xref: /linux/net/core/dev_ioctl.c (revision d8f87aa5fa0a4276491fa8ef436cd22605a3f9ba)
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/ptp_clock_kernel.h>
10 #include <linux/wireless.h>
11 #include <linux/if_bridge.h>
12 #include <net/dsa_stubs.h>
13 #include <net/netdev_lock.h>
14 #include <net/wext.h>
15 
16 #include "dev.h"
17 
18 /*
19  *	Map an interface index to its name (SIOCGIFNAME)
20  */
21 
22 /*
23  *	We need this ioctl for efficient implementation of the
24  *	if_indextoname() function required by the IPv6 API.  Without
25  *	it, we would have to search all the interfaces to find a
26  *	match.  --pb
27  */
28 
29 static int dev_ifname(struct net *net, struct ifreq *ifr)
30 {
31 	ifr->ifr_name[IFNAMSIZ-1] = 0;
32 	return netdev_get_name(net, ifr->ifr_name, ifr->ifr_ifindex);
33 }
34 
35 /*
36  *	Perform a SIOCGIFCONF call. This structure will change
37  *	size eventually, and there is nothing I can do about it.
38  *	Thus we will need a 'compatibility mode'.
39  */
40 int dev_ifconf(struct net *net, struct ifconf __user *uifc)
41 {
42 	struct net_device *dev;
43 	void __user *pos;
44 	size_t size;
45 	int len, total = 0, done;
46 
47 	/* both the ifconf and the ifreq structures are slightly different */
48 	if (in_compat_syscall()) {
49 		struct compat_ifconf ifc32;
50 
51 		if (copy_from_user(&ifc32, uifc, sizeof(struct compat_ifconf)))
52 			return -EFAULT;
53 
54 		pos = compat_ptr(ifc32.ifcbuf);
55 		len = ifc32.ifc_len;
56 		size = sizeof(struct compat_ifreq);
57 	} else {
58 		struct ifconf ifc;
59 
60 		if (copy_from_user(&ifc, uifc, sizeof(struct ifconf)))
61 			return -EFAULT;
62 
63 		pos = ifc.ifc_buf;
64 		len = ifc.ifc_len;
65 		size = sizeof(struct ifreq);
66 	}
67 
68 	/* Loop over the interfaces, and write an info block for each. */
69 	rtnl_net_lock(net);
70 	for_each_netdev(net, dev) {
71 		if (!pos)
72 			done = inet_gifconf(dev, NULL, 0, size);
73 		else
74 			done = inet_gifconf(dev, pos + total,
75 					    len - total, size);
76 		if (done < 0) {
77 			rtnl_net_unlock(net);
78 			return -EFAULT;
79 		}
80 		total += done;
81 	}
82 	rtnl_net_unlock(net);
83 
84 	return put_user(total, &uifc->ifc_len);
85 }
86 
87 static int dev_getifmap(struct net_device *dev, struct ifreq *ifr)
88 {
89 	struct ifmap *ifmap = &ifr->ifr_map;
90 
91 	if (in_compat_syscall()) {
92 		struct compat_ifmap *cifmap = (struct compat_ifmap *)ifmap;
93 
94 		cifmap->mem_start = dev->mem_start;
95 		cifmap->mem_end   = dev->mem_end;
96 		cifmap->base_addr = dev->base_addr;
97 		cifmap->irq       = dev->irq;
98 		cifmap->dma       = dev->dma;
99 		cifmap->port      = dev->if_port;
100 
101 		return 0;
102 	}
103 
104 	ifmap->mem_start  = dev->mem_start;
105 	ifmap->mem_end    = dev->mem_end;
106 	ifmap->base_addr  = dev->base_addr;
107 	ifmap->irq        = dev->irq;
108 	ifmap->dma        = dev->dma;
109 	ifmap->port       = dev->if_port;
110 
111 	return 0;
112 }
113 
114 static int netif_setifmap(struct net_device *dev, struct ifreq *ifr)
115 {
116 	struct compat_ifmap *cifmap = (struct compat_ifmap *)&ifr->ifr_map;
117 
118 	if (!dev->netdev_ops->ndo_set_config)
119 		return -EOPNOTSUPP;
120 
121 	if (in_compat_syscall()) {
122 		struct ifmap ifmap = {
123 			.mem_start  = cifmap->mem_start,
124 			.mem_end    = cifmap->mem_end,
125 			.base_addr  = cifmap->base_addr,
126 			.irq        = cifmap->irq,
