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Kobject: remove kobject_register()
[linux-2.6/mini2440.git] / net / ieee80211 / ieee80211_tx.c
blob6d06f1385e2803cd1f263917e8bd6f8d2684a834
1 /******************************************************************************
2
3 Copyright(c) 2003 - 2005 Intel Corporation. All rights reserved.
4
5 This program is free software; you can redistribute it and/or modify it
6 under the terms of version 2 of the GNU General Public License as
7 published by the Free Software Foundation.
8
9 This program is distributed in the hope that it will be useful, but WITHOUT
10 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 more details.
13
14 You should have received a copy of the GNU General Public License along with
15 this program; if not, write to the Free Software Foundation, Inc., 59
16 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17
18 The full GNU General Public License is included in this distribution in the
19 file called LICENSE.
20
21 Contact Information:
22 James P. Ketrenos <ipw2100-admin@linux.intel.com>
23 Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
24
25 ******************************************************************************/
26 #include <linux/compiler.h>
27 #include <linux/errno.h>
28 #include <linux/if_arp.h>
29 #include <linux/in6.h>
30 #include <linux/in.h>
31 #include <linux/ip.h>
32 #include <linux/kernel.h>
33 #include <linux/module.h>
34 #include <linux/netdevice.h>
35 #include <linux/proc_fs.h>
36 #include <linux/skbuff.h>
37 #include <linux/slab.h>
38 #include <linux/tcp.h>
39 #include <linux/types.h>
40 #include <linux/wireless.h>
41 #include <linux/etherdevice.h>
42 #include <asm/uaccess.h>
43
44 #include <net/ieee80211.h>
45
46 /*
47
48 802.11 Data Frame
49
50 ,-------------------------------------------------------------------.
51 Bytes | 2 | 2 | 6 | 6 | 6 | 2 | 0..2312 | 4 |
52 |------|------|---------|---------|---------|------|---------|------|
53 Desc. | ctrl | dura | DA/RA | TA | SA | Sequ | Frame | fcs |
54 | | tion | (BSSID) | | | ence | data | |
55 `--------------------------------------------------| |------'
56 Total: 28 non-data bytes `----.----'
57 |
58 .- 'Frame data' expands, if WEP enabled, to <----------'
59 |
60 V
61 ,-----------------------.
62 Bytes | 4 | 0-2296 | 4 |
63 |-----|-----------|-----|
64 Desc. | IV | Encrypted | ICV |
65 | | Packet | |
66 `-----| |-----'
67 `-----.-----'
68 |
69 .- 'Encrypted Packet' expands to
70 |
71 V
72 ,---------------------------------------------------.
73 Bytes | 1 | 1 | 1 | 3 | 2 | 0-2304 |
74 |------|------|---------|----------|------|---------|
75 Desc. | SNAP | SNAP | Control |Eth Tunnel| Type | IP |
76 | DSAP | SSAP | | | | Packet |
77 | 0xAA | 0xAA |0x03 (UI)|0x00-00-F8| | |
78 `----------------------------------------------------
79 Total: 8 non-data bytes
80
81 802.3 Ethernet Data Frame
82
83 ,-----------------------------------------.
84 Bytes | 6 | 6 | 2 | Variable | 4 |
85 |-------|-------|------|-----------|------|
86 Desc. | Dest. | Source| Type | IP Packet | fcs |
87 | MAC | MAC | | | |
88 `-----------------------------------------'
89 Total: 18 non-data bytes
90
91 In the event that fragmentation is required, the incoming payload is split into
92 N parts of size ieee->fts. The first fragment contains the SNAP header and the
93 remaining packets are just data.
94
95 If encryption is enabled, each fragment payload size is reduced by enough space
96 to add the prefix and postfix (IV and ICV totalling 8 bytes in the case of WEP)
97 So if you have 1500 bytes of payload with ieee->fts set to 500 without
98 encryption it will take 3 frames. With WEP it will take 4 frames as the
99 payload of each frame is reduced to 492 bytes.
