xref: /linux/net/core/net-sysfs.c (revision 6ee738610f41b59733f63718f0bdbcba7d3a3f12)
1 /*
2  * net-sysfs.c - network device class and attributes
3  *
4  * Copyright (c) 2003 Stephen Hemminger <shemminger@osdl.org>
5  *
6  *	This program is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License
8  *	as published by the Free Software Foundation; either version
9  *	2 of the License, or (at your option) any later version.
10  */
11 
12 #include <linux/capability.h>
13 #include <linux/kernel.h>
14 #include <linux/netdevice.h>
15 #include <linux/if_arp.h>
16 #include <net/sock.h>
17 #include <linux/rtnetlink.h>
18 #include <linux/wireless.h>
19 #include <net/wext.h>
20 
21 #include "net-sysfs.h"
22 
23 #ifdef CONFIG_SYSFS
24 static const char fmt_hex[] = "%#x\n";
25 static const char fmt_long_hex[] = "%#lx\n";
26 static const char fmt_dec[] = "%d\n";
27 static const char fmt_ulong[] = "%lu\n";
28 
29 static inline int dev_isalive(const struct net_device *dev)
30 {
31 	return dev->reg_state <= NETREG_REGISTERED;
32 }
33 
34 /* use same locking rules as GIF* ioctl's */
35 static ssize_t netdev_show(const struct device *dev,
36 			   struct device_attribute *attr, char *buf,
37 			   ssize_t (*format)(const struct net_device *, char *))
38 {
39 	struct net_device *net = to_net_dev(dev);
40 	ssize_t ret = -EINVAL;
41 
42 	read_lock(&dev_base_lock);
43 	if (dev_isalive(net))
44 		ret = (*format)(net, buf);
45 	read_unlock(&dev_base_lock);
46 
47 	return ret;
48 }
49 
50 /* generate a show function for simple field */
51 #define NETDEVICE_SHOW(field, format_string)				\
52 static ssize_t format_##field(const struct net_device *net, char *buf)	\
53 {									\
54 	return sprintf(buf, format_string, net->field);			\
55 }									\
56 static ssize_t show_##field(struct device *dev,				\
57 			    struct device_attribute *attr, char *buf)	\
58 {									\
59 	return netdev_show(dev, attr, buf, format_##field);		\
60 }
61 
62 
63 /* use same locking and permission rules as SIF* ioctl's */
64 static ssize_t netdev_store(struct device *dev, struct device_attribute *attr,
65 			    const char *buf, size_t len,
66 			    int (*set)(struct net_device *, unsigned long))
67 {
68 	struct net_device *net = to_net_dev(dev);
69 	char *endp;
70 	unsigned long new;
71 	int ret = -EINVAL;
72 
73 	if (!capable(CAP_NET_ADMIN))
74 		return -EPERM;
75 
76 	new = simple_strtoul(buf, &endp, 0);
77 	if (endp == buf)
78 		goto err;
79 
80 	if (!rtnl_trylock())
81 		return restart_syscall();
82 
83 	if (dev_isalive(net)) {
84 		if ((ret = (*set)(net, new)) == 0)
85 			ret = len;
86 	}
87 	rtnl_unlock();
88  err:
89 	return ret;
90 }
91 
92 NETDEVICE_SHOW(dev_id, fmt_hex);
93 NETDEVICE_SHOW(addr_len, fmt_dec);
94 NETDEVICE_SHOW(iflink, fmt_dec);
95 NETDEVICE_SHOW(ifindex, fmt_dec);
96 NETDEVICE_SHOW(features, fmt_long_hex);
97 NETDEVICE_SHOW(type, fmt_dec);
98 NETDEVICE_SHOW(link_mode, fmt_dec);
99 
100 /* use same locking rules as GIFHWADDR ioctl's */
101 static ssize_t show_address(struct device *dev, struct device_attribute *attr,
102 			    char *buf)
103 {
104 	struct net_device *net = to_net_dev(dev);
105 	ssize_t ret = -EINVAL;
106 
107 	read_lock(&dev_base_lock);
108 	if (dev_isalive(net))
109 		ret = sysfs_format_mac(buf, net->dev_addr, net->addr_len);
110 	read_unlock(&dev_base_lock);
111 	return ret;
112 }
113 
