xref: /linux/net/ipv6/addrconf.c (revision d0b73b488c55df905ea8faaad079f8535629ed26)
1 /*
2  *	IPv6 Address [auto]configuration
3  *	Linux INET6 implementation
4  *
5  *	Authors:
6  *	Pedro Roque		<roque@di.fc.ul.pt>
7  *	Alexey Kuznetsov	<kuznet@ms2.inr.ac.ru>
8  *
9  *	This program is free software; you can redistribute it and/or
10  *      modify it under the terms of the GNU General Public License
11  *      as published by the Free Software Foundation; either version
12  *      2 of the License, or (at your option) any later version.
13  */
14 
15 /*
16  *	Changes:
17  *
18  *	Janos Farkas			:	delete timer on ifdown
19  *	<chexum@bankinf.banki.hu>
20  *	Andi Kleen			:	kill double kfree on module
21  *						unload.
22  *	Maciej W. Rozycki		:	FDDI support
23  *	sekiya@USAGI			:	Don't send too many RS
24  *						packets.
25  *	yoshfuji@USAGI			:       Fixed interval between DAD
26  *						packets.
27  *	YOSHIFUJI Hideaki @USAGI	:	improved accuracy of
28  *						address validation timer.
29  *	YOSHIFUJI Hideaki @USAGI	:	Privacy Extensions (RFC3041)
30  *						support.
31  *	Yuji SEKIYA @USAGI		:	Don't assign a same IPv6
32  *						address on a same interface.
33  *	YOSHIFUJI Hideaki @USAGI	:	ARCnet support
34  *	YOSHIFUJI Hideaki @USAGI	:	convert /proc/net/if_inet6 to
35  *						seq_file.
36  *	YOSHIFUJI Hideaki @USAGI	:	improved source address
37  *						selection; consider scope,
38  *						status etc.
39  */
40 
41 #define pr_fmt(fmt) "IPv6: " fmt
42 
43 #include <linux/errno.h>
44 #include <linux/types.h>
45 #include <linux/kernel.h>
46 #include <linux/socket.h>
47 #include <linux/sockios.h>
48 #include <linux/net.h>
49 #include <linux/in6.h>
50 #include <linux/netdevice.h>
51 #include <linux/if_addr.h>
52 #include <linux/if_arp.h>
53 #include <linux/if_arcnet.h>
54 #include <linux/if_infiniband.h>
55 #include <linux/route.h>
56 #include <linux/inetdevice.h>
57 #include <linux/init.h>
58 #include <linux/slab.h>
59 #ifdef CONFIG_SYSCTL
60 #include <linux/sysctl.h>
61 #endif
62 #include <linux/capability.h>
63 #include <linux/delay.h>
64 #include <linux/notifier.h>
65 #include <linux/string.h>
66 #include <linux/hash.h>
67 
68 #include <net/net_namespace.h>
69 #include <net/sock.h>
70 #include <net/snmp.h>
71 
72 #include <net/af_ieee802154.h>
73 #include <net/ipv6.h>
74 #include <net/protocol.h>
75 #include <net/ndisc.h>
76 #include <net/ip6_route.h>
77 #include <net/addrconf.h>
78 #include <net/tcp.h>
79 #include <net/ip.h>
80 #include <net/netlink.h>
81 #include <net/pkt_sched.h>
82 #include <linux/if_tunnel.h>
83 #include <linux/rtnetlink.h>
84 #include <linux/netconf.h>
85 
86 #ifdef CONFIG_IPV6_PRIVACY
87 #include <linux/random.h>
88 #endif
89 
90 #include <linux/uaccess.h>
91 #include <asm/unaligned.h>
92 
93 #include <linux/proc_fs.h>
94 #include <linux/seq_file.h>
95 #include <linux/export.h>
96 
97 /* Set to 3 to get tracing... */
98 #define ACONF_DEBUG 2
99 
100 #if ACONF_DEBUG >= 3
101 #define ADBG(x) printk x
102 #else
103 #define ADBG(x)
104 #endif
105 
106 #define	INFINITY_LIFE_TIME	0xFFFFFFFF
107 
108 static inline u32 cstamp_delta(unsigned long cstamp)
109 {
110 	return (cstamp - INITIAL_JIFFIES) * 100UL / HZ;
111 }
112 
113 #define ADDRCONF_TIMER_FUZZ_MINUS	(HZ > 50 ? HZ/50 : 1)
114 #define ADDRCONF_TIMER_FUZZ		(HZ / 4)
115 #define ADDRCONF_TIMER_FUZZ_MAX		(HZ)
116 
117 #ifdef CONFIG_SYSCTL
118 static void addrconf_sysctl_register(struct inet6_dev *idev);
119 static void addrconf_sysctl_unregister(struct inet6_dev *idev);
120 #else
121 static inline void addrconf_sysctl_register(struct inet6_dev *idev)
122 {
123 }
124 
125 static inline void addrconf_sysctl_unregister(struct inet6_dev *idev)
126 {
127 }
128 #endif
129 
130 #ifdef CONFIG_IPV6_PRIVACY
131 static void __ipv6_regen_rndid(struct inet6_dev *idev);
132 static void __ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr);
133 static void ipv6_regen_rndid(unsigned long data);
134 #endif
135 
136 static int ipv6_generate_eui64(u8 *eui, struct net_device *dev);
137 static int ipv6_count_addresses(struct inet6_dev *idev);
138 
139 /*
140  *	Configured unicast address hash table
141  */
142 static struct hlist_head inet6_addr_lst[IN6_ADDR_HSIZE];
143 static DEFINE_SPINLOCK(addrconf_hash_lock);
144 
145 static void addrconf_verify(unsigned long);
146 
147 static DEFINE_TIMER(addr_chk_timer, addrconf_verify, 0, 0);
148 static DEFINE_SPINLOCK(addrconf_verify_lock);
149 
150 static void addrconf_join_anycast(struct inet6_ifaddr *ifp);
151 static void addrconf_leave_anycast(struct inet6_ifaddr *ifp);
152 
153 static void addrconf_type_change(struct net_device *dev,
154 				 unsigned long event);
155 static int addrconf_ifdown(struct net_device *dev, int how);
156 
157 static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
158 						  int plen,
159 						  const struct net_device *dev,
160 						  u32 flags, u32 noflags);
161 
162 static void addrconf_dad_start(struct inet6_ifaddr *ifp);
163 static void addrconf_dad_timer(unsigned long data);
164 static void addrconf_dad_completed(struct inet6_ifaddr *ifp);
165 static void addrconf_dad_run(struct inet6_dev *idev);
166 static void addrconf_rs_timer(unsigned long data);
167 static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifa);
168 static void ipv6_ifa_notify(int event, struct inet6_ifaddr *ifa);
169 
170 static void inet6_prefix_notify(int event, struct inet6_dev *idev,
171 				struct prefix_info *pinfo);
172 static bool ipv6_chk_same_addr(struct net *net, const struct in6_addr *addr,
173 			       struct net_device *dev);
174 
175 static ATOMIC_NOTIFIER_HEAD(inet6addr_chain);
176 
177 static struct ipv6_devconf ipv6_devconf __read_mostly = {
178 	.forwarding		= 0,
179 	.hop_limit		= IPV6_DEFAULT_HOPLIMIT,
180 	.mtu6			= IPV6_MIN_MTU,
181 	.accept_ra		= 1,
182 	.accept_redirects	= 1,
183 	.autoconf		= 1,
184 	.force_mld_version	= 0,
185 	.dad_transmits		= 1,
186 	.rtr_solicits		= MAX_RTR_SOLICITATIONS,
187 	.rtr_solicit_interval	= RTR_SOLICITATION_INTERVAL,
188 	.rtr_solicit_delay	= MAX_RTR_SOLICITATION_DELAY,
189 #ifdef CONFIG_IPV6_PRIVACY
190 	.use_tempaddr 		= 0,
191 	.temp_valid_lft		= TEMP_VALID_LIFETIME,
192 	.temp_prefered_lft	= TEMP_PREFERRED_LIFETIME,
193 	.regen_max_retry	= REGEN_MAX_RETRY,
194 	.max_desync_factor	= MAX_DESYNC_FACTOR,
195 #endif
196 	.max_addresses		= IPV6_MAX_ADDRESSES,
197 	.accept_ra_defrtr	= 1,
198 	.accept_ra_pinfo	= 1,
199 #ifdef CONFIG_IPV6_ROUTER_PREF
200 	.accept_ra_rtr_pref	= 1,
201 	.rtr_probe_interval	= 60 * HZ,
202 #ifdef CONFIG_IPV6_ROUTE_INFO
203 	.accept_ra_rt_info_max_plen = 0,
204 #endif
205 #endif
206 	.proxy_ndp		= 0,
207 	.accept_source_route	= 0,	/* we do not accept RH0 by default. */
208 	.disable_ipv6		= 0,
209 	.accept_dad		= 1,
210 };
211 
212 static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
213 	.forwarding		= 0,
214 	.hop_limit		= IPV6_DEFAULT_HOPLIMIT,
215 	.mtu6			= IPV6_MIN_MTU,
216 	.accept_ra		= 1,
217 	.accept_redirects	= 1,
218 	.autoconf		= 1,
219 	.dad_transmits		= 1,
220 	.rtr_solicits		= MAX_RTR_SOLICITATIONS,
221 	.rtr_solicit_interval	= RTR_SOLICITATION_INTERVAL,
222 	.rtr_solicit_delay	= MAX_RTR_SOLICITATION_DELAY,
223 #ifdef CONFIG_IPV6_PRIVACY
224 	.use_tempaddr		= 0,
225 	.temp_valid_lft		= TEMP_VALID_LIFETIME,
226 	.temp_prefered_lft	= TEMP_PREFERRED_LIFETIME,
227 	.regen_max_retry	= REGEN_MAX_RETRY,
228 	.max_desync_factor	= MAX_DESYNC_FACTOR,
229 #endif
230 	.max_addresses		= IPV6_MAX_ADDRESSES,
231 	.accept_ra_defrtr	= 1,
232 	.accept_ra_pinfo	= 1,
233 #ifdef CONFIG_IPV6_ROUTER_PREF
234 	.accept_ra_rtr_pref	= 1,
235 	.rtr_probe_interval	= 60 * HZ,
236 #ifdef CONFIG_IPV6_ROUTE_INFO
237 	.accept_ra_rt_info_max_plen = 0,
238 #endif
239 #endif
240 	.proxy_ndp		= 0,
241 	.accept_source_route	= 0,	/* we do not accept RH0 by default. */
242 	.disable_ipv6		= 0,
243 	.accept_dad		= 1,
244 };
245 
246 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
247 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
248 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
249 const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
250 const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
251 
252 /* Check if a valid qdisc is available */
253 static inline bool addrconf_qdisc_ok(const struct net_device *dev)
254 {
255 	return !qdisc_tx_is_noop(dev);
256 }
257 
258 static void addrconf_del_timer(struct inet6_ifaddr *ifp)
259 {
260 	if (del_timer(&ifp->timer))
261 		__in6_ifa_put(ifp);
262 }
263 
264 enum addrconf_timer_t {
265 	AC_NONE,
266 	AC_DAD,
267 	AC_RS,
268 };
269 
270 static void addrconf_mod_timer(struct inet6_ifaddr *ifp,
271 			       enum addrconf_timer_t what,
272 			       unsigned long when)
273 {
274 	if (!del_timer(&ifp->timer))
275 		in6_ifa_hold(ifp);
276 
277 	switch (what) {
278 	case AC_DAD:
279 		ifp->timer.function = addrconf_dad_timer;
280 		break;
281 	case AC_RS:
282 		ifp->timer.function = addrconf_rs_timer;
283 		break;
284 	default:
285 		break;
286 	}
287 	ifp->timer.expires = jiffies + when;
288 	add_timer(&ifp->timer);
289 }
290 
291 static int snmp6_alloc_dev(struct inet6_dev *idev)
292 {
293 	if (snmp_mib_init((void __percpu **)idev->stats.ipv6,
294 			  sizeof(struct ipstats_mib),
295 			  __alignof__(struct ipstats_mib)) < 0)
296 		goto err_ip;
297 	idev->stats.icmpv6dev = kzalloc(sizeof(struct icmpv6_mib_device),
298 					GFP_KERNEL);
299 	if (!idev->stats.icmpv6dev)
300 		goto err_icmp;
301 	idev->stats.icmpv6msgdev = kzalloc(sizeof(struct icmpv6msg_mib_device),
302 					   GFP_KERNEL);
303 	if (!idev->stats.icmpv6msgdev)
304 		goto err_icmpmsg;
305 
306 	return 0;
307 
308 err_icmpmsg:
309 	kfree(idev->stats.icmpv6dev);
310 err_icmp:
311 	snmp_mib_free((void __percpu **)idev->stats.ipv6);
312 err_ip:
313 	return -ENOMEM;
314 }
315 
316 static void snmp6_free_dev(struct inet6_dev *idev)
317 {
318 	kfree(idev->stats.icmpv6msgdev);
319 	kfree(idev->stats.icmpv6dev);
320 	snmp_mib_free((void __percpu **)idev->stats.ipv6);
321 }
322 
323 /* Nobody refers to this device, we may destroy it. */
324 
325 void in6_dev_finish_destroy(struct inet6_dev *idev)
326 {
327 	struct net_device *dev = idev->dev;
328 
329 	WARN_ON(!list_empty(&idev->addr_list));
330 	WARN_ON(idev->mc_list != NULL);
331 
332 #ifdef NET_REFCNT_DEBUG
333 	pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
334 #endif
335 	dev_put(dev);
336 	if (!idev->dead) {
337 		pr_warn("Freeing alive inet6 device %p\n", idev);
338 		return;
339 	}
340 	snmp6_free_dev(idev);
341 	kfree_rcu(idev, rcu);
342 }
343 EXPORT_SYMBOL(in6_dev_finish_destroy);
344 
345 static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
346 {
347 	struct inet6_dev *ndev;
348 
349 	ASSERT_RTNL();
350 
351 	if (dev->mtu < IPV6_MIN_MTU)
352 		return NULL;
353 
354 	ndev = kzalloc(sizeof(struct inet6_dev), GFP_KERNEL);
355 
356 	if (ndev == NULL)
357 		return NULL;
358 
359 	rwlock_init(&ndev->lock);
360 	ndev->dev = dev;
361 	INIT_LIST_HEAD(&ndev->addr_list);
362 
363 	memcpy(&ndev->cnf, dev_net(dev)->ipv6.devconf_dflt, sizeof(ndev->cnf));
364 	ndev->cnf.mtu6 = dev->mtu;
365 	ndev->cnf.sysctl = NULL;
366 	ndev->nd_parms = neigh_parms_alloc(dev, &nd_tbl);
367 	if (ndev->nd_parms == NULL) {
368 		kfree(ndev);
369 		return NULL;
370 	}
371 	if (ndev->cnf.forwarding)
372 		dev_disable_lro(dev);
373 	/* We refer to the device */
374 	dev_hold(dev);
375 
376 	if (snmp6_alloc_dev(ndev) < 0) {
377 		ADBG((KERN_WARNING
378 			"%s: cannot allocate memory for statistics; dev=%s.\n",
379 			__func__, dev->name));
380 		neigh_parms_release(&nd_tbl, ndev->nd_parms);
381 		dev_put(dev);
382 		kfree(ndev);
383 		return NULL;
384 	}
385 
386 	if (snmp6_register_dev(ndev) < 0) {
387 		ADBG((KERN_WARNING
388 			"%s: cannot create /proc/net/dev_snmp6/%s\n",
389 			__func__, dev->name));
390 		neigh_parms_release(&nd_tbl, ndev->nd_parms);
391 		ndev->dead = 1;
392 		in6_dev_finish_destroy(ndev);
393 		return NULL;
394 	}
395 
396 	/* One reference from device.  We must do this before
397 	 * we invoke __ipv6_regen_rndid().
398 	 */
399 	in6_dev_hold(ndev);
400 
401 	if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
402 		ndev->cnf.accept_dad = -1;
403 
404 #if IS_ENABLED(CONFIG_IPV6_SIT)
405 	if (dev->type == ARPHRD_SIT && (dev->priv_flags & IFF_ISATAP)) {
406 		pr_info("%s: Disabled Multicast RS\n", dev->name);
407 		ndev->cnf.rtr_solicits = 0;
408 	}
409 #endif
410 
411 #ifdef CONFIG_IPV6_PRIVACY
412 	INIT_LIST_HEAD(&ndev->tempaddr_list);
413 	setup_timer(&ndev->regen_timer, ipv6_regen_rndid, (unsigned long)ndev);
414 	if ((dev->flags&IFF_LOOPBACK) ||
415 	    dev->type == ARPHRD_TUNNEL ||
416 	    dev->type == ARPHRD_TUNNEL6 ||
417 	    dev->type == ARPHRD_SIT ||
418 	    dev->type == ARPHRD_NONE) {
419 		ndev->cnf.use_tempaddr = -1;
420 	} else {
421 		in6_dev_hold(ndev);
422 		ipv6_regen_rndid((unsigned long) ndev);
423 	}
424 #endif
425 
426 	if (netif_running(dev) && addrconf_qdisc_ok(dev))
427 		ndev->if_flags |= IF_READY;
428 
429 	ipv6_mc_init_dev(ndev);
430 	ndev->tstamp = jiffies;
431 	addrconf_sysctl_register(ndev);
432 	/* protected by rtnl_lock */
433 	rcu_assign_pointer(dev->ip6_ptr, ndev);
434 
435 	/* Join all-node multicast group */
436 	ipv6_dev_mc_inc(dev, &in6addr_linklocal_allnodes);
437 
438 	/* Join all-router multicast group if forwarding is set */
439 	if (ndev->cnf.forwarding && (dev->flags & IFF_MULTICAST))
440 		ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters);
441 
442 	return ndev;
443 }
444 
445 static struct inet6_dev *ipv6_find_idev(struct net_device *dev)
446 {
447 	struct inet6_dev *idev;
448 
449 	ASSERT_RTNL();
450 
451 	idev = __in6_dev_get(dev);
452 	if (!idev) {
453 		idev = ipv6_add_dev(dev);
454 		if (!idev)
455 			return NULL;
456 	}
457 
458 	if (dev->flags&IFF_UP)
459 		ipv6_mc_up(idev);
460 	return idev;
461 }
462 
463 static int inet6_netconf_msgsize_devconf(int type)
464 {
465 	int size =  NLMSG_ALIGN(sizeof(struct netconfmsg))
466 		    + nla_total_size(4);	/* NETCONFA_IFINDEX */
467 
468 	/* type -1 is used for ALL */
469 	if (type == -1 || type == NETCONFA_FORWARDING)
470 		size += nla_total_size(4);
471 #ifdef CONFIG_IPV6_MROUTE
472 	if (type == -1 || type == NETCONFA_MC_FORWARDING)
473 		size += nla_total_size(4);
474 #endif
475 
476 	return size;
477 }
478 
479 static int inet6_netconf_fill_devconf(struct sk_buff *skb, int ifindex,
480 				      struct ipv6_devconf *devconf, u32 portid,
481 				      u32 seq, int event, unsigned int flags,
482 				      int type)
483 {
484 	struct nlmsghdr  *nlh;
485 	struct netconfmsg *ncm;
486 
487 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
488 			flags);
489 	if (nlh == NULL)
490 		return -EMSGSIZE;
491 
492 	ncm = nlmsg_data(nlh);
493 	ncm->ncm_family = AF_INET6;
494 
495 	if (nla_put_s32(skb, NETCONFA_IFINDEX, ifindex) < 0)
496 		goto nla_put_failure;
497 
498 	/* type -1 is used for ALL */
499 	if ((type == -1 || type == NETCONFA_FORWARDING) &&
500 	    nla_put_s32(skb, NETCONFA_FORWARDING, devconf->forwarding) < 0)
501 		goto nla_put_failure;
502 #ifdef CONFIG_IPV6_MROUTE
503 	if ((type == -1 || type == NETCONFA_MC_FORWARDING) &&
504 	    nla_put_s32(skb, NETCONFA_MC_FORWARDING,
505 			devconf->mc_forwarding) < 0)
506 		goto nla_put_failure;
507 #endif
508 	return nlmsg_end(skb, nlh);
509 
510 nla_put_failure:
511 	nlmsg_cancel(skb, nlh);
512 	return -EMSGSIZE;
513 }
514 
515 void inet6_netconf_notify_devconf(struct net *net, int type, int ifindex,
516 				  struct ipv6_devconf *devconf)
517 {
518 	struct sk_buff *skb;
519 	int err = -ENOBUFS;
520 
521 	skb = nlmsg_new(inet6_netconf_msgsize_devconf(type), GFP_ATOMIC);
522 	if (skb == NULL)
523 		goto errout;
524 
525 	err = inet6_netconf_fill_devconf(skb, ifindex, devconf, 0, 0,
526 					 RTM_NEWNETCONF, 0, type);
527 	if (err < 0) {
528 		/* -EMSGSIZE implies BUG in inet6_netconf_msgsize_devconf() */
529 		WARN_ON(err == -EMSGSIZE);
530 		kfree_skb(skb);
531 		goto errout;
532 	}
533 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_NETCONF, NULL, GFP_ATOMIC);
534 	return;
535 errout:
536 	rtnl_set_sk_err(net, RTNLGRP_IPV6_NETCONF, err);
537 }
538 
539 static const struct nla_policy devconf_ipv6_policy[NETCONFA_MAX+1] = {
540 	[NETCONFA_IFINDEX]	= { .len = sizeof(int) },
541 	[NETCONFA_FORWARDING]	= { .len = sizeof(int) },
542 };
543 
544 static int inet6_netconf_get_devconf(struct sk_buff *in_skb,
545 				     struct nlmsghdr *nlh,
546 				     void *arg)
547 {
548 	struct net *net = sock_net(in_skb->sk);
549 	struct nlattr *tb[NETCONFA_MAX+1];
550 	struct netconfmsg *ncm;
551 	struct sk_buff *skb;
552 	struct ipv6_devconf *devconf;
553 	struct inet6_dev *in6_dev;
554 	struct net_device *dev;
555 	int ifindex;
556 	int err;
557 
558 	err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX,
559 			  devconf_ipv6_policy);
560 	if (err < 0)
561 		goto errout;
562 
563 	err = EINVAL;
564 	if (!tb[NETCONFA_IFINDEX])
565 		goto errout;
566 
567 	ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
568 	switch (ifindex) {
569 	case NETCONFA_IFINDEX_ALL:
570 		devconf = net->ipv6.devconf_all;
571 		break;
572 	case NETCONFA_IFINDEX_DEFAULT:
573 		devconf = net->ipv6.devconf_dflt;
574 		break;
575 	default:
576 		dev = __dev_get_by_index(net, ifindex);
577 		if (dev == NULL)
578 			goto errout;
579 		in6_dev = __in6_dev_get(dev);
580 		if (in6_dev == NULL)
581 			goto errout;
582 		devconf = &in6_dev->cnf;
583 		break;
584 	}
585 
586 	err = -ENOBUFS;
587 	skb = nlmsg_new(inet6_netconf_msgsize_devconf(-1), GFP_ATOMIC);
588 	if (skb == NULL)
589 		goto errout;
590 
591 	err = inet6_netconf_fill_devconf(skb, ifindex, devconf,
592 					 NETLINK_CB(in_skb).portid,
593 					 nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
594 					 -1);
595 	if (err < 0) {
596 		/* -EMSGSIZE implies BUG in inet6_netconf_msgsize_devconf() */
597 		WARN_ON(err == -EMSGSIZE);
598 		kfree_skb(skb);
599 		goto errout;
600 	}
601 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
602 errout:
603 	return err;
604 }
605 
606 #ifdef CONFIG_SYSCTL
607 static void dev_forward_change(struct inet6_dev *idev)
608 {
609 	struct net_device *dev;
610 	struct inet6_ifaddr *ifa;
611 
612 	if (!idev)
613 		return;
614 	dev = idev->dev;
615 	if (idev->cnf.forwarding)
616 		dev_disable_lro(dev);
617 	if (dev->flags & IFF_MULTICAST) {
618 		if (idev->cnf.forwarding)
619 			ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters);
620 		else
621 			ipv6_dev_mc_dec(dev, &in6addr_linklocal_allrouters);
622 	}
623 
624 	list_for_each_entry(ifa, &idev->addr_list, if_list) {
625 		if (ifa->flags&IFA_F_TENTATIVE)
626 			continue;
627 		if (idev->cnf.forwarding)
628 			addrconf_join_anycast(ifa);
629 		else
630 			addrconf_leave_anycast(ifa);
631 	}
632 	inet6_netconf_notify_devconf(dev_net(dev), NETCONFA_FORWARDING,
633 				     dev->ifindex, &idev->cnf);
634 }
635 
636 
637 static void addrconf_forward_change(struct net *net, __s32 newf)
638 {
639 	struct net_device *dev;
640 	struct inet6_dev *idev;
641 
642 	for_each_netdev(net, dev) {
643 		idev = __in6_dev_get(dev);
644 		if (idev) {
645 			int changed = (!idev->cnf.forwarding) ^ (!newf);
646 			idev->cnf.forwarding = newf;
647 			if (changed)
648 				dev_forward_change(idev);
649 		}
650 	}
651 }
652 
653 static int addrconf_fixup_forwarding(struct ctl_table *table, int *p, int newf)
654 {
655 	struct net *net;
656 	int old;
657 
658 	if (!rtnl_trylock())
659 		return restart_syscall();
660 
661 	net = (struct net *)table->extra2;
662 	old = *p;
663 	*p = newf;
664 
665 	if (p == &net->ipv6.devconf_dflt->forwarding) {
666 		if ((!newf) ^ (!old))
667 			inet6_netconf_notify_devconf(net, NETCONFA_FORWARDING,
668 						     NETCONFA_IFINDEX_DEFAULT,
669 						     net->ipv6.devconf_dflt);
670 		rtnl_unlock();
671 		return 0;
672 	}
673 
674 	if (p == &net->ipv6.devconf_all->forwarding) {
675 		net->ipv6.devconf_dflt->forwarding = newf;
676 		addrconf_forward_change(net, newf);
677 		if ((!newf) ^ (!old))
678 			inet6_netconf_notify_devconf(net, NETCONFA_FORWARDING,
679 						     NETCONFA_IFINDEX_ALL,
680 						     net->ipv6.devconf_all);
681 	} else if ((!newf) ^ (!old))
682 		dev_forward_change((struct inet6_dev *)table->extra1);
683 	rtnl_unlock();
684 
685 	if (newf)
686 		rt6_purge_dflt_routers(net);
687 	return 1;
688 }
689 #endif
690 
691 /* Nobody refers to this ifaddr, destroy it */
692 void inet6_ifa_finish_destroy(struct inet6_ifaddr *ifp)
693 {
694 	WARN_ON(!hlist_unhashed(&ifp->addr_lst));
695 
696 #ifdef NET_REFCNT_DEBUG
697 	pr_debug("%s\n", __func__);
698 #endif
699 
700 	in6_dev_put(ifp->idev);
701 
702 	if (del_timer(&ifp->timer))
703 		pr_notice("Timer is still running, when freeing ifa=%p\n", ifp);
704 
705 	if (ifp->state != INET6_IFADDR_STATE_DEAD) {
706 		pr_warn("Freeing alive inet6 address %p\n", ifp);
707 		return;
708 	}
709 	ip6_rt_put(ifp->rt);
710 
711 	kfree_rcu(ifp, rcu);
712 }
713 
714 static void
715 ipv6_link_dev_addr(struct inet6_dev *idev, struct inet6_ifaddr *ifp)
716 {
717 	struct list_head *p;
718 	int ifp_scope = ipv6_addr_src_scope(&ifp->addr);
719 
720 	/*
721 	 * Each device address list is sorted in order of scope -
722 	 * global before linklocal.