127 			.dma        = cifmap->dma,
128 			.port       = cifmap->port,
129 		};
130 
131 		return dev->netdev_ops->ndo_set_config(dev, &ifmap);
132 	}
133 
134 	return dev->netdev_ops->ndo_set_config(dev, &ifr->ifr_map);
135 }
136 
137 /*
138  *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
139  */
140 static int dev_ifsioc_locked(struct net *net, struct ifreq *ifr, unsigned int cmd)
141 {
142 	int err;
143 	struct net_device *dev = dev_get_by_name_rcu(net, ifr->ifr_name);
144 
145 	if (!dev)
146 		return -ENODEV;
147 
148 	switch (cmd) {
149 	case SIOCGIFFLAGS:	/* Get interface flags */
150 		ifr->ifr_flags = (short)netif_get_flags(dev);
151 		return 0;
152 
153 	case SIOCGIFMETRIC:	/* Get the metric on the interface
154 				   (currently unused) */
155 		ifr->ifr_metric = 0;
156 		return 0;
157 
158 	case SIOCGIFMTU:	/* Get the MTU of a device */
159 		ifr->ifr_mtu = dev->mtu;
160 		return 0;
161 
162 	case SIOCGIFSLAVE:
163 		err = -EINVAL;
164 		break;
165 
166 	case SIOCGIFMAP:
167 		return dev_getifmap(dev, ifr);
168 
169 	case SIOCGIFINDEX:
170 		ifr->ifr_ifindex = dev->ifindex;
171 		return 0;
172 
173 	case SIOCGIFTXQLEN:
174 		ifr->ifr_qlen = dev->tx_queue_len;
175 		return 0;
176 
177 	default:
178 		/* dev_ioctl() should ensure this case
179 		 * is never reached
180 		 */
181 		WARN_ON(1);
182 		err = -ENOTTY;
183 		break;
184 
185 	}
186 	return err;
187 }
188 
189 int net_hwtstamp_validate(const struct kernel_hwtstamp_config *cfg)
190 {
191 	enum hwtstamp_tx_types tx_type;
192 	enum hwtstamp_rx_filters rx_filter;
193 	int tx_type_valid = 0;
194 	int rx_filter_valid = 0;
195 
196 	if (cfg->flags & ~HWTSTAMP_FLAG_MASK)
197 		return -EINVAL;
198 
199 	tx_type = cfg->tx_type;
200 	rx_filter = cfg->rx_filter;
201 
202 	switch (tx_type) {
203 	case HWTSTAMP_TX_OFF:
204 	case HWTSTAMP_TX_ON:
205 	case HWTSTAMP_TX_ONESTEP_SYNC:
206 	case HWTSTAMP_TX_ONESTEP_P2P:
207 		tx_type_valid = 1;
208 		break;
209 	case __HWTSTAMP_TX_CNT:
210 		/* not a real value */
211 		break;
212 	}
213 
214 	switch (rx_filter) {
215 	case HWTSTAMP_FILTER_NONE:
216 	case HWTSTAMP_FILTER_ALL:
217 	case HWTSTAMP_FILTER_SOME:
218 	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
219 	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
220 	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
221 	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
222 	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
223 	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
224 	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
225 	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
226 	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
227 	case HWTSTAMP_FILTER_PTP_V2_EVENT:
228 	case HWTSTAMP_FILTER_PTP_V2_SYNC:
229 	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
230 	case HWTSTAMP_FILTER_NTP_ALL:
231 		rx_filter_valid = 1;
232 		break;
233 	case __HWTSTAMP_FILTER_CNT:
234 		/* not a real value */
235 		break;
236 	}
237 
238 	if (!tx_type_valid || !rx_filter_valid)
239 		return -ERANGE;
240 
241 	return 0;
242 }
243 
244 /**
245  * dev_get_hwtstamp_phylib() - Get hardware timestamping settings of NIC
246  *	or of attached phylib PHY
247  * @dev: Network device
248  * @cfg: Timestamping configuration structure
249  *
250  * Helper for calling the default hardware provider timestamping.
