1// SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1)
2/*
3 *
4 * Ether/802.11 conversions and packet buffer routines
5 *
6 * Copyright (C) 1999 AbsoluteValue Systems, Inc. All Rights Reserved.
7 * --------------------------------------------------------------------
8 *
9 * linux-wlan
10 *
11 * --------------------------------------------------------------------
12 *
13 * Inquiries regarding the linux-wlan Open Source project can be
14 * made directly to:
15 *
16 * AbsoluteValue Systems Inc.
17 * info@linux-wlan.com
18 * http://www.linux-wlan.com
19 *
20 * --------------------------------------------------------------------
21 *
22 * Portions of the development of this software were funded by
23 * Intersil Corporation as part of PRISM(R) chipset product development.
24 *
25 * --------------------------------------------------------------------
26 *
27 * This file defines the functions that perform Ethernet to/from
28 * 802.11 frame conversions.
29 *
30 * --------------------------------------------------------------------
31 *
32 *================================================================
33 */
34
35#include <linux/module.h>
36#include <linux/kernel.h>
37#include <linux/sched.h>
38#include <linux/types.h>
39#include <linux/skbuff.h>
40#include <linux/slab.h>
41#include <linux/wireless.h>
42#include <linux/netdevice.h>
43#include <linux/etherdevice.h>
44#include <linux/if_ether.h>
45#include <linux/byteorder/generic.h>
46
47#include <asm/byteorder.h>
48
49#include "p80211types.h"
50#include "p80211hdr.h"
51#include "p80211conv.h"
52#include "p80211mgmt.h"
53#include "p80211msg.h"
54#include "p80211netdev.h"
55#include "p80211ioctl.h"
56#include "p80211req.h"
57
58static const u8 oui_rfc1042[] = { 0x00, 0x00, 0x00 };
59static const u8 oui_8021h[] = { 0x00, 0x00, 0xf8 };
60
61/*----------------------------------------------------------------
62 * p80211pb_ether_to_80211
63 *
64 * Uses the contents of the ether frame and the etherconv setting
65 * to build the elements of the 802.11 frame.
66 *
67 * We don't actually set
68 * up the frame header here. That's the MAC's job. We're only handling
69 * conversion of DIXII or 802.3+LLC frames to something that works
70 * with 802.11.
71 *
72 * Note -- 802.11 header is NOT part of the skb. Likewise, the 802.11
73 * FCS is also not present and will need to be added elsewhere.
74 *
75 * Arguments:
76 * ethconv Conversion type to perform
77 * skb skbuff containing the ether frame
78 * p80211_hdr 802.11 header
79 *
80 * Returns:
81 * 0 on success, non-zero otherwise
82 *
83 * Call context:
84 * May be called in interrupt or non-interrupt context
85 *----------------------------------------------------------------
86 */
87int skb_ether_to_p80211(struct wlandevice *wlandev, u32 ethconv,
88 struct sk_buff *skb, struct p80211_hdr *p80211_hdr,
89 struct p80211_metawep *p80211_wep)
90{
91 __le16 fc;
92 u16 proto;
93 struct wlan_ethhdr e_hdr;
94 struct wlan_llc *e_llc;
95 struct wlan_snap *e_snap;
96 int foo;
97
98 memcpy(&e_hdr, skb->data, sizeof(e_hdr));
99
100 if (skb->len <= 0) {
101 pr_debug("zero-length skb!\n");
102 return 1;
103 }
104
105 if (ethconv == WLAN_ETHCONV_ENCAP) { /* simplest case */
106 pr_debug("ENCAP len: %d\n", skb->len);
107 /* here, we don't care what kind of ether frm. Just stick it */
108 /* in the 80211 payload */
109 /* which is to say, leave the skb alone. */
110 } else {
