xref: /linux/net/core/net-sysfs.c (revision c6bd5bcc4983f1a2d2f87a3769bf309482ee8c04)
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 <linux/export.h>
24 #include <linux/jiffies.h>
25 #include <net/wext.h>
26 
27 #include "net-sysfs.h"
28 
29 #ifdef CONFIG_SYSFS
30 static const char fmt_hex[] = "%#x\n";
31 static const char fmt_long_hex[] = "%#lx\n";
32 static const char fmt_dec[] = "%d\n";
33 static const char fmt_udec[] = "%u\n";
34 static const char fmt_ulong[] = "%lu\n";
35 static const char fmt_u64[] = "%llu\n";
36 
37 static inline int dev_isalive(const struct net_device *dev)
38 {
39 	return dev->reg_state <= NETREG_REGISTERED;
40 }
41 
42 /* use same locking rules as GIF* ioctl's */
43 static ssize_t netdev_show(const struct device *dev,
44 			   struct device_attribute *attr, char *buf,
45 			   ssize_t (*format)(const struct net_device *, char *))
46 {
47 	struct net_device *net = to_net_dev(dev);
48 	ssize_t ret = -EINVAL;
49 
50 	read_lock(&dev_base_lock);
51 	if (dev_isalive(net))
52 		ret = (*format)(net, buf);
53 	read_unlock(&dev_base_lock);
54 
55 	return ret;
56 }
57 
58 /* generate a show function for simple field */
59 #define NETDEVICE_SHOW(field, format_string)				\
60 static ssize_t format_##field(const struct net_device *net, char *buf)	\
61 {									\
62 	return sprintf(buf, format_string, net->field);			\
63 }									\
64 static ssize_t show_##field(struct device *dev,				\
65 			    struct device_attribute *attr, char *buf)	\
66 {									\
67 	return netdev_show(dev, attr, buf, format_##field);		\
68 }
69 
70 
71 /* use same locking and permission rules as SIF* ioctl's */
72 static ssize_t netdev_store(struct device *dev, struct device_attribute *attr,
73 			    const char *buf, size_t len,
74 			    int (*set)(struct net_device *, unsigned long))
75 {
76 	struct net_device *net = to_net_dev(dev);
77 	unsigned long new;
78 	int ret = -EINVAL;
79 
80 	if (!capable(CAP_NET_ADMIN))
81 		return -EPERM;
82 
83 	ret = kstrtoul(buf, 0, &new);
84 	if (ret)
85 		goto err;
86 
87 	if (!rtnl_trylock())
88 		return restart_syscall();
89 
90 	if (dev_isalive(net)) {
91 		if ((ret = (*set)(net, new)) == 0)
92 			ret = len;
93 	}
94 	rtnl_unlock();
95  err:
96 	return ret;
97 }
98 
99 NETDEVICE_SHOW(dev_id, fmt_hex);
100 NETDEVICE_SHOW(addr_assign_type, fmt_dec);
101 NETDEVICE_SHOW(addr_len, fmt_dec);
102 NETDEVICE_SHOW(iflink, fmt_dec);
103 NETDEVICE_SHOW(ifindex, fmt_dec);
104 NETDEVICE_SHOW(type, fmt_dec);
105 NETDEVICE_SHOW(link_mode, fmt_dec);
106 
107 /* use same locking rules as GIFHWADDR ioctl's */
108 static ssize_t show_address(struct device *dev, struct device_attribute *attr,
109 			    char *buf)
110 {
111 	struct net_device *net = to_net_dev(dev);
112 	ssize_t ret = -EINVAL;
113 
114 	read_lock(&dev_base_lock);
115 	if (dev_isalive(net))
116 		ret = sysfs_format_mac(buf, net->dev_addr, net->addr_len);
117 	read_unlock(&dev_base_lock);
118 	return ret;
119 }
120 
121 static ssize_t show_broadcast(struct device *dev,
122 			    struct device_attribute *attr, char *buf)
123 {
124 	struct net_device *net = to_net_dev(dev);
125 	if (dev_isalive(net))
126 		return sysfs_format_mac(buf, net->broadcast, net->addr_len);
127 	return -EINVAL;
128 }
129 
130 static ssize_t show_carrier(struct device *dev,
131 			    struct device_attribute *attr, char *buf)
132 {
133 	struct net_device *netdev = to_net_dev(dev);
134 	if (netif_running(netdev)) {
135 		return sprintf(buf, fmt_dec, !!netif_carrier_ok(netdev));
136 	}
137 	return -EINVAL;
138 }
139 
140 static ssize_t show_speed(struct device *dev,
141 			  struct device_attribute *attr, char *buf)
142 {
143 	struct net_device *netdev = to_net_dev(dev);
144 	int ret = -EINVAL;
145 
146 	if (!rtnl_trylock())
147 		return restart_syscall();
148 
149 	if (netif_running(netdev)) {
150 		struct ethtool_cmd cmd;
151 		if (!__ethtool_get_settings(netdev, &cmd))
152 			ret = sprintf(buf, fmt_udec, ethtool_cmd_speed(&cmd));
153 	}
154 	rtnl_unlock();
155 	return ret;
156 }
157 
158 static ssize_t show_duplex(struct device *dev,
159 			   struct device_attribute *attr, char *buf)
160 {
161 	struct net_device *netdev = to_net_dev(dev);
162 	int ret = -EINVAL;
163 
164 	if (!rtnl_trylock())
165 		return restart_syscall();
166 
167 	if (netif_running(netdev)) {
168 		struct ethtool_cmd cmd;
169 		if (!__ethtool_get_settings(netdev, &cmd)) {
170 			const char *duplex;
171 			switch (cmd.duplex) {
172 			case DUPLEX_HALF:
173 				duplex = "half";
174 				break;
175 			case DUPLEX_FULL:
176 				duplex = "full";
177 				break;
178 			default:
179 				duplex = "unknown";
180 				break;
181 			}
182 			ret = sprintf(buf, "%s\n", duplex);
183 		}
184 	}
185 	rtnl_unlock();
186 	return ret;
187 }
188 
189 static ssize_t show_dormant(struct device *dev,
190 			    struct device_attribute *attr, char *buf)
191 {
192 	struct net_device *netdev = to_net_dev(dev);
193 
194 	if (netif_running(netdev))
195 		return sprintf(buf, fmt_dec, !!netif_dormant(netdev));
196 
197 	return -EINVAL;
198 }
199 
200 static const char *const operstates[] = {
201 	"unknown",
202 	"notpresent", /* currently unused */
203 	"down",
204 	"lowerlayerdown",
205 	"testing", /* currently unused */
206 	"dormant",
207 	"up"
208 };
209 
210 static ssize_t show_operstate(struct device *dev,
211 			      struct device_attribute *attr, char *buf)