251  *
252  * Note: phy_mii_ioctl() only handles SIOCSHWTSTAMP (not SIOCGHWTSTAMP), but
253  * phydev->mii_ts has both hwtstamp_get() and hwtstamp_set() methods. So this
254  * will return -EOPNOTSUPP for phylib only if hwtstamp_get() is not
255  * implemented for now, which is still more accurate than letting the netdev
256  * handle the GET request.
257  */
258 int dev_get_hwtstamp_phylib(struct net_device *dev,
259 			    struct kernel_hwtstamp_config *cfg)
260 {
261 	struct hwtstamp_provider *hwprov;
262 
263 	hwprov = rtnl_dereference(dev->hwprov);
264 	if (hwprov) {
265 		cfg->qualifier = hwprov->desc.qualifier;
266 		if (hwprov->source == HWTSTAMP_SOURCE_PHYLIB &&
267 		    hwprov->phydev)
268 			return phy_hwtstamp_get(hwprov->phydev, cfg);
269 
270 		if (hwprov->source == HWTSTAMP_SOURCE_NETDEV)
271 			return dev->netdev_ops->ndo_hwtstamp_get(dev, cfg);
272 
273 		return -EOPNOTSUPP;
274 	}
275 
276 	if (phy_is_default_hwtstamp(dev->phydev))
277 		return phy_hwtstamp_get(dev->phydev, cfg);
278 
279 	return dev->netdev_ops->ndo_hwtstamp_get(dev, cfg);
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 -EOPNOTSUPP;
291 
292 	if (!netif_device_present(dev))
293 		return -ENODEV;
294 
295 	kernel_cfg.ifr = ifr;
296 	netdev_lock_ops(dev);
297 	err = dev_get_hwtstamp_phylib(dev, &kernel_cfg);
298 	netdev_unlock_ops(dev);
299 	if (err)
300 		return err;
301 
302 	/* If the request was resolved through an unconverted driver, omit
303 	 * the copy_to_user(), since the implementation has already done that
304 	 */
305 	if (!kernel_cfg.copied_to_user) {
306 		hwtstamp_config_from_kernel(&cfg, &kernel_cfg);
307 
308 		if (copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)))
309 			return -EFAULT;
310 	}
311 
312 	return 0;
313 }
314 
315 /**
316  * dev_set_hwtstamp_phylib() - Change hardware timestamping of NIC
317  *	or of attached phylib PHY
318  * @dev: Network device
319  * @cfg: Timestamping configuration structure
320  * @extack: Netlink extended ack message structure, for error reporting
321  *
322  * Helper for enforcing a common policy that phylib timestamping, if available,
323  * should take precedence in front of hardware timestamping provided by the
324  * netdev. If the netdev driver needs to perform specific actions even for PHY
325  * timestamping to work properly (a switch port must trap the timestamped
326  * frames and not forward them), it must set dev->see_all_hwtstamp_requests.
327  */
328 int dev_set_hwtstamp_phylib(struct net_device *dev,
329 			    struct kernel_hwtstamp_config *cfg,
330 			    struct netlink_ext_ack *extack)
331 {
332 	const struct net_device_ops *ops = dev->netdev_ops;
333 	struct kernel_hwtstamp_config old_cfg = {};
334 	struct hwtstamp_provider *hwprov;
335 	struct phy_device *phydev;
336 	bool changed = false;
337 	bool phy_ts;
338 	int err;
339 
340 	hwprov = rtnl_dereference(dev->hwprov);
341 	if (hwprov) {
342 		if (hwprov->source == HWTSTAMP_SOURCE_PHYLIB &&
343 		    hwprov->phydev) {
344 			phy_ts = true;
345 			phydev = hwprov->phydev;
346 		} else if (hwprov->source == HWTSTAMP_SOURCE_NETDEV) {
347 			phy_ts = false;
348 		} else {
349 			return -EOPNOTSUPP;
350 		}
351 
352 		cfg->qualifier = hwprov->desc.qualifier;
353 	} else {
354 		phy_ts = phy_is_default_hwtstamp(dev->phydev);
355 		if (phy_ts)
356 			phydev = dev->phydev;
357 	}
358 
