xref: /linux/net/core/net-sysfs.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 <linux/nsproxy.h>
18 #include <net/sock.h>
19 #include <net/net_namespace.h>
20 #include <linux/rtnetlink.h>
21 #include <linux/wireless.h>
22 #include <linux/vmalloc.h>
23 #include <net/wext.h>
24 
25 #include "net-sysfs.h"
26 
27 #ifdef CONFIG_SYSFS
28 static const char fmt_hex[] = "%#x\n";
29 static const char fmt_long_hex[] = "%#lx\n";
30 static const char fmt_dec[] = "%d\n";
31 static const char fmt_ulong[] = "%lu\n";
32 static const char fmt_u64[] = "%llu\n";
33 
34 static inline int dev_isalive(const struct net_device *dev)
35 {
36 	return dev->reg_state <= NETREG_REGISTERED;
37 }
38 
39 /* use same locking rules as GIF* ioctl's */
40 static ssize_t netdev_show(const struct device *dev,
41 			   struct device_attribute *attr, char *buf,
42 			   ssize_t (*format)(const struct net_device *, char *))
43 {
44 	struct net_device *net = to_net_dev(dev);
45 	ssize_t ret = -EINVAL;
46 
47 	read_lock(&dev_base_lock);
48 	if (dev_isalive(net))
49 		ret = (*format)(net, buf);
50 	read_unlock(&dev_base_lock);
51 
52 	return ret;
53 }
54 
55 /* generate a show function for simple field */
56 #define NETDEVICE_SHOW(field, format_string)				\
57 static ssize_t format_##field(const struct net_device *net, char *buf)	\
58 {									\
59 	return sprintf(buf, format_string, net->field);			\
60 }									\
61 static ssize_t show_##field(struct device *dev,				\
62 			    struct device_attribute *attr, char *buf)	\
63 {									\
64 	return netdev_show(dev, attr, buf, format_##field);		\
65 }
66 
67 
68 /* use same locking and permission rules as SIF* ioctl's */
69 static ssize_t netdev_store(struct device *dev, struct device_attribute *attr,
70 			    const char *buf, size_t len,
71 			    int (*set)(struct net_device *, unsigned long))
72 {
73 	struct net_device *net = to_net_dev(dev);
74 	char *endp;
75 	unsigned long new;
76 	int ret = -EINVAL;
77 
78 	if (!capable(CAP_NET_ADMIN))
79 		return -EPERM;
80 
81 	new = simple_strtoul(buf, &endp, 0);
82 	if (endp == buf)
83 		goto err;
84 
85 	if (!rtnl_trylock())
86 		return restart_syscall();
87 
88 	if (dev_isalive(net)) {
89 		if ((ret = (*set)(net, new)) == 0)
90 			ret = len;
91 	}
92 	rtnl_unlock();
93  err:
94 	return ret;
95 }
96 
97 NETDEVICE_SHOW(dev_id, fmt_hex);
98 NETDEVICE_SHOW(addr_assign_type, fmt_dec);
99 NETDEVICE_SHOW(addr_len, fmt_dec);
100 NETDEVICE_SHOW(iflink, fmt_dec);
101 NETDEVICE_SHOW(ifindex, fmt_dec);
102 NETDEVICE_SHOW(features, fmt_long_hex);
103 NETDEVICE_SHOW(type, fmt_dec);
104 NETDEVICE_SHOW(link_mode, fmt_dec);
105 
106 /* use same locking rules as GIFHWADDR ioctl's */
107 static ssize_t show_address(struct device *dev, struct device_attribute *attr,
108 			    char *buf)
109 {
110 	struct net_device *net = to_net_dev(dev);
111 	ssize_t ret = -EINVAL;
112 
113 	read_lock(&dev_base_lock);
114 	if (dev_isalive(net))
115 		ret = sysfs_format_mac(buf, net->dev_addr, net->addr_len);
116 	read_unlock(&dev_base_lock);
117 	return ret;
118 }
119 
120 static ssize_t show_broadcast(struct device *dev,
121 			    struct device_attribute *attr, char *buf)
122 {
123 	struct net_device *net = to_net_dev(dev);
124 	if (dev_isalive(net))
125 		return sysfs_format_mac(buf, net->broadcast, net->addr_len);
126 	return -EINVAL;
127 }
128 
