xref: /linux/net/core/dev_ioctl.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kmod.h>
3 #include <linux/netdevice.h>
4 #include <linux/inetdevice.h>
5 #include <linux/etherdevice.h>
6 #include <linux/rtnetlink.h>
7 #include <linux/net_tstamp.h>
8 #include <linux/phylib_stubs.h>
9 #include <linux/wireless.h>
10 #include <linux/if_bridge.h>
11 #include <net/dsa_stubs.h>
12 #include <net/wext.h>
13 
14 #include "dev.h"
15 
16 /*
17  *	Map an interface index to its name (SIOCGIFNAME)
18  */
19 
20 /*
21  *	We need this ioctl for efficient implementation of the
22  *	if_indextoname() function required by the IPv6 API.  Without
23  *	it, we would have to search all the interfaces to find a
24  *	match.  --pb
25  */
26 
27 static int dev_ifname(struct net *net, struct ifreq *ifr)
28 {
29 	ifr->ifr_name[IFNAMSIZ-1] = 0;
30 	return netdev_get_name(net, ifr->ifr_name, ifr->ifr_ifindex);
31 }
32 
33 /*
34  *	Perform a SIOCGIFCONF call. This structure will change
35  *	size eventually, and there is nothing I can do about it.
36  *	Thus we will need a 'compatibility mode'.
37  */
38 int dev_ifconf(struct net *net, struct ifconf __user *uifc)
39 {
40 	struct net_device *dev;
41 	void __user *pos;
42 	size_t size;
43 	int len, total = 0, done;
44 
45 	/* both the ifconf and the ifreq structures are slightly different */
46 	if (in_compat_syscall()) {
47 		struct compat_ifconf ifc32;
48 
49 		if (copy_from_user(&ifc32, uifc, sizeof(struct compat_ifconf)))
50 			return -EFAULT;
51 
52 		pos = compat_ptr(ifc32.ifcbuf);
53 		len = ifc32.ifc_len;
54 		size = sizeof(struct compat_ifreq);
55 	} else {
56 		struct ifconf ifc;
57 
58 		if (copy_from_user(&ifc, uifc, sizeof(struct ifconf)))
59 			return -EFAULT;
60 
61 		pos = ifc.ifc_buf;
62 		len = ifc.ifc_len;
63 		size = sizeof(struct ifreq);
64 	}
65 
66 	/* Loop over the interfaces, and write an info block for each. */
67 	rtnl_net_lock(net);
68 	for_each_netdev(net, dev) {
69 		if (!pos)
70 			done = inet_gifconf(dev, NULL, 0, size);
71 		else
72 			done = inet_gifconf(dev, pos + total,
73 					    len - total, size);
74 		if (done < 0) {
75 			rtnl_net_unlock(net);
76 			return -EFAULT;
77 		}
78 		total += done;
79 	}
80 	rtnl_net_unlock(net);
81 
82 	return put_user(total, &uifc->ifc_len);
83 }
84 
85 static int dev_getifmap(struct net_device *dev, struct ifreq *ifr)
86 {
87 	struct ifmap *ifmap = &ifr->ifr_map;
88 
89 	if (in_compat_syscall()) {
90 		struct compat_ifmap *cifmap = (struct compat_ifmap *)ifmap;
91 
92 		cifmap->mem_start = dev->mem_start;
93 		cifmap->mem_end   = dev->mem_end;
94 		cifmap->base_addr = dev->base_addr;
95 		cifmap->irq       = dev->irq;
96 		cifmap->dma       = dev->dma;
97 		cifmap->port      = dev->if_port;
98 
99 		return 0;
100 	}
101 
102 	ifmap->mem_start  = dev->mem_start;
103 	ifmap->mem_end    = dev->mem_end;
104 	ifmap->base_addr  = dev->base_addr;
105 	ifmap->irq        = dev->irq;
106 	ifmap->dma        = dev->dma;
107 	ifmap->port       = dev->if_port;
108 
109 	return 0;
110 }
111 
112 static int dev_setifmap(struct net_device *dev, struct ifreq *ifr)
113 {
114 	struct compat_ifmap *cifmap = (struct compat_ifmap *)&ifr->ifr_map;
115 
116 	if (!dev->netdev_ops->ndo_set_config)
117 		return -EOPNOTSUPP;
118 
119 	if (in_compat_syscall()) {
120 		struct ifmap ifmap = {
121 			.mem_start  = cifmap->mem_start,
122 			.mem_end    = cifmap->mem_end,
123 			.base_addr  = cifmap->base_addr,
124 			.irq        = cifmap->irq,
125 			.dma        = cifmap->dma,
126 			.port       = cifmap->port,
127 		};
128 
129 		return dev->netdev_ops->ndo_set_config(dev, &ifmap);