111 /* step 1: classify ether frame, DIX or 802.3? */
112 proto = ntohs(e_hdr.type);
113 if (proto <= ETH_DATA_LEN) {
114 pr_debug("802.3 len: %d\n", skb->len);
115 /* codes <= 1500 reserved for 802.3 lengths */
116 /* it's 802.3, pass ether payload unchanged, */
117
118 /* trim off ethernet header */
119 skb_pull(skb, ETH_HLEN);
120
121 /* leave off any PAD octets. */
122 skb_trim(skb, len: proto);
123 } else {
124 pr_debug("DIXII len: %d\n", skb->len);
125 /* it's DIXII, time for some conversion */
126
127 /* trim off ethernet header */
128 skb_pull(skb, ETH_HLEN);
129
130 /* tack on SNAP */
131 e_snap = skb_push(skb, len: sizeof(struct wlan_snap));
132 e_snap->type = htons(proto);
133 if (ethconv == WLAN_ETHCONV_8021h &&
134 p80211_stt_findproto(proto)) {
135 memcpy(e_snap->oui, oui_8021h,
136 WLAN_IEEE_OUI_LEN);
137 } else {
138 memcpy(e_snap->oui, oui_rfc1042,
139 WLAN_IEEE_OUI_LEN);
140 }
141
142 /* tack on llc */
143 e_llc = skb_push(skb, len: sizeof(struct wlan_llc));
144 e_llc->dsap = 0xAA; /* SNAP, see IEEE 802 */
145 e_llc->ssap = 0xAA;
146 e_llc->ctl = 0x03;
147 }
148 }
149
150 /* Set up the 802.11 header */
151 /* It's a data frame */
152 fc = cpu_to_le16(WLAN_SET_FC_FTYPE(WLAN_FTYPE_DATA) |
153 WLAN_SET_FC_FSTYPE(WLAN_FSTYPE_DATAONLY));
154
155 switch (wlandev->macmode) {
156 case WLAN_MACMODE_IBSS_STA:
157 memcpy(p80211_hdr->address1, &e_hdr.daddr, ETH_ALEN);
158 memcpy(p80211_hdr->address2, wlandev->netdev->dev_addr, ETH_ALEN);
159 memcpy(p80211_hdr->address3, wlandev->bssid, ETH_ALEN);
160 break;
161 case WLAN_MACMODE_ESS_STA:
162 fc |= cpu_to_le16(WLAN_SET_FC_TODS(1));
163 memcpy(p80211_hdr->address1, wlandev->bssid, ETH_ALEN);
164 memcpy(p80211_hdr->address2, wlandev->netdev->dev_addr, ETH_ALEN);
165 memcpy(p80211_hdr->address3, &e_hdr.daddr, ETH_ALEN);
166 break;
167 case WLAN_MACMODE_ESS_AP:
168 fc |= cpu_to_le16(WLAN_SET_FC_FROMDS(1));
169 memcpy(p80211_hdr->address1, &e_hdr.daddr, ETH_ALEN);
170 memcpy(p80211_hdr->address2, wlandev->bssid, ETH_ALEN);
171 memcpy(p80211_hdr->address3, &e_hdr.saddr, ETH_ALEN);
172 break;
173 default:
174 netdev_err(dev: wlandev->netdev,
175 format: "Error: Converting eth to wlan in unknown mode.\n");
176 return 1;
177 }
178
179 p80211_wep->data = NULL;
180
181 if ((wlandev->hostwep & HOSTWEP_PRIVACYINVOKED) &&
182 (wlandev->hostwep & HOSTWEP_ENCRYPT)) {
183 /* XXXX need to pick keynum other than default? */
184
185 p80211_wep->data = kmalloc(size: skb->len, GFP_ATOMIC);
186 if (!p80211_wep->data)
187 return -ENOMEM;
188 foo = wep_encrypt(wlandev, buf: skb->data, dst: p80211_wep->data,
189 len: skb->len,
190 keynum: wlandev->hostwep & HOSTWEP_DEFAULTKEY_MASK,
191 iv: p80211_wep->iv, icv: p80211_wep->icv);
192 if (foo) {
193 netdev_warn(dev: wlandev->netdev,
194 format: "Host en-WEP failed, dropping frame (%d).\n",
195 foo);
196 kfree(objp: p80211_wep->data);
197 return 2;
198 }
199 fc |= cpu_to_le16(WLAN_SET_FC_ISWEP(1));
200 }
201
202 /* skb->nh.raw = skb->data; */
203
204 p80211_hdr->frame_control = fc;
205 p80211_hdr->duration_id = 0;
206 p80211_hdr->sequence_control = 0;
207
208 return 0;
209}
210
211/* jkriegl: from orinoco, modified */
212static void orinoco_spy_gather(struct wlandevice *wlandev, char *mac,
213 struct p80211_rxmeta *rxmeta)
214{
215 int i;
216
217 /* Gather wireless spy statistics: for each packet, compare the
218 * source address with out list, and if match, get the stats...
