xref: /openbmc/linux/net/wireless/wext-core.c (revision bc3b2d7f)
1 /*
2  * This file implement the Wireless Extensions core API.
3  *
4  * Authors :	Jean Tourrilhes - HPL - <jt@hpl.hp.com>
5  * Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
6  * Copyright	2009 Johannes Berg <johannes@sipsolutions.net>
7  *
8  * (As all part of the Linux kernel, this file is GPL)
9  */
10 #include <linux/kernel.h>
11 #include <linux/netdevice.h>
12 #include <linux/rtnetlink.h>
13 #include <linux/slab.h>
14 #include <linux/wireless.h>
15 #include <linux/uaccess.h>
16 #include <linux/export.h>
17 #include <net/cfg80211.h>
18 #include <net/iw_handler.h>
19 #include <net/netlink.h>
20 #include <net/wext.h>
21 #include <net/net_namespace.h>
22 
23 typedef int (*wext_ioctl_func)(struct net_device *, struct iwreq *,
24 			       unsigned int, struct iw_request_info *,
25 			       iw_handler);
26 
27 
28 /*
29  * Meta-data about all the standard Wireless Extension request we
30  * know about.
31  */
32 static const struct iw_ioctl_description standard_ioctl[] = {
33 	[IW_IOCTL_IDX(SIOCSIWCOMMIT)] = {
34 		.header_type	= IW_HEADER_TYPE_NULL,
35 	},
36 	[IW_IOCTL_IDX(SIOCGIWNAME)] = {
37 		.header_type	= IW_HEADER_TYPE_CHAR,
38 		.flags		= IW_DESCR_FLAG_DUMP,
39 	},
40 	[IW_IOCTL_IDX(SIOCSIWNWID)] = {
41 		.header_type	= IW_HEADER_TYPE_PARAM,
42 		.flags		= IW_DESCR_FLAG_EVENT,
43 	},
44 	[IW_IOCTL_IDX(SIOCGIWNWID)] = {
45 		.header_type	= IW_HEADER_TYPE_PARAM,
46 		.flags		= IW_DESCR_FLAG_DUMP,
47 	},
48 	[IW_IOCTL_IDX(SIOCSIWFREQ)] = {
49 		.header_type	= IW_HEADER_TYPE_FREQ,
50 		.flags		= IW_DESCR_FLAG_EVENT,
51 	},
52 	[IW_IOCTL_IDX(SIOCGIWFREQ)] = {
53 		.header_type	= IW_HEADER_TYPE_FREQ,
54 		.flags		= IW_DESCR_FLAG_DUMP,
55 	},
56 	[IW_IOCTL_IDX(SIOCSIWMODE)] = {
57 		.header_type	= IW_HEADER_TYPE_UINT,
58 		.flags		= IW_DESCR_FLAG_EVENT,
59 	},
60 	[IW_IOCTL_IDX(SIOCGIWMODE)] = {
61 		.header_type	= IW_HEADER_TYPE_UINT,
62 		.flags		= IW_DESCR_FLAG_DUMP,
63 	},
64 	[IW_IOCTL_IDX(SIOCSIWSENS)] = {
65 		.header_type	= IW_HEADER_TYPE_PARAM,
66 	},
67 	[IW_IOCTL_IDX(SIOCGIWSENS)] = {
68 		.header_type	= IW_HEADER_TYPE_PARAM,
69 	},
70 	[IW_IOCTL_IDX(SIOCSIWRANGE)] = {
71 		.header_type	= IW_HEADER_TYPE_NULL,
72 	},
73 	[IW_IOCTL_IDX(SIOCGIWRANGE)] = {
74 		.header_type	= IW_HEADER_TYPE_POINT,
75 		.token_size	= 1,
76 		.max_tokens	= sizeof(struct iw_range),
77 		.flags		= IW_DESCR_FLAG_DUMP,
78 	},
79 	[IW_IOCTL_IDX(SIOCSIWPRIV)] = {
80 		.header_type	= IW_HEADER_TYPE_NULL,
81 	},
82 	[IW_IOCTL_IDX(SIOCGIWPRIV)] = { /* (handled directly by us) */
83 		.header_type	= IW_HEADER_TYPE_POINT,
84 		.token_size	= sizeof(struct iw_priv_args),
85 		.max_tokens	= 16,
86 		.flags		= IW_DESCR_FLAG_NOMAX,
87 	},
88 	[IW_IOCTL_IDX(SIOCSIWSTATS)] = {
89 		.header_type	= IW_HEADER_TYPE_NULL,
90 	},
91 	[IW_IOCTL_IDX(SIOCGIWSTATS)] = { /* (handled directly by us) */
92 		.header_type	= IW_HEADER_TYPE_POINT,
93 		.token_size	= 1,
94 		.max_tokens	= sizeof(struct iw_statistics),
95 		.flags		= IW_DESCR_FLAG_DUMP,
96 	},
97 	[IW_IOCTL_IDX(SIOCSIWSPY)] = {
98 		.header_type	= IW_HEADER_TYPE_POINT,
99 		.token_size	= sizeof(struct sockaddr),
100 		.max_tokens	= IW_MAX_SPY,
101 	},
102 	[IW_IOCTL_IDX(SIOCGIWSPY)] = {
103 		.header_type	= IW_HEADER_TYPE_POINT,
104 		.token_size	= sizeof(struct sockaddr) +
105 				  sizeof(struct iw_quality),
106 		.max_tokens	= IW_MAX_SPY,
107 	},
108 	[IW_IOCTL_IDX(SIOCSIWTHRSPY)] = {
109 		.header_type	= IW_HEADER_TYPE_POINT,
110 		.token_size	= sizeof(struct iw_thrspy),
111 		.min_tokens	= 1,
112 		.max_tokens	= 1,
113 	},
114 	[IW_IOCTL_IDX(SIOCGIWTHRSPY)] = {
115 		.header_type	= IW_HEADER_TYPE_POINT,
116 		.token_size	= sizeof(struct iw_thrspy),
