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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 /* System Includes */
54 
55 
56 #include <linux/module.h>
57 #include <linux/kernel.h>
58 #include <linux/sched.h>
59 #include <linux/types.h>
60 #include <linux/skbuff.h>
61 #include <linux/slab.h>
62 #include <linux/wireless.h>
63 #include <linux/netdevice.h>
64 #include <linux/etherdevice.h>
65 #include <linux/if_ether.h>
66 
67 #include <asm/byteorder.h>
68 
69 #include "wlan_compat.h"
70 
71 /*================================================================*/
72 /* Project Includes */
73 
74 #include "p80211types.h"
75 #include "p80211hdr.h"
76 #include "p80211conv.h"
77 #include "p80211mgmt.h"
78 #include "p80211msg.h"
79 #include "p80211netdev.h"
80 #include "p80211ioctl.h"
81 #include "p80211req.h"
82 
83 
84 /*================================================================*/
85 /* Local Constants */
86 
87 /*================================================================*/
88 /* Local Macros */
89 
90 
91 /*================================================================*/
92 /* Local Types */
93 
94 
95 /*================================================================*/
96 /* Local Static Definitions */
97 
98 static u8	oui_rfc1042[] = {0x00, 0x00, 0x00};
99 static u8	oui_8021h[] = {0x00, 0x00, 0xf8};
100 
101 /*================================================================*/
102 /* Local Function Declarations */
103 
104 
105 /*================================================================*/
106 /* Function Definitions */
107 
108 /*----------------------------------------------------------------
109 * p80211pb_ether_to_80211
110 *
111 * Uses the contents of the ether frame and the etherconv setting
112 * to build the elements of the 802.11 frame.
113 *
114 * We don't actually set
115 * up the frame header here.  That's the MAC's job.  We're only handling
116 * conversion of DIXII or 802.3+LLC frames to something that works
117 * with 802.11.
118 *
119 * Note -- 802.11 header is NOT part of the skb.  Likewise, the 802.11
120 *         FCS is also not present and will need to be added elsewhere.
121 *
122 * Arguments:
123 *	ethconv		Conversion type to perform
124 *	skb		skbuff containing the ether frame
125 *       p80211_hdr      802.11 header
126 *
127 * Returns:
128 *	0 on success, non-zero otherwise
129 *
130 * Call context:
131 *	May be called in interrupt or non-interrupt context
132 ----------------------------------------------------------------*/
skb_ether_to_p80211(wlandevice_t * wlandev,u32 ethconv,struct sk_buff * skb,p80211_hdr_t * p80211_hdr,p80211_metawep_t * p80211_wep)133 int skb_ether_to_p80211( wlandevice_t *wlandev, u32 ethconv, struct sk_buff *skb, p80211_hdr_t *p80211_hdr, p80211_metawep_t *p80211_wep)
134 {
135 
136 	u16          fc;
137 	u16          proto;
138 	wlan_ethhdr_t   e_hdr;
139 	wlan_llc_t      *e_llc;
140 	wlan_snap_t     *e_snap;
141 	int foo;
142 
143 	DBFENTER;
144 	memcpy(&e_hdr, skb->data, sizeof(e_hdr));
145 
