xref: /openbmc/linux/net/wireless/wext-core.c (revision 9cfc5c90)
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 int 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 int 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 	if (nla_put_string(skb, IFLA_IFNAME, dev->name))
406 		goto nla_put_failure;
407 
408 	return nlh;
409  nla_put_failure:
410 	nlmsg_cancel(skb, nlh);
411 	return NULL;
412 }
413 
414 
415 /*
416  * Main event dispatcher. Called from other parts and drivers.
417  * Send the event on the appropriate channels.
418  * May be called from interrupt context.
419  */
420 void wireless_send_event(struct net_device *	dev,
421 			 unsigned int		cmd,
422 			 union iwreq_data *	wrqu,
423 			 const char *		extra)
424 {
425 	const struct iw_ioctl_description *	descr = NULL;
426 	int extra_len = 0;
427 	struct iw_event  *event;		/* Mallocated whole event */
428 	int event_len;				/* Its size */
429 	int hdr_len;				/* Size of the event header */
430 	int wrqu_off = 0;			/* Offset in wrqu */
431 	/* Don't "optimise" the following variable, it will crash */
432 	unsigned int	cmd_index;		/* *MUST* be unsigned */
433 	struct sk_buff *skb;
434 	struct nlmsghdr *nlh;
435 	struct nlattr *nla;
436 #ifdef CONFIG_COMPAT
437 	struct __compat_iw_event *compat_event;
438 	struct compat_iw_point compat_wrqu;
439 	struct sk_buff *compskb;
440 #endif
441 
442 	/*
443 	 * Nothing in the kernel sends scan events with data, be safe.
444 	 * This is necessary because we cannot fix up scan event data
445 	 * for compat, due to being contained in 'extra', but normally
446 	 * applications are required to retrieve the scan data anyway
447 	 * and no data is included in the event, this codifies that
448 	 * practice.
449 	 */
450 	if (WARN_ON(cmd == SIOCGIWSCAN && extra))
451 		extra = NULL;
452 
453 	/* Get the description of the Event */
454 	if (cmd <= SIOCIWLAST) {
455 		cmd_index = IW_IOCTL_IDX(cmd);
456 		if (cmd_index < standard_ioctl_num)
457 			descr = &(standard_ioctl[cmd_index]);
458 	} else {
459 		cmd_index = IW_EVENT_IDX(cmd);
460 		if (cmd_index < standard_event_num)
461 			descr = &(standard_event[cmd_index]);
462 	}
463 	/* Don't accept unknown events */
464 	if (descr == NULL) {
465 		/* Note : we don't return an error to the driver, because
466 		 * the driver would not know what to do about it. It can't
467 		 * return an error to the user, because the event is not
468 		 * initiated by a user request.
469 		 * The best the driver could do is to log an error message.
470 		 * We will do it ourselves instead...
471 		 */
472 		netdev_err(dev, "(WE) : Invalid/Unknown Wireless Event (0x%04X)\n",
473 			   cmd);
474 		return;
475 	}
476 
477 	/* Check extra parameters and set extra_len */
478 	if (descr->header_type == IW_HEADER_TYPE_POINT) {
479 		/* Check if number of token fits within bounds */
480 		if (wrqu->data.length > descr->max_tokens) {
481 			netdev_err(dev, "(WE) : Wireless Event (cmd=0x%04X) too big (%d)\n",
482 				   cmd, wrqu->data.length);
483 			return;
484 		}
485 		if (wrqu->data.length < descr->min_tokens) {
486 			netdev_err(dev, "(WE) : Wireless Event (cmd=0x%04X) too small (%d)\n",
487 				   cmd, wrqu->data.length);
488 			return;
489 		}
490 		/* Calculate extra_len - extra is NULL for restricted events */
491 		if (extra != NULL)
492 			extra_len = wrqu->data.length * descr->token_size;
493 		/* Always at an offset in wrqu */
494 		wrqu_off = IW_EV_POINT_OFF;
495 	}
496 
497 	/* Total length of the event */
498 	hdr_len = event_type_size[descr->header_type];
499 	event_len = hdr_len + extra_len;
500 
501 	/*
502 	 * The problem for 64/32 bit.
503 	 *
504 	 * On 64-bit, a regular event is laid out as follows:
505 	 *      |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |
506 	 *      | event.len | event.cmd |     p a d d i n g     |
507 	 *      | wrqu data ... (with the correct size)         |
508 	 *
509 	 * This padding exists because we manipulate event->u,
510 	 * and 'event' is not packed.