129 static ssize_t show_carrier(struct device *dev,
130 			    struct device_attribute *attr, char *buf)
131 {
132 	struct net_device *netdev = to_net_dev(dev);
133 	if (netif_running(netdev)) {
134 		return sprintf(buf, fmt_dec, !!netif_carrier_ok(netdev));
135 	}
136 	return -EINVAL;
137 }
138 
139 static ssize_t show_speed(struct device *dev,
140 			  struct device_attribute *attr, char *buf)
141 {
142 	struct net_device *netdev = to_net_dev(dev);
143 	int ret = -EINVAL;
144 
145 	if (!rtnl_trylock())
146 		return restart_syscall();
147 
148 	if (netif_running(netdev) &&
149 	    netdev->ethtool_ops &&
150 	    netdev->ethtool_ops->get_settings) {
151 		struct ethtool_cmd cmd = { ETHTOOL_GSET };
152 
153 		if (!netdev->ethtool_ops->get_settings(netdev, &cmd))
154 			ret = sprintf(buf, fmt_dec, ethtool_cmd_speed(&cmd));
155 	}
156 	rtnl_unlock();
157 	return ret;
158 }
159 
160 static ssize_t show_duplex(struct device *dev,
161 			   struct device_attribute *attr, char *buf)
162 {
163 	struct net_device *netdev = to_net_dev(dev);
164 	int ret = -EINVAL;
165 
166 	if (!rtnl_trylock())
167 		return restart_syscall();
168 
169 	if (netif_running(netdev) &&
170 	    netdev->ethtool_ops &&
171 	    netdev->ethtool_ops->get_settings) {
172 		struct ethtool_cmd cmd = { ETHTOOL_GSET };
173 
174 		if (!netdev->ethtool_ops->get_settings(netdev, &cmd))
175 			ret = sprintf(buf, "%s\n", cmd.duplex ? "full" : "half");
176 	}
177 	rtnl_unlock();
178 	return ret;
179 }
180 
181 static ssize_t show_dormant(struct device *dev,
182 			    struct device_attribute *attr, char *buf)
183 {
184 	struct net_device *netdev = to_net_dev(dev);
185 
186 	if (netif_running(netdev))
187 		return sprintf(buf, fmt_dec, !!netif_dormant(netdev));
188 
189 	return -EINVAL;
190 }
191 
192 static const char *const operstates[] = {
193 	"unknown",
194 	"notpresent", /* currently unused */
195 	"down",
196 	"lowerlayerdown",
197 	"testing", /* currently unused */
198 	"dormant",
199 	"up"
200 };
201 
202 static ssize_t show_operstate(struct device *dev,
203 			      struct device_attribute *attr, char *buf)
204 {
205 	const struct net_device *netdev = to_net_dev(dev);
206 	unsigned char operstate;
207 
208 	read_lock(&dev_base_lock);
209 	operstate = netdev->operstate;
210 	if (!netif_running(netdev))
211 		operstate = IF_OPER_DOWN;
212 	read_unlock(&dev_base_lock);
213 
214 	if (operstate >= ARRAY_SIZE(operstates))
215 		return -EINVAL; /* should not happen */
216 
217 	return sprintf(buf, "%s\n", operstates[operstate]);
218 }
219 
220 /* read-write attributes */
221 NETDEVICE_SHOW(mtu, fmt_dec);
222 
223 static int change_mtu(struct net_device *net, unsigned long new_mtu)
224 {
225 	return dev_set_mtu(net, (int) new_mtu);
226 }
227 
228 static ssize_t store_mtu(struct device *dev, struct device_attribute *attr,
229 			 const char *buf, size_t len)
230 {
231 	return netdev_store(dev, attr, buf, len, change_mtu);
232 }
233 
234 NETDEVICE_SHOW(flags, fmt_hex);
235 
236 static int change_flags(struct net_device *net, unsigned long new_flags)
237 {
238 	return dev_change_flags(net, (unsigned) new_flags);
239 }
240 
241 static ssize_t store_flags(struct device *dev, struct device_attribute *attr,
242 			   const char *buf, size_t len)
243 {
244 	return netdev_store(dev, attr, buf, len, change_flags);
245 }
246 