146 	if (skb->len <= 0) {
147 		WLAN_LOG_DEBUG(1, "zero-length skb!\n");
148 		return 1;
149 	}
150 
151 	if ( ethconv == WLAN_ETHCONV_ENCAP ) { /* simplest case */
152 	        WLAN_LOG_DEBUG(3, "ENCAP len: %d\n", skb->len);
153 		/* here, we don't care what kind of ether frm. Just stick it */
154 		/*  in the 80211 payload */
155 		/* which is to say, leave the skb alone. */
156 	} else {
157 		/* step 1: classify ether frame, DIX or 802.3? */
158 		proto = ntohs(e_hdr.type);
159 		if ( proto <= 1500 ) {
160 		        WLAN_LOG_DEBUG(3, "802.3 len: %d\n", skb->len);
161                         /* codes <= 1500 reserved for 802.3 lengths */
162 			/* it's 802.3, pass ether payload unchanged,  */
163 
164 			/* trim off ethernet header */
165 			skb_pull(skb, WLAN_ETHHDR_LEN);
166 
167 			/*   leave off any PAD octets.  */
168 			skb_trim(skb, proto);
169 		} else {
170 		        WLAN_LOG_DEBUG(3, "DIXII len: %d\n", skb->len);
171 			/* it's DIXII, time for some conversion */
172 
173 			/* trim off ethernet header */
174 			skb_pull(skb, WLAN_ETHHDR_LEN);
175 
176 			/* tack on SNAP */
177 			e_snap = (wlan_snap_t *) skb_push(skb, sizeof(wlan_snap_t));
178 			e_snap->type = htons(proto);
179 			if ( ethconv == WLAN_ETHCONV_8021h && p80211_stt_findproto(proto) ) {
180 				memcpy( e_snap->oui, oui_8021h, WLAN_IEEE_OUI_LEN);
181 			} else {
182 				memcpy( e_snap->oui, oui_rfc1042, WLAN_IEEE_OUI_LEN);
183 			}
184 
185 			/* tack on llc */
186 			e_llc = (wlan_llc_t *) skb_push(skb, sizeof(wlan_llc_t));
187 			e_llc->dsap = 0xAA;	/* SNAP, see IEEE 802 */
188 			e_llc->ssap = 0xAA;
189 			e_llc->ctl = 0x03;
190 
191 		}
192 	}
193 
194 	/* Set up the 802.11 header */
195 	/* It's a data frame */
196 	fc = host2ieee16( WLAN_SET_FC_FTYPE(WLAN_FTYPE_DATA) |
197 			  WLAN_SET_FC_FSTYPE(WLAN_FSTYPE_DATAONLY));
198 
199 	switch ( wlandev->macmode ) {
200 	case WLAN_MACMODE_IBSS_STA:
201 		memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, WLAN_ADDR_LEN);
202 		memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, WLAN_ADDR_LEN);
203 		memcpy(p80211_hdr->a3.a3, wlandev->bssid, WLAN_ADDR_LEN);
204 		break;
205 	case WLAN_MACMODE_ESS_STA:
206 		fc |= host2ieee16(WLAN_SET_FC_TODS(1));
207 		memcpy(p80211_hdr->a3.a1, wlandev->bssid, WLAN_ADDR_LEN);
208 		memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, WLAN_ADDR_LEN);
209 		memcpy(p80211_hdr->a3.a3, &e_hdr.daddr, WLAN_ADDR_LEN);
210 		break;
211 	case WLAN_MACMODE_ESS_AP:
212 		fc |= host2ieee16(WLAN_SET_FC_FROMDS(1));
213 		memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, WLAN_ADDR_LEN);
214 		memcpy(p80211_hdr->a3.a2, wlandev->bssid, WLAN_ADDR_LEN);
215 		memcpy(p80211_hdr->a3.a3, &e_hdr.saddr, WLAN_ADDR_LEN);
216 		break;
217 	default:
218 		WLAN_LOG_ERROR("Error: Converting eth to wlan in unknown mode.\n");
219 		return 1;
220 		break;
221 	}
222 
223 	p80211_wep->data = NULL;
224 
225 	if ((wlandev->hostwep & HOSTWEP_PRIVACYINVOKED) && (wlandev->hostwep & HOSTWEP_ENCRYPT)) {
226 		// XXXX need to pick keynum other than default?
