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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 
inet_addr_hash(const struct net * net,__be32 addr)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 
inet_hash_insert(struct net * net,struct in_ifaddr * ifa)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 
inet_hash_remove(struct in_ifaddr * ifa)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  */
__ip_dev_find(struct net * net,__be32 addr,bool devref)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 */
inet_lookup_ifaddr_rcu(struct net * net,__be32 addr)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
devinet_sysctl_register(struct in_device * idev)205 static int devinet_sysctl_register(struct in_device *idev)
206 {
207 	return 0;
208 }
devinet_sysctl_unregister(struct in_device * idev)209 static void devinet_sysctl_unregister(struct in_device *idev)
210 {
211 }
212 #endif
213 
214 /* Locks all the inet devices. */
215 
inet_alloc_ifa(void)216 static struct in_ifaddr *inet_alloc_ifa(void)
217 {
218 	return kzalloc(sizeof(struct in_ifaddr), GFP_KERNEL);
219 }
220 
inet_rcu_free_ifa(struct rcu_head * head)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 
inet_free_ifa(struct in_ifaddr * ifa)229 static void inet_free_ifa(struct in_ifaddr *ifa)
230 {
231 	call_rcu(&ifa->rcu_head, inet_rcu_free_ifa);
232 }
233 
in_dev_finish_destroy(struct in_device * idev)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 
inetdev_init(struct net_device * dev)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 
in_dev_rcu_put(struct rcu_head * head)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 
inetdev_destroy(struct in_device * in_dev)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 
inet_addr_onlink(struct in_device * in_dev,__be32 a,__be32 b)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 
__inet_del_ifa(struct in_device * in_dev,struct in_ifaddr __rcu ** ifap,int destroy,struct nlmsghdr * nlh,u32 portid)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 __rcu **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 = ifap;
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->ifa_next;
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);
440 			rcu_assign_pointer(promote->ifa_next, last_sec);
441 			rcu_assign_pointer(*last_prim, 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 
inet_del_ifa(struct in_device * in_dev,struct in_ifaddr __rcu ** ifap,int destroy)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 
__inet_insert_ifa(struct in_ifaddr * ifa,struct nlmsghdr * nlh,u32 portid,struct netlink_ext_ack * extack)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 
inet_insert_ifa(struct in_ifaddr * ifa)558 static int inet_insert_ifa(struct in_ifaddr *ifa)
559 {
560 	return __inet_insert_ifa(ifa, NULL, 0, NULL);
561 }
562 
inet_set_ifa(struct net_device * dev,struct in_ifaddr * ifa)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  */
inetdev_by_index(struct net * net,int ifindex)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 
inet_ifa_byprefix(struct in_device * in_dev,__be32 prefix,__be32 mask)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 
ip_mc_autojoin_config(struct net * net,bool join,const struct in_ifaddr * ifa)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 
inet_rtm_deladdr(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)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 
654 	int err = -EINVAL;
655 
656 	ASSERT_RTNL();
657 
658 	err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFA_MAX,
659 				     ifa_ipv4_policy, extack);
660 	if (err < 0)
661 		goto errout;
662 
663 	ifm = nlmsg_data(nlh);
664 	in_dev = inetdev_by_index(net, ifm->ifa_index);
665 	if (!in_dev) {
666 		err = -ENODEV;
667 		goto errout;
668 	}
669 
670 	for (ifap = &in_dev->ifa_list; (ifa = rtnl_dereference(*ifap)) != NULL;
671 	     ifap = &ifa->ifa_next) {
672 		if (tb[IFA_LOCAL] &&
673 		    ifa->ifa_local != nla_get_in_addr(tb[IFA_LOCAL]))
674 			continue;
675 
676 		if (tb[IFA_LABEL] && nla_strcmp(tb[IFA_LABEL], ifa->ifa_label))
677 			continue;
678 
679 		if (tb[IFA_ADDRESS] &&
680 		    (ifm->ifa_prefixlen != ifa->ifa_prefixlen ||
681 		    !inet_ifa_match(nla_get_in_addr(tb[IFA_ADDRESS]), ifa)))
682 			continue;
683 
684 		if (ipv4_is_multicast(ifa->ifa_address))
685 			ip_mc_autojoin_config(net, false, ifa);
686 		__inet_del_ifa(in_dev, ifap, 1, nlh, NETLINK_CB(skb).portid);
687 		return 0;
688 	}
689 
690 	err = -EADDRNOTAVAIL;
691 errout:
692 	return err;
693 }
694 
695 #define INFINITY_LIFE_TIME	0xFFFFFFFF
696 
check_lifetime(struct work_struct * work)697 static void check_lifetime(struct work_struct *work)
698 {
699 	unsigned long now, next, next_sec, next_sched;
700 	struct in_ifaddr *ifa;
701 	struct hlist_node *n;
702 	int i;
703 
704 	now = jiffies;
705 	next = round_jiffies_up(now + ADDR_CHECK_FREQUENCY);
706 
707 	for (i = 0; i < IN4_ADDR_HSIZE; i++) {
708 		bool change_needed = false;
709 
710 		rcu_read_lock();
711 		hlist_for_each_entry_rcu(ifa, &inet_addr_lst[i], hash) {
712 			unsigned long age;
713 
714 			if (ifa->ifa_flags & IFA_F_PERMANENT)
715 				continue;
716 
717 			/* We try to batch several events at once. */
718 			age = (now - ifa->ifa_tstamp +
719 			       ADDRCONF_TIMER_FUZZ_MINUS) / HZ;
720 
721 			if (ifa->ifa_valid_lft != INFINITY_LIFE_TIME &&
722 			    age >= ifa->ifa_valid_lft) {
723 				change_needed = true;
724 			} else if (ifa->ifa_preferred_lft ==
725 				   INFINITY_LIFE_TIME) {
726 				continue;
727 			} else if (age >= ifa->ifa_preferred_lft) {
728 				if (time_before(ifa->ifa_tstamp +
729 						ifa->ifa_valid_lft * HZ, next))
730 					next = ifa->ifa_tstamp +
731 					       ifa->ifa_valid_lft * HZ;
732 
733 				if (!(ifa->ifa_flags & IFA_F_DEPRECATED))
734 					change_needed = true;
735 			} else if (time_before(ifa->ifa_tstamp +
736 					       ifa->ifa_preferred_lft * HZ,
737 					       next)) {
738 				next = ifa->ifa_tstamp +
739 				       ifa->ifa_preferred_lft * HZ;
740 			}
741 		}
742 		rcu_read_unlock();
743 		if (!change_needed)
744 			continue;
745 		rtnl_lock();
746 		hlist_for_each_entry_safe(ifa, n, &inet_addr_lst[i], hash) {
747 			unsigned long age;
748 
749 			if (ifa->ifa_flags & IFA_F_PERMANENT)
750 				continue;
751 
752 			/* We try to batch several events at once. */
753 			age = (now - ifa->ifa_tstamp +
754 			       ADDRCONF_TIMER_FUZZ_MINUS) / HZ;
755 
756 			if (ifa->ifa_valid_lft != INFINITY_LIFE_TIME &&
757 			    age >= ifa->ifa_valid_lft) {
758 				struct in_ifaddr __rcu **ifap;
759 				struct in_ifaddr *tmp;
760 
761 				ifap = &ifa->ifa_dev->ifa_list;
762 				tmp = rtnl_dereference(*ifap);
763 				while (tmp) {
764 					if (tmp == ifa) {
765 						inet_del_ifa(ifa->ifa_dev,
766 							     ifap, 1);
767 						break;
768 					}
769 					ifap = &tmp->ifa_next;
770 					tmp = rtnl_dereference(*ifap);
771 				}
772 			} else if (ifa->ifa_preferred_lft !=
773 				   INFINITY_LIFE_TIME &&
774 				   age >= ifa->ifa_preferred_lft &&
775 				   !(ifa->ifa_flags & IFA_F_DEPRECATED)) {
776 				ifa->ifa_flags |= IFA_F_DEPRECATED;
777 				rtmsg_ifa(RTM_NEWADDR, ifa, NULL, 0);
778 			}
779 		}
780 		rtnl_unlock();
781 	}
782 
783 	next_sec = round_jiffies_up(next);
784 	next_sched = next;
785 
786 	/* If rounded timeout is accurate enough, accept it. */
787 	if (time_before(next_sec, next + ADDRCONF_TIMER_FUZZ))
788 		next_sched = next_sec;
789 
790 	now = jiffies;
791 	/* And minimum interval is ADDRCONF_TIMER_FUZZ_MAX. */
792 	if (time_before(next_sched, now + ADDRCONF_TIMER_FUZZ_MAX))
793 		next_sched = now + ADDRCONF_TIMER_FUZZ_MAX;
794 
795 	queue_delayed_work(system_power_efficient_wq, &check_lifetime_work,
796 			next_sched - now);
797 }
798 
set_ifa_lifetime(struct in_ifaddr * ifa,__u32 valid_lft,__u32 prefered_lft)799 static void set_ifa_lifetime(struct in_ifaddr *ifa, __u32 valid_lft,
800 			     __u32 prefered_lft)
801 {
802 	unsigned long timeout;
803 
804 	ifa->ifa_flags &= ~(IFA_F_PERMANENT | IFA_F_DEPRECATED);
805 
806 	timeout = addrconf_timeout_fixup(valid_lft, HZ);
807 	if (addrconf_finite_timeout(timeout))
808 		ifa->ifa_valid_lft = timeout;
809 	else
810 		ifa->ifa_flags |= IFA_F_PERMANENT;
811 
812 	timeout = addrconf_timeout_fixup(prefered_lft, HZ);
813 	if (addrconf_finite_timeout(timeout)) {
814 		if (timeout == 0)
815 			ifa->ifa_flags |= IFA_F_DEPRECATED;
816 		ifa->ifa_preferred_lft = timeout;
817 	}
818 	ifa->ifa_tstamp = jiffies;
819 	if (!ifa->ifa_cstamp)
820 		ifa->ifa_cstamp = ifa->ifa_tstamp;
821 }
822 
rtm_to_ifaddr(struct net * net,struct nlmsghdr * nlh,__u32 * pvalid_lft,__u32 * pprefered_lft,struct netlink_ext_ack * extack)823 static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh,
824 				       __u32 *pvalid_lft, __u32 *pprefered_lft,
825 				       struct netlink_ext_ack *extack)
826 {
827 	struct nlattr *tb[IFA_MAX+1];
828 	struct in_ifaddr *ifa;
829 	struct ifaddrmsg *ifm;
830 	struct net_device *dev;
831 	struct in_device *in_dev;
832 	int err;
833 
834 	err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFA_MAX,
835 				     ifa_ipv4_policy, extack);
836 	if (err < 0)
837 		goto errout;
838 
839 	ifm = nlmsg_data(nlh);
840 	err = -EINVAL;
841 	if (ifm->ifa_prefixlen > 32 || !tb[IFA_LOCAL])
842 		goto errout;
843 
844 	dev = __dev_get_by_index(net, ifm->ifa_index);
845 	err = -ENODEV;
846 	if (!dev)
847 		goto errout;
848 
849 	in_dev = __in_dev_get_rtnl(dev);
850 	err = -ENOBUFS;
851 	if (!in_dev)
852 		goto errout;
853 
854 	ifa = inet_alloc_ifa();
855 	if (!ifa)
856 		/*
857 		 * A potential indev allocation can be left alive, it stays
858 		 * assigned to its device and is destroy with it.
