xref: /linux/net/wireless/ibss.c (revision 722ecdbce68a87de2d9296f91308f44ea900a039)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Some IBSS support code for cfg80211.
4  *
5  * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
6  * Copyright (C) 2020-2022 Intel Corporation
7  */
8 
9 #include <linux/etherdevice.h>
10 #include <linux/if_arp.h>
11 #include <linux/slab.h>
12 #include <linux/export.h>
13 #include <net/cfg80211.h>
14 #include "wext-compat.h"
15 #include "nl80211.h"
16 #include "rdev-ops.h"
17 
18 
19 void __cfg80211_ibss_joined(struct net_device *dev, const u8 *bssid,
20 			    struct ieee80211_channel *channel)
21 {
22 	struct wireless_dev *wdev = dev->ieee80211_ptr;
23 	struct cfg80211_bss *bss;
24 #ifdef CONFIG_CFG80211_WEXT
25 	union iwreq_data wrqu;
26 #endif
27 
28 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
29 		return;
30 
31 	if (!wdev->ssid_len)
32 		return;
33 
34 	bss = cfg80211_get_bss(wdev->wiphy, channel, bssid, NULL, 0,
35 			       IEEE80211_BSS_TYPE_IBSS, IEEE80211_PRIVACY_ANY);
36 
37 	if (WARN_ON(!bss))
38 		return;
39 
40 	if (wdev->current_bss) {
41 		cfg80211_unhold_bss(wdev->current_bss);
42 		cfg80211_put_bss(wdev->wiphy, &wdev->current_bss->pub);
43 	}
44 
45 	cfg80211_hold_bss(bss_from_pub(bss));
46 	wdev->current_bss = bss_from_pub(bss);
47 
48 	if (!(wdev->wiphy->flags & WIPHY_FLAG_HAS_STATIC_WEP))
49 		cfg80211_upload_connect_keys(wdev);
50 
51 	nl80211_send_ibss_bssid(wiphy_to_rdev(wdev->wiphy), dev, bssid,
52 				GFP_KERNEL);
53 #ifdef CONFIG_CFG80211_WEXT
54 	memset(&wrqu, 0, sizeof(wrqu));
55 	memcpy(wrqu.ap_addr.sa_data, bssid, ETH_ALEN);
56 	wireless_send_event(dev, SIOCGIWAP, &wrqu, NULL);
57 #endif
58 }
59 
60 void cfg80211_ibss_joined(struct net_device *dev, const u8 *bssid,
61 			  struct ieee80211_channel *channel, gfp_t gfp)
62 {
63 	struct wireless_dev *wdev = dev->ieee80211_ptr;
64 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
65 	struct cfg80211_event *ev;
66 	unsigned long flags;
67 
68 	trace_cfg80211_ibss_joined(dev, bssid, channel);
69 
70 	if (WARN_ON(!channel))
71 		return;
72 
73 	ev = kzalloc(sizeof(*ev), gfp);
74 	if (!ev)
75 		return;
76 
77 	ev->type = EVENT_IBSS_JOINED;
78 	memcpy(ev->ij.bssid, bssid, ETH_ALEN);
79 	ev->ij.channel = channel;
80 
81 	spin_lock_irqsave(&wdev->event_lock, flags);
82 	list_add_tail(&ev->list, &wdev->event_list);
83 	spin_unlock_irqrestore(&wdev->event_lock, flags);
84 	queue_work(cfg80211_wq, &rdev->event_work);
85 }
86 EXPORT_SYMBOL(cfg80211_ibss_joined);
87 
88 int __cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
89 			 struct net_device *dev,
90 			 struct cfg80211_ibss_params *params,
91 			 struct cfg80211_cached_keys *connkeys)
92 {
93 	struct wireless_dev *wdev = dev->ieee80211_ptr;
94 	int err;
95 
96 	lockdep_assert_held(&rdev->wiphy.mtx);
97 	ASSERT_WDEV_LOCK(wdev);
98 
99 	if (wdev->ssid_len)
100 		return -EALREADY;
101 
102 	if (!params->basic_rates) {
103 		/*
104 		* If no rates were explicitly configured,
105 		* use the mandatory rate set for 11b or
106 		* 11a for maximum compatibility.
