xref: /linux/net/atm/resources.c (revision 44f57d78) 
1 // SPDX-License-Identifier: GPL-2.0
2 /* net/atm/resources.c - Statically allocated resources */
3 
4 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
5 
6 /* Fixes
7  * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
8  * 2002/01 - don't free the whole struct sock on sk->destruct time,
9  * 	     use the default destruct function initialized by sock_init_data */
10 
11 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
12 
13 #include <linux/ctype.h>
14 #include <linux/string.h>
15 #include <linux/atmdev.h>
16 #include <linux/sonet.h>
17 #include <linux/kernel.h> /* for barrier */
18 #include <linux/module.h>
19 #include <linux/bitops.h>
20 #include <linux/capability.h>
21 #include <linux/delay.h>
22 #include <linux/mutex.h>
23 #include <linux/slab.h>
24 
25 #include <net/sock.h>	 /* for struct sock */
26 
27 #include "common.h"
28 #include "resources.h"
29 #include "addr.h"
30 
31 
32 LIST_HEAD(atm_devs);
33 DEFINE_MUTEX(atm_dev_mutex);
34 
35 static struct atm_dev *__alloc_atm_dev(const char *type)
36 {
37 	struct atm_dev *dev;
38 
39 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
40 	if (!dev)
41 		return NULL;
42 	dev->type = type;
43 	dev->signal = ATM_PHY_SIG_UNKNOWN;
44 	dev->link_rate = ATM_OC3_PCR;
45 	spin_lock_init(&dev->lock);
46 	INIT_LIST_HEAD(&dev->local);
47 	INIT_LIST_HEAD(&dev->lecs);
48 
49 	return dev;
50 }
51 
52 static struct atm_dev *__atm_dev_lookup(int number)
53 {
54 	struct atm_dev *dev;
55 	struct list_head *p;
56 
57 	list_for_each(p, &atm_devs) {
58 		dev = list_entry(p, struct atm_dev, dev_list);
59 		if (dev->number == number) {
60 			atm_dev_hold(dev);
61 			return dev;
62 		}
63 	}
64 	return NULL;
65 }
66 
67 struct atm_dev *atm_dev_lookup(int number)
68 {
69 	struct atm_dev *dev;
70 
71 	mutex_lock(&atm_dev_mutex);
72 	dev = __atm_dev_lookup(number);
73 	mutex_unlock(&atm_dev_mutex);
74 	return dev;
75 }
76 EXPORT_SYMBOL(atm_dev_lookup);
77 
78 struct atm_dev *atm_dev_register(const char *type, struct device *parent,
79 				 const struct atmdev_ops *ops, int number,
80 				 unsigned long *flags)
81 {
82 	struct atm_dev *dev, *inuse;
83 
84 	dev = __alloc_atm_dev(type);
85 	if (!dev) {
86 		pr_err("no space for dev %s\n", type);
87 		return NULL;
88 	}
89 	mutex_lock(&atm_dev_mutex);
90 	if (number != -1) {
91 		inuse = __atm_dev_lookup(number);
92 		if (inuse) {
93 			atm_dev_put(inuse);
94 			mutex_unlock(&atm_dev_mutex);
95 			kfree(dev);
96 			return NULL;
97 		}
98 		dev->number = number;
99 	} else {
100 		dev->number = 0;
101 		while ((inuse = __atm_dev_lookup(dev->number))) {
102 			atm_dev_put(inuse);
103 			dev->number++;
104 		}
105 	}
106 
107 	dev->ops = ops;
108 	if (flags)
109 		dev->flags = *flags;
110 	else
111 		memset(&dev->flags, 0, sizeof(dev->flags));
112 	memset(&dev->stats, 0, sizeof(dev->stats));
113 	refcount_set(&dev->refcnt, 1);
114 
115 	if (atm_proc_dev_register(dev) < 0) {
116 		pr_err("atm_proc_dev_register failed for dev %s\n", type);