212 {
213 	const struct net_device *netdev = to_net_dev(dev);
214 	unsigned char operstate;
215 
216 	read_lock(&dev_base_lock);
217 	operstate = netdev->operstate;
218 	if (!netif_running(netdev))
219 		operstate = IF_OPER_DOWN;
220 	read_unlock(&dev_base_lock);
221 
222 	if (operstate >= ARRAY_SIZE(operstates))
223 		return -EINVAL; /* should not happen */
224 
225 	return sprintf(buf, "%s\n", operstates[operstate]);
226 }
227 
228 /* read-write attributes */
229 NETDEVICE_SHOW(mtu, fmt_dec);
230 
231 static int change_mtu(struct net_device *net, unsigned long new_mtu)
232 {
233 	return dev_set_mtu(net, (int) new_mtu);
234 }
235 
236 static ssize_t store_mtu(struct device *dev, struct device_attribute *attr,
237 			 const char *buf, size_t len)
238 {
239 	return netdev_store(dev, attr, buf, len, change_mtu);
240 }
241 
242 NETDEVICE_SHOW(flags, fmt_hex);
243 
244 static int change_flags(struct net_device *net, unsigned long new_flags)
245 {
246 	return dev_change_flags(net, (unsigned int) new_flags);
247 }
248 
249 static ssize_t store_flags(struct device *dev, struct device_attribute *attr,
250 			   const char *buf, size_t len)
251 {
252 	return netdev_store(dev, attr, buf, len, change_flags);
253 }
254 
255 NETDEVICE_SHOW(tx_queue_len, fmt_ulong);
256 
257 static int change_tx_queue_len(struct net_device *net, unsigned long new_len)
258 {
259 	net->tx_queue_len = new_len;
260 	return 0;
261 }
262 
263 static ssize_t store_tx_queue_len(struct device *dev,
264 				  struct device_attribute *attr,
265 				  const char *buf, size_t len)
266 {
267 	return netdev_store(dev, attr, buf, len, change_tx_queue_len);
268 }
269 
270 static ssize_t store_ifalias(struct device *dev, struct device_attribute *attr,
271 			     const char *buf, size_t len)
272 {
273 	struct net_device *netdev = to_net_dev(dev);
274 	size_t count = len;
275 	ssize_t ret;
276 
277 	if (!capable(CAP_NET_ADMIN))
278 		return -EPERM;
279 
280 	/* ignore trailing newline */
281 	if (len >  0 && buf[len - 1] == '\n')
282 		--count;
283 
284 	if (!rtnl_trylock())
285 		return restart_syscall();
286 	ret = dev_set_alias(netdev, buf, count);
287 	rtnl_unlock();
288 
289 	return ret < 0 ? ret : len;
290 }
291 
292 static ssize_t show_ifalias(struct device *dev,
293 			    struct device_attribute *attr, char *buf)
294 {
295 	const struct net_device *netdev = to_net_dev(dev);
296 	ssize_t ret = 0;
297 
298 	if (!rtnl_trylock())
299 		return restart_syscall();
300 	if (netdev->ifalias)
301 		ret = sprintf(buf, "%s\n", netdev->ifalias);
302 	rtnl_unlock();
303 	return ret;
304 }
305 
306 NETDEVICE_SHOW(group, fmt_dec);
307 
308 static int change_group(struct net_device *net, unsigned long new_group)
309 {
310 	dev_set_group(net, (int) new_group);
311 	return 0;
312 }
313 
314 static ssize_t store_group(struct device *dev, struct device_attribute *attr,
315 			 const char *buf, size_t len)
316 {
317 	return netdev_store(dev, attr, buf, len, change_group);
318 }
319 
320 static struct device_attribute net_class_attributes[] = {
321 	__ATTR(addr_assign_type, S_IRUGO, show_addr_assign_type, NULL),
322 	__ATTR(addr_len, S_IRUGO, show_addr_len, NULL),
323 	__ATTR(dev_id, S_IRUGO, show_dev_id, NULL),
324 	__ATTR(ifalias, S_IRUGO | S_IWUSR, show_ifalias, store_ifalias),
325 	__ATTR(iflink, S_IRUGO, show_iflink, NULL),
326 	__ATTR(ifindex, S_IRUGO, show_ifindex, NULL),
327 	__ATTR(type, S_IRUGO, show_type, NULL),
328 	__ATTR(link_mode, S_IRUGO, show_link_mode, NULL),
329 	__ATTR(address, S_IRUGO, show_address, NULL),
330 	__ATTR(broadcast, S_IRUGO, show_broadcast, NULL),
331 	__ATTR(carrier, S_IRUGO, show_carrier, NULL),
332 	__ATTR(speed, S_IRUGO, show_speed, NULL),
333 	__ATTR(duplex, S_IRUGO, show_duplex, NULL),
334 	__ATTR(dormant, S_IRUGO, show_dormant, NULL),
335 	__ATTR(operstate, S_IRUGO, show_operstate, NULL),
336 	__ATTR(mtu, S_IRUGO | S_IWUSR, show_mtu, store_mtu),
337 	__ATTR(flags, S_IRUGO | S_IWUSR, show_flags, store_flags),
338 	__ATTR(tx_queue_len, S_IRUGO | S_IWUSR, show_tx_queue_len,
339 	       store_tx_queue_len),
340 	__ATTR(netdev_group, S_IRUGO | S_IWUSR, show_group, store_group),
341 	{}
342 };
343 
344 /* Show a given an attribute in the statistics group */
345 static ssize_t netstat_show(const struct device *d,
346 			    struct device_attribute *attr, char *buf,
347 			    unsigned long offset)
348 {
349 	struct net_device *dev = to_net_dev(d);
350 	ssize_t ret = -EINVAL;
351 
352 	WARN_ON(offset > sizeof(struct rtnl_link_stats64) ||
353 			offset % sizeof(u64) != 0);
354 
355 	read_lock(&dev_base_lock);
356 	if (dev_isalive(dev)) {
357 		struct rtnl_link_stats64 temp;
358 		const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp);
359 
360 		ret = sprintf(buf, fmt_u64, *(u64 *)(((u8 *) stats) + offset));
361 	}
362 	read_unlock(&dev_base_lock);
363 	return ret;
364 }
365 
366 /* generate a read-only statistics attribute */
367 #define NETSTAT_ENTRY(name)						\
368 static ssize_t show_##name(struct device *d,				\
369 			   struct device_attribute *attr, char *buf) 	\
370 {									\
371 	return netstat_show(d, attr, buf,				\
372 			    offsetof(struct rtnl_link_stats64, name));	\
373 }									\
374 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
375 
376 NETSTAT_ENTRY(rx_packets);
377 NETSTAT_ENTRY(tx_packets);
378 NETSTAT_ENTRY(rx_bytes);
379 NETSTAT_ENTRY(tx_bytes);
