xref: /openbmc/linux/net/atm/resources.c (revision 2359ccdd) 
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 #ifndef CONFIG_COMPAT
207 	compat = 0; /* Just so the compiler _knows_ */
208 #endif
209 
210 	switch (cmd) {
211 	case ATM_GETNAMES:
212 		if (compat) {
213 #ifdef CONFIG_COMPAT
214 			struct compat_atm_iobuf __user *ciobuf = arg;
215 			compat_uptr_t cbuf;
216 			iobuf_len = &ciobuf->length;
217 			if (get_user(cbuf, &ciobuf->buffer))
218 				return -EFAULT;
219 			buf = compat_ptr(cbuf);
220 #endif
221 		} else {
222 			struct atm_iobuf __user *iobuf = arg;
223 			iobuf_len = &iobuf->length;
224 			if (get_user(buf, &iobuf->buffer))
225 				return -EFAULT;
226 		}
227 		if (get_user(len, iobuf_len))
228 			return -EFAULT;
229 		mutex_lock(&atm_dev_mutex);
230 		list_for_each(p, &atm_devs)
231 			size += sizeof(int);
232 		if (size > len) {
233 			mutex_unlock(&atm_dev_mutex);
234 			return -E2BIG;
235 		}
236 		tmp_buf = kmalloc(size, GFP_ATOMIC);
237 		if (!tmp_buf) {
238 			mutex_unlock(&atm_dev_mutex);
239 			return -ENOMEM;
240 		}
241 		tmp_p = tmp_buf;
242 		list_for_each(p, &atm_devs) {
243 			dev = list_entry(p, struct atm_dev, dev_list);
244 			*tmp_p++ = dev->number;
245 		}
246 		mutex_unlock(&atm_dev_mutex);
247 		error = ((copy_to_user(buf, tmp_buf, size)) ||
248 			 put_user(size, iobuf_len))
249 			? -EFAULT : 0;
250 		kfree(tmp_buf);
251 		return error;
252 	default:
253 		break;
254 	}
255 
256 	if (compat) {
257 #ifdef CONFIG_COMPAT
258 		struct compat_atmif_sioc __user *csioc = arg;
259 		compat_uptr_t carg;
260 
261 		sioc_len = &csioc->length;
262 		if (get_user(carg, &csioc->arg))
263 			return -EFAULT;
264 		buf = compat_ptr(carg);
265 
266 		if (get_user(len, &csioc->length))
267 			return -EFAULT;
268 		if (get_user(number, &csioc->number))
269 			return -EFAULT;
270 #endif
271 	} else {
272 		struct atmif_sioc __user *sioc = arg;
273 
274 		sioc_len = &sioc->length;
275 		if (get_user(buf, &sioc->arg))
276 			return -EFAULT;
277 		if (get_user(len, &sioc->length))
278 			return -EFAULT;
279 		if (get_user(number, &sioc->number))
280 			return -EFAULT;
281 	}
282 
283 	dev = try_then_request_module(atm_dev_lookup(number), "atm-device-%d",
284 				      number);
285 	if (!dev)
286 		return -ENODEV;
287 
288 	switch (cmd) {
289 	case ATM_GETTYPE:
290 		size = strlen(dev->type) + 1;
291 		if (copy_to_user(buf, dev->type, size)) {
292 			error = -EFAULT;
293 			goto done;
294 		}
295 		break;
296 	case ATM_GETESI:
297 		size = ESI_LEN;
298 		if (copy_to_user(buf, dev->esi, size)) {
299 			error = -EFAULT;
300 			goto done;
301 		}
302 		break;
303 	case ATM_SETESI:
304 	{
305 		int i;
306 
307 		for (i = 0; i < ESI_LEN; i++)
308 			if (dev->esi[i]) {
309 				error = -EEXIST;
310 				goto done;
311 			}
312 	}
313 	/* fall through */
314 	case ATM_SETESIF:
315 	{
316 		unsigned char esi[ESI_LEN];
317 
318 		if (!capable(CAP_NET_ADMIN)) {
319 			error = -EPERM;
320 			goto done;
321 		}
322 		if (copy_from_user(esi, buf, ESI_LEN)) {
323 			error = -EFAULT;
324 			goto done;
325 		}
326 		memcpy(dev->esi, esi, ESI_LEN);
327 		error =  ESI_LEN;
328 		goto done;
329 	}
330 	case ATM_GETSTATZ:
331 		if (!capable(CAP_NET_ADMIN)) {
332 			error = -EPERM;
333 			goto done;
334 		}
335 		/* fall through */
336 	case ATM_GETSTAT:
337 		size = sizeof(struct atm_dev_stats);
338 		error = fetch_stats(dev, buf, cmd == ATM_GETSTATZ);
339 		if (error)
340 			goto done;
341 		break;
342 	case ATM_GETCIRANGE:
343 		size = sizeof(struct atm_cirange);
344 		if (copy_to_user(buf, &dev->ci_range, size)) {
345 			error = -EFAULT;
346 			goto done;
347 		}
348 		break;
349 	case ATM_GETLINKRATE:
350 		size = sizeof(int);
351 		if (copy_to_user(buf, &dev->link_rate, size)) {
352 			error = -EFAULT;
353 			goto done;
354 		}
355 		break;
356 	case ATM_RSTADDR:
357 		if (!capable(CAP_NET_ADMIN)) {
358 			error = -EPERM;
359 			goto done;
360 		}
361 		atm_reset_addr(dev, ATM_ADDR_LOCAL);
362 		break;
363 	case ATM_ADDADDR:
364 	case ATM_DELADDR:
365 	case ATM_ADDLECSADDR:
366 	case ATM_DELLECSADDR:
367 	{
368 		struct sockaddr_atmsvc addr;
369 
370 		if (!capable(CAP_NET_ADMIN)) {
371 			error = -EPERM;
372 			goto done;
373 		}
374 
375 		if (copy_from_user(&addr, buf, sizeof(addr))) {
376 			error = -EFAULT;
377 			goto done;
378 		}
379 		if (cmd == ATM_ADDADDR || cmd == ATM_ADDLECSADDR)
380 			error = atm_add_addr(dev, &addr,
381 					     (cmd == ATM_ADDADDR ?
382 					      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
383 		else
384 			error = atm_del_addr(dev, &addr,
385 					     (cmd == ATM_DELADDR ?
386 					      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
387 		goto done;
388 	}
389 	case ATM_GETADDR:
390 	case ATM_GETLECSADDR:
391 		error = atm_get_addr(dev, buf, len,
392 				     (cmd == ATM_GETADDR ?
393 				      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
394 		if (error < 0)
395 			goto done;
396 		size = error;
397 		/* may return 0, but later on size == 0 means "don't
398 		   write the length" */
399 		error = put_user(size, sioc_len) ? -EFAULT : 0;
400 		goto done;
401 	case ATM_SETLOOP:
402 		if (__ATM_LM_XTRMT((int) (unsigned long) buf) &&
403 		    __ATM_LM_XTLOC((int) (unsigned long) buf) >
404 		    __ATM_LM_XTRMT((int) (unsigned long) buf)) {
405 			error = -EINVAL;
406 			goto done;
407 		}
408 		/* fall through */
409 	case ATM_SETCIRANGE:
410 	case SONET_GETSTATZ:
411 	case SONET_SETDIAG:
412 	case SONET_CLRDIAG:
413 	case SONET_SETFRAMING:
414 		if (!capable(CAP_NET_ADMIN)) {
415 			error = -EPERM;
416 			goto done;
417 		}
418 		/* fall through */
419 	default:
420 		if (compat) {
421 #ifdef CONFIG_COMPAT
422 			if (!dev->ops->compat_ioctl) {
423 				error = -EINVAL;
424 				goto done;
425 			}
426 			size = dev->ops->compat_ioctl(dev, cmd, buf);
427 #endif
428 		} else {
429 			if (!dev->ops->ioctl) {
430 				error = -EINVAL;
431 				goto done;
432 			}
433 			size = dev->ops->ioctl(dev, cmd, buf);
434 		}
435 		if (size < 0) {
436 			error = (size == -ENOIOCTLCMD ? -ENOTTY : size);
437 			goto done;
438 		}
439 	}
440 
441 	if (size)
442 		error = put_user(size, sioc_len) ? -EFAULT : 0;
443 	else
444 		error = 0;
445 done:
446 	atm_dev_put(dev);
447 	return error;
448 }
449 
450 void *atm_dev_seq_start(struct seq_file *seq, loff_t *pos)
451 {
452 	mutex_lock(&atm_dev_mutex);
453 	return seq_list_start_head(&atm_devs, *pos);
454 }
455 
456 void atm_dev_seq_stop(struct seq_file *seq, void *v)
457 {
458 	mutex_unlock(&atm_dev_mutex);
459 }
460 
461 void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
462 {
463 	return seq_list_next(v, &atm_devs, pos);
464 }
465