 * header still being in there. We are being given
1426 * a precooked IEEE80211 header so no need for
1427 * normal processing
1428 */
1429 skb_set_mac_header(skb, len_rthdr);
1430 /*
1431 * these are just fixed to the end of the rt area since we
1432 * don't have any better information and at this point, nobody cares
1433 */
1434 skb_set_network_header(skb, len_rthdr);
1435 skb_set_transport_header(skb, len_rthdr);
1436
1437 /* pass the radiotap header up to the next stage intact */
1438 dev_queue_xmit(skb);
1439 return NETDEV_TX_OK;
1440
1441 fail:
1442 dev_kfree_skb(skb);
1443 return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1444 }
1445
1446 /**
1447 * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1448 * subinterfaces (wlan#, WDS, and VLAN interfaces)
1449 * @skb: packet to be sent
1450 * @dev: incoming interface
1451 *
1452 * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1453 * not be freed, and caller is responsible for either retrying later or freeing
1454 * skb).
1455 *
1456 * This function takes in an Ethernet header and encapsulates it with suitable
1457 * IEEE 802.11 header based on which interface the packet is coming in. The
1458 * encapsulated packet will then be passed to master interface, wlan#.11, for
1459 * transmission (through low-level driver).
1460 */
ieee80211_subif_start_xmit(struct sk_buff * skb,struct net_device * dev)1461 int ieee80211_subif_start_xmit(struct sk_buff *skb,
1462 struct net_device *dev)
1463 {
1464 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1465 struct ieee80211_local *local = sdata->local;
1466 int ret = 1, head_need;
1467 u16 ethertype, hdrlen, meshhdrlen = 0;
1468 __le16 fc;
1469 struct ieee80211_hdr hdr;
1470 struct ieee80211s_hdr mesh_hdr;
1471 const u8 *encaps_data;
1472 int encaps_len, skip_header_bytes;
1473 int nh_pos, h_pos;
1474 struct sta_info *sta;
1475 u32 sta_flags = 0;
1476
1477 if (unlikely(skb->len < ETH_HLEN)) {
1478 ret = 0;
1479 goto fail;
1480 }
1481
1482 if (!(local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS) &&
1483 local->dynamic_ps_timeout > 0) {
1484 if (local->hw.conf.flags & IEEE80211_CONF_PS) {
1485 ieee80211_stop_queues_by_reason(&local->hw,
1486 IEEE80211_QUEUE_STOP_REASON_PS);
1487 queue_work(local->hw.workqueue,
1488 &local->dynamic_ps_disable_work);
1489 }
1490
1491 mod_timer(&local->dynamic_ps_timer, jiffies +
1492 msecs_to_jiffies(local->dynamic_ps_timeout));
1493 }
1494
1495 nh_pos = skb_network_header(skb) - skb->data;
1496 h_pos = skb_transport_header(skb) - skb->data;
1497
1498 /* convert Ethernet header to proper 802.11 header (based on
1499 * operation mode) */
1500 ethertype = (skb->data[12] << 8) | skb->data[13];
1501 fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1502
1503 switch (sdata->vif.type) {
1504 case NL80211_IFTYPE_AP:
1505 case NL80211_IFTYPE_AP_VLAN:
1506 fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1507 /* DA BSSID SA */
1508 memcpy(hdr.addr1, skb->data, ETH_ALEN);
1509 memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
1510 memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1511 hdrlen = 24;
1512 break;
1513 case NL80211_IFTYPE_WDS:
1514 fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1515 /* RA TA DA SA */
