xref: /linux/net/ipv4/devinet.c (revision 23f50b5ac331c8c27c421a7116618355508e8427)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	NET3	IP device support routines.
4  *
5  *	Derived from the IP parts of dev.c 1.0.19
6  * 		Authors:	Ross Biro
7  *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
8  *				Mark Evans, <evansmp@uhura.aston.ac.uk>
9  *
10  *	Additional Authors:
11  *		Alan Cox, <gw4pts@gw4pts.ampr.org>
12  *		Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13  *
14  *	Changes:
15  *		Alexey Kuznetsov:	pa_* fields are replaced with ifaddr
16  *					lists.
17  *		Cyrus Durgin:		updated for kmod
18  *		Matthias Andree:	in devinet_ioctl, compare label and
19  *					address (4.4BSD alias style support),
20  *					fall back to comparing just the label
21  *					if no match found.
22  */
23 
24 
25 #include <linux/uaccess.h>
26 #include <linux/bitops.h>
27 #include <linux/capability.h>
28 #include <linux/module.h>
29 #include <linux/types.h>
30 #include <linux/kernel.h>
31 #include <linux/sched/signal.h>
32 #include <linux/string.h>
33 #include <linux/mm.h>
34 #include <linux/socket.h>
35 #include <linux/sockios.h>
36 #include <linux/in.h>
37 #include <linux/errno.h>
38 #include <linux/interrupt.h>
39 #include <linux/if_addr.h>
40 #include <linux/if_ether.h>
41 #include <linux/inet.h>
42 #include <linux/netdevice.h>
43 #include <linux/etherdevice.h>
44 #include <linux/skbuff.h>
45 #include <linux/init.h>
46 #include <linux/notifier.h>
47 #include <linux/inetdevice.h>
48 #include <linux/igmp.h>
49 #include <linux/slab.h>
50 #include <linux/hash.h>
51 #ifdef CONFIG_SYSCTL
52 #include <linux/sysctl.h>
53 #endif
54 #include <linux/kmod.h>
55 #include <linux/netconf.h>
56 
57 #include <net/arp.h>
58 #include <net/ip.h>
59 #include <net/route.h>
60 #include <net/ip_fib.h>
61 #include <net/rtnetlink.h>
62 #include <net/net_namespace.h>
63 #include <net/addrconf.h>
64 
65 #define IPV6ONLY_FLAGS	\
66 		(IFA_F_NODAD | IFA_F_OPTIMISTIC | IFA_F_DADFAILED | \
67 		 IFA_F_HOMEADDRESS | IFA_F_TENTATIVE | \
68 		 IFA_F_MANAGETEMPADDR | IFA_F_STABLE_PRIVACY)
69 
70 static struct ipv4_devconf ipv4_devconf = {
71 	.data = {
72 		[IPV4_DEVCONF_ACCEPT_REDIRECTS - 1] = 1,
73 		[IPV4_DEVCONF_SEND_REDIRECTS - 1] = 1,
74 		[IPV4_DEVCONF_SECURE_REDIRECTS - 1] = 1,
75 		[IPV4_DEVCONF_SHARED_MEDIA - 1] = 1,
76 		[IPV4_DEVCONF_IGMPV2_UNSOLICITED_REPORT_INTERVAL - 1] = 10000 /*ms*/,
77 		[IPV4_DEVCONF_IGMPV3_UNSOLICITED_REPORT_INTERVAL - 1] =  1000 /*ms*/,
78 	},
79 };
80 
81 static struct ipv4_devconf ipv4_devconf_dflt = {
82 	.data = {
83 		[IPV4_DEVCONF_ACCEPT_REDIRECTS - 1] = 1,
84 		[IPV4_DEVCONF_SEND_REDIRECTS - 1] = 1,
85 		[IPV4_DEVCONF_SECURE_REDIRECTS - 1] = 1,
86 		[IPV4_DEVCONF_SHARED_MEDIA - 1] = 1,
87 		[IPV4_DEVCONF_ACCEPT_SOURCE_ROUTE - 1] = 1,
88 		[IPV4_DEVCONF_IGMPV2_UNSOLICITED_REPORT_INTERVAL - 1] = 10000 /*ms*/,
89 		[IPV4_DEVCONF_IGMPV3_UNSOLICITED_REPORT_INTERVAL - 1] =  1000 /*ms*/,
90 	},
91 };
92 
93 #define IPV4_DEVCONF_DFLT(net, attr) \
94 	IPV4_DEVCONF((*net->ipv4.devconf_dflt), attr)
95 
96 static const struct nla_policy ifa_ipv4_policy[IFA_MAX+1] = {
97 	[IFA_LOCAL]     	= { .type = NLA_U32 },
98 	[IFA_ADDRESS]   	= { .type = NLA_U32 },
99 	[IFA_BROADCAST] 	= { .type = NLA_U32 },
100 	[IFA_LABEL]     	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
101 	[IFA_CACHEINFO]		= { .len = sizeof(struct ifa_cacheinfo) },
102 	[IFA_FLAGS]		= { .type = NLA_U32 },
103 	[IFA_RT_PRIORITY]	= { .type = NLA_U32 },
104 	[IFA_TARGET_NETNSID]	= { .type = NLA_S32 },
105 };
106 
107 struct inet_fill_args {
108 	u32 portid;
109 	u32 seq;
110 	int event;
111 	unsigned int flags;
112 	int netnsid;
113 	int ifindex;
114 };
115 
116 #define IN4_ADDR_HSIZE_SHIFT	8
117 #define IN4_ADDR_HSIZE		(1U << IN4_ADDR_HSIZE_SHIFT)
118 
119 static struct hlist_head inet_addr_lst[IN4_ADDR_HSIZE];
120 
121 static u32 inet_addr_hash(const struct net *net, __be32 addr)
122 {
123 	u32 val = (__force u32) addr ^ net_hash_mix(net);
124 
125 	return hash_32(val, IN4_ADDR_HSIZE_SHIFT);
126 }
127 
128 static void inet_hash_insert(struct net *net, struct in_ifaddr *ifa)
129 {
130 	u32 hash = inet_addr_hash(net, ifa->ifa_local);
131 
132 	ASSERT_RTNL();
133 	hlist_add_head_rcu(&ifa->hash, &inet_addr_lst[hash]);
134 }
135 
136 static void inet_hash_remove(struct in_ifaddr *ifa)
137 {
138 	ASSERT_RTNL();
139 	hlist_del_init_rcu(&ifa->hash);
140 }
141 
142 /**
143  * __ip_dev_find - find the first device with a given source address.
144  * @net: the net namespace
145  * @addr: the source address
146  * @devref: if true, take a reference on the found device
147  *
148  * If a caller uses devref=false, it should be protected by RCU, or RTNL
149  */
150 struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref)
151 {
152 	struct net_device *result = NULL;
153 	struct in_ifaddr *ifa;
154 
155 	rcu_read_lock();
156 	ifa = inet_lookup_ifaddr_rcu(net, addr);
157 	if (!ifa) {
158 		struct flowi4 fl4 = { .daddr = addr };
159 		struct fib_result res = { 0 };
160 		struct fib_table *local;
161 
162 		/* Fallback to FIB local table so that communication
163 		 * over loopback subnets work.
164 		 */
165 		local = fib_get_table(net, RT_TABLE_LOCAL);
166 		if (local &&
167 		    !fib_table_lookup(local, &fl4, &res, FIB_LOOKUP_NOREF) &&
168 		    res.type == RTN_LOCAL)
169 			result = FIB_RES_DEV(res);
170 	} else {
171 		result = ifa->ifa_dev->dev;
172 	}
173 	if (result && devref)
174 		dev_hold(result);
175 	rcu_read_unlock();
176 	return result;
177 }
178 EXPORT_SYMBOL(__ip_dev_find);
179 
180 /* called under RCU lock */
181 struct in_ifaddr *inet_lookup_ifaddr_rcu(struct net *net, __be32 addr)
182 {
183 	u32 hash = inet_addr_hash(net, addr);
184 	struct in_ifaddr *ifa;
185 
186 	hlist_for_each_entry_rcu(ifa, &inet_addr_lst[hash], hash)
187 		if (ifa->ifa_local == addr &&
188 		    net_eq(dev_net(ifa->ifa_dev->dev), net))
189 			return ifa;
190 
191 	return NULL;
192 }
193 
194 static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);
195 
196 static BLOCKING_NOTIFIER_HEAD(inetaddr_chain);
197 static BLOCKING_NOTIFIER_HEAD(inetaddr_validator_chain);
198 static void inet_del_ifa(struct in_device *in_dev,
199 			 struct in_ifaddr __rcu **ifap,
200 			 int destroy);
201 #ifdef CONFIG_SYSCTL
202 static int devinet_sysctl_register(struct in_device *idev);
203 static void devinet_sysctl_unregister(struct in_device *idev);
204 #else
205 static int devinet_sysctl_register(struct in_device *idev)
206 {
207 	return 0;
208 }
209 static void devinet_sysctl_unregister(struct in_device *idev)
210 {
211 }
212 #endif
213 
214 /* Locks all the inet devices. */
215 
216 static struct in_ifaddr *inet_alloc_ifa(void)
217 {
218 	return kzalloc(sizeof(struct in_ifaddr), GFP_KERNEL);
219 }
220 
221 static void inet_rcu_free_ifa(struct rcu_head *head)
222 {
223 	struct in_ifaddr *ifa = container_of(head, struct in_ifaddr, rcu_head);
224 	if (ifa->ifa_dev)
225 		in_dev_put(ifa->ifa_dev);
226 	kfree(ifa);
227 }
228 
229 static void inet_free_ifa(struct in_ifaddr *ifa)
230 {
231 	call_rcu(&ifa->rcu_head, inet_rcu_free_ifa);
232 }
233 
234 void in_dev_finish_destroy(struct in_device *idev)
235 {
236 	struct net_device *dev = idev->dev;
237 
238 	WARN_ON(idev->ifa_list);
239 	WARN_ON(idev->mc_list);
240 	kfree(rcu_dereference_protected(idev->mc_hash, 1));
241 #ifdef NET_REFCNT_DEBUG
242 	pr_debug("%s: %p=%s\n", __func__, idev, dev ? dev->name : "NIL");
243 #endif
244 	dev_put(dev);
245 	if (!idev->dead)
246 		pr_err("Freeing alive in_device %p\n", idev);
247 	else
248 		kfree(idev);
249 }
250 EXPORT_SYMBOL(in_dev_finish_destroy);
251 
252 static struct in_device *inetdev_init(struct net_device *dev)
253 {
254 	struct in_device *in_dev;
255 	int err = -ENOMEM;
256 
257 	ASSERT_RTNL();
258 
259 	in_dev = kzalloc(sizeof(*in_dev), GFP_KERNEL);
260 	if (!in_dev)
261 		goto out;
262 	memcpy(&in_dev->cnf, dev_net(dev)->ipv4.devconf_dflt,
263 			sizeof(in_dev->cnf));
264 	in_dev->cnf.sysctl = NULL;
265 	in_dev->dev = dev;
266 	in_dev->arp_parms = neigh_parms_alloc(dev, &arp_tbl);
267 	if (!in_dev->arp_parms)
268 		goto out_kfree;
269 	if (IPV4_DEVCONF(in_dev->cnf, FORWARDING))
270 		dev_disable_lro(dev);
271 	/* Reference in_dev->dev */
272 	dev_hold(dev);
273 	/* Account for reference dev->ip_ptr (below) */
274 	refcount_set(&in_dev->refcnt, 1);
275 
276 	err = devinet_sysctl_register(in_dev);
277 	if (err) {
278 		in_dev->dead = 1;
279 		neigh_parms_release(&arp_tbl, in_dev->arp_parms);
280 		in_dev_put(in_dev);
281 		in_dev = NULL;
282 		goto out;
283 	}
284 	ip_mc_init_dev(in_dev);
285 	if (dev->flags & IFF_UP)
286 		ip_mc_up(in_dev);
287 
288 	/* we can receive as soon as ip_ptr is set -- do this last */
289 	rcu_assign_pointer(dev->ip_ptr, in_dev);
290 out:
291 	return in_dev ?: ERR_PTR(err);
292 out_kfree:
293 	kfree(in_dev);
294 	in_dev = NULL;
295 	goto out;
296 }
297 
298 static void in_dev_rcu_put(struct rcu_head *head)
299 {
300 	struct in_device *idev = container_of(head, struct in_device, rcu_head);
301 	in_dev_put(idev);
302 }
303 
304 static void inetdev_destroy(struct in_device *in_dev)
305 {
306 	struct net_device *dev;
307 	struct in_ifaddr *ifa;
308 
309 	ASSERT_RTNL();
310 
311 	dev = in_dev->dev;
312 
313 	in_dev->dead = 1;
314 
315 	ip_mc_destroy_dev(in_dev);
316 
317 	while ((ifa = rtnl_dereference(in_dev->ifa_list)) != NULL) {
318 		inet_del_ifa(in_dev, &in_dev->ifa_list, 0);
319 		inet_free_ifa(ifa);
320 	}
321 
322 	RCU_INIT_POINTER(dev->ip_ptr, NULL);
323 
324 	devinet_sysctl_unregister(in_dev);
325 	neigh_parms_release(&arp_tbl, in_dev->arp_parms);
326 	arp_ifdown(dev);
327 
328 	call_rcu(&in_dev->rcu_head, in_dev_rcu_put);
329 }
330 
331 int inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b)
332 {
333 	const struct in_ifaddr *ifa;
334 
335 	rcu_read_lock();
336 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
337 		if (inet_ifa_match(a, ifa)) {
338 			if (!b || inet_ifa_match(b, ifa)) {
339 				rcu_read_unlock();
340 				return 1;
341 			}
342 		}
343 	}
344 	rcu_read_unlock();
345 	return 0;
346 }
347 
348 static void __inet_del_ifa(struct in_device *in_dev,
349 			   struct in_ifaddr __rcu **ifap,
350 			   int destroy, struct nlmsghdr *nlh, u32 portid)
351 {
352 	struct in_ifaddr *promote = NULL;
353 	struct in_ifaddr *ifa, *ifa1;
354 	struct in_ifaddr *last_prim;
355 	struct in_ifaddr *prev_prom = NULL;
356 	int do_promote = IN_DEV_PROMOTE_SECONDARIES(in_dev);
357 
358 	ASSERT_RTNL();
359 
360 	ifa1 = rtnl_dereference(*ifap);
361 	last_prim = rtnl_dereference(in_dev->ifa_list);
362 	if (in_dev->dead)
363 		goto no_promotions;
364 
365 	/* 1. Deleting primary ifaddr forces deletion all secondaries
366 	 * unless alias promotion is set
367 	 **/
368 
369 	if (!(ifa1->ifa_flags & IFA_F_SECONDARY)) {
370 		struct in_ifaddr __rcu **ifap1 = &ifa1->ifa_next;
371 
372 		while ((ifa = rtnl_dereference(*ifap1)) != NULL) {
373 			if (!(ifa->ifa_flags & IFA_F_SECONDARY) &&
374 			    ifa1->ifa_scope <= ifa->ifa_scope)
375 				last_prim = ifa;
376 
377 			if (!(ifa->ifa_flags & IFA_F_SECONDARY) ||
378 			    ifa1->ifa_mask != ifa->ifa_mask ||
379 			    !inet_ifa_match(ifa1->ifa_address, ifa)) {
380 				ifap1 = &ifa->ifa_next;
381 				prev_prom = ifa;
382 				continue;
383 			}
384 
385 			if (!do_promote) {
386 				inet_hash_remove(ifa);
387 				*ifap1 = ifa->ifa_next;
388 
389 				rtmsg_ifa(RTM_DELADDR, ifa, nlh, portid);
390 				blocking_notifier_call_chain(&inetaddr_chain,
391 						NETDEV_DOWN, ifa);
392 				inet_free_ifa(ifa);
393 			} else {
394 				promote = ifa;
395 				break;
396 			}
397 		}
398 	}
399 
400 	/* On promotion all secondaries from subnet are changing
401 	 * the primary IP, we must remove all their routes silently
402 	 * and later to add them back with new prefsrc. Do this
403 	 * while all addresses are on the device list.