380 NETSTAT_ENTRY(rx_errors);
381 NETSTAT_ENTRY(tx_errors);
382 NETSTAT_ENTRY(rx_dropped);
383 NETSTAT_ENTRY(tx_dropped);
384 NETSTAT_ENTRY(multicast);
385 NETSTAT_ENTRY(collisions);
386 NETSTAT_ENTRY(rx_length_errors);
387 NETSTAT_ENTRY(rx_over_errors);
388 NETSTAT_ENTRY(rx_crc_errors);
389 NETSTAT_ENTRY(rx_frame_errors);
390 NETSTAT_ENTRY(rx_fifo_errors);
391 NETSTAT_ENTRY(rx_missed_errors);
392 NETSTAT_ENTRY(tx_aborted_errors);
393 NETSTAT_ENTRY(tx_carrier_errors);
394 NETSTAT_ENTRY(tx_fifo_errors);
395 NETSTAT_ENTRY(tx_heartbeat_errors);
396 NETSTAT_ENTRY(tx_window_errors);
397 NETSTAT_ENTRY(rx_compressed);
398 NETSTAT_ENTRY(tx_compressed);
399 
400 static struct attribute *netstat_attrs[] = {
401 	&dev_attr_rx_packets.attr,
402 	&dev_attr_tx_packets.attr,
403 	&dev_attr_rx_bytes.attr,
404 	&dev_attr_tx_bytes.attr,
405 	&dev_attr_rx_errors.attr,
406 	&dev_attr_tx_errors.attr,
407 	&dev_attr_rx_dropped.attr,
408 	&dev_attr_tx_dropped.attr,
409 	&dev_attr_multicast.attr,
410 	&dev_attr_collisions.attr,
411 	&dev_attr_rx_length_errors.attr,
412 	&dev_attr_rx_over_errors.attr,
413 	&dev_attr_rx_crc_errors.attr,
414 	&dev_attr_rx_frame_errors.attr,
415 	&dev_attr_rx_fifo_errors.attr,
416 	&dev_attr_rx_missed_errors.attr,
417 	&dev_attr_tx_aborted_errors.attr,
418 	&dev_attr_tx_carrier_errors.attr,
419 	&dev_attr_tx_fifo_errors.attr,
420 	&dev_attr_tx_heartbeat_errors.attr,
421 	&dev_attr_tx_window_errors.attr,
422 	&dev_attr_rx_compressed.attr,
423 	&dev_attr_tx_compressed.attr,
424 	NULL
425 };
426 
427 
428 static struct attribute_group netstat_group = {
429 	.name  = "statistics",
430 	.attrs  = netstat_attrs,
431 };
432 
433 #if IS_ENABLED(CONFIG_WIRELESS_EXT) || IS_ENABLED(CONFIG_CFG80211)
434 static struct attribute *wireless_attrs[] = {
435 	NULL
436 };
437 
438 static struct attribute_group wireless_group = {
439 	.name = "wireless",
440 	.attrs = wireless_attrs,
441 };
442 #endif
443 #endif /* CONFIG_SYSFS */
444 
445 #ifdef CONFIG_RPS
446 /*
447  * RX queue sysfs structures and functions.
448  */
449 struct rx_queue_attribute {
450 	struct attribute attr;
451 	ssize_t (*show)(struct netdev_rx_queue *queue,
452 	    struct rx_queue_attribute *attr, char *buf);
453 	ssize_t (*store)(struct netdev_rx_queue *queue,
454 	    struct rx_queue_attribute *attr, const char *buf, size_t len);
455 };
456 #define to_rx_queue_attr(_attr) container_of(_attr,		\
457     struct rx_queue_attribute, attr)
458 
459 #define to_rx_queue(obj) container_of(obj, struct netdev_rx_queue, kobj)
460 
461 static ssize_t rx_queue_attr_show(struct kobject *kobj, struct attribute *attr,
462 				  char *buf)
463 {
464 	struct rx_queue_attribute *attribute = to_rx_queue_attr(attr);
465 	struct netdev_rx_queue *queue = to_rx_queue(kobj);
466 
467 	if (!attribute->show)
468 		return -EIO;
469 
470 	return attribute->show(queue, attribute, buf);
471 }
472 
473 static ssize_t rx_queue_attr_store(struct kobject *kobj, struct attribute *attr,
474 				   const char *buf, size_t count)
475 {
476 	struct rx_queue_attribute *attribute = to_rx_queue_attr(attr);
477 	struct netdev_rx_queue *queue = to_rx_queue(kobj);
478 
479 	if (!attribute->store)
480 		return -EIO;
481 
482 	return attribute->store(queue, attribute, buf, count);
483 }
484 
485 static const struct sysfs_ops rx_queue_sysfs_ops = {
486 	.show = rx_queue_attr_show,
487 	.store = rx_queue_attr_store,
488 };
489 
490 static ssize_t show_rps_map(struct netdev_rx_queue *queue,
491 			    struct rx_queue_attribute *attribute, char *buf)
492 {
493 	struct rps_map *map;
494 	cpumask_var_t mask;
495 	size_t len = 0;
496 	int i;
497 
498 	if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
499 		return -ENOMEM;
500 
501 	rcu_read_lock();
502 	map = rcu_dereference(queue->rps_map);
503 	if (map)
504 		for (i = 0; i < map->len; i++)
505 			cpumask_set_cpu(map->cpus[i], mask);
506 
507 	len += cpumask_scnprintf(buf + len, PAGE_SIZE, mask);
508 	if (PAGE_SIZE - len < 3) {
509 		rcu_read_unlock();
510 		free_cpumask_var(mask);
511 		return -EINVAL;
512 	}
513 	rcu_read_unlock();
514 
515 	free_cpumask_var(mask);
516 	len += sprintf(buf + len, "\n");
517 	return len;
518 }
519 
520 static ssize_t store_rps_map(struct netdev_rx_queue *queue,
521 		      struct rx_queue_attribute *attribute,
522 		      const char *buf, size_t len)
523 {
524 	struct rps_map *old_map, *map;
525 	cpumask_var_t mask;
526 	int err, cpu, i;
527 	static DEFINE_SPINLOCK(rps_map_lock);
528 
529 	if (!capable(CAP_NET_ADMIN))
530 		return -EPERM;
531 
532 	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
533 		return -ENOMEM;
534 
535 	err = bitmap_parse(buf, len, cpumask_bits(mask), nr_cpumask_bits);
536 	if (err) {
537 		free_cpumask_var(mask);
538 		return err;
539 	}
540 
541 	map = kzalloc(max_t(unsigned int,
542 	    RPS_MAP_SIZE(cpumask_weight(mask)), L1_CACHE_BYTES),
543 	    GFP_KERNEL);
544 	if (!map) {
545 		free_cpumask_var(mask);
546 		return -ENOMEM;
547 	}
548 
549 	i = 0;
550 	for_each_cpu_and(cpu, mask, cpu_online_mask)
551 		map->cpus[i++] = cpu;
552 
553 	if (i)
554 		map->len = i;
555 	else {
556 		kfree(map);
557 		map = NULL;
558 	}
559 
560 	spin_lock(&rps_map_lock);
561 	old_map = rcu_dereference_protected(queue->rps_map,
562 					    lockdep_is_held(&rps_map_lock));
563 	rcu_assign_pointer(queue->rps_map, map);
564 	spin_unlock(&rps_map_lock);