1516 memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1517 memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
1518 memcpy(hdr.addr3, skb->data, ETH_ALEN);
1519 memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1520 hdrlen = 30;
1521 break;
1522 #ifdef CONFIG_MAC80211_MESH
1523 case NL80211_IFTYPE_MESH_POINT:
1524 fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1525 if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1526 /* Do not send frames with mesh_ttl == 0 */
1527 sdata->u.mesh.mshstats.dropped_frames_ttl++;
1528 ret = 0;
1529 goto fail;
1530 }
1531 memset(&mesh_hdr, 0, sizeof(mesh_hdr));
1532
1533 if (compare_ether_addr(dev->dev_addr,
1534 skb->data + ETH_ALEN) == 0) {
1535 /* RA TA DA SA */
1536 memset(hdr.addr1, 0, ETH_ALEN);
1537 memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
1538 memcpy(hdr.addr3, skb->data, ETH_ALEN);
1539 memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1540 meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr, sdata);
1541 } else {
1542 /* packet from other interface */
1543 struct mesh_path *mppath;
1544
1545 memset(hdr.addr1, 0, ETH_ALEN);
1546 memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
1547 memcpy(hdr.addr4, dev->dev_addr, ETH_ALEN);
1548
1549 if (is_multicast_ether_addr(skb->data))
1550 memcpy(hdr.addr3, skb->data, ETH_ALEN);
1551 else {
1552 rcu_read_lock();
1553 mppath = mpp_path_lookup(skb->data, sdata);
1554 if (mppath)
1555 memcpy(hdr.addr3, mppath->mpp, ETH_ALEN);
1556 else
1557 memset(hdr.addr3, 0xff, ETH_ALEN);
1558 rcu_read_unlock();
1559 }
1560
1561 mesh_hdr.flags |= MESH_FLAGS_AE_A5_A6;
1562 mesh_hdr.ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
1563 put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &mesh_hdr.seqnum);
1564 memcpy(mesh_hdr.eaddr1, skb->data, ETH_ALEN);
1565 memcpy(mesh_hdr.eaddr2, skb->data + ETH_ALEN, ETH_ALEN);
1566 sdata->u.mesh.mesh_seqnum++;
1567 meshhdrlen = 18;
1568 }
1569 hdrlen = 30;
1570 break;
1571 #endif
1572 case NL80211_IFTYPE_STATION:
1573 fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1574 /* BSSID SA DA */
1575 memcpy(hdr.addr1, sdata->u.sta.bssid, ETH_ALEN);
1576 memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1577 memcpy(hdr.addr3, skb->data, ETH_ALEN);
1578 hdrlen = 24;
1579 break;
1580 case NL80211_IFTYPE_ADHOC:
1581 /* DA SA BSSID */
1582 memcpy(hdr.addr1, skb->data, ETH_ALEN);
1583 memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1584 memcpy(hdr.addr3, sdata->u.sta.bssid, ETH_ALEN);
1585 hdrlen = 24;
1586 break;
1587 default:
1588 ret = 0;
1589 goto fail;
1590 }
1591
1592 /*
1593 * There's no need to try to look up the destination
1594 * if it is a multicast address (which can only happen
1595 * in AP mode)
1596 */
1597 if (!is_multicast_ether_addr(hdr.addr1)) {
1598 rcu_read_lock();
1599 sta = sta_info_get(local, hdr.addr1);
1600 if (sta)
1601 sta_flags = get_sta_flags(sta);
1602 rcu_read_unlock();
1603 }
1604
1605 /* receiver and we are QoS enabled, use a QoS type frame */
1606 if (sta_flags & WLAN_STA_WME &&
1607 ieee80211_num_regular_queues(&local->hw) >= 4) {
1608 fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1609 hdrlen += 2;
1610 }
1611
1612 /*
1613 * Drop unicast frames to unauthorised stations unless they are
1614 * EAPOL frames from the local station.