723 	 */
724 	list_for_each(p, &idev->addr_list) {
725 		struct inet6_ifaddr *ifa
726 			= list_entry(p, struct inet6_ifaddr, if_list);
727 		if (ifp_scope >= ipv6_addr_src_scope(&ifa->addr))
728 			break;
729 	}
730 
731 	list_add_tail(&ifp->if_list, p);
732 }
733 
734 static u32 inet6_addr_hash(const struct in6_addr *addr)
735 {
736 	return hash_32(ipv6_addr_hash(addr), IN6_ADDR_HSIZE_SHIFT);
737 }
738 
739 /* On success it returns ifp with increased reference count */
740 
741 static struct inet6_ifaddr *
742 ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen,
743 	      int scope, u32 flags)
744 {
745 	struct inet6_ifaddr *ifa = NULL;
746 	struct rt6_info *rt;
747 	unsigned int hash;
748 	int err = 0;
749 	int addr_type = ipv6_addr_type(addr);
750 
751 	if (addr_type == IPV6_ADDR_ANY ||
752 	    addr_type & IPV6_ADDR_MULTICAST ||
753 	    (!(idev->dev->flags & IFF_LOOPBACK) &&
754 	     addr_type & IPV6_ADDR_LOOPBACK))
755 		return ERR_PTR(-EADDRNOTAVAIL);
756 
757 	rcu_read_lock_bh();
758 	if (idev->dead) {
759 		err = -ENODEV;			/*XXX*/
760 		goto out2;
761 	}
762 
763 	if (idev->cnf.disable_ipv6) {
764 		err = -EACCES;
765 		goto out2;
766 	}
767 
768 	spin_lock(&addrconf_hash_lock);
769 
770 	/* Ignore adding duplicate addresses on an interface */
771 	if (ipv6_chk_same_addr(dev_net(idev->dev), addr, idev->dev)) {
772 		ADBG(("ipv6_add_addr: already assigned\n"));
773 		err = -EEXIST;
774 		goto out;
775 	}
776 
777 	ifa = kzalloc(sizeof(struct inet6_ifaddr), GFP_ATOMIC);
778 
779 	if (ifa == NULL) {
780 		ADBG(("ipv6_add_addr: malloc failed\n"));
781 		err = -ENOBUFS;
782 		goto out;
783 	}
784 
785 	rt = addrconf_dst_alloc(idev, addr, false);
786 	if (IS_ERR(rt)) {
787 		err = PTR_ERR(rt);
788 		goto out;
789 	}
790 
791 	ifa->addr = *addr;
792 
793 	spin_lock_init(&ifa->lock);
794 	spin_lock_init(&ifa->state_lock);
795 	init_timer(&ifa->timer);
796 	INIT_HLIST_NODE(&ifa->addr_lst);
797 	ifa->timer.data = (unsigned long) ifa;
798 	ifa->scope = scope;
799 	ifa->prefix_len = pfxlen;
800 	ifa->flags = flags | IFA_F_TENTATIVE;
801 	ifa->cstamp = ifa->tstamp = jiffies;
802 
803 	ifa->rt = rt;
804 
805 	ifa->idev = idev;
806 	in6_dev_hold(idev);
807 	/* For caller */
808 	in6_ifa_hold(ifa);
809 
810 	/* Add to big hash table */
811 	hash = inet6_addr_hash(addr);
812 
813 	hlist_add_head_rcu(&ifa->addr_lst, &inet6_addr_lst[hash]);
814 	spin_unlock(&addrconf_hash_lock);
815 
816 	write_lock(&idev->lock);
817 	/* Add to inet6_dev unicast addr list. */
818 	ipv6_link_dev_addr(idev, ifa);
819 
820 #ifdef CONFIG_IPV6_PRIVACY
821 	if (ifa->flags&IFA_F_TEMPORARY) {
822 		list_add(&ifa->tmp_list, &idev->tempaddr_list);
823 		in6_ifa_hold(ifa);
824 	}
825 #endif
826 
827 	in6_ifa_hold(ifa);
828 	write_unlock(&idev->lock);
829 out2:
830 	rcu_read_unlock_bh();
831 
832 	if (likely(err == 0))
833 		atomic_notifier_call_chain(&inet6addr_chain, NETDEV_UP, ifa);
834 	else {
835 		kfree(ifa);
836 		ifa = ERR_PTR(err);
837 	}
838 
839 	return ifa;
840 out:
841 	spin_unlock(&addrconf_hash_lock);
842 	goto out2;
843 }
844 
845 /* This function wants to get referenced ifp and releases it before return */
846 
847 static void ipv6_del_addr(struct inet6_ifaddr *ifp)
848 {
849 	struct inet6_ifaddr *ifa, *ifn;
850 	struct inet6_dev *idev = ifp->idev;
851 	int state;
852 	int deleted = 0, onlink = 0;
853 	unsigned long expires = jiffies;
854 
855 	spin_lock_bh(&ifp->state_lock);
856 	state = ifp->state;
857 	ifp->state = INET6_IFADDR_STATE_DEAD;
858 	spin_unlock_bh(&ifp->state_lock);
859 
860 	if (state == INET6_IFADDR_STATE_DEAD)
861 		goto out;
862 
863 	spin_lock_bh(&addrconf_hash_lock);
864 	hlist_del_init_rcu(&ifp->addr_lst);
865 	spin_unlock_bh(&addrconf_hash_lock);
866 
867 	write_lock_bh(&idev->lock);
868 #ifdef CONFIG_IPV6_PRIVACY
869 	if (ifp->flags&IFA_F_TEMPORARY) {
870 		list_del(&ifp->tmp_list);
871 		if (ifp->ifpub) {
872 			in6_ifa_put(ifp->ifpub);
873 			ifp->ifpub = NULL;
874 		}
875 		__in6_ifa_put(ifp);
876 	}
877 #endif
878 
879 	list_for_each_entry_safe(ifa, ifn, &idev->addr_list, if_list) {
880 		if (ifa == ifp) {
881 			list_del_init(&ifp->if_list);
882 			__in6_ifa_put(ifp);
883 
884 			if (!(ifp->flags & IFA_F_PERMANENT) || onlink > 0)
885 				break;
886 			deleted = 1;
887 			continue;
888 		} else if (ifp->flags & IFA_F_PERMANENT) {
889 			if (ipv6_prefix_equal(&ifa->addr, &ifp->addr,
890 					      ifp->prefix_len)) {
891 				if (ifa->flags & IFA_F_PERMANENT) {
892 					onlink = 1;
893 					if (deleted)
894 						break;
895 				} else {
896 					unsigned long lifetime;
897 
898 					if (!onlink)
899 						onlink = -1;
900 
901 					spin_lock(&ifa->lock);
902 
903 					lifetime = addrconf_timeout_fixup(ifa->valid_lft, HZ);
904 					/*
905 					 * Note: Because this address is
906 					 * not permanent, lifetime <
907 					 * LONG_MAX / HZ here.
908 					 */
909 					if (time_before(expires,
910 							ifa->tstamp + lifetime * HZ))
911 						expires = ifa->tstamp + lifetime * HZ;
912 					spin_unlock(&ifa->lock);
913 				}
914 			}
915 		}
916 	}
917 	write_unlock_bh(&idev->lock);
918 
919 	addrconf_del_timer(ifp);
920 
921 	ipv6_ifa_notify(RTM_DELADDR, ifp);
922 
923 	atomic_notifier_call_chain(&inet6addr_chain, NETDEV_DOWN, ifp);
924 
925 	/*
926 	 * Purge or update corresponding prefix
927 	 *
928 	 * 1) we don't purge prefix here if address was not permanent.
929 	 *    prefix is managed by its own lifetime.
930 	 * 2) if there're no addresses, delete prefix.
931 	 * 3) if there're still other permanent address(es),
932 	 *    corresponding prefix is still permanent.
933 	 * 4) otherwise, update prefix lifetime to the
934 	 *    longest valid lifetime among the corresponding
935 	 *    addresses on the device.
936 	 *    Note: subsequent RA will update lifetime.
937 	 *
938 	 * --yoshfuji
939 	 */
940 	if ((ifp->flags & IFA_F_PERMANENT) && onlink < 1) {
941 		struct in6_addr prefix;
942 		struct rt6_info *rt;
943 
944 		ipv6_addr_prefix(&prefix, &ifp->addr, ifp->prefix_len);
945 
946 		rt = addrconf_get_prefix_route(&prefix,
947 					       ifp->prefix_len,
948 					       ifp->idev->dev,
949 					       0, RTF_GATEWAY | RTF_DEFAULT);
950 
951 		if (rt) {
952 			if (onlink == 0) {
953 				ip6_del_rt(rt);
954 				rt = NULL;
955 			} else if (!(rt->rt6i_flags & RTF_EXPIRES)) {
956 				rt6_set_expires(rt, expires);
957 			}
958 		}
959 		ip6_rt_put(rt);
960 	}
961 
962 	/* clean up prefsrc entries */
963 	rt6_remove_prefsrc(ifp);
964 out:
965 	in6_ifa_put(ifp);
966 }
967 
968 #ifdef CONFIG_IPV6_PRIVACY
969 static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, struct inet6_ifaddr *ift)
970 {
971 	struct inet6_dev *idev = ifp->idev;
972 	struct in6_addr addr, *tmpaddr;
973 	unsigned long tmp_prefered_lft, tmp_valid_lft, tmp_tstamp, age;
974 	unsigned long regen_advance;
975 	int tmp_plen;
976 	int ret = 0;
977 	int max_addresses;
978 	u32 addr_flags;
979 	unsigned long now = jiffies;
980 
981 	write_lock(&idev->lock);
982 	if (ift) {
983 		spin_lock_bh(&ift->lock);
984 		memcpy(&addr.s6_addr[8], &ift->addr.s6_addr[8], 8);
985 		spin_unlock_bh(&ift->lock);
986 		tmpaddr = &addr;
987 	} else {
988 		tmpaddr = NULL;
989 	}
990 retry:
991 	in6_dev_hold(idev);
992 	if (idev->cnf.use_tempaddr <= 0) {
993 		write_unlock(&idev->lock);
994 		pr_info("%s: use_tempaddr is disabled\n", __func__);
995 		in6_dev_put(idev);
996 		ret = -1;
997 		goto out;
998 	}
999 	spin_lock_bh(&ifp->lock);
1000 	if (ifp->regen_count++ >= idev->cnf.regen_max_retry) {
1001 		idev->cnf.use_tempaddr = -1;	/*XXX*/
1002 		spin_unlock_bh(&ifp->lock);
1003 		write_unlock(&idev->lock);
1004 		pr_warn("%s: regeneration time exceeded - disabled temporary address support\n",
1005 			__func__);
1006 		in6_dev_put(idev);
1007 		ret = -1;
1008 		goto out;
1009 	}
1010 	in6_ifa_hold(ifp);
1011 	memcpy(addr.s6_addr, ifp->addr.s6_addr, 8);
1012 	__ipv6_try_regen_rndid(idev, tmpaddr);
1013 	memcpy(&addr.s6_addr[8], idev->rndid, 8);
1014 	age = (now - ifp->tstamp) / HZ;
1015 	tmp_valid_lft = min_t(__u32,
1016 			      ifp->valid_lft,
1017 			      idev->cnf.temp_valid_lft + age);
1018 	tmp_prefered_lft = min_t(__u32,
1019 				 ifp->prefered_lft,
1020 				 idev->cnf.temp_prefered_lft + age -
1021 				 idev->cnf.max_desync_factor);
1022 	tmp_plen = ifp->prefix_len;
1023 	max_addresses = idev->cnf.max_addresses;
1024 	tmp_tstamp = ifp->tstamp;
1025 	spin_unlock_bh(&ifp->lock);
1026 
1027 	regen_advance = idev->cnf.regen_max_retry *
1028 	                idev->cnf.dad_transmits *
1029 	                idev->nd_parms->retrans_time / HZ;
1030 	write_unlock(&idev->lock);
1031 
1032 	/* A temporary address is created only if this calculated Preferred
1033 	 * Lifetime is greater than REGEN_ADVANCE time units.  In particular,
1034 	 * an implementation must not create a temporary address with a zero
1035 	 * Preferred Lifetime.
1036 	 */
1037 	if (tmp_prefered_lft <= regen_advance) {
1038 		in6_ifa_put(ifp);
1039 		in6_dev_put(idev);
1040 		ret = -1;
1041 		goto out;
1042 	}
1043 
1044 	addr_flags = IFA_F_TEMPORARY;
1045 	/* set in addrconf_prefix_rcv() */
1046 	if (ifp->flags & IFA_F_OPTIMISTIC)
1047 		addr_flags |= IFA_F_OPTIMISTIC;
1048 
1049 	ift = !max_addresses ||
1050 	      ipv6_count_addresses(idev) < max_addresses ?
1051 		ipv6_add_addr(idev, &addr, tmp_plen,
1052 			      ipv6_addr_type(&addr)&IPV6_ADDR_SCOPE_MASK,
1053 			      addr_flags) : NULL;
1054 	if (!ift || IS_ERR(ift)) {
1055 		in6_ifa_put(ifp);
1056 		in6_dev_put(idev);
1057 		pr_info("%s: retry temporary address regeneration\n", __func__);
1058 		tmpaddr = &addr;
1059 		write_lock(&idev->lock);
1060 		goto retry;
1061 	}
1062 
1063 	spin_lock_bh(&ift->lock);
1064 	ift->ifpub = ifp;
1065 	ift->valid_lft = tmp_valid_lft;
1066 	ift->prefered_lft = tmp_prefered_lft;
1067 	ift->cstamp = now;
1068 	ift->tstamp = tmp_tstamp;
1069 	spin_unlock_bh(&ift->lock);
1070 
1071 	addrconf_dad_start(ift);
1072 	in6_ifa_put(ift);
1073 	in6_dev_put(idev);
1074 out:
1075 	return ret;
1076 }
1077 #endif
1078 
1079 /*
1080  *	Choose an appropriate source address (RFC3484)
1081  */
1082 enum {
1083 	IPV6_SADDR_RULE_INIT = 0,
1084 	IPV6_SADDR_RULE_LOCAL,
1085 	IPV6_SADDR_RULE_SCOPE,
1086 	IPV6_SADDR_RULE_PREFERRED,
1087 #ifdef CONFIG_IPV6_MIP6
1088 	IPV6_SADDR_RULE_HOA,
1089 #endif
1090 	IPV6_SADDR_RULE_OIF,
1091 	IPV6_SADDR_RULE_LABEL,
1092 #ifdef CONFIG_IPV6_PRIVACY
1093 	IPV6_SADDR_RULE_PRIVACY,
1094 #endif
1095 	IPV6_SADDR_RULE_ORCHID,
1096 	IPV6_SADDR_RULE_PREFIX,
1097 	IPV6_SADDR_RULE_MAX
1098 };
1099 
1100 struct ipv6_saddr_score {
1101 	int			rule;
1102 	int			addr_type;
1103 	struct inet6_ifaddr	*ifa;
1104 	DECLARE_BITMAP(scorebits, IPV6_SADDR_RULE_MAX);
1105 	int			scopedist;
1106 	int			matchlen;
1107 };
1108 
1109 struct ipv6_saddr_dst {
1110 	const struct in6_addr *addr;
1111 	int ifindex;
1112 	int scope;
1113 	int label;
1114 	unsigned int prefs;
1115 };
1116 
1117 static inline int ipv6_saddr_preferred(int type)
1118 {
1119 	if (type & (IPV6_ADDR_MAPPED|IPV6_ADDR_COMPATv4|IPV6_ADDR_LOOPBACK))
1120 		return 1;
1121 	return 0;
1122 }
1123 
1124 static int ipv6_get_saddr_eval(struct net *net,
1125 			       struct ipv6_saddr_score *score,
1126 			       struct ipv6_saddr_dst *dst,
1127 			       int i)
1128 {
1129 	int ret;
1130 
1131 	if (i <= score->rule) {
1132 		switch (i) {
1133 		case IPV6_SADDR_RULE_SCOPE:
1134 			ret = score->scopedist;
1135 			break;
1136 		case IPV6_SADDR_RULE_PREFIX:
1137 			ret = score->matchlen;
1138 			break;
1139 		default:
1140 			ret = !!test_bit(i, score->scorebits);
1141 		}
1142 		goto out;
1143 	}
1144 
1145 	switch (i) {
1146 	case IPV6_SADDR_RULE_INIT:
1147 		/* Rule 0: remember if hiscore is not ready yet */
1148 		ret = !!score->ifa;
1149 		break;
1150 	case IPV6_SADDR_RULE_LOCAL:
1151 		/* Rule 1: Prefer same address */
1152 		ret = ipv6_addr_equal(&score->ifa->addr, dst->addr);
1153 		break;
1154 	case IPV6_SADDR_RULE_SCOPE:
1155 		/* Rule 2: Prefer appropriate scope
1156 		 *
1157 		 *      ret
1158 		 *       ^
1159 		 *    -1 |  d 15
1160 		 *    ---+--+-+---> scope
1161 		 *       |
1162 		 *       |             d is scope of the destination.
1163 		 *  B-d  |  \
1164 		 *       |   \      <- smaller scope is better if
1165 		 *  B-15 |    \        if scope is enough for destinaion.
1166 		 *       |             ret = B - scope (-1 <= scope >= d <= 15).
1167 		 * d-C-1 | /
1168 		 *       |/         <- greater is better
1169 		 *   -C  /             if scope is not enough for destination.
1170 		 *      /|             ret = scope - C (-1 <= d < scope <= 15).
1171 		 *
1172 		 * d - C - 1 < B -15 (for all -1 <= d <= 15).
1173 		 * C > d + 14 - B >= 15 + 14 - B = 29 - B.
1174 		 * Assume B = 0 and we get C > 29.
1175 		 */
1176 		ret = __ipv6_addr_src_scope(score->addr_type);
1177 		if (ret >= dst->scope)
1178 			ret = -ret;
1179 		else
1180 			ret -= 128;	/* 30 is enough */
1181 		score->scopedist = ret;
1182 		break;
1183 	case IPV6_SADDR_RULE_PREFERRED:
1184 		/* Rule 3: Avoid deprecated and optimistic addresses */
1185 		ret = ipv6_saddr_preferred(score->addr_type) ||
1186 		      !(score->ifa->flags & (IFA_F_DEPRECATED|IFA_F_OPTIMISTIC));
1187 		break;
1188 #ifdef CONFIG_IPV6_MIP6
1189 	case IPV6_SADDR_RULE_HOA:
1190 	    {
1191 		/* Rule 4: Prefer home address */
1192 		int prefhome = !(dst->prefs & IPV6_PREFER_SRC_COA);
1193 		ret = !(score->ifa->flags & IFA_F_HOMEADDRESS) ^ prefhome;
1194 		break;
1195 	    }
1196 #endif
1197 	case IPV6_SADDR_RULE_OIF:
1198 		/* Rule 5: Prefer outgoing interface */
1199 		ret = (!dst->ifindex ||
1200 		       dst->ifindex == score->ifa->idev->dev->ifindex);
1201 		break;
1202 	case IPV6_SADDR_RULE_LABEL:
1203 		/* Rule 6: Prefer matching label */
1204 		ret = ipv6_addr_label(net,
1205 				      &score->ifa->addr, score->addr_type,
1206 				      score->ifa->idev->dev->ifindex) == dst->label;
1207 		break;
1208 #ifdef CONFIG_IPV6_PRIVACY
1209 	case IPV6_SADDR_RULE_PRIVACY:
1210 	    {
1211 		/* Rule 7: Prefer public address
1212 		 * Note: prefer temporary address if use_tempaddr >= 2
1213 		 */
1214 		int preftmp = dst->prefs & (IPV6_PREFER_SRC_PUBLIC|IPV6_PREFER_SRC_TMP) ?
1215 				!!(dst->prefs & IPV6_PREFER_SRC_TMP) :
1216 				score->ifa->idev->cnf.use_tempaddr >= 2;
1217 		ret = (!(score->ifa->flags & IFA_F_TEMPORARY)) ^ preftmp;
1218 		break;
1219 	    }
1220 #endif
1221 	case IPV6_SADDR_RULE_ORCHID:
1222 		/* Rule 8-: Prefer ORCHID vs ORCHID or
1223 		 *	    non-ORCHID vs non-ORCHID
1224 		 */
1225 		ret = !(ipv6_addr_orchid(&score->ifa->addr) ^
1226 			ipv6_addr_orchid(dst->addr));
1227 		break;
1228 	case IPV6_SADDR_RULE_PREFIX:
1229 		/* Rule 8: Use longest matching prefix */
1230 		ret = ipv6_addr_diff(&score->ifa->addr, dst->addr);
1231 		if (ret > score->ifa->prefix_len)
1232 			ret = score->ifa->prefix_len;
1233 		score->matchlen = ret;
1234 		break;
1235 	default:
1236 		ret = 0;
1237 	}
1238 
1239 	if (ret)
1240 		__set_bit(i, score->scorebits);
1241 	score->rule = i;
1242 out:
1243 	return ret;
1244 }
1245 
1246 int ipv6_dev_get_saddr(struct net *net, const struct net_device *dst_dev,
1247 		       const struct in6_addr *daddr, unsigned int prefs,
1248 		       struct in6_addr *saddr)
1249 {
1250 	struct ipv6_saddr_score scores[2],
1251 				*score = &scores[0], *hiscore = &scores[1];
1252 	struct ipv6_saddr_dst dst;
1253 	struct net_device *dev;
1254 	int dst_type;
1255 
1256 	dst_type = __ipv6_addr_type(daddr);
1257 	dst.addr = daddr;
1258 	dst.ifindex = dst_dev ? dst_dev->ifindex : 0;
1259 	dst.scope = __ipv6_addr_src_scope(dst_type);
1260 	dst.label = ipv6_addr_label(net, daddr, dst_type, dst.ifindex);
1261 	dst.prefs = prefs;
1262 
1263 	hiscore->rule = -1;
1264 	hiscore->ifa = NULL;
1265 
1266 	rcu_read_lock();
1267 
1268 	for_each_netdev_rcu(net, dev) {
1269 		struct inet6_dev *idev;
1270 
1271 		/* Candidate Source Address (section 4)
1272 		 *  - multicast and link-local destination address,
1273 		 *    the set of candidate source address MUST only
1274 		 *    include addresses assigned to interfaces
1275 		 *    belonging to the same link as the outgoing
1276 		 *    interface.
