1 /* src/p80211/p80211conv.c
2 *
3 * Ether/802.11 conversions and packet buffer routines
4 *
5 * Copyright (C) 1999 AbsoluteValue Systems, Inc.  All Rights Reserved.
6 * --------------------------------------------------------------------
7 *
8 * linux-wlan
9 *
10 *   The contents of this file are subject to the Mozilla Public
11 *   License Version 1.1 (the "License"); you may not use this file
12 *   except in compliance with the License. You may obtain a copy of
13 *   the License at http://www.mozilla.org/MPL/
14 *
15 *   Software distributed under the License is distributed on an "AS
16 *   IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
17 *   implied. See the License for the specific language governing
18 *   rights and limitations under the License.
19 *
20 *   Alternatively, the contents of this file may be used under the
21 *   terms of the GNU Public License version 2 (the "GPL"), in which
22 *   case the provisions of the GPL are applicable instead of the
23 *   above.  If you wish to allow the use of your version of this file
24 *   only under the terms of the GPL and not to allow others to use
25 *   your version of this file under the MPL, indicate your decision
26 *   by deleting the provisions above and replace them with the notice
27 *   and other provisions required by the GPL.  If you do not delete
28 *   the provisions above, a recipient may use your version of this
29 *   file under either the MPL or the GPL.
30 *
31 * --------------------------------------------------------------------
32 *
33 * Inquiries regarding the linux-wlan Open Source project can be
34 * made directly to:
35 *
36 * AbsoluteValue Systems Inc.
37 * info@linux-wlan.com
38 * http://www.linux-wlan.com
39 *
40 * --------------------------------------------------------------------
41 *
42 * Portions of the development of this software were funded by
43 * Intersil Corporation as part of PRISM(R) chipset product development.
44 *
45 * --------------------------------------------------------------------
46 *
47 * This file defines the functions that perform Ethernet to/from
48 * 802.11 frame conversions.
49 *
50 * --------------------------------------------------------------------
51 *
52 *================================================================
53 */
54 
55 #include <linux/module.h>
56 #include <linux/kernel.h>
57 #include <linux/sched.h>
58 #include <linux/types.h>
59 #include <linux/skbuff.h>
60 #include <linux/slab.h>
61 #include <linux/wireless.h>
62 #include <linux/netdevice.h>
63 #include <linux/etherdevice.h>
64 #include <linux/if_ether.h>
65 #include <linux/byteorder/generic.h>
66 
67 #include <asm/byteorder.h>
68 
69 #include "p80211types.h"
70 #include "p80211hdr.h"
71 #include "p80211conv.h"
72 #include "p80211mgmt.h"
73 #include "p80211msg.h"
74 #include "p80211netdev.h"
75 #include "p80211ioctl.h"
76 #include "p80211req.h"
77 
78 static u8 oui_rfc1042[] = { 0x00, 0x00, 0x00 };
79 static u8 oui_8021h[] = { 0x00, 0x00, 0xf8 };
80 
81 /*----------------------------------------------------------------
82 * p80211pb_ether_to_80211
83 *
84 * Uses the contents of the ether frame and the etherconv setting
85 * to build the elements of the 802.11 frame.
86 *
87 * We don't actually set
88 * up the frame header here.  That's the MAC's job.  We're only handling
89 * conversion of DIXII or 802.3+LLC frames to something that works
90 * with 802.11.
91 *
92 * Note -- 802.11 header is NOT part of the skb.  Likewise, the 802.11
93 *         FCS is also not present and will need to be added elsewhere.