219 */
220
221 for (i = 0; i < wlandev->spy_number; i++) {
222 if (!memcmp(p: wlandev->spy_address[i], q: mac, ETH_ALEN)) {
223 wlandev->spy_stat[i].level = rxmeta->signal;
224 wlandev->spy_stat[i].noise = rxmeta->noise;
225 wlandev->spy_stat[i].qual =
226 (rxmeta->signal >
227 rxmeta->noise) ? (rxmeta->signal -
228 rxmeta->noise) : 0;
229 wlandev->spy_stat[i].updated = 0x7;
230 }
231 }
232}
233
234/*----------------------------------------------------------------
235 * p80211pb_80211_to_ether
236 *
237 * Uses the contents of a received 802.11 frame and the etherconv
238 * setting to build an ether frame.
239 *
240 * This function extracts the src and dest address from the 802.11
241 * frame to use in the construction of the eth frame.
242 *
243 * Arguments:
244 * ethconv Conversion type to perform
245 * skb Packet buffer containing the 802.11 frame
246 *
247 * Returns:
248 * 0 on success, non-zero otherwise
249 *
250 * Call context:
251 * May be called in interrupt or non-interrupt context
252 *----------------------------------------------------------------
253 */
254int skb_p80211_to_ether(struct wlandevice *wlandev, u32 ethconv,
255 struct sk_buff *skb)
256{
257 struct net_device *netdev = wlandev->netdev;
258 u16 fc;
259 unsigned int payload_length;
260 unsigned int payload_offset;
261 u8 daddr[ETH_ALEN];
262 u8 saddr[ETH_ALEN];
263 struct p80211_hdr *w_hdr;
264 struct wlan_ethhdr *e_hdr;
265 struct wlan_llc *e_llc;
266 struct wlan_snap *e_snap;
267
268 int foo;
269
270 payload_length = skb->len - WLAN_HDR_A3_LEN - WLAN_CRC_LEN;
271 payload_offset = WLAN_HDR_A3_LEN;
272
273 w_hdr = (struct p80211_hdr *)skb->data;
274
275 /* setup some vars for convenience */
276 fc = le16_to_cpu(w_hdr->frame_control);
277 if ((WLAN_GET_FC_TODS(fc) == 0) && (WLAN_GET_FC_FROMDS(fc) == 0)) {
278 ether_addr_copy(dst: daddr, src: w_hdr->address1);
279 ether_addr_copy(dst: saddr, src: w_hdr->address2);
280 } else if ((WLAN_GET_FC_TODS(fc) == 0) &&
281 (WLAN_GET_FC_FROMDS(fc) == 1)) {
282 ether_addr_copy(dst: daddr, src: w_hdr->address1);
283 ether_addr_copy(dst: saddr, src: w_hdr->address3);
284 } else if ((WLAN_GET_FC_TODS(fc) == 1) &&
285 (WLAN_GET_FC_FROMDS(fc) == 0)) {
286 ether_addr_copy(dst: daddr, src: w_hdr->address3);
287 ether_addr_copy(dst: saddr, src: w_hdr->address2);
288 } else {
289 payload_offset = WLAN_HDR_A4_LEN;
290 if (payload_length < WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN) {
291 netdev_err(dev: netdev, format: "A4 frame too short!\n");
292 return 1;
293 }
294 payload_length -= (WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN);
295 ether_addr_copy(dst: daddr, src: w_hdr->address3);
296 ether_addr_copy(dst: saddr, src: w_hdr->address4);
297 }
298
299 /* perform de-wep if necessary.. */
300 if ((wlandev->hostwep & HOSTWEP_PRIVACYINVOKED) &&
301 WLAN_GET_FC_ISWEP(fc) &&
302 (wlandev->hostwep & HOSTWEP_DECRYPT)) {
303 if (payload_length <= 8) {
304 netdev_err(dev: netdev,
305 format: "WEP frame too short (%u).\n", skb->len);
306 return 1;
307 }
308 foo = wep_decrypt(wlandev, buf: skb->data + payload_offset + 4,
309 len: payload_length - 8, key_override: -1,
310 iv: skb->data + payload_offset,
311 icv: skb->data + payload_offset +
312 payload_length - 4);
313 if (foo) {
314 /* de-wep failed, drop skb. */
315 netdev_dbg(netdev, "Host de-WEP failed, dropping frame (%d).\n",