859 		 */
860 		goto errout;
861 
862 	ipv4_devconf_setall(in_dev);
863 	neigh_parms_data_state_setall(in_dev->arp_parms);
864 	in_dev_hold(in_dev);
865 
866 	if (!tb[IFA_ADDRESS])
867 		tb[IFA_ADDRESS] = tb[IFA_LOCAL];
868 
869 	INIT_HLIST_NODE(&ifa->hash);
870 	ifa->ifa_prefixlen = ifm->ifa_prefixlen;
871 	ifa->ifa_mask = inet_make_mask(ifm->ifa_prefixlen);
872 	ifa->ifa_flags = tb[IFA_FLAGS] ? nla_get_u32(tb[IFA_FLAGS]) :
873 					 ifm->ifa_flags;
874 	ifa->ifa_scope = ifm->ifa_scope;
875 	ifa->ifa_dev = in_dev;
876 
877 	ifa->ifa_local = nla_get_in_addr(tb[IFA_LOCAL]);
878 	ifa->ifa_address = nla_get_in_addr(tb[IFA_ADDRESS]);
879 
880 	if (tb[IFA_BROADCAST])
881 		ifa->ifa_broadcast = nla_get_in_addr(tb[IFA_BROADCAST]);
882 
883 	if (tb[IFA_LABEL])
884 		nla_strlcpy(ifa->ifa_label, tb[IFA_LABEL], IFNAMSIZ);
885 	else
886 		memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
887 
888 	if (tb[IFA_RT_PRIORITY])
889 		ifa->ifa_rt_priority = nla_get_u32(tb[IFA_RT_PRIORITY]);
890 
891 	if (tb[IFA_CACHEINFO]) {
892 		struct ifa_cacheinfo *ci;
893 
894 		ci = nla_data(tb[IFA_CACHEINFO]);
895 		if (!ci->ifa_valid || ci->ifa_prefered > ci->ifa_valid) {
896 			err = -EINVAL;
897 			goto errout_free;
898 		}
899 		*pvalid_lft = ci->ifa_valid;
900 		*pprefered_lft = ci->ifa_prefered;
901 	}
902 
903 	return ifa;
904 
905 errout_free:
906 	inet_free_ifa(ifa);
907 errout:
908 	return ERR_PTR(err);
909 }
910 
find_matching_ifa(struct in_ifaddr * ifa)911 static struct in_ifaddr *find_matching_ifa(struct in_ifaddr *ifa)
912 {
913 	struct in_device *in_dev = ifa->ifa_dev;
914 	struct in_ifaddr *ifa1;
915 
916 	if (!ifa->ifa_local)
917 		return NULL;
918 
919 	in_dev_for_each_ifa_rtnl(ifa1, in_dev) {
920 		if (ifa1->ifa_mask == ifa->ifa_mask &&
921 		    inet_ifa_match(ifa1->ifa_address, ifa) &&
922 		    ifa1->ifa_local == ifa->ifa_local)
923 			return ifa1;
924 	}
925 	return NULL;
926 }
927 
inet_rtm_newaddr(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)928 static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh,
929 			    struct netlink_ext_ack *extack)
930 {
931 	struct net *net = sock_net(skb->sk);
932 	struct in_ifaddr *ifa;
933 	struct in_ifaddr *ifa_existing;
934 	__u32 valid_lft = INFINITY_LIFE_TIME;
935 	__u32 prefered_lft = INFINITY_LIFE_TIME;
936 
937 	ASSERT_RTNL();
938 
939 	ifa = rtm_to_ifaddr(net, nlh, &valid_lft, &prefered_lft, extack);
940 	if (IS_ERR(ifa))
941 		return PTR_ERR(ifa);
942 
943 	ifa_existing = find_matching_ifa(ifa);
944 	if (!ifa_existing) {
945 		/* It would be best to check for !NLM_F_CREATE here but
946 		 * userspace already relies on not having to provide this.
947 		 */
948 		set_ifa_lifetime(ifa, valid_lft, prefered_lft);
949 		if (ifa->ifa_flags & IFA_F_MCAUTOJOIN) {
950 			int ret = ip_mc_autojoin_config(net, true, ifa);
951 
952 			if (ret < 0) {
953 				inet_free_ifa(ifa);
954 				return ret;
955 			}
956 		}
957 		return __inet_insert_ifa(ifa, nlh, NETLINK_CB(skb).portid,
958 					 extack);
959 	} else {
960 		u32 new_metric = ifa->ifa_rt_priority;
961 
962 		inet_free_ifa(ifa);
963 
964 		if (nlh->nlmsg_flags & NLM_F_EXCL ||
965 		    !(nlh->nlmsg_flags & NLM_F_REPLACE))
966 			return -EEXIST;
967 		ifa = ifa_existing;
968 
969 		if (ifa->ifa_rt_priority != new_metric) {
970 			fib_modify_prefix_metric(ifa, new_metric);
971 			ifa->ifa_rt_priority = new_metric;
972 		}
973 
974 		set_ifa_lifetime(ifa, valid_lft, prefered_lft);
975 		cancel_delayed_work(&check_lifetime_work);
976 		queue_delayed_work(system_power_efficient_wq,
977 				&check_lifetime_work, 0);
978 		rtmsg_ifa(RTM_NEWADDR, ifa, nlh, NETLINK_CB(skb).portid);
979 	}
980 	return 0;
981 }
982 
983 /*
984  *	Determine a default network mask, based on the IP address.
985  */
986 
inet_abc_len(__be32 addr)987 static int inet_abc_len(__be32 addr)
988 {
989 	int rc = -1;	/* Something else, probably a multicast. */
990 
991 	if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
992 		rc = 0;
993 	else {
994 		__u32 haddr = ntohl(addr);
995 		if (IN_CLASSA(haddr))
996 			rc = 8;
997 		else if (IN_CLASSB(haddr))
998 			rc = 16;
999 		else if (IN_CLASSC(haddr))
1000 			rc = 24;
1001 		else if (IN_CLASSE(haddr))
1002 			rc = 32;
1003 	}
1004 
1005 	return rc;
1006 }
1007 
1008 
devinet_ioctl(struct net * net,unsigned int cmd,struct ifreq * ifr)1009 int devinet_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr)
1010 {
1011 	struct sockaddr_in sin_orig;
1012 	struct sockaddr_in *sin = (struct sockaddr_in *)&ifr->ifr_addr;
1013 	struct in_ifaddr __rcu **ifap = NULL;
1014 	struct in_device *in_dev;
1015 	struct in_ifaddr *ifa = NULL;
1016 	struct net_device *dev;
1017 	char *colon;
1018 	int ret = -EFAULT;
1019 	int tryaddrmatch = 0;
1020 
1021 	ifr->ifr_name[IFNAMSIZ - 1] = 0;
1022 
1023 	/* save original address for comparison */
1024 	memcpy(&sin_orig, sin, sizeof(*sin));
1025 
1026 	colon = strchr(ifr->ifr_name, ':');
1027 	if (colon)
1028 		*colon = 0;
1029 
1030 	dev_load(net, ifr->ifr_name);
1031 
1032 	switch (cmd) {
1033 	case SIOCGIFADDR:	/* Get interface address */
1034 	case SIOCGIFBRDADDR:	/* Get the broadcast address */
1035 	case SIOCGIFDSTADDR:	/* Get the destination address */
1036 	case SIOCGIFNETMASK:	/* Get the netmask for the interface */
1037 		/* Note that these ioctls will not sleep,
1038 		   so that we do not impose a lock.
1039 		   One day we will be forced to put shlock here (I mean SMP)
1040 		 */
1041 		tryaddrmatch = (sin_orig.sin_family == AF_INET);
1042 		memset(sin, 0, sizeof(*sin));
1043 		sin->sin_family = AF_INET;
1044 		break;
1045 
1046 	case SIOCSIFFLAGS:
1047 		ret = -EPERM;
1048 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1049 			goto out;
1050 		break;
1051 	case SIOCSIFADDR:	/* Set interface address (and family) */
1052 	case SIOCSIFBRDADDR:	/* Set the broadcast address */
1053 	case SIOCSIFDSTADDR:	/* Set the destination address */
1054 	case SIOCSIFNETMASK: 	/* Set the netmask for the interface */
1055 		ret = -EPERM;
1056 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1057 			goto out;
1058 		ret = -EINVAL;
1059 		if (sin->sin_family != AF_INET)
1060 			goto out;
1061 		break;
1062 	default:
1063 		ret = -EINVAL;
1064 		goto out;
1065 	}
1066 
1067 	rtnl_lock();
1068 
1069 	ret = -ENODEV;
1070 	dev = __dev_get_by_name(net, ifr->ifr_name);
1071 	if (!dev)
1072 		goto done;
1073 
1074 	if (colon)
1075 		*colon = ':';
1076 
1077 	in_dev = __in_dev_get_rtnl(dev);
1078 	if (in_dev) {
1079 		if (tryaddrmatch) {
1080 			/* Matthias Andree */
1081 			/* compare label and address (4.4BSD style) */
1082 			/* note: we only do this for a limited set of ioctls
1083 			   and only if the original address family was AF_INET.
1084 			   This is checked above. */
1085 
1086 			for (ifap = &in_dev->ifa_list;
1087 			     (ifa = rtnl_dereference(*ifap)) != NULL;
1088 			     ifap = &ifa->ifa_next) {
1089 				if (!strcmp(ifr->ifr_name, ifa->ifa_label) &&
1090 				    sin_orig.sin_addr.s_addr ==
1091 							ifa->ifa_local) {
1092 					break; /* found */
1093 				}
1094 			}
1095 		}
1096 		/* we didn't get a match, maybe the application is
1097 		   4.3BSD-style and passed in junk so we fall back to
1098 		   comparing just the label */
1099 		if (!ifa) {
1100 			for (ifap = &in_dev->ifa_list;
1101 			     (ifa = rtnl_dereference(*ifap)) != NULL;
1102 			     ifap = &ifa->ifa_next)
1103 				if (!strcmp(ifr->ifr_name, ifa->ifa_label))
1104 					break;
1105 		}
1106 	}
1107 
1108 	ret = -EADDRNOTAVAIL;
1109 	if (!ifa && cmd != SIOCSIFADDR && cmd != SIOCSIFFLAGS)
1110 		goto done;
1111 
1112 	switch (cmd) {
1113 	case SIOCGIFADDR:	/* Get interface address */
1114 		ret = 0;
1115 		sin->sin_addr.s_addr = ifa->ifa_local;
1116 		break;
1117 
1118 	case SIOCGIFBRDADDR:	/* Get the broadcast address */
1119 		ret = 0;
1120 		sin->sin_addr.s_addr = ifa->ifa_broadcast;
1121 		break;
1122 
1123 	case SIOCGIFDSTADDR:	/* Get the destination address */
1124 		ret = 0;
1125 		sin->sin_addr.s_addr = ifa->ifa_address;
1126 		break;
1127 
1128 	case SIOCGIFNETMASK:	/* Get the netmask for the interface */
1129 		ret = 0;
1130 		sin->sin_addr.s_addr = ifa->ifa_mask;
1131 		break;
1132 
1133 	case SIOCSIFFLAGS:
1134 		if (colon) {
1135 			ret = -EADDRNOTAVAIL;
1136 			if (!ifa)
1137 				break;
1138 			ret = 0;
1139 			if (!(ifr->ifr_flags & IFF_UP))
1140 				inet_del_ifa(in_dev, ifap, 1);
1141 			break;
1142 		}
1143 		ret = dev_change_flags(dev, ifr->ifr_flags, NULL);
1144 		break;
1145 
1146 	case SIOCSIFADDR:	/* Set interface address (and family) */
1147 		ret = -EINVAL;
1148 		if (inet_abc_len(sin->sin_addr.s_addr) < 0)
1149 			break;
1150 
1151 		if (!ifa) {
1152 			ret = -ENOBUFS;
1153 			ifa = inet_alloc_ifa();
1154 			if (!ifa)
1155 				break;
1156 			INIT_HLIST_NODE(&ifa->hash);
1157 			if (colon)
1158 				memcpy(ifa->ifa_label, ifr->ifr_name, IFNAMSIZ);
1159 			else
1160 				memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
1161 		} else {
1162 			ret = 0;
1163 			if (ifa->ifa_local == sin->sin_addr.s_addr)
1164 				break;
1165 			inet_del_ifa(in_dev, ifap, 0);
1166 			ifa->ifa_broadcast = 0;
1167 			ifa->ifa_scope = 0;
1168 		}
1169 
1170 		ifa->ifa_address = ifa->ifa_local = sin->sin_addr.s_addr;
1171 
1172 		if (!(dev->flags & IFF_POINTOPOINT)) {
1173 			ifa->ifa_prefixlen = inet_abc_len(ifa->ifa_address);
1174 			ifa->ifa_mask = inet_make_mask(ifa->ifa_prefixlen);
1175 			if ((dev->flags & IFF_BROADCAST) &&
1176 			    ifa->ifa_prefixlen < 31)
1177 				ifa->ifa_broadcast = ifa->ifa_address |
1178 						     ~ifa->ifa_mask;
1179 		} else {
1180 			ifa->ifa_prefixlen = 32;
1181 			ifa->ifa_mask = inet_make_mask(32);
1182 		}
1183 		set_ifa_lifetime(ifa, INFINITY_LIFE_TIME, INFINITY_LIFE_TIME);
1184 		ret = inet_set_ifa(dev, ifa);
1185 		break;
1186 
1187 	case SIOCSIFBRDADDR:	/* Set the broadcast address */
1188 		ret = 0;
1189 		if (ifa->ifa_broadcast != sin->sin_addr.s_addr) {
1190 			inet_del_ifa(in_dev, ifap, 0);
1191 			ifa->ifa_broadcast = sin->sin_addr.s_addr;
1192 			inet_insert_ifa(ifa);
1193 		}
1194 		break;
1195 
1196 	case SIOCSIFDSTADDR:	/* Set the destination address */
1197 		ret = 0;
1198 		if (ifa->ifa_address == sin->sin_addr.s_addr)
1199 			break;
1200 		ret = -EINVAL;
1201 		if (inet_abc_len(sin->sin_addr.s_addr) < 0)
1202 			break;
1203 		ret = 0;
1204 		inet_del_ifa(in_dev, ifap, 0);
1205 		ifa->ifa_address = sin->sin_addr.s_addr;
1206 		inet_insert_ifa(ifa);
1207 		break;
1208 
1209 	case SIOCSIFNETMASK: 	/* Set the netmask for the interface */
1210 
1211 		/*
1212 		 *	The mask we set must be legal.