117 		.min_tokens	= 1,
118 		.max_tokens	= 1,
119 	},
120 	[IW_IOCTL_IDX(SIOCSIWAP)] = {
121 		.header_type	= IW_HEADER_TYPE_ADDR,
122 	},
123 	[IW_IOCTL_IDX(SIOCGIWAP)] = {
124 		.header_type	= IW_HEADER_TYPE_ADDR,
125 		.flags		= IW_DESCR_FLAG_DUMP,
126 	},
127 	[IW_IOCTL_IDX(SIOCSIWMLME)] = {
128 		.header_type	= IW_HEADER_TYPE_POINT,
129 		.token_size	= 1,
130 		.min_tokens	= sizeof(struct iw_mlme),
131 		.max_tokens	= sizeof(struct iw_mlme),
132 	},
133 	[IW_IOCTL_IDX(SIOCGIWAPLIST)] = {
134 		.header_type	= IW_HEADER_TYPE_POINT,
135 		.token_size	= sizeof(struct sockaddr) +
136 				  sizeof(struct iw_quality),
137 		.max_tokens	= IW_MAX_AP,
138 		.flags		= IW_DESCR_FLAG_NOMAX,
139 	},
140 	[IW_IOCTL_IDX(SIOCSIWSCAN)] = {
141 		.header_type	= IW_HEADER_TYPE_POINT,
142 		.token_size	= 1,
143 		.min_tokens	= 0,
144 		.max_tokens	= sizeof(struct iw_scan_req),
145 	},
146 	[IW_IOCTL_IDX(SIOCGIWSCAN)] = {
147 		.header_type	= IW_HEADER_TYPE_POINT,
148 		.token_size	= 1,
149 		.max_tokens	= IW_SCAN_MAX_DATA,
150 		.flags		= IW_DESCR_FLAG_NOMAX,
151 	},
152 	[IW_IOCTL_IDX(SIOCSIWESSID)] = {
153 		.header_type	= IW_HEADER_TYPE_POINT,
154 		.token_size	= 1,
155 		.max_tokens	= IW_ESSID_MAX_SIZE,
156 		.flags		= IW_DESCR_FLAG_EVENT,
157 	},
158 	[IW_IOCTL_IDX(SIOCGIWESSID)] = {
159 		.header_type	= IW_HEADER_TYPE_POINT,
160 		.token_size	= 1,
161 		.max_tokens	= IW_ESSID_MAX_SIZE,
162 		.flags		= IW_DESCR_FLAG_DUMP,
163 	},
164 	[IW_IOCTL_IDX(SIOCSIWNICKN)] = {
165 		.header_type	= IW_HEADER_TYPE_POINT,
166 		.token_size	= 1,
167 		.max_tokens	= IW_ESSID_MAX_SIZE,
168 	},
169 	[IW_IOCTL_IDX(SIOCGIWNICKN)] = {
170 		.header_type	= IW_HEADER_TYPE_POINT,
171 		.token_size	= 1,
172 		.max_tokens	= IW_ESSID_MAX_SIZE,
173 	},
174 	[IW_IOCTL_IDX(SIOCSIWRATE)] = {
175 		.header_type	= IW_HEADER_TYPE_PARAM,
176 	},
177 	[IW_IOCTL_IDX(SIOCGIWRATE)] = {
178 		.header_type	= IW_HEADER_TYPE_PARAM,
179 	},
180 	[IW_IOCTL_IDX(SIOCSIWRTS)] = {
181 		.header_type	= IW_HEADER_TYPE_PARAM,
182 	},
183 	[IW_IOCTL_IDX(SIOCGIWRTS)] = {
184 		.header_type	= IW_HEADER_TYPE_PARAM,
185 	},
186 	[IW_IOCTL_IDX(SIOCSIWFRAG)] = {
187 		.header_type	= IW_HEADER_TYPE_PARAM,
188 	},
189 	[IW_IOCTL_IDX(SIOCGIWFRAG)] = {
190 		.header_type	= IW_HEADER_TYPE_PARAM,
191 	},
192 	[IW_IOCTL_IDX(SIOCSIWTXPOW)] = {
193 		.header_type	= IW_HEADER_TYPE_PARAM,
194 	},
195 	[IW_IOCTL_IDX(SIOCGIWTXPOW)] = {
196 		.header_type	= IW_HEADER_TYPE_PARAM,
197 	},
198 	[IW_IOCTL_IDX(SIOCSIWRETRY)] = {
199 		.header_type	= IW_HEADER_TYPE_PARAM,
200 	},
201 	[IW_IOCTL_IDX(SIOCGIWRETRY)] = {
202 		.header_type	= IW_HEADER_TYPE_PARAM,
203 	},
204 	[IW_IOCTL_IDX(SIOCSIWENCODE)] = {
205 		.header_type	= IW_HEADER_TYPE_POINT,
206 		.token_size	= 1,
207 		.max_tokens	= IW_ENCODING_TOKEN_MAX,
208 		.flags		= IW_DESCR_FLAG_EVENT | IW_DESCR_FLAG_RESTRICT,
209 	},
210 	[IW_IOCTL_IDX(SIOCGIWENCODE)] = {
211 		.header_type	= IW_HEADER_TYPE_POINT,
212 		.token_size	= 1,
213 		.max_tokens	= IW_ENCODING_TOKEN_MAX,
214 		.flags		= IW_DESCR_FLAG_DUMP | IW_DESCR_FLAG_RESTRICT,
215 	},
216 	[IW_IOCTL_IDX(SIOCSIWPOWER)] = {
217 		.header_type	= IW_HEADER_TYPE_PARAM,
218 	},
219 	[IW_IOCTL_IDX(SIOCGIWPOWER)] = {
220 		.header_type	= IW_HEADER_TYPE_PARAM,
221 	},
222 	[IW_IOCTL_IDX(SIOCSIWGENIE)] = {
223 		.header_type	= IW_HEADER_TYPE_POINT,
224 		.token_size	= 1,
225 		.max_tokens	= IW_GENERIC_IE_MAX,
226 	},
227 	[IW_IOCTL_IDX(SIOCGIWGENIE)] = {
228 		.header_type	= IW_HEADER_TYPE_POINT,
229 		.token_size	= 1,
230 		.max_tokens	= IW_GENERIC_IE_MAX,
231 	},
232 	[IW_IOCTL_IDX(SIOCSIWAUTH)] = {
233 		.header_type	= IW_HEADER_TYPE_PARAM,
234 	},
235 	[IW_IOCTL_IDX(SIOCGIWAUTH)] = {
236 		.header_type	= IW_HEADER_TYPE_PARAM,