94 *
95 * Arguments:
96 *	ethconv		Conversion type to perform
97 *	skb		skbuff containing the ether frame
98 *       p80211_hdr      802.11 header
99 *
100 * Returns:
101 *	0 on success, non-zero otherwise
102 *
103 * Call context:
104 *	May be called in interrupt or non-interrupt context
105 *----------------------------------------------------------------
106 */
107 int skb_ether_to_p80211(wlandevice_t *wlandev, u32 ethconv,
108 			struct sk_buff *skb, union p80211_hdr *p80211_hdr,
109 			struct p80211_metawep *p80211_wep)
110 {
111 	__le16 fc;
112 	u16 proto;
113 	struct wlan_ethhdr e_hdr;
114 	struct wlan_llc *e_llc;
115 	struct wlan_snap *e_snap;
116 	int foo;
117 
118 	memcpy(&e_hdr, skb->data, sizeof(e_hdr));
119 
120 	if (skb->len <= 0) {
121 		pr_debug("zero-length skb!\n");
122 		return 1;
123 	}
124 
125 	if (ethconv == WLAN_ETHCONV_ENCAP) {	/* simplest case */
126 		pr_debug("ENCAP len: %d\n", skb->len);
127 		/* here, we don't care what kind of ether frm. Just stick it */
128 		/*  in the 80211 payload */
129 		/* which is to say, leave the skb alone. */
130 	} else {
131 		/* step 1: classify ether frame, DIX or 802.3? */
132 		proto = ntohs(e_hdr.type);
133 		if (proto <= ETH_DATA_LEN) {
134 			pr_debug("802.3 len: %d\n", skb->len);
135 			/* codes <= 1500 reserved for 802.3 lengths */
136 			/* it's 802.3, pass ether payload unchanged,  */
137 
138 			/* trim off ethernet header */
139 			skb_pull(skb, ETH_HLEN);
140 
141 			/*   leave off any PAD octets.  */
142 			skb_trim(skb, proto);
143 		} else {
144 			pr_debug("DIXII len: %d\n", skb->len);
145 			/* it's DIXII, time for some conversion */
146 
147 			/* trim off ethernet header */
148 			skb_pull(skb, ETH_HLEN);
149 
150 			/* tack on SNAP */
151 			e_snap =
152 			    (struct wlan_snap *)skb_push(skb,
153 				sizeof(struct wlan_snap));
154 			e_snap->type = htons(proto);
155 			if (ethconv == WLAN_ETHCONV_8021h &&
156 			    p80211_stt_findproto(proto)) {
157 				memcpy(e_snap->oui, oui_8021h,
158 				       WLAN_IEEE_OUI_LEN);
159 			} else {
160 				memcpy(e_snap->oui, oui_rfc1042,
161 				       WLAN_IEEE_OUI_LEN);
162 			}
163 
164 			/* tack on llc */
165 			e_llc =
166 			    (struct wlan_llc *)skb_push(skb,
167 				sizeof(struct wlan_llc));
168 			e_llc->dsap = 0xAA;	/* SNAP, see IEEE 802 */
169 			e_llc->ssap = 0xAA;
170 			e_llc->ctl = 0x03;
171 		}
172 	}
173 
174 	/* Set up the 802.11 header */
175 	/* It's a data frame */
176 	fc = cpu_to_le16(WLAN_SET_FC_FTYPE(WLAN_FTYPE_DATA) |
177 			 WLAN_SET_FC_FSTYPE(WLAN_FSTYPE_DATAONLY));
178 
179 	switch (wlandev->macmode) {
180 	case WLAN_MACMODE_IBSS_STA:
181 		memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, ETH_ALEN);
182 		memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, ETH_ALEN);
