xref: /linux/net/core/net-sysfs.c (revision a33f32244d8550da8b4a26e277ce07d5c6d158b5)
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 <linux/slab.h>
17 #include <net/sock.h>
18 #include <linux/rtnetlink.h>
19 #include <linux/wireless.h>
20 #include <net/wext.h>
21 
22 #include "net-sysfs.h"
23 
24 #ifdef CONFIG_SYSFS
25 static const char fmt_hex[] = "%#x\n";
26 static const char fmt_long_hex[] = "%#lx\n";
27 static const char fmt_dec[] = "%d\n";
28 static const char fmt_ulong[] = "%lu\n";
29 
30 static inline int dev_isalive(const struct net_device *dev)
31 {
32 	return dev->reg_state <= NETREG_REGISTERED;
33 }
34 
35 /* use same locking rules as GIF* ioctl's */
36 static ssize_t netdev_show(const struct device *dev,
37 			   struct device_attribute *attr, char *buf,
38 			   ssize_t (*format)(const struct net_device *, char *))
39 {
40 	struct net_device *net = to_net_dev(dev);
41 	ssize_t ret = -EINVAL;
42 
43 	read_lock(&dev_base_lock);
44 	if (dev_isalive(net))
45 		ret = (*format)(net, buf);
46 	read_unlock(&dev_base_lock);
47 
48 	return ret;
49 }
50 
51 /* generate a show function for simple field */
52 #define NETDEVICE_SHOW(field, format_string)				\
53 static ssize_t format_##field(const struct net_device *net, char *buf)	\
54 {									\
55 	return sprintf(buf, format_string, net->field);			\
56 }									\
57 static ssize_t show_##field(struct device *dev,				\
58 			    struct device_attribute *attr, char *buf)	\
59 {									\
60 	return netdev_show(dev, attr, buf, format_##field);		\
61 }
62 
63 
64 /* use same locking and permission rules as SIF* ioctl's */
65 static ssize_t netdev_store(struct device *dev, struct device_attribute *attr,
66 			    const char *buf, size_t len,
67 			    int (*set)(struct net_device *, unsigned long))
68 {
69 	struct net_device *net = to_net_dev(dev);
70 	char *endp;
71 	unsigned long new;
72 	int ret = -EINVAL;
73 
74 	if (!capable(CAP_NET_ADMIN))
75 		return -EPERM;
76 
77 	new = simple_strtoul(buf, &endp, 0);
78 	if (endp == buf)
79 		goto err;
80 
81 	if (!rtnl_trylock())
82 		return restart_syscall();
83 
84 	if (dev_isalive(net)) {
85 		if ((ret = (*set)(net, new)) == 0)
86 			ret = len;
87 	}
88 	rtnl_unlock();
89  err:
90 	return ret;
91 }
92 
93 NETDEVICE_SHOW(dev_id, fmt_hex);
94 NETDEVICE_SHOW(addr_len, fmt_dec);
95 NETDEVICE_SHOW(iflink, fmt_dec);
96 NETDEVICE_SHOW(ifindex, fmt_dec);
97 NETDEVICE_SHOW(features, fmt_long_hex);
98 NETDEVICE_SHOW(type, fmt_dec);
99 NETDEVICE_SHOW(link_mode, fmt_dec);
100 
101 /* use same locking rules as GIFHWADDR ioctl's */
102 static ssize_t show_address(struct device *dev, struct device_attribute *attr,
103 			    char *buf)
104 {
105 	struct net_device *net = to_net_dev(dev);
106 	ssize_t ret = -EINVAL;
107 
108 	read_lock(&dev_base_lock);
109 	if (dev_isalive(net))
110 		ret = sysfs_format_mac(buf, net->dev_addr, net->addr_len);
111 	read_unlock(&dev_base_lock);
112 	return ret;
113 }
114 
115 static ssize_t show_broadcast(struct device *dev,
116 			    struct device_attribute *attr, char *buf)
117 {
118 	struct net_device *net = to_net_dev(dev);
119 	if (dev_isalive(net))
120 		return sysfs_format_mac(buf, net->broadcast, net->addr_len);
121 	return -EINVAL;
122 }
123 
124 static ssize_t show_carrier(struct device *dev,
125 			    struct device_attribute *attr, char *buf)
126 {
127 	struct net_device *netdev = to_net_dev(dev);
128 	if (netif_running(netdev)) {
129 		return sprintf(buf, fmt_dec, !!netif_carrier_ok(netdev));
130 	}
131 	return -EINVAL;
132 }
133 
134 static ssize_t show_speed(struct device *dev,
135 			  struct device_attribute *attr, char *buf)