227 
228 #if 1
229 		p80211_wep->data = kmalloc(skb->len, GFP_ATOMIC);
230 #else
231 		p80211_wep->data = skb->data;
232 #endif
233 
234 		if ((foo = wep_encrypt(wlandev, skb->data, p80211_wep->data,
235 				       skb->len,
236 				(wlandev->hostwep & HOSTWEP_DEFAULTKEY_MASK),
237 				p80211_wep->iv, p80211_wep->icv))) {
238 			WLAN_LOG_WARNING("Host en-WEP failed, dropping frame (%d).\n", foo);
239 			return 2;
240 		}
241 		fc |= host2ieee16(WLAN_SET_FC_ISWEP(1));
242 	}
243 
244 
245 	//	skb->nh.raw = skb->data;
246 
247 	p80211_hdr->a3.fc = fc;
248 	p80211_hdr->a3.dur = 0;
249 	p80211_hdr->a3.seq = 0;
250 
251 	DBFEXIT;
252 	return 0;
253 }
254 
255 /* jkriegl: from orinoco, modified */
orinoco_spy_gather(wlandevice_t * wlandev,char * mac,p80211_rxmeta_t * rxmeta)256 static void orinoco_spy_gather(wlandevice_t *wlandev, char *mac,
257 			       p80211_rxmeta_t *rxmeta)
258 {
259         int i;
260 
261         /* Gather wireless spy statistics: for each packet, compare the
262          * source address with out list, and if match, get the stats... */
263 
264         for (i = 0; i < wlandev->spy_number; i++) {
265 
266                 if (!memcmp(wlandev->spy_address[i], mac, ETH_ALEN)) {
267 			memcpy(wlandev->spy_address[i], mac, ETH_ALEN);
268                         wlandev->spy_stat[i].level = rxmeta->signal;
269                         wlandev->spy_stat[i].noise = rxmeta->noise;
270                         wlandev->spy_stat[i].qual = (rxmeta->signal > rxmeta->noise) ? \
271                                                      (rxmeta->signal - rxmeta->noise) : 0;
272                         wlandev->spy_stat[i].updated = 0x7;
273                 }
274         }
275 }
276 
277 /*----------------------------------------------------------------
278 * p80211pb_80211_to_ether
279 *
280 * Uses the contents of a received 802.11 frame and the etherconv
281 * setting to build an ether frame.
282 *
283 * This function extracts the src and dest address from the 802.11
284 * frame to use in the construction of the eth frame.
285 *
286 * Arguments:
287 *	ethconv		Conversion type to perform
288 *	skb		Packet buffer containing the 802.11 frame
289 *
290 * Returns:
291 *	0 on success, non-zero otherwise
292 *
293 * Call context:
294 *	May be called in interrupt or non-interrupt context
295 ----------------------------------------------------------------*/
skb_p80211_to_ether(wlandevice_t * wlandev,u32 ethconv,struct sk_buff * skb)296 int skb_p80211_to_ether( wlandevice_t *wlandev, u32 ethconv, struct sk_buff *skb)
297 {
298 	netdevice_t     *netdev = wlandev->netdev;
299 	u16          fc;
300 	unsigned int            payload_length;
301 	unsigned int            payload_offset;
302 	u8		daddr[WLAN_ETHADDR_LEN];
303 	u8		saddr[WLAN_ETHADDR_LEN];
304 	p80211_hdr_t    *w_hdr;
305 	wlan_ethhdr_t   *e_hdr;
306 	wlan_llc_t      *e_llc;
307 	wlan_snap_t     *e_snap;
308 
309 	int foo;
310 
311 	DBFENTER;
312 
313 	payload_length = skb->len - WLAN_HDR_A3_LEN - WLAN_CRC_LEN;
314 	payload_offset = WLAN_HDR_A3_LEN;
315 
316 	w_hdr = (p80211_hdr_t *) skb->data;
317 
318         /* setup some vars for convenience */
319 	fc = ieee2host16(w_hdr->a3.fc);
320 	if ( (WLAN_GET_FC_TODS(fc) == 0) && (WLAN_GET_FC_FROMDS(fc) == 0) ) {
321 		memcpy(daddr, w_hdr->a3.a1, WLAN_ETHADDR_LEN);
322 		memcpy(saddr, w_hdr->a3.a2, WLAN_ETHADDR_LEN);
323 	} else if( (WLAN_GET_FC_TODS(fc) == 0) && (WLAN_GET_FC_FROMDS(fc) == 1) ) {