404 	 */
405 	for (ifa = promote; ifa; ifa = rtnl_dereference(ifa->ifa_next)) {
406 		if (ifa1->ifa_mask == ifa->ifa_mask &&
407 		    inet_ifa_match(ifa1->ifa_address, ifa))
408 			fib_del_ifaddr(ifa, ifa1);
409 	}
410 
411 no_promotions:
412 	/* 2. Unlink it */
413 
414 	*ifap = ifa1->ifa_next;
415 	inet_hash_remove(ifa1);
416 
417 	/* 3. Announce address deletion */
418 
419 	/* Send message first, then call notifier.
420 	   At first sight, FIB update triggered by notifier
421 	   will refer to already deleted ifaddr, that could confuse
422 	   netlink listeners. It is not true: look, gated sees
423 	   that route deleted and if it still thinks that ifaddr
424 	   is valid, it will try to restore deleted routes... Grr.
425 	   So that, this order is correct.
426 	 */
427 	rtmsg_ifa(RTM_DELADDR, ifa1, nlh, portid);
428 	blocking_notifier_call_chain(&inetaddr_chain, NETDEV_DOWN, ifa1);
429 
430 	if (promote) {
431 		struct in_ifaddr *next_sec;
432 
433 		next_sec = rtnl_dereference(promote->ifa_next);
434 		if (prev_prom) {
435 			struct in_ifaddr *last_sec;
436 
437 			rcu_assign_pointer(prev_prom->ifa_next, next_sec);
438 
439 			last_sec = rtnl_dereference(last_prim->ifa_next);
440 			rcu_assign_pointer(promote->ifa_next, last_sec);
441 			rcu_assign_pointer(last_prim->ifa_next, promote);
442 		}
443 
444 		promote->ifa_flags &= ~IFA_F_SECONDARY;
445 		rtmsg_ifa(RTM_NEWADDR, promote, nlh, portid);
446 		blocking_notifier_call_chain(&inetaddr_chain,
447 				NETDEV_UP, promote);
448 		for (ifa = next_sec; ifa;
449 		     ifa = rtnl_dereference(ifa->ifa_next)) {
450 			if (ifa1->ifa_mask != ifa->ifa_mask ||
451 			    !inet_ifa_match(ifa1->ifa_address, ifa))
452 					continue;
453 			fib_add_ifaddr(ifa);
454 		}
455 
456 	}
457 	if (destroy)
458 		inet_free_ifa(ifa1);
459 }
460 
461 static void inet_del_ifa(struct in_device *in_dev,
462 			 struct in_ifaddr __rcu **ifap,
463 			 int destroy)
464 {
465 	__inet_del_ifa(in_dev, ifap, destroy, NULL, 0);
466 }
467 
468 static void check_lifetime(struct work_struct *work);
469 
470 static DECLARE_DELAYED_WORK(check_lifetime_work, check_lifetime);
471 
472 static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
473 			     u32 portid, struct netlink_ext_ack *extack)
474 {
475 	struct in_ifaddr __rcu **last_primary, **ifap;
476 	struct in_device *in_dev = ifa->ifa_dev;
477 	struct in_validator_info ivi;
478 	struct in_ifaddr *ifa1;
479 	int ret;
480 
481 	ASSERT_RTNL();
482 
483 	if (!ifa->ifa_local) {
484 		inet_free_ifa(ifa);
485 		return 0;
486 	}
487 
488 	ifa->ifa_flags &= ~IFA_F_SECONDARY;
489 	last_primary = &in_dev->ifa_list;
490 
491 	/* Don't set IPv6 only flags to IPv4 addresses */
492 	ifa->ifa_flags &= ~IPV6ONLY_FLAGS;
493 
494 	ifap = &in_dev->ifa_list;
495 	ifa1 = rtnl_dereference(*ifap);
496 
497 	while (ifa1) {
498 		if (!(ifa1->ifa_flags & IFA_F_SECONDARY) &&
499 		    ifa->ifa_scope <= ifa1->ifa_scope)
500 			last_primary = &ifa1->ifa_next;
501 		if (ifa1->ifa_mask == ifa->ifa_mask &&
502 		    inet_ifa_match(ifa1->ifa_address, ifa)) {
503 			if (ifa1->ifa_local == ifa->ifa_local) {
504 				inet_free_ifa(ifa);
505 				return -EEXIST;
506 			}
507 			if (ifa1->ifa_scope != ifa->ifa_scope) {
508 				inet_free_ifa(ifa);
509 				return -EINVAL;
510 			}
511 			ifa->ifa_flags |= IFA_F_SECONDARY;
512 		}
513 
514 		ifap = &ifa1->ifa_next;
515 		ifa1 = rtnl_dereference(*ifap);
516 	}
517 
518 	/* Allow any devices that wish to register ifaddr validtors to weigh
519 	 * in now, before changes are committed.  The rntl lock is serializing
520 	 * access here, so the state should not change between a validator call
521 	 * and a final notify on commit.  This isn't invoked on promotion under
522 	 * the assumption that validators are checking the address itself, and
523 	 * not the flags.
524 	 */
525 	ivi.ivi_addr = ifa->ifa_address;
526 	ivi.ivi_dev = ifa->ifa_dev;
527 	ivi.extack = extack;
528 	ret = blocking_notifier_call_chain(&inetaddr_validator_chain,
529 					   NETDEV_UP, &ivi);
530 	ret = notifier_to_errno(ret);
531 	if (ret) {
532 		inet_free_ifa(ifa);
533 		return ret;
534 	}
535 
536 	if (!(ifa->ifa_flags & IFA_F_SECONDARY)) {
537 		prandom_seed((__force u32) ifa->ifa_local);
538 		ifap = last_primary;
539 	}
540 
541 	rcu_assign_pointer(ifa->ifa_next, *ifap);
542 	rcu_assign_pointer(*ifap, ifa);
543 
544 	inet_hash_insert(dev_net(in_dev->dev), ifa);
545 
546 	cancel_delayed_work(&check_lifetime_work);
547 	queue_delayed_work(system_power_efficient_wq, &check_lifetime_work, 0);
548 
549 	/* Send message first, then call notifier.
550 	   Notifier will trigger FIB update, so that
551 	   listeners of netlink will know about new ifaddr */
552 	rtmsg_ifa(RTM_NEWADDR, ifa, nlh, portid);
553 	blocking_notifier_call_chain(&inetaddr_chain, NETDEV_UP, ifa);
554 
555 	return 0;
556 }
557 
558 static int inet_insert_ifa(struct in_ifaddr *ifa)
559 {
560 	return __inet_insert_ifa(ifa, NULL, 0, NULL);
561 }
562 
563 static int inet_set_ifa(struct net_device *dev, struct in_ifaddr *ifa)
564 {
565 	struct in_device *in_dev = __in_dev_get_rtnl(dev);
566 
567 	ASSERT_RTNL();
568 
569 	if (!in_dev) {
570 		inet_free_ifa(ifa);
571 		return -ENOBUFS;
572 	}
573 	ipv4_devconf_setall(in_dev);
574 	neigh_parms_data_state_setall(in_dev->arp_parms);
575 	if (ifa->ifa_dev != in_dev) {
576 		WARN_ON(ifa->ifa_dev);
577 		in_dev_hold(in_dev);
578 		ifa->ifa_dev = in_dev;
579 	}
580 	if (ipv4_is_loopback(ifa->ifa_local))
581 		ifa->ifa_scope = RT_SCOPE_HOST;
582 	return inet_insert_ifa(ifa);
583 }
584 
585 /* Caller must hold RCU or RTNL :
586  * We dont take a reference on found in_device
587  */
588 struct in_device *inetdev_by_index(struct net *net, int ifindex)
589 {
590 	struct net_device *dev;
591 	struct in_device *in_dev = NULL;
592 
593 	rcu_read_lock();
594 	dev = dev_get_by_index_rcu(net, ifindex);
595 	if (dev)
596 		in_dev = rcu_dereference_rtnl(dev->ip_ptr);
597 	rcu_read_unlock();
598 	return in_dev;
599 }
600 EXPORT_SYMBOL(inetdev_by_index);
601 
602 /* Called only from RTNL semaphored context. No locks. */
603 
604 struct in_ifaddr *inet_ifa_byprefix(struct in_device *in_dev, __be32 prefix,
605 				    __be32 mask)
606 {
607 	struct in_ifaddr *ifa;
608 
609 	ASSERT_RTNL();
610 
611 	in_dev_for_each_ifa_rtnl(ifa, in_dev) {
612 		if (ifa->ifa_mask == mask && inet_ifa_match(prefix, ifa))
613 			return ifa;
614 	}
615 	return NULL;
616 }
617 
618 static int ip_mc_autojoin_config(struct net *net, bool join,
619 				 const struct in_ifaddr *ifa)
620 {
621 #if defined(CONFIG_IP_MULTICAST)
622 	struct ip_mreqn mreq = {
623 		.imr_multiaddr.s_addr = ifa->ifa_address,
624 		.imr_ifindex = ifa->ifa_dev->dev->ifindex,
625 	};
626 	struct sock *sk = net->ipv4.mc_autojoin_sk;
627 	int ret;
628 
629 	ASSERT_RTNL();
630 
631 	lock_sock(sk);
632 	if (join)
633 		ret = ip_mc_join_group(sk, &mreq);
634 	else
635 		ret = ip_mc_leave_group(sk, &mreq);
636 	release_sock(sk);
637 
638 	return ret;
639 #else
640 	return -EOPNOTSUPP;
641 #endif
642 }
643 
644 static int inet_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh,
645 			    struct netlink_ext_ack *extack)
646 {
647 	struct net *net = sock_net(skb->sk);
648 	struct in_ifaddr __rcu **ifap;
649 	struct nlattr *tb[IFA_MAX+1];
650 	struct in_device *in_dev;
651 	struct ifaddrmsg *ifm;
652 	struct in_ifaddr *ifa;
653 	int err;
654 
655 	ASSERT_RTNL();
656 
657 	err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFA_MAX,
658 				     ifa_ipv4_policy, extack);
659 	if (err < 0)
660 		goto errout;
661 
662 	ifm = nlmsg_data(nlh);
663 	in_dev = inetdev_by_index(net, ifm->ifa_index);
664 	if (!in_dev) {
665 		err = -ENODEV;
666 		goto errout;
667 	}
668 
669 	for (ifap = &in_dev->ifa_list; (ifa = rtnl_dereference(*ifap)) != NULL;
670 	     ifap = &ifa->ifa_next) {
671 		if (tb[IFA_LOCAL] &&
672 		    ifa->ifa_local != nla_get_in_addr(tb[IFA_LOCAL]))
673 			continue;
674 
675 		if (tb[IFA_LABEL] && nla_strcmp(tb[IFA_LABEL], ifa->ifa_label))
676 			continue;
677 
678 		if (tb[IFA_ADDRESS] &&
679 		    (ifm->ifa_prefixlen != ifa->ifa_prefixlen ||
680 		    !inet_ifa_match(nla_get_in_addr(tb[IFA_ADDRESS]), ifa)))
681 			continue;
682 
683 		if (ipv4_is_multicast(ifa->ifa_address))
684 			ip_mc_autojoin_config(net, false, ifa);
685 		__inet_del_ifa(in_dev, ifap, 1, nlh, NETLINK_CB(skb).portid);
686 		return 0;
687 	}
688 
689 	err = -EADDRNOTAVAIL;
690 errout:
691 	return err;
692 }
693 
694 #define INFINITY_LIFE_TIME	0xFFFFFFFF
695 
696 static void check_lifetime(struct work_struct *work)
697 {
698 	unsigned long now, next, next_sec, next_sched;
699 	struct in_ifaddr *ifa;
700 	struct hlist_node *n;
701 	int i;
702 
703 	now = jiffies;
704 	next = round_jiffies_up(now + ADDR_CHECK_FREQUENCY);
705 
706 	for (i = 0; i < IN4_ADDR_HSIZE; i++) {
707 		bool change_needed = false;
708 
709 		rcu_read_lock();
710 		hlist_for_each_entry_rcu(ifa, &inet_addr_lst[i], hash) {
711 			unsigned long age;
712 
713 			if (ifa->ifa_flags & IFA_F_PERMANENT)
714 				continue;
715 
716 			/* We try to batch several events at once. */
717 			age = (now - ifa->ifa_tstamp +
718 			       ADDRCONF_TIMER_FUZZ_MINUS) / HZ;
719 
720 			if (ifa->ifa_valid_lft != INFINITY_LIFE_TIME &&
721 			    age >= ifa->ifa_valid_lft) {