1213 		 */
1214 		ret = -EINVAL;
1215 		if (bad_mask(sin->sin_addr.s_addr, 0))
1216 			break;
1217 		ret = 0;
1218 		if (ifa->ifa_mask != sin->sin_addr.s_addr) {
1219 			__be32 old_mask = ifa->ifa_mask;
1220 			inet_del_ifa(in_dev, ifap, 0);
1221 			ifa->ifa_mask = sin->sin_addr.s_addr;
1222 			ifa->ifa_prefixlen = inet_mask_len(ifa->ifa_mask);
1223 
1224 			/* See if current broadcast address matches
1225 			 * with current netmask, then recalculate
1226 			 * the broadcast address. Otherwise it's a
1227 			 * funny address, so don't touch it since
1228 			 * the user seems to know what (s)he's doing...
1229 			 */
1230 			if ((dev->flags & IFF_BROADCAST) &&
1231 			    (ifa->ifa_prefixlen < 31) &&
1232 			    (ifa->ifa_broadcast ==
1233 			     (ifa->ifa_local|~old_mask))) {
1234 				ifa->ifa_broadcast = (ifa->ifa_local |
1235 						      ~sin->sin_addr.s_addr);
1236 			}
1237 			inet_insert_ifa(ifa);
1238 		}
1239 		break;
1240 	}
1241 done:
1242 	rtnl_unlock();
1243 out:
1244 	return ret;
1245 }
1246 
inet_gifconf(struct net_device * dev,char __user * buf,int len,int size)1247 int inet_gifconf(struct net_device *dev, char __user *buf, int len, int size)
1248 {
1249 	struct in_device *in_dev = __in_dev_get_rtnl(dev);
1250 	const struct in_ifaddr *ifa;
1251 	struct ifreq ifr;
1252 	int done = 0;
1253 
1254 	if (WARN_ON(size > sizeof(struct ifreq)))
1255 		goto out;
1256 
1257 	if (!in_dev)
1258 		goto out;
1259 
1260 	in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1261 		if (!buf) {
1262 			done += size;
1263 			continue;
1264 		}
1265 		if (len < size)
1266 			break;
1267 		memset(&ifr, 0, sizeof(struct ifreq));
1268 		strcpy(ifr.ifr_name, ifa->ifa_label);
1269 
1270 		(*(struct sockaddr_in *)&ifr.ifr_addr).sin_family = AF_INET;
1271 		(*(struct sockaddr_in *)&ifr.ifr_addr).sin_addr.s_addr =
1272 								ifa->ifa_local;
1273 
1274 		if (copy_to_user(buf + done, &ifr, size)) {
1275 			done = -EFAULT;
1276 			break;
1277 		}
1278 		len  -= size;
1279 		done += size;
1280 	}
1281 out:
1282 	return done;
1283 }
1284 
in_dev_select_addr(const struct in_device * in_dev,int scope)1285 static __be32 in_dev_select_addr(const struct in_device *in_dev,
1286 				 int scope)
1287 {
1288 	const struct in_ifaddr *ifa;
1289 
1290 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
1291 		if (ifa->ifa_flags & IFA_F_SECONDARY)
1292 			continue;
1293 		if (ifa->ifa_scope != RT_SCOPE_LINK &&
1294 		    ifa->ifa_scope <= scope)
1295 			return ifa->ifa_local;
1296 	}
1297 
1298 	return 0;
1299 }
1300 
inet_select_addr(const struct net_device * dev,__be32 dst,int scope)1301 __be32 inet_select_addr(const struct net_device *dev, __be32 dst, int scope)
1302 {
1303 	const struct in_ifaddr *ifa;
1304 	__be32 addr = 0;
1305 	unsigned char localnet_scope = RT_SCOPE_HOST;
1306 	struct in_device *in_dev;
1307 	struct net *net = dev_net(dev);
1308 	int master_idx;
1309 
1310 	rcu_read_lock();
1311 	in_dev = __in_dev_get_rcu(dev);
1312 	if (!in_dev)
1313 		goto no_in_dev;
1314 
1315 	if (unlikely(IN_DEV_ROUTE_LOCALNET(in_dev)))
1316 		localnet_scope = RT_SCOPE_LINK;
1317 
1318 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
1319 		if (ifa->ifa_flags & IFA_F_SECONDARY)
1320 			continue;
1321 		if (min(ifa->ifa_scope, localnet_scope) > scope)
1322 			continue;
1323 		if (!dst || inet_ifa_match(dst, ifa)) {
1324 			addr = ifa->ifa_local;
1325 			break;
1326 		}
1327 		if (!addr)
1328 			addr = ifa->ifa_local;
1329 	}
1330 
1331 	if (addr)
1332 		goto out_unlock;
1333 no_in_dev:
1334 	master_idx = l3mdev_master_ifindex_rcu(dev);
1335 
1336 	/* For VRFs, the VRF device takes the place of the loopback device,
1337 	 * with addresses on it being preferred.  Note in such cases the
1338 	 * loopback device will be among the devices that fail the master_idx
1339 	 * equality check in the loop below.
1340 	 */
1341 	if (master_idx &&
1342 	    (dev = dev_get_by_index_rcu(net, master_idx)) &&
1343 	    (in_dev = __in_dev_get_rcu(dev))) {
1344 		addr = in_dev_select_addr(in_dev, scope);
1345 		if (addr)
1346 			goto out_unlock;
1347 	}
1348 
1349 	/* Not loopback addresses on loopback should be preferred
1350 	   in this case. It is important that lo is the first interface
1351 	   in dev_base list.
1352 	 */
1353 	for_each_netdev_rcu(net, dev) {
1354 		if (l3mdev_master_ifindex_rcu(dev) != master_idx)
1355 			continue;
1356 
1357 		in_dev = __in_dev_get_rcu(dev);
1358 		if (!in_dev)
1359 			continue;
1360 
1361 		addr = in_dev_select_addr(in_dev, scope);
1362 		if (addr)
1363 			goto out_unlock;
1364 	}
1365 out_unlock:
1366 	rcu_read_unlock();
1367 	return addr;
1368 }
1369 EXPORT_SYMBOL(inet_select_addr);
1370 
confirm_addr_indev(struct in_device * in_dev,__be32 dst,__be32 local,int scope)1371 static __be32 confirm_addr_indev(struct in_device *in_dev, __be32 dst,
1372 			      __be32 local, int scope)
1373 {
1374 	unsigned char localnet_scope = RT_SCOPE_HOST;
1375 	const struct in_ifaddr *ifa;
1376 	__be32 addr = 0;
1377 	int same = 0;
1378 
1379 	if (unlikely(IN_DEV_ROUTE_LOCALNET(in_dev)))
1380 		localnet_scope = RT_SCOPE_LINK;
1381 
1382 	in_dev_for_each_ifa_rcu(ifa, in_dev) {
1383 		unsigned char min_scope = min(ifa->ifa_scope, localnet_scope);
1384 
1385 		if (!addr &&
1386 		    (local == ifa->ifa_local || !local) &&
1387 		    min_scope <= scope) {
1388 			addr = ifa->ifa_local;
1389 			if (same)
1390 				break;
1391 		}
1392 		if (!same) {
1393 			same = (!local || inet_ifa_match(local, ifa)) &&
1394 				(!dst || inet_ifa_match(dst, ifa));
1395 			if (same && addr) {
1396 				if (local || !dst)
1397 					break;
1398 				/* Is the selected addr into dst subnet? */
1399 				if (inet_ifa_match(addr, ifa))
1400 					break;
1401 				/* No, then can we use new local src? */
1402 				if (min_scope <= scope) {
1403 					addr = ifa->ifa_local;
1404 					break;
1405 				}
1406 				/* search for large dst subnet for addr */
1407 				same = 0;
1408 			}
1409 		}
1410 	}
1411 
1412 	return same ? addr : 0;
1413 }
1414 
1415 /*
1416  * Confirm that local IP address exists using wildcards:
1417  * - net: netns to check, cannot be NULL
1418  * - in_dev: only on this interface, NULL=any interface
1419  * - dst: only in the same subnet as dst, 0=any dst
1420  * - local: address, 0=autoselect the local address
1421  * - scope: maximum allowed scope value for the local address
1422  */
inet_confirm_addr(struct net * net,struct in_device * in_dev,__be32 dst,__be32 local,int scope)1423 __be32 inet_confirm_addr(struct net *net, struct in_device *in_dev,
1424 			 __be32 dst, __be32 local, int scope)
1425 {
1426 	__be32 addr = 0;
1427 	struct net_device *dev;
1428 
1429 	if (in_dev)
1430 		return confirm_addr_indev(in_dev, dst, local, scope);
1431 
1432 	rcu_read_lock();
1433 	for_each_netdev_rcu(net, dev) {
1434 		in_dev = __in_dev_get_rcu(dev);
1435 		if (in_dev) {
1436 			addr = confirm_addr_indev(in_dev, dst, local, scope);
1437 			if (addr)
1438 				break;
1439 		}
1440 	}
1441 	rcu_read_unlock();
1442 
1443 	return addr;
1444 }
1445 EXPORT_SYMBOL(inet_confirm_addr);
1446 
1447 /*
1448  *	Device notifier
1449  */
1450 
register_inetaddr_notifier(struct notifier_block * nb)1451 int register_inetaddr_notifier(struct notifier_block *nb)
1452 {
1453 	return blocking_notifier_chain_register(&inetaddr_chain, nb);
1454 }
1455 EXPORT_SYMBOL(register_inetaddr_notifier);
1456 
unregister_inetaddr_notifier(struct notifier_block * nb)1457 int unregister_inetaddr_notifier(struct notifier_block *nb)
1458 {
1459 	return blocking_notifier_chain_unregister(&inetaddr_chain, nb);
1460 }
1461 EXPORT_SYMBOL(unregister_inetaddr_notifier);
1462 
register_inetaddr_validator_notifier(struct notifier_block * nb)1463 int register_inetaddr_validator_notifier(struct notifier_block *nb)
1464 {
1465 	return blocking_notifier_chain_register(&inetaddr_validator_chain, nb);
1466 }
1467 EXPORT_SYMBOL(register_inetaddr_validator_notifier);
1468 
unregister_inetaddr_validator_notifier(struct notifier_block * nb)1469 int unregister_inetaddr_validator_notifier(struct notifier_block *nb)
1470 {
1471 	return blocking_notifier_chain_unregister(&inetaddr_validator_chain,
1472 	    nb);
1473 }
1474 EXPORT_SYMBOL(unregister_inetaddr_validator_notifier);
1475 
1476 /* Rename ifa_labels for a device name change. Make some effort to preserve
1477  * existing alias numbering and to create unique labels if possible.