107 		*/
108 		struct ieee80211_supported_band *sband;
109 		enum nl80211_band band;
110 		u32 flag;
111 		int j;
112 
113 		band = params->chandef.chan->band;
114 		if (band == NL80211_BAND_5GHZ ||
115 		    band == NL80211_BAND_6GHZ)
116 			flag = IEEE80211_RATE_MANDATORY_A;
117 		else
118 			flag = IEEE80211_RATE_MANDATORY_B;
119 
120 		sband = rdev->wiphy.bands[band];
121 		for (j = 0; j < sband->n_bitrates; j++) {
122 			if (sband->bitrates[j].flags & flag)
123 				params->basic_rates |= BIT(j);
124 		}
125 	}
126 
127 	if (WARN_ON(connkeys && connkeys->def < 0))
128 		return -EINVAL;
129 
130 	if (WARN_ON(wdev->connect_keys))
131 		kfree_sensitive(wdev->connect_keys);
132 	wdev->connect_keys = connkeys;
133 
134 	wdev->chandef = params->chandef;
135 	if (connkeys) {
136 		params->wep_keys = connkeys->params;
137 		params->wep_tx_key = connkeys->def;
138 	}
139 
140 #ifdef CONFIG_CFG80211_WEXT
141 	wdev->wext.ibss.chandef = params->chandef;
142 #endif
143 	err = rdev_join_ibss(rdev, dev, params);
144 	if (err) {
145 		wdev->connect_keys = NULL;
146 		return err;
147 	}
148 
149 	memcpy(wdev->ssid, params->ssid, params->ssid_len);
150 	wdev->ssid_len = params->ssid_len;
151 
152 	return 0;
153 }
154 
155 static void __cfg80211_clear_ibss(struct net_device *dev, bool nowext)
156 {
157 	struct wireless_dev *wdev = dev->ieee80211_ptr;
158 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
159 	int i;
160 
161 	ASSERT_WDEV_LOCK(wdev);
162 
163 	kfree_sensitive(wdev->connect_keys);
164 	wdev->connect_keys = NULL;
165 
166 	rdev_set_qos_map(rdev, dev, NULL);
167 
168 	/*
169 	 * Delete all the keys ... pairwise keys can't really
170 	 * exist any more anyway, but default keys might.
171 	 */
172 	if (rdev->ops->del_key)
173 		for (i = 0; i < 6; i++)
174 			rdev_del_key(rdev, dev, i, false, NULL);
175 
176 	if (wdev->current_bss) {
177 		cfg80211_unhold_bss(wdev->current_bss);
178 		cfg80211_put_bss(wdev->wiphy, &wdev->current_bss->pub);
179 	}
180 
181 	wdev->current_bss = NULL;
182 	wdev->ssid_len = 0;
183 	memset(&wdev->chandef, 0, sizeof(wdev->chandef));
184 #ifdef CONFIG_CFG80211_WEXT
185 	if (!nowext)
186 		wdev->wext.ibss.ssid_len = 0;
187 #endif
188 	cfg80211_sched_dfs_chan_update(rdev);
189 }
190 
191 void cfg80211_clear_ibss(struct net_device *dev, bool nowext)
192 {
193 	struct wireless_dev *wdev = dev->ieee80211_ptr;
194 
195 	wdev_lock(wdev);
196 	__cfg80211_clear_ibss(dev, nowext);
197 	wdev_unlock(wdev);
198 }
199 
200 int __cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
201 			  struct net_device *dev, bool nowext)
202 {
203 	struct wireless_dev *wdev = dev->ieee80211_ptr;
204 	int err;
205 
206 	ASSERT_WDEV_LOCK(wdev);
207 
208 	if (!wdev->ssid_len)
209 		return -ENOLINK;
210 
211 	err = rdev_leave_ibss(rdev, dev);
212 
213 	if (err)
214 		return err;
215 
216 	wdev->conn_owner_nlportid = 0;
