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
56	list_for_each_entry(dev, &atm_devs, dev_list) {
57		if (dev->number == number) {
58			atm_dev_hold(dev);
59			return dev;
60		}
61	}
62	return NULL;
63}
64
65struct atm_dev *atm_dev_lookup(int number)
66{
67	struct atm_dev *dev;
68
69	mutex_lock(&atm_dev_mutex);
70	dev = __atm_dev_lookup(number);
71	mutex_unlock(&atm_dev_mutex);
72	return dev;
73}
74EXPORT_SYMBOL(atm_dev_lookup);
75
76struct atm_dev *atm_dev_register(const char *type, struct device *parent,
77				 const struct atmdev_ops *ops, int number,
78				 unsigned long *flags)
79{
80	struct atm_dev *dev, *inuse;
81
82	dev = __alloc_atm_dev(type);
83	if (!dev) {
84		pr_err("no space for dev %s\n", type);
85		return NULL;
86	}
87	mutex_lock(&atm_dev_mutex);
88	if (number != -1) {
89		inuse = __atm_dev_lookup(number);
90		if (inuse) {
91			atm_dev_put(inuse);
92			mutex_unlock(&atm_dev_mutex);
93			kfree(dev);
94			return NULL;
95		}
96		dev->number = number;
97	} else {
98		dev->number = 0;
99		while ((inuse = __atm_dev_lookup(dev->number))) {
100			atm_dev_put(inuse);
101			dev->number++;
102		}
103	}
104
105	dev->ops = ops;
106	if (flags)
107		dev->flags = *flags;
108	else
109		memset(&dev->flags, 0, sizeof(dev->flags));
110	memset(&dev->stats, 0, sizeof(dev->stats));
111	refcount_set(&dev->refcnt, 1);
112
113	if (atm_proc_dev_register(dev) < 0) {
114		pr_err("atm_proc_dev_register failed for dev %s\n", type);
115		goto out_fail;
116	}
117
118	if (atm_register_sysfs(dev, parent) < 0) {
119		pr_err("atm_register_sysfs failed for dev %s\n", type);
120		atm_proc_dev_deregister(dev);
121		goto out_fail;
122	}
123
124	list_add_tail(&dev->dev_list, &atm_devs);
125
126out:
127	mutex_unlock(&atm_dev_mutex);
128	return dev;
129
130out_fail:
131	kfree(dev);
132	dev = NULL;
133	goto out;
134}
135EXPORT_SYMBOL(atm_dev_register);
136
137void atm_dev_deregister(struct atm_dev *dev)
138{
139	BUG_ON(test_bit(ATM_DF_REMOVED, &dev->flags));
140	set_bit(ATM_DF_REMOVED, &dev->flags);
141
142	/*
143	 * if we remove current device from atm_devs list, new device
144	 * with same number can appear, such we need deregister proc,
145	 * release async all vccs and remove them from vccs list too
146	 */
147	mutex_lock(&atm_dev_mutex);
148	list_del(&dev->dev_list);
149	mutex_unlock(&atm_dev_mutex);
150
151	atm_dev_release_vccs(dev);
152	atm_unregister_sysfs(dev);
153	atm_proc_dev_deregister(dev);
154
155	atm_dev_put(dev);
156}
157EXPORT_SYMBOL(atm_dev_deregister);
158
159static void copy_aal_stats(struct k_atm_aal_stats *from,
160    struct atm_aal_stats *to)
161{
162#define __HANDLE_ITEM(i) to->i = atomic_read(&from->i)
163	__AAL_STAT_ITEMS
164#undef __HANDLE_ITEM
165}
166
167static void subtract_aal_stats(struct k_atm_aal_stats *from,
168    struct atm_aal_stats *to)
169{
170#define __HANDLE_ITEM(i) atomic_sub(to->i, &from->i)
171	__AAL_STAT_ITEMS
172#undef __HANDLE_ITEM
173}
174
175static int fetch_stats(struct atm_dev *dev, struct atm_dev_stats __user *arg,