1478 */
inetdev_changename(struct net_device * dev,struct in_device * in_dev)1479 static void inetdev_changename(struct net_device *dev, struct in_device *in_dev)
1480 {
1481 	struct in_ifaddr *ifa;
1482 	int named = 0;
1483 
1484 	in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1485 		char old[IFNAMSIZ], *dot;
1486 
1487 		memcpy(old, ifa->ifa_label, IFNAMSIZ);
1488 		memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
1489 		if (named++ == 0)
1490 			goto skip;
1491 		dot = strchr(old, ':');
1492 		if (!dot) {
1493 			sprintf(old, ":%d", named);
1494 			dot = old;
1495 		}
1496 		if (strlen(dot) + strlen(dev->name) < IFNAMSIZ)
1497 			strcat(ifa->ifa_label, dot);
1498 		else
1499 			strcpy(ifa->ifa_label + (IFNAMSIZ - strlen(dot) - 1), dot);
1500 skip:
1501 		rtmsg_ifa(RTM_NEWADDR, ifa, NULL, 0);
1502 	}
1503 }
1504 
inetdev_send_gratuitous_arp(struct net_device * dev,struct in_device * in_dev)1505 static void inetdev_send_gratuitous_arp(struct net_device *dev,
1506 					struct in_device *in_dev)
1507 
1508 {
1509 	const struct in_ifaddr *ifa;
1510 
1511 	in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1512 		arp_send(ARPOP_REQUEST, ETH_P_ARP,
1513 			 ifa->ifa_local, dev,
1514 			 ifa->ifa_local, NULL,
1515 			 dev->dev_addr, NULL);
1516 	}
1517 }
1518 
1519 /* Called only under RTNL semaphore */
1520 
inetdev_event(struct notifier_block * this,unsigned long event,void * ptr)1521 static int inetdev_event(struct notifier_block *this, unsigned long event,
1522 			 void *ptr)
1523 {
1524 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1525 	struct in_device *in_dev = __in_dev_get_rtnl(dev);
1526 
1527 	ASSERT_RTNL();
1528 
1529 	if (!in_dev) {
1530 		if (event == NETDEV_REGISTER) {
1531 			in_dev = inetdev_init(dev);
1532 			if (IS_ERR(in_dev))
1533 				return notifier_from_errno(PTR_ERR(in_dev));
1534 			if (dev->flags & IFF_LOOPBACK) {
1535 				IN_DEV_CONF_SET(in_dev, NOXFRM, 1);
1536 				IN_DEV_CONF_SET(in_dev, NOPOLICY, 1);
1537 			}
1538 		} else if (event == NETDEV_CHANGEMTU) {
1539 			/* Re-enabling IP */
1540 			if (inetdev_valid_mtu(dev->mtu))
1541 				in_dev = inetdev_init(dev);
1542 		}
1543 		goto out;
1544 	}
1545 
1546 	switch (event) {
1547 	case NETDEV_REGISTER:
1548 		pr_debug("%s: bug\n", __func__);
1549 		RCU_INIT_POINTER(dev->ip_ptr, NULL);
1550 		break;
1551 	case NETDEV_UP:
1552 		if (!inetdev_valid_mtu(dev->mtu))
1553 			break;
1554 		if (dev->flags & IFF_LOOPBACK) {
1555 			struct in_ifaddr *ifa = inet_alloc_ifa();
1556 
1557 			if (ifa) {
1558 				INIT_HLIST_NODE(&ifa->hash);
1559 				ifa->ifa_local =
1560 				  ifa->ifa_address = htonl(INADDR_LOOPBACK);
1561 				ifa->ifa_prefixlen = 8;
1562 				ifa->ifa_mask = inet_make_mask(8);
1563 				in_dev_hold(in_dev);
1564 				ifa->ifa_dev = in_dev;
1565 				ifa->ifa_scope = RT_SCOPE_HOST;
1566 				memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
1567 				set_ifa_lifetime(ifa, INFINITY_LIFE_TIME,
1568 						 INFINITY_LIFE_TIME);
1569 				ipv4_devconf_setall(in_dev);
1570 				neigh_parms_data_state_setall(in_dev->arp_parms);
1571 				inet_insert_ifa(ifa);
1572 			}
1573 		}
1574 		ip_mc_up(in_dev);
1575 		fallthrough;
1576 	case NETDEV_CHANGEADDR:
1577 		if (!IN_DEV_ARP_NOTIFY(in_dev))
1578 			break;
1579 		fallthrough;
1580 	case NETDEV_NOTIFY_PEERS:
1581 		/* Send gratuitous ARP to notify of link change */
1582 		inetdev_send_gratuitous_arp(dev, in_dev);
1583 		break;
1584 	case NETDEV_DOWN:
1585 		ip_mc_down(in_dev);
1586 		break;
1587 	case NETDEV_PRE_TYPE_CHANGE:
1588 		ip_mc_unmap(in_dev);
1589 		break;
1590 	case NETDEV_POST_TYPE_CHANGE:
1591 		ip_mc_remap(in_dev);
1592 		break;
1593 	case NETDEV_CHANGEMTU:
1594 		if (inetdev_valid_mtu(dev->mtu))
1595 			break;
1596 		/* disable IP when MTU is not enough */
1597 		fallthrough;
1598 	case NETDEV_UNREGISTER:
1599 		inetdev_destroy(in_dev);
1600 		break;
1601 	case NETDEV_CHANGENAME:
1602 		/* Do not notify about label change, this event is
1603 		 * not interesting to applications using netlink.
1604 		 */
1605 		inetdev_changename(dev, in_dev);
1606 
1607 		devinet_sysctl_unregister(in_dev);
1608 		devinet_sysctl_register(in_dev);
1609 		break;
1610 	}
1611 out:
1612 	return NOTIFY_DONE;
1613 }
1614 
1615 static struct notifier_block ip_netdev_notifier = {
1616 	.notifier_call = inetdev_event,
1617 };
1618 
inet_nlmsg_size(void)1619 static size_t inet_nlmsg_size(void)
1620 {
1621 	return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
1622 	       + nla_total_size(4) /* IFA_ADDRESS */
1623 	       + nla_total_size(4) /* IFA_LOCAL */
1624 	       + nla_total_size(4) /* IFA_BROADCAST */
1625 	       + nla_total_size(IFNAMSIZ) /* IFA_LABEL */
1626 	       + nla_total_size(4)  /* IFA_FLAGS */
1627 	       + nla_total_size(4)  /* IFA_RT_PRIORITY */
1628 	       + nla_total_size(sizeof(struct ifa_cacheinfo)); /* IFA_CACHEINFO */
1629 }
1630 
cstamp_delta(unsigned long cstamp)1631 static inline u32 cstamp_delta(unsigned long cstamp)
1632 {
1633 	return (cstamp - INITIAL_JIFFIES) * 100UL / HZ;
1634 }
1635 
put_cacheinfo(struct sk_buff * skb,unsigned long cstamp,unsigned long tstamp,u32 preferred,u32 valid)1636 static int put_cacheinfo(struct sk_buff *skb, unsigned long cstamp,
1637 			 unsigned long tstamp, u32 preferred, u32 valid)
1638 {
1639 	struct ifa_cacheinfo ci;
1640 
1641 	ci.cstamp = cstamp_delta(cstamp);
1642 	ci.tstamp = cstamp_delta(tstamp);
1643 	ci.ifa_prefered = preferred;
1644 	ci.ifa_valid = valid;
1645 
1646 	return nla_put(skb, IFA_CACHEINFO, sizeof(ci), &ci);
1647 }
1648 
inet_fill_ifaddr(struct sk_buff * skb,struct in_ifaddr * ifa,struct inet_fill_args * args)1649 static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
1650 			    struct inet_fill_args *args)
1651 {
1652 	struct ifaddrmsg *ifm;
1653 	struct nlmsghdr  *nlh;
1654 	u32 preferred, valid;
1655 
1656 	nlh = nlmsg_put(skb, args->portid, args->seq, args->event, sizeof(*ifm),
1657 			args->flags);
1658 	if (!nlh)
1659 		return -EMSGSIZE;
1660 
1661 	ifm = nlmsg_data(nlh);
1662 	ifm->ifa_family = AF_INET;
1663 	ifm->ifa_prefixlen = ifa->ifa_prefixlen;
1664 	ifm->ifa_flags = ifa->ifa_flags;
1665 	ifm->ifa_scope = ifa->ifa_scope;
1666 	ifm->ifa_index = ifa->ifa_dev->dev->ifindex;
1667 
1668 	if (args->netnsid >= 0 &&
1669 	    nla_put_s32(skb, IFA_TARGET_NETNSID, args->netnsid))
1670 		goto nla_put_failure;
1671 
1672 	if (!(ifm->ifa_flags & IFA_F_PERMANENT)) {
1673 		preferred = ifa->ifa_preferred_lft;
1674 		valid = ifa->ifa_valid_lft;
1675 		if (preferred != INFINITY_LIFE_TIME) {
1676 			long tval = (jiffies - ifa->ifa_tstamp) / HZ;
1677 
1678 			if (preferred > tval)
1679 				preferred -= tval;
1680 			else
1681 				preferred = 0;
1682 			if (valid != INFINITY_LIFE_TIME) {
1683 				if (valid > tval)
1684 					valid -= tval;
1685 				else
1686 					valid = 0;
1687 			}
1688 		}
1689 	} else {
1690 		preferred = INFINITY_LIFE_TIME;
1691 		valid = INFINITY_LIFE_TIME;
1692 	}
1693 	if ((ifa->ifa_address &&
1694 	     nla_put_in_addr(skb, IFA_ADDRESS, ifa->ifa_address)) ||
1695 	    (ifa->ifa_local &&
1696 	     nla_put_in_addr(skb, IFA_LOCAL, ifa->ifa_local)) ||
1697 	    (ifa->ifa_broadcast &&
1698 	     nla_put_in_addr(skb, IFA_BROADCAST, ifa->ifa_broadcast)) ||
1699 	    (ifa->ifa_label[0] &&
1700 	     nla_put_string(skb, IFA_LABEL, ifa->ifa_label)) ||
1701 	    nla_put_u32(skb, IFA_FLAGS, ifa->ifa_flags) ||
1702 	    (ifa->ifa_rt_priority &&
1703 	     nla_put_u32(skb, IFA_RT_PRIORITY, ifa->ifa_rt_priority)) ||
1704 	    put_cacheinfo(skb, ifa->ifa_cstamp, ifa->ifa_tstamp,
1705 			  preferred, valid))
1706 		goto nla_put_failure;
1707 
1708 	nlmsg_end(skb, nlh);
1709 	return 0;
1710 
1711 nla_put_failure:
1712 	nlmsg_cancel(skb, nlh);
1713 	return -EMSGSIZE;
1714 }
1715 
inet_valid_dump_ifaddr_req(const struct nlmsghdr * nlh,struct inet_fill_args * fillargs,struct net ** tgt_net,struct sock * sk,struct netlink_callback * cb)1716 static int inet_valid_dump_ifaddr_req(const struct nlmsghdr *nlh,
1717 				      struct inet_fill_args *fillargs,
1718 				      struct net **tgt_net, struct sock *sk,
1719 				      struct netlink_callback *cb)
1720 {
1721 	struct netlink_ext_ack *extack = cb->extack;
1722 	struct nlattr *tb[IFA_MAX+1];
1723 	struct ifaddrmsg *ifm;
1724 	int err, i;
1725 
1726 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
1727 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for address dump request");
1728 		return -EINVAL;
1729 	}
1730 
1731 	ifm = nlmsg_data(nlh);
1732 	if (ifm->ifa_prefixlen || ifm->ifa_flags || ifm->ifa_scope) {