100
101 * SKB visualization
102 *
103 * ,- skb->data
104 * |
105 * | ETHERNET HEADER ,-<-- PAYLOAD
106 * | | 14 bytes from skb->data
107 * | 2 bytes for Type --> ,T. | (sizeof ethhdr)
108 * | | | |
109 * |,-Dest.--. ,--Src.---. | | |
110 * | 6 bytes| | 6 bytes | | | |
111 * v | | | | | |
112 * 0 | v 1 | v | v 2
113 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
114 * ^ | ^ | ^ |
115 * | | | | | |
116 * | | | | `T' <---- 2 bytes for Type
117 * | | | |
118 * | | '---SNAP--' <-------- 6 bytes for SNAP
119 * | |
120 * `-IV--' <-------------------- 4 bytes for IV (WEP)
121 *
122 * SNAP HEADER
123 *
124 */
125
126 static u8 P802_1H_OUI[P80211_OUI_LEN] = { 0x00, 0x00, 0xf8 };
127 static u8 RFC1042_OUI[P80211_OUI_LEN] = { 0x00, 0x00, 0x00 };
128
129 static int ieee80211_copy_snap(u8 * data, u16 h_proto)
130 {
131 struct ieee80211_snap_hdr *snap;
132 u8 *oui;
133
134 snap = (struct ieee80211_snap_hdr *)data;
135 snap->dsap = 0xaa;
136 snap->ssap = 0xaa;
137 snap->ctrl = 0x03;
138
139 if (h_proto == 0x8137 || h_proto == 0x80f3)
140 oui = P802_1H_OUI;
141 else
142 oui = RFC1042_OUI;
143 snap->oui[0] = oui[0];
144 snap->oui[1] = oui[1];
145 snap->oui[2] = oui[2];
146
147 h_proto = htons(h_proto);
148 memcpy(data + SNAP_SIZE, &h_proto, sizeof(u16));
149
150 return SNAP_SIZE + sizeof(u16);
151 }
152
153 static int ieee80211_encrypt_fragment(struct ieee80211_device *ieee,
154 struct sk_buff *frag, int hdr_len)
155 {
156 struct ieee80211_crypt_data *crypt = ieee->crypt[ieee->tx_keyidx];
157 int res;
158
159 if (crypt == NULL)
160 return -1;
161
162 /* To encrypt, frame format is:
163 * IV (4 bytes), clear payload (including SNAP), ICV (4 bytes) */
164 atomic_inc(&crypt->refcnt);
165 res = 0;
166 if (crypt->ops && crypt->ops->encrypt_mpdu)
167 res = crypt->ops->encrypt_mpdu(frag, hdr_len, crypt->priv);
168
169 atomic_dec(&crypt->refcnt);
170 if (res < 0) {
171 printk(KERN_INFO "%s: Encryption failed: len=%d.\n",
172 ieee->dev->name, frag->len);
173 ieee->ieee_stats.tx_discards++;
174 return -1;
175 }
176
177 return 0;
178 }
179
180 void ieee80211_txb_free(struct ieee80211_txb *txb)
181 {
182 int i;
183 if (unlikely(!txb))
184 return;
185 for (i = 0; i < txb->nr_frags; i++)
186 if (txb->fragments[i])
187 dev_kfree_skb_any(txb->fragments[i]);
188 kfree(txb);
189 }
190
191 static struct ieee80211_txb *ieee80211_alloc_txb(int nr_frags, int txb_size,
192 int headroom, gfp_t gfp_mask)
193 {
194 struct ieee80211_txb *txb;
195 int i;
196 txb = kmalloc(sizeof(struct ieee80211_txb) + (sizeof(u8 *) * nr_frags),
197 gfp_mask);
198 if (!txb)
199 return NULL;
200
201 memset(txb, 0, sizeof(struct ieee80211_txb));
202 txb->nr_frags = nr_frags;
203 txb->frag_size = txb_size;
204
205 for (i = 0; i < nr_frags; i++) {
206 txb->fragments[i] = __dev_alloc_skb(txb_size + headroom,
207 gfp_mask);
208 if (unlikely(!txb->fragments[i])) {
209 i--;
210 break;
211 }
212 skb_reserve(txb->fragments[i], headroom);
213 }
214 if (unlikely(i != nr_frags)) {
215 while (i >= 0)
216 dev_kfree_skb_any(txb->fragments[i--]);
217 kfree(txb);
218 return NULL;
219 }
220 return txb;
221 }
222