1277 		 * (- For site-local destination addresses, the
1278 		 *    set of candidate source addresses MUST only
1279 		 *    include addresses assigned to interfaces
1280 		 *    belonging to the same site as the outgoing
1281 		 *    interface.)
1282 		 */
1283 		if (((dst_type & IPV6_ADDR_MULTICAST) ||
1284 		     dst.scope <= IPV6_ADDR_SCOPE_LINKLOCAL) &&
1285 		    dst.ifindex && dev->ifindex != dst.ifindex)
1286 			continue;
1287 
1288 		idev = __in6_dev_get(dev);
1289 		if (!idev)
1290 			continue;
1291 
1292 		read_lock_bh(&idev->lock);
1293 		list_for_each_entry(score->ifa, &idev->addr_list, if_list) {
1294 			int i;
1295 
1296 			/*
1297 			 * - Tentative Address (RFC2462 section 5.4)
1298 			 *  - A tentative address is not considered
1299 			 *    "assigned to an interface" in the traditional
1300 			 *    sense, unless it is also flagged as optimistic.
1301 			 * - Candidate Source Address (section 4)
1302 			 *  - In any case, anycast addresses, multicast
1303 			 *    addresses, and the unspecified address MUST
1304 			 *    NOT be included in a candidate set.
1305 			 */
1306 			if ((score->ifa->flags & IFA_F_TENTATIVE) &&
1307 			    (!(score->ifa->flags & IFA_F_OPTIMISTIC)))
1308 				continue;
1309 
1310 			score->addr_type = __ipv6_addr_type(&score->ifa->addr);
1311 
1312 			if (unlikely(score->addr_type == IPV6_ADDR_ANY ||
1313 				     score->addr_type & IPV6_ADDR_MULTICAST)) {
1314 				LIMIT_NETDEBUG(KERN_DEBUG
1315 					       "ADDRCONF: unspecified / multicast address "
1316 					       "assigned as unicast address on %s",
1317 					       dev->name);
1318 				continue;
1319 			}
1320 
1321 			score->rule = -1;
1322 			bitmap_zero(score->scorebits, IPV6_SADDR_RULE_MAX);
1323 
1324 			for (i = 0; i < IPV6_SADDR_RULE_MAX; i++) {
1325 				int minihiscore, miniscore;
1326 
1327 				minihiscore = ipv6_get_saddr_eval(net, hiscore, &dst, i);
1328 				miniscore = ipv6_get_saddr_eval(net, score, &dst, i);
1329 
1330 				if (minihiscore > miniscore) {
1331 					if (i == IPV6_SADDR_RULE_SCOPE &&
1332 					    score->scopedist > 0) {
1333 						/*
1334 						 * special case:
1335 						 * each remaining entry
1336 						 * has too small (not enough)
1337 						 * scope, because ifa entries
1338 						 * are sorted by their scope
1339 						 * values.
1340 						 */
1341 						goto try_nextdev;
1342 					}
1343 					break;
1344 				} else if (minihiscore < miniscore) {
1345 					if (hiscore->ifa)
1346 						in6_ifa_put(hiscore->ifa);
1347 
1348 					in6_ifa_hold(score->ifa);
1349 
1350 					swap(hiscore, score);
1351 
1352 					/* restore our iterator */
1353 					score->ifa = hiscore->ifa;
1354 
1355 					break;
1356 				}
1357 			}
1358 		}
1359 try_nextdev:
1360 		read_unlock_bh(&idev->lock);
1361 	}
1362 	rcu_read_unlock();
1363 
1364 	if (!hiscore->ifa)
1365 		return -EADDRNOTAVAIL;
1366 
1367 	*saddr = hiscore->ifa->addr;
1368 	in6_ifa_put(hiscore->ifa);
1369 	return 0;
1370 }
1371 EXPORT_SYMBOL(ipv6_dev_get_saddr);
1372 
1373 int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr,
1374 		    unsigned char banned_flags)
1375 {
1376 	struct inet6_dev *idev;
1377 	int err = -EADDRNOTAVAIL;
1378 
1379 	rcu_read_lock();
1380 	idev = __in6_dev_get(dev);
1381 	if (idev) {
1382 		struct inet6_ifaddr *ifp;
1383 
1384 		read_lock_bh(&idev->lock);
1385 		list_for_each_entry(ifp, &idev->addr_list, if_list) {
1386 			if (ifp->scope == IFA_LINK &&
1387 			    !(ifp->flags & banned_flags)) {
1388 				*addr = ifp->addr;
1389 				err = 0;
1390 				break;
1391 			}
1392 		}
1393 		read_unlock_bh(&idev->lock);
1394 	}
1395 	rcu_read_unlock();
1396 	return err;
1397 }
1398 
1399 static int ipv6_count_addresses(struct inet6_dev *idev)
1400 {
1401 	int cnt = 0;
1402 	struct inet6_ifaddr *ifp;
1403 
1404 	read_lock_bh(&idev->lock);
1405 	list_for_each_entry(ifp, &idev->addr_list, if_list)
1406 		cnt++;
1407 	read_unlock_bh(&idev->lock);
1408 	return cnt;
1409 }
1410 
1411 int ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
1412 		  struct net_device *dev, int strict)
1413 {
1414 	struct inet6_ifaddr *ifp;
1415 	struct hlist_node *node;
1416 	unsigned int hash = inet6_addr_hash(addr);
1417 
1418 	rcu_read_lock_bh();
1419 	hlist_for_each_entry_rcu(ifp, node, &inet6_addr_lst[hash], addr_lst) {
1420 		if (!net_eq(dev_net(ifp->idev->dev), net))
1421 			continue;
1422 		if (ipv6_addr_equal(&ifp->addr, addr) &&
1423 		    !(ifp->flags&IFA_F_TENTATIVE) &&
1424 		    (dev == NULL || ifp->idev->dev == dev ||
1425 		     !(ifp->scope&(IFA_LINK|IFA_HOST) || strict))) {
1426 			rcu_read_unlock_bh();
1427 			return 1;
1428 		}
1429 	}
1430 
1431 	rcu_read_unlock_bh();
1432 	return 0;
1433 }
1434 EXPORT_SYMBOL(ipv6_chk_addr);
1435 
1436 static bool ipv6_chk_same_addr(struct net *net, const struct in6_addr *addr,
1437 			       struct net_device *dev)
1438 {
1439 	unsigned int hash = inet6_addr_hash(addr);
1440 	struct inet6_ifaddr *ifp;
1441 	struct hlist_node *node;
1442 
1443 	hlist_for_each_entry(ifp, node, &inet6_addr_lst[hash], addr_lst) {
1444 		if (!net_eq(dev_net(ifp->idev->dev), net))
1445 			continue;
1446 		if (ipv6_addr_equal(&ifp->addr, addr)) {
1447 			if (dev == NULL || ifp->idev->dev == dev)
1448 				return true;
1449 		}
1450 	}
1451 	return false;
1452 }
1453 
1454 int ipv6_chk_prefix(const struct in6_addr *addr, struct net_device *dev)
1455 {
1456 	struct inet6_dev *idev;
1457 	struct inet6_ifaddr *ifa;
1458 	int	onlink;
1459 
1460 	onlink = 0;
1461 	rcu_read_lock();
1462 	idev = __in6_dev_get(dev);
1463 	if (idev) {
1464 		read_lock_bh(&idev->lock);
1465 		list_for_each_entry(ifa, &idev->addr_list, if_list) {
1466 			onlink = ipv6_prefix_equal(addr, &ifa->addr,
1467 						   ifa->prefix_len);
1468 			if (onlink)
1469 				break;
1470 		}
1471 		read_unlock_bh(&idev->lock);
1472 	}
1473 	rcu_read_unlock();
1474 	return onlink;
1475 }
1476 EXPORT_SYMBOL(ipv6_chk_prefix);
1477 
1478 struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *addr,
1479 				     struct net_device *dev, int strict)
1480 {
1481 	struct inet6_ifaddr *ifp, *result = NULL;
1482 	unsigned int hash = inet6_addr_hash(addr);
1483 	struct hlist_node *node;
1484 
1485 	rcu_read_lock_bh();
1486 	hlist_for_each_entry_rcu_bh(ifp, node, &inet6_addr_lst[hash], addr_lst) {
1487 		if (!net_eq(dev_net(ifp->idev->dev), net))
1488 			continue;
1489 		if (ipv6_addr_equal(&ifp->addr, addr)) {
1490 			if (dev == NULL || ifp->idev->dev == dev ||
1491 			    !(ifp->scope&(IFA_LINK|IFA_HOST) || strict)) {
1492 				result = ifp;
1493 				in6_ifa_hold(ifp);
1494 				break;
1495 			}
1496 		}
1497 	}
1498 	rcu_read_unlock_bh();
1499 
1500 	return result;
1501 }
1502 
1503 /* Gets referenced address, destroys ifaddr */
1504 
1505 static void addrconf_dad_stop(struct inet6_ifaddr *ifp, int dad_failed)
1506 {
1507 	if (ifp->flags&IFA_F_PERMANENT) {
1508 		spin_lock_bh(&ifp->lock);
1509 		addrconf_del_timer(ifp);
1510 		ifp->flags |= IFA_F_TENTATIVE;
1511 		if (dad_failed)
1512 			ifp->flags |= IFA_F_DADFAILED;
1513 		spin_unlock_bh(&ifp->lock);
1514 		if (dad_failed)
1515 			ipv6_ifa_notify(0, ifp);
1516 		in6_ifa_put(ifp);
1517 #ifdef CONFIG_IPV6_PRIVACY
1518 	} else if (ifp->flags&IFA_F_TEMPORARY) {
1519 		struct inet6_ifaddr *ifpub;
1520 		spin_lock_bh(&ifp->lock);
1521 		ifpub = ifp->ifpub;
1522 		if (ifpub) {
1523 			in6_ifa_hold(ifpub);
1524 			spin_unlock_bh(&ifp->lock);
1525 			ipv6_create_tempaddr(ifpub, ifp);
1526 			in6_ifa_put(ifpub);
1527 		} else {
1528 			spin_unlock_bh(&ifp->lock);
1529 		}
1530 		ipv6_del_addr(ifp);
1531 #endif
1532 	} else
1533 		ipv6_del_addr(ifp);
1534 }
1535 
1536 static int addrconf_dad_end(struct inet6_ifaddr *ifp)
1537 {
1538 	int err = -ENOENT;
1539 
1540 	spin_lock(&ifp->state_lock);
1541 	if (ifp->state == INET6_IFADDR_STATE_DAD) {
1542 		ifp->state = INET6_IFADDR_STATE_POSTDAD;
1543 		err = 0;
1544 	}
1545 	spin_unlock(&ifp->state_lock);
1546 
1547 	return err;
1548 }
1549 
1550 void addrconf_dad_failure(struct inet6_ifaddr *ifp)
1551 {
1552 	struct inet6_dev *idev = ifp->idev;
1553 
1554 	if (addrconf_dad_end(ifp)) {
1555 		in6_ifa_put(ifp);
1556 		return;
1557 	}
1558 
1559 	net_info_ratelimited("%s: IPv6 duplicate address %pI6c detected!\n",
1560 			     ifp->idev->dev->name, &ifp->addr);
1561 
1562 	if (idev->cnf.accept_dad > 1 && !idev->cnf.disable_ipv6) {
1563 		struct in6_addr addr;
1564 
1565 		addr.s6_addr32[0] = htonl(0xfe800000);
1566 		addr.s6_addr32[1] = 0;
1567 
1568 		if (!ipv6_generate_eui64(addr.s6_addr + 8, idev->dev) &&
1569 		    ipv6_addr_equal(&ifp->addr, &addr)) {
1570 			/* DAD failed for link-local based on MAC address */
1571 			idev->cnf.disable_ipv6 = 1;
1572 
1573 			pr_info("%s: IPv6 being disabled!\n",
1574 				ifp->idev->dev->name);
1575 		}
1576 	}
1577 
1578 	addrconf_dad_stop(ifp, 1);
1579 }
1580 
1581 /* Join to solicited addr multicast group. */
1582 
1583 void addrconf_join_solict(struct net_device *dev, const struct in6_addr *addr)
1584 {
1585 	struct in6_addr maddr;
1586 
1587 	if (dev->flags&(IFF_LOOPBACK|IFF_NOARP))
1588 		return;
1589 
1590 	addrconf_addr_solict_mult(addr, &maddr);
1591 	ipv6_dev_mc_inc(dev, &maddr);
1592 }
1593 
1594 void addrconf_leave_solict(struct inet6_dev *idev, const struct in6_addr *addr)
1595 {
1596 	struct in6_addr maddr;
1597 
1598 	if (idev->dev->flags&(IFF_LOOPBACK|IFF_NOARP))
1599 		return;
1600 
1601 	addrconf_addr_solict_mult(addr, &maddr);
1602 	__ipv6_dev_mc_dec(idev, &maddr);
1603 }
1604 
1605 static void addrconf_join_anycast(struct inet6_ifaddr *ifp)
1606 {
1607 	struct in6_addr addr;
1608 	if (ifp->prefix_len == 127) /* RFC 6164 */
1609 		return;
1610 	ipv6_addr_prefix(&addr, &ifp->addr, ifp->prefix_len);
1611 	if (ipv6_addr_any(&addr))
1612 		return;
1613 	ipv6_dev_ac_inc(ifp->idev->dev, &addr);
1614 }
1615 
1616 static void addrconf_leave_anycast(struct inet6_ifaddr *ifp)
1617 {
1618 	struct in6_addr addr;
1619 	if (ifp->prefix_len == 127) /* RFC 6164 */
1620 		return;
1621 	ipv6_addr_prefix(&addr, &ifp->addr, ifp->prefix_len);
1622 	if (ipv6_addr_any(&addr))
1623 		return;
1624 	__ipv6_dev_ac_dec(ifp->idev, &addr);
1625 }
1626 
1627 static int addrconf_ifid_eui48(u8 *eui, struct net_device *dev)
1628 {
1629 	if (dev->addr_len != ETH_ALEN)
1630 		return -1;
1631 	memcpy(eui, dev->dev_addr, 3);
1632 	memcpy(eui + 5, dev->dev_addr + 3, 3);
1633 
1634 	/*
1635 	 * The zSeries OSA network cards can be shared among various
1636 	 * OS instances, but the OSA cards have only one MAC address.
1637 	 * This leads to duplicate address conflicts in conjunction
1638 	 * with IPv6 if more than one instance uses the same card.
1639 	 *
1640 	 * The driver for these cards can deliver a unique 16-bit
1641 	 * identifier for each instance sharing the same card.  It is
1642 	 * placed instead of 0xFFFE in the interface identifier.  The
1643 	 * "u" bit of the interface identifier is not inverted in this
1644 	 * case.  Hence the resulting interface identifier has local
1645 	 * scope according to RFC2373.
1646 	 */
1647 	if (dev->dev_id) {
1648 		eui[3] = (dev->dev_id >> 8) & 0xFF;
1649 		eui[4] = dev->dev_id & 0xFF;
1650 	} else {
1651 		eui[3] = 0xFF;
1652 		eui[4] = 0xFE;
1653 		eui[0] ^= 2;
1654 	}
1655 	return 0;
1656 }
1657 
1658 static int addrconf_ifid_eui64(u8 *eui, struct net_device *dev)
1659 {
1660 	if (dev->addr_len != IEEE802154_ADDR_LEN)
1661 		return -1;
1662 	memcpy(eui, dev->dev_addr, 8);
1663 	eui[0] ^= 2;
1664 	return 0;
1665 }
1666 
1667 static int addrconf_ifid_arcnet(u8 *eui, struct net_device *dev)
1668 {
1669 	/* XXX: inherit EUI-64 from other interface -- yoshfuji */
1670 	if (dev->addr_len != ARCNET_ALEN)
1671 		return -1;
1672 	memset(eui, 0, 7);
1673 	eui[7] = *(u8 *)dev->dev_addr;
1674 	return 0;
1675 }
1676 
1677 static int addrconf_ifid_infiniband(u8 *eui, struct net_device *dev)
1678 {
1679 	if (dev->addr_len != INFINIBAND_ALEN)
1680 		return -1;
1681 	memcpy(eui, dev->dev_addr + 12, 8);
1682 	eui[0] |= 2;
1683 	return 0;
1684 }
1685 
1686 static int __ipv6_isatap_ifid(u8 *eui, __be32 addr)
1687 {
1688 	if (addr == 0)
1689 		return -1;
1690 	eui[0] = (ipv4_is_zeronet(addr) || ipv4_is_private_10(addr) ||
1691 		  ipv4_is_loopback(addr) || ipv4_is_linklocal_169(addr) ||
1692 		  ipv4_is_private_172(addr) || ipv4_is_test_192(addr) ||
1693 		  ipv4_is_anycast_6to4(addr) || ipv4_is_private_192(addr) ||
1694 		  ipv4_is_test_198(addr) || ipv4_is_multicast(addr) ||
1695 		  ipv4_is_lbcast(addr)) ? 0x00 : 0x02;
1696 	eui[1] = 0;
1697 	eui[2] = 0x5E;
1698 	eui[3] = 0xFE;
1699 	memcpy(eui + 4, &addr, 4);
1700 	return 0;
1701 }
1702 
1703 static int addrconf_ifid_sit(u8 *eui, struct net_device *dev)
1704 {
1705 	if (dev->priv_flags & IFF_ISATAP)
1706 		return __ipv6_isatap_ifid(eui, *(__be32 *)dev->dev_addr);
1707 	return -1;
1708 }
1709 
1710 static int addrconf_ifid_gre(u8 *eui, struct net_device *dev)
1711 {
1712 	return __ipv6_isatap_ifid(eui, *(__be32 *)dev->dev_addr);
1713 }
1714 
1715 static int ipv6_generate_eui64(u8 *eui, struct net_device *dev)
1716 {
1717 	switch (dev->type) {
1718 	case ARPHRD_ETHER:
1719 	case ARPHRD_FDDI:
1720 		return addrconf_ifid_eui48(eui, dev);
1721 	case ARPHRD_ARCNET:
1722 		return addrconf_ifid_arcnet(eui, dev);
1723 	case ARPHRD_INFINIBAND:
1724 		return addrconf_ifid_infiniband(eui, dev);
1725 	case ARPHRD_SIT:
1726 		return addrconf_ifid_sit(eui, dev);
1727 	case ARPHRD_IPGRE:
1728 		return addrconf_ifid_gre(eui, dev);
1729 	case ARPHRD_IEEE802154:
1730 		return addrconf_ifid_eui64(eui, dev);
1731 	}
1732 	return -1;
1733 }
1734 
1735 static int ipv6_inherit_eui64(u8 *eui, struct inet6_dev *idev)
1736 {
1737 	int err = -1;
1738 	struct inet6_ifaddr *ifp;
1739 
1740 	read_lock_bh(&idev->lock);
1741 	list_for_each_entry(ifp, &idev->addr_list, if_list) {
1742 		if (ifp->scope == IFA_LINK && !(ifp->flags&IFA_F_TENTATIVE)) {
1743 			memcpy(eui, ifp->addr.s6_addr+8, 8);
1744 			err = 0;
1745 			break;
1746 		}
1747 	}
1748 	read_unlock_bh(&idev->lock);
1749 	return err;
1750 }
1751 
1752 #ifdef CONFIG_IPV6_PRIVACY
1753 /* (re)generation of randomized interface identifier (RFC 3041 3.2, 3.5) */
1754 static void __ipv6_regen_rndid(struct inet6_dev *idev)
1755 {
1756 regen:
1757 	get_random_bytes(idev->rndid, sizeof(idev->rndid));
1758 	idev->rndid[0] &= ~0x02;
1759 
1760 	/*
1761 	 * <draft-ietf-ipngwg-temp-addresses-v2-00.txt>:
1762 	 * check if generated address is not inappropriate
1763 	 *
1764 	 *  - Reserved subnet anycast (RFC 2526)
1765 	 *	11111101 11....11 1xxxxxxx
1766 	 *  - ISATAP (RFC4214) 6.1
1767 	 *	00-00-5E-FE-xx-xx-xx-xx
1768 	 *  - value 0
1769 	 *  - XXX: already assigned to an address on the device
1770 	 */
1771 	if (idev->rndid[0] == 0xfd &&
1772 	    (idev->rndid[1]&idev->rndid[2]&idev->rndid[3]&idev->rndid[4]&idev->rndid[5]&idev->rndid[6]) == 0xff &&
1773 	    (idev->rndid[7]&0x80))
1774 		goto regen;
1775 	if ((idev->rndid[0]|idev->rndid[1]) == 0) {
1776 		if (idev->rndid[2] == 0x5e && idev->rndid[3] == 0xfe)
1777 			goto regen;
1778 		if ((idev->rndid[2]|idev->rndid[3]|idev->rndid[4]|idev->rndid[5]|idev->rndid[6]|idev->rndid[7]) == 0x00)
1779 			goto regen;
1780 	}
1781 }
1782 
1783 static void ipv6_regen_rndid(unsigned long data)
1784 {
1785 	struct inet6_dev *idev = (struct inet6_dev *) data;
1786 	unsigned long expires;
1787 
1788 	rcu_read_lock_bh();
1789 	write_lock_bh(&idev->lock);
1790 
1791 	if (idev->dead)
1792 		goto out;
1793 
1794 	__ipv6_regen_rndid(idev);
1795 
1796 	expires = jiffies +
1797 		idev->cnf.temp_prefered_lft * HZ -
1798 		idev->cnf.regen_max_retry * idev->cnf.dad_transmits * idev->nd_parms->retrans_time -
1799 		idev->cnf.max_desync_factor * HZ;
1800 	if (time_before(expires, jiffies)) {
1801 		pr_warn("%s: too short regeneration interval; timer disabled for %s\n",
1802 			__func__, idev->dev->name);
1803 		goto out;
1804 	}
1805 
1806 	if (!mod_timer(&idev->regen_timer, expires))
1807 		in6_dev_hold(idev);
1808 
1809 out:
1810 	write_unlock_bh(&idev->lock);
1811 	rcu_read_unlock_bh();
1812 	in6_dev_put(idev);
1813 }
1814 
1815 static void  __ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr)
1816 {
1817 	if (tmpaddr && memcmp(idev->rndid, &tmpaddr->s6_addr[8], 8) == 0)
1818 		__ipv6_regen_rndid(idev);
1819 }
1820 #endif
1821 
1822 /*
1823  *	Add prefix route.
1824  */
1825 
1826 static void
1827 addrconf_prefix_route(struct in6_addr *pfx, int plen, struct net_device *dev,
1828 		      unsigned long expires, u32 flags)
1829 {
1830 	struct fib6_config cfg = {
1831 		.fc_table = RT6_TABLE_PREFIX,
1832 		.fc_metric = IP6_RT_PRIO_ADDRCONF,
1833 		.fc_ifindex = dev->ifindex,
1834 		.fc_expires = expires,
1835 		.fc_dst_len = plen,
1836 		.fc_flags = RTF_UP | flags,
1837 		.fc_nlinfo.nl_net = dev_net(dev),
1838 		.fc_protocol = RTPROT_KERNEL,
1839 	};
1840 
1841 	cfg.fc_dst = *pfx;
1842 
1843 	/* Prevent useless cloning on PtP SIT.
1844 	   This thing is done here expecting that the whole
1845 	   class of non-broadcast devices need not cloning.