217 	__cfg80211_clear_ibss(dev, nowext);
218 
219 	return 0;
220 }
221 
222 int cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
223 			struct net_device *dev, bool nowext)
224 {
225 	struct wireless_dev *wdev = dev->ieee80211_ptr;
226 	int err;
227 
228 	wdev_lock(wdev);
229 	err = __cfg80211_leave_ibss(rdev, dev, nowext);
230 	wdev_unlock(wdev);
231 
232 	return err;
233 }
234 
235 #ifdef CONFIG_CFG80211_WEXT
236 int cfg80211_ibss_wext_join(struct cfg80211_registered_device *rdev,
237 			    struct wireless_dev *wdev)
238 {
239 	struct cfg80211_cached_keys *ck = NULL;
240 	enum nl80211_band band;
241 	int i, err;
242 
243 	ASSERT_WDEV_LOCK(wdev);
244 
245 	if (!wdev->wext.ibss.beacon_interval)
246 		wdev->wext.ibss.beacon_interval = 100;
247 
248 	/* try to find an IBSS channel if none requested ... */
249 	if (!wdev->wext.ibss.chandef.chan) {
250 		struct ieee80211_channel *new_chan = NULL;
251 
252 		for (band = 0; band < NUM_NL80211_BANDS; band++) {
253 			struct ieee80211_supported_band *sband;
254 			struct ieee80211_channel *chan;
255 
256 			sband = rdev->wiphy.bands[band];
257 			if (!sband)
258 				continue;
259 
260 			for (i = 0; i < sband->n_channels; i++) {
261 				chan = &sband->channels[i];
262 				if (chan->flags & IEEE80211_CHAN_NO_IR)
263 					continue;
264 				if (chan->flags & IEEE80211_CHAN_DISABLED)
265 					continue;
266 				new_chan = chan;
267 				break;
268 			}
269 
270 			if (new_chan)
271 				break;
272 		}
273 
274 		if (!new_chan)
275 			return -EINVAL;
276 
277 		cfg80211_chandef_create(&wdev->wext.ibss.chandef, new_chan,
278 					NL80211_CHAN_NO_HT);
279 	}
280 
281 	/* don't join -- SSID is not there */
282 	if (!wdev->wext.ibss.ssid_len)
283 		return 0;
284 
285 	if (!netif_running(wdev->netdev))
286 		return 0;
287 
288 	if (wdev->wext.keys)
289 		wdev->wext.keys->def = wdev->wext.default_key;
290 
291 	wdev->wext.ibss.privacy = wdev->wext.default_key != -1;
292 
293 	if (wdev->wext.keys && wdev->wext.keys->def != -1) {
294 		ck = kmemdup(wdev->wext.keys, sizeof(*ck), GFP_KERNEL);
295 		if (!ck)
296 			return -ENOMEM;
297 		for (i = 0; i < CFG80211_MAX_WEP_KEYS; i++)
298 			ck->params[i].key = ck->data[i];
299 	}
300 	err = __cfg80211_join_ibss(rdev, wdev->netdev,
301 				   &wdev->wext.ibss, ck);
302 	if (err)
303 		kfree(ck);
304 
305 	return err;
306 }
307 
308 int cfg80211_ibss_wext_siwfreq(struct net_device *dev,
309 			       struct iw_request_info *info,
310 			       struct iw_freq *wextfreq, char *extra)
311 {
312 	struct wireless_dev *wdev = dev->ieee80211_ptr;
313 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
314 	struct ieee80211_channel *chan = NULL;
315 	int err, freq;
316 
317 	/* call only for ibss! */
318 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
319 		return -EINVAL;
320 
321 	if (!rdev->ops->join_ibss)
322 		return -EOPNOTSUPP;
323 
