xref: /linux/net/ipv6/addrconf.c (revision d96fc832bcb6269d96e33d506f33033d7ed08598)
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/sched/signal.h>
47 #include <linux/socket.h>
48 #include <linux/sockios.h>
49 #include <linux/net.h>
50 #include <linux/inet.h>
51 #include <linux/in6.h>
52 #include <linux/netdevice.h>
53 #include <linux/if_addr.h>
54 #include <linux/if_arp.h>
55 #include <linux/if_arcnet.h>
56 #include <linux/if_infiniband.h>
57 #include <linux/route.h>
58 #include <linux/inetdevice.h>
59 #include <linux/init.h>
60 #include <linux/slab.h>
61 #ifdef CONFIG_SYSCTL
62 #include <linux/sysctl.h>
63 #endif
64 #include <linux/capability.h>
65 #include <linux/delay.h>
66 #include <linux/notifier.h>
67 #include <linux/string.h>
68 #include <linux/hash.h>
69 
70 #include <net/net_namespace.h>
71 #include <net/sock.h>
72 #include <net/snmp.h>
73 
74 #include <net/6lowpan.h>
75 #include <net/firewire.h>
76 #include <net/ipv6.h>
77 #include <net/protocol.h>
78 #include <net/ndisc.h>
79 #include <net/ip6_route.h>
80 #include <net/addrconf.h>
81 #include <net/tcp.h>
82 #include <net/ip.h>
83 #include <net/netlink.h>
84 #include <net/pkt_sched.h>
85 #include <net/l3mdev.h>
86 #include <linux/if_tunnel.h>
87 #include <linux/rtnetlink.h>
88 #include <linux/netconf.h>
89 #include <linux/random.h>
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(fmt, ...) printk(fmt, ##__VA_ARGS__)
102 #else
103 #define ADBG(fmt, ...) do { if (0) printk(fmt, ##__VA_ARGS__); } while (0)
104 #endif
105 
106 #define	INFINITY_LIFE_TIME	0xFFFFFFFF
107 
108 #define IPV6_MAX_STRLEN \
109 	sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")
110 
111 static inline u32 cstamp_delta(unsigned long cstamp)
112 {
113 	return (cstamp - INITIAL_JIFFIES) * 100UL / HZ;
114 }
115 
116 static inline s32 rfc3315_s14_backoff_init(s32 irt)
117 {
118 	/* multiply 'initial retransmission time' by 0.9 .. 1.1 */
119 	u64 tmp = (900000 + prandom_u32() % 200001) * (u64)irt;
120 	do_div(tmp, 1000000);
121 	return (s32)tmp;
122 }
123 
124 static inline s32 rfc3315_s14_backoff_update(s32 rt, s32 mrt)
125 {
126 	/* multiply 'retransmission timeout' by 1.9 .. 2.1 */
127 	u64 tmp = (1900000 + prandom_u32() % 200001) * (u64)rt;
128 	do_div(tmp, 1000000);
129 	if ((s32)tmp > mrt) {
130 		/* multiply 'maximum retransmission time' by 0.9 .. 1.1 */
131 		tmp = (900000 + prandom_u32() % 200001) * (u64)mrt;
132 		do_div(tmp, 1000000);
133 	}
134 	return (s32)tmp;
135 }
136 
137 #ifdef CONFIG_SYSCTL
138 static int addrconf_sysctl_register(struct inet6_dev *idev);
139 static void addrconf_sysctl_unregister(struct inet6_dev *idev);
140 #else
141 static inline int addrconf_sysctl_register(struct inet6_dev *idev)
142 {
143 	return 0;
144 }
145 
146 static inline void addrconf_sysctl_unregister(struct inet6_dev *idev)
147 {
148 }
149 #endif
150 
151 static void ipv6_regen_rndid(struct inet6_dev *idev);
152 static void ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr);
153 
154 static int ipv6_generate_eui64(u8 *eui, struct net_device *dev);
155 static int ipv6_count_addresses(const struct inet6_dev *idev);
156 static int ipv6_generate_stable_address(struct in6_addr *addr,
157 					u8 dad_count,
158 					const struct inet6_dev *idev);
159 
160 #define IN6_ADDR_HSIZE_SHIFT	8
161 #define IN6_ADDR_HSIZE		(1 << IN6_ADDR_HSIZE_SHIFT)
162 /*
163  *	Configured unicast address hash table
164  */
165 static struct hlist_head inet6_addr_lst[IN6_ADDR_HSIZE];
166 static DEFINE_SPINLOCK(addrconf_hash_lock);
167 
168 static void addrconf_verify(void);
169 static void addrconf_verify_rtnl(void);
170 static void addrconf_verify_work(struct work_struct *);
171 
172 static struct workqueue_struct *addrconf_wq;
173 static DECLARE_DELAYED_WORK(addr_chk_work, addrconf_verify_work);
174 
175 static void addrconf_join_anycast(struct inet6_ifaddr *ifp);
176 static void addrconf_leave_anycast(struct inet6_ifaddr *ifp);
177 
178 static void addrconf_type_change(struct net_device *dev,
179 				 unsigned long event);
180 static int addrconf_ifdown(struct net_device *dev, int how);
181 
182 static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
183 						  int plen,
184 						  const struct net_device *dev,
185 						  u32 flags, u32 noflags);
186 
187 static void addrconf_dad_start(struct inet6_ifaddr *ifp);
188 static void addrconf_dad_work(struct work_struct *w);
189 static void addrconf_dad_completed(struct inet6_ifaddr *ifp, bool bump_id,
190 				   bool send_na);
191 static void addrconf_dad_run(struct inet6_dev *idev);
192 static void addrconf_rs_timer(struct timer_list *t);
193 static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifa);
194 static void ipv6_ifa_notify(int event, struct inet6_ifaddr *ifa);
195 
196 static void inet6_prefix_notify(int event, struct inet6_dev *idev,
197 				struct prefix_info *pinfo);
198 
199 static struct ipv6_devconf ipv6_devconf __read_mostly = {
200 	.forwarding		= 0,
201 	.hop_limit		= IPV6_DEFAULT_HOPLIMIT,
202 	.mtu6			= IPV6_MIN_MTU,
203 	.accept_ra		= 1,
204 	.accept_redirects	= 1,
205 	.autoconf		= 1,
206 	.force_mld_version	= 0,
207 	.mldv1_unsolicited_report_interval = 10 * HZ,
208 	.mldv2_unsolicited_report_interval = HZ,
209 	.dad_transmits		= 1,
210 	.rtr_solicits		= MAX_RTR_SOLICITATIONS,
211 	.rtr_solicit_interval	= RTR_SOLICITATION_INTERVAL,
212 	.rtr_solicit_max_interval = RTR_SOLICITATION_MAX_INTERVAL,
213 	.rtr_solicit_delay	= MAX_RTR_SOLICITATION_DELAY,
214 	.use_tempaddr		= 0,
215 	.temp_valid_lft		= TEMP_VALID_LIFETIME,
216 	.temp_prefered_lft	= TEMP_PREFERRED_LIFETIME,
217 	.regen_max_retry	= REGEN_MAX_RETRY,
218 	.max_desync_factor	= MAX_DESYNC_FACTOR,
219 	.max_addresses		= IPV6_MAX_ADDRESSES,
220 	.accept_ra_defrtr	= 1,
221 	.accept_ra_from_local	= 0,
222 	.accept_ra_min_hop_limit= 1,
223 	.accept_ra_pinfo	= 1,
224 #ifdef CONFIG_IPV6_ROUTER_PREF
225 	.accept_ra_rtr_pref	= 1,
226 	.rtr_probe_interval	= 60 * HZ,
227 #ifdef CONFIG_IPV6_ROUTE_INFO
228 	.accept_ra_rt_info_min_plen = 0,
229 	.accept_ra_rt_info_max_plen = 0,
230 #endif
231 #endif
232 	.proxy_ndp		= 0,
233 	.accept_source_route	= 0,	/* we do not accept RH0 by default. */
234 	.disable_ipv6		= 0,
235 	.accept_dad		= 0,
236 	.suppress_frag_ndisc	= 1,
237 	.accept_ra_mtu		= 1,
238 	.stable_secret		= {
239 		.initialized = false,
240 	},
241 	.use_oif_addrs_only	= 0,
242 	.ignore_routes_with_linkdown = 0,
243 	.keep_addr_on_down	= 0,
244 	.seg6_enabled		= 0,
245 #ifdef CONFIG_IPV6_SEG6_HMAC
246 	.seg6_require_hmac	= 0,
247 #endif
248 	.enhanced_dad           = 1,
249 	.addr_gen_mode		= IN6_ADDR_GEN_MODE_EUI64,
250 	.disable_policy		= 0,
251 };
252 
253 static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
254 	.forwarding		= 0,
255 	.hop_limit		= IPV6_DEFAULT_HOPLIMIT,
256 	.mtu6			= IPV6_MIN_MTU,
257 	.accept_ra		= 1,
258 	.accept_redirects	= 1,
259 	.autoconf		= 1,
260 	.force_mld_version	= 0,
261 	.mldv1_unsolicited_report_interval = 10 * HZ,
262 	.mldv2_unsolicited_report_interval = HZ,
263 	.dad_transmits		= 1,
264 	.rtr_solicits		= MAX_RTR_SOLICITATIONS,
265 	.rtr_solicit_interval	= RTR_SOLICITATION_INTERVAL,
266 	.rtr_solicit_max_interval = RTR_SOLICITATION_MAX_INTERVAL,
267 	.rtr_solicit_delay	= MAX_RTR_SOLICITATION_DELAY,
268 	.use_tempaddr		= 0,
269 	.temp_valid_lft		= TEMP_VALID_LIFETIME,
270 	.temp_prefered_lft	= TEMP_PREFERRED_LIFETIME,
271 	.regen_max_retry	= REGEN_MAX_RETRY,
272 	.max_desync_factor	= MAX_DESYNC_FACTOR,
273 	.max_addresses		= IPV6_MAX_ADDRESSES,
274 	.accept_ra_defrtr	= 1,
275 	.accept_ra_from_local	= 0,
276 	.accept_ra_min_hop_limit= 1,
277 	.accept_ra_pinfo	= 1,
278 #ifdef CONFIG_IPV6_ROUTER_PREF
279 	.accept_ra_rtr_pref	= 1,
280 	.rtr_probe_interval	= 60 * HZ,
281 #ifdef CONFIG_IPV6_ROUTE_INFO
282 	.accept_ra_rt_info_min_plen = 0,
283 	.accept_ra_rt_info_max_plen = 0,
284 #endif
285 #endif
286 	.proxy_ndp		= 0,
287 	.accept_source_route	= 0,	/* we do not accept RH0 by default. */
288 	.disable_ipv6		= 0,
289 	.accept_dad		= 1,
290 	.suppress_frag_ndisc	= 1,
291 	.accept_ra_mtu		= 1,
292 	.stable_secret		= {
293 		.initialized = false,
294 	},
295 	.use_oif_addrs_only	= 0,
296 	.ignore_routes_with_linkdown = 0,
297 	.keep_addr_on_down	= 0,
298 	.seg6_enabled		= 0,
299 #ifdef CONFIG_IPV6_SEG6_HMAC
300 	.seg6_require_hmac	= 0,
301 #endif
302 	.enhanced_dad           = 1,
303 	.addr_gen_mode		= IN6_ADDR_GEN_MODE_EUI64,
304 	.disable_policy		= 0,
305 };
306 
307 /* Check if link is ready: is it up and is a valid qdisc available */
308 static inline bool addrconf_link_ready(const struct net_device *dev)
309 {
310 	return netif_oper_up(dev) && !qdisc_tx_is_noop(dev);
311 }
312 
313 static void addrconf_del_rs_timer(struct inet6_dev *idev)
314 {
315 	if (del_timer(&idev->rs_timer))
316 		__in6_dev_put(idev);
317 }
318 
319 static void addrconf_del_dad_work(struct inet6_ifaddr *ifp)
320 {
321 	if (cancel_delayed_work(&ifp->dad_work))
322 		__in6_ifa_put(ifp);
323 }
324 
325 static void addrconf_mod_rs_timer(struct inet6_dev *idev,
326 				  unsigned long when)
327 {
328 	if (!timer_pending(&idev->rs_timer))
329 		in6_dev_hold(idev);
330 	mod_timer(&idev->rs_timer, jiffies + when);
331 }
332 
333 static void addrconf_mod_dad_work(struct inet6_ifaddr *ifp,
334 				   unsigned long delay)
335 {
336 	in6_ifa_hold(ifp);
337 	if (mod_delayed_work(addrconf_wq, &ifp->dad_work, delay))
338 		in6_ifa_put(ifp);
339 }
340 
341 static int snmp6_alloc_dev(struct inet6_dev *idev)
342 {
343 	int i;
344 
345 	idev->stats.ipv6 = alloc_percpu(struct ipstats_mib);
346 	if (!idev->stats.ipv6)
347 		goto err_ip;
348 
349 	for_each_possible_cpu(i) {
350 		struct ipstats_mib *addrconf_stats;
351 		addrconf_stats = per_cpu_ptr(idev->stats.ipv6, i);
352 		u64_stats_init(&addrconf_stats->syncp);
353 	}
354 
355 
356 	idev->stats.icmpv6dev = kzalloc(sizeof(struct icmpv6_mib_device),
357 					GFP_KERNEL);
358 	if (!idev->stats.icmpv6dev)
359 		goto err_icmp;
360 	idev->stats.icmpv6msgdev = kzalloc(sizeof(struct icmpv6msg_mib_device),
361 					   GFP_KERNEL);
362 	if (!idev->stats.icmpv6msgdev)
363 		goto err_icmpmsg;
364 
365 	return 0;
366 
367 err_icmpmsg:
368 	kfree(idev->stats.icmpv6dev);
369 err_icmp:
370 	free_percpu(idev->stats.ipv6);
371 err_ip:
372 	return -ENOMEM;
373 }
374 
375 static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
376 {
377 	struct inet6_dev *ndev;
378 	int err = -ENOMEM;
379 
380 	ASSERT_RTNL();
381 
382 	if (dev->mtu < IPV6_MIN_MTU)
383 		return ERR_PTR(-EINVAL);
384 
385 	ndev = kzalloc(sizeof(struct inet6_dev), GFP_KERNEL);
386 	if (!ndev)
387 		return ERR_PTR(err);
388 
389 	rwlock_init(&ndev->lock);
390 	ndev->dev = dev;
391 	INIT_LIST_HEAD(&ndev->addr_list);
392 	timer_setup(&ndev->rs_timer, addrconf_rs_timer, 0);
393 	memcpy(&ndev->cnf, dev_net(dev)->ipv6.devconf_dflt, sizeof(ndev->cnf));
394 
395 	if (ndev->cnf.stable_secret.initialized)
396 		ndev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY;
397 	else
398 		ndev->cnf.addr_gen_mode = ipv6_devconf_dflt.addr_gen_mode;
399 
400 	ndev->cnf.mtu6 = dev->mtu;
401 	ndev->nd_parms = neigh_parms_alloc(dev, &nd_tbl);
402 	if (!ndev->nd_parms) {
403 		kfree(ndev);
404 		return ERR_PTR(err);
405 	}
406 	if (ndev->cnf.forwarding)
407 		dev_disable_lro(dev);
408 	/* We refer to the device */
409 	dev_hold(dev);
410 
411 	if (snmp6_alloc_dev(ndev) < 0) {
412 		ADBG(KERN_WARNING
413 			"%s: cannot allocate memory for statistics; dev=%s.\n",
414 			__func__, dev->name);
415 		neigh_parms_release(&nd_tbl, ndev->nd_parms);
416 		dev_put(dev);
417 		kfree(ndev);
418 		return ERR_PTR(err);
419 	}
420 
421 	if (snmp6_register_dev(ndev) < 0) {
422 		ADBG(KERN_WARNING
423 			"%s: cannot create /proc/net/dev_snmp6/%s\n",
424 			__func__, dev->name);
425 		goto err_release;
426 	}
427 
428 	/* One reference from device. */
429 	refcount_set(&ndev->refcnt, 1);
430 
431 	if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
432 		ndev->cnf.accept_dad = -1;
433 
434 #if IS_ENABLED(CONFIG_IPV6_SIT)
435 	if (dev->type == ARPHRD_SIT && (dev->priv_flags & IFF_ISATAP)) {
436 		pr_info("%s: Disabled Multicast RS\n", dev->name);
437 		ndev->cnf.rtr_solicits = 0;
438 	}
439 #endif
440 
441 	INIT_LIST_HEAD(&ndev->tempaddr_list);
442 	ndev->desync_factor = U32_MAX;
443 	if ((dev->flags&IFF_LOOPBACK) ||
444 	    dev->type == ARPHRD_TUNNEL ||
445 	    dev->type == ARPHRD_TUNNEL6 ||
446 	    dev->type == ARPHRD_SIT ||
447 	    dev->type == ARPHRD_NONE) {
448 		ndev->cnf.use_tempaddr = -1;
449 	} else
450 		ipv6_regen_rndid(ndev);
451 
452 	ndev->token = in6addr_any;
453 
454 	if (netif_running(dev) && addrconf_link_ready(dev))
455 		ndev->if_flags |= IF_READY;
456 
457 	ipv6_mc_init_dev(ndev);
458 	ndev->tstamp = jiffies;
459 	err = addrconf_sysctl_register(ndev);
460 	if (err) {
461 		ipv6_mc_destroy_dev(ndev);
462 		snmp6_unregister_dev(ndev);
463 		goto err_release;
464 	}
465 	/* protected by rtnl_lock */
466 	rcu_assign_pointer(dev->ip6_ptr, ndev);
467 
468 	/* Join interface-local all-node multicast group */
469 	ipv6_dev_mc_inc(dev, &in6addr_interfacelocal_allnodes);
470 
471 	/* Join all-node multicast group */
472 	ipv6_dev_mc_inc(dev, &in6addr_linklocal_allnodes);
473 
474 	/* Join all-router multicast group if forwarding is set */
475 	if (ndev->cnf.forwarding && (dev->flags & IFF_MULTICAST))
476 		ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters);
477 
478 	return ndev;
479 
480 err_release:
481 	neigh_parms_release(&nd_tbl, ndev->nd_parms);
482 	ndev->dead = 1;
483 	in6_dev_finish_destroy(ndev);
484 	return ERR_PTR(err);
485 }
486 
487 static struct inet6_dev *ipv6_find_idev(struct net_device *dev)
488 {
489 	struct inet6_dev *idev;
490 
491 	ASSERT_RTNL();
492 
493 	idev = __in6_dev_get(dev);
494 	if (!idev) {
495 		idev = ipv6_add_dev(dev);
496 		if (IS_ERR(idev))
497 			return NULL;
498 	}
499 
500 	if (dev->flags&IFF_UP)
501 		ipv6_mc_up(idev);
502 	return idev;
503 }
504 
505 static int inet6_netconf_msgsize_devconf(int type)
506 {
507 	int size =  NLMSG_ALIGN(sizeof(struct netconfmsg))
508 		    + nla_total_size(4);	/* NETCONFA_IFINDEX */
509 	bool all = false;
510 
511 	if (type == NETCONFA_ALL)
512 		all = true;
513 
514 	if (all || type == NETCONFA_FORWARDING)
515 		size += nla_total_size(4);
516 #ifdef CONFIG_IPV6_MROUTE
517 	if (all || type == NETCONFA_MC_FORWARDING)
518 		size += nla_total_size(4);
519 #endif
520 	if (all || type == NETCONFA_PROXY_NEIGH)
521 		size += nla_total_size(4);
522 
523 	if (all || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN)
524 		size += nla_total_size(4);
525 
526 	return size;
527 }
528 
529 static int inet6_netconf_fill_devconf(struct sk_buff *skb, int ifindex,
530 				      struct ipv6_devconf *devconf, u32 portid,
531 				      u32 seq, int event, unsigned int flags,
532 				      int type)
533 {
534 	struct nlmsghdr  *nlh;
535 	struct netconfmsg *ncm;
536 	bool all = false;
537 
538 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
539 			flags);
540 	if (!nlh)
541 		return -EMSGSIZE;
542 
543 	if (type == NETCONFA_ALL)
544 		all = true;
545 
546 	ncm = nlmsg_data(nlh);
547 	ncm->ncm_family = AF_INET6;
548 
549 	if (nla_put_s32(skb, NETCONFA_IFINDEX, ifindex) < 0)
550 		goto nla_put_failure;
551 
552 	if (!devconf)
553 		goto out;
554 
555 	if ((all || type == NETCONFA_FORWARDING) &&
556 	    nla_put_s32(skb, NETCONFA_FORWARDING, devconf->forwarding) < 0)
557 		goto nla_put_failure;
558 #ifdef CONFIG_IPV6_MROUTE
559 	if ((all || type == NETCONFA_MC_FORWARDING) &&
560 	    nla_put_s32(skb, NETCONFA_MC_FORWARDING,
561 			devconf->mc_forwarding) < 0)
562 		goto nla_put_failure;
563 #endif
564 	if ((all || type == NETCONFA_PROXY_NEIGH) &&
565 	    nla_put_s32(skb, NETCONFA_PROXY_NEIGH, devconf->proxy_ndp) < 0)
566 		goto nla_put_failure;
567 
568 	if ((all || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN) &&
569 	    nla_put_s32(skb, NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
570 			devconf->ignore_routes_with_linkdown) < 0)
571 		goto nla_put_failure;
572 
573 out:
574 	nlmsg_end(skb, nlh);
575 	return 0;
576 
577 nla_put_failure:
578 	nlmsg_cancel(skb, nlh);
579 	return -EMSGSIZE;
580 }
581 
582 void inet6_netconf_notify_devconf(struct net *net, int event, int type,
583 				  int ifindex, struct ipv6_devconf *devconf)
584 {
585 	struct sk_buff *skb;
586 	int err = -ENOBUFS;
587 
588 	skb = nlmsg_new(inet6_netconf_msgsize_devconf(type), GFP_KERNEL);
589 	if (!skb)
590 		goto errout;
591 
592 	err = inet6_netconf_fill_devconf(skb, ifindex, devconf, 0, 0,
593 					 event, 0, type);
594 	if (err < 0) {
595 		/* -EMSGSIZE implies BUG in inet6_netconf_msgsize_devconf() */
596 		WARN_ON(err == -EMSGSIZE);
597 		kfree_skb(skb);
598 		goto errout;
599 	}
600 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_NETCONF, NULL, GFP_KERNEL);
601 	return;
602 errout:
603 	rtnl_set_sk_err(net, RTNLGRP_IPV6_NETCONF, err);
604 }
605 
606 static const struct nla_policy devconf_ipv6_policy[NETCONFA_MAX+1] = {
607 	[NETCONFA_IFINDEX]	= { .len = sizeof(int) },
608 	[NETCONFA_FORWARDING]	= { .len = sizeof(int) },
609 	[NETCONFA_PROXY_NEIGH]	= { .len = sizeof(int) },
610 	[NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN]	= { .len = sizeof(int) },
611 };
612 
613 static int inet6_netconf_get_devconf(struct sk_buff *in_skb,
614 				     struct nlmsghdr *nlh,
615 				     struct netlink_ext_ack *extack)
616 {
617 	struct net *net = sock_net(in_skb->sk);
618 	struct nlattr *tb[NETCONFA_MAX+1];
619 	struct inet6_dev *in6_dev = NULL;
620 	struct net_device *dev = NULL;
621 	struct netconfmsg *ncm;
622 	struct sk_buff *skb;
623 	struct ipv6_devconf *devconf;
624 	int ifindex;
625 	int err;
626 
627 	err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX,
628 			  devconf_ipv6_policy, extack);
629 	if (err < 0)
630 		return err;
631 
632 	if (!tb[NETCONFA_IFINDEX])
633 		return -EINVAL;
634 
635 	err = -EINVAL;
636 	ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
637 	switch (ifindex) {
638 	case NETCONFA_IFINDEX_ALL:
639 		devconf = net->ipv6.devconf_all;
640 		break;
641 	case NETCONFA_IFINDEX_DEFAULT:
642 		devconf = net->ipv6.devconf_dflt;
643 		break;
644 	default:
645 		dev = dev_get_by_index(net, ifindex);
646 		if (!dev)
647 			return -EINVAL;
648 		in6_dev = in6_dev_get(dev);
649 		if (!in6_dev)
650 			goto errout;
651 		devconf = &in6_dev->cnf;
652 		break;
653 	}
654 
655 	err = -ENOBUFS;
656 	skb = nlmsg_new(inet6_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
657 	if (!skb)
658 		goto errout;
659 
660 	err = inet6_netconf_fill_devconf(skb, ifindex, devconf,
661 					 NETLINK_CB(in_skb).portid,
662 					 nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
663 					 NETCONFA_ALL);
664 	if (err < 0) {
665 		/* -EMSGSIZE implies BUG in inet6_netconf_msgsize_devconf() */
666 		WARN_ON(err == -EMSGSIZE);
667 		kfree_skb(skb);
668 		goto errout;
669 	}
670 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
671 errout:
672 	if (in6_dev)
673 		in6_dev_put(in6_dev);
674 	if (dev)
675 		dev_put(dev);
676 	return err;
677 }
678 
679 static int inet6_netconf_dump_devconf(struct sk_buff *skb,
680 				      struct netlink_callback *cb)
681 {
682 	struct net *net = sock_net(skb->sk);
683 	int h, s_h;
684 	int idx, s_idx;
685 	struct net_device *dev;
686 	struct inet6_dev *idev;
687 	struct hlist_head *head;
688 
689 	s_h = cb->args[0];
690 	s_idx = idx = cb->args[1];
691 
692 	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
693 		idx = 0;
694 		head = &net->dev_index_head[h];
695 		rcu_read_lock();
696 		cb->seq = atomic_read(&net->ipv6.dev_addr_genid) ^
697 			  net->dev_base_seq;
698 		hlist_for_each_entry_rcu(dev, head, index_hlist) {
699 			if (idx < s_idx)
700 				goto cont;
701 			idev = __in6_dev_get(dev);
702 			if (!idev)
703 				goto cont;
704 
705 			if (inet6_netconf_fill_devconf(skb, dev->ifindex,
706 						       &idev->cnf,
707 						       NETLINK_CB(cb->skb).portid,
708 						       cb->nlh->nlmsg_seq,
709 						       RTM_NEWNETCONF,
710 						       NLM_F_MULTI,
711 						       NETCONFA_ALL) < 0) {
712 				rcu_read_unlock();
713 				goto done;
714 			}
715 			nl_dump_check_consistent(cb, nlmsg_hdr(skb));
716 cont:
717 			idx++;
718 		}
719 		rcu_read_unlock();
720 	}
721 	if (h == NETDEV_HASHENTRIES) {
722 		if (inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL,
723 					       net->ipv6.devconf_all,
724 					       NETLINK_CB(cb->skb).portid,
725 					       cb->nlh->nlmsg_seq,
726 					       RTM_NEWNETCONF, NLM_F_MULTI,
727 					       NETCONFA_ALL) < 0)
728 			goto done;
729 		else
730 			h++;
731 	}
732 	if (h == NETDEV_HASHENTRIES + 1) {
733 		if (inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT,
734 					       net->ipv6.devconf_dflt,
735 					       NETLINK_CB(cb->skb).portid,
736 					       cb->nlh->nlmsg_seq,
737 					       RTM_NEWNETCONF, NLM_F_MULTI,
738 					       NETCONFA_ALL) < 0)
739 			goto done;
740 		else
741 			h++;
742 	}
743 done:
744 	cb->args[0] = h;
745 	cb->args[1] = idx;
746 
747 	return skb->len;
748 }
749 
750 #ifdef CONFIG_SYSCTL
751 static void dev_forward_change(struct inet6_dev *idev)
752 {
753 	struct net_device *dev;
754 	struct inet6_ifaddr *ifa;
755 
756 	if (!idev)
757 		return;
758 	dev = idev->dev;
759 	if (idev->cnf.forwarding)
760 		dev_disable_lro(dev);
761 	if (dev->flags & IFF_MULTICAST) {
762 		if (idev->cnf.forwarding) {
763 			ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters);
764 			ipv6_dev_mc_inc(dev, &in6addr_interfacelocal_allrouters);
765 			ipv6_dev_mc_inc(dev, &in6addr_sitelocal_allrouters);
766 		} else {
767 			ipv6_dev_mc_dec(dev, &in6addr_linklocal_allrouters);
768 			ipv6_dev_mc_dec(dev, &in6addr_interfacelocal_allrouters);
769 			ipv6_dev_mc_dec(dev, &in6addr_sitelocal_allrouters);
770 		}
771 	}
772 
773 	list_for_each_entry(ifa, &idev->addr_list, if_list) {
774 		if (ifa->flags&IFA_F_TENTATIVE)
775 			continue;
776 		if (idev->cnf.forwarding)
777 			addrconf_join_anycast(ifa);
778 		else
779 			addrconf_leave_anycast(ifa);
780 	}
781 	inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
782 				     NETCONFA_FORWARDING,
783 				     dev->ifindex, &idev->cnf);
784 }
785 
786 
787 static void addrconf_forward_change(struct net *net, __s32 newf)
788 {
789 	struct net_device *dev;
790 	struct inet6_dev *idev;
791 
792 	for_each_netdev(net, dev) {
793 		idev = __in6_dev_get(dev);
794 		if (idev) {
795 			int changed = (!idev->cnf.forwarding) ^ (!newf);
796 			idev->cnf.forwarding = newf;
797 			if (changed)
798 				dev_forward_change(idev);
799 		}
800 	}
801 }
802 
803 static int addrconf_fixup_forwarding(struct ctl_table *table, int *p, int newf)
804 {
805 	struct net *net;
806 	int old;
807 
808 	if (!rtnl_trylock())
809 		return restart_syscall();
810 
811 	net = (struct net *)table->extra2;
812 	old = *p;
813 	*p = newf;
814 
815 	if (p == &net->ipv6.devconf_dflt->forwarding) {
816 		if ((!newf) ^ (!old))
817 			inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
818 						     NETCONFA_FORWARDING,
819 						     NETCONFA_IFINDEX_DEFAULT,
820 						     net->ipv6.devconf_dflt);
821 		rtnl_unlock();
822 		return 0;
823 	}
824 
825 	if (p == &net->ipv6.devconf_all->forwarding) {
826 		int old_dflt = net->ipv6.devconf_dflt->forwarding;
827 
828 		net->ipv6.devconf_dflt->forwarding = newf;
829 		if ((!newf) ^ (!old_dflt))
830 			inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
831 						     NETCONFA_FORWARDING,
832 						     NETCONFA_IFINDEX_DEFAULT,
833 						     net->ipv6.devconf_dflt);
834 
835 		addrconf_forward_change(net, newf);
836 		if ((!newf) ^ (!old))
837 			inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
838 						     NETCONFA_FORWARDING,
839 						     NETCONFA_IFINDEX_ALL,
840 						     net->ipv6.devconf_all);
841 	} else if ((!newf) ^ (!old))
842 		dev_forward_change((struct inet6_dev *)table->extra1);
843 	rtnl_unlock();
844 
845 	if (newf)
846 		rt6_purge_dflt_routers(net);
847 	return 1;
848 }
849 
850 static void addrconf_linkdown_change(struct net *net, __s32 newf)
851 {
852 	struct net_device *dev;
853 	struct inet6_dev *idev;
854 
855 	for_each_netdev(net, dev) {
856 		idev = __in6_dev_get(dev);
857 		if (idev) {
858 			int changed = (!idev->cnf.ignore_routes_with_linkdown) ^ (!newf);
859 
860 			idev->cnf.ignore_routes_with_linkdown = newf;
861 			if (changed)
862 				inet6_netconf_notify_devconf(dev_net(dev),
863 							     RTM_NEWNETCONF,
864 							     NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
865 							     dev->ifindex,
866 							     &idev->cnf);
867 		}
868 	}
869 }
870 
871 static int addrconf_fixup_linkdown(struct ctl_table *table, int *p, int newf)
872 {
873 	struct net *net;
874 	int old;
875 
876 	if (!rtnl_trylock())
877 		return restart_syscall();
878 
879 	net = (struct net *)table->extra2;
880 	old = *p;
881 	*p = newf;
882 
883 	if (p == &net->ipv6.devconf_dflt->ignore_routes_with_linkdown) {
884 		if ((!newf) ^ (!old))
885 			inet6_netconf_notify_devconf(net,
886 						     RTM_NEWNETCONF,
887 						     NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
888 						     NETCONFA_IFINDEX_DEFAULT,
889 						     net->ipv6.devconf_dflt);
890 		rtnl_unlock();
891 		return 0;
892 	}
893 
894 	if (p == &net->ipv6.devconf_all->ignore_routes_with_linkdown) {
895 		net->ipv6.devconf_dflt->ignore_routes_with_linkdown = newf;
896 		addrconf_linkdown_change(net, newf);
897 		if ((!newf) ^ (!old))
898 			inet6_netconf_notify_devconf(net,
899 						     RTM_NEWNETCONF,
900 						     NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
901 						     NETCONFA_IFINDEX_ALL,
902 						     net->ipv6.devconf_all);
903 	}
904 	rtnl_unlock();
905 
906 	return 1;
907 }
908 
909 #endif
910 
911 /* Nobody refers to this ifaddr, destroy it */
912 void inet6_ifa_finish_destroy(struct inet6_ifaddr *ifp)
913 {
914 	WARN_ON(!hlist_unhashed(&ifp->addr_lst));
915 
916 #ifdef NET_REFCNT_DEBUG
917 	pr_debug("%s\n", __func__);
918 #endif
919 
920 	in6_dev_put(ifp->idev);
921 
922 	if (cancel_delayed_work(&ifp->dad_work))
923 		pr_notice("delayed DAD work was pending while freeing ifa=%p\n",
924 			  ifp);
925 
926 	if (ifp->state != INET6_IFADDR_STATE_DEAD) {
927 		pr_warn("Freeing alive inet6 address %p\n", ifp);
928 		return;
929 	}
930 	ip6_rt_put(ifp->rt);
931 
932 	kfree_rcu(ifp, rcu);
933 }
934 
935 static void
936 ipv6_link_dev_addr(struct inet6_dev *idev, struct inet6_ifaddr *ifp)
937 {
938 	struct list_head *p;
939 	int ifp_scope = ipv6_addr_src_scope(&ifp->addr);
940 
941 	/*
942 	 * Each device address list is sorted in order of scope -
943 	 * global before linklocal.