247 NETDEVICE_SHOW(tx_queue_len, fmt_ulong);
248 
249 static int change_tx_queue_len(struct net_device *net, unsigned long new_len)
250 {
251 	net->tx_queue_len = new_len;
252 	return 0;
253 }
254 
255 static ssize_t store_tx_queue_len(struct device *dev,
256 				  struct device_attribute *attr,
257 				  const char *buf, size_t len)
258 {
259 	return netdev_store(dev, attr, buf, len, change_tx_queue_len);
260 }
261 
262 static ssize_t store_ifalias(struct device *dev, struct device_attribute *attr,
263 			     const char *buf, size_t len)
264 {
265 	struct net_device *netdev = to_net_dev(dev);
266 	size_t count = len;
267 	ssize_t ret;
268 
269 	if (!capable(CAP_NET_ADMIN))
270 		return -EPERM;
271 
272 	/* ignore trailing newline */
273 	if (len >  0 && buf[len - 1] == '\n')
274 		--count;
275 
276 	if (!rtnl_trylock())
277 		return restart_syscall();
278 	ret = dev_set_alias(netdev, buf, count);
279 	rtnl_unlock();
280 
281 	return ret < 0 ? ret : len;
282 }
283 
284 static ssize_t show_ifalias(struct device *dev,
285 			    struct device_attribute *attr, char *buf)
286 {
287 	const struct net_device *netdev = to_net_dev(dev);
288 	ssize_t ret = 0;
289 
290 	if (!rtnl_trylock())
291 		return restart_syscall();
292 	if (netdev->ifalias)
293 		ret = sprintf(buf, "%s\n", netdev->ifalias);
294 	rtnl_unlock();
295 	return ret;
296 }
297 
298 static struct device_attribute net_class_attributes[] = {
299 	__ATTR(addr_assign_type, S_IRUGO, show_addr_assign_type, NULL),
300 	__ATTR(addr_len, S_IRUGO, show_addr_len, NULL),
301 	__ATTR(dev_id, S_IRUGO, show_dev_id, NULL),
302 	__ATTR(ifalias, S_IRUGO | S_IWUSR, show_ifalias, store_ifalias),
303 	__ATTR(iflink, S_IRUGO, show_iflink, NULL),
304 	__ATTR(ifindex, S_IRUGO, show_ifindex, NULL),
305 	__ATTR(features, S_IRUGO, show_features, NULL),
306 	__ATTR(type, S_IRUGO, show_type, NULL),
307 	__ATTR(link_mode, S_IRUGO, show_link_mode, NULL),
308 	__ATTR(address, S_IRUGO, show_address, NULL),
309 	__ATTR(broadcast, S_IRUGO, show_broadcast, NULL),
310 	__ATTR(carrier, S_IRUGO, show_carrier, NULL),
311 	__ATTR(speed, S_IRUGO, show_speed, NULL),
312 	__ATTR(duplex, S_IRUGO, show_duplex, NULL),
313 	__ATTR(dormant, S_IRUGO, show_dormant, NULL),
314 	__ATTR(operstate, S_IRUGO, show_operstate, NULL),
315 	__ATTR(mtu, S_IRUGO | S_IWUSR, show_mtu, store_mtu),
316 	__ATTR(flags, S_IRUGO | S_IWUSR, show_flags, store_flags),
317 	__ATTR(tx_queue_len, S_IRUGO | S_IWUSR, show_tx_queue_len,
318 	       store_tx_queue_len),
319 	{}
320 };
321 
322 /* Show a given an attribute in the statistics group */
323 static ssize_t netstat_show(const struct device *d,
324 			    struct device_attribute *attr, char *buf,
325 			    unsigned long offset)
326 {
327 	struct net_device *dev = to_net_dev(d);
328 	ssize_t ret = -EINVAL;
329 
330 	WARN_ON(offset > sizeof(struct rtnl_link_stats64) ||
331 			offset % sizeof(u64) != 0);
332 
333 	read_lock(&dev_base_lock);
334 	if (dev_isalive(dev)) {
335 		struct rtnl_link_stats64 temp;
336 		const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp);
337 
338 		ret = sprintf(buf, fmt_u64, *(u64 *)(((u8 *) stats) + offset));
339 	}
340 	read_unlock(&dev_base_lock);
341 	return ret;
342 }
343 
344 /* generate a read-only statistics attribute */
345 #define NETSTAT_ENTRY(name)						\
346 static ssize_t show_##name(struct device *d,				\