722 				change_needed = true;
723 			} else if (ifa->ifa_preferred_lft ==
724 				   INFINITY_LIFE_TIME) {
725 				continue;
726 			} else if (age >= ifa->ifa_preferred_lft) {
727 				if (time_before(ifa->ifa_tstamp +
728 						ifa->ifa_valid_lft * HZ, next))
729 					next = ifa->ifa_tstamp +
730 					       ifa->ifa_valid_lft * HZ;
731 
732 				if (!(ifa->ifa_flags & IFA_F_DEPRECATED))
733 					change_needed = true;
734 			} else if (time_before(ifa->ifa_tstamp +
735 					       ifa->ifa_preferred_lft * HZ,
736 					       next)) {
737 				next = ifa->ifa_tstamp +
738 				       ifa->ifa_preferred_lft * HZ;
739 			}
740 		}
741 		rcu_read_unlock();
742 		if (!change_needed)
743 			continue;
744 		rtnl_lock();
745 		hlist_for_each_entry_safe(ifa, n, &inet_addr_lst[i], hash) {
746 			unsigned long age;
747 
748 			if (ifa->ifa_flags & IFA_F_PERMANENT)
749 				continue;
750 
751 			/* We try to batch several events at once. */
752 			age = (now - ifa->ifa_tstamp +
753 			       ADDRCONF_TIMER_FUZZ_MINUS) / HZ;
754 
755 			if (ifa->ifa_valid_lft != INFINITY_LIFE_TIME &&
756 			    age >= ifa->ifa_valid_lft) {
757 				struct in_ifaddr __rcu **ifap;
758 				struct in_ifaddr *tmp;
759 
760 				ifap = &ifa->ifa_dev->ifa_list;
761 				tmp = rtnl_dereference(*ifap);
762 				while (tmp) {
763 					if (tmp == ifa) {
764 						inet_del_ifa(ifa->ifa_dev,
765 							     ifap, 1);
766 						break;
767 					}
768 					ifap = &tmp->ifa_next;
769 					tmp = rtnl_dereference(*ifap);
770 				}
771 			} else if (ifa->ifa_preferred_lft !=
772 				   INFINITY_LIFE_TIME &&
773 				   age >= ifa->ifa_preferred_lft &&
774 				   !(ifa->ifa_flags & IFA_F_DEPRECATED)) {
775 				ifa->ifa_flags |= IFA_F_DEPRECATED;
776 				rtmsg_ifa(RTM_NEWADDR, ifa, NULL, 0);
777 			}
778 		}
779 		rtnl_unlock();
780 	}
781 
782 	next_sec = round_jiffies_up(next);
783 	next_sched = next;
784 
785 	/* If rounded timeout is accurate enough, accept it. */
786 	if (time_before(next_sec, next + ADDRCONF_TIMER_FUZZ))
787 		next_sched = next_sec;
788 
789 	now = jiffies;
790 	/* And minimum interval is ADDRCONF_TIMER_FUZZ_MAX. */
791 	if (time_before(next_sched, now + ADDRCONF_TIMER_FUZZ_MAX))
792 		next_sched = now + ADDRCONF_TIMER_FUZZ_MAX;
793 
794 	queue_delayed_work(system_power_efficient_wq, &check_lifetime_work,
795 			next_sched - now);
796 }
797 
798 static void set_ifa_lifetime(struct in_ifaddr *ifa, __u32 valid_lft,
799 			     __u32 prefered_lft)
800 {
801 	unsigned long timeout;
802 
803 	ifa->ifa_flags &= ~(IFA_F_PERMANENT | IFA_F_DEPRECATED);
804 
805 	timeout = addrconf_timeout_fixup(valid_lft, HZ);
806 	if (addrconf_finite_timeout(timeout))
807 		ifa->ifa_valid_lft = timeout;
808 	else
809 		ifa->ifa_flags |= IFA_F_PERMANENT;
810 
811 	timeout = addrconf_timeout_fixup(prefered_lft, HZ);
812 	if (addrconf_finite_timeout(timeout)) {
813 		if (timeout == 0)
814 			ifa->ifa_flags |= IFA_F_DEPRECATED;
815 		ifa->ifa_preferred_lft = timeout;
816 	}
817 	ifa->ifa_tstamp = jiffies;
818 	if (!ifa->ifa_cstamp)
819 		ifa->ifa_cstamp = ifa->ifa_tstamp;
820 }
821 
822 static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh,
823 				       __u32 *pvalid_lft, __u32 *pprefered_lft,
824 				       struct netlink_ext_ack *extack)
825 {
826 	struct nlattr *tb[IFA_MAX+1];
827 	struct in_ifaddr *ifa;
828 	struct ifaddrmsg *ifm;
829 	struct net_device *dev;
830 	struct in_device *in_dev;
831 	int err;
832 
833 	err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFA_MAX,
834 				     ifa_ipv4_policy, extack);
835 	if (err < 0)
836 		goto errout;
837 
838 	ifm = nlmsg_data(nlh);
839 	err = -EINVAL;
840 	if (ifm->ifa_prefixlen > 32 || !tb[IFA_LOCAL])
841 		goto errout;
842 
843 	dev = __dev_get_by_index(net, ifm->ifa_index);
844 	err = -ENODEV;
845 	if (!dev)
846 		goto errout;
847 
848 	in_dev = __in_dev_get_rtnl(dev);
849 	err = -ENOBUFS;
850 	if (!in_dev)
851 		goto errout;
852 
853 	ifa = inet_alloc_ifa();
854 	if (!ifa)
855 		/*
856 		 * A potential indev allocation can be left alive, it stays
857 		 * assigned to its device and is destroy with it.
858 		 */
859 		goto errout;
860 
861 	ipv4_devconf_setall(in_dev);
862 	neigh_parms_data_state_setall(in_dev->arp_parms);
863 	in_dev_hold(in_dev);
864 
865 	if (!tb[IFA_ADDRESS])
866 		tb[IFA_ADDRESS] = tb[IFA_LOCAL];
867 
868 	INIT_HLIST_NODE(&ifa->hash);
869 	ifa->ifa_prefixlen = ifm->ifa_prefixlen;
870 	ifa->ifa_mask = inet_make_mask(ifm->ifa_prefixlen);
871 	ifa->ifa_flags = tb[IFA_FLAGS] ? nla_get_u32(tb[IFA_FLAGS]) :
872 					 ifm->ifa_flags;
873 	ifa->ifa_scope = ifm->ifa_scope;
874 	ifa->ifa_dev = in_dev;
875 
876 	ifa->ifa_local = nla_get_in_addr(tb[IFA_LOCAL]);
877 	ifa->ifa_address = nla_get_in_addr(tb[IFA_ADDRESS]);
878 
879 	if (tb[IFA_BROADCAST])
880 		ifa->ifa_broadcast = nla_get_in_addr(tb[IFA_BROADCAST]);
881 
882 	if (tb[IFA_LABEL])
883 		nla_strscpy(ifa->ifa_label, tb[IFA_LABEL], IFNAMSIZ);
884 	else
885 		memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
886 
887 	if (tb[IFA_RT_PRIORITY])
888 		ifa->ifa_rt_priority = nla_get_u32(tb[IFA_RT_PRIORITY]);
889 
890 	if (tb[IFA_CACHEINFO]) {
891 		struct ifa_cacheinfo *ci;
892 
893 		ci = nla_data(tb[IFA_CACHEINFO]);
894 		if (!ci->ifa_valid || ci->ifa_prefered > ci->ifa_valid) {
895 			err = -EINVAL;
896 			goto errout_free;
897 		}
898 		*pvalid_lft = ci->ifa_valid;
899 		*pprefered_lft = ci->ifa_prefered;
900 	}
901 
902 	return ifa;
903 
904 errout_free:
905 	inet_free_ifa(ifa);
906 errout:
907 	return ERR_PTR(err);
908 }
909 
910 static struct in_ifaddr *find_matching_ifa(struct in_ifaddr *ifa)
911 {
912 	struct in_device *in_dev = ifa->ifa_dev;
913 	struct in_ifaddr *ifa1;
914 
915 	if (!ifa->ifa_local)
916 		return NULL;
917 
918 	in_dev_for_each_ifa_rtnl(ifa1, in_dev) {
919 		if (ifa1->ifa_mask == ifa->ifa_mask &&
920 		    inet_ifa_match(ifa1->ifa_address, ifa) &&
921 		    ifa1->ifa_local == ifa->ifa_local)
922 			return ifa1;
923 	}
924 	return NULL;
925 }
926 
927 static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh,
928 			    struct netlink_ext_ack *extack)
929 {
930 	struct net *net = sock_net(skb->sk);
931 	struct in_ifaddr *ifa;
932 	struct in_ifaddr *ifa_existing;
933 	__u32 valid_lft = INFINITY_LIFE_TIME;
934 	__u32 prefered_lft = INFINITY_LIFE_TIME;
935 
936 	ASSERT_RTNL();
937 
938 	ifa = rtm_to_ifaddr(net, nlh, &valid_lft, &prefered_lft, extack);
939 	if (IS_ERR(ifa))
940 		return PTR_ERR(ifa);
941 
942 	ifa_existing = find_matching_ifa(ifa);
943 	if (!ifa_existing) {
944 		/* It would be best to check for !NLM_F_CREATE here but
945 		 * userspace already relies on not having to provide this.
946 		 */
947 		set_ifa_lifetime(ifa, valid_lft, prefered_lft);
948 		if (ifa->ifa_flags & IFA_F_MCAUTOJOIN) {
949 			int ret = ip_mc_autojoin_config(net, true, ifa);
950 
951 			if (ret < 0) {
952 				inet_free_ifa(ifa);
953 				return ret;
954 			}
955 		}
956 		return __inet_insert_ifa(ifa, nlh, NETLINK_CB(skb).portid,
957 					 extack);
958 	} else {
959 		u32 new_metric = ifa->ifa_rt_priority;
960 
961 		inet_free_ifa(ifa);
962 
963 		if (nlh->nlmsg_flags & NLM_F_EXCL ||
964 		    !(nlh->nlmsg_flags & NLM_F_REPLACE))
965 			return -EEXIST;
966 		ifa = ifa_existing;
967 
968 		if (ifa->ifa_rt_priority != new_metric) {
969 			fib_modify_prefix_metric(ifa, new_metric);
970 			ifa->ifa_rt_priority = new_metric;
971 		}
972 
973 		set_ifa_lifetime(ifa, valid_lft, prefered_lft);
974 		cancel_delayed_work(&check_lifetime_work);
975 		queue_delayed_work(system_power_efficient_wq,
976 				&check_lifetime_work, 0);
977 		rtmsg_ifa(RTM_NEWADDR, ifa, nlh, NETLINK_CB(skb).portid);
978 	}
979 	return 0;
980 }
981 
982 /*
983  *	Determine a default network mask, based on the IP address.
984  */
985 
986 static int inet_abc_len(__be32 addr)
987 {
988 	int rc = -1;	/* Something else, probably a multicast. */
989 
990 	if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
991 		rc = 0;
992 	else {
993 		__u32 haddr = ntohl(addr);
994 		if (IN_CLASSA(haddr))
995 			rc = 8;
996 		else if (IN_CLASSB(haddr))
997 			rc = 16;
998 		else if (IN_CLASSC(haddr))
999 			rc = 24;
1000 		else if (IN_CLASSE(haddr))
1001 			rc = 32;
1002 	}
1003 
1004 	return rc;
1005 }
1006 
1007 
1008 int devinet_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr)
1009 {
1010 	struct sockaddr_in sin_orig;
1011 	struct sockaddr_in *sin = (struct sockaddr_in *)&ifr->ifr_addr;
1012 	struct in_ifaddr __rcu **ifap = NULL;
1013 	struct in_device *in_dev;
1014 	struct in_ifaddr *ifa = NULL;
1015 	struct net_device *dev;
1016 	char *colon;
1017 	int ret = -EFAULT;
1018 	int tryaddrmatch = 0;
1019 
1020 	ifr->ifr_name[IFNAMSIZ - 1] = 0;
1021 
1022 	/* save original address for comparison */
1023 	memcpy(&sin_orig, sin, sizeof(*sin));
1024 
1025 	colon = strchr(ifr->ifr_name, ':');
1026 	if (colon)
1027 		*colon = 0;
1028 
1029 	dev_load(net, ifr->ifr_name);
1030 
1031 	switch (cmd) {
1032 	case SIOCGIFADDR:	/* Get interface address */
1033 	case SIOCGIFBRDADDR:	/* Get the broadcast address */
1034 	case SIOCGIFDSTADDR:	/* Get the destination address */
1035 	case SIOCGIFNETMASK:	/* Get the netmask for the interface */
1036 		/* Note that these ioctls will not sleep,
1037 		   so that we do not impose a lock.