1733 		NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for address dump request");
1734 		return -EINVAL;
1735 	}
1736 
1737 	fillargs->ifindex = ifm->ifa_index;
1738 	if (fillargs->ifindex) {
1739 		cb->answer_flags |= NLM_F_DUMP_FILTERED;
1740 		fillargs->flags |= NLM_F_DUMP_FILTERED;
1741 	}
1742 
1743 	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*ifm), tb, IFA_MAX,
1744 					    ifa_ipv4_policy, extack);
1745 	if (err < 0)
1746 		return err;
1747 
1748 	for (i = 0; i <= IFA_MAX; ++i) {
1749 		if (!tb[i])
1750 			continue;
1751 
1752 		if (i == IFA_TARGET_NETNSID) {
1753 			struct net *net;
1754 
1755 			fillargs->netnsid = nla_get_s32(tb[i]);
1756 
1757 			net = rtnl_get_net_ns_capable(sk, fillargs->netnsid);
1758 			if (IS_ERR(net)) {
1759 				fillargs->netnsid = -1;
1760 				NL_SET_ERR_MSG(extack, "ipv4: Invalid target network namespace id");
1761 				return PTR_ERR(net);
1762 			}
1763 			*tgt_net = net;
1764 		} else {
1765 			NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in dump request");
1766 			return -EINVAL;
1767 		}
1768 	}
1769 
1770 	return 0;
1771 }
1772 
in_dev_dump_addr(struct in_device * in_dev,struct sk_buff * skb,struct netlink_callback * cb,int s_ip_idx,struct inet_fill_args * fillargs)1773 static int in_dev_dump_addr(struct in_device *in_dev, struct sk_buff *skb,
1774 			    struct netlink_callback *cb, int s_ip_idx,
1775 			    struct inet_fill_args *fillargs)
1776 {
1777 	struct in_ifaddr *ifa;
1778 	int ip_idx = 0;
1779 	int err;
1780 
1781 	in_dev_for_each_ifa_rtnl(ifa, in_dev) {
1782 		if (ip_idx < s_ip_idx) {
1783 			ip_idx++;
1784 			continue;
1785 		}
1786 		err = inet_fill_ifaddr(skb, ifa, fillargs);
1787 		if (err < 0)
1788 			goto done;
1789 
1790 		nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1791 		ip_idx++;
1792 	}
1793 	err = 0;
1794 
1795 done:
1796 	cb->args[2] = ip_idx;
1797 
1798 	return err;
1799 }
1800 
1801 /* Combine dev_addr_genid and dev_base_seq to detect changes.
1802  */
inet_base_seq(const struct net * net)1803 static u32 inet_base_seq(const struct net *net)
1804 {
1805 	u32 res = atomic_read(&net->ipv4.dev_addr_genid) +
1806 		  net->dev_base_seq;
1807 
1808 	/* Must not return 0 (see nl_dump_check_consistent()).
1809 	 * Chose a value far away from 0.
1810 	 */
1811 	if (!res)
1812 		res = 0x80000000;
1813 	return res;
1814 }
1815 
inet_dump_ifaddr(struct sk_buff * skb,struct netlink_callback * cb)1816 static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
1817 {
1818 	const struct nlmsghdr *nlh = cb->nlh;
1819 	struct inet_fill_args fillargs = {
1820 		.portid = NETLINK_CB(cb->skb).portid,
1821 		.seq = nlh->nlmsg_seq,
1822 		.event = RTM_NEWADDR,
1823 		.flags = NLM_F_MULTI,
1824 		.netnsid = -1,
1825 	};
1826 	struct net *net = sock_net(skb->sk);
1827 	struct net *tgt_net = net;
1828 	int h, s_h;
1829 	int idx, s_idx;
1830 	int s_ip_idx;
1831 	struct net_device *dev;
1832 	struct in_device *in_dev;
1833 	struct hlist_head *head;
1834 	int err = 0;
1835 
1836 	s_h = cb->args[0];
1837 	s_idx = idx = cb->args[1];
1838 	s_ip_idx = cb->args[2];
1839 
1840 	if (cb->strict_check) {
1841 		err = inet_valid_dump_ifaddr_req(nlh, &fillargs, &tgt_net,
1842 						 skb->sk, cb);
1843 		if (err < 0)
1844 			goto put_tgt_net;
1845 
1846 		err = 0;
1847 		if (fillargs.ifindex) {
1848 			dev = __dev_get_by_index(tgt_net, fillargs.ifindex);
1849 			if (!dev) {
1850 				err = -ENODEV;
1851 				goto put_tgt_net;
1852 			}
1853 
1854 			in_dev = __in_dev_get_rtnl(dev);
1855 			if (in_dev) {
1856 				err = in_dev_dump_addr(in_dev, skb, cb, s_ip_idx,
1857 						       &fillargs);
1858 			}
1859 			goto put_tgt_net;
1860 		}
1861 	}
1862 
1863 	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
1864 		idx = 0;
1865 		head = &tgt_net->dev_index_head[h];
1866 		rcu_read_lock();
1867 		cb->seq = inet_base_seq(tgt_net);
1868 		hlist_for_each_entry_rcu(dev, head, index_hlist) {
1869 			if (idx < s_idx)
1870 				goto cont;
1871 			if (h > s_h || idx > s_idx)
1872 				s_ip_idx = 0;
1873 			in_dev = __in_dev_get_rcu(dev);
1874 			if (!in_dev)
1875 				goto cont;
1876 
1877 			err = in_dev_dump_addr(in_dev, skb, cb, s_ip_idx,
1878 					       &fillargs);
1879 			if (err < 0) {
1880 				rcu_read_unlock();
1881 				goto done;
1882 			}
1883 cont:
1884 			idx++;
1885 		}
1886 		rcu_read_unlock();
1887 	}
1888 
1889 done:
1890 	cb->args[0] = h;
1891 	cb->args[1] = idx;
1892 put_tgt_net:
1893 	if (fillargs.netnsid >= 0)
1894 		put_net(tgt_net);
1895 
1896 	return skb->len ? : err;
1897 }
1898 
rtmsg_ifa(int event,struct in_ifaddr * ifa,struct nlmsghdr * nlh,u32 portid)1899 static void rtmsg_ifa(int event, struct in_ifaddr *ifa, struct nlmsghdr *nlh,
1900 		      u32 portid)
1901 {
1902 	struct inet_fill_args fillargs = {
1903 		.portid = portid,
1904 		.seq = nlh ? nlh->nlmsg_seq : 0,
1905 		.event = event,
1906 		.flags = 0,
1907 		.netnsid = -1,
1908 	};
1909 	struct sk_buff *skb;
1910 	int err = -ENOBUFS;
1911 	struct net *net;
1912 
1913 	net = dev_net(ifa->ifa_dev->dev);
1914 	skb = nlmsg_new(inet_nlmsg_size(), GFP_KERNEL);
1915 	if (!skb)
1916 		goto errout;
1917 
1918 	err = inet_fill_ifaddr(skb, ifa, &fillargs);
1919 	if (err < 0) {
1920 		/* -EMSGSIZE implies BUG in inet_nlmsg_size() */
1921 		WARN_ON(err == -EMSGSIZE);
1922 		kfree_skb(skb);
1923 		goto errout;
1924 	}
1925 	rtnl_notify(skb, net, portid, RTNLGRP_IPV4_IFADDR, nlh, GFP_KERNEL);
1926 	return;
1927 errout:
1928 	if (err < 0)
1929 		rtnl_set_sk_err(net, RTNLGRP_IPV4_IFADDR, err);
1930 }
1931 
inet_get_link_af_size(const struct net_device * dev,u32 ext_filter_mask)1932 static size_t inet_get_link_af_size(const struct net_device *dev,
1933 				    u32 ext_filter_mask)
1934 {
1935 	struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr);
1936 
1937 	if (!in_dev)
1938 		return 0;
1939 
1940 	return nla_total_size(IPV4_DEVCONF_MAX * 4); /* IFLA_INET_CONF */
1941 }
1942 
inet_fill_link_af(struct sk_buff * skb,const struct net_device * dev,u32 ext_filter_mask)1943 static int inet_fill_link_af(struct sk_buff *skb, const struct net_device *dev,
1944 			     u32 ext_filter_mask)
1945 {
1946 	struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr);
1947 	struct nlattr *nla;
1948 	int i;
1949 
1950 	if (!in_dev)
1951 		return -ENODATA;
1952 
1953 	nla = nla_reserve(skb, IFLA_INET_CONF, IPV4_DEVCONF_MAX * 4);
1954 	if (!nla)
1955 		return -EMSGSIZE;
1956 
1957 	for (i = 0; i < IPV4_DEVCONF_MAX; i++)
1958 		((u32 *) nla_data(nla))[i] = in_dev->cnf.data[i];
1959 
1960 	return 0;
1961 }
1962 
1963 static const struct nla_policy inet_af_policy[IFLA_INET_MAX+1] = {
1964 	[IFLA_INET_CONF]	= { .type = NLA_NESTED },
1965 };
1966 
inet_validate_link_af(const struct net_device * dev,const struct nlattr * nla)1967 static int inet_validate_link_af(const struct net_device *dev,
1968 				 const struct nlattr *nla)
1969 {
1970 	struct nlattr *a, *tb[IFLA_INET_MAX+1];
1971 	int err, rem;
1972 
1973 	if (dev && !__in_dev_get_rcu(dev))
1974 		return -EAFNOSUPPORT;
1975 
1976 	err = nla_parse_nested_deprecated(tb, IFLA_INET_MAX, nla,
1977 					  inet_af_policy, NULL);
1978 	if (err < 0)
1979 		return err;
1980 
1981 	if (tb[IFLA_INET_CONF]) {
1982 		nla_for_each_nested(a, tb[IFLA_INET_CONF], rem) {
1983 			int cfgid = nla_type(a);
1984 
1985 			if (nla_len(a) < 4)
1986 				return -EINVAL;
1987 
1988 			if (cfgid <= 0 || cfgid > IPV4_DEVCONF_MAX)
1989 				return -EINVAL;
1990 		}
1991 	}
1992 
1993 	return 0;
1994 }
1995 
inet_set_link_af(struct net_device * dev,const struct nlattr * nla)1996 static int inet_set_link_af(struct net_device *dev, const struct nlattr *nla)
1997 {
1998 	struct in_device *in_dev = __in_dev_get_rcu(dev);
1999 	struct nlattr *a, *tb[IFLA_INET_MAX+1];
2000 	int rem;
2001 
2002 	if (!in_dev)
2003 		return -EAFNOSUPPORT;
2004 
2005 	if (nla_parse_nested_deprecated(tb, IFLA_INET_MAX, nla, NULL, NULL) < 0)
2006 		return -EINVAL;
2007 
2008 	if (tb[IFLA_INET_CONF]) {
2009 		nla_for_each_nested(a, tb[IFLA_INET_CONF], rem)
2010 			ipv4_devconf_set(in_dev, nla_type(a), nla_get_u32(a));
2011 	}
2012 
2013 	return 0;
2014 }
2015 
inet_netconf_msgsize_devconf(int type)2016 static int inet_netconf_msgsize_devconf(int type)
2017 {
2018 	int size = NLMSG_ALIGN(sizeof(struct netconfmsg))
2019 		   + nla_total_size(4);	/* NETCONFA_IFINDEX */
2020 	bool all = false;
2021 
2022 	if (type == NETCONFA_ALL)
2023 		all = true;
2024 
2025 	if (all || type == NETCONFA_FORWARDING)
2026 		size += nla_total_size(4);
2027 	if (all || type == NETCONFA_RP_FILTER)
2028 		size += nla_total_size(4);
2029 	if (all || type == NETCONFA_MC_FORWARDING)