183 		memcpy(p80211_hdr->a3.a3, wlandev->bssid, ETH_ALEN);
184 		break;
185 	case WLAN_MACMODE_ESS_STA:
186 		fc |= cpu_to_le16(WLAN_SET_FC_TODS(1));
187 		memcpy(p80211_hdr->a3.a1, wlandev->bssid, ETH_ALEN);
188 		memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, ETH_ALEN);
189 		memcpy(p80211_hdr->a3.a3, &e_hdr.daddr, ETH_ALEN);
190 		break;
191 	case WLAN_MACMODE_ESS_AP:
192 		fc |= cpu_to_le16(WLAN_SET_FC_FROMDS(1));
193 		memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, ETH_ALEN);
194 		memcpy(p80211_hdr->a3.a2, wlandev->bssid, ETH_ALEN);
195 		memcpy(p80211_hdr->a3.a3, &e_hdr.saddr, ETH_ALEN);
196 		break;
197 	default:
198 		netdev_err(wlandev->netdev,
199 			   "Error: Converting eth to wlan in unknown mode.\n");
200 		return 1;
201 	}
202 
203 	p80211_wep->data = NULL;
204 
205 	if ((wlandev->hostwep & HOSTWEP_PRIVACYINVOKED) &&
206 	    (wlandev->hostwep & HOSTWEP_ENCRYPT)) {
207 		/* XXXX need to pick keynum other than default? */
208 
209 		p80211_wep->data = kmalloc(skb->len, GFP_ATOMIC);
210 		if (!p80211_wep->data)
211 			return -ENOMEM;
212 		foo = wep_encrypt(wlandev, skb->data, p80211_wep->data,
213 				  skb->len,
214 				  (wlandev->hostwep & HOSTWEP_DEFAULTKEY_MASK),
215 				  p80211_wep->iv, p80211_wep->icv);
216 		if (foo) {
217 			netdev_warn(wlandev->netdev,
218 				    "Host en-WEP failed, dropping frame (%d).\n",
219 				    foo);
220 			return 2;
221 		}
222 		fc |= cpu_to_le16(WLAN_SET_FC_ISWEP(1));
223 	}
224 
225 	/*      skb->nh.raw = skb->data; */
226 
227 	p80211_hdr->a3.fc = fc;
228 	p80211_hdr->a3.dur = 0;
229 	p80211_hdr->a3.seq = 0;
230 
231 	return 0;
232 }
233 
234 /* jkriegl: from orinoco, modified */
235 static void orinoco_spy_gather(wlandevice_t *wlandev, char *mac,
236 			       struct p80211_rxmeta *rxmeta)
237 {
238 	int i;
239 
240 	/* Gather wireless spy statistics: for each packet, compare the
241 	 * source address with out list, and if match, get the stats...
242 	 */
243 
244 	for (i = 0; i < wlandev->spy_number; i++) {
245 		if (!memcmp(wlandev->spy_address[i], mac, ETH_ALEN)) {
246 			memcpy(wlandev->spy_address[i], mac, ETH_ALEN);
247 			wlandev->spy_stat[i].level = rxmeta->signal;
248 			wlandev->spy_stat[i].noise = rxmeta->noise;
249 			wlandev->spy_stat[i].qual =
250 			    (rxmeta->signal >
251 			     rxmeta->noise) ? (rxmeta->signal -
252 					       rxmeta->noise) : 0;
253 			wlandev->spy_stat[i].updated = 0x7;
254 		}
255 	}
256 }
257 
258 /*----------------------------------------------------------------
259 * p80211pb_80211_to_ether
260 *
261 * Uses the contents of a received 802.11 frame and the etherconv
262 * setting to build an ether frame.
263 *
264 * This function extracts the src and dest address from the 802.11
265 * frame to use in the construction of the eth frame.