223 static int ieee80211_classify(struct sk_buff *skb)
224 {
225 struct ethhdr *eth;
226 struct iphdr *ip;
227
228 eth = (struct ethhdr *)skb->data;
229 if (eth->h_proto != htons(ETH_P_IP))
230 return 0;
231
232 ip = ip_hdr(skb);
233 switch (ip->tos & 0xfc) {
234 case 0x20:
235 return 2;
236 case 0x40:
237 return 1;
238 case 0x60:
239 return 3;
240 case 0x80:
241 return 4;
242 case 0xa0:
243 return 5;
244 case 0xc0:
245 return 6;
246 case 0xe0:
247 return 7;
248 default:
249 return 0;
250 }
251 }
252
253 /* Incoming skb is converted to a txb which consists of
254 * a block of 802.11 fragment packets (stored as skbs) */
255 int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
256 {
257 struct ieee80211_device *ieee = netdev_priv(dev);
258 struct ieee80211_txb *txb = NULL;
259 struct ieee80211_hdr_3addrqos *frag_hdr;
260 int i, bytes_per_frag, nr_frags, bytes_last_frag, frag_size,
261 rts_required;
262 unsigned long flags;
263 struct net_device_stats *stats = &ieee->stats;
264 int ether_type, encrypt, host_encrypt, host_encrypt_msdu, host_build_iv;
265 int bytes, fc, hdr_len;
266 struct sk_buff *skb_frag;
267 struct ieee80211_hdr_3addrqos header = {/* Ensure zero initialized */
268 .duration_id = 0,
269 .seq_ctl = 0,
270 .qos_ctl = 0
271 };
272 u8 dest[ETH_ALEN], src[ETH_ALEN];
273 struct ieee80211_crypt_data *crypt;
274 int priority = skb->priority;
275 int snapped = 0;
276
277 if (ieee->is_queue_full && (*ieee->is_queue_full) (dev, priority))
278 return NETDEV_TX_BUSY;
279
280 spin_lock_irqsave(&ieee->lock, flags);
281
282 /* If there is no driver handler to take the TXB, dont' bother
283 * creating it... */
284 if (!ieee->hard_start_xmit) {
285 printk(KERN_WARNING "%s: No xmit handler.\n", ieee->dev->name);
286 goto success;
287 }
288
289 if (unlikely(skb->len < SNAP_SIZE + sizeof(u16))) {
290 printk(KERN_WARNING "%s: skb too small (%d).\n",
291 ieee->dev->name, skb->len);
292 goto success;
293 }
294
295 ether_type = ntohs(((struct ethhdr *)skb->data)->h_proto);
296
297 crypt = ieee->crypt[ieee->tx_keyidx];
298
299 encrypt = !(ether_type == ETH_P_PAE && ieee->ieee802_1x) &&
300 ieee->sec.encrypt;
301
302 host_encrypt = ieee->host_encrypt && encrypt && crypt;
303 host_encrypt_msdu = ieee->host_encrypt_msdu && encrypt && crypt;
304 host_build_iv = ieee->host_build_iv && encrypt && crypt;
305
306 if (!encrypt && ieee->ieee802_1x &&
307 ieee->drop_unencrypted && ether_type != ETH_P_PAE) {
308 stats->tx_dropped++;
309 goto success;
310 }
311
312 /* Save source and destination addresses */
313 skb_copy_from_linear_data(skb, dest, ETH_ALEN);
314 skb_copy_from_linear_data_offset(skb, ETH_ALEN, src, ETH_ALEN);
315
316 if (host_encrypt || host_build_iv)
317 fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA |
318 IEEE80211_FCTL_PROTECTED;
319 else
320 fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;
321
322 if (ieee->iw_mode == IW_MODE_INFRA) {
323 fc |= IEEE80211_FCTL_TODS;
324 /* To DS: Addr1 = BSSID, Addr2 = SA, Addr3 = DA */
325 memcpy(header.addr1, ieee->bssid, ETH_ALEN);
326 memcpy(header.addr2, src, ETH_ALEN);
327 memcpy(header.addr3, dest, ETH_ALEN);