347 			   struct device_attribute *attr, char *buf) 	\
348 {									\
349 	return netstat_show(d, attr, buf,				\
350 			    offsetof(struct rtnl_link_stats64, name));	\
351 }									\
352 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
353 
354 NETSTAT_ENTRY(rx_packets);
355 NETSTAT_ENTRY(tx_packets);
356 NETSTAT_ENTRY(rx_bytes);
357 NETSTAT_ENTRY(tx_bytes);
358 NETSTAT_ENTRY(rx_errors);
359 NETSTAT_ENTRY(tx_errors);
360 NETSTAT_ENTRY(rx_dropped);
361 NETSTAT_ENTRY(tx_dropped);
362 NETSTAT_ENTRY(multicast);
363 NETSTAT_ENTRY(collisions);
364 NETSTAT_ENTRY(rx_length_errors);
365 NETSTAT_ENTRY(rx_over_errors);
366 NETSTAT_ENTRY(rx_crc_errors);
367 NETSTAT_ENTRY(rx_frame_errors);
368 NETSTAT_ENTRY(rx_fifo_errors);
369 NETSTAT_ENTRY(rx_missed_errors);
370 NETSTAT_ENTRY(tx_aborted_errors);
371 NETSTAT_ENTRY(tx_carrier_errors);
372 NETSTAT_ENTRY(tx_fifo_errors);
373 NETSTAT_ENTRY(tx_heartbeat_errors);
374 NETSTAT_ENTRY(tx_window_errors);
375 NETSTAT_ENTRY(rx_compressed);
376 NETSTAT_ENTRY(tx_compressed);
377 
378 static struct attribute *netstat_attrs[] = {
379 	&dev_attr_rx_packets.attr,
380 	&dev_attr_tx_packets.attr,
381 	&dev_attr_rx_bytes.attr,
382 	&dev_attr_tx_bytes.attr,
383 	&dev_attr_rx_errors.attr,
384 	&dev_attr_tx_errors.attr,
385 	&dev_attr_rx_dropped.attr,
386 	&dev_attr_tx_dropped.attr,
387 	&dev_attr_multicast.attr,
388 	&dev_attr_collisions.attr,
389 	&dev_attr_rx_length_errors.attr,
390 	&dev_attr_rx_over_errors.attr,
391 	&dev_attr_rx_crc_errors.attr,
392 	&dev_attr_rx_frame_errors.attr,
393 	&dev_attr_rx_fifo_errors.attr,
394 	&dev_attr_rx_missed_errors.attr,
395 	&dev_attr_tx_aborted_errors.attr,
396 	&dev_attr_tx_carrier_errors.attr,
397 	&dev_attr_tx_fifo_errors.attr,
398 	&dev_attr_tx_heartbeat_errors.attr,
399 	&dev_attr_tx_window_errors.attr,
400 	&dev_attr_rx_compressed.attr,
401 	&dev_attr_tx_compressed.attr,
402 	NULL
403 };
404 
405 
406 static struct attribute_group netstat_group = {
407 	.name  = "statistics",
408 	.attrs  = netstat_attrs,
409 };
410 
411 #ifdef CONFIG_WIRELESS_EXT_SYSFS
412 /* helper function that does all the locking etc for wireless stats */
413 static ssize_t wireless_show(struct device *d, char *buf,
414 			     ssize_t (*format)(const struct iw_statistics *,
415 					       char *))
416 {
417 	struct net_device *dev = to_net_dev(d);
418 	const struct iw_statistics *iw;
419 	ssize_t ret = -EINVAL;
420 
421 	if (!rtnl_trylock())
422 		return restart_syscall();
423 	if (dev_isalive(dev)) {
424 		iw = get_wireless_stats(dev);
425 		if (iw)
426 			ret = (*format)(iw, buf);
427 	}
428 	rtnl_unlock();
429 
430 	return ret;
431 }
432 
433 /* show function template for wireless fields */
434 #define WIRELESS_SHOW(name, field, format_string)			\
435 static ssize_t format_iw_##name(const struct iw_statistics *iw, char *buf) \
436 {									\
437 	return sprintf(buf, format_string, iw->field);			\
438 }									\
439 static ssize_t show_iw_##name(struct device *d,				\
440 			      struct device_attribute *attr, char *buf)	\
441 {									\
442 	return wireless_show(d, buf, format_iw_##name);			\
443 }									\
444 static DEVICE_ATTR(name, S_IRUGO, show_iw_##name, NULL)
445 
446 WIRELESS_SHOW(status, status, fmt_hex);
447 WIRELESS_SHOW(link, qual.qual, fmt_dec);
448 WIRELESS_SHOW(level, qual.level, fmt_dec);