1038 		   One day we will be forced to put shlock here (I mean SMP)
1039 		 */
1040 		tryaddrmatch = (sin_orig.sin_family == AF_INET);
1041 		memset(sin, 0, sizeof(*sin));
1042 		sin->sin_family = AF_INET;
1043 		break;
1044 
1045 	case SIOCSIFFLAGS:
1046 		ret = -EPERM;
1047 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1048 			goto out;
1049 		break;
1050 	case SIOCSIFADDR:	/* Set interface address (and family) */
1051 	case SIOCSIFBRDADDR:	/* Set the broadcast address */
1052 	case SIOCSIFDSTADDR:	/* Set the destination address */
1053 	case SIOCSIFNETMASK: 	/* Set the netmask for the interface */
1054 		ret = -EPERM;
1055 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1056 			goto out;
1057 		ret = -EINVAL;
1058 		if (sin->sin_family != AF_INET)
1059 			goto out;
1060 		break;
1061 	default:
1062 		ret = -EINVAL;
1063 		goto out;
1064 	}
1065 
1066 	rtnl_lock();
1067 
1068 	ret = -ENODEV;
1069 	dev = __dev_get_by_name(net, ifr->ifr_name);
1070 	if (!dev)
1071 		goto done;
1072 
1073 	if (colon)
1074 		*colon = ':';
1075 
1076 	in_dev = __in_dev_get_rtnl(dev);
1077 	if (in_dev) {
1078 		if (tryaddrmatch) {
1079 			/* Matthias Andree */
1080 			/* compare label and address (4.4BSD style) */
1081 			/* note: we only do this for a limited set of ioctls
1082 			   and only if the original address family was AF_INET.
1083 			   This is checked above. */
1084 
1085 			for (ifap = &in_dev->ifa_list;
1086 			     (ifa = rtnl_dereference(*ifap)) != NULL;
1087 			     ifap = &ifa->ifa_next) {
1088 				if (!strcmp(ifr->ifr_name, ifa->ifa_label) &&
1089 				    sin_orig.sin_addr.s_addr ==
1090 							ifa->ifa_local) {
1091 					break; /* found */
1092 				}
1093 			}
1094 		}
1095 		/* we didn't get a match, maybe the application is
1096 		   4.3BSD-style and passed in junk so we fall back to
1097 		   comparing just the label */
1098 		if (!ifa) {
1099 			for (ifap = &in_dev->ifa_list;
1100 			     (ifa = rtnl_dereference(*ifap)) != NULL;
1101 			     ifap = &ifa->ifa_next)
1102 				if (!strcmp(ifr->ifr_name, ifa->ifa_label))
1103 					break;
1104 		}
1105 	}
1106 
1107 	ret = -EADDRNOTAVAIL;
1108 	if (!ifa && cmd != SIOCSIFADDR && cmd != SIOCSIFFLAGS)
1109 		goto done;
1110 
1111 	switch (cmd) {
1112 	case SIOCGIFADDR:	/* Get interface address */
1113 		ret = 0;
1114 		sin->sin_addr.s_addr = ifa->ifa_local;
1115 		break;
1116 
1117 	case SIOCGIFBRDADDR:	/* Get the broadcast address */
1118 		ret = 0;
1119 		sin->sin_addr.s_addr = ifa->ifa_broadcast;
1120 		break;
1121 
1122 	case SIOCGIFDSTADDR:	/* Get the destination address */
1123 		ret = 0;
1124 		sin->sin_addr.s_addr = ifa->ifa_address;
1125 		break;
1126 
1127 	case SIOCGIFNETMASK:	/* Get the netmask for the interface */
1128 		ret = 0;
1129 		sin->sin_addr.s_addr = ifa->ifa_mask;
1130 		break;
1131 
1132 	case SIOCSIFFLAGS:
1133 		if (colon) {
1134 			ret = -EADDRNOTAVAIL;
1135 			if (!ifa)
1136 				break;
1137 			ret = 0;
1138 			if (!(ifr->ifr_flags & IFF_UP))
1139 				inet_del_ifa(in_dev, ifap, 1);
1140 			break;
1141 		}
1142 		ret = dev_change_flags(dev, ifr->ifr_flags, NULL);
1143 		break;
1144 
1145 	case SIOCSIFADDR:	/* Set interface address (and family) */
1146 		ret = -EINVAL;
1147 		if (inet_abc_len(sin->sin_addr.s_addr) < 0)
1148 			break;
1149 
1150 		if (!ifa) {
1151 			ret = -ENOBUFS;
1152 			ifa = inet_alloc_ifa();
1153 			if (!ifa)
1154 				break;
1155 			INIT_HLIST_NODE(&ifa->hash);
1156 			if (colon)
1157 				memcpy(ifa->ifa_label, ifr->ifr_name, IFNAMSIZ);
1158 			else
1159 				memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
1160 		} else {
1161 			ret = 0;
1162 			if (ifa->ifa_local == sin->sin_addr.s_addr)
1163 				break;
1164 			inet_del_ifa(in_dev, ifap, 0);
1165 			ifa->ifa_broadcast = 0;
1166 			ifa->ifa_scope = 0;
1167 		}
1168 
1169 		ifa->ifa_address = ifa->ifa_local = sin->sin_addr.s_addr;
1170 
1171 		if (!(dev->flags & IFF_POINTOPOINT)) {
1172 			ifa->ifa_prefixlen = inet_abc_len(ifa->ifa_address);
1173 			ifa->ifa_mask = inet_make_mask(ifa->ifa_prefixlen);
1174 			if ((dev->flags & IFF_BROADCAST) &&
1175 			    ifa->ifa_prefixlen < 31)
1176 				ifa->ifa_broadcast = ifa->ifa_address |
1177 						     ~ifa->ifa_mask;
1178 		} else {
1179 			ifa->ifa_prefixlen = 32;
1180 			ifa->ifa_mask = inet_make_mask(32);
1181 		}
1182 		set_ifa_lifetime(ifa, INFINITY_LIFE_TIME, INFINITY_LIFE_TIME);
1183 		ret = inet_set_ifa(dev, ifa);
1184 		break;
1185 
1186 	case SIOCSIFBRDADDR:	/* Set the broadcast address */
1187 		ret = 0;
1188 		if (ifa->ifa_broadcast != sin->sin_addr.s_addr) {
1189 			inet_del_ifa(in_dev, ifap, 0);
1190 			ifa->ifa_broadcast = sin->sin_addr.s_addr;
1191 			inet_insert_ifa(ifa);
1192 		}
1193 		break;
1194 
1195 	case SIOCSIFDSTADDR:	/* Set the destination address */
1196 		ret = 0;
1197 		if (ifa->ifa_address == sin->sin_addr.s_addr)
1198 			break;
1199 		ret = -EINVAL;
1200 		if (inet_abc_len(sin->sin_addr.s_addr) < 0)
1201 			break;
1202 		ret = 0;
1203 		inet_del_ifa(in_dev, ifap, 0);
1204 		ifa->ifa_address = sin->sin_addr.s_addr;
1205 		inet_insert_ifa(ifa);
1206 		break;
1207 
1208 	case SIOCSIFNETMASK: 	/* Set the netmask for the interface */
1209 
1210 		/*
1211 		 *	The mask we set must be legal.
1212 		 */
1213 		ret = -EINVAL;
1214 		if (bad_mask(sin->sin_addr.s_addr, 0))
1215 			break;
1216 		ret = 0;
1217 		if (ifa->ifa_mask != sin->sin_addr.s_addr) {
1218 			__be32 old_mask = ifa->ifa_mask;
1219 			inet_del_ifa(in_dev, ifap, 0);
1220 			ifa->ifa_mask = sin->sin_addr.s_addr;
1221 			ifa->ifa_prefixlen = inet_mask_len(ifa->ifa_mask);
1222 
1223 			/* See if current broadcast address matches
1224 			 * with current netmask, then recalculate
1225 			 * the broadcast address. Otherwise it's a
1226 			 * funny address, so don't touch it since
1227 			 * the user seems to know what (s)he's doing...
1228 			 */
1229 			if ((dev->flags & IFF_BROADCAST) &&
1230 			    (ifa->ifa_prefixlen < 31) &&
1231 			    (ifa->ifa_broadcast ==
1232 			     (ifa->ifa_local|~old_mask))) {
1233 				ifa->ifa_broadcast = (ifa->ifa_local |
1234 						      ~sin->sin_addr.s_addr);
1235 			}
1236 			inet_insert_ifa(ifa);
1237 		}
1238 		break;
1239 	}
1240 done:
1241 	rtnl_unlock();
1242 out:
1243 	return ret;
1244 }
1245 
1246 static int inet_gifconf(struct net_device *dev, char __user *buf, int len, int size)
1247 {
1248 	struct in_device *in_dev = __in_dev_get_rtnl(dev);
1249 	const struct in_ifaddr *ifa;
1250 	struct ifreq ifr;
1251 	int done = 0;
1252 
1253 	if (WARN_ON(size > sizeof(struct ifreq)))
1254 		goto out;
1255 
1256 	if (!in_dev)
1257 		goto out;
1258 
1259 	in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1260 		if (!buf) {
1261 			done += size;
1262 			continue;
1263 		}
1264 		if (len < size)
1265 			break;
1266 		memset(&ifr, 0, sizeof(struct ifreq));
1267 		strcpy(ifr.ifr_name, ifa->ifa_label);
1268 
1269 		(*(struct sockaddr_in *)&ifr.ifr_addr).sin_family = AF_INET;
1270 		(*(struct sockaddr_in *)&ifr.ifr_addr).sin_addr.s_addr =
1271 								ifa->ifa_local;
1272 
1273 		if (copy_to_user(buf + done, &ifr, size)) {
1274 			done = -EFAULT;
1275 			break;
1276 		}
1277 		len  -= size;
1278 		done += size;
1279 	}
1280 out:
1281 	return done;
1282 }
1283 
1284 static __be32 in_dev_select_addr(const struct in_device *in_dev,
1285 				 int scope)
1286 {
1287 	const struct in_ifaddr *ifa;
1288 
1289 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
1290 		if (ifa->ifa_flags & IFA_F_SECONDARY)
1291 			continue;
1292 		if (ifa->ifa_scope != RT_SCOPE_LINK &&
1293 		    ifa->ifa_scope <= scope)
1294 			return ifa->ifa_local;
1295 	}
1296 
1297 	return 0;
1298 }
1299 
1300 __be32 inet_select_addr(const struct net_device *dev, __be32 dst, int scope)
1301 {
1302 	const struct in_ifaddr *ifa;
1303 	__be32 addr = 0;
1304 	unsigned char localnet_scope = RT_SCOPE_HOST;
1305 	struct in_device *in_dev;
1306 	struct net *net = dev_net(dev);
1307 	int master_idx;
1308 
1309 	rcu_read_lock();
1310 	in_dev = __in_dev_get_rcu(dev);
1311 	if (!in_dev)
1312 		goto no_in_dev;
1313 
1314 	if (unlikely(IN_DEV_ROUTE_LOCALNET(in_dev)))
1315 		localnet_scope = RT_SCOPE_LINK;
1316 
1317 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
1318 		if (ifa->ifa_flags & IFA_F_SECONDARY)
1319 			continue;
1320 		if (min(ifa->ifa_scope, localnet_scope) > scope)
1321 			continue;
1322 		if (!dst || inet_ifa_match(dst, ifa)) {
1323 			addr = ifa->ifa_local;
1324 			break;
1325 		}
1326 		if (!addr)
1327 			addr = ifa->ifa_local;
1328 	}
1329 
1330 	if (addr)
1331 		goto out_unlock;
1332 no_in_dev:
1333 	master_idx = l3mdev_master_ifindex_rcu(dev);
1334 
1335 	/* For VRFs, the VRF device takes the place of the loopback device,
1336 	 * with addresses on it being preferred.  Note in such cases the
1337 	 * loopback device will be among the devices that fail the master_idx
1338 	 * equality check in the loop below.
1339 	 */
1340 	if (master_idx &&
1341 	    (dev = dev_get_by_index_rcu(net, master_idx)) &&
1342 	    (in_dev = __in_dev_get_rcu(dev))) {
1343 		addr = in_dev_select_addr(in_dev, scope);
1344 		if (addr)
1345 			goto out_unlock;
1346 	}
1347 
1348 	/* Not loopback addresses on loopback should be preferred
1349 	   in this case. It is important that lo is the first interface
1350 	   in dev_base list.
1351 	 */
1352 	for_each_netdev_rcu(net, dev) {
1353 		if (l3mdev_master_ifindex_rcu(dev) != master_idx)
1354 			continue;
1355 
1356 		in_dev = __in_dev_get_rcu(dev);
1357 		if (!in_dev)
1358 			continue;
1359 
1360 		addr = in_dev_select_addr(in_dev, scope);
1361 		if (addr)
1362 			goto out_unlock;
1363 	}
1364 out_unlock:
1365 	rcu_read_unlock();
1366 	return addr;
1367 }
1368 EXPORT_SYMBOL(inet_select_addr);
1369 
1370 static __be32 confirm_addr_indev(struct in_device *in_dev, __be32 dst,
1371 			      __be32 local, int scope)
1372 {
1373 	unsigned char localnet_scope = RT_SCOPE_HOST;
1374 	const struct in_ifaddr *ifa;
1375 	__be32 addr = 0;
1376 	int same = 0;
1377 
1378 	if (unlikely(IN_DEV_ROUTE_LOCALNET(in_dev)))
1379 		localnet_scope = RT_SCOPE_LINK;
1380 
1381 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
1382 		unsigned char min_scope = min(ifa->ifa_scope, localnet_scope);
1383 
1384 		if (!addr &&
1385 		    (local == ifa->ifa_local || !local) &&
1386 		    min_scope <= scope) {
1387 			addr = ifa->ifa_local;
1388 			if (same)
1389 				break;
1390 		}
1391 		if (!same) {
1392 			same = (!local || inet_ifa_match(local, ifa)) &&
1393 				(!dst || inet_ifa_match(dst, ifa));
1394 			if (same && addr) {
1395 				if (local || !dst)
1396 					break;
1397 				/* Is the selected addr into dst subnet? */
1398 				if (inet_ifa_match(addr, ifa))
1399 					break;
1400 				/* No, then can we use new local src? */
1401 				if (min_scope <= scope) {
1402 					addr = ifa->ifa_local;
1403 					break;
1404 				}
1405 				/* search for large dst subnet for addr */
1406 				same = 0;
1407 			}
1408 		}
1409 	}
1410 
1411 	return same ? addr : 0;
1412 }
1413 
1414 /*
1415  * Confirm that local IP address exists using wildcards:
1416  * - net: netns to check, cannot be NULL
1417  * - in_dev: only on this interface, NULL=any interface
1418  * - dst: only in the same subnet as dst, 0=any dst
1419  * - local: address, 0=autoselect the local address
1420  * - scope: maximum allowed scope value for the local address
1421  */
1422 __be32 inet_confirm_addr(struct net *net, struct in_device *in_dev,
1423 			 __be32 dst, __be32 local, int scope)
1424 {
1425 	__be32 addr = 0;
1426 	struct net_device *dev;
1427 
1428 	if (in_dev)
1429 		return confirm_addr_indev(in_dev, dst, local, scope);
1430 
1431 	rcu_read_lock();
1432 	for_each_netdev_rcu(net, dev) {
1433 		in_dev = __in_dev_get_rcu(dev);
1434 		if (in_dev) {
1435 			addr = confirm_addr_indev(in_dev, dst, local, scope);
1436 			if (addr)
1437 				break;
1438 		}
1439 	}
1440 	rcu_read_unlock();
1441 
1442 	return addr;
1443 }
1444 EXPORT_SYMBOL(inet_confirm_addr);
1445 
1446 /*
1447  *	Device notifier
1448  */
1449 
1450 int register_inetaddr_notifier(struct notifier_block *nb)
1451 {
1452 	return blocking_notifier_chain_register(&inetaddr_chain, nb);
1453 }
1454 EXPORT_SYMBOL(register_inetaddr_notifier);
1455 
1456 int unregister_inetaddr_notifier(struct notifier_block *nb)
1457 {
1458 	return blocking_notifier_chain_unregister(&inetaddr_chain, nb);
1459 }
1460 EXPORT_SYMBOL(unregister_inetaddr_notifier);
1461 
1462 int register_inetaddr_validator_notifier(struct notifier_block *nb)
1463 {
1464 	return blocking_notifier_chain_register(&inetaddr_validator_chain, nb);
1465 }
1466 EXPORT_SYMBOL(register_inetaddr_validator_notifier);
1467 
1468 int unregister_inetaddr_validator_notifier(struct notifier_block *nb)
1469 {
1470 	return blocking_notifier_chain_unregister(&inetaddr_validator_chain,
1471 	    nb);
1472 }
1473 EXPORT_SYMBOL(unregister_inetaddr_validator_notifier);
1474 
1475 /* Rename ifa_labels for a device name change. Make some effort to preserve
1476  * existing alias numbering and to create unique labels if possible.