266 *
267 * Arguments:
268 *	ethconv		Conversion type to perform
269 *	skb		Packet buffer containing the 802.11 frame
270 *
271 * Returns:
272 *	0 on success, non-zero otherwise
273 *
274 * Call context:
275 *	May be called in interrupt or non-interrupt context
276 *----------------------------------------------------------------
277 */
278 int skb_p80211_to_ether(wlandevice_t *wlandev, u32 ethconv,
279 			struct sk_buff *skb)
280 {
281 	netdevice_t *netdev = wlandev->netdev;
282 	u16 fc;
283 	unsigned int payload_length;
284 	unsigned int payload_offset;
285 	u8 daddr[ETH_ALEN];
286 	u8 saddr[ETH_ALEN];
287 	union p80211_hdr *w_hdr;
288 	struct wlan_ethhdr *e_hdr;
289 	struct wlan_llc *e_llc;
290 	struct wlan_snap *e_snap;
291 
292 	int foo;
293 
294 	payload_length = skb->len - WLAN_HDR_A3_LEN - WLAN_CRC_LEN;
295 	payload_offset = WLAN_HDR_A3_LEN;
296 
297 	w_hdr = (union p80211_hdr *)skb->data;
298 
299 	/* setup some vars for convenience */
300 	fc = le16_to_cpu(w_hdr->a3.fc);
301 	if ((WLAN_GET_FC_TODS(fc) == 0) && (WLAN_GET_FC_FROMDS(fc) == 0)) {
302 		ether_addr_copy(daddr, w_hdr->a3.a1);
303 		ether_addr_copy(saddr, w_hdr->a3.a2);
304 	} else if ((WLAN_GET_FC_TODS(fc) == 0) &&
305 		   (WLAN_GET_FC_FROMDS(fc) == 1)) {
306 		ether_addr_copy(daddr, w_hdr->a3.a1);
307 		ether_addr_copy(saddr, w_hdr->a3.a3);
308 	} else if ((WLAN_GET_FC_TODS(fc) == 1) &&
309 		   (WLAN_GET_FC_FROMDS(fc) == 0)) {
310 		ether_addr_copy(daddr, w_hdr->a3.a3);
311 		ether_addr_copy(saddr, w_hdr->a3.a2);
312 	} else {
313 		payload_offset = WLAN_HDR_A4_LEN;
314 		if (payload_length < WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN) {
315 			netdev_err(netdev, "A4 frame too short!\n");
316 			return 1;
317 		}
318 		payload_length -= (WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN);
319 		ether_addr_copy(daddr, w_hdr->a4.a3);
320 		ether_addr_copy(saddr, w_hdr->a4.a4);
321 	}
322 
323 	/* perform de-wep if necessary.. */
324 	if ((wlandev->hostwep & HOSTWEP_PRIVACYINVOKED) &&
325 	    WLAN_GET_FC_ISWEP(fc) &&
326 	    (wlandev->hostwep & HOSTWEP_DECRYPT)) {
327 		if (payload_length <= 8) {
328 			netdev_err(netdev,
329 				   "WEP frame too short (%u).\n", skb->len);
330 			return 1;
331 		}
332 		foo = wep_decrypt(wlandev, skb->data + payload_offset + 4,
333 				  payload_length - 8, -1,
334 				  skb->data + payload_offset,
335 				  skb->data + payload_offset +
336 				  payload_length - 4);
337 		if (foo) {
338 			/* de-wep failed, drop skb. */
339 			pr_debug("Host de-WEP failed, dropping frame (%d).\n",
340 				 foo);
341 			wlandev->rx.decrypt_err++;
342 			return 2;
343 		}
344 
345 		/* subtract the IV+ICV length off the payload */
346 		payload_length -= 8;
347 		/* chop off the IV */
348 		skb_pull(skb, 4);
349 		/* chop off the ICV. */
350 		skb_trim(skb, skb->len - 4);
351 
352 		wlandev->rx.decrypt++;
353 	}
354 
355 	e_hdr = (struct wlan_ethhdr *)(skb->data + payload_offset);
356 
357 	e_llc = (struct wlan_llc *)(skb->data + payload_offset);
358 	e_snap =
359 	    (struct wlan_snap *)(skb->data + payload_offset +
360 		sizeof(struct wlan_llc));
361 
362 	/* Test for the various encodings */
363 	if ((payload_length >= sizeof(struct wlan_ethhdr)) &&
364 	    (e_llc->dsap != 0xaa || e_llc->ssap != 0xaa) &&