565 
566 	if (map)
567 		static_key_slow_inc(&rps_needed);
568 	if (old_map) {
569 		kfree_rcu(old_map, rcu);
570 		static_key_slow_dec(&rps_needed);
571 	}
572 	free_cpumask_var(mask);
573 	return len;
574 }
575 
576 static ssize_t show_rps_dev_flow_table_cnt(struct netdev_rx_queue *queue,
577 					   struct rx_queue_attribute *attr,
578 					   char *buf)
579 {
580 	struct rps_dev_flow_table *flow_table;
581 	unsigned long val = 0;
582 
583 	rcu_read_lock();
584 	flow_table = rcu_dereference(queue->rps_flow_table);
585 	if (flow_table)
586 		val = (unsigned long)flow_table->mask + 1;
587 	rcu_read_unlock();
588 
589 	return sprintf(buf, "%lu\n", val);
590 }
591 
592 static void rps_dev_flow_table_release_work(struct work_struct *work)
593 {
594 	struct rps_dev_flow_table *table = container_of(work,
595 	    struct rps_dev_flow_table, free_work);
596 
597 	vfree(table);
598 }
599 
600 static void rps_dev_flow_table_release(struct rcu_head *rcu)
601 {
602 	struct rps_dev_flow_table *table = container_of(rcu,
603 	    struct rps_dev_flow_table, rcu);
604 
605 	INIT_WORK(&table->free_work, rps_dev_flow_table_release_work);
606 	schedule_work(&table->free_work);
607 }
608 
609 static ssize_t store_rps_dev_flow_table_cnt(struct netdev_rx_queue *queue,
610 				     struct rx_queue_attribute *attr,
611 				     const char *buf, size_t len)
612 {
613 	unsigned long mask, count;
614 	struct rps_dev_flow_table *table, *old_table;
615 	static DEFINE_SPINLOCK(rps_dev_flow_lock);
616 	int rc;
617 
618 	if (!capable(CAP_NET_ADMIN))
619 		return -EPERM;
620 
621 	rc = kstrtoul(buf, 0, &count);
622 	if (rc < 0)
623 		return rc;
624 
625 	if (count) {
626 		mask = count - 1;
627 		/* mask = roundup_pow_of_two(count) - 1;
628 		 * without overflows...
629 		 */
630 		while ((mask | (mask >> 1)) != mask)
631 			mask |= (mask >> 1);
632 		/* On 64 bit arches, must check mask fits in table->mask (u32),
633 		 * and on 32bit arches, must check RPS_DEV_FLOW_TABLE_SIZE(mask + 1)
634 		 * doesnt overflow.
635 		 */
636 #if BITS_PER_LONG > 32
637 		if (mask > (unsigned long)(u32)mask)
638 			return -EINVAL;
639 #else
640 		if (mask > (ULONG_MAX - RPS_DEV_FLOW_TABLE_SIZE(1))
641 				/ sizeof(struct rps_dev_flow)) {
642 			/* Enforce a limit to prevent overflow */
643 			return -EINVAL;
644 		}
645 #endif
646 		table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(mask + 1));
647 		if (!table)
648 			return -ENOMEM;
649 
650 		table->mask = mask;
651 		for (count = 0; count <= mask; count++)
652 			table->flows[count].cpu = RPS_NO_CPU;
653 	} else
654 		table = NULL;
655 
656 	spin_lock(&rps_dev_flow_lock);
657 	old_table = rcu_dereference_protected(queue->rps_flow_table,
658 					      lockdep_is_held(&rps_dev_flow_lock));
659 	rcu_assign_pointer(queue->rps_flow_table, table);
660 	spin_unlock(&rps_dev_flow_lock);
661 
662 	if (old_table)
663 		call_rcu(&old_table->rcu, rps_dev_flow_table_release);
664 
665 	return len;
666 }
667 
668 static struct rx_queue_attribute rps_cpus_attribute =
669 	__ATTR(rps_cpus, S_IRUGO | S_IWUSR, show_rps_map, store_rps_map);
670 
671 
672 static struct rx_queue_attribute rps_dev_flow_table_cnt_attribute =
673 	__ATTR(rps_flow_cnt, S_IRUGO | S_IWUSR,
674 	    show_rps_dev_flow_table_cnt, store_rps_dev_flow_table_cnt);
675 
676 static struct attribute *rx_queue_default_attrs[] = {
677 	&rps_cpus_attribute.attr,
678 	&rps_dev_flow_table_cnt_attribute.attr,
679 	NULL
680 };
681 
682 static void rx_queue_release(struct kobject *kobj)
683 {
684 	struct netdev_rx_queue *queue = to_rx_queue(kobj);
685 	struct rps_map *map;
686 	struct rps_dev_flow_table *flow_table;
687 
688 
689 	map = rcu_dereference_protected(queue->rps_map, 1);
690 	if (map) {
691 		RCU_INIT_POINTER(queue->rps_map, NULL);
692 		kfree_rcu(map, rcu);
693 	}
694 
695 	flow_table = rcu_dereference_protected(queue->rps_flow_table, 1);
696 	if (flow_table) {
697 		RCU_INIT_POINTER(queue->rps_flow_table, NULL);
698 		call_rcu(&flow_table->rcu, rps_dev_flow_table_release);
699 	}
700 
701 	memset(kobj, 0, sizeof(*kobj));
702 	dev_put(queue->dev);
703 }
704 
705 static struct kobj_type rx_queue_ktype = {
706 	.sysfs_ops = &rx_queue_sysfs_ops,
707 	.release = rx_queue_release,
708 	.default_attrs = rx_queue_default_attrs,
709 };
710 
711 static int rx_queue_add_kobject(struct net_device *net, int index)
712 {
713 	struct netdev_rx_queue *queue = net->_rx + index;
714 	struct kobject *kobj = &queue->kobj;
715 	int error = 0;
716 
717 	kobj->kset = net->queues_kset;
718 	error = kobject_init_and_add(kobj, &rx_queue_ktype, NULL,
719 	    "rx-%u", index);
720 	if (error) {
721 		kobject_put(kobj);
722 		return error;
723 	}
724 
725 	kobject_uevent(kobj, KOBJ_ADD);
726 	dev_hold(queue->dev);
727 
728 	return error;
729 }
730 #endif /* CONFIG_RPS */
731 
732 int
733 net_rx_queue_update_kobjects(struct net_device *net, int old_num, int new_num)
734 {
735 #ifdef CONFIG_RPS
736 	int i;
737 	int error = 0;
738 
739 	for (i = old_num; i < new_num; i++) {
740 		error = rx_queue_add_kobject(net, i);
741 		if (error) {
742 			new_num = old_num;
743 			break;
744 		}
745 	}
746 
747 	while (--i >= new_num)
748 		kobject_put(&net->_rx[i].kobj);
749 
750 	return error;
751 #else
752 	return 0;
753 #endif
754 }
755 
756 #ifdef CONFIG_SYSFS
757 /*
758  * netdev_queue sysfs structures and functions.