114 static ssize_t show_broadcast(struct device *dev,
115 			    struct device_attribute *attr, char *buf)
116 {
117 	struct net_device *net = to_net_dev(dev);
118 	if (dev_isalive(net))
119 		return sysfs_format_mac(buf, net->broadcast, net->addr_len);
120 	return -EINVAL;
121 }
122 
123 static ssize_t show_carrier(struct device *dev,
124 			    struct device_attribute *attr, char *buf)
125 {
126 	struct net_device *netdev = to_net_dev(dev);
127 	if (netif_running(netdev)) {
128 		return sprintf(buf, fmt_dec, !!netif_carrier_ok(netdev));
129 	}
130 	return -EINVAL;
131 }
132 
133 static ssize_t show_dormant(struct device *dev,
134 			    struct device_attribute *attr, char *buf)
135 {
136 	struct net_device *netdev = to_net_dev(dev);
137 
138 	if (netif_running(netdev))
139 		return sprintf(buf, fmt_dec, !!netif_dormant(netdev));
140 
141 	return -EINVAL;
142 }
143 
144 static const char *const operstates[] = {
145 	"unknown",
146 	"notpresent", /* currently unused */
147 	"down",
148 	"lowerlayerdown",
149 	"testing", /* currently unused */
150 	"dormant",
151 	"up"
152 };
153 
154 static ssize_t show_operstate(struct device *dev,
155 			      struct device_attribute *attr, char *buf)
156 {
157 	const struct net_device *netdev = to_net_dev(dev);
158 	unsigned char operstate;
159 
160 	read_lock(&dev_base_lock);
161 	operstate = netdev->operstate;
162 	if (!netif_running(netdev))
163 		operstate = IF_OPER_DOWN;
164 	read_unlock(&dev_base_lock);
165 
166 	if (operstate >= ARRAY_SIZE(operstates))
167 		return -EINVAL; /* should not happen */
168 
169 	return sprintf(buf, "%s\n", operstates[operstate]);
170 }
171 
172 /* read-write attributes */
173 NETDEVICE_SHOW(mtu, fmt_dec);
174 
175 static int change_mtu(struct net_device *net, unsigned long new_mtu)
176 {
177 	return dev_set_mtu(net, (int) new_mtu);
178 }
179 
180 static ssize_t store_mtu(struct device *dev, struct device_attribute *attr,
181 			 const char *buf, size_t len)
182 {
183 	return netdev_store(dev, attr, buf, len, change_mtu);
184 }
185 
186 NETDEVICE_SHOW(flags, fmt_hex);
187 
188 static int change_flags(struct net_device *net, unsigned long new_flags)
189 {
190 	return dev_change_flags(net, (unsigned) new_flags);
191 }
192 
193 static ssize_t store_flags(struct device *dev, struct device_attribute *attr,
194 			   const char *buf, size_t len)
195 {
196 	return netdev_store(dev, attr, buf, len, change_flags);
197 }
198 
199 NETDEVICE_SHOW(tx_queue_len, fmt_ulong);
200 
201 static int change_tx_queue_len(struct net_device *net, unsigned long new_len)
202 {
203 	net->tx_queue_len = new_len;
204 	return 0;
205 }
206 
207 static ssize_t store_tx_queue_len(struct device *dev,
208 				  struct device_attribute *attr,
209 				  const char *buf, size_t len)
210 {
211 	return netdev_store(dev, attr, buf, len, change_tx_queue_len);
212 }
213 
214 static ssize_t store_ifalias(struct device *dev, struct device_attribute *attr,
215 			     const char *buf, size_t len)
216 {
217 	struct net_device *netdev = to_net_dev(dev);
218 	size_t count = len;
219 	ssize_t ret;
220 
221 	if (!capable(CAP_NET_ADMIN))
222 		return -EPERM;
223 
224 	/* ignore trailing newline */
225 	if (len >  0 && buf[len - 1] == '\n')
226 		--count;
227 
228 	if (!rtnl_trylock())
229 		return restart_syscall();
230 	ret = dev_set_alias(netdev, buf, count);
231 	rtnl_unlock();
232 
233 	return ret < 0 ? ret : len;
234 }