365 	    ((!ether_addr_equal_unaligned(daddr, e_hdr->daddr)) ||
366 	     (!ether_addr_equal_unaligned(saddr, e_hdr->saddr)))) {
367 		pr_debug("802.3 ENCAP len: %d\n", payload_length);
368 		/* 802.3 Encapsulated */
369 		/* Test for an overlength frame */
370 		if (payload_length > (netdev->mtu + ETH_HLEN)) {
371 			/* A bogus length ethfrm has been encap'd. */
372 			/* Is someone trying an oflow attack? */
373 			netdev_err(netdev, "ENCAP frame too large (%d > %d)\n",
374 				   payload_length, netdev->mtu + ETH_HLEN);
375 			return 1;
376 		}
377 
378 		/* Chop off the 802.11 header.  it's already sane. */
379 		skb_pull(skb, payload_offset);
380 		/* chop off the 802.11 CRC */
381 		skb_trim(skb, skb->len - WLAN_CRC_LEN);
382 
383 	} else if ((payload_length >= sizeof(struct wlan_llc) +
384 		sizeof(struct wlan_snap)) &&
385 		(e_llc->dsap == 0xaa) &&
386 		(e_llc->ssap == 0xaa) &&
387 		(e_llc->ctl == 0x03) &&
388 		   (((memcmp(e_snap->oui, oui_rfc1042,
389 		   WLAN_IEEE_OUI_LEN) == 0) &&
390 		   (ethconv == WLAN_ETHCONV_8021h) &&
391 		   (p80211_stt_findproto(le16_to_cpu(e_snap->type)))) ||
392 		   (memcmp(e_snap->oui, oui_rfc1042, WLAN_IEEE_OUI_LEN) !=
393 			0))) {
394 		pr_debug("SNAP+RFC1042 len: %d\n", payload_length);
395 		/* it's a SNAP + RFC1042 frame && protocol is in STT */
396 		/* build 802.3 + RFC1042 */
397 
398 		/* Test for an overlength frame */
399 		if (payload_length > netdev->mtu) {
400 			/* A bogus length ethfrm has been sent. */
401 			/* Is someone trying an oflow attack? */
402 			netdev_err(netdev, "SNAP frame too large (%d > %d)\n",
403 				   payload_length, netdev->mtu);
404 			return 1;
405 		}
406 
407 		/* chop 802.11 header from skb. */
408 		skb_pull(skb, payload_offset);
409 
410 		/* create 802.3 header at beginning of skb. */
411 		e_hdr = (struct wlan_ethhdr *)skb_push(skb, ETH_HLEN);
412 		ether_addr_copy(e_hdr->daddr, daddr);
413 		ether_addr_copy(e_hdr->saddr, saddr);
414 		e_hdr->type = htons(payload_length);
415 
416 		/* chop off the 802.11 CRC */
417 		skb_trim(skb, skb->len - WLAN_CRC_LEN);
418 
419 	} else if ((payload_length >= sizeof(struct wlan_llc) +
420 		sizeof(struct wlan_snap)) &&
421 		(e_llc->dsap == 0xaa) &&
422 		(e_llc->ssap == 0xaa) &&
423 		(e_llc->ctl == 0x03)) {
424 		pr_debug("802.1h/RFC1042 len: %d\n", payload_length);
425 		/* it's an 802.1h frame || (an RFC1042 && protocol not in STT)
426 		 * build a DIXII + RFC894
427 		 */
428 
429 		/* Test for an overlength frame */
430 		if ((payload_length - sizeof(struct wlan_llc) -
431 			sizeof(struct wlan_snap))
432 			> netdev->mtu) {
433 			/* A bogus length ethfrm has been sent. */
434 			/* Is someone trying an oflow attack? */
435 			netdev_err(netdev, "DIXII frame too large (%ld > %d)\n",
436 				   (long int)(payload_length -
437 				   sizeof(struct wlan_llc) -
438 				   sizeof(struct wlan_snap)), netdev->mtu);
439 			return 1;
440 		}
441 
442 		/* chop 802.11 header from skb. */
443 		skb_pull(skb, payload_offset);
444 
445 		/* chop llc header from skb. */
446 		skb_pull(skb, sizeof(struct wlan_llc));
447 
448 		/* chop snap header from skb. */
449 		skb_pull(skb, sizeof(struct wlan_snap));
450 
451 		/* create 802.3 header at beginning of skb. */