2030 		size += nla_total_size(4);
2031 	if (all || type == NETCONFA_BC_FORWARDING)
2032 		size += nla_total_size(4);
2033 	if (all || type == NETCONFA_PROXY_NEIGH)
2034 		size += nla_total_size(4);
2035 	if (all || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN)
2036 		size += nla_total_size(4);
2037 
2038 	return size;
2039 }
2040 
inet_netconf_fill_devconf(struct sk_buff * skb,int ifindex,struct ipv4_devconf * devconf,u32 portid,u32 seq,int event,unsigned int flags,int type)2041 static int inet_netconf_fill_devconf(struct sk_buff *skb, int ifindex,
2042 				     struct ipv4_devconf *devconf, u32 portid,
2043 				     u32 seq, int event, unsigned int flags,
2044 				     int type)
2045 {
2046 	struct nlmsghdr  *nlh;
2047 	struct netconfmsg *ncm;
2048 	bool all = false;
2049 
2050 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
2051 			flags);
2052 	if (!nlh)
2053 		return -EMSGSIZE;
2054 
2055 	if (type == NETCONFA_ALL)
2056 		all = true;
2057 
2058 	ncm = nlmsg_data(nlh);
2059 	ncm->ncm_family = AF_INET;
2060 
2061 	if (nla_put_s32(skb, NETCONFA_IFINDEX, ifindex) < 0)
2062 		goto nla_put_failure;
2063 
2064 	if (!devconf)
2065 		goto out;
2066 
2067 	if ((all || type == NETCONFA_FORWARDING) &&
2068 	    nla_put_s32(skb, NETCONFA_FORWARDING,
2069 			IPV4_DEVCONF(*devconf, FORWARDING)) < 0)
2070 		goto nla_put_failure;
2071 	if ((all || type == NETCONFA_RP_FILTER) &&
2072 	    nla_put_s32(skb, NETCONFA_RP_FILTER,
2073 			IPV4_DEVCONF(*devconf, RP_FILTER)) < 0)
2074 		goto nla_put_failure;
2075 	if ((all || type == NETCONFA_MC_FORWARDING) &&
2076 	    nla_put_s32(skb, NETCONFA_MC_FORWARDING,
2077 			IPV4_DEVCONF(*devconf, MC_FORWARDING)) < 0)
2078 		goto nla_put_failure;
2079 	if ((all || type == NETCONFA_BC_FORWARDING) &&
2080 	    nla_put_s32(skb, NETCONFA_BC_FORWARDING,
2081 			IPV4_DEVCONF(*devconf, BC_FORWARDING)) < 0)
2082 		goto nla_put_failure;
2083 	if ((all || type == NETCONFA_PROXY_NEIGH) &&
2084 	    nla_put_s32(skb, NETCONFA_PROXY_NEIGH,
2085 			IPV4_DEVCONF(*devconf, PROXY_ARP)) < 0)
2086 		goto nla_put_failure;
2087 	if ((all || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN) &&
2088 	    nla_put_s32(skb, NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
2089 			IPV4_DEVCONF(*devconf, IGNORE_ROUTES_WITH_LINKDOWN)) < 0)
2090 		goto nla_put_failure;
2091 
2092 out:
2093 	nlmsg_end(skb, nlh);
2094 	return 0;
2095 
2096 nla_put_failure:
2097 	nlmsg_cancel(skb, nlh);
2098 	return -EMSGSIZE;
2099 }
2100 
inet_netconf_notify_devconf(struct net * net,int event,int type,int ifindex,struct ipv4_devconf * devconf)2101 void inet_netconf_notify_devconf(struct net *net, int event, int type,
2102 				 int ifindex, struct ipv4_devconf *devconf)
2103 {
2104 	struct sk_buff *skb;
2105 	int err = -ENOBUFS;
2106 
2107 	skb = nlmsg_new(inet_netconf_msgsize_devconf(type), GFP_KERNEL);
2108 	if (!skb)
2109 		goto errout;
2110 
2111 	err = inet_netconf_fill_devconf(skb, ifindex, devconf, 0, 0,
2112 					event, 0, type);
2113 	if (err < 0) {
2114 		/* -EMSGSIZE implies BUG in inet_netconf_msgsize_devconf() */
2115 		WARN_ON(err == -EMSGSIZE);
2116 		kfree_skb(skb);
2117 		goto errout;
2118 	}
2119 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_NETCONF, NULL, GFP_KERNEL);
2120 	return;
2121 errout:
2122 	if (err < 0)
2123 		rtnl_set_sk_err(net, RTNLGRP_IPV4_NETCONF, err);
2124 }
2125 
2126 static const struct nla_policy devconf_ipv4_policy[NETCONFA_MAX+1] = {
2127 	[NETCONFA_IFINDEX]	= { .len = sizeof(int) },
2128 	[NETCONFA_FORWARDING]	= { .len = sizeof(int) },
2129 	[NETCONFA_RP_FILTER]	= { .len = sizeof(int) },
2130 	[NETCONFA_PROXY_NEIGH]	= { .len = sizeof(int) },
2131 	[NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN]	= { .len = sizeof(int) },
2132 };
2133 
inet_netconf_valid_get_req(struct sk_buff * skb,const struct nlmsghdr * nlh,struct nlattr ** tb,struct netlink_ext_ack * extack)2134 static int inet_netconf_valid_get_req(struct sk_buff *skb,
2135 				      const struct nlmsghdr *nlh,
2136 				      struct nlattr **tb,
2137 				      struct netlink_ext_ack *extack)
2138 {
2139 	int i, err;
2140 
2141 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) {
2142 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for netconf get request");
2143 		return -EINVAL;
2144 	}
2145 
2146 	if (!netlink_strict_get_check(skb))
2147 		return nlmsg_parse_deprecated(nlh, sizeof(struct netconfmsg),
2148 					      tb, NETCONFA_MAX,
2149 					      devconf_ipv4_policy, extack);
2150 
2151 	err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct netconfmsg),
2152 					    tb, NETCONFA_MAX,
2153 					    devconf_ipv4_policy, extack);
2154 	if (err)
2155 		return err;
2156 
2157 	for (i = 0; i <= NETCONFA_MAX; i++) {
2158 		if (!tb[i])
2159 			continue;
2160 
2161 		switch (i) {
2162 		case NETCONFA_IFINDEX:
2163 			break;
2164 		default:
2165 			NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in netconf get request");
2166 			return -EINVAL;
2167 		}
2168 	}
2169 
2170 	return 0;
2171 }
2172 
inet_netconf_get_devconf(struct sk_buff * in_skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)2173 static int inet_netconf_get_devconf(struct sk_buff *in_skb,
2174 				    struct nlmsghdr *nlh,
2175 				    struct netlink_ext_ack *extack)
2176 {
2177 	struct net *net = sock_net(in_skb->sk);
2178 	struct nlattr *tb[NETCONFA_MAX+1];
2179 	struct sk_buff *skb;
2180 	struct ipv4_devconf *devconf;
2181 	struct in_device *in_dev;
2182 	struct net_device *dev;
2183 	int ifindex;
2184 	int err;
2185 
2186 	err = inet_netconf_valid_get_req(in_skb, nlh, tb, extack);
2187 	if (err)
2188 		goto errout;
2189 
2190 	err = -EINVAL;
2191 	if (!tb[NETCONFA_IFINDEX])
2192 		goto errout;
2193 
2194 	ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
2195 	switch (ifindex) {
2196 	case NETCONFA_IFINDEX_ALL:
2197 		devconf = net->ipv4.devconf_all;
2198 		break;
2199 	case NETCONFA_IFINDEX_DEFAULT:
2200 		devconf = net->ipv4.devconf_dflt;
2201 		break;
2202 	default:
2203 		dev = __dev_get_by_index(net, ifindex);
2204 		if (!dev)
2205 			goto errout;
2206 		in_dev = __in_dev_get_rtnl(dev);
2207 		if (!in_dev)
2208 			goto errout;
2209 		devconf = &in_dev->cnf;
2210 		break;
2211 	}
2212 
2213 	err = -ENOBUFS;
2214 	skb = nlmsg_new(inet_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
2215 	if (!skb)
2216 		goto errout;
2217 
2218 	err = inet_netconf_fill_devconf(skb, ifindex, devconf,
2219 					NETLINK_CB(in_skb).portid,
2220 					nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
2221 					NETCONFA_ALL);
2222 	if (err < 0) {
2223 		/* -EMSGSIZE implies BUG in inet_netconf_msgsize_devconf() */
2224 		WARN_ON(err == -EMSGSIZE);
2225 		kfree_skb(skb);
2226 		goto errout;
2227 	}
2228 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2229 errout:
2230 	return err;
2231 }
2232 
inet_netconf_dump_devconf(struct sk_buff * skb,struct netlink_callback * cb)2233 static int inet_netconf_dump_devconf(struct sk_buff *skb,
2234 				     struct netlink_callback *cb)
2235 {
2236 	const struct nlmsghdr *nlh = cb->nlh;
2237 	struct net *net = sock_net(skb->sk);
2238 	int h, s_h;
2239 	int idx, s_idx;
2240 	struct net_device *dev;
2241 	struct in_device *in_dev;
2242 	struct hlist_head *head;
2243 
2244 	if (cb->strict_check) {
2245 		struct netlink_ext_ack *extack = cb->extack;
2246 		struct netconfmsg *ncm;
2247 
2248 		if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
2249 			NL_SET_ERR_MSG(extack, "ipv4: Invalid header for netconf dump request");
2250 			return -EINVAL;
2251 		}
2252 
2253 		if (nlmsg_attrlen(nlh, sizeof(*ncm))) {
2254 			NL_SET_ERR_MSG(extack, "ipv4: Invalid data after header in netconf dump request");
2255 			return -EINVAL;
2256 		}
2257 	}
2258 
2259 	s_h = cb->args[0];
2260 	s_idx = idx = cb->args[1];
2261 
2262 	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
2263 		idx = 0;
2264 		head = &net->dev_index_head[h];
2265 		rcu_read_lock();
2266 		cb->seq = inet_base_seq(net);
2267 		hlist_for_each_entry_rcu(dev, head, index_hlist) {
2268 			if (idx < s_idx)
2269 				goto cont;
2270 			in_dev = __in_dev_get_rcu(dev);
2271 			if (!in_dev)
2272 				goto cont;
2273 
2274 			if (inet_netconf_fill_devconf(skb, dev->ifindex,
2275 						      &in_dev->cnf,
2276 						      NETLINK_CB(cb->skb).portid,
2277 						      nlh->nlmsg_seq,
2278 						      RTM_NEWNETCONF,
2279 						      NLM_F_MULTI,
2280 						      NETCONFA_ALL) < 0) {
2281 				rcu_read_unlock();
2282 				goto done;
2283 			}
2284 			nl_dump_check_consistent(cb, nlmsg_hdr(skb));
2285 cont:
2286 			idx++;
2287 		}