759  */
760 struct netdev_queue_attribute {
761 	struct attribute attr;
762 	ssize_t (*show)(struct netdev_queue *queue,
763 	    struct netdev_queue_attribute *attr, char *buf);
764 	ssize_t (*store)(struct netdev_queue *queue,
765 	    struct netdev_queue_attribute *attr, const char *buf, size_t len);
766 };
767 #define to_netdev_queue_attr(_attr) container_of(_attr,		\
768     struct netdev_queue_attribute, attr)
769 
770 #define to_netdev_queue(obj) container_of(obj, struct netdev_queue, kobj)
771 
772 static ssize_t netdev_queue_attr_show(struct kobject *kobj,
773 				      struct attribute *attr, char *buf)
774 {
775 	struct netdev_queue_attribute *attribute = to_netdev_queue_attr(attr);
776 	struct netdev_queue *queue = to_netdev_queue(kobj);
777 
778 	if (!attribute->show)
779 		return -EIO;
780 
781 	return attribute->show(queue, attribute, buf);
782 }
783 
784 static ssize_t netdev_queue_attr_store(struct kobject *kobj,
785 				       struct attribute *attr,
786 				       const char *buf, size_t count)
787 {
788 	struct netdev_queue_attribute *attribute = to_netdev_queue_attr(attr);
789 	struct netdev_queue *queue = to_netdev_queue(kobj);
790 
791 	if (!attribute->store)
792 		return -EIO;
793 
794 	return attribute->store(queue, attribute, buf, count);
795 }
796 
797 static const struct sysfs_ops netdev_queue_sysfs_ops = {
798 	.show = netdev_queue_attr_show,
799 	.store = netdev_queue_attr_store,
800 };
801 
802 static ssize_t show_trans_timeout(struct netdev_queue *queue,
803 				  struct netdev_queue_attribute *attribute,
804 				  char *buf)
805 {
806 	unsigned long trans_timeout;
807 
808 	spin_lock_irq(&queue->_xmit_lock);
809 	trans_timeout = queue->trans_timeout;
810 	spin_unlock_irq(&queue->_xmit_lock);
811 
812 	return sprintf(buf, "%lu", trans_timeout);
813 }
814 
815 static struct netdev_queue_attribute queue_trans_timeout =
816 	__ATTR(tx_timeout, S_IRUGO, show_trans_timeout, NULL);
817 
818 #ifdef CONFIG_BQL
819 /*
820  * Byte queue limits sysfs structures and functions.
821  */
822 static ssize_t bql_show(char *buf, unsigned int value)
823 {
824 	return sprintf(buf, "%u\n", value);
825 }
826 
827 static ssize_t bql_set(const char *buf, const size_t count,
828 		       unsigned int *pvalue)
829 {
830 	unsigned int value;
831 	int err;
832 
833 	if (!strcmp(buf, "max") || !strcmp(buf, "max\n"))
834 		value = DQL_MAX_LIMIT;
835 	else {
836 		err = kstrtouint(buf, 10, &value);
837 		if (err < 0)
838 			return err;
839 		if (value > DQL_MAX_LIMIT)
840 			return -EINVAL;
841 	}
842 
843 	*pvalue = value;
844 
845 	return count;
846 }
847 
848 static ssize_t bql_show_hold_time(struct netdev_queue *queue,
849 				  struct netdev_queue_attribute *attr,
850 				  char *buf)
851 {
852 	struct dql *dql = &queue->dql;
853 
854 	return sprintf(buf, "%u\n", jiffies_to_msecs(dql->slack_hold_time));
855 }
856 
857 static ssize_t bql_set_hold_time(struct netdev_queue *queue,
858 				 struct netdev_queue_attribute *attribute,
859 				 const char *buf, size_t len)
860 {
861 	struct dql *dql = &queue->dql;
862 	unsigned int value;
863 	int err;
864 
865 	err = kstrtouint(buf, 10, &value);
866 	if (err < 0)
867 		return err;
868 
869 	dql->slack_hold_time = msecs_to_jiffies(value);
870 
871 	return len;
872 }
873 
874 static struct netdev_queue_attribute bql_hold_time_attribute =
875 	__ATTR(hold_time, S_IRUGO | S_IWUSR, bql_show_hold_time,
876 	    bql_set_hold_time);
877 
878 static ssize_t bql_show_inflight(struct netdev_queue *queue,
879 				 struct netdev_queue_attribute *attr,
880 				 char *buf)
881 {
882 	struct dql *dql = &queue->dql;
883 
884 	return sprintf(buf, "%u\n", dql->num_queued - dql->num_completed);
885 }
886 
887 static struct netdev_queue_attribute bql_inflight_attribute =
888 	__ATTR(inflight, S_IRUGO, bql_show_inflight, NULL);
889 
890 #define BQL_ATTR(NAME, FIELD)						\
891 static ssize_t bql_show_ ## NAME(struct netdev_queue *queue,		\
892 				 struct netdev_queue_attribute *attr,	\
893 				 char *buf)				\
894 {									\
895 	return bql_show(buf, queue->dql.FIELD);				\
896 }									\
897 									\
898 static ssize_t bql_set_ ## NAME(struct netdev_queue *queue,		\
899 				struct netdev_queue_attribute *attr,	\
900 				const char *buf, size_t len)		\
901 {									\
902 	return bql_set(buf, len, &queue->dql.FIELD);			\
903 }									\
904 									\
905 static struct netdev_queue_attribute bql_ ## NAME ## _attribute =	\
906 	__ATTR(NAME, S_IRUGO | S_IWUSR, bql_show_ ## NAME,		\