511 	 *
512 	 * An iw_point event is laid out like this instead:
513 	 *      |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |
514 	 *      | event.len | event.cmd |     p a d d i n g     |
515 	 *      | iwpnt.len | iwpnt.flg |     p a d d i n g     |
516 	 *      | extra data  ...
517 	 *
518 	 * The second padding exists because struct iw_point is extended,
519 	 * but this depends on the platform...
520 	 *
521 	 * On 32-bit, all the padding shouldn't be there.
522 	 */
523 
524 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
525 	if (!skb)
526 		return;
527 
528 	/* Send via the RtNetlink event channel */
529 	nlh = rtnetlink_ifinfo_prep(dev, skb);
530 	if (WARN_ON(!nlh)) {
531 		kfree_skb(skb);
532 		return;
533 	}
534 
535 	/* Add the wireless events in the netlink packet */
536 	nla = nla_reserve(skb, IFLA_WIRELESS, event_len);
537 	if (!nla) {
538 		kfree_skb(skb);
539 		return;
540 	}
541 	event = nla_data(nla);
542 
543 	/* Fill event - first clear to avoid data leaking */
544 	memset(event, 0, hdr_len);
545 	event->len = event_len;
546 	event->cmd = cmd;
547 	memcpy(&event->u, ((char *) wrqu) + wrqu_off, hdr_len - IW_EV_LCP_LEN);
548 	if (extra_len)
549 		memcpy(((char *) event) + hdr_len, extra, extra_len);
550 
551 	nlmsg_end(skb, nlh);
552 #ifdef CONFIG_COMPAT
553 	hdr_len = compat_event_type_size[descr->header_type];
554 	event_len = hdr_len + extra_len;
555 
556 	compskb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
557 	if (!compskb) {
558 		kfree_skb(skb);
559 		return;
560 	}
561 
562 	/* Send via the RtNetlink event channel */
563 	nlh = rtnetlink_ifinfo_prep(dev, compskb);
564 	if (WARN_ON(!nlh)) {
565 		kfree_skb(skb);
566 		kfree_skb(compskb);
567 		return;
568 	}
569 
570 	/* Add the wireless events in the netlink packet */
571 	nla = nla_reserve(compskb, IFLA_WIRELESS, event_len);
572 	if (!nla) {
573 		kfree_skb(skb);
574 		kfree_skb(compskb);
575 		return;
576 	}
577 	compat_event = nla_data(nla);
578 
579 	compat_event->len = event_len;
580 	compat_event->cmd = cmd;
581 	if (descr->header_type == IW_HEADER_TYPE_POINT) {
582 		compat_wrqu.length = wrqu->data.length;
583 		compat_wrqu.flags = wrqu->data.flags;
584 		memcpy(&compat_event->pointer,
585 			((char *) &compat_wrqu) + IW_EV_COMPAT_POINT_OFF,
586 			hdr_len - IW_EV_COMPAT_LCP_LEN);
587 		if (extra_len)
588 			memcpy(((char *) compat_event) + hdr_len,
589 				extra, extra_len);
590 	} else {
591 		/* extra_len must be zero, so no if (extra) needed */
592 		memcpy(&compat_event->pointer, wrqu,
593 			hdr_len - IW_EV_COMPAT_LCP_LEN);
594 	}
595 
596 	nlmsg_end(compskb, nlh);
597 
598 	skb_shinfo(skb)->frag_list = compskb;
599 #endif
600 	skb_queue_tail(&dev_net(dev)->wext_nlevents, skb);
601 	schedule_work(&wireless_nlevent_work);
602 }
603 EXPORT_SYMBOL(wireless_send_event);
604 
605 
606 
607 /* IW handlers */
608 
609 struct iw_statistics *get_wireless_stats(struct net_device *dev)
610 {
611 #ifdef CONFIG_WIRELESS_EXT
612 	if ((dev->wireless_handlers != NULL) &&
613 	   (dev->wireless_handlers->get_wireless_stats != NULL))
614 		return dev->wireless_handlers->get_wireless_stats(dev);
615 #endif
616 
617 #ifdef CONFIG_CFG80211_WEXT
618 	if (dev->ieee80211_ptr &&
619 	    dev->ieee80211_ptr->wiphy &&
620 	    dev->ieee80211_ptr->wiphy->wext &&
621 	    dev->ieee80211_ptr->wiphy->wext->get_wireless_stats)
622 		return dev->ieee80211_ptr->wiphy->wext->get_wireless_stats(dev);
623 #endif
624 
625 	/* not found */
626 	return NULL;
627 }
628 
