xref: /kernel/linux/linux-5.10/net/atm/resources.c (revision 8c2ecf20) 
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
32LIST_HEAD(atm_devs);
33DEFINE_MUTEX(atm_dev_mutex);
34
35static 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
52static 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
67struct 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}
76EXPORT_SYMBOL(atm_dev_lookup);
77
78struct 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
128out:
129	mutex_unlock(&atm_dev_mutex);
130	return dev;
131
132out_fail:
133	kfree(dev);
134	dev = NULL;
135	goto out;
136}
137EXPORT_SYMBOL(atm_dev_register);
138
139void 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}
159EXPORT_SYMBOL(atm_dev_deregister);
160
161static 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
169static 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
177static 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
196int atm_getnames(void __user *buf, int __user *iobuf_len)
197{
198	int error, len, size = 0;
199	struct atm_dev *dev;
200	struct list_head *p;
201	int *tmp_buf, *tmp_p;
202
203	if (get_user(len, iobuf_len))
204		return -EFAULT;
205	mutex_lock(&atm_dev_mutex);
206	list_for_each(p, &atm_devs)
207		size += sizeof(int);
208	if (size > len) {
209		mutex_unlock(&atm_dev_mutex);
210		return -E2BIG;
211	}
212	tmp_buf = kmalloc(size, GFP_ATOMIC);
213	if (!tmp_buf) {
214		mutex_unlock(&atm_dev_mutex);
215		return -ENOMEM;
216	}
217	tmp_p = tmp_buf;
218	list_for_each(p, &atm_devs) {
219		dev = list_entry(p, struct atm_dev, dev_list);
220		*tmp_p++ = dev->number;
221	}
222	mutex_unlock(&atm_dev_mutex);
223	error = ((copy_to_user(buf, tmp_buf, size)) ||
224		 put_user(size, iobuf_len))
225		? -EFAULT : 0;
226	kfree(tmp_buf);
227	return error;
228}
229
230int atm_dev_ioctl(unsigned int cmd, void __user *buf, int __user *sioc_len,
231		  int number, int compat)
232{
233	int error, len, size = 0;
234	struct atm_dev *dev;
235
236	if (get_user(len, sioc_len))
237		return -EFAULT;
238
239	dev = try_then_request_module(atm_dev_lookup(number), "atm-device-%d",
240				      number);
241	if (!dev)
242		return -ENODEV;
243
244	switch (cmd) {
245	case ATM_GETTYPE:
246		size = strlen(dev->type) + 1;
247		if (copy_to_user(buf, dev->type, size)) {
248			error = -EFAULT;
249			goto done;
250		}
251		break;
252	case ATM_GETESI:
253		size = ESI_LEN;
254		if (copy_to_user(buf, dev->esi, size)) {
255			error = -EFAULT;
256			goto done;
257		}
258		break;
259	case ATM_SETESI:
260	{
261		int i;
262
263		for (i = 0; i < ESI_LEN; i++)
264			if (dev->esi[i]) {
265				error = -EEXIST;
266				goto done;
267			}
268	}
269		fallthrough;
270	case ATM_SETESIF:
271	{
272		unsigned char esi[ESI_LEN];
273
274		if (!capable(CAP_NET_ADMIN)) {
275			error = -EPERM;
276			goto done;
277		}
278		if (copy_from_user(esi, buf, ESI_LEN)) {
279			error = -EFAULT;
280			goto done;
281		}
282		memcpy(dev->esi, esi, ESI_LEN);
283		error =  ESI_LEN;
284		goto done;
285	}
286	case ATM_GETSTATZ:
287		if (!capable(CAP_NET_ADMIN)) {
288			error = -EPERM;
289			goto done;
290		}
291		fallthrough;
292	case ATM_GETSTAT:
293		size = sizeof(struct atm_dev_stats);