136 {
137 	struct net_device *netdev = to_net_dev(dev);
138 	int ret = -EINVAL;
139 
140 	if (!rtnl_trylock())
141 		return restart_syscall();
142 
143 	if (netif_running(netdev) &&
144 	    netdev->ethtool_ops &&
145 	    netdev->ethtool_ops->get_settings) {
146 		struct ethtool_cmd cmd = { ETHTOOL_GSET };
147 
148 		if (!netdev->ethtool_ops->get_settings(netdev, &cmd))
149 			ret = sprintf(buf, fmt_dec, ethtool_cmd_speed(&cmd));
150 	}
151 	rtnl_unlock();
152 	return ret;
153 }
154 
155 static ssize_t show_duplex(struct device *dev,
156 			   struct device_attribute *attr, char *buf)
157 {
158 	struct net_device *netdev = to_net_dev(dev);
159 	int ret = -EINVAL;
160 
161 	if (!rtnl_trylock())
162 		return restart_syscall();
163 
164 	if (netif_running(netdev) &&
165 	    netdev->ethtool_ops &&
166 	    netdev->ethtool_ops->get_settings) {
167 		struct ethtool_cmd cmd = { ETHTOOL_GSET };
168 
169 		if (!netdev->ethtool_ops->get_settings(netdev, &cmd))
170 			ret = sprintf(buf, "%s\n", cmd.duplex ? "full" : "half");
171 	}
172 	rtnl_unlock();
173 	return ret;
174 }
175 
176 static ssize_t show_dormant(struct device *dev,
177 			    struct device_attribute *attr, char *buf)
178 {
179 	struct net_device *netdev = to_net_dev(dev);
180 
181 	if (netif_running(netdev))
182 		return sprintf(buf, fmt_dec, !!netif_dormant(netdev));
183 
184 	return -EINVAL;
185 }
186 
187 static const char *const operstates[] = {
188 	"unknown",
189 	"notpresent", /* currently unused */
190 	"down",
191 	"lowerlayerdown",
192 	"testing", /* currently unused */
193 	"dormant",
194 	"up"
195 };
196 
197 static ssize_t show_operstate(struct device *dev,
198 			      struct device_attribute *attr, char *buf)
199 {
200 	const struct net_device *netdev = to_net_dev(dev);
201 	unsigned char operstate;
202 
203 	read_lock(&dev_base_lock);
204 	operstate = netdev->operstate;
205 	if (!netif_running(netdev))
206 		operstate = IF_OPER_DOWN;
207 	read_unlock(&dev_base_lock);
208 
209 	if (operstate >= ARRAY_SIZE(operstates))
210 		return -EINVAL; /* should not happen */
211 
212 	return sprintf(buf, "%s\n", operstates[operstate]);
213 }
214 
215 /* read-write attributes */
216 NETDEVICE_SHOW(mtu, fmt_dec);
217 
218 static int change_mtu(struct net_device *net, unsigned long new_mtu)
219 {
220 	return dev_set_mtu(net, (int) new_mtu);
221 }
222 
223 static ssize_t store_mtu(struct device *dev, struct device_attribute *attr,
224 			 const char *buf, size_t len)
225 {
226 	return netdev_store(dev, attr, buf, len, change_mtu);
227 }
228 
229 NETDEVICE_SHOW(flags, fmt_hex);
230 
231 static int change_flags(struct net_device *net, unsigned long new_flags)
232 {
233 	return dev_change_flags(net, (unsigned) new_flags);
234 }
235 
236 static ssize_t store_flags(struct device *dev, struct device_attribute *attr,
237 			   const char *buf, size_t len)
238 {
239 	return netdev_store(dev, attr, buf, len, change_flags);
240 }
241 
242 NETDEVICE_SHOW(tx_queue_len, fmt_ulong);
243 
244 static int change_tx_queue_len(struct net_device *net, unsigned long new_len)
245 {
246 	net->tx_queue_len = new_len;
247 	return 0;
248 }
249 
250 static ssize_t store_tx_queue_len(struct device *dev,
251 				  struct device_attribute *attr,
252 				  const char *buf, size_t len)
253 {
254 	return netdev_store(dev, attr, buf, len, change_tx_queue_len);
255 }
256 
257 static ssize_t store_ifalias(struct device *dev, struct device_attribute *attr,
258 			     const char *buf, size_t len)
259 {
260 	struct net_device *netdev = to_net_dev(dev);
261 	size_t count = len;
262 	ssize_t ret;
263 