324 	freq = cfg80211_wext_freq(wextfreq);
325 	if (freq < 0)
326 		return freq;
327 
328 	if (freq) {
329 		chan = ieee80211_get_channel(wdev->wiphy, freq);
330 		if (!chan)
331 			return -EINVAL;
332 		if (chan->flags & IEEE80211_CHAN_NO_IR ||
333 		    chan->flags & IEEE80211_CHAN_DISABLED)
334 			return -EINVAL;
335 	}
336 
337 	if (wdev->wext.ibss.chandef.chan == chan)
338 		return 0;
339 
340 	wdev_lock(wdev);
341 	err = 0;
342 	if (wdev->ssid_len)
343 		err = __cfg80211_leave_ibss(rdev, dev, true);
344 	wdev_unlock(wdev);
345 
346 	if (err)
347 		return err;
348 
349 	if (chan) {
350 		cfg80211_chandef_create(&wdev->wext.ibss.chandef, chan,
351 					NL80211_CHAN_NO_HT);
352 		wdev->wext.ibss.channel_fixed = true;
353 	} else {
354 		/* cfg80211_ibss_wext_join will pick one if needed */
355 		wdev->wext.ibss.channel_fixed = false;
356 	}
357 
358 	wdev_lock(wdev);
359 	err = cfg80211_ibss_wext_join(rdev, wdev);
360 	wdev_unlock(wdev);
361 
362 	return err;
363 }
364 
365 int cfg80211_ibss_wext_giwfreq(struct net_device *dev,
366 			       struct iw_request_info *info,
367 			       struct iw_freq *freq, char *extra)
368 {
369 	struct wireless_dev *wdev = dev->ieee80211_ptr;
370 	struct ieee80211_channel *chan = NULL;
371 
372 	/* call only for ibss! */
373 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
374 		return -EINVAL;
375 
376 	wdev_lock(wdev);
377 	if (wdev->current_bss)
378 		chan = wdev->current_bss->pub.channel;
379 	else if (wdev->wext.ibss.chandef.chan)
380 		chan = wdev->wext.ibss.chandef.chan;
381 	wdev_unlock(wdev);
382 
383 	if (chan) {
384 		freq->m = chan->center_freq;
385 		freq->e = 6;
386 		return 0;
387 	}
388 
389 	/* no channel if not joining */
390 	return -EINVAL;
391 }
392 
393 int cfg80211_ibss_wext_siwessid(struct net_device *dev,
394 				struct iw_request_info *info,
395 				struct iw_point *data, char *ssid)
396 {
397 	struct wireless_dev *wdev = dev->ieee80211_ptr;
398 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
399 	size_t len = data->length;
400 	int err;
401 
402 	/* call only for ibss! */
403 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
404 		return -EINVAL;
405 
406 	if (!rdev->ops->join_ibss)
407 		return -EOPNOTSUPP;
408 
409 	wdev_lock(wdev);
410 	err = 0;
411 	if (wdev->ssid_len)
412 		err = __cfg80211_leave_ibss(rdev, dev, true);
413 	wdev_unlock(wdev);
414 
415 	if (err)
416 		return err;
417 
418 	/* iwconfig uses nul termination in SSID.. */
419 	if (len > 0 && ssid[len - 1] == '\0')
420 		len--;
421 
422 	memcpy(wdev->ssid, ssid, len);
423 	wdev->wext.ibss.ssid = wdev->ssid;
424 	wdev->wext.ibss.ssid_len = len;
425 
426 	wdev_lock(wdev);
427 	err = cfg80211_ibss_wext_join(rdev, wdev);
428 	wdev_unlock(wdev);
429 
430 	return err;
431 }
432 
433 int cfg80211_ibss_wext_giwessid(struct net_device *dev,
434 				struct iw_request_info *info,