328 } else if (ieee->iw_mode == IW_MODE_ADHOC) {
329 /* not From/To DS: Addr1 = DA, Addr2 = SA, Addr3 = BSSID */
330 memcpy(header.addr1, dest, ETH_ALEN);
331 memcpy(header.addr2, src, ETH_ALEN);
332 memcpy(header.addr3, ieee->bssid, ETH_ALEN);
333 }
334 hdr_len = IEEE80211_3ADDR_LEN;
335
336 if (ieee->is_qos_active && ieee->is_qos_active(dev, skb)) {
337 fc |= IEEE80211_STYPE_QOS_DATA;
338 hdr_len += 2;
339
340 skb->priority = ieee80211_classify(skb);
341 header.qos_ctl |= cpu_to_le16(skb->priority & IEEE80211_QCTL_TID);
342 }
343 header.frame_ctl = cpu_to_le16(fc);
344
345 /* Advance the SKB to the start of the payload */
346 skb_pull(skb, sizeof(struct ethhdr));
347
348 /* Determine total amount of storage required for TXB packets */
349 bytes = skb->len + SNAP_SIZE + sizeof(u16);
350
351 /* Encrypt msdu first on the whole data packet. */
352 if ((host_encrypt || host_encrypt_msdu) &&
353 crypt && crypt->ops && crypt->ops->encrypt_msdu) {
354 int res = 0;
355 int len = bytes + hdr_len + crypt->ops->extra_msdu_prefix_len +
356 crypt->ops->extra_msdu_postfix_len;
357 struct sk_buff *skb_new = dev_alloc_skb(len);
358
359 if (unlikely(!skb_new))
360 goto failed;
361
362 skb_reserve(skb_new, crypt->ops->extra_msdu_prefix_len);
363 memcpy(skb_put(skb_new, hdr_len), &header, hdr_len);
364 snapped = 1;
365 ieee80211_copy_snap(skb_put(skb_new, SNAP_SIZE + sizeof(u16)),
366 ether_type);
367 skb_copy_from_linear_data(skb, skb_put(skb_new, skb->len), skb->len);
368 res = crypt->ops->encrypt_msdu(skb_new, hdr_len, crypt->priv);
369 if (res < 0) {
370 IEEE80211_ERROR("msdu encryption failed\n");
371 dev_kfree_skb_any(skb_new);
372 goto failed;
373 }
374 dev_kfree_skb_any(skb);
375 skb = skb_new;
376 bytes += crypt->ops->extra_msdu_prefix_len +
377 crypt->ops->extra_msdu_postfix_len;
378 skb_pull(skb, hdr_len);
379 }
380
381 if (host_encrypt || ieee->host_open_frag) {
382 /* Determine fragmentation size based on destination (multicast
383 * and broadcast are not fragmented) */
384 if (is_multicast_ether_addr(dest) ||
385 is_broadcast_ether_addr(dest))
386 frag_size = MAX_FRAG_THRESHOLD;
387 else
388 frag_size = ieee->fts;
389
390 /* Determine amount of payload per fragment. Regardless of if
391 * this stack is providing the full 802.11 header, one will
392 * eventually be affixed to this fragment -- so we must account
393 * for it when determining the amount of payload space. */
394 bytes_per_frag = frag_size - hdr_len;
395 if (ieee->config &
396 (CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS))
397 bytes_per_frag -= IEEE80211_FCS_LEN;
398
399 /* Each fragment may need to have room for encryptiong
400 * pre/postfix */
401 if (host_encrypt)
402 bytes_per_frag -= crypt->ops->extra_mpdu_prefix_len +
403 crypt->ops->extra_mpdu_postfix_len;
404
405 /* Number of fragments is the total
406 * bytes_per_frag / payload_per_fragment */
407 nr_frags = bytes / bytes_per_frag;
408 bytes_last_frag = bytes % bytes_per_frag;
409 if (bytes_last_frag)
410 nr_frags++;
411 else
412 bytes_last_frag = bytes_per_frag;
413 } else {
414 nr_frags = 1;