2288 		rcu_read_unlock();
2289 	}
2290 	if (h == NETDEV_HASHENTRIES) {
2291 		if (inet_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL,
2292 					      net->ipv4.devconf_all,
2293 					      NETLINK_CB(cb->skb).portid,
2294 					      nlh->nlmsg_seq,
2295 					      RTM_NEWNETCONF, NLM_F_MULTI,
2296 					      NETCONFA_ALL) < 0)
2297 			goto done;
2298 		else
2299 			h++;
2300 	}
2301 	if (h == NETDEV_HASHENTRIES + 1) {
2302 		if (inet_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT,
2303 					      net->ipv4.devconf_dflt,
2304 					      NETLINK_CB(cb->skb).portid,
2305 					      nlh->nlmsg_seq,
2306 					      RTM_NEWNETCONF, NLM_F_MULTI,
2307 					      NETCONFA_ALL) < 0)
2308 			goto done;
2309 		else
2310 			h++;
2311 	}
2312 done:
2313 	cb->args[0] = h;
2314 	cb->args[1] = idx;
2315 
2316 	return skb->len;
2317 }
2318 
2319 #ifdef CONFIG_SYSCTL
2320 
devinet_copy_dflt_conf(struct net * net,int i)2321 static void devinet_copy_dflt_conf(struct net *net, int i)
2322 {
2323 	struct net_device *dev;
2324 
2325 	rcu_read_lock();
2326 	for_each_netdev_rcu(net, dev) {
2327 		struct in_device *in_dev;
2328 
2329 		in_dev = __in_dev_get_rcu(dev);
2330 		if (in_dev && !test_bit(i, in_dev->cnf.state))
2331 			in_dev->cnf.data[i] = net->ipv4.devconf_dflt->data[i];
2332 	}
2333 	rcu_read_unlock();
2334 }
2335 
2336 /* called with RTNL locked */
inet_forward_change(struct net * net)2337 static void inet_forward_change(struct net *net)
2338 {
2339 	struct net_device *dev;
2340 	int on = IPV4_DEVCONF_ALL(net, FORWARDING);
2341 
2342 	IPV4_DEVCONF_ALL(net, ACCEPT_REDIRECTS) = !on;
2343 	IPV4_DEVCONF_DFLT(net, FORWARDING) = on;
2344 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2345 				    NETCONFA_FORWARDING,
2346 				    NETCONFA_IFINDEX_ALL,
2347 				    net->ipv4.devconf_all);
2348 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2349 				    NETCONFA_FORWARDING,
2350 				    NETCONFA_IFINDEX_DEFAULT,
2351 				    net->ipv4.devconf_dflt);
2352 
2353 	for_each_netdev(net, dev) {
2354 		struct in_device *in_dev;
2355 
2356 		if (on)
2357 			dev_disable_lro(dev);
2358 
2359 		in_dev = __in_dev_get_rtnl(dev);
2360 		if (in_dev) {
2361 			IN_DEV_CONF_SET(in_dev, FORWARDING, on);
2362 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2363 						    NETCONFA_FORWARDING,
2364 						    dev->ifindex, &in_dev->cnf);
2365 		}
2366 	}
2367 }
2368 
devinet_conf_ifindex(struct net * net,struct ipv4_devconf * cnf)2369 static int devinet_conf_ifindex(struct net *net, struct ipv4_devconf *cnf)
2370 {
2371 	if (cnf == net->ipv4.devconf_dflt)
2372 		return NETCONFA_IFINDEX_DEFAULT;
2373 	else if (cnf == net->ipv4.devconf_all)
2374 		return NETCONFA_IFINDEX_ALL;
2375 	else {
2376 		struct in_device *idev
2377 			= container_of(cnf, struct in_device, cnf);
2378 		return idev->dev->ifindex;
2379 	}
2380 }
2381 
devinet_conf_proc(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)2382 static int devinet_conf_proc(struct ctl_table *ctl, int write,
2383 			     void *buffer, size_t *lenp, loff_t *ppos)
2384 {
2385 	int old_value = *(int *)ctl->data;
2386 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
2387 	int new_value = *(int *)ctl->data;
2388 
2389 	if (write) {
2390 		struct ipv4_devconf *cnf = ctl->extra1;
2391 		struct net *net = ctl->extra2;
2392 		int i = (int *)ctl->data - cnf->data;
2393 		int ifindex;
2394 
2395 		set_bit(i, cnf->state);
2396 
2397 		if (cnf == net->ipv4.devconf_dflt)
2398 			devinet_copy_dflt_conf(net, i);
2399 		if (i == IPV4_DEVCONF_ACCEPT_LOCAL - 1 ||
2400 		    i == IPV4_DEVCONF_ROUTE_LOCALNET - 1)
2401 			if ((new_value == 0) && (old_value != 0))
2402 				rt_cache_flush(net);
2403 
2404 		if (i == IPV4_DEVCONF_BC_FORWARDING - 1 &&
2405 		    new_value != old_value)
2406 			rt_cache_flush(net);
2407 
2408 		if (i == IPV4_DEVCONF_RP_FILTER - 1 &&
2409 		    new_value != old_value) {
2410 			ifindex = devinet_conf_ifindex(net, cnf);
2411 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2412 						    NETCONFA_RP_FILTER,
2413 						    ifindex, cnf);
2414 		}
2415 		if (i == IPV4_DEVCONF_PROXY_ARP - 1 &&
2416 		    new_value != old_value) {
2417 			ifindex = devinet_conf_ifindex(net, cnf);
2418 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2419 						    NETCONFA_PROXY_NEIGH,
2420 						    ifindex, cnf);
2421 		}
2422 		if (i == IPV4_DEVCONF_IGNORE_ROUTES_WITH_LINKDOWN - 1 &&
2423 		    new_value != old_value) {
2424 			ifindex = devinet_conf_ifindex(net, cnf);
2425 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2426 						    NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
2427 						    ifindex, cnf);
2428 		}
2429 	}
2430 
2431 	return ret;
2432 }
2433 
devinet_sysctl_forward(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)2434 static int devinet_sysctl_forward(struct ctl_table *ctl, int write,
2435 				  void *buffer, size_t *lenp, loff_t *ppos)
2436 {
2437 	int *valp = ctl->data;
2438 	int val = *valp;
2439 	loff_t pos = *ppos;
2440 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
2441 
2442 	if (write && *valp != val) {
2443 		struct net *net = ctl->extra2;
2444 
2445 		if (valp != &IPV4_DEVCONF_DFLT(net, FORWARDING)) {
2446 			if (!rtnl_trylock()) {
2447 				/* Restore the original values before restarting */
2448 				*valp = val;
2449 				*ppos = pos;
2450 				return restart_syscall();
2451 			}
2452 			if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING)) {
2453 				inet_forward_change(net);
2454 			} else {
2455 				struct ipv4_devconf *cnf = ctl->extra1;
2456 				struct in_device *idev =
2457 					container_of(cnf, struct in_device, cnf);
2458 				if (*valp)
2459 					dev_disable_lro(idev->dev);
2460 				inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2461 							    NETCONFA_FORWARDING,
2462 							    idev->dev->ifindex,
2463 							    cnf);
2464 			}
2465 			rtnl_unlock();
2466 			rt_cache_flush(net);
2467 		} else
2468 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
2469 						    NETCONFA_FORWARDING,
2470 						    NETCONFA_IFINDEX_DEFAULT,
2471 						    net->ipv4.devconf_dflt);
2472 	}
2473 
2474 	return ret;
2475 }
2476 
ipv4_doint_and_flush(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)2477 static int ipv4_doint_and_flush(struct ctl_table *ctl, int write,
2478 				void *buffer, size_t *lenp, loff_t *ppos)
2479 {
2480 	int *valp = ctl->data;
2481 	int val = *valp;
2482 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
2483 	struct net *net = ctl->extra2;
2484 
2485 	if (write && *valp != val)
2486 		rt_cache_flush(net);
2487 
2488 	return ret;
2489 }
2490 
2491 #define DEVINET_SYSCTL_ENTRY(attr, name, mval, proc) \
2492 	{ \
2493 		.procname	= name, \
2494 		.data		= ipv4_devconf.data + \
2495 				  IPV4_DEVCONF_ ## attr - 1, \
2496 		.maxlen		= sizeof(int), \
2497 		.mode		= mval, \
2498 		.proc_handler	= proc, \
2499 		.extra1		= &ipv4_devconf, \
2500 	}
2501 
2502 #define DEVINET_SYSCTL_RW_ENTRY(attr, name) \
2503 	DEVINET_SYSCTL_ENTRY(attr, name, 0644, devinet_conf_proc)
2504 
2505 #define DEVINET_SYSCTL_RO_ENTRY(attr, name) \
2506 	DEVINET_SYSCTL_ENTRY(attr, name, 0444, devinet_conf_proc)
2507 
2508 #define DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, proc) \
2509 	DEVINET_SYSCTL_ENTRY(attr, name, 0644, proc)
2510 
2511 #define DEVINET_SYSCTL_FLUSHING_ENTRY(attr, name) \
2512 	DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, ipv4_doint_and_flush)
2513 
2514 static struct devinet_sysctl_table {
2515 	struct ctl_table_header *sysctl_header;
2516 	struct ctl_table devinet_vars[__IPV4_DEVCONF_MAX];
2517 } devinet_sysctl = {
2518 	.devinet_vars = {
2519 		DEVINET_SYSCTL_COMPLEX_ENTRY(FORWARDING, "forwarding",
2520 					     devinet_sysctl_forward),
2521 		DEVINET_SYSCTL_RO_ENTRY(MC_FORWARDING, "mc_forwarding"),
2522 		DEVINET_SYSCTL_RW_ENTRY(BC_FORWARDING, "bc_forwarding"),
2523 
2524 		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_REDIRECTS, "accept_redirects"),
2525 		DEVINET_SYSCTL_RW_ENTRY(SECURE_REDIRECTS, "secure_redirects"),
2526 		DEVINET_SYSCTL_RW_ENTRY(SHARED_MEDIA, "shared_media"),
2527 		DEVINET_SYSCTL_RW_ENTRY(RP_FILTER, "rp_filter"),
2528 		DEVINET_SYSCTL_RW_ENTRY(SEND_REDIRECTS, "send_redirects"),
2529 		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_SOURCE_ROUTE,
2530 					"accept_source_route"),
2531 		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_LOCAL, "accept_local"),
2532 		DEVINET_SYSCTL_RW_ENTRY(SRC_VMARK, "src_valid_mark"),
2533 		DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP, "proxy_arp"),