1615 */
1616 if (!ieee80211_vif_is_mesh(&sdata->vif) &&
1617 unlikely(!is_multicast_ether_addr(hdr.addr1) &&
1618 !(sta_flags & WLAN_STA_AUTHORIZED) &&
1619 !(ethertype == ETH_P_PAE &&
1620 compare_ether_addr(dev->dev_addr,
1621 skb->data + ETH_ALEN) == 0))) {
1622 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1623 if (net_ratelimit())
1624 printk(KERN_DEBUG "%s: dropped frame to %pM"
1625 " (unauthorized port)\n", dev->name,
1626 hdr.addr1);
1627 #endif
1628
1629 I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
1630
1631 ret = 0;
1632 goto fail;
1633 }
1634
1635 hdr.frame_control = fc;
1636 hdr.duration_id = 0;
1637 hdr.seq_ctrl = 0;
1638
1639 skip_header_bytes = ETH_HLEN;
1640 if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
1641 encaps_data = bridge_tunnel_header;
1642 encaps_len = sizeof(bridge_tunnel_header);
1643 skip_header_bytes -= 2;
1644 } else if (ethertype >= 0x600) {
1645 encaps_data = rfc1042_header;
1646 encaps_len = sizeof(rfc1042_header);
1647 skip_header_bytes -= 2;
1648 } else {
1649 encaps_data = NULL;
1650 encaps_len = 0;
1651 }
1652
1653 skb_pull(skb, skip_header_bytes);
1654 nh_pos -= skip_header_bytes;
1655 h_pos -= skip_header_bytes;
1656
1657 head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
1658
1659 /*
1660 * So we need to modify the skb header and hence need a copy of
1661 * that. The head_need variable above doesn't, so far, include
1662 * the needed header space that we don't need right away. If we
1663 * can, then we don't reallocate right now but only after the
1664 * frame arrives at the master device (if it does...)
1665 *
1666 * If we cannot, however, then we will reallocate to include all
1667 * the ever needed space. Also, if we need to reallocate it anyway,
1668 * make it big enough for everything we may ever need.
1669 */
1670
1671 if (head_need > 0 || skb_cloned(skb)) {
1672 head_need += IEEE80211_ENCRYPT_HEADROOM;
1673 head_need += local->tx_headroom;
1674 head_need = max_t(int, 0, head_need);
1675 if (ieee80211_skb_resize(local, skb, head_need, true))
1676 goto fail;
1677 }
1678
1679 if (encaps_data) {
1680 memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
1681 nh_pos += encaps_len;
1682 h_pos += encaps_len;
1683 }
1684
1685 if (meshhdrlen > 0) {
1686 memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
1687 nh_pos += meshhdrlen;
1688 h_pos += meshhdrlen;
1689 }
1690
1691 if (ieee80211_is_data_qos(fc)) {
1692 __le16 *qos_control;
1693
1694 qos_control = (__le16*) skb_push(skb, 2);
1695 memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
1696 /*
1697 * Maybe we could actually set some fields here, for now just
1698 * initialise to zero to indicate no special operation.
1699 */
1700 *qos_control = 0;
1701 } else
1702 memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
1703
1704 nh_pos += hdrlen;
1705 h_pos += hdrlen;
1706
1707 skb->iif = dev->ifindex;
1708
1709 skb->dev = local->mdev;
1710 dev->stats.tx_packets++;
1711 dev->stats.tx_bytes += skb->len;
1712
1713 /* Update skb pointers to various headers since this modified frame
1714 * is going to go through Linux networking code that may potentially
1715 * need things like pointer to IP header. */
1716 skb_set_mac_header(skb, 0);
1717 skb_set_network_header(skb, nh_pos);
1718 skb_set_transport_header(skb, h_pos);
1719
1720 dev->trans_start = jiffies;
1721 dev_queue_xmit(skb);
1722
1723 return 0;
1724
1725 fail:
1726 if (!ret)
1727 dev_kfree_skb(skb);
1728
1729 return ret;
1730 }
1731
1732
1733 /*
1734 * ieee80211_clear_tx_pending may not be called in a context where
1735 * it is possible that it packets could come in again.
1736 */
ieee80211_clear_tx_pending(struct ieee80211_local * local)1737 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
1738 {
1739 int i, j;
1740 struct ieee80211_tx_stored_packet *store;
1741
1742 for (i = 0; i < ieee80211_num_regular_queues(&local->hw); i++) {
1743 if (!test_bit(i, local->queues_pending))
1744 continue;
1745 store = &local->pending_packet[i];
1746 kfree_skb(store->skb);
1747 for (j = 0; j < store->num_extra_frag; j++)
1748 kfree_skb(store->extra_frag[j]);
1749 kfree(store->extra_frag);
1750 clear_bit(i, local->queues_pending);
1751 }
1752 }
1753
1754 /*
1755 * Transmit all pending packets. Called from tasklet, locks master device
1756 * TX lock so that no new packets can come in.