237 	},
238 	[IW_IOCTL_IDX(SIOCSIWENCODEEXT)] = {
239 		.header_type	= IW_HEADER_TYPE_POINT,
240 		.token_size	= 1,
241 		.min_tokens	= sizeof(struct iw_encode_ext),
242 		.max_tokens	= sizeof(struct iw_encode_ext) +
243 				  IW_ENCODING_TOKEN_MAX,
244 	},
245 	[IW_IOCTL_IDX(SIOCGIWENCODEEXT)] = {
246 		.header_type	= IW_HEADER_TYPE_POINT,
247 		.token_size	= 1,
248 		.min_tokens	= sizeof(struct iw_encode_ext),
249 		.max_tokens	= sizeof(struct iw_encode_ext) +
250 				  IW_ENCODING_TOKEN_MAX,
251 	},
252 	[IW_IOCTL_IDX(SIOCSIWPMKSA)] = {
253 		.header_type	= IW_HEADER_TYPE_POINT,
254 		.token_size	= 1,
255 		.min_tokens	= sizeof(struct iw_pmksa),
256 		.max_tokens	= sizeof(struct iw_pmksa),
257 	},
258 };
259 static const unsigned standard_ioctl_num = ARRAY_SIZE(standard_ioctl);
260 
261 /*
262  * Meta-data about all the additional standard Wireless Extension events
263  * we know about.
264  */
265 static const struct iw_ioctl_description standard_event[] = {
266 	[IW_EVENT_IDX(IWEVTXDROP)] = {
267 		.header_type	= IW_HEADER_TYPE_ADDR,
268 	},
269 	[IW_EVENT_IDX(IWEVQUAL)] = {
270 		.header_type	= IW_HEADER_TYPE_QUAL,
271 	},
272 	[IW_EVENT_IDX(IWEVCUSTOM)] = {
273 		.header_type	= IW_HEADER_TYPE_POINT,
274 		.token_size	= 1,
275 		.max_tokens	= IW_CUSTOM_MAX,
276 	},
277 	[IW_EVENT_IDX(IWEVREGISTERED)] = {
278 		.header_type	= IW_HEADER_TYPE_ADDR,
279 	},
280 	[IW_EVENT_IDX(IWEVEXPIRED)] = {
281 		.header_type	= IW_HEADER_TYPE_ADDR,
282 	},
283 	[IW_EVENT_IDX(IWEVGENIE)] = {
284 		.header_type	= IW_HEADER_TYPE_POINT,
285 		.token_size	= 1,
286 		.max_tokens	= IW_GENERIC_IE_MAX,
287 	},
288 	[IW_EVENT_IDX(IWEVMICHAELMICFAILURE)] = {
289 		.header_type	= IW_HEADER_TYPE_POINT,
290 		.token_size	= 1,
291 		.max_tokens	= sizeof(struct iw_michaelmicfailure),
292 	},
293 	[IW_EVENT_IDX(IWEVASSOCREQIE)] = {
294 		.header_type	= IW_HEADER_TYPE_POINT,
295 		.token_size	= 1,
296 		.max_tokens	= IW_GENERIC_IE_MAX,
297 	},
298 	[IW_EVENT_IDX(IWEVASSOCRESPIE)] = {
299 		.header_type	= IW_HEADER_TYPE_POINT,
300 		.token_size	= 1,
301 		.max_tokens	= IW_GENERIC_IE_MAX,
302 	},
303 	[IW_EVENT_IDX(IWEVPMKIDCAND)] = {
304 		.header_type	= IW_HEADER_TYPE_POINT,
305 		.token_size	= 1,
306 		.max_tokens	= sizeof(struct iw_pmkid_cand),
307 	},
308 };
309 static const unsigned standard_event_num = ARRAY_SIZE(standard_event);
310 
311 /* Size (in bytes) of various events */
312 static const int event_type_size[] = {
313 	IW_EV_LCP_LEN,			/* IW_HEADER_TYPE_NULL */
314 	0,
315 	IW_EV_CHAR_LEN,			/* IW_HEADER_TYPE_CHAR */
316 	0,
317 	IW_EV_UINT_LEN,			/* IW_HEADER_TYPE_UINT */
318 	IW_EV_FREQ_LEN,			/* IW_HEADER_TYPE_FREQ */
319 	IW_EV_ADDR_LEN,			/* IW_HEADER_TYPE_ADDR */
320 	0,
321 	IW_EV_POINT_LEN,		/* Without variable payload */
322 	IW_EV_PARAM_LEN,		/* IW_HEADER_TYPE_PARAM */
323 	IW_EV_QUAL_LEN,			/* IW_HEADER_TYPE_QUAL */
324 };
325 
326 #ifdef CONFIG_COMPAT
327 static const int compat_event_type_size[] = {
328 	IW_EV_COMPAT_LCP_LEN,		/* IW_HEADER_TYPE_NULL */
329 	0,
330 	IW_EV_COMPAT_CHAR_LEN,		/* IW_HEADER_TYPE_CHAR */
331 	0,
332 	IW_EV_COMPAT_UINT_LEN,		/* IW_HEADER_TYPE_UINT */
333 	IW_EV_COMPAT_FREQ_LEN,		/* IW_HEADER_TYPE_FREQ */
334 	IW_EV_COMPAT_ADDR_LEN,		/* IW_HEADER_TYPE_ADDR */
335 	0,
336 	IW_EV_COMPAT_POINT_LEN,		/* Without variable payload */
337 	IW_EV_COMPAT_PARAM_LEN,		/* IW_HEADER_TYPE_PARAM */
338 	IW_EV_COMPAT_QUAL_LEN,		/* IW_HEADER_TYPE_QUAL */
339 };
340 #endif
341 
342 
343 /* IW event code */
344 
345 static int __net_init wext_pernet_init(struct net *net)
346 {
347 	skb_queue_head_init(&net->wext_nlevents);
348 	return 0;
349 }
350 
351 static void __net_exit wext_pernet_exit(struct net *net)
352 {