176		       int zero)
177{
178	struct atm_dev_stats tmp;
179	int error = 0;
180
181	copy_aal_stats(&dev->stats.aal0, &tmp.aal0);
182	copy_aal_stats(&dev->stats.aal34, &tmp.aal34);
183	copy_aal_stats(&dev->stats.aal5, &tmp.aal5);
184	if (arg)
185		error = copy_to_user(arg, &tmp, sizeof(tmp));
186	if (zero && !error) {
187		subtract_aal_stats(&dev->stats.aal0, &tmp.aal0);
188		subtract_aal_stats(&dev->stats.aal34, &tmp.aal34);
189		subtract_aal_stats(&dev->stats.aal5, &tmp.aal5);
190	}
191	return error ? -EFAULT : 0;
192}
193
194int atm_getnames(void __user *buf, int __user *iobuf_len)
195{
196	int error, len, size = 0;
197	struct atm_dev *dev;
198	struct list_head *p;
199	int *tmp_buf, *tmp_p;
200
201	if (get_user(len, iobuf_len))
202		return -EFAULT;
203	mutex_lock(&atm_dev_mutex);
204	list_for_each(p, &atm_devs)
205		size += sizeof(int);
206	if (size > len) {
207		mutex_unlock(&atm_dev_mutex);
208		return -E2BIG;
209	}
210	tmp_buf = kmalloc(size, GFP_ATOMIC);
211	if (!tmp_buf) {
212		mutex_unlock(&atm_dev_mutex);
213		return -ENOMEM;
214	}
215	tmp_p = tmp_buf;
216	list_for_each_entry(dev, &atm_devs, dev_list) {
217		*tmp_p++ = dev->number;
218	}
219	mutex_unlock(&atm_dev_mutex);
220	error = ((copy_to_user(buf, tmp_buf, size)) ||
221		 put_user(size, iobuf_len))
222		? -EFAULT : 0;
223	kfree(tmp_buf);
224	return error;
225}
226
227int atm_dev_ioctl(unsigned int cmd, void __user *buf, int __user *sioc_len,
228		  int number, int compat)
229{
230	int error, len, size = 0;
231	struct atm_dev *dev;
232
233	if (get_user(len, sioc_len))
234		return -EFAULT;
235
236	dev = try_then_request_module(atm_dev_lookup(number), "atm-device-%d",
237				      number);
238	if (!dev)
239		return -ENODEV;
240
241	switch (cmd) {
242	case ATM_GETTYPE:
243		size = strlen(dev->type) + 1;
244		if (copy_to_user(buf, dev->type, size)) {
245			error = -EFAULT;
246			goto done;
247		}
248		break;
249	case ATM_GETESI:
250		size = ESI_LEN;
251		if (copy_to_user(buf, dev->esi, size)) {
252			error = -EFAULT;
253			goto done;
254		}
255		break;
256	case ATM_SETESI:
257	{
258		int i;
259
260		for (i = 0; i < ESI_LEN; i++)
261			if (dev->esi[i]) {
262				error = -EEXIST;
263				goto done;
264			}
265	}
266		fallthrough;
267	case ATM_SETESIF:
268	{
269		unsigned char esi[ESI_LEN];
270
271		if (!capable(CAP_NET_ADMIN)) {
272			error = -EPERM;
273			goto done;
274		}
275		if (copy_from_user(esi, buf, ESI_LEN)) {
276			error = -EFAULT;
277			goto done;
278		}
279		memcpy(dev->esi, esi, ESI_LEN);
280		error =  ESI_LEN;
281		goto done;
282	}
283	case ATM_GETSTATZ:
284		if (!capable(CAP_NET_ADMIN)) {
285			error = -EPERM;
286			goto done;
287		}
288		fallthrough;
289	case ATM_GETSTAT:
290		size = sizeof(struct atm_dev_stats);
291		error = fetch_stats(dev, buf, cmd == ATM_GETSTATZ);
292		if (error)
293			goto done;
294		break;
295	case ATM_GETCIRANGE:
296		size = sizeof(struct atm_cirange);
297		if (copy_to_user(buf, &dev->ci_range, size)) {
298			error = -EFAULT;