1757 */
ieee80211_tx_pending(unsigned long data)1758 void ieee80211_tx_pending(unsigned long data)
1759 {
1760 struct ieee80211_local *local = (struct ieee80211_local *)data;
1761 struct net_device *dev = local->mdev;
1762 struct ieee80211_tx_stored_packet *store;
1763 struct ieee80211_tx_data tx;
1764 int i, ret;
1765
1766 netif_tx_lock_bh(dev);
1767 for (i = 0; i < ieee80211_num_regular_queues(&local->hw); i++) {
1768 /* Check that this queue is ok */
1769 if (__netif_subqueue_stopped(local->mdev, i) &&
1770 !test_bit(i, local->queues_pending_run))
1771 continue;
1772
1773 if (!test_bit(i, local->queues_pending)) {
1774 clear_bit(i, local->queues_pending_run);
1775 ieee80211_wake_queue(&local->hw, i);
1776 continue;
1777 }
1778
1779 clear_bit(i, local->queues_pending_run);
1780 netif_start_subqueue(local->mdev, i);
1781
1782 store = &local->pending_packet[i];
1783 tx.extra_frag = store->extra_frag;
1784 tx.num_extra_frag = store->num_extra_frag;
1785 tx.flags = 0;
1786 ret = __ieee80211_tx(local, store->skb, &tx);
1787 if (ret) {
1788 if (ret == IEEE80211_TX_FRAG_AGAIN)
1789 store->skb = NULL;
1790 } else {
1791 clear_bit(i, local->queues_pending);
1792 ieee80211_wake_queue(&local->hw, i);
1793 }
1794 }
1795 netif_tx_unlock_bh(dev);
1796 }
1797
1798 /* functions for drivers to get certain frames */
1799
ieee80211_beacon_add_tim(struct ieee80211_if_ap * bss,struct sk_buff * skb,struct beacon_data * beacon)1800 static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
1801 struct sk_buff *skb,
1802 struct beacon_data *beacon)
1803 {
1804 u8 *pos, *tim;
1805 int aid0 = 0;
1806 int i, have_bits = 0, n1, n2;
1807
1808 /* Generate bitmap for TIM only if there are any STAs in power save
1809 * mode. */
1810 if (atomic_read(&bss->num_sta_ps) > 0)
1811 /* in the hope that this is faster than
1812 * checking byte-for-byte */
1813 have_bits = !bitmap_empty((unsigned long*)bss->tim,
1814 IEEE80211_MAX_AID+1);
1815
1816 if (bss->dtim_count == 0)
1817 bss->dtim_count = beacon->dtim_period - 1;
1818 else
1819 bss->dtim_count--;
1820
1821 tim = pos = (u8 *) skb_put(skb, 6);
1822 *pos++ = WLAN_EID_TIM;
1823 *pos++ = 4;
1824 *pos++ = bss->dtim_count;
1825 *pos++ = beacon->dtim_period;
1826
1827 if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
1828 aid0 = 1;
1829
1830 if (have_bits) {
1831 /* Find largest even number N1 so that bits numbered 1 through
1832 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
1833 * (N2 + 1) x 8 through 2007 are 0. */
1834 n1 = 0;
1835 for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
1836 if (bss->tim[i]) {
1837 n1 = i & 0xfe;
1838 break;
1839 }
1840 }
1841 n2 = n1;
1842 for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
1843 if (bss->tim[i]) {
1844 n2 = i;
1845 break;
1846 }
1847 }
1848
1849 /* Bitmap control */
1850 *pos++ = n1 | aid0;
1851 /* Part Virt Bitmap */
1852 memcpy(pos, bss->tim + n1, n2 - n1 + 1);
1853
1854 tim[1] = n2 - n1 + 4;
1855 skb_put(skb, n2 - n1);
1856 } else {
1857 *pos++ = aid0; /* Bitmap control */
1858 *pos++ = 0; /* Part Virt Bitmap */
1859 }
1860 }
1861
ieee80211_beacon_get(struct ieee80211_hw * hw,struct ieee80211_vif * vif)1862 struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
1863 struct ieee80211_vif *vif)
1864 {
1865 struct ieee80211_local *local = hw_to_local(hw);
1866 struct sk_buff *skb = NULL;
1867 struct ieee80211_tx_info *info;
1868 struct ieee80211_sub_if_data *sdata = NULL;
1869 struct ieee80211_if_ap *ap = NULL;
1870 struct ieee80211_if_sta *ifsta = NULL;