1846 	 */
1847 #if IS_ENABLED(CONFIG_IPV6_SIT)
1848 	if (dev->type == ARPHRD_SIT && (dev->flags & IFF_POINTOPOINT))
1849 		cfg.fc_flags |= RTF_NONEXTHOP;
1850 #endif
1851 
1852 	ip6_route_add(&cfg);
1853 }
1854 
1855 
1856 static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
1857 						  int plen,
1858 						  const struct net_device *dev,
1859 						  u32 flags, u32 noflags)
1860 {
1861 	struct fib6_node *fn;
1862 	struct rt6_info *rt = NULL;
1863 	struct fib6_table *table;
1864 
1865 	table = fib6_get_table(dev_net(dev), RT6_TABLE_PREFIX);
1866 	if (table == NULL)
1867 		return NULL;
1868 
1869 	read_lock_bh(&table->tb6_lock);
1870 	fn = fib6_locate(&table->tb6_root, pfx, plen, NULL, 0);
1871 	if (!fn)
1872 		goto out;
1873 	for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
1874 		if (rt->dst.dev->ifindex != dev->ifindex)
1875 			continue;
1876 		if ((rt->rt6i_flags & flags) != flags)
1877 			continue;
1878 		if ((rt->rt6i_flags & noflags) != 0)
1879 			continue;
1880 		dst_hold(&rt->dst);
1881 		break;
1882 	}
1883 out:
1884 	read_unlock_bh(&table->tb6_lock);
1885 	return rt;
1886 }
1887 
1888 
1889 /* Create "default" multicast route to the interface */
1890 
1891 static void addrconf_add_mroute(struct net_device *dev)
1892 {
1893 	struct fib6_config cfg = {
1894 		.fc_table = RT6_TABLE_LOCAL,
1895 		.fc_metric = IP6_RT_PRIO_ADDRCONF,
1896 		.fc_ifindex = dev->ifindex,
1897 		.fc_dst_len = 8,
1898 		.fc_flags = RTF_UP,
1899 		.fc_nlinfo.nl_net = dev_net(dev),
1900 	};
1901 
1902 	ipv6_addr_set(&cfg.fc_dst, htonl(0xFF000000), 0, 0, 0);
1903 
1904 	ip6_route_add(&cfg);
1905 }
1906 
1907 #if IS_ENABLED(CONFIG_IPV6_SIT)
1908 static void sit_route_add(struct net_device *dev)
1909 {
1910 	struct fib6_config cfg = {
1911 		.fc_table = RT6_TABLE_MAIN,
1912 		.fc_metric = IP6_RT_PRIO_ADDRCONF,
1913 		.fc_ifindex = dev->ifindex,
1914 		.fc_dst_len = 96,
1915 		.fc_flags = RTF_UP | RTF_NONEXTHOP,
1916 		.fc_nlinfo.nl_net = dev_net(dev),
1917 	};
1918 
1919 	/* prefix length - 96 bits "::d.d.d.d" */
1920 	ip6_route_add(&cfg);
1921 }
1922 #endif
1923 
1924 static struct inet6_dev *addrconf_add_dev(struct net_device *dev)
1925 {
1926 	struct inet6_dev *idev;
1927 
1928 	ASSERT_RTNL();
1929 
1930 	idev = ipv6_find_idev(dev);
1931 	if (!idev)
1932 		return ERR_PTR(-ENOBUFS);
1933 
1934 	if (idev->cnf.disable_ipv6)
1935 		return ERR_PTR(-EACCES);
1936 
1937 	/* Add default multicast route */
1938 	if (!(dev->flags & IFF_LOOPBACK))
1939 		addrconf_add_mroute(dev);
1940 
1941 	return idev;
1942 }
1943 
1944 void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao)
1945 {
1946 	struct prefix_info *pinfo;
1947 	__u32 valid_lft;
1948 	__u32 prefered_lft;
1949 	int addr_type;
1950 	struct inet6_dev *in6_dev;
1951 	struct net *net = dev_net(dev);
1952 
1953 	pinfo = (struct prefix_info *) opt;
1954 
1955 	if (len < sizeof(struct prefix_info)) {
1956 		ADBG(("addrconf: prefix option too short\n"));
1957 		return;
1958 	}
1959 
1960 	/*
1961 	 *	Validation checks ([ADDRCONF], page 19)
1962 	 */
1963 
1964 	addr_type = ipv6_addr_type(&pinfo->prefix);
1965 
1966 	if (addr_type & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL))
1967 		return;
1968 
1969 	valid_lft = ntohl(pinfo->valid);
1970 	prefered_lft = ntohl(pinfo->prefered);
1971 
1972 	if (prefered_lft > valid_lft) {
1973 		net_warn_ratelimited("addrconf: prefix option has invalid lifetime\n");
1974 		return;
1975 	}
1976 
1977 	in6_dev = in6_dev_get(dev);
1978 
1979 	if (in6_dev == NULL) {
1980 		net_dbg_ratelimited("addrconf: device %s not configured\n",
1981 				    dev->name);
1982 		return;
1983 	}
1984 
1985 	/*
1986 	 *	Two things going on here:
1987 	 *	1) Add routes for on-link prefixes
1988 	 *	2) Configure prefixes with the auto flag set
1989 	 */
1990 
1991 	if (pinfo->onlink) {
1992 		struct rt6_info *rt;
1993 		unsigned long rt_expires;
1994 
1995 		/* Avoid arithmetic overflow. Really, we could
1996 		 * save rt_expires in seconds, likely valid_lft,
1997 		 * but it would require division in fib gc, that it
1998 		 * not good.
1999 		 */
2000 		if (HZ > USER_HZ)
2001 			rt_expires = addrconf_timeout_fixup(valid_lft, HZ);
2002 		else
2003 			rt_expires = addrconf_timeout_fixup(valid_lft, USER_HZ);
2004 
2005 		if (addrconf_finite_timeout(rt_expires))
2006 			rt_expires *= HZ;
2007 
2008 		rt = addrconf_get_prefix_route(&pinfo->prefix,
2009 					       pinfo->prefix_len,
2010 					       dev,
2011 					       RTF_ADDRCONF | RTF_PREFIX_RT,
2012 					       RTF_GATEWAY | RTF_DEFAULT);
2013 
2014 		if (rt) {
2015 			/* Autoconf prefix route */
2016 			if (valid_lft == 0) {
2017 				ip6_del_rt(rt);
2018 				rt = NULL;
2019 			} else if (addrconf_finite_timeout(rt_expires)) {
2020 				/* not infinity */
2021 				rt6_set_expires(rt, jiffies + rt_expires);
2022 			} else {
2023 				rt6_clean_expires(rt);
2024 			}
2025 		} else if (valid_lft) {
2026 			clock_t expires = 0;
2027 			int flags = RTF_ADDRCONF | RTF_PREFIX_RT;
2028 			if (addrconf_finite_timeout(rt_expires)) {
2029 				/* not infinity */
2030 				flags |= RTF_EXPIRES;
2031 				expires = jiffies_to_clock_t(rt_expires);
2032 			}
2033 			addrconf_prefix_route(&pinfo->prefix, pinfo->prefix_len,
2034 					      dev, expires, flags);
2035 		}
2036 		ip6_rt_put(rt);
2037 	}
2038 
2039 	/* Try to figure out our local address for this prefix */
2040 
2041 	if (pinfo->autoconf && in6_dev->cnf.autoconf) {
2042 		struct inet6_ifaddr *ifp;
2043 		struct in6_addr addr;
2044 		int create = 0, update_lft = 0;
2045 
2046 		if (pinfo->prefix_len == 64) {
2047 			memcpy(&addr, &pinfo->prefix, 8);
2048 			if (ipv6_generate_eui64(addr.s6_addr + 8, dev) &&
2049 			    ipv6_inherit_eui64(addr.s6_addr + 8, in6_dev)) {
2050 				in6_dev_put(in6_dev);
2051 				return;
2052 			}
2053 			goto ok;
2054 		}
2055 		net_dbg_ratelimited("IPv6 addrconf: prefix with wrong length %d\n",
2056 				    pinfo->prefix_len);
2057 		in6_dev_put(in6_dev);
2058 		return;
2059 
2060 ok:
2061 
2062 		ifp = ipv6_get_ifaddr(net, &addr, dev, 1);
2063 
2064 		if (ifp == NULL && valid_lft) {
2065 			int max_addresses = in6_dev->cnf.max_addresses;
2066 			u32 addr_flags = 0;
2067 
2068 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
2069 			if (in6_dev->cnf.optimistic_dad &&
2070 			    !net->ipv6.devconf_all->forwarding && sllao)
2071 				addr_flags = IFA_F_OPTIMISTIC;
2072 #endif
2073 
2074 			/* Do not allow to create too much of autoconfigured
2075 			 * addresses; this would be too easy way to crash kernel.
2076 			 */
2077 			if (!max_addresses ||
2078 			    ipv6_count_addresses(in6_dev) < max_addresses)
2079 				ifp = ipv6_add_addr(in6_dev, &addr, pinfo->prefix_len,
2080 						    addr_type&IPV6_ADDR_SCOPE_MASK,
2081 						    addr_flags);
2082 
2083 			if (!ifp || IS_ERR(ifp)) {
2084 				in6_dev_put(in6_dev);
2085 				return;
2086 			}
2087 
2088 			update_lft = create = 1;
2089 			ifp->cstamp = jiffies;
2090 			addrconf_dad_start(ifp);
2091 		}
2092 
2093 		if (ifp) {
2094 			int flags;
2095 			unsigned long now;
2096 #ifdef CONFIG_IPV6_PRIVACY
2097 			struct inet6_ifaddr *ift;
2098 #endif
2099 			u32 stored_lft;
2100 
2101 			/* update lifetime (RFC2462 5.5.3 e) */
2102 			spin_lock(&ifp->lock);
2103 			now = jiffies;
2104 			if (ifp->valid_lft > (now - ifp->tstamp) / HZ)
2105 				stored_lft = ifp->valid_lft - (now - ifp->tstamp) / HZ;
2106 			else
2107 				stored_lft = 0;
2108 			if (!update_lft && stored_lft) {
2109 				if (valid_lft > MIN_VALID_LIFETIME ||
2110 				    valid_lft > stored_lft)
2111 					update_lft = 1;
2112 				else if (stored_lft <= MIN_VALID_LIFETIME) {
2113 					/* valid_lft <= stored_lft is always true */
2114 					/*
2115 					 * RFC 4862 Section 5.5.3e:
2116 					 * "Note that the preferred lifetime of
2117 					 *  the corresponding address is always
2118 					 *  reset to the Preferred Lifetime in
2119 					 *  the received Prefix Information
2120 					 *  option, regardless of whether the
2121 					 *  valid lifetime is also reset or
2122 					 *  ignored."
2123 					 *
2124 					 *  So if the preferred lifetime in
2125 					 *  this advertisement is different
2126 					 *  than what we have stored, but the
2127 					 *  valid lifetime is invalid, just
2128 					 *  reset prefered_lft.
2129 					 *
2130 					 *  We must set the valid lifetime
2131 					 *  to the stored lifetime since we'll
2132 					 *  be updating the timestamp below,
2133 					 *  else we'll set it back to the
2134 					 *  minimum.
2135 					 */
2136 					if (prefered_lft != ifp->prefered_lft) {
2137 						valid_lft = stored_lft;
2138 						update_lft = 1;
2139 					}
2140 				} else {
2141 					valid_lft = MIN_VALID_LIFETIME;
2142 					if (valid_lft < prefered_lft)
2143 						prefered_lft = valid_lft;
2144 					update_lft = 1;
2145 				}
2146 			}
2147 
2148 			if (update_lft) {
2149 				ifp->valid_lft = valid_lft;
2150 				ifp->prefered_lft = prefered_lft;
2151 				ifp->tstamp = now;
2152 				flags = ifp->flags;
2153 				ifp->flags &= ~IFA_F_DEPRECATED;
2154 				spin_unlock(&ifp->lock);
2155 
2156 				if (!(flags&IFA_F_TENTATIVE))
2157 					ipv6_ifa_notify(0, ifp);
2158 			} else
2159 				spin_unlock(&ifp->lock);
2160 
2161 #ifdef CONFIG_IPV6_PRIVACY
2162 			read_lock_bh(&in6_dev->lock);
2163 			/* update all temporary addresses in the list */
2164 			list_for_each_entry(ift, &in6_dev->tempaddr_list,
2165 					    tmp_list) {
2166 				int age, max_valid, max_prefered;
2167 
2168 				if (ifp != ift->ifpub)
2169 					continue;
2170 
2171 				/*
2172 				 * RFC 4941 section 3.3:
2173 				 * If a received option will extend the lifetime
2174 				 * of a public address, the lifetimes of
2175 				 * temporary addresses should be extended,
2176 				 * subject to the overall constraint that no
2177 				 * temporary addresses should ever remain
2178 				 * "valid" or "preferred" for a time longer than
2179 				 * (TEMP_VALID_LIFETIME) or
2180 				 * (TEMP_PREFERRED_LIFETIME - DESYNC_FACTOR),
2181 				 * respectively.
2182 				 */
2183 				age = (now - ift->cstamp) / HZ;
2184 				max_valid = in6_dev->cnf.temp_valid_lft - age;
2185 				if (max_valid < 0)
2186 					max_valid = 0;
2187 
2188 				max_prefered = in6_dev->cnf.temp_prefered_lft -
2189 					       in6_dev->cnf.max_desync_factor -
2190 					       age;
2191 				if (max_prefered < 0)
2192 					max_prefered = 0;
2193 
2194 				if (valid_lft > max_valid)
2195 					valid_lft = max_valid;
2196 
2197 				if (prefered_lft > max_prefered)
2198 					prefered_lft = max_prefered;
2199 
2200 				spin_lock(&ift->lock);
2201 				flags = ift->flags;
2202 				ift->valid_lft = valid_lft;
2203 				ift->prefered_lft = prefered_lft;
2204 				ift->tstamp = now;
2205 				if (prefered_lft > 0)
2206 					ift->flags &= ~IFA_F_DEPRECATED;
2207 
2208 				spin_unlock(&ift->lock);
2209 				if (!(flags&IFA_F_TENTATIVE))
2210 					ipv6_ifa_notify(0, ift);
2211 			}
2212 
2213 			if ((create || list_empty(&in6_dev->tempaddr_list)) && in6_dev->cnf.use_tempaddr > 0) {
2214 				/*
2215 				 * When a new public address is created as
2216 				 * described in [ADDRCONF], also create a new
2217 				 * temporary address. Also create a temporary
2218 				 * address if it's enabled but no temporary
2219 				 * address currently exists.
2220 				 */
2221 				read_unlock_bh(&in6_dev->lock);
2222 				ipv6_create_tempaddr(ifp, NULL);
2223 			} else {
2224 				read_unlock_bh(&in6_dev->lock);
2225 			}
2226 #endif
2227 			in6_ifa_put(ifp);
2228 			addrconf_verify(0);
2229 		}
2230 	}
2231 	inet6_prefix_notify(RTM_NEWPREFIX, in6_dev, pinfo);
2232 	in6_dev_put(in6_dev);
2233 }
2234 
2235 /*
2236  *	Set destination address.
2237  *	Special case for SIT interfaces where we create a new "virtual"
2238  *	device.
2239  */
2240 int addrconf_set_dstaddr(struct net *net, void __user *arg)
2241 {
2242 	struct in6_ifreq ireq;
2243 	struct net_device *dev;
2244 	int err = -EINVAL;
2245 
2246 	rtnl_lock();
2247 
2248 	err = -EFAULT;
2249 	if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
2250 		goto err_exit;
2251 
2252 	dev = __dev_get_by_index(net, ireq.ifr6_ifindex);
2253 
2254 	err = -ENODEV;
2255 	if (dev == NULL)
2256 		goto err_exit;
2257 
2258 #if IS_ENABLED(CONFIG_IPV6_SIT)
2259 	if (dev->type == ARPHRD_SIT) {
2260 		const struct net_device_ops *ops = dev->netdev_ops;
2261 		struct ifreq ifr;
2262 		struct ip_tunnel_parm p;
2263 
2264 		err = -EADDRNOTAVAIL;
2265 		if (!(ipv6_addr_type(&ireq.ifr6_addr) & IPV6_ADDR_COMPATv4))
2266 			goto err_exit;
2267 
2268 		memset(&p, 0, sizeof(p));
2269 		p.iph.daddr = ireq.ifr6_addr.s6_addr32[3];
2270 		p.iph.saddr = 0;
2271 		p.iph.version = 4;
2272 		p.iph.ihl = 5;
2273 		p.iph.protocol = IPPROTO_IPV6;
2274 		p.iph.ttl = 64;
2275 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
2276 
2277 		if (ops->ndo_do_ioctl) {
2278 			mm_segment_t oldfs = get_fs();
2279 
2280 			set_fs(KERNEL_DS);
2281 			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
2282 			set_fs(oldfs);
2283 		} else
2284 			err = -EOPNOTSUPP;
2285 
2286 		if (err == 0) {
2287 			err = -ENOBUFS;
2288 			dev = __dev_get_by_name(net, p.name);
2289 			if (!dev)
2290 				goto err_exit;
2291 			err = dev_open(dev);
2292 		}
2293 	}
2294 #endif
2295 
2296 err_exit:
2297 	rtnl_unlock();
2298 	return err;
2299 }
2300 
2301 /*
2302  *	Manual configuration of address on an interface
2303  */
2304 static int inet6_addr_add(struct net *net, int ifindex, const struct in6_addr *pfx,
2305 			  unsigned int plen, __u8 ifa_flags, __u32 prefered_lft,
2306 			  __u32 valid_lft)
2307 {
2308 	struct inet6_ifaddr *ifp;
2309 	struct inet6_dev *idev;
2310 	struct net_device *dev;
2311 	int scope;
2312 	u32 flags;
2313 	clock_t expires;
2314 	unsigned long timeout;
2315 
2316 	ASSERT_RTNL();
2317 
2318 	if (plen > 128)
2319 		return -EINVAL;
2320 
2321 	/* check the lifetime */
2322 	if (!valid_lft || prefered_lft > valid_lft)
2323 		return -EINVAL;
2324 
2325 	dev = __dev_get_by_index(net, ifindex);
2326 	if (!dev)
2327 		return -ENODEV;
2328 
2329 	idev = addrconf_add_dev(dev);
2330 	if (IS_ERR(idev))
2331 		return PTR_ERR(idev);
2332 
2333 	scope = ipv6_addr_scope(pfx);
2334 
2335 	timeout = addrconf_timeout_fixup(valid_lft, HZ);
2336 	if (addrconf_finite_timeout(timeout)) {
2337 		expires = jiffies_to_clock_t(timeout * HZ);
2338 		valid_lft = timeout;
2339 		flags = RTF_EXPIRES;
2340 	} else {
2341 		expires = 0;
2342 		flags = 0;
2343 		ifa_flags |= IFA_F_PERMANENT;
2344 	}
2345 
2346 	timeout = addrconf_timeout_fixup(prefered_lft, HZ);
2347 	if (addrconf_finite_timeout(timeout)) {
2348 		if (timeout == 0)
2349 			ifa_flags |= IFA_F_DEPRECATED;
2350 		prefered_lft = timeout;
2351 	}
2352 
2353 	ifp = ipv6_add_addr(idev, pfx, plen, scope, ifa_flags);
2354 
2355 	if (!IS_ERR(ifp)) {
2356 		spin_lock_bh(&ifp->lock);
2357 		ifp->valid_lft = valid_lft;
2358 		ifp->prefered_lft = prefered_lft;
2359 		ifp->tstamp = jiffies;
2360 		spin_unlock_bh(&ifp->lock);
2361 
2362 		addrconf_prefix_route(&ifp->addr, ifp->prefix_len, dev,
2363 				      expires, flags);
2364 		/*
2365 		 * Note that section 3.1 of RFC 4429 indicates
2366 		 * that the Optimistic flag should not be set for
2367 		 * manually configured addresses
2368 		 */
2369 		addrconf_dad_start(ifp);
2370 		in6_ifa_put(ifp);
2371 		addrconf_verify(0);
2372 		return 0;
2373 	}
2374 
2375 	return PTR_ERR(ifp);
2376 }
2377 
2378 static int inet6_addr_del(struct net *net, int ifindex, const struct in6_addr *pfx,
2379 			  unsigned int plen)
2380 {
2381 	struct inet6_ifaddr *ifp;
2382 	struct inet6_dev *idev;
2383 	struct net_device *dev;
2384 
2385 	if (plen > 128)
2386 		return -EINVAL;
2387 
2388 	dev = __dev_get_by_index(net, ifindex);
2389 	if (!dev)
2390 		return -ENODEV;
2391 
2392 	if ((idev = __in6_dev_get(dev)) == NULL)
2393 		return -ENXIO;
2394 
2395 	read_lock_bh(&idev->lock);
2396 	list_for_each_entry(ifp, &idev->addr_list, if_list) {
2397 		if (ifp->prefix_len == plen &&
2398 		    ipv6_addr_equal(pfx, &ifp->addr)) {
2399 			in6_ifa_hold(ifp);
2400 			read_unlock_bh(&idev->lock);
2401 
2402 			ipv6_del_addr(ifp);
2403 
2404 			/* If the last address is deleted administratively,
2405 			   disable IPv6 on this interface.