449 WIRELESS_SHOW(noise, qual.noise, fmt_dec);
450 WIRELESS_SHOW(nwid, discard.nwid, fmt_dec);
451 WIRELESS_SHOW(crypt, discard.code, fmt_dec);
452 WIRELESS_SHOW(fragment, discard.fragment, fmt_dec);
453 WIRELESS_SHOW(misc, discard.misc, fmt_dec);
454 WIRELESS_SHOW(retries, discard.retries, fmt_dec);
455 WIRELESS_SHOW(beacon, miss.beacon, fmt_dec);
456 
457 static struct attribute *wireless_attrs[] = {
458 	&dev_attr_status.attr,
459 	&dev_attr_link.attr,
460 	&dev_attr_level.attr,
461 	&dev_attr_noise.attr,
462 	&dev_attr_nwid.attr,
463 	&dev_attr_crypt.attr,
464 	&dev_attr_fragment.attr,
465 	&dev_attr_retries.attr,
466 	&dev_attr_misc.attr,
467 	&dev_attr_beacon.attr,
468 	NULL
469 };
470 
471 static struct attribute_group wireless_group = {
472 	.name = "wireless",
473 	.attrs = wireless_attrs,
474 };
475 #endif
476 #endif /* CONFIG_SYSFS */
477 
478 #ifdef CONFIG_RPS
479 /*
480  * RX queue sysfs structures and functions.
481  */
482 struct rx_queue_attribute {
483 	struct attribute attr;
484 	ssize_t (*show)(struct netdev_rx_queue *queue,
485 	    struct rx_queue_attribute *attr, char *buf);
486 	ssize_t (*store)(struct netdev_rx_queue *queue,
487 	    struct rx_queue_attribute *attr, const char *buf, size_t len);
488 };
489 #define to_rx_queue_attr(_attr) container_of(_attr,		\
490     struct rx_queue_attribute, attr)
491 
492 #define to_rx_queue(obj) container_of(obj, struct netdev_rx_queue, kobj)
493 
494 static ssize_t rx_queue_attr_show(struct kobject *kobj, struct attribute *attr,
495 				  char *buf)
496 {
497 	struct rx_queue_attribute *attribute = to_rx_queue_attr(attr);
498 	struct netdev_rx_queue *queue = to_rx_queue(kobj);
499 
500 	if (!attribute->show)
501 		return -EIO;
502 
503 	return attribute->show(queue, attribute, buf);
504 }
505 
506 static ssize_t rx_queue_attr_store(struct kobject *kobj, struct attribute *attr,
507 				   const char *buf, size_t count)
508 {
509 	struct rx_queue_attribute *attribute = to_rx_queue_attr(attr);
510 	struct netdev_rx_queue *queue = to_rx_queue(kobj);
511 
512 	if (!attribute->store)
513 		return -EIO;
514 
515 	return attribute->store(queue, attribute, buf, count);
516 }
517 
518 static struct sysfs_ops rx_queue_sysfs_ops = {
519 	.show = rx_queue_attr_show,
520 	.store = rx_queue_attr_store,
521 };
522 
523 static ssize_t show_rps_map(struct netdev_rx_queue *queue,
524 			    struct rx_queue_attribute *attribute, char *buf)
525 {
526 	struct rps_map *map;
527 	cpumask_var_t mask;
528 	size_t len = 0;
529 	int i;
530 
531 	if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
532 		return -ENOMEM;
533 
534 	rcu_read_lock();
535 	map = rcu_dereference(queue->rps_map);
536 	if (map)
537 		for (i = 0; i < map->len; i++)
538 			cpumask_set_cpu(map->cpus[i], mask);
539 
540 	len += cpumask_scnprintf(buf + len, PAGE_SIZE, mask);
541 	if (PAGE_SIZE - len < 3) {
542 		rcu_read_unlock();
543 		free_cpumask_var(mask);
544 		return -EINVAL;
545 	}
546 	rcu_read_unlock();
547 
548 	free_cpumask_var(mask);
549 	len += sprintf(buf + len, "\n");
550 	return len;
551 }
552 
553 static void rps_map_release(struct rcu_head *rcu)
554 {
555 	struct rps_map *map = container_of(rcu, struct rps_map, rcu);
556 
557 	kfree(map);
558 }
559 
560 static ssize_t store_rps_map(struct netdev_rx_queue *queue,
561 		      struct rx_queue_attribute *attribute,
