xref: /linux/net/core/dev_ioctl.c (revision c797ce168930ce3d62a9b7fc4d7040963ee6a01e)
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_lock();
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_unlock();
76 			return -EFAULT;
77 		}
78 		total += done;
79 	}
80 	rtnl_unlock();
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 selected 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 	enum timestamping_layer ts_layer = dev->ts_layer;
273 
274 	if (ts_layer == PHY_TIMESTAMPING)
275 		return phy_hwtstamp_get(dev->phydev, cfg);
276 	else if (ts_layer == MAC_TIMESTAMPING)
277 		return dev->netdev_ops->ndo_hwtstamp_get(dev, cfg);
278 
279 	return -EOPNOTSUPP;
280 }
281 
282 static int dev_get_hwtstamp(struct net_device *dev, struct ifreq *ifr)
283 {
284 	const struct net_device_ops *ops = dev->netdev_ops;
285 	struct kernel_hwtstamp_config kernel_cfg = {};
286 	struct hwtstamp_config cfg;
287 	int err;
288 
289 	if (!ops->ndo_hwtstamp_get)
290 		return dev_eth_ioctl(dev, ifr, SIOCGHWTSTAMP); /* legacy */
291 
292 	if (!netif_device_present(dev))
293 		return -ENODEV;
294 
295 	kernel_cfg.ifr = ifr;
296 	err = dev_get_hwtstamp_phylib(dev, &kernel_cfg);
297 	if (err)
298 		return err;
299 
300 	/* If the request was resolved through an unconverted driver, omit
301 	 * the copy_to_user(), since the implementation has already done that
302 	 */
303 	if (!kernel_cfg.copied_to_user) {
304 		hwtstamp_config_from_kernel(&cfg, &kernel_cfg);
305 
306 		if (copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)))
307 			return -EFAULT;
308 	}
309 
310 	return 0;
311 }
312 
313 /**
314  * dev_set_hwtstamp_phylib() - Change hardware timestamping of NIC
315  *	or of attached phylib PHY
316  * @dev: Network device
317  * @cfg: Timestamping configuration structure
318  * @extack: Netlink extended ack message structure, for error reporting
319  *
320  * Helper for calling the selected hardware provider timestamping.
321  * If the netdev driver needs to perform specific actions even for PHY
322  * timestamping to work properly (a switch port must trap the timestamped
323  * frames and not forward them), it must set IFF_SEE_ALL_HWTSTAMP_REQUESTS in
324  * dev->priv_flags.
325  */
326 int dev_set_hwtstamp_phylib(struct net_device *dev,
327 			    struct kernel_hwtstamp_config *cfg,
328 			    struct netlink_ext_ack *extack)
329 {
330 	const struct net_device_ops *ops = dev->netdev_ops;
331 	enum timestamping_layer ts_layer = dev->ts_layer;
332 	struct kernel_hwtstamp_config old_cfg = {};
333 	bool changed = false;
334 	int err;
335 
336 	cfg->source = ts_layer;
337 
338 	if (ts_layer != PHY_TIMESTAMPING &&
339 	    ts_layer != MAC_TIMESTAMPING)
340 		return -EOPNOTSUPP;
341 
342 	if (ts_layer == PHY_TIMESTAMPING &&
343 	    dev->priv_flags & IFF_SEE_ALL_HWTSTAMP_REQUESTS) {
344 		err = ops->ndo_hwtstamp_get(dev, &old_cfg);
345 		if (err)
346 			return err;
347 	}
348 
349 	if (ts_layer == MAC_TIMESTAMPING ||
350 	    dev->priv_flags & IFF_SEE_ALL_HWTSTAMP_REQUESTS) {
351 		err = ops->ndo_hwtstamp_set(dev, cfg, extack);
352 		if (err) {
353 			if (extack->_msg)
354 				netdev_err(dev, "%s\n", extack->_msg);
355 			return err;
356 		}
357 	}
358 
359 	if (ts_layer == PHY_TIMESTAMPING &&
360 	    dev->priv_flags & IFF_SEE_ALL_HWTSTAMP_REQUESTS)