2406 			 */
2407 			if (list_empty(&idev->addr_list))
2408 				addrconf_ifdown(idev->dev, 1);
2409 			return 0;
2410 		}
2411 	}
2412 	read_unlock_bh(&idev->lock);
2413 	return -EADDRNOTAVAIL;
2414 }
2415 
2416 
2417 int addrconf_add_ifaddr(struct net *net, void __user *arg)
2418 {
2419 	struct in6_ifreq ireq;
2420 	int err;
2421 
2422 	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2423 		return -EPERM;
2424 
2425 	if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
2426 		return -EFAULT;
2427 
2428 	rtnl_lock();
2429 	err = inet6_addr_add(net, ireq.ifr6_ifindex, &ireq.ifr6_addr,
2430 			     ireq.ifr6_prefixlen, IFA_F_PERMANENT,
2431 			     INFINITY_LIFE_TIME, INFINITY_LIFE_TIME);
2432 	rtnl_unlock();
2433 	return err;
2434 }
2435 
2436 int addrconf_del_ifaddr(struct net *net, void __user *arg)
2437 {
2438 	struct in6_ifreq ireq;
2439 	int err;
2440 
2441 	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2442 		return -EPERM;
2443 
2444 	if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
2445 		return -EFAULT;
2446 
2447 	rtnl_lock();
2448 	err = inet6_addr_del(net, ireq.ifr6_ifindex, &ireq.ifr6_addr,
2449 			     ireq.ifr6_prefixlen);
2450 	rtnl_unlock();
2451 	return err;
2452 }
2453 
2454 static void add_addr(struct inet6_dev *idev, const struct in6_addr *addr,
2455 		     int plen, int scope)
2456 {
2457 	struct inet6_ifaddr *ifp;
2458 
2459 	ifp = ipv6_add_addr(idev, addr, plen, scope, IFA_F_PERMANENT);
2460 	if (!IS_ERR(ifp)) {
2461 		spin_lock_bh(&ifp->lock);
2462 		ifp->flags &= ~IFA_F_TENTATIVE;
2463 		spin_unlock_bh(&ifp->lock);
2464 		ipv6_ifa_notify(RTM_NEWADDR, ifp);
2465 		in6_ifa_put(ifp);
2466 	}
2467 }
2468 
2469 #if IS_ENABLED(CONFIG_IPV6_SIT)
2470 static void sit_add_v4_addrs(struct inet6_dev *idev)
2471 {
2472 	struct in6_addr addr;
2473 	struct net_device *dev;
2474 	struct net *net = dev_net(idev->dev);
2475 	int scope;
2476 
2477 	ASSERT_RTNL();
2478 
2479 	memset(&addr, 0, sizeof(struct in6_addr));
2480 	memcpy(&addr.s6_addr32[3], idev->dev->dev_addr, 4);
2481 
2482 	if (idev->dev->flags&IFF_POINTOPOINT) {
2483 		addr.s6_addr32[0] = htonl(0xfe800000);
2484 		scope = IFA_LINK;
2485 	} else {
2486 		scope = IPV6_ADDR_COMPATv4;
2487 	}
2488 
2489 	if (addr.s6_addr32[3]) {
2490 		add_addr(idev, &addr, 128, scope);
2491 		return;
2492 	}
2493 
2494 	for_each_netdev(net, dev) {
2495 		struct in_device *in_dev = __in_dev_get_rtnl(dev);
2496 		if (in_dev && (dev->flags & IFF_UP)) {
2497 			struct in_ifaddr *ifa;
2498 
2499 			int flag = scope;
2500 
2501 			for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
2502 				int plen;
2503 
2504 				addr.s6_addr32[3] = ifa->ifa_local;
2505 
2506 				if (ifa->ifa_scope == RT_SCOPE_LINK)
2507 					continue;
2508 				if (ifa->ifa_scope >= RT_SCOPE_HOST) {
2509 					if (idev->dev->flags&IFF_POINTOPOINT)
2510 						continue;
2511 					flag |= IFA_HOST;
2512 				}
2513 				if (idev->dev->flags&IFF_POINTOPOINT)
2514 					plen = 64;
2515 				else
2516 					plen = 96;
2517 
2518 				add_addr(idev, &addr, plen, flag);
2519 			}
2520 		}
2521 	}
2522 }
2523 #endif
2524 
2525 static void init_loopback(struct net_device *dev)
2526 {
2527 	struct inet6_dev  *idev;
2528 
2529 	/* ::1 */
2530 
2531 	ASSERT_RTNL();
2532 
2533 	if ((idev = ipv6_find_idev(dev)) == NULL) {
2534 		pr_debug("%s: add_dev failed\n", __func__);
2535 		return;
2536 	}
2537 
2538 	add_addr(idev, &in6addr_loopback, 128, IFA_HOST);
2539 }
2540 
2541 static void addrconf_add_linklocal(struct inet6_dev *idev, const struct in6_addr *addr)
2542 {
2543 	struct inet6_ifaddr *ifp;
2544 	u32 addr_flags = IFA_F_PERMANENT;
2545 
2546 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
2547 	if (idev->cnf.optimistic_dad &&
2548 	    !dev_net(idev->dev)->ipv6.devconf_all->forwarding)
2549 		addr_flags |= IFA_F_OPTIMISTIC;
2550 #endif
2551 
2552 
2553 	ifp = ipv6_add_addr(idev, addr, 64, IFA_LINK, addr_flags);
2554 	if (!IS_ERR(ifp)) {
2555 		addrconf_prefix_route(&ifp->addr, ifp->prefix_len, idev->dev, 0, 0);
2556 		addrconf_dad_start(ifp);
2557 		in6_ifa_put(ifp);
2558 	}
2559 }
2560 
2561 static void addrconf_dev_config(struct net_device *dev)
2562 {
2563 	struct in6_addr addr;
2564 	struct inet6_dev *idev;
2565 
2566 	ASSERT_RTNL();
2567 
2568 	if ((dev->type != ARPHRD_ETHER) &&
2569 	    (dev->type != ARPHRD_FDDI) &&
2570 	    (dev->type != ARPHRD_ARCNET) &&
2571 	    (dev->type != ARPHRD_INFINIBAND) &&
2572 	    (dev->type != ARPHRD_IEEE802154)) {
2573 		/* Alas, we support only Ethernet autoconfiguration. */
2574 		return;
2575 	}
2576 
2577 	idev = addrconf_add_dev(dev);
2578 	if (IS_ERR(idev))
2579 		return;
2580 
2581 	memset(&addr, 0, sizeof(struct in6_addr));
2582 	addr.s6_addr32[0] = htonl(0xFE800000);
2583 
2584 	if (ipv6_generate_eui64(addr.s6_addr + 8, dev) == 0)
2585 		addrconf_add_linklocal(idev, &addr);
2586 }
2587 
2588 #if IS_ENABLED(CONFIG_IPV6_SIT)
2589 static void addrconf_sit_config(struct net_device *dev)
2590 {
2591 	struct inet6_dev *idev;
2592 
2593 	ASSERT_RTNL();
2594 
2595 	/*
2596 	 * Configure the tunnel with one of our IPv4
2597 	 * addresses... we should configure all of
2598 	 * our v4 addrs in the tunnel
2599 	 */
2600 
2601 	if ((idev = ipv6_find_idev(dev)) == NULL) {
2602 		pr_debug("%s: add_dev failed\n", __func__);
2603 		return;
2604 	}
2605 
2606 	if (dev->priv_flags & IFF_ISATAP) {
2607 		struct in6_addr addr;
2608 
2609 		ipv6_addr_set(&addr,  htonl(0xFE800000), 0, 0, 0);
2610 		addrconf_prefix_route(&addr, 64, dev, 0, 0);
2611 		if (!ipv6_generate_eui64(addr.s6_addr + 8, dev))
2612 			addrconf_add_linklocal(idev, &addr);
2613 		return;
2614 	}
2615 
2616 	sit_add_v4_addrs(idev);
2617 
2618 	if (dev->flags&IFF_POINTOPOINT)
2619 		addrconf_add_mroute(dev);
2620 	else
2621 		sit_route_add(dev);
2622 }
2623 #endif
2624 
2625 #if IS_ENABLED(CONFIG_NET_IPGRE)
2626 static void addrconf_gre_config(struct net_device *dev)
2627 {
2628 	struct inet6_dev *idev;
2629 	struct in6_addr addr;
2630 
2631 	pr_info("%s(%s)\n", __func__, dev->name);
2632 
2633 	ASSERT_RTNL();
2634 
2635 	if ((idev = ipv6_find_idev(dev)) == NULL) {
2636 		pr_debug("%s: add_dev failed\n", __func__);
2637 		return;
2638 	}
2639 
2640 	ipv6_addr_set(&addr,  htonl(0xFE800000), 0, 0, 0);
2641 	addrconf_prefix_route(&addr, 64, dev, 0, 0);
2642 
2643 	if (!ipv6_generate_eui64(addr.s6_addr + 8, dev))
2644 		addrconf_add_linklocal(idev, &addr);
2645 }
2646 #endif
2647 
2648 static inline int
2649 ipv6_inherit_linklocal(struct inet6_dev *idev, struct net_device *link_dev)
2650 {
2651 	struct in6_addr lladdr;
2652 
2653 	if (!ipv6_get_lladdr(link_dev, &lladdr, IFA_F_TENTATIVE)) {
2654 		addrconf_add_linklocal(idev, &lladdr);
2655 		return 0;
2656 	}
2657 	return -1;
2658 }
2659 
2660 static void ip6_tnl_add_linklocal(struct inet6_dev *idev)
2661 {
2662 	struct net_device *link_dev;
2663 	struct net *net = dev_net(idev->dev);
2664 
2665 	/* first try to inherit the link-local address from the link device */
2666 	if (idev->dev->iflink &&
2667 	    (link_dev = __dev_get_by_index(net, idev->dev->iflink))) {
2668 		if (!ipv6_inherit_linklocal(idev, link_dev))
2669 			return;
2670 	}
2671 	/* then try to inherit it from any device */
2672 	for_each_netdev(net, link_dev) {
2673 		if (!ipv6_inherit_linklocal(idev, link_dev))
2674 			return;
2675 	}
2676 	pr_debug("init ip6-ip6: add_linklocal failed\n");
2677 }
2678 
2679 /*
2680  * Autoconfigure tunnel with a link-local address so routing protocols,
2681  * DHCPv6, MLD etc. can be run over the virtual link
2682  */
2683 
2684 static void addrconf_ip6_tnl_config(struct net_device *dev)
2685 {
2686 	struct inet6_dev *idev;
2687 
2688 	ASSERT_RTNL();
2689 
2690 	idev = addrconf_add_dev(dev);
2691 	if (IS_ERR(idev)) {
2692 		pr_debug("init ip6-ip6: add_dev failed\n");
2693 		return;
2694 	}
2695 	ip6_tnl_add_linklocal(idev);
2696 }
2697 
2698 static int addrconf_notify(struct notifier_block *this, unsigned long event,
2699 			   void *data)
2700 {
2701 	struct net_device *dev = (struct net_device *) data;
2702 	struct inet6_dev *idev = __in6_dev_get(dev);
2703 	int run_pending = 0;
2704 	int err;
2705 
2706 	switch (event) {
2707 	case NETDEV_REGISTER:
2708 		if (!idev && dev->mtu >= IPV6_MIN_MTU) {
2709 			idev = ipv6_add_dev(dev);
2710 			if (!idev)
2711 				return notifier_from_errno(-ENOMEM);
2712 		}
2713 		break;
2714 
2715 	case NETDEV_UP:
2716 	case NETDEV_CHANGE:
2717 		if (dev->flags & IFF_SLAVE)
2718 			break;
2719 
2720 		if (event == NETDEV_UP) {
2721 			if (!addrconf_qdisc_ok(dev)) {
2722 				/* device is not ready yet. */
2723 				pr_info("ADDRCONF(NETDEV_UP): %s: link is not ready\n",
2724 					dev->name);
2725 				break;
2726 			}
2727 
2728 			if (!idev && dev->mtu >= IPV6_MIN_MTU)
2729 				idev = ipv6_add_dev(dev);
2730 
2731 			if (idev) {
2732 				idev->if_flags |= IF_READY;
2733 				run_pending = 1;
2734 			}
2735 		} else {
2736 			if (!addrconf_qdisc_ok(dev)) {
2737 				/* device is still not ready. */
2738 				break;
2739 			}
2740 
2741 			if (idev) {
2742 				if (idev->if_flags & IF_READY)
2743 					/* device is already configured. */
2744 					break;
2745 				idev->if_flags |= IF_READY;
2746 			}
2747 
2748 			pr_info("ADDRCONF(NETDEV_CHANGE): %s: link becomes ready\n",
2749 				dev->name);
2750 
2751 			run_pending = 1;
2752 		}
2753 
2754 		switch (dev->type) {
2755 #if IS_ENABLED(CONFIG_IPV6_SIT)
2756 		case ARPHRD_SIT:
2757 			addrconf_sit_config(dev);
2758 			break;
2759 #endif
2760 #if IS_ENABLED(CONFIG_NET_IPGRE)
2761 		case ARPHRD_IPGRE:
2762 			addrconf_gre_config(dev);
2763 			break;
2764 #endif
2765 		case ARPHRD_TUNNEL6:
2766 			addrconf_ip6_tnl_config(dev);
2767 			break;
2768 		case ARPHRD_LOOPBACK:
2769 			init_loopback(dev);
2770 			break;
2771 
2772 		default:
2773 			addrconf_dev_config(dev);
2774 			break;
2775 		}
2776 
2777 		if (idev) {
2778 			if (run_pending)
2779 				addrconf_dad_run(idev);
2780 
2781 			/*
2782 			 * If the MTU changed during the interface down,
2783 			 * when the interface up, the changed MTU must be
2784 			 * reflected in the idev as well as routers.
2785 			 */
2786 			if (idev->cnf.mtu6 != dev->mtu &&
2787 			    dev->mtu >= IPV6_MIN_MTU) {
2788 				rt6_mtu_change(dev, dev->mtu);
2789 				idev->cnf.mtu6 = dev->mtu;
2790 			}
2791 			idev->tstamp = jiffies;
2792 			inet6_ifinfo_notify(RTM_NEWLINK, idev);
2793 
2794 			/*
2795 			 * If the changed mtu during down is lower than
2796 			 * IPV6_MIN_MTU stop IPv6 on this interface.
2797 			 */
2798 			if (dev->mtu < IPV6_MIN_MTU)
2799 				addrconf_ifdown(dev, 1);
2800 		}
2801 		break;
2802 
2803 	case NETDEV_CHANGEMTU:
2804 		if (idev && dev->mtu >= IPV6_MIN_MTU) {
2805 			rt6_mtu_change(dev, dev->mtu);
2806 			idev->cnf.mtu6 = dev->mtu;
2807 			break;
2808 		}
2809 
2810 		if (!idev && dev->mtu >= IPV6_MIN_MTU) {
2811 			idev = ipv6_add_dev(dev);
2812 			if (idev)
2813 				break;
2814 		}
2815 
2816 		/*
2817 		 * MTU falled under IPV6_MIN_MTU.
2818 		 * Stop IPv6 on this interface.
2819 		 */
2820 
2821 	case NETDEV_DOWN:
2822 	case NETDEV_UNREGISTER:
2823 		/*
2824 		 *	Remove all addresses from this interface.
2825 		 */
2826 		addrconf_ifdown(dev, event != NETDEV_DOWN);
2827 		break;
2828 
2829 	case NETDEV_CHANGENAME:
2830 		if (idev) {
2831 			snmp6_unregister_dev(idev);
2832 			addrconf_sysctl_unregister(idev);
2833 			addrconf_sysctl_register(idev);
2834 			err = snmp6_register_dev(idev);
2835 			if (err)
2836 				return notifier_from_errno(err);
2837 		}
2838 		break;
2839 
2840 	case NETDEV_PRE_TYPE_CHANGE:
2841 	case NETDEV_POST_TYPE_CHANGE:
2842 		addrconf_type_change(dev, event);
2843 		break;
2844 	}
2845 
2846 	return NOTIFY_OK;
2847 }
2848 
2849 /*
2850  *	addrconf module should be notified of a device going up
2851  */
2852 static struct notifier_block ipv6_dev_notf = {
2853 	.notifier_call = addrconf_notify,
2854 };
2855 
2856 static void addrconf_type_change(struct net_device *dev, unsigned long event)
2857 {
2858 	struct inet6_dev *idev;
2859 	ASSERT_RTNL();
2860 
2861 	idev = __in6_dev_get(dev);
2862 
2863 	if (event == NETDEV_POST_TYPE_CHANGE)
2864 		ipv6_mc_remap(idev);
2865 	else if (event == NETDEV_PRE_TYPE_CHANGE)
2866 		ipv6_mc_unmap(idev);
2867 }
2868 
2869 static int addrconf_ifdown(struct net_device *dev, int how)
2870 {
2871 	struct net *net = dev_net(dev);
2872 	struct inet6_dev *idev;
2873 	struct inet6_ifaddr *ifa;
2874 	int state, i;
2875 
2876 	ASSERT_RTNL();
2877 
2878 	rt6_ifdown(net, dev);
2879 	neigh_ifdown(&nd_tbl, dev);
2880 
2881 	idev = __in6_dev_get(dev);
2882 	if (idev == NULL)
2883 		return -ENODEV;
2884 
2885 	/*
2886 	 * Step 1: remove reference to ipv6 device from parent device.
2887 	 *	   Do not dev_put!
2888 	 */
2889 	if (how) {
2890 		idev->dead = 1;
2891 
2892 		/* protected by rtnl_lock */
2893 		RCU_INIT_POINTER(dev->ip6_ptr, NULL);
2894 
2895 		/* Step 1.5: remove snmp6 entry */
2896 		snmp6_unregister_dev(idev);
2897 
2898 	}
2899 
2900 	/* Step 2: clear hash table */
2901 	for (i = 0; i < IN6_ADDR_HSIZE; i++) {
2902 		struct hlist_head *h = &inet6_addr_lst[i];
2903 		struct hlist_node *n;
2904 
2905 		spin_lock_bh(&addrconf_hash_lock);
2906 	restart:
2907 		hlist_for_each_entry_rcu(ifa, n, h, addr_lst) {
2908 			if (ifa->idev == idev) {
2909 				hlist_del_init_rcu(&ifa->addr_lst);
2910 				addrconf_del_timer(ifa);
2911 				goto restart;
2912 			}
2913 		}
2914 		spin_unlock_bh(&addrconf_hash_lock);
2915 	}
2916 
2917 	write_lock_bh(&idev->lock);
2918 
2919 	/* Step 2: clear flags for stateless addrconf */
2920 	if (!how)
2921 		idev->if_flags &= ~(IF_RS_SENT|IF_RA_RCVD|IF_READY);
2922 
2923 #ifdef CONFIG_IPV6_PRIVACY
2924 	if (how && del_timer(&idev->regen_timer))
2925 		in6_dev_put(idev);
2926 
2927 	/* Step 3: clear tempaddr list */
2928 	while (!list_empty(&idev->tempaddr_list)) {
2929 		ifa = list_first_entry(&idev->tempaddr_list,
2930 				       struct inet6_ifaddr, tmp_list);
2931 		list_del(&ifa->tmp_list);
2932 		write_unlock_bh(&idev->lock);
2933 		spin_lock_bh(&ifa->lock);
2934 
2935 		if (ifa->ifpub) {
2936 			in6_ifa_put(ifa->ifpub);
2937 			ifa->ifpub = NULL;
2938 		}
2939 		spin_unlock_bh(&ifa->lock);
2940 		in6_ifa_put(ifa);
2941 		write_lock_bh(&idev->lock);
2942 	}
2943 #endif
2944 
2945 	while (!list_empty(&idev->addr_list)) {
2946 		ifa = list_first_entry(&idev->addr_list,
2947 				       struct inet6_ifaddr, if_list);
2948 		addrconf_del_timer(ifa);
2949 
2950 		list_del(&ifa->if_list);
2951 
2952 		write_unlock_bh(&idev->lock);
2953 
2954 		spin_lock_bh(&ifa->state_lock);
2955 		state = ifa->state;
2956 		ifa->state = INET6_IFADDR_STATE_DEAD;
2957 		spin_unlock_bh(&ifa->state_lock);
2958 
2959 		if (state != INET6_IFADDR_STATE_DEAD) {
2960 			__ipv6_ifa_notify(RTM_DELADDR, ifa);
2961 			atomic_notifier_call_chain(&inet6addr_chain, NETDEV_DOWN, ifa);
2962 		}
2963 		in6_ifa_put(ifa);
2964 
2965 		write_lock_bh(&idev->lock);
2966 	}
2967 
2968 	write_unlock_bh(&idev->lock);
2969 
2970 	/* Step 5: Discard multicast list */
2971 	if (how)
2972 		ipv6_mc_destroy_dev(idev);
2973 	else
2974 		ipv6_mc_down(idev);
2975 
2976 	idev->tstamp = jiffies;
2977 
2978 	/* Last: Shot the device (if unregistered) */
2979 	if (how) {
2980 		addrconf_sysctl_unregister(idev);
2981 		neigh_parms_release(&nd_tbl, idev->nd_parms);
2982 		neigh_ifdown(&nd_tbl, dev);
2983 		in6_dev_put(idev);
2984 	}
2985 	return 0;
2986 }
2987 
2988 static void addrconf_rs_timer(unsigned long data)
2989 {
2990 	struct inet6_ifaddr *ifp = (struct inet6_ifaddr *) data;
2991 	struct inet6_dev *idev = ifp->idev;
2992 
2993 	read_lock(&idev->lock);
2994 	if (idev->dead || !(idev->if_flags & IF_READY))
2995 		goto out;
2996 
2997 	if (!ipv6_accept_ra(idev))
2998 		goto out;
2999 
3000 	/* Announcement received after solicitation was sent */
3001 	if (idev->if_flags & IF_RA_RCVD)
3002 		goto out;
3003 
3004 	spin_lock(&ifp->lock);
3005 	if (ifp->probes++ < idev->cnf.rtr_solicits) {
3006 		/* The wait after the last probe can be shorter */
3007 		addrconf_mod_timer(ifp, AC_RS,
3008 				   (ifp->probes == idev->cnf.rtr_solicits) ?
3009 				   idev->cnf.rtr_solicit_delay :
3010 				   idev->cnf.rtr_solicit_interval);
3011 		spin_unlock(&ifp->lock);
3012 
3013 		ndisc_send_rs(idev->dev, &ifp->addr, &in6addr_linklocal_allrouters);
3014 	} else {
3015 		spin_unlock(&ifp->lock);
3016 		/*
3017 		 * Note: we do not support deprecated "all on-link"
3018 		 * assumption any longer.
3019 		 */
3020 		pr_debug("%s: no IPv6 routers present\n", idev->dev->name);
3021 	}
3022 
3023 out:
3024 	read_unlock(&idev->lock);
3025 	in6_ifa_put(ifp);
3026 }
3027 
3028 /*
3029  *	Duplicate Address Detection
3030  */
3031 static void addrconf_dad_kick(struct inet6_ifaddr *ifp)
3032 {
3033 	unsigned long rand_num;
3034 	struct inet6_dev *idev = ifp->idev;
3035 
3036 	if (ifp->flags & IFA_F_OPTIMISTIC)
3037 		rand_num = 0;
3038 	else
3039 		rand_num = net_random() % (idev->cnf.rtr_solicit_delay ? : 1);
3040 
3041 	ifp->probes = idev->cnf.dad_transmits;
3042 	addrconf_mod_timer(ifp, AC_DAD, rand_num);
3043 }
3044 
3045 static void addrconf_dad_start(struct inet6_ifaddr *ifp)
3046 {
3047 	struct inet6_dev *idev = ifp->idev;
3048 	struct net_device *dev = idev->dev;
3049 
3050 	addrconf_join_solict(dev, &ifp->addr);
3051 
3052 	net_srandom(ifp->addr.s6_addr32[3]);
3053 
3054 	read_lock_bh(&idev->lock);
3055 	spin_lock(&ifp->lock);
3056 	if (ifp->state == INET6_IFADDR_STATE_DEAD)
3057 		goto out;
3058 
3059 	if (dev->flags&(IFF_NOARP|IFF_LOOPBACK) ||
3060 	    idev->cnf.accept_dad < 1 ||
3061 	    !(ifp->flags&IFA_F_TENTATIVE) ||
3062 	    ifp->flags & IFA_F_NODAD) {
3063 		ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC|IFA_F_DADFAILED);
3064 		spin_unlock(&ifp->lock);
3065 		read_unlock_bh(&idev->lock);
3066 
3067 		addrconf_dad_completed(ifp);
3068 		return;
3069 	}
3070 
3071 	if (!(idev->if_flags & IF_READY)) {
3072 		spin_unlock(&ifp->lock);
3073 		read_unlock_bh(&idev->lock);
3074 		/*
3075 		 * If the device is not ready:
3076 		 * - keep it tentative if it is a permanent address.
3077 		 * - otherwise, kill it.
3078 		 */
3079 		in6_ifa_hold(ifp);
3080 		addrconf_dad_stop(ifp, 0);
3081 		return;
3082 	}
3083 
3084 	/*
3085 	 * Optimistic nodes can start receiving
3086 	 * Frames right away
3087 	 */
3088 	if (ifp->flags & IFA_F_OPTIMISTIC)
3089 		ip6_ins_rt(ifp->rt);
3090 
3091 	addrconf_dad_kick(ifp);
3092 out:
3093 	spin_unlock(&ifp->lock);
3094 	read_unlock_bh(&idev->lock);
3095 }
3096 
3097 static void addrconf_dad_timer(unsigned long data)
3098 {
3099 	struct inet6_ifaddr *ifp = (struct inet6_ifaddr *) data;
3100 	struct inet6_dev *idev = ifp->idev;
3101 	struct in6_addr mcaddr;
3102 
3103 	if (!ifp->probes && addrconf_dad_end(ifp))
3104 		goto out;
3105 
3106 	read_lock(&idev->lock);
3107 	if (idev->dead || !(idev->if_flags & IF_READY)) {
3108 		read_unlock(&idev->lock);
3109 		goto out;
3110 	}
3111 
3112 	spin_lock(&ifp->lock);
3113 	if (ifp->state == INET6_IFADDR_STATE_DEAD) {
3114 		spin_unlock(&ifp->lock);
3115 		read_unlock(&idev->lock);
3116 		goto out;
3117 	}
3118 
3119 	if (ifp->probes == 0) {
3120 		/*
3121 		 * DAD was successful
3122 		 */
3123 
3124 		ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC|IFA_F_DADFAILED);
3125 		spin_unlock(&ifp->lock);
3126 		read_unlock(&idev->lock);
3127 
3128 		addrconf_dad_completed(ifp);
3129 
3130 		goto out;
3131 	}
3132 
3133 	ifp->probes--;
3134 	addrconf_mod_timer(ifp, AC_DAD, ifp->idev->nd_parms->retrans_time);
3135 	spin_unlock(&ifp->lock);
3136 	read_unlock(&idev->lock);
3137 
3138 	/* send a neighbour solicitation for our addr */
3139 	addrconf_addr_solict_mult(&ifp->addr, &mcaddr);
3140 	ndisc_send_ns(ifp->idev->dev, NULL, &ifp->addr, &mcaddr, &in6addr_any);
3141 out:
3142 	in6_ifa_put(ifp);
3143 }
3144 
3145 static void addrconf_dad_completed(struct inet6_ifaddr *ifp)
3146 {
3147 	struct net_device *dev = ifp->idev->dev;
3148 
3149 	/*
3150 	 *	Configure the address for reception. Now it is valid.
3151 	 */
3152 
3153 	ipv6_ifa_notify(RTM_NEWADDR, ifp);
3154 
3155 	/* If added prefix is link local and we are prepared to process
3156 	   router advertisements, start sending router solicitations.