435 				struct iw_point *data, char *ssid)
436 {
437 	struct wireless_dev *wdev = dev->ieee80211_ptr;
438 
439 	/* call only for ibss! */
440 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
441 		return -EINVAL;
442 
443 	data->flags = 0;
444 
445 	wdev_lock(wdev);
446 	if (wdev->ssid_len) {
447 		data->flags = 1;
448 		data->length = wdev->ssid_len;
449 		memcpy(ssid, wdev->ssid, data->length);
450 	} else if (wdev->wext.ibss.ssid && wdev->wext.ibss.ssid_len) {
451 		data->flags = 1;
452 		data->length = wdev->wext.ibss.ssid_len;
453 		memcpy(ssid, wdev->wext.ibss.ssid, data->length);
454 	}
455 	wdev_unlock(wdev);
456 
457 	return 0;
458 }
459 
460 int cfg80211_ibss_wext_siwap(struct net_device *dev,
461 			     struct iw_request_info *info,
462 			     struct sockaddr *ap_addr, char *extra)
463 {
464 	struct wireless_dev *wdev = dev->ieee80211_ptr;
465 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
466 	u8 *bssid = ap_addr->sa_data;
467 	int err;
468 
469 	/* call only for ibss! */
470 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
471 		return -EINVAL;
472 
473 	if (!rdev->ops->join_ibss)
474 		return -EOPNOTSUPP;
475 
476 	if (ap_addr->sa_family != ARPHRD_ETHER)
477 		return -EINVAL;
478 
479 	/* automatic mode */
480 	if (is_zero_ether_addr(bssid) || is_broadcast_ether_addr(bssid))
481 		bssid = NULL;
482 
483 	if (bssid && !is_valid_ether_addr(bssid))
484 		return -EINVAL;
485 
486 	/* both automatic */
487 	if (!bssid && !wdev->wext.ibss.bssid)
488 		return 0;
489 
490 	/* fixed already - and no change */
491 	if (wdev->wext.ibss.bssid && bssid &&
492 	    ether_addr_equal(bssid, wdev->wext.ibss.bssid))
493 		return 0;
494 
495 	wdev_lock(wdev);
496 	err = 0;
497 	if (wdev->ssid_len)
498 		err = __cfg80211_leave_ibss(rdev, dev, true);
499 	wdev_unlock(wdev);
500 
501 	if (err)
502 		return err;
503 
504 	if (bssid) {
505 		memcpy(wdev->wext.bssid, bssid, ETH_ALEN);
506 		wdev->wext.ibss.bssid = wdev->wext.bssid;
507 	} else
508 		wdev->wext.ibss.bssid = NULL;
509 
510 	wdev_lock(wdev);
511 	err = cfg80211_ibss_wext_join(rdev, wdev);
512 	wdev_unlock(wdev);
513 
514 	return err;
515 }
516 
517 int cfg80211_ibss_wext_giwap(struct net_device *dev,
518 			     struct iw_request_info *info,
519 			     struct sockaddr *ap_addr, char *extra)
520 {
521 	struct wireless_dev *wdev = dev->ieee80211_ptr;
522 
523 	/* call only for ibss! */
524 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
525 		return -EINVAL;
526 
527 	ap_addr->sa_family = ARPHRD_ETHER;
528 
529 	wdev_lock(wdev);
530 	if (wdev->current_bss)
531 		memcpy(ap_addr->sa_data, wdev->current_bss->pub.bssid, ETH_ALEN);
532 	else if (wdev->wext.ibss.bssid)
533 		memcpy(ap_addr->sa_data, wdev->wext.ibss.bssid, ETH_ALEN);
534 	else
535 		eth_zero_addr(ap_addr->sa_data);
536 
537 	wdev_unlock(wdev);
538 
539 	return 0;
540 }
541 #endif
542