316 foo);
317 wlandev->rx.decrypt_err++;
318 return 2;
319 }
320
321 /* subtract the IV+ICV length off the payload */
322 payload_length -= 8;
323 /* chop off the IV */
324 skb_pull(skb, len: 4);
325 /* chop off the ICV. */
326 skb_trim(skb, len: skb->len - 4);
327
328 wlandev->rx.decrypt++;
329 }
330
331 e_hdr = (struct wlan_ethhdr *)(skb->data + payload_offset);
332
333 e_llc = (struct wlan_llc *)(skb->data + payload_offset);
334 e_snap =
335 (struct wlan_snap *)(skb->data + payload_offset +
336 sizeof(struct wlan_llc));
337
338 /* Test for the various encodings */
339 if ((payload_length >= sizeof(struct wlan_ethhdr)) &&
340 (e_llc->dsap != 0xaa || e_llc->ssap != 0xaa) &&
341 ((!ether_addr_equal_unaligned(addr1: daddr, addr2: e_hdr->daddr)) ||
342 (!ether_addr_equal_unaligned(addr1: saddr, addr2: e_hdr->saddr)))) {
343 netdev_dbg(netdev, "802.3 ENCAP len: %d\n", payload_length);
344 /* 802.3 Encapsulated */
345 /* Test for an overlength frame */
346 if (payload_length > (netdev->mtu + ETH_HLEN)) {
347 /* A bogus length ethfrm has been encap'd. */
348 /* Is someone trying an oflow attack? */
349 netdev_err(dev: netdev, format: "ENCAP frame too large (%d > %d)\n",
350 payload_length, netdev->mtu + ETH_HLEN);
351 return 1;
352 }
353
354 /* Chop off the 802.11 header. it's already sane. */
355 skb_pull(skb, len: payload_offset);
356 /* chop off the 802.11 CRC */
357 skb_trim(skb, len: skb->len - WLAN_CRC_LEN);
358
359 } else if ((payload_length >= sizeof(struct wlan_llc) +
360 sizeof(struct wlan_snap)) &&
361 (e_llc->dsap == 0xaa) &&
362 (e_llc->ssap == 0xaa) &&
363 (e_llc->ctl == 0x03) &&
364 (((memcmp(p: e_snap->oui, q: oui_rfc1042,
365 WLAN_IEEE_OUI_LEN) == 0) &&
366 (ethconv == WLAN_ETHCONV_8021h) &&
367 (p80211_stt_findproto(be16_to_cpu(e_snap->type)))) ||
368 (memcmp(p: e_snap->oui, q: oui_rfc1042, WLAN_IEEE_OUI_LEN) !=
369 0))) {
370 netdev_dbg(netdev, "SNAP+RFC1042 len: %d\n", payload_length);
371 /* it's a SNAP + RFC1042 frame && protocol is in STT */
372 /* build 802.3 + RFC1042 */
373
374 /* Test for an overlength frame */
375 if (payload_length > netdev->mtu) {
376 /* A bogus length ethfrm has been sent. */
377 /* Is someone trying an oflow attack? */
378 netdev_err(dev: netdev, format: "SNAP frame too large (%d > %d)\n",
379 payload_length, netdev->mtu);
380 return 1;
381 }
382
383 /* chop 802.11 header from skb. */
384 skb_pull(skb, len: payload_offset);
385
386 /* create 802.3 header at beginning of skb. */
387 e_hdr = skb_push(skb, ETH_HLEN);
388 ether_addr_copy(dst: e_hdr->daddr, src: daddr);
389 ether_addr_copy(dst: e_hdr->saddr, src: saddr);
390 e_hdr->type = htons(payload_length);
391
392 /* chop off the 802.11 CRC */
393 skb_trim(skb, len: skb->len - WLAN_CRC_LEN);
394
395 } else if ((payload_length >= sizeof(struct wlan_llc) +
396 sizeof(struct wlan_snap)) &&
397 (e_llc->dsap == 0xaa) &&
398 (e_llc->ssap == 0xaa) &&
399 (e_llc->ctl == 0x03)) {
400 netdev_dbg(netdev, "802.1h/RFC1042 len: %d\n", payload_length);
401 /* it's an 802.1h frame || (an RFC1042 && protocol not in STT)
402 * build a DIXII + RFC894
403 */
404
405 /* Test for an overlength frame */
406 if ((payload_length - sizeof(struct wlan_llc) -
407 sizeof(struct wlan_snap))
408 > netdev->mtu) {
409 /* A bogus length ethfrm has been sent. */
410 /* Is someone trying an oflow attack? */