944 	 */
945 	list_for_each(p, &idev->addr_list) {
946 		struct inet6_ifaddr *ifa
947 			= list_entry(p, struct inet6_ifaddr, if_list);
948 		if (ifp_scope >= ipv6_addr_src_scope(&ifa->addr))
949 			break;
950 	}
951 
952 	list_add_tail_rcu(&ifp->if_list, p);
953 }
954 
955 static u32 inet6_addr_hash(const struct net *net, const struct in6_addr *addr)
956 {
957 	u32 val = ipv6_addr_hash(addr) ^ net_hash_mix(net);
958 
959 	return hash_32(val, IN6_ADDR_HSIZE_SHIFT);
960 }
961 
962 static bool ipv6_chk_same_addr(struct net *net, const struct in6_addr *addr,
963 			       struct net_device *dev, unsigned int hash)
964 {
965 	struct inet6_ifaddr *ifp;
966 
967 	hlist_for_each_entry(ifp, &inet6_addr_lst[hash], addr_lst) {
968 		if (!net_eq(dev_net(ifp->idev->dev), net))
969 			continue;
970 		if (ipv6_addr_equal(&ifp->addr, addr)) {
971 			if (!dev || ifp->idev->dev == dev)
972 				return true;
973 		}
974 	}
975 	return false;
976 }
977 
978 static int ipv6_add_addr_hash(struct net_device *dev, struct inet6_ifaddr *ifa)
979 {
980 	unsigned int hash = inet6_addr_hash(dev_net(dev), &ifa->addr);
981 	int err = 0;
982 
983 	spin_lock(&addrconf_hash_lock);
984 
985 	/* Ignore adding duplicate addresses on an interface */
986 	if (ipv6_chk_same_addr(dev_net(dev), &ifa->addr, dev, hash)) {
987 		ADBG("ipv6_add_addr: already assigned\n");
988 		err = -EEXIST;
989 	} else {
990 		hlist_add_head_rcu(&ifa->addr_lst, &inet6_addr_lst[hash]);
991 	}
992 
993 	spin_unlock(&addrconf_hash_lock);
994 
995 	return err;
996 }
997 
998 /* On success it returns ifp with increased reference count */
999 
1000 static struct inet6_ifaddr *
1001 ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr,
1002 	      const struct in6_addr *peer_addr, int pfxlen,
1003 	      int scope, u32 flags, u32 valid_lft, u32 prefered_lft,
1004 	      bool can_block, struct netlink_ext_ack *extack)
1005 {
1006 	gfp_t gfp_flags = can_block ? GFP_KERNEL : GFP_ATOMIC;
1007 	struct net *net = dev_net(idev->dev);
1008 	struct inet6_ifaddr *ifa = NULL;
1009 	struct rt6_info *rt = NULL;
1010 	int err = 0;
1011 	int addr_type = ipv6_addr_type(addr);
1012 
1013 	if (addr_type == IPV6_ADDR_ANY ||
1014 	    addr_type & IPV6_ADDR_MULTICAST ||
1015 	    (!(idev->dev->flags & IFF_LOOPBACK) &&
1016 	     addr_type & IPV6_ADDR_LOOPBACK))
1017 		return ERR_PTR(-EADDRNOTAVAIL);
1018 
1019 	if (idev->dead) {
1020 		err = -ENODEV;			/*XXX*/
1021 		goto out;
1022 	}
1023 
1024 	if (idev->cnf.disable_ipv6) {
1025 		err = -EACCES;
1026 		goto out;
1027 	}
1028 
1029 	/* validator notifier needs to be blocking;
1030 	 * do not call in atomic context
1031 	 */
1032 	if (can_block) {
1033 		struct in6_validator_info i6vi = {
1034 			.i6vi_addr = *addr,
1035 			.i6vi_dev = idev,
1036 			.extack = extack,
1037 		};
1038 
1039 		err = inet6addr_validator_notifier_call_chain(NETDEV_UP, &i6vi);
1040 		err = notifier_to_errno(err);
1041 		if (err < 0)
1042 			goto out;
1043 	}
1044 
1045 	ifa = kzalloc(sizeof(*ifa), gfp_flags);
1046 	if (!ifa) {
1047 		ADBG("ipv6_add_addr: malloc failed\n");
1048 		err = -ENOBUFS;
1049 		goto out;
1050 	}
1051 
1052 	rt = addrconf_dst_alloc(idev, addr, false);
1053 	if (IS_ERR(rt)) {
1054 		err = PTR_ERR(rt);
1055 		rt = NULL;
1056 		goto out;
1057 	}
1058 
1059 	if (net->ipv6.devconf_all->disable_policy ||
1060 	    idev->cnf.disable_policy)
1061 		rt->dst.flags |= DST_NOPOLICY;
1062 
1063 	neigh_parms_data_state_setall(idev->nd_parms);
1064 
1065 	ifa->addr = *addr;
1066 	if (peer_addr)
1067 		ifa->peer_addr = *peer_addr;
1068 
1069 	spin_lock_init(&ifa->lock);
1070 	INIT_DELAYED_WORK(&ifa->dad_work, addrconf_dad_work);
1071 	INIT_HLIST_NODE(&ifa->addr_lst);
1072 	ifa->scope = scope;
1073 	ifa->prefix_len = pfxlen;
1074 	ifa->flags = flags;
1075 	/* No need to add the TENTATIVE flag for addresses with NODAD */
1076 	if (!(flags & IFA_F_NODAD))
1077 		ifa->flags |= IFA_F_TENTATIVE;
1078 	ifa->valid_lft = valid_lft;
1079 	ifa->prefered_lft = prefered_lft;
1080 	ifa->cstamp = ifa->tstamp = jiffies;
1081 	ifa->tokenized = false;
1082 
1083 	ifa->rt = rt;
1084 
1085 	ifa->idev = idev;
1086 	in6_dev_hold(idev);
1087 
1088 	/* For caller */
1089 	refcount_set(&ifa->refcnt, 1);
1090 
1091 	rcu_read_lock_bh();
1092 
1093 	err = ipv6_add_addr_hash(idev->dev, ifa);
1094 	if (err < 0) {
1095 		rcu_read_unlock_bh();
1096 		goto out;
1097 	}
1098 
1099 	write_lock(&idev->lock);
1100 
1101 	/* Add to inet6_dev unicast addr list. */
1102 	ipv6_link_dev_addr(idev, ifa);
1103 
1104 	if (ifa->flags&IFA_F_TEMPORARY) {
1105 		list_add(&ifa->tmp_list, &idev->tempaddr_list);
1106 		in6_ifa_hold(ifa);
1107 	}
1108 
1109 	in6_ifa_hold(ifa);
1110 	write_unlock(&idev->lock);
1111 
1112 	rcu_read_unlock_bh();
1113 
1114 	inet6addr_notifier_call_chain(NETDEV_UP, ifa);
1115 out:
1116 	if (unlikely(err < 0)) {
1117 		if (rt)
1118 			ip6_rt_put(rt);
1119 		if (ifa) {
1120 			if (ifa->idev)
1121 				in6_dev_put(ifa->idev);
1122 			kfree(ifa);
1123 		}
1124 		ifa = ERR_PTR(err);
1125 	}
1126 
1127 	return ifa;
1128 }
1129 
1130 enum cleanup_prefix_rt_t {
1131 	CLEANUP_PREFIX_RT_NOP,    /* no cleanup action for prefix route */
1132 	CLEANUP_PREFIX_RT_DEL,    /* delete the prefix route */
1133 	CLEANUP_PREFIX_RT_EXPIRE, /* update the lifetime of the prefix route */
1134 };
1135 
1136 /*
1137  * Check, whether the prefix for ifp would still need a prefix route
1138  * after deleting ifp. The function returns one of the CLEANUP_PREFIX_RT_*
1139  * constants.
1140  *
1141  * 1) we don't purge prefix if address was not permanent.
1142  *    prefix is managed by its own lifetime.
1143  * 2) we also don't purge, if the address was IFA_F_NOPREFIXROUTE.
1144  * 3) if there are no addresses, delete prefix.
1145  * 4) if there are still other permanent address(es),
1146  *    corresponding prefix is still permanent.
1147  * 5) if there are still other addresses with IFA_F_NOPREFIXROUTE,
1148  *    don't purge the prefix, assume user space is managing it.
1149  * 6) otherwise, update prefix lifetime to the
1150  *    longest valid lifetime among the corresponding
1151  *    addresses on the device.
1152  *    Note: subsequent RA will update lifetime.
1153  **/
1154 static enum cleanup_prefix_rt_t
1155 check_cleanup_prefix_route(struct inet6_ifaddr *ifp, unsigned long *expires)
1156 {
1157 	struct inet6_ifaddr *ifa;
1158 	struct inet6_dev *idev = ifp->idev;
1159 	unsigned long lifetime;
1160 	enum cleanup_prefix_rt_t action = CLEANUP_PREFIX_RT_DEL;
1161 
1162 	*expires = jiffies;
1163 
1164 	list_for_each_entry(ifa, &idev->addr_list, if_list) {
1165 		if (ifa == ifp)
1166 			continue;
1167 		if (!ipv6_prefix_equal(&ifa->addr, &ifp->addr,
1168 				       ifp->prefix_len))
1169 			continue;
1170 		if (ifa->flags & (IFA_F_PERMANENT | IFA_F_NOPREFIXROUTE))
1171 			return CLEANUP_PREFIX_RT_NOP;
1172 
1173 		action = CLEANUP_PREFIX_RT_EXPIRE;
1174 
1175 		spin_lock(&ifa->lock);
1176 
1177 		lifetime = addrconf_timeout_fixup(ifa->valid_lft, HZ);
1178 		/*
1179 		 * Note: Because this address is
1180 		 * not permanent, lifetime <
1181 		 * LONG_MAX / HZ here.
1182 		 */
1183 		if (time_before(*expires, ifa->tstamp + lifetime * HZ))
1184 			*expires = ifa->tstamp + lifetime * HZ;
1185 		spin_unlock(&ifa->lock);
1186 	}
1187 
1188 	return action;
1189 }
1190 
1191 static void
1192 cleanup_prefix_route(struct inet6_ifaddr *ifp, unsigned long expires, bool del_rt)
1193 {
1194 	struct rt6_info *rt;
1195 
1196 	rt = addrconf_get_prefix_route(&ifp->addr,
1197 				       ifp->prefix_len,
1198 				       ifp->idev->dev,
1199 				       0, RTF_GATEWAY | RTF_DEFAULT);
1200 	if (rt) {
1201 		if (del_rt)
1202 			ip6_del_rt(rt);
1203 		else {
1204 			if (!(rt->rt6i_flags & RTF_EXPIRES))
1205 				rt6_set_expires(rt, expires);
1206 			ip6_rt_put(rt);
1207 		}
1208 	}
1209 }
1210 
1211 
1212 /* This function wants to get referenced ifp and releases it before return */
1213 
1214 static void ipv6_del_addr(struct inet6_ifaddr *ifp)
1215 {
1216 	int state;
1217 	enum cleanup_prefix_rt_t action = CLEANUP_PREFIX_RT_NOP;
1218 	unsigned long expires;
1219 
1220 	ASSERT_RTNL();
1221 
1222 	spin_lock_bh(&ifp->lock);
1223 	state = ifp->state;
1224 	ifp->state = INET6_IFADDR_STATE_DEAD;
1225 	spin_unlock_bh(&ifp->lock);
1226 
1227 	if (state == INET6_IFADDR_STATE_DEAD)
1228 		goto out;
1229 
1230 	spin_lock_bh(&addrconf_hash_lock);
1231 	hlist_del_init_rcu(&ifp->addr_lst);
1232 	spin_unlock_bh(&addrconf_hash_lock);
1233 
1234 	write_lock_bh(&ifp->idev->lock);
1235 
1236 	if (ifp->flags&IFA_F_TEMPORARY) {
1237 		list_del(&ifp->tmp_list);
1238 		if (ifp->ifpub) {
1239 			in6_ifa_put(ifp->ifpub);
1240 			ifp->ifpub = NULL;
1241 		}
1242 		__in6_ifa_put(ifp);
1243 	}
1244 
1245 	if (ifp->flags & IFA_F_PERMANENT && !(ifp->flags & IFA_F_NOPREFIXROUTE))
1246 		action = check_cleanup_prefix_route(ifp, &expires);
1247 
1248 	list_del_rcu(&ifp->if_list);
1249 	__in6_ifa_put(ifp);
1250 
1251 	write_unlock_bh(&ifp->idev->lock);
1252 
1253 	addrconf_del_dad_work(ifp);
1254 
1255 	ipv6_ifa_notify(RTM_DELADDR, ifp);
1256 
1257 	inet6addr_notifier_call_chain(NETDEV_DOWN, ifp);
1258 
1259 	if (action != CLEANUP_PREFIX_RT_NOP) {
1260 		cleanup_prefix_route(ifp, expires,
1261 			action == CLEANUP_PREFIX_RT_DEL);
1262 	}
1263 
1264 	/* clean up prefsrc entries */
1265 	rt6_remove_prefsrc(ifp);
1266 out:
1267 	in6_ifa_put(ifp);
1268 }
1269 
1270 static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp,
1271 				struct inet6_ifaddr *ift,
1272 				bool block)
1273 {
1274 	struct inet6_dev *idev = ifp->idev;
1275 	struct in6_addr addr, *tmpaddr;
1276 	unsigned long tmp_prefered_lft, tmp_valid_lft, tmp_tstamp, age;
1277 	unsigned long regen_advance;
1278 	int tmp_plen;
1279 	int ret = 0;
1280 	u32 addr_flags;
1281 	unsigned long now = jiffies;
1282 	long max_desync_factor;
1283 	s32 cnf_temp_preferred_lft;
1284 
1285 	write_lock_bh(&idev->lock);
1286 	if (ift) {
1287 		spin_lock_bh(&ift->lock);
1288 		memcpy(&addr.s6_addr[8], &ift->addr.s6_addr[8], 8);
1289 		spin_unlock_bh(&ift->lock);
1290 		tmpaddr = &addr;
1291 	} else {
1292 		tmpaddr = NULL;
1293 	}
1294 retry:
1295 	in6_dev_hold(idev);
1296 	if (idev->cnf.use_tempaddr <= 0) {
1297 		write_unlock_bh(&idev->lock);
1298 		pr_info("%s: use_tempaddr is disabled\n", __func__);
1299 		in6_dev_put(idev);
1300 		ret = -1;
1301 		goto out;
1302 	}
1303 	spin_lock_bh(&ifp->lock);
1304 	if (ifp->regen_count++ >= idev->cnf.regen_max_retry) {
1305 		idev->cnf.use_tempaddr = -1;	/*XXX*/
1306 		spin_unlock_bh(&ifp->lock);
1307 		write_unlock_bh(&idev->lock);
1308 		pr_warn("%s: regeneration time exceeded - disabled temporary address support\n",
1309 			__func__);
1310 		in6_dev_put(idev);
1311 		ret = -1;
1312 		goto out;
1313 	}
1314 	in6_ifa_hold(ifp);
1315 	memcpy(addr.s6_addr, ifp->addr.s6_addr, 8);
1316 	ipv6_try_regen_rndid(idev, tmpaddr);
1317 	memcpy(&addr.s6_addr[8], idev->rndid, 8);
1318 	age = (now - ifp->tstamp) / HZ;
1319 
1320 	regen_advance = idev->cnf.regen_max_retry *
1321 			idev->cnf.dad_transmits *
1322 			NEIGH_VAR(idev->nd_parms, RETRANS_TIME) / HZ;
1323 
1324 	/* recalculate max_desync_factor each time and update
1325 	 * idev->desync_factor if it's larger
1326 	 */
1327 	cnf_temp_preferred_lft = READ_ONCE(idev->cnf.temp_prefered_lft);
1328 	max_desync_factor = min_t(__u32,
1329 				  idev->cnf.max_desync_factor,
1330 				  cnf_temp_preferred_lft - regen_advance);
1331 
1332 	if (unlikely(idev->desync_factor > max_desync_factor)) {
1333 		if (max_desync_factor > 0) {
1334 			get_random_bytes(&idev->desync_factor,
1335 					 sizeof(idev->desync_factor));
1336 			idev->desync_factor %= max_desync_factor;
1337 		} else {
1338 			idev->desync_factor = 0;
1339 		}
1340 	}
1341 
1342 	tmp_valid_lft = min_t(__u32,
1343 			      ifp->valid_lft,
1344 			      idev->cnf.temp_valid_lft + age);
1345 	tmp_prefered_lft = cnf_temp_preferred_lft + age -
1346 			    idev->desync_factor;
1347 	tmp_prefered_lft = min_t(__u32, ifp->prefered_lft, tmp_prefered_lft);
1348 	tmp_plen = ifp->prefix_len;
1349 	tmp_tstamp = ifp->tstamp;
1350 	spin_unlock_bh(&ifp->lock);
1351 
1352 	write_unlock_bh(&idev->lock);
1353 
1354 	/* A temporary address is created only if this calculated Preferred
1355 	 * Lifetime is greater than REGEN_ADVANCE time units.  In particular,
1356 	 * an implementation must not create a temporary address with a zero
1357 	 * Preferred Lifetime.
1358 	 * Use age calculation as in addrconf_verify to avoid unnecessary
1359 	 * temporary addresses being generated.
1360 	 */
1361 	age = (now - tmp_tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ;
1362 	if (tmp_prefered_lft <= regen_advance + age) {
1363 		in6_ifa_put(ifp);
1364 		in6_dev_put(idev);
1365 		ret = -1;
1366 		goto out;
1367 	}
1368 
1369 	addr_flags = IFA_F_TEMPORARY;
1370 	/* set in addrconf_prefix_rcv() */
1371 	if (ifp->flags & IFA_F_OPTIMISTIC)
1372 		addr_flags |= IFA_F_OPTIMISTIC;
1373 
1374 	ift = ipv6_add_addr(idev, &addr, NULL, tmp_plen,
1375 			    ipv6_addr_scope(&addr), addr_flags,
1376 			    tmp_valid_lft, tmp_prefered_lft, block, NULL);
1377 	if (IS_ERR(ift)) {
1378 		in6_ifa_put(ifp);
1379 		in6_dev_put(idev);
1380 		pr_info("%s: retry temporary address regeneration\n", __func__);
1381 		tmpaddr = &addr;
1382 		write_lock_bh(&idev->lock);
1383 		goto retry;
1384 	}
1385 
1386 	spin_lock_bh(&ift->lock);
1387 	ift->ifpub = ifp;
1388 	ift->cstamp = now;
1389 	ift->tstamp = tmp_tstamp;
1390 	spin_unlock_bh(&ift->lock);
1391 
1392 	addrconf_dad_start(ift);
1393 	in6_ifa_put(ift);
1394 	in6_dev_put(idev);
1395 out:
1396 	return ret;
1397 }
1398 
1399 /*
1400  *	Choose an appropriate source address (RFC3484)
1401  */
1402 enum {
1403 	IPV6_SADDR_RULE_INIT = 0,
1404 	IPV6_SADDR_RULE_LOCAL,
1405 	IPV6_SADDR_RULE_SCOPE,
1406 	IPV6_SADDR_RULE_PREFERRED,
1407 #ifdef CONFIG_IPV6_MIP6
1408 	IPV6_SADDR_RULE_HOA,
1409 #endif
1410 	IPV6_SADDR_RULE_OIF,
1411 	IPV6_SADDR_RULE_LABEL,
1412 	IPV6_SADDR_RULE_PRIVACY,
1413 	IPV6_SADDR_RULE_ORCHID,
1414 	IPV6_SADDR_RULE_PREFIX,
1415 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1416 	IPV6_SADDR_RULE_NOT_OPTIMISTIC,
1417 #endif
1418 	IPV6_SADDR_RULE_MAX
1419 };
1420 
1421 struct ipv6_saddr_score {
1422 	int			rule;
1423 	int			addr_type;
1424 	struct inet6_ifaddr	*ifa;
1425 	DECLARE_BITMAP(scorebits, IPV6_SADDR_RULE_MAX);
1426 	int			scopedist;
1427 	int			matchlen;
1428 };
1429 
1430 struct ipv6_saddr_dst {
1431 	const struct in6_addr *addr;
1432 	int ifindex;
1433 	int scope;
1434 	int label;
1435 	unsigned int prefs;
1436 };
1437 
1438 static inline int ipv6_saddr_preferred(int type)
1439 {
1440 	if (type & (IPV6_ADDR_MAPPED|IPV6_ADDR_COMPATv4|IPV6_ADDR_LOOPBACK))
1441 		return 1;
1442 	return 0;
1443 }
1444 
1445 static bool ipv6_use_optimistic_addr(struct net *net,
1446 				     struct inet6_dev *idev)
1447 {
1448 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1449 	if (!idev)
1450 		return false;
1451 	if (!net->ipv6.devconf_all->optimistic_dad && !idev->cnf.optimistic_dad)
1452 		return false;
1453 	if (!net->ipv6.devconf_all->use_optimistic && !idev->cnf.use_optimistic)
1454 		return false;
1455 
1456 	return true;
1457 #else
1458 	return false;
1459 #endif
1460 }
1461 
1462 static int ipv6_get_saddr_eval(struct net *net,
1463 			       struct ipv6_saddr_score *score,
1464 			       struct ipv6_saddr_dst *dst,
1465 			       int i)
1466 {
1467 	int ret;
1468 
1469 	if (i <= score->rule) {
1470 		switch (i) {
1471 		case IPV6_SADDR_RULE_SCOPE:
1472 			ret = score->scopedist;
1473 			break;
1474 		case IPV6_SADDR_RULE_PREFIX:
1475 			ret = score->matchlen;
1476 			break;
1477 		default:
1478 			ret = !!test_bit(i, score->scorebits);
1479 		}
1480 		goto out;
1481 	}
1482 
1483 	switch (i) {
1484 	case IPV6_SADDR_RULE_INIT:
1485 		/* Rule 0: remember if hiscore is not ready yet */
1486 		ret = !!score->ifa;
1487 		break;
1488 	case IPV6_SADDR_RULE_LOCAL:
1489 		/* Rule 1: Prefer same address */
1490 		ret = ipv6_addr_equal(&score->ifa->addr, dst->addr);
1491 		break;
1492 	case IPV6_SADDR_RULE_SCOPE:
1493 		/* Rule 2: Prefer appropriate scope
1494 		 *
1495 		 *      ret
1496 		 *       ^
1497 		 *    -1 |  d 15
1498 		 *    ---+--+-+---> scope
1499 		 *       |
1500 		 *       |             d is scope of the destination.
1501 		 *  B-d  |  \
1502 		 *       |   \      <- smaller scope is better if
1503 		 *  B-15 |    \        if scope is enough for destination.
1504 		 *       |             ret = B - scope (-1 <= scope >= d <= 15).
1505 		 * d-C-1 | /
1506 		 *       |/         <- greater is better
1507 		 *   -C  /             if scope is not enough for destination.
1508 		 *      /|             ret = scope - C (-1 <= d < scope <= 15).
1509 		 *
1510 		 * d - C - 1 < B -15 (for all -1 <= d <= 15).
1511 		 * C > d + 14 - B >= 15 + 14 - B = 29 - B.
1512 		 * Assume B = 0 and we get C > 29.
1513 		 */
1514 		ret = __ipv6_addr_src_scope(score->addr_type);
1515 		if (ret >= dst->scope)
1516 			ret = -ret;
1517 		else
1518 			ret -= 128;	/* 30 is enough */
1519 		score->scopedist = ret;
1520 		break;
1521 	case IPV6_SADDR_RULE_PREFERRED:
1522 	    {
1523 		/* Rule 3: Avoid deprecated and optimistic addresses */
1524 		u8 avoid = IFA_F_DEPRECATED;
1525 
1526 		if (!ipv6_use_optimistic_addr(net, score->ifa->idev))
1527 			avoid |= IFA_F_OPTIMISTIC;
1528 		ret = ipv6_saddr_preferred(score->addr_type) ||
1529 		      !(score->ifa->flags & avoid);
1530 		break;
1531 	    }
1532 #ifdef CONFIG_IPV6_MIP6
1533 	case IPV6_SADDR_RULE_HOA:
1534 	    {
1535 		/* Rule 4: Prefer home address */
1536 		int prefhome = !(dst->prefs & IPV6_PREFER_SRC_COA);
1537 		ret = !(score->ifa->flags & IFA_F_HOMEADDRESS) ^ prefhome;
1538 		break;
1539 	    }
1540 #endif
1541 	case IPV6_SADDR_RULE_OIF:
1542 		/* Rule 5: Prefer outgoing interface */
1543 		ret = (!dst->ifindex ||
1544 		       dst->ifindex == score->ifa->idev->dev->ifindex);
1545 		break;
1546 	case IPV6_SADDR_RULE_LABEL:
1547 		/* Rule 6: Prefer matching label */
1548 		ret = ipv6_addr_label(net,
1549 				      &score->ifa->addr, score->addr_type,
1550 				      score->ifa->idev->dev->ifindex) == dst->label;
1551 		break;
1552 	case IPV6_SADDR_RULE_PRIVACY:
1553 	    {
1554 		/* Rule 7: Prefer public address
1555 		 * Note: prefer temporary address if use_tempaddr >= 2
1556 		 */
1557 		int preftmp = dst->prefs & (IPV6_PREFER_SRC_PUBLIC|IPV6_PREFER_SRC_TMP) ?
1558 				!!(dst->prefs & IPV6_PREFER_SRC_TMP) :
1559 				score->ifa->idev->cnf.use_tempaddr >= 2;
1560 		ret = (!(score->ifa->flags & IFA_F_TEMPORARY)) ^ preftmp;
1561 		break;
1562 	    }
1563 	case IPV6_SADDR_RULE_ORCHID:
1564 		/* Rule 8-: Prefer ORCHID vs ORCHID or
1565 		 *	    non-ORCHID vs non-ORCHID
1566 		 */
1567 		ret = !(ipv6_addr_orchid(&score->ifa->addr) ^
1568 			ipv6_addr_orchid(dst->addr));
1569 		break;
1570 	case IPV6_SADDR_RULE_PREFIX:
1571 		/* Rule 8: Use longest matching prefix */
1572 		ret = ipv6_addr_diff(&score->ifa->addr, dst->addr);
1573 		if (ret > score->ifa->prefix_len)
1574 			ret = score->ifa->prefix_len;
1575 		score->matchlen = ret;
1576 		break;
1577 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1578 	case IPV6_SADDR_RULE_NOT_OPTIMISTIC:
1579 		/* Optimistic addresses still have lower precedence than other
1580 		 * preferred addresses.
1581 		 */
1582 		ret = !(score->ifa->flags & IFA_F_OPTIMISTIC);
1583 		break;
1584 #endif
1585 	default:
1586 		ret = 0;
1587 	}
1588 
1589 	if (ret)
1590 		__set_bit(i, score->scorebits);
1591 	score->rule = i;
1592 out:
1593 	return ret;
1594 }
1595 
1596 static int __ipv6_dev_get_saddr(struct net *net,
1597 				struct ipv6_saddr_dst *dst,
1598 				struct inet6_dev *idev,
1599 				struct ipv6_saddr_score *scores,
1600 				int hiscore_idx)
1601 {
1602 	struct ipv6_saddr_score *score = &scores[1 - hiscore_idx], *hiscore = &scores[hiscore_idx];
1603 
1604 	list_for_each_entry_rcu(score->ifa, &idev->addr_list, if_list) {
1605 		int i;
1606 
1607 		/*
1608 		 * - Tentative Address (RFC2462 section 5.4)
1609 		 *  - A tentative address is not considered
1610 		 *    "assigned to an interface" in the traditional
1611 		 *    sense, unless it is also flagged as optimistic.
1612 		 * - Candidate Source Address (section 4)
1613 		 *  - In any case, anycast addresses, multicast
1614 		 *    addresses, and the unspecified address MUST
1615 		 *    NOT be included in a candidate set.
1616 		 */
1617 		if ((score->ifa->flags & IFA_F_TENTATIVE) &&
1618 		    (!(score->ifa->flags & IFA_F_OPTIMISTIC)))
1619 			continue;
1620 
1621 		score->addr_type = __ipv6_addr_type(&score->ifa->addr);
1622 
1623 		if (unlikely(score->addr_type == IPV6_ADDR_ANY ||
1624 			     score->addr_type & IPV6_ADDR_MULTICAST)) {
1625 			net_dbg_ratelimited("ADDRCONF: unspecified / multicast address assigned as unicast address on %s",
1626 					    idev->dev->name);
1627 			continue;
1628 		}
1629 
1630 		score->rule = -1;
1631 		bitmap_zero(score->scorebits, IPV6_SADDR_RULE_MAX);
1632 
1633 		for (i = 0; i < IPV6_SADDR_RULE_MAX; i++) {
1634 			int minihiscore, miniscore;
1635 
1636 			minihiscore = ipv6_get_saddr_eval(net, hiscore, dst, i);
1637 			miniscore = ipv6_get_saddr_eval(net, score, dst, i);
1638 
1639 			if (minihiscore > miniscore) {
1640 				if (i == IPV6_SADDR_RULE_SCOPE &&
1641 				    score->scopedist > 0) {
1642 					/*
1643 					 * special case:
1644 					 * each remaining entry
1645 					 * has too small (not enough)
1646 					 * scope, because ifa entries
1647 					 * are sorted by their scope
1648 					 * values.
1649 					 */
1650 					goto out;
1651 				}
1652 				break;
1653 			} else if (minihiscore < miniscore) {
1654 				swap(hiscore, score);
1655 				hiscore_idx = 1 - hiscore_idx;
1656 
1657 				/* restore our iterator */
1658 				score->ifa = hiscore->ifa;
1659 
1660 				break;
1661 			}
1662 		}
1663 	}
1664 out:
1665 	return hiscore_idx;
1666 }
1667 
1668 static int ipv6_get_saddr_master(struct net *net,
1669 				 const struct net_device *dst_dev,
1670 				 const struct net_device *master,
1671 				 struct ipv6_saddr_dst *dst,
1672 				 struct ipv6_saddr_score *scores,
1673 				 int hiscore_idx)
1674 {
1675 	struct inet6_dev *idev;
1676 
1677 	idev = __in6_dev_get(dst_dev);
1678 	if (idev)
1679 		hiscore_idx = __ipv6_dev_get_saddr(net, dst, idev,
1680 						   scores, hiscore_idx);
1681 
1682 	idev = __in6_dev_get(master);
1683 	if (idev)
1684 		hiscore_idx = __ipv6_dev_get_saddr(net, dst, idev,
1685 						   scores, hiscore_idx);
1686 
1687 	return hiscore_idx;
1688 }
1689 
1690 int ipv6_dev_get_saddr(struct net *net, const struct net_device *dst_dev,
1691 		       const struct in6_addr *daddr, unsigned int prefs,
1692 		       struct in6_addr *saddr)
1693 {
1694 	struct ipv6_saddr_score scores[2], *hiscore;
1695 	struct ipv6_saddr_dst dst;
1696 	struct inet6_dev *idev;
1697 	struct net_device *dev;
1698 	int dst_type;
1699 	bool use_oif_addr = false;
1700 	int hiscore_idx = 0;
1701 	int ret = 0;
1702 
1703 	dst_type = __ipv6_addr_type(daddr);
1704 	dst.addr = daddr;
1705 	dst.ifindex = dst_dev ? dst_dev->ifindex : 0;
1706 	dst.scope = __ipv6_addr_src_scope(dst_type);
1707 	dst.label = ipv6_addr_label(net, daddr, dst_type, dst.ifindex);
1708 	dst.prefs = prefs;
1709 
1710 	scores[hiscore_idx].rule = -1;
1711 	scores[hiscore_idx].ifa = NULL;
1712 
1713 	rcu_read_lock();
1714 
1715 	/* Candidate Source Address (section 4)
1716 	 *  - multicast and link-local destination address,
1717 	 *    the set of candidate source address MUST only
1718 	 *    include addresses assigned to interfaces
1719 	 *    belonging to the same link as the outgoing
1720 	 *    interface.
1721 	 * (- For site-local destination addresses, the
1722 	 *    set of candidate source addresses MUST only
1723 	 *    include addresses assigned to interfaces
1724 	 *    belonging to the same site as the outgoing
1725 	 *    interface.)