235 
236 static ssize_t show_ifalias(struct device *dev,
237 			    struct device_attribute *attr, char *buf)
238 {
239 	const struct net_device *netdev = to_net_dev(dev);
240 	ssize_t ret = 0;
241 
242 	if (!rtnl_trylock())
243 		return restart_syscall();
244 	if (netdev->ifalias)
245 		ret = sprintf(buf, "%s\n", netdev->ifalias);
246 	rtnl_unlock();
247 	return ret;
248 }
249 
250 static struct device_attribute net_class_attributes[] = {
251 	__ATTR(addr_len, S_IRUGO, show_addr_len, NULL),
252 	__ATTR(dev_id, S_IRUGO, show_dev_id, NULL),
253 	__ATTR(ifalias, S_IRUGO | S_IWUSR, show_ifalias, store_ifalias),
254 	__ATTR(iflink, S_IRUGO, show_iflink, NULL),
255 	__ATTR(ifindex, S_IRUGO, show_ifindex, NULL),
256 	__ATTR(features, S_IRUGO, show_features, NULL),
257 	__ATTR(type, S_IRUGO, show_type, NULL),
258 	__ATTR(link_mode, S_IRUGO, show_link_mode, NULL),
259 	__ATTR(address, S_IRUGO, show_address, NULL),
260 	__ATTR(broadcast, S_IRUGO, show_broadcast, NULL),
261 	__ATTR(carrier, S_IRUGO, show_carrier, NULL),
262 	__ATTR(dormant, S_IRUGO, show_dormant, NULL),
263 	__ATTR(operstate, S_IRUGO, show_operstate, NULL),
264 	__ATTR(mtu, S_IRUGO | S_IWUSR, show_mtu, store_mtu),
265 	__ATTR(flags, S_IRUGO | S_IWUSR, show_flags, store_flags),
266 	__ATTR(tx_queue_len, S_IRUGO | S_IWUSR, show_tx_queue_len,
267 	       store_tx_queue_len),
268 	{}
269 };
270 
271 /* Show a given an attribute in the statistics group */
272 static ssize_t netstat_show(const struct device *d,
273 			    struct device_attribute *attr, char *buf,
274 			    unsigned long offset)
275 {
276 	struct net_device *dev = to_net_dev(d);
277 	ssize_t ret = -EINVAL;
278 
279 	WARN_ON(offset > sizeof(struct net_device_stats) ||
280 			offset % sizeof(unsigned long) != 0);
281 
282 	read_lock(&dev_base_lock);
283 	if (dev_isalive(dev)) {
284 		const struct net_device_stats *stats = dev_get_stats(dev);
285 		ret = sprintf(buf, fmt_ulong,
286 			      *(unsigned long *)(((u8 *) stats) + offset));
287 	}
288 	read_unlock(&dev_base_lock);
289 	return ret;
290 }
291 
292 /* generate a read-only statistics attribute */
293 #define NETSTAT_ENTRY(name)						\
294 static ssize_t show_##name(struct device *d,				\
295 			   struct device_attribute *attr, char *buf) 	\
296 {									\
297 	return netstat_show(d, attr, buf,				\
298 			    offsetof(struct net_device_stats, name));	\
299 }									\
300 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
301 
302 NETSTAT_ENTRY(rx_packets);
303 NETSTAT_ENTRY(tx_packets);
304 NETSTAT_ENTRY(rx_bytes);
305 NETSTAT_ENTRY(tx_bytes);
306 NETSTAT_ENTRY(rx_errors);
307 NETSTAT_ENTRY(tx_errors);
308 NETSTAT_ENTRY(rx_dropped);
309 NETSTAT_ENTRY(tx_dropped);
310 NETSTAT_ENTRY(multicast);
311 NETSTAT_ENTRY(collisions);
312 NETSTAT_ENTRY(rx_length_errors);
313 NETSTAT_ENTRY(rx_over_errors);
314 NETSTAT_ENTRY(rx_crc_errors);
315 NETSTAT_ENTRY(rx_frame_errors);
316 NETSTAT_ENTRY(rx_fifo_errors);
317 NETSTAT_ENTRY(rx_missed_errors);
318 NETSTAT_ENTRY(tx_aborted_errors);
319 NETSTAT_ENTRY(tx_carrier_errors);
320 NETSTAT_ENTRY(tx_fifo_errors);
321 NETSTAT_ENTRY(tx_heartbeat_errors);
322 NETSTAT_ENTRY(tx_window_errors);
323 NETSTAT_ENTRY(rx_compressed);
324 NETSTAT_ENTRY(tx_compressed);
325 
326 static struct attribute *netstat_attrs[] = {
327 	&dev_attr_rx_packets.attr,
328 	&dev_attr_tx_packets.attr,
329 	&dev_attr_rx_bytes.attr,