411 netdev_err(dev: netdev, format: "DIXII frame too large (%ld > %d)\n",
412 (long)(payload_length -
413 sizeof(struct wlan_llc) -
414 sizeof(struct wlan_snap)), netdev->mtu);
415 return 1;
416 }
417
418 /* chop 802.11 header from skb. */
419 skb_pull(skb, len: payload_offset);
420
421 /* chop llc header from skb. */
422 skb_pull(skb, len: sizeof(struct wlan_llc));
423
424 /* chop snap header from skb. */
425 skb_pull(skb, len: sizeof(struct wlan_snap));
426
427 /* create 802.3 header at beginning of skb. */
428 e_hdr = skb_push(skb, ETH_HLEN);
429 e_hdr->type = e_snap->type;
430 ether_addr_copy(dst: e_hdr->daddr, src: daddr);
431 ether_addr_copy(dst: e_hdr->saddr, src: saddr);
432
433 /* chop off the 802.11 CRC */
434 skb_trim(skb, len: skb->len - WLAN_CRC_LEN);
435 } else {
436 netdev_dbg(netdev, "NON-ENCAP len: %d\n", payload_length);
437 /* any NON-ENCAP */
438 /* it's a generic 80211+LLC or IPX 'Raw 802.3' */
439 /* build an 802.3 frame */
440 /* allocate space and setup hostbuf */
441
442 /* Test for an overlength frame */
443 if (payload_length > netdev->mtu) {
444 /* A bogus length ethfrm has been sent. */
445 /* Is someone trying an oflow attack? */
446 netdev_err(dev: netdev, format: "OTHER frame too large (%d > %d)\n",
447 payload_length, netdev->mtu);
448 return 1;
449 }
450
451 /* Chop off the 802.11 header. */
452 skb_pull(skb, len: payload_offset);
453
454 /* create 802.3 header at beginning of skb. */
455 e_hdr = skb_push(skb, ETH_HLEN);
456 ether_addr_copy(dst: e_hdr->daddr, src: daddr);
457 ether_addr_copy(dst: e_hdr->saddr, src: saddr);
458 e_hdr->type = htons(payload_length);
459
460 /* chop off the 802.11 CRC */
461 skb_trim(skb, len: skb->len - WLAN_CRC_LEN);
462 }
463
464 /*
465 * Note that eth_type_trans() expects an skb w/ skb->data pointing
466 * at the MAC header, it then sets the following skb members:
467 * skb->mac_header,
468 * skb->data, and
469 * skb->pkt_type.
470 * It then _returns_ the value that _we're_ supposed to stuff in
471 * skb->protocol. This is nuts.
472 */
473 skb->protocol = eth_type_trans(skb, dev: netdev);
474
475 /* jkriegl: process signal and noise as set in hfa384x_int_rx() */
476 /* jkriegl: only process signal/noise if requested by iwspy */
477 if (wlandev->spy_number)
478 orinoco_spy_gather(wlandev, mac: eth_hdr(skb)->h_source,
479 rxmeta: p80211skb_rxmeta(skb));
480
481 /* Free the metadata */
482 p80211skb_rxmeta_detach(skb);
483
484 return 0;
485}
486
487/*----------------------------------------------------------------
488 * p80211_stt_findproto
489 *
490 * Searches the 802.1h Selective Translation Table for a given
491 * protocol.
492 *
493 * Arguments:
494 * proto protocol number (in host order) to search for.
495 *
496 * Returns:
497 * 1 - if the table is empty or a match is found.
498 * 0 - if the table is non-empty and a match is not found.
499 *
500 * Call context:
501 * May be called in interrupt or non-interrupt context
502 *----------------------------------------------------------------
503 */
504int p80211_stt_findproto(u16 proto)
505{
506 /* Always return found for now. This is the behavior used by the */
507 /* Zoom Win95 driver when 802.1h mode is selected */
508 /* TODO: If necessary, add an actual search we'll probably
509 * need this to match the CMAC's way of doing things.
510 * Need to do some testing to confirm.