264 	if (!capable(CAP_NET_ADMIN))
265 		return -EPERM;
266 
267 	/* ignore trailing newline */
268 	if (len >  0 && buf[len - 1] == '\n')
269 		--count;
270 
271 	if (!rtnl_trylock())
272 		return restart_syscall();
273 	ret = dev_set_alias(netdev, buf, count);
274 	rtnl_unlock();
275 
276 	return ret < 0 ? ret : len;
277 }
278 
279 static ssize_t show_ifalias(struct device *dev,
280 			    struct device_attribute *attr, char *buf)
281 {
282 	const struct net_device *netdev = to_net_dev(dev);
283 	ssize_t ret = 0;
284 
285 	if (!rtnl_trylock())
286 		return restart_syscall();
287 	if (netdev->ifalias)
288 		ret = sprintf(buf, "%s\n", netdev->ifalias);
289 	rtnl_unlock();
290 	return ret;
291 }
292 
293 static struct device_attribute net_class_attributes[] = {
294 	__ATTR(addr_len, S_IRUGO, show_addr_len, NULL),
295 	__ATTR(dev_id, S_IRUGO, show_dev_id, NULL),
296 	__ATTR(ifalias, S_IRUGO | S_IWUSR, show_ifalias, store_ifalias),
297 	__ATTR(iflink, S_IRUGO, show_iflink, NULL),
298 	__ATTR(ifindex, S_IRUGO, show_ifindex, NULL),
299 	__ATTR(features, S_IRUGO, show_features, NULL),
300 	__ATTR(type, S_IRUGO, show_type, NULL),
301 	__ATTR(link_mode, S_IRUGO, show_link_mode, NULL),
302 	__ATTR(address, S_IRUGO, show_address, NULL),
303 	__ATTR(broadcast, S_IRUGO, show_broadcast, NULL),
304 	__ATTR(carrier, S_IRUGO, show_carrier, NULL),
305 	__ATTR(speed, S_IRUGO, show_speed, NULL),
306 	__ATTR(duplex, S_IRUGO, show_duplex, NULL),
307 	__ATTR(dormant, S_IRUGO, show_dormant, NULL),
308 	__ATTR(operstate, S_IRUGO, show_operstate, NULL),
309 	__ATTR(mtu, S_IRUGO | S_IWUSR, show_mtu, store_mtu),
310 	__ATTR(flags, S_IRUGO | S_IWUSR, show_flags, store_flags),
311 	__ATTR(tx_queue_len, S_IRUGO | S_IWUSR, show_tx_queue_len,
312 	       store_tx_queue_len),
313 	{}
314 };
315 
316 /* Show a given an attribute in the statistics group */
317 static ssize_t netstat_show(const struct device *d,
318 			    struct device_attribute *attr, char *buf,
319 			    unsigned long offset)
320 {
321 	struct net_device *dev = to_net_dev(d);
322 	ssize_t ret = -EINVAL;
323 
324 	WARN_ON(offset > sizeof(struct net_device_stats) ||
325 			offset % sizeof(unsigned long) != 0);
326 
327 	read_lock(&dev_base_lock);
328 	if (dev_isalive(dev)) {
329 		const struct net_device_stats *stats = dev_get_stats(dev);
330 		ret = sprintf(buf, fmt_ulong,
331 			      *(unsigned long *)(((u8 *) stats) + offset));
332 	}
333 	read_unlock(&dev_base_lock);
334 	return ret;
335 }
336 
337 /* generate a read-only statistics attribute */
338 #define NETSTAT_ENTRY(name)						\
339 static ssize_t show_##name(struct device *d,				\
340 			   struct device_attribute *attr, char *buf) 	\
341 {									\
342 	return netstat_show(d, attr, buf,				\
343 			    offsetof(struct net_device_stats, name));	\
344 }									\
345 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
346 
347 NETSTAT_ENTRY(rx_packets);
348 NETSTAT_ENTRY(tx_packets);
349 NETSTAT_ENTRY(rx_bytes);
350 NETSTAT_ENTRY(tx_bytes);
351 NETSTAT_ENTRY(rx_errors);
352 NETSTAT_ENTRY(tx_errors);
353 NETSTAT_ENTRY(rx_dropped);
354 NETSTAT_ENTRY(tx_dropped);
355 NETSTAT_ENTRY(multicast);
356 NETSTAT_ENTRY(collisions);
357 NETSTAT_ENTRY(rx_length_errors);
358 NETSTAT_ENTRY(rx_over_errors);
359 NETSTAT_ENTRY(rx_crc_errors);
360 NETSTAT_ENTRY(rx_frame_errors);
361 NETSTAT_ENTRY(rx_fifo_errors);
362 NETSTAT_ENTRY(rx_missed_errors);
363 NETSTAT_ENTRY(tx_aborted_errors);
364 NETSTAT_ENTRY(tx_carrier_errors);
365 NETSTAT_ENTRY(tx_fifo_errors);
366 NETSTAT_ENTRY(tx_heartbeat_errors);
367 NETSTAT_ENTRY(tx_window_errors);
368 NETSTAT_ENTRY(rx_compressed);