359 	cfg->source = phy_ts ? HWTSTAMP_SOURCE_PHYLIB : HWTSTAMP_SOURCE_NETDEV;
360 
361 	if (phy_ts && dev->see_all_hwtstamp_requests) {
362 		err = ops->ndo_hwtstamp_get(dev, &old_cfg);
363 		if (err)
364 			return err;
365 	}
366 
367 	if (!phy_ts || dev->see_all_hwtstamp_requests) {
368 		err = ops->ndo_hwtstamp_set(dev, cfg, extack);
369 		if (err) {
370 			if (extack->_msg)
371 				netdev_err(dev, "%s\n", extack->_msg);
372 			return err;
373 		}
374 	}
375 
376 	if (phy_ts && dev->see_all_hwtstamp_requests)
377 		changed = kernel_hwtstamp_config_changed(&old_cfg, cfg);
378 
379 	if (phy_ts) {
380 		err = phy_hwtstamp_set(phydev, cfg, extack);
381 		if (err) {
382 			if (changed)
383 				ops->ndo_hwtstamp_set(dev, &old_cfg, NULL);
384 			return err;
385 		}
386 	}
387 
388 	return 0;
389 }
390 
391 static int dev_set_hwtstamp(struct net_device *dev, struct ifreq *ifr)
392 {
393 	const struct net_device_ops *ops = dev->netdev_ops;
394 	struct kernel_hwtstamp_config kernel_cfg = {};
395 	struct netlink_ext_ack extack = {};
396 	struct hwtstamp_config cfg;
397 	int err;
398 
399 	if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
400 		return -EFAULT;
401 
402 	hwtstamp_config_to_kernel(&kernel_cfg, &cfg);
403 	kernel_cfg.ifr = ifr;
404 
405 	err = net_hwtstamp_validate(&kernel_cfg);
406 	if (err)
407 		return err;
408 
409 	err = dsa_conduit_hwtstamp_validate(dev, &kernel_cfg, &extack);
410 	if (err) {
411 		if (extack._msg)
412 			netdev_err(dev, "%s\n", extack._msg);
413 		return err;
414 	}
415 
416 	if (!ops->ndo_hwtstamp_set)
417 		return -EOPNOTSUPP;
418 
419 	if (!netif_device_present(dev))
420 		return -ENODEV;
421 
422 	netdev_lock_ops(dev);
423 	err = dev_set_hwtstamp_phylib(dev, &kernel_cfg, &extack);
424 	netdev_unlock_ops(dev);
425 	if (err)
426 		return err;
427 
428 	/* The driver may have modified the configuration, so copy the
429 	 * updated version of it back to user space
430 	 */
431 	if (!kernel_cfg.copied_to_user) {
432 		hwtstamp_config_from_kernel(&cfg, &kernel_cfg);
433 
434 		if (copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)))
435 			return -EFAULT;
436 	}
437 
438 	return 0;
439 }
440 
441 int generic_hwtstamp_get_lower(struct net_device *dev,
442 			       struct kernel_hwtstamp_config *kernel_cfg)
443 {
444 	const struct net_device_ops *ops = dev->netdev_ops;
445 	int err;
446 
447 	if (!netif_device_present(dev))
448 		return -ENODEV;
449 
450 	if (!ops->ndo_hwtstamp_get)
451 		return -EOPNOTSUPP;
452 
453 	netdev_lock_ops(dev);
454 	err = dev_get_hwtstamp_phylib(dev, kernel_cfg);
455 	netdev_unlock_ops(dev);
456 
457 	return err;
458 }
459 EXPORT_SYMBOL(generic_hwtstamp_get_lower);
460 
461 int generic_hwtstamp_set_lower(struct net_device *dev,
462 			       struct kernel_hwtstamp_config *kernel_cfg,
463 			       struct netlink_ext_ack *extack)
464 {
465 	const struct net_device_ops *ops = dev->netdev_ops;
466 	int err;
467 
468 	if (!netif_device_present(dev))
469 		return -ENODEV;
470 
471 	if (!ops->ndo_hwtstamp_set)
472 		return -EOPNOTSUPP;
473 
474 	netdev_lock_ops(dev);
475 	err = dev_set_hwtstamp_phylib(dev, kernel_cfg, extack);
476 	netdev_unlock_ops(dev);
477 
478 	return err;
479 }
480 EXPORT_SYMBOL(generic_hwtstamp_set_lower);
481 
482 static int dev_siocbond(struct net_device *dev,
483 			struct ifreq *ifr, unsigned int cmd)
484 {