324 		memcpy(daddr, w_hdr->a3.a1, WLAN_ETHADDR_LEN);
325 		memcpy(saddr, w_hdr->a3.a3, WLAN_ETHADDR_LEN);
326 	} else if( (WLAN_GET_FC_TODS(fc) == 1) && (WLAN_GET_FC_FROMDS(fc) == 0) ) {
327 		memcpy(daddr, w_hdr->a3.a3, WLAN_ETHADDR_LEN);
328 		memcpy(saddr, w_hdr->a3.a2, WLAN_ETHADDR_LEN);
329 	} else {
330 		payload_offset = WLAN_HDR_A4_LEN;
331 		if (payload_length < WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN) {
332 			WLAN_LOG_ERROR("A4 frame too short!\n");
333 			return 1;
334 		}
335 		payload_length -= (WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN);
336 		memcpy(daddr, w_hdr->a4.a3, WLAN_ETHADDR_LEN);
337 		memcpy(saddr, w_hdr->a4.a4, WLAN_ETHADDR_LEN);
338 	}
339 
340 	/* perform de-wep if necessary.. */
341 	if ((wlandev->hostwep & HOSTWEP_PRIVACYINVOKED) && WLAN_GET_FC_ISWEP(fc) && (wlandev->hostwep & HOSTWEP_DECRYPT)) {
342 		if (payload_length <= 8) {
343 			WLAN_LOG_ERROR("WEP frame too short (%u).\n",
344 					skb->len);
345 			return 1;
346 		}
347 		if ((foo = wep_decrypt(wlandev, skb->data + payload_offset + 4,
348 				       payload_length - 8, -1,
349 				       skb->data + payload_offset,
350 				       skb->data + payload_offset + payload_length - 4))) {
351 			/* de-wep failed, drop skb. */
352 			WLAN_LOG_DEBUG(1, "Host de-WEP failed, dropping frame (%d).\n", foo);
353 			wlandev->rx.decrypt_err++;
354 			return 2;
355 		}
356 
357 		/* subtract the IV+ICV length off the payload */
358 		payload_length -= 8;
359 		/* chop off the IV */
360 		skb_pull(skb, 4);
361 		/* chop off the ICV. */
362 		skb_trim(skb, skb->len - 4);
363 
364 		wlandev->rx.decrypt++;
365 	}
366 
367 	e_hdr = (wlan_ethhdr_t *) (skb->data + payload_offset);
368 
369 	e_llc = (wlan_llc_t *) (skb->data + payload_offset);
370 	e_snap = (wlan_snap_t *) (skb->data + payload_offset + sizeof(wlan_llc_t));
371 
372 	/* Test for the various encodings */
373 	if ( (payload_length >= sizeof(wlan_ethhdr_t)) &&
374 	     ( e_llc->dsap != 0xaa || e_llc->ssap != 0xaa ) &&
375 	     ((memcmp(daddr, e_hdr->daddr, WLAN_ETHADDR_LEN) == 0) ||
376 	     (memcmp(saddr, e_hdr->saddr, WLAN_ETHADDR_LEN) == 0))) {
377 		WLAN_LOG_DEBUG(3, "802.3 ENCAP len: %d\n", payload_length);
378 		/* 802.3 Encapsulated */
379 		/* Test for an overlength frame */
380 		if ( payload_length > (netdev->mtu + WLAN_ETHHDR_LEN)) {
381 			/* A bogus length ethfrm has been encap'd. */
382 			/* Is someone trying an oflow attack? */
383 			WLAN_LOG_ERROR("ENCAP frame too large (%d > %d)\n",
384 				payload_length, netdev->mtu + WLAN_ETHHDR_LEN);
385 			return 1;
386 		}
387 
388 		/* Chop off the 802.11 header.  it's already sane. */
389 		skb_pull(skb, payload_offset);
390 		/* chop off the 802.11 CRC */
391 		skb_trim(skb, skb->len - WLAN_CRC_LEN);
392 
393 	} else if ((payload_length >= sizeof(wlan_llc_t) + sizeof(wlan_snap_t)) &&
394 		   (e_llc->dsap == 0xaa) &&
395 		   (e_llc->ssap == 0xaa) &&
396 		   (e_llc->ctl == 0x03) &&
397 		   (((memcmp( e_snap->oui, oui_rfc1042, WLAN_IEEE_OUI_LEN)==0) &&
398 		    (ethconv == WLAN_ETHCONV_8021h) &&
399 		    (p80211_stt_findproto(ieee2host16(e_snap->type)))) ||
400 		    (memcmp( e_snap->oui, oui_rfc1042, WLAN_IEEE_OUI_LEN)!=0)))
401 	{
402 		WLAN_LOG_DEBUG(3, "SNAP+RFC1042 len: %d\n", payload_length);
403 		/* it's a SNAP + RFC1042 frame && protocol is in STT */
404 		/* build 802.3 + RFC1042 */
405 