511 */
512
513 if (proto == ETH_P_AARP) /* APPLETALK */
514 return 1;
515
516 return 0;
517}
518
519/*----------------------------------------------------------------
520 * p80211skb_rxmeta_detach
521 *
522 * Disconnects the frmmeta and rxmeta from an skb.
523 *
524 * Arguments:
525 * wlandev The wlandev this skb belongs to.
526 * skb The skb we're attaching to.
527 *
528 * Returns:
529 * 0 on success, non-zero otherwise
530 *
531 * Call context:
532 * May be called in interrupt or non-interrupt context
533 *----------------------------------------------------------------
534 */
535void p80211skb_rxmeta_detach(struct sk_buff *skb)
536{
537 struct p80211_rxmeta *rxmeta;
538 struct p80211_frmmeta *frmmeta;
539
540 /* Sanity checks */
541 if (!skb) { /* bad skb */
542 pr_debug("Called w/ null skb.\n");
543 return;
544 }
545 frmmeta = p80211skb_frmmeta(skb);
546 if (!frmmeta) { /* no magic */
547 pr_debug("Called w/ bad frmmeta magic.\n");
548 return;
549 }
550 rxmeta = frmmeta->rx;
551 if (!rxmeta) { /* bad meta ptr */
552 pr_debug("Called w/ bad rxmeta ptr.\n");
553 return;
554 }
555
556 /* Free rxmeta */
557 kfree(objp: rxmeta);
558
559 /* Clear skb->cb */
560 memset(skb->cb, 0, sizeof(skb->cb));
561}
562
563/*----------------------------------------------------------------
564 * p80211skb_rxmeta_attach
565 *
566 * Allocates a p80211rxmeta structure, initializes it, and attaches
567 * it to an skb.
568 *
569 * Arguments:
570 * wlandev The wlandev this skb belongs to.
571 * skb The skb we're attaching to.
572 *
573 * Returns:
574 * 0 on success, non-zero otherwise
575 *
576 * Call context:
577 * May be called in interrupt or non-interrupt context
578 *----------------------------------------------------------------
579 */
580int p80211skb_rxmeta_attach(struct wlandevice *wlandev, struct sk_buff *skb)
581{
582 int result = 0;
583 struct p80211_rxmeta *rxmeta;
584 struct p80211_frmmeta *frmmeta;
585
586 /* If these already have metadata, we error out! */
587 if (p80211skb_rxmeta(skb)) {
588 netdev_err(dev: wlandev->netdev,
589 format: "%s: RXmeta already attached!\n", wlandev->name);
590 result = 0;
591 goto exit;
592 }
593
594 /* Allocate the rxmeta */
595 rxmeta = kzalloc(size: sizeof(*rxmeta), GFP_ATOMIC);
596
597 if (!rxmeta) {
598 result = 1;
599 goto exit;
600 }
601
602 /* Initialize the rxmeta */
603 rxmeta->wlandev = wlandev;
604 rxmeta->hosttime = jiffies;
605
606 /* Overlay a frmmeta_t onto skb->cb */
607 memset(skb->cb, 0, sizeof(struct p80211_frmmeta));
608 frmmeta = (struct p80211_frmmeta *)(skb->cb);
609 frmmeta->magic = P80211_FRMMETA_MAGIC;
610 frmmeta->rx = rxmeta;
611exit:
612 return result;
613}
614
615/*----------------------------------------------------------------
616 * p80211skb_free
617 *
618 * Frees an entire p80211skb by checking and freeing the meta struct
619 * and then freeing the skb.
620 *
621 * Arguments:
622 * wlandev The wlandev this skb belongs to.
623 * skb The skb we're attaching to.
624 *
625 * Returns:
626 * 0 on success, non-zero otherwise
627 *
628 * Call context:
629 * May be called in interrupt or non-interrupt context
630 *----------------------------------------------------------------
631 */
632void p80211skb_free(struct wlandevice *wlandev, struct sk_buff *skb)
633{
634 struct p80211_frmmeta *meta;
635
636 meta = p80211skb_frmmeta(skb);
637 if (meta && meta->rx)
638 p80211skb_rxmeta_detach(skb);
639 else
640 netdev_err(dev: wlandev->netdev,
641 format: "Freeing an skb (%p) w/ no frmmeta.\n", skb);
642 dev_kfree_skb(skb);
643}
644

source code of linux/drivers/staging/wlan-ng/p80211conv.c