1477 */
1478 static void inetdev_changename(struct net_device *dev, struct in_device *in_dev)
1479 {
1480 	struct in_ifaddr *ifa;
1481 	int named = 0;
1482 
1483 	in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1484 		char old[IFNAMSIZ], *dot;
1485 
1486 		memcpy(old, ifa->ifa_label, IFNAMSIZ);
1487 		memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
1488 		if (named++ == 0)
1489 			goto skip;
1490 		dot = strchr(old, ':');
1491 		if (!dot) {
1492 			sprintf(old, ":%d", named);
1493 			dot = old;
1494 		}
1495 		if (strlen(dot) + strlen(dev->name) < IFNAMSIZ)
1496 			strcat(ifa->ifa_label, dot);
1497 		else
1498 			strcpy(ifa->ifa_label + (IFNAMSIZ - strlen(dot) - 1), dot);
1499 skip:
1500 		rtmsg_ifa(RTM_NEWADDR, ifa, NULL, 0);
1501 	}
1502 }
1503 
1504 static void inetdev_send_gratuitous_arp(struct net_device *dev,
1505 					struct in_device *in_dev)
1506 
1507 {
1508 	const struct in_ifaddr *ifa;
1509 
1510 	in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1511 		arp_send(ARPOP_REQUEST, ETH_P_ARP,
1512 			 ifa->ifa_local, dev,
1513 			 ifa->ifa_local, NULL,
1514 			 dev->dev_addr, NULL);
1515 	}
1516 }
1517 
1518 /* Called only under RTNL semaphore */
1519 
1520 static int inetdev_event(struct notifier_block *this, unsigned long event,
1521 			 void *ptr)
1522 {
1523 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1524 	struct in_device *in_dev = __in_dev_get_rtnl(dev);
1525 
1526 	ASSERT_RTNL();
1527 
1528 	if (!in_dev) {
1529 		if (event == NETDEV_REGISTER) {
1530 			in_dev = inetdev_init(dev);
1531 			if (IS_ERR(in_dev))
1532 				return notifier_from_errno(PTR_ERR(in_dev));
1533 			if (dev->flags & IFF_LOOPBACK) {
1534 				IN_DEV_CONF_SET(in_dev, NOXFRM, 1);
1535 				IN_DEV_CONF_SET(in_dev, NOPOLICY, 1);
1536 			}
1537 		} else if (event == NETDEV_CHANGEMTU) {
1538 			/* Re-enabling IP */
1539 			if (inetdev_valid_mtu(dev->mtu))
1540 				in_dev = inetdev_init(dev);
1541 		}
1542 		goto out;
1543 	}
1544 
1545 	switch (event) {
1546 	case NETDEV_REGISTER:
1547 		pr_debug("%s: bug\n", __func__);
1548 		RCU_INIT_POINTER(dev->ip_ptr, NULL);
1549 		break;
1550 	case NETDEV_UP:
1551 		if (!inetdev_valid_mtu(dev->mtu))
1552 			break;
1553 		if (dev->flags & IFF_LOOPBACK) {
1554 			struct in_ifaddr *ifa = inet_alloc_ifa();
1555 
1556 			if (ifa) {
1557 				INIT_HLIST_NODE(&ifa->hash);
1558 				ifa->ifa_local =
1559 				  ifa->ifa_address = htonl(INADDR_LOOPBACK);
1560 				ifa->ifa_prefixlen = 8;
1561 				ifa->ifa_mask = inet_make_mask(8);
1562 				in_dev_hold(in_dev);
1563 				ifa->ifa_dev = in_dev;
1564 				ifa->ifa_scope = RT_SCOPE_HOST;
1565 				memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
1566 				set_ifa_lifetime(ifa, INFINITY_LIFE_TIME,
1567 						 INFINITY_LIFE_TIME);
1568 				ipv4_devconf_setall(in_dev);
1569 				neigh_parms_data_state_setall(in_dev->arp_parms);
1570 				inet_insert_ifa(ifa);
1571 			}
1572 		}
1573 		ip_mc_up(in_dev);
1574 		fallthrough;
1575 	case NETDEV_CHANGEADDR:
1576 		if (!IN_DEV_ARP_NOTIFY(in_dev))
1577 			break;
1578 		fallthrough;
1579 	case NETDEV_NOTIFY_PEERS:
1580 		/* Send gratuitous ARP to notify of link change */
1581 		inetdev_send_gratuitous_arp(dev, in_dev);
1582 		break;
1583 	case NETDEV_DOWN:
1584 		ip_mc_down(in_dev);
1585 		break;
1586 	case NETDEV_PRE_TYPE_CHANGE:
1587 		ip_mc_unmap(in_dev);
1588 		break;
1589 	case NETDEV_POST_TYPE_CHANGE:
1590 		ip_mc_remap(in_dev);
1591 		break;
1592 	case NETDEV_CHANGEMTU:
1593 		if (inetdev_valid_mtu(dev->mtu))
1594 			break;
1595 		/* disable IP when MTU is not enough */
1596 		fallthrough;
1597 	case NETDEV_UNREGISTER:
1598 		inetdev_destroy(in_dev);
1599 		break;
1600 	case NETDEV_CHANGENAME:
1601 		/* Do not notify about label change, this event is
1602 		 * not interesting to applications using netlink.
1603 		 */
1604 		inetdev_changename(dev, in_dev);
1605 
1606 		devinet_sysctl_unregister(in_dev);
1607 		devinet_sysctl_register(in_dev);
1608 		break;
1609 	}
1610 out:
1611 	return NOTIFY_DONE;
1612 }
1613 
1614 static struct notifier_block ip_netdev_notifier = {
1615 	.notifier_call = inetdev_event,
1616 };
1617 
1618 static size_t inet_nlmsg_size(void)
1619 {
1620 	return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
1621 	       + nla_total_size(4) /* IFA_ADDRESS */
1622 	       + nla_total_size(4) /* IFA_LOCAL */
1623 	       + nla_total_size(4) /* IFA_BROADCAST */
1624 	       + nla_total_size(IFNAMSIZ) /* IFA_LABEL */
1625 	       + nla_total_size(4)  /* IFA_FLAGS */
1626 	       + nla_total_size(4)  /* IFA_RT_PRIORITY */
1627 	       + nla_total_size(sizeof(struct ifa_cacheinfo)); /* IFA_CACHEINFO */
1628 }
1629 
1630 static inline u32 cstamp_delta(unsigned long cstamp)
1631 {
1632 	return (cstamp - INITIAL_JIFFIES) * 100UL / HZ;
1633 }
1634 
1635 static int put_cacheinfo(struct sk_buff *skb, unsigned long cstamp,
1636 			 unsigned long tstamp, u32 preferred, u32 valid)
1637 {
1638 	struct ifa_cacheinfo ci;
1639 
1640 	ci.cstamp = cstamp_delta(cstamp);
1641 	ci.tstamp = cstamp_delta(tstamp);
1642 	ci.ifa_prefered = preferred;
1643 	ci.ifa_valid = valid;
1644 
1645 	return nla_put(skb, IFA_CACHEINFO, sizeof(ci), &ci);
1646 }
1647 
1648 static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
1649 			    struct inet_fill_args *args)
1650 {
1651 	struct ifaddrmsg *ifm;
1652 	struct nlmsghdr  *nlh;
1653 	u32 preferred, valid;
1654 
1655 	nlh = nlmsg_put(skb, args->portid, args->seq, args->event, sizeof(*ifm),
1656 			args->flags);
1657 	if (!nlh)
1658 		return -EMSGSIZE;
1659 
1660 	ifm = nlmsg_data(nlh);
1661 	ifm->ifa_family = AF_INET;
1662 	ifm->ifa_prefixlen = ifa->ifa_prefixlen;
1663 	ifm->ifa_flags = ifa->ifa_flags;
1664 	ifm->ifa_scope = ifa->ifa_scope;
1665 	ifm->ifa_index = ifa->ifa_dev->dev->ifindex;
1666 
1667 	if (args->netnsid >= 0 &&
1668 	    nla_put_s32(skb, IFA_TARGET_NETNSID, args->netnsid))
1669 		goto nla_put_failure;
1670 
1671 	if (!(ifm->ifa_flags & IFA_F_PERMANENT)) {
1672 		preferred = ifa->ifa_preferred_lft;
1673 		valid = ifa->ifa_valid_lft;
1674 		if (preferred != INFINITY_LIFE_TIME) {
1675 			long tval = (jiffies - ifa->ifa_tstamp) / HZ;
1676 
1677 			if (preferred > tval)
1678 				preferred -= tval;
1679 			else
1680 				preferred = 0;
1681 			if (valid != INFINITY_LIFE_TIME) {
1682 				if (valid > tval)
1683 					valid -= tval;
1684 				else
1685 					valid = 0;
1686 			}
1687 		}
1688 	} else {
1689 		preferred = INFINITY_LIFE_TIME;
1690 		valid = INFINITY_LIFE_TIME;
1691 	}
1692 	if ((ifa->ifa_address &&
1693 	     nla_put_in_addr(skb, IFA_ADDRESS, ifa->ifa_address)) ||
1694 	    (ifa->ifa_local &&
1695 	     nla_put_in_addr(skb, IFA_LOCAL, ifa->ifa_local)) ||
1696 	    (ifa->ifa_broadcast &&
1697 	     nla_put_in_addr(skb, IFA_BROADCAST, ifa->ifa_broadcast)) ||
1698 	    (ifa->ifa_label[0] &&
1699 	     nla_put_string(skb, IFA_LABEL, ifa->ifa_label)) ||
1700 	    nla_put_u32(skb, IFA_FLAGS, ifa->ifa_flags) ||
1701 	    (ifa->ifa_rt_priority &&
1702 	     nla_put_u32(skb, IFA_RT_PRIORITY, ifa->ifa_rt_priority)) ||
1703 	    put_cacheinfo(skb, ifa->ifa_cstamp, ifa->ifa_tstamp,
1704 			  preferred, valid))
1705 		goto nla_put_failure;
1706 
1707 	nlmsg_end(skb, nlh);
1708 	return 0;
1709 
1710 nla_put_failure:
1711 	nlmsg_cancel(skb, nlh);
1712 	return -EMSGSIZE;
1713 }
1714 
1715 static int inet_valid_dump_ifaddr_req(const struct nlmsghdr *nlh,
1716 				      struct inet_fill_args *fillargs,
1717 				      struct net **tgt_net, struct sock *sk,
1718 				      struct netlink_callback *cb)
1719 {
1720 	struct netlink_ext_ack *extack = cb->extack;
1721 	struct nlattr *tb[IFA_MAX+1];
1722 	struct ifaddrmsg *ifm;
1723 	int err, i;
1724 
1725 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
1726 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for address dump request");
1727 		return -EINVAL;
1728 	}
1729 
1730 	ifm = nlmsg_data(nlh);
1731 	if (ifm->ifa_prefixlen || ifm->ifa_flags || ifm->ifa_scope) {
1732 		NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for address dump request");
1733 		return -EINVAL;
1734 	}
1735 
1736 	fillargs->ifindex = ifm->ifa_index;
1737 	if (fillargs->ifindex) {
1738 		cb->answer_flags |= NLM_F_DUMP_FILTERED;
1739 		fillargs->flags |= NLM_F_DUMP_FILTERED;
1740 	}
1741 
1742 	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*ifm), tb, IFA_MAX,
1743 					    ifa_ipv4_policy, extack);
1744 	if (err < 0)
1745 		return err;
1746 
1747 	for (i = 0; i <= IFA_MAX; ++i) {
1748 		if (!tb[i])
1749 			continue;
1750 
1751 		if (i == IFA_TARGET_NETNSID) {
1752 			struct net *net;
1753 
1754 			fillargs->netnsid = nla_get_s32(tb[i]);
1755 
1756 			net = rtnl_get_net_ns_capable(sk, fillargs->netnsid);
1757 			if (IS_ERR(net)) {
1758 				fillargs->netnsid = -1;
1759 				NL_SET_ERR_MSG(extack, "ipv4: Invalid target network namespace id");
1760 				return PTR_ERR(net);
1761 			}
1762 			*tgt_net = net;
1763 		} else {
1764 			NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in dump request");
1765 			return -EINVAL;
1766 		}
1767 	}
1768 
1769 	return 0;
1770 }
1771 
1772 static int in_dev_dump_addr(struct in_device *in_dev, struct sk_buff *skb,
1773 			    struct netlink_callback *cb, int s_ip_idx,
1774 			    struct inet_fill_args *fillargs)
1775 {
1776 	struct in_ifaddr *ifa;
1777 	int ip_idx = 0;
1778 	int err;
1779 
1780 	in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1781 		if (ip_idx < s_ip_idx) {
1782 			ip_idx++;
1783 			continue;
1784 		}
1785 		err = inet_fill_ifaddr(skb, ifa, fillargs);
1786 		if (err < 0)
1787 			goto done;
1788 
1789 		nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1790 		ip_idx++;
1791 	}
1792 	err = 0;
1793 
1794 done:
1795 	cb->args[2] = ip_idx;
1796 
1797 	return err;
1798 }
1799 
1800 static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
1801 {
1802 	const struct nlmsghdr *nlh = cb->nlh;
1803 	struct inet_fill_args fillargs = {
1804 		.portid = NETLINK_CB(cb->skb).portid,
1805 		.seq = nlh->nlmsg_seq,
1806 		.event = RTM_NEWADDR,
1807 		.flags = NLM_F_MULTI,
1808 		.netnsid = -1,