130 	}
131 
132 	return dev->netdev_ops->ndo_set_config(dev, &ifr->ifr_map);
133 }
134 
135 /*
136  *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
137  */
138 static int dev_ifsioc_locked(struct net *net, struct ifreq *ifr, unsigned int cmd)
139 {
140 	int err;
141 	struct net_device *dev = dev_get_by_name_rcu(net, ifr->ifr_name);
142 
143 	if (!dev)
144 		return -ENODEV;
145 
146 	switch (cmd) {
147 	case SIOCGIFFLAGS:	/* Get interface flags */
148 		ifr->ifr_flags = (short) dev_get_flags(dev);
149 		return 0;
150 
151 	case SIOCGIFMETRIC:	/* Get the metric on the interface
152 				   (currently unused) */
153 		ifr->ifr_metric = 0;
154 		return 0;
155 
156 	case SIOCGIFMTU:	/* Get the MTU of a device */
157 		ifr->ifr_mtu = dev->mtu;
158 		return 0;
159 
160 	case SIOCGIFSLAVE:
161 		err = -EINVAL;
162 		break;
163 
164 	case SIOCGIFMAP:
165 		return dev_getifmap(dev, ifr);
166 
167 	case SIOCGIFINDEX:
168 		ifr->ifr_ifindex = dev->ifindex;
169 		return 0;
170 
171 	case SIOCGIFTXQLEN:
172 		ifr->ifr_qlen = dev->tx_queue_len;
173 		return 0;
174 
175 	default:
176 		/* dev_ioctl() should ensure this case
177 		 * is never reached
178 		 */
179 		WARN_ON(1);
180 		err = -ENOTTY;
181 		break;
182 
183 	}
184 	return err;
185 }
186 
187 static int net_hwtstamp_validate(const struct kernel_hwtstamp_config *cfg)
188 {
189 	enum hwtstamp_tx_types tx_type;
190 	enum hwtstamp_rx_filters rx_filter;
191 	int tx_type_valid = 0;
192 	int rx_filter_valid = 0;
193 
194 	if (cfg->flags & ~HWTSTAMP_FLAG_MASK)
195 		return -EINVAL;
196 
197 	tx_type = cfg->tx_type;
198 	rx_filter = cfg->rx_filter;
199 
200 	switch (tx_type) {
201 	case HWTSTAMP_TX_OFF:
202 	case HWTSTAMP_TX_ON:
203 	case HWTSTAMP_TX_ONESTEP_SYNC:
204 	case HWTSTAMP_TX_ONESTEP_P2P:
205 		tx_type_valid = 1;
206 		break;
207 	case __HWTSTAMP_TX_CNT:
208 		/* not a real value */
209 		break;
210 	}
211 
212 	switch (rx_filter) {
213 	case HWTSTAMP_FILTER_NONE:
214 	case HWTSTAMP_FILTER_ALL:
215 	case HWTSTAMP_FILTER_SOME:
216 	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
217 	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
218 	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
219 	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
220 	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
221 	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
222 	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
223 	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
224 	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
225 	case HWTSTAMP_FILTER_PTP_V2_EVENT:
226 	case HWTSTAMP_FILTER_PTP_V2_SYNC:
227 	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
228 	case HWTSTAMP_FILTER_NTP_ALL:
229 		rx_filter_valid = 1;
230 		break;
231 	case __HWTSTAMP_FILTER_CNT:
232 		/* not a real value */
233 		break;
234 	}
235 
236 	if (!tx_type_valid || !rx_filter_valid)
237 		return -ERANGE;
238 
239 	return 0;
240 }
241 
242 static int dev_eth_ioctl(struct net_device *dev,
243 			 struct ifreq *ifr, unsigned int cmd)
244 {
245 	const struct net_device_ops *ops = dev->netdev_ops;
246 
247 	if (!ops->ndo_eth_ioctl)
248 		return -EOPNOTSUPP;
249 
250 	if (!netif_device_present(dev))
251 		return -ENODEV;
252 
253 	return ops->ndo_eth_ioctl(dev, ifr, cmd);
254 }
255 
256 /**
257  * dev_get_hwtstamp_phylib() - Get hardware timestamping settings of NIC
258  *	or of attached phylib PHY
259  * @dev: Network device
260  * @cfg: Timestamping configuration structure
261  *
262  * Helper for calling the default hardware provider timestamping.