907 	    bql_set_ ## NAME);
908 
909 BQL_ATTR(limit, limit)
910 BQL_ATTR(limit_max, max_limit)
911 BQL_ATTR(limit_min, min_limit)
912 
913 static struct attribute *dql_attrs[] = {
914 	&bql_limit_attribute.attr,
915 	&bql_limit_max_attribute.attr,
916 	&bql_limit_min_attribute.attr,
917 	&bql_hold_time_attribute.attr,
918 	&bql_inflight_attribute.attr,
919 	NULL
920 };
921 
922 static struct attribute_group dql_group = {
923 	.name  = "byte_queue_limits",
924 	.attrs  = dql_attrs,
925 };
926 #endif /* CONFIG_BQL */
927 
928 #ifdef CONFIG_XPS
929 static inline unsigned int get_netdev_queue_index(struct netdev_queue *queue)
930 {
931 	struct net_device *dev = queue->dev;
932 	int i;
933 
934 	for (i = 0; i < dev->num_tx_queues; i++)
935 		if (queue == &dev->_tx[i])
936 			break;
937 
938 	BUG_ON(i >= dev->num_tx_queues);
939 
940 	return i;
941 }
942 
943 
944 static ssize_t show_xps_map(struct netdev_queue *queue,
945 			    struct netdev_queue_attribute *attribute, char *buf)
946 {
947 	struct net_device *dev = queue->dev;
948 	struct xps_dev_maps *dev_maps;
949 	cpumask_var_t mask;
950 	unsigned long index;
951 	size_t len = 0;
952 	int i;
953 
954 	if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
955 		return -ENOMEM;
956 
957 	index = get_netdev_queue_index(queue);
958 
959 	rcu_read_lock();
960 	dev_maps = rcu_dereference(dev->xps_maps);
961 	if (dev_maps) {
962 		for_each_possible_cpu(i) {
963 			struct xps_map *map =
964 			    rcu_dereference(dev_maps->cpu_map[i]);
965 			if (map) {
966 				int j;
967 				for (j = 0; j < map->len; j++) {
968 					if (map->queues[j] == index) {
969 						cpumask_set_cpu(i, mask);
970 						break;
971 					}
972 				}
973 			}
974 		}
975 	}
976 	rcu_read_unlock();
977 
978 	len += cpumask_scnprintf(buf + len, PAGE_SIZE, mask);
979 	if (PAGE_SIZE - len < 3) {
980 		free_cpumask_var(mask);
981 		return -EINVAL;
982 	}
983 
984 	free_cpumask_var(mask);
985 	len += sprintf(buf + len, "\n");
986 	return len;
987 }
988 
989 static DEFINE_MUTEX(xps_map_mutex);
990 #define xmap_dereference(P)		\
991 	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
992 
993 static void xps_queue_release(struct netdev_queue *queue)
994 {
995 	struct net_device *dev = queue->dev;
996 	struct xps_dev_maps *dev_maps;
997 	struct xps_map *map;
998 	unsigned long index;
999 	int i, pos, nonempty = 0;
1000 
1001 	index = get_netdev_queue_index(queue);
1002 
1003 	mutex_lock(&xps_map_mutex);
1004 	dev_maps = xmap_dereference(dev->xps_maps);
1005 
1006 	if (dev_maps) {
1007 		for_each_possible_cpu(i) {
1008 			map = xmap_dereference(dev_maps->cpu_map[i]);
1009 			if (!map)
1010 				continue;
1011 
1012 			for (pos = 0; pos < map->len; pos++)
1013 				if (map->queues[pos] == index)
1014 					break;
1015 
1016 			if (pos < map->len) {
1017 				if (map->len > 1)
1018 					map->queues[pos] =
1019 					    map->queues[--map->len];
1020 				else {
1021 					RCU_INIT_POINTER(dev_maps->cpu_map[i],
1022 					    NULL);
1023 					kfree_rcu(map, rcu);
1024 					map = NULL;
1025 				}
1026 			}
1027 			if (map)
1028 				nonempty = 1;
1029 		}
1030 
1031 		if (!nonempty) {
1032 			RCU_INIT_POINTER(dev->xps_maps, NULL);
1033 			kfree_rcu(dev_maps, rcu);
1034 		}
1035 	}
1036 	mutex_unlock(&xps_map_mutex);
1037 }
1038 
1039 static ssize_t store_xps_map(struct netdev_queue *queue,
1040 		      struct netdev_queue_attribute *attribute,
1041 		      const char *buf, size_t len)
1042 {
1043 	struct net_device *dev = queue->dev;
1044 	cpumask_var_t mask;
1045 	int err, i, cpu, pos, map_len, alloc_len, need_set;
1046 	unsigned long index;
1047 	struct xps_map *map, *new_map;
1048 	struct xps_dev_maps *dev_maps, *new_dev_maps;
1049 	int nonempty = 0;
1050 	int numa_node_id = -2;
1051 
1052 	if (!capable(CAP_NET_ADMIN))
1053 		return -EPERM;
1054 
1055 	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
1056 		return -ENOMEM;
1057 
1058 	index = get_netdev_queue_index(queue);
1059 
1060 	err = bitmap_parse(buf, len, cpumask_bits(mask), nr_cpumask_bits);
1061 	if (err) {
1062 		free_cpumask_var(mask);
1063 		return err;
1064 	}
1065 
1066 	new_dev_maps = kzalloc(max_t(unsigned int,
1067 	    XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES), GFP_KERNEL);
1068 	if (!new_dev_maps) {
1069 		free_cpumask_var(mask);
1070 		return -ENOMEM;
1071 	}
1072 
1073 	mutex_lock(&xps_map_mutex);
1074 
1075 	dev_maps = xmap_dereference(dev->xps_maps);
1076 
1077 	for_each_possible_cpu(cpu) {
1078 		map = dev_maps ?