353 	skb_queue_purge(&net->wext_nlevents);
354 }
355 
356 static struct pernet_operations wext_pernet_ops = {
357 	.init = wext_pernet_init,
358 	.exit = wext_pernet_exit,
359 };
360 
361 static int __init wireless_nlevent_init(void)
362 {
363 	return register_pernet_subsys(&wext_pernet_ops);
364 }
365 
366 subsys_initcall(wireless_nlevent_init);
367 
368 /* Process events generated by the wireless layer or the driver. */
369 static void wireless_nlevent_process(struct work_struct *work)
370 {
371 	struct sk_buff *skb;
372 	struct net *net;
373 
374 	rtnl_lock();
375 
376 	for_each_net(net) {
377 		while ((skb = skb_dequeue(&net->wext_nlevents)))
378 			rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL,
379 				    GFP_KERNEL);
380 	}
381 
382 	rtnl_unlock();
383 }
384 
385 static DECLARE_WORK(wireless_nlevent_work, wireless_nlevent_process);
386 
387 static struct nlmsghdr *rtnetlink_ifinfo_prep(struct net_device *dev,
388 					      struct sk_buff *skb)
389 {
390 	struct ifinfomsg *r;
391 	struct nlmsghdr  *nlh;
392 
393 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWLINK, sizeof(*r), 0);
394 	if (!nlh)
395 		return NULL;
396 
397 	r = nlmsg_data(nlh);
398 	r->ifi_family = AF_UNSPEC;
399 	r->__ifi_pad = 0;
400 	r->ifi_type = dev->type;
401 	r->ifi_index = dev->ifindex;
402 	r->ifi_flags = dev_get_flags(dev);
403 	r->ifi_change = 0;	/* Wireless changes don't affect those flags */
404 
405 	NLA_PUT_STRING(skb, IFLA_IFNAME, dev->name);
406 
407 	return nlh;
408  nla_put_failure:
409 	nlmsg_cancel(skb, nlh);
410 	return NULL;
411 }
412 
413 
414 /*
415  * Main event dispatcher. Called from other parts and drivers.
416  * Send the event on the appropriate channels.
417  * May be called from interrupt context.
418  */
419 void wireless_send_event(struct net_device *	dev,
420 			 unsigned int		cmd,
421 			 union iwreq_data *	wrqu,
422 			 const char *		extra)
423 {
424 	const struct iw_ioctl_description *	descr = NULL;
425 	int extra_len = 0;
426 	struct iw_event  *event;		/* Mallocated whole event */
427 	int event_len;				/* Its size */
428 	int hdr_len;				/* Size of the event header */
429 	int wrqu_off = 0;			/* Offset in wrqu */
430 	/* Don't "optimise" the following variable, it will crash */
431 	unsigned	cmd_index;		/* *MUST* be unsigned */
432 	struct sk_buff *skb;
433 	struct nlmsghdr *nlh;
434 	struct nlattr *nla;
435 #ifdef CONFIG_COMPAT
436 	struct __compat_iw_event *compat_event;
437 	struct compat_iw_point compat_wrqu;
438 	struct sk_buff *compskb;
439 #endif
440 
441 	/*
442 	 * Nothing in the kernel sends scan events with data, be safe.
443 	 * This is necessary because we cannot fix up scan event data
444 	 * for compat, due to being contained in 'extra', but normally
445 	 * applications are required to retrieve the scan data anyway
446 	 * and no data is included in the event, this codifies that
447 	 * practice.
448 	 */
449 	if (WARN_ON(cmd == SIOCGIWSCAN && extra))
450 		extra = NULL;
451 
452 	/* Get the description of the Event */
453 	if (cmd <= SIOCIWLAST) {
454 		cmd_index = IW_IOCTL_IDX(cmd);
455 		if (cmd_index < standard_ioctl_num)
456 			descr = &(standard_ioctl[cmd_index]);
457 	} else {
458 		cmd_index = IW_EVENT_IDX(cmd);
459 		if (cmd_index < standard_event_num)
460 			descr = &(standard_event[cmd_index]);
461 	}
462 	/* Don't accept unknown events */
463 	if (descr == NULL) {
464 		/* Note : we don't return an error to the driver, because
465 		 * the driver would not know what to do about it. It can't
466 		 * return an error to the user, because the event is not
467 		 * initiated by a user request.
468 		 * The best the driver could do is to log an error message.
469 		 * We will do it ourselves instead...