485 	const struct net_device_ops *ops = dev->netdev_ops;
486 
487 	if (ops->ndo_siocbond) {
488 		int ret = -ENODEV;
489 
490 		netdev_lock_ops(dev);
491 		if (netif_device_present(dev))
492 			ret = ops->ndo_siocbond(dev, ifr, cmd);
493 		netdev_unlock_ops(dev);
494 
495 		return ret;
496 	}
497 
498 	return -EOPNOTSUPP;
499 }
500 
501 static int dev_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
502 			      void __user *data, unsigned int cmd)
503 {
504 	const struct net_device_ops *ops = dev->netdev_ops;
505 
506 	if (ops->ndo_siocdevprivate) {
507 		int ret = -ENODEV;
508 
509 		netdev_lock_ops(dev);
510 		if (netif_device_present(dev))
511 			ret = ops->ndo_siocdevprivate(dev, ifr, data, cmd);
512 		netdev_unlock_ops(dev);
513 
514 		return ret;
515 	}
516 
517 	return -EOPNOTSUPP;
518 }
519 
520 static int dev_siocwandev(struct net_device *dev, struct if_settings *ifs)
521 {
522 	const struct net_device_ops *ops = dev->netdev_ops;
523 
524 	if (ops->ndo_siocwandev) {
525 		int ret = -ENODEV;
526 
527 		netdev_lock_ops(dev);
528 		if (netif_device_present(dev))
529 			ret = ops->ndo_siocwandev(dev, ifs);
530 		netdev_unlock_ops(dev);
531 
532 		return ret;
533 	}
534 
535 	return -EOPNOTSUPP;
536 }
537 
538 /*
539  *	Perform the SIOCxIFxxx calls, inside rtnl_net_lock()
540  */
541 static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,
542 		      unsigned int cmd)
543 {
544 	int err;
545 	struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
546 	const struct net_device_ops *ops;
547 
548 	if (!dev)
549 		return -ENODEV;
550 
551 	ops = dev->netdev_ops;
552 
553 	switch (cmd) {
554 	case SIOCSIFFLAGS:	/* Set interface flags */
555 		return dev_change_flags(dev, ifr->ifr_flags, NULL);
556 
557 	case SIOCSIFMETRIC:	/* Set the metric on the interface
558 				   (currently unused) */
559 		return -EOPNOTSUPP;
560 
561 	case SIOCSIFMTU:	/* Set the MTU of a device */
562 		return dev_set_mtu(dev, ifr->ifr_mtu);
563 
564 	case SIOCSIFHWADDR:
565 		if (dev->addr_len > sizeof(ifr->ifr_hwaddr))
566 			return -EINVAL;
567 		return dev_set_mac_address_user(dev,
568 						(struct sockaddr_storage *)&ifr->ifr_hwaddr,
569 						NULL);
570 
571 	case SIOCSIFHWBROADCAST:
572 		if (ifr->ifr_hwaddr.sa_family != dev->type)
573 			return -EINVAL;
574 		memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
575 		       min(sizeof(ifr->ifr_hwaddr.sa_data),
576 			   (size_t)dev->addr_len));
577 		netdev_lock_ops(dev);
578 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
579 		netdev_unlock_ops(dev);
580 		return 0;
581 
582 	case SIOCSIFMAP:
583 		netdev_lock_ops(dev);
584 		err = netif_setifmap(dev, ifr);
585 		netdev_unlock_ops(dev);
586 		return err;
587 
588 	case SIOCADDMULTI:
589 		if (!ops->ndo_set_rx_mode ||
590 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
591 			return -EINVAL;
592 		if (!netif_device_present(dev))
593 			return -ENODEV;
594 		netdev_lock_ops(dev);
595 		err = dev_mc_add_global(dev, ifr->ifr_hwaddr.sa_data);
596 		netdev_unlock_ops(dev);
597 		return err;
598 
599 	case SIOCDELMULTI:
600 		if (!ops->ndo_set_rx_mode ||
601 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
602 			return -EINVAL;
603 		if (!netif_device_present(dev))
604 			return -ENODEV;
605 		netdev_lock_ops(dev);
606 		err = dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);