3157 	 */
3158 
3159 	if (ipv6_accept_ra(ifp->idev) &&
3160 	    ifp->idev->cnf.rtr_solicits > 0 &&
3161 	    (dev->flags&IFF_LOOPBACK) == 0 &&
3162 	    (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)) {
3163 		/*
3164 		 *	If a host as already performed a random delay
3165 		 *	[...] as part of DAD [...] there is no need
3166 		 *	to delay again before sending the first RS
3167 		 */
3168 		ndisc_send_rs(ifp->idev->dev, &ifp->addr, &in6addr_linklocal_allrouters);
3169 
3170 		spin_lock_bh(&ifp->lock);
3171 		ifp->probes = 1;
3172 		ifp->idev->if_flags |= IF_RS_SENT;
3173 		addrconf_mod_timer(ifp, AC_RS, ifp->idev->cnf.rtr_solicit_interval);
3174 		spin_unlock_bh(&ifp->lock);
3175 	}
3176 }
3177 
3178 static void addrconf_dad_run(struct inet6_dev *idev)
3179 {
3180 	struct inet6_ifaddr *ifp;
3181 
3182 	read_lock_bh(&idev->lock);
3183 	list_for_each_entry(ifp, &idev->addr_list, if_list) {
3184 		spin_lock(&ifp->lock);
3185 		if (ifp->flags & IFA_F_TENTATIVE &&
3186 		    ifp->state == INET6_IFADDR_STATE_DAD)
3187 			addrconf_dad_kick(ifp);
3188 		spin_unlock(&ifp->lock);
3189 	}
3190 	read_unlock_bh(&idev->lock);
3191 }
3192 
3193 #ifdef CONFIG_PROC_FS
3194 struct if6_iter_state {
3195 	struct seq_net_private p;
3196 	int bucket;
3197 	int offset;
3198 };
3199 
3200 static struct inet6_ifaddr *if6_get_first(struct seq_file *seq, loff_t pos)
3201 {
3202 	struct inet6_ifaddr *ifa = NULL;
3203 	struct if6_iter_state *state = seq->private;
3204 	struct net *net = seq_file_net(seq);
3205 	int p = 0;
3206 
3207 	/* initial bucket if pos is 0 */
3208 	if (pos == 0) {
3209 		state->bucket = 0;
3210 		state->offset = 0;
3211 	}
3212 
3213 	for (; state->bucket < IN6_ADDR_HSIZE; ++state->bucket) {
3214 		struct hlist_node *n;
3215 		hlist_for_each_entry_rcu_bh(ifa, n, &inet6_addr_lst[state->bucket],
3216 					 addr_lst) {
3217 			if (!net_eq(dev_net(ifa->idev->dev), net))
3218 				continue;
3219 			/* sync with offset */
3220 			if (p < state->offset) {
3221 				p++;
3222 				continue;
3223 			}
3224 			state->offset++;
3225 			return ifa;
3226 		}
3227 
3228 		/* prepare for next bucket */
3229 		state->offset = 0;
3230 		p = 0;
3231 	}
3232 	return NULL;
3233 }
3234 
3235 static struct inet6_ifaddr *if6_get_next(struct seq_file *seq,
3236 					 struct inet6_ifaddr *ifa)
3237 {
3238 	struct if6_iter_state *state = seq->private;
3239 	struct net *net = seq_file_net(seq);
3240 	struct hlist_node *n = &ifa->addr_lst;
3241 
3242 	hlist_for_each_entry_continue_rcu_bh(ifa, n, addr_lst) {
3243 		if (!net_eq(dev_net(ifa->idev->dev), net))
3244 			continue;
3245 		state->offset++;
3246 		return ifa;
3247 	}
3248 
3249 	while (++state->bucket < IN6_ADDR_HSIZE) {
3250 		state->offset = 0;
3251 		hlist_for_each_entry_rcu_bh(ifa, n,
3252 				     &inet6_addr_lst[state->bucket], addr_lst) {
3253 			if (!net_eq(dev_net(ifa->idev->dev), net))
3254 				continue;
3255 			state->offset++;
3256 			return ifa;
3257 		}
3258 	}
3259 
3260 	return NULL;
3261 }
3262 
3263 static void *if6_seq_start(struct seq_file *seq, loff_t *pos)
3264 	__acquires(rcu_bh)
3265 {
3266 	rcu_read_lock_bh();
3267 	return if6_get_first(seq, *pos);
3268 }
3269 
3270 static void *if6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3271 {
3272 	struct inet6_ifaddr *ifa;
3273 
3274 	ifa = if6_get_next(seq, v);
3275 	++*pos;
3276 	return ifa;
3277 }
3278 
3279 static void if6_seq_stop(struct seq_file *seq, void *v)
3280 	__releases(rcu_bh)
3281 {
3282 	rcu_read_unlock_bh();
3283 }
3284 
3285 static int if6_seq_show(struct seq_file *seq, void *v)
3286 {
3287 	struct inet6_ifaddr *ifp = (struct inet6_ifaddr *)v;
3288 	seq_printf(seq, "%pi6 %02x %02x %02x %02x %8s\n",
3289 		   &ifp->addr,
3290 		   ifp->idev->dev->ifindex,
3291 		   ifp->prefix_len,
3292 		   ifp->scope,
3293 		   ifp->flags,
3294 		   ifp->idev->dev->name);
3295 	return 0;
3296 }
3297 
3298 static const struct seq_operations if6_seq_ops = {
3299 	.start	= if6_seq_start,
3300 	.next	= if6_seq_next,
3301 	.show	= if6_seq_show,
3302 	.stop	= if6_seq_stop,
3303 };
3304 
3305 static int if6_seq_open(struct inode *inode, struct file *file)
3306 {
3307 	return seq_open_net(inode, file, &if6_seq_ops,
3308 			    sizeof(struct if6_iter_state));
3309 }
3310 
3311 static const struct file_operations if6_fops = {
3312 	.owner		= THIS_MODULE,
3313 	.open		= if6_seq_open,
3314 	.read		= seq_read,
3315 	.llseek		= seq_lseek,
3316 	.release	= seq_release_net,
3317 };
3318 
3319 static int __net_init if6_proc_net_init(struct net *net)
3320 {
3321 	if (!proc_net_fops_create(net, "if_inet6", S_IRUGO, &if6_fops))
3322 		return -ENOMEM;
3323 	return 0;
3324 }
3325 
3326 static void __net_exit if6_proc_net_exit(struct net *net)
3327 {
3328        proc_net_remove(net, "if_inet6");
3329 }
3330 
3331 static struct pernet_operations if6_proc_net_ops = {
3332        .init = if6_proc_net_init,
3333        .exit = if6_proc_net_exit,
3334 };
3335 
3336 int __init if6_proc_init(void)
3337 {
3338 	return register_pernet_subsys(&if6_proc_net_ops);
3339 }
3340 
3341 void if6_proc_exit(void)
3342 {
3343 	unregister_pernet_subsys(&if6_proc_net_ops);
3344 }
3345 #endif	/* CONFIG_PROC_FS */
3346 
3347 #if IS_ENABLED(CONFIG_IPV6_MIP6)
3348 /* Check if address is a home address configured on any interface. */
3349 int ipv6_chk_home_addr(struct net *net, const struct in6_addr *addr)
3350 {
3351 	int ret = 0;
3352 	struct inet6_ifaddr *ifp = NULL;
3353 	struct hlist_node *n;
3354 	unsigned int hash = inet6_addr_hash(addr);
3355 
3356 	rcu_read_lock_bh();
3357 	hlist_for_each_entry_rcu_bh(ifp, n, &inet6_addr_lst[hash], addr_lst) {
3358 		if (!net_eq(dev_net(ifp->idev->dev), net))
3359 			continue;
3360 		if (ipv6_addr_equal(&ifp->addr, addr) &&
3361 		    (ifp->flags & IFA_F_HOMEADDRESS)) {
3362 			ret = 1;
3363 			break;
3364 		}
3365 	}
3366 	rcu_read_unlock_bh();
3367 	return ret;
3368 }
3369 #endif
3370 
3371 /*
3372  *	Periodic address status verification
3373  */
3374 
3375 static void addrconf_verify(unsigned long foo)
3376 {
3377 	unsigned long now, next, next_sec, next_sched;
3378 	struct inet6_ifaddr *ifp;
3379 	struct hlist_node *node;
3380 	int i;
3381 
3382 	rcu_read_lock_bh();
3383 	spin_lock(&addrconf_verify_lock);
3384 	now = jiffies;
3385 	next = round_jiffies_up(now + ADDR_CHECK_FREQUENCY);
3386 
3387 	del_timer(&addr_chk_timer);
3388 
3389 	for (i = 0; i < IN6_ADDR_HSIZE; i++) {
3390 restart:
3391 		hlist_for_each_entry_rcu_bh(ifp, node,
3392 					 &inet6_addr_lst[i], addr_lst) {
3393 			unsigned long age;
3394 
3395 			if (ifp->flags & IFA_F_PERMANENT)
3396 				continue;
3397 
3398 			spin_lock(&ifp->lock);
3399 			/* We try to batch several events at once. */
3400 			age = (now - ifp->tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ;
3401 
3402 			if (ifp->valid_lft != INFINITY_LIFE_TIME &&
3403 			    age >= ifp->valid_lft) {
3404 				spin_unlock(&ifp->lock);
3405 				in6_ifa_hold(ifp);
3406 				ipv6_del_addr(ifp);
3407 				goto restart;
3408 			} else if (ifp->prefered_lft == INFINITY_LIFE_TIME) {
3409 				spin_unlock(&ifp->lock);
3410 				continue;
3411 			} else if (age >= ifp->prefered_lft) {
3412 				/* jiffies - ifp->tstamp > age >= ifp->prefered_lft */
3413 				int deprecate = 0;
3414 
3415 				if (!(ifp->flags&IFA_F_DEPRECATED)) {
3416 					deprecate = 1;
3417 					ifp->flags |= IFA_F_DEPRECATED;
3418 				}
3419 
3420 				if (time_before(ifp->tstamp + ifp->valid_lft * HZ, next))
3421 					next = ifp->tstamp + ifp->valid_lft * HZ;
3422 
3423 				spin_unlock(&ifp->lock);
3424 
3425 				if (deprecate) {
3426 					in6_ifa_hold(ifp);
3427 
3428 					ipv6_ifa_notify(0, ifp);
3429 					in6_ifa_put(ifp);
3430 					goto restart;
3431 				}
3432 #ifdef CONFIG_IPV6_PRIVACY
3433 			} else if ((ifp->flags&IFA_F_TEMPORARY) &&
3434 				   !(ifp->flags&IFA_F_TENTATIVE)) {
3435 				unsigned long regen_advance = ifp->idev->cnf.regen_max_retry *
3436 					ifp->idev->cnf.dad_transmits *
3437 					ifp->idev->nd_parms->retrans_time / HZ;
3438 
3439 				if (age >= ifp->prefered_lft - regen_advance) {
3440 					struct inet6_ifaddr *ifpub = ifp->ifpub;
3441 					if (time_before(ifp->tstamp + ifp->prefered_lft * HZ, next))
3442 						next = ifp->tstamp + ifp->prefered_lft * HZ;
3443 					if (!ifp->regen_count && ifpub) {
3444 						ifp->regen_count++;
3445 						in6_ifa_hold(ifp);
3446 						in6_ifa_hold(ifpub);
3447 						spin_unlock(&ifp->lock);
3448 
3449 						spin_lock(&ifpub->lock);
3450 						ifpub->regen_count = 0;
3451 						spin_unlock(&ifpub->lock);
3452 						ipv6_create_tempaddr(ifpub, ifp);
3453 						in6_ifa_put(ifpub);
3454 						in6_ifa_put(ifp);
3455 						goto restart;
3456 					}
3457 				} else if (time_before(ifp->tstamp + ifp->prefered_lft * HZ - regen_advance * HZ, next))
3458 					next = ifp->tstamp + ifp->prefered_lft * HZ - regen_advance * HZ;
3459 				spin_unlock(&ifp->lock);
3460 #endif
3461 			} else {
3462 				/* ifp->prefered_lft <= ifp->valid_lft */
3463 				if (time_before(ifp->tstamp + ifp->prefered_lft * HZ, next))
3464 					next = ifp->tstamp + ifp->prefered_lft * HZ;
3465 				spin_unlock(&ifp->lock);
3466 			}
3467 		}
3468 	}
3469 
3470 	next_sec = round_jiffies_up(next);
3471 	next_sched = next;
3472 
3473 	/* If rounded timeout is accurate enough, accept it. */
3474 	if (time_before(next_sec, next + ADDRCONF_TIMER_FUZZ))
3475 		next_sched = next_sec;
3476 
3477 	/* And minimum interval is ADDRCONF_TIMER_FUZZ_MAX. */
3478 	if (time_before(next_sched, jiffies + ADDRCONF_TIMER_FUZZ_MAX))
3479 		next_sched = jiffies + ADDRCONF_TIMER_FUZZ_MAX;
3480 
3481 	ADBG((KERN_DEBUG "now = %lu, schedule = %lu, rounded schedule = %lu => %lu\n",
3482 	      now, next, next_sec, next_sched));
3483 
3484 	addr_chk_timer.expires = next_sched;
3485 	add_timer(&addr_chk_timer);
3486 	spin_unlock(&addrconf_verify_lock);
3487 	rcu_read_unlock_bh();
3488 }
3489 
3490 static struct in6_addr *extract_addr(struct nlattr *addr, struct nlattr *local)
3491 {
3492 	struct in6_addr *pfx = NULL;
3493 
3494 	if (addr)
3495 		pfx = nla_data(addr);
3496 
3497 	if (local) {
3498 		if (pfx && nla_memcmp(local, pfx, sizeof(*pfx)))
3499 			pfx = NULL;
3500 		else
3501 			pfx = nla_data(local);
3502 	}
3503 
3504 	return pfx;
3505 }
3506 
3507 static const struct nla_policy ifa_ipv6_policy[IFA_MAX+1] = {
3508 	[IFA_ADDRESS]		= { .len = sizeof(struct in6_addr) },
3509 	[IFA_LOCAL]		= { .len = sizeof(struct in6_addr) },
3510 	[IFA_CACHEINFO]		= { .len = sizeof(struct ifa_cacheinfo) },
3511 };
3512 
3513 static int
3514 inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
3515 {
3516 	struct net *net = sock_net(skb->sk);
3517 	struct ifaddrmsg *ifm;
3518 	struct nlattr *tb[IFA_MAX+1];
3519 	struct in6_addr *pfx;
3520 	int err;
3521 
3522 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
3523 	if (err < 0)
3524 		return err;
3525 
3526 	ifm = nlmsg_data(nlh);
3527 	pfx = extract_addr(tb[IFA_ADDRESS], tb[IFA_LOCAL]);
3528 	if (pfx == NULL)
3529 		return -EINVAL;
3530 
3531 	return inet6_addr_del(net, ifm->ifa_index, pfx, ifm->ifa_prefixlen);
3532 }
3533 
3534 static int inet6_addr_modify(struct inet6_ifaddr *ifp, u8 ifa_flags,
3535 			     u32 prefered_lft, u32 valid_lft)
3536 {
3537 	u32 flags;
3538 	clock_t expires;
3539 	unsigned long timeout;
3540 
3541 	if (!valid_lft || (prefered_lft > valid_lft))
3542 		return -EINVAL;
3543 
3544 	timeout = addrconf_timeout_fixup(valid_lft, HZ);
3545 	if (addrconf_finite_timeout(timeout)) {
3546 		expires = jiffies_to_clock_t(timeout * HZ);
3547 		valid_lft = timeout;
3548 		flags = RTF_EXPIRES;
3549 	} else {
3550 		expires = 0;
3551 		flags = 0;
3552 		ifa_flags |= IFA_F_PERMANENT;
3553 	}
3554 
3555 	timeout = addrconf_timeout_fixup(prefered_lft, HZ);
3556 	if (addrconf_finite_timeout(timeout)) {
3557 		if (timeout == 0)
3558 			ifa_flags |= IFA_F_DEPRECATED;
3559 		prefered_lft = timeout;
3560 	}
3561 
3562 	spin_lock_bh(&ifp->lock);
3563 	ifp->flags = (ifp->flags & ~(IFA_F_DEPRECATED | IFA_F_PERMANENT | IFA_F_NODAD | IFA_F_HOMEADDRESS)) | ifa_flags;
3564 	ifp->tstamp = jiffies;
3565 	ifp->valid_lft = valid_lft;
3566 	ifp->prefered_lft = prefered_lft;
3567 
3568 	spin_unlock_bh(&ifp->lock);
3569 	if (!(ifp->flags&IFA_F_TENTATIVE))
3570 		ipv6_ifa_notify(0, ifp);
3571 
3572 	addrconf_prefix_route(&ifp->addr, ifp->prefix_len, ifp->idev->dev,
3573 			      expires, flags);
3574 	addrconf_verify(0);
3575 
3576 	return 0;
3577 }
3578 
3579 static int
3580 inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
3581 {
3582 	struct net *net = sock_net(skb->sk);
3583 	struct ifaddrmsg *ifm;
3584 	struct nlattr *tb[IFA_MAX+1];
3585 	struct in6_addr *pfx;
3586 	struct inet6_ifaddr *ifa;
3587 	struct net_device *dev;
3588 	u32 valid_lft = INFINITY_LIFE_TIME, preferred_lft = INFINITY_LIFE_TIME;
3589 	u8 ifa_flags;
3590 	int err;
3591 
3592 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
3593 	if (err < 0)
3594 		return err;
3595 
3596 	ifm = nlmsg_data(nlh);
3597 	pfx = extract_addr(tb[IFA_ADDRESS], tb[IFA_LOCAL]);
3598 	if (pfx == NULL)
3599 		return -EINVAL;
3600 
3601 	if (tb[IFA_CACHEINFO]) {
3602 		struct ifa_cacheinfo *ci;
3603 
3604 		ci = nla_data(tb[IFA_CACHEINFO]);
3605 		valid_lft = ci->ifa_valid;
3606 		preferred_lft = ci->ifa_prefered;
3607 	} else {
3608 		preferred_lft = INFINITY_LIFE_TIME;
3609 		valid_lft = INFINITY_LIFE_TIME;
3610 	}
3611 
3612 	dev =  __dev_get_by_index(net, ifm->ifa_index);
3613 	if (dev == NULL)
3614 		return -ENODEV;
3615 
3616 	/* We ignore other flags so far. */
3617 	ifa_flags = ifm->ifa_flags & (IFA_F_NODAD | IFA_F_HOMEADDRESS);
3618 
3619 	ifa = ipv6_get_ifaddr(net, pfx, dev, 1);
3620 	if (ifa == NULL) {
3621 		/*
3622 		 * It would be best to check for !NLM_F_CREATE here but
3623 		 * userspace alreay relies on not having to provide this.