117 		goto out_fail;
118 	}
119 
120 	if (atm_register_sysfs(dev, parent) < 0) {
121 		pr_err("atm_register_sysfs failed for dev %s\n", type);
122 		atm_proc_dev_deregister(dev);
123 		goto out_fail;
124 	}
125 
126 	list_add_tail(&dev->dev_list, &atm_devs);
127 
128 out:
129 	mutex_unlock(&atm_dev_mutex);
130 	return dev;
131 
132 out_fail:
133 	kfree(dev);
134 	dev = NULL;
135 	goto out;
136 }
137 EXPORT_SYMBOL(atm_dev_register);
138 
139 void atm_dev_deregister(struct atm_dev *dev)
140 {
141 	BUG_ON(test_bit(ATM_DF_REMOVED, &dev->flags));
142 	set_bit(ATM_DF_REMOVED, &dev->flags);
143 
144 	/*
145 	 * if we remove current device from atm_devs list, new device
146 	 * with same number can appear, such we need deregister proc,
147 	 * release async all vccs and remove them from vccs list too
148 	 */
149 	mutex_lock(&atm_dev_mutex);
150 	list_del(&dev->dev_list);
151 	mutex_unlock(&atm_dev_mutex);
152 
153 	atm_dev_release_vccs(dev);
154 	atm_unregister_sysfs(dev);
155 	atm_proc_dev_deregister(dev);
156 
157 	atm_dev_put(dev);
158 }
159 EXPORT_SYMBOL(atm_dev_deregister);
160 
161 static void copy_aal_stats(struct k_atm_aal_stats *from,
162     struct atm_aal_stats *to)
163 {
164 #define __HANDLE_ITEM(i) to->i = atomic_read(&from->i)
165 	__AAL_STAT_ITEMS
166 #undef __HANDLE_ITEM
167 }
168 
169 static void subtract_aal_stats(struct k_atm_aal_stats *from,
170     struct atm_aal_stats *to)
171 {
172 #define __HANDLE_ITEM(i) atomic_sub(to->i, &from->i)
173 	__AAL_STAT_ITEMS
174 #undef __HANDLE_ITEM
175 }
176 
177 static int fetch_stats(struct atm_dev *dev, struct atm_dev_stats __user *arg,
178 		       int zero)
179 {
180 	struct atm_dev_stats tmp;
181 	int error = 0;
182 
183 	copy_aal_stats(&dev->stats.aal0, &tmp.aal0);
184 	copy_aal_stats(&dev->stats.aal34, &tmp.aal34);
185 	copy_aal_stats(&dev->stats.aal5, &tmp.aal5);
186 	if (arg)
187 		error = copy_to_user(arg, &tmp, sizeof(tmp));
188 	if (zero && !error) {
189 		subtract_aal_stats(&dev->stats.aal0, &tmp.aal0);
190 		subtract_aal_stats(&dev->stats.aal34, &tmp.aal34);
191 		subtract_aal_stats(&dev->stats.aal5, &tmp.aal5);
192 	}
193 	return error ? -EFAULT : 0;
194 }
195 
196 int atm_dev_ioctl(unsigned int cmd, void __user *arg, int compat)
197 {
198 	void __user *buf;
199 	int error, len, number, size = 0;
200 	struct atm_dev *dev;
201 	struct list_head *p;
202 	int *tmp_buf, *tmp_p;
203 	int __user *sioc_len;
204 	int __user *iobuf_len;
205 
206 	switch (cmd) {
207 	case ATM_GETNAMES:
208 		if (IS_ENABLED(CONFIG_COMPAT) && compat) {
209 #ifdef CONFIG_COMPAT
210 			struct compat_atm_iobuf __user *ciobuf = arg;
211 			compat_uptr_t cbuf;
212 			iobuf_len = &ciobuf->length;
213 			if (get_user(cbuf, &ciobuf->buffer))
214 				return -EFAULT;
215 			buf = compat_ptr(cbuf);
216 #endif
217 		} else {
218 			struct atm_iobuf __user *iobuf = arg;
219 			iobuf_len = &iobuf->length;
220 			if (get_user(buf, &iobuf->buffer))
221 				return -EFAULT;
222 		}
223 		if (get_user(len, iobuf_len))