629 static int iw_handler_get_iwstats(struct net_device *		dev,
630 				  struct iw_request_info *	info,
631 				  union iwreq_data *		wrqu,
632 				  char *			extra)
633 {
634 	/* Get stats from the driver */
635 	struct iw_statistics *stats;
636 
637 	stats = get_wireless_stats(dev);
638 	if (stats) {
639 		/* Copy statistics to extra */
640 		memcpy(extra, stats, sizeof(struct iw_statistics));
641 		wrqu->data.length = sizeof(struct iw_statistics);
642 
643 		/* Check if we need to clear the updated flag */
644 		if (wrqu->data.flags != 0)
645 			stats->qual.updated &= ~IW_QUAL_ALL_UPDATED;
646 		return 0;
647 	} else
648 		return -EOPNOTSUPP;
649 }
650 
651 static iw_handler get_handler(struct net_device *dev, unsigned int cmd)
652 {
653 	/* Don't "optimise" the following variable, it will crash */
654 	unsigned int	index;		/* *MUST* be unsigned */
655 	const struct iw_handler_def *handlers = NULL;
656 
657 #ifdef CONFIG_CFG80211_WEXT
658 	if (dev->ieee80211_ptr && dev->ieee80211_ptr->wiphy)
659 		handlers = dev->ieee80211_ptr->wiphy->wext;
660 #endif
661 #ifdef CONFIG_WIRELESS_EXT
662 	if (dev->wireless_handlers)
663 		handlers = dev->wireless_handlers;
664 #endif
665 
666 	if (!handlers)
667 		return NULL;
668 
669 	/* Try as a standard command */
670 	index = IW_IOCTL_IDX(cmd);
671 	if (index < handlers->num_standard)
672 		return handlers->standard[index];
673 
674 #ifdef CONFIG_WEXT_PRIV
675 	/* Try as a private command */
676 	index = cmd - SIOCIWFIRSTPRIV;
677 	if (index < handlers->num_private)
678 		return handlers->private[index];
679 #endif
680 
681 	/* Not found */
682 	return NULL;
683 }
684 
685 static int ioctl_standard_iw_point(struct iw_point *iwp, unsigned int cmd,
686 				   const struct iw_ioctl_description *descr,
687 				   iw_handler handler, struct net_device *dev,
688 				   struct iw_request_info *info)
689 {
690 	int err, extra_size, user_length = 0, essid_compat = 0;
691 	char *extra;
692 
693 	/* Calculate space needed by arguments. Always allocate
694 	 * for max space.
695 	 */
696 	extra_size = descr->max_tokens * descr->token_size;
697 
698 	/* Check need for ESSID compatibility for WE < 21 */
699 	switch (cmd) {
700 	case SIOCSIWESSID:
701 	case SIOCGIWESSID:
702 	case SIOCSIWNICKN:
703 	case SIOCGIWNICKN:
704 		if (iwp->length == descr->max_tokens + 1)
705 			essid_compat = 1;
706 		else if (IW_IS_SET(cmd) && (iwp->length != 0)) {
707 			char essid[IW_ESSID_MAX_SIZE + 1];
708 			unsigned int len;
709 			len = iwp->length * descr->token_size;
710 
711 			if (len > IW_ESSID_MAX_SIZE)
712 				return -EFAULT;
713 
714 			err = copy_from_user(essid, iwp->pointer, len);
715 			if (err)
716 				return -EFAULT;
717 
718 			if (essid[iwp->length - 1] == '\0')
719 				essid_compat = 1;
720 		}
721 		break;
722 	default:
723 		break;
724 	}
725 
726 	iwp->length -= essid_compat;
727 
728 	/* Check what user space is giving us */
729 	if (IW_IS_SET(cmd)) {
730 		/* Check NULL pointer */
731 		if (!iwp->pointer && iwp->length != 0)
732 			return -EFAULT;
733 		/* Check if number of token fits within bounds */
734 		if (iwp->length > descr->max_tokens)
735 			return -E2BIG;
736 		if (iwp->length < descr->min_tokens)
737 			return -EINVAL;
738 	} else {
739 		/* Check NULL pointer */
740 		if (!iwp->pointer)
741 			return -EFAULT;
742 		/* Save user space buffer size for checking */
743 		user_length = iwp->length;
744 
745 		/* Don't check if user_length > max to allow forward
746 		 * compatibility. The test user_length < min is
747 		 * implied by the test at the end.