562 		      const char *buf, size_t len)
563 {
564 	struct rps_map *old_map, *map;
565 	cpumask_var_t mask;
566 	int err, cpu, i;
567 	static DEFINE_SPINLOCK(rps_map_lock);
568 
569 	if (!capable(CAP_NET_ADMIN))
570 		return -EPERM;
571 
572 	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
573 		return -ENOMEM;
574 
575 	err = bitmap_parse(buf, len, cpumask_bits(mask), nr_cpumask_bits);
576 	if (err) {
577 		free_cpumask_var(mask);
578 		return err;
579 	}
580 
581 	map = kzalloc(max_t(unsigned,
582 	    RPS_MAP_SIZE(cpumask_weight(mask)), L1_CACHE_BYTES),
583 	    GFP_KERNEL);
584 	if (!map) {
585 		free_cpumask_var(mask);
586 		return -ENOMEM;
587 	}
588 
589 	i = 0;
590 	for_each_cpu_and(cpu, mask, cpu_online_mask)
591 		map->cpus[i++] = cpu;
592 
593 	if (i)
594 		map->len = i;
595 	else {
596 		kfree(map);
597 		map = NULL;
598 	}
599 
600 	spin_lock(&rps_map_lock);
601 	old_map = queue->rps_map;
602 	rcu_assign_pointer(queue->rps_map, map);
603 	spin_unlock(&rps_map_lock);
604 
605 	if (old_map)
606 		call_rcu(&old_map->rcu, rps_map_release);
607 
608 	free_cpumask_var(mask);
609 	return len;
610 }
611 
612 static ssize_t show_rps_dev_flow_table_cnt(struct netdev_rx_queue *queue,
613 					   struct rx_queue_attribute *attr,
614 					   char *buf)
615 {
616 	struct rps_dev_flow_table *flow_table;
617 	unsigned int val = 0;
618 
619 	rcu_read_lock();
620 	flow_table = rcu_dereference(queue->rps_flow_table);
621 	if (flow_table)
622 		val = flow_table->mask + 1;
623 	rcu_read_unlock();
624 
625 	return sprintf(buf, "%u\n", val);
626 }
627 
628 static void rps_dev_flow_table_release_work(struct work_struct *work)
629 {
630 	struct rps_dev_flow_table *table = container_of(work,
631 	    struct rps_dev_flow_table, free_work);
632 
633 	vfree(table);
634 }
635 
636 static void rps_dev_flow_table_release(struct rcu_head *rcu)
637 {
638 	struct rps_dev_flow_table *table = container_of(rcu,
639 	    struct rps_dev_flow_table, rcu);
640 
641 	INIT_WORK(&table->free_work, rps_dev_flow_table_release_work);
642 	schedule_work(&table->free_work);
643 }
644 
645 static ssize_t store_rps_dev_flow_table_cnt(struct netdev_rx_queue *queue,
646 				     struct rx_queue_attribute *attr,
647 				     const char *buf, size_t len)
648 {
649 	unsigned int count;
650 	char *endp;
651 	struct rps_dev_flow_table *table, *old_table;
652 	static DEFINE_SPINLOCK(rps_dev_flow_lock);
653 
654 	if (!capable(CAP_NET_ADMIN))
655 		return -EPERM;
656 
657 	count = simple_strtoul(buf, &endp, 0);
658 	if (endp == buf)
659 		return -EINVAL;
660 
661 	if (count) {
662 		int i;
663 
664 		if (count > 1<<30) {
665 			/* Enforce a limit to prevent overflow */
666 			return -EINVAL;
667 		}
668 		count = roundup_pow_of_two(count);
669 		table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(count));
670 		if (!table)
671 			return -ENOMEM;
672 
673 		table->mask = count - 1;
674 		for (i = 0; i < count; i++)
675 			table->flows[i].cpu = RPS_NO_CPU;
676 	} else
677 		table = NULL;
678 
679 	spin_lock(&rps_dev_flow_lock);
680 	old_table = queue->rps_flow_table;
681 	rcu_assign_pointer(queue->rps_flow_table, table);
682 	spin_unlock(&rps_dev_flow_lock);
683 
684 	if (old_table)
685 		call_rcu(&old_table->rcu, rps_dev_flow_table_release);
686 
687 	return len;
688 }
689 
690 static struct rx_queue_attribute rps_cpus_attribute =