452 		e_hdr = (struct wlan_ethhdr *)skb_push(skb, ETH_HLEN);
453 		e_hdr->type = e_snap->type;
454 		ether_addr_copy(e_hdr->daddr, daddr);
455 		ether_addr_copy(e_hdr->saddr, saddr);
456 
457 		/* chop off the 802.11 CRC */
458 		skb_trim(skb, skb->len - WLAN_CRC_LEN);
459 	} else {
460 		pr_debug("NON-ENCAP len: %d\n", payload_length);
461 		/* any NON-ENCAP */
462 		/* it's a generic 80211+LLC or IPX 'Raw 802.3' */
463 		/*  build an 802.3 frame */
464 		/* allocate space and setup hostbuf */
465 
466 		/* Test for an overlength frame */
467 		if (payload_length > netdev->mtu) {
468 			/* A bogus length ethfrm has been sent. */
469 			/* Is someone trying an oflow attack? */
470 			netdev_err(netdev, "OTHER frame too large (%d > %d)\n",
471 				   payload_length, netdev->mtu);
472 			return 1;
473 		}
474 
475 		/* Chop off the 802.11 header. */
476 		skb_pull(skb, payload_offset);
477 
478 		/* create 802.3 header at beginning of skb. */
479 		e_hdr = (struct wlan_ethhdr *)skb_push(skb, ETH_HLEN);
480 		ether_addr_copy(e_hdr->daddr, daddr);
481 		ether_addr_copy(e_hdr->saddr, saddr);
482 		e_hdr->type = htons(payload_length);
483 
484 		/* chop off the 802.11 CRC */
485 		skb_trim(skb, skb->len - WLAN_CRC_LEN);
486 	}
487 
488 	/*
489 	 * Note that eth_type_trans() expects an skb w/ skb->data pointing
490 	 * at the MAC header, it then sets the following skb members:
491 	 * skb->mac_header,
492 	 * skb->data, and
493 	 * skb->pkt_type.
494 	 * It then _returns_ the value that _we're_ supposed to stuff in
495 	 * skb->protocol.  This is nuts.
496 	 */
497 	skb->protocol = eth_type_trans(skb, netdev);
498 
499 	/* jkriegl: process signal and noise as set in hfa384x_int_rx() */
500 	/* jkriegl: only process signal/noise if requested by iwspy */
501 	if (wlandev->spy_number)
502 		orinoco_spy_gather(wlandev, eth_hdr(skb)->h_source,
503 				   P80211SKB_RXMETA(skb));
504 
505 	/* Free the metadata */
506 	p80211skb_rxmeta_detach(skb);
507 
508 	return 0;
509 }
510 
511 /*----------------------------------------------------------------
512 * p80211_stt_findproto
513 *
514 * Searches the 802.1h Selective Translation Table for a given
515 * protocol.
516 *
517 * Arguments:
518 *	proto	protocol number (in host order) to search for.
519 *
520 * Returns:
521 *	1 - if the table is empty or a match is found.
522 *	0 - if the table is non-empty and a match is not found.
523 *
524 * Call context:
525 *	May be called in interrupt or non-interrupt context
526 *----------------------------------------------------------------
527 */
528 int p80211_stt_findproto(u16 proto)
529 {
530 	/* Always return found for now.  This is the behavior used by the */
531 	/* Zoom Win95 driver when 802.1h mode is selected */
532 	/* TODO: If necessary, add an actual search we'll probably
533 	 * need this to match the CMAC's way of doing things.
534 	 * Need to do some testing to confirm.
535 	 */
536 
537 	if (proto == ETH_P_AARP)	/* APPLETALK */
538 		return 1;
539 
540 	return 0;
541 }
542 
543 /*----------------------------------------------------------------
544 * p80211skb_rxmeta_detach
545 *
546 * Disconnects the frmmeta and rxmeta from an skb.
547 *
548 * Arguments:
549 *	wlandev		The wlandev this skb belongs to.
550 *	skb		The skb we're attaching to.