406 		/* Test for an overlength frame */
407 		if ( payload_length > netdev->mtu ) {
408 			/* A bogus length ethfrm has been sent. */
409 			/* Is someone trying an oflow attack? */
410 			WLAN_LOG_ERROR("SNAP frame too large (%d > %d)\n",
411 				payload_length, netdev->mtu);
412 			return 1;
413 		}
414 
415 		/* chop 802.11 header from skb. */
416 		skb_pull(skb, payload_offset);
417 
418 		/* create 802.3 header at beginning of skb. */
419 		e_hdr = (wlan_ethhdr_t *) skb_push(skb, WLAN_ETHHDR_LEN);
420 		memcpy(e_hdr->daddr, daddr, WLAN_ETHADDR_LEN);
421 		memcpy(e_hdr->saddr, saddr, WLAN_ETHADDR_LEN);
422 		e_hdr->type = htons(payload_length);
423 
424 		/* chop off the 802.11 CRC */
425 		skb_trim(skb, skb->len - WLAN_CRC_LEN);
426 
427 	}  else if ((payload_length >= sizeof(wlan_llc_t) + sizeof(wlan_snap_t)) &&
428 		    (e_llc->dsap == 0xaa) &&
429 		    (e_llc->ssap == 0xaa) &&
430 		    (e_llc->ctl == 0x03) ) {
431 		WLAN_LOG_DEBUG(3, "802.1h/RFC1042 len: %d\n", payload_length);
432 		/* it's an 802.1h frame || (an RFC1042 && protocol is not in STT) */
433 		/* build a DIXII + RFC894 */
434 
435 		/* Test for an overlength frame */
436 		if ((payload_length - sizeof(wlan_llc_t) - sizeof(wlan_snap_t))
437 		    > netdev->mtu) {
438 			/* A bogus length ethfrm has been sent. */
439 			/* Is someone trying an oflow attack? */
440 			WLAN_LOG_ERROR("DIXII frame too large (%ld > %d)\n",
441 					(long int) (payload_length - sizeof(wlan_llc_t) -
442 						    sizeof(wlan_snap_t)),
443 					netdev->mtu);
444 			return 1;
445 		}
446 
447 		/* chop 802.11 header from skb. */
448 		skb_pull(skb, payload_offset);
449 
450 		/* chop llc header from skb. */
451 		skb_pull(skb, sizeof(wlan_llc_t));
452 
453 		/* chop snap header from skb. */
454 		skb_pull(skb, sizeof(wlan_snap_t));
455 
456 		/* create 802.3 header at beginning of skb. */
457 		e_hdr = (wlan_ethhdr_t *) skb_push(skb, WLAN_ETHHDR_LEN);
458 		e_hdr->type = e_snap->type;
459 		memcpy(e_hdr->daddr, daddr, WLAN_ETHADDR_LEN);
460 		memcpy(e_hdr->saddr, saddr, WLAN_ETHADDR_LEN);
461 
462 		/* chop off the 802.11 CRC */
463 		skb_trim(skb, skb->len - WLAN_CRC_LEN);
464 	} else {
465 		WLAN_LOG_DEBUG(3, "NON-ENCAP len: %d\n", payload_length);
466 		/* any NON-ENCAP */
467 		/* it's a generic 80211+LLC or IPX 'Raw 802.3' */
468 		/*  build an 802.3 frame */
469 		/* allocate space and setup hostbuf */
470 
471 		/* Test for an overlength frame */
472 		if ( payload_length > netdev->mtu ) {
473 			/* A bogus length ethfrm has been sent. */
474 			/* Is someone trying an oflow attack? */
475 			WLAN_LOG_ERROR("OTHER frame too large (%d > %d)\n",
476 				payload_length,
477 				netdev->mtu);
478 			return 1;
479 		}
480 
481 		/* Chop off the 802.11 header. */
482 		skb_pull(skb, payload_offset);
483 
484 		/* create 802.3 header at beginning of skb. */
485 		e_hdr = (wlan_ethhdr_t *) skb_push(skb, WLAN_ETHHDR_LEN);
486 		memcpy(e_hdr->daddr, daddr, WLAN_ETHADDR_LEN);
487 		memcpy(e_hdr->saddr, saddr, WLAN_ETHADDR_LEN);
488 		e_hdr->type = htons(payload_length);
489 
490 		/* chop off the 802.11 CRC */
491 		skb_trim(skb, skb->len - WLAN_CRC_LEN);
492 
493 	}
494 
495         /*
496          * Note that eth_type_trans() expects an skb w/ skb->data pointing
497          * at the MAC header, it then sets the following skb members:
498          * skb->mac_header,
499          * skb->data, and
500          * skb->pkt_type.