299			goto done;
300		}
301		break;
302	case ATM_GETLINKRATE:
303		size = sizeof(int);
304		if (copy_to_user(buf, &dev->link_rate, size)) {
305			error = -EFAULT;
306			goto done;
307		}
308		break;
309	case ATM_RSTADDR:
310		if (!capable(CAP_NET_ADMIN)) {
311			error = -EPERM;
312			goto done;
313		}
314		atm_reset_addr(dev, ATM_ADDR_LOCAL);
315		break;
316	case ATM_ADDADDR:
317	case ATM_DELADDR:
318	case ATM_ADDLECSADDR:
319	case ATM_DELLECSADDR:
320	{
321		struct sockaddr_atmsvc addr;
322
323		if (!capable(CAP_NET_ADMIN)) {
324			error = -EPERM;
325			goto done;
326		}
327
328		if (copy_from_user(&addr, buf, sizeof(addr))) {
329			error = -EFAULT;
330			goto done;
331		}
332		if (cmd == ATM_ADDADDR || cmd == ATM_ADDLECSADDR)
333			error = atm_add_addr(dev, &addr,
334					     (cmd == ATM_ADDADDR ?
335					      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
336		else
337			error = atm_del_addr(dev, &addr,
338					     (cmd == ATM_DELADDR ?
339					      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
340		goto done;
341	}
342	case ATM_GETADDR:
343	case ATM_GETLECSADDR:
344		error = atm_get_addr(dev, buf, len,
345				     (cmd == ATM_GETADDR ?
346				      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
347		if (error < 0)
348			goto done;
349		size = error;
350		/* may return 0, but later on size == 0 means "don't
351		   write the length" */
352		error = put_user(size, sioc_len) ? -EFAULT : 0;
353		goto done;
354	case ATM_SETLOOP:
355		if (__ATM_LM_XTRMT((int) (unsigned long) buf) &&
356		    __ATM_LM_XTLOC((int) (unsigned long) buf) >
357		    __ATM_LM_XTRMT((int) (unsigned long) buf)) {
358			error = -EINVAL;
359			goto done;
360		}
361		fallthrough;
362	case ATM_SETCIRANGE:
363	case SONET_GETSTATZ:
364	case SONET_SETDIAG:
365	case SONET_CLRDIAG:
366	case SONET_SETFRAMING:
367		if (!capable(CAP_NET_ADMIN)) {
368			error = -EPERM;
369			goto done;
370		}
371		fallthrough;
372	default:
373		if (IS_ENABLED(CONFIG_COMPAT) && compat) {
374#ifdef CONFIG_COMPAT
375			if (!dev->ops->compat_ioctl) {
376				error = -EINVAL;
377				goto done;
378			}
379			size = dev->ops->compat_ioctl(dev, cmd, buf);
380#endif
381		} else {
382			if (!dev->ops->ioctl) {
383				error = -EINVAL;
384				goto done;
385			}
386			size = dev->ops->ioctl(dev, cmd, buf);
387		}
388		if (size < 0) {
389			error = (size == -ENOIOCTLCMD ? -ENOTTY : size);
390			goto done;
391		}
392	}
393
394	if (size)
395		error = put_user(size, sioc_len) ? -EFAULT : 0;
396	else
397		error = 0;
398done:
399	atm_dev_put(dev);
400	return error;
401}
402
403#ifdef CONFIG_PROC_FS
404void *atm_dev_seq_start(struct seq_file *seq, loff_t *pos)
405{
406	mutex_lock(&atm_dev_mutex);
407	return seq_list_start_head(&atm_devs, *pos);
408}
409
410void atm_dev_seq_stop(struct seq_file *seq, void *v)
411{
412	mutex_unlock(&atm_dev_mutex);
413}
414
415void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
416{
417	return seq_list_next(v, &atm_devs, pos);
418}
419#endif
420