1809 	};
1810 	struct net *net = sock_net(skb->sk);
1811 	struct net *tgt_net = net;
1812 	int h, s_h;
1813 	int idx, s_idx;
1814 	int s_ip_idx;
1815 	struct net_device *dev;
1816 	struct in_device *in_dev;
1817 	struct hlist_head *head;
1818 	int err = 0;
1819 
1820 	s_h = cb->args[0];
1821 	s_idx = idx = cb->args[1];
1822 	s_ip_idx = cb->args[2];
1823 
1824 	if (cb->strict_check) {
1825 		err = inet_valid_dump_ifaddr_req(nlh, &fillargs, &tgt_net,
1826 						 skb->sk, cb);
1827 		if (err < 0)
1828 			goto put_tgt_net;
1829 
1830 		err = 0;
1831 		if (fillargs.ifindex) {
1832 			dev = __dev_get_by_index(tgt_net, fillargs.ifindex);
1833 			if (!dev) {
1834 				err = -ENODEV;
1835 				goto put_tgt_net;
1836 			}
1837 
1838 			in_dev = __in_dev_get_rtnl(dev);
1839 			if (in_dev) {
1840 				err = in_dev_dump_addr(in_dev, skb, cb, s_ip_idx,
1841 						       &fillargs);
1842 			}
1843 			goto put_tgt_net;
1844 		}
1845 	}
1846 
1847 	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
1848 		idx = 0;
1849 		head = &tgt_net->dev_index_head[h];
1850 		rcu_read_lock();
1851 		cb->seq = atomic_read(&tgt_net->ipv4.dev_addr_genid) ^
1852 			  tgt_net->dev_base_seq;
1853 		hlist_for_each_entry_rcu(dev, head, index_hlist) {
1854 			if (idx < s_idx)
1855 				goto cont;
1856 			if (h > s_h || idx > s_idx)
1857 				s_ip_idx = 0;
1858 			in_dev = __in_dev_get_rcu(dev);
1859 			if (!in_dev)
1860 				goto cont;
1861 
1862 			err = in_dev_dump_addr(in_dev, skb, cb, s_ip_idx,
1863 					       &fillargs);
1864 			if (err < 0) {
1865 				rcu_read_unlock();
1866 				goto done;
1867 			}
1868 cont:
1869 			idx++;
1870 		}
1871 		rcu_read_unlock();
1872 	}
1873 
1874 done:
1875 	cb->args[0] = h;
1876 	cb->args[1] = idx;
1877 put_tgt_net:
1878 	if (fillargs.netnsid >= 0)
1879 		put_net(tgt_net);
1880 
1881 	return skb->len ? : err;
1882 }
1883 
1884 static void rtmsg_ifa(int event, struct in_ifaddr *ifa, struct nlmsghdr *nlh,
1885 		      u32 portid)
1886 {
1887 	struct inet_fill_args fillargs = {
1888 		.portid = portid,
1889 		.seq = nlh ? nlh->nlmsg_seq : 0,
1890 		.event = event,
1891 		.flags = 0,
1892 		.netnsid = -1,
1893 	};
1894 	struct sk_buff *skb;
1895 	int err = -ENOBUFS;
1896 	struct net *net;
1897 
1898 	net = dev_net(ifa->ifa_dev->dev);
1899 	skb = nlmsg_new(inet_nlmsg_size(), GFP_KERNEL);
1900 	if (!skb)
1901 		goto errout;
1902 
1903 	err = inet_fill_ifaddr(skb, ifa, &fillargs);
1904 	if (err < 0) {
1905 		/* -EMSGSIZE implies BUG in inet_nlmsg_size() */
1906 		WARN_ON(err == -EMSGSIZE);
1907 		kfree_skb(skb);
1908 		goto errout;
1909 	}
1910 	rtnl_notify(skb, net, portid, RTNLGRP_IPV4_IFADDR, nlh, GFP_KERNEL);
1911 	return;
1912 errout:
1913 	if (err < 0)
1914 		rtnl_set_sk_err(net, RTNLGRP_IPV4_IFADDR, err);
1915 }
1916 
1917 static size_t inet_get_link_af_size(const struct net_device *dev,
1918 				    u32 ext_filter_mask)
1919 {
1920 	struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr);
1921 
1922 	if (!in_dev)
1923 		return 0;
1924 
1925 	return nla_total_size(IPV4_DEVCONF_MAX * 4); /* IFLA_INET_CONF */
1926 }
1927 
1928 static int inet_fill_link_af(struct sk_buff *skb, const struct net_device *dev,
1929 			     u32 ext_filter_mask)
1930 {
1931 	struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr);
1932 	struct nlattr *nla;
1933 	int i;
1934 
1935 	if (!in_dev)
1936 		return -ENODATA;
1937 
1938 	nla = nla_reserve(skb, IFLA_INET_CONF, IPV4_DEVCONF_MAX * 4);
1939 	if (!nla)
1940 		return -EMSGSIZE;
1941 
1942 	for (i = 0; i < IPV4_DEVCONF_MAX; i++)
1943 		((u32 *) nla_data(nla))[i] = in_dev->cnf.data[i];
1944 
1945 	return 0;
1946 }
1947 
1948 static const struct nla_policy inet_af_policy[IFLA_INET_MAX+1] = {
1949 	[IFLA_INET_CONF]	= { .type = NLA_NESTED },
1950 };
1951 
1952 static int inet_validate_link_af(const struct net_device *dev,
1953 				 const struct nlattr *nla)
1954 {
1955 	struct nlattr *a, *tb[IFLA_INET_MAX+1];
1956 	int err, rem;
1957 
1958 	if (dev && !__in_dev_get_rcu(dev))
1959 		return -EAFNOSUPPORT;
1960 
1961 	err = nla_parse_nested_deprecated(tb, IFLA_INET_MAX, nla,
1962 					  inet_af_policy, NULL);
1963 	if (err < 0)
1964 		return err;
1965 
1966 	if (tb[IFLA_INET_CONF]) {
1967 		nla_for_each_nested(a, tb[IFLA_INET_CONF], rem) {
1968 			int cfgid = nla_type(a);
1969 
1970 			if (nla_len(a) < 4)
1971 				return -EINVAL;
1972 
1973 			if (cfgid <= 0 || cfgid > IPV4_DEVCONF_MAX)
1974 				return -EINVAL;
1975 		}
1976 	}
1977 
1978 	return 0;
1979 }
1980 
1981 static int inet_set_link_af(struct net_device *dev, const struct nlattr *nla)
1982 {
1983 	struct in_device *in_dev = __in_dev_get_rcu(dev);
1984 	struct nlattr *a, *tb[IFLA_INET_MAX+1];
1985 	int rem;
1986 
1987 	if (!in_dev)
1988 		return -EAFNOSUPPORT;
1989 
1990 	if (nla_parse_nested_deprecated(tb, IFLA_INET_MAX, nla, NULL, NULL) < 0)
1991 		BUG();
1992 
1993 	if (tb[IFLA_INET_CONF]) {
1994 		nla_for_each_nested(a, tb[IFLA_INET_CONF], rem)
1995 			ipv4_devconf_set(in_dev, nla_type(a), nla_get_u32(a));
1996 	}
1997 
1998 	return 0;
1999 }
2000 
2001 static int inet_netconf_msgsize_devconf(int type)
2002 {
2003 	int size = NLMSG_ALIGN(sizeof(struct netconfmsg))
2004 		   + nla_total_size(4);	/* NETCONFA_IFINDEX */
2005 	bool all = false;
2006 
2007 	if (type == NETCONFA_ALL)
2008 		all = true;
2009 
2010 	if (all || type == NETCONFA_FORWARDING)
2011 		size += nla_total_size(4);
2012 	if (all || type == NETCONFA_RP_FILTER)
2013 		size += nla_total_size(4);
2014 	if (all || type == NETCONFA_MC_FORWARDING)
2015 		size += nla_total_size(4);
2016 	if (all || type == NETCONFA_BC_FORWARDING)
2017 		size += nla_total_size(4);
2018 	if (all || type == NETCONFA_PROXY_NEIGH)
2019 		size += nla_total_size(4);
2020 	if (all || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN)
2021 		size += nla_total_size(4);
2022 
2023 	return size;
2024 }
2025 
2026 static int inet_netconf_fill_devconf(struct sk_buff *skb, int ifindex,
2027 				     struct ipv4_devconf *devconf, u32 portid,
2028 				     u32 seq, int event, unsigned int flags,
2029 				     int type)
2030 {
2031 	struct nlmsghdr  *nlh;
2032 	struct netconfmsg *ncm;
2033 	bool all = false;
2034 
2035 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
2036 			flags);
2037 	if (!nlh)
2038 		return -EMSGSIZE;
2039 
2040 	if (type == NETCONFA_ALL)
2041 		all = true;
2042 
2043 	ncm = nlmsg_data(nlh);
2044 	ncm->ncm_family = AF_INET;
2045 
2046 	if (nla_put_s32(skb, NETCONFA_IFINDEX, ifindex) < 0)
2047 		goto nla_put_failure;
2048 
2049 	if (!devconf)
2050 		goto out;
2051 
2052 	if ((all || type == NETCONFA_FORWARDING) &&
2053 	    nla_put_s32(skb, NETCONFA_FORWARDING,
2054 			IPV4_DEVCONF(*devconf, FORWARDING)) < 0)
2055 		goto nla_put_failure;
2056 	if ((all || type == NETCONFA_RP_FILTER) &&
2057 	    nla_put_s32(skb, NETCONFA_RP_FILTER,
2058 			IPV4_DEVCONF(*devconf, RP_FILTER)) < 0)
2059 		goto nla_put_failure;
2060 	if ((all || type == NETCONFA_MC_FORWARDING) &&
2061 	    nla_put_s32(skb, NETCONFA_MC_FORWARDING,
2062 			IPV4_DEVCONF(*devconf, MC_FORWARDING)) < 0)
2063 		goto nla_put_failure;
2064 	if ((all || type == NETCONFA_BC_FORWARDING) &&
2065 	    nla_put_s32(skb, NETCONFA_BC_FORWARDING,
2066 			IPV4_DEVCONF(*devconf, BC_FORWARDING)) < 0)
2067 		goto nla_put_failure;
2068 	if ((all || type == NETCONFA_PROXY_NEIGH) &&
2069 	    nla_put_s32(skb, NETCONFA_PROXY_NEIGH,
2070 			IPV4_DEVCONF(*devconf, PROXY_ARP)) < 0)
2071 		goto nla_put_failure;
2072 	if ((all || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN) &&
2073 	    nla_put_s32(skb, NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
2074 			IPV4_DEVCONF(*devconf, IGNORE_ROUTES_WITH_LINKDOWN)) < 0)
2075 		goto nla_put_failure;
2076 
2077 out:
2078 	nlmsg_end(skb, nlh);
2079 	return 0;
2080 
2081 nla_put_failure:
2082 	nlmsg_cancel(skb, nlh);
2083 	return -EMSGSIZE;
2084 }
2085 
2086 void inet_netconf_notify_devconf(struct net *net, int event, int type,
2087 				 int ifindex, struct ipv4_devconf *devconf)
2088 {
2089 	struct sk_buff *skb;
2090 	int err = -ENOBUFS;
2091 
2092 	skb = nlmsg_new(inet_netconf_msgsize_devconf(type), GFP_KERNEL);
2093 	if (!skb)
2094 		goto errout;
2095 
2096 	err = inet_netconf_fill_devconf(skb, ifindex, devconf, 0, 0,
2097 					event, 0, type);
2098 	if (err < 0) {
2099 		/* -EMSGSIZE implies BUG in inet_netconf_msgsize_devconf() */
2100 		WARN_ON(err == -EMSGSIZE);
2101 		kfree_skb(skb);
2102 		goto errout;
2103 	}
2104 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_NETCONF, NULL, GFP_KERNEL);
2105 	return;
2106 errout:
2107 	if (err < 0)
2108 		rtnl_set_sk_err(net, RTNLGRP_IPV4_NETCONF, err);
2109 }
2110 
2111 static const struct nla_policy devconf_ipv4_policy[NETCONFA_MAX+1] = {
2112 	[NETCONFA_IFINDEX]	= { .len = sizeof(int) },
2113 	[NETCONFA_FORWARDING]	= { .len = sizeof(int) },
2114 	[NETCONFA_RP_FILTER]	= { .len = sizeof(int) },
2115 	[NETCONFA_PROXY_NEIGH]	= { .len = sizeof(int) },
2116 	[NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN]	= { .len = sizeof(int) },
2117 };
2118 
2119 static int inet_netconf_valid_get_req(struct sk_buff *skb,
2120 				      const struct nlmsghdr *nlh,
2121 				      struct nlattr **tb,
2122 				      struct netlink_ext_ack *extack)
2123 {
2124 	int i, err;
2125 
2126 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) {
2127 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for netconf get request");
2128 		return -EINVAL;
2129 	}
2130 
2131 	if (!netlink_strict_get_check(skb))
2132 		return nlmsg_parse_deprecated(nlh, sizeof(struct netconfmsg),
2133 					      tb, NETCONFA_MAX,
2134 					      devconf_ipv4_policy, extack);
2135 
2136 	err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct netconfmsg),
2137 					    tb, NETCONFA_MAX,
2138 					    devconf_ipv4_policy, extack);
2139 	if (err)
2140 		return err;
2141 
2142 	for (i = 0; i <= NETCONFA_MAX; i++) {
2143 		if (!tb[i])
2144 			continue;
2145 
2146 		switch (i) {
2147 		case NETCONFA_IFINDEX:
2148 			break;
2149 		default:
2150 			NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in netconf get request");