1871 struct beacon_data *beacon;
1872 struct ieee80211_supported_band *sband;
1873 enum ieee80211_band band = local->hw.conf.channel->band;
1874
1875 sband = local->hw.wiphy->bands[band];
1876
1877 rcu_read_lock();
1878
1879 sdata = vif_to_sdata(vif);
1880
1881 if (sdata->vif.type == NL80211_IFTYPE_AP) {
1882 ap = &sdata->u.ap;
1883 beacon = rcu_dereference(ap->beacon);
1884 if (ap && beacon) {
1885 /*
1886 * headroom, head length,
1887 * tail length and maximum TIM length
1888 */
1889 skb = dev_alloc_skb(local->tx_headroom +
1890 beacon->head_len +
1891 beacon->tail_len + 256);
1892 if (!skb)
1893 goto out;
1894
1895 skb_reserve(skb, local->tx_headroom);
1896 memcpy(skb_put(skb, beacon->head_len), beacon->head,
1897 beacon->head_len);
1898
1899 /*
1900 * Not very nice, but we want to allow the driver to call
1901 * ieee80211_beacon_get() as a response to the set_tim()
1902 * callback. That, however, is already invoked under the
1903 * sta_lock to guarantee consistent and race-free update
1904 * of the tim bitmap in mac80211 and the driver.
1905 */
1906 if (local->tim_in_locked_section) {
1907 ieee80211_beacon_add_tim(ap, skb, beacon);
1908 } else {
1909 unsigned long flags;
1910
1911 spin_lock_irqsave(&local->sta_lock, flags);
1912 ieee80211_beacon_add_tim(ap, skb, beacon);
1913 spin_unlock_irqrestore(&local->sta_lock, flags);
1914 }
1915
1916 if (beacon->tail)
1917 memcpy(skb_put(skb, beacon->tail_len),
1918 beacon->tail, beacon->tail_len);
1919 } else
1920 goto out;
1921 } else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
1922 struct ieee80211_hdr *hdr;
1923 ifsta = &sdata->u.sta;
1924
1925 if (!ifsta->probe_resp)
1926 goto out;
1927
1928 skb = skb_copy(ifsta->probe_resp, GFP_ATOMIC);
1929 if (!skb)
1930 goto out;
1931
1932 hdr = (struct ieee80211_hdr *) skb->data;
1933 hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
1934 IEEE80211_STYPE_BEACON);
1935
1936 } else if (ieee80211_vif_is_mesh(&sdata->vif)) {
1937 struct ieee80211_mgmt *mgmt;
1938 u8 *pos;
1939
1940 /* headroom, head length, tail length and maximum TIM length */
1941 skb = dev_alloc_skb(local->tx_headroom + 400);
1942 if (!skb)
1943 goto out;
1944
1945 skb_reserve(skb, local->hw.extra_tx_headroom);
1946 mgmt = (struct ieee80211_mgmt *)
1947 skb_put(skb, 24 + sizeof(mgmt->u.beacon));
1948 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
1949 mgmt->frame_control =
1950 cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
1951 memset(mgmt->da, 0xff, ETH_ALEN);
1952 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
1953 /* BSSID is left zeroed, wildcard value */
1954 mgmt->u.beacon.beacon_int =
1955 cpu_to_le16(local->hw.conf.beacon_int);
1956 mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */
1957
1958 pos = skb_put(skb, 2);
1959 *pos++ = WLAN_EID_SSID;
1960 *pos++ = 0x0;
1961
1962 mesh_mgmt_ies_add(skb, sdata);
1963 } else {
1964 WARN_ON(1);
1965 goto out;
1966 }
1967
1968 info = IEEE80211_SKB_CB(skb);
1969
1970 skb->do_not_encrypt = 1;
1971
1972 info->band = band;
1973 /*
1974 * XXX: For now, always use the lowest rate
1975 */
1976 info->control.rates[0].idx = 0;
1977 info->control.rates[0].count = 1;
1978 info->control.rates[1].idx = -1;
1979 info->control.rates[2].idx = -1;
1980 info->control.rates[3].idx = -1;
1981 info->control.rates[4].idx = -1;
1982 BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
1983
1984 info->control.vif = vif;
1985
1986 info->flags |= IEEE80211_TX_CTL_NO_ACK;