1726 	 *  - "It is RECOMMENDED that the candidate source addresses
1727 	 *    be the set of unicast addresses assigned to the
1728 	 *    interface that will be used to send to the destination
1729 	 *    (the 'outgoing' interface)." (RFC 6724)
1730 	 */
1731 	if (dst_dev) {
1732 		idev = __in6_dev_get(dst_dev);
1733 		if ((dst_type & IPV6_ADDR_MULTICAST) ||
1734 		    dst.scope <= IPV6_ADDR_SCOPE_LINKLOCAL ||
1735 		    (idev && idev->cnf.use_oif_addrs_only)) {
1736 			use_oif_addr = true;
1737 		}
1738 	}
1739 
1740 	if (use_oif_addr) {
1741 		if (idev)
1742 			hiscore_idx = __ipv6_dev_get_saddr(net, &dst, idev, scores, hiscore_idx);
1743 	} else {
1744 		const struct net_device *master;
1745 		int master_idx = 0;
1746 
1747 		/* if dst_dev exists and is enslaved to an L3 device, then
1748 		 * prefer addresses from dst_dev and then the master over
1749 		 * any other enslaved devices in the L3 domain.
1750 		 */
1751 		master = l3mdev_master_dev_rcu(dst_dev);
1752 		if (master) {
1753 			master_idx = master->ifindex;
1754 
1755 			hiscore_idx = ipv6_get_saddr_master(net, dst_dev,
1756 							    master, &dst,
1757 							    scores, hiscore_idx);
1758 
1759 			if (scores[hiscore_idx].ifa)
1760 				goto out;
1761 		}
1762 
1763 		for_each_netdev_rcu(net, dev) {
1764 			/* only consider addresses on devices in the
1765 			 * same L3 domain
1766 			 */
1767 			if (l3mdev_master_ifindex_rcu(dev) != master_idx)
1768 				continue;
1769 			idev = __in6_dev_get(dev);
1770 			if (!idev)
1771 				continue;
1772 			hiscore_idx = __ipv6_dev_get_saddr(net, &dst, idev, scores, hiscore_idx);
1773 		}
1774 	}
1775 
1776 out:
1777 	hiscore = &scores[hiscore_idx];
1778 	if (!hiscore->ifa)
1779 		ret = -EADDRNOTAVAIL;
1780 	else
1781 		*saddr = hiscore->ifa->addr;
1782 
1783 	rcu_read_unlock();
1784 	return ret;
1785 }
1786 EXPORT_SYMBOL(ipv6_dev_get_saddr);
1787 
1788 int __ipv6_get_lladdr(struct inet6_dev *idev, struct in6_addr *addr,
1789 		      u32 banned_flags)
1790 {
1791 	struct inet6_ifaddr *ifp;
1792 	int err = -EADDRNOTAVAIL;
1793 
1794 	list_for_each_entry_reverse(ifp, &idev->addr_list, if_list) {
1795 		if (ifp->scope > IFA_LINK)
1796 			break;
1797 		if (ifp->scope == IFA_LINK &&
1798 		    !(ifp->flags & banned_flags)) {
1799 			*addr = ifp->addr;
1800 			err = 0;
1801 			break;
1802 		}
1803 	}
1804 	return err;
1805 }
1806 
1807 int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr,
1808 		    u32 banned_flags)
1809 {
1810 	struct inet6_dev *idev;
1811 	int err = -EADDRNOTAVAIL;
1812 
1813 	rcu_read_lock();
1814 	idev = __in6_dev_get(dev);
1815 	if (idev) {
1816 		read_lock_bh(&idev->lock);
1817 		err = __ipv6_get_lladdr(idev, addr, banned_flags);
1818 		read_unlock_bh(&idev->lock);
1819 	}
1820 	rcu_read_unlock();
1821 	return err;
1822 }
1823 
1824 static int ipv6_count_addresses(const struct inet6_dev *idev)
1825 {
1826 	const struct inet6_ifaddr *ifp;
1827 	int cnt = 0;
1828 
1829 	rcu_read_lock();
1830 	list_for_each_entry_rcu(ifp, &idev->addr_list, if_list)
1831 		cnt++;
1832 	rcu_read_unlock();
1833 	return cnt;
1834 }
1835 
1836 int ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
1837 		  const struct net_device *dev, int strict)
1838 {
1839 	return ipv6_chk_addr_and_flags(net, addr, dev, strict, IFA_F_TENTATIVE);
1840 }
1841 EXPORT_SYMBOL(ipv6_chk_addr);
1842 
1843 int ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr,
1844 			    const struct net_device *dev, int strict,
1845 			    u32 banned_flags)
1846 {
1847 	unsigned int hash = inet6_addr_hash(net, addr);
1848 	struct inet6_ifaddr *ifp;
1849 	u32 ifp_flags;
1850 
1851 	rcu_read_lock();
1852 	hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) {
1853 		if (!net_eq(dev_net(ifp->idev->dev), net))
1854 			continue;
1855 		/* Decouple optimistic from tentative for evaluation here.
1856 		 * Ban optimistic addresses explicitly, when required.
1857 		 */
1858 		ifp_flags = (ifp->flags&IFA_F_OPTIMISTIC)
1859 			    ? (ifp->flags&~IFA_F_TENTATIVE)
1860 			    : ifp->flags;
1861 		if (ipv6_addr_equal(&ifp->addr, addr) &&
1862 		    !(ifp_flags&banned_flags) &&
1863 		    (!dev || ifp->idev->dev == dev ||
1864 		     !(ifp->scope&(IFA_LINK|IFA_HOST) || strict))) {
1865 			rcu_read_unlock();
1866 			return 1;
1867 		}
1868 	}
1869 
1870 	rcu_read_unlock();
1871 	return 0;
1872 }
1873 EXPORT_SYMBOL(ipv6_chk_addr_and_flags);
1874 
1875 
1876 /* Compares an address/prefix_len with addresses on device @dev.
1877  * If one is found it returns true.
1878  */
1879 bool ipv6_chk_custom_prefix(const struct in6_addr *addr,
1880 	const unsigned int prefix_len, struct net_device *dev)
1881 {
1882 	const struct inet6_ifaddr *ifa;
1883 	const struct inet6_dev *idev;
1884 	bool ret = false;
1885 
1886 	rcu_read_lock();
1887 	idev = __in6_dev_get(dev);
1888 	if (idev) {
1889 		list_for_each_entry_rcu(ifa, &idev->addr_list, if_list) {
1890 			ret = ipv6_prefix_equal(addr, &ifa->addr, prefix_len);
1891 			if (ret)
1892 				break;
1893 		}
1894 	}
1895 	rcu_read_unlock();
1896 
1897 	return ret;
1898 }
1899 EXPORT_SYMBOL(ipv6_chk_custom_prefix);
1900 
1901 int ipv6_chk_prefix(const struct in6_addr *addr, struct net_device *dev)
1902 {
1903 	const struct inet6_ifaddr *ifa;
1904 	const struct inet6_dev *idev;
1905 	int	onlink;
1906 
1907 	onlink = 0;
1908 	rcu_read_lock();
1909 	idev = __in6_dev_get(dev);
1910 	if (idev) {
1911 		list_for_each_entry_rcu(ifa, &idev->addr_list, if_list) {
1912 			onlink = ipv6_prefix_equal(addr, &ifa->addr,
1913 						   ifa->prefix_len);
1914 			if (onlink)
1915 				break;
1916 		}
1917 	}
1918 	rcu_read_unlock();
1919 	return onlink;
1920 }
1921 EXPORT_SYMBOL(ipv6_chk_prefix);
1922 
1923 struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *addr,
1924 				     struct net_device *dev, int strict)
1925 {
1926 	unsigned int hash = inet6_addr_hash(net, addr);
1927 	struct inet6_ifaddr *ifp, *result = NULL;
1928 
1929 	rcu_read_lock();
1930 	hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) {
1931 		if (!net_eq(dev_net(ifp->idev->dev), net))
1932 			continue;
1933 		if (ipv6_addr_equal(&ifp->addr, addr)) {
1934 			if (!dev || ifp->idev->dev == dev ||
1935 			    !(ifp->scope&(IFA_LINK|IFA_HOST) || strict)) {
1936 				result = ifp;
1937 				in6_ifa_hold(ifp);
1938 				break;
1939 			}
1940 		}
1941 	}
1942 	rcu_read_unlock();
1943 
1944 	return result;
1945 }
1946 
1947 /* Gets referenced address, destroys ifaddr */
1948 
1949 static void addrconf_dad_stop(struct inet6_ifaddr *ifp, int dad_failed)
1950 {
1951 	if (dad_failed)
1952 		ifp->flags |= IFA_F_DADFAILED;
1953 
1954 	if (ifp->flags&IFA_F_TEMPORARY) {
1955 		struct inet6_ifaddr *ifpub;
1956 		spin_lock_bh(&ifp->lock);
1957 		ifpub = ifp->ifpub;
1958 		if (ifpub) {
1959 			in6_ifa_hold(ifpub);
1960 			spin_unlock_bh(&ifp->lock);
1961 			ipv6_create_tempaddr(ifpub, ifp, true);
1962 			in6_ifa_put(ifpub);
1963 		} else {
1964 			spin_unlock_bh(&ifp->lock);
1965 		}
1966 		ipv6_del_addr(ifp);
1967 	} else if (ifp->flags&IFA_F_PERMANENT || !dad_failed) {
1968 		spin_lock_bh(&ifp->lock);
1969 		addrconf_del_dad_work(ifp);
1970 		ifp->flags |= IFA_F_TENTATIVE;
1971 		spin_unlock_bh(&ifp->lock);
1972 		if (dad_failed)
1973 			ipv6_ifa_notify(0, ifp);
1974 		in6_ifa_put(ifp);
1975 	} else {
1976 		ipv6_del_addr(ifp);
1977 	}
1978 }
1979 
1980 static int addrconf_dad_end(struct inet6_ifaddr *ifp)
1981 {
1982 	int err = -ENOENT;
1983 
1984 	spin_lock_bh(&ifp->lock);
1985 	if (ifp->state == INET6_IFADDR_STATE_DAD) {
1986 		ifp->state = INET6_IFADDR_STATE_POSTDAD;
1987 		err = 0;
1988 	}
1989 	spin_unlock_bh(&ifp->lock);
1990 
1991 	return err;
1992 }
1993 
1994 void addrconf_dad_failure(struct sk_buff *skb, struct inet6_ifaddr *ifp)
1995 {
1996 	struct inet6_dev *idev = ifp->idev;
1997 	struct net *net = dev_net(ifp->idev->dev);
1998 
1999 	if (addrconf_dad_end(ifp)) {
2000 		in6_ifa_put(ifp);
2001 		return;
2002 	}
2003 
2004 	net_info_ratelimited("%s: IPv6 duplicate address %pI6c used by %pM detected!\n",
2005 			     ifp->idev->dev->name, &ifp->addr, eth_hdr(skb)->h_source);
2006 
2007 	spin_lock_bh(&ifp->lock);
2008 
2009 	if (ifp->flags & IFA_F_STABLE_PRIVACY) {
2010 		int scope = ifp->scope;
2011 		u32 flags = ifp->flags;
2012 		struct in6_addr new_addr;
2013 		struct inet6_ifaddr *ifp2;
2014 		u32 valid_lft, preferred_lft;
2015 		int pfxlen = ifp->prefix_len;
2016 		int retries = ifp->stable_privacy_retry + 1;
2017 
2018 		if (retries > net->ipv6.sysctl.idgen_retries) {
2019 			net_info_ratelimited("%s: privacy stable address generation failed because of DAD conflicts!\n",
2020 					     ifp->idev->dev->name);
2021 			goto errdad;
2022 		}
2023 
2024 		new_addr = ifp->addr;
2025 		if (ipv6_generate_stable_address(&new_addr, retries,
2026 						 idev))
2027 			goto errdad;
2028 
2029 		valid_lft = ifp->valid_lft;
2030 		preferred_lft = ifp->prefered_lft;
2031 
2032 		spin_unlock_bh(&ifp->lock);
2033 
2034 		if (idev->cnf.max_addresses &&
2035 		    ipv6_count_addresses(idev) >=
2036 		    idev->cnf.max_addresses)
2037 			goto lock_errdad;
2038 
2039 		net_info_ratelimited("%s: generating new stable privacy address because of DAD conflict\n",
2040 				     ifp->idev->dev->name);
2041 
2042 		ifp2 = ipv6_add_addr(idev, &new_addr, NULL, pfxlen,
2043 				     scope, flags, valid_lft,
2044 				     preferred_lft, false, NULL);
2045 		if (IS_ERR(ifp2))
2046 			goto lock_errdad;
2047 
2048 		spin_lock_bh(&ifp2->lock);
2049 		ifp2->stable_privacy_retry = retries;
2050 		ifp2->state = INET6_IFADDR_STATE_PREDAD;
2051 		spin_unlock_bh(&ifp2->lock);
2052 
2053 		addrconf_mod_dad_work(ifp2, net->ipv6.sysctl.idgen_delay);
2054 		in6_ifa_put(ifp2);
2055 lock_errdad:
2056 		spin_lock_bh(&ifp->lock);
2057 	}
2058 
2059 errdad:
2060 	/* transition from _POSTDAD to _ERRDAD */
2061 	ifp->state = INET6_IFADDR_STATE_ERRDAD;
2062 	spin_unlock_bh(&ifp->lock);
2063 
2064 	addrconf_mod_dad_work(ifp, 0);
2065 	in6_ifa_put(ifp);
2066 }
2067 
2068 /* Join to solicited addr multicast group.
2069  * caller must hold RTNL */
2070 void addrconf_join_solict(struct net_device *dev, const struct in6_addr *addr)
2071 {
2072 	struct in6_addr maddr;
2073 
2074 	if (dev->flags&(IFF_LOOPBACK|IFF_NOARP))
2075 		return;
2076 
2077 	addrconf_addr_solict_mult(addr, &maddr);
2078 	ipv6_dev_mc_inc(dev, &maddr);
2079 }
2080 
2081 /* caller must hold RTNL */
2082 void addrconf_leave_solict(struct inet6_dev *idev, const struct in6_addr *addr)
2083 {
2084 	struct in6_addr maddr;
2085 
2086 	if (idev->dev->flags&(IFF_LOOPBACK|IFF_NOARP))
2087 		return;
2088 
2089 	addrconf_addr_solict_mult(addr, &maddr);
2090 	__ipv6_dev_mc_dec(idev, &maddr);
2091 }
2092 
2093 /* caller must hold RTNL */
2094 static void addrconf_join_anycast(struct inet6_ifaddr *ifp)
2095 {
2096 	struct in6_addr addr;
2097 
2098 	if (ifp->prefix_len >= 127) /* RFC 6164 */
2099 		return;
2100 	ipv6_addr_prefix(&addr, &ifp->addr, ifp->prefix_len);
2101 	if (ipv6_addr_any(&addr))
2102 		return;
2103 	__ipv6_dev_ac_inc(ifp->idev, &addr);
2104 }
2105 
2106 /* caller must hold RTNL */
2107 static void addrconf_leave_anycast(struct inet6_ifaddr *ifp)
2108 {
2109 	struct in6_addr addr;
2110 
2111 	if (ifp->prefix_len >= 127) /* RFC 6164 */
2112 		return;
2113 	ipv6_addr_prefix(&addr, &ifp->addr, ifp->prefix_len);
2114 	if (ipv6_addr_any(&addr))
2115 		return;
2116 	__ipv6_dev_ac_dec(ifp->idev, &addr);
2117 }
2118 
2119 static int addrconf_ifid_6lowpan(u8 *eui, struct net_device *dev)
2120 {
2121 	switch (dev->addr_len) {
2122 	case ETH_ALEN:
2123 		memcpy(eui, dev->dev_addr, 3);
2124 		eui[3] = 0xFF;
2125 		eui[4] = 0xFE;
2126 		memcpy(eui + 5, dev->dev_addr + 3, 3);
2127 		break;
2128 	case EUI64_ADDR_LEN:
2129 		memcpy(eui, dev->dev_addr, EUI64_ADDR_LEN);
2130 		eui[0] ^= 2;
2131 		break;
2132 	default:
2133 		return -1;
2134 	}
2135 
2136 	return 0;
2137 }
2138 
2139 static int addrconf_ifid_ieee1394(u8 *eui, struct net_device *dev)
2140 {
2141 	union fwnet_hwaddr *ha;
2142 
2143 	if (dev->addr_len != FWNET_ALEN)
2144 		return -1;
2145 
2146 	ha = (union fwnet_hwaddr *)dev->dev_addr;
2147 
2148 	memcpy(eui, &ha->uc.uniq_id, sizeof(ha->uc.uniq_id));
2149 	eui[0] ^= 2;
2150 	return 0;
2151 }
2152 
2153 static int addrconf_ifid_arcnet(u8 *eui, struct net_device *dev)
2154 {
2155 	/* XXX: inherit EUI-64 from other interface -- yoshfuji */
2156 	if (dev->addr_len != ARCNET_ALEN)
2157 		return -1;
2158 	memset(eui, 0, 7);
2159 	eui[7] = *(u8 *)dev->dev_addr;
2160 	return 0;
2161 }
2162 
2163 static int addrconf_ifid_infiniband(u8 *eui, struct net_device *dev)
2164 {
2165 	if (dev->addr_len != INFINIBAND_ALEN)
2166 		return -1;
2167 	memcpy(eui, dev->dev_addr + 12, 8);
2168 	eui[0] |= 2;
2169 	return 0;
2170 }
2171 
2172 static int __ipv6_isatap_ifid(u8 *eui, __be32 addr)
2173 {
2174 	if (addr == 0)
2175 		return -1;
2176 	eui[0] = (ipv4_is_zeronet(addr) || ipv4_is_private_10(addr) ||
2177 		  ipv4_is_loopback(addr) || ipv4_is_linklocal_169(addr) ||
2178 		  ipv4_is_private_172(addr) || ipv4_is_test_192(addr) ||
2179 		  ipv4_is_anycast_6to4(addr) || ipv4_is_private_192(addr) ||
2180 		  ipv4_is_test_198(addr) || ipv4_is_multicast(addr) ||
2181 		  ipv4_is_lbcast(addr)) ? 0x00 : 0x02;
2182 	eui[1] = 0;
2183 	eui[2] = 0x5E;
2184 	eui[3] = 0xFE;
2185 	memcpy(eui + 4, &addr, 4);
2186 	return 0;
2187 }
2188 
2189 static int addrconf_ifid_sit(u8 *eui, struct net_device *dev)
2190 {
2191 	if (dev->priv_flags & IFF_ISATAP)
2192 		return __ipv6_isatap_ifid(eui, *(__be32 *)dev->dev_addr);
2193 	return -1;
2194 }
2195 
2196 static int addrconf_ifid_gre(u8 *eui, struct net_device *dev)
2197 {
2198 	return __ipv6_isatap_ifid(eui, *(__be32 *)dev->dev_addr);
2199 }
2200 
2201 static int addrconf_ifid_ip6tnl(u8 *eui, struct net_device *dev)
2202 {
2203 	memcpy(eui, dev->perm_addr, 3);
2204 	memcpy(eui + 5, dev->perm_addr + 3, 3);
2205 	eui[3] = 0xFF;
2206 	eui[4] = 0xFE;
2207 	eui[0] ^= 2;
2208 	return 0;
2209 }
2210 
2211 static int ipv6_generate_eui64(u8 *eui, struct net_device *dev)
2212 {
2213 	switch (dev->type) {
2214 	case ARPHRD_ETHER:
2215 	case ARPHRD_FDDI:
2216 		return addrconf_ifid_eui48(eui, dev);
2217 	case ARPHRD_ARCNET:
2218 		return addrconf_ifid_arcnet(eui, dev);
2219 	case ARPHRD_INFINIBAND:
2220 		return addrconf_ifid_infiniband(eui, dev);
2221 	case ARPHRD_SIT:
2222 		return addrconf_ifid_sit(eui, dev);
2223 	case ARPHRD_IPGRE:
2224 	case ARPHRD_TUNNEL:
2225 		return addrconf_ifid_gre(eui, dev);
2226 	case ARPHRD_6LOWPAN:
2227 		return addrconf_ifid_6lowpan(eui, dev);
2228 	case ARPHRD_IEEE1394:
2229 		return addrconf_ifid_ieee1394(eui, dev);
2230 	case ARPHRD_TUNNEL6:
2231 	case ARPHRD_IP6GRE:
2232 		return addrconf_ifid_ip6tnl(eui, dev);
2233 	}
2234 	return -1;
2235 }
2236 
2237 static int ipv6_inherit_eui64(u8 *eui, struct inet6_dev *idev)
2238 {
2239 	int err = -1;
2240 	struct inet6_ifaddr *ifp;
2241 
2242 	read_lock_bh(&idev->lock);
2243 	list_for_each_entry_reverse(ifp, &idev->addr_list, if_list) {
2244 		if (ifp->scope > IFA_LINK)
2245 			break;
2246 		if (ifp->scope == IFA_LINK && !(ifp->flags&IFA_F_TENTATIVE)) {
2247 			memcpy(eui, ifp->addr.s6_addr+8, 8);
2248 			err = 0;
2249 			break;
2250 		}
2251 	}
2252 	read_unlock_bh(&idev->lock);
2253 	return err;
2254 }
2255 
2256 /* (re)generation of randomized interface identifier (RFC 3041 3.2, 3.5) */
2257 static void ipv6_regen_rndid(struct inet6_dev *idev)
2258 {
2259 regen:
2260 	get_random_bytes(idev->rndid, sizeof(idev->rndid));
2261 	idev->rndid[0] &= ~0x02;
2262 
2263 	/*
2264 	 * <draft-ietf-ipngwg-temp-addresses-v2-00.txt>:
2265 	 * check if generated address is not inappropriate
2266 	 *
2267 	 *  - Reserved subnet anycast (RFC 2526)
2268 	 *	11111101 11....11 1xxxxxxx
2269 	 *  - ISATAP (RFC4214) 6.1
2270 	 *	00-00-5E-FE-xx-xx-xx-xx
2271 	 *  - value 0
2272 	 *  - XXX: already assigned to an address on the device
2273 	 */
2274 	if (idev->rndid[0] == 0xfd &&
2275 	    (idev->rndid[1]&idev->rndid[2]&idev->rndid[3]&idev->rndid[4]&idev->rndid[5]&idev->rndid[6]) == 0xff &&
2276 	    (idev->rndid[7]&0x80))
2277 		goto regen;
2278 	if ((idev->rndid[0]|idev->rndid[1]) == 0) {
2279 		if (idev->rndid[2] == 0x5e && idev->rndid[3] == 0xfe)
2280 			goto regen;
2281 		if ((idev->rndid[2]|idev->rndid[3]|idev->rndid[4]|idev->rndid[5]|idev->rndid[6]|idev->rndid[7]) == 0x00)
2282 			goto regen;
2283 	}
2284 }
2285 
2286 static void  ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr)
2287 {
2288 	if (tmpaddr && memcmp(idev->rndid, &tmpaddr->s6_addr[8], 8) == 0)
2289 		ipv6_regen_rndid(idev);
2290 }
2291 
2292 /*
2293  *	Add prefix route.
2294  */
2295 
2296 static void
2297 addrconf_prefix_route(struct in6_addr *pfx, int plen, struct net_device *dev,
2298 		      unsigned long expires, u32 flags)
2299 {
2300 	struct fib6_config cfg = {
2301 		.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_PREFIX,
2302 		.fc_metric = IP6_RT_PRIO_ADDRCONF,
2303 		.fc_ifindex = dev->ifindex,
2304 		.fc_expires = expires,
2305 		.fc_dst_len = plen,
2306 		.fc_flags = RTF_UP | flags,
2307 		.fc_nlinfo.nl_net = dev_net(dev),
2308 		.fc_protocol = RTPROT_KERNEL,
2309 	};
2310 
2311 	cfg.fc_dst = *pfx;
2312 
2313 	/* Prevent useless cloning on PtP SIT.
2314 	   This thing is done here expecting that the whole
2315 	   class of non-broadcast devices need not cloning.
2316 	 */
2317 #if IS_ENABLED(CONFIG_IPV6_SIT)
2318 	if (dev->type == ARPHRD_SIT && (dev->flags & IFF_POINTOPOINT))
2319 		cfg.fc_flags |= RTF_NONEXTHOP;
2320 #endif
2321 
2322 	ip6_route_add(&cfg, NULL);
2323 }
2324 
2325 
2326 static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
2327 						  int plen,
2328 						  const struct net_device *dev,
2329 						  u32 flags, u32 noflags)
2330 {
2331 	struct fib6_node *fn;
2332 	struct rt6_info *rt = NULL;
2333 	struct fib6_table *table;
2334 	u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_PREFIX;
2335 
2336 	table = fib6_get_table(dev_net(dev), tb_id);
2337 	if (!table)
2338 		return NULL;
2339 
2340 	rcu_read_lock();
2341 	fn = fib6_locate(&table->tb6_root, pfx, plen, NULL, 0, true);
2342 	if (!fn)
2343 		goto out;
2344 
2345 	for_each_fib6_node_rt_rcu(fn) {
2346 		if (rt->dst.dev->ifindex != dev->ifindex)
2347 			continue;
2348 		if ((rt->rt6i_flags & flags) != flags)
2349 			continue;
2350 		if ((rt->rt6i_flags & noflags) != 0)
2351 			continue;
2352 		if (!dst_hold_safe(&rt->dst))
2353 			rt = NULL;
2354 		break;
2355 	}
2356 out:
2357 	rcu_read_unlock();
2358 	return rt;
2359 }
2360 
2361 
2362 /* Create "default" multicast route to the interface */
2363 
2364 static void addrconf_add_mroute(struct net_device *dev)
2365 {
2366 	struct fib6_config cfg = {
2367 		.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_LOCAL,
2368 		.fc_metric = IP6_RT_PRIO_ADDRCONF,
2369 		.fc_ifindex = dev->ifindex,
2370 		.fc_dst_len = 8,
2371 		.fc_flags = RTF_UP,
2372 		.fc_nlinfo.nl_net = dev_net(dev),
2373 	};
2374 
2375 	ipv6_addr_set(&cfg.fc_dst, htonl(0xFF000000), 0, 0, 0);
2376 
2377 	ip6_route_add(&cfg, NULL);
2378 }
2379 
2380 static struct inet6_dev *addrconf_add_dev(struct net_device *dev)
2381 {
2382 	struct inet6_dev *idev;
2383 
2384 	ASSERT_RTNL();
2385 
2386 	idev = ipv6_find_idev(dev);
2387 	if (!idev)
2388 		return ERR_PTR(-ENOBUFS);
2389 
2390 	if (idev->cnf.disable_ipv6)
2391 		return ERR_PTR(-EACCES);
2392 
2393 	/* Add default multicast route */
2394 	if (!(dev->flags & IFF_LOOPBACK) && !netif_is_l3_master(dev))
2395 		addrconf_add_mroute(dev);
2396 
2397 	return idev;
2398 }
2399 
2400 static void manage_tempaddrs(struct inet6_dev *idev,
2401 			     struct inet6_ifaddr *ifp,
2402 			     __u32 valid_lft, __u32 prefered_lft,
2403 			     bool create, unsigned long now)
2404 {
2405 	u32 flags;
2406 	struct inet6_ifaddr *ift;
2407 
2408 	read_lock_bh(&idev->lock);
2409 	/* update all temporary addresses in the list */
2410 	list_for_each_entry(ift, &idev->tempaddr_list, tmp_list) {
2411 		int age, max_valid, max_prefered;
2412 
2413 		if (ifp != ift->ifpub)
2414 			continue;
2415 
2416 		/* RFC 4941 section 3.3:
2417 		 * If a received option will extend the lifetime of a public
2418 		 * address, the lifetimes of temporary addresses should
2419 		 * be extended, subject to the overall constraint that no
2420 		 * temporary addresses should ever remain "valid" or "preferred"
2421 		 * for a time longer than (TEMP_VALID_LIFETIME) or
2422 		 * (TEMP_PREFERRED_LIFETIME - DESYNC_FACTOR), respectively.
2423 		 */
2424 		age = (now - ift->cstamp) / HZ;
2425 		max_valid = idev->cnf.temp_valid_lft - age;
2426 		if (max_valid < 0)
2427 			max_valid = 0;
2428 
2429 		max_prefered = idev->cnf.temp_prefered_lft -
2430 			       idev->desync_factor - age;
2431 		if (max_prefered < 0)
2432 			max_prefered = 0;
2433 
2434 		if (valid_lft > max_valid)
2435 			valid_lft = max_valid;
2436 
2437 		if (prefered_lft > max_prefered)
2438 			prefered_lft = max_prefered;
2439 
2440 		spin_lock(&ift->lock);
2441 		flags = ift->flags;
2442 		ift->valid_lft = valid_lft;
2443 		ift->prefered_lft = prefered_lft;
2444 		ift->tstamp = now;
2445 		if (prefered_lft > 0)
2446 			ift->flags &= ~IFA_F_DEPRECATED;
2447 
2448 		spin_unlock(&ift->lock);
2449 		if (!(flags&IFA_F_TENTATIVE))
2450 			ipv6_ifa_notify(0, ift);
2451 	}
2452 
2453 	if ((create || list_empty(&idev->tempaddr_list)) &&
2454 	    idev->cnf.use_tempaddr > 0) {
2455 		/* When a new public address is created as described
2456 		 * in [ADDRCONF], also create a new temporary address.
2457 		 * Also create a temporary address if it's enabled but
2458 		 * no temporary address currently exists.
2459 		 */
2460 		read_unlock_bh(&idev->lock);
2461 		ipv6_create_tempaddr(ifp, NULL, false);
2462 	} else {
2463 		read_unlock_bh(&idev->lock);
2464 	}
2465 }
2466 
2467 static bool is_addr_mode_generate_stable(struct inet6_dev *idev)
2468 {
2469 	return idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY ||
2470 	       idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_RANDOM;
2471 }
2472 
2473 int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev,
2474 				 const struct prefix_info *pinfo,
2475 				 struct inet6_dev *in6_dev,
2476 				 const struct in6_addr *addr, int addr_type,
2477 				 u32 addr_flags, bool sllao, bool tokenized,
2478 				 __u32 valid_lft, u32 prefered_lft)
2479 {
2480 	struct inet6_ifaddr *ifp = ipv6_get_ifaddr(net, addr, dev, 1);
2481 	int create = 0, update_lft = 0;
2482 
2483 	if (!ifp && valid_lft) {
2484 		int max_addresses = in6_dev->cnf.max_addresses;
2485 
2486 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
2487 		if ((net->ipv6.devconf_all->optimistic_dad ||
2488 		     in6_dev->cnf.optimistic_dad) &&
2489 		    !net->ipv6.devconf_all->forwarding && sllao)
2490 			addr_flags |= IFA_F_OPTIMISTIC;
2491 #endif
2492 
2493 		/* Do not allow to create too much of autoconfigured
2494 		 * addresses; this would be too easy way to crash kernel.
2495 		 */
2496 		if (!max_addresses ||
2497 		    ipv6_count_addresses(in6_dev) < max_addresses)
2498 			ifp = ipv6_add_addr(in6_dev, addr, NULL,
2499 					    pinfo->prefix_len,
2500 					    addr_type&IPV6_ADDR_SCOPE_MASK,
2501 					    addr_flags, valid_lft,
2502 					    prefered_lft, false, NULL);
2503 
2504 		if (IS_ERR_OR_NULL(ifp))
2505 			return -1;
2506 
2507 		update_lft = 0;
2508 		create = 1;
2509 		spin_lock_bh(&ifp->lock);
2510 		ifp->flags |= IFA_F_MANAGETEMPADDR;
2511 		ifp->cstamp = jiffies;
2512 		ifp->tokenized = tokenized;
2513 		spin_unlock_bh(&ifp->lock);
2514 		addrconf_dad_start(ifp);
2515 	}
2516 
2517 	if (ifp) {
2518 		u32 flags;
2519 		unsigned long now;
2520 		u32 stored_lft;
2521 
2522 		/* update lifetime (RFC2462 5.5.3 e) */
2523 		spin_lock_bh(&ifp->lock);
2524 		now = jiffies;
2525 		if (ifp->valid_lft > (now - ifp->tstamp) / HZ)
2526 			stored_lft = ifp->valid_lft - (now - ifp->tstamp) / HZ;
2527 		else
2528 			stored_lft = 0;
2529 		if (!update_lft && !create && stored_lft) {
2530 			const u32 minimum_lft = min_t(u32,
2531 				stored_lft, MIN_VALID_LIFETIME);
2532 			valid_lft = max(valid_lft, minimum_lft);
2533 
2534 			/* RFC4862 Section 5.5.3e:
2535 			 * "Note that the preferred lifetime of the
2536 			 *  corresponding address is always reset to
2537 			 *  the Preferred Lifetime in the received
2538 			 *  Prefix Information option, regardless of
2539 			 *  whether the valid lifetime is also reset or
2540 			 *  ignored."
2541 			 *
2542 			 * So we should always update prefered_lft here.
