resources.c

  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		mutex_unlock(&atm_dev_mutex);
116		kfree(dev);
117		return NULL;
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	put_device(&dev->class_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	atm_dev_release_vccs(dev);
152	atm_unregister_sysfs(dev);
153	atm_proc_dev_deregister(dev);
154	mutex_unlock(&atm_dev_mutex);
155
156	atm_dev_put(dev);
157}
158EXPORT_SYMBOL(atm_dev_deregister);
159
160static void copy_aal_stats(struct k_atm_aal_stats *from,
161    struct atm_aal_stats *to)
162{
163#define __HANDLE_ITEM(i) to->i = atomic_read(&from->i)
164	__AAL_STAT_ITEMS
165#undef __HANDLE_ITEM
166}
167
168static void subtract_aal_stats(struct k_atm_aal_stats *from,
169    struct atm_aal_stats *to)
170{
171#define __HANDLE_ITEM(i) atomic_sub(to->i, &from->i)
172	__AAL_STAT_ITEMS
173#undef __HANDLE_ITEM
174}
175
176static int fetch_stats(struct atm_dev *dev, struct atm_dev_stats __user *arg,
177		       int zero)
178{
179	struct atm_dev_stats tmp;
180	int error = 0;
181
182	copy_aal_stats(&dev->stats.aal0, &tmp.aal0);
183	copy_aal_stats(&dev->stats.aal34, &tmp.aal34);
184	copy_aal_stats(&dev->stats.aal5, &tmp.aal5);
185	if (arg)
186		error = copy_to_user(arg, &tmp, sizeof(tmp));
187	if (zero && !error) {
188		subtract_aal_stats(&dev->stats.aal0, &tmp.aal0);
189		subtract_aal_stats(&dev->stats.aal34, &tmp.aal34);
190		subtract_aal_stats(&dev->stats.aal5, &tmp.aal5);
191	}
192	return error ? -EFAULT : 0;
193}
194
195int atm_getnames(void __user *buf, int __user *iobuf_len)
196{
197	int error, len, size = 0;
198	struct atm_dev *dev;
199	struct list_head *p;
200	int *tmp_buf, *tmp_p;
201
202	if (get_user(len, iobuf_len))
203		return -EFAULT;
204	mutex_lock(&atm_dev_mutex);
205	list_for_each(p, &atm_devs)
206		size += sizeof(int);
207	if (size > len) {
208		mutex_unlock(&atm_dev_mutex);
209		return -E2BIG;
210	}
211	tmp_buf = kmalloc(size, GFP_ATOMIC);
212	if (!tmp_buf) {
213		mutex_unlock(&atm_dev_mutex);
214		return -ENOMEM;
215	}
216	tmp_p = tmp_buf;
217	list_for_each_entry(dev, &atm_devs, dev_list) {
218		*tmp_p++ = dev->number;
219	}
220	mutex_unlock(&atm_dev_mutex);
221	error = ((copy_to_user(buf, tmp_buf, size)) ||
222		 put_user(size, iobuf_len))
223		? -EFAULT : 0;
224	kfree(tmp_buf);
225	return error;
226}
227
228int atm_dev_ioctl(unsigned int cmd, void __user *buf, int __user *sioc_len,
229		  int number, int compat)
230{
231	int error, len, size = 0;
232	struct atm_dev *dev;
233
234	if (get_user(len, sioc_len))
235		return -EFAULT;
236
237	dev = try_then_request_module(atm_dev_lookup(number), "atm-device-%d",
238				      number);
239	if (!dev)
240		return -ENODEV;
241
242	switch (cmd) {
243	case ATM_GETTYPE:
244		size = strlen(dev->type) + 1;
245		if (copy_to_user(buf, dev->type, size)) {
246			error = -EFAULT;
247			goto done;
248		}
249		break;
250	case ATM_GETESI:
251		size = ESI_LEN;
252		if (copy_to_user(buf, dev->esi, size)) {
253			error = -EFAULT;
254			goto done;
255		}
256		break;
257	case ATM_SETESI:
258	{
259		int i;
260
261		for (i = 0; i < ESI_LEN; i++)
262			if (dev->esi[i]) {
263				error = -EEXIST;
264				goto done;
265			}
266	}
267		fallthrough;
268	case ATM_SETESIF:
269	{
270		unsigned char esi[ESI_LEN];
271
272		if (!capable(CAP_NET_ADMIN)) {
273			error = -EPERM;
274			goto done;
275		}
276		if (copy_from_user(esi, buf, ESI_LEN)) {
277			error = -EFAULT;
278			goto done;
279		}
280		memcpy(dev->esi, esi, ESI_LEN);