1987 info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1988 info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
1989 out:
1990 rcu_read_unlock();
1991 return skb;
1992 }
1993 EXPORT_SYMBOL(ieee80211_beacon_get);
1994
ieee80211_rts_get(struct ieee80211_hw * hw,struct ieee80211_vif * vif,const void * frame,size_t frame_len,const struct ieee80211_tx_info * frame_txctl,struct ieee80211_rts * rts)1995 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
1996 const void *frame, size_t frame_len,
1997 const struct ieee80211_tx_info *frame_txctl,
1998 struct ieee80211_rts *rts)
1999 {
2000 const struct ieee80211_hdr *hdr = frame;
2001
2002 rts->frame_control =
2003 cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2004 rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2005 frame_txctl);
2006 memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2007 memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2008 }
2009 EXPORT_SYMBOL(ieee80211_rts_get);
2010
ieee80211_ctstoself_get(struct ieee80211_hw * hw,struct ieee80211_vif * vif,const void * frame,size_t frame_len,const struct ieee80211_tx_info * frame_txctl,struct ieee80211_cts * cts)2011 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2012 const void *frame, size_t frame_len,
2013 const struct ieee80211_tx_info *frame_txctl,
2014 struct ieee80211_cts *cts)
2015 {
2016 const struct ieee80211_hdr *hdr = frame;
2017
2018 cts->frame_control =
2019 cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2020 cts->duration = ieee80211_ctstoself_duration(hw, vif,
2021 frame_len, frame_txctl);
2022 memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2023 }
2024 EXPORT_SYMBOL(ieee80211_ctstoself_get);
2025
2026 struct sk_buff *
ieee80211_get_buffered_bc(struct ieee80211_hw * hw,struct ieee80211_vif * vif)2027 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2028 struct ieee80211_vif *vif)
2029 {
2030 struct ieee80211_local *local = hw_to_local(hw);
2031 struct sk_buff *skb = NULL;
2032 struct sta_info *sta;
2033 struct ieee80211_tx_data tx;
2034 struct ieee80211_sub_if_data *sdata;
2035 struct ieee80211_if_ap *bss = NULL;
2036 struct beacon_data *beacon;
2037 struct ieee80211_tx_info *info;
2038
2039 sdata = vif_to_sdata(vif);
2040 bss = &sdata->u.ap;
2041
2042 if (!bss)
2043 return NULL;
2044
2045 rcu_read_lock();
2046 beacon = rcu_dereference(bss->beacon);
2047
2048 if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2049 goto out;
2050
2051 if (bss->dtim_count != 0)
2052 goto out; /* send buffered bc/mc only after DTIM beacon */
2053
2054 while (1) {
2055 skb = skb_dequeue(&bss->ps_bc_buf);
2056 if (!skb)
2057 goto out;
2058 local->total_ps_buffered--;
2059
2060 if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
2061 struct ieee80211_hdr *hdr =
2062 (struct ieee80211_hdr *) skb->data;
2063 /* more buffered multicast/broadcast frames ==> set
2064 * MoreData flag in IEEE 802.11 header to inform PS
2065 * STAs */
2066 hdr->frame_control |=
2067 cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2068 }
2069
2070 if (!ieee80211_tx_prepare(local, &tx, skb))
2071 break;
2072 dev_kfree_skb_any(skb);
2073 }
2074
2075 info = IEEE80211_SKB_CB(skb);
2076
2077 sta = tx.sta;
2078 tx.flags |= IEEE80211_TX_PS_BUFFERED;
2079 tx.channel = local->hw.conf.channel;
2080 info->band = tx.channel->band;
2081
2082 if (invoke_tx_handlers(&tx))
2083 skb = NULL;
2084 out:
2085 rcu_read_unlock();
2086
2087 return skb;
2088 }
2089 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2090