607 		netdev_unlock_ops(dev);
608 		return err;
609 
610 	case SIOCSIFTXQLEN:
611 		if (ifr->ifr_qlen < 0)
612 			return -EINVAL;
613 		return dev_change_tx_queue_len(dev, ifr->ifr_qlen);
614 
615 	case SIOCSIFNAME:
616 		ifr->ifr_newname[IFNAMSIZ-1] = '\0';
617 		return dev_change_name(dev, ifr->ifr_newname);
618 
619 	case SIOCWANDEV:
620 		return dev_siocwandev(dev, &ifr->ifr_settings);
621 
622 	case SIOCDEVPRIVATE ... SIOCDEVPRIVATE + 15:
623 		return dev_siocdevprivate(dev, ifr, data, cmd);
624 
625 	case SIOCSHWTSTAMP:
626 		return dev_set_hwtstamp(dev, ifr);
627 
628 	case SIOCGHWTSTAMP:
629 		return dev_get_hwtstamp(dev, ifr);
630 
631 	case SIOCGMIIPHY:
632 	case SIOCGMIIREG:
633 	case SIOCSMIIREG:
634 		return dev_eth_ioctl(dev, ifr, cmd);
635 
636 	case SIOCBONDENSLAVE:
637 	case SIOCBONDRELEASE:
638 	case SIOCBONDSETHWADDR:
639 	case SIOCBONDSLAVEINFOQUERY:
640 	case SIOCBONDINFOQUERY:
641 	case SIOCBONDCHANGEACTIVE:
642 		return dev_siocbond(dev, ifr, cmd);
643 
644 	/* Unknown ioctl */
645 	default:
646 		err = -EINVAL;
647 	}
648 	return err;
649 }
650 
651 /**
652  *	dev_load 	- load a network module
653  *	@net: the applicable net namespace
654  *	@name: name of interface
655  *
656  *	If a network interface is not present and the process has suitable
657  *	privileges this function loads the module. If module loading is not
658  *	available in this kernel then it becomes a nop.
659  */
660 
661 void dev_load(struct net *net, const char *name)
662 {
663 	struct net_device *dev;
664 	int no_module;
665 
666 	rcu_read_lock();
667 	dev = dev_get_by_name_rcu(net, name);
668 	rcu_read_unlock();
669 
670 	no_module = !dev;
671 	if (no_module && capable(CAP_NET_ADMIN))
672 		no_module = request_module("netdev-%s", name);
673 	if (no_module && capable(CAP_SYS_MODULE))
674 		request_module("%s", name);
675 }
676 EXPORT_SYMBOL(dev_load);
677 
678 /*
679  *	This function handles all "interface"-type I/O control requests. The actual
680  *	'doing' part of this is dev_ifsioc above.
681  */
682 
683 /**
684  *	dev_ioctl	-	network device ioctl
685  *	@net: the applicable net namespace
686  *	@cmd: command to issue
687  *	@ifr: pointer to a struct ifreq in user space
688  *	@data: data exchanged with userspace
689  *	@need_copyout: whether or not copy_to_user() should be called
690  *
691  *	Issue ioctl functions to devices. This is normally called by the
692  *	user space syscall interfaces but can sometimes be useful for
693  *	other purposes. The return value is the return from the syscall if
694  *	positive or a negative errno code on error.
695  */
696 
697 int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr,
698 	      void __user *data, bool *need_copyout)
699 {
700 	int ret;
701 	char *colon;
702 
703 	if (need_copyout)
704 		*need_copyout = true;
705 	if (cmd == SIOCGIFNAME)
706 		return dev_ifname(net, ifr);
707 
708 	ifr->ifr_name[IFNAMSIZ-1] = 0;
709 
710 	colon = strchr(ifr->ifr_name, ':');
711 	if (colon)
712 		*colon = 0;
713 
714 	/*
715 	 *	See which interface the caller is talking about.
716 	 */
717 
718 	switch (cmd) {
719 	case SIOCGIFHWADDR:
720 		dev_load(net, ifr->ifr_name);
721 		ret = netif_get_mac_address(&ifr->ifr_hwaddr, net,
722 					    ifr->ifr_name);
723 		if (colon)
724 			*colon = ':';
725 		return ret;
726 	/*
727 	 *	These ioctl calls:
728 	 *	- can be done by all.