691 	__ATTR(rps_cpus, S_IRUGO | S_IWUSR, show_rps_map, store_rps_map);
692 
693 
694 static struct rx_queue_attribute rps_dev_flow_table_cnt_attribute =
695 	__ATTR(rps_flow_cnt, S_IRUGO | S_IWUSR,
696 	    show_rps_dev_flow_table_cnt, store_rps_dev_flow_table_cnt);
697 
698 static struct attribute *rx_queue_default_attrs[] = {
699 	&rps_cpus_attribute.attr,
700 	&rps_dev_flow_table_cnt_attribute.attr,
701 	NULL
702 };
703 
704 static void rx_queue_release(struct kobject *kobj)
705 {
706 	struct netdev_rx_queue *queue = to_rx_queue(kobj);
707 	struct netdev_rx_queue *first = queue->first;
708 
709 	if (queue->rps_map)
710 		call_rcu(&queue->rps_map->rcu, rps_map_release);
711 
712 	if (queue->rps_flow_table)
713 		call_rcu(&queue->rps_flow_table->rcu,
714 		    rps_dev_flow_table_release);
715 
716 	if (atomic_dec_and_test(&first->count))
717 		kfree(first);
718 }
719 
720 static struct kobj_type rx_queue_ktype = {
721 	.sysfs_ops = &rx_queue_sysfs_ops,
722 	.release = rx_queue_release,
723 	.default_attrs = rx_queue_default_attrs,
724 };
725 
726 static int rx_queue_add_kobject(struct net_device *net, int index)
727 {
728 	struct netdev_rx_queue *queue = net->_rx + index;
729 	struct kobject *kobj = &queue->kobj;
730 	int error = 0;
731 
732 	kobj->kset = net->queues_kset;
733 	error = kobject_init_and_add(kobj, &rx_queue_ktype, NULL,
734 	    "rx-%u", index);
735 	if (error) {
736 		kobject_put(kobj);
737 		return error;
738 	}
739 
740 	kobject_uevent(kobj, KOBJ_ADD);
741 
742 	return error;
743 }
744 
745 static int rx_queue_register_kobjects(struct net_device *net)
746 {
747 	int i;
748 	int error = 0;
749 
750 	net->queues_kset = kset_create_and_add("queues",
751 	    NULL, &net->dev.kobj);
752 	if (!net->queues_kset)
753 		return -ENOMEM;
754 	for (i = 0; i < net->num_rx_queues; i++) {
755 		error = rx_queue_add_kobject(net, i);
756 		if (error)
757 			break;
758 	}
759 
760 	if (error)
761 		while (--i >= 0)
762 			kobject_put(&net->_rx[i].kobj);
763 
764 	return error;
765 }
766 
767 static void rx_queue_remove_kobjects(struct net_device *net)
768 {
769 	int i;
770 
771 	for (i = 0; i < net->num_rx_queues; i++)
772 		kobject_put(&net->_rx[i].kobj);
773 	kset_unregister(net->queues_kset);
774 }
775 #endif /* CONFIG_RPS */
776 
777 static const void *net_current_ns(void)
778 {
779 	return current->nsproxy->net_ns;
780 }
781 
782 static const void *net_initial_ns(void)
783 {
784 	return &init_net;
785 }
786 
787 static const void *net_netlink_ns(struct sock *sk)
788 {
789 	return sock_net(sk);
790 }
791 
792 static struct kobj_ns_type_operations net_ns_type_operations = {
793 	.type = KOBJ_NS_TYPE_NET,
794 	.current_ns = net_current_ns,
795 	.netlink_ns = net_netlink_ns,
796 	.initial_ns = net_initial_ns,
797 };
798 
799 static void net_kobj_ns_exit(struct net *net)
800 {
801 	kobj_ns_exit(KOBJ_NS_TYPE_NET, net);
802 }
803 
804 static struct pernet_operations kobj_net_ops = {
805 	.exit = net_kobj_ns_exit,
806 };
807 
808 
809 #ifdef CONFIG_HOTPLUG
810 static int netdev_uevent(struct device *d, struct kobj_uevent_env *env)
811 {
812 	struct net_device *dev = to_net_dev(d);
813 	int retval;
814 
815 	/* pass interface to uevent. */
816 	retval = add_uevent_var(env, "INTERFACE=%s", dev->name);
817 	if (retval)
818 		goto exit;
819 
820 	/* pass ifindex to uevent.
