xref: /linux/net/atm/resources.c (revision 54a8a2220c936a47840c9a3d74910c5a56fae2ed)
1 /* net/atm/resources.c - Statically allocated resources */
2 
3 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
4 
5 /* Fixes
6  * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
7  * 2002/01 - don't free the whole struct sock on sk->destruct time,
8  * 	     use the default destruct function initialized by sock_init_data */
9 
10 
11 #include <linux/config.h>
12 #include <linux/ctype.h>
13 #include <linux/string.h>
14 #include <linux/atmdev.h>
15 #include <linux/sonet.h>
16 #include <linux/kernel.h> /* for barrier */
17 #include <linux/module.h>
18 #include <linux/bitops.h>
19 #include <linux/delay.h>
20 #include <net/sock.h>	 /* for struct sock */
21 
22 #include "common.h"
23 #include "resources.h"
24 #include "addr.h"
25 
26 
27 LIST_HEAD(atm_devs);
28 DEFINE_SPINLOCK(atm_dev_lock);
29 
30 static struct atm_dev *__alloc_atm_dev(const char *type)
31 {
32 	struct atm_dev *dev;
33 
34 	dev = kmalloc(sizeof(*dev), GFP_KERNEL);
35 	if (!dev)
36 		return NULL;
37 	memset(dev, 0, sizeof(*dev));
38 	dev->type = type;
39 	dev->signal = ATM_PHY_SIG_UNKNOWN;
40 	dev->link_rate = ATM_OC3_PCR;
41 	spin_lock_init(&dev->lock);
42 	INIT_LIST_HEAD(&dev->local);
43 	INIT_LIST_HEAD(&dev->lecs);
44 
45 	return dev;
46 }
47 
48 static struct atm_dev *__atm_dev_lookup(int number)
49 {
50 	struct atm_dev *dev;
51 	struct list_head *p;
52 
53 	list_for_each(p, &atm_devs) {
54 		dev = list_entry(p, struct atm_dev, dev_list);
55 		if ((dev->ops) && (dev->number == number)) {
56 			atm_dev_hold(dev);
57 			return dev;
58 		}
59 	}
60 	return NULL;
61 }
62 
63 struct atm_dev *atm_dev_lookup(int number)
64 {
65 	struct atm_dev *dev;
66 
67 	spin_lock(&atm_dev_lock);
68 	dev = __atm_dev_lookup(number);
69 	spin_unlock(&atm_dev_lock);
70 	return dev;
71 }
72 
73 struct atm_dev *atm_dev_register(const char *type, const struct atmdev_ops *ops,
74 				 int number, unsigned long *flags)
75 {
76 	struct atm_dev *dev, *inuse;
77 
78 	dev = __alloc_atm_dev(type);
79 	if (!dev) {
80 		printk(KERN_ERR "atm_dev_register: no space for dev %s\n",
81 		    type);
82 		return NULL;
83 	}
84 	spin_lock(&atm_dev_lock);
85 	if (number != -1) {
86 		if ((inuse = __atm_dev_lookup(number))) {
87 			atm_dev_put(inuse);
88 			spin_unlock(&atm_dev_lock);
89 			kfree(dev);
90 			return NULL;
91 		}
92 		dev->number = number;
93 	} else {
94 		dev->number = 0;
95 		while ((inuse = __atm_dev_lookup(dev->number))) {
96 			atm_dev_put(inuse);
97 			dev->number++;
98 		}
99 	}
100 
101 	dev->ops = ops;
102 	if (flags)
103 		dev->flags = *flags;
104 	else
105 		memset(&dev->flags, 0, sizeof(dev->flags));
106 	memset(&dev->stats, 0, sizeof(dev->stats));
107 	atomic_set(&dev->refcnt, 1);
108 	list_add_tail(&dev->dev_list, &atm_devs);
109 	spin_unlock(&atm_dev_lock);
110 
111 	if (atm_proc_dev_register(dev) < 0) {
112 		printk(KERN_ERR "atm_dev_register: "
113 		       "atm_proc_dev_register failed for dev %s\n",
114 		       type);