748 		 */
749 
750 		/* Support for very large requests */
751 		if ((descr->flags & IW_DESCR_FLAG_NOMAX) &&
752 		    (user_length > descr->max_tokens)) {
753 			/* Allow userspace to GET more than max so
754 			 * we can support any size GET requests.
755 			 * There is still a limit : -ENOMEM.
756 			 */
757 			extra_size = user_length * descr->token_size;
758 
759 			/* Note : user_length is originally a __u16,
760 			 * and token_size is controlled by us,
761 			 * so extra_size won't get negative and
762 			 * won't overflow...
763 			 */
764 		}
765 	}
766 
767 	/* kzalloc() ensures NULL-termination for essid_compat. */
768 	extra = kzalloc(extra_size, GFP_KERNEL);
769 	if (!extra)
770 		return -ENOMEM;
771 
772 	/* If it is a SET, get all the extra data in here */
773 	if (IW_IS_SET(cmd) && (iwp->length != 0)) {
774 		if (copy_from_user(extra, iwp->pointer,
775 				   iwp->length *
776 				   descr->token_size)) {
777 			err = -EFAULT;
778 			goto out;
779 		}
780 
781 		if (cmd == SIOCSIWENCODEEXT) {
782 			struct iw_encode_ext *ee = (void *) extra;
783 
784 			if (iwp->length < sizeof(*ee) + ee->key_len) {
785 				err = -EFAULT;
786 				goto out;
787 			}
788 		}
789 	}
790 
791 	if (IW_IS_GET(cmd) && !(descr->flags & IW_DESCR_FLAG_NOMAX)) {
792 		/*
793 		 * If this is a GET, but not NOMAX, it means that the extra
794 		 * data is not bounded by userspace, but by max_tokens. Thus
795 		 * set the length to max_tokens. This matches the extra data
796 		 * allocation.
797 		 * The driver should fill it with the number of tokens it
798 		 * provided, and it may check iwp->length rather than having
799 		 * knowledge of max_tokens. If the driver doesn't change the
800 		 * iwp->length, this ioctl just copies back max_token tokens
801 		 * filled with zeroes. Hopefully the driver isn't claiming
802 		 * them to be valid data.
803 		 */
804 		iwp->length = descr->max_tokens;
805 	}
806 
807 	err = handler(dev, info, (union iwreq_data *) iwp, extra);
808 
809 	iwp->length += essid_compat;
810 
811 	/* If we have something to return to the user */
812 	if (!err && IW_IS_GET(cmd)) {
813 		/* Check if there is enough buffer up there */
814 		if (user_length < iwp->length) {
815 			err = -E2BIG;
816 			goto out;
817 		}
818 
819 		if (copy_to_user(iwp->pointer, extra,
820 				 iwp->length *
821 				 descr->token_size)) {
822 			err = -EFAULT;
823 			goto out;
824 		}
825 	}
826 
827 	/* Generate an event to notify listeners of the change */
828 	if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
829 	    ((err == 0) || (err == -EIWCOMMIT))) {
830 		union iwreq_data *data = (union iwreq_data *) iwp;
831 
832 		if (descr->flags & IW_DESCR_FLAG_RESTRICT)
833 			/* If the event is restricted, don't
834 			 * export the payload.
835 			 */
836 			wireless_send_event(dev, cmd, data, NULL);
837 		else
838 			wireless_send_event(dev, cmd, data, extra);
839 	}
840 
841 out:
842 	kfree(extra);
843 	return err;
844 }
845 
846 /*
847  * Call the commit handler in the driver
848  * (if exist and if conditions are right)
849  *
850  * Note : our current commit strategy is currently pretty dumb,
851  * but we will be able to improve on that...
852  * The goal is to try to agreagate as many changes as possible
853  * before doing the commit. Drivers that will define a commit handler
854  * are usually those that need a reset after changing parameters, so
855  * we want to minimise the number of reset.
856  * A cool idea is to use a timer : at each "set" command, we re-set the
857  * timer, when the timer eventually fires, we call the driver.
858  * Hopefully, more on that later.
859  *
860  * Also, I'm waiting to see how many people will complain about the
861  * netif_running(dev) test. I'm open on that one...