2543 			 */
2544 			update_lft = 1;
2545 		}
2546 
2547 		if (update_lft) {
2548 			ifp->valid_lft = valid_lft;
2549 			ifp->prefered_lft = prefered_lft;
2550 			ifp->tstamp = now;
2551 			flags = ifp->flags;
2552 			ifp->flags &= ~IFA_F_DEPRECATED;
2553 			spin_unlock_bh(&ifp->lock);
2554 
2555 			if (!(flags&IFA_F_TENTATIVE))
2556 				ipv6_ifa_notify(0, ifp);
2557 		} else
2558 			spin_unlock_bh(&ifp->lock);
2559 
2560 		manage_tempaddrs(in6_dev, ifp, valid_lft, prefered_lft,
2561 				 create, now);
2562 
2563 		in6_ifa_put(ifp);
2564 		addrconf_verify();
2565 	}
2566 
2567 	return 0;
2568 }
2569 EXPORT_SYMBOL_GPL(addrconf_prefix_rcv_add_addr);
2570 
2571 void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao)
2572 {
2573 	struct prefix_info *pinfo;
2574 	__u32 valid_lft;
2575 	__u32 prefered_lft;
2576 	int addr_type, err;
2577 	u32 addr_flags = 0;
2578 	struct inet6_dev *in6_dev;
2579 	struct net *net = dev_net(dev);
2580 
2581 	pinfo = (struct prefix_info *) opt;
2582 
2583 	if (len < sizeof(struct prefix_info)) {
2584 		ADBG("addrconf: prefix option too short\n");
2585 		return;
2586 	}
2587 
2588 	/*
2589 	 *	Validation checks ([ADDRCONF], page 19)
2590 	 */
2591 
2592 	addr_type = ipv6_addr_type(&pinfo->prefix);
2593 
2594 	if (addr_type & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL))
2595 		return;
2596 
2597 	valid_lft = ntohl(pinfo->valid);
2598 	prefered_lft = ntohl(pinfo->prefered);
2599 
2600 	if (prefered_lft > valid_lft) {
2601 		net_warn_ratelimited("addrconf: prefix option has invalid lifetime\n");
2602 		return;
2603 	}
2604 
2605 	in6_dev = in6_dev_get(dev);
2606 
2607 	if (!in6_dev) {
2608 		net_dbg_ratelimited("addrconf: device %s not configured\n",
2609 				    dev->name);
2610 		return;
2611 	}
2612 
2613 	/*
2614 	 *	Two things going on here:
2615 	 *	1) Add routes for on-link prefixes
2616 	 *	2) Configure prefixes with the auto flag set
2617 	 */
2618 
2619 	if (pinfo->onlink) {
2620 		struct rt6_info *rt;
2621 		unsigned long rt_expires;
2622 
2623 		/* Avoid arithmetic overflow. Really, we could
2624 		 * save rt_expires in seconds, likely valid_lft,
2625 		 * but it would require division in fib gc, that it
2626 		 * not good.
2627 		 */
2628 		if (HZ > USER_HZ)
2629 			rt_expires = addrconf_timeout_fixup(valid_lft, HZ);
2630 		else
2631 			rt_expires = addrconf_timeout_fixup(valid_lft, USER_HZ);
2632 
2633 		if (addrconf_finite_timeout(rt_expires))
2634 			rt_expires *= HZ;
2635 
2636 		rt = addrconf_get_prefix_route(&pinfo->prefix,
2637 					       pinfo->prefix_len,
2638 					       dev,
2639 					       RTF_ADDRCONF | RTF_PREFIX_RT,
2640 					       RTF_GATEWAY | RTF_DEFAULT);
2641 
2642 		if (rt) {
2643 			/* Autoconf prefix route */
2644 			if (valid_lft == 0) {
2645 				ip6_del_rt(rt);
2646 				rt = NULL;
2647 			} else if (addrconf_finite_timeout(rt_expires)) {
2648 				/* not infinity */
2649 				rt6_set_expires(rt, jiffies + rt_expires);
2650 			} else {
2651 				rt6_clean_expires(rt);
2652 			}
2653 		} else if (valid_lft) {
2654 			clock_t expires = 0;
2655 			int flags = RTF_ADDRCONF | RTF_PREFIX_RT;
2656 			if (addrconf_finite_timeout(rt_expires)) {
2657 				/* not infinity */
2658 				flags |= RTF_EXPIRES;
2659 				expires = jiffies_to_clock_t(rt_expires);
2660 			}
2661 			addrconf_prefix_route(&pinfo->prefix, pinfo->prefix_len,
2662 					      dev, expires, flags);
2663 		}
2664 		ip6_rt_put(rt);
2665 	}
2666 
2667 	/* Try to figure out our local address for this prefix */
2668 
2669 	if (pinfo->autoconf && in6_dev->cnf.autoconf) {
2670 		struct in6_addr addr;
2671 		bool tokenized = false, dev_addr_generated = false;
2672 
2673 		if (pinfo->prefix_len == 64) {
2674 			memcpy(&addr, &pinfo->prefix, 8);
2675 
2676 			if (!ipv6_addr_any(&in6_dev->token)) {
2677 				read_lock_bh(&in6_dev->lock);
2678 				memcpy(addr.s6_addr + 8,
2679 				       in6_dev->token.s6_addr + 8, 8);
2680 				read_unlock_bh(&in6_dev->lock);
2681 				tokenized = true;
2682 			} else if (is_addr_mode_generate_stable(in6_dev) &&
2683 				   !ipv6_generate_stable_address(&addr, 0,
2684 								 in6_dev)) {
2685 				addr_flags |= IFA_F_STABLE_PRIVACY;
2686 				goto ok;
2687 			} else if (ipv6_generate_eui64(addr.s6_addr + 8, dev) &&
2688 				   ipv6_inherit_eui64(addr.s6_addr + 8, in6_dev)) {
2689 				goto put;
2690 			} else {
2691 				dev_addr_generated = true;
2692 			}
2693 			goto ok;
2694 		}
2695 		net_dbg_ratelimited("IPv6 addrconf: prefix with wrong length %d\n",
2696 				    pinfo->prefix_len);
2697 		goto put;
2698 
2699 ok:
2700 		err = addrconf_prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
2701 						   &addr, addr_type,
2702 						   addr_flags, sllao,
2703 						   tokenized, valid_lft,
2704 						   prefered_lft);
2705 		if (err)
2706 			goto put;
2707 
2708 		/* Ignore error case here because previous prefix add addr was
2709 		 * successful which will be notified.
2710 		 */
2711 		ndisc_ops_prefix_rcv_add_addr(net, dev, pinfo, in6_dev, &addr,
2712 					      addr_type, addr_flags, sllao,
2713 					      tokenized, valid_lft,
2714 					      prefered_lft,
2715 					      dev_addr_generated);
2716 	}
2717 	inet6_prefix_notify(RTM_NEWPREFIX, in6_dev, pinfo);
2718 put:
2719 	in6_dev_put(in6_dev);
2720 }
2721 
2722 /*
2723  *	Set destination address.
2724  *	Special case for SIT interfaces where we create a new "virtual"
2725  *	device.
2726  */
2727 int addrconf_set_dstaddr(struct net *net, void __user *arg)
2728 {
2729 	struct in6_ifreq ireq;
2730 	struct net_device *dev;
2731 	int err = -EINVAL;
2732 
2733 	rtnl_lock();
2734 
2735 	err = -EFAULT;
2736 	if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
2737 		goto err_exit;
2738 
2739 	dev = __dev_get_by_index(net, ireq.ifr6_ifindex);
2740 
2741 	err = -ENODEV;
2742 	if (!dev)
2743 		goto err_exit;
2744 
2745 #if IS_ENABLED(CONFIG_IPV6_SIT)
2746 	if (dev->type == ARPHRD_SIT) {
2747 		const struct net_device_ops *ops = dev->netdev_ops;
2748 		struct ifreq ifr;
2749 		struct ip_tunnel_parm p;
2750 
2751 		err = -EADDRNOTAVAIL;
2752 		if (!(ipv6_addr_type(&ireq.ifr6_addr) & IPV6_ADDR_COMPATv4))
2753 			goto err_exit;
2754 
2755 		memset(&p, 0, sizeof(p));
2756 		p.iph.daddr = ireq.ifr6_addr.s6_addr32[3];
2757 		p.iph.saddr = 0;
2758 		p.iph.version = 4;
2759 		p.iph.ihl = 5;
2760 		p.iph.protocol = IPPROTO_IPV6;
2761 		p.iph.ttl = 64;
2762 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
2763 
2764 		if (ops->ndo_do_ioctl) {
2765 			mm_segment_t oldfs = get_fs();
2766 
2767 			set_fs(KERNEL_DS);
2768 			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
2769 			set_fs(oldfs);
2770 		} else
2771 			err = -EOPNOTSUPP;
2772 
2773 		if (err == 0) {
2774 			err = -ENOBUFS;
2775 			dev = __dev_get_by_name(net, p.name);
2776 			if (!dev)
2777 				goto err_exit;
2778 			err = dev_open(dev);
2779 		}
2780 	}
2781 #endif
2782 
2783 err_exit:
2784 	rtnl_unlock();
2785 	return err;
2786 }
2787 
2788 static int ipv6_mc_config(struct sock *sk, bool join,
2789 			  const struct in6_addr *addr, int ifindex)
2790 {
2791 	int ret;
2792 
2793 	ASSERT_RTNL();
2794 
2795 	lock_sock(sk);
2796 	if (join)
2797 		ret = ipv6_sock_mc_join(sk, ifindex, addr);
2798 	else
2799 		ret = ipv6_sock_mc_drop(sk, ifindex, addr);
2800 	release_sock(sk);
2801 
2802 	return ret;
2803 }
2804 
2805 /*
2806  *	Manual configuration of address on an interface
2807  */
2808 static int inet6_addr_add(struct net *net, int ifindex,
2809 			  const struct in6_addr *pfx,
2810 			  const struct in6_addr *peer_pfx,
2811 			  unsigned int plen, __u32 ifa_flags,
2812 			  __u32 prefered_lft, __u32 valid_lft,
2813 			  struct netlink_ext_ack *extack)
2814 {
2815 	struct inet6_ifaddr *ifp;
2816 	struct inet6_dev *idev;
2817 	struct net_device *dev;
2818 	unsigned long timeout;
2819 	clock_t expires;
2820 	int scope;
2821 	u32 flags;
2822 
2823 	ASSERT_RTNL();
2824 
2825 	if (plen > 128)
2826 		return -EINVAL;
2827 
2828 	/* check the lifetime */
2829 	if (!valid_lft || prefered_lft > valid_lft)
2830 		return -EINVAL;
2831 
2832 	if (ifa_flags & IFA_F_MANAGETEMPADDR && plen != 64)
2833 		return -EINVAL;
2834 
2835 	dev = __dev_get_by_index(net, ifindex);
2836 	if (!dev)
2837 		return -ENODEV;
2838 
2839 	idev = addrconf_add_dev(dev);
2840 	if (IS_ERR(idev))
2841 		return PTR_ERR(idev);
2842 
2843 	if (ifa_flags & IFA_F_MCAUTOJOIN) {
2844 		int ret = ipv6_mc_config(net->ipv6.mc_autojoin_sk,
2845 					 true, pfx, ifindex);
2846 
2847 		if (ret < 0)
2848 			return ret;
2849 	}
2850 
2851 	scope = ipv6_addr_scope(pfx);
2852 
2853 	timeout = addrconf_timeout_fixup(valid_lft, HZ);
2854 	if (addrconf_finite_timeout(timeout)) {
2855 		expires = jiffies_to_clock_t(timeout * HZ);
2856 		valid_lft = timeout;
2857 		flags = RTF_EXPIRES;
2858 	} else {
2859 		expires = 0;
2860 		flags = 0;
2861 		ifa_flags |= IFA_F_PERMANENT;
2862 	}
2863 
2864 	timeout = addrconf_timeout_fixup(prefered_lft, HZ);
2865 	if (addrconf_finite_timeout(timeout)) {
2866 		if (timeout == 0)
2867 			ifa_flags |= IFA_F_DEPRECATED;
2868 		prefered_lft = timeout;
2869 	}
2870 
2871 	ifp = ipv6_add_addr(idev, pfx, peer_pfx, plen, scope, ifa_flags,
2872 			    valid_lft, prefered_lft, true, extack);
2873 
2874 	if (!IS_ERR(ifp)) {
2875 		if (!(ifa_flags & IFA_F_NOPREFIXROUTE)) {
2876 			addrconf_prefix_route(&ifp->addr, ifp->prefix_len, dev,
2877 					      expires, flags);
2878 		}
2879 
2880 		/*
2881 		 * Note that section 3.1 of RFC 4429 indicates
2882 		 * that the Optimistic flag should not be set for
2883 		 * manually configured addresses
2884 		 */
2885 		addrconf_dad_start(ifp);
2886 		if (ifa_flags & IFA_F_MANAGETEMPADDR)
2887 			manage_tempaddrs(idev, ifp, valid_lft, prefered_lft,
2888 					 true, jiffies);
2889 		in6_ifa_put(ifp);
2890 		addrconf_verify_rtnl();
2891 		return 0;
2892 	} else if (ifa_flags & IFA_F_MCAUTOJOIN) {
2893 		ipv6_mc_config(net->ipv6.mc_autojoin_sk,
2894 			       false, pfx, ifindex);
2895 	}
2896 
2897 	return PTR_ERR(ifp);
2898 }
2899 
2900 static int inet6_addr_del(struct net *net, int ifindex, u32 ifa_flags,
2901 			  const struct in6_addr *pfx, unsigned int plen)
2902 {
2903 	struct inet6_ifaddr *ifp;
2904 	struct inet6_dev *idev;
2905 	struct net_device *dev;
2906 
2907 	if (plen > 128)
2908 		return -EINVAL;
2909 
2910 	dev = __dev_get_by_index(net, ifindex);
2911 	if (!dev)
2912 		return -ENODEV;
2913 
2914 	idev = __in6_dev_get(dev);
2915 	if (!idev)
2916 		return -ENXIO;
2917 
2918 	read_lock_bh(&idev->lock);
2919 	list_for_each_entry(ifp, &idev->addr_list, if_list) {
2920 		if (ifp->prefix_len == plen &&
2921 		    ipv6_addr_equal(pfx, &ifp->addr)) {
2922 			in6_ifa_hold(ifp);
2923 			read_unlock_bh(&idev->lock);
2924 
2925 			if (!(ifp->flags & IFA_F_TEMPORARY) &&
2926 			    (ifa_flags & IFA_F_MANAGETEMPADDR))
2927 				manage_tempaddrs(idev, ifp, 0, 0, false,
2928 						 jiffies);
2929 			ipv6_del_addr(ifp);
2930 			addrconf_verify_rtnl();
2931 			if (ipv6_addr_is_multicast(pfx)) {
2932 				ipv6_mc_config(net->ipv6.mc_autojoin_sk,
2933 					       false, pfx, dev->ifindex);
2934 			}
2935 			return 0;
2936 		}
2937 	}
2938 	read_unlock_bh(&idev->lock);
2939 	return -EADDRNOTAVAIL;
2940 }
2941 
2942 
2943 int addrconf_add_ifaddr(struct net *net, void __user *arg)
2944 {
2945 	struct in6_ifreq ireq;
2946 	int err;
2947 
2948 	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2949 		return -EPERM;
2950 
2951 	if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
2952 		return -EFAULT;
2953 
2954 	rtnl_lock();
2955 	err = inet6_addr_add(net, ireq.ifr6_ifindex, &ireq.ifr6_addr, NULL,
2956 			     ireq.ifr6_prefixlen, IFA_F_PERMANENT,
2957 			     INFINITY_LIFE_TIME, INFINITY_LIFE_TIME, NULL);
2958 	rtnl_unlock();
2959 	return err;
2960 }
2961 
2962 int addrconf_del_ifaddr(struct net *net, void __user *arg)
2963 {
2964 	struct in6_ifreq ireq;
2965 	int err;
2966 
2967 	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2968 		return -EPERM;
2969 
2970 	if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
2971 		return -EFAULT;
2972 
2973 	rtnl_lock();
2974 	err = inet6_addr_del(net, ireq.ifr6_ifindex, 0, &ireq.ifr6_addr,
2975 			     ireq.ifr6_prefixlen);
2976 	rtnl_unlock();
2977 	return err;
2978 }
2979 
2980 static void add_addr(struct inet6_dev *idev, const struct in6_addr *addr,
2981 		     int plen, int scope)
2982 {
2983 	struct inet6_ifaddr *ifp;
2984 
2985 	ifp = ipv6_add_addr(idev, addr, NULL, plen,
2986 			    scope, IFA_F_PERMANENT,
2987 			    INFINITY_LIFE_TIME, INFINITY_LIFE_TIME,
2988 			    true, NULL);
2989 	if (!IS_ERR(ifp)) {
2990 		spin_lock_bh(&ifp->lock);
2991 		ifp->flags &= ~IFA_F_TENTATIVE;
2992 		spin_unlock_bh(&ifp->lock);
2993 		rt_genid_bump_ipv6(dev_net(idev->dev));
2994 		ipv6_ifa_notify(RTM_NEWADDR, ifp);
2995 		in6_ifa_put(ifp);
2996 	}
2997 }
2998 
2999 #if IS_ENABLED(CONFIG_IPV6_SIT)
3000 static void sit_add_v4_addrs(struct inet6_dev *idev)
3001 {
3002 	struct in6_addr addr;
3003 	struct net_device *dev;
3004 	struct net *net = dev_net(idev->dev);
3005 	int scope, plen;
3006 	u32 pflags = 0;
3007 
3008 	ASSERT_RTNL();
3009 
3010 	memset(&addr, 0, sizeof(struct in6_addr));
3011 	memcpy(&addr.s6_addr32[3], idev->dev->dev_addr, 4);
3012 
3013 	if (idev->dev->flags&IFF_POINTOPOINT) {
3014 		addr.s6_addr32[0] = htonl(0xfe800000);
3015 		scope = IFA_LINK;
3016 		plen = 64;
3017 	} else {
3018 		scope = IPV6_ADDR_COMPATv4;
3019 		plen = 96;
3020 		pflags |= RTF_NONEXTHOP;
3021 	}
3022 
3023 	if (addr.s6_addr32[3]) {
3024 		add_addr(idev, &addr, plen, scope);
3025 		addrconf_prefix_route(&addr, plen, idev->dev, 0, pflags);
3026 		return;
3027 	}
3028 
3029 	for_each_netdev(net, dev) {
3030 		struct in_device *in_dev = __in_dev_get_rtnl(dev);
3031 		if (in_dev && (dev->flags & IFF_UP)) {
3032 			struct in_ifaddr *ifa;
3033 
3034 			int flag = scope;
3035 
3036 			for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
3037 
3038 				addr.s6_addr32[3] = ifa->ifa_local;
3039 
3040 				if (ifa->ifa_scope == RT_SCOPE_LINK)
3041 					continue;
3042 				if (ifa->ifa_scope >= RT_SCOPE_HOST) {
3043 					if (idev->dev->flags&IFF_POINTOPOINT)
3044 						continue;
3045 					flag |= IFA_HOST;
3046 				}
3047 
3048 				add_addr(idev, &addr, plen, flag);
3049 				addrconf_prefix_route(&addr, plen, idev->dev, 0,
3050 						      pflags);
3051 			}
3052 		}
3053 	}
3054 }
3055 #endif
3056 
3057 static void init_loopback(struct net_device *dev)
3058 {
3059 	struct inet6_dev  *idev;
3060 
3061 	/* ::1 */
3062 
3063 	ASSERT_RTNL();
3064 
3065 	idev = ipv6_find_idev(dev);
3066 	if (!idev) {
3067 		pr_debug("%s: add_dev failed\n", __func__);
3068 		return;
3069 	}
3070 
3071 	add_addr(idev, &in6addr_loopback, 128, IFA_HOST);
3072 }
3073 
3074 void addrconf_add_linklocal(struct inet6_dev *idev,
3075 			    const struct in6_addr *addr, u32 flags)
3076 {
3077 	struct inet6_ifaddr *ifp;
3078 	u32 addr_flags = flags | IFA_F_PERMANENT;
3079 
3080 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
3081 	if ((dev_net(idev->dev)->ipv6.devconf_all->optimistic_dad ||
3082 	     idev->cnf.optimistic_dad) &&
3083 	    !dev_net(idev->dev)->ipv6.devconf_all->forwarding)
3084 		addr_flags |= IFA_F_OPTIMISTIC;
3085 #endif
3086 
3087 	ifp = ipv6_add_addr(idev, addr, NULL, 64, IFA_LINK, addr_flags,
3088 			    INFINITY_LIFE_TIME, INFINITY_LIFE_TIME, true, NULL);
3089 	if (!IS_ERR(ifp)) {
3090 		addrconf_prefix_route(&ifp->addr, ifp->prefix_len, idev->dev, 0, 0);
3091 		addrconf_dad_start(ifp);
3092 		in6_ifa_put(ifp);
3093 	}
3094 }
3095 EXPORT_SYMBOL_GPL(addrconf_add_linklocal);
3096 
3097 static bool ipv6_reserved_interfaceid(struct in6_addr address)
3098 {
3099 	if ((address.s6_addr32[2] | address.s6_addr32[3]) == 0)
3100 		return true;
3101 
3102 	if (address.s6_addr32[2] == htonl(0x02005eff) &&
3103 	    ((address.s6_addr32[3] & htonl(0xfe000000)) == htonl(0xfe000000)))
3104 		return true;
3105 
3106 	if (address.s6_addr32[2] == htonl(0xfdffffff) &&
3107 	    ((address.s6_addr32[3] & htonl(0xffffff80)) == htonl(0xffffff80)))
3108 		return true;
3109 
3110 	return false;
3111 }
3112 
3113 static int ipv6_generate_stable_address(struct in6_addr *address,
3114 					u8 dad_count,
3115 					const struct inet6_dev *idev)
3116 {
3117 	static DEFINE_SPINLOCK(lock);
3118 	static __u32 digest[SHA_DIGEST_WORDS];
3119 	static __u32 workspace[SHA_WORKSPACE_WORDS];
3120 
3121 	static union {
3122 		char __data[SHA_MESSAGE_BYTES];
3123 		struct {
3124 			struct in6_addr secret;
3125 			__be32 prefix[2];
3126 			unsigned char hwaddr[MAX_ADDR_LEN];
3127 			u8 dad_count;
3128 		} __packed;
3129 	} data;
3130 
3131 	struct in6_addr secret;
3132 	struct in6_addr temp;
3133 	struct net *net = dev_net(idev->dev);
3134 
3135 	BUILD_BUG_ON(sizeof(data.__data) != sizeof(data));
3136 
3137 	if (idev->cnf.stable_secret.initialized)
3138 		secret = idev->cnf.stable_secret.secret;
3139 	else if (net->ipv6.devconf_dflt->stable_secret.initialized)
3140 		secret = net->ipv6.devconf_dflt->stable_secret.secret;
3141 	else
3142 		return -1;
3143 
3144 retry:
3145 	spin_lock_bh(&lock);
3146 
3147 	sha_init(digest);
3148 	memset(&data, 0, sizeof(data));
3149 	memset(workspace, 0, sizeof(workspace));
3150 	memcpy(data.hwaddr, idev->dev->perm_addr, idev->dev->addr_len);
3151 	data.prefix[0] = address->s6_addr32[0];
3152 	data.prefix[1] = address->s6_addr32[1];
3153 	data.secret = secret;
3154 	data.dad_count = dad_count;
3155 
3156 	sha_transform(digest, data.__data, workspace);
3157 
3158 	temp = *address;
3159 	temp.s6_addr32[2] = (__force __be32)digest[0];
3160 	temp.s6_addr32[3] = (__force __be32)digest[1];
3161 
3162 	spin_unlock_bh(&lock);
3163 
3164 	if (ipv6_reserved_interfaceid(temp)) {
3165 		dad_count++;
3166 		if (dad_count > dev_net(idev->dev)->ipv6.sysctl.idgen_retries)
3167 			return -1;
3168 		goto retry;
3169 	}
3170 
3171 	*address = temp;
3172 	return 0;
3173 }
3174 
3175 static void ipv6_gen_mode_random_init(struct inet6_dev *idev)
3176 {
3177 	struct ipv6_stable_secret *s = &idev->cnf.stable_secret;
3178 
3179 	if (s->initialized)
3180 		return;
3181 	s = &idev->cnf.stable_secret;
3182 	get_random_bytes(&s->secret, sizeof(s->secret));
3183 	s->initialized = true;
3184 }
3185 
3186 static void addrconf_addr_gen(struct inet6_dev *idev, bool prefix_route)
3187 {
3188 	struct in6_addr addr;
3189 
3190 	/* no link local addresses on L3 master devices */
3191 	if (netif_is_l3_master(idev->dev))
3192 		return;
3193 
3194 	ipv6_addr_set(&addr, htonl(0xFE800000), 0, 0, 0);
3195 
3196 	switch (idev->cnf.addr_gen_mode) {
3197 	case IN6_ADDR_GEN_MODE_RANDOM:
3198 		ipv6_gen_mode_random_init(idev);
3199 		/* fallthrough */
3200 	case IN6_ADDR_GEN_MODE_STABLE_PRIVACY:
3201 		if (!ipv6_generate_stable_address(&addr, 0, idev))
3202 			addrconf_add_linklocal(idev, &addr,
3203 					       IFA_F_STABLE_PRIVACY);
3204 		else if (prefix_route)
3205 			addrconf_prefix_route(&addr, 64, idev->dev, 0, 0);
3206 		break;
3207 	case IN6_ADDR_GEN_MODE_EUI64:
3208 		/* addrconf_add_linklocal also adds a prefix_route and we
3209 		 * only need to care about prefix routes if ipv6_generate_eui64
3210 		 * couldn't generate one.
3211 		 */
3212 		if (ipv6_generate_eui64(addr.s6_addr + 8, idev->dev) == 0)
3213 			addrconf_add_linklocal(idev, &addr, 0);
3214 		else if (prefix_route)
3215 			addrconf_prefix_route(&addr, 64, idev->dev, 0, 0);
3216 		break;
3217 	case IN6_ADDR_GEN_MODE_NONE:
3218 	default:
3219 		/* will not add any link local address */
3220 		break;
3221 	}
3222 }
3223 
3224 static void addrconf_dev_config(struct net_device *dev)
3225 {
3226 	struct inet6_dev *idev;
3227 
3228 	ASSERT_RTNL();
3229 
3230 	if ((dev->type != ARPHRD_ETHER) &&
3231 	    (dev->type != ARPHRD_FDDI) &&
3232 	    (dev->type != ARPHRD_ARCNET) &&
3233 	    (dev->type != ARPHRD_INFINIBAND) &&
3234 	    (dev->type != ARPHRD_IEEE1394) &&
3235 	    (dev->type != ARPHRD_TUNNEL6) &&
3236 	    (dev->type != ARPHRD_6LOWPAN) &&
3237 	    (dev->type != ARPHRD_IP6GRE) &&
3238 	    (dev->type != ARPHRD_IPGRE) &&
3239 	    (dev->type != ARPHRD_TUNNEL) &&
3240 	    (dev->type != ARPHRD_NONE)) {
3241 		/* Alas, we support only Ethernet autoconfiguration. */
3242 		return;
3243 	}
3244 
3245 	idev = addrconf_add_dev(dev);
3246 	if (IS_ERR(idev))
3247 		return;
3248 
3249 	/* this device type has no EUI support */
3250 	if (dev->type == ARPHRD_NONE &&
3251 	    idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_EUI64)
3252 		idev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_RANDOM;
3253 
3254 	addrconf_addr_gen(idev, false);
3255 }
3256 
3257 #if IS_ENABLED(CONFIG_IPV6_SIT)
3258 static void addrconf_sit_config(struct net_device *dev)
3259 {
3260 	struct inet6_dev *idev;
3261 
3262 	ASSERT_RTNL();
3263 
3264 	/*
3265 	 * Configure the tunnel with one of our IPv4
3266 	 * addresses... we should configure all of
3267 	 * our v4 addrs in the tunnel
3268 	 */
3269 
3270 	idev = ipv6_find_idev(dev);
3271 	if (!idev) {
3272 		pr_debug("%s: add_dev failed\n", __func__);
3273 		return;
3274 	}
3275 
3276 	if (dev->priv_flags & IFF_ISATAP) {
3277 		addrconf_addr_gen(idev, false);
3278 		return;
3279 	}
3280 
3281 	sit_add_v4_addrs(idev);
3282 
3283 	if (dev->flags&IFF_POINTOPOINT)
3284 		addrconf_add_mroute(dev);
3285 }
3286 #endif
3287 
3288 #if IS_ENABLED(CONFIG_NET_IPGRE)
3289 static void addrconf_gre_config(struct net_device *dev)
3290 {
3291 	struct inet6_dev *idev;
3292 
3293 	ASSERT_RTNL();
3294 
3295 	idev = ipv6_find_idev(dev);
3296 	if (!idev) {
3297 		pr_debug("%s: add_dev failed\n", __func__);
3298 		return;
3299 	}
3300 
3301 	addrconf_addr_gen(idev, true);
3302 	if (dev->flags & IFF_POINTOPOINT)
3303 		addrconf_add_mroute(dev);
3304 }
3305 #endif
3306 
3307 static int fixup_permanent_addr(struct inet6_dev *idev,
3308 				struct inet6_ifaddr *ifp)
3309 {
3310 	/* !rt6i_node means the host route was removed from the
3311 	 * FIB, for example, if 'lo' device is taken down. In that
3312 	 * case regenerate the host route.
3313 	 */
3314 	if (!ifp->rt || !ifp->rt->rt6i_node) {
3315 		struct rt6_info *rt, *prev;
3316 
3317 		rt = addrconf_dst_alloc(idev, &ifp->addr, false);
3318 		if (IS_ERR(rt))
3319 			return PTR_ERR(rt);
3320 
3321 		/* ifp->rt can be accessed outside of rtnl */
3322 		spin_lock(&ifp->lock);
3323 		prev = ifp->rt;
3324 		ifp->rt = rt;
3325 		spin_unlock(&ifp->lock);
3326 
3327 		ip6_rt_put(prev);
3328 	}
3329 
3330 	if (!(ifp->flags & IFA_F_NOPREFIXROUTE)) {
3331 		addrconf_prefix_route(&ifp->addr, ifp->prefix_len,
3332 				      idev->dev, 0, 0);
3333 	}
3334 
3335 	if (ifp->state == INET6_IFADDR_STATE_PREDAD)
3336 		addrconf_dad_start(ifp);
3337 
3338 	return 0;
3339 }
3340 
3341 static void addrconf_permanent_addr(struct net_device *dev)
3342 {
3343 	struct inet6_ifaddr *ifp, *tmp;
3344 	struct inet6_dev *idev;
3345 
3346 	idev = __in6_dev_get(dev);
3347 	if (!idev)
3348 		return;
3349 
3350 	write_lock_bh(&idev->lock);
3351 
3352 	list_for_each_entry_safe(ifp, tmp, &idev->addr_list, if_list) {
3353 		if ((ifp->flags & IFA_F_PERMANENT) &&
3354 		    fixup_permanent_addr(idev, ifp) < 0) {
3355 			write_unlock_bh(&idev->lock);
3356 			in6_ifa_hold(ifp);
3357 			ipv6_del_addr(ifp);
3358 			write_lock_bh(&idev->lock);
3359 
3360 			net_info_ratelimited("%s: Failed to add prefix route for address %pI6c; dropping\n",
3361 					     idev->dev->name, &ifp->addr);
3362 		}
3363 	}
3364 
3365 	write_unlock_bh(&idev->lock);
3366 }
3367 
3368 static int addrconf_notify(struct notifier_block *this, unsigned long event,
3369 			   void *ptr)
3370 {
3371 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3372 	struct netdev_notifier_changeupper_info *info;
3373 	struct inet6_dev *idev = __in6_dev_get(dev);
3374 	struct net *net = dev_net(dev);
3375 	int run_pending = 0;
3376 	int err;
3377 
3378 	switch (event) {
3379 	case NETDEV_REGISTER:
3380 		if (!idev && dev->mtu >= IPV6_MIN_MTU) {
3381 			idev = ipv6_add_dev(dev);
3382 			if (IS_ERR(idev))
3383 				return notifier_from_errno(PTR_ERR(idev));
3384 		}
3385 		break;
3386 
3387 	case NETDEV_CHANGEMTU:
3388 		/* if MTU under IPV6_MIN_MTU stop IPv6 on this interface. */
3389 		if (dev->mtu < IPV6_MIN_MTU) {
3390 			addrconf_ifdown(dev, dev != net->loopback_dev);
3391 			break;
3392 		}
3393 
3394 		if (idev) {
3395 			rt6_mtu_change(dev, dev->mtu);
3396 			idev->cnf.mtu6 = dev->mtu;
3397 			break;
3398 		}
3399 
3400 		/* allocate new idev */
3401 		idev = ipv6_add_dev(dev);
3402 		if (IS_ERR(idev))
3403 			break;
3404 
3405 		/* device is still not ready */
3406 		if (!(idev->if_flags & IF_READY))
3407 			break;
3408 
3409 		run_pending = 1;
3410 
3411 		/* fall through */
3412 
3413 	case NETDEV_UP:
3414 	case NETDEV_CHANGE:
3415 		if (dev->flags & IFF_SLAVE)
3416 			break;
3417 
3418 		if (idev && idev->cnf.disable_ipv6)
3419 			break;
3420 
3421 		if (event == NETDEV_UP) {
3422 			/* restore routes for permanent addresses */
3423 			addrconf_permanent_addr(dev);
3424 
3425 			if (!addrconf_link_ready(dev)) {
3426 				/* device is not ready yet. */
3427 				pr_info("ADDRCONF(NETDEV_UP): %s: link is not ready\n",
3428 					dev->name);
3429 				break;
3430 			}
3431 
3432 			if (!idev && dev->mtu >= IPV6_MIN_MTU)
3433 				idev = ipv6_add_dev(dev);
3434 
3435 			if (!IS_ERR_OR_NULL(idev)) {
3436 				idev->if_flags |= IF_READY;
3437 				run_pending = 1;
3438 			}
3439 		} else if (event == NETDEV_CHANGE) {
3440 			if (!addrconf_link_ready(dev)) {
3441 				/* device is still not ready. */
3442 				rt6_sync_down_dev(dev, event);
3443 				break;
3444 			}
3445 
3446 			if (idev) {
3447 				if (idev->if_flags & IF_READY) {
3448 					/* device is already configured -
3449 					 * but resend MLD reports, we might
3450 					 * have roamed and need to update
3451 					 * multicast snooping switches
3452 					 */
3453 					ipv6_mc_up(idev);
3454 					rt6_sync_up(dev, RTNH_F_LINKDOWN);
3455 					break;
3456 				}
3457 				idev->if_flags |= IF_READY;
3458 			}
3459 
3460 			pr_info("ADDRCONF(NETDEV_CHANGE): %s: link becomes ready\n",
3461 				dev->name);
3462 
3463 			run_pending = 1;
3464 		}
3465 
3466 		switch (dev->type) {
3467 #if IS_ENABLED(CONFIG_IPV6_SIT)
3468 		case ARPHRD_SIT:
3469 			addrconf_sit_config(dev);
3470 			break;
3471 #endif
3472 #if IS_ENABLED(CONFIG_NET_IPGRE)
3473 		case ARPHRD_IPGRE:
3474 			addrconf_gre_config(dev);
3475 			break;
3476 #endif
3477 		case ARPHRD_LOOPBACK:
3478 			init_loopback(dev);
3479 			break;
3480 
3481 		default:
3482 			addrconf_dev_config(dev);
3483 			break;
3484 		}
3485 
3486 		if (!IS_ERR_OR_NULL(idev)) {
3487 			if (run_pending)
3488 				addrconf_dad_run(idev);
3489 
3490 			/* Device has an address by now */
3491 			rt6_sync_up(dev, RTNH_F_DEAD);
3492 
3493 			/*
3494 			 * If the MTU changed during the interface down,
3495 			 * when the interface up, the changed MTU must be
3496 			 * reflected in the idev as well as routers.