3624 		 */
3625 		return inet6_addr_add(net, ifm->ifa_index, pfx,
3626 				      ifm->ifa_prefixlen, ifa_flags,
3627 				      preferred_lft, valid_lft);
3628 	}
3629 
3630 	if (nlh->nlmsg_flags & NLM_F_EXCL ||
3631 	    !(nlh->nlmsg_flags & NLM_F_REPLACE))
3632 		err = -EEXIST;
3633 	else
3634 		err = inet6_addr_modify(ifa, ifa_flags, preferred_lft, valid_lft);
3635 
3636 	in6_ifa_put(ifa);
3637 
3638 	return err;
3639 }
3640 
3641 static void put_ifaddrmsg(struct nlmsghdr *nlh, u8 prefixlen, u8 flags,
3642 			  u8 scope, int ifindex)
3643 {
3644 	struct ifaddrmsg *ifm;
3645 
3646 	ifm = nlmsg_data(nlh);
3647 	ifm->ifa_family = AF_INET6;
3648 	ifm->ifa_prefixlen = prefixlen;
3649 	ifm->ifa_flags = flags;
3650 	ifm->ifa_scope = scope;
3651 	ifm->ifa_index = ifindex;
3652 }
3653 
3654 static int put_cacheinfo(struct sk_buff *skb, unsigned long cstamp,
3655 			 unsigned long tstamp, u32 preferred, u32 valid)
3656 {
3657 	struct ifa_cacheinfo ci;
3658 
3659 	ci.cstamp = cstamp_delta(cstamp);
3660 	ci.tstamp = cstamp_delta(tstamp);
3661 	ci.ifa_prefered = preferred;
3662 	ci.ifa_valid = valid;
3663 
3664 	return nla_put(skb, IFA_CACHEINFO, sizeof(ci), &ci);
3665 }
3666 
3667 static inline int rt_scope(int ifa_scope)
3668 {
3669 	if (ifa_scope & IFA_HOST)
3670 		return RT_SCOPE_HOST;
3671 	else if (ifa_scope & IFA_LINK)
3672 		return RT_SCOPE_LINK;
3673 	else if (ifa_scope & IFA_SITE)
3674 		return RT_SCOPE_SITE;
3675 	else
3676 		return RT_SCOPE_UNIVERSE;
3677 }
3678 
3679 static inline int inet6_ifaddr_msgsize(void)
3680 {
3681 	return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
3682 	       + nla_total_size(16) /* IFA_ADDRESS */
3683 	       + nla_total_size(sizeof(struct ifa_cacheinfo));
3684 }
3685 
3686 static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
3687 			     u32 portid, u32 seq, int event, unsigned int flags)
3688 {
3689 	struct nlmsghdr  *nlh;
3690 	u32 preferred, valid;
3691 
3692 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct ifaddrmsg), flags);
3693 	if (nlh == NULL)
3694 		return -EMSGSIZE;
3695 
3696 	put_ifaddrmsg(nlh, ifa->prefix_len, ifa->flags, rt_scope(ifa->scope),
3697 		      ifa->idev->dev->ifindex);
3698 
3699 	if (!(ifa->flags&IFA_F_PERMANENT)) {
3700 		preferred = ifa->prefered_lft;
3701 		valid = ifa->valid_lft;
3702 		if (preferred != INFINITY_LIFE_TIME) {
3703 			long tval = (jiffies - ifa->tstamp)/HZ;
3704 			if (preferred > tval)
3705 				preferred -= tval;
3706 			else
3707 				preferred = 0;
3708 			if (valid != INFINITY_LIFE_TIME) {
3709 				if (valid > tval)
3710 					valid -= tval;
3711 				else
3712 					valid = 0;
3713 			}
3714 		}
3715 	} else {
3716 		preferred = INFINITY_LIFE_TIME;
3717 		valid = INFINITY_LIFE_TIME;
3718 	}
3719 
3720 	if (nla_put(skb, IFA_ADDRESS, 16, &ifa->addr) < 0 ||
3721 	    put_cacheinfo(skb, ifa->cstamp, ifa->tstamp, preferred, valid) < 0) {
3722 		nlmsg_cancel(skb, nlh);
3723 		return -EMSGSIZE;
3724 	}
3725 
3726 	return nlmsg_end(skb, nlh);
3727 }
3728 
3729 static int inet6_fill_ifmcaddr(struct sk_buff *skb, struct ifmcaddr6 *ifmca,
3730 				u32 portid, u32 seq, int event, u16 flags)
3731 {
3732 	struct nlmsghdr  *nlh;
3733 	u8 scope = RT_SCOPE_UNIVERSE;
3734 	int ifindex = ifmca->idev->dev->ifindex;
3735 
3736 	if (ipv6_addr_scope(&ifmca->mca_addr) & IFA_SITE)
3737 		scope = RT_SCOPE_SITE;
3738 
3739 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct ifaddrmsg), flags);
3740 	if (nlh == NULL)
3741 		return -EMSGSIZE;
3742 
3743 	put_ifaddrmsg(nlh, 128, IFA_F_PERMANENT, scope, ifindex);
3744 	if (nla_put(skb, IFA_MULTICAST, 16, &ifmca->mca_addr) < 0 ||
3745 	    put_cacheinfo(skb, ifmca->mca_cstamp, ifmca->mca_tstamp,
3746 			  INFINITY_LIFE_TIME, INFINITY_LIFE_TIME) < 0) {
3747 		nlmsg_cancel(skb, nlh);
3748 		return -EMSGSIZE;
3749 	}
3750 
3751 	return nlmsg_end(skb, nlh);
3752 }
3753 
3754 static int inet6_fill_ifacaddr(struct sk_buff *skb, struct ifacaddr6 *ifaca,
3755 				u32 portid, u32 seq, int event, unsigned int flags)
3756 {
3757 	struct nlmsghdr  *nlh;
3758 	u8 scope = RT_SCOPE_UNIVERSE;
3759 	int ifindex = ifaca->aca_idev->dev->ifindex;
3760 
3761 	if (ipv6_addr_scope(&ifaca->aca_addr) & IFA_SITE)
3762 		scope = RT_SCOPE_SITE;
3763 
3764 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct ifaddrmsg), flags);
3765 	if (nlh == NULL)
3766 		return -EMSGSIZE;
3767 
3768 	put_ifaddrmsg(nlh, 128, IFA_F_PERMANENT, scope, ifindex);
3769 	if (nla_put(skb, IFA_ANYCAST, 16, &ifaca->aca_addr) < 0 ||
3770 	    put_cacheinfo(skb, ifaca->aca_cstamp, ifaca->aca_tstamp,
3771 			  INFINITY_LIFE_TIME, INFINITY_LIFE_TIME) < 0) {
3772 		nlmsg_cancel(skb, nlh);
3773 		return -EMSGSIZE;
3774 	}
3775 
3776 	return nlmsg_end(skb, nlh);
3777 }
3778 
3779 enum addr_type_t {
3780 	UNICAST_ADDR,
3781 	MULTICAST_ADDR,
3782 	ANYCAST_ADDR,
3783 };
3784 
3785 /* called with rcu_read_lock() */
3786 static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb,
3787 			  struct netlink_callback *cb, enum addr_type_t type,
3788 			  int s_ip_idx, int *p_ip_idx)
3789 {
3790 	struct ifmcaddr6 *ifmca;
3791 	struct ifacaddr6 *ifaca;
3792 	int err = 1;
3793 	int ip_idx = *p_ip_idx;
3794 
3795 	read_lock_bh(&idev->lock);
3796 	switch (type) {
3797 	case UNICAST_ADDR: {
3798 		struct inet6_ifaddr *ifa;
3799 
3800 		/* unicast address incl. temp addr */
3801 		list_for_each_entry(ifa, &idev->addr_list, if_list) {
3802 			if (++ip_idx < s_ip_idx)
3803 				continue;
3804 			err = inet6_fill_ifaddr(skb, ifa,
3805 						NETLINK_CB(cb->skb).portid,
3806 						cb->nlh->nlmsg_seq,
3807 						RTM_NEWADDR,
3808 						NLM_F_MULTI);
3809 			if (err <= 0)
3810 				break;
3811 		}
3812 		break;
3813 	}
3814 	case MULTICAST_ADDR:
3815 		/* multicast address */
3816 		for (ifmca = idev->mc_list; ifmca;
3817 		     ifmca = ifmca->next, ip_idx++) {
3818 			if (ip_idx < s_ip_idx)
3819 				continue;
3820 			err = inet6_fill_ifmcaddr(skb, ifmca,
3821 						  NETLINK_CB(cb->skb).portid,
3822 						  cb->nlh->nlmsg_seq,
3823 						  RTM_GETMULTICAST,
3824 						  NLM_F_MULTI);
3825 			if (err <= 0)
3826 				break;
3827 		}
3828 		break;
3829 	case ANYCAST_ADDR:
3830 		/* anycast address */
3831 		for (ifaca = idev->ac_list; ifaca;
3832 		     ifaca = ifaca->aca_next, ip_idx++) {
3833 			if (ip_idx < s_ip_idx)
3834 				continue;
3835 			err = inet6_fill_ifacaddr(skb, ifaca,
3836 						  NETLINK_CB(cb->skb).portid,
3837 						  cb->nlh->nlmsg_seq,
3838 						  RTM_GETANYCAST,
3839 						  NLM_F_MULTI);
3840 			if (err <= 0)
3841 				break;
3842 		}
3843 		break;
3844 	default:
3845 		break;
3846 	}
3847 	read_unlock_bh(&idev->lock);
3848 	*p_ip_idx = ip_idx;
3849 	return err;
3850 }
3851 
3852 static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb,
3853 			   enum addr_type_t type)
3854 {
3855 	struct net *net = sock_net(skb->sk);
3856 	int h, s_h;
3857 	int idx, ip_idx;
3858 	int s_idx, s_ip_idx;
3859 	struct net_device *dev;
3860 	struct inet6_dev *idev;
3861 	struct hlist_head *head;
3862 	struct hlist_node *node;
3863 
3864 	s_h = cb->args[0];
3865 	s_idx = idx = cb->args[1];
3866 	s_ip_idx = ip_idx = cb->args[2];
3867 
3868 	rcu_read_lock();
3869 	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
3870 		idx = 0;
3871 		head = &net->dev_index_head[h];
3872 		hlist_for_each_entry_rcu(dev, node, head, index_hlist) {
3873 			if (idx < s_idx)
3874 				goto cont;
3875 			if (h > s_h || idx > s_idx)
3876 				s_ip_idx = 0;
3877 			ip_idx = 0;
3878 			idev = __in6_dev_get(dev);
3879 			if (!idev)
3880 				goto cont;
3881 
3882 			if (in6_dump_addrs(idev, skb, cb, type,
3883 					   s_ip_idx, &ip_idx) <= 0)
3884 				goto done;
3885 cont:
3886 			idx++;
3887 		}
3888 	}
3889 done:
3890 	rcu_read_unlock();
3891 	cb->args[0] = h;
3892 	cb->args[1] = idx;
3893 	cb->args[2] = ip_idx;
3894 
3895 	return skb->len;
3896 }
3897 
3898 static int inet6_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
3899 {
3900 	enum addr_type_t type = UNICAST_ADDR;
3901 
3902 	return inet6_dump_addr(skb, cb, type);
3903 }
3904 
3905 static int inet6_dump_ifmcaddr(struct sk_buff *skb, struct netlink_callback *cb)
3906 {
3907 	enum addr_type_t type = MULTICAST_ADDR;
3908 
3909 	return inet6_dump_addr(skb, cb, type);
3910 }
3911 
3912 
3913 static int inet6_dump_ifacaddr(struct sk_buff *skb, struct netlink_callback *cb)
3914 {
3915 	enum addr_type_t type = ANYCAST_ADDR;
3916 
3917 	return inet6_dump_addr(skb, cb, type);
3918 }
3919 
3920 static int inet6_rtm_getaddr(struct sk_buff *in_skb, struct nlmsghdr *nlh,
3921 			     void *arg)
3922 {
3923 	struct net *net = sock_net(in_skb->sk);
3924 	struct ifaddrmsg *ifm;
3925 	struct nlattr *tb[IFA_MAX+1];
3926 	struct in6_addr *addr = NULL;
3927 	struct net_device *dev = NULL;
3928 	struct inet6_ifaddr *ifa;
3929 	struct sk_buff *skb;
3930 	int err;
3931 
3932 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy);
3933 	if (err < 0)
3934 		goto errout;
3935 
3936 	addr = extract_addr(tb[IFA_ADDRESS], tb[IFA_LOCAL]);
3937 	if (addr == NULL) {
3938 		err = -EINVAL;
3939 		goto errout;
3940 	}
3941 
3942 	ifm = nlmsg_data(nlh);
3943 	if (ifm->ifa_index)
3944 		dev = __dev_get_by_index(net, ifm->ifa_index);
3945 
3946 	ifa = ipv6_get_ifaddr(net, addr, dev, 1);
3947 	if (!ifa) {
3948 		err = -EADDRNOTAVAIL;
3949 		goto errout;
3950 	}
3951 
3952 	skb = nlmsg_new(inet6_ifaddr_msgsize(), GFP_KERNEL);
3953 	if (!skb) {
3954 		err = -ENOBUFS;
3955 		goto errout_ifa;
3956 	}
3957 
3958 	err = inet6_fill_ifaddr(skb, ifa, NETLINK_CB(in_skb).portid,
3959 				nlh->nlmsg_seq, RTM_NEWADDR, 0);
3960 	if (err < 0) {
3961 		/* -EMSGSIZE implies BUG in inet6_ifaddr_msgsize() */
3962 		WARN_ON(err == -EMSGSIZE);
3963 		kfree_skb(skb);
3964 		goto errout_ifa;
3965 	}
3966 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3967 errout_ifa:
3968 	in6_ifa_put(ifa);
3969 errout:
3970 	return err;
3971 }
3972 
3973 static void inet6_ifa_notify(int event, struct inet6_ifaddr *ifa)
3974 {
3975 	struct sk_buff *skb;
3976 	struct net *net = dev_net(ifa->idev->dev);
3977 	int err = -ENOBUFS;
3978 
3979 	skb = nlmsg_new(inet6_ifaddr_msgsize(), GFP_ATOMIC);
3980 	if (skb == NULL)
3981 		goto errout;
3982 
3983 	err = inet6_fill_ifaddr(skb, ifa, 0, 0, event, 0);
3984 	if (err < 0) {
3985 		/* -EMSGSIZE implies BUG in inet6_ifaddr_msgsize() */
3986 		WARN_ON(err == -EMSGSIZE);
3987 		kfree_skb(skb);
3988 		goto errout;
3989 	}
3990 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_IFADDR, NULL, GFP_ATOMIC);
3991 	return;
3992 errout:
3993 	if (err < 0)
3994 		rtnl_set_sk_err(net, RTNLGRP_IPV6_IFADDR, err);
3995 }
3996 
3997 static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
3998 				__s32 *array, int bytes)
3999 {
4000 	BUG_ON(bytes < (DEVCONF_MAX * 4));
4001 
4002 	memset(array, 0, bytes);
4003 	array[DEVCONF_FORWARDING] = cnf->forwarding;
4004 	array[DEVCONF_HOPLIMIT] = cnf->hop_limit;
4005 	array[DEVCONF_MTU6] = cnf->mtu6;
4006 	array[DEVCONF_ACCEPT_RA] = cnf->accept_ra;
4007 	array[DEVCONF_ACCEPT_REDIRECTS] = cnf->accept_redirects;
4008 	array[DEVCONF_AUTOCONF] = cnf->autoconf;
4009 	array[DEVCONF_DAD_TRANSMITS] = cnf->dad_transmits;
4010 	array[DEVCONF_RTR_SOLICITS] = cnf->rtr_solicits;
4011 	array[DEVCONF_RTR_SOLICIT_INTERVAL] =
4012 		jiffies_to_msecs(cnf->rtr_solicit_interval);
4013 	array[DEVCONF_RTR_SOLICIT_DELAY] =
4014 		jiffies_to_msecs(cnf->rtr_solicit_delay);
4015 	array[DEVCONF_FORCE_MLD_VERSION] = cnf->force_mld_version;
4016 #ifdef CONFIG_IPV6_PRIVACY
4017 	array[DEVCONF_USE_TEMPADDR] = cnf->use_tempaddr;
4018 	array[DEVCONF_TEMP_VALID_LFT] = cnf->temp_valid_lft;
4019 	array[DEVCONF_TEMP_PREFERED_LFT] = cnf->temp_prefered_lft;
4020 	array[DEVCONF_REGEN_MAX_RETRY] = cnf->regen_max_retry;
4021 	array[DEVCONF_MAX_DESYNC_FACTOR] = cnf->max_desync_factor;
4022 #endif
4023 	array[DEVCONF_MAX_ADDRESSES] = cnf->max_addresses;
4024 	array[DEVCONF_ACCEPT_RA_DEFRTR] = cnf->accept_ra_defrtr;
4025 	array[DEVCONF_ACCEPT_RA_PINFO] = cnf->accept_ra_pinfo;
4026 #ifdef CONFIG_IPV6_ROUTER_PREF
4027 	array[DEVCONF_ACCEPT_RA_RTR_PREF] = cnf->accept_ra_rtr_pref;
4028 	array[DEVCONF_RTR_PROBE_INTERVAL] =
4029 		jiffies_to_msecs(cnf->rtr_probe_interval);
4030 #ifdef CONFIG_IPV6_ROUTE_INFO
4031 	array[DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN] = cnf->accept_ra_rt_info_max_plen;
4032 #endif
4033 #endif
4034 	array[DEVCONF_PROXY_NDP] = cnf->proxy_ndp;
4035 	array[DEVCONF_ACCEPT_SOURCE_ROUTE] = cnf->accept_source_route;
4036 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
4037 	array[DEVCONF_OPTIMISTIC_DAD] = cnf->optimistic_dad;
4038 #endif
4039 #ifdef CONFIG_IPV6_MROUTE
4040 	array[DEVCONF_MC_FORWARDING] = cnf->mc_forwarding;
4041 #endif
4042 	array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6;
4043 	array[DEVCONF_ACCEPT_DAD] = cnf->accept_dad;
4044 	array[DEVCONF_FORCE_TLLAO] = cnf->force_tllao;
4045 	array[DEVCONF_NDISC_NOTIFY] = cnf->ndisc_notify;
4046 }
4047 
4048 static inline size_t inet6_ifla6_size(void)
4049 {
4050 	return nla_total_size(4) /* IFLA_INET6_FLAGS */
4051 	     + nla_total_size(sizeof(struct ifla_cacheinfo))
4052 	     + nla_total_size(DEVCONF_MAX * 4) /* IFLA_INET6_CONF */
4053 	     + nla_total_size(IPSTATS_MIB_MAX * 8) /* IFLA_INET6_STATS */
4054 	     + nla_total_size(ICMP6_MIB_MAX * 8); /* IFLA_INET6_ICMP6STATS */
4055 }
4056 
4057 static inline size_t inet6_if_nlmsg_size(void)
4058 {
4059 	return NLMSG_ALIGN(sizeof(struct ifinfomsg))
4060 	       + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
4061 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
4062 	       + nla_total_size(4) /* IFLA_MTU */
4063 	       + nla_total_size(4) /* IFLA_LINK */
4064 	       + nla_total_size(inet6_ifla6_size()); /* IFLA_PROTINFO */
4065 }
4066 
4067 static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
4068 				      int items, int bytes)
4069 {
4070 	int i;
4071 	int pad = bytes - sizeof(u64) * items;
4072 	BUG_ON(pad < 0);
4073 
4074 	/* Use put_unaligned() because stats may not be aligned for u64. */
4075 	put_unaligned(items, &stats[0]);
4076 	for (i = 1; i < items; i++)
4077 		put_unaligned(atomic_long_read(&mib[i]), &stats[i]);
4078 
4079 	memset(&stats[items], 0, pad);
4080 }
4081 
4082 static inline void __snmp6_fill_stats64(u64 *stats, void __percpu **mib,
4083 				      int items, int bytes, size_t syncpoff)
4084 {
4085 	int i;
4086 	int pad = bytes - sizeof(u64) * items;
4087 	BUG_ON(pad < 0);
4088 
4089 	/* Use put_unaligned() because stats may not be aligned for u64. */
4090 	put_unaligned(items, &stats[0]);
4091 	for (i = 1; i < items; i++)
4092 		put_unaligned(snmp_fold_field64(mib, i, syncpoff), &stats[i]);
4093 
4094 	memset(&stats[items], 0, pad);
4095 }
4096 
4097 static void snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int attrtype,
4098 			     int bytes)
4099 {
4100 	switch (attrtype) {
4101 	case IFLA_INET6_STATS:
4102 		__snmp6_fill_stats64(stats, (void __percpu **)idev->stats.ipv6,
4103 				     IPSTATS_MIB_MAX, bytes, offsetof(struct ipstats_mib, syncp));
4104 		break;
4105 	case IFLA_INET6_ICMP6STATS:
4106 		__snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs, ICMP6_MIB_MAX, bytes);
4107 		break;
4108 	}
4109 }
4110 
4111 static int inet6_fill_ifla6_attrs(struct sk_buff *skb, struct inet6_dev *idev)
4112 {
4113 	struct nlattr *nla;
4114 	struct ifla_cacheinfo ci;
4115 
4116 	if (nla_put_u32(skb, IFLA_INET6_FLAGS, idev->if_flags))
4117 		goto nla_put_failure;
4118 	ci.max_reasm_len = IPV6_MAXPLEN;
4119 	ci.tstamp = cstamp_delta(idev->tstamp);
4120 	ci.reachable_time = jiffies_to_msecs(idev->nd_parms->reachable_time);
4121 	ci.retrans_time = jiffies_to_msecs(idev->nd_parms->retrans_time);
4122 	if (nla_put(skb, IFLA_INET6_CACHEINFO, sizeof(ci), &ci))
4123 		goto nla_put_failure;
4124 	nla = nla_reserve(skb, IFLA_INET6_CONF, DEVCONF_MAX * sizeof(s32));
4125 	if (nla == NULL)
4126 		goto nla_put_failure;
4127 	ipv6_store_devconf(&idev->cnf, nla_data(nla), nla_len(nla));
4128 
4129 	/* XXX - MC not implemented */
4130 
4131 	nla = nla_reserve(skb, IFLA_INET6_STATS, IPSTATS_MIB_MAX * sizeof(u64));
4132 	if (nla == NULL)
4133 		goto nla_put_failure;
4134 	snmp6_fill_stats(nla_data(nla), idev, IFLA_INET6_STATS, nla_len(nla));
4135 
4136 	nla = nla_reserve(skb, IFLA_INET6_ICMP6STATS, ICMP6_MIB_MAX * sizeof(u64));
4137 	if (nla == NULL)
4138 		goto nla_put_failure;
4139 	snmp6_fill_stats(nla_data(nla), idev, IFLA_INET6_ICMP6STATS, nla_len(nla));
4140 
4141 	return 0;
4142 
4143 nla_put_failure:
4144 	return -EMSGSIZE;
4145 }
4146 
4147 static size_t inet6_get_link_af_size(const struct net_device *dev)
4148 {
4149 	if (!__in6_dev_get(dev))
4150 		return 0;
4151 
4152 	return inet6_ifla6_size();
4153 }
4154 
4155 static int inet6_fill_link_af(struct sk_buff *skb, const struct net_device *dev)
4156 {
4157 	struct inet6_dev *idev = __in6_dev_get(dev);
4158 
4159 	if (!idev)
4160 		return -ENODATA;
4161 
4162 	if (inet6_fill_ifla6_attrs(skb, idev) < 0)
4163 		return -EMSGSIZE;
4164 
4165 	return 0;
4166 }
4167 
4168 static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev,
4169 			     u32 portid, u32 seq, int event, unsigned int flags)
4170 {
4171 	struct net_device *dev = idev->dev;
4172 	struct ifinfomsg *hdr;
4173 	struct nlmsghdr *nlh;
4174 	void *protoinfo;
4175 
4176 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*hdr), flags);
4177 	if (nlh == NULL)
4178 		return -EMSGSIZE;
4179 
4180 	hdr = nlmsg_data(nlh);
4181 	hdr->ifi_family = AF_INET6;
4182 	hdr->__ifi_pad = 0;
4183 	hdr->ifi_type = dev->type;
4184 	hdr->ifi_index = dev->ifindex;
4185 	hdr->ifi_flags = dev_get_flags(dev);
4186 	hdr->ifi_change = 0;
4187 
4188 	if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
4189 	    (dev->addr_len &&
4190 	     nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) ||
4191 	    nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
4192 	    (dev->ifindex != dev->iflink &&
4193 	     nla_put_u32(skb, IFLA_LINK, dev->iflink)))
4194 		goto nla_put_failure;
4195 	protoinfo = nla_nest_start(skb, IFLA_PROTINFO);
4196 	if (protoinfo == NULL)
4197 		goto nla_put_failure;
4198 
4199 	if (inet6_fill_ifla6_attrs(skb, idev) < 0)
4200 		goto nla_put_failure;
4201 
4202 	nla_nest_end(skb, protoinfo);
4203 	return nlmsg_end(skb, nlh);
4204 
4205 nla_put_failure:
4206 	nlmsg_cancel(skb, nlh);
4207 	return -EMSGSIZE;
4208 }
4209 
4210 static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
4211 {
4212 	struct net *net = sock_net(skb->sk);
4213 	int h, s_h;
4214 	int idx = 0, s_idx;
4215 	struct net_device *dev;
4216 	struct inet6_dev *idev;
4217 	struct hlist_head *head;
4218 	struct hlist_node *node;
4219 
4220 	s_h = cb->args[0];
4221 	s_idx = cb->args[1];
4222 
4223 	rcu_read_lock();
4224 	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
4225 		idx = 0;
4226 		head = &net->dev_index_head[h];
4227 		hlist_for_each_entry_rcu(dev, node, head, index_hlist) {
4228 			if (idx < s_idx)
4229 				goto cont;
4230 			idev = __in6_dev_get(dev);
4231 			if (!idev)
4232 				goto cont;
4233 			if (inet6_fill_ifinfo(skb, idev,
4234 					      NETLINK_CB(cb->skb).portid,
4235 					      cb->nlh->nlmsg_seq,
4236 					      RTM_NEWLINK, NLM_F_MULTI) <= 0)
4237 				goto out;
4238 cont:
4239 			idx++;
4240 		}
4241 	}
4242 out:
4243 	rcu_read_unlock();
4244 	cb->args[1] = idx;
4245 	cb->args[0] = h;
4246 
4247 	return skb->len;
4248 }
4249 
4250 void inet6_ifinfo_notify(int event, struct inet6_dev *idev)
4251 {
4252 	struct sk_buff *skb;
4253 	struct net *net = dev_net(idev->dev);
4254 	int err = -ENOBUFS;
4255 
4256 	skb = nlmsg_new(inet6_if_nlmsg_size(), GFP_ATOMIC);
4257 	if (skb == NULL)
4258 		goto errout;
4259 
4260 	err = inet6_fill_ifinfo(skb, idev, 0, 0, event, 0);
4261 	if (err < 0) {
4262 		/* -EMSGSIZE implies BUG in inet6_if_nlmsg_size() */
4263 		WARN_ON(err == -EMSGSIZE);
4264 		kfree_skb(skb);
4265 		goto errout;
4266 	}
4267 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_IFINFO, NULL, GFP_ATOMIC);
4268 	return;
4269 errout:
4270 	if (err < 0)
4271 		rtnl_set_sk_err(net, RTNLGRP_IPV6_IFINFO, err);
4272 }
4273 
4274 static inline size_t inet6_prefix_nlmsg_size(void)
4275 {
4276 	return NLMSG_ALIGN(sizeof(struct prefixmsg))
4277 	       + nla_total_size(sizeof(struct in6_addr))
4278 	       + nla_total_size(sizeof(struct prefix_cacheinfo));
4279 }
4280 
4281 static int inet6_fill_prefix(struct sk_buff *skb, struct inet6_dev *idev,
4282 			     struct prefix_info *pinfo, u32 portid, u32 seq,
4283 			     int event, unsigned int flags)
4284 {
4285 	struct prefixmsg *pmsg;
4286 	struct nlmsghdr *nlh;
4287 	struct prefix_cacheinfo	ci;
4288 
4289 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*pmsg), flags);
4290 	if (nlh == NULL)
4291 		return -EMSGSIZE;
4292 
4293 	pmsg = nlmsg_data(nlh);
4294 	pmsg->prefix_family = AF_INET6;
4295 	pmsg->prefix_pad1 = 0;
4296 	pmsg->prefix_pad2 = 0;
4297 	pmsg->prefix_ifindex = idev->dev->ifindex;
4298 	pmsg->prefix_len = pinfo->prefix_len;
4299 	pmsg->prefix_type = pinfo->type;
4300 	pmsg->prefix_pad3 = 0;
4301 	pmsg->prefix_flags = 0;
4302 	if (pinfo->onlink)
4303 		pmsg->prefix_flags |= IF_PREFIX_ONLINK;
4304 	if (pinfo->autoconf)
4305 		pmsg->prefix_flags |= IF_PREFIX_AUTOCONF;
4306 
4307 	if (nla_put(skb, PREFIX_ADDRESS, sizeof(pinfo->prefix), &pinfo->prefix))
4308 		goto nla_put_failure;
4309 	ci.preferred_time = ntohl(pinfo->prefered);
4310 	ci.valid_time = ntohl(pinfo->valid);
4311 	if (nla_put(skb, PREFIX_CACHEINFO, sizeof(ci), &ci))
4312 		goto nla_put_failure;
4313 	return nlmsg_end(skb, nlh);
4314 
4315 nla_put_failure:
4316 	nlmsg_cancel(skb, nlh);
4317 	return -EMSGSIZE;
4318 }
4319 
4320 static void inet6_prefix_notify(int event, struct inet6_dev *idev,
4321 			 struct prefix_info *pinfo)
4322 {
4323 	struct sk_buff *skb;
4324 	struct net *net = dev_net(idev->dev);
4325 	int err = -ENOBUFS;
4326 
4327 	skb = nlmsg_new(inet6_prefix_nlmsg_size(), GFP_ATOMIC);
4328 	if (skb == NULL)
4329 		goto errout;
4330 
4331 	err = inet6_fill_prefix(skb, idev, pinfo, 0, 0, event, 0);
4332 	if (err < 0) {
4333 		/* -EMSGSIZE implies BUG in inet6_prefix_nlmsg_size() */
4334 		WARN_ON(err == -EMSGSIZE);
4335 		kfree_skb(skb);
4336 		goto errout;
4337 	}
4338 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_PREFIX, NULL, GFP_ATOMIC);
4339 	return;
4340 errout:
4341 	if (err < 0)
4342 		rtnl_set_sk_err(net, RTNLGRP_IPV6_PREFIX, err);
4343 }
4344 
4345 static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
4346 {
4347 	inet6_ifa_notify(event ? : RTM_NEWADDR, ifp);
4348 
4349 	switch (event) {
4350 	case RTM_NEWADDR:
4351 		/*
4352 		 * If the address was optimistic
4353 		 * we inserted the route at the start of
4354 		 * our DAD process, so we don't need
4355 		 * to do it again
4356 		 */
4357 		if (!(ifp->rt->rt6i_node))
4358 			ip6_ins_rt(ifp->rt);
4359 		if (ifp->idev->cnf.forwarding)
4360 			addrconf_join_anycast(ifp);
4361 		break;
4362 	case RTM_DELADDR:
4363 		if (ifp->idev->cnf.forwarding)
4364 			addrconf_leave_anycast(ifp);
4365 		addrconf_leave_solict(ifp->idev, &ifp->addr);
4366 		dst_hold(&ifp->rt->dst);
4367 
4368 		if (ip6_del_rt(ifp->rt))
4369 			dst_free(&ifp->rt->dst);
4370 		break;
4371 	}
4372 }
4373 
4374 static void ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
4375 {
4376 	rcu_read_lock_bh();
4377 	if (likely(ifp->idev->dead == 0))
4378 		__ipv6_ifa_notify(event, ifp);
4379 	rcu_read_unlock_bh();
4380 }
4381 
4382 #ifdef CONFIG_SYSCTL
4383 
4384 static
4385 int addrconf_sysctl_forward(ctl_table *ctl, int write,
4386 			   void __user *buffer, size_t *lenp, loff_t *ppos)
4387 {
4388 	int *valp = ctl->data;
4389 	int val = *valp;
4390 	loff_t pos = *ppos;
4391 	ctl_table lctl;
4392 	int ret;
4393 
4394 	/*
4395 	 * ctl->data points to idev->cnf.forwarding, we should
4396 	 * not modify it until we get the rtnl lock.