862  * Hopefully, the driver will remember to do a commit in "open()" ;-)
863  */
864 int call_commit_handler(struct net_device *dev)
865 {
866 #ifdef CONFIG_WIRELESS_EXT
867 	if ((netif_running(dev)) &&
868 	   (dev->wireless_handlers->standard[0] != NULL))
869 		/* Call the commit handler on the driver */
870 		return dev->wireless_handlers->standard[0](dev, NULL,
871 							   NULL, NULL);
872 	else
873 		return 0;		/* Command completed successfully */
874 #else
875 	/* cfg80211 has no commit */
876 	return 0;
877 #endif
878 }
879 
880 /*
881  * Main IOCTl dispatcher.
882  * Check the type of IOCTL and call the appropriate wrapper...
883  */
884 static int wireless_process_ioctl(struct net *net, struct ifreq *ifr,
885 				  unsigned int cmd,
886 				  struct iw_request_info *info,
887 				  wext_ioctl_func standard,
888 				  wext_ioctl_func private)
889 {
890 	struct iwreq *iwr = (struct iwreq *) ifr;
891 	struct net_device *dev;
892 	iw_handler	handler;
893 
894 	/* Permissions are already checked in dev_ioctl() before calling us.
895 	 * The copy_to/from_user() of ifr is also dealt with in there */
896 
897 	/* Make sure the device exist */
898 	if ((dev = __dev_get_by_name(net, ifr->ifr_name)) == NULL)
899 		return -ENODEV;
900 
901 	/* A bunch of special cases, then the generic case...
902 	 * Note that 'cmd' is already filtered in dev_ioctl() with
903 	 * (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) */
904 	if (cmd == SIOCGIWSTATS)
905 		return standard(dev, iwr, cmd, info,
906 				&iw_handler_get_iwstats);
907 
908 #ifdef CONFIG_WEXT_PRIV
909 	if (cmd == SIOCGIWPRIV && dev->wireless_handlers)
910 		return standard(dev, iwr, cmd, info,
911 				iw_handler_get_private);
912 #endif
913 
914 	/* Basic check */
915 	if (!netif_device_present(dev))
916 		return -ENODEV;
917 
918 	/* New driver API : try to find the handler */
919 	handler = get_handler(dev, cmd);
920 	if (handler) {
921 		/* Standard and private are not the same */
922 		if (cmd < SIOCIWFIRSTPRIV)
923 			return standard(dev, iwr, cmd, info, handler);
924 		else if (private)
925 			return private(dev, iwr, cmd, info, handler);
926 	}
927 	/* Old driver API : call driver ioctl handler */
928 	if (dev->netdev_ops->ndo_do_ioctl)
929 		return dev->netdev_ops->ndo_do_ioctl(dev, ifr, cmd);
930 	return -EOPNOTSUPP;
931 }
932 
933 /* If command is `set a parameter', or `get the encoding parameters',
934  * check if the user has the right to do it.
935  */
936 static int wext_permission_check(unsigned int cmd)
937 {
938 	if ((IW_IS_SET(cmd) || cmd == SIOCGIWENCODE ||
939 	     cmd == SIOCGIWENCODEEXT) &&
940 	    !capable(CAP_NET_ADMIN))
941 		return -EPERM;
942 
943 	return 0;
944 }
945 
946 /* entry point from dev ioctl */
947 static int wext_ioctl_dispatch(struct net *net, struct ifreq *ifr,
948 			       unsigned int cmd, struct iw_request_info *info,
949 			       wext_ioctl_func standard,
950 			       wext_ioctl_func private)
951 {
952 	int ret = wext_permission_check(cmd);
953 
954 	if (ret)
955 		return ret;
956 
957 	dev_load(net, ifr->ifr_name);
958 	rtnl_lock();
959 	ret = wireless_process_ioctl(net, ifr, cmd, info, standard, private);
960 	rtnl_unlock();
961 
962 	return ret;
963 }
964 
965 /*
966  * Wrapper to call a standard Wireless Extension handler.
967  * We do various checks and also take care of moving data between
968  * user space and kernel space.