281		error =  ESI_LEN;
282		goto done;
283	}
284	case ATM_GETSTATZ:
285		if (!capable(CAP_NET_ADMIN)) {
286			error = -EPERM;
287			goto done;
288		}
289		fallthrough;
290	case ATM_GETSTAT:
291		size = sizeof(struct atm_dev_stats);
292		error = fetch_stats(dev, buf, cmd == ATM_GETSTATZ);
293		if (error)
294			goto done;
295		break;
296	case ATM_GETCIRANGE:
297		size = sizeof(struct atm_cirange);
298		if (copy_to_user(buf, &dev->ci_range, size)) {
299			error = -EFAULT;
300			goto done;
301		}
302		break;
303	case ATM_GETLINKRATE:
304		size = sizeof(int);
305		if (copy_to_user(buf, &dev->link_rate, size)) {
306			error = -EFAULT;
307			goto done;
308		}
309		break;
310	case ATM_RSTADDR:
311		if (!capable(CAP_NET_ADMIN)) {
312			error = -EPERM;
313			goto done;
314		}
315		atm_reset_addr(dev, ATM_ADDR_LOCAL);
316		break;
317	case ATM_ADDADDR:
318	case ATM_DELADDR:
319	case ATM_ADDLECSADDR:
320	case ATM_DELLECSADDR:
321	{
322		struct sockaddr_atmsvc addr;
323
324		if (!capable(CAP_NET_ADMIN)) {
325			error = -EPERM;
326			goto done;
327		}
328
329		if (copy_from_user(&addr, buf, sizeof(addr))) {
330			error = -EFAULT;
331			goto done;
332		}
333		if (cmd == ATM_ADDADDR || cmd == ATM_ADDLECSADDR)
334			error = atm_add_addr(dev, &addr,
335					     (cmd == ATM_ADDADDR ?
336					      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
337		else
338			error = atm_del_addr(dev, &addr,
339					     (cmd == ATM_DELADDR ?
340					      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
341		goto done;
342	}
343	case ATM_GETADDR:
344	case ATM_GETLECSADDR:
345		error = atm_get_addr(dev, buf, len,
346				     (cmd == ATM_GETADDR ?
347				      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
348		if (error < 0)
349			goto done;
350		size = error;
351		/* may return 0, but later on size == 0 means "don't
352		   write the length" */
353		error = put_user(size, sioc_len) ? -EFAULT : 0;
354		goto done;
355	case ATM_SETLOOP:
356		if (__ATM_LM_XTRMT((int) (unsigned long) buf) &&
357		    __ATM_LM_XTLOC((int) (unsigned long) buf) >
358		    __ATM_LM_XTRMT((int) (unsigned long) buf)) {
359			error = -EINVAL;
360			goto done;
361		}
362		fallthrough;
363	case ATM_SETCIRANGE:
364	case SONET_GETSTATZ:
365	case SONET_SETDIAG:
366	case SONET_CLRDIAG:
367	case SONET_SETFRAMING:
368		if (!capable(CAP_NET_ADMIN)) {
369			error = -EPERM;
370			goto done;
371		}
372		fallthrough;
373	default:
374		if (IS_ENABLED(CONFIG_COMPAT) && compat) {
375#ifdef CONFIG_COMPAT
376			if (!dev->ops->compat_ioctl) {
377				error = -EINVAL;
378				goto done;
379			}
380			size = dev->ops->compat_ioctl(dev, cmd, buf);
381#endif
382		} else {
383			if (!dev->ops->ioctl) {
384				error = -EINVAL;
385				goto done;
386			}
387			size = dev->ops->ioctl(dev, cmd, buf);
388		}
389		if (size < 0) {
390			error = (size == -ENOIOCTLCMD ? -ENOTTY : size);
391			goto done;
392		}
393	}
394
395	if (size)
396		error = put_user(size, sioc_len) ? -EFAULT : 0;
397	else
398		error = 0;
399done:
400	atm_dev_put(dev);
401	return error;
402}
403
404#ifdef CONFIG_PROC_FS
405void *atm_dev_seq_start(struct seq_file *seq, loff_t *pos)
406{
407	mutex_lock(&atm_dev_mutex);
408	return seq_list_start_head(&atm_devs, *pos);
409}
410
411void atm_dev_seq_stop(struct seq_file *seq, void *v)
412{
413	mutex_unlock(&atm_dev_mutex);
414}
415
416void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
417{
418	return seq_list_next(v, &atm_devs, pos);
419}
420#endif