729 	 *	- atomic and do not require locking.
730 	 *	- return a value
731 	 */
732 	case SIOCGIFFLAGS:
733 	case SIOCGIFMETRIC:
734 	case SIOCGIFMTU:
735 	case SIOCGIFSLAVE:
736 	case SIOCGIFMAP:
737 	case SIOCGIFINDEX:
738 	case SIOCGIFTXQLEN:
739 		dev_load(net, ifr->ifr_name);
740 		rcu_read_lock();
741 		ret = dev_ifsioc_locked(net, ifr, cmd);
742 		rcu_read_unlock();
743 		if (colon)
744 			*colon = ':';
745 		return ret;
746 
747 	case SIOCETHTOOL:
748 		dev_load(net, ifr->ifr_name);
749 		ret = dev_ethtool(net, ifr, data);
750 		if (colon)
751 			*colon = ':';
752 		return ret;
753 
754 	/*
755 	 *	These ioctl calls:
756 	 *	- require superuser power.
757 	 *	- require strict serialization.
758 	 *	- return a value
759 	 */
760 	case SIOCGMIIPHY:
761 	case SIOCGMIIREG:
762 	case SIOCSIFNAME:
763 		dev_load(net, ifr->ifr_name);
764 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
765 			return -EPERM;
766 
767 		rtnl_net_lock(net);
768 		ret = dev_ifsioc(net, ifr, data, cmd);
769 		rtnl_net_unlock(net);
770 
771 		if (colon)
772 			*colon = ':';
773 		return ret;
774 
775 	/*
776 	 *	These ioctl calls:
777 	 *	- require superuser power.
778 	 *	- require strict serialization.
779 	 *	- do not return a value
780 	 */
781 	case SIOCSIFMAP:
782 	case SIOCSIFTXQLEN:
783 		if (!capable(CAP_NET_ADMIN))
784 			return -EPERM;
785 		fallthrough;
786 	/*
787 	 *	These ioctl calls:
788 	 *	- require local superuser power.
789 	 *	- require strict serialization.
790 	 *	- do not return a value
791 	 */
792 	case SIOCSIFFLAGS:
793 	case SIOCSIFMETRIC:
794 	case SIOCSIFMTU:
795 	case SIOCSIFHWADDR:
796 	case SIOCSIFSLAVE:
797 	case SIOCADDMULTI:
798 	case SIOCDELMULTI:
799 	case SIOCSIFHWBROADCAST:
800 	case SIOCSMIIREG:
801 	case SIOCBONDENSLAVE:
802 	case SIOCBONDRELEASE:
803 	case SIOCBONDSETHWADDR:
804 	case SIOCBONDCHANGEACTIVE:
805 	case SIOCSHWTSTAMP:
806 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
807 			return -EPERM;
808 		fallthrough;
809 	case SIOCBONDSLAVEINFOQUERY:
810 	case SIOCBONDINFOQUERY:
811 		dev_load(net, ifr->ifr_name);
812 
813 		rtnl_net_lock(net);
814 		ret = dev_ifsioc(net, ifr, data, cmd);
815 		rtnl_net_unlock(net);
816 
817 		if (need_copyout)
818 			*need_copyout = false;
819 		return ret;
820 
821 	case SIOCGIFMEM:
822 		/* Get the per device memory space. We can add this but
823 		 * currently do not support it */
824 	case SIOCSIFMEM:
825 		/* Set the per device memory buffer space.
826 		 * Not applicable in our case */
827 	case SIOCSIFLINK:
828 		return -ENOTTY;
829 
830 	/*
831 	 *	Unknown or private ioctl.
832 	 */
833 	default:
834 		if (cmd == SIOCWANDEV ||
835 		    cmd == SIOCGHWTSTAMP ||
836 		    (cmd >= SIOCDEVPRIVATE &&
837 		     cmd <= SIOCDEVPRIVATE + 15)) {
838 			dev_load(net, ifr->ifr_name);
839 
840 			rtnl_net_lock(net);
841 			ret = dev_ifsioc(net, ifr, data, cmd);
842 			rtnl_net_unlock(net);
843 			return ret;
844 		}
845 		return -ENOTTY;
846 	}
847 }
848