2151 			return -EINVAL;
2152 		}
2153 	}
2154 
2155 	return 0;
2156 }
2157 
2158 static int inet_netconf_get_devconf(struct sk_buff *in_skb,
2159 				    struct nlmsghdr *nlh,
2160 				    struct netlink_ext_ack *extack)
2161 {
2162 	struct net *net = sock_net(in_skb->sk);
2163 	struct nlattr *tb[NETCONFA_MAX+1];
2164 	struct sk_buff *skb;
2165 	struct ipv4_devconf *devconf;
2166 	struct in_device *in_dev;
2167 	struct net_device *dev;
2168 	int ifindex;
2169 	int err;
2170 
2171 	err = inet_netconf_valid_get_req(in_skb, nlh, tb, extack);
2172 	if (err)
2173 		goto errout;
2174 
2175 	err = -EINVAL;
2176 	if (!tb[NETCONFA_IFINDEX])
2177 		goto errout;
2178 
2179 	ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
2180 	switch (ifindex) {
2181 	case NETCONFA_IFINDEX_ALL:
2182 		devconf = net->ipv4.devconf_all;
2183 		break;
2184 	case NETCONFA_IFINDEX_DEFAULT:
2185 		devconf = net->ipv4.devconf_dflt;
2186 		break;
2187 	default:
2188 		dev = __dev_get_by_index(net, ifindex);
2189 		if (!dev)
2190 			goto errout;
2191 		in_dev = __in_dev_get_rtnl(dev);
2192 		if (!in_dev)
2193 			goto errout;
2194 		devconf = &in_dev->cnf;
2195 		break;
2196 	}
2197 
2198 	err = -ENOBUFS;
2199 	skb = nlmsg_new(inet_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
2200 	if (!skb)
2201 		goto errout;
2202 
2203 	err = inet_netconf_fill_devconf(skb, ifindex, devconf,
2204 					NETLINK_CB(in_skb).portid,
2205 					nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
2206 					NETCONFA_ALL);
2207 	if (err < 0) {
2208 		/* -EMSGSIZE implies BUG in inet_netconf_msgsize_devconf() */
2209 		WARN_ON(err == -EMSGSIZE);
2210 		kfree_skb(skb);
2211 		goto errout;
2212 	}
2213 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2214 errout:
2215 	return err;
2216 }
2217 
2218 static int inet_netconf_dump_devconf(struct sk_buff *skb,
2219 				     struct netlink_callback *cb)
2220 {
2221 	const struct nlmsghdr *nlh = cb->nlh;
2222 	struct net *net = sock_net(skb->sk);
2223 	int h, s_h;
2224 	int idx, s_idx;
2225 	struct net_device *dev;
2226 	struct in_device *in_dev;
2227 	struct hlist_head *head;
2228 
2229 	if (cb->strict_check) {
2230 		struct netlink_ext_ack *extack = cb->extack;
2231 		struct netconfmsg *ncm;
2232 
2233 		if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
2234 			NL_SET_ERR_MSG(extack, "ipv4: Invalid header for netconf dump request");
2235 			return -EINVAL;
2236 		}
2237 
2238 		if (nlmsg_attrlen(nlh, sizeof(*ncm))) {
2239 			NL_SET_ERR_MSG(extack, "ipv4: Invalid data after header in netconf dump request");
2240 			return -EINVAL;
2241 		}
2242 	}
2243 
2244 	s_h = cb->args[0];
2245 	s_idx = idx = cb->args[1];
2246 
2247 	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
2248 		idx = 0;
2249 		head = &net->dev_index_head[h];
2250 		rcu_read_lock();
2251 		cb->seq = atomic_read(&net->ipv4.dev_addr_genid) ^
2252 			  net->dev_base_seq;
2253 		hlist_for_each_entry_rcu(dev, head, index_hlist) {
2254 			if (idx < s_idx)
2255 				goto cont;
2256 			in_dev = __in_dev_get_rcu(dev);
2257 			if (!in_dev)
2258 				goto cont;
2259 
2260 			if (inet_netconf_fill_devconf(skb, dev->ifindex,
2261 						      &in_dev->cnf,
2262 						      NETLINK_CB(cb->skb).portid,
2263 						      nlh->nlmsg_seq,
2264 						      RTM_NEWNETCONF,
2265 						      NLM_F_MULTI,
2266 						      NETCONFA_ALL) < 0) {
2267 				rcu_read_unlock();
2268 				goto done;
2269 			}
2270 			nl_dump_check_consistent(cb, nlmsg_hdr(skb));
2271 cont:
2272 			idx++;
2273 		}
2274 		rcu_read_unlock();
2275 	}
2276 	if (h == NETDEV_HASHENTRIES) {
2277 		if (inet_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL,
2278 					      net->ipv4.devconf_all,
2279 					      NETLINK_CB(cb->skb).portid,
2280 					      nlh->nlmsg_seq,
2281 					      RTM_NEWNETCONF, NLM_F_MULTI,
2282 					      NETCONFA_ALL) < 0)
2283 			goto done;
2284 		else
2285 			h++;
2286 	}
2287 	if (h == NETDEV_HASHENTRIES + 1) {
2288 		if (inet_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT,
2289 					      net->ipv4.devconf_dflt,
2290 					      NETLINK_CB(cb->skb).portid,
2291 					      nlh->nlmsg_seq,
2292 					      RTM_NEWNETCONF, NLM_F_MULTI,
2293 					      NETCONFA_ALL) < 0)
2294 			goto done;
2295 		else
2296 			h++;
2297 	}
2298 done:
2299 	cb->args[0] = h;
2300 	cb->args[1] = idx;
2301 
2302 	return skb->len;
2303 }
2304 
2305 #ifdef CONFIG_SYSCTL
2306 
2307 static void devinet_copy_dflt_conf(struct net *net, int i)
2308 {
2309 	struct net_device *dev;
2310 
2311 	rcu_read_lock();
2312 	for_each_netdev_rcu(net, dev) {
2313 		struct in_device *in_dev;
2314 
2315 		in_dev = __in_dev_get_rcu(dev);
2316 		if (in_dev && !test_bit(i, in_dev->cnf.state))
2317 			in_dev->cnf.data[i] = net->ipv4.devconf_dflt->data[i];
2318 	}
2319 	rcu_read_unlock();
2320 }
2321 
2322 /* called with RTNL locked */
2323 static void inet_forward_change(struct net *net)
2324 {
2325 	struct net_device *dev;
2326 	int on = IPV4_DEVCONF_ALL(net, FORWARDING);
2327 
2328 	IPV4_DEVCONF_ALL(net, ACCEPT_REDIRECTS) = !on;
2329 	IPV4_DEVCONF_DFLT(net, FORWARDING) = on;
2330 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2331 				    NETCONFA_FORWARDING,
2332 				    NETCONFA_IFINDEX_ALL,
2333 				    net->ipv4.devconf_all);
2334 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2335 				    NETCONFA_FORWARDING,
2336 				    NETCONFA_IFINDEX_DEFAULT,
2337 				    net->ipv4.devconf_dflt);
2338 
2339 	for_each_netdev(net, dev) {
2340 		struct in_device *in_dev;
2341 
2342 		if (on)
2343 			dev_disable_lro(dev);
2344 
2345 		in_dev = __in_dev_get_rtnl(dev);
2346 		if (in_dev) {
2347 			IN_DEV_CONF_SET(in_dev, FORWARDING, on);
2348 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2349 						    NETCONFA_FORWARDING,
2350 						    dev->ifindex, &in_dev->cnf);
2351 		}
2352 	}
2353 }
2354 
2355 static int devinet_conf_ifindex(struct net *net, struct ipv4_devconf *cnf)
2356 {
2357 	if (cnf == net->ipv4.devconf_dflt)
2358 		return NETCONFA_IFINDEX_DEFAULT;
2359 	else if (cnf == net->ipv4.devconf_all)
2360 		return NETCONFA_IFINDEX_ALL;
2361 	else {
2362 		struct in_device *idev
2363 			= container_of(cnf, struct in_device, cnf);
2364 		return idev->dev->ifindex;
2365 	}
2366 }
2367 
2368 static int devinet_conf_proc(struct ctl_table *ctl, int write,
2369 			     void *buffer, size_t *lenp, loff_t *ppos)
2370 {
2371 	int old_value = *(int *)ctl->data;
2372 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
2373 	int new_value = *(int *)ctl->data;
2374 
2375 	if (write) {
2376 		struct ipv4_devconf *cnf = ctl->extra1;
2377 		struct net *net = ctl->extra2;
2378 		int i = (int *)ctl->data - cnf->data;
2379 		int ifindex;
2380 
2381 		set_bit(i, cnf->state);
2382 
2383 		if (cnf == net->ipv4.devconf_dflt)
2384 			devinet_copy_dflt_conf(net, i);
2385 		if (i == IPV4_DEVCONF_ACCEPT_LOCAL - 1 ||
2386 		    i == IPV4_DEVCONF_ROUTE_LOCALNET - 1)
2387 			if ((new_value == 0) && (old_value != 0))
2388 				rt_cache_flush(net);
2389 
2390 		if (i == IPV4_DEVCONF_BC_FORWARDING - 1 &&
2391 		    new_value != old_value)
2392 			rt_cache_flush(net);
2393 
2394 		if (i == IPV4_DEVCONF_RP_FILTER - 1 &&
2395 		    new_value != old_value) {
2396 			ifindex = devinet_conf_ifindex(net, cnf);
2397 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2398 						    NETCONFA_RP_FILTER,
2399 						    ifindex, cnf);
2400 		}
2401 		if (i == IPV4_DEVCONF_PROXY_ARP - 1 &&
2402 		    new_value != old_value) {
2403 			ifindex = devinet_conf_ifindex(net, cnf);
2404 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2405 						    NETCONFA_PROXY_NEIGH,
2406 						    ifindex, cnf);
2407 		}
2408 		if (i == IPV4_DEVCONF_IGNORE_ROUTES_WITH_LINKDOWN - 1 &&
2409 		    new_value != old_value) {
2410 			ifindex = devinet_conf_ifindex(net, cnf);
2411 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2412 						    NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
2413 						    ifindex, cnf);
2414 		}
2415 	}
2416 
2417 	return ret;
2418 }
2419 
2420 static int devinet_sysctl_forward(struct ctl_table *ctl, int write,
2421 				  void *buffer, size_t *lenp, loff_t *ppos)
2422 {
2423 	int *valp = ctl->data;
2424 	int val = *valp;
2425 	loff_t pos = *ppos;
2426 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
2427 
2428 	if (write && *valp != val) {
2429 		struct net *net = ctl->extra2;
2430 
2431 		if (valp != &IPV4_DEVCONF_DFLT(net, FORWARDING)) {
2432 			if (!rtnl_trylock()) {
2433 				/* Restore the original values before restarting */
2434 				*valp = val;
2435 				*ppos = pos;
2436 				return restart_syscall();
2437 			}
2438 			if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING)) {
2439 				inet_forward_change(net);
2440 			} else {
2441 				struct ipv4_devconf *cnf = ctl->extra1;
2442 				struct in_device *idev =
2443 					container_of(cnf, struct in_device, cnf);
2444 				if (*valp)
2445 					dev_disable_lro(idev->dev);
2446 				inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2447 							    NETCONFA_FORWARDING,
2448 							    idev->dev->ifindex,
2449 							    cnf);
2450 			}
2451 			rtnl_unlock();
2452 			rt_cache_flush(net);
2453 		} else
2454 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2455 						    NETCONFA_FORWARDING,
2456 						    NETCONFA_IFINDEX_DEFAULT,
2457 						    net->ipv4.devconf_dflt);
2458 	}
2459 
2460 	return ret;
2461 }
2462 
2463 static int ipv4_doint_and_flush(struct ctl_table *ctl, int write,
2464 				void *buffer, size_t *lenp, loff_t *ppos)
2465 {
2466 	int *valp = ctl->data;
2467 	int val = *valp;
2468 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
2469 	struct net *net = ctl->extra2;
2470 
2471 	if (write && *valp != val)
2472 		rt_cache_flush(net);
2473 
2474 	return ret;
2475 }
2476 
2477 #define DEVINET_SYSCTL_ENTRY(attr, name, mval, proc) \
2478 	{ \
2479 		.procname	= name, \
2480 		.data		= ipv4_devconf.data + \
2481 				  IPV4_DEVCONF_ ## attr - 1, \
2482 		.maxlen		= sizeof(int), \
2483 		.mode		= mval, \
2484 		.proc_handler	= proc, \
2485 		.extra1		= &ipv4_devconf, \