3497 			 */
3498 			if (idev->cnf.mtu6 != dev->mtu &&
3499 			    dev->mtu >= IPV6_MIN_MTU) {
3500 				rt6_mtu_change(dev, dev->mtu);
3501 				idev->cnf.mtu6 = dev->mtu;
3502 			}
3503 			idev->tstamp = jiffies;
3504 			inet6_ifinfo_notify(RTM_NEWLINK, idev);
3505 
3506 			/*
3507 			 * If the changed mtu during down is lower than
3508 			 * IPV6_MIN_MTU stop IPv6 on this interface.
3509 			 */
3510 			if (dev->mtu < IPV6_MIN_MTU)
3511 				addrconf_ifdown(dev, dev != net->loopback_dev);
3512 		}
3513 		break;
3514 
3515 	case NETDEV_DOWN:
3516 	case NETDEV_UNREGISTER:
3517 		/*
3518 		 *	Remove all addresses from this interface.
3519 		 */
3520 		addrconf_ifdown(dev, event != NETDEV_DOWN);
3521 		break;
3522 
3523 	case NETDEV_CHANGENAME:
3524 		if (idev) {
3525 			snmp6_unregister_dev(idev);
3526 			addrconf_sysctl_unregister(idev);
3527 			err = addrconf_sysctl_register(idev);
3528 			if (err)
3529 				return notifier_from_errno(err);
3530 			err = snmp6_register_dev(idev);
3531 			if (err) {
3532 				addrconf_sysctl_unregister(idev);
3533 				return notifier_from_errno(err);
3534 			}
3535 		}
3536 		break;
3537 
3538 	case NETDEV_PRE_TYPE_CHANGE:
3539 	case NETDEV_POST_TYPE_CHANGE:
3540 		if (idev)
3541 			addrconf_type_change(dev, event);
3542 		break;
3543 
3544 	case NETDEV_CHANGEUPPER:
3545 		info = ptr;
3546 
3547 		/* flush all routes if dev is linked to or unlinked from
3548 		 * an L3 master device (e.g., VRF)
3549 		 */
3550 		if (info->upper_dev && netif_is_l3_master(info->upper_dev))
3551 			addrconf_ifdown(dev, 0);
3552 	}
3553 
3554 	return NOTIFY_OK;
3555 }
3556 
3557 /*
3558  *	addrconf module should be notified of a device going up
3559  */
3560 static struct notifier_block ipv6_dev_notf = {
3561 	.notifier_call = addrconf_notify,
3562 	.priority = ADDRCONF_NOTIFY_PRIORITY,
3563 };
3564 
3565 static void addrconf_type_change(struct net_device *dev, unsigned long event)
3566 {
3567 	struct inet6_dev *idev;
3568 	ASSERT_RTNL();
3569 
3570 	idev = __in6_dev_get(dev);
3571 
3572 	if (event == NETDEV_POST_TYPE_CHANGE)
3573 		ipv6_mc_remap(idev);
3574 	else if (event == NETDEV_PRE_TYPE_CHANGE)
3575 		ipv6_mc_unmap(idev);
3576 }
3577 
3578 static bool addr_is_local(const struct in6_addr *addr)
3579 {
3580 	return ipv6_addr_type(addr) &
3581 		(IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);
3582 }
3583 
3584 static int addrconf_ifdown(struct net_device *dev, int how)
3585 {
3586 	unsigned long event = how ? NETDEV_UNREGISTER : NETDEV_DOWN;
3587 	struct net *net = dev_net(dev);
3588 	struct inet6_dev *idev;
3589 	struct inet6_ifaddr *ifa, *tmp;
3590 	int _keep_addr;
3591 	bool keep_addr;
3592 	int state, i;
3593 
3594 	ASSERT_RTNL();
3595 
3596 	rt6_disable_ip(dev, event);
3597 
3598 	idev = __in6_dev_get(dev);
3599 	if (!idev)
3600 		return -ENODEV;
3601 
3602 	/*
3603 	 * Step 1: remove reference to ipv6 device from parent device.
3604 	 *	   Do not dev_put!
3605 	 */
3606 	if (how) {
3607 		idev->dead = 1;
3608 
3609 		/* protected by rtnl_lock */
3610 		RCU_INIT_POINTER(dev->ip6_ptr, NULL);
3611 
3612 		/* Step 1.5: remove snmp6 entry */
3613 		snmp6_unregister_dev(idev);
3614 
3615 	}
3616 
3617 	/* aggregate the system setting and interface setting */
3618 	_keep_addr = net->ipv6.devconf_all->keep_addr_on_down;
3619 	if (!_keep_addr)
3620 		_keep_addr = idev->cnf.keep_addr_on_down;
3621 
3622 	/* combine the user config with event to determine if permanent
3623 	 * addresses are to be removed from address hash table
3624 	 */
3625 	keep_addr = !(how || _keep_addr <= 0 || idev->cnf.disable_ipv6);
3626 
3627 	/* Step 2: clear hash table */
3628 	for (i = 0; i < IN6_ADDR_HSIZE; i++) {
3629 		struct hlist_head *h = &inet6_addr_lst[i];
3630 
3631 		spin_lock_bh(&addrconf_hash_lock);
3632 restart:
3633 		hlist_for_each_entry_rcu(ifa, h, addr_lst) {
3634 			if (ifa->idev == idev) {
3635 				addrconf_del_dad_work(ifa);
3636 				/* combined flag + permanent flag decide if
3637 				 * address is retained on a down event
3638 				 */
3639 				if (!keep_addr ||
3640 				    !(ifa->flags & IFA_F_PERMANENT) ||
3641 				    addr_is_local(&ifa->addr)) {
3642 					hlist_del_init_rcu(&ifa->addr_lst);
3643 					goto restart;
3644 				}
3645 			}
3646 		}
3647 		spin_unlock_bh(&addrconf_hash_lock);
3648 	}
3649 
3650 	write_lock_bh(&idev->lock);
3651 
3652 	addrconf_del_rs_timer(idev);
3653 
3654 	/* Step 2: clear flags for stateless addrconf */
3655 	if (!how)
3656 		idev->if_flags &= ~(IF_RS_SENT|IF_RA_RCVD|IF_READY);
3657 
3658 	/* Step 3: clear tempaddr list */
3659 	while (!list_empty(&idev->tempaddr_list)) {
3660 		ifa = list_first_entry(&idev->tempaddr_list,
3661 				       struct inet6_ifaddr, tmp_list);
3662 		list_del(&ifa->tmp_list);
3663 		write_unlock_bh(&idev->lock);
3664 		spin_lock_bh(&ifa->lock);
3665 
3666 		if (ifa->ifpub) {
3667 			in6_ifa_put(ifa->ifpub);
3668 			ifa->ifpub = NULL;
3669 		}
3670 		spin_unlock_bh(&ifa->lock);
3671 		in6_ifa_put(ifa);
3672 		write_lock_bh(&idev->lock);
3673 	}
3674 
3675 	/* re-combine the user config with event to determine if permanent
3676 	 * addresses are to be removed from the interface list
3677 	 */
3678 	keep_addr = (!how && _keep_addr > 0 && !idev->cnf.disable_ipv6);
3679 
3680 	list_for_each_entry_safe(ifa, tmp, &idev->addr_list, if_list) {
3681 		struct rt6_info *rt = NULL;
3682 		bool keep;
3683 
3684 		addrconf_del_dad_work(ifa);
3685 
3686 		keep = keep_addr && (ifa->flags & IFA_F_PERMANENT) &&
3687 			!addr_is_local(&ifa->addr);
3688 
3689 		write_unlock_bh(&idev->lock);
3690 		spin_lock_bh(&ifa->lock);
3691 
3692 		if (keep) {
3693 			/* set state to skip the notifier below */
3694 			state = INET6_IFADDR_STATE_DEAD;
3695 			ifa->state = INET6_IFADDR_STATE_PREDAD;
3696 			if (!(ifa->flags & IFA_F_NODAD))
3697 				ifa->flags |= IFA_F_TENTATIVE;
3698 
3699 			rt = ifa->rt;
3700 			ifa->rt = NULL;
3701 		} else {
3702 			state = ifa->state;
3703 			ifa->state = INET6_IFADDR_STATE_DEAD;
3704 		}
3705 
3706 		spin_unlock_bh(&ifa->lock);
3707 
3708 		if (rt)
3709 			ip6_del_rt(rt);
3710 
3711 		if (state != INET6_IFADDR_STATE_DEAD) {
3712 			__ipv6_ifa_notify(RTM_DELADDR, ifa);
3713 			inet6addr_notifier_call_chain(NETDEV_DOWN, ifa);
3714 		} else {
3715 			if (idev->cnf.forwarding)
3716 				addrconf_leave_anycast(ifa);
3717 			addrconf_leave_solict(ifa->idev, &ifa->addr);
3718 		}
3719 
3720 		write_lock_bh(&idev->lock);
3721 		if (!keep) {
3722 			list_del_rcu(&ifa->if_list);
3723 			in6_ifa_put(ifa);
3724 		}
3725 	}
3726 
3727 	write_unlock_bh(&idev->lock);
3728 
3729 	/* Step 5: Discard anycast and multicast list */
3730 	if (how) {
3731 		ipv6_ac_destroy_dev(idev);
3732 		ipv6_mc_destroy_dev(idev);
3733 	} else {
3734 		ipv6_mc_down(idev);
3735 	}
3736 
3737 	idev->tstamp = jiffies;
3738 
3739 	/* Last: Shot the device (if unregistered) */
3740 	if (how) {
3741 		addrconf_sysctl_unregister(idev);
3742 		neigh_parms_release(&nd_tbl, idev->nd_parms);
3743 		neigh_ifdown(&nd_tbl, dev);
3744 		in6_dev_put(idev);
3745 	}
3746 	return 0;
3747 }
3748 
3749 static void addrconf_rs_timer(struct timer_list *t)
3750 {
3751 	struct inet6_dev *idev = from_timer(idev, t, rs_timer);
3752 	struct net_device *dev = idev->dev;
3753 	struct in6_addr lladdr;
3754 
3755 	write_lock(&idev->lock);
3756 	if (idev->dead || !(idev->if_flags & IF_READY))
3757 		goto out;
3758 
3759 	if (!ipv6_accept_ra(idev))
3760 		goto out;
3761 
3762 	/* Announcement received after solicitation was sent */
3763 	if (idev->if_flags & IF_RA_RCVD)
3764 		goto out;
3765 
3766 	if (idev->rs_probes++ < idev->cnf.rtr_solicits || idev->cnf.rtr_solicits < 0) {
3767 		write_unlock(&idev->lock);
3768 		if (!ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE))
3769 			ndisc_send_rs(dev, &lladdr,
3770 				      &in6addr_linklocal_allrouters);
3771 		else
3772 			goto put;
3773 
3774 		write_lock(&idev->lock);
3775 		idev->rs_interval = rfc3315_s14_backoff_update(
3776 			idev->rs_interval, idev->cnf.rtr_solicit_max_interval);
3777 		/* The wait after the last probe can be shorter */
3778 		addrconf_mod_rs_timer(idev, (idev->rs_probes ==
3779 					     idev->cnf.rtr_solicits) ?
3780 				      idev->cnf.rtr_solicit_delay :
3781 				      idev->rs_interval);
3782 	} else {
3783 		/*
3784 		 * Note: we do not support deprecated "all on-link"
3785 		 * assumption any longer.
3786 		 */
3787 		pr_debug("%s: no IPv6 routers present\n", idev->dev->name);
3788 	}
3789 
3790 out:
3791 	write_unlock(&idev->lock);
3792 put:
3793 	in6_dev_put(idev);
3794 }
3795 
3796 /*
3797  *	Duplicate Address Detection
3798  */
3799 static void addrconf_dad_kick(struct inet6_ifaddr *ifp)
3800 {
3801 	unsigned long rand_num;
3802 	struct inet6_dev *idev = ifp->idev;
3803 	u64 nonce;
3804 
3805 	if (ifp->flags & IFA_F_OPTIMISTIC)
3806 		rand_num = 0;
3807 	else
3808 		rand_num = prandom_u32() % (idev->cnf.rtr_solicit_delay ? : 1);
3809 
3810 	nonce = 0;
3811 	if (idev->cnf.enhanced_dad ||
3812 	    dev_net(idev->dev)->ipv6.devconf_all->enhanced_dad) {
3813 		do
3814 			get_random_bytes(&nonce, 6);
3815 		while (nonce == 0);
3816 	}
3817 	ifp->dad_nonce = nonce;
3818 	ifp->dad_probes = idev->cnf.dad_transmits;
3819 	addrconf_mod_dad_work(ifp, rand_num);
3820 }
3821 
3822 static void addrconf_dad_begin(struct inet6_ifaddr *ifp)
3823 {
3824 	struct inet6_dev *idev = ifp->idev;
3825 	struct net_device *dev = idev->dev;
3826 	bool bump_id, notify = false;
3827 
3828 	addrconf_join_solict(dev, &ifp->addr);
3829 
3830 	prandom_seed((__force u32) ifp->addr.s6_addr32[3]);
3831 
3832 	read_lock_bh(&idev->lock);
3833 	spin_lock(&ifp->lock);
3834 	if (ifp->state == INET6_IFADDR_STATE_DEAD)
3835 		goto out;
3836 
3837 	if (dev->flags&(IFF_NOARP|IFF_LOOPBACK) ||
3838 	    (dev_net(dev)->ipv6.devconf_all->accept_dad < 1 &&
3839 	     idev->cnf.accept_dad < 1) ||
3840 	    !(ifp->flags&IFA_F_TENTATIVE) ||
3841 	    ifp->flags & IFA_F_NODAD) {
3842 		bool send_na = false;
3843 
3844 		if (ifp->flags & IFA_F_TENTATIVE &&
3845 		    !(ifp->flags & IFA_F_OPTIMISTIC))
3846 			send_na = true;
3847 		bump_id = ifp->flags & IFA_F_TENTATIVE;
3848 		ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC|IFA_F_DADFAILED);
3849 		spin_unlock(&ifp->lock);
3850 		read_unlock_bh(&idev->lock);
3851 
3852 		addrconf_dad_completed(ifp, bump_id, send_na);
3853 		return;
3854 	}
3855 
3856 	if (!(idev->if_flags & IF_READY)) {
3857 		spin_unlock(&ifp->lock);
3858 		read_unlock_bh(&idev->lock);
3859 		/*
3860 		 * If the device is not ready:
3861 		 * - keep it tentative if it is a permanent address.
3862 		 * - otherwise, kill it.
3863 		 */
3864 		in6_ifa_hold(ifp);
3865 		addrconf_dad_stop(ifp, 0);
3866 		return;
3867 	}
3868 
3869 	/*
3870 	 * Optimistic nodes can start receiving
3871 	 * Frames right away
3872 	 */
3873 	if (ifp->flags & IFA_F_OPTIMISTIC) {
3874 		ip6_ins_rt(ifp->rt);
3875 		if (ipv6_use_optimistic_addr(dev_net(dev), idev)) {
3876 			/* Because optimistic nodes can use this address,
3877 			 * notify listeners. If DAD fails, RTM_DELADDR is sent.
3878 			 */
3879 			notify = true;
3880 		}
3881 	}
3882 
3883 	addrconf_dad_kick(ifp);
3884 out:
3885 	spin_unlock(&ifp->lock);
3886 	read_unlock_bh(&idev->lock);
3887 	if (notify)
3888 		ipv6_ifa_notify(RTM_NEWADDR, ifp);
3889 }
3890 
3891 static void addrconf_dad_start(struct inet6_ifaddr *ifp)
3892 {
3893 	bool begin_dad = false;
3894 
3895 	spin_lock_bh(&ifp->lock);
3896 	if (ifp->state != INET6_IFADDR_STATE_DEAD) {
3897 		ifp->state = INET6_IFADDR_STATE_PREDAD;
3898 		begin_dad = true;
3899 	}
3900 	spin_unlock_bh(&ifp->lock);
3901 
3902 	if (begin_dad)
3903 		addrconf_mod_dad_work(ifp, 0);
3904 }
3905 
3906 static void addrconf_dad_work(struct work_struct *w)
3907 {
3908 	struct inet6_ifaddr *ifp = container_of(to_delayed_work(w),
3909 						struct inet6_ifaddr,
3910 						dad_work);
3911 	struct inet6_dev *idev = ifp->idev;
3912 	bool bump_id, disable_ipv6 = false;
3913 	struct in6_addr mcaddr;
3914 
3915 	enum {
3916 		DAD_PROCESS,
3917 		DAD_BEGIN,
3918 		DAD_ABORT,
3919 	} action = DAD_PROCESS;
3920 
3921 	rtnl_lock();
3922 
3923 	spin_lock_bh(&ifp->lock);
3924 	if (ifp->state == INET6_IFADDR_STATE_PREDAD) {
3925 		action = DAD_BEGIN;
3926 		ifp->state = INET6_IFADDR_STATE_DAD;
3927 	} else if (ifp->state == INET6_IFADDR_STATE_ERRDAD) {
3928 		action = DAD_ABORT;
3929 		ifp->state = INET6_IFADDR_STATE_POSTDAD;
3930 
3931 		if ((dev_net(idev->dev)->ipv6.devconf_all->accept_dad > 1 ||
3932 		     idev->cnf.accept_dad > 1) &&
3933 		    !idev->cnf.disable_ipv6 &&
3934 		    !(ifp->flags & IFA_F_STABLE_PRIVACY)) {
3935 			struct in6_addr addr;
3936 
3937 			addr.s6_addr32[0] = htonl(0xfe800000);
3938 			addr.s6_addr32[1] = 0;
3939 
3940 			if (!ipv6_generate_eui64(addr.s6_addr + 8, idev->dev) &&
3941 			    ipv6_addr_equal(&ifp->addr, &addr)) {
3942 				/* DAD failed for link-local based on MAC */
3943 				idev->cnf.disable_ipv6 = 1;
3944 
3945 				pr_info("%s: IPv6 being disabled!\n",
3946 					ifp->idev->dev->name);
3947 				disable_ipv6 = true;
3948 			}
3949 		}
3950 	}
3951 	spin_unlock_bh(&ifp->lock);
3952 
3953 	if (action == DAD_BEGIN) {
3954 		addrconf_dad_begin(ifp);
3955 		goto out;
3956 	} else if (action == DAD_ABORT) {
3957 		in6_ifa_hold(ifp);
3958 		addrconf_dad_stop(ifp, 1);
3959 		if (disable_ipv6)
3960 			addrconf_ifdown(idev->dev, 0);
3961 		goto out;
3962 	}
3963 
3964 	if (!ifp->dad_probes && addrconf_dad_end(ifp))
3965 		goto out;
3966 
3967 	write_lock_bh(&idev->lock);
3968 	if (idev->dead || !(idev->if_flags & IF_READY)) {
3969 		write_unlock_bh(&idev->lock);
3970 		goto out;
3971 	}
3972 
3973 	spin_lock(&ifp->lock);
3974 	if (ifp->state == INET6_IFADDR_STATE_DEAD) {
3975 		spin_unlock(&ifp->lock);
3976 		write_unlock_bh(&idev->lock);
3977 		goto out;
3978 	}
3979 
3980 	if (ifp->dad_probes == 0) {
3981 		bool send_na = false;
3982 
3983 		/*
3984 		 * DAD was successful
3985 		 */
3986 
3987 		if (ifp->flags & IFA_F_TENTATIVE &&
3988 		    !(ifp->flags & IFA_F_OPTIMISTIC))
3989 			send_na = true;
3990 		bump_id = ifp->flags & IFA_F_TENTATIVE;
3991 		ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC|IFA_F_DADFAILED);
3992 		spin_unlock(&ifp->lock);
3993 		write_unlock_bh(&idev->lock);
3994 
3995 		addrconf_dad_completed(ifp, bump_id, send_na);
3996 
3997 		goto out;
3998 	}
3999 
4000 	ifp->dad_probes--;
4001 	addrconf_mod_dad_work(ifp,
4002 			      NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME));
4003 	spin_unlock(&ifp->lock);
4004 	write_unlock_bh(&idev->lock);
4005 
4006 	/* send a neighbour solicitation for our addr */
4007 	addrconf_addr_solict_mult(&ifp->addr, &mcaddr);
4008 	ndisc_send_ns(ifp->idev->dev, &ifp->addr, &mcaddr, &in6addr_any,
4009 		      ifp->dad_nonce);
4010 out:
4011 	in6_ifa_put(ifp);
4012 	rtnl_unlock();
4013 }
4014 
4015 /* ifp->idev must be at least read locked */
4016 static bool ipv6_lonely_lladdr(struct inet6_ifaddr *ifp)
4017 {
4018 	struct inet6_ifaddr *ifpiter;
4019 	struct inet6_dev *idev = ifp->idev;
4020 
4021 	list_for_each_entry_reverse(ifpiter, &idev->addr_list, if_list) {
4022 		if (ifpiter->scope > IFA_LINK)
4023 			break;
4024 		if (ifp != ifpiter && ifpiter->scope == IFA_LINK &&
4025 		    (ifpiter->flags & (IFA_F_PERMANENT|IFA_F_TENTATIVE|
4026 				       IFA_F_OPTIMISTIC|IFA_F_DADFAILED)) ==
4027 		    IFA_F_PERMANENT)
4028 			return false;
4029 	}
4030 	return true;
4031 }
4032 
4033 static void addrconf_dad_completed(struct inet6_ifaddr *ifp, bool bump_id,
4034 				   bool send_na)
4035 {
4036 	struct net_device *dev = ifp->idev->dev;
4037 	struct in6_addr lladdr;
4038 	bool send_rs, send_mld;
4039 
4040 	addrconf_del_dad_work(ifp);
4041 
4042 	/*
4043 	 *	Configure the address for reception. Now it is valid.
4044 	 */
4045 
4046 	ipv6_ifa_notify(RTM_NEWADDR, ifp);
4047 
4048 	/* If added prefix is link local and we are prepared to process
4049 	   router advertisements, start sending router solicitations.
4050 	 */
4051 
4052 	read_lock_bh(&ifp->idev->lock);
4053 	send_mld = ifp->scope == IFA_LINK && ipv6_lonely_lladdr(ifp);
4054 	send_rs = send_mld &&
4055 		  ipv6_accept_ra(ifp->idev) &&
4056 		  ifp->idev->cnf.rtr_solicits != 0 &&
4057 		  (dev->flags&IFF_LOOPBACK) == 0;
4058 	read_unlock_bh(&ifp->idev->lock);
4059 
4060 	/* While dad is in progress mld report's source address is in6_addrany.
4061 	 * Resend with proper ll now.
4062 	 */
4063 	if (send_mld)
4064 		ipv6_mc_dad_complete(ifp->idev);
4065 
4066 	/* send unsolicited NA if enabled */
4067 	if (send_na &&
4068 	    (ifp->idev->cnf.ndisc_notify ||
4069 	     dev_net(dev)->ipv6.devconf_all->ndisc_notify)) {
4070 		ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifp->addr,
4071 			      /*router=*/ !!ifp->idev->cnf.forwarding,
4072 			      /*solicited=*/ false, /*override=*/ true,
4073 			      /*inc_opt=*/ true);
4074 	}
4075 
4076 	if (send_rs) {
4077 		/*
4078 		 *	If a host as already performed a random delay
4079 		 *	[...] as part of DAD [...] there is no need
4080 		 *	to delay again before sending the first RS
4081 		 */
4082 		if (ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE))
4083 			return;
4084 		ndisc_send_rs(dev, &lladdr, &in6addr_linklocal_allrouters);
4085 
4086 		write_lock_bh(&ifp->idev->lock);
4087 		spin_lock(&ifp->lock);
4088 		ifp->idev->rs_interval = rfc3315_s14_backoff_init(
4089 			ifp->idev->cnf.rtr_solicit_interval);
4090 		ifp->idev->rs_probes = 1;
4091 		ifp->idev->if_flags |= IF_RS_SENT;
4092 		addrconf_mod_rs_timer(ifp->idev, ifp->idev->rs_interval);
4093 		spin_unlock(&ifp->lock);
4094 		write_unlock_bh(&ifp->idev->lock);
4095 	}
4096 
4097 	if (bump_id)
4098 		rt_genid_bump_ipv6(dev_net(dev));
4099 
4100 	/* Make sure that a new temporary address will be created
4101 	 * before this temporary address becomes deprecated.
4102 	 */
4103 	if (ifp->flags & IFA_F_TEMPORARY)
4104 		addrconf_verify_rtnl();
4105 }
4106 
4107 static void addrconf_dad_run(struct inet6_dev *idev)
4108 {
4109 	struct inet6_ifaddr *ifp;
4110 
4111 	read_lock_bh(&idev->lock);
4112 	list_for_each_entry(ifp, &idev->addr_list, if_list) {
4113 		spin_lock(&ifp->lock);
4114 		if (ifp->flags & IFA_F_TENTATIVE &&
4115 		    ifp->state == INET6_IFADDR_STATE_DAD)
4116 			addrconf_dad_kick(ifp);
4117 		spin_unlock(&ifp->lock);
4118 	}
4119 	read_unlock_bh(&idev->lock);
4120 }
4121 
4122 #ifdef CONFIG_PROC_FS
4123 struct if6_iter_state {
4124 	struct seq_net_private p;
4125 	int bucket;
4126 	int offset;
4127 };
4128 
4129 static struct inet6_ifaddr *if6_get_first(struct seq_file *seq, loff_t pos)
4130 {
4131 	struct if6_iter_state *state = seq->private;
4132 	struct net *net = seq_file_net(seq);
4133 	struct inet6_ifaddr *ifa = NULL;
4134 	int p = 0;
4135 
4136 	/* initial bucket if pos is 0 */
4137 	if (pos == 0) {
4138 		state->bucket = 0;
4139 		state->offset = 0;
4140 	}
4141 
4142 	for (; state->bucket < IN6_ADDR_HSIZE; ++state->bucket) {
4143 		hlist_for_each_entry_rcu(ifa, &inet6_addr_lst[state->bucket],
4144 					 addr_lst) {
4145 			if (!net_eq(dev_net(ifa->idev->dev), net))
4146 				continue;
4147 			/* sync with offset */
4148 			if (p < state->offset) {
4149 				p++;
4150 				continue;
4151 			}
4152 			state->offset++;
4153 			return ifa;
4154 		}
4155 
4156 		/* prepare for next bucket */
4157 		state->offset = 0;
4158 		p = 0;
4159 	}
4160 	return NULL;
4161 }
4162 
4163 static struct inet6_ifaddr *if6_get_next(struct seq_file *seq,
4164 					 struct inet6_ifaddr *ifa)
4165 {
4166 	struct if6_iter_state *state = seq->private;
4167 	struct net *net = seq_file_net(seq);
4168 
4169 	hlist_for_each_entry_continue_rcu(ifa, addr_lst) {
4170 		if (!net_eq(dev_net(ifa->idev->dev), net))
4171 			continue;
4172 		state->offset++;
4173 		return ifa;
4174 	}
4175 
4176 	while (++state->bucket < IN6_ADDR_HSIZE) {
4177 		state->offset = 0;
4178 		hlist_for_each_entry_rcu(ifa,
4179 				     &inet6_addr_lst[state->bucket], addr_lst) {
4180 			if (!net_eq(dev_net(ifa->idev->dev), net))
4181 				continue;
4182 			state->offset++;
4183 			return ifa;
4184 		}
4185 	}
4186 
4187 	return NULL;
4188 }
4189 
4190 static void *if6_seq_start(struct seq_file *seq, loff_t *pos)
4191 	__acquires(rcu)
4192 {
4193 	rcu_read_lock();
4194 	return if6_get_first(seq, *pos);
4195 }
4196 
4197 static void *if6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4198 {
4199 	struct inet6_ifaddr *ifa;
4200 
4201 	ifa = if6_get_next(seq, v);
4202 	++*pos;
4203 	return ifa;
4204 }
4205 
4206 static void if6_seq_stop(struct seq_file *seq, void *v)
4207 	__releases(rcu)
4208 {
4209 	rcu_read_unlock();
4210 }
4211 
4212 static int if6_seq_show(struct seq_file *seq, void *v)
4213 {
4214 	struct inet6_ifaddr *ifp = (struct inet6_ifaddr *)v;
4215 	seq_printf(seq, "%pi6 %02x %02x %02x %02x %8s\n",
4216 		   &ifp->addr,
4217 		   ifp->idev->dev->ifindex,
4218 		   ifp->prefix_len,
4219 		   ifp->scope,
4220 		   (u8) ifp->flags,
4221 		   ifp->idev->dev->name);
4222 	return 0;
4223 }
4224 
4225 static const struct seq_operations if6_seq_ops = {
4226 	.start	= if6_seq_start,
4227 	.next	= if6_seq_next,
4228 	.show	= if6_seq_show,
4229 	.stop	= if6_seq_stop,
4230 };
4231 
4232 static int if6_seq_open(struct inode *inode, struct file *file)
4233 {
4234 	return seq_open_net(inode, file, &if6_seq_ops,
4235 			    sizeof(struct if6_iter_state));
4236 }
4237 
4238 static const struct file_operations if6_fops = {
4239 	.open		= if6_seq_open,
4240 	.read		= seq_read,
4241 	.llseek		= seq_lseek,
4242 	.release	= seq_release_net,
4243 };
4244 
4245 static int __net_init if6_proc_net_init(struct net *net)
4246 {
4247 	if (!proc_create("if_inet6", S_IRUGO, net->proc_net, &if6_fops))
4248 		return -ENOMEM;
4249 	return 0;
4250 }
4251 
4252 static void __net_exit if6_proc_net_exit(struct net *net)
4253 {
4254 	remove_proc_entry("if_inet6", net->proc_net);
4255 }
4256 
4257 static struct pernet_operations if6_proc_net_ops = {
4258 	.init = if6_proc_net_init,
4259 	.exit = if6_proc_net_exit,
4260 	.async = true,
4261 };
4262 
4263 int __init if6_proc_init(void)
4264 {
4265 	return register_pernet_subsys(&if6_proc_net_ops);
4266 }
4267 
4268 void if6_proc_exit(void)
4269 {
4270 	unregister_pernet_subsys(&if6_proc_net_ops);
4271 }
4272 #endif	/* CONFIG_PROC_FS */
4273 
4274 #if IS_ENABLED(CONFIG_IPV6_MIP6)
4275 /* Check if address is a home address configured on any interface. */
4276 int ipv6_chk_home_addr(struct net *net, const struct in6_addr *addr)
4277 {
4278 	unsigned int hash = inet6_addr_hash(net, addr);
4279 	struct inet6_ifaddr *ifp = NULL;
4280 	int ret = 0;
4281 
4282 	rcu_read_lock();
4283 	hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) {
4284 		if (!net_eq(dev_net(ifp->idev->dev), net))
4285 			continue;
4286 		if (ipv6_addr_equal(&ifp->addr, addr) &&
4287 		    (ifp->flags & IFA_F_HOMEADDRESS)) {
4288 			ret = 1;
4289 			break;
4290 		}
4291 	}
4292 	rcu_read_unlock();
4293 	return ret;
4294 }
4295 #endif
4296 
4297 /*
4298  *	Periodic address status verification
4299  */
4300 
4301 static void addrconf_verify_rtnl(void)
4302 {
4303 	unsigned long now, next, next_sec, next_sched;
4304 	struct inet6_ifaddr *ifp;
4305 	int i;
4306 
4307 	ASSERT_RTNL();
4308 
4309 	rcu_read_lock_bh();
4310 	now = jiffies;
4311 	next = round_jiffies_up(now + ADDR_CHECK_FREQUENCY);
4312 
4313 	cancel_delayed_work(&addr_chk_work);
4314 
4315 	for (i = 0; i < IN6_ADDR_HSIZE; i++) {
4316 restart:
4317 		hlist_for_each_entry_rcu_bh(ifp, &inet6_addr_lst[i], addr_lst) {
4318 			unsigned long age;
4319 
4320 			/* When setting preferred_lft to a value not zero or
4321 			 * infinity, while valid_lft is infinity
4322 			 * IFA_F_PERMANENT has a non-infinity life time.