470 		 */
471 		netdev_err(dev, "(WE) : Invalid/Unknown Wireless Event (0x%04X)\n",
472 			   cmd);
473 		return;
474 	}
475 
476 	/* Check extra parameters and set extra_len */
477 	if (descr->header_type == IW_HEADER_TYPE_POINT) {
478 		/* Check if number of token fits within bounds */
479 		if (wrqu->data.length > descr->max_tokens) {
480 			netdev_err(dev, "(WE) : Wireless Event too big (%d)\n",
481 				   wrqu->data.length);
482 			return;
483 		}
484 		if (wrqu->data.length < descr->min_tokens) {
485 			netdev_err(dev, "(WE) : Wireless Event too small (%d)\n",
486 				   wrqu->data.length);
487 			return;
488 		}
489 		/* Calculate extra_len - extra is NULL for restricted events */
490 		if (extra != NULL)
491 			extra_len = wrqu->data.length * descr->token_size;
492 		/* Always at an offset in wrqu */
493 		wrqu_off = IW_EV_POINT_OFF;
494 	}
495 
496 	/* Total length of the event */
497 	hdr_len = event_type_size[descr->header_type];
498 	event_len = hdr_len + extra_len;
499 
500 	/*
501 	 * The problem for 64/32 bit.
502 	 *
503 	 * On 64-bit, a regular event is laid out as follows:
504 	 *      |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |
505 	 *      | event.len | event.cmd |     p a d d i n g     |
506 	 *      | wrqu data ... (with the correct size)         |
507 	 *
508 	 * This padding exists because we manipulate event->u,
509 	 * and 'event' is not packed.
510 	 *
511 	 * An iw_point event is laid out like this instead:
512 	 *      |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |
513 	 *      | event.len | event.cmd |     p a d d i n g     |
514 	 *      | iwpnt.len | iwpnt.flg |     p a d d i n g     |
515 	 *      | extra data  ...
516 	 *
517 	 * The second padding exists because struct iw_point is extended,
518 	 * but this depends on the platform...
519 	 *
520 	 * On 32-bit, all the padding shouldn't be there.
521 	 */
522 
523 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
524 	if (!skb)
525 		return;
526 
527 	/* Send via the RtNetlink event channel */
528 	nlh = rtnetlink_ifinfo_prep(dev, skb);
529 	if (WARN_ON(!nlh)) {
530 		kfree_skb(skb);
531 		return;
532 	}
533 
534 	/* Add the wireless events in the netlink packet */
535 	nla = nla_reserve(skb, IFLA_WIRELESS, event_len);
536 	if (!nla) {
537 		kfree_skb(skb);
538 		return;
539 	}
540 	event = nla_data(nla);
541 
542 	/* Fill event - first clear to avoid data leaking */
543 	memset(event, 0, hdr_len);
544 	event->len = event_len;
545 	event->cmd = cmd;
546 	memcpy(&event->u, ((char *) wrqu) + wrqu_off, hdr_len - IW_EV_LCP_LEN);
547 	if (extra_len)
548 		memcpy(((char *) event) + hdr_len, extra, extra_len);
549 
550 	nlmsg_end(skb, nlh);
551 #ifdef CONFIG_COMPAT
552 	hdr_len = compat_event_type_size[descr->header_type];
553 	event_len = hdr_len + extra_len;
554 
555 	compskb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
556 	if (!compskb) {
557 		kfree_skb(skb);
558 		return;
559 	}
560 
561 	/* Send via the RtNetlink event channel */
562 	nlh = rtnetlink_ifinfo_prep(dev, compskb);
563 	if (WARN_ON(!nlh)) {
564 		kfree_skb(skb);
565 		kfree_skb(compskb);
566 		return;
567 	}
568 
569 	/* Add the wireless events in the netlink packet */
570 	nla = nla_reserve(compskb, IFLA_WIRELESS, event_len);
571 	if (!nla) {
572 		kfree_skb(skb);
573 		kfree_skb(compskb);
574 		return;
575 	}
576 	compat_event = nla_data(nla);
577 
578 	compat_event->len = event_len;
579 	compat_event->cmd = cmd;
580 	if (descr->header_type == IW_HEADER_TYPE_POINT) {
581 		compat_wrqu.length = wrqu->data.length;
582 		compat_wrqu.flags = wrqu->data.flags;
583 		memcpy(&compat_event->pointer,
584 			((char *) &compat_wrqu) + IW_EV_COMPAT_POINT_OFF,
585 			hdr_len - IW_EV_COMPAT_LCP_LEN);
586 		if (extra_len)
587 			memcpy(((char *) compat_event) + hdr_len,
588 				extra, extra_len);
589 	} else {
590 		/* extra_len must be zero, so no if (extra) needed */
591 		memcpy(&compat_event->pointer, wrqu,
592 			hdr_len - IW_EV_COMPAT_LCP_LEN);
593 	}
594 
595 	nlmsg_end(compskb, nlh);
596 
597 	skb_shinfo(skb)->frag_list = compskb;
598 #endif
599 	skb_queue_tail(&dev_net(dev)->wext_nlevents, skb);
600 	schedule_work(&wireless_nlevent_work);
601 }
602 EXPORT_SYMBOL(wireless_send_event);
603 
604 
605 
606 /* IW handlers */
607 
608 struct iw_statistics *get_wireless_stats(struct net_device *dev)
609 {
610 #ifdef CONFIG_WIRELESS_EXT
611 	if ((dev->wireless_handlers != NULL) &&
612 	   (dev->wireless_handlers->get_wireless_stats != NULL))
613 		return dev->wireless_handlers->get_wireless_stats(dev);
614 #endif
615 
616 #ifdef CONFIG_CFG80211_WEXT
617 	if (dev->ieee80211_ptr &&
618 	    dev->ieee80211_ptr->wiphy &&
619 	    dev->ieee80211_ptr->wiphy->wext &&
620 	    dev->ieee80211_ptr->wiphy->wext->get_wireless_stats)
621 		return dev->ieee80211_ptr->wiphy->wext->get_wireless_stats(dev);
622 #endif
623 
624 	/* not found */
625 	return NULL;
626 }
627 
628 static int iw_handler_get_iwstats(struct net_device *		dev,