501          * It then _returns_ the value that _we're_ supposed to stuff in
502          * skb->protocol.  This is nuts.
503          */
504 	skb->protocol = eth_type_trans(skb, netdev);
505 
506         /* jkriegl: process signal and noise as set in hfa384x_int_rx() */
507 	/* jkriegl: only process signal/noise if requested by iwspy */
508         if (wlandev->spy_number)
509                 orinoco_spy_gather(wlandev, eth_hdr(skb)->h_source, P80211SKB_RXMETA(skb));
510 
511 	/* Free the metadata */
512 	p80211skb_rxmeta_detach(skb);
513 
514 	DBFEXIT;
515 	return 0;
516 }
517 
518 /*----------------------------------------------------------------
519 * p80211_stt_findproto
520 *
521 * Searches the 802.1h Selective Translation Table for a given
522 * protocol.
523 *
524 * Arguments:
525 *	proto	protocl number (in host order) to search for.
526 *
527 * Returns:
528 *	1 - if the table is empty or a match is found.
529 *	0 - if the table is non-empty and a match is not found.
530 *
531 * Call context:
532 *	May be called in interrupt or non-interrupt context
533 ----------------------------------------------------------------*/
p80211_stt_findproto(u16 proto)534 int p80211_stt_findproto(u16 proto)
535 {
536 	/* Always return found for now.  This is the behavior used by the */
537 	/*  Zoom Win95 driver when 802.1h mode is selected */
538 	/* TODO: If necessary, add an actual search we'll probably
539 		 need this to match the CMAC's way of doing things.
540 		 Need to do some testing to confirm.
541 	*/
542 
543 	if (proto == 0x80f3)  /* APPLETALK */
544 		return 1;
545 
546 	return 0;
547 }
548 
549 /*----------------------------------------------------------------
550 * p80211skb_rxmeta_detach
551 *
552 * Disconnects the frmmeta and rxmeta from an skb.
553 *
554 * Arguments:
555 *	wlandev		The wlandev this skb belongs to.
556 *	skb		The skb we're attaching to.
557 *
558 * Returns:
559 *	0 on success, non-zero otherwise
560 *
561 * Call context:
562 *	May be called in interrupt or non-interrupt context
563 ----------------------------------------------------------------*/
564 void
p80211skb_rxmeta_detach(struct sk_buff * skb)565 p80211skb_rxmeta_detach(struct sk_buff *skb)
566 {
567 	p80211_rxmeta_t		*rxmeta;
568 	p80211_frmmeta_t	*frmmeta;
569 
570 	DBFENTER;
571 	/* Sanity checks */
572 	if ( skb==NULL ) {			/* bad skb */
573 		WLAN_LOG_DEBUG(1, "Called w/ null skb.\n");
574 		goto exit;
575 	}
576 	frmmeta = P80211SKB_FRMMETA(skb);
577 	if ( frmmeta == NULL ) { 		/* no magic */
578 		WLAN_LOG_DEBUG(1, "Called w/ bad frmmeta magic.\n");
579 		goto exit;
580 	}
581 	rxmeta = frmmeta->rx;
582 	if ( rxmeta == NULL ) {			/* bad meta ptr */
583 		WLAN_LOG_DEBUG(1, "Called w/ bad rxmeta ptr.\n");
584 		goto exit;
585 	}
586 
587 	/* Free rxmeta */
588 	kfree(rxmeta);
589 
590 	/* Clear skb->cb */
591 	memset(skb->cb, 0, sizeof(skb->cb));
592 exit:
593 	DBFEXIT;
594 	return;
595 }
596 
597 /*----------------------------------------------------------------
598 * p80211skb_rxmeta_attach
599 *
600 * Allocates a p80211rxmeta structure, initializes it, and attaches
601 * it to an skb.