263  *
264  * Note: phy_mii_ioctl() only handles SIOCSHWTSTAMP (not SIOCGHWTSTAMP), and
265  * there only exists a phydev->mii_ts->hwtstamp() method. So this will return
266  * -EOPNOTSUPP for phylib for now, which is still more accurate than letting
267  * the netdev handle the GET request.
268  */
269 static int dev_get_hwtstamp_phylib(struct net_device *dev,
270 				   struct kernel_hwtstamp_config *cfg)
271 {
272 	if (phy_is_default_hwtstamp(dev->phydev))
273 		return phy_hwtstamp_get(dev->phydev, cfg);
274 
275 	return dev->netdev_ops->ndo_hwtstamp_get(dev, cfg);
276 }
277 
278 static int dev_get_hwtstamp(struct net_device *dev, struct ifreq *ifr)
279 {
280 	const struct net_device_ops *ops = dev->netdev_ops;
281 	struct kernel_hwtstamp_config kernel_cfg = {};
282 	struct hwtstamp_config cfg;
283 	int err;
284 
285 	if (!ops->ndo_hwtstamp_get)
286 		return dev_eth_ioctl(dev, ifr, SIOCGHWTSTAMP); /* legacy */
287 
288 	if (!netif_device_present(dev))
289 		return -ENODEV;
290 
291 	kernel_cfg.ifr = ifr;
292 	err = dev_get_hwtstamp_phylib(dev, &kernel_cfg);
293 	if (err)
294 		return err;
295 
296 	/* If the request was resolved through an unconverted driver, omit
297 	 * the copy_to_user(), since the implementation has already done that
298 	 */
299 	if (!kernel_cfg.copied_to_user) {
300 		hwtstamp_config_from_kernel(&cfg, &kernel_cfg);
301 
302 		if (copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)))
303 			return -EFAULT;
304 	}
305 
306 	return 0;
307 }
308 
309 /**
310  * dev_set_hwtstamp_phylib() - Change hardware timestamping of NIC
311  *	or of attached phylib PHY
312  * @dev: Network device
313  * @cfg: Timestamping configuration structure
314  * @extack: Netlink extended ack message structure, for error reporting
315  *
316  * Helper for enforcing a common policy that phylib timestamping, if available,
317  * should take precedence in front of hardware timestamping provided by the
318  * netdev. If the netdev driver needs to perform specific actions even for PHY
319  * timestamping to work properly (a switch port must trap the timestamped
320  * frames and not forward them), it must set dev->see_all_hwtstamp_requests.