361 		changed = kernel_hwtstamp_config_changed(&old_cfg, cfg);
362 
363 	if (ts_layer == PHY_TIMESTAMPING) {
364 		err = phy_hwtstamp_set(dev->phydev, cfg, extack);
365 		if (err) {
366 			if (changed)
367 				ops->ndo_hwtstamp_set(dev, &old_cfg, NULL);
368 			return err;
369 		}
370 	}
371 
372 	return 0;
373 }
374 EXPORT_SYMBOL_GPL(dev_set_hwtstamp_phylib);
375 
376 static int dev_set_hwtstamp(struct net_device *dev, struct ifreq *ifr)
377 {
378 	const struct net_device_ops *ops = dev->netdev_ops;
379 	struct kernel_hwtstamp_config kernel_cfg = {};
380 	struct netlink_ext_ack extack = {};
381 	struct hwtstamp_config cfg;
382 	int err;
383 
384 	if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
385 		return -EFAULT;
386 
387 	hwtstamp_config_to_kernel(&kernel_cfg, &cfg);
388 	kernel_cfg.ifr = ifr;
389 
390 	err = net_hwtstamp_validate(&kernel_cfg);
391 	if (err)
392 		return err;
393 
394 	err = dsa_conduit_hwtstamp_validate(dev, &kernel_cfg, &extack);
395 	if (err) {
396 		if (extack._msg)
397 			netdev_err(dev, "%s\n", extack._msg);
398 		return err;
399 	}
400 
401 	if (!ops->ndo_hwtstamp_set)
402 		return dev_eth_ioctl(dev, ifr, SIOCSHWTSTAMP); /* legacy */
403 
404 	if (!netif_device_present(dev))
405 		return -ENODEV;
406 
407 	err = dev_set_hwtstamp_phylib(dev, &kernel_cfg, &extack);
408 	if (err)
409 		return err;
410 
411 	/* The driver may have modified the configuration, so copy the
412 	 * updated version of it back to user space
413 	 */
414 	if (!kernel_cfg.copied_to_user) {
415 		hwtstamp_config_from_kernel(&cfg, &kernel_cfg);
416 
417 		if (copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)))
418 			return -EFAULT;
419 	}
420 
421 	return 0;
422 }
423 
424 static int generic_hwtstamp_ioctl_lower(struct net_device *dev, int cmd,
425 					struct kernel_hwtstamp_config *kernel_cfg)
426 {
427 	struct ifreq ifrr;
428 	int err;
429 
430 	strscpy_pad(ifrr.ifr_name, dev->name, IFNAMSIZ);
431 	ifrr.ifr_ifru = kernel_cfg->ifr->ifr_ifru;
432 
433 	err = dev_eth_ioctl(dev, &ifrr, cmd);
434 	if (err)
435 		return err;
436 
437 	kernel_cfg->ifr->ifr_ifru = ifrr.ifr_ifru;
438 	kernel_cfg->copied_to_user = true;
439 
440 	return 0;
441 }
442 
443 int generic_hwtstamp_get_lower(struct net_device *dev,
444 			       struct kernel_hwtstamp_config *kernel_cfg)
445 {
446 	const struct net_device_ops *ops = dev->netdev_ops;
447 
448 	if (!netif_device_present(dev))
449 		return -ENODEV;
450 
451 	if (ops->ndo_hwtstamp_get)
452 		return dev_get_hwtstamp_phylib(dev, kernel_cfg);
453 
454 	/* Legacy path: unconverted lower driver */
455 	return generic_hwtstamp_ioctl_lower(dev, SIOCGHWTSTAMP, kernel_cfg);
456 }
457 EXPORT_SYMBOL(generic_hwtstamp_get_lower);
458 
459 int generic_hwtstamp_set_lower(struct net_device *dev,
460 			       struct kernel_hwtstamp_config *kernel_cfg,
461 			       struct netlink_ext_ack *extack)
462 {
463 	const struct net_device_ops *ops = dev->netdev_ops;
464 
465 	if (!netif_device_present(dev))
466 		return -ENODEV;
467 
468 	if (ops->ndo_hwtstamp_set)
469 		return dev_set_hwtstamp_phylib(dev, kernel_cfg, extack);
470 
471 	/* Legacy path: unconverted lower driver */
472 	return generic_hwtstamp_ioctl_lower(dev, SIOCSHWTSTAMP, kernel_cfg);
473 }
474 EXPORT_SYMBOL(generic_hwtstamp_set_lower);
475 
476 static int dev_siocbond(struct net_device *dev,