115 		spin_lock(&atm_dev_lock);
116 		list_del(&dev->dev_list);
117 		spin_unlock(&atm_dev_lock);
118 		kfree(dev);
119 		return NULL;
120 	}
121 
122 	return dev;
123 }
124 
125 
126 void atm_dev_deregister(struct atm_dev *dev)
127 {
128 	unsigned long warning_time;
129 
130 	atm_proc_dev_deregister(dev);
131 
132 	spin_lock(&atm_dev_lock);
133 	list_del(&dev->dev_list);
134 	spin_unlock(&atm_dev_lock);
135 
136         warning_time = jiffies;
137         while (atomic_read(&dev->refcnt) != 1) {
138                 msleep(250);
139                 if ((jiffies - warning_time) > 10 * HZ) {
140                         printk(KERN_EMERG "atm_dev_deregister: waiting for "
141                                "dev %d to become free. Usage count = %d\n",
142                                dev->number, atomic_read(&dev->refcnt));
143                         warning_time = jiffies;
144                 }
145         }
146 
147 	kfree(dev);
148 }
149 
150 void shutdown_atm_dev(struct atm_dev *dev)
151 {
152 	if (atomic_read(&dev->refcnt) > 1) {
153 		set_bit(ATM_DF_CLOSE, &dev->flags);
154 		return;
155 	}
156 	if (dev->ops->dev_close)
157 		dev->ops->dev_close(dev);
158 	atm_dev_deregister(dev);
159 }
160 
161 
162 static void copy_aal_stats(struct k_atm_aal_stats *from,
163     struct atm_aal_stats *to)
164 {
165 #define __HANDLE_ITEM(i) to->i = atomic_read(&from->i)
166 	__AAL_STAT_ITEMS
167 #undef __HANDLE_ITEM
168 }
169 
170 
171 static void subtract_aal_stats(struct k_atm_aal_stats *from,
172     struct atm_aal_stats *to)
173 {
174 #define __HANDLE_ITEM(i) atomic_sub(to->i, &from->i)
175 	__AAL_STAT_ITEMS
176 #undef __HANDLE_ITEM
177 }
178 
179 
180 static int fetch_stats(struct atm_dev *dev, struct atm_dev_stats __user *arg, int zero)
181 {
182 	struct atm_dev_stats tmp;
183 	int error = 0;
184 
185 	copy_aal_stats(&dev->stats.aal0, &tmp.aal0);
186 	copy_aal_stats(&dev->stats.aal34, &tmp.aal34);
187 	copy_aal_stats(&dev->stats.aal5, &tmp.aal5);
188 	if (arg)
189 		error = copy_to_user(arg, &tmp, sizeof(tmp));
190 	if (zero && !error) {
191 		subtract_aal_stats(&dev->stats.aal0, &tmp.aal0);
192 		subtract_aal_stats(&dev->stats.aal34, &tmp.aal34);
193 		subtract_aal_stats(&dev->stats.aal5, &tmp.aal5);
194 	}
195 	return error ? -EFAULT : 0;
196 }
197 
198 
199 int atm_dev_ioctl(unsigned int cmd, void __user *arg)
200 {
201 	void __user *buf;
202 	int error, len, number, size = 0;
203 	struct atm_dev *dev;
204 	struct list_head *p;
205 	int *tmp_buf, *tmp_p;
206 	struct atm_iobuf __user *iobuf = arg;
207 	struct atmif_sioc __user *sioc = arg;
208 	switch (cmd) {
209 		case ATM_GETNAMES:
210 			if (get_user(buf, &iobuf->buffer))
211 				return -EFAULT;
212 			if (get_user(len, &iobuf->length))
213 				return -EFAULT;
214 			spin_lock(&atm_dev_lock);
215 			list_for_each(p, &atm_devs)
216 				size += sizeof(int);
217 			if (size > len) {
218 				spin_unlock(&atm_dev_lock);
219 				return -E2BIG;
220 			}
221 			tmp_buf = kmalloc(size, GFP_ATOMIC);
222 			if (!tmp_buf) {