330 	&dev_attr_tx_bytes.attr,
331 	&dev_attr_rx_errors.attr,
332 	&dev_attr_tx_errors.attr,
333 	&dev_attr_rx_dropped.attr,
334 	&dev_attr_tx_dropped.attr,
335 	&dev_attr_multicast.attr,
336 	&dev_attr_collisions.attr,
337 	&dev_attr_rx_length_errors.attr,
338 	&dev_attr_rx_over_errors.attr,
339 	&dev_attr_rx_crc_errors.attr,
340 	&dev_attr_rx_frame_errors.attr,
341 	&dev_attr_rx_fifo_errors.attr,
342 	&dev_attr_rx_missed_errors.attr,
343 	&dev_attr_tx_aborted_errors.attr,
344 	&dev_attr_tx_carrier_errors.attr,
345 	&dev_attr_tx_fifo_errors.attr,
346 	&dev_attr_tx_heartbeat_errors.attr,
347 	&dev_attr_tx_window_errors.attr,
348 	&dev_attr_rx_compressed.attr,
349 	&dev_attr_tx_compressed.attr,
350 	NULL
351 };
352 
353 
354 static struct attribute_group netstat_group = {
355 	.name  = "statistics",
356 	.attrs  = netstat_attrs,
357 };
358 
359 #ifdef CONFIG_WIRELESS_EXT_SYSFS
360 /* helper function that does all the locking etc for wireless stats */
361 static ssize_t wireless_show(struct device *d, char *buf,
362 			     ssize_t (*format)(const struct iw_statistics *,
363 					       char *))
364 {
365 	struct net_device *dev = to_net_dev(d);
366 	const struct iw_statistics *iw;
367 	ssize_t ret = -EINVAL;
368 
369 	rtnl_lock();
370 	if (dev_isalive(dev)) {
371 		iw = get_wireless_stats(dev);
372 		if (iw)
373 			ret = (*format)(iw, buf);
374 	}
375 	rtnl_unlock();
376 
377 	return ret;
378 }
379 
380 /* show function template for wireless fields */
381 #define WIRELESS_SHOW(name, field, format_string)			\
382 static ssize_t format_iw_##name(const struct iw_statistics *iw, char *buf) \
383 {									\
384 	return sprintf(buf, format_string, iw->field);			\
385 }									\
386 static ssize_t show_iw_##name(struct device *d,				\
387 			      struct device_attribute *attr, char *buf)	\
388 {									\
389 	return wireless_show(d, buf, format_iw_##name);			\
390 }									\
391 static DEVICE_ATTR(name, S_IRUGO, show_iw_##name, NULL)
392 
393 WIRELESS_SHOW(status, status, fmt_hex);
394 WIRELESS_SHOW(link, qual.qual, fmt_dec);
395 WIRELESS_SHOW(level, qual.level, fmt_dec);
396 WIRELESS_SHOW(noise, qual.noise, fmt_dec);
397 WIRELESS_SHOW(nwid, discard.nwid, fmt_dec);
398 WIRELESS_SHOW(crypt, discard.code, fmt_dec);
399 WIRELESS_SHOW(fragment, discard.fragment, fmt_dec);
400 WIRELESS_SHOW(misc, discard.misc, fmt_dec);
401 WIRELESS_SHOW(retries, discard.retries, fmt_dec);
402 WIRELESS_SHOW(beacon, miss.beacon, fmt_dec);
403 
404 static struct attribute *wireless_attrs[] = {
405 	&dev_attr_status.attr,
406 	&dev_attr_link.attr,
407 	&dev_attr_level.attr,
408 	&dev_attr_noise.attr,
409 	&dev_attr_nwid.attr,
410 	&dev_attr_crypt.attr,
411 	&dev_attr_fragment.attr,
412 	&dev_attr_retries.attr,
413 	&dev_attr_misc.attr,
414 	&dev_attr_beacon.attr,
415 	NULL
416 };
417 
418 static struct attribute_group wireless_group = {
419 	.name = "wireless",
420 	.attrs = wireless_attrs,
421 };
422 #endif
423 
424 #endif /* CONFIG_SYSFS */
425 
426 #ifdef CONFIG_HOTPLUG
427 static int netdev_uevent(struct device *d, struct kobj_uevent_env *env)
428 {
429 	struct net_device *dev = to_net_dev(d);
430 	int retval;
431 
432 	if (!net_eq(dev_net(dev), &init_net))
433 		return 0;
434 
435 	/* pass interface to uevent. */
436 	retval = add_uevent_var(env, "INTERFACE=%s", dev->name);
437 	if (retval)
438 		goto exit;
439 
440 	/* pass ifindex to uevent.