1079 			xmap_dereference(dev_maps->cpu_map[cpu]) : NULL;
1080 		new_map = map;
1081 		if (map) {
1082 			for (pos = 0; pos < map->len; pos++)
1083 				if (map->queues[pos] == index)
1084 					break;
1085 			map_len = map->len;
1086 			alloc_len = map->alloc_len;
1087 		} else
1088 			pos = map_len = alloc_len = 0;
1089 
1090 		need_set = cpumask_test_cpu(cpu, mask) && cpu_online(cpu);
1091 #ifdef CONFIG_NUMA
1092 		if (need_set) {
1093 			if (numa_node_id == -2)
1094 				numa_node_id = cpu_to_node(cpu);
1095 			else if (numa_node_id != cpu_to_node(cpu))
1096 				numa_node_id = -1;
1097 		}
1098 #endif
1099 		if (need_set && pos >= map_len) {
1100 			/* Need to add queue to this CPU's map */
1101 			if (map_len >= alloc_len) {
1102 				alloc_len = alloc_len ?
1103 				    2 * alloc_len : XPS_MIN_MAP_ALLOC;
1104 				new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len),
1105 						       GFP_KERNEL,
1106 						       cpu_to_node(cpu));
1107 				if (!new_map)
1108 					goto error;
1109 				new_map->alloc_len = alloc_len;
1110 				for (i = 0; i < map_len; i++)
1111 					new_map->queues[i] = map->queues[i];
1112 				new_map->len = map_len;
1113 			}
1114 			new_map->queues[new_map->len++] = index;
1115 		} else if (!need_set && pos < map_len) {
1116 			/* Need to remove queue from this CPU's map */
1117 			if (map_len > 1)
1118 				new_map->queues[pos] =
1119 				    new_map->queues[--new_map->len];
1120 			else
1121 				new_map = NULL;
1122 		}
1123 		RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], new_map);
1124 	}
1125 
1126 	/* Cleanup old maps */
1127 	for_each_possible_cpu(cpu) {
1128 		map = dev_maps ?
1129 			xmap_dereference(dev_maps->cpu_map[cpu]) : NULL;
1130 		if (map && xmap_dereference(new_dev_maps->cpu_map[cpu]) != map)
1131 			kfree_rcu(map, rcu);
1132 		if (new_dev_maps->cpu_map[cpu])
1133 			nonempty = 1;
1134 	}
1135 
1136 	if (nonempty) {
1137 		rcu_assign_pointer(dev->xps_maps, new_dev_maps);
1138 	} else {
1139 		kfree(new_dev_maps);
1140 		RCU_INIT_POINTER(dev->xps_maps, NULL);
1141 	}
1142 
1143 	if (dev_maps)
1144 		kfree_rcu(dev_maps, rcu);
1145 
1146 	netdev_queue_numa_node_write(queue, (numa_node_id >= 0) ? numa_node_id :
1147 					    NUMA_NO_NODE);
1148 
1149 	mutex_unlock(&xps_map_mutex);
1150 
1151 	free_cpumask_var(mask);
1152 	return len;
1153 
1154 error:
1155 	mutex_unlock(&xps_map_mutex);
1156 
1157 	if (new_dev_maps)
1158 		for_each_possible_cpu(i)
1159 			kfree(rcu_dereference_protected(
1160 				new_dev_maps->cpu_map[i],
1161 				1));
1162 	kfree(new_dev_maps);
1163 	free_cpumask_var(mask);
1164 	return -ENOMEM;
1165 }
1166 
1167 static struct netdev_queue_attribute xps_cpus_attribute =
1168     __ATTR(xps_cpus, S_IRUGO | S_IWUSR, show_xps_map, store_xps_map);
1169 #endif /* CONFIG_XPS */
1170 
1171 static struct attribute *netdev_queue_default_attrs[] = {
1172 	&queue_trans_timeout.attr,
1173 #ifdef CONFIG_XPS
1174 	&xps_cpus_attribute.attr,
1175 #endif
1176 	NULL
1177 };
1178 
1179 static void netdev_queue_release(struct kobject *kobj)
1180 {
1181 	struct netdev_queue *queue = to_netdev_queue(kobj);
1182 
1183 #ifdef CONFIG_XPS
1184 	xps_queue_release(queue);
1185 #endif
1186 
1187 	memset(kobj, 0, sizeof(*kobj));
1188 	dev_put(queue->dev);
1189 }
1190 
1191 static struct kobj_type netdev_queue_ktype = {
1192 	.sysfs_ops = &netdev_queue_sysfs_ops,
1193 	.release = netdev_queue_release,
1194 	.default_attrs = netdev_queue_default_attrs,
1195 };
1196 
1197 static int netdev_queue_add_kobject(struct net_device *net, int index)
1198 {
1199 	struct netdev_queue *queue = net->_tx + index;
1200 	struct kobject *kobj = &queue->kobj;
1201 	int error = 0;
1202 
1203 	kobj->kset = net->queues_kset;
1204 	error = kobject_init_and_add(kobj, &netdev_queue_ktype, NULL,
1205 	    "tx-%u", index);
1206 	if (error)
1207 		goto exit;
1208 
1209 #ifdef CONFIG_BQL
1210 	error = sysfs_create_group(kobj, &dql_group);
1211 	if (error)
1212 		goto exit;
1213 #endif
1214 
1215 	kobject_uevent(kobj, KOBJ_ADD);
1216 	dev_hold(queue->dev);
1217 
1218 	return 0;
1219 exit:
1220 	kobject_put(kobj);
1221 	return error;
1222 }
1223 #endif /* CONFIG_SYSFS */
1224 
1225 int
1226 netdev_queue_update_kobjects(struct net_device *net, int old_num, int new_num)
1227 {
1228 #ifdef CONFIG_SYSFS
1229 	int i;
1230 	int error = 0;
1231 
1232 	for (i = old_num; i < new_num; i++) {
1233 		error = netdev_queue_add_kobject(net, i);
1234 		if (error) {
1235 			new_num = old_num;
1236 			break;
1237 		}
1238 	}
1239 
1240 	while (--i >= new_num) {
1241 		struct netdev_queue *queue = net->_tx + i;
1242 
1243 #ifdef CONFIG_BQL
1244 		sysfs_remove_group(&queue->kobj, &dql_group);
1245 #endif
1246 		kobject_put(&queue->kobj);
1247 	}
1248 
1249 	return error;
1250 #else
1251 	return 0;
1252 #endif /* CONFIG_SYSFS */
1253 }
1254 
1255 static int register_queue_kobjects(struct net_device *net)
1256 {
1257 	int error = 0, txq = 0, rxq = 0, real_rx = 0, real_tx = 0;
1258 
1259 #ifdef CONFIG_SYSFS
1260 	net->queues_kset = kset_create_and_add("queues",
1261 	    NULL, &net->dev.kobj);
1262 	if (!net->queues_kset)
1263 		return -ENOMEM;
1264 #endif
1265 
1266 #ifdef CONFIG_RPS