224 			return -EFAULT;
225 		mutex_lock(&atm_dev_mutex);
226 		list_for_each(p, &atm_devs)
227 			size += sizeof(int);
228 		if (size > len) {
229 			mutex_unlock(&atm_dev_mutex);
230 			return -E2BIG;
231 		}
232 		tmp_buf = kmalloc(size, GFP_ATOMIC);
233 		if (!tmp_buf) {
234 			mutex_unlock(&atm_dev_mutex);
235 			return -ENOMEM;
236 		}
237 		tmp_p = tmp_buf;
238 		list_for_each(p, &atm_devs) {
239 			dev = list_entry(p, struct atm_dev, dev_list);
240 			*tmp_p++ = dev->number;
241 		}
242 		mutex_unlock(&atm_dev_mutex);
243 		error = ((copy_to_user(buf, tmp_buf, size)) ||
244 			 put_user(size, iobuf_len))
245 			? -EFAULT : 0;
246 		kfree(tmp_buf);
247 		return error;
248 	default:
249 		break;
250 	}
251 
252 	if (IS_ENABLED(CONFIG_COMPAT) && compat) {
253 #ifdef CONFIG_COMPAT
254 		struct compat_atmif_sioc __user *csioc = arg;
255 		compat_uptr_t carg;
256 
257 		sioc_len = &csioc->length;
258 		if (get_user(carg, &csioc->arg))
259 			return -EFAULT;
260 		buf = compat_ptr(carg);
261 
262 		if (get_user(len, &csioc->length))
263 			return -EFAULT;
264 		if (get_user(number, &csioc->number))
265 			return -EFAULT;
266 #endif
267 	} else {
268 		struct atmif_sioc __user *sioc = arg;
269 
270 		sioc_len = &sioc->length;
271 		if (get_user(buf, &sioc->arg))
272 			return -EFAULT;
273 		if (get_user(len, &sioc->length))
274 			return -EFAULT;
275 		if (get_user(number, &sioc->number))
276 			return -EFAULT;
277 	}
278 
279 	dev = try_then_request_module(atm_dev_lookup(number), "atm-device-%d",
280 				      number);
281 	if (!dev)
282 		return -ENODEV;
283 
284 	switch (cmd) {
285 	case ATM_GETTYPE:
286 		size = strlen(dev->type) + 1;
287 		if (copy_to_user(buf, dev->type, size)) {
288 			error = -EFAULT;
289 			goto done;
290 		}
291 		break;
292 	case ATM_GETESI:
293 		size = ESI_LEN;
294 		if (copy_to_user(buf, dev->esi, size)) {
295 			error = -EFAULT;
296 			goto done;
297 		}
298 		break;
299 	case ATM_SETESI:
300 	{
301 		int i;
302 
303 		for (i = 0; i < ESI_LEN; i++)
304 			if (dev->esi[i]) {
305 				error = -EEXIST;
306 				goto done;
307 			}
308 	}
309 	/* fall through */
310 	case ATM_SETESIF:
311 	{
312 		unsigned char esi[ESI_LEN];
313 
314 		if (!capable(CAP_NET_ADMIN)) {
315 			error = -EPERM;
316 			goto done;
317 		}
318 		if (copy_from_user(esi, buf, ESI_LEN)) {
319 			error = -EFAULT;
320 			goto done;
321 		}
322 		memcpy(dev->esi, esi, ESI_LEN);
323 		error =  ESI_LEN;
324 		goto done;
325 	}
326 	case ATM_GETSTATZ:
327 		if (!capable(CAP_NET_ADMIN)) {
328 			error = -EPERM;
329 			goto done;
330 		}
331 		/* fall through */
332 	case ATM_GETSTAT:
333 		size = sizeof(struct atm_dev_stats);
334 		error = fetch_stats(dev, buf, cmd == ATM_GETSTATZ);
335 		if (error)
336 			goto done;
337 		break;
338 	case ATM_GETCIRANGE:
339 		size = sizeof(struct atm_cirange);
340 		if (copy_to_user(buf, &dev->ci_range, size)) {
341 			error = -EFAULT;
342 			goto done;
343 		}
344 		break;
345 	case ATM_GETLINKRATE:
346 		size = sizeof(int);
347 		if (copy_to_user(buf, &dev->link_rate, size)) {
348 			error = -EFAULT;
349 			goto done;
350 		}
351 		break;
352 	case ATM_RSTADDR:
353 		if (!capable(CAP_NET_ADMIN)) {
354 			error = -EPERM;
355 			goto done;
356 		}
357 		atm_reset_addr(dev, ATM_ADDR_LOCAL);
358 		break;
359 	case ATM_ADDADDR:
360 	case ATM_DELADDR:
361 	case ATM_ADDLECSADDR:
362 	case ATM_DELLECSADDR:
363 	{
364 		struct sockaddr_atmsvc addr;
365 
366 		if (!capable(CAP_NET_ADMIN)) {
367 			error = -EPERM;
368 			goto done;
369 		}
370 
371 		if (copy_from_user(&addr, buf, sizeof(addr))) {
372 			error = -EFAULT;
373 			goto done;
374 		}
375 		if (cmd == ATM_ADDADDR || cmd == ATM_ADDLECSADDR)
376 			error = atm_add_addr(dev, &addr,
377 					     (cmd == ATM_ADDADDR ?
378 					      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
379 		else
380 			error = atm_del_addr(dev, &addr,
381 					     (cmd == ATM_DELADDR ?
382 					      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
383 		goto done;
384 	}
385 	case ATM_GETADDR:
386 	case ATM_GETLECSADDR:
387 		error = atm_get_addr(dev, buf, len,
388 				     (cmd == ATM_GETADDR ?
389 				      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
390 		if (error < 0)
391 			goto done;
392 		size = error;
393 		/* may return 0, but later on size == 0 means "don't
394 		   write the length" */
395 		error = put_user(size, sioc_len) ? -EFAULT : 0;
396 		goto done;
397 	case ATM_SETLOOP:
398 		if (__ATM_LM_XTRMT((int) (unsigned long) buf) &&
399 		    __ATM_LM_XTLOC((int) (unsigned long) buf) >
400 		    __ATM_LM_XTRMT((int) (unsigned long) buf)) {
401 			error = -EINVAL;
402 			goto done;
403 		}
404 		/* fall through */
405 	case ATM_SETCIRANGE:
406 	case SONET_GETSTATZ:
407 	case SONET_SETDIAG:
408 	case SONET_CLRDIAG:
409 	case SONET_SETFRAMING:
410 		if (!capable(CAP_NET_ADMIN)) {
411 			error = -EPERM;
412 			goto done;
413 		}
414 		/* fall through */
415 	default:
416 		if (IS_ENABLED(CONFIG_COMPAT) && compat) {
417 #ifdef CONFIG_COMPAT
418 			if (!dev->ops->compat_ioctl) {
419 				error = -EINVAL;
420 				goto done;
421 			}
422 			size = dev->ops->compat_ioctl(dev, cmd, buf);
423 #endif
424 		} else {
425 			if (!dev->ops->ioctl) {
426 				error = -EINVAL;
427 				goto done;
428 			}
429 			size = dev->ops->ioctl(dev, cmd, buf);
430 		}
431 		if (size < 0) {
432 			error = (size == -ENOIOCTLCMD ? -ENOTTY : size);
433 			goto done;
434 		}
435 	}
436 
437 	if (size)
438 		error = put_user(size, sioc_len) ? -EFAULT : 0;
439 	else
440 		error = 0;
441 done:
442 	atm_dev_put(dev);
443 	return error;
444 }
445 
446 void *atm_dev_seq_start(struct seq_file *seq, loff_t *pos)
447 {
448 	mutex_lock(&atm_dev_mutex);
449 	return seq_list_start_head(&atm_devs, *pos);
450 }
451 
452 void atm_dev_seq_stop(struct seq_file *seq, void *v)
453 {
454 	mutex_unlock(&atm_dev_mutex);
455 }
456 
457 void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
458 {
459 	return seq_list_next(v, &atm_devs, pos);
460 }
461