369 NETSTAT_ENTRY(tx_compressed);
370 
371 static struct attribute *netstat_attrs[] = {
372 	&dev_attr_rx_packets.attr,
373 	&dev_attr_tx_packets.attr,
374 	&dev_attr_rx_bytes.attr,
375 	&dev_attr_tx_bytes.attr,
376 	&dev_attr_rx_errors.attr,
377 	&dev_attr_tx_errors.attr,
378 	&dev_attr_rx_dropped.attr,
379 	&dev_attr_tx_dropped.attr,
380 	&dev_attr_multicast.attr,
381 	&dev_attr_collisions.attr,
382 	&dev_attr_rx_length_errors.attr,
383 	&dev_attr_rx_over_errors.attr,
384 	&dev_attr_rx_crc_errors.attr,
385 	&dev_attr_rx_frame_errors.attr,
386 	&dev_attr_rx_fifo_errors.attr,
387 	&dev_attr_rx_missed_errors.attr,
388 	&dev_attr_tx_aborted_errors.attr,
389 	&dev_attr_tx_carrier_errors.attr,
390 	&dev_attr_tx_fifo_errors.attr,
391 	&dev_attr_tx_heartbeat_errors.attr,
392 	&dev_attr_tx_window_errors.attr,
393 	&dev_attr_rx_compressed.attr,
394 	&dev_attr_tx_compressed.attr,
395 	NULL
396 };
397 
398 
399 static struct attribute_group netstat_group = {
400 	.name  = "statistics",
401 	.attrs  = netstat_attrs,
402 };
403 
404 #ifdef CONFIG_WIRELESS_EXT_SYSFS
405 /* helper function that does all the locking etc for wireless stats */
406 static ssize_t wireless_show(struct device *d, char *buf,
407 			     ssize_t (*format)(const struct iw_statistics *,
408 					       char *))
409 {
410 	struct net_device *dev = to_net_dev(d);
411 	const struct iw_statistics *iw;
412 	ssize_t ret = -EINVAL;
413 
414 	if (!rtnl_trylock())
415 		return restart_syscall();
416 	if (dev_isalive(dev)) {
417 		iw = get_wireless_stats(dev);
418 		if (iw)
419 			ret = (*format)(iw, buf);
420 	}
421 	rtnl_unlock();
422 
423 	return ret;
424 }
425 
426 /* show function template for wireless fields */
427 #define WIRELESS_SHOW(name, field, format_string)			\
428 static ssize_t format_iw_##name(const struct iw_statistics *iw, char *buf) \
429 {									\
430 	return sprintf(buf, format_string, iw->field);			\
431 }									\
432 static ssize_t show_iw_##name(struct device *d,				\
433 			      struct device_attribute *attr, char *buf)	\
434 {									\
435 	return wireless_show(d, buf, format_iw_##name);			\
436 }									\
437 static DEVICE_ATTR(name, S_IRUGO, show_iw_##name, NULL)
438 
439 WIRELESS_SHOW(status, status, fmt_hex);
440 WIRELESS_SHOW(link, qual.qual, fmt_dec);
441 WIRELESS_SHOW(level, qual.level, fmt_dec);
442 WIRELESS_SHOW(noise, qual.noise, fmt_dec);
443 WIRELESS_SHOW(nwid, discard.nwid, fmt_dec);
444 WIRELESS_SHOW(crypt, discard.code, fmt_dec);
445 WIRELESS_SHOW(fragment, discard.fragment, fmt_dec);
446 WIRELESS_SHOW(misc, discard.misc, fmt_dec);
447 WIRELESS_SHOW(retries, discard.retries, fmt_dec);
448 WIRELESS_SHOW(beacon, miss.beacon, fmt_dec);
449 
450 static struct attribute *wireless_attrs[] = {
451 	&dev_attr_status.attr,
452 	&dev_attr_link.attr,
453 	&dev_attr_level.attr,
454 	&dev_attr_noise.attr,
455 	&dev_attr_nwid.attr,
456 	&dev_attr_crypt.attr,
457 	&dev_attr_fragment.attr,
458 	&dev_attr_retries.attr,
459 	&dev_attr_misc.attr,
460 	&dev_attr_beacon.attr,
461 	NULL
462 };
463 
464 static struct attribute_group wireless_group = {
465 	.name = "wireless",
466 	.attrs = wireless_attrs,
467 };
468 #endif
469 
470 #endif /* CONFIG_SYSFS */
471 
472 #ifdef CONFIG_HOTPLUG
473 static int netdev_uevent(struct device *d, struct kobj_uevent_env *env)
474 {
475 	struct net_device *dev = to_net_dev(d);
476 	int retval;
477 
478 	if (!net_eq(dev_net(dev), &init_net))
479 		return 0;
480 
481 	/* pass interface to uevent. */
482 	retval = add_uevent_var(env, "INTERFACE=%s", dev->name);
483 	if (retval)
484 		goto exit;
485 
486 	/* pass ifindex to uevent.