629 				  struct iw_request_info *	info,
630 				  union iwreq_data *		wrqu,
631 				  char *			extra)
632 {
633 	/* Get stats from the driver */
634 	struct iw_statistics *stats;
635 
636 	stats = get_wireless_stats(dev);
637 	if (stats) {
638 		/* Copy statistics to extra */
639 		memcpy(extra, stats, sizeof(struct iw_statistics));
640 		wrqu->data.length = sizeof(struct iw_statistics);
641 
642 		/* Check if we need to clear the updated flag */
643 		if (wrqu->data.flags != 0)
644 			stats->qual.updated &= ~IW_QUAL_ALL_UPDATED;
645 		return 0;
646 	} else
647 		return -EOPNOTSUPP;
648 }
649 
650 static iw_handler get_handler(struct net_device *dev, unsigned int cmd)
651 {
652 	/* Don't "optimise" the following variable, it will crash */
653 	unsigned int	index;		/* *MUST* be unsigned */
654 	const struct iw_handler_def *handlers = NULL;
655 
656 #ifdef CONFIG_CFG80211_WEXT
657 	if (dev->ieee80211_ptr && dev->ieee80211_ptr->wiphy)
658 		handlers = dev->ieee80211_ptr->wiphy->wext;
659 #endif
660 #ifdef CONFIG_WIRELESS_EXT
661 	if (dev->wireless_handlers)
662 		handlers = dev->wireless_handlers;
663 #endif
664 
665 	if (!handlers)
666 		return NULL;
667 
668 	/* Try as a standard command */
669 	index = IW_IOCTL_IDX(cmd);
670 	if (index < handlers->num_standard)
671 		return handlers->standard[index];
672 
673 #ifdef CONFIG_WEXT_PRIV
674 	/* Try as a private command */
675 	index = cmd - SIOCIWFIRSTPRIV;
676 	if (index < handlers->num_private)
677 		return handlers->private[index];
678 #endif
679 
680 	/* Not found */
681 	return NULL;
682 }
683 
684 static int ioctl_standard_iw_point(struct iw_point *iwp, unsigned int cmd,
685 				   const struct iw_ioctl_description *descr,
686 				   iw_handler handler, struct net_device *dev,
687 				   struct iw_request_info *info)
688 {
689 	int err, extra_size, user_length = 0, essid_compat = 0;
690 	char *extra;
691 
692 	/* Calculate space needed by arguments. Always allocate
693 	 * for max space.
694 	 */
695 	extra_size = descr->max_tokens * descr->token_size;
696 
697 	/* Check need for ESSID compatibility for WE < 21 */
698 	switch (cmd) {
699 	case SIOCSIWESSID:
700 	case SIOCGIWESSID:
701 	case SIOCSIWNICKN:
702 	case SIOCGIWNICKN:
703 		if (iwp->length == descr->max_tokens + 1)
704 			essid_compat = 1;
705 		else if (IW_IS_SET(cmd) && (iwp->length != 0)) {
706 			char essid[IW_ESSID_MAX_SIZE + 1];
707 			unsigned int len;
708 			len = iwp->length * descr->token_size;
709 
710 			if (len > IW_ESSID_MAX_SIZE)
711 				return -EFAULT;
712 
713 			err = copy_from_user(essid, iwp->pointer, len);
714 			if (err)
715 				return -EFAULT;
716 
717 			if (essid[iwp->length - 1] == '\0')
718 				essid_compat = 1;
719 		}
720 		break;
721 	default:
722 		break;
723 	}
724 
725 	iwp->length -= essid_compat;
726 
727 	/* Check what user space is giving us */
728 	if (IW_IS_SET(cmd)) {
729 		/* Check NULL pointer */
730 		if (!iwp->pointer && iwp->length != 0)
731 			return -EFAULT;
732 		/* Check if number of token fits within bounds */
733 		if (iwp->length > descr->max_tokens)
734 			return -E2BIG;
735 		if (iwp->length < descr->min_tokens)
736 			return -EINVAL;
737 	} else {
738 		/* Check NULL pointer */
739 		if (!iwp->pointer)
740 			return -EFAULT;
741 		/* Save user space buffer size for checking */
742 		user_length = iwp->length;
743 
744 		/* Don't check if user_length > max to allow forward
745 		 * compatibility. The test user_length < min is
746 		 * implied by the test at the end.
747 		 */
748 
749 		/* Support for very large requests */
750 		if ((descr->flags & IW_DESCR_FLAG_NOMAX) &&
751 		    (user_length > descr->max_tokens)) {
752 			/* Allow userspace to GET more than max so
753 			 * we can support any size GET requests.
754 			 * There is still a limit : -ENOMEM.
755 			 */
756 			extra_size = user_length * descr->token_size;
757 
758 			/* Note : user_length is originally a __u16,
759 			 * and token_size is controlled by us,
760 			 * so extra_size won't get negative and
761 			 * won't overflow...
762 			 */
763 		}
764 	}
765 
766 	/* kzalloc() ensures NULL-termination for essid_compat. */
767 	extra = kzalloc(extra_size, GFP_KERNEL);
768 	if (!extra)
769 		return -ENOMEM;
770 
771 	/* If it is a SET, get all the extra data in here */
772 	if (IW_IS_SET(cmd) && (iwp->length != 0)) {
773 		if (copy_from_user(extra, iwp->pointer,
774 				   iwp->length *
775 				   descr->token_size)) {
776 			err = -EFAULT;
777 			goto out;
778 		}
779 
780 		if (cmd == SIOCSIWENCODEEXT) {
781 			struct iw_encode_ext *ee = (void *) extra;
782 
783 			if (iwp->length < sizeof(*ee) + ee->key_len)
784 				return -EFAULT;
785 		}
786 	}
787 
788 	if (IW_IS_GET(cmd) && !(descr->flags & IW_DESCR_FLAG_NOMAX)) {
789 		/*
790 		 * If this is a GET, but not NOMAX, it means that the extra
791 		 * data is not bounded by userspace, but by max_tokens. Thus
792 		 * set the length to max_tokens. This matches the extra data
793 		 * allocation.