4323 			 */
4324 			if ((ifp->flags & IFA_F_PERMANENT) &&
4325 			    (ifp->prefered_lft == INFINITY_LIFE_TIME))
4326 				continue;
4327 
4328 			spin_lock(&ifp->lock);
4329 			/* We try to batch several events at once. */
4330 			age = (now - ifp->tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ;
4331 
4332 			if (ifp->valid_lft != INFINITY_LIFE_TIME &&
4333 			    age >= ifp->valid_lft) {
4334 				spin_unlock(&ifp->lock);
4335 				in6_ifa_hold(ifp);
4336 				ipv6_del_addr(ifp);
4337 				goto restart;
4338 			} else if (ifp->prefered_lft == INFINITY_LIFE_TIME) {
4339 				spin_unlock(&ifp->lock);
4340 				continue;
4341 			} else if (age >= ifp->prefered_lft) {
4342 				/* jiffies - ifp->tstamp > age >= ifp->prefered_lft */
4343 				int deprecate = 0;
4344 
4345 				if (!(ifp->flags&IFA_F_DEPRECATED)) {
4346 					deprecate = 1;
4347 					ifp->flags |= IFA_F_DEPRECATED;
4348 				}
4349 
4350 				if ((ifp->valid_lft != INFINITY_LIFE_TIME) &&
4351 				    (time_before(ifp->tstamp + ifp->valid_lft * HZ, next)))
4352 					next = ifp->tstamp + ifp->valid_lft * HZ;
4353 
4354 				spin_unlock(&ifp->lock);
4355 
4356 				if (deprecate) {
4357 					in6_ifa_hold(ifp);
4358 
4359 					ipv6_ifa_notify(0, ifp);
4360 					in6_ifa_put(ifp);
4361 					goto restart;
4362 				}
4363 			} else if ((ifp->flags&IFA_F_TEMPORARY) &&
4364 				   !(ifp->flags&IFA_F_TENTATIVE)) {
4365 				unsigned long regen_advance = ifp->idev->cnf.regen_max_retry *
4366 					ifp->idev->cnf.dad_transmits *
4367 					NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME) / HZ;
4368 
4369 				if (age >= ifp->prefered_lft - regen_advance) {
4370 					struct inet6_ifaddr *ifpub = ifp->ifpub;
4371 					if (time_before(ifp->tstamp + ifp->prefered_lft * HZ, next))
4372 						next = ifp->tstamp + ifp->prefered_lft * HZ;
4373 					if (!ifp->regen_count && ifpub) {
4374 						ifp->regen_count++;
4375 						in6_ifa_hold(ifp);
4376 						in6_ifa_hold(ifpub);
4377 						spin_unlock(&ifp->lock);
4378 
4379 						spin_lock(&ifpub->lock);
4380 						ifpub->regen_count = 0;
4381 						spin_unlock(&ifpub->lock);
4382 						rcu_read_unlock_bh();
4383 						ipv6_create_tempaddr(ifpub, ifp, true);
4384 						in6_ifa_put(ifpub);
4385 						in6_ifa_put(ifp);
4386 						rcu_read_lock_bh();
4387 						goto restart;
4388 					}
4389 				} else if (time_before(ifp->tstamp + ifp->prefered_lft * HZ - regen_advance * HZ, next))
4390 					next = ifp->tstamp + ifp->prefered_lft * HZ - regen_advance * HZ;
4391 				spin_unlock(&ifp->lock);
4392 			} else {
4393 				/* ifp->prefered_lft <= ifp->valid_lft */
4394 				if (time_before(ifp->tstamp + ifp->prefered_lft * HZ, next))
4395 					next = ifp->tstamp + ifp->prefered_lft * HZ;
4396 				spin_unlock(&ifp->lock);
4397 			}
4398 		}
4399 	}
4400 
4401 	next_sec = round_jiffies_up(next);
4402 	next_sched = next;
4403 
4404 	/* If rounded timeout is accurate enough, accept it. */
4405 	if (time_before(next_sec, next + ADDRCONF_TIMER_FUZZ))
4406 		next_sched = next_sec;
4407 
4408 	/* And minimum interval is ADDRCONF_TIMER_FUZZ_MAX. */
4409 	if (time_before(next_sched, jiffies + ADDRCONF_TIMER_FUZZ_MAX))
4410 		next_sched = jiffies + ADDRCONF_TIMER_FUZZ_MAX;
4411 
4412 	ADBG(KERN_DEBUG "now = %lu, schedule = %lu, rounded schedule = %lu => %lu\n",
4413 	      now, next, next_sec, next_sched);
4414 	mod_delayed_work(addrconf_wq, &addr_chk_work, next_sched - now);
4415 	rcu_read_unlock_bh();
4416 }
4417 
4418 static void addrconf_verify_work(struct work_struct *w)
4419 {
4420 	rtnl_lock();
4421 	addrconf_verify_rtnl();
4422 	rtnl_unlock();
4423 }
4424 
4425 static void addrconf_verify(void)
4426 {
4427 	mod_delayed_work(addrconf_wq, &addr_chk_work, 0);
4428 }
4429 
4430 static struct in6_addr *extract_addr(struct nlattr *addr, struct nlattr *local,
4431 				     struct in6_addr **peer_pfx)
4432 {
4433 	struct in6_addr *pfx = NULL;
4434 
4435 	*peer_pfx = NULL;
4436 
4437 	if (addr)
4438 		pfx = nla_data(addr);
4439 
4440 	if (local) {
4441 		if (pfx && nla_memcmp(local, pfx, sizeof(*pfx)))
4442 			*peer_pfx = pfx;
4443 		pfx = nla_data(local);
4444 	}
4445 
4446 	return pfx;
4447 }
4448 
4449 static const struct nla_policy ifa_ipv6_policy[IFA_MAX+1] = {
4450 	[IFA_ADDRESS]		= { .len = sizeof(struct in6_addr) },
4451 	[IFA_LOCAL]		= { .len = sizeof(struct in6_addr) },
4452 	[IFA_CACHEINFO]		= { .len = sizeof(struct ifa_cacheinfo) },
4453 	[IFA_FLAGS]		= { .len = sizeof(u32) },
4454 };
4455 
4456 static int
4457 inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh,
4458 		  struct netlink_ext_ack *extack)
4459 {
4460 	struct net *net = sock_net(skb->sk);
4461 	struct ifaddrmsg *ifm;
4462 	struct nlattr *tb[IFA_MAX+1];
4463 	struct in6_addr *pfx, *peer_pfx;
4464 	u32 ifa_flags;
4465 	int err;
4466 
4467 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy,
4468 			  extack);
4469 	if (err < 0)
4470 		return err;
4471 
4472 	ifm = nlmsg_data(nlh);
4473 	pfx = extract_addr(tb[IFA_ADDRESS], tb[IFA_LOCAL], &peer_pfx);
4474 	if (!pfx)
4475 		return -EINVAL;
4476 
4477 	ifa_flags = tb[IFA_FLAGS] ? nla_get_u32(tb[IFA_FLAGS]) : ifm->ifa_flags;
4478 
4479 	/* We ignore other flags so far. */
4480 	ifa_flags &= IFA_F_MANAGETEMPADDR;
4481 
4482 	return inet6_addr_del(net, ifm->ifa_index, ifa_flags, pfx,
4483 			      ifm->ifa_prefixlen);
4484 }
4485 
4486 static int inet6_addr_modify(struct inet6_ifaddr *ifp, u32 ifa_flags,
4487 			     u32 prefered_lft, u32 valid_lft)
4488 {
4489 	u32 flags;
4490 	clock_t expires;
4491 	unsigned long timeout;
4492 	bool was_managetempaddr;
4493 	bool had_prefixroute;
4494 
4495 	ASSERT_RTNL();
4496 
4497 	if (!valid_lft || (prefered_lft > valid_lft))
4498 		return -EINVAL;
4499 
4500 	if (ifa_flags & IFA_F_MANAGETEMPADDR &&
4501 	    (ifp->flags & IFA_F_TEMPORARY || ifp->prefix_len != 64))
4502 		return -EINVAL;
4503 
4504 	timeout = addrconf_timeout_fixup(valid_lft, HZ);
4505 	if (addrconf_finite_timeout(timeout)) {
4506 		expires = jiffies_to_clock_t(timeout * HZ);
4507 		valid_lft = timeout;
4508 		flags = RTF_EXPIRES;
4509 	} else {
4510 		expires = 0;
4511 		flags = 0;
4512 		ifa_flags |= IFA_F_PERMANENT;
4513 	}
4514 
4515 	timeout = addrconf_timeout_fixup(prefered_lft, HZ);
4516 	if (addrconf_finite_timeout(timeout)) {
4517 		if (timeout == 0)
4518 			ifa_flags |= IFA_F_DEPRECATED;
4519 		prefered_lft = timeout;
4520 	}
4521 
4522 	spin_lock_bh(&ifp->lock);
4523 	was_managetempaddr = ifp->flags & IFA_F_MANAGETEMPADDR;
4524 	had_prefixroute = ifp->flags & IFA_F_PERMANENT &&
4525 			  !(ifp->flags & IFA_F_NOPREFIXROUTE);
4526 	ifp->flags &= ~(IFA_F_DEPRECATED | IFA_F_PERMANENT | IFA_F_NODAD |
4527 			IFA_F_HOMEADDRESS | IFA_F_MANAGETEMPADDR |
4528 			IFA_F_NOPREFIXROUTE);
4529 	ifp->flags |= ifa_flags;
4530 	ifp->tstamp = jiffies;
4531 	ifp->valid_lft = valid_lft;
4532 	ifp->prefered_lft = prefered_lft;
4533 
4534 	spin_unlock_bh(&ifp->lock);
4535 	if (!(ifp->flags&IFA_F_TENTATIVE))
4536 		ipv6_ifa_notify(0, ifp);
4537 
4538 	if (!(ifa_flags & IFA_F_NOPREFIXROUTE)) {
4539 		addrconf_prefix_route(&ifp->addr, ifp->prefix_len, ifp->idev->dev,
4540 				      expires, flags);
4541 	} else if (had_prefixroute) {
4542 		enum cleanup_prefix_rt_t action;
4543 		unsigned long rt_expires;
4544 
4545 		write_lock_bh(&ifp->idev->lock);
4546 		action = check_cleanup_prefix_route(ifp, &rt_expires);
4547 		write_unlock_bh(&ifp->idev->lock);
4548 
4549 		if (action != CLEANUP_PREFIX_RT_NOP) {
4550 			cleanup_prefix_route(ifp, rt_expires,
4551 				action == CLEANUP_PREFIX_RT_DEL);
4552 		}
4553 	}
4554 
4555 	if (was_managetempaddr || ifp->flags & IFA_F_MANAGETEMPADDR) {
4556 		if (was_managetempaddr && !(ifp->flags & IFA_F_MANAGETEMPADDR))
4557 			valid_lft = prefered_lft = 0;
4558 		manage_tempaddrs(ifp->idev, ifp, valid_lft, prefered_lft,
4559 				 !was_managetempaddr, jiffies);
4560 	}
4561 
4562 	addrconf_verify_rtnl();
4563 
4564 	return 0;
4565 }
4566 
4567 static int
4568 inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh,
4569 		  struct netlink_ext_ack *extack)
4570 {
4571 	struct net *net = sock_net(skb->sk);
4572 	struct ifaddrmsg *ifm;
4573 	struct nlattr *tb[IFA_MAX+1];
4574 	struct in6_addr *pfx, *peer_pfx;
4575 	struct inet6_ifaddr *ifa;
4576 	struct net_device *dev;
4577 	u32 valid_lft = INFINITY_LIFE_TIME, preferred_lft = INFINITY_LIFE_TIME;
4578 	u32 ifa_flags;
4579 	int err;
4580 
4581 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy,
4582 			  extack);
4583 	if (err < 0)
4584 		return err;
4585 
4586 	ifm = nlmsg_data(nlh);
4587 	pfx = extract_addr(tb[IFA_ADDRESS], tb[IFA_LOCAL], &peer_pfx);
4588 	if (!pfx)
4589 		return -EINVAL;
4590 
4591 	if (tb[IFA_CACHEINFO]) {
4592 		struct ifa_cacheinfo *ci;
4593 
4594 		ci = nla_data(tb[IFA_CACHEINFO]);
4595 		valid_lft = ci->ifa_valid;
4596 		preferred_lft = ci->ifa_prefered;
4597 	} else {
4598 		preferred_lft = INFINITY_LIFE_TIME;
4599 		valid_lft = INFINITY_LIFE_TIME;
4600 	}
4601 
4602 	dev =  __dev_get_by_index(net, ifm->ifa_index);
4603 	if (!dev)
4604 		return -ENODEV;
4605 
4606 	ifa_flags = tb[IFA_FLAGS] ? nla_get_u32(tb[IFA_FLAGS]) : ifm->ifa_flags;
4607 
4608 	/* We ignore other flags so far. */
4609 	ifa_flags &= IFA_F_NODAD | IFA_F_HOMEADDRESS | IFA_F_MANAGETEMPADDR |
4610 		     IFA_F_NOPREFIXROUTE | IFA_F_MCAUTOJOIN;
4611 
4612 	ifa = ipv6_get_ifaddr(net, pfx, dev, 1);
4613 	if (!ifa) {
4614 		/*
4615 		 * It would be best to check for !NLM_F_CREATE here but
4616 		 * userspace already relies on not having to provide this.
4617 		 */
4618 		return inet6_addr_add(net, ifm->ifa_index, pfx, peer_pfx,
4619 				      ifm->ifa_prefixlen, ifa_flags,
4620 				      preferred_lft, valid_lft, extack);
4621 	}
4622 
4623 	if (nlh->nlmsg_flags & NLM_F_EXCL ||
4624 	    !(nlh->nlmsg_flags & NLM_F_REPLACE))
4625 		err = -EEXIST;
4626 	else
4627 		err = inet6_addr_modify(ifa, ifa_flags, preferred_lft, valid_lft);
4628 
4629 	in6_ifa_put(ifa);
4630 
4631 	return err;
4632 }
4633 
4634 static void put_ifaddrmsg(struct nlmsghdr *nlh, u8 prefixlen, u32 flags,
4635 			  u8 scope, int ifindex)
4636 {
4637 	struct ifaddrmsg *ifm;
4638 
4639 	ifm = nlmsg_data(nlh);
4640 	ifm->ifa_family = AF_INET6;
4641 	ifm->ifa_prefixlen = prefixlen;
4642 	ifm->ifa_flags = flags;
4643 	ifm->ifa_scope = scope;
4644 	ifm->ifa_index = ifindex;
4645 }
4646 
4647 static int put_cacheinfo(struct sk_buff *skb, unsigned long cstamp,
4648 			 unsigned long tstamp, u32 preferred, u32 valid)
4649 {
4650 	struct ifa_cacheinfo ci;
4651 
4652 	ci.cstamp = cstamp_delta(cstamp);
4653 	ci.tstamp = cstamp_delta(tstamp);
4654 	ci.ifa_prefered = preferred;
4655 	ci.ifa_valid = valid;
4656 
4657 	return nla_put(skb, IFA_CACHEINFO, sizeof(ci), &ci);
4658 }
4659 
4660 static inline int rt_scope(int ifa_scope)
4661 {
4662 	if (ifa_scope & IFA_HOST)
4663 		return RT_SCOPE_HOST;
4664 	else if (ifa_scope & IFA_LINK)
4665 		return RT_SCOPE_LINK;
4666 	else if (ifa_scope & IFA_SITE)
4667 		return RT_SCOPE_SITE;
4668 	else
4669 		return RT_SCOPE_UNIVERSE;
4670 }
4671 
4672 static inline int inet6_ifaddr_msgsize(void)
4673 {
4674 	return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
4675 	       + nla_total_size(16) /* IFA_LOCAL */
4676 	       + nla_total_size(16) /* IFA_ADDRESS */
4677 	       + nla_total_size(sizeof(struct ifa_cacheinfo))
4678 	       + nla_total_size(4)  /* IFA_FLAGS */;
4679 }
4680 
4681 static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
4682 			     u32 portid, u32 seq, int event, unsigned int flags)
4683 {
4684 	struct nlmsghdr  *nlh;
4685 	u32 preferred, valid;
4686 
4687 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct ifaddrmsg), flags);
4688 	if (!nlh)
4689 		return -EMSGSIZE;
4690 
4691 	put_ifaddrmsg(nlh, ifa->prefix_len, ifa->flags, rt_scope(ifa->scope),
4692 		      ifa->idev->dev->ifindex);
4693 
4694 	if (!((ifa->flags&IFA_F_PERMANENT) &&
4695 	      (ifa->prefered_lft == INFINITY_LIFE_TIME))) {
4696 		preferred = ifa->prefered_lft;
4697 		valid = ifa->valid_lft;
4698 		if (preferred != INFINITY_LIFE_TIME) {
4699 			long tval = (jiffies - ifa->tstamp)/HZ;
4700 			if (preferred > tval)
4701 				preferred -= tval;
4702 			else
4703 				preferred = 0;
4704 			if (valid != INFINITY_LIFE_TIME) {
4705 				if (valid > tval)
4706 					valid -= tval;
4707 				else
4708 					valid = 0;
4709 			}
4710 		}
4711 	} else {
4712 		preferred = INFINITY_LIFE_TIME;
4713 		valid = INFINITY_LIFE_TIME;
4714 	}
4715 
4716 	if (!ipv6_addr_any(&ifa->peer_addr)) {
4717 		if (nla_put_in6_addr(skb, IFA_LOCAL, &ifa->addr) < 0 ||
4718 		    nla_put_in6_addr(skb, IFA_ADDRESS, &ifa->peer_addr) < 0)
4719 			goto error;
4720 	} else
4721 		if (nla_put_in6_addr(skb, IFA_ADDRESS, &ifa->addr) < 0)
4722 			goto error;
4723 
4724 	if (put_cacheinfo(skb, ifa->cstamp, ifa->tstamp, preferred, valid) < 0)
4725 		goto error;
4726 
4727 	if (nla_put_u32(skb, IFA_FLAGS, ifa->flags) < 0)
4728 		goto error;
4729 
4730 	nlmsg_end(skb, nlh);
4731 	return 0;
4732 
4733 error:
4734 	nlmsg_cancel(skb, nlh);
4735 	return -EMSGSIZE;
4736 }
4737 
4738 static int inet6_fill_ifmcaddr(struct sk_buff *skb, struct ifmcaddr6 *ifmca,
4739 				u32 portid, u32 seq, int event, u16 flags)
4740 {
4741 	struct nlmsghdr  *nlh;
4742 	u8 scope = RT_SCOPE_UNIVERSE;
4743 	int ifindex = ifmca->idev->dev->ifindex;
4744 
4745 	if (ipv6_addr_scope(&ifmca->mca_addr) & IFA_SITE)
4746 		scope = RT_SCOPE_SITE;
4747 
4748 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct ifaddrmsg), flags);
4749 	if (!nlh)
4750 		return -EMSGSIZE;
4751 
4752 	put_ifaddrmsg(nlh, 128, IFA_F_PERMANENT, scope, ifindex);
4753 	if (nla_put_in6_addr(skb, IFA_MULTICAST, &ifmca->mca_addr) < 0 ||
4754 	    put_cacheinfo(skb, ifmca->mca_cstamp, ifmca->mca_tstamp,
4755 			  INFINITY_LIFE_TIME, INFINITY_LIFE_TIME) < 0) {
4756 		nlmsg_cancel(skb, nlh);
4757 		return -EMSGSIZE;
4758 	}
4759 
4760 	nlmsg_end(skb, nlh);
4761 	return 0;
4762 }
4763 
4764 static int inet6_fill_ifacaddr(struct sk_buff *skb, struct ifacaddr6 *ifaca,
4765 				u32 portid, u32 seq, int event, unsigned int flags)
4766 {
4767 	struct nlmsghdr  *nlh;
4768 	u8 scope = RT_SCOPE_UNIVERSE;
4769 	int ifindex = ifaca->aca_idev->dev->ifindex;
4770 
4771 	if (ipv6_addr_scope(&ifaca->aca_addr) & IFA_SITE)
4772 		scope = RT_SCOPE_SITE;
4773 
4774 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct ifaddrmsg), flags);
4775 	if (!nlh)
4776 		return -EMSGSIZE;
4777 
4778 	put_ifaddrmsg(nlh, 128, IFA_F_PERMANENT, scope, ifindex);
4779 	if (nla_put_in6_addr(skb, IFA_ANYCAST, &ifaca->aca_addr) < 0 ||
4780 	    put_cacheinfo(skb, ifaca->aca_cstamp, ifaca->aca_tstamp,
4781 			  INFINITY_LIFE_TIME, INFINITY_LIFE_TIME) < 0) {
4782 		nlmsg_cancel(skb, nlh);
4783 		return -EMSGSIZE;
4784 	}
4785 
4786 	nlmsg_end(skb, nlh);
4787 	return 0;
4788 }
4789 
4790 enum addr_type_t {
4791 	UNICAST_ADDR,
4792 	MULTICAST_ADDR,
4793 	ANYCAST_ADDR,
4794 };
4795 
4796 /* called with rcu_read_lock() */
4797 static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb,
4798 			  struct netlink_callback *cb, enum addr_type_t type,
4799 			  int s_ip_idx, int *p_ip_idx)
4800 {
4801 	struct ifmcaddr6 *ifmca;
4802 	struct ifacaddr6 *ifaca;
4803 	int err = 1;
4804 	int ip_idx = *p_ip_idx;
4805 
4806 	read_lock_bh(&idev->lock);
4807 	switch (type) {
4808 	case UNICAST_ADDR: {
4809 		struct inet6_ifaddr *ifa;
4810 
4811 		/* unicast address incl. temp addr */
4812 		list_for_each_entry(ifa, &idev->addr_list, if_list) {
4813 			if (++ip_idx < s_ip_idx)
4814 				continue;
4815 			err = inet6_fill_ifaddr(skb, ifa,
4816 						NETLINK_CB(cb->skb).portid,
4817 						cb->nlh->nlmsg_seq,
4818 						RTM_NEWADDR,
4819 						NLM_F_MULTI);
4820 			if (err < 0)
4821 				break;
4822 			nl_dump_check_consistent(cb, nlmsg_hdr(skb));
4823 		}
4824 		break;
4825 	}
4826 	case MULTICAST_ADDR:
4827 		/* multicast address */
4828 		for (ifmca = idev->mc_list; ifmca;
4829 		     ifmca = ifmca->next, ip_idx++) {
4830 			if (ip_idx < s_ip_idx)
4831 				continue;
4832 			err = inet6_fill_ifmcaddr(skb, ifmca,
4833 						  NETLINK_CB(cb->skb).portid,
4834 						  cb->nlh->nlmsg_seq,
4835 						  RTM_GETMULTICAST,
4836 						  NLM_F_MULTI);
4837 			if (err < 0)
4838 				break;
4839 		}
4840 		break;
4841 	case ANYCAST_ADDR:
4842 		/* anycast address */
4843 		for (ifaca = idev->ac_list; ifaca;
4844 		     ifaca = ifaca->aca_next, ip_idx++) {
4845 			if (ip_idx < s_ip_idx)
4846 				continue;
4847 			err = inet6_fill_ifacaddr(skb, ifaca,
4848 						  NETLINK_CB(cb->skb).portid,
4849 						  cb->nlh->nlmsg_seq,
4850 						  RTM_GETANYCAST,
4851 						  NLM_F_MULTI);
4852 			if (err < 0)
4853 				break;
4854 		}
4855 		break;
4856 	default:
4857 		break;
4858 	}
4859 	read_unlock_bh(&idev->lock);
4860 	*p_ip_idx = ip_idx;
4861 	return err;
4862 }
4863 
4864 static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb,
4865 			   enum addr_type_t type)
4866 {
4867 	struct net *net = sock_net(skb->sk);
4868 	int h, s_h;
4869 	int idx, ip_idx;
4870 	int s_idx, s_ip_idx;
4871 	struct net_device *dev;
4872 	struct inet6_dev *idev;
4873 	struct hlist_head *head;
4874 
4875 	s_h = cb->args[0];
4876 	s_idx = idx = cb->args[1];
4877 	s_ip_idx = ip_idx = cb->args[2];
4878 
4879 	rcu_read_lock();
4880 	cb->seq = atomic_read(&net->ipv6.dev_addr_genid) ^ net->dev_base_seq;
4881 	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
4882 		idx = 0;
4883 		head = &net->dev_index_head[h];
4884 		hlist_for_each_entry_rcu(dev, head, index_hlist) {
4885 			if (idx < s_idx)
4886 				goto cont;
4887 			if (h > s_h || idx > s_idx)
4888 				s_ip_idx = 0;
4889 			ip_idx = 0;
4890 			idev = __in6_dev_get(dev);
4891 			if (!idev)
4892 				goto cont;
4893 
4894 			if (in6_dump_addrs(idev, skb, cb, type,
4895 					   s_ip_idx, &ip_idx) < 0)
4896 				goto done;
4897 cont:
4898 			idx++;
4899 		}
4900 	}
4901 done:
4902 	rcu_read_unlock();
4903 	cb->args[0] = h;
4904 	cb->args[1] = idx;
4905 	cb->args[2] = ip_idx;
4906 
4907 	return skb->len;
4908 }
4909 
4910 static int inet6_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
4911 {
4912 	enum addr_type_t type = UNICAST_ADDR;
4913 
4914 	return inet6_dump_addr(skb, cb, type);
4915 }
4916 
4917 static int inet6_dump_ifmcaddr(struct sk_buff *skb, struct netlink_callback *cb)
4918 {
4919 	enum addr_type_t type = MULTICAST_ADDR;
4920 
4921 	return inet6_dump_addr(skb, cb, type);
4922 }
4923 
4924 
4925 static int inet6_dump_ifacaddr(struct sk_buff *skb, struct netlink_callback *cb)
4926 {
4927 	enum addr_type_t type = ANYCAST_ADDR;
4928 
4929 	return inet6_dump_addr(skb, cb, type);
4930 }
4931 
4932 static int inet6_rtm_getaddr(struct sk_buff *in_skb, struct nlmsghdr *nlh,
4933 			     struct netlink_ext_ack *extack)
4934 {
4935 	struct net *net = sock_net(in_skb->sk);
4936 	struct ifaddrmsg *ifm;
4937 	struct nlattr *tb[IFA_MAX+1];
4938 	struct in6_addr *addr = NULL, *peer;
4939 	struct net_device *dev = NULL;
4940 	struct inet6_ifaddr *ifa;
4941 	struct sk_buff *skb;
4942 	int err;
4943 
4944 	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv6_policy,
4945 			  extack);
4946 	if (err < 0)
4947 		return err;
4948 
4949 	addr = extract_addr(tb[IFA_ADDRESS], tb[IFA_LOCAL], &peer);
4950 	if (!addr)
4951 		return -EINVAL;
4952 
4953 	ifm = nlmsg_data(nlh);
4954 	if (ifm->ifa_index)
4955 		dev = dev_get_by_index(net, ifm->ifa_index);
4956 
4957 	ifa = ipv6_get_ifaddr(net, addr, dev, 1);
4958 	if (!ifa) {
4959 		err = -EADDRNOTAVAIL;
4960 		goto errout;
4961 	}
4962 
4963 	skb = nlmsg_new(inet6_ifaddr_msgsize(), GFP_KERNEL);
4964 	if (!skb) {
4965 		err = -ENOBUFS;
4966 		goto errout_ifa;
4967 	}
4968 
4969 	err = inet6_fill_ifaddr(skb, ifa, NETLINK_CB(in_skb).portid,
4970 				nlh->nlmsg_seq, RTM_NEWADDR, 0);
4971 	if (err < 0) {
4972 		/* -EMSGSIZE implies BUG in inet6_ifaddr_msgsize() */
4973 		WARN_ON(err == -EMSGSIZE);
4974 		kfree_skb(skb);
4975 		goto errout_ifa;
4976 	}
4977 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
4978 errout_ifa:
4979 	in6_ifa_put(ifa);
4980 errout:
4981 	if (dev)
4982 		dev_put(dev);
4983 	return err;
4984 }
4985 
4986 static void inet6_ifa_notify(int event, struct inet6_ifaddr *ifa)
4987 {
4988 	struct sk_buff *skb;
4989 	struct net *net = dev_net(ifa->idev->dev);
4990 	int err = -ENOBUFS;
4991 
4992 	/* Don't send DELADDR notification for TENTATIVE address,
4993 	 * since NEWADDR notification is sent only after removing
4994 	 * TENTATIVE flag, if DAD has not failed.
4995 	 */
4996 	if (ifa->flags & IFA_F_TENTATIVE && !(ifa->flags & IFA_F_DADFAILED) &&
4997 	    event == RTM_DELADDR)
4998 		return;
4999 
5000 	skb = nlmsg_new(inet6_ifaddr_msgsize(), GFP_ATOMIC);
5001 	if (!skb)
5002 		goto errout;
5003 
5004 	err = inet6_fill_ifaddr(skb, ifa, 0, 0, event, 0);
5005 	if (err < 0) {
5006 		/* -EMSGSIZE implies BUG in inet6_ifaddr_msgsize() */
5007 		WARN_ON(err == -EMSGSIZE);
5008 		kfree_skb(skb);
5009 		goto errout;
5010 	}
5011 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_IFADDR, NULL, GFP_ATOMIC);
5012 	return;
5013 errout:
5014 	if (err < 0)
5015 		rtnl_set_sk_err(net, RTNLGRP_IPV6_IFADDR, err);
5016 }
5017 
5018 static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
5019 				__s32 *array, int bytes)
5020 {
5021 	BUG_ON(bytes < (DEVCONF_MAX * 4));
5022 
5023 	memset(array, 0, bytes);
5024 	array[DEVCONF_FORWARDING] = cnf->forwarding;
5025 	array[DEVCONF_HOPLIMIT] = cnf->hop_limit;
5026 	array[DEVCONF_MTU6] = cnf->mtu6;
5027 	array[DEVCONF_ACCEPT_RA] = cnf->accept_ra;
5028 	array[DEVCONF_ACCEPT_REDIRECTS] = cnf->accept_redirects;
5029 	array[DEVCONF_AUTOCONF] = cnf->autoconf;
5030 	array[DEVCONF_DAD_TRANSMITS] = cnf->dad_transmits;
5031 	array[DEVCONF_RTR_SOLICITS] = cnf->rtr_solicits;
5032 	array[DEVCONF_RTR_SOLICIT_INTERVAL] =
5033 		jiffies_to_msecs(cnf->rtr_solicit_interval);
5034 	array[DEVCONF_RTR_SOLICIT_MAX_INTERVAL] =
5035 		jiffies_to_msecs(cnf->rtr_solicit_max_interval);
5036 	array[DEVCONF_RTR_SOLICIT_DELAY] =
5037 		jiffies_to_msecs(cnf->rtr_solicit_delay);
5038 	array[DEVCONF_FORCE_MLD_VERSION] = cnf->force_mld_version;
5039 	array[DEVCONF_MLDV1_UNSOLICITED_REPORT_INTERVAL] =
5040 		jiffies_to_msecs(cnf->mldv1_unsolicited_report_interval);
5041 	array[DEVCONF_MLDV2_UNSOLICITED_REPORT_INTERVAL] =
5042 		jiffies_to_msecs(cnf->mldv2_unsolicited_report_interval);
5043 	array[DEVCONF_USE_TEMPADDR] = cnf->use_tempaddr;
5044 	array[DEVCONF_TEMP_VALID_LFT] = cnf->temp_valid_lft;
5045 	array[DEVCONF_TEMP_PREFERED_LFT] = cnf->temp_prefered_lft;
5046 	array[DEVCONF_REGEN_MAX_RETRY] = cnf->regen_max_retry;
5047 	array[DEVCONF_MAX_DESYNC_FACTOR] = cnf->max_desync_factor;
5048 	array[DEVCONF_MAX_ADDRESSES] = cnf->max_addresses;
5049 	array[DEVCONF_ACCEPT_RA_DEFRTR] = cnf->accept_ra_defrtr;
5050 	array[DEVCONF_ACCEPT_RA_MIN_HOP_LIMIT] = cnf->accept_ra_min_hop_limit;
5051 	array[DEVCONF_ACCEPT_RA_PINFO] = cnf->accept_ra_pinfo;
5052 #ifdef CONFIG_IPV6_ROUTER_PREF
5053 	array[DEVCONF_ACCEPT_RA_RTR_PREF] = cnf->accept_ra_rtr_pref;
5054 	array[DEVCONF_RTR_PROBE_INTERVAL] =
5055 		jiffies_to_msecs(cnf->rtr_probe_interval);
5056 #ifdef CONFIG_IPV6_ROUTE_INFO
5057 	array[DEVCONF_ACCEPT_RA_RT_INFO_MIN_PLEN] = cnf->accept_ra_rt_info_min_plen;
5058 	array[DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN] = cnf->accept_ra_rt_info_max_plen;
5059 #endif
5060 #endif
5061 	array[DEVCONF_PROXY_NDP] = cnf->proxy_ndp;
5062 	array[DEVCONF_ACCEPT_SOURCE_ROUTE] = cnf->accept_source_route;
5063 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
5064 	array[DEVCONF_OPTIMISTIC_DAD] = cnf->optimistic_dad;
5065 	array[DEVCONF_USE_OPTIMISTIC] = cnf->use_optimistic;
5066 #endif
5067 #ifdef CONFIG_IPV6_MROUTE
5068 	array[DEVCONF_MC_FORWARDING] = cnf->mc_forwarding;
5069 #endif
5070 	array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6;
5071 	array[DEVCONF_ACCEPT_DAD] = cnf->accept_dad;
5072 	array[DEVCONF_FORCE_TLLAO] = cnf->force_tllao;
5073 	array[DEVCONF_NDISC_NOTIFY] = cnf->ndisc_notify;
5074 	array[DEVCONF_SUPPRESS_FRAG_NDISC] = cnf->suppress_frag_ndisc;
5075 	array[DEVCONF_ACCEPT_RA_FROM_LOCAL] = cnf->accept_ra_from_local;
5076 	array[DEVCONF_ACCEPT_RA_MTU] = cnf->accept_ra_mtu;
5077 	array[DEVCONF_IGNORE_ROUTES_WITH_LINKDOWN] = cnf->ignore_routes_with_linkdown;
5078 	/* we omit DEVCONF_STABLE_SECRET for now */
5079 	array[DEVCONF_USE_OIF_ADDRS_ONLY] = cnf->use_oif_addrs_only;
5080 	array[DEVCONF_DROP_UNICAST_IN_L2_MULTICAST] = cnf->drop_unicast_in_l2_multicast;
5081 	array[DEVCONF_DROP_UNSOLICITED_NA] = cnf->drop_unsolicited_na;
5082 	array[DEVCONF_KEEP_ADDR_ON_DOWN] = cnf->keep_addr_on_down;
5083 	array[DEVCONF_SEG6_ENABLED] = cnf->seg6_enabled;
5084 #ifdef CONFIG_IPV6_SEG6_HMAC
5085 	array[DEVCONF_SEG6_REQUIRE_HMAC] = cnf->seg6_require_hmac;
5086 #endif
5087 	array[DEVCONF_ENHANCED_DAD] = cnf->enhanced_dad;
5088 	array[DEVCONF_ADDR_GEN_MODE] = cnf->addr_gen_mode;
5089 	array[DEVCONF_DISABLE_POLICY] = cnf->disable_policy;
5090 	array[DEVCONF_NDISC_TCLASS] = cnf->ndisc_tclass;
5091 }
5092 
5093 static inline size_t inet6_ifla6_size(void)
5094 {
5095 	return nla_total_size(4) /* IFLA_INET6_FLAGS */
5096 	     + nla_total_size(sizeof(struct ifla_cacheinfo))
5097 	     + nla_total_size(DEVCONF_MAX * 4) /* IFLA_INET6_CONF */
5098 	     + nla_total_size(IPSTATS_MIB_MAX * 8) /* IFLA_INET6_STATS */
5099 	     + nla_total_size(ICMP6_MIB_MAX * 8) /* IFLA_INET6_ICMP6STATS */
5100 	     + nla_total_size(sizeof(struct in6_addr)); /* IFLA_INET6_TOKEN */
5101 }
5102 
5103 static inline size_t inet6_if_nlmsg_size(void)
5104 {
5105 	return NLMSG_ALIGN(sizeof(struct ifinfomsg))
5106 	       + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
5107 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
5108 	       + nla_total_size(4) /* IFLA_MTU */
5109 	       + nla_total_size(4) /* IFLA_LINK */
5110 	       + nla_total_size(1) /* IFLA_OPERSTATE */
5111 	       + nla_total_size(inet6_ifla6_size()); /* IFLA_PROTINFO */
5112 }
5113 
5114 static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
5115 					int bytes)
5116 {
5117 	int i;
5118 	int pad = bytes - sizeof(u64) * ICMP6_MIB_MAX;
5119 	BUG_ON(pad < 0);
5120 
5121 	/* Use put_unaligned() because stats may not be aligned for u64. */
5122 	put_unaligned(ICMP6_MIB_MAX, &stats[0]);
5123 	for (i = 1; i < ICMP6_MIB_MAX; i++)
5124 		put_unaligned(atomic_long_read(&mib[i]), &stats[i]);
5125 
5126 	memset(&stats[ICMP6_MIB_MAX], 0, pad);
5127 }
5128 
5129 static inline void __snmp6_fill_stats64(u64 *stats, void __percpu *mib,
5130 					int bytes, size_t syncpoff)
5131 {
5132 	int i, c;
5133 	u64 buff[IPSTATS_MIB_MAX];
5134 	int pad = bytes - sizeof(u64) * IPSTATS_MIB_MAX;
5135 
5136 	BUG_ON(pad < 0);
5137 
5138 	memset(buff, 0, sizeof(buff));
5139 	buff[0] = IPSTATS_MIB_MAX;
5140 
5141 	for_each_possible_cpu(c) {
5142 		for (i = 1; i < IPSTATS_MIB_MAX; i++)
5143 			buff[i] += snmp_get_cpu_field64(mib, c, i, syncpoff);
5144 	}
5145 
5146 	memcpy(stats, buff, IPSTATS_MIB_MAX * sizeof(u64));
5147 	memset(&stats[IPSTATS_MIB_MAX], 0, pad);
5148 }
5149 
5150 static void snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int attrtype,
5151 			     int bytes)
5152 {
5153 	switch (attrtype) {
5154 	case IFLA_INET6_STATS:
5155 		__snmp6_fill_stats64(stats, idev->stats.ipv6, bytes,
5156 				     offsetof(struct ipstats_mib, syncp));
5157 		break;
5158 	case IFLA_INET6_ICMP6STATS:
5159 		__snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs, bytes);
5160 		break;
5161 	}
5162 }
5163 
5164 static int inet6_fill_ifla6_attrs(struct sk_buff *skb, struct inet6_dev *idev,
5165 				  u32 ext_filter_mask)
5166 {
5167 	struct nlattr *nla;
5168 	struct ifla_cacheinfo ci;
5169 
5170 	if (nla_put_u32(skb, IFLA_INET6_FLAGS, idev->if_flags))
5171 		goto nla_put_failure;
5172 	ci.max_reasm_len = IPV6_MAXPLEN;
5173 	ci.tstamp = cstamp_delta(idev->tstamp);
5174 	ci.reachable_time = jiffies_to_msecs(idev->nd_parms->reachable_time);
5175 	ci.retrans_time = jiffies_to_msecs(NEIGH_VAR(idev->nd_parms, RETRANS_TIME));
5176 	if (nla_put(skb, IFLA_INET6_CACHEINFO, sizeof(ci), &ci))
5177 		goto nla_put_failure;
5178 	nla = nla_reserve(skb, IFLA_INET6_CONF, DEVCONF_MAX * sizeof(s32));
5179 	if (!nla)
5180 		goto nla_put_failure;
5181 	ipv6_store_devconf(&idev->cnf, nla_data(nla), nla_len(nla));
5182 
5183 	/* XXX - MC not implemented */
5184 
5185 	if (ext_filter_mask & RTEXT_FILTER_SKIP_STATS)
5186 		return 0;
5187 
5188 	nla = nla_reserve(skb, IFLA_INET6_STATS, IPSTATS_MIB_MAX * sizeof(u64));
5189 	if (!nla)
5190 		goto nla_put_failure;
5191 	snmp6_fill_stats(nla_data(nla), idev, IFLA_INET6_STATS, nla_len(nla));
5192 
5193 	nla = nla_reserve(skb, IFLA_INET6_ICMP6STATS, ICMP6_MIB_MAX * sizeof(u64));
5194 	if (!nla)
5195 		goto nla_put_failure;
5196 	snmp6_fill_stats(nla_data(nla), idev, IFLA_INET6_ICMP6STATS, nla_len(nla));
5197 
5198 	nla = nla_reserve(skb, IFLA_INET6_TOKEN, sizeof(struct in6_addr));
5199 	if (!nla)
5200 		goto nla_put_failure;
5201 
5202 	if (nla_put_u8(skb, IFLA_INET6_ADDR_GEN_MODE, idev->cnf.addr_gen_mode))
5203 		goto nla_put_failure;
5204 
5205 	read_lock_bh(&idev->lock);
5206 	memcpy(nla_data(nla), idev->token.s6_addr, nla_len(nla));
5207 	read_unlock_bh(&idev->lock);
5208 
5209 	return 0;
5210 
5211 nla_put_failure:
5212 	return -EMSGSIZE;
5213 }
5214 
5215 static size_t inet6_get_link_af_size(const struct net_device *dev,
5216 				     u32 ext_filter_mask)
5217 {
5218 	if (!__in6_dev_get(dev))
5219 		return 0;
5220 
5221 	return inet6_ifla6_size();
5222 }
5223 
5224 static int inet6_fill_link_af(struct sk_buff *skb, const struct net_device *dev,
5225 			      u32 ext_filter_mask)
5226 {
5227 	struct inet6_dev *idev = __in6_dev_get(dev);
5228 
5229 	if (!idev)
5230 		return -ENODATA;
5231 
5232 	if (inet6_fill_ifla6_attrs(skb, idev, ext_filter_mask) < 0)
5233 		return -EMSGSIZE;
5234 
5235 	return 0;
5236 }
5237 
5238 static int inet6_set_iftoken(struct inet6_dev *idev, struct in6_addr *token)
5239 {
5240 	struct inet6_ifaddr *ifp;
5241 	struct net_device *dev = idev->dev;
5242 	bool clear_token, update_rs = false;
5243 	struct in6_addr ll_addr;
5244 
5245 	ASSERT_RTNL();
5246 
5247 	if (!token)
5248 		return -EINVAL;
5249 	if (dev->flags & (IFF_LOOPBACK | IFF_NOARP))
5250 		return -EINVAL;
5251 	if (!ipv6_accept_ra(idev))
5252 		return -EINVAL;
5253 	if (idev->cnf.rtr_solicits == 0)
5254 		return -EINVAL;
5255 
5256 	write_lock_bh(&idev->lock);
5257 
5258 	BUILD_BUG_ON(sizeof(token->s6_addr) != 16);
5259 	memcpy(idev->token.s6_addr + 8, token->s6_addr + 8, 8);
5260 
5261 	write_unlock_bh(&idev->lock);
5262 
5263 	clear_token = ipv6_addr_any(token);
5264 	if (clear_token)
5265 		goto update_lft;
5266 
5267 	if (!idev->dead && (idev->if_flags & IF_READY) &&
5268 	    !ipv6_get_lladdr(dev, &ll_addr, IFA_F_TENTATIVE |
5269 			     IFA_F_OPTIMISTIC)) {
5270 		/* If we're not ready, then normal ifup will take care
5271 		 * of this. Otherwise, we need to request our rs here.
5272 		 */
5273 		ndisc_send_rs(dev, &ll_addr, &in6addr_linklocal_allrouters);
5274 		update_rs = true;
5275 	}
5276 
5277 update_lft:
5278 	write_lock_bh(&idev->lock);
5279 
5280 	if (update_rs) {
5281 		idev->if_flags |= IF_RS_SENT;
5282 		idev->rs_interval = rfc3315_s14_backoff_init(
5283 			idev->cnf.rtr_solicit_interval);
5284 		idev->rs_probes = 1;
5285 		addrconf_mod_rs_timer(idev, idev->rs_interval);
5286 	}
5287 
5288 	/* Well, that's kinda nasty ... */
5289 	list_for_each_entry(ifp, &idev->addr_list, if_list) {
5290 		spin_lock(&ifp->lock);
5291 		if (ifp->tokenized) {
5292 			ifp->valid_lft = 0;
5293 			ifp->prefered_lft = 0;
5294 		}
5295 		spin_unlock(&ifp->lock);
5296 	}
5297 
5298 	write_unlock_bh(&idev->lock);
5299 	inet6_ifinfo_notify(RTM_NEWLINK, idev);
5300 	addrconf_verify_rtnl();
5301 	return 0;
5302 }
5303 
5304 static const struct nla_policy inet6_af_policy[IFLA_INET6_MAX + 1] = {
5305 	[IFLA_INET6_ADDR_GEN_MODE]	= { .type = NLA_U8 },
5306 	[IFLA_INET6_TOKEN]		= { .len = sizeof(struct in6_addr) },
5307 };
5308 
5309 static int inet6_validate_link_af(const struct net_device *dev,
5310 				  const struct nlattr *nla)
5311 {
5312 	struct nlattr *tb[IFLA_INET6_MAX + 1];
5313 
5314 	if (dev && !__in6_dev_get(dev))
5315 		return -EAFNOSUPPORT;
5316 
5317 	return nla_parse_nested(tb, IFLA_INET6_MAX, nla, inet6_af_policy,
5318 				NULL);
5319 }
5320 
5321 static int check_addr_gen_mode(int mode)
5322 {
5323 	if (mode != IN6_ADDR_GEN_MODE_EUI64 &&
5324 	    mode != IN6_ADDR_GEN_MODE_NONE &&
5325 	    mode != IN6_ADDR_GEN_MODE_STABLE_PRIVACY &&
5326 	    mode != IN6_ADDR_GEN_MODE_RANDOM)
5327 		return -EINVAL;
5328 	return 1;
5329 }
5330 
5331 static int check_stable_privacy(struct inet6_dev *idev, struct net *net,
5332 				int mode)
5333 {
5334 	if (mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY &&
5335 	    !idev->cnf.stable_secret.initialized &&
5336 	    !net->ipv6.devconf_dflt->stable_secret.initialized)
5337 		return -EINVAL;
5338 	return 1;
5339 }
5340 
5341 static int inet6_set_link_af(struct net_device *dev, const struct nlattr *nla)
5342 {
5343 	int err = -EINVAL;
5344 	struct inet6_dev *idev = __in6_dev_get(dev);
5345 	struct nlattr *tb[IFLA_INET6_MAX + 1];
5346 
5347 	if (!idev)
5348 		return -EAFNOSUPPORT;
5349 
5350 	if (nla_parse_nested(tb, IFLA_INET6_MAX, nla, NULL, NULL) < 0)
5351 		BUG();
5352 
5353 	if (tb[IFLA_INET6_TOKEN]) {
5354 		err = inet6_set_iftoken(idev, nla_data(tb[IFLA_INET6_TOKEN]));
5355 		if (err)
5356 			return err;
5357 	}
5358 
5359 	if (tb[IFLA_INET6_ADDR_GEN_MODE]) {
5360 		u8 mode = nla_get_u8(tb[IFLA_INET6_ADDR_GEN_MODE]);
5361 
5362 		if (check_addr_gen_mode(mode) < 0 ||
5363 		    check_stable_privacy(idev, dev_net(dev), mode) < 0)
5364 			return -EINVAL;
5365 
5366 		idev->cnf.addr_gen_mode = mode;
5367 		err = 0;
5368 	}
5369 
5370 	return err;
5371 }
5372 
5373 static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev,
5374 			     u32 portid, u32 seq, int event, unsigned int flags)
5375 {
5376 	struct net_device *dev = idev->dev;
5377 	struct ifinfomsg *hdr;
5378 	struct nlmsghdr *nlh;
5379 	void *protoinfo;
5380 
5381 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*hdr), flags);
5382 	if (!nlh)
5383 		return -EMSGSIZE;
5384 
5385 	hdr = nlmsg_data(nlh);
5386 	hdr->ifi_family = AF_INET6;
5387 	hdr->__ifi_pad = 0;
5388 	hdr->ifi_type = dev->type;
5389 	hdr->ifi_index = dev->ifindex;
5390 	hdr->ifi_flags = dev_get_flags(dev);
5391 	hdr->ifi_change = 0;
5392 
5393 	if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
5394 	    (dev->addr_len &&
5395 	     nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) ||
5396 	    nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
5397 	    (dev->ifindex != dev_get_iflink(dev) &&
5398 	     nla_put_u32(skb, IFLA_LINK, dev_get_iflink(dev))) ||
5399 	    nla_put_u8(skb, IFLA_OPERSTATE,
5400 		       netif_running(dev) ? dev->operstate : IF_OPER_DOWN))
5401 		goto nla_put_failure;
5402 	protoinfo = nla_nest_start(skb, IFLA_PROTINFO);
5403 	if (!protoinfo)
5404 		goto nla_put_failure;
5405 
5406 	if (inet6_fill_ifla6_attrs(skb, idev, 0) < 0)
5407 		goto nla_put_failure;
5408 
5409 	nla_nest_end(skb, protoinfo);
5410 	nlmsg_end(skb, nlh);
5411 	return 0;
5412 
5413 nla_put_failure:
5414 	nlmsg_cancel(skb, nlh);
5415 	return -EMSGSIZE;
5416 }
5417 
5418 static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
5419 {
5420 	struct net *net = sock_net(skb->sk);
5421 	int h, s_h;
5422 	int idx = 0, s_idx;
5423 	struct net_device *dev;
5424 	struct inet6_dev *idev;
5425 	struct hlist_head *head;
5426 
5427 	s_h = cb->args[0];
5428 	s_idx = cb->args[1];
5429 
5430 	rcu_read_lock();
5431 	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
5432 		idx = 0;
5433 		head = &net->dev_index_head[h];
5434 		hlist_for_each_entry_rcu(dev, head, index_hlist) {
5435 			if (idx < s_idx)
5436 				goto cont;
5437 			idev = __in6_dev_get(dev);
5438 			if (!idev)
5439 				goto cont;
5440 			if (inet6_fill_ifinfo(skb, idev,
5441 					      NETLINK_CB(cb->skb).portid,
5442 					      cb->nlh->nlmsg_seq,
5443 					      RTM_NEWLINK, NLM_F_MULTI) < 0)
5444 				goto out;
5445 cont:
5446 			idx++;
5447 		}
5448 	}
5449 out:
5450 	rcu_read_unlock();
5451 	cb->args[1] = idx;
5452 	cb->args[0] = h;
5453 
5454 	return skb->len;
5455 }
5456 
5457 void inet6_ifinfo_notify(int event, struct inet6_dev *idev)
5458 {
5459 	struct sk_buff *skb;
5460 	struct net *net = dev_net(idev->dev);
5461 	int err = -ENOBUFS;
5462 
5463 	skb = nlmsg_new(inet6_if_nlmsg_size(), GFP_ATOMIC);
5464 	if (!skb)
5465 		goto errout;
5466 
5467 	err = inet6_fill_ifinfo(skb, idev, 0, 0, event, 0);
5468 	if (err < 0) {
5469 		/* -EMSGSIZE implies BUG in inet6_if_nlmsg_size() */
5470 		WARN_ON(err == -EMSGSIZE);
5471 		kfree_skb(skb);
5472 		goto errout;
5473 	}
5474 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_IFINFO, NULL, GFP_ATOMIC);
5475 	return;
5476 errout:
5477 	if (err < 0)
5478 		rtnl_set_sk_err(net, RTNLGRP_IPV6_IFINFO, err);
5479 }
5480 
5481 static inline size_t inet6_prefix_nlmsg_size(void)
5482 {
5483 	return NLMSG_ALIGN(sizeof(struct prefixmsg))
5484 	       + nla_total_size(sizeof(struct in6_addr))
5485 	       + nla_total_size(sizeof(struct prefix_cacheinfo));
5486 }
5487 
5488 static int inet6_fill_prefix(struct sk_buff *skb, struct inet6_dev *idev,
5489 			     struct prefix_info *pinfo, u32 portid, u32 seq,
5490 			     int event, unsigned int flags)
5491 {
5492 	struct prefixmsg *pmsg;
5493 	struct nlmsghdr *nlh;
5494 	struct prefix_cacheinfo	ci;
5495 
5496 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*pmsg), flags);
5497 	if (!nlh)
5498 		return -EMSGSIZE;
5499 
5500 	pmsg = nlmsg_data(nlh);
5501 	pmsg->prefix_family = AF_INET6;
5502 	pmsg->prefix_pad1 = 0;
5503 	pmsg->prefix_pad2 = 0;
5504 	pmsg->prefix_ifindex = idev->dev->ifindex;
5505 	pmsg->prefix_len = pinfo->prefix_len;
5506 	pmsg->prefix_type = pinfo->type;
5507 	pmsg->prefix_pad3 = 0;
5508 	pmsg->prefix_flags = 0;
5509 	if (pinfo->onlink)
5510 		pmsg->prefix_flags |= IF_PREFIX_ONLINK;
5511 	if (pinfo->autoconf)
5512 		pmsg->prefix_flags |= IF_PREFIX_AUTOCONF;
5513 
5514 	if (nla_put(skb, PREFIX_ADDRESS, sizeof(pinfo->prefix), &pinfo->prefix))
5515 		goto nla_put_failure;
5516 	ci.preferred_time = ntohl(pinfo->prefered);
5517 	ci.valid_time = ntohl(pinfo->valid);
5518 	if (nla_put(skb, PREFIX_CACHEINFO, sizeof(ci), &ci))
5519 		goto nla_put_failure;
5520 	nlmsg_end(skb, nlh);
5521 	return 0;
5522 
5523 nla_put_failure:
5524 	nlmsg_cancel(skb, nlh);
5525 	return -EMSGSIZE;
5526 }
5527 
5528 static void inet6_prefix_notify(int event, struct inet6_dev *idev,
5529 			 struct prefix_info *pinfo)
5530 {
5531 	struct sk_buff *skb;
5532 	struct net *net = dev_net(idev->dev);
5533 	int err = -ENOBUFS;
5534 
5535 	skb = nlmsg_new(inet6_prefix_nlmsg_size(), GFP_ATOMIC);
5536 	if (!skb)
5537 		goto errout;
5538 
5539 	err = inet6_fill_prefix(skb, idev, pinfo, 0, 0, event, 0);
5540 	if (err < 0) {
5541 		/* -EMSGSIZE implies BUG in inet6_prefix_nlmsg_size() */
5542 		WARN_ON(err == -EMSGSIZE);
5543 		kfree_skb(skb);
5544 		goto errout;
5545 	}
5546 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_PREFIX, NULL, GFP_ATOMIC);
5547 	return;
5548 errout:
5549 	if (err < 0)
5550 		rtnl_set_sk_err(net, RTNLGRP_IPV6_PREFIX, err);
5551 }
5552 
5553 static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
5554 {
5555 	struct net *net = dev_net(ifp->idev->dev);
5556 
5557 	if (event)
5558 		ASSERT_RTNL();
5559 
5560 	inet6_ifa_notify(event ? : RTM_NEWADDR, ifp);
5561 
5562 	switch (event) {
5563 	case RTM_NEWADDR:
5564 		/*
5565 		 * If the address was optimistic
5566 		 * we inserted the route at the start of
5567 		 * our DAD process, so we don't need
5568 		 * to do it again
5569 		 */
5570 		if (!rcu_access_pointer(ifp->rt->rt6i_node))
5571 			ip6_ins_rt(ifp->rt);
5572 		if (ifp->idev->cnf.forwarding)
5573 			addrconf_join_anycast(ifp);
5574 		if (!ipv6_addr_any(&ifp->peer_addr))
5575 			addrconf_prefix_route(&ifp->peer_addr, 128,
5576 					      ifp->idev->dev, 0, 0);
5577 		break;
5578 	case RTM_DELADDR:
5579 		if (ifp->idev->cnf.forwarding)
5580 			addrconf_leave_anycast(ifp);
5581 		addrconf_leave_solict(ifp->idev, &ifp->addr);
5582 		if (!ipv6_addr_any(&ifp->peer_addr)) {
5583 			struct rt6_info *rt;
5584 
5585 			rt = addrconf_get_prefix_route(&ifp->peer_addr, 128,
5586 						       ifp->idev->dev, 0, 0);
5587 			if (rt)
5588 				ip6_del_rt(rt);
5589 		}
5590 		if (ifp->rt) {
5591 			if (dst_hold_safe(&ifp->rt->dst))
5592 				ip6_del_rt(ifp->rt);
5593 		}
5594 		rt_genid_bump_ipv6(net);
5595 		break;
5596 	}
5597 	atomic_inc(&net->ipv6.dev_addr_genid);
5598 }
5599 
5600 static void ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
5601 {
5602 	rcu_read_lock_bh();
5603 	if (likely(ifp->idev->dead == 0))
5604 		__ipv6_ifa_notify(event, ifp);
5605 	rcu_read_unlock_bh();
5606 }
5607 
5608 #ifdef CONFIG_SYSCTL
5609 
5610 static
5611 int addrconf_sysctl_forward(struct ctl_table *ctl, int write,
5612 			   void __user *buffer, size_t *lenp, loff_t *ppos)
5613 {
5614 	int *valp = ctl->data;
5615 	int val = *valp;
5616 	loff_t pos = *ppos;
5617 	struct ctl_table lctl;
5618 	int ret;
5619 
5620 	/*
5621 	 * ctl->data points to idev->cnf.forwarding, we should
5622 	 * not modify it until we get the rtnl lock.
5623 	 */
5624 	lctl = *ctl;
5625 	lctl.data = &val;
5626 
5627 	ret = proc_dointvec(&lctl, write, buffer, lenp, ppos);
5628 
5629 	if (write)
5630 		ret = addrconf_fixup_forwarding(ctl, valp, val);
5631 	if (ret)
5632 		*ppos = pos;
5633 	return ret;
5634 }
5635 
5636 static
5637 int addrconf_sysctl_mtu(struct ctl_table *ctl, int write,
5638 			void __user *buffer, size_t *lenp, loff_t *ppos)
5639 {
5640 	struct inet6_dev *idev = ctl->extra1;
5641 	int min_mtu = IPV6_MIN_MTU;
5642 	struct ctl_table lctl;
5643 
5644 	lctl = *ctl;
5645 	lctl.extra1 = &min_mtu;
5646 	lctl.extra2 = idev ? &idev->dev->mtu : NULL;
5647 
5648 	return proc_dointvec_minmax(&lctl, write, buffer, lenp, ppos);
5649 }
5650 
5651 static void dev_disable_change(struct inet6_dev *idev)
5652 {
5653 	struct netdev_notifier_info info;
5654 
5655 	if (!idev || !idev->dev)
5656 		return;
5657 
5658 	netdev_notifier_info_init(&info, idev->dev);
5659 	if (idev->cnf.disable_ipv6)
5660 		addrconf_notify(NULL, NETDEV_DOWN, &info);
5661 	else
5662 		addrconf_notify(NULL, NETDEV_UP, &info);
5663 }
5664 
5665 static void addrconf_disable_change(struct net *net, __s32 newf)
5666 {
5667 	struct net_device *dev;
5668 	struct inet6_dev *idev;
5669 
5670 	for_each_netdev(net, dev) {
5671 		idev = __in6_dev_get(dev);
5672 		if (idev) {
5673 			int changed = (!idev->cnf.disable_ipv6) ^ (!newf);
5674 			idev->cnf.disable_ipv6 = newf;
5675 			if (changed)
5676 				dev_disable_change(idev);
5677 		}
5678 	}
5679 }
5680 
5681 static int addrconf_disable_ipv6(struct ctl_table *table, int *p, int newf)
5682 {
5683 	struct net *net;
5684 	int old;
5685 
5686 	if (!rtnl_trylock())
5687 		return restart_syscall();
5688 
5689 	net = (struct net *)table->extra2;
5690 	old = *p;
5691 	*p = newf;
5692 
5693 	if (p == &net->ipv6.devconf_dflt->disable_ipv6) {
5694 		rtnl_unlock();
5695 		return 0;
5696 	}
5697 
5698 	if (p == &net->ipv6.devconf_all->disable_ipv6) {
5699 		net->ipv6.devconf_dflt->disable_ipv6 = newf;
5700 		addrconf_disable_change(net, newf);
5701 	} else if ((!newf) ^ (!old))
5702 		dev_disable_change((struct inet6_dev *)table->extra1);
5703 
5704 	rtnl_unlock();
5705 	return 0;
5706 }
5707 
5708 static
5709 int addrconf_sysctl_disable(struct ctl_table *ctl, int write,
5710 			    void __user *buffer, size_t *lenp, loff_t *ppos)
5711 {
5712 	int *valp = ctl->data;
5713 	int val = *valp;
5714 	loff_t pos = *ppos;
5715 	struct ctl_table lctl;
5716 	int ret;
5717 
5718 	/*
5719 	 * ctl->data points to idev->cnf.disable_ipv6, we should
5720 	 * not modify it until we get the rtnl lock.
5721 	 */
5722 	lctl = *ctl;
5723 	lctl.data = &val;
5724 
5725 	ret = proc_dointvec(&lctl, write, buffer, lenp, ppos);
5726 
5727 	if (write)
5728 		ret = addrconf_disable_ipv6(ctl, valp, val);
5729 	if (ret)
5730 		*ppos = pos;
5731 	return ret;
5732 }
5733 
5734 static
5735 int addrconf_sysctl_proxy_ndp(struct ctl_table *ctl, int write,
5736 			      void __user *buffer, size_t *lenp, loff_t *ppos)
5737 {
5738 	int *valp = ctl->data;
5739 	int ret;
5740 	int old, new;
5741 
5742 	old = *valp;
5743 	ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
5744 	new = *valp;
5745 
5746 	if (write && old != new) {
5747 		struct net *net = ctl->extra2;
5748 
5749 		if (!rtnl_trylock())
5750 			return restart_syscall();
5751 
5752 		if (valp == &net->ipv6.devconf_dflt->proxy_ndp)
5753 			inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
5754 						     NETCONFA_PROXY_NEIGH,
5755 						     NETCONFA_IFINDEX_DEFAULT,
5756 						     net->ipv6.devconf_dflt);
5757 		else if (valp == &net->ipv6.devconf_all->proxy_ndp)
5758 			inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
5759 						     NETCONFA_PROXY_NEIGH,
5760 						     NETCONFA_IFINDEX_ALL,
5761 						     net->ipv6.devconf_all);
5762 		else {
5763 			struct inet6_dev *idev = ctl->extra1;
5764 
5765 			inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
5766 						     NETCONFA_PROXY_NEIGH,
5767 						     idev->dev->ifindex,
5768 						     &idev->cnf);
5769 		}
5770 		rtnl_unlock();
5771 	}
5772 
5773 	return ret;
5774 }
5775 
5776 static int addrconf_sysctl_addr_gen_mode(struct ctl_table *ctl, int write,
5777 					 void __user *buffer, size_t *lenp,
5778 					 loff_t *ppos)
5779 {
5780 	int ret = 0;
5781 	int new_val;
5782 	struct inet6_dev *idev = (struct inet6_dev *)ctl->extra1;
5783 	struct net *net = (struct net *)ctl->extra2;
5784 
5785 	if (!rtnl_trylock())
5786 		return restart_syscall();
5787 
5788 	ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
5789 
5790 	if (write) {
5791 		new_val = *((int *)ctl->data);
5792 
5793 		if (check_addr_gen_mode(new_val) < 0) {
5794 			ret = -EINVAL;
5795 			goto out;
5796 		}
5797 
5798 		/* request for default */
5799 		if (&net->ipv6.devconf_dflt->addr_gen_mode == ctl->data) {
5800 			ipv6_devconf_dflt.addr_gen_mode = new_val;
5801 
5802 		/* request for individual net device */
5803 		} else {
5804 			if (!idev)
5805 				goto out;
5806 
5807 			if (check_stable_privacy(idev, net, new_val) < 0) {
5808 				ret = -EINVAL;
5809 				goto out;
5810 			}
5811 
5812 			if (idev->cnf.addr_gen_mode != new_val) {
5813 				idev->cnf.addr_gen_mode = new_val;
5814 				addrconf_dev_config(idev->dev);
5815 			}
5816 		}
5817 	}
5818 
5819 out:
5820 	rtnl_unlock();
5821 
5822 	return ret;
5823 }
5824 
5825 static int addrconf_sysctl_stable_secret(struct ctl_table *ctl, int write,
5826 					 void __user *buffer, size_t *lenp,
5827 					 loff_t *ppos)
5828 {
5829 	int err;
5830 	struct in6_addr addr;
5831 	char str[IPV6_MAX_STRLEN];
5832 	struct ctl_table lctl = *ctl;
5833 	struct net *net = ctl->extra2;
5834 	struct ipv6_stable_secret *secret = ctl->data;
5835 
5836 	if (&net->ipv6.devconf_all->stable_secret == ctl->data)
5837 		return -EIO;
5838 
5839 	lctl.maxlen = IPV6_MAX_STRLEN;
5840 	lctl.data = str;
5841 
5842 	if (!rtnl_trylock())
5843 		return restart_syscall();
5844 
5845 	if (!write && !secret->initialized) {
5846 		err = -EIO;
5847 		goto out;
5848 	}
5849 
5850 	err = snprintf(str, sizeof(str), "%pI6", &secret->secret);
5851 	if (err >= sizeof(str)) {
5852 		err = -EIO;
5853 		goto out;
5854 	}
5855 
5856 	err = proc_dostring(&lctl, write, buffer, lenp, ppos);
5857 	if (err || !write)
5858 		goto out;
5859 
5860 	if (in6_pton(str, -1, addr.in6_u.u6_addr8, -1, NULL) != 1) {
5861 		err = -EIO;
5862 		goto out;
5863 	}
5864 
5865 	secret->initialized = true;
5866 	secret->secret = addr;
5867 
5868 	if (&net->ipv6.devconf_dflt->stable_secret == ctl->data) {
5869 		struct net_device *dev;
5870 
5871 		for_each_netdev(net, dev) {
5872 			struct inet6_dev *idev = __in6_dev_get(dev);
5873 
5874 			if (idev) {
5875 				idev->cnf.addr_gen_mode =
5876 					IN6_ADDR_GEN_MODE_STABLE_PRIVACY;
5877 			}
5878 		}
5879 	} else {
5880 		struct inet6_dev *idev = ctl->extra1;
5881 
5882 		idev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY;
5883 	}
5884 
5885 out:
5886 	rtnl_unlock();
5887 
5888 	return err;
5889 }
5890 
5891 static
5892 int addrconf_sysctl_ignore_routes_with_linkdown(struct ctl_table *ctl,
5893 						int write,
5894 						void __user *buffer,
5895 						size_t *lenp,
5896 						loff_t *ppos)
5897 {
5898 	int *valp = ctl->data;
5899 	int val = *valp;
5900 	loff_t pos = *ppos;
5901 	struct ctl_table lctl;
5902 	int ret;
5903 
5904 	/* ctl->data points to idev->cnf.ignore_routes_when_linkdown
5905 	 * we should not modify it until we get the rtnl lock.
5906 	 */
5907 	lctl = *ctl;
5908 	lctl.data = &val;
5909 
5910 	ret = proc_dointvec(&lctl, write, buffer, lenp, ppos);
5911 
5912 	if (write)
5913 		ret = addrconf_fixup_linkdown(ctl, valp, val);
5914 	if (ret)
5915 		*ppos = pos;
5916 	return ret;
5917 }
5918 
5919 static
5920 void addrconf_set_nopolicy(struct rt6_info *rt, int action)
5921 {
5922 	if (rt) {
5923 		if (action)
5924 			rt->dst.flags |= DST_NOPOLICY;
5925 		else
5926 			rt->dst.flags &= ~DST_NOPOLICY;
5927 	}
5928 }
5929 
5930 static
5931 void addrconf_disable_policy_idev(struct inet6_dev *idev, int val)
5932 {
5933 	struct inet6_ifaddr *ifa;
5934 
5935 	read_lock_bh(&idev->lock);
5936 	list_for_each_entry(ifa, &idev->addr_list, if_list) {
5937 		spin_lock(&ifa->lock);
5938 		if (ifa->rt) {
5939 			struct rt6_info *rt = ifa->rt;
5940 			int cpu;
5941 
5942 			rcu_read_lock();
5943 			addrconf_set_nopolicy(ifa->rt, val);
5944 			if (rt->rt6i_pcpu) {
5945 				for_each_possible_cpu(cpu) {
5946 					struct rt6_info **rtp;
5947 
5948 					rtp = per_cpu_ptr(rt->rt6i_pcpu, cpu);
5949 					addrconf_set_nopolicy(*rtp, val);
5950 				}
5951 			}
5952 			rcu_read_unlock();
5953 		}
5954 		spin_unlock(&ifa->lock);
5955 	}
5956 	read_unlock_bh(&idev->lock);
5957 }
5958 
5959 static
5960 int addrconf_disable_policy(struct ctl_table *ctl, int *valp, int val)
5961 {
5962 	struct inet6_dev *idev;
5963 	struct net *net;
5964 
5965 	if (!rtnl_trylock())
5966 		return restart_syscall();
5967 
5968 	*valp = val;
5969 
5970 	net = (struct net *)ctl->extra2;
5971 	if (valp == &net->ipv6.devconf_dflt->disable_policy) {
5972 		rtnl_unlock();
5973 		return 0;
5974 	}
5975 
5976 	if (valp == &net->ipv6.devconf_all->disable_policy)  {
5977 		struct net_device *dev;
5978 
5979 		for_each_netdev(net, dev) {
5980 			idev = __in6_dev_get(dev);
5981 			if (idev)
5982 				addrconf_disable_policy_idev(idev, val);
5983 		}
5984 	} else {
5985 		idev = (struct inet6_dev *)ctl->extra1;
5986 		addrconf_disable_policy_idev(idev, val);
5987 	}
5988 
5989 	rtnl_unlock();
5990 	return 0;
5991 }
5992 
5993 static
5994 int addrconf_sysctl_disable_policy(struct ctl_table *ctl, int write,
5995 				   void __user *buffer, size_t *lenp,
5996 				   loff_t *ppos)
5997 {
5998 	int *valp = ctl->data;
5999 	int val = *valp;
6000 	loff_t pos = *ppos;
6001 	struct ctl_table lctl;
6002 	int ret;
6003 
6004 	lctl = *ctl;
6005 	lctl.data = &val;
6006 	ret = proc_dointvec(&lctl, write, buffer, lenp, ppos);
6007 
6008 	if (write && (*valp != val))
6009 		ret = addrconf_disable_policy(ctl, valp, val);
6010 
6011 	if (ret)
6012 		*ppos = pos;
6013 
6014 	return ret;
6015 }
6016 
6017 static int minus_one = -1;
6018 static const int zero = 0;
6019 static const int one = 1;
6020 static const int two_five_five = 255;
6021 
6022 static const struct ctl_table addrconf_sysctl[] = {
6023 	{
6024 		.procname	= "forwarding",
6025 		.data		= &ipv6_devconf.forwarding,
6026 		.maxlen		= sizeof(int),
6027 		.mode		= 0644,
6028 		.proc_handler	= addrconf_sysctl_forward,
6029 	},
6030 	{
6031 		.procname	= "hop_limit",
6032 		.data		= &ipv6_devconf.hop_limit,
6033 		.maxlen		= sizeof(int),
6034 		.mode		= 0644,
6035 		.proc_handler	= proc_dointvec_minmax,
6036 		.extra1		= (void *)&one,
6037 		.extra2		= (void *)&two_five_five,
6038 	},
6039 	{
6040 		.procname	= "mtu",
6041 		.data		= &ipv6_devconf.mtu6,
6042 		.maxlen		= sizeof(int),
6043 		.mode		= 0644,
6044 		.proc_handler	= addrconf_sysctl_mtu,
6045 	},
6046 	{
6047 		.procname	= "accept_ra",
6048 		.data		= &ipv6_devconf.accept_ra,
6049 		.maxlen		= sizeof(int),
6050 		.mode		= 0644,
6051 		.proc_handler	= proc_dointvec,
6052 	},
6053 	{
6054 		.procname	= "accept_redirects",
6055 		.data		= &ipv6_devconf.accept_redirects,
6056 		.maxlen		= sizeof(int),
6057 		.mode		= 0644,
6058 		.proc_handler	= proc_dointvec,
6059 	},
6060 	{
6061 		.procname	= "autoconf",
6062 		.data		= &ipv6_devconf.autoconf,
6063 		.maxlen		= sizeof(int),
6064 		.mode		= 0644,
6065 		.proc_handler	= proc_dointvec,
6066 	},
6067 	{
6068 		.procname	= "dad_transmits",
6069 		.data		= &ipv6_devconf.dad_transmits,
6070 		.maxlen		= sizeof(int),
6071 		.mode		= 0644,
6072 		.proc_handler	= proc_dointvec,
6073 	},
6074 	{
6075 		.procname	= "router_solicitations",
6076 		.data		= &ipv6_devconf.rtr_solicits,
6077 		.maxlen		= sizeof(int),
6078 		.mode		= 0644,
6079 		.proc_handler	= proc_dointvec_minmax,
6080 		.extra1		= &minus_one,
6081 	},
6082 	{
6083 		.procname	= "router_solicitation_interval",
6084 		.data		= &ipv6_devconf.rtr_solicit_interval,
6085 		.maxlen		= sizeof(int),
6086 		.mode		= 0644,
6087 		.proc_handler	= proc_dointvec_jiffies,
6088 	},
6089 	{
6090 		.procname	= "router_solicitation_max_interval",
6091 		.data		= &ipv6_devconf.rtr_solicit_max_interval,
6092 		.maxlen		= sizeof(int),
6093 		.mode		= 0644,
6094 		.proc_handler	= proc_dointvec_jiffies,
6095 	},
6096 	{
6097 		.procname	= "router_solicitation_delay",
6098 		.data		= &ipv6_devconf.rtr_solicit_delay,
6099 		.maxlen		= sizeof(int),
6100 		.mode		= 0644,
6101 		.proc_handler	= proc_dointvec_jiffies,
6102 	},
6103 	{
6104 		.procname	= "force_mld_version",
6105 		.data		= &ipv6_devconf.force_mld_version,
6106 		.maxlen		= sizeof(int),
6107 		.mode		= 0644,
6108 		.proc_handler	= proc_dointvec,
6109 	},
6110 	{
6111 		.procname	= "mldv1_unsolicited_report_interval",
6112 		.data		=
6113 			&ipv6_devconf.mldv1_unsolicited_report_interval,
6114 		.maxlen		= sizeof(int),
6115 		.mode		= 0644,
6116 		.proc_handler	= proc_dointvec_ms_jiffies,
6117 	},
6118 	{
6119 		.procname	= "mldv2_unsolicited_report_interval",
6120 		.data		=
6121 			&ipv6_devconf.mldv2_unsolicited_report_interval,
6122 		.maxlen		= sizeof(int),
6123 		.mode		= 0644,
6124 		.proc_handler	= proc_dointvec_ms_jiffies,
6125 	},
6126 	{
6127 		.procname	= "use_tempaddr",
6128 		.data		= &ipv6_devconf.use_tempaddr,
6129 		.maxlen		= sizeof(int),
6130 		.mode		= 0644,
6131 		.proc_handler	= proc_dointvec,
6132 	},
6133 	{
6134 		.procname	= "temp_valid_lft",
6135 		.data		= &ipv6_devconf.temp_valid_lft,
6136 		.maxlen		= sizeof(int),
6137 		.mode		= 0644,
6138 		.proc_handler	= proc_dointvec,
6139 	},
6140 	{
6141 		.procname	= "temp_prefered_lft",
6142 		.data		= &ipv6_devconf.temp_prefered_lft,
6143 		.maxlen		= sizeof(int),
6144 		.mode		= 0644,
6145 		.proc_handler	= proc_dointvec,
6146 	},
6147 	{
6148 		.procname	= "regen_max_retry",
6149 		.data		= &ipv6_devconf.regen_max_retry,
6150 		.maxlen		= sizeof(int),
6151 		.mode		= 0644,
6152 		.proc_handler	= proc_dointvec,
6153 	},
6154 	{
6155 		.procname	= "max_desync_factor",
6156 		.data		= &ipv6_devconf.max_desync_factor,
6157 		.maxlen		= sizeof(int),
6158 		.mode		= 0644,
6159 		.proc_handler	= proc_dointvec,
6160 	},
6161 	{
6162 		.procname	= "max_addresses",
6163 		.data		= &ipv6_devconf.max_addresses,
6164 		.maxlen		= sizeof(int),
6165 		.mode		= 0644,
6166 		.proc_handler	= proc_dointvec,
6167 	},
6168 	{
6169 		.procname	= "accept_ra_defrtr",
6170 		.data		= &ipv6_devconf.accept_ra_defrtr,
6171 		.maxlen		= sizeof(int),
6172 		.mode		= 0644,
6173 		.proc_handler	= proc_dointvec,
6174 	},
6175 	{
6176 		.procname	= "accept_ra_min_hop_limit",
6177 		.data		= &ipv6_devconf.accept_ra_min_hop_limit,
6178 		.maxlen		= sizeof(int),
6179 		.mode		= 0644,
6180 		.proc_handler	= proc_dointvec,
6181 	},
6182 	{
6183 		.procname	= "accept_ra_pinfo",
6184 		.data		= &ipv6_devconf.accept_ra_pinfo,
6185 		.maxlen		= sizeof(int),
6186 		.mode		= 0644,
6187 		.proc_handler	= proc_dointvec,
6188 	},
6189 #ifdef CONFIG_IPV6_ROUTER_PREF
6190 	{
6191 		.procname	= "accept_ra_rtr_pref",
6192 		.data		= &ipv6_devconf.accept_ra_rtr_pref,
6193 		.maxlen		= sizeof(int),
6194 		.mode		= 0644,
6195 		.proc_handler	= proc_dointvec,
6196 	},
6197 	{
6198 		.procname	= "router_probe_interval",
6199 		.data		= &ipv6_devconf.rtr_probe_interval,
6200 		.maxlen		= sizeof(int),
6201 		.mode		= 0644,
6202 		.proc_handler	= proc_dointvec_jiffies,
6203 	},
6204 #ifdef CONFIG_IPV6_ROUTE_INFO
6205 	{
6206 		.procname	= "accept_ra_rt_info_min_plen",
6207 		.data		= &ipv6_devconf.accept_ra_rt_info_min_plen,
6208 		.maxlen		= sizeof(int),
6209 		.mode		= 0644,
6210 		.proc_handler	= proc_dointvec,
6211 	},
6212 	{
6213 		.procname	= "accept_ra_rt_info_max_plen",
6214 		.data		= &ipv6_devconf.accept_ra_rt_info_max_plen,
6215 		.maxlen		= sizeof(int),
6216 		.mode		= 0644,
6217 		.proc_handler	= proc_dointvec,
6218 	},
6219 #endif
6220 #endif
6221 	{
6222 		.procname	= "proxy_ndp",
6223 		.data		= &ipv6_devconf.proxy_ndp,
6224 		.maxlen		= sizeof(int),
6225 		.mode		= 0644,
6226 		.proc_handler	= addrconf_sysctl_proxy_ndp,
6227 	},
6228 	{
6229 		.procname	= "accept_source_route",
6230 		.data		= &ipv6_devconf.accept_source_route,
6231 		.maxlen		= sizeof(int),
6232 		.mode		= 0644,
6233 		.proc_handler	= proc_dointvec,
6234 	},
6235 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
6236 	{
6237 		.procname	= "optimistic_dad",
6238 		.data		= &ipv6_devconf.optimistic_dad,
6239 		.maxlen		= sizeof(int),
6240 		.mode		= 0644,
6241 		.proc_handler   = proc_dointvec,
6242 	},
6243 	{
6244 		.procname	= "use_optimistic",
6245 		.data		= &ipv6_devconf.use_optimistic,
6246 		.maxlen		= sizeof(int),
6247 		.mode		= 0644,
6248 		.proc_handler	= proc_dointvec,
6249 	},
6250 #endif
6251 #ifdef CONFIG_IPV6_MROUTE
6252 	{
6253 		.procname	= "mc_forwarding",
6254 		.data		= &ipv6_devconf.mc_forwarding,
6255 		.maxlen		= sizeof(int),
6256 		.mode		= 0444,
6257 		.proc_handler	= proc_dointvec,
6258 	},
6259 #endif
6260 	{
6261 		.procname	= "disable_ipv6",
6262 		.data		= &ipv6_devconf.disable_ipv6,
6263 		.maxlen		= sizeof(int),
6264 		.mode		= 0644,
6265 		.proc_handler	= addrconf_sysctl_disable,
6266 	},
6267 	{
6268 		.procname	= "accept_dad",
6269 		.data		= &ipv6_devconf.accept_dad,
6270 		.maxlen		= sizeof(int),
6271 		.mode		= 0644,
6272 		.proc_handler	= proc_dointvec,
6273 	},
6274 	{
6275 		.procname	= "force_tllao",
6276 		.data		= &ipv6_devconf.force_tllao,
6277 		.maxlen		= sizeof(int),
6278 		.mode		= 0644,
6279 		.proc_handler	= proc_dointvec
6280 	},
6281 	{
6282 		.procname	= "ndisc_notify",
6283 		.data		= &ipv6_devconf.ndisc_notify,
6284 		.maxlen		= sizeof(int),
6285 		.mode		= 0644,
6286 		.proc_handler	= proc_dointvec
6287 	},
6288 	{
6289 		.procname	= "suppress_frag_ndisc",
6290 		.data		= &ipv6_devconf.suppress_frag_ndisc,
6291 		.maxlen		= sizeof(int),
6292 		.mode		= 0644,
6293 		.proc_handler	= proc_dointvec
6294 	},
6295 	{
6296 		.procname	= "accept_ra_from_local",
6297 		.data		= &ipv6_devconf.accept_ra_from_local,
6298 		.maxlen		= sizeof(int),
6299 		.mode		= 0644,
6300 		.proc_handler	= proc_dointvec,
6301 	},
6302 	{
6303 		.procname	= "accept_ra_mtu",
6304 		.data		= &ipv6_devconf.accept_ra_mtu,
6305 		.maxlen		= sizeof(int),
6306 		.mode		= 0644,
6307 		.proc_handler	= proc_dointvec,
6308 	},
6309 	{
6310 		.procname	= "stable_secret",
6311 		.data		= &ipv6_devconf.stable_secret,
6312 		.maxlen		= IPV6_MAX_STRLEN,
6313 		.mode		= 0600,
6314 		.proc_handler	= addrconf_sysctl_stable_secret,
6315 	},
6316 	{
6317 		.procname	= "use_oif_addrs_only",
6318 		.data		= &ipv6_devconf.use_oif_addrs_only,
6319 		.maxlen		= sizeof(int),
6320 		.mode		= 0644,
6321 		.proc_handler	= proc_dointvec,
6322 	},
6323 	{
6324 		.procname	= "ignore_routes_with_linkdown",
6325 		.data		= &ipv6_devconf.ignore_routes_with_linkdown,
6326 		.maxlen		= sizeof(int),
6327 		.mode		= 0644,
6328 		.proc_handler	= addrconf_sysctl_ignore_routes_with_linkdown,
6329 	},
6330 	{
6331 		.procname	= "drop_unicast_in_l2_multicast",
6332 		.data		= &ipv6_devconf.drop_unicast_in_l2_multicast,
6333 		.maxlen		= sizeof(int),
6334 		.mode		= 0644,
6335 		.proc_handler	= proc_dointvec,
6336 	},
6337 	{
6338 		.procname	= "drop_unsolicited_na",
6339 		.data		= &ipv6_devconf.drop_unsolicited_na,
6340 		.maxlen		= sizeof(int),
6341 		.mode		= 0644,
6342 		.proc_handler	= proc_dointvec,
6343 	},
6344 	{
6345 		.procname	= "keep_addr_on_down",
6346 		.data		= &ipv6_devconf.keep_addr_on_down,
6347 		.maxlen		= sizeof(int),
6348 		.mode		= 0644,
6349 		.proc_handler	= proc_dointvec,
6350 
6351 	},
6352 	{
6353 		.procname	= "seg6_enabled",
6354 		.data		= &ipv6_devconf.seg6_enabled,
6355 		.maxlen		= sizeof(int),
6356 		.mode		= 0644,
6357 		.proc_handler	= proc_dointvec,
6358 	},
6359 #ifdef CONFIG_IPV6_SEG6_HMAC
6360 	{
6361 		.procname	= "seg6_require_hmac",
6362 		.data		= &ipv6_devconf.seg6_require_hmac,
6363 		.maxlen		= sizeof(int),
6364 		.mode		= 0644,
6365 		.proc_handler	= proc_dointvec,
6366 	},
6367 #endif
6368 	{
6369 		.procname       = "enhanced_dad",
6370 		.data           = &ipv6_devconf.enhanced_dad,
6371 		.maxlen         = sizeof(int),
6372 		.mode           = 0644,
6373 		.proc_handler   = proc_dointvec,
6374 	},
6375 	{
6376 		.procname		= "addr_gen_mode",
6377 		.data			= &ipv6_devconf.addr_gen_mode,
6378 		.maxlen			= sizeof(int),
6379 		.mode			= 0644,
6380 		.proc_handler	= addrconf_sysctl_addr_gen_mode,
6381 	},
6382 	{
6383 		.procname       = "disable_policy",
6384 		.data           = &ipv6_devconf.disable_policy,
6385 		.maxlen         = sizeof(int),
6386 		.mode           = 0644,
6387 		.proc_handler   = addrconf_sysctl_disable_policy,
6388 	},
6389 	{
6390 		.procname	= "ndisc_tclass",
6391 		.data		= &ipv6_devconf.ndisc_tclass,
6392 		.maxlen		= sizeof(int),
6393 		.mode		= 0644,
6394 		.proc_handler	= proc_dointvec_minmax,
6395 		.extra1		= (void *)&zero,
6396 		.extra2		= (void *)&two_five_five,
6397 	},
6398 	{
6399 		/* sentinel */
6400 	}
6401 };
6402 
6403 static int __addrconf_sysctl_register(struct net *net, char *dev_name,
6404 		struct inet6_dev *idev, struct ipv6_devconf *p)
6405 {
6406 	int i, ifindex;
6407 	struct ctl_table *table;
6408 	char path[sizeof("net/ipv6/conf/") + IFNAMSIZ];
6409 
6410 	table = kmemdup(addrconf_sysctl, sizeof(addrconf_sysctl), GFP_KERNEL);
6411 	if (!table)
6412 		goto out;
6413 
6414 	for (i = 0; table[i].data; i++) {
6415 		table[i].data += (char *)p - (char *)&ipv6_devconf;
6416 		/* If one of these is already set, then it is not safe to
6417 		 * overwrite either of them: this makes proc_dointvec_minmax
6418 		 * usable.
6419 		 */
6420 		if (!table[i].extra1 && !table[i].extra2) {
6421 			table[i].extra1 = idev; /* embedded; no ref */
6422 			table[i].extra2 = net;
6423 		}
6424 	}
6425 
6426 	snprintf(path, sizeof(path), "net/ipv6/conf/%s", dev_name);
6427 
6428 	p->sysctl_header = register_net_sysctl(net, path, table);
6429 	if (!p->sysctl_header)
6430 		goto free;
6431 
6432 	if (!strcmp(dev_name, "all"))
6433 		ifindex = NETCONFA_IFINDEX_ALL;
6434 	else if (!strcmp(dev_name, "default"))
6435 		ifindex = NETCONFA_IFINDEX_DEFAULT;
6436 	else
6437 		ifindex = idev->dev->ifindex;
6438 	inet6_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL,
6439 				     ifindex, p);
6440 	return 0;
6441 
6442 free:
6443 	kfree(table);
6444 out:
6445 	return -ENOBUFS;
6446 }
6447 
6448 static void __addrconf_sysctl_unregister(struct net *net,
6449 					 struct ipv6_devconf *p, int ifindex)
6450 {
6451 	struct ctl_table *table;
6452 
6453 	if (!p->sysctl_header)
6454 		return;
6455 
6456 	table = p->sysctl_header->ctl_table_arg;
6457 	unregister_net_sysctl_table(p->sysctl_header);
6458 	p->sysctl_header = NULL;
6459 	kfree(table);
6460 
6461 	inet6_netconf_notify_devconf(net, RTM_DELNETCONF, 0, ifindex, NULL);
6462 }
6463 
6464 static int addrconf_sysctl_register(struct inet6_dev *idev)
6465 {
6466 	int err;
6467 
6468 	if (!sysctl_dev_name_is_allowed(idev->dev->name))
6469 		return -EINVAL;
6470 
6471 	err = neigh_sysctl_register(idev->dev, idev->nd_parms,
6472 				    &ndisc_ifinfo_sysctl_change);
6473 	if (err)
6474 		return err;
6475 	err = __addrconf_sysctl_register(dev_net(idev->dev), idev->dev->name,
6476 					 idev, &idev->cnf);
6477 	if (err)
6478 		neigh_sysctl_unregister(idev->nd_parms);
6479 
6480 	return err;
6481 }
6482 
6483 static void addrconf_sysctl_unregister(struct inet6_dev *idev)
6484 {
6485 	__addrconf_sysctl_unregister(dev_net(idev->dev), &idev->cnf,
6486 				     idev->dev->ifindex);
6487 	neigh_sysctl_unregister(idev->nd_parms);
6488 }
6489 
6490 
6491 #endif
6492 
6493 static int __net_init addrconf_init_net(struct net *net)
6494 {
6495 	int err = -ENOMEM;
6496 	struct ipv6_devconf *all, *dflt;
6497 
6498 	all = kmemdup(&ipv6_devconf, sizeof(ipv6_devconf), GFP_KERNEL);
6499 	if (!all)
6500 		goto err_alloc_all;
6501 
6502 	dflt = kmemdup(&ipv6_devconf_dflt, sizeof(ipv6_devconf_dflt), GFP_KERNEL);
6503 	if (!dflt)
6504 		goto err_alloc_dflt;
6505 
6506 	/* these will be inherited by all namespaces */
6507 	dflt->autoconf = ipv6_defaults.autoconf;
6508 	dflt->disable_ipv6 = ipv6_defaults.disable_ipv6;
6509 
6510 	dflt->stable_secret.initialized = false;
6511 	all->stable_secret.initialized = false;
6512 
6513 	net->ipv6.devconf_all = all;
6514 	net->ipv6.devconf_dflt = dflt;
6515 
6516 #ifdef CONFIG_SYSCTL
6517 	err = __addrconf_sysctl_register(net, "all", NULL, all);
6518 	if (err < 0)
6519 		goto err_reg_all;
6520 
6521 	err = __addrconf_sysctl_register(net, "default", NULL, dflt);
6522 	if (err < 0)
6523 		goto err_reg_dflt;
6524 #endif
6525 	return 0;
6526 
6527 #ifdef CONFIG_SYSCTL
6528 err_reg_dflt:
6529 	__addrconf_sysctl_unregister(net, all, NETCONFA_IFINDEX_ALL);
6530 err_reg_all:
6531 	kfree(dflt);
6532 #endif
6533 err_alloc_dflt:
6534 	kfree(all);
6535 err_alloc_all:
6536 	return err;
6537 }
6538 
6539 static void __net_exit addrconf_exit_net(struct net *net)
6540 {
6541 #ifdef CONFIG_SYSCTL
6542 	__addrconf_sysctl_unregister(net, net->ipv6.devconf_dflt,
6543 				     NETCONFA_IFINDEX_DEFAULT);
6544 	__addrconf_sysctl_unregister(net, net->ipv6.devconf_all,
6545 				     NETCONFA_IFINDEX_ALL);
6546 #endif
6547 	kfree(net->ipv6.devconf_dflt);
6548 	kfree(net->ipv6.devconf_all);
6549 }
6550 
6551 static struct pernet_operations addrconf_ops = {
6552 	.init = addrconf_init_net,
6553 	.exit = addrconf_exit_net,
6554 	.async = true,
6555 };
6556 
6557 static struct rtnl_af_ops inet6_ops __read_mostly = {
6558 	.family		  = AF_INET6,
6559 	.fill_link_af	  = inet6_fill_link_af,
6560 	.get_link_af_size = inet6_get_link_af_size,
6561 	.validate_link_af = inet6_validate_link_af,
6562 	.set_link_af	  = inet6_set_link_af,
6563 };
6564 
6565 /*
6566  *	Init / cleanup code
6567  */
6568 
6569 int __init addrconf_init(void)
6570 {
6571 	struct inet6_dev *idev;
6572 	int i, err;
6573 
6574 	err = ipv6_addr_label_init();
6575 	if (err < 0) {
6576 		pr_crit("%s: cannot initialize default policy table: %d\n",
6577 			__func__, err);
6578 		goto out;
6579 	}
6580 
6581 	err = register_pernet_subsys(&addrconf_ops);
6582 	if (err < 0)
6583 		goto out_addrlabel;
6584 
6585 	addrconf_wq = create_workqueue("ipv6_addrconf");
6586 	if (!addrconf_wq) {
6587 		err = -ENOMEM;
6588 		goto out_nowq;
6589 	}
6590 
6591 	/* The addrconf netdev notifier requires that loopback_dev
6592 	 * has it's ipv6 private information allocated and setup
6593 	 * before it can bring up and give link-local addresses
6594 	 * to other devices which are up.
6595 	 *
6596 	 * Unfortunately, loopback_dev is not necessarily the first
6597 	 * entry in the global dev_base list of net devices.  In fact,
6598 	 * it is likely to be the very last entry on that list.
6599 	 * So this causes the notifier registry below to try and
6600 	 * give link-local addresses to all devices besides loopback_dev
6601 	 * first, then loopback_dev, which cases all the non-loopback_dev
6602 	 * devices to fail to get a link-local address.
6603 	 *
6604 	 * So, as a temporary fix, allocate the ipv6 structure for
6605 	 * loopback_dev first by hand.
6606 	 * Longer term, all of the dependencies ipv6 has upon the loopback
6607 	 * device and it being up should be removed.
6608 	 */
6609 	rtnl_lock();
6610 	idev = ipv6_add_dev(init_net.loopback_dev);
6611 	rtnl_unlock();
6612 	if (IS_ERR(idev)) {
6613 		err = PTR_ERR(idev);
6614 		goto errlo;
6615 	}
6616 
6617 	ip6_route_init_special_entries();
6618 
6619 	for (i = 0; i < IN6_ADDR_HSIZE; i++)
6620 		INIT_HLIST_HEAD(&inet6_addr_lst[i]);
6621 
6622 	register_netdevice_notifier(&ipv6_dev_notf);
6623 
6624 	addrconf_verify();
6625 
6626 	rtnl_af_register(&inet6_ops);
6627 
6628 	err = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETLINK,
6629 				   NULL, inet6_dump_ifinfo, 0);
6630 	if (err < 0)
6631 		goto errout;
6632 
6633 	err = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWADDR,
6634 				   inet6_rtm_newaddr, NULL, 0);
6635 	if (err < 0)
6636 		goto errout;
6637 	err = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELADDR,
6638 				   inet6_rtm_deladdr, NULL, 0);
6639 	if (err < 0)
6640 		goto errout;
6641 	err = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETADDR,
6642 				   inet6_rtm_getaddr, inet6_dump_ifaddr,
6643 				   RTNL_FLAG_DOIT_UNLOCKED);
6644 	if (err < 0)
6645 		goto errout;
6646 	err = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETMULTICAST,
6647 				   NULL, inet6_dump_ifmcaddr, 0);
6648 	if (err < 0)
6649 		goto errout;
6650 	err = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETANYCAST,
6651 				   NULL, inet6_dump_ifacaddr, 0);
6652 	if (err < 0)
6653 		goto errout;
6654 	err = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETNETCONF,
6655 				   inet6_netconf_get_devconf,
6656 				   inet6_netconf_dump_devconf,
6657 				   RTNL_FLAG_DOIT_UNLOCKED);
6658 	if (err < 0)
6659 		goto errout;
6660 	err = ipv6_addr_label_rtnl_register();
6661 	if (err < 0)
6662 		goto errout;
6663 
6664 	return 0;
6665 errout:
6666 	rtnl_unregister_all(PF_INET6);
6667 	rtnl_af_unregister(&inet6_ops);
6668 	unregister_netdevice_notifier(&ipv6_dev_notf);
6669 errlo:
6670 	destroy_workqueue(addrconf_wq);
6671 out_nowq:
6672 	unregister_pernet_subsys(&addrconf_ops);
6673 out_addrlabel:
6674 	ipv6_addr_label_cleanup();
6675 out:
6676 	return err;
6677 }
6678 
6679 void addrconf_cleanup(void)
6680 {
6681 	struct net_device *dev;
6682 	int i;
6683 
6684 	unregister_netdevice_notifier(&ipv6_dev_notf);
6685 	unregister_pernet_subsys(&addrconf_ops);
6686 	ipv6_addr_label_cleanup();
6687 
6688 	rtnl_af_unregister(&inet6_ops);
6689 
6690 	rtnl_lock();
6691 
6692 	/* clean dev list */
6693 	for_each_netdev(&init_net, dev) {
6694 		if (__in6_dev_get(dev) == NULL)
6695 			continue;
6696 		addrconf_ifdown(dev, 1);
6697 	}
6698 	addrconf_ifdown(init_net.loopback_dev, 2);
6699 
6700 	/*
6701 	 *	Check hash table.
6702 	 */
6703 	spin_lock_bh(&addrconf_hash_lock);
6704 	for (i = 0; i < IN6_ADDR_HSIZE; i++)
6705 		WARN_ON(!hlist_empty(&inet6_addr_lst[i]));
6706 	spin_unlock_bh(&addrconf_hash_lock);
6707 	cancel_delayed_work(&addr_chk_work);
6708 	rtnl_unlock();
6709 
6710 	destroy_workqueue(addrconf_wq);
6711 }
6712