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TOMOYO Linux Cross Reference
Linux/net/ipv6/addrconf.c

Version: ~ [ linux-6.0 ] ~ [ linux-5.19.12 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.71 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.146 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.215 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.260 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.295 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.330 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.302 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
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  1 // SPDX-License-Identifier: GPL-2.0-or-later
  2 /*
  3  *      IPv6 Address [auto]configuration
  4  *      Linux INET6 implementation
  5  *
  6  *      Authors:
  7  *      Pedro Roque             <roque@di.fc.ul.pt>
  8  *      Alexey Kuznetsov        <kuznet@ms2.inr.ac.ru>
  9  */
 10 
 11 /*
 12  *      Changes:
 13  *
 14  *      Janos Farkas                    :       delete timer on ifdown
 15  *      <chexum@bankinf.banki.hu>
 16  *      Andi Kleen                      :       kill double kfree on module
 17  *                                              unload.
 18  *      Maciej W. Rozycki               :       FDDI support
 19  *      sekiya@USAGI                    :       Don't send too many RS
 20  *                                              packets.
 21  *      yoshfuji@USAGI                  :       Fixed interval between DAD
 22  *                                              packets.
 23  *      YOSHIFUJI Hideaki @USAGI        :       improved accuracy of
 24  *                                              address validation timer.
 25  *      YOSHIFUJI Hideaki @USAGI        :       Privacy Extensions (RFC3041)
 26  *                                              support.
 27  *      Yuji SEKIYA @USAGI              :       Don't assign a same IPv6
 28  *                                              address on a same interface.
 29  *      YOSHIFUJI Hideaki @USAGI        :       ARCnet support
 30  *      YOSHIFUJI Hideaki @USAGI        :       convert /proc/net/if_inet6 to
 31  *                                              seq_file.
 32  *      YOSHIFUJI Hideaki @USAGI        :       improved source address
 33  *                                              selection; consider scope,
 34  *                                              status etc.
 35  */
 36 
 37 #define pr_fmt(fmt) "IPv6: " fmt
 38 
 39 #include <linux/errno.h>
 40 #include <linux/types.h>
 41 #include <linux/kernel.h>
 42 #include <linux/sched/signal.h>
 43 #include <linux/socket.h>
 44 #include <linux/sockios.h>
 45 #include <linux/net.h>
 46 #include <linux/inet.h>
 47 #include <linux/in6.h>
 48 #include <linux/netdevice.h>
 49 #include <linux/if_addr.h>
 50 #include <linux/if_arp.h>
 51 #include <linux/if_arcnet.h>
 52 #include <linux/if_infiniband.h>
 53 #include <linux/route.h>
 54 #include <linux/inetdevice.h>
 55 #include <linux/init.h>
 56 #include <linux/slab.h>
 57 #ifdef CONFIG_SYSCTL
 58 #include <linux/sysctl.h>
 59 #endif
 60 #include <linux/capability.h>
 61 #include <linux/delay.h>
 62 #include <linux/notifier.h>
 63 #include <linux/string.h>
 64 #include <linux/hash.h>
 65 
 66 #include <net/net_namespace.h>
 67 #include <net/sock.h>
 68 #include <net/snmp.h>
 69 
 70 #include <net/6lowpan.h>
 71 #include <net/firewire.h>
 72 #include <net/ipv6.h>
 73 #include <net/protocol.h>
 74 #include <net/ndisc.h>
 75 #include <net/ip6_route.h>
 76 #include <net/addrconf.h>
 77 #include <net/tcp.h>
 78 #include <net/ip.h>
 79 #include <net/netlink.h>
 80 #include <net/pkt_sched.h>
 81 #include <net/l3mdev.h>
 82 #include <linux/if_tunnel.h>
 83 #include <linux/rtnetlink.h>
 84 #include <linux/netconf.h>
 85 #include <linux/random.h>
 86 #include <linux/uaccess.h>
 87 #include <asm/unaligned.h>
 88 
 89 #include <linux/proc_fs.h>
 90 #include <linux/seq_file.h>
 91 #include <linux/export.h>
 92 
 93 #define INFINITY_LIFE_TIME      0xFFFFFFFF
 94 
 95 #define IPV6_MAX_STRLEN \
 96         sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")
 97 
 98 static inline u32 cstamp_delta(unsigned long cstamp)
 99 {
100         return (cstamp - INITIAL_JIFFIES) * 100UL / HZ;
101 }
102 
103 static inline s32 rfc3315_s14_backoff_init(s32 irt)
104 {
105         /* multiply 'initial retransmission time' by 0.9 .. 1.1 */
106         u64 tmp = (900000 + prandom_u32() % 200001) * (u64)irt;
107         do_div(tmp, 1000000);
108         return (s32)tmp;
109 }
110 
111 static inline s32 rfc3315_s14_backoff_update(s32 rt, s32 mrt)
112 {
113         /* multiply 'retransmission timeout' by 1.9 .. 2.1 */
114         u64 tmp = (1900000 + prandom_u32() % 200001) * (u64)rt;
115         do_div(tmp, 1000000);
116         if ((s32)tmp > mrt) {
117                 /* multiply 'maximum retransmission time' by 0.9 .. 1.1 */
118                 tmp = (900000 + prandom_u32() % 200001) * (u64)mrt;
119                 do_div(tmp, 1000000);
120         }
121         return (s32)tmp;
122 }
123 
124 #ifdef CONFIG_SYSCTL
125 static int addrconf_sysctl_register(struct inet6_dev *idev);
126 static void addrconf_sysctl_unregister(struct inet6_dev *idev);
127 #else
128 static inline int addrconf_sysctl_register(struct inet6_dev *idev)
129 {
130         return 0;
131 }
132 
133 static inline void addrconf_sysctl_unregister(struct inet6_dev *idev)
134 {
135 }
136 #endif
137 
138 static void ipv6_gen_rnd_iid(struct in6_addr *addr);
139 
140 static int ipv6_generate_eui64(u8 *eui, struct net_device *dev);
141 static int ipv6_count_addresses(const struct inet6_dev *idev);
142 static int ipv6_generate_stable_address(struct in6_addr *addr,
143                                         u8 dad_count,
144                                         const struct inet6_dev *idev);
145 
146 #define IN6_ADDR_HSIZE_SHIFT    8
147 #define IN6_ADDR_HSIZE          (1 << IN6_ADDR_HSIZE_SHIFT)
148 /*
149  *      Configured unicast address hash table
150  */
151 static struct hlist_head inet6_addr_lst[IN6_ADDR_HSIZE];
152 static DEFINE_SPINLOCK(addrconf_hash_lock);
153 
154 static void addrconf_verify(void);
155 static void addrconf_verify_rtnl(void);
156 static void addrconf_verify_work(struct work_struct *);
157 
158 static struct workqueue_struct *addrconf_wq;
159 static DECLARE_DELAYED_WORK(addr_chk_work, addrconf_verify_work);
160 
161 static void addrconf_join_anycast(struct inet6_ifaddr *ifp);
162 static void addrconf_leave_anycast(struct inet6_ifaddr *ifp);
163 
164 static void addrconf_type_change(struct net_device *dev,
165                                  unsigned long event);
166 static int addrconf_ifdown(struct net_device *dev, bool unregister);
167 
168 static struct fib6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
169                                                   int plen,
170                                                   const struct net_device *dev,
171                                                   u32 flags, u32 noflags,
172                                                   bool no_gw);
173 
174 static void addrconf_dad_start(struct inet6_ifaddr *ifp);
175 static void addrconf_dad_work(struct work_struct *w);
176 static void addrconf_dad_completed(struct inet6_ifaddr *ifp, bool bump_id,
177                                    bool send_na);
178 static void addrconf_dad_run(struct inet6_dev *idev, bool restart);
179 static void addrconf_rs_timer(struct timer_list *t);
180 static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifa);
181 static void ipv6_ifa_notify(int event, struct inet6_ifaddr *ifa);
182 
183 static void inet6_prefix_notify(int event, struct inet6_dev *idev,
184                                 struct prefix_info *pinfo);
185 
186 static struct ipv6_devconf ipv6_devconf __read_mostly = {
187         .forwarding             = 0,
188         .hop_limit              = IPV6_DEFAULT_HOPLIMIT,
189         .mtu6                   = IPV6_MIN_MTU,
190         .accept_ra              = 1,
191         .accept_redirects       = 1,
192         .autoconf               = 1,
193         .force_mld_version      = 0,
194         .mldv1_unsolicited_report_interval = 10 * HZ,
195         .mldv2_unsolicited_report_interval = HZ,
196         .dad_transmits          = 1,
197         .rtr_solicits           = MAX_RTR_SOLICITATIONS,
198         .rtr_solicit_interval   = RTR_SOLICITATION_INTERVAL,
199         .rtr_solicit_max_interval = RTR_SOLICITATION_MAX_INTERVAL,
200         .rtr_solicit_delay      = MAX_RTR_SOLICITATION_DELAY,
201         .use_tempaddr           = 0,
202         .temp_valid_lft         = TEMP_VALID_LIFETIME,
203         .temp_prefered_lft      = TEMP_PREFERRED_LIFETIME,
204         .regen_max_retry        = REGEN_MAX_RETRY,
205         .max_desync_factor      = MAX_DESYNC_FACTOR,
206         .max_addresses          = IPV6_MAX_ADDRESSES,
207         .accept_ra_defrtr       = 1,
208         .ra_defrtr_metric       = IP6_RT_PRIO_USER,
209         .accept_ra_from_local   = 0,
210         .accept_ra_min_hop_limit= 1,
211         .accept_ra_pinfo        = 1,
212 #ifdef CONFIG_IPV6_ROUTER_PREF
213         .accept_ra_rtr_pref     = 1,
214         .rtr_probe_interval     = 60 * HZ,
215 #ifdef CONFIG_IPV6_ROUTE_INFO
216         .accept_ra_rt_info_min_plen = 0,
217         .accept_ra_rt_info_max_plen = 0,
218 #endif
219 #endif
220         .proxy_ndp              = 0,
221         .accept_source_route    = 0,    /* we do not accept RH0 by default. */
222         .disable_ipv6           = 0,
223         .accept_dad             = 0,
224         .suppress_frag_ndisc    = 1,
225         .accept_ra_mtu          = 1,
226         .stable_secret          = {
227                 .initialized = false,
228         },
229         .use_oif_addrs_only     = 0,
230         .ignore_routes_with_linkdown = 0,
231         .keep_addr_on_down      = 0,
232         .seg6_enabled           = 0,
233 #ifdef CONFIG_IPV6_SEG6_HMAC
234         .seg6_require_hmac      = 0,
235 #endif
236         .enhanced_dad           = 1,
237         .addr_gen_mode          = IN6_ADDR_GEN_MODE_EUI64,
238         .disable_policy         = 0,
239         .rpl_seg_enabled        = 0,
240 };
241 
242 static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
243         .forwarding             = 0,
244         .hop_limit              = IPV6_DEFAULT_HOPLIMIT,
245         .mtu6                   = IPV6_MIN_MTU,
246         .accept_ra              = 1,
247         .accept_redirects       = 1,
248         .autoconf               = 1,
249         .force_mld_version      = 0,
250         .mldv1_unsolicited_report_interval = 10 * HZ,
251         .mldv2_unsolicited_report_interval = HZ,
252         .dad_transmits          = 1,
253         .rtr_solicits           = MAX_RTR_SOLICITATIONS,
254         .rtr_solicit_interval   = RTR_SOLICITATION_INTERVAL,
255         .rtr_solicit_max_interval = RTR_SOLICITATION_MAX_INTERVAL,
256         .rtr_solicit_delay      = MAX_RTR_SOLICITATION_DELAY,
257         .use_tempaddr           = 0,
258         .temp_valid_lft         = TEMP_VALID_LIFETIME,
259         .temp_prefered_lft      = TEMP_PREFERRED_LIFETIME,
260         .regen_max_retry        = REGEN_MAX_RETRY,
261         .max_desync_factor      = MAX_DESYNC_FACTOR,
262         .max_addresses          = IPV6_MAX_ADDRESSES,
263         .accept_ra_defrtr       = 1,
264         .ra_defrtr_metric       = IP6_RT_PRIO_USER,
265         .accept_ra_from_local   = 0,
266         .accept_ra_min_hop_limit= 1,
267         .accept_ra_pinfo        = 1,
268 #ifdef CONFIG_IPV6_ROUTER_PREF
269         .accept_ra_rtr_pref     = 1,
270         .rtr_probe_interval     = 60 * HZ,
271 #ifdef CONFIG_IPV6_ROUTE_INFO
272         .accept_ra_rt_info_min_plen = 0,
273         .accept_ra_rt_info_max_plen = 0,
274 #endif
275 #endif
276         .proxy_ndp              = 0,
277         .accept_source_route    = 0,    /* we do not accept RH0 by default. */
278         .disable_ipv6           = 0,
279         .accept_dad             = 1,
280         .suppress_frag_ndisc    = 1,
281         .accept_ra_mtu          = 1,
282         .stable_secret          = {
283                 .initialized = false,
284         },
285         .use_oif_addrs_only     = 0,
286         .ignore_routes_with_linkdown = 0,
287         .keep_addr_on_down      = 0,
288         .seg6_enabled           = 0,
289 #ifdef CONFIG_IPV6_SEG6_HMAC
290         .seg6_require_hmac      = 0,
291 #endif
292         .enhanced_dad           = 1,
293         .addr_gen_mode          = IN6_ADDR_GEN_MODE_EUI64,
294         .disable_policy         = 0,
295         .rpl_seg_enabled        = 0,
296 };
297 
298 /* Check if link is ready: is it up and is a valid qdisc available */
299 static inline bool addrconf_link_ready(const struct net_device *dev)
300 {
301         return netif_oper_up(dev) && !qdisc_tx_is_noop(dev);
302 }
303 
304 static void addrconf_del_rs_timer(struct inet6_dev *idev)
305 {
306         if (del_timer(&idev->rs_timer))
307                 __in6_dev_put(idev);
308 }
309 
310 static void addrconf_del_dad_work(struct inet6_ifaddr *ifp)
311 {
312         if (cancel_delayed_work(&ifp->dad_work))
313                 __in6_ifa_put(ifp);
314 }
315 
316 static void addrconf_mod_rs_timer(struct inet6_dev *idev,
317                                   unsigned long when)
318 {
319         if (!timer_pending(&idev->rs_timer))
320                 in6_dev_hold(idev);
321         mod_timer(&idev->rs_timer, jiffies + when);
322 }
323 
324 static void addrconf_mod_dad_work(struct inet6_ifaddr *ifp,
325                                    unsigned long delay)
326 {
327         in6_ifa_hold(ifp);
328         if (mod_delayed_work(addrconf_wq, &ifp->dad_work, delay))
329                 in6_ifa_put(ifp);
330 }
331 
332 static int snmp6_alloc_dev(struct inet6_dev *idev)
333 {
334         int i;
335 
336         idev->stats.ipv6 = alloc_percpu(struct ipstats_mib);
337         if (!idev->stats.ipv6)
338                 goto err_ip;
339 
340         for_each_possible_cpu(i) {
341                 struct ipstats_mib *addrconf_stats;
342                 addrconf_stats = per_cpu_ptr(idev->stats.ipv6, i);
343                 u64_stats_init(&addrconf_stats->syncp);
344         }
345 
346 
347         idev->stats.icmpv6dev = kzalloc(sizeof(struct icmpv6_mib_device),
348                                         GFP_KERNEL);
349         if (!idev->stats.icmpv6dev)
350                 goto err_icmp;
351         idev->stats.icmpv6msgdev = kzalloc(sizeof(struct icmpv6msg_mib_device),
352                                            GFP_KERNEL);
353         if (!idev->stats.icmpv6msgdev)
354                 goto err_icmpmsg;
355 
356         return 0;
357 
358 err_icmpmsg:
359         kfree(idev->stats.icmpv6dev);
360 err_icmp:
361         free_percpu(idev->stats.ipv6);
362 err_ip:
363         return -ENOMEM;
364 }
365 
366 static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
367 {
368         struct inet6_dev *ndev;
369         int err = -ENOMEM;
370 
371         ASSERT_RTNL();
372 
373         if (dev->mtu < IPV6_MIN_MTU)
374                 return ERR_PTR(-EINVAL);
375 
376         ndev = kzalloc(sizeof(struct inet6_dev), GFP_KERNEL);
377         if (!ndev)
378                 return ERR_PTR(err);
379 
380         rwlock_init(&ndev->lock);
381         ndev->dev = dev;
382         INIT_LIST_HEAD(&ndev->addr_list);
383         timer_setup(&ndev->rs_timer, addrconf_rs_timer, 0);
384         memcpy(&ndev->cnf, dev_net(dev)->ipv6.devconf_dflt, sizeof(ndev->cnf));
385 
386         if (ndev->cnf.stable_secret.initialized)
387                 ndev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY;
388 
389         ndev->cnf.mtu6 = dev->mtu;
390         ndev->nd_parms = neigh_parms_alloc(dev, &nd_tbl);
391         if (!ndev->nd_parms) {
392                 kfree(ndev);
393                 return ERR_PTR(err);
394         }
395         if (ndev->cnf.forwarding)
396                 dev_disable_lro(dev);
397         /* We refer to the device */
398         dev_hold(dev);
399 
400         if (snmp6_alloc_dev(ndev) < 0) {
401                 netdev_dbg(dev, "%s: cannot allocate memory for statistics\n",
402                            __func__);
403                 neigh_parms_release(&nd_tbl, ndev->nd_parms);
404                 dev_put(dev);
405                 kfree(ndev);
406                 return ERR_PTR(err);
407         }
408 
409         if (snmp6_register_dev(ndev) < 0) {
410                 netdev_dbg(dev, "%s: cannot create /proc/net/dev_snmp6/%s\n",
411                            __func__, dev->name);
412                 goto err_release;
413         }
414 
415         /* One reference from device. */
416         refcount_set(&ndev->refcnt, 1);
417 
418         if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
419                 ndev->cnf.accept_dad = -1;
420 
421 #if IS_ENABLED(CONFIG_IPV6_SIT)
422         if (dev->type == ARPHRD_SIT && (dev->priv_flags & IFF_ISATAP)) {
423                 pr_info("%s: Disabled Multicast RS\n", dev->name);
424                 ndev->cnf.rtr_solicits = 0;
425         }
426 #endif
427 
428         INIT_LIST_HEAD(&ndev->tempaddr_list);
429         ndev->desync_factor = U32_MAX;
430         if ((dev->flags&IFF_LOOPBACK) ||
431             dev->type == ARPHRD_TUNNEL ||
432             dev->type == ARPHRD_TUNNEL6 ||
433             dev->type == ARPHRD_SIT ||
434             dev->type == ARPHRD_NONE) {
435                 ndev->cnf.use_tempaddr = -1;
436         }
437 
438         ndev->token = in6addr_any;
439 
440         if (netif_running(dev) && addrconf_link_ready(dev))
441                 ndev->if_flags |= IF_READY;
442 
443         ipv6_mc_init_dev(ndev);
444         ndev->tstamp = jiffies;
445         err = addrconf_sysctl_register(ndev);
446         if (err) {
447                 ipv6_mc_destroy_dev(ndev);
448                 snmp6_unregister_dev(ndev);
449                 goto err_release;
450         }
451         /* protected by rtnl_lock */
452         rcu_assign_pointer(dev->ip6_ptr, ndev);
453 
454         /* Join interface-local all-node multicast group */
455         ipv6_dev_mc_inc(dev, &in6addr_interfacelocal_allnodes);
456 
457         /* Join all-node multicast group */
458         ipv6_dev_mc_inc(dev, &in6addr_linklocal_allnodes);
459 
460         /* Join all-router multicast group if forwarding is set */
461         if (ndev->cnf.forwarding && (dev->flags & IFF_MULTICAST))
462                 ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters);
463 
464         return ndev;
465 
466 err_release:
467         neigh_parms_release(&nd_tbl, ndev->nd_parms);
468         ndev->dead = 1;
469         in6_dev_finish_destroy(ndev);
470         return ERR_PTR(err);
471 }
472 
473 static struct inet6_dev *ipv6_find_idev(struct net_device *dev)
474 {
475         struct inet6_dev *idev;
476 
477         ASSERT_RTNL();
478 
479         idev = __in6_dev_get(dev);
480         if (!idev) {
481                 idev = ipv6_add_dev(dev);
482                 if (IS_ERR(idev))
483                         return idev;
484         }
485 
486         if (dev->flags&IFF_UP)
487                 ipv6_mc_up(idev);
488         return idev;
489 }
490 
491 static int inet6_netconf_msgsize_devconf(int type)
492 {
493         int size =  NLMSG_ALIGN(sizeof(struct netconfmsg))
494                     + nla_total_size(4);        /* NETCONFA_IFINDEX */
495         bool all = false;
496 
497         if (type == NETCONFA_ALL)
498                 all = true;
499 
500         if (all || type == NETCONFA_FORWARDING)
501                 size += nla_total_size(4);
502 #ifdef CONFIG_IPV6_MROUTE
503         if (all || type == NETCONFA_MC_FORWARDING)
504                 size += nla_total_size(4);
505 #endif
506         if (all || type == NETCONFA_PROXY_NEIGH)
507                 size += nla_total_size(4);
508 
509         if (all || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN)
510                 size += nla_total_size(4);
511 
512         return size;
513 }
514 
515 static int inet6_netconf_fill_devconf(struct sk_buff *skb, int ifindex,
516                                       struct ipv6_devconf *devconf, u32 portid,
517                                       u32 seq, int event, unsigned int flags,
518                                       int type)
519 {
520         struct nlmsghdr  *nlh;
521         struct netconfmsg *ncm;
522         bool all = false;
523 
524         nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
525                         flags);
526         if (!nlh)
527                 return -EMSGSIZE;
528 
529         if (type == NETCONFA_ALL)
530                 all = true;
531 
532         ncm = nlmsg_data(nlh);
533         ncm->ncm_family = AF_INET6;
534 
535         if (nla_put_s32(skb, NETCONFA_IFINDEX, ifindex) < 0)
536                 goto nla_put_failure;
537 
538         if (!devconf)
539                 goto out;
540 
541         if ((all || type == NETCONFA_FORWARDING) &&
542             nla_put_s32(skb, NETCONFA_FORWARDING, devconf->forwarding) < 0)
543                 goto nla_put_failure;
544 #ifdef CONFIG_IPV6_MROUTE
545         if ((all || type == NETCONFA_MC_FORWARDING) &&
546             nla_put_s32(skb, NETCONFA_MC_FORWARDING,
547                         devconf->mc_forwarding) < 0)
548                 goto nla_put_failure;
549 #endif
550         if ((all || type == NETCONFA_PROXY_NEIGH) &&
551             nla_put_s32(skb, NETCONFA_PROXY_NEIGH, devconf->proxy_ndp) < 0)
552                 goto nla_put_failure;
553 
554         if ((all || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN) &&
555             nla_put_s32(skb, NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
556                         devconf->ignore_routes_with_linkdown) < 0)
557                 goto nla_put_failure;
558 
559 out:
560         nlmsg_end(skb, nlh);
561         return 0;
562 
563 nla_put_failure:
564         nlmsg_cancel(skb, nlh);
565         return -EMSGSIZE;
566 }
567 
568 void inet6_netconf_notify_devconf(struct net *net, int event, int type,
569                                   int ifindex, struct ipv6_devconf *devconf)
570 {
571         struct sk_buff *skb;
572         int err = -ENOBUFS;
573 
574         skb = nlmsg_new(inet6_netconf_msgsize_devconf(type), GFP_KERNEL);
575         if (!skb)
576                 goto errout;
577 
578         err = inet6_netconf_fill_devconf(skb, ifindex, devconf, 0, 0,
579                                          event, 0, type);
580         if (err < 0) {
581                 /* -EMSGSIZE implies BUG in inet6_netconf_msgsize_devconf() */
582                 WARN_ON(err == -EMSGSIZE);
583                 kfree_skb(skb);
584                 goto errout;
585         }
586         rtnl_notify(skb, net, 0, RTNLGRP_IPV6_NETCONF, NULL, GFP_KERNEL);
587         return;
588 errout:
589         rtnl_set_sk_err(net, RTNLGRP_IPV6_NETCONF, err);
590 }
591 
592 static const struct nla_policy devconf_ipv6_policy[NETCONFA_MAX+1] = {
593         [NETCONFA_IFINDEX]      = { .len = sizeof(int) },
594         [NETCONFA_FORWARDING]   = { .len = sizeof(int) },
595         [NETCONFA_PROXY_NEIGH]  = { .len = sizeof(int) },
596         [NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN]  = { .len = sizeof(int) },
597 };
598 
599 static int inet6_netconf_valid_get_req(struct sk_buff *skb,
600                                        const struct nlmsghdr *nlh,
601                                        struct nlattr **tb,
602                                        struct netlink_ext_ack *extack)
603 {
604         int i, err;
605 
606         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) {
607                 NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf get request");
608                 return -EINVAL;
609         }
610 
611         if (!netlink_strict_get_check(skb))
612                 return nlmsg_parse_deprecated(nlh, sizeof(struct netconfmsg),
613                                               tb, NETCONFA_MAX,
614                                               devconf_ipv6_policy, extack);
615 
616         err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct netconfmsg),
617                                             tb, NETCONFA_MAX,
618                                             devconf_ipv6_policy, extack);
619         if (err)
620                 return err;
621 
622         for (i = 0; i <= NETCONFA_MAX; i++) {
623                 if (!tb[i])
624                         continue;
625 
626                 switch (i) {
627                 case NETCONFA_IFINDEX:
628                         break;
629                 default:
630                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in netconf get request");
631                         return -EINVAL;
632                 }
633         }
634 
635         return 0;
636 }
637 
638 static int inet6_netconf_get_devconf(struct sk_buff *in_skb,
639                                      struct nlmsghdr *nlh,
640                                      struct netlink_ext_ack *extack)
641 {
642         struct net *net = sock_net(in_skb->sk);
643         struct nlattr *tb[NETCONFA_MAX+1];
644         struct inet6_dev *in6_dev = NULL;
645         struct net_device *dev = NULL;
646         struct sk_buff *skb;
647         struct ipv6_devconf *devconf;
648         int ifindex;
649         int err;
650 
651         err = inet6_netconf_valid_get_req(in_skb, nlh, tb, extack);
652         if (err < 0)
653                 return err;
654 
655         if (!tb[NETCONFA_IFINDEX])
656                 return -EINVAL;
657 
658         err = -EINVAL;
659         ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
660         switch (ifindex) {
661         case NETCONFA_IFINDEX_ALL:
662                 devconf = net->ipv6.devconf_all;
663                 break;
664         case NETCONFA_IFINDEX_DEFAULT:
665                 devconf = net->ipv6.devconf_dflt;
666                 break;
667         default:
668                 dev = dev_get_by_index(net, ifindex);
669                 if (!dev)
670                         return -EINVAL;
671                 in6_dev = in6_dev_get(dev);
672                 if (!in6_dev)
673                         goto errout;
674                 devconf = &in6_dev->cnf;
675                 break;
676         }
677 
678         err = -ENOBUFS;
679         skb = nlmsg_new(inet6_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
680         if (!skb)
681                 goto errout;
682 
683         err = inet6_netconf_fill_devconf(skb, ifindex, devconf,
684                                          NETLINK_CB(in_skb).portid,
685                                          nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
686                                          NETCONFA_ALL);
687         if (err < 0) {
688                 /* -EMSGSIZE implies BUG in inet6_netconf_msgsize_devconf() */
689                 WARN_ON(err == -EMSGSIZE);
690                 kfree_skb(skb);
691                 goto errout;
692         }
693         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
694 errout:
695         if (in6_dev)
696                 in6_dev_put(in6_dev);
697         if (dev)
698                 dev_put(dev);
699         return err;
700 }
701 
702 static int inet6_netconf_dump_devconf(struct sk_buff *skb,
703                                       struct netlink_callback *cb)
704 {
705         const struct nlmsghdr *nlh = cb->nlh;
706         struct net *net = sock_net(skb->sk);
707         int h, s_h;
708         int idx, s_idx;
709         struct net_device *dev;
710         struct inet6_dev *idev;
711         struct hlist_head *head;
712 
713         if (cb->strict_check) {
714                 struct netlink_ext_ack *extack = cb->extack;
715                 struct netconfmsg *ncm;
716 
717                 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
718                         NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf dump request");
719                         return -EINVAL;
720                 }
721 
722                 if (nlmsg_attrlen(nlh, sizeof(*ncm))) {
723                         NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in netconf dump request");
724                         return -EINVAL;
725                 }
726         }
727 
728         s_h = cb->args[0];
729         s_idx = idx = cb->args[1];
730 
731         for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
732                 idx = 0;
733                 head = &net->dev_index_head[h];
734                 rcu_read_lock();
735                 cb->seq = atomic_read(&net->ipv6.dev_addr_genid) ^
736                           net->dev_base_seq;
737                 hlist_for_each_entry_rcu(dev, head, index_hlist) {
738                         if (idx < s_idx)
739                                 goto cont;
740                         idev = __in6_dev_get(dev);
741                         if (!idev)
742                                 goto cont;
743 
744                         if (inet6_netconf_fill_devconf(skb, dev->ifindex,
745                                                        &idev->cnf,
746                                                        NETLINK_CB(cb->skb).portid,
747                                                        nlh->nlmsg_seq,
748                                                        RTM_NEWNETCONF,
749                                                        NLM_F_MULTI,
750                                                        NETCONFA_ALL) < 0) {
751                                 rcu_read_unlock();
752                                 goto done;
753                         }
754                         nl_dump_check_consistent(cb, nlmsg_hdr(skb));
755 cont:
756                         idx++;
757                 }
758                 rcu_read_unlock();
759         }
760         if (h == NETDEV_HASHENTRIES) {
761                 if (inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL,
762                                                net->ipv6.devconf_all,
763                                                NETLINK_CB(cb->skb).portid,
764                                                nlh->nlmsg_seq,
765                                                RTM_NEWNETCONF, NLM_F_MULTI,
766                                                NETCONFA_ALL) < 0)
767                         goto done;
768                 else
769                         h++;
770         }
771         if (h == NETDEV_HASHENTRIES + 1) {
772                 if (inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT,
773                                                net->ipv6.devconf_dflt,
774                                                NETLINK_CB(cb->skb).portid,
775                                                nlh->nlmsg_seq,
776                                                RTM_NEWNETCONF, NLM_F_MULTI,
777                                                NETCONFA_ALL) < 0)
778                         goto done;
779                 else
780                         h++;
781         }
782 done:
783         cb->args[0] = h;
784         cb->args[1] = idx;
785 
786         return skb->len;
787 }
788 
789 #ifdef CONFIG_SYSCTL
790 static void dev_forward_change(struct inet6_dev *idev)
791 {
792         struct net_device *dev;
793         struct inet6_ifaddr *ifa;
794 
795         if (!idev)
796                 return;
797         dev = idev->dev;
798         if (idev->cnf.forwarding)
799                 dev_disable_lro(dev);
800         if (dev->flags & IFF_MULTICAST) {
801                 if (idev->cnf.forwarding) {
802                         ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters);
803                         ipv6_dev_mc_inc(dev, &in6addr_interfacelocal_allrouters);
804                         ipv6_dev_mc_inc(dev, &in6addr_sitelocal_allrouters);
805                 } else {
806                         ipv6_dev_mc_dec(dev, &in6addr_linklocal_allrouters);
807                         ipv6_dev_mc_dec(dev, &in6addr_interfacelocal_allrouters);
808                         ipv6_dev_mc_dec(dev, &in6addr_sitelocal_allrouters);
809                 }
810         }
811 
812         list_for_each_entry(ifa, &idev->addr_list, if_list) {
813                 if (ifa->flags&IFA_F_TENTATIVE)
814                         continue;
815                 if (idev->cnf.forwarding)
816                         addrconf_join_anycast(ifa);
817                 else
818                         addrconf_leave_anycast(ifa);
819         }
820         inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
821                                      NETCONFA_FORWARDING,
822                                      dev->ifindex, &idev->cnf);
823 }
824 
825 
826 static void addrconf_forward_change(struct net *net, __s32 newf)
827 {
828         struct net_device *dev;
829         struct inet6_dev *idev;
830 
831         for_each_netdev(net, dev) {
832                 idev = __in6_dev_get(dev);
833                 if (idev) {
834                         int changed = (!idev->cnf.forwarding) ^ (!newf);
835                         idev->cnf.forwarding = newf;
836                         if (changed)
837                                 dev_forward_change(idev);
838                 }
839         }
840 }
841 
842 static int addrconf_fixup_forwarding(struct ctl_table *table, int *p, int newf)
843 {
844         struct net *net;
845         int old;
846 
847         if (!rtnl_trylock())
848                 return restart_syscall();
849 
850         net = (struct net *)table->extra2;
851         old = *p;
852         *p = newf;
853 
854         if (p == &net->ipv6.devconf_dflt->forwarding) {
855                 if ((!newf) ^ (!old))
856                         inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
857                                                      NETCONFA_FORWARDING,
858                                                      NETCONFA_IFINDEX_DEFAULT,
859                                                      net->ipv6.devconf_dflt);
860                 rtnl_unlock();
861                 return 0;
862         }
863 
864         if (p == &net->ipv6.devconf_all->forwarding) {
865                 int old_dflt = net->ipv6.devconf_dflt->forwarding;
866 
867                 net->ipv6.devconf_dflt->forwarding = newf;
868                 if ((!newf) ^ (!old_dflt))
869                         inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
870                                                      NETCONFA_FORWARDING,
871                                                      NETCONFA_IFINDEX_DEFAULT,
872                                                      net->ipv6.devconf_dflt);
873 
874                 addrconf_forward_change(net, newf);
875                 if ((!newf) ^ (!old))
876                         inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
877                                                      NETCONFA_FORWARDING,
878                                                      NETCONFA_IFINDEX_ALL,
879                                                      net->ipv6.devconf_all);
880         } else if ((!newf) ^ (!old))
881                 dev_forward_change((struct inet6_dev *)table->extra1);
882         rtnl_unlock();
883 
884         if (newf)
885                 rt6_purge_dflt_routers(net);
886         return 1;
887 }
888 
889 static void addrconf_linkdown_change(struct net *net, __s32 newf)
890 {
891         struct net_device *dev;
892         struct inet6_dev *idev;
893 
894         for_each_netdev(net, dev) {
895                 idev = __in6_dev_get(dev);
896                 if (idev) {
897                         int changed = (!idev->cnf.ignore_routes_with_linkdown) ^ (!newf);
898 
899                         idev->cnf.ignore_routes_with_linkdown = newf;
900                         if (changed)
901                                 inet6_netconf_notify_devconf(dev_net(dev),
902                                                              RTM_NEWNETCONF,
903                                                              NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
904                                                              dev->ifindex,
905                                                              &idev->cnf);
906                 }
907         }
908 }
909 
910 static int addrconf_fixup_linkdown(struct ctl_table *table, int *p, int newf)
911 {
912         struct net *net;
913         int old;
914 
915         if (!rtnl_trylock())
916                 return restart_syscall();
917 
918         net = (struct net *)table->extra2;
919         old = *p;
920         *p = newf;
921 
922         if (p == &net->ipv6.devconf_dflt->ignore_routes_with_linkdown) {
923                 if ((!newf) ^ (!old))
924                         inet6_netconf_notify_devconf(net,
925                                                      RTM_NEWNETCONF,
926                                                      NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
927                                                      NETCONFA_IFINDEX_DEFAULT,
928                                                      net->ipv6.devconf_dflt);
929                 rtnl_unlock();
930                 return 0;
931         }
932 
933         if (p == &net->ipv6.devconf_all->ignore_routes_with_linkdown) {
934                 net->ipv6.devconf_dflt->ignore_routes_with_linkdown = newf;
935                 addrconf_linkdown_change(net, newf);
936                 if ((!newf) ^ (!old))
937                         inet6_netconf_notify_devconf(net,
938                                                      RTM_NEWNETCONF,
939                                                      NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN,
940                                                      NETCONFA_IFINDEX_ALL,
941                                                      net->ipv6.devconf_all);
942         }
943         rtnl_unlock();
944 
945         return 1;
946 }
947 
948 #endif
949 
950 /* Nobody refers to this ifaddr, destroy it */
951 void inet6_ifa_finish_destroy(struct inet6_ifaddr *ifp)
952 {
953         WARN_ON(!hlist_unhashed(&ifp->addr_lst));
954 
955 #ifdef NET_REFCNT_DEBUG
956         pr_debug("%s\n", __func__);
957 #endif
958 
959         in6_dev_put(ifp->idev);
960 
961         if (cancel_delayed_work(&ifp->dad_work))
962                 pr_notice("delayed DAD work was pending while freeing ifa=%p\n",
963                           ifp);
964 
965         if (ifp->state != INET6_IFADDR_STATE_DEAD) {
966                 pr_warn("Freeing alive inet6 address %p\n", ifp);
967                 return;
968         }
969 
970         kfree_rcu(ifp, rcu);
971 }
972 
973 static void
974 ipv6_link_dev_addr(struct inet6_dev *idev, struct inet6_ifaddr *ifp)
975 {
976         struct list_head *p;
977         int ifp_scope = ipv6_addr_src_scope(&ifp->addr);
978 
979         /*
980          * Each device address list is sorted in order of scope -
981          * global before linklocal.
982          */
983         list_for_each(p, &idev->addr_list) {
984                 struct inet6_ifaddr *ifa
985                         = list_entry(p, struct inet6_ifaddr, if_list);
986                 if (ifp_scope >= ipv6_addr_src_scope(&ifa->addr))
987                         break;
988         }
989 
990         list_add_tail_rcu(&ifp->if_list, p);
991 }
992 
993 static u32 inet6_addr_hash(const struct net *net, const struct in6_addr *addr)
994 {
995         u32 val = ipv6_addr_hash(addr) ^ net_hash_mix(net);
996 
997         return hash_32(val, IN6_ADDR_HSIZE_SHIFT);
998 }
999 
1000 static bool ipv6_chk_same_addr(struct net *net, const struct in6_addr *addr,
1001                                struct net_device *dev, unsigned int hash)
1002 {
1003         struct inet6_ifaddr *ifp;
1004 
1005         hlist_for_each_entry(ifp, &inet6_addr_lst[hash], addr_lst) {
1006                 if (!net_eq(dev_net(ifp->idev->dev), net))
1007                         continue;
1008                 if (ipv6_addr_equal(&ifp->addr, addr)) {
1009                         if (!dev || ifp->idev->dev == dev)
1010                                 return true;
1011                 }
1012         }
1013         return false;
1014 }
1015 
1016 static int ipv6_add_addr_hash(struct net_device *dev, struct inet6_ifaddr *ifa)
1017 {
1018         unsigned int hash = inet6_addr_hash(dev_net(dev), &ifa->addr);
1019         int err = 0;
1020 
1021         spin_lock(&addrconf_hash_lock);
1022 
1023         /* Ignore adding duplicate addresses on an interface */
1024         if (ipv6_chk_same_addr(dev_net(dev), &ifa->addr, dev, hash)) {
1025                 netdev_dbg(dev, "ipv6_add_addr: already assigned\n");
1026                 err = -EEXIST;
1027         } else {
1028                 hlist_add_head_rcu(&ifa->addr_lst, &inet6_addr_lst[hash]);
1029         }
1030 
1031         spin_unlock(&addrconf_hash_lock);
1032 
1033         return err;
1034 }
1035 
1036 /* On success it returns ifp with increased reference count */
1037 
1038 static struct inet6_ifaddr *
1039 ipv6_add_addr(struct inet6_dev *idev, struct ifa6_config *cfg,
1040               bool can_block, struct netlink_ext_ack *extack)
1041 {
1042         gfp_t gfp_flags = can_block ? GFP_KERNEL : GFP_ATOMIC;
1043         int addr_type = ipv6_addr_type(cfg->pfx);
1044         struct net *net = dev_net(idev->dev);
1045         struct inet6_ifaddr *ifa = NULL;
1046         struct fib6_info *f6i = NULL;
1047         int err = 0;
1048 
1049         if (addr_type == IPV6_ADDR_ANY ||
1050             (addr_type & IPV6_ADDR_MULTICAST &&
1051              !(cfg->ifa_flags & IFA_F_MCAUTOJOIN)) ||
1052             (!(idev->dev->flags & IFF_LOOPBACK) &&
1053              !netif_is_l3_master(idev->dev) &&
1054              addr_type & IPV6_ADDR_LOOPBACK))
1055                 return ERR_PTR(-EADDRNOTAVAIL);
1056 
1057         if (idev->dead) {
1058                 err = -ENODEV;                  /*XXX*/
1059                 goto out;
1060         }
1061 
1062         if (idev->cnf.disable_ipv6) {
1063                 err = -EACCES;
1064                 goto out;
1065         }
1066 
1067         /* validator notifier needs to be blocking;
1068          * do not call in atomic context
1069          */
1070         if (can_block) {
1071                 struct in6_validator_info i6vi = {
1072                         .i6vi_addr = *cfg->pfx,
1073                         .i6vi_dev = idev,
1074                         .extack = extack,
1075                 };
1076 
1077                 err = inet6addr_validator_notifier_call_chain(NETDEV_UP, &i6vi);
1078                 err = notifier_to_errno(err);
1079                 if (err < 0)
1080                         goto out;
1081         }
1082 
1083         ifa = kzalloc(sizeof(*ifa), gfp_flags);
1084         if (!ifa) {
1085                 err = -ENOBUFS;
1086                 goto out;
1087         }
1088 
1089         f6i = addrconf_f6i_alloc(net, idev, cfg->pfx, false, gfp_flags);
1090         if (IS_ERR(f6i)) {
1091                 err = PTR_ERR(f6i);
1092                 f6i = NULL;
1093                 goto out;
1094         }
1095 
1096         if (net->ipv6.devconf_all->disable_policy ||
1097             idev->cnf.disable_policy)
1098                 f6i->dst_nopolicy = true;
1099 
1100         neigh_parms_data_state_setall(idev->nd_parms);
1101 
1102         ifa->addr = *cfg->pfx;
1103         if (cfg->peer_pfx)
1104                 ifa->peer_addr = *cfg->peer_pfx;
1105 
1106         spin_lock_init(&ifa->lock);
1107         INIT_DELAYED_WORK(&ifa->dad_work, addrconf_dad_work);
1108         INIT_HLIST_NODE(&ifa->addr_lst);
1109         ifa->scope = cfg->scope;
1110         ifa->prefix_len = cfg->plen;
1111         ifa->rt_priority = cfg->rt_priority;
1112         ifa->flags = cfg->ifa_flags;
1113         /* No need to add the TENTATIVE flag for addresses with NODAD */
1114         if (!(cfg->ifa_flags & IFA_F_NODAD))
1115                 ifa->flags |= IFA_F_TENTATIVE;
1116         ifa->valid_lft = cfg->valid_lft;
1117         ifa->prefered_lft = cfg->preferred_lft;
1118         ifa->cstamp = ifa->tstamp = jiffies;
1119         ifa->tokenized = false;
1120 
1121         ifa->rt = f6i;
1122 
1123         ifa->idev = idev;
1124         in6_dev_hold(idev);
1125 
1126         /* For caller */
1127         refcount_set(&ifa->refcnt, 1);
1128 
1129         rcu_read_lock_bh();
1130 
1131         err = ipv6_add_addr_hash(idev->dev, ifa);
1132         if (err < 0) {
1133                 rcu_read_unlock_bh();
1134                 goto out;
1135         }
1136 
1137         write_lock(&idev->lock);
1138 
1139         /* Add to inet6_dev unicast addr list. */
1140         ipv6_link_dev_addr(idev, ifa);
1141 
1142         if (ifa->flags&IFA_F_TEMPORARY) {
1143                 list_add(&ifa->tmp_list, &idev->tempaddr_list);
1144                 in6_ifa_hold(ifa);
1145         }
1146 
1147         in6_ifa_hold(ifa);
1148         write_unlock(&idev->lock);
1149 
1150         rcu_read_unlock_bh();
1151 
1152         inet6addr_notifier_call_chain(NETDEV_UP, ifa);
1153 out:
1154         if (unlikely(err < 0)) {
1155                 fib6_info_release(f6i);
1156 
1157                 if (ifa) {
1158                         if (ifa->idev)
1159                                 in6_dev_put(ifa->idev);
1160                         kfree(ifa);
1161                 }
1162                 ifa = ERR_PTR(err);
1163         }
1164 
1165         return ifa;
1166 }
1167 
1168 enum cleanup_prefix_rt_t {
1169         CLEANUP_PREFIX_RT_NOP,    /* no cleanup action for prefix route */
1170         CLEANUP_PREFIX_RT_DEL,    /* delete the prefix route */
1171         CLEANUP_PREFIX_RT_EXPIRE, /* update the lifetime of the prefix route */
1172 };
1173 
1174 /*
1175  * Check, whether the prefix for ifp would still need a prefix route
1176  * after deleting ifp. The function returns one of the CLEANUP_PREFIX_RT_*
1177  * constants.
1178  *
1179  * 1) we don't purge prefix if address was not permanent.
1180  *    prefix is managed by its own lifetime.
1181  * 2) we also don't purge, if the address was IFA_F_NOPREFIXROUTE.
1182  * 3) if there are no addresses, delete prefix.
1183  * 4) if there are still other permanent address(es),
1184  *    corresponding prefix is still permanent.
1185  * 5) if there are still other addresses with IFA_F_NOPREFIXROUTE,
1186  *    don't purge the prefix, assume user space is managing it.
1187  * 6) otherwise, update prefix lifetime to the
1188  *    longest valid lifetime among the corresponding
1189  *    addresses on the device.
1190  *    Note: subsequent RA will update lifetime.
1191  **/
1192 static enum cleanup_prefix_rt_t
1193 check_cleanup_prefix_route(struct inet6_ifaddr *ifp, unsigned long *expires)
1194 {
1195         struct inet6_ifaddr *ifa;
1196         struct inet6_dev *idev = ifp->idev;
1197         unsigned long lifetime;
1198         enum cleanup_prefix_rt_t action = CLEANUP_PREFIX_RT_DEL;
1199 
1200         *expires = jiffies;
1201 
1202         list_for_each_entry(ifa, &idev->addr_list, if_list) {
1203                 if (ifa == ifp)
1204                         continue;
1205                 if (ifa->prefix_len != ifp->prefix_len ||
1206                     !ipv6_prefix_equal(&ifa->addr, &ifp->addr,
1207                                        ifp->prefix_len))
1208                         continue;
1209                 if (ifa->flags & (IFA_F_PERMANENT | IFA_F_NOPREFIXROUTE))
1210                         return CLEANUP_PREFIX_RT_NOP;
1211 
1212                 action = CLEANUP_PREFIX_RT_EXPIRE;
1213 
1214                 spin_lock(&ifa->lock);
1215 
1216                 lifetime = addrconf_timeout_fixup(ifa->valid_lft, HZ);
1217                 /*
1218                  * Note: Because this address is
1219                  * not permanent, lifetime <
1220                  * LONG_MAX / HZ here.
1221                  */
1222                 if (time_before(*expires, ifa->tstamp + lifetime * HZ))
1223                         *expires = ifa->tstamp + lifetime * HZ;
1224                 spin_unlock(&ifa->lock);
1225         }
1226 
1227         return action;
1228 }
1229 
1230 static void
1231 cleanup_prefix_route(struct inet6_ifaddr *ifp, unsigned long expires,
1232                      bool del_rt, bool del_peer)
1233 {
1234         struct fib6_info *f6i;
1235 
1236         f6i = addrconf_get_prefix_route(del_peer ? &ifp->peer_addr : &ifp->addr,
1237                                         ifp->prefix_len,
1238                                         ifp->idev->dev, 0, RTF_DEFAULT, true);
1239         if (f6i) {
1240                 if (del_rt)
1241                         ip6_del_rt(dev_net(ifp->idev->dev), f6i, false);
1242                 else {
1243                         if (!(f6i->fib6_flags & RTF_EXPIRES))
1244                                 fib6_set_expires(f6i, expires);
1245                         fib6_info_release(f6i);
1246                 }
1247         }
1248 }
1249 
1250 
1251 /* This function wants to get referenced ifp and releases it before return */
1252 
1253 static void ipv6_del_addr(struct inet6_ifaddr *ifp)
1254 {
1255         int state;
1256         enum cleanup_prefix_rt_t action = CLEANUP_PREFIX_RT_NOP;
1257         unsigned long expires;
1258 
1259         ASSERT_RTNL();
1260 
1261         spin_lock_bh(&ifp->lock);
1262         state = ifp->state;
1263         ifp->state = INET6_IFADDR_STATE_DEAD;
1264         spin_unlock_bh(&ifp->lock);
1265 
1266         if (state == INET6_IFADDR_STATE_DEAD)
1267                 goto out;
1268 
1269         spin_lock_bh(&addrconf_hash_lock);
1270         hlist_del_init_rcu(&ifp->addr_lst);
1271         spin_unlock_bh(&addrconf_hash_lock);
1272 
1273         write_lock_bh(&ifp->idev->lock);
1274 
1275         if (ifp->flags&IFA_F_TEMPORARY) {
1276                 list_del(&ifp->tmp_list);
1277                 if (ifp->ifpub) {
1278                         in6_ifa_put(ifp->ifpub);
1279                         ifp->ifpub = NULL;
1280                 }
1281                 __in6_ifa_put(ifp);
1282         }
1283 
1284         if (ifp->flags & IFA_F_PERMANENT && !(ifp->flags & IFA_F_NOPREFIXROUTE))
1285                 action = check_cleanup_prefix_route(ifp, &expires);
1286 
1287         list_del_rcu(&ifp->if_list);
1288         __in6_ifa_put(ifp);
1289 
1290         write_unlock_bh(&ifp->idev->lock);
1291 
1292         addrconf_del_dad_work(ifp);
1293 
1294         ipv6_ifa_notify(RTM_DELADDR, ifp);
1295 
1296         inet6addr_notifier_call_chain(NETDEV_DOWN, ifp);
1297 
1298         if (action != CLEANUP_PREFIX_RT_NOP) {
1299                 cleanup_prefix_route(ifp, expires,
1300                         action == CLEANUP_PREFIX_RT_DEL, false);
1301         }
1302 
1303         /* clean up prefsrc entries */
1304         rt6_remove_prefsrc(ifp);
1305 out:
1306         in6_ifa_put(ifp);
1307 }
1308 
1309 static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, bool block)
1310 {
1311         struct inet6_dev *idev = ifp->idev;
1312         unsigned long tmp_tstamp, age;
1313         unsigned long regen_advance;
1314         unsigned long now = jiffies;
1315         s32 cnf_temp_preferred_lft;
1316         struct inet6_ifaddr *ift;
1317         struct ifa6_config cfg;
1318         long max_desync_factor;
1319         struct in6_addr addr;
1320         int ret = 0;
1321 
1322         write_lock_bh(&idev->lock);
1323 
1324 retry:
1325         in6_dev_hold(idev);
1326         if (idev->cnf.use_tempaddr <= 0) {
1327                 write_unlock_bh(&idev->lock);
1328                 pr_info("%s: use_tempaddr is disabled\n", __func__);
1329                 in6_dev_put(idev);
1330                 ret = -1;
1331                 goto out;
1332         }
1333         spin_lock_bh(&ifp->lock);
1334         if (ifp->regen_count++ >= idev->cnf.regen_max_retry) {
1335                 idev->cnf.use_tempaddr = -1;    /*XXX*/
1336                 spin_unlock_bh(&ifp->lock);
1337                 write_unlock_bh(&idev->lock);
1338                 pr_warn("%s: regeneration time exceeded - disabled temporary address support\n",
1339                         __func__);
1340                 in6_dev_put(idev);
1341                 ret = -1;
1342                 goto out;
1343         }
1344         in6_ifa_hold(ifp);
1345         memcpy(addr.s6_addr, ifp->addr.s6_addr, 8);
1346         ipv6_gen_rnd_iid(&addr);
1347 
1348         age = (now - ifp->tstamp) / HZ;
1349 
1350         regen_advance = idev->cnf.regen_max_retry *
1351                         idev->cnf.dad_transmits *
1352                         max(NEIGH_VAR(idev->nd_parms, RETRANS_TIME), HZ/100) / HZ;
1353 
1354         /* recalculate max_desync_factor each time and update
1355          * idev->desync_factor if it's larger
1356          */
1357         cnf_temp_preferred_lft = READ_ONCE(idev->cnf.temp_prefered_lft);
1358         max_desync_factor = min_t(__u32,
1359                                   idev->cnf.max_desync_factor,
1360                                   cnf_temp_preferred_lft - regen_advance);
1361 
1362         if (unlikely(idev->desync_factor > max_desync_factor)) {
1363                 if (max_desync_factor > 0) {
1364                         get_random_bytes(&idev->desync_factor,
1365                                          sizeof(idev->desync_factor));
1366                         idev->desync_factor %= max_desync_factor;
1367                 } else {
1368                         idev->desync_factor = 0;
1369                 }
1370         }
1371 
1372         memset(&cfg, 0, sizeof(cfg));
1373         cfg.valid_lft = min_t(__u32, ifp->valid_lft,
1374                               idev->cnf.temp_valid_lft + age);
1375         cfg.preferred_lft = cnf_temp_preferred_lft + age - idev->desync_factor;
1376         cfg.preferred_lft = min_t(__u32, ifp->prefered_lft, cfg.preferred_lft);
1377 
1378         cfg.plen = ifp->prefix_len;
1379         tmp_tstamp = ifp->tstamp;
1380         spin_unlock_bh(&ifp->lock);
1381 
1382         write_unlock_bh(&idev->lock);
1383 
1384         /* A temporary address is created only if this calculated Preferred
1385          * Lifetime is greater than REGEN_ADVANCE time units.  In particular,
1386          * an implementation must not create a temporary address with a zero
1387          * Preferred Lifetime.
1388          * Use age calculation as in addrconf_verify to avoid unnecessary
1389          * temporary addresses being generated.
1390          */
1391         age = (now - tmp_tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ;
1392         if (cfg.preferred_lft <= regen_advance + age) {
1393                 in6_ifa_put(ifp);
1394                 in6_dev_put(idev);
1395                 ret = -1;
1396                 goto out;
1397         }
1398 
1399         cfg.ifa_flags = IFA_F_TEMPORARY;
1400         /* set in addrconf_prefix_rcv() */
1401         if (ifp->flags & IFA_F_OPTIMISTIC)
1402                 cfg.ifa_flags |= IFA_F_OPTIMISTIC;
1403 
1404         cfg.pfx = &addr;
1405         cfg.scope = ipv6_addr_scope(cfg.pfx);
1406 
1407         ift = ipv6_add_addr(idev, &cfg, block, NULL);
1408         if (IS_ERR(ift)) {
1409                 in6_ifa_put(ifp);
1410                 in6_dev_put(idev);
1411                 pr_info("%s: retry temporary address regeneration\n", __func__);
1412                 write_lock_bh(&idev->lock);
1413                 goto retry;
1414         }
1415 
1416         spin_lock_bh(&ift->lock);
1417         ift->ifpub = ifp;
1418         ift->cstamp = now;
1419         ift->tstamp = tmp_tstamp;
1420         spin_unlock_bh(&ift->lock);
1421 
1422         addrconf_dad_start(ift);
1423         in6_ifa_put(ift);
1424         in6_dev_put(idev);
1425 out:
1426         return ret;
1427 }
1428 
1429 /*
1430  *      Choose an appropriate source address (RFC3484)
1431  */
1432 enum {
1433         IPV6_SADDR_RULE_INIT = 0,
1434         IPV6_SADDR_RULE_LOCAL,
1435         IPV6_SADDR_RULE_SCOPE,
1436         IPV6_SADDR_RULE_PREFERRED,
1437 #ifdef CONFIG_IPV6_MIP6
1438         IPV6_SADDR_RULE_HOA,
1439 #endif
1440         IPV6_SADDR_RULE_OIF,
1441         IPV6_SADDR_RULE_LABEL,
1442         IPV6_SADDR_RULE_PRIVACY,
1443         IPV6_SADDR_RULE_ORCHID,
1444         IPV6_SADDR_RULE_PREFIX,
1445 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1446         IPV6_SADDR_RULE_NOT_OPTIMISTIC,
1447 #endif
1448         IPV6_SADDR_RULE_MAX
1449 };
1450 
1451 struct ipv6_saddr_score {
1452         int                     rule;
1453         int                     addr_type;
1454         struct inet6_ifaddr     *ifa;
1455         DECLARE_BITMAP(scorebits, IPV6_SADDR_RULE_MAX);
1456         int                     scopedist;
1457         int                     matchlen;
1458 };
1459 
1460 struct ipv6_saddr_dst {
1461         const struct in6_addr *addr;
1462         int ifindex;
1463         int scope;
1464         int label;
1465         unsigned int prefs;
1466 };
1467 
1468 static inline int ipv6_saddr_preferred(int type)
1469 {
1470         if (type & (IPV6_ADDR_MAPPED|IPV6_ADDR_COMPATv4|IPV6_ADDR_LOOPBACK))
1471                 return 1;
1472         return 0;
1473 }
1474 
1475 static bool ipv6_use_optimistic_addr(struct net *net,
1476                                      struct inet6_dev *idev)
1477 {
1478 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1479         if (!idev)
1480                 return false;
1481         if (!net->ipv6.devconf_all->optimistic_dad && !idev->cnf.optimistic_dad)
1482                 return false;
1483         if (!net->ipv6.devconf_all->use_optimistic && !idev->cnf.use_optimistic)
1484                 return false;
1485 
1486         return true;
1487 #else
1488         return false;
1489 #endif
1490 }
1491 
1492 static bool ipv6_allow_optimistic_dad(struct net *net,
1493                                       struct inet6_dev *idev)
1494 {
1495 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1496         if (!idev)
1497                 return false;
1498         if (!net->ipv6.devconf_all->optimistic_dad && !idev->cnf.optimistic_dad)
1499                 return false;
1500 
1501         return true;
1502 #else
1503         return false;
1504 #endif
1505 }
1506 
1507 static int ipv6_get_saddr_eval(struct net *net,
1508                                struct ipv6_saddr_score *score,
1509                                struct ipv6_saddr_dst *dst,
1510                                int i)
1511 {
1512         int ret;
1513 
1514         if (i <= score->rule) {
1515                 switch (i) {
1516                 case IPV6_SADDR_RULE_SCOPE:
1517                         ret = score->scopedist;
1518                         break;
1519                 case IPV6_SADDR_RULE_PREFIX:
1520                         ret = score->matchlen;
1521                         break;
1522                 default:
1523                         ret = !!test_bit(i, score->scorebits);
1524                 }
1525                 goto out;
1526         }
1527 
1528         switch (i) {
1529         case IPV6_SADDR_RULE_INIT:
1530                 /* Rule 0: remember if hiscore is not ready yet */
1531                 ret = !!score->ifa;
1532                 break;
1533         case IPV6_SADDR_RULE_LOCAL:
1534                 /* Rule 1: Prefer same address */
1535                 ret = ipv6_addr_equal(&score->ifa->addr, dst->addr);
1536                 break;
1537         case IPV6_SADDR_RULE_SCOPE:
1538                 /* Rule 2: Prefer appropriate scope
1539                  *
1540                  *      ret
1541                  *       ^
1542                  *    -1 |  d 15
1543                  *    ---+--+-+---> scope
1544                  *       |
1545                  *       |             d is scope of the destination.
1546                  *  B-d  |  \
1547                  *       |   \      <- smaller scope is better if
1548                  *  B-15 |    \        if scope is enough for destination.
1549                  *       |             ret = B - scope (-1 <= scope >= d <= 15).
1550                  * d-C-1 | /
1551                  *       |/         <- greater is better
1552                  *   -C  /             if scope is not enough for destination.
1553                  *      /|             ret = scope - C (-1 <= d < scope <= 15).
1554                  *
1555                  * d - C - 1 < B -15 (for all -1 <= d <= 15).
1556                  * C > d + 14 - B >= 15 + 14 - B = 29 - B.
1557                  * Assume B = 0 and we get C > 29.
1558                  */
1559                 ret = __ipv6_addr_src_scope(score->addr_type);
1560                 if (ret >= dst->scope)
1561                         ret = -ret;
1562                 else
1563                         ret -= 128;     /* 30 is enough */
1564                 score->scopedist = ret;
1565                 break;
1566         case IPV6_SADDR_RULE_PREFERRED:
1567             {
1568                 /* Rule 3: Avoid deprecated and optimistic addresses */
1569                 u8 avoid = IFA_F_DEPRECATED;
1570 
1571                 if (!ipv6_use_optimistic_addr(net, score->ifa->idev))
1572                         avoid |= IFA_F_OPTIMISTIC;
1573                 ret = ipv6_saddr_preferred(score->addr_type) ||
1574                       !(score->ifa->flags & avoid);
1575                 break;
1576             }
1577 #ifdef CONFIG_IPV6_MIP6
1578         case IPV6_SADDR_RULE_HOA:
1579             {
1580                 /* Rule 4: Prefer home address */
1581                 int prefhome = !(dst->prefs & IPV6_PREFER_SRC_COA);
1582                 ret = !(score->ifa->flags & IFA_F_HOMEADDRESS) ^ prefhome;
1583                 break;
1584             }
1585 #endif
1586         case IPV6_SADDR_RULE_OIF:
1587                 /* Rule 5: Prefer outgoing interface */
1588                 ret = (!dst->ifindex ||
1589                        dst->ifindex == score->ifa->idev->dev->ifindex);
1590                 break;
1591         case IPV6_SADDR_RULE_LABEL:
1592                 /* Rule 6: Prefer matching label */
1593                 ret = ipv6_addr_label(net,
1594                                       &score->ifa->addr, score->addr_type,
1595                                       score->ifa->idev->dev->ifindex) == dst->label;
1596                 break;
1597         case IPV6_SADDR_RULE_PRIVACY:
1598             {
1599                 /* Rule 7: Prefer public address
1600                  * Note: prefer temporary address if use_tempaddr >= 2
1601                  */
1602                 int preftmp = dst->prefs & (IPV6_PREFER_SRC_PUBLIC|IPV6_PREFER_SRC_TMP) ?
1603                                 !!(dst->prefs & IPV6_PREFER_SRC_TMP) :
1604                                 score->ifa->idev->cnf.use_tempaddr >= 2;
1605                 ret = (!(score->ifa->flags & IFA_F_TEMPORARY)) ^ preftmp;
1606                 break;
1607             }
1608         case IPV6_SADDR_RULE_ORCHID:
1609                 /* Rule 8-: Prefer ORCHID vs ORCHID or
1610                  *          non-ORCHID vs non-ORCHID
1611                  */
1612                 ret = !(ipv6_addr_orchid(&score->ifa->addr) ^
1613                         ipv6_addr_orchid(dst->addr));
1614                 break;
1615         case IPV6_SADDR_RULE_PREFIX:
1616                 /* Rule 8: Use longest matching prefix */
1617                 ret = ipv6_addr_diff(&score->ifa->addr, dst->addr);
1618                 if (ret > score->ifa->prefix_len)
1619                         ret = score->ifa->prefix_len;
1620                 score->matchlen = ret;
1621                 break;
1622 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
1623         case IPV6_SADDR_RULE_NOT_OPTIMISTIC:
1624                 /* Optimistic addresses still have lower precedence than other
1625                  * preferred addresses.
1626                  */
1627                 ret = !(score->ifa->flags & IFA_F_OPTIMISTIC);
1628                 break;
1629 #endif
1630         default:
1631                 ret = 0;
1632         }
1633 
1634         if (ret)
1635                 __set_bit(i, score->scorebits);
1636         score->rule = i;
1637 out:
1638         return ret;
1639 }
1640 
1641 static int __ipv6_dev_get_saddr(struct net *net,
1642                                 struct ipv6_saddr_dst *dst,
1643                                 struct inet6_dev *idev,
1644                                 struct ipv6_saddr_score *scores,
1645                                 int hiscore_idx)
1646 {
1647         struct ipv6_saddr_score *score = &scores[1 - hiscore_idx], *hiscore = &scores[hiscore_idx];
1648 
1649         list_for_each_entry_rcu(score->ifa, &idev->addr_list, if_list) {
1650                 int i;
1651 
1652                 /*
1653                  * - Tentative Address (RFC2462 section 5.4)
1654                  *  - A tentative address is not considered
1655                  *    "assigned to an interface" in the traditional
1656                  *    sense, unless it is also flagged as optimistic.
1657                  * - Candidate Source Address (section 4)
1658                  *  - In any case, anycast addresses, multicast
1659                  *    addresses, and the unspecified address MUST
1660                  *    NOT be included in a candidate set.
1661                  */
1662                 if ((score->ifa->flags & IFA_F_TENTATIVE) &&
1663                     (!(score->ifa->flags & IFA_F_OPTIMISTIC)))
1664                         continue;
1665 
1666                 score->addr_type = __ipv6_addr_type(&score->ifa->addr);
1667 
1668                 if (unlikely(score->addr_type == IPV6_ADDR_ANY ||
1669                              score->addr_type & IPV6_ADDR_MULTICAST)) {
1670                         net_dbg_ratelimited("ADDRCONF: unspecified / multicast address assigned as unicast address on %s",
1671                                             idev->dev->name);
1672                         continue;
1673                 }
1674 
1675                 score->rule = -1;
1676                 bitmap_zero(score->scorebits, IPV6_SADDR_RULE_MAX);
1677 
1678                 for (i = 0; i < IPV6_SADDR_RULE_MAX; i++) {
1679                         int minihiscore, miniscore;
1680 
1681                         minihiscore = ipv6_get_saddr_eval(net, hiscore, dst, i);
1682                         miniscore = ipv6_get_saddr_eval(net, score, dst, i);
1683 
1684                         if (minihiscore > miniscore) {
1685                                 if (i == IPV6_SADDR_RULE_SCOPE &&
1686                                     score->scopedist > 0) {
1687                                         /*
1688                                          * special case:
1689                                          * each remaining entry
1690                                          * has too small (not enough)
1691                                          * scope, because ifa entries
1692                                          * are sorted by their scope
1693                                          * values.
1694                                          */
1695                                         goto out;
1696                                 }
1697                                 break;
1698                         } else if (minihiscore < miniscore) {
1699                                 swap(hiscore, score);
1700                                 hiscore_idx = 1 - hiscore_idx;
1701 
1702                                 /* restore our iterator */
1703                                 score->ifa = hiscore->ifa;
1704 
1705                                 break;
1706                         }
1707                 }
1708         }
1709 out:
1710         return hiscore_idx;
1711 }
1712 
1713 static int ipv6_get_saddr_master(struct net *net,
1714                                  const struct net_device *dst_dev,
1715                                  const struct net_device *master,
1716                                  struct ipv6_saddr_dst *dst,
1717                                  struct ipv6_saddr_score *scores,
1718                                  int hiscore_idx)
1719 {
1720         struct inet6_dev *idev;
1721 
1722         idev = __in6_dev_get(dst_dev);
1723         if (idev)
1724                 hiscore_idx = __ipv6_dev_get_saddr(net, dst, idev,
1725                                                    scores, hiscore_idx);
1726 
1727         idev = __in6_dev_get(master);
1728         if (idev)
1729                 hiscore_idx = __ipv6_dev_get_saddr(net, dst, idev,
1730                                                    scores, hiscore_idx);
1731 
1732         return hiscore_idx;
1733 }
1734 
1735 int ipv6_dev_get_saddr(struct net *net, const struct net_device *dst_dev,
1736                        const struct in6_addr *daddr, unsigned int prefs,
1737                        struct in6_addr *saddr)
1738 {
1739         struct ipv6_saddr_score scores[2], *hiscore;
1740         struct ipv6_saddr_dst dst;
1741         struct inet6_dev *idev;
1742         struct net_device *dev;
1743         int dst_type;
1744         bool use_oif_addr = false;
1745         int hiscore_idx = 0;
1746         int ret = 0;
1747 
1748         dst_type = __ipv6_addr_type(daddr);
1749         dst.addr = daddr;
1750         dst.ifindex = dst_dev ? dst_dev->ifindex : 0;
1751         dst.scope = __ipv6_addr_src_scope(dst_type);
1752         dst.label = ipv6_addr_label(net, daddr, dst_type, dst.ifindex);
1753         dst.prefs = prefs;
1754 
1755         scores[hiscore_idx].rule = -1;
1756         scores[hiscore_idx].ifa = NULL;
1757 
1758         rcu_read_lock();
1759 
1760         /* Candidate Source Address (section 4)
1761          *  - multicast and link-local destination address,
1762          *    the set of candidate source address MUST only
1763          *    include addresses assigned to interfaces
1764          *    belonging to the same link as the outgoing
1765          *    interface.
1766          * (- For site-local destination addresses, the
1767          *    set of candidate source addresses MUST only
1768          *    include addresses assigned to interfaces
1769          *    belonging to the same site as the outgoing
1770          *    interface.)
1771          *  - "It is RECOMMENDED that the candidate source addresses
1772          *    be the set of unicast addresses assigned to the
1773          *    interface that will be used to send to the destination
1774          *    (the 'outgoing' interface)." (RFC 6724)
1775          */
1776         if (dst_dev) {
1777                 idev = __in6_dev_get(dst_dev);
1778                 if ((dst_type & IPV6_ADDR_MULTICAST) ||
1779                     dst.scope <= IPV6_ADDR_SCOPE_LINKLOCAL ||
1780                     (idev && idev->cnf.use_oif_addrs_only)) {
1781                         use_oif_addr = true;
1782                 }
1783         }
1784 
1785         if (use_oif_addr) {
1786                 if (idev)
1787                         hiscore_idx = __ipv6_dev_get_saddr(net, &dst, idev, scores, hiscore_idx);
1788         } else {
1789                 const struct net_device *master;
1790                 int master_idx = 0;
1791 
1792                 /* if dst_dev exists and is enslaved to an L3 device, then
1793                  * prefer addresses from dst_dev and then the master over
1794                  * any other enslaved devices in the L3 domain.
1795                  */
1796                 master = l3mdev_master_dev_rcu(dst_dev);
1797                 if (master) {
1798                         master_idx = master->ifindex;
1799 
1800                         hiscore_idx = ipv6_get_saddr_master(net, dst_dev,
1801                                                             master, &dst,
1802                                                             scores, hiscore_idx);
1803 
1804                         if (scores[hiscore_idx].ifa)
1805                                 goto out;
1806                 }
1807 
1808                 for_each_netdev_rcu(net, dev) {
1809                         /* only consider addresses on devices in the
1810                          * same L3 domain
1811                          */
1812                         if (l3mdev_master_ifindex_rcu(dev) != master_idx)
1813                                 continue;
1814                         idev = __in6_dev_get(dev);
1815                         if (!idev)
1816                                 continue;
1817                         hiscore_idx = __ipv6_dev_get_saddr(net, &dst, idev, scores, hiscore_idx);
1818                 }
1819         }
1820 
1821 out:
1822         hiscore = &scores[hiscore_idx];
1823         if (!hiscore->ifa)
1824                 ret = -EADDRNOTAVAIL;
1825         else
1826                 *saddr = hiscore->ifa->addr;
1827 
1828         rcu_read_unlock();
1829         return ret;
1830 }
1831 EXPORT_SYMBOL(ipv6_dev_get_saddr);
1832 
1833 int __ipv6_get_lladdr(struct inet6_dev *idev, struct in6_addr *addr,
1834                       u32 banned_flags)
1835 {
1836         struct inet6_ifaddr *ifp;
1837         int err = -EADDRNOTAVAIL;
1838 
1839         list_for_each_entry_reverse(ifp, &idev->addr_list, if_list) {
1840                 if (ifp->scope > IFA_LINK)
1841                         break;
1842                 if (ifp->scope == IFA_LINK &&
1843                     !(ifp->flags & banned_flags)) {
1844                         *addr = ifp->addr;
1845                         err = 0;
1846                         break;
1847                 }
1848         }
1849         return err;
1850 }
1851 
1852 int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr,
1853                     u32 banned_flags)
1854 {
1855         struct inet6_dev *idev;
1856         int err = -EADDRNOTAVAIL;
1857 
1858         rcu_read_lock();
1859         idev = __in6_dev_get(dev);
1860         if (idev) {
1861                 read_lock_bh(&idev->lock);
1862                 err = __ipv6_get_lladdr(idev, addr, banned_flags);
1863                 read_unlock_bh(&idev->lock);
1864         }
1865         rcu_read_unlock();
1866         return err;
1867 }
1868 
1869 static int ipv6_count_addresses(const struct inet6_dev *idev)
1870 {
1871         const struct inet6_ifaddr *ifp;
1872         int cnt = 0;
1873 
1874         rcu_read_lock();
1875         list_for_each_entry_rcu(ifp, &idev->addr_list, if_list)
1876                 cnt++;
1877         rcu_read_unlock();
1878         return cnt;
1879 }
1880 
1881 int ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
1882                   const struct net_device *dev, int strict)
1883 {
1884         return ipv6_chk_addr_and_flags(net, addr, dev, !dev,
1885                                        strict, IFA_F_TENTATIVE);
1886 }
1887 EXPORT_SYMBOL(ipv6_chk_addr);
1888 
1889 /* device argument is used to find the L3 domain of interest. If
1890  * skip_dev_check is set, then the ifp device is not checked against
1891  * the passed in dev argument. So the 2 cases for addresses checks are:
1892  *   1. does the address exist in the L3 domain that dev is part of
1893  *      (skip_dev_check = true), or
1894  *
1895  *   2. does the address exist on the specific device
1896  *      (skip_dev_check = false)
1897  */
1898 static struct net_device *
1899 __ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr,
1900                           const struct net_device *dev, bool skip_dev_check,
1901                           int strict, u32 banned_flags)
1902 {
1903         unsigned int hash = inet6_addr_hash(net, addr);
1904         struct net_device *l3mdev, *ndev;
1905         struct inet6_ifaddr *ifp;
1906         u32 ifp_flags;
1907 
1908         rcu_read_lock();
1909 
1910         l3mdev = l3mdev_master_dev_rcu(dev);
1911         if (skip_dev_check)
1912                 dev = NULL;
1913 
1914         hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) {
1915                 ndev = ifp->idev->dev;
1916                 if (!net_eq(dev_net(ndev), net))
1917                         continue;
1918 
1919                 if (l3mdev_master_dev_rcu(ndev) != l3mdev)
1920                         continue;
1921 
1922                 /* Decouple optimistic from tentative for evaluation here.
1923                  * Ban optimistic addresses explicitly, when required.
1924                  */
1925                 ifp_flags = (ifp->flags&IFA_F_OPTIMISTIC)
1926                             ? (ifp->flags&~IFA_F_TENTATIVE)
1927                             : ifp->flags;
1928                 if (ipv6_addr_equal(&ifp->addr, addr) &&
1929                     !(ifp_flags&banned_flags) &&
1930                     (!dev || ndev == dev ||
1931                      !(ifp->scope&(IFA_LINK|IFA_HOST) || strict))) {
1932                         rcu_read_unlock();
1933                         return ndev;
1934                 }
1935         }
1936 
1937         rcu_read_unlock();
1938         return NULL;
1939 }
1940 
1941 int ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr,
1942                             const struct net_device *dev, bool skip_dev_check,
1943                             int strict, u32 banned_flags)
1944 {
1945         return __ipv6_chk_addr_and_flags(net, addr, dev, skip_dev_check,
1946                                          strict, banned_flags) ? 1 : 0;
1947 }
1948 EXPORT_SYMBOL(ipv6_chk_addr_and_flags);
1949 
1950 
1951 /* Compares an address/prefix_len with addresses on device @dev.
1952  * If one is found it returns true.
1953  */
1954 bool ipv6_chk_custom_prefix(const struct in6_addr *addr,
1955         const unsigned int prefix_len, struct net_device *dev)
1956 {
1957         const struct inet6_ifaddr *ifa;
1958         const struct inet6_dev *idev;
1959         bool ret = false;
1960 
1961         rcu_read_lock();
1962         idev = __in6_dev_get(dev);
1963         if (idev) {
1964                 list_for_each_entry_rcu(ifa, &idev->addr_list, if_list) {
1965                         ret = ipv6_prefix_equal(addr, &ifa->addr, prefix_len);
1966                         if (ret)
1967                                 break;
1968                 }
1969         }
1970         rcu_read_unlock();
1971 
1972         return ret;
1973 }
1974 EXPORT_SYMBOL(ipv6_chk_custom_prefix);
1975 
1976 int ipv6_chk_prefix(const struct in6_addr *addr, struct net_device *dev)
1977 {
1978         const struct inet6_ifaddr *ifa;
1979         const struct inet6_dev *idev;
1980         int     onlink;
1981 
1982         onlink = 0;
1983         rcu_read_lock();
1984         idev = __in6_dev_get(dev);
1985         if (idev) {
1986                 list_for_each_entry_rcu(ifa, &idev->addr_list, if_list) {
1987                         onlink = ipv6_prefix_equal(addr, &ifa->addr,
1988                                                    ifa->prefix_len);
1989                         if (onlink)
1990                                 break;
1991                 }
1992         }
1993         rcu_read_unlock();
1994         return onlink;
1995 }
1996 EXPORT_SYMBOL(ipv6_chk_prefix);
1997 
1998 /**
1999  * ipv6_dev_find - find the first device with a given source address.
2000  * @net: the net namespace
2001  * @addr: the source address
2002  * @dev: used to find the L3 domain of interest
2003  *
2004  * The caller should be protected by RCU, or RTNL.
2005  */
2006 struct net_device *ipv6_dev_find(struct net *net, const struct in6_addr *addr,
2007                                  struct net_device *dev)
2008 {
2009         return __ipv6_chk_addr_and_flags(net, addr, dev, !dev, 1,
2010                                          IFA_F_TENTATIVE);
2011 }
2012 EXPORT_SYMBOL(ipv6_dev_find);
2013 
2014 struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *addr,
2015                                      struct net_device *dev, int strict)
2016 {
2017         unsigned int hash = inet6_addr_hash(net, addr);
2018         struct inet6_ifaddr *ifp, *result = NULL;
2019 
2020         rcu_read_lock();
2021         hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) {
2022                 if (!net_eq(dev_net(ifp->idev->dev), net))
2023                         continue;
2024                 if (ipv6_addr_equal(&ifp->addr, addr)) {
2025                         if (!dev || ifp->idev->dev == dev ||
2026                             !(ifp->scope&(IFA_LINK|IFA_HOST) || strict)) {
2027                                 result = ifp;
2028                                 in6_ifa_hold(ifp);
2029                                 break;
2030                         }
2031                 }
2032         }
2033         rcu_read_unlock();
2034 
2035         return result;
2036 }
2037 
2038 /* Gets referenced address, destroys ifaddr */
2039 
2040 static void addrconf_dad_stop(struct inet6_ifaddr *ifp, int dad_failed)
2041 {
2042         if (dad_failed)
2043                 ifp->flags |= IFA_F_DADFAILED;
2044 
2045         if (ifp->flags&IFA_F_TEMPORARY) {
2046                 struct inet6_ifaddr *ifpub;
2047                 spin_lock_bh(&ifp->lock);
2048                 ifpub = ifp->ifpub;
2049                 if (ifpub) {
2050                         in6_ifa_hold(ifpub);
2051                         spin_unlock_bh(&ifp->lock);
2052                         ipv6_create_tempaddr(ifpub, true);
2053                         in6_ifa_put(ifpub);
2054                 } else {
2055                         spin_unlock_bh(&ifp->lock);
2056                 }
2057                 ipv6_del_addr(ifp);
2058         } else if (ifp->flags&IFA_F_PERMANENT || !dad_failed) {
2059                 spin_lock_bh(&ifp->lock);
2060                 addrconf_del_dad_work(ifp);
2061                 ifp->flags |= IFA_F_TENTATIVE;
2062                 if (dad_failed)
2063                         ifp->flags &= ~IFA_F_OPTIMISTIC;
2064                 spin_unlock_bh(&ifp->lock);
2065                 if (dad_failed)
2066                         ipv6_ifa_notify(0, ifp);
2067                 in6_ifa_put(ifp);
2068         } else {
2069                 ipv6_del_addr(ifp);
2070         }
2071 }
2072 
2073 static int addrconf_dad_end(struct inet6_ifaddr *ifp)
2074 {
2075         int err = -ENOENT;
2076 
2077         spin_lock_bh(&ifp->lock);
2078         if (ifp->state == INET6_IFADDR_STATE_DAD) {
2079                 ifp->state = INET6_IFADDR_STATE_POSTDAD;
2080                 err = 0;
2081         }
2082         spin_unlock_bh(&ifp->lock);
2083 
2084         return err;
2085 }
2086 
2087 void addrconf_dad_failure(struct sk_buff *skb, struct inet6_ifaddr *ifp)
2088 {
2089         struct inet6_dev *idev = ifp->idev;
2090         struct net *net = dev_net(ifp->idev->dev);
2091 
2092         if (addrconf_dad_end(ifp)) {
2093                 in6_ifa_put(ifp);
2094                 return;
2095         }
2096 
2097         net_info_ratelimited("%s: IPv6 duplicate address %pI6c used by %pM detected!\n",
2098                              ifp->idev->dev->name, &ifp->addr, eth_hdr(skb)->h_source);
2099 
2100         spin_lock_bh(&ifp->lock);
2101 
2102         if (ifp->flags & IFA_F_STABLE_PRIVACY) {
2103                 struct in6_addr new_addr;
2104                 struct inet6_ifaddr *ifp2;
2105                 int retries = ifp->stable_privacy_retry + 1;
2106                 struct ifa6_config cfg = {
2107                         .pfx = &new_addr,
2108                         .plen = ifp->prefix_len,
2109                         .ifa_flags = ifp->flags,
2110                         .valid_lft = ifp->valid_lft,
2111                         .preferred_lft = ifp->prefered_lft,
2112                         .scope = ifp->scope,
2113                 };
2114 
2115                 if (retries > net->ipv6.sysctl.idgen_retries) {
2116                         net_info_ratelimited("%s: privacy stable address generation failed because of DAD conflicts!\n",
2117                                              ifp->idev->dev->name);
2118                         goto errdad;
2119                 }
2120 
2121                 new_addr = ifp->addr;
2122                 if (ipv6_generate_stable_address(&new_addr, retries,
2123                                                  idev))
2124                         goto errdad;
2125 
2126                 spin_unlock_bh(&ifp->lock);
2127 
2128                 if (idev->cnf.max_addresses &&
2129                     ipv6_count_addresses(idev) >=
2130                     idev->cnf.max_addresses)
2131                         goto lock_errdad;
2132 
2133                 net_info_ratelimited("%s: generating new stable privacy address because of DAD conflict\n",
2134                                      ifp->idev->dev->name);
2135 
2136                 ifp2 = ipv6_add_addr(idev, &cfg, false, NULL);
2137                 if (IS_ERR(ifp2))
2138                         goto lock_errdad;
2139 
2140                 spin_lock_bh(&ifp2->lock);
2141                 ifp2->stable_privacy_retry = retries;
2142                 ifp2->state = INET6_IFADDR_STATE_PREDAD;
2143                 spin_unlock_bh(&ifp2->lock);
2144 
2145                 addrconf_mod_dad_work(ifp2, net->ipv6.sysctl.idgen_delay);
2146                 in6_ifa_put(ifp2);
2147 lock_errdad:
2148                 spin_lock_bh(&ifp->lock);
2149         }
2150 
2151 errdad:
2152         /* transition from _POSTDAD to _ERRDAD */
2153         ifp->state = INET6_IFADDR_STATE_ERRDAD;
2154         spin_unlock_bh(&ifp->lock);
2155 
2156         addrconf_mod_dad_work(ifp, 0);
2157         in6_ifa_put(ifp);
2158 }
2159 
2160 /* Join to solicited addr multicast group.
2161  * caller must hold RTNL */
2162 void addrconf_join_solict(struct net_device *dev, const struct in6_addr *addr)
2163 {
2164         struct in6_addr maddr;
2165 
2166         if (dev->flags&(IFF_LOOPBACK|IFF_NOARP))
2167                 return;
2168 
2169         addrconf_addr_solict_mult(addr, &maddr);
2170         ipv6_dev_mc_inc(dev, &maddr);
2171 }
2172 
2173 /* caller must hold RTNL */
2174 void addrconf_leave_solict(struct inet6_dev *idev, const struct in6_addr *addr)
2175 {
2176         struct in6_addr maddr;
2177 
2178         if (idev->dev->flags&(IFF_LOOPBACK|IFF_NOARP))
2179                 return;
2180 
2181         addrconf_addr_solict_mult(addr, &maddr);
2182         __ipv6_dev_mc_dec(idev, &maddr);
2183 }
2184 
2185 /* caller must hold RTNL */
2186 static void addrconf_join_anycast(struct inet6_ifaddr *ifp)
2187 {
2188         struct in6_addr addr;
2189 
2190         if (ifp->prefix_len >= 127) /* RFC 6164 */
2191                 return;
2192         ipv6_addr_prefix(&addr, &ifp->addr, ifp->prefix_len);
2193         if (ipv6_addr_any(&addr))
2194                 return;
2195         __ipv6_dev_ac_inc(ifp->idev, &addr);
2196 }
2197 
2198 /* caller must hold RTNL */
2199 static void addrconf_leave_anycast(struct inet6_ifaddr *ifp)
2200 {
2201         struct in6_addr addr;
2202 
2203         if (ifp->prefix_len >= 127) /* RFC 6164 */
2204                 return;
2205         ipv6_addr_prefix(&addr, &ifp->addr, ifp->prefix_len);
2206         if (ipv6_addr_any(&addr))
2207                 return;
2208         __ipv6_dev_ac_dec(ifp->idev, &addr);
2209 }
2210 
2211 static int addrconf_ifid_6lowpan(u8 *eui, struct net_device *dev)
2212 {
2213         switch (dev->addr_len) {
2214         case ETH_ALEN:
2215                 memcpy(eui, dev->dev_addr, 3);
2216                 eui[3] = 0xFF;
2217                 eui[4] = 0xFE;
2218                 memcpy(eui + 5, dev->dev_addr + 3, 3);
2219                 break;
2220         case EUI64_ADDR_LEN:
2221                 memcpy(eui, dev->dev_addr, EUI64_ADDR_LEN);
2222                 eui[0] ^= 2;
2223                 break;
2224         default:
2225                 return -1;
2226         }
2227 
2228         return 0;
2229 }
2230 
2231 static int addrconf_ifid_ieee1394(u8 *eui, struct net_device *dev)
2232 {
2233         union fwnet_hwaddr *ha;
2234 
2235         if (dev->addr_len != FWNET_ALEN)
2236                 return -1;
2237 
2238         ha = (union fwnet_hwaddr *)dev->dev_addr;
2239 
2240         memcpy(eui, &ha->uc.uniq_id, sizeof(ha->uc.uniq_id));
2241         eui[0] ^= 2;
2242         return 0;
2243 }
2244 
2245 static int addrconf_ifid_arcnet(u8 *eui, struct net_device *dev)
2246 {
2247         /* XXX: inherit EUI-64 from other interface -- yoshfuji */
2248         if (dev->addr_len != ARCNET_ALEN)
2249                 return -1;
2250         memset(eui, 0, 7);
2251         eui[7] = *(u8 *)dev->dev_addr;
2252         return 0;
2253 }
2254 
2255 static int addrconf_ifid_infiniband(u8 *eui, struct net_device *dev)
2256 {
2257         if (dev->addr_len != INFINIBAND_ALEN)
2258                 return -1;
2259         memcpy(eui, dev->dev_addr + 12, 8);
2260         eui[0] |= 2;
2261         return 0;
2262 }
2263 
2264 static int __ipv6_isatap_ifid(u8 *eui, __be32 addr)
2265 {
2266         if (addr == 0)
2267                 return -1;
2268         eui[0] = (ipv4_is_zeronet(addr) || ipv4_is_private_10(addr) ||
2269                   ipv4_is_loopback(addr) || ipv4_is_linklocal_169(addr) ||
2270                   ipv4_is_private_172(addr) || ipv4_is_test_192(addr) ||
2271                   ipv4_is_anycast_6to4(addr) || ipv4_is_private_192(addr) ||
2272                   ipv4_is_test_198(addr) || ipv4_is_multicast(addr) ||
2273                   ipv4_is_lbcast(addr)) ? 0x00 : 0x02;
2274         eui[1] = 0;
2275         eui[2] = 0x5E;
2276         eui[3] = 0xFE;
2277         memcpy(eui + 4, &addr, 4);
2278         return 0;
2279 }
2280 
2281 static int addrconf_ifid_sit(u8 *eui, struct net_device *dev)
2282 {
2283         if (dev->priv_flags & IFF_ISATAP)
2284                 return __ipv6_isatap_ifid(eui, *(__be32 *)dev->dev_addr);
2285         return -1;
2286 }
2287 
2288 static int addrconf_ifid_gre(u8 *eui, struct net_device *dev)
2289 {
2290         return __ipv6_isatap_ifid(eui, *(__be32 *)dev->dev_addr);
2291 }
2292 
2293 static int addrconf_ifid_ip6tnl(u8 *eui, struct net_device *dev)
2294 {
2295         memcpy(eui, dev->perm_addr, 3);
2296         memcpy(eui + 5, dev->perm_addr + 3, 3);
2297         eui[3] = 0xFF;
2298         eui[4] = 0xFE;
2299         eui[0] ^= 2;
2300         return 0;
2301 }
2302 
2303 static int ipv6_generate_eui64(u8 *eui, struct net_device *dev)
2304 {
2305         switch (dev->type) {
2306         case ARPHRD_ETHER:
2307         case ARPHRD_FDDI:
2308                 return addrconf_ifid_eui48(eui, dev);
2309         case ARPHRD_ARCNET:
2310                 return addrconf_ifid_arcnet(eui, dev);
2311         case ARPHRD_INFINIBAND:
2312                 return addrconf_ifid_infiniband(eui, dev);
2313         case ARPHRD_SIT:
2314                 return addrconf_ifid_sit(eui, dev);
2315         case ARPHRD_IPGRE:
2316         case ARPHRD_TUNNEL:
2317                 return addrconf_ifid_gre(eui, dev);
2318         case ARPHRD_6LOWPAN:
2319                 return addrconf_ifid_6lowpan(eui, dev);
2320         case ARPHRD_IEEE1394:
2321                 return addrconf_ifid_ieee1394(eui, dev);
2322         case ARPHRD_TUNNEL6:
2323         case ARPHRD_IP6GRE:
2324         case ARPHRD_RAWIP:
2325                 return addrconf_ifid_ip6tnl(eui, dev);
2326         }
2327         return -1;
2328 }
2329 
2330 static int ipv6_inherit_eui64(u8 *eui, struct inet6_dev *idev)
2331 {
2332         int err = -1;
2333         struct inet6_ifaddr *ifp;
2334 
2335         read_lock_bh(&idev->lock);
2336         list_for_each_entry_reverse(ifp, &idev->addr_list, if_list) {
2337                 if (ifp->scope > IFA_LINK)
2338                         break;
2339                 if (ifp->scope == IFA_LINK && !(ifp->flags&IFA_F_TENTATIVE)) {
2340                         memcpy(eui, ifp->addr.s6_addr+8, 8);
2341                         err = 0;
2342                         break;
2343                 }
2344         }
2345         read_unlock_bh(&idev->lock);
2346         return err;
2347 }
2348 
2349 /* Generation of a randomized Interface Identifier
2350  * draft-ietf-6man-rfc4941bis, Section 3.3.1
2351  */
2352 
2353 static void ipv6_gen_rnd_iid(struct in6_addr *addr)
2354 {
2355 regen:
2356         get_random_bytes(&addr->s6_addr[8], 8);
2357 
2358         /* <draft-ietf-6man-rfc4941bis-08.txt>, Section 3.3.1:
2359          * check if generated address is not inappropriate:
2360          *
2361          * - Reserved IPv6 Interface Identifiers
2362          * - XXX: already assigned to an address on the device
2363          */
2364 
2365         /* Subnet-router anycast: 0000:0000:0000:0000 */
2366         if (!(addr->s6_addr32[2] | addr->s6_addr32[3]))
2367                 goto regen;
2368 
2369         /* IANA Ethernet block: 0200:5EFF:FE00:0000-0200:5EFF:FE00:5212
2370          * Proxy Mobile IPv6:   0200:5EFF:FE00:5213
2371          * IANA Ethernet block: 0200:5EFF:FE00:5214-0200:5EFF:FEFF:FFFF
2372          */
2373         if (ntohl(addr->s6_addr32[2]) == 0x02005eff &&
2374             (ntohl(addr->s6_addr32[3]) & 0Xff000000) == 0xfe000000)
2375                 goto regen;
2376 
2377         /* Reserved subnet anycast addresses */
2378         if (ntohl(addr->s6_addr32[2]) == 0xfdffffff &&
2379             ntohl(addr->s6_addr32[3]) >= 0Xffffff80)
2380                 goto regen;
2381 }
2382 
2383 /*
2384  *      Add prefix route.
2385  */
2386 
2387 static void
2388 addrconf_prefix_route(struct in6_addr *pfx, int plen, u32 metric,
2389                       struct net_device *dev, unsigned long expires,
2390                       u32 flags, gfp_t gfp_flags)
2391 {
2392         struct fib6_config cfg = {
2393                 .fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_PREFIX,
2394                 .fc_metric = metric ? : IP6_RT_PRIO_ADDRCONF,
2395                 .fc_ifindex = dev->ifindex,
2396                 .fc_expires = expires,
2397                 .fc_dst_len = plen,
2398                 .fc_flags = RTF_UP | flags,
2399                 .fc_nlinfo.nl_net = dev_net(dev),
2400                 .fc_protocol = RTPROT_KERNEL,
2401                 .fc_type = RTN_UNICAST,
2402         };
2403 
2404         cfg.fc_dst = *pfx;
2405 
2406         /* Prevent useless cloning on PtP SIT.
2407            This thing is done here expecting that the whole
2408            class of non-broadcast devices need not cloning.
2409          */
2410 #if IS_ENABLED(CONFIG_IPV6_SIT)
2411         if (dev->type == ARPHRD_SIT && (dev->flags & IFF_POINTOPOINT))
2412                 cfg.fc_flags |= RTF_NONEXTHOP;
2413 #endif
2414 
2415         ip6_route_add(&cfg, gfp_flags, NULL);
2416 }
2417 
2418 
2419 static struct fib6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
2420                                                   int plen,
2421                                                   const struct net_device *dev,
2422                                                   u32 flags, u32 noflags,
2423                                                   bool no_gw)
2424 {
2425         struct fib6_node *fn;
2426         struct fib6_info *rt = NULL;
2427         struct fib6_table *table;
2428         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_PREFIX;
2429 
2430         table = fib6_get_table(dev_net(dev), tb_id);
2431         if (!table)
2432                 return NULL;
2433 
2434         rcu_read_lock();
2435         fn = fib6_locate(&table->tb6_root, pfx, plen, NULL, 0, true);
2436         if (!fn)
2437                 goto out;
2438 
2439         for_each_fib6_node_rt_rcu(fn) {
2440                 /* prefix routes only use builtin fib6_nh */
2441                 if (rt->nh)
2442                         continue;
2443 
2444                 if (rt->fib6_nh->fib_nh_dev->ifindex != dev->ifindex)
2445                         continue;
2446                 if (no_gw && rt->fib6_nh->fib_nh_gw_family)
2447                         continue;
2448                 if ((rt->fib6_flags & flags) != flags)
2449                         continue;
2450                 if ((rt->fib6_flags & noflags) != 0)
2451                         continue;
2452                 if (!fib6_info_hold_safe(rt))
2453                         continue;
2454                 break;
2455         }
2456 out:
2457         rcu_read_unlock();
2458         return rt;
2459 }
2460 
2461 
2462 /* Create "default" multicast route to the interface */
2463 
2464 static void addrconf_add_mroute(struct net_device *dev)
2465 {
2466         struct fib6_config cfg = {
2467                 .fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_LOCAL,
2468                 .fc_metric = IP6_RT_PRIO_ADDRCONF,
2469                 .fc_ifindex = dev->ifindex,
2470                 .fc_dst_len = 8,
2471                 .fc_flags = RTF_UP,
2472                 .fc_type = RTN_MULTICAST,
2473                 .fc_nlinfo.nl_net = dev_net(dev),
2474                 .fc_protocol = RTPROT_KERNEL,
2475         };
2476 
2477         ipv6_addr_set(&cfg.fc_dst, htonl(0xFF000000), 0, 0, 0);
2478 
2479         ip6_route_add(&cfg, GFP_KERNEL, NULL);
2480 }
2481 
2482 static struct inet6_dev *addrconf_add_dev(struct net_device *dev)
2483 {
2484         struct inet6_dev *idev;
2485 
2486         ASSERT_RTNL();
2487 
2488         idev = ipv6_find_idev(dev);
2489         if (IS_ERR(idev))
2490                 return idev;
2491 
2492         if (idev->cnf.disable_ipv6)
2493                 return ERR_PTR(-EACCES);
2494 
2495         /* Add default multicast route */
2496         if (!(dev->flags & IFF_LOOPBACK) && !netif_is_l3_master(dev))
2497                 addrconf_add_mroute(dev);
2498 
2499         return idev;
2500 }
2501 
2502 static void manage_tempaddrs(struct inet6_dev *idev,
2503                              struct inet6_ifaddr *ifp,
2504                              __u32 valid_lft, __u32 prefered_lft,
2505                              bool create, unsigned long now)
2506 {
2507         u32 flags;
2508         struct inet6_ifaddr *ift;
2509 
2510         read_lock_bh(&idev->lock);
2511         /* update all temporary addresses in the list */
2512         list_for_each_entry(ift, &idev->tempaddr_list, tmp_list) {
2513                 int age, max_valid, max_prefered;
2514 
2515                 if (ifp != ift->ifpub)
2516                         continue;
2517 
2518                 /* RFC 4941 section 3.3:
2519                  * If a received option will extend the lifetime of a public
2520                  * address, the lifetimes of temporary addresses should
2521                  * be extended, subject to the overall constraint that no
2522                  * temporary addresses should ever remain "valid" or "preferred"
2523                  * for a time longer than (TEMP_VALID_LIFETIME) or
2524                  * (TEMP_PREFERRED_LIFETIME - DESYNC_FACTOR), respectively.
2525                  */
2526                 age = (now - ift->cstamp) / HZ;
2527                 max_valid = idev->cnf.temp_valid_lft - age;
2528                 if (max_valid < 0)
2529                         max_valid = 0;
2530 
2531                 max_prefered = idev->cnf.temp_prefered_lft -
2532                                idev->desync_factor - age;
2533                 if (max_prefered < 0)
2534                         max_prefered = 0;
2535 
2536                 if (valid_lft > max_valid)
2537                         valid_lft = max_valid;
2538 
2539                 if (prefered_lft > max_prefered)
2540                         prefered_lft = max_prefered;
2541 
2542                 spin_lock(&ift->lock);
2543                 flags = ift->flags;
2544                 ift->valid_lft = valid_lft;
2545                 ift->prefered_lft = prefered_lft;
2546                 ift->tstamp = now;
2547                 if (prefered_lft > 0)
2548                         ift->flags &= ~IFA_F_DEPRECATED;
2549 
2550                 spin_unlock(&ift->lock);
2551                 if (!(flags&IFA_F_TENTATIVE))
2552                         ipv6_ifa_notify(0, ift);
2553         }
2554 
2555         if ((create || list_empty(&idev->tempaddr_list)) &&
2556             idev->cnf.use_tempaddr > 0) {
2557                 /* When a new public address is created as described
2558                  * in [ADDRCONF], also create a new temporary address.
2559                  * Also create a temporary address if it's enabled but
2560                  * no temporary address currently exists.
2561                  */
2562                 read_unlock_bh(&idev->lock);
2563                 ipv6_create_tempaddr(ifp, false);
2564         } else {
2565                 read_unlock_bh(&idev->lock);
2566         }
2567 }
2568 
2569 static bool is_addr_mode_generate_stable(struct inet6_dev *idev)
2570 {
2571         return idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY ||
2572                idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_RANDOM;
2573 }
2574 
2575 int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev,
2576                                  const struct prefix_info *pinfo,
2577                                  struct inet6_dev *in6_dev,
2578                                  const struct in6_addr *addr, int addr_type,
2579                                  u32 addr_flags, bool sllao, bool tokenized,
2580                                  __u32 valid_lft, u32 prefered_lft)
2581 {
2582         struct inet6_ifaddr *ifp = ipv6_get_ifaddr(net, addr, dev, 1);
2583         int create = 0;
2584 
2585         if (!ifp && valid_lft) {
2586                 int max_addresses = in6_dev->cnf.max_addresses;
2587                 struct ifa6_config cfg = {
2588                         .pfx = addr,
2589                         .plen = pinfo->prefix_len,
2590                         .ifa_flags = addr_flags,
2591                         .valid_lft = valid_lft,
2592                         .preferred_lft = prefered_lft,
2593                         .scope = addr_type & IPV6_ADDR_SCOPE_MASK,
2594                 };
2595 
2596 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
2597                 if ((net->ipv6.devconf_all->optimistic_dad ||
2598                      in6_dev->cnf.optimistic_dad) &&
2599                     !net->ipv6.devconf_all->forwarding && sllao)
2600                         cfg.ifa_flags |= IFA_F_OPTIMISTIC;
2601 #endif
2602 
2603                 /* Do not allow to create too much of autoconfigured
2604                  * addresses; this would be too easy way to crash kernel.
2605                  */
2606                 if (!max_addresses ||
2607                     ipv6_count_addresses(in6_dev) < max_addresses)
2608                         ifp = ipv6_add_addr(in6_dev, &cfg, false, NULL);
2609 
2610                 if (IS_ERR_OR_NULL(ifp))
2611                         return -1;
2612 
2613                 create = 1;
2614                 spin_lock_bh(&ifp->lock);
2615                 ifp->flags |= IFA_F_MANAGETEMPADDR;
2616                 ifp->cstamp = jiffies;
2617                 ifp->tokenized = tokenized;
2618                 spin_unlock_bh(&ifp->lock);
2619                 addrconf_dad_start(ifp);
2620         }
2621 
2622         if (ifp) {
2623                 u32 flags;
2624                 unsigned long now;
2625                 u32 stored_lft;
2626 
2627                 /* Update lifetime (RFC4862 5.5.3 e)
2628                  * We deviate from RFC4862 by honoring all Valid Lifetimes to
2629                  * improve the reaction of SLAAC to renumbering events
2630                  * (draft-gont-6man-slaac-renum-06, Section 4.2)
2631                  */
2632                 spin_lock_bh(&ifp->lock);
2633                 now = jiffies;
2634                 if (ifp->valid_lft > (now - ifp->tstamp) / HZ)
2635                         stored_lft = ifp->valid_lft - (now - ifp->tstamp) / HZ;
2636                 else
2637                         stored_lft = 0;
2638 
2639                 if (!create && stored_lft) {
2640                         ifp->valid_lft = valid_lft;
2641                         ifp->prefered_lft = prefered_lft;
2642                         ifp->tstamp = now;
2643                         flags = ifp->flags;
2644                         ifp->flags &= ~IFA_F_DEPRECATED;
2645                         spin_unlock_bh(&ifp->lock);
2646 
2647                         if (!(flags&IFA_F_TENTATIVE))
2648                                 ipv6_ifa_notify(0, ifp);
2649                 } else
2650                         spin_unlock_bh(&ifp->lock);
2651 
2652                 manage_tempaddrs(in6_dev, ifp, valid_lft, prefered_lft,
2653                                  create, now);
2654 
2655                 in6_ifa_put(ifp);
2656                 addrconf_verify();
2657         }
2658 
2659         return 0;
2660 }
2661 EXPORT_SYMBOL_GPL(addrconf_prefix_rcv_add_addr);
2662 
2663 void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao)
2664 {
2665         struct prefix_info *pinfo;
2666         __u32 valid_lft;
2667         __u32 prefered_lft;
2668         int addr_type, err;
2669         u32 addr_flags = 0;
2670         struct inet6_dev *in6_dev;
2671         struct net *net = dev_net(dev);
2672 
2673         pinfo = (struct prefix_info *) opt;
2674 
2675         if (len < sizeof(struct prefix_info)) {
2676                 netdev_dbg(dev, "addrconf: prefix option too short\n");
2677                 return;
2678         }
2679 
2680         /*
2681          *      Validation checks ([ADDRCONF], page 19)
2682          */
2683 
2684         addr_type = ipv6_addr_type(&pinfo->prefix);
2685 
2686         if (addr_type & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL))
2687                 return;
2688 
2689         valid_lft = ntohl(pinfo->valid);
2690         prefered_lft = ntohl(pinfo->prefered);
2691 
2692         if (prefered_lft > valid_lft) {
2693                 net_warn_ratelimited("addrconf: prefix option has invalid lifetime\n");
2694                 return;
2695         }
2696 
2697         in6_dev = in6_dev_get(dev);
2698 
2699         if (!in6_dev) {
2700                 net_dbg_ratelimited("addrconf: device %s not configured\n",
2701                                     dev->name);
2702                 return;
2703         }
2704 
2705         /*
2706          *      Two things going on here:
2707          *      1) Add routes for on-link prefixes
2708          *      2) Configure prefixes with the auto flag set
2709          */
2710 
2711         if (pinfo->onlink) {
2712                 struct fib6_info *rt;
2713                 unsigned long rt_expires;
2714 
2715                 /* Avoid arithmetic overflow. Really, we could
2716                  * save rt_expires in seconds, likely valid_lft,
2717                  * but it would require division in fib gc, that it
2718                  * not good.
2719                  */
2720                 if (HZ > USER_HZ)
2721                         rt_expires = addrconf_timeout_fixup(valid_lft, HZ);
2722                 else
2723                         rt_expires = addrconf_timeout_fixup(valid_lft, USER_HZ);
2724 
2725                 if (addrconf_finite_timeout(rt_expires))
2726                         rt_expires *= HZ;
2727 
2728                 rt = addrconf_get_prefix_route(&pinfo->prefix,
2729                                                pinfo->prefix_len,
2730                                                dev,
2731                                                RTF_ADDRCONF | RTF_PREFIX_RT,
2732                                                RTF_DEFAULT, true);
2733 
2734                 if (rt) {
2735                         /* Autoconf prefix route */
2736                         if (valid_lft == 0) {
2737                                 ip6_del_rt(net, rt, false);
2738                                 rt = NULL;
2739                         } else if (addrconf_finite_timeout(rt_expires)) {
2740                                 /* not infinity */
2741                                 fib6_set_expires(rt, jiffies + rt_expires);
2742                         } else {
2743                                 fib6_clean_expires(rt);
2744                         }
2745                 } else if (valid_lft) {
2746                         clock_t expires = 0;
2747                         int flags = RTF_ADDRCONF | RTF_PREFIX_RT;
2748                         if (addrconf_finite_timeout(rt_expires)) {
2749                                 /* not infinity */
2750                                 flags |= RTF_EXPIRES;
2751                                 expires = jiffies_to_clock_t(rt_expires);
2752                         }
2753                         addrconf_prefix_route(&pinfo->prefix, pinfo->prefix_len,
2754                                               0, dev, expires, flags,
2755                                               GFP_ATOMIC);
2756                 }
2757                 fib6_info_release(rt);
2758         }
2759 
2760         /* Try to figure out our local address for this prefix */
2761 
2762         if (pinfo->autoconf && in6_dev->cnf.autoconf) {
2763                 struct in6_addr addr;
2764                 bool tokenized = false, dev_addr_generated = false;
2765 
2766                 if (pinfo->prefix_len == 64) {
2767                         memcpy(&addr, &pinfo->prefix, 8);
2768 
2769                         if (!ipv6_addr_any(&in6_dev->token)) {
2770                                 read_lock_bh(&in6_dev->lock);
2771                                 memcpy(addr.s6_addr + 8,
2772                                        in6_dev->token.s6_addr + 8, 8);
2773                                 read_unlock_bh(&in6_dev->lock);
2774                                 tokenized = true;
2775                         } else if (is_addr_mode_generate_stable(in6_dev) &&
2776                                    !ipv6_generate_stable_address(&addr, 0,
2777                                                                  in6_dev)) {
2778                                 addr_flags |= IFA_F_STABLE_PRIVACY;
2779                                 goto ok;
2780                         } else if (ipv6_generate_eui64(addr.s6_addr + 8, dev) &&
2781                                    ipv6_inherit_eui64(addr.s6_addr + 8, in6_dev)) {
2782                                 goto put;
2783                         } else {
2784                                 dev_addr_generated = true;
2785                         }
2786                         goto ok;
2787                 }
2788                 net_dbg_ratelimited("IPv6 addrconf: prefix with wrong length %d\n",
2789                                     pinfo->prefix_len);
2790                 goto put;
2791 
2792 ok:
2793                 err = addrconf_prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
2794                                                    &addr, addr_type,
2795                                                    addr_flags, sllao,
2796                                                    tokenized, valid_lft,
2797                                                    prefered_lft);
2798                 if (err)
2799                         goto put;
2800 
2801                 /* Ignore error case here because previous prefix add addr was
2802                  * successful which will be notified.
2803                  */
2804                 ndisc_ops_prefix_rcv_add_addr(net, dev, pinfo, in6_dev, &addr,
2805                                               addr_type, addr_flags, sllao,
2806                                               tokenized, valid_lft,
2807                                               prefered_lft,
2808                                               dev_addr_generated);
2809         }
2810         inet6_prefix_notify(RTM_NEWPREFIX, in6_dev, pinfo);
2811 put:
2812         in6_dev_put(in6_dev);
2813 }
2814 
2815 static int addrconf_set_sit_dstaddr(struct net *net, struct net_device *dev,
2816                 struct in6_ifreq *ireq)
2817 {
2818         struct ip_tunnel_parm p = { };
2819         int err;
2820 
2821         if (!(ipv6_addr_type(&ireq->ifr6_addr) & IPV6_ADDR_COMPATv4))
2822                 return -EADDRNOTAVAIL;
2823 
2824         p.iph.daddr = ireq->ifr6_addr.s6_addr32[3];
2825         p.iph.version = 4;
2826         p.iph.ihl = 5;
2827         p.iph.protocol = IPPROTO_IPV6;
2828         p.iph.ttl = 64;
2829 
2830         if (!dev->netdev_ops->ndo_tunnel_ctl)
2831                 return -EOPNOTSUPP;
2832         err = dev->netdev_ops->ndo_tunnel_ctl(dev, &p, SIOCADDTUNNEL);
2833         if (err)
2834                 return err;
2835 
2836         dev = __dev_get_by_name(net, p.name);
2837         if (!dev)
2838                 return -ENOBUFS;
2839         return dev_open(dev, NULL);
2840 }
2841 
2842 /*
2843  *      Set destination address.
2844  *      Special case for SIT interfaces where we create a new "virtual"
2845  *      device.
2846  */
2847 int addrconf_set_dstaddr(struct net *net, void __user *arg)
2848 {
2849         struct net_device *dev;
2850         struct in6_ifreq ireq;
2851         int err = -ENODEV;
2852 
2853         if (!IS_ENABLED(CONFIG_IPV6_SIT))
2854                 return -ENODEV;
2855         if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
2856                 return -EFAULT;
2857 
2858         rtnl_lock();
2859         dev = __dev_get_by_index(net, ireq.ifr6_ifindex);
2860         if (dev && dev->type == ARPHRD_SIT)
2861                 err = addrconf_set_sit_dstaddr(net, dev, &ireq);
2862         rtnl_unlock();
2863         return err;
2864 }
2865 
2866 static int ipv6_mc_config(struct sock *sk, bool join,
2867                           const struct in6_addr *addr, int ifindex)
2868 {
2869         int ret;
2870 
2871         ASSERT_RTNL();
2872 
2873         lock_sock(sk);
2874         if (join)
2875                 ret = ipv6_sock_mc_join(sk, ifindex, addr);
2876         else
2877                 ret = ipv6_sock_mc_drop(sk, ifindex, addr);
2878         release_sock(sk);
2879 
2880         return ret;
2881 }
2882 
2883 /*
2884  *      Manual configuration of address on an interface
2885  */
2886 static int inet6_addr_add(struct net *net, int ifindex,
2887                           struct ifa6_config *cfg,
2888                           struct netlink_ext_ack *extack)
2889 {
2890         struct inet6_ifaddr *ifp;
2891         struct inet6_dev *idev;
2892         struct net_device *dev;
2893         unsigned long timeout;
2894         clock_t expires;
2895         u32 flags;
2896 
2897         ASSERT_RTNL();
2898 
2899         if (cfg->plen > 128)
2900                 return -EINVAL;
2901 
2902         /* check the lifetime */
2903         if (!cfg->valid_lft || cfg->preferred_lft > cfg->valid_lft)
2904                 return -EINVAL;
2905 
2906         if (cfg->ifa_flags & IFA_F_MANAGETEMPADDR && cfg->plen != 64)
2907                 return -EINVAL;
2908 
2909         dev = __dev_get_by_index(net, ifindex);
2910         if (!dev)
2911                 return -ENODEV;
2912 
2913         idev = addrconf_add_dev(dev);
2914         if (IS_ERR(idev))
2915                 return PTR_ERR(idev);
2916 
2917         if (cfg->ifa_flags & IFA_F_MCAUTOJOIN) {
2918                 int ret = ipv6_mc_config(net->ipv6.mc_autojoin_sk,
2919                                          true, cfg->pfx, ifindex);
2920 
2921                 if (ret < 0)
2922                         return ret;
2923         }
2924 
2925         cfg->scope = ipv6_addr_scope(cfg->pfx);
2926 
2927         timeout = addrconf_timeout_fixup(cfg->valid_lft, HZ);
2928         if (addrconf_finite_timeout(timeout)) {
2929                 expires = jiffies_to_clock_t(timeout * HZ);
2930                 cfg->valid_lft = timeout;
2931                 flags = RTF_EXPIRES;
2932         } else {
2933                 expires = 0;
2934                 flags = 0;
2935                 cfg->ifa_flags |= IFA_F_PERMANENT;
2936         }
2937 
2938         timeout = addrconf_timeout_fixup(cfg->preferred_lft, HZ);
2939         if (addrconf_finite_timeout(timeout)) {
2940                 if (timeout == 0)
2941                         cfg->ifa_flags |= IFA_F_DEPRECATED;
2942                 cfg->preferred_lft = timeout;
2943         }
2944 
2945         ifp = ipv6_add_addr(idev, cfg, true, extack);
2946         if (!IS_ERR(ifp)) {
2947                 if (!(cfg->ifa_flags & IFA_F_NOPREFIXROUTE)) {
2948                         addrconf_prefix_route(&ifp->addr, ifp->prefix_len,
2949                                               ifp->rt_priority, dev, expires,
2950                                               flags, GFP_KERNEL);
2951                 }
2952 
2953                 /* Send a netlink notification if DAD is enabled and
2954                  * optimistic flag is not set
2955                  */
2956                 if (!(ifp->flags & (IFA_F_OPTIMISTIC | IFA_F_NODAD)))
2957                         ipv6_ifa_notify(0, ifp);
2958                 /*
2959                  * Note that section 3.1 of RFC 4429 indicates
2960                  * that the Optimistic flag should not be set for
2961                  * manually configured addresses
2962                  */
2963                 addrconf_dad_start(ifp);
2964                 if (cfg->ifa_flags & IFA_F_MANAGETEMPADDR)
2965                         manage_tempaddrs(idev, ifp, cfg->valid_lft,
2966                                          cfg->preferred_lft, true, jiffies);
2967                 in6_ifa_put(ifp);
2968                 addrconf_verify_rtnl();
2969                 return 0;
2970         } else if (cfg->ifa_flags & IFA_F_MCAUTOJOIN) {
2971                 ipv6_mc_config(net->ipv6.mc_autojoin_sk, false,
2972                                cfg->pfx, ifindex);
2973         }
2974 
2975         return PTR_ERR(ifp);
2976 }
2977 
2978 static