441 	 * ifindex is useful as it won't change (interface name may change)
442 	 * and is what RtNetlink uses natively. */
443 	retval = add_uevent_var(env, "IFINDEX=%d", dev->ifindex);
444 
445 exit:
446 	return retval;
447 }
448 #endif
449 
450 /*
451  *	netdev_release -- destroy and free a dead device.
452  *	Called when last reference to device kobject is gone.
453  */
454 static void netdev_release(struct device *d)
455 {
456 	struct net_device *dev = to_net_dev(d);
457 
458 	BUG_ON(dev->reg_state != NETREG_RELEASED);
459 
460 	kfree(dev->ifalias);
461 	kfree((char *)dev - dev->padded);
462 }
463 
464 static struct class net_class = {
465 	.name = "net",
466 	.dev_release = netdev_release,
467 #ifdef CONFIG_SYSFS
468 	.dev_attrs = net_class_attributes,
469 #endif /* CONFIG_SYSFS */
470 #ifdef CONFIG_HOTPLUG
471 	.dev_uevent = netdev_uevent,
472 #endif
473 };
474 
475 /* Delete sysfs entries but hold kobject reference until after all
476  * netdev references are gone.
477  */
478 void netdev_unregister_kobject(struct net_device * net)
479 {
480 	struct device *dev = &(net->dev);
481 
482 	kobject_get(&dev->kobj);
483 
484 	if (dev_net(net) != &init_net)
485 		return;
486 
487 	device_del(dev);
488 }
489 
490 /* Create sysfs entries for network device. */
491 int netdev_register_kobject(struct net_device *net)
492 {
493 	struct device *dev = &(net->dev);
494 	const struct attribute_group **groups = net->sysfs_groups;
495 
496 	dev->class = &net_class;
497 	dev->platform_data = net;
498 	dev->groups = groups;
499 
500 	dev_set_name(dev, "%s", net->name);
501 
502 #ifdef CONFIG_SYSFS
503 	*groups++ = &netstat_group;
504 
505 #ifdef CONFIG_WIRELESS_EXT_SYSFS
506 	if (net->wireless_handlers || net->ieee80211_ptr)
507 		*groups++ = &wireless_group;
508 #endif
509 #endif /* CONFIG_SYSFS */
510 
511 	if (dev_net(net) != &init_net)
512 		return 0;
513 
514 	return device_add(dev);
515 }
516 
517 int netdev_class_create_file(struct class_attribute *class_attr)
518 {
519 	return class_create_file(&net_class, class_attr);
520 }
521 
522 void netdev_class_remove_file(struct class_attribute *class_attr)
523 {
524 	class_remove_file(&net_class, class_attr);
525 }
526 
527 EXPORT_SYMBOL(netdev_class_create_file);
528 EXPORT_SYMBOL(netdev_class_remove_file);
529 
530 void netdev_initialize_kobject(struct net_device *net)
531 {
532 	struct device *device = &(net->dev);
533 	device_initialize(device);
534 }
535 
536 int netdev_kobject_init(void)
537 {
538 	return class_register(&net_class);
539 }
540