477 			struct ifreq *ifr, unsigned int cmd)
478 {
479 	const struct net_device_ops *ops = dev->netdev_ops;
480 
481 	if (ops->ndo_siocbond) {
482 		if (netif_device_present(dev))
483 			return ops->ndo_siocbond(dev, ifr, cmd);
484 		else
485 			return -ENODEV;
486 	}
487 
488 	return -EOPNOTSUPP;
489 }
490 
491 static int dev_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
492 			      void __user *data, unsigned int cmd)
493 {
494 	const struct net_device_ops *ops = dev->netdev_ops;
495 
496 	if (ops->ndo_siocdevprivate) {
497 		if (netif_device_present(dev))
498 			return ops->ndo_siocdevprivate(dev, ifr, data, cmd);
499 		else
500 			return -ENODEV;
501 	}
502 
503 	return -EOPNOTSUPP;
504 }
505 
506 static int dev_siocwandev(struct net_device *dev, struct if_settings *ifs)
507 {
508 	const struct net_device_ops *ops = dev->netdev_ops;
509 
510 	if (ops->ndo_siocwandev) {
511 		if (netif_device_present(dev))
512 			return ops->ndo_siocwandev(dev, ifs);
513 		else
514 			return -ENODEV;
515 	}
516 
517 	return -EOPNOTSUPP;
518 }
519 
520 /*
521  *	Perform the SIOCxIFxxx calls, inside rtnl_lock()
522  */
523 static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,
524 		      unsigned int cmd)
525 {
526 	int err;
527 	struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
528 	const struct net_device_ops *ops;
529 	netdevice_tracker dev_tracker;
530 
531 	if (!dev)
532 		return -ENODEV;
533 
534 	ops = dev->netdev_ops;
535 
536 	switch (cmd) {
537 	case SIOCSIFFLAGS:	/* Set interface flags */
538 		return dev_change_flags(dev, ifr->ifr_flags, NULL);
539 
540 	case SIOCSIFMETRIC:	/* Set the metric on the interface
541 				   (currently unused) */
542 		return -EOPNOTSUPP;
543 
544 	case SIOCSIFMTU:	/* Set the MTU of a device */
545 		return dev_set_mtu(dev, ifr->ifr_mtu);
546 
547 	case SIOCSIFHWADDR:
548 		if (dev->addr_len > sizeof(struct sockaddr))
549 			return -EINVAL;
550 		return dev_set_mac_address_user(dev, &ifr->ifr_hwaddr, NULL);
551 
552 	case SIOCSIFHWBROADCAST:
553 		if (ifr->ifr_hwaddr.sa_family != dev->type)
554 			return -EINVAL;
555 		memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
556 		       min(sizeof(ifr->ifr_hwaddr.sa_data_min),
557 			   (size_t)dev->addr_len));
558 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
559 		return 0;
560 
561 	case SIOCSIFMAP:
562 		return dev_setifmap(dev, ifr);
563 
564 	case SIOCADDMULTI:
565 		if (!ops->ndo_set_rx_mode ||
566 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
567 			return -EINVAL;
568 		if (!netif_device_present(dev))
569 			return -ENODEV;
570 		return dev_mc_add_global(dev, ifr->ifr_hwaddr.sa_data);
571 
572 	case SIOCDELMULTI:
573 		if (!ops->ndo_set_rx_mode ||
574 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
575 			return -EINVAL;
576 		if (!netif_device_present(dev))
577 			return -ENODEV;
578 		return dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);
579 
580 	case SIOCSIFTXQLEN:
581 		if (ifr->ifr_qlen < 0)
582 			return -EINVAL;
583 		return dev_change_tx_queue_len(dev, ifr->ifr_qlen);
584 
585 	case SIOCSIFNAME:
586 		ifr->ifr_newname[IFNAMSIZ-1] = '\0';
587 		return dev_change_name(dev, ifr->ifr_newname);
588 
589 	case SIOCWANDEV:
590 		return dev_siocwandev(dev, &ifr->ifr_settings);
591 
592 	case SIOCBRADDIF:
593 	case SIOCBRDELIF:
594 		if (!netif_device_present(dev))
595 			return -ENODEV;
596 		if (!netif_is_bridge_master(dev))
597 			return -EOPNOTSUPP;
598 		netdev_hold(dev, &dev_tracker, GFP_KERNEL);
599 		rtnl_unlock();
600 		err = br_ioctl_call(net, netdev_priv(dev), cmd, ifr, NULL);
601 		netdev_put(dev, &dev_tracker);
602 		rtnl_lock();
603 		return err;
604 
605 	case SIOCDEVPRIVATE ... SIOCDEVPRIVATE + 15:
606 		return dev_siocdevprivate(dev, ifr, data, cmd);
607 
608 	case SIOCSHWTSTAMP:
609 		return dev_set_hwtstamp(dev, ifr);
610 
611 	case SIOCGHWTSTAMP:
612 		return dev_get_hwtstamp(dev, ifr);
613 
614 	case SIOCGMIIPHY:
615 	case SIOCGMIIREG:
616 	case SIOCSMIIREG:
617 		return dev_eth_ioctl(dev, ifr, cmd);
618 
619 	case SIOCBONDENSLAVE:
620 	case SIOCBONDRELEASE:
621 	case SIOCBONDSETHWADDR:
622 	case SIOCBONDSLAVEINFOQUERY:
623 	case SIOCBONDINFOQUERY:
624 	case SIOCBONDCHANGEACTIVE:
625 		return dev_siocbond(dev, ifr, cmd);
626 
627 	/* Unknown ioctl */
628 	default:
629 		err = -EINVAL;
630 	}
631 	return err;
632 }
633 
634 /**
635  *	dev_load 	- load a network module
636  *	@net: the applicable net namespace
637  *	@name: name of interface
638  *
639  *	If a network interface is not present and the process has suitable
640  *	privileges this function loads the module. If module loading is not
641  *	available in this kernel then it becomes a nop.
642  */
643 
644 void dev_load(struct net *net, const char *name)
645 {
646 	struct net_device *dev;
647 	int no_module;
648 
649 	rcu_read_lock();
650 	dev = dev_get_by_name_rcu(net, name);
651 	rcu_read_unlock();
652 
653 	no_module = !dev;
654 	if (no_module && capable(CAP_NET_ADMIN))
655 		no_module = request_module("netdev-%s", name);
656 	if (no_module && capable(CAP_SYS_MODULE))
657 		request_module("%s", name);
658 }
659 EXPORT_SYMBOL(dev_load);
660 
661 /*
662  *	This function handles all "interface"-type I/O control requests. The actual
663  *	'doing' part of this is dev_ifsioc above.
664  */
665 
666 /**
667  *	dev_ioctl	-	network device ioctl
668  *	@net: the applicable net namespace
669  *	@cmd: command to issue
670  *	@ifr: pointer to a struct ifreq in user space
671  *	@data: data exchanged with userspace
672  *	@need_copyout: whether or not copy_to_user() should be called
673  *
674  *	Issue ioctl functions to devices. This is normally called by the
675  *	user space syscall interfaces but can sometimes be useful for
676  *	other purposes. The return value is the return from the syscall if
677  *	positive or a negative errno code on error.
678  */
679 
680 int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr,
681 	      void __user *data, bool *need_copyout)
682 {
683 	int ret;
684 	char *colon;
685 
686 	if (need_copyout)
687 		*need_copyout = true;
688 	if (cmd == SIOCGIFNAME)
689 		return dev_ifname(net, ifr);
690 
691 	ifr->ifr_name[IFNAMSIZ-1] = 0;
692 
693 	colon = strchr(ifr->ifr_name, ':');
694 	if (colon)
695 		*colon = 0;
696 
697 	/*
698 	 *	See which interface the caller is talking about.
699 	 */
700 
701 	switch (cmd) {
702 	case SIOCGIFHWADDR:
703 		dev_load(net, ifr->ifr_name);
704 		ret = dev_get_mac_address(&ifr->ifr_hwaddr, net, ifr->ifr_name);
705 		if (colon)
706 			*colon = ':';
707 		return ret;
708 	/*
709 	 *	These ioctl calls:
710 	 *	- can be done by all.