415 bytes_per_frag = bytes_last_frag = bytes;
416 frag_size = bytes + hdr_len;
417 }
418
419 rts_required = (frag_size > ieee->rts
420 && ieee->config & CFG_IEEE80211_RTS);
421 if (rts_required)
422 nr_frags++;
423
424 /* When we allocate the TXB we allocate enough space for the reserve
425 * and full fragment bytes (bytes_per_frag doesn't include prefix,
426 * postfix, header, FCS, etc.) */
427 txb = ieee80211_alloc_txb(nr_frags, frag_size,
428 ieee->tx_headroom, GFP_ATOMIC);
429 if (unlikely(!txb)) {
430 printk(KERN_WARNING "%s: Could not allocate TXB\n",
431 ieee->dev->name);
432 goto failed;
433 }
434 txb->encrypted = encrypt;
435 if (host_encrypt)
436 txb->payload_size = frag_size * (nr_frags - 1) +
437 bytes_last_frag;
438 else
439 txb->payload_size = bytes;
440
441 if (rts_required) {
442 skb_frag = txb->fragments[0];
443 frag_hdr =
444 (struct ieee80211_hdr_3addrqos *)skb_put(skb_frag, hdr_len);
445
446 /*
447 * Set header frame_ctl to the RTS.
448 */
449 header.frame_ctl =
450 cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
451 memcpy(frag_hdr, &header, hdr_len);
452
453 /*
454 * Restore header frame_ctl to the original data setting.
455 */
456 header.frame_ctl = cpu_to_le16(fc);
457
458 if (ieee->config &
459 (CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS))
460 skb_put(skb_frag, 4);
461
462 txb->rts_included = 1;
463 i = 1;
464 } else
465 i = 0;
466
467 for (; i < nr_frags; i++) {
468 skb_frag = txb->fragments[i];
469
470 if (host_encrypt || host_build_iv)
471 skb_reserve(skb_frag,
472 crypt->ops->extra_mpdu_prefix_len);
473
474 frag_hdr =
475 (struct ieee80211_hdr_3addrqos *)skb_put(skb_frag, hdr_len);
476 memcpy(frag_hdr, &header, hdr_len);
477
478 /* If this is not the last fragment, then add the MOREFRAGS
479 * bit to the frame control */
480 if (i != nr_frags - 1) {
481 frag_hdr->frame_ctl =
482 cpu_to_le16(fc | IEEE80211_FCTL_MOREFRAGS);
483 bytes = bytes_per_frag;
484 } else {
485 /* The last fragment takes the remaining length */
486 bytes = bytes_last_frag;
487 }
488
489 if (i == 0 && !snapped) {
490 ieee80211_copy_snap(skb_put
491 (skb_frag, SNAP_SIZE + sizeof(u16)),
492 ether_type);
493 bytes -= SNAP_SIZE + sizeof(u16);
494 }
495
496 skb_copy_from_linear_data(skb, skb_put(skb_frag, bytes), bytes);
497
498 /* Advance the SKB... */
499 skb_pull(skb, bytes);
500
501 /* Encryption routine will move the header forward in order
502 * to insert the IV between the header and the payload */
503 if (host_encrypt)
504 ieee80211_encrypt_fragment(ieee, skb_frag, hdr_len);
505 else if (host_build_iv) {
506 atomic_inc(&crypt->refcnt);
507 if (crypt->ops->build_iv)
508 crypt->ops->build_iv(skb_frag, hdr_len,
509 ieee->sec.keys[ieee->sec.active_key],
510 ieee->sec.key_sizes[ieee->sec.active_key],
511 crypt->priv);
512 atomic_dec(&crypt->refcnt);
513 }
514
515 if (ieee->config &
516 (CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS))
517 skb_put(skb_frag, 4);
518 }
519
520 success:
521 spin_unlock_irqrestore(&ieee->lock, flags);
522
523 dev_kfree_skb_any(skb);
524
525 if (txb) {
526 int ret = (*ieee->hard_start_xmit) (txb, dev, priority);