794 		 * The driver should fill it with the number of tokens it
795 		 * provided, and it may check iwp->length rather than having
796 		 * knowledge of max_tokens. If the driver doesn't change the
797 		 * iwp->length, this ioctl just copies back max_token tokens
798 		 * filled with zeroes. Hopefully the driver isn't claiming
799 		 * them to be valid data.
800 		 */
801 		iwp->length = descr->max_tokens;
802 	}
803 
804 	err = handler(dev, info, (union iwreq_data *) iwp, extra);
805 
806 	iwp->length += essid_compat;
807 
808 	/* If we have something to return to the user */
809 	if (!err && IW_IS_GET(cmd)) {
810 		/* Check if there is enough buffer up there */
811 		if (user_length < iwp->length) {
812 			err = -E2BIG;
813 			goto out;
814 		}
815 
816 		if (copy_to_user(iwp->pointer, extra,
817 				 iwp->length *
818 				 descr->token_size)) {
819 			err = -EFAULT;
820 			goto out;
821 		}
822 	}
823 
824 	/* Generate an event to notify listeners of the change */
825 	if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
826 	    ((err == 0) || (err == -EIWCOMMIT))) {
827 		union iwreq_data *data = (union iwreq_data *) iwp;
828 
829 		if (descr->flags & IW_DESCR_FLAG_RESTRICT)
830 			/* If the event is restricted, don't
831 			 * export the payload.
832 			 */
833 			wireless_send_event(dev, cmd, data, NULL);
834 		else
835 			wireless_send_event(dev, cmd, data, extra);
836 	}
837 
838 out:
839 	kfree(extra);
840 	return err;
841 }
842 
843 /*
844  * Call the commit handler in the driver
845  * (if exist and if conditions are right)
846  *
847  * Note : our current commit strategy is currently pretty dumb,
848  * but we will be able to improve on that...
849  * The goal is to try to agreagate as many changes as possible
850  * before doing the commit. Drivers that will define a commit handler
851  * are usually those that need a reset after changing parameters, so
852  * we want to minimise the number of reset.
853  * A cool idea is to use a timer : at each "set" command, we re-set the
854  * timer, when the timer eventually fires, we call the driver.
855  * Hopefully, more on that later.
856  *
857  * Also, I'm waiting to see how many people will complain about the
858  * netif_running(dev) test. I'm open on that one...
859  * Hopefully, the driver will remember to do a commit in "open()" ;-)
860  */
861 int call_commit_handler(struct net_device *dev)
862 {
863 #ifdef CONFIG_WIRELESS_EXT
864 	if ((netif_running(dev)) &&
865 	   (dev->wireless_handlers->standard[0] != NULL))
866 		/* Call the commit handler on the driver */
867 		return dev->wireless_handlers->standard[0](dev, NULL,
868 							   NULL, NULL);
869 	else
870 		return 0;		/* Command completed successfully */
871 #else
872 	/* cfg80211 has no commit */
873 	return 0;
874 #endif
875 }
876 
877 /*
878  * Main IOCTl dispatcher.
879  * Check the type of IOCTL and call the appropriate wrapper...
880  */
881 static int wireless_process_ioctl(struct net *net, struct ifreq *ifr,
882 				  unsigned int cmd,
883 				  struct iw_request_info *info,
884 				  wext_ioctl_func standard,
885 				  wext_ioctl_func private)
886 {
887 	struct iwreq *iwr = (struct iwreq *) ifr;
888 	struct net_device *dev;
889 	iw_handler	handler;
890 
891 	/* Permissions are already checked in dev_ioctl() before calling us.
892 	 * The copy_to/from_user() of ifr is also dealt with in there */
893 
894 	/* Make sure the device exist */
895 	if ((dev = __dev_get_by_name(net, ifr->ifr_name)) == NULL)
896 		return -ENODEV;
897 
898 	/* A bunch of special cases, then the generic case...
899 	 * Note that 'cmd' is already filtered in dev_ioctl() with
900 	 * (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) */
901 	if (cmd == SIOCGIWSTATS)
902 		return standard(dev, iwr, cmd, info,
903 				&iw_handler_get_iwstats);
904 
905 #ifdef CONFIG_WEXT_PRIV
906 	if (cmd == SIOCGIWPRIV && dev->wireless_handlers)
907 		return standard(dev, iwr, cmd, info,
908 				iw_handler_get_private);
909 #endif
910 
911 	/* Basic check */
912 	if (!netif_device_present(dev))
913 		return -ENODEV;
914 
915 	/* New driver API : try to find the handler */
916 	handler = get_handler(dev, cmd);
917 	if (handler) {
918 		/* Standard and private are not the same */
919 		if (cmd < SIOCIWFIRSTPRIV)
920 			return standard(dev, iwr, cmd, info, handler);
921 		else if (private)
922 			return private(dev, iwr, cmd, info, handler);
923 	}
924 	/* Old driver API : call driver ioctl handler */
925 	if (dev->netdev_ops->ndo_do_ioctl)
926 		return dev->netdev_ops->ndo_do_ioctl(dev, ifr, cmd);
927 	return -EOPNOTSUPP;
928 }
929 
930 /* If command is `set a parameter', or `get the encoding parameters',
931  * check if the user has the right to do it.