602 *
603 * Arguments:
604 *	wlandev		The wlandev this skb belongs to.
605 *	skb		The skb we're attaching to.
606 *
607 * Returns:
608 *	0 on success, non-zero otherwise
609 *
610 * Call context:
611 *	May be called in interrupt or non-interrupt context
612 ----------------------------------------------------------------*/
613 int
p80211skb_rxmeta_attach(struct wlandevice * wlandev,struct sk_buff * skb)614 p80211skb_rxmeta_attach(struct wlandevice *wlandev, struct sk_buff *skb)
615 {
616 	int			result = 0;
617 	p80211_rxmeta_t		*rxmeta;
618 	p80211_frmmeta_t	*frmmeta;
619 
620 	DBFENTER;
621 
622 	/* If these already have metadata, we error out! */
623 	if (P80211SKB_RXMETA(skb) != NULL) {
624 		WLAN_LOG_ERROR("%s: RXmeta already attached!\n",
625 				wlandev->name);
626 		result = 0;
627 		goto exit;
628 	}
629 
630 	/* Allocate the rxmeta */
631 	rxmeta = kmalloc(sizeof(p80211_rxmeta_t), GFP_ATOMIC);
632 
633 	if ( rxmeta == NULL ) {
634 		WLAN_LOG_ERROR("%s: Failed to allocate rxmeta.\n",
635 				wlandev->name);
636 		result = 1;
637 		goto exit;
638 	}
639 
640 	/* Initialize the rxmeta */
641 	memset(rxmeta, 0, sizeof(p80211_rxmeta_t));
642 	rxmeta->wlandev = wlandev;
643 	rxmeta->hosttime = jiffies;
644 
645 	/* Overlay a frmmeta_t onto skb->cb */
646 	memset(skb->cb, 0, sizeof(p80211_frmmeta_t));
647 	frmmeta = (p80211_frmmeta_t*)(skb->cb);
648 	frmmeta->magic = P80211_FRMMETA_MAGIC;
649 	frmmeta->rx = rxmeta;
650 exit:
651 	DBFEXIT;
652 	return result;
653 }
654 
655 /*----------------------------------------------------------------
656 * p80211skb_free
657 *
658 * Frees an entire p80211skb by checking and freeing the meta struct
659 * and then freeing the skb.
660 *
661 * Arguments:
662 *	wlandev		The wlandev this skb belongs to.
663 *	skb		The skb we're attaching to.
664 *
665 * Returns:
666 *	0 on success, non-zero otherwise
667 *
668 * Call context:
669 *	May be called in interrupt or non-interrupt context
670 ----------------------------------------------------------------*/
671 void
p80211skb_free(struct wlandevice * wlandev,struct sk_buff * skb)672 p80211skb_free(struct wlandevice *wlandev, struct sk_buff *skb)
673 {
674 	p80211_frmmeta_t	*meta;
675 	DBFENTER;
676 	meta = P80211SKB_FRMMETA(skb);
677 	if ( meta && meta->rx) {
678 		p80211skb_rxmeta_detach(skb);
679 	} else {
680 		WLAN_LOG_ERROR("Freeing an skb (%p) w/ no frmmeta.\n", skb);
681 	}
682 
683 	dev_kfree_skb(skb);
684 	DBFEXIT;
685 	return;
686 }
687