2534 		DEVINET_SYSCTL_RW_ENTRY(MEDIUM_ID, "medium_id"),
2535 		DEVINET_SYSCTL_RW_ENTRY(BOOTP_RELAY, "bootp_relay"),
2536 		DEVINET_SYSCTL_RW_ENTRY(LOG_MARTIANS, "log_martians"),
2537 		DEVINET_SYSCTL_RW_ENTRY(TAG, "tag"),
2538 		DEVINET_SYSCTL_RW_ENTRY(ARPFILTER, "arp_filter"),
2539 		DEVINET_SYSCTL_RW_ENTRY(ARP_ANNOUNCE, "arp_announce"),
2540 		DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"),
2541 		DEVINET_SYSCTL_RW_ENTRY(ARP_ACCEPT, "arp_accept"),
2542 		DEVINET_SYSCTL_RW_ENTRY(ARP_NOTIFY, "arp_notify"),
2543 		DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP_PVLAN, "proxy_arp_pvlan"),
2544 		DEVINET_SYSCTL_RW_ENTRY(FORCE_IGMP_VERSION,
2545 					"force_igmp_version"),
2546 		DEVINET_SYSCTL_RW_ENTRY(IGMPV2_UNSOLICITED_REPORT_INTERVAL,
2547 					"igmpv2_unsolicited_report_interval"),
2548 		DEVINET_SYSCTL_RW_ENTRY(IGMPV3_UNSOLICITED_REPORT_INTERVAL,
2549 					"igmpv3_unsolicited_report_interval"),
2550 		DEVINET_SYSCTL_RW_ENTRY(IGNORE_ROUTES_WITH_LINKDOWN,
2551 					"ignore_routes_with_linkdown"),
2552 		DEVINET_SYSCTL_RW_ENTRY(DROP_GRATUITOUS_ARP,
2553 					"drop_gratuitous_arp"),
2554 
2555 		DEVINET_SYSCTL_FLUSHING_ENTRY(NOXFRM, "disable_xfrm"),
2556 		DEVINET_SYSCTL_FLUSHING_ENTRY(NOPOLICY, "disable_policy"),
2557 		DEVINET_SYSCTL_FLUSHING_ENTRY(PROMOTE_SECONDARIES,
2558 					      "promote_secondaries"),
2559 		DEVINET_SYSCTL_FLUSHING_ENTRY(ROUTE_LOCALNET,
2560 					      "route_localnet"),
2561 		DEVINET_SYSCTL_FLUSHING_ENTRY(DROP_UNICAST_IN_L2_MULTICAST,
2562 					      "drop_unicast_in_l2_multicast"),
2563 	},
2564 };
2565 
__devinet_sysctl_register(struct net * net,char * dev_name,int ifindex,struct ipv4_devconf * p)2566 static int __devinet_sysctl_register(struct net *net, char *dev_name,
2567 				     int ifindex, struct ipv4_devconf *p)
2568 {
2569 	int i;
2570 	struct devinet_sysctl_table *t;
2571 	char path[sizeof("net/ipv4/conf/") + IFNAMSIZ];
2572 
2573 	t = kmemdup(&devinet_sysctl, sizeof(*t), GFP_KERNEL);
2574 	if (!t)
2575 		goto out;
2576 
2577 	for (i = 0; i < ARRAY_SIZE(t->devinet_vars) - 1; i++) {
2578 		t->devinet_vars[i].data += (char *)p - (char *)&ipv4_devconf;
2579 		t->devinet_vars[i].extra1 = p;
2580 		t->devinet_vars[i].extra2 = net;
2581 	}
2582 
2583 	snprintf(path, sizeof(path), "net/ipv4/conf/%s", dev_name);
2584 
2585 	t->sysctl_header = register_net_sysctl(net, path, t->devinet_vars);
2586 	if (!t->sysctl_header)
2587 		goto free;
2588 
2589 	p->sysctl = t;
2590 
2591 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL,
2592 				    ifindex, p);
2593 	return 0;
2594 
2595 free:
2596 	kfree(t);
2597 out:
2598 	return -ENOMEM;
2599 }
2600 
__devinet_sysctl_unregister(struct net * net,struct ipv4_devconf * cnf,int ifindex)2601 static void __devinet_sysctl_unregister(struct net *net,
2602 					struct ipv4_devconf *cnf, int ifindex)
2603 {
2604 	struct devinet_sysctl_table *t = cnf->sysctl;
2605 
2606 	if (t) {
2607 		cnf->sysctl = NULL;
2608 		unregister_net_sysctl_table(t->sysctl_header);
2609 		kfree(t);
2610 	}
2611 
2612 	inet_netconf_notify_devconf(net, RTM_DELNETCONF, 0, ifindex, NULL);
2613 }
2614 
devinet_sysctl_register(struct in_device * idev)2615 static int devinet_sysctl_register(struct in_device *idev)
2616 {
2617 	int err;
2618 
2619 	if (!sysctl_dev_name_is_allowed(idev->dev->name))
2620 		return -EINVAL;
2621 
2622 	err = neigh_sysctl_register(idev->dev, idev->arp_parms, NULL);
2623 	if (err)
2624 		return err;
2625 	err = __devinet_sysctl_register(dev_net(idev->dev), idev->dev->name,
2626 					idev->dev->ifindex, &idev->cnf);
2627 	if (err)
2628 		neigh_sysctl_unregister(idev->arp_parms);
2629 	return err;
2630 }
2631 
devinet_sysctl_unregister(struct in_device * idev)2632 static void devinet_sysctl_unregister(struct in_device *idev)
2633 {
2634 	struct net *net = dev_net(idev->dev);
2635 
2636 	__devinet_sysctl_unregister(net, &idev->cnf, idev->dev->ifindex);
2637 	neigh_sysctl_unregister(idev->arp_parms);
2638 }
2639 
2640 static struct ctl_table ctl_forward_entry[] = {
2641 	{
2642 		.procname	= "ip_forward",
2643 		.data		= &ipv4_devconf.data[
2644 					IPV4_DEVCONF_FORWARDING - 1],
2645 		.maxlen		= sizeof(int),
2646 		.mode		= 0644,
2647 		.proc_handler	= devinet_sysctl_forward,
2648 		.extra1		= &ipv4_devconf,
2649 		.extra2		= &init_net,
2650 	},
2651 	{ },
2652 };
2653 #endif
2654 
devinet_init_net(struct net * net)2655 static __net_init int devinet_init_net(struct net *net)
2656 {
2657 	int err;
2658 	struct ipv4_devconf *all, *dflt;
2659 #ifdef CONFIG_SYSCTL
2660 	struct ctl_table *tbl;
2661 	struct ctl_table_header *forw_hdr;
2662 #endif
2663 
2664 	err = -ENOMEM;
2665 	all = kmemdup(&ipv4_devconf, sizeof(ipv4_devconf), GFP_KERNEL);
2666 	if (!all)
2667 		goto err_alloc_all;
2668 
2669 	dflt = kmemdup(&ipv4_devconf_dflt, sizeof(ipv4_devconf_dflt), GFP_KERNEL);
2670 	if (!dflt)
2671 		goto err_alloc_dflt;
2672 
2673 #ifdef CONFIG_SYSCTL
2674 	tbl = kmemdup(ctl_forward_entry, sizeof(ctl_forward_entry), GFP_KERNEL);
2675 	if (!tbl)
2676 		goto err_alloc_ctl;
2677 
2678 	tbl[0].data = &all->data[IPV4_DEVCONF_FORWARDING - 1];
2679 	tbl[0].extra1 = all;
2680 	tbl[0].extra2 = net;
2681 #endif
2682 
2683 	if (!net_eq(net, &init_net)) {
2684 		switch (net_inherit_devconf()) {
2685 		case 3:
2686 			/* copy from the current netns */
2687 			memcpy(all, current->nsproxy->net_ns->ipv4.devconf_all,
2688 			       sizeof(ipv4_devconf));
2689 			memcpy(dflt,
2690 			       current->nsproxy->net_ns->ipv4.devconf_dflt,
2691 			       sizeof(ipv4_devconf_dflt));
2692 			break;
2693 		case 0:
2694 		case 1:
2695 			/* copy from init_net */
2696 			memcpy(all, init_net.ipv4.devconf_all,
2697 			       sizeof(ipv4_devconf));
2698 			memcpy(dflt, init_net.ipv4.devconf_dflt,
2699 			       sizeof(ipv4_devconf_dflt));
2700 			break;
2701 		case 2:
2702 			/* use compiled values */
2703 			break;
2704 		}
2705 	}
2706 
2707 #ifdef CONFIG_SYSCTL
2708 	err = __devinet_sysctl_register(net, "all", NETCONFA_IFINDEX_ALL, all);
2709 	if (err < 0)
2710 		goto err_reg_all;
2711 
2712 	err = __devinet_sysctl_register(net, "default",
2713 					NETCONFA_IFINDEX_DEFAULT, dflt);
2714 	if (err < 0)
2715 		goto err_reg_dflt;
2716 
2717 	err = -ENOMEM;
2718 	forw_hdr = register_net_sysctl(net, "net/ipv4", tbl);
2719 	if (!forw_hdr)
2720 		goto err_reg_ctl;
2721 	net->ipv4.forw_hdr = forw_hdr;
2722 #endif
2723 
2724 	net->ipv4.devconf_all = all;
2725 	net->ipv4.devconf_dflt = dflt;
2726 	return 0;
2727 
2728 #ifdef CONFIG_SYSCTL
2729 err_reg_ctl:
2730 	__devinet_sysctl_unregister(net, dflt, NETCONFA_IFINDEX_DEFAULT);
2731 err_reg_dflt:
2732 	__devinet_sysctl_unregister(net, all, NETCONFA_IFINDEX_ALL);
2733 err_reg_all:
2734 	kfree(tbl);
2735 err_alloc_ctl:
2736 #endif
2737 	kfree(dflt);
2738 err_alloc_dflt:
2739 	kfree(all);
2740 err_alloc_all:
2741 	return err;
2742 }
2743 
devinet_exit_net(struct net * net)2744 static __net_exit void devinet_exit_net(struct net *net)
2745 {
2746 #ifdef CONFIG_SYSCTL
2747 	struct ctl_table *tbl;
2748 
2749 	tbl = net->ipv4.forw_hdr->ctl_table_arg;
2750 	unregister_net_sysctl_table(net->ipv4.forw_hdr);
2751 	__devinet_sysctl_unregister(net, net->ipv4.devconf_dflt,
2752 				    NETCONFA_IFINDEX_DEFAULT);
2753 	__devinet_sysctl_unregister(net, net->ipv4.devconf_all,
2754 				    NETCONFA_IFINDEX_ALL);
2755 	kfree(tbl);
2756 #endif
2757 	kfree(net->ipv4.devconf_dflt);
2758 	kfree(net->ipv4.devconf_all);
2759 }
2760 
2761 static __net_initdata struct pernet_operations devinet_ops = {
2762 	.init = devinet_init_net,
2763 	.exit = devinet_exit_net,
2764 };
2765 
2766 static struct rtnl_af_ops inet_af_ops __read_mostly = {
2767 	.family		  = AF_INET,
2768 	.fill_link_af	  = inet_fill_link_af,
2769 	.get_link_af_size = inet_get_link_af_size,
2770 	.validate_link_af = inet_validate_link_af,
2771 	.set_link_af	  = inet_set_link_af,
2772 };
2773 
devinet_init(void)2774 void __init devinet_init(void)
2775 {
2776 	int i;
2777 
2778 	for (i = 0; i < IN4_ADDR_HSIZE; i++)
2779 		INIT_HLIST_HEAD(&inet_addr_lst[i]);
2780 
2781 	register_pernet_subsys(&devinet_ops);
2782 	register_netdevice_notifier(&ip_netdev_notifier);
2783 
2784 	queue_delayed_work(system_power_efficient_wq, &check_lifetime_work, 0);
2785 
2786 	rtnl_af_register(&inet_af_ops);
2787 
2788 	rtnl_register(PF_INET, RTM_NEWADDR, inet_rtm_newaddr, NULL, 0);
2789 	rtnl_register(PF_INET, RTM_DELADDR, inet_rtm_deladdr, NULL, 0);
2790 	rtnl_register(PF_INET, RTM_GETADDR, NULL, inet_dump_ifaddr, 0);
2791 	rtnl_register(PF_INET, RTM_GETNETCONF, inet_netconf_get_devconf,
2792 		      inet_netconf_dump_devconf, 0);
2793 }
2794