321  */
322 int dev_set_hwtstamp_phylib(struct net_device *dev,
323 			    struct kernel_hwtstamp_config *cfg,
324 			    struct netlink_ext_ack *extack)
325 {
326 	const struct net_device_ops *ops = dev->netdev_ops;
327 	bool phy_ts = phy_is_default_hwtstamp(dev->phydev);
328 	struct kernel_hwtstamp_config old_cfg = {};
329 	bool changed = false;
330 	int err;
331 
332 	cfg->source = phy_ts ? HWTSTAMP_SOURCE_PHYLIB : HWTSTAMP_SOURCE_NETDEV;
333 
334 	if (phy_ts && dev->see_all_hwtstamp_requests) {
335 		err = ops->ndo_hwtstamp_get(dev, &old_cfg);
336 		if (err)
337 			return err;
338 	}
339 
340 	if (!phy_ts || dev->see_all_hwtstamp_requests) {
341 		err = ops->ndo_hwtstamp_set(dev, cfg, extack);
342 		if (err) {
343 			if (extack->_msg)
344 				netdev_err(dev, "%s\n", extack->_msg);
345 			return err;
346 		}
347 	}
348 
349 	if (phy_ts && dev->see_all_hwtstamp_requests)
350 		changed = kernel_hwtstamp_config_changed(&old_cfg, cfg);
351 
352 	if (phy_ts) {
353 		err = phy_hwtstamp_set(dev->phydev, cfg, extack);
354 		if (err) {
355 			if (changed)
356 				ops->ndo_hwtstamp_set(dev, &old_cfg, NULL);
357 			return err;
358 		}
359 	}
360 
361 	return 0;
362 }
363 
364 static int dev_set_hwtstamp(struct net_device *dev, struct ifreq *ifr)
365 {
366 	const struct net_device_ops *ops = dev->netdev_ops;
367 	struct kernel_hwtstamp_config kernel_cfg = {};
368 	struct netlink_ext_ack extack = {};
369 	struct hwtstamp_config cfg;
370 	int err;
371 
372 	if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
373 		return -EFAULT;
374 
375 	hwtstamp_config_to_kernel(&kernel_cfg, &cfg);
376 	kernel_cfg.ifr = ifr;
377 
378 	err = net_hwtstamp_validate(&kernel_cfg);
379 	if (err)
380 		return err;
381 
382 	err = dsa_conduit_hwtstamp_validate(dev, &kernel_cfg, &extack);
383 	if (err) {
384 		if (extack._msg)
385 			netdev_err(dev, "%s\n", extack._msg);
386 		return err;
387 	}
388 
389 	if (!ops->ndo_hwtstamp_set)
390 		return dev_eth_ioctl(dev, ifr, SIOCSHWTSTAMP); /* legacy */
391 
392 	if (!netif_device_present(dev))
393 		return -ENODEV;
394 
395 	err = dev_set_hwtstamp_phylib(dev, &kernel_cfg, &extack);
396 	if (err)
397 		return err;
398 
399 	/* The driver may have modified the configuration, so copy the
400 	 * updated version of it back to user space
401 	 */
402 	if (!kernel_cfg.copied_to_user) {
403 		hwtstamp_config_from_kernel(&cfg, &kernel_cfg);
404 
405 		if (copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)))
406 			return -EFAULT;
407 	}
408 
409 	return 0;
410 }
411 
412 static int generic_hwtstamp_ioctl_lower(struct net_device *dev, int cmd,
413 					struct kernel_hwtstamp_config *kernel_cfg)
414 {
415 	struct ifreq ifrr;
416 	int err;
417 
418 	strscpy_pad(ifrr.ifr_name, dev->name, IFNAMSIZ);
419 	ifrr.ifr_ifru = kernel_cfg->ifr->ifr_ifru;
420 
421 	err = dev_eth_ioctl(dev, &ifrr, cmd);
422 	if (err)
423 		return err;
424 
425 	kernel_cfg->ifr->ifr_ifru = ifrr.ifr_ifru;
426 	kernel_cfg->copied_to_user = true;
427 
428 	return 0;
429 }
430 
431 int generic_hwtstamp_get_lower(struct net_device *dev,
432 			       struct kernel_hwtstamp_config *kernel_cfg)
433 {
434 	const struct net_device_ops *ops = dev->netdev_ops;
435 
436 	if (!netif_device_present(dev))
437 		return -ENODEV;
438 
439 	if (ops->ndo_hwtstamp_get)
440 		return dev_get_hwtstamp_phylib(dev, kernel_cfg);
441 
442 	/* Legacy path: unconverted lower driver */
443 	return generic_hwtstamp_ioctl_lower(dev, SIOCGHWTSTAMP, kernel_cfg);
444 }
445 EXPORT_SYMBOL(generic_hwtstamp_get_lower);
446 
447 int generic_hwtstamp_set_lower(struct net_device *dev,