527 if (ret == 0) {
528 stats->tx_packets++;
529 stats->tx_bytes += txb->payload_size;
530 return 0;
531 }
532
533 ieee80211_txb_free(txb);
534 }
535
536 return 0;
537
538 failed:
539 spin_unlock_irqrestore(&ieee->lock, flags);
540 netif_stop_queue(dev);
541 stats->tx_errors++;
542 return 1;
543 }
544
545 /* Incoming 802.11 strucure is converted to a TXB
546 * a block of 802.11 fragment packets (stored as skbs) */
547 int ieee80211_tx_frame(struct ieee80211_device *ieee,
548 struct ieee80211_hdr *frame, int hdr_len, int total_len,
549 int encrypt_mpdu)
550 {
551 struct ieee80211_txb *txb = NULL;
552 unsigned long flags;
553 struct net_device_stats *stats = &ieee->stats;
554 struct sk_buff *skb_frag;
555 int priority = -1;
556 int fraglen = total_len;
557 int headroom = ieee->tx_headroom;
558 struct ieee80211_crypt_data *crypt = ieee->crypt[ieee->tx_keyidx];
559
560 spin_lock_irqsave(&ieee->lock, flags);
561
562 if (encrypt_mpdu && (!ieee->sec.encrypt || !crypt))
563 encrypt_mpdu = 0;
564
565 /* If there is no driver handler to take the TXB, dont' bother
566 * creating it... */
567 if (!ieee->hard_start_xmit) {
568 printk(KERN_WARNING "%s: No xmit handler.\n", ieee->dev->name);
569 goto success;
570 }
571
572 if (unlikely(total_len < 24)) {
573 printk(KERN_WARNING "%s: skb too small (%d).\n",
574 ieee->dev->name, total_len);
575 goto success;
576 }
577
578 if (encrypt_mpdu) {
579 frame->frame_ctl |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
580 fraglen += crypt->ops->extra_mpdu_prefix_len +
581 crypt->ops->extra_mpdu_postfix_len;
582 headroom += crypt->ops->extra_mpdu_prefix_len;
583 }
584
585 /* When we allocate the TXB we allocate enough space for the reserve
586 * and full fragment bytes (bytes_per_frag doesn't include prefix,
587 * postfix, header, FCS, etc.) */
588 txb = ieee80211_alloc_txb(1, fraglen, headroom, GFP_ATOMIC);
589 if (unlikely(!txb)) {
590 printk(KERN_WARNING "%s: Could not allocate TXB\n",
591 ieee->dev->name);
592 goto failed;
593 }
594 txb->encrypted = 0;
595 txb->payload_size = fraglen;
596
597 skb_frag = txb->fragments[0];
598
599 memcpy(skb_put(skb_frag, total_len), frame, total_len);
600
601 if (ieee->config &
602 (CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS))
603 skb_put(skb_frag, 4);
604
605 /* To avoid overcomplicating things, we do the corner-case frame
606 * encryption in software. The only real situation where encryption is
607 * needed here is during software-based shared key authentication. */
608 if (encrypt_mpdu)
609 ieee80211_encrypt_fragment(ieee, skb_frag, hdr_len);
610
611 success:
612 spin_unlock_irqrestore(&ieee->lock, flags);
613
614 if (txb) {
615 if ((*ieee->hard_start_xmit) (txb, ieee->dev, priority) == 0) {
616 stats->tx_packets++;
617 stats->tx_bytes += txb->payload_size;
618 return 0;
619 }
620 ieee80211_txb_free(txb);
621 }
622 return 0;
623
624 failed:
625 spin_unlock_irqrestore(&ieee->lock, flags);
626 stats->tx_errors++;
627 return 1;
628 }
629
630 EXPORT_SYMBOL(ieee80211_tx_frame);
631 EXPORT_SYMBOL(ieee80211_txb_free);
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