487 	 * ifindex is useful as it won't change (interface name may change)
488 	 * and is what RtNetlink uses natively. */
489 	retval = add_uevent_var(env, "IFINDEX=%d", dev->ifindex);
490 
491 exit:
492 	return retval;
493 }
494 #endif
495 
496 /*
497  *	netdev_release -- destroy and free a dead device.
498  *	Called when last reference to device kobject is gone.
499  */
500 static void netdev_release(struct device *d)
501 {
502 	struct net_device *dev = to_net_dev(d);
503 
504 	BUG_ON(dev->reg_state != NETREG_RELEASED);
505 
506 	kfree(dev->ifalias);
507 	kfree((char *)dev - dev->padded);
508 }
509 
510 static struct class net_class = {
511 	.name = "net",
512 	.dev_release = netdev_release,
513 #ifdef CONFIG_SYSFS
514 	.dev_attrs = net_class_attributes,
515 #endif /* CONFIG_SYSFS */
516 #ifdef CONFIG_HOTPLUG
517 	.dev_uevent = netdev_uevent,
518 #endif
519 };
520 
521 /* Delete sysfs entries but hold kobject reference until after all
522  * netdev references are gone.
523  */
524 void netdev_unregister_kobject(struct net_device * net)
525 {
526 	struct device *dev = &(net->dev);
527 
528 	kobject_get(&dev->kobj);
529 
530 	if (!net_eq(dev_net(net), &init_net))
531 		return;
532 
533 	device_del(dev);
534 }
535 
536 /* Create sysfs entries for network device. */
537 int netdev_register_kobject(struct net_device *net)
538 {
539 	struct device *dev = &(net->dev);
540 	const struct attribute_group **groups = net->sysfs_groups;
541 
542 	dev->class = &net_class;
543 	dev->platform_data = net;
544 	dev->groups = groups;
545 
546 	dev_set_name(dev, "%s", net->name);
547 
548 #ifdef CONFIG_SYSFS
549 	/* Allow for a device specific group */
550 	if (*groups)
551 		groups++;
552 
553 	*groups++ = &netstat_group;
554 #ifdef CONFIG_WIRELESS_EXT_SYSFS
555 	if (net->ieee80211_ptr)
556 		*groups++ = &wireless_group;
557 #ifdef CONFIG_WIRELESS_EXT
558 	else if (net->wireless_handlers)
559 		*groups++ = &wireless_group;
560 #endif
561 #endif
562 #endif /* CONFIG_SYSFS */
563 
564 	if (!net_eq(dev_net(net), &init_net))
565 		return 0;
566 
567 	return device_add(dev);
568 }
569 
570 int netdev_class_create_file(struct class_attribute *class_attr)
571 {
572 	return class_create_file(&net_class, class_attr);
573 }
574 
575 void netdev_class_remove_file(struct class_attribute *class_attr)
576 {
577 	class_remove_file(&net_class, class_attr);
578 }
579 
580 EXPORT_SYMBOL(netdev_class_create_file);
581 EXPORT_SYMBOL(netdev_class_remove_file);
582 
583 void netdev_initialize_kobject(struct net_device *net)
584 {
585 	struct device *device = &(net->dev);
586 	device_initialize(device);
587 }
588 
589 int netdev_kobject_init(void)
590 {
591 	return class_register(&net_class);
592 }
593