223 				spin_unlock(&atm_dev_lock);
224 				return -ENOMEM;
225 			}
226 			tmp_p = tmp_buf;
227 			list_for_each(p, &atm_devs) {
228 				dev = list_entry(p, struct atm_dev, dev_list);
229 				*tmp_p++ = dev->number;
230 			}
231 			spin_unlock(&atm_dev_lock);
232 		        error = ((copy_to_user(buf, tmp_buf, size)) ||
233 					put_user(size, &iobuf->length))
234 						? -EFAULT : 0;
235 			kfree(tmp_buf);
236 			return error;
237 		default:
238 			break;
239 	}
240 
241 	if (get_user(buf, &sioc->arg))
242 		return -EFAULT;
243 	if (get_user(len, &sioc->length))
244 		return -EFAULT;
245 	if (get_user(number, &sioc->number))
246 		return -EFAULT;
247 
248 	if (!(dev = atm_dev_lookup(number)))
249 		return -ENODEV;
250 
251 	switch (cmd) {
252 		case ATM_GETTYPE:
253 			size = strlen(dev->type) + 1;
254 			if (copy_to_user(buf, dev->type, size)) {
255 				error = -EFAULT;
256 				goto done;
257 			}
258 			break;
259 		case ATM_GETESI:
260 			size = ESI_LEN;
261 			if (copy_to_user(buf, dev->esi, size)) {
262 				error = -EFAULT;
263 				goto done;
264 			}
265 			break;
266 		case ATM_SETESI:
267 			{
268 				int i;
269 
270 				for (i = 0; i < ESI_LEN; i++)
271 					if (dev->esi[i]) {
272 						error = -EEXIST;
273 						goto done;
274 					}
275 			}
276 			/* fall through */
277 		case ATM_SETESIF:
278 			{
279 				unsigned char esi[ESI_LEN];
280 
281 				if (!capable(CAP_NET_ADMIN)) {
282 					error = -EPERM;
283 					goto done;
284 				}
285 				if (copy_from_user(esi, buf, ESI_LEN)) {
286 					error = -EFAULT;
287 					goto done;
288 				}
289 				memcpy(dev->esi, esi, ESI_LEN);
290 				error =  ESI_LEN;
291 				goto done;
292 			}
293 		case ATM_GETSTATZ:
294 			if (!capable(CAP_NET_ADMIN)) {
295 				error = -EPERM;
296 				goto done;
297 			}
298 			/* fall through */
299 		case ATM_GETSTAT:
300 			size = sizeof(struct atm_dev_stats);
301 			error = fetch_stats(dev, buf, cmd == ATM_GETSTATZ);
302 			if (error)
303 				goto done;
304 			break;
305 		case ATM_GETCIRANGE:
306 			size = sizeof(struct atm_cirange);
307 			if (copy_to_user(buf, &dev->ci_range, size)) {
308 				error = -EFAULT;
309 				goto done;
310 			}
311 			break;
312 		case ATM_GETLINKRATE:
313 			size = sizeof(int);
314 			if (copy_to_user(buf, &dev->link_rate, size)) {
315 				error = -EFAULT;
316 				goto done;
317 			}
318 			break;
319 		case ATM_RSTADDR:
320 			if (!capable(CAP_NET_ADMIN)) {
321 				error = -EPERM;
322 				goto done;
323 			}
324 			atm_reset_addr(dev, ATM_ADDR_LOCAL);
325 			break;
326 		case ATM_ADDADDR:
327 		case ATM_DELADDR:
328 		case ATM_ADDLECSADDR:
329 		case ATM_DELLECSADDR:
330 			if (!capable(CAP_NET_ADMIN)) {
331 				error = -EPERM;
332 				goto done;
333 			}
334 			{
335 				struct sockaddr_atmsvc addr;
336 
337 				if (copy_from_user(&addr, buf, sizeof(addr))) {
338 					error = -EFAULT;
339 					goto done;
340 				}
341 				if (cmd == ATM_ADDADDR || cmd == ATM_ADDLECSADDR)
342 					error = atm_add_addr(dev, &addr,
343 							     (cmd == ATM_ADDADDR ?