932  */
933 static int wext_permission_check(unsigned int cmd)
934 {
935 	if ((IW_IS_SET(cmd) || cmd == SIOCGIWENCODE ||
936 	     cmd == SIOCGIWENCODEEXT) &&
937 	    !capable(CAP_NET_ADMIN))
938 		return -EPERM;
939 
940 	return 0;
941 }
942 
943 /* entry point from dev ioctl */
944 static int wext_ioctl_dispatch(struct net *net, struct ifreq *ifr,
945 			       unsigned int cmd, struct iw_request_info *info,
946 			       wext_ioctl_func standard,
947 			       wext_ioctl_func private)
948 {
949 	int ret = wext_permission_check(cmd);
950 
951 	if (ret)
952 		return ret;
953 
954 	dev_load(net, ifr->ifr_name);
955 	rtnl_lock();
956 	ret = wireless_process_ioctl(net, ifr, cmd, info, standard, private);
957 	rtnl_unlock();
958 
959 	return ret;
960 }
961 
962 /*
963  * Wrapper to call a standard Wireless Extension handler.
964  * We do various checks and also take care of moving data between
965  * user space and kernel space.
966  */
967 static int ioctl_standard_call(struct net_device *	dev,
968 			       struct iwreq		*iwr,
969 			       unsigned int		cmd,
970 			       struct iw_request_info	*info,
971 			       iw_handler		handler)
972 {
973 	const struct iw_ioctl_description *	descr;
974 	int					ret = -EINVAL;
975 
976 	/* Get the description of the IOCTL */
977 	if (IW_IOCTL_IDX(cmd) >= standard_ioctl_num)
978 		return -EOPNOTSUPP;
979 	descr = &(standard_ioctl[IW_IOCTL_IDX(cmd)]);
980 
981 	/* Check if we have a pointer to user space data or not */
982 	if (descr->header_type != IW_HEADER_TYPE_POINT) {
983 
984 		/* No extra arguments. Trivial to handle */
985 		ret = handler(dev, info, &(iwr->u), NULL);
986 
987 		/* Generate an event to notify listeners of the change */
988 		if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
989 		   ((ret == 0) || (ret == -EIWCOMMIT)))
990 			wireless_send_event(dev, cmd, &(iwr->u), NULL);
991 	} else {
992 		ret = ioctl_standard_iw_point(&iwr->u.data, cmd, descr,
993 					      handler, dev, info);
994 	}
995 
996 	/* Call commit handler if needed and defined */
997 	if (ret == -EIWCOMMIT)
998 		ret = call_commit_handler(dev);
999 
1000 	/* Here, we will generate the appropriate event if needed */
1001 
1002 	return ret;
1003 }
1004 
1005 
1006 int wext_handle_ioctl(struct net *net, struct ifreq *ifr, unsigned int cmd,
1007 		      void __user *arg)
1008 {
1009 	struct iw_request_info info = { .cmd = cmd, .flags = 0 };
1010 	int ret;
1011 
1012 	ret = wext_ioctl_dispatch(net, ifr, cmd, &info,
1013 				  ioctl_standard_call,
1014 				  ioctl_private_call);
1015 	if (ret >= 0 &&
1016 	    IW_IS_GET(cmd) &&
1017 	    copy_to_user(arg, ifr, sizeof(struct iwreq)))
1018 		return -EFAULT;
1019 
1020 	return ret;
1021 }
1022 
1023 #ifdef CONFIG_COMPAT
1024 static int compat_standard_call(struct net_device	*dev,
1025 				struct iwreq		*iwr,
1026 				unsigned int		cmd,
1027 				struct iw_request_info	*info,
1028 				iw_handler		handler)
1029 {
1030 	const struct iw_ioctl_description *descr;
1031 	struct compat_iw_point *iwp_compat;
1032 	struct iw_point iwp;
1033 	int err;
1034 
1035 	descr = standard_ioctl + IW_IOCTL_IDX(cmd);
1036 
1037 	if (descr->header_type != IW_HEADER_TYPE_POINT)
1038 		return ioctl_standard_call(dev, iwr, cmd, info, handler);
1039 
1040 	iwp_compat = (struct compat_iw_point *) &iwr->u.data;
1041 	iwp.pointer = compat_ptr(iwp_compat->pointer);
1042 	iwp.length = iwp_compat->length;
1043 	iwp.flags = iwp_compat->flags;
1044 
1045 	err = ioctl_standard_iw_point(&iwp, cmd, descr, handler, dev, info);
1046 
1047 	iwp_compat->pointer = ptr_to_compat(iwp.pointer);
1048 	iwp_compat->length = iwp.length;
1049 	iwp_compat->flags = iwp.flags;
1050 
1051 	return err;
1052 }
1053 
1054 int compat_wext_handle_ioctl(struct net *net, unsigned int cmd,
1055 			     unsigned long arg)
1056 {
1057 	void __user *argp = (void __user *)arg;
1058 	struct iw_request_info info;
1059 	struct iwreq iwr;
1060 	char *colon;
1061 	int ret;
1062 
1063 	if (copy_from_user(&iwr, argp, sizeof(struct iwreq)))
1064 		return -EFAULT;
1065 
1066 	iwr.ifr_name[IFNAMSIZ-1] = 0;
1067 	colon = strchr(iwr.ifr_name, ':');
1068 	if (colon)
1069 		*colon = 0;
1070 
1071 	info.cmd = cmd;
1072 	info.flags = IW_REQUEST_FLAG_COMPAT;
1073 
1074 	ret = wext_ioctl_dispatch(net, (struct ifreq *) &iwr, cmd, &info,
1075 				  compat_standard_call,
1076 				  compat_private_call);
1077 
1078 	if (ret >= 0 &&
1079 	    IW_IS_GET(cmd) &&
1080 	    copy_to_user(argp, &iwr, sizeof(struct iwreq)))
1081 		return -EFAULT;
1082 
1083 	return ret;
1084 }
1085 #endif
1086