448 			       struct kernel_hwtstamp_config *kernel_cfg,
449 			       struct netlink_ext_ack *extack)
450 {
451 	const struct net_device_ops *ops = dev->netdev_ops;
452 
453 	if (!netif_device_present(dev))
454 		return -ENODEV;
455 
456 	if (ops->ndo_hwtstamp_set)
457 		return dev_set_hwtstamp_phylib(dev, kernel_cfg, extack);
458 
459 	/* Legacy path: unconverted lower driver */
460 	return generic_hwtstamp_ioctl_lower(dev, SIOCSHWTSTAMP, kernel_cfg);
461 }
462 EXPORT_SYMBOL(generic_hwtstamp_set_lower);
463 
464 static int dev_siocbond(struct net_device *dev,
465 			struct ifreq *ifr, unsigned int cmd)
466 {
467 	const struct net_device_ops *ops = dev->netdev_ops;
468 
469 	if (ops->ndo_siocbond) {
470 		if (netif_device_present(dev))
471 			return ops->ndo_siocbond(dev, ifr, cmd);
472 		else
473 			return -ENODEV;
474 	}
475 
476 	return -EOPNOTSUPP;
477 }
478 
479 static int dev_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
480 			      void __user *data, unsigned int cmd)
481 {
482 	const struct net_device_ops *ops = dev->netdev_ops;
483 
484 	if (ops->ndo_siocdevprivate) {
485 		if (netif_device_present(dev))
486 			return ops->ndo_siocdevprivate(dev, ifr, data, cmd);
487 		else
488 			return -ENODEV;
489 	}
490 
491 	return -EOPNOTSUPP;
492 }
493 
494 static int dev_siocwandev(struct net_device *dev, struct if_settings *ifs)
495 {
496 	const struct net_device_ops *ops = dev->netdev_ops;
497 
498 	if (ops->ndo_siocwandev) {
499 		if (netif_device_present(dev))
500 			return ops->ndo_siocwandev(dev, ifs);
501 		else
502 			return -ENODEV;
503 	}
504 
505 	return -EOPNOTSUPP;
506 }
507 
508 /*
509  *	Perform the SIOCxIFxxx calls, inside rtnl_lock()
510  */
511 static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,
512 		      unsigned int cmd)
513 {
514 	int err;
515 	struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
516 	const struct net_device_ops *ops;
517 	netdevice_tracker dev_tracker;
518 
519 	if (!dev)
520 		return -ENODEV;
521 
522 	ops = dev->netdev_ops;
523 
524 	switch (cmd) {
525 	case SIOCSIFFLAGS:	/* Set interface flags */
526 		return dev_change_flags(dev, ifr->ifr_flags, NULL);
527 
528 	case SIOCSIFMETRIC:	/* Set the metric on the interface
529 				   (currently unused) */
530 		return -EOPNOTSUPP;
531 
532 	case SIOCSIFMTU:	/* Set the MTU of a device */
533 		return dev_set_mtu(dev, ifr->ifr_mtu);
534 
535 	case SIOCSIFHWADDR:
536 		if (dev->addr_len > sizeof(struct sockaddr))
537 			return -EINVAL;
538 		return dev_set_mac_address_user(dev, &ifr->ifr_hwaddr, NULL);
539 
540 	case SIOCSIFHWBROADCAST:
541 		if (ifr->ifr_hwaddr.sa_family != dev->type)
542 			return -EINVAL;
543 		memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
544 		       min(sizeof(ifr->ifr_hwaddr.sa_data_min),
545 			   (size_t)dev->addr_len));
546 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
547 		return 0;
548 
549 	case SIOCSIFMAP:
550 		return dev_setifmap(dev, ifr);
551 
552 	case SIOCADDMULTI:
553 		if (!ops->ndo_set_rx_mode ||
554 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
555 			return -EINVAL;
556 		if (!netif_device_present(dev))
557 			return -ENODEV;
558 		return dev_mc_add_global(dev, ifr->ifr_hwaddr.sa_data);
559 
560 	case SIOCDELMULTI:
561 		if (!ops->ndo_set_rx_mode ||
562 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
563 			return -EINVAL;
564 		if (!netif_device_present(dev))
565 			return -ENODEV;
566 		return dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);
567 
568 	case SIOCSIFTXQLEN:
569 		if (ifr->ifr_qlen < 0)
570 			return -EINVAL;