4397 	 */
4398 	lctl = *ctl;
4399 	lctl.data = &val;
4400 
4401 	ret = proc_dointvec(&lctl, write, buffer, lenp, ppos);
4402 
4403 	if (write)
4404 		ret = addrconf_fixup_forwarding(ctl, valp, val);
4405 	if (ret)
4406 		*ppos = pos;
4407 	return ret;
4408 }
4409 
4410 static void dev_disable_change(struct inet6_dev *idev)
4411 {
4412 	if (!idev || !idev->dev)
4413 		return;
4414 
4415 	if (idev->cnf.disable_ipv6)
4416 		addrconf_notify(NULL, NETDEV_DOWN, idev->dev);
4417 	else
4418 		addrconf_notify(NULL, NETDEV_UP, idev->dev);
4419 }
4420 
4421 static void addrconf_disable_change(struct net *net, __s32 newf)
4422 {
4423 	struct net_device *dev;
4424 	struct inet6_dev *idev;
4425 
4426 	rcu_read_lock();
4427 	for_each_netdev_rcu(net, dev) {
4428 		idev = __in6_dev_get(dev);
4429 		if (idev) {
4430 			int changed = (!idev->cnf.disable_ipv6) ^ (!newf);
4431 			idev->cnf.disable_ipv6 = newf;
4432 			if (changed)
4433 				dev_disable_change(idev);
4434 		}
4435 	}
4436 	rcu_read_unlock();
4437 }
4438 
4439 static int addrconf_disable_ipv6(struct ctl_table *table, int *p, int newf)
4440 {
4441 	struct net *net;
4442 	int old;
4443 
4444 	if (!rtnl_trylock())
4445 		return restart_syscall();
4446 
4447 	net = (struct net *)table->extra2;
4448 	old = *p;
4449 	*p = newf;
4450 
4451 	if (p == &net->ipv6.devconf_dflt->disable_ipv6) {
4452 		rtnl_unlock();
4453 		return 0;
4454 	}
4455 
4456 	if (p == &net->ipv6.devconf_all->disable_ipv6) {
4457 		net->ipv6.devconf_dflt->disable_ipv6 = newf;
4458 		addrconf_disable_change(net, newf);
4459 	} else if ((!newf) ^ (!old))
4460 		dev_disable_change((struct inet6_dev *)table->extra1);
4461 
4462 	rtnl_unlock();
4463 	return 0;
4464 }
4465 
4466 static
4467 int addrconf_sysctl_disable(ctl_table *ctl, int write,
4468 			    void __user *buffer, size_t *lenp, loff_t *ppos)
4469 {
4470 	int *valp = ctl->data;
4471 	int val = *valp;
4472 	loff_t pos = *ppos;
4473 	ctl_table lctl;
4474 	int ret;
4475 
4476 	/*
4477 	 * ctl->data points to idev->cnf.disable_ipv6, we should
4478 	 * not modify it until we get the rtnl lock.
4479 	 */
4480 	lctl = *ctl;
4481 	lctl.data = &val;
4482 
4483 	ret = proc_dointvec(&lctl, write, buffer, lenp, ppos);
4484 
4485 	if (write)
4486 		ret = addrconf_disable_ipv6(ctl, valp, val);
4487 	if (ret)
4488 		*ppos = pos;
4489 	return ret;
4490 }
4491 
4492 static struct addrconf_sysctl_table
4493 {
4494 	struct ctl_table_header *sysctl_header;
4495 	ctl_table addrconf_vars[DEVCONF_MAX+1];
4496 } addrconf_sysctl __read_mostly = {
4497 	.sysctl_header = NULL,
4498 	.addrconf_vars = {
4499 		{
4500 			.procname	= "forwarding",
4501 			.data		= &ipv6_devconf.forwarding,
4502 			.maxlen		= sizeof(int),
4503 			.mode		= 0644,
4504 			.proc_handler	= addrconf_sysctl_forward,
4505 		},
4506 		{
4507 			.procname	= "hop_limit",
4508 			.data		= &ipv6_devconf.hop_limit,
4509 			.maxlen		= sizeof(int),
4510 			.mode		= 0644,
4511 			.proc_handler	= proc_dointvec,
4512 		},
4513 		{
4514 			.procname	= "mtu",
4515 			.data		= &ipv6_devconf.mtu6,
4516 			.maxlen		= sizeof(int),
4517 			.mode		= 0644,
4518 			.proc_handler	= proc_dointvec,
4519 		},
4520 		{
4521 			.procname	= "accept_ra",
4522 			.data		= &ipv6_devconf.accept_ra,
4523 			.maxlen		= sizeof(int),
4524 			.mode		= 0644,
4525 			.proc_handler	= proc_dointvec,
4526 		},
4527 		{
4528 			.procname	= "accept_redirects",
4529 			.data		= &ipv6_devconf.accept_redirects,
4530 			.maxlen		= sizeof(int),
4531 			.mode		= 0644,
4532 			.proc_handler	= proc_dointvec,
4533 		},
4534 		{
4535 			.procname	= "autoconf",
4536 			.data		= &ipv6_devconf.autoconf,
4537 			.maxlen		= sizeof(int),
4538 			.mode		= 0644,
4539 			.proc_handler	= proc_dointvec,
4540 		},
4541 		{
4542 			.procname	= "dad_transmits",
4543 			.data		= &ipv6_devconf.dad_transmits,
4544 			.maxlen		= sizeof(int),
4545 			.mode		= 0644,
4546 			.proc_handler	= proc_dointvec,
4547 		},
4548 		{
4549 			.procname	= "router_solicitations",
4550 			.data		= &ipv6_devconf.rtr_solicits,
4551 			.maxlen		= sizeof(int),
4552 			.mode		= 0644,
4553 			.proc_handler	= proc_dointvec,
4554 		},
4555 		{
4556 			.procname	= "router_solicitation_interval",
4557 			.data		= &ipv6_devconf.rtr_solicit_interval,
4558 			.maxlen		= sizeof(int),
4559 			.mode		= 0644,
4560 			.proc_handler	= proc_dointvec_jiffies,
4561 		},
4562 		{
4563 			.procname	= "router_solicitation_delay",
4564 			.data		= &ipv6_devconf.rtr_solicit_delay,
4565 			.maxlen		= sizeof(int),
4566 			.mode		= 0644,
4567 			.proc_handler	= proc_dointvec_jiffies,
4568 		},
4569 		{
4570 			.procname	= "force_mld_version",
4571 			.data		= &ipv6_devconf.force_mld_version,
4572 			.maxlen		= sizeof(int),
4573 			.mode		= 0644,
4574 			.proc_handler	= proc_dointvec,
4575 		},
4576 #ifdef CONFIG_IPV6_PRIVACY
4577 		{
4578 			.procname	= "use_tempaddr",
4579 			.data		= &ipv6_devconf.use_tempaddr,
4580 			.maxlen		= sizeof(int),
4581 			.mode		= 0644,
4582 			.proc_handler	= proc_dointvec,
4583 		},
4584 		{
4585 			.procname	= "temp_valid_lft",
4586 			.data		= &ipv6_devconf.temp_valid_lft,
4587 			.maxlen		= sizeof(int),
4588 			.mode		= 0644,
4589 			.proc_handler	= proc_dointvec,
4590 		},
4591 		{
4592 			.procname	= "temp_prefered_lft",
4593 			.data		= &ipv6_devconf.temp_prefered_lft,
4594 			.maxlen		= sizeof(int),
4595 			.mode		= 0644,
4596 			.proc_handler	= proc_dointvec,
4597 		},
4598 		{
4599 			.procname	= "regen_max_retry",
4600 			.data		= &ipv6_devconf.regen_max_retry,
4601 			.maxlen		= sizeof(int),
4602 			.mode		= 0644,
4603 			.proc_handler	= proc_dointvec,
4604 		},
4605 		{
4606 			.procname	= "max_desync_factor",
4607 			.data		= &ipv6_devconf.max_desync_factor,
4608 			.maxlen		= sizeof(int),
4609 			.mode		= 0644,
4610 			.proc_handler	= proc_dointvec,
4611 		},
4612 #endif
4613 		{
4614 			.procname	= "max_addresses",
4615 			.data		= &ipv6_devconf.max_addresses,
4616 			.maxlen		= sizeof(int),
4617 			.mode		= 0644,
4618 			.proc_handler	= proc_dointvec,
4619 		},
4620 		{
4621 			.procname	= "accept_ra_defrtr",
4622 			.data		= &ipv6_devconf.accept_ra_defrtr,
4623 			.maxlen		= sizeof(int),
4624 			.mode		= 0644,
4625 			.proc_handler	= proc_dointvec,
4626 		},
4627 		{
4628 			.procname	= "accept_ra_pinfo",
4629 			.data		= &ipv6_devconf.accept_ra_pinfo,
4630 			.maxlen		= sizeof(int),
4631 			.mode		= 0644,
4632 			.proc_handler	= proc_dointvec,
4633 		},
4634 #ifdef CONFIG_IPV6_ROUTER_PREF
4635 		{
4636 			.procname	= "accept_ra_rtr_pref",
4637 			.data		= &ipv6_devconf.accept_ra_rtr_pref,
4638 			.maxlen		= sizeof(int),
4639 			.mode		= 0644,
4640 			.proc_handler	= proc_dointvec,
4641 		},
4642 		{
4643 			.procname	= "router_probe_interval",
4644 			.data		= &ipv6_devconf.rtr_probe_interval,
4645 			.maxlen		= sizeof(int),
4646 			.mode		= 0644,
4647 			.proc_handler	= proc_dointvec_jiffies,
4648 		},
4649 #ifdef CONFIG_IPV6_ROUTE_INFO
4650 		{
4651 			.procname	= "accept_ra_rt_info_max_plen",
4652 			.data		= &ipv6_devconf.accept_ra_rt_info_max_plen,
4653 			.maxlen		= sizeof(int),
4654 			.mode		= 0644,
4655 			.proc_handler	= proc_dointvec,
4656 		},
4657 #endif
4658 #endif
4659 		{
4660 			.procname	= "proxy_ndp",
4661 			.data		= &ipv6_devconf.proxy_ndp,
4662 			.maxlen		= sizeof(int),
4663 			.mode		= 0644,
4664 			.proc_handler	= proc_dointvec,
4665 		},
4666 		{
4667 			.procname	= "accept_source_route",
4668 			.data		= &ipv6_devconf.accept_source_route,
4669 			.maxlen		= sizeof(int),
4670 			.mode		= 0644,
4671 			.proc_handler	= proc_dointvec,
4672 		},
4673 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
4674 		{
4675 			.procname       = "optimistic_dad",
4676 			.data           = &ipv6_devconf.optimistic_dad,
4677 			.maxlen         = sizeof(int),
4678 			.mode           = 0644,
4679 			.proc_handler   = proc_dointvec,
4680 
4681 		},
4682 #endif
4683 #ifdef CONFIG_IPV6_MROUTE
4684 		{
4685 			.procname	= "mc_forwarding",
4686 			.data		= &ipv6_devconf.mc_forwarding,
4687 			.maxlen		= sizeof(int),
4688 			.mode		= 0444,
4689 			.proc_handler	= proc_dointvec,
4690 		},
4691 #endif
4692 		{
4693 			.procname	= "disable_ipv6",
4694 			.data		= &ipv6_devconf.disable_ipv6,
4695 			.maxlen		= sizeof(int),
4696 			.mode		= 0644,
4697 			.proc_handler	= addrconf_sysctl_disable,
4698 		},
4699 		{
4700 			.procname	= "accept_dad",
4701 			.data		= &ipv6_devconf.accept_dad,
4702 			.maxlen		= sizeof(int),
4703 			.mode		= 0644,
4704 			.proc_handler	= proc_dointvec,
4705 		},
4706 		{
4707 			.procname       = "force_tllao",
4708 			.data           = &ipv6_devconf.force_tllao,
4709 			.maxlen         = sizeof(int),
4710 			.mode           = 0644,
4711 			.proc_handler   = proc_dointvec
4712 		},
4713 		{
4714 			.procname       = "ndisc_notify",
4715 			.data           = &ipv6_devconf.ndisc_notify,
4716 			.maxlen         = sizeof(int),
4717 			.mode           = 0644,
4718 			.proc_handler   = proc_dointvec
4719 		},
4720 		{
4721 			/* sentinel */
4722 		}
4723 	},
4724 };
4725 
4726 static int __addrconf_sysctl_register(struct net *net, char *dev_name,
4727 		struct inet6_dev *idev, struct ipv6_devconf *p)
4728 {
4729 	int i;
4730 	struct addrconf_sysctl_table *t;
4731 	char path[sizeof("net/ipv6/conf/") + IFNAMSIZ];
4732 
4733 	t = kmemdup(&addrconf_sysctl, sizeof(*t), GFP_KERNEL);
4734 	if (t == NULL)
4735 		goto out;
4736 
4737 	for (i = 0; t->addrconf_vars[i].data; i++) {
4738 		t->addrconf_vars[i].data += (char *)p - (char *)&ipv6_devconf;
4739 		t->addrconf_vars[i].extra1 = idev; /* embedded; no ref */
4740 		t->addrconf_vars[i].extra2 = net;
4741 	}
4742 
4743 	snprintf(path, sizeof(path), "net/ipv6/conf/%s", dev_name);
4744 
4745 	t->sysctl_header = register_net_sysctl(net, path, t->addrconf_vars);
4746 	if (t->sysctl_header == NULL)
4747 		goto free;
4748 
4749 	p->sysctl = t;
4750 	return 0;
4751 
4752 free:
4753 	kfree(t);
4754 out:
4755 	return -ENOBUFS;
4756 }
4757 
4758 static void __addrconf_sysctl_unregister(struct ipv6_devconf *p)
4759 {
4760 	struct addrconf_sysctl_table *t;
4761 
4762 	if (p->sysctl == NULL)
4763 		return;
4764 
4765 	t = p->sysctl;
4766 	p->sysctl = NULL;
4767 	unregister_net_sysctl_table(t->sysctl_header);
4768 	kfree(t);
4769 }
4770 
4771 static void addrconf_sysctl_register(struct inet6_dev *idev)
4772 {
4773 	neigh_sysctl_register(idev->dev, idev->nd_parms, "ipv6",
4774 			      &ndisc_ifinfo_sysctl_change);
4775 	__addrconf_sysctl_register(dev_net(idev->dev), idev->dev->name,
4776 					idev, &idev->cnf);
4777 }
4778 
4779 static void addrconf_sysctl_unregister(struct inet6_dev *idev)
4780 {
4781 	__addrconf_sysctl_unregister(&idev->cnf);
4782 	neigh_sysctl_unregister(idev->nd_parms);
4783 }
4784 
4785 
4786 #endif
4787 
4788 static int __net_init addrconf_init_net(struct net *net)
4789 {
4790 	int err;
4791 	struct ipv6_devconf *all, *dflt;
4792 
4793 	err = -ENOMEM;
4794 	all = &ipv6_devconf;
4795 	dflt = &ipv6_devconf_dflt;
4796 
4797 	if (!net_eq(net, &init_net)) {
4798 		all = kmemdup(all, sizeof(ipv6_devconf), GFP_KERNEL);
4799 		if (all == NULL)
4800 			goto err_alloc_all;
4801 
4802 		dflt = kmemdup(dflt, sizeof(ipv6_devconf_dflt), GFP_KERNEL);
4803 		if (dflt == NULL)
4804 			goto err_alloc_dflt;
4805 	} else {
4806 		/* these will be inherited by all namespaces */
4807 		dflt->autoconf = ipv6_defaults.autoconf;
4808 		dflt->disable_ipv6 = ipv6_defaults.disable_ipv6;
4809 	}
4810 
4811 	net->ipv6.devconf_all = all;
4812 	net->ipv6.devconf_dflt = dflt;
4813 
4814 #ifdef CONFIG_SYSCTL
4815 	err = __addrconf_sysctl_register(net, "all", NULL, all);
4816 	if (err < 0)
4817 		goto err_reg_all;
4818 
4819 	err = __addrconf_sysctl_register(net, "default", NULL, dflt);
4820 	if (err < 0)
4821 		goto err_reg_dflt;
4822 #endif
4823 	return 0;
4824 
4825 #ifdef CONFIG_SYSCTL
4826 err_reg_dflt:
4827 	__addrconf_sysctl_unregister(all);
4828 err_reg_all:
4829 	kfree(dflt);
4830 #endif
4831 err_alloc_dflt:
4832 	kfree(all);
4833 err_alloc_all:
4834 	return err;
4835 }
4836 
4837 static void __net_exit addrconf_exit_net(struct net *net)
4838 {
4839 #ifdef CONFIG_SYSCTL
4840 	__addrconf_sysctl_unregister(net->ipv6.devconf_dflt);
4841 	__addrconf_sysctl_unregister(net->ipv6.devconf_all);
4842 #endif
4843 	if (!net_eq(net, &init_net)) {
4844 		kfree(net->ipv6.devconf_dflt);
4845 		kfree(net->ipv6.devconf_all);
4846 	}
4847 }
4848 
4849 static struct pernet_operations addrconf_ops = {
4850 	.init = addrconf_init_net,
4851 	.exit = addrconf_exit_net,
4852 };
4853 
4854 /*
4855  *      Device notifier
4856  */
4857 
4858 int register_inet6addr_notifier(struct notifier_block *nb)
4859 {
4860 	return atomic_notifier_chain_register(&inet6addr_chain, nb);
4861 }
4862 EXPORT_SYMBOL(register_inet6addr_notifier);
4863 
4864 int unregister_inet6addr_notifier(struct notifier_block *nb)
4865 {
4866 	return atomic_notifier_chain_unregister(&inet6addr_chain, nb);
4867 }
4868 EXPORT_SYMBOL(unregister_inet6addr_notifier);
4869 
4870 static struct rtnl_af_ops inet6_ops = {
4871 	.family		  = AF_INET6,
4872 	.fill_link_af	  = inet6_fill_link_af,
4873 	.get_link_af_size = inet6_get_link_af_size,
4874 };
4875 
4876 /*
4877  *	Init / cleanup code
4878  */
4879 
4880 int __init addrconf_init(void)
4881 {
4882 	int i, err;
4883 
4884 	err = ipv6_addr_label_init();
4885 	if (err < 0) {
4886 		pr_crit("%s: cannot initialize default policy table: %d\n",
4887 			__func__, err);
4888 		goto out;
4889 	}
4890 
4891 	err = register_pernet_subsys(&addrconf_ops);
4892 	if (err < 0)
4893 		goto out_addrlabel;
4894 
4895 	/* The addrconf netdev notifier requires that loopback_dev
4896 	 * has it's ipv6 private information allocated and setup
4897 	 * before it can bring up and give link-local addresses
4898 	 * to other devices which are up.
4899 	 *
4900 	 * Unfortunately, loopback_dev is not necessarily the first
4901 	 * entry in the global dev_base list of net devices.  In fact,
4902 	 * it is likely to be the very last entry on that list.
4903 	 * So this causes the notifier registry below to try and
4904 	 * give link-local addresses to all devices besides loopback_dev
4905 	 * first, then loopback_dev, which cases all the non-loopback_dev
4906 	 * devices to fail to get a link-local address.
4907 	 *
4908 	 * So, as a temporary fix, allocate the ipv6 structure for
4909 	 * loopback_dev first by hand.
4910 	 * Longer term, all of the dependencies ipv6 has upon the loopback
4911 	 * device and it being up should be removed.
4912 	 */
4913 	rtnl_lock();
4914 	if (!ipv6_add_dev(init_net.loopback_dev))
4915 		err = -ENOMEM;
4916 	rtnl_unlock();
4917 	if (err)
4918 		goto errlo;
4919 
4920 	for (i = 0; i < IN6_ADDR_HSIZE; i++)
4921 		INIT_HLIST_HEAD(&inet6_addr_lst[i]);
4922 
4923 	register_netdevice_notifier(&ipv6_dev_notf);
4924 
4925 	addrconf_verify(0);
4926 
4927 	err = rtnl_af_register(&inet6_ops);
4928 	if (err < 0)
4929 		goto errout_af;
4930 
4931 	err = __rtnl_register(PF_INET6, RTM_GETLINK, NULL, inet6_dump_ifinfo,
4932 			      NULL);
4933 	if (err < 0)
4934 		goto errout;
4935 
4936 	/* Only the first call to __rtnl_register can fail */
4937 	__rtnl_register(PF_INET6, RTM_NEWADDR, inet6_rtm_newaddr, NULL, NULL);
4938 	__rtnl_register(PF_INET6, RTM_DELADDR, inet6_rtm_deladdr, NULL, NULL);
4939 	__rtnl_register(PF_INET6, RTM_GETADDR, inet6_rtm_getaddr,
4940 			inet6_dump_ifaddr, NULL);
4941 	__rtnl_register(PF_INET6, RTM_GETMULTICAST, NULL,
4942 			inet6_dump_ifmcaddr, NULL);
4943 	__rtnl_register(PF_INET6, RTM_GETANYCAST, NULL,
4944 			inet6_dump_ifacaddr, NULL);
4945 	__rtnl_register(PF_INET6, RTM_GETNETCONF, inet6_netconf_get_devconf,
4946 			NULL, NULL);
4947 
4948 	ipv6_addr_label_rtnl_register();
4949 
4950 	return 0;
4951 errout:
4952 	rtnl_af_unregister(&inet6_ops);
4953 errout_af:
4954 	unregister_netdevice_notifier(&ipv6_dev_notf);
4955 errlo:
4956 	unregister_pernet_subsys(&addrconf_ops);
4957 out_addrlabel:
4958 	ipv6_addr_label_cleanup();
4959 out:
4960 	return err;
4961 }
4962 
4963 void addrconf_cleanup(void)
4964 {
4965 	struct net_device *dev;
4966 	int i;
4967 
4968 	unregister_netdevice_notifier(&ipv6_dev_notf);
4969 	unregister_pernet_subsys(&addrconf_ops);
4970 	ipv6_addr_label_cleanup();
4971 
4972 	rtnl_lock();
4973 
4974 	__rtnl_af_unregister(&inet6_ops);
4975 
4976 	/* clean dev list */
4977 	for_each_netdev(&init_net, dev) {
4978 		if (__in6_dev_get(dev) == NULL)
4979 			continue;
4980 		addrconf_ifdown(dev, 1);
4981 	}
4982 	addrconf_ifdown(init_net.loopback_dev, 2);
4983 
4984 	/*
4985 	 *	Check hash table.
4986 	 */
4987 	spin_lock_bh(&addrconf_hash_lock);
4988 	for (i = 0; i < IN6_ADDR_HSIZE; i++)
4989 		WARN_ON(!hlist_empty(&inet6_addr_lst[i]));
4990 	spin_unlock_bh(&addrconf_hash_lock);
4991 
4992 	del_timer(&addr_chk_timer);
4993 	rtnl_unlock();
4994 }
4995