551 *
552 * Returns:
553 *	0 on success, non-zero otherwise
554 *
555 * Call context:
556 *	May be called in interrupt or non-interrupt context
557 *----------------------------------------------------------------
558 */
559 void p80211skb_rxmeta_detach(struct sk_buff *skb)
560 {
561 	struct p80211_rxmeta *rxmeta;
562 	struct p80211_frmmeta *frmmeta;
563 
564 	/* Sanity checks */
565 	if (!skb) {	/* bad skb */
566 		pr_debug("Called w/ null skb.\n");
567 		return;
568 	}
569 	frmmeta = P80211SKB_FRMMETA(skb);
570 	if (!frmmeta) {	/* no magic */
571 		pr_debug("Called w/ bad frmmeta magic.\n");
572 		return;
573 	}
574 	rxmeta = frmmeta->rx;
575 	if (!rxmeta) {	/* bad meta ptr */
576 		pr_debug("Called w/ bad rxmeta ptr.\n");
577 		return;
578 	}
579 
580 	/* Free rxmeta */
581 	kfree(rxmeta);
582 
583 	/* Clear skb->cb */
584 	memset(skb->cb, 0, sizeof(skb->cb));
585 }
586 
587 /*----------------------------------------------------------------
588 * p80211skb_rxmeta_attach
589 *
590 * Allocates a p80211rxmeta structure, initializes it, and attaches
591 * it to an skb.
592 *
593 * Arguments:
594 *	wlandev		The wlandev this skb belongs to.
595 *	skb		The skb we're attaching to.
596 *
597 * Returns:
598 *	0 on success, non-zero otherwise
599 *
600 * Call context:
601 *	May be called in interrupt or non-interrupt context
602 *----------------------------------------------------------------
603 */
604 int p80211skb_rxmeta_attach(struct wlandevice *wlandev, struct sk_buff *skb)
605 {
606 	int result = 0;
607 	struct p80211_rxmeta *rxmeta;
608 	struct p80211_frmmeta *frmmeta;
609 
610 	/* If these already have metadata, we error out! */
611 	if (P80211SKB_RXMETA(skb)) {
612 		netdev_err(wlandev->netdev,
613 			   "%s: RXmeta already attached!\n", wlandev->name);
614 		result = 0;
615 		goto exit;
616 	}
617 
618 	/* Allocate the rxmeta */
619 	rxmeta = kzalloc(sizeof(struct p80211_rxmeta), GFP_ATOMIC);
620 
621 	if (!rxmeta) {
622 		netdev_err(wlandev->netdev,
623 			   "%s: Failed to allocate rxmeta.\n", wlandev->name);
624 		result = 1;
625 		goto exit;
626 	}
627 
628 	/* Initialize the rxmeta */
629 	rxmeta->wlandev = wlandev;
630 	rxmeta->hosttime = jiffies;
631 
632 	/* Overlay a frmmeta_t onto skb->cb */
633 	memset(skb->cb, 0, sizeof(struct p80211_frmmeta));
634 	frmmeta = (struct p80211_frmmeta *)(skb->cb);
635 	frmmeta->magic = P80211_FRMMETA_MAGIC;
636 	frmmeta->rx = rxmeta;
637 exit:
638 	return result;
639 }
640 
641 /*----------------------------------------------------------------
642 * p80211skb_free
643 *
644 * Frees an entire p80211skb by checking and freeing the meta struct
645 * and then freeing the skb.
646 *
647 * Arguments:
648 *	wlandev		The wlandev this skb belongs to.
649 *	skb		The skb we're attaching to.
650 *
651 * Returns:
652 *	0 on success, non-zero otherwise
653 *
654 * Call context:
655 *	May be called in interrupt or non-interrupt context
656 *----------------------------------------------------------------
657 */
658 void p80211skb_free(struct wlandevice *wlandev, struct sk_buff *skb)
659 {
660 	struct p80211_frmmeta *meta;
661 
662 	meta = P80211SKB_FRMMETA(skb);
663 	if (meta && meta->rx)
664 		p80211skb_rxmeta_detach(skb);
665 	else
666 		netdev_err(wlandev->netdev,
667 			   "Freeing an skb (%p) w/ no frmmeta.\n", skb);
668 	dev_kfree_skb(skb);
669 }
670