711 	 *	- atomic and do not require locking.
712 	 *	- return a value
713 	 */
714 	case SIOCGIFFLAGS:
715 	case SIOCGIFMETRIC:
716 	case SIOCGIFMTU:
717 	case SIOCGIFSLAVE:
718 	case SIOCGIFMAP:
719 	case SIOCGIFINDEX:
720 	case SIOCGIFTXQLEN:
721 		dev_load(net, ifr->ifr_name);
722 		rcu_read_lock();
723 		ret = dev_ifsioc_locked(net, ifr, cmd);
724 		rcu_read_unlock();
725 		if (colon)
726 			*colon = ':';
727 		return ret;
728 
729 	case SIOCETHTOOL:
730 		dev_load(net, ifr->ifr_name);
731 		ret = dev_ethtool(net, ifr, data);
732 		if (colon)
733 			*colon = ':';
734 		return ret;
735 
736 	/*
737 	 *	These ioctl calls:
738 	 *	- require superuser power.
739 	 *	- require strict serialization.
740 	 *	- return a value
741 	 */
742 	case SIOCGMIIPHY:
743 	case SIOCGMIIREG:
744 	case SIOCSIFNAME:
745 		dev_load(net, ifr->ifr_name);
746 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
747 			return -EPERM;
748 		rtnl_lock();
749 		ret = dev_ifsioc(net, ifr, data, cmd);
750 		rtnl_unlock();
751 		if (colon)
752 			*colon = ':';
753 		return ret;
754 
755 	/*
756 	 *	These ioctl calls:
757 	 *	- require superuser power.
758 	 *	- require strict serialization.
759 	 *	- do not return a value
760 	 */
761 	case SIOCSIFMAP:
762 	case SIOCSIFTXQLEN:
763 		if (!capable(CAP_NET_ADMIN))
764 			return -EPERM;
765 		fallthrough;
766 	/*
767 	 *	These ioctl calls:
768 	 *	- require local superuser power.
769 	 *	- require strict serialization.
770 	 *	- do not return a value
771 	 */
772 	case SIOCSIFFLAGS:
773 	case SIOCSIFMETRIC:
774 	case SIOCSIFMTU:
775 	case SIOCSIFHWADDR:
776 	case SIOCSIFSLAVE:
777 	case SIOCADDMULTI:
778 	case SIOCDELMULTI:
779 	case SIOCSIFHWBROADCAST:
780 	case SIOCSMIIREG:
781 	case SIOCBONDENSLAVE:
782 	case SIOCBONDRELEASE:
783 	case SIOCBONDSETHWADDR:
784 	case SIOCBONDCHANGEACTIVE:
785 	case SIOCBRADDIF:
786 	case SIOCBRDELIF:
787 	case SIOCSHWTSTAMP:
788 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
789 			return -EPERM;
790 		fallthrough;
791 	case SIOCBONDSLAVEINFOQUERY:
792 	case SIOCBONDINFOQUERY:
793 		dev_load(net, ifr->ifr_name);
794 		rtnl_lock();
795 		ret = dev_ifsioc(net, ifr, data, cmd);
796 		rtnl_unlock();
797 		if (need_copyout)
798 			*need_copyout = false;
799 		return ret;
800 
801 	case SIOCGIFMEM:
802 		/* Get the per device memory space. We can add this but
803 		 * currently do not support it */
804 	case SIOCSIFMEM:
805 		/* Set the per device memory buffer space.
806 		 * Not applicable in our case */
807 	case SIOCSIFLINK:
808 		return -ENOTTY;
809 
810 	/*
811 	 *	Unknown or private ioctl.
812 	 */
813 	default:
814 		if (cmd == SIOCWANDEV ||
815 		    cmd == SIOCGHWTSTAMP ||
816 		    (cmd >= SIOCDEVPRIVATE &&
817 		     cmd <= SIOCDEVPRIVATE + 15)) {
818 			dev_load(net, ifr->ifr_name);
819 			rtnl_lock();
820 			ret = dev_ifsioc(net, ifr, data, cmd);
821 			rtnl_unlock();
822 			return ret;
823 		}
824 		return -ENOTTY;
825 	}
826 }
827