2486 	}
2487 
2488 #define DEVINET_SYSCTL_RW_ENTRY(attr, name) \
2489 	DEVINET_SYSCTL_ENTRY(attr, name, 0644, devinet_conf_proc)
2490 
2491 #define DEVINET_SYSCTL_RO_ENTRY(attr, name) \
2492 	DEVINET_SYSCTL_ENTRY(attr, name, 0444, devinet_conf_proc)
2493 
2494 #define DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, proc) \
2495 	DEVINET_SYSCTL_ENTRY(attr, name, 0644, proc)
2496 
2497 #define DEVINET_SYSCTL_FLUSHING_ENTRY(attr, name) \
2498 	DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, ipv4_doint_and_flush)
2499 
2500 static struct devinet_sysctl_table {
2501 	struct ctl_table_header *sysctl_header;
2502 	struct ctl_table devinet_vars[__IPV4_DEVCONF_MAX];
2503 } devinet_sysctl = {
2504 	.devinet_vars = {
2505 		DEVINET_SYSCTL_COMPLEX_ENTRY(FORWARDING, "forwarding",
2506 					     devinet_sysctl_forward),
2507 		DEVINET_SYSCTL_RO_ENTRY(MC_FORWARDING, "mc_forwarding"),
2508 		DEVINET_SYSCTL_RW_ENTRY(BC_FORWARDING, "bc_forwarding"),
2509 
2510 		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_REDIRECTS, "accept_redirects"),
2511 		DEVINET_SYSCTL_RW_ENTRY(SECURE_REDIRECTS, "secure_redirects"),
2512 		DEVINET_SYSCTL_RW_ENTRY(SHARED_MEDIA, "shared_media"),
2513 		DEVINET_SYSCTL_RW_ENTRY(RP_FILTER, "rp_filter"),
2514 		DEVINET_SYSCTL_RW_ENTRY(SEND_REDIRECTS, "send_redirects"),
2515 		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_SOURCE_ROUTE,
2516 					"accept_source_route"),
2517 		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_LOCAL, "accept_local"),
2518 		DEVINET_SYSCTL_RW_ENTRY(SRC_VMARK, "src_valid_mark"),
2519 		DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP, "proxy_arp"),
2520 		DEVINET_SYSCTL_RW_ENTRY(MEDIUM_ID, "medium_id"),
2521 		DEVINET_SYSCTL_RW_ENTRY(BOOTP_RELAY, "bootp_relay"),
2522 		DEVINET_SYSCTL_RW_ENTRY(LOG_MARTIANS, "log_martians"),
2523 		DEVINET_SYSCTL_RW_ENTRY(TAG, "tag"),
2524 		DEVINET_SYSCTL_RW_ENTRY(ARPFILTER, "arp_filter"),
2525 		DEVINET_SYSCTL_RW_ENTRY(ARP_ANNOUNCE, "arp_announce"),
2526 		DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"),
2527 		DEVINET_SYSCTL_RW_ENTRY(ARP_ACCEPT, "arp_accept"),
2528 		DEVINET_SYSCTL_RW_ENTRY(ARP_NOTIFY, "arp_notify"),
2529 		DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP_PVLAN, "proxy_arp_pvlan"),
2530 		DEVINET_SYSCTL_RW_ENTRY(FORCE_IGMP_VERSION,
2531 					"force_igmp_version"),
2532 		DEVINET_SYSCTL_RW_ENTRY(IGMPV2_UNSOLICITED_REPORT_INTERVAL,
2533 					"igmpv2_unsolicited_report_interval"),
2534 		DEVINET_SYSCTL_RW_ENTRY(IGMPV3_UNSOLICITED_REPORT_INTERVAL,
2535 					"igmpv3_unsolicited_report_interval"),
2536 		DEVINET_SYSCTL_RW_ENTRY(IGNORE_ROUTES_WITH_LINKDOWN,
2537 					"ignore_routes_with_linkdown"),
2538 		DEVINET_SYSCTL_RW_ENTRY(DROP_GRATUITOUS_ARP,
2539 					"drop_gratuitous_arp"),
2540 
2541 		DEVINET_SYSCTL_FLUSHING_ENTRY(NOXFRM, "disable_xfrm"),
2542 		DEVINET_SYSCTL_FLUSHING_ENTRY(NOPOLICY, "disable_policy"),
2543 		DEVINET_SYSCTL_FLUSHING_ENTRY(PROMOTE_SECONDARIES,
2544 					      "promote_secondaries"),
2545 		DEVINET_SYSCTL_FLUSHING_ENTRY(ROUTE_LOCALNET,
2546 					      "route_localnet"),
2547 		DEVINET_SYSCTL_FLUSHING_ENTRY(DROP_UNICAST_IN_L2_MULTICAST,
2548 					      "drop_unicast_in_l2_multicast"),
2549 	},
2550 };
2551 
2552 static int __devinet_sysctl_register(struct net *net, char *dev_name,
2553 				     int ifindex, struct ipv4_devconf *p)
2554 {
2555 	int i;
2556 	struct devinet_sysctl_table *t;
2557 	char path[sizeof("net/ipv4/conf/") + IFNAMSIZ];
2558 
2559 	t = kmemdup(&devinet_sysctl, sizeof(*t), GFP_KERNEL);
2560 	if (!t)
2561 		goto out;
2562 
2563 	for (i = 0; i < ARRAY_SIZE(t->devinet_vars) - 1; i++) {
2564 		t->devinet_vars[i].data += (char *)p - (char *)&ipv4_devconf;
2565 		t->devinet_vars[i].extra1 = p;
2566 		t->devinet_vars[i].extra2 = net;
2567 	}
2568 
2569 	snprintf(path, sizeof(path), "net/ipv4/conf/%s", dev_name);
2570 
2571 	t->sysctl_header = register_net_sysctl(net, path, t->devinet_vars);
2572 	if (!t->sysctl_header)
2573 		goto free;
2574 
2575 	p->sysctl = t;
2576 
2577 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL,
2578 				    ifindex, p);
2579 	return 0;
2580 
2581 free:
2582 	kfree(t);
2583 out:
2584 	return -ENOBUFS;
2585 }
2586 
2587 static void __devinet_sysctl_unregister(struct net *net,
2588 					struct ipv4_devconf *cnf, int ifindex)
2589 {
2590 	struct devinet_sysctl_table *t = cnf->sysctl;
2591 
2592 	if (t) {
2593 		cnf->sysctl = NULL;
2594 		unregister_net_sysctl_table(t->sysctl_header);
2595 		kfree(t);
2596 	}
2597 
2598 	inet_netconf_notify_devconf(net, RTM_DELNETCONF, 0, ifindex, NULL);
2599 }
2600 
2601 static int devinet_sysctl_register(struct in_device *idev)
2602 {
2603 	int err;
2604 
2605 	if (!sysctl_dev_name_is_allowed(idev->dev->name))
2606 		return -EINVAL;
2607 
2608 	err = neigh_sysctl_register(idev->dev, idev->arp_parms, NULL);
2609 	if (err)
2610 		return err;
2611 	err = __devinet_sysctl_register(dev_net(idev->dev), idev->dev->name,
2612 					idev->dev->ifindex, &idev->cnf);
2613 	if (err)
2614 		neigh_sysctl_unregister(idev->arp_parms);
2615 	return err;
2616 }
2617 
2618 static void devinet_sysctl_unregister(struct in_device *idev)
2619 {
2620 	struct net *net = dev_net(idev->dev);
2621 
2622 	__devinet_sysctl_unregister(net, &idev->cnf, idev->dev->ifindex);
2623 	neigh_sysctl_unregister(idev->arp_parms);
2624 }
2625 
2626 static struct ctl_table ctl_forward_entry[] = {
2627 	{
2628 		.procname	= "ip_forward",
2629 		.data		= &ipv4_devconf.data[
2630 					IPV4_DEVCONF_FORWARDING - 1],
2631 		.maxlen		= sizeof(int),
2632 		.mode		= 0644,
2633 		.proc_handler	= devinet_sysctl_forward,
2634 		.extra1		= &ipv4_devconf,
2635 		.extra2		= &init_net,
2636 	},
2637 	{ },
2638 };
2639 #endif
2640 
2641 static __net_init int devinet_init_net(struct net *net)
2642 {
2643 	int err;
2644 	struct ipv4_devconf *all, *dflt;
2645 #ifdef CONFIG_SYSCTL
2646 	struct ctl_table *tbl;
2647 	struct ctl_table_header *forw_hdr;
2648 #endif
2649 
2650 	err = -ENOMEM;
2651 	all = kmemdup(&ipv4_devconf, sizeof(ipv4_devconf), GFP_KERNEL);
2652 	if (!all)
2653 		goto err_alloc_all;
2654 
2655 	dflt = kmemdup(&ipv4_devconf_dflt, sizeof(ipv4_devconf_dflt), GFP_KERNEL);
2656 	if (!dflt)
2657 		goto err_alloc_dflt;
2658 
2659 #ifdef CONFIG_SYSCTL
2660 	tbl = kmemdup(ctl_forward_entry, sizeof(ctl_forward_entry), GFP_KERNEL);
2661 	if (!tbl)
2662 		goto err_alloc_ctl;
2663 
2664 	tbl[0].data = &all->data[IPV4_DEVCONF_FORWARDING - 1];
2665 	tbl[0].extra1 = all;
2666 	tbl[0].extra2 = net;
2667 #endif
2668 
2669 	if (!net_eq(net, &init_net)) {
2670 		if (IS_ENABLED(CONFIG_SYSCTL) &&
2671 		    sysctl_devconf_inherit_init_net == 3) {
2672 			/* copy from the current netns */
2673 			memcpy(all, current->nsproxy->net_ns->ipv4.devconf_all,
2674 			       sizeof(ipv4_devconf));
2675 			memcpy(dflt,
2676 			       current->nsproxy->net_ns->ipv4.devconf_dflt,
2677 			       sizeof(ipv4_devconf_dflt));
2678 		} else if (!IS_ENABLED(CONFIG_SYSCTL) ||
2679 			   sysctl_devconf_inherit_init_net != 2) {
2680 			/* inherit == 0 or 1: copy from init_net */
2681 			memcpy(all, init_net.ipv4.devconf_all,
2682 			       sizeof(ipv4_devconf));
2683 			memcpy(dflt, init_net.ipv4.devconf_dflt,
2684 			       sizeof(ipv4_devconf_dflt));
2685 		}
2686 		/* else inherit == 2: use compiled values */
2687 	}
2688 
2689 #ifdef CONFIG_SYSCTL
2690 	err = __devinet_sysctl_register(net, "all", NETCONFA_IFINDEX_ALL, all);
2691 	if (err < 0)
2692 		goto err_reg_all;
2693 
2694 	err = __devinet_sysctl_register(net, "default",
2695 					NETCONFA_IFINDEX_DEFAULT, dflt);
2696 	if (err < 0)
2697 		goto err_reg_dflt;
2698 
2699 	err = -ENOMEM;
2700 	forw_hdr = register_net_sysctl(net, "net/ipv4", tbl);
2701 	if (!forw_hdr)
2702 		goto err_reg_ctl;
2703 	net->ipv4.forw_hdr = forw_hdr;
2704 #endif
2705 
2706 	net->ipv4.devconf_all = all;
2707 	net->ipv4.devconf_dflt = dflt;
2708 	return 0;
2709 
2710 #ifdef CONFIG_SYSCTL
2711 err_reg_ctl:
2712 	__devinet_sysctl_unregister(net, dflt, NETCONFA_IFINDEX_DEFAULT);
2713 err_reg_dflt:
2714 	__devinet_sysctl_unregister(net, all, NETCONFA_IFINDEX_ALL);
2715 err_reg_all:
2716 	kfree(tbl);
2717 err_alloc_ctl:
2718 #endif
2719 	kfree(dflt);
2720 err_alloc_dflt:
2721 	kfree(all);
2722 err_alloc_all:
2723 	return err;
2724 }
2725 
2726 static __net_exit void devinet_exit_net(struct net *net)
2727 {
2728 #ifdef CONFIG_SYSCTL
2729 	struct ctl_table *tbl;
2730 
2731 	tbl = net->ipv4.forw_hdr->ctl_table_arg;
2732 	unregister_net_sysctl_table(net->ipv4.forw_hdr);
2733 	__devinet_sysctl_unregister(net, net->ipv4.devconf_dflt,
2734 				    NETCONFA_IFINDEX_DEFAULT);
2735 	__devinet_sysctl_unregister(net, net->ipv4.devconf_all,
2736 				    NETCONFA_IFINDEX_ALL);
2737 	kfree(tbl);
2738 #endif
2739 	kfree(net->ipv4.devconf_dflt);
2740 	kfree(net->ipv4.devconf_all);
2741 }
2742 
2743 static __net_initdata struct pernet_operations devinet_ops = {
2744 	.init = devinet_init_net,
2745 	.exit = devinet_exit_net,
2746 };
2747 
2748 static struct rtnl_af_ops inet_af_ops __read_mostly = {
2749 	.family		  = AF_INET,
2750 	.fill_link_af	  = inet_fill_link_af,
2751 	.get_link_af_size = inet_get_link_af_size,
2752 	.validate_link_af = inet_validate_link_af,
2753 	.set_link_af	  = inet_set_link_af,
2754 };
2755 
2756 void __init devinet_init(void)
2757 {
2758 	int i;
2759 
2760 	for (i = 0; i < IN4_ADDR_HSIZE; i++)
2761 		INIT_HLIST_HEAD(&inet_addr_lst[i]);
2762 
2763 	register_pernet_subsys(&devinet_ops);
2764 
2765 	register_gifconf(PF_INET, inet_gifconf);
2766 	register_netdevice_notifier(&ip_netdev_notifier);
2767 
2768 	queue_delayed_work(system_power_efficient_wq, &check_lifetime_work, 0);
2769 
2770 	rtnl_af_register(&inet_af_ops);
2771 
2772 	rtnl_register(PF_INET, RTM_NEWADDR, inet_rtm_newaddr, NULL, 0);
2773 	rtnl_register(PF_INET, RTM_DELADDR, inet_rtm_deladdr, NULL, 0);
2774 	rtnl_register(PF_INET, RTM_GETADDR, NULL, inet_dump_ifaddr, 0);
2775 	rtnl_register(PF_INET, RTM_GETNETCONF, inet_netconf_get_devconf,
2776 		      inet_netconf_dump_devconf, 0);
2777 }
2778