969  */
970 static int ioctl_standard_call(struct net_device *	dev,
971 			       struct iwreq		*iwr,
972 			       unsigned int		cmd,
973 			       struct iw_request_info	*info,
974 			       iw_handler		handler)
975 {
976 	const struct iw_ioctl_description *	descr;
977 	int					ret = -EINVAL;
978 
979 	/* Get the description of the IOCTL */
980 	if (IW_IOCTL_IDX(cmd) >= standard_ioctl_num)
981 		return -EOPNOTSUPP;
982 	descr = &(standard_ioctl[IW_IOCTL_IDX(cmd)]);
983 
984 	/* Check if we have a pointer to user space data or not */
985 	if (descr->header_type != IW_HEADER_TYPE_POINT) {
986 
987 		/* No extra arguments. Trivial to handle */
988 		ret = handler(dev, info, &(iwr->u), NULL);
989 
990 		/* Generate an event to notify listeners of the change */
991 		if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
992 		   ((ret == 0) || (ret == -EIWCOMMIT)))
993 			wireless_send_event(dev, cmd, &(iwr->u), NULL);
994 	} else {
995 		ret = ioctl_standard_iw_point(&iwr->u.data, cmd, descr,
996 					      handler, dev, info);
997 	}
998 
999 	/* Call commit handler if needed and defined */
1000 	if (ret == -EIWCOMMIT)
1001 		ret = call_commit_handler(dev);
1002 
1003 	/* Here, we will generate the appropriate event if needed */
1004 
1005 	return ret;
1006 }
1007 
1008 
1009 int wext_handle_ioctl(struct net *net, struct ifreq *ifr, unsigned int cmd,
1010 		      void __user *arg)
1011 {
1012 	struct iw_request_info info = { .cmd = cmd, .flags = 0 };
1013 	int ret;
1014 
1015 	ret = wext_ioctl_dispatch(net, ifr, cmd, &info,
1016 				  ioctl_standard_call,
1017 				  ioctl_private_call);
1018 	if (ret >= 0 &&
1019 	    IW_IS_GET(cmd) &&
1020 	    copy_to_user(arg, ifr, sizeof(struct iwreq)))
1021 		return -EFAULT;
1022 
1023 	return ret;
1024 }
1025 
1026 #ifdef CONFIG_COMPAT
1027 static int compat_standard_call(struct net_device	*dev,
1028 				struct iwreq		*iwr,
1029 				unsigned int		cmd,
1030 				struct iw_request_info	*info,
1031 				iw_handler		handler)
1032 {
1033 	const struct iw_ioctl_description *descr;
1034 	struct compat_iw_point *iwp_compat;
1035 	struct iw_point iwp;
1036 	int err;
1037 
1038 	descr = standard_ioctl + IW_IOCTL_IDX(cmd);
1039 
1040 	if (descr->header_type != IW_HEADER_TYPE_POINT)
1041 		return ioctl_standard_call(dev, iwr, cmd, info, handler);
1042 
1043 	iwp_compat = (struct compat_iw_point *) &iwr->u.data;
1044 	iwp.pointer = compat_ptr(iwp_compat->pointer);
1045 	iwp.length = iwp_compat->length;
1046 	iwp.flags = iwp_compat->flags;
1047 
1048 	err = ioctl_standard_iw_point(&iwp, cmd, descr, handler, dev, info);
1049 
1050 	iwp_compat->pointer = ptr_to_compat(iwp.pointer);
1051 	iwp_compat->length = iwp.length;
1052 	iwp_compat->flags = iwp.flags;
1053 
1054 	return err;
1055 }
1056 
1057 int compat_wext_handle_ioctl(struct net *net, unsigned int cmd,
1058 			     unsigned long arg)
1059 {
1060 	void __user *argp = (void __user *)arg;
1061 	struct iw_request_info info;
1062 	struct iwreq iwr;
1063 	char *colon;
1064 	int ret;
1065 
1066 	if (copy_from_user(&iwr, argp, sizeof(struct iwreq)))
1067 		return -EFAULT;
1068 
1069 	iwr.ifr_name[IFNAMSIZ-1] = 0;
1070 	colon = strchr(iwr.ifr_name, ':');
1071 	if (colon)
1072 		*colon = 0;
1073 
1074 	info.cmd = cmd;
1075 	info.flags = IW_REQUEST_FLAG_COMPAT;
1076 
1077 	ret = wext_ioctl_dispatch(net, (struct ifreq *) &iwr, cmd, &info,
1078 				  compat_standard_call,
1079 				  compat_private_call);
1080 
1081 	if (ret >= 0 &&
1082 	    IW_IS_GET(cmd) &&
1083 	    copy_to_user(argp, &iwr, sizeof(struct iwreq)))
1084 		return -EFAULT;
1085 
1086 	return ret;
1087 }
1088 #endif
1089