821 	 * ifindex is useful as it won't change (interface name may change)
822 	 * and is what RtNetlink uses natively. */
823 	retval = add_uevent_var(env, "IFINDEX=%d", dev->ifindex);
824 
825 exit:
826 	return retval;
827 }
828 #endif
829 
830 /*
831  *	netdev_release -- destroy and free a dead device.
832  *	Called when last reference to device kobject is gone.
833  */
834 static void netdev_release(struct device *d)
835 {
836 	struct net_device *dev = to_net_dev(d);
837 
838 	BUG_ON(dev->reg_state != NETREG_RELEASED);
839 
840 	kfree(dev->ifalias);
841 	kfree((char *)dev - dev->padded);
842 }
843 
844 static const void *net_namespace(struct device *d)
845 {
846 	struct net_device *dev;
847 	dev = container_of(d, struct net_device, dev);
848 	return dev_net(dev);
849 }
850 
851 static struct class net_class = {
852 	.name = "net",
853 	.dev_release = netdev_release,
854 #ifdef CONFIG_SYSFS
855 	.dev_attrs = net_class_attributes,
856 #endif /* CONFIG_SYSFS */
857 #ifdef CONFIG_HOTPLUG
858 	.dev_uevent = netdev_uevent,
859 #endif
860 	.ns_type = &net_ns_type_operations,
861 	.namespace = net_namespace,
862 };
863 
864 /* Delete sysfs entries but hold kobject reference until after all
865  * netdev references are gone.
866  */
867 void netdev_unregister_kobject(struct net_device * net)
868 {
869 	struct device *dev = &(net->dev);
870 
871 	kobject_get(&dev->kobj);
872 
873 #ifdef CONFIG_RPS
874 	rx_queue_remove_kobjects(net);
875 #endif
876 
877 	device_del(dev);
878 }
879 
880 /* Create sysfs entries for network device. */
881 int netdev_register_kobject(struct net_device *net)
882 {
883 	struct device *dev = &(net->dev);
884 	const struct attribute_group **groups = net->sysfs_groups;
885 	int error = 0;
886 
887 	device_initialize(dev);
888 	dev->class = &net_class;
889 	dev->platform_data = net;
890 	dev->groups = groups;
891 
892 	dev_set_name(dev, "%s", net->name);
893 
894 #ifdef CONFIG_SYSFS
895 	/* Allow for a device specific group */
896 	if (*groups)
897 		groups++;
898 
899 	*groups++ = &netstat_group;
900 #ifdef CONFIG_WIRELESS_EXT_SYSFS
901 	if (net->ieee80211_ptr)
902 		*groups++ = &wireless_group;
903 #ifdef CONFIG_WIRELESS_EXT
904 	else if (net->wireless_handlers)
905 		*groups++ = &wireless_group;
906 #endif
907 #endif
908 #endif /* CONFIG_SYSFS */
909 
910 	error = device_add(dev);
911 	if (error)
912 		return error;
913 
914 #ifdef CONFIG_RPS
915 	error = rx_queue_register_kobjects(net);
916 	if (error) {
917 		device_del(dev);
918 		return error;
919 	}
920 #endif
921 
922 	return error;
923 }
924 
925 int netdev_class_create_file(struct class_attribute *class_attr)
926 {
927 	return class_create_file(&net_class, class_attr);
928 }
929 EXPORT_SYMBOL(netdev_class_create_file);
930 
931 void netdev_class_remove_file(struct class_attribute *class_attr)
932 {
933 	class_remove_file(&net_class, class_attr);
934 }
935 EXPORT_SYMBOL(netdev_class_remove_file);
936 
937 int netdev_kobject_init(void)
938 {
939 	kobj_ns_type_register(&net_ns_type_operations);
940 	register_pernet_subsys(&kobj_net_ops);
941 	return class_register(&net_class);
942 }
943