1267 	real_rx = net->real_num_rx_queues;
1268 #endif
1269 	real_tx = net->real_num_tx_queues;
1270 
1271 	error = net_rx_queue_update_kobjects(net, 0, real_rx);
1272 	if (error)
1273 		goto error;
1274 	rxq = real_rx;
1275 
1276 	error = netdev_queue_update_kobjects(net, 0, real_tx);
1277 	if (error)
1278 		goto error;
1279 	txq = real_tx;
1280 
1281 	return 0;
1282 
1283 error:
1284 	netdev_queue_update_kobjects(net, txq, 0);
1285 	net_rx_queue_update_kobjects(net, rxq, 0);
1286 	return error;
1287 }
1288 
1289 static void remove_queue_kobjects(struct net_device *net)
1290 {
1291 	int real_rx = 0, real_tx = 0;
1292 
1293 #ifdef CONFIG_RPS
1294 	real_rx = net->real_num_rx_queues;
1295 #endif
1296 	real_tx = net->real_num_tx_queues;
1297 
1298 	net_rx_queue_update_kobjects(net, real_rx, 0);
1299 	netdev_queue_update_kobjects(net, real_tx, 0);
1300 #ifdef CONFIG_SYSFS
1301 	kset_unregister(net->queues_kset);
1302 #endif
1303 }
1304 
1305 static void *net_grab_current_ns(void)
1306 {
1307 	struct net *ns = current->nsproxy->net_ns;
1308 #ifdef CONFIG_NET_NS
1309 	if (ns)
1310 		atomic_inc(&ns->passive);
1311 #endif
1312 	return ns;
1313 }
1314 
1315 static const void *net_initial_ns(void)
1316 {
1317 	return &init_net;
1318 }
1319 
1320 static const void *net_netlink_ns(struct sock *sk)
1321 {
1322 	return sock_net(sk);
1323 }
1324 
1325 struct kobj_ns_type_operations net_ns_type_operations = {
1326 	.type = KOBJ_NS_TYPE_NET,
1327 	.grab_current_ns = net_grab_current_ns,
1328 	.netlink_ns = net_netlink_ns,
1329 	.initial_ns = net_initial_ns,
1330 	.drop_ns = net_drop_ns,
1331 };
1332 EXPORT_SYMBOL_GPL(net_ns_type_operations);
1333 
1334 #ifdef CONFIG_HOTPLUG
1335 static int netdev_uevent(struct device *d, struct kobj_uevent_env *env)
1336 {
1337 	struct net_device *dev = to_net_dev(d);
1338 	int retval;
1339 
1340 	/* pass interface to uevent. */
1341 	retval = add_uevent_var(env, "INTERFACE=%s", dev->name);
1342 	if (retval)
1343 		goto exit;
1344 
1345 	/* pass ifindex to uevent.
1346 	 * ifindex is useful as it won't change (interface name may change)
1347 	 * and is what RtNetlink uses natively. */
1348 	retval = add_uevent_var(env, "IFINDEX=%d", dev->ifindex);
1349 
1350 exit:
1351 	return retval;
1352 }
1353 #endif
1354 
1355 /*
1356  *	netdev_release -- destroy and free a dead device.
1357  *	Called when last reference to device kobject is gone.
1358  */
1359 static void netdev_release(struct device *d)
1360 {
1361 	struct net_device *dev = to_net_dev(d);
1362 
1363 	BUG_ON(dev->reg_state != NETREG_RELEASED);
1364 
1365 	kfree(dev->ifalias);
1366 	kfree((char *)dev - dev->padded);
1367 }
1368 
1369 static const void *net_namespace(struct device *d)
1370 {
1371 	struct net_device *dev;
1372 	dev = container_of(d, struct net_device, dev);
1373 	return dev_net(dev);
1374 }
1375 
1376 static struct class net_class = {
1377 	.name = "net",
1378 	.dev_release = netdev_release,
1379 #ifdef CONFIG_SYSFS
1380 	.dev_attrs = net_class_attributes,
1381 #endif /* CONFIG_SYSFS */
1382 #ifdef CONFIG_HOTPLUG
1383 	.dev_uevent = netdev_uevent,
1384 #endif
1385 	.ns_type = &net_ns_type_operations,
1386 	.namespace = net_namespace,
1387 };
1388 
1389 /* Delete sysfs entries but hold kobject reference until after all
1390  * netdev references are gone.
1391  */
1392 void netdev_unregister_kobject(struct net_device * net)
1393 {
1394 	struct device *dev = &(net->dev);
1395 
1396 	kobject_get(&dev->kobj);
1397 
1398 	remove_queue_kobjects(net);
1399 
1400 	device_del(dev);
1401 }
1402 
1403 /* Create sysfs entries for network device. */
1404 int netdev_register_kobject(struct net_device *net)
1405 {
1406 	struct device *dev = &(net->dev);
1407 	const struct attribute_group **groups = net->sysfs_groups;
1408 	int error = 0;
1409 
1410 	device_initialize(dev);
1411 	dev->class = &net_class;
1412 	dev->platform_data = net;
1413 	dev->groups = groups;
1414 
1415 	dev_set_name(dev, "%s", net->name);
1416 
1417 #ifdef CONFIG_SYSFS
1418 	/* Allow for a device specific group */
1419 	if (*groups)
1420 		groups++;
1421 
1422 	*groups++ = &netstat_group;
1423 
1424 #if IS_ENABLED(CONFIG_WIRELESS_EXT) || IS_ENABLED(CONFIG_CFG80211)
1425 	if (net->ieee80211_ptr)
1426 		*groups++ = &wireless_group;
1427 #if IS_ENABLED(CONFIG_WIRELESS_EXT)
1428 	else if (net->wireless_handlers)
1429 		*groups++ = &wireless_group;
1430 #endif
1431 #endif
1432 #endif /* CONFIG_SYSFS */
1433 
1434 	error = device_add(dev);
1435 	if (error)
1436 		return error;
1437 
1438 	error = register_queue_kobjects(net);
1439 	if (error) {
1440 		device_del(dev);
1441 		return error;
1442 	}
1443 
1444 	return error;
1445 }
1446 
1447 int netdev_class_create_file(struct class_attribute *class_attr)
1448 {
1449 	return class_create_file(&net_class, class_attr);
1450 }
1451 EXPORT_SYMBOL(netdev_class_create_file);
1452 
1453 void netdev_class_remove_file(struct class_attribute *class_attr)
1454 {
1455 	class_remove_file(&net_class, class_attr);
1456 }
1457 EXPORT_SYMBOL(netdev_class_remove_file);
1458 
1459 int netdev_kobject_init(void)
1460 {
1461 	kobj_ns_type_register(&net_ns_type_operations);
1462 	return class_register(&net_class);
1463 }
1464