344 							      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
345 				else
346 					error = atm_del_addr(dev, &addr,
347 							     (cmd == ATM_DELADDR ?
348 							      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
349 				goto done;
350 			}
351 		case ATM_GETADDR:
352 		case ATM_GETLECSADDR:
353 			error = atm_get_addr(dev, buf, len,
354 					     (cmd == ATM_GETADDR ?
355 					      ATM_ADDR_LOCAL : ATM_ADDR_LECS));
356 			if (error < 0)
357 				goto done;
358 			size = error;
359 			/* may return 0, but later on size == 0 means "don't
360 			   write the length" */
361 			error = put_user(size, &sioc->length)
362 				? -EFAULT : 0;
363 			goto done;
364 		case ATM_SETLOOP:
365 			if (__ATM_LM_XTRMT((int) (unsigned long) buf) &&
366 			    __ATM_LM_XTLOC((int) (unsigned long) buf) >
367 			    __ATM_LM_XTRMT((int) (unsigned long) buf)) {
368 				error = -EINVAL;
369 				goto done;
370 			}
371 			/* fall through */
372 		case ATM_SETCIRANGE:
373 		case SONET_GETSTATZ:
374 		case SONET_SETDIAG:
375 		case SONET_CLRDIAG:
376 		case SONET_SETFRAMING:
377 			if (!capable(CAP_NET_ADMIN)) {
378 				error = -EPERM;
379 				goto done;
380 			}
381 			/* fall through */
382 		default:
383 			if (!dev->ops->ioctl) {
384 				error = -EINVAL;
385 				goto done;
386 			}
387 			size = dev->ops->ioctl(dev, cmd, buf);
388 			if (size < 0) {
389 				error = (size == -ENOIOCTLCMD ? -EINVAL : size);
390 				goto done;
391 			}
392 	}
393 
394 	if (size)
395 		error = put_user(size, &sioc->length)
396 			? -EFAULT : 0;
397 	else
398 		error = 0;
399 done:
400 	atm_dev_put(dev);
401 	return error;
402 }
403 
404 static __inline__ void *dev_get_idx(loff_t left)
405 {
406 	struct list_head *p;
407 
408 	list_for_each(p, &atm_devs) {
409 		if (!--left)
410 			break;
411 	}
412 	return (p != &atm_devs) ? p : NULL;
413 }
414 
415 void *atm_dev_seq_start(struct seq_file *seq, loff_t *pos)
416 {
417  	spin_lock(&atm_dev_lock);
418 	return *pos ? dev_get_idx(*pos) : (void *) 1;
419 }
420 
421 void atm_dev_seq_stop(struct seq_file *seq, void *v)
422 {
423  	spin_unlock(&atm_dev_lock);
424 }
425 
426 void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
427 {
428 	++*pos;
429 	v = (v == (void *)1) ? atm_devs.next : ((struct list_head *)v)->next;
430 	return (v == &atm_devs) ? NULL : v;
431 }
432 
433 
434 EXPORT_SYMBOL(atm_dev_register);
435 EXPORT_SYMBOL(atm_dev_deregister);
436 EXPORT_SYMBOL(atm_dev_lookup);
437 EXPORT_SYMBOL(shutdown_atm_dev);
438