294		error = fetch_stats(dev, buf, cmd == ATM_GETSTATZ);
295		if (error)
296			goto done;
297		break;
298	case ATM_GETCIRANGE:
299		size = sizeof(struct atm_cirange);
300		if (copy_to_user(buf, &dev->ci_range, size)) {
301			error = -EFAULT;
302			goto done;
303		}
304		break;
305	case ATM_GETLINKRATE:
306		size = sizeof(int);
307		if (copy_to_user(buf, &dev->link_rate, size)) {
308			error = -EFAULT;
309			goto done;
310		}
311		break;
312	case ATM_RSTADDR:
313		if (!capable(CAP_NET_ADMIN)) {
314			error = -EPERM;
315			goto done;
316		}
317		atm_reset_addr(dev, ATM_ADDR_LOCAL);
318		break;
319	case ATM_ADDADDR:
320	case ATM_DELADDR:
321	case ATM_ADDLECSADDR:
322	case ATM_DELLECSADDR:
323	{
324		struct sockaddr_atmsvc addr;
325
326		if (!capable(CAP_NET_ADMIN)) {
327			error = -EPERM;
328			goto done;
329		}
330
331		if (copy_from_user(&addr, buf, sizeof(addr))) {
332			error = -EFAULT;
333			goto done;
334		}
335		if (cmd == ATM_ADDADDR || cmd == ATM_ADDLECSADDR)
336			error = atm_add_addr(dev, &addr,
337					     (cmd == ATM_ADDADDR ?
338					      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
339		else
340			error = atm_del_addr(dev, &addr,
341					     (cmd == ATM_DELADDR ?
342					      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
343		goto done;
344	}
345	case ATM_GETADDR:
346	case ATM_GETLECSADDR:
347		error = atm_get_addr(dev, buf, len,
348				     (cmd == ATM_GETADDR ?
349				      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
350		if (error < 0)
351			goto done;
352		size = error;
353		/* may return 0, but later on size == 0 means "don't
354		   write the length" */
355		error = put_user(size, sioc_len) ? -EFAULT : 0;
356		goto done;
357	case ATM_SETLOOP:
358		if (__ATM_LM_XTRMT((int) (unsigned long) buf) &&
359		    __ATM_LM_XTLOC((int) (unsigned long) buf) >
360		    __ATM_LM_XTRMT((int) (unsigned long) buf)) {
361			error = -EINVAL;
362			goto done;
363		}
364		fallthrough;
365	case ATM_SETCIRANGE:
366	case SONET_GETSTATZ:
367	case SONET_SETDIAG:
368	case SONET_CLRDIAG:
369	case SONET_SETFRAMING:
370		if (!capable(CAP_NET_ADMIN)) {
371			error = -EPERM;
372			goto done;
373		}
374		fallthrough;
375	default:
376		if (IS_ENABLED(CONFIG_COMPAT) && compat) {
377#ifdef CONFIG_COMPAT
378			if (!dev->ops->compat_ioctl) {
379				error = -EINVAL;
380				goto done;
381			}
382			size = dev->ops->compat_ioctl(dev, cmd, buf);
383#endif
384		} else {
385			if (!dev->ops->ioctl) {
386				error = -EINVAL;
387				goto done;
388			}
389			size = dev->ops->ioctl(dev, cmd, buf);
390		}
391		if (size < 0) {
392			error = (size == -ENOIOCTLCMD ? -ENOTTY : size);
393			goto done;
394		}
395	}
396
397	if (size)
398		error = put_user(size, sioc_len) ? -EFAULT : 0;
399	else
400		error = 0;
401done:
402	atm_dev_put(dev);
403	return error;
404}
405
406#ifdef CONFIG_PROC_FS
407void *atm_dev_seq_start(struct seq_file *seq, loff_t *pos)
408{
409	mutex_lock(&atm_dev_mutex);
410	return seq_list_start_head(&atm_devs, *pos);
411}
412
413void atm_dev_seq_stop(struct seq_file *seq, void *v)
414{
415	mutex_unlock(&atm_dev_mutex);
416}
417
418void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
419{
420	return seq_list_next(v, &atm_devs, pos);
421}
422#endif
423