571 		return dev_change_tx_queue_len(dev, ifr->ifr_qlen);
572 
573 	case SIOCSIFNAME:
574 		ifr->ifr_newname[IFNAMSIZ-1] = '\0';
575 		return dev_change_name(dev, ifr->ifr_newname);
576 
577 	case SIOCWANDEV:
578 		return dev_siocwandev(dev, &ifr->ifr_settings);
579 
580 	case SIOCBRADDIF:
581 	case SIOCBRDELIF:
582 		if (!netif_device_present(dev))
583 			return -ENODEV;
584 		if (!netif_is_bridge_master(dev))
585 			return -EOPNOTSUPP;
586 		netdev_hold(dev, &dev_tracker, GFP_KERNEL);
587 		rtnl_unlock();
588 		err = br_ioctl_call(net, netdev_priv(dev), cmd, ifr, NULL);
589 		netdev_put(dev, &dev_tracker);
590 		rtnl_lock();
591 		return err;
592 
593 	case SIOCDEVPRIVATE ... SIOCDEVPRIVATE + 15:
594 		return dev_siocdevprivate(dev, ifr, data, cmd);
595 
596 	case SIOCSHWTSTAMP:
597 		return dev_set_hwtstamp(dev, ifr);
598 
599 	case SIOCGHWTSTAMP:
600 		return dev_get_hwtstamp(dev, ifr);
601 
602 	case SIOCGMIIPHY:
603 	case SIOCGMIIREG:
604 	case SIOCSMIIREG:
605 		return dev_eth_ioctl(dev, ifr, cmd);
606 
607 	case SIOCBONDENSLAVE:
608 	case SIOCBONDRELEASE:
609 	case SIOCBONDSETHWADDR:
610 	case SIOCBONDSLAVEINFOQUERY:
611 	case SIOCBONDINFOQUERY:
612 	case SIOCBONDCHANGEACTIVE:
613 		return dev_siocbond(dev, ifr, cmd);
614 
615 	/* Unknown ioctl */
616 	default:
617 		err = -EINVAL;
618 	}
619 	return err;
620 }
621 
622 /**
623  *	dev_load 	- load a network module
624  *	@net: the applicable net namespace
625  *	@name: name of interface
626  *
627  *	If a network interface is not present and the process has suitable
628  *	privileges this function loads the module. If module loading is not
629  *	available in this kernel then it becomes a nop.
630  */
631 
632 void dev_load(struct net *net, const char *name)
633 {
634 	struct net_device *dev;
635 	int no_module;
636 
637 	rcu_read_lock();
638 	dev = dev_get_by_name_rcu(net, name);
639 	rcu_read_unlock();
640 
641 	no_module = !dev;
642 	if (no_module && capable(CAP_NET_ADMIN))
643 		no_module = request_module("netdev-%s", name);
644 	if (no_module && capable(CAP_SYS_MODULE))
645 		request_module("%s", name);
646 }
647 EXPORT_SYMBOL(dev_load);
648 
649 /*
650  *	This function handles all "interface"-type I/O control requests. The actual
651  *	'doing' part of this is dev_ifsioc above.
652  */
653 
654 /**
655  *	dev_ioctl	-	network device ioctl
656  *	@net: the applicable net namespace
657  *	@cmd: command to issue
658  *	@ifr: pointer to a struct ifreq in user space
659  *	@data: data exchanged with userspace
660  *	@need_copyout: whether or not copy_to_user() should be called
661  *
662  *	Issue ioctl functions to devices. This is normally called by the
663  *	user space syscall interfaces but can sometimes be useful for
664  *	other purposes. The return value is the return from the syscall if
665  *	positive or a negative errno code on error.
666  */
667 
668 int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr,
669 	      void __user *data, bool *need_copyout)
670 {
671 	int ret;
672 	char *colon;
673 
674 	if (need_copyout)
675 		*need_copyout = true;
676 	if (cmd == SIOCGIFNAME)
677 		return dev_ifname(net, ifr);
678 
679 	ifr->ifr_name[IFNAMSIZ-1] = 0;
680 
681 	colon = strchr(ifr->ifr_name, ':');
682 	if (colon)
683 		*colon = 0;
684 
685 	/*
686 	 *	See which interface the caller is talking about.
687 	 */
688 
689 	switch (cmd) {
690 	case SIOCGIFHWADDR:
691 		dev_load(net, ifr->ifr_name);
692 		ret = dev_get_mac_address(&ifr->ifr_hwaddr, net, ifr->ifr_name);
693 		if (colon)
694 			*colon = ':';
695 		return ret;
696 	/*
697 	 *	These ioctl calls:
698 	 *	- can be done by all.
699 	 *	- atomic and do not require locking.
700 	 *	- return a value
701 	 */
702 	case SIOCGIFFLAGS:
703 	case SIOCGIFMETRIC:
704 	case SIOCGIFMTU:
705 	case SIOCGIFSLAVE:
706 	case SIOCGIFMAP:
707 	case SIOCGIFINDEX:
708 	case SIOCGIFTXQLEN:
709 		dev_load(net, ifr->ifr_name);
710 		rcu_read_lock();
711 		ret = dev_ifsioc_locked(net, ifr, cmd);
712 		rcu_read_unlock();
713 		if (colon)
714 			*colon = ':';
715 		return ret;
716 
717 	case SIOCETHTOOL:
718 		dev_load(net, ifr->ifr_name);
719 		ret = dev_ethtool(net, ifr, data);
720 		if (colon)
721 			*colon = ':';
722 		return ret;
723 
724 	/*
725 	 *	These ioctl calls:
726 	 *	- require superuser power.
727 	 *	- require strict serialization.
728 	 *	- return a value
729 	 */
730 	case SIOCGMIIPHY:
731 	case SIOCGMIIREG:
732 	case SIOCSIFNAME:
733 		dev_load(net, ifr->ifr_name);
734 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
735 			return -EPERM;
736 		rtnl_lock();
737 		ret = dev_ifsioc(net, ifr, data, cmd);
738 		rtnl_unlock();
739 		if (colon)
740 			*colon = ':';
741 		return ret;
742 
743 	/*
744 	 *	These ioctl calls:
745 	 *	- require superuser power.
746 	 *	- require strict serialization.
747 	 *	- do not return a value
748 	 */
749 	case SIOCSIFMAP:
750 	case SIOCSIFTXQLEN:
751 		if (!capable(CAP_NET_ADMIN))
752 			return -EPERM;
753 		fallthrough;
754 	/*
755 	 *	These ioctl calls:
756 	 *	- require local superuser power.
757 	 *	- require strict serialization.
758 	 *	- do not return a value
759 	 */
760 	case SIOCSIFFLAGS:
761 	case SIOCSIFMETRIC:
762 	case SIOCSIFMTU:
763 	case SIOCSIFHWADDR:
764 	case SIOCSIFSLAVE:
765 	case SIOCADDMULTI:
766 	case SIOCDELMULTI:
767 	case SIOCSIFHWBROADCAST:
768 	case SIOCSMIIREG:
769 	case SIOCBONDENSLAVE:
770 	case SIOCBONDRELEASE:
771 	case SIOCBONDSETHWADDR:
772 	case SIOCBONDCHANGEACTIVE:
773 	case SIOCBRADDIF:
774 	case SIOCBRDELIF:
775 	case SIOCSHWTSTAMP:
776 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
777 			return -EPERM;
778 		fallthrough;
779 	case SIOCBONDSLAVEINFOQUERY:
780 	case SIOCBONDINFOQUERY:
781 		dev_load(net, ifr->ifr_name);
782 		rtnl_lock();
783 		ret = dev_ifsioc(net, ifr, data, cmd);
784 		rtnl_unlock();
785 		if (need_copyout)
786 			*need_copyout = false;
787 		return ret;
788 
789 	case SIOCGIFMEM:
790 		/* Get the per device memory space. We can add this but
791 		 * currently do not support it */
792 	case SIOCSIFMEM:
793 		/* Set the per device memory buffer space.
794 		 * Not applicable in our case */
795 	case SIOCSIFLINK:
796 		return -ENOTTY;
797 
798 	/*
799 	 *	Unknown or private ioctl.
800 	 */
801 	default:
802 		if (cmd == SIOCWANDEV ||
803 		    cmd == SIOCGHWTSTAMP ||
804 		    (cmd >= SIOCDEVPRIVATE &&
805 		     cmd <= SIOCDEVPRIVATE + 15)) {
806 			dev_load(net, ifr->ifr_name);
807 			rtnl_lock();
808 			ret = dev_ifsioc(net, ifr, data, cmd);
809 			rtnl_unlock();
810 			return ret;
811 		}
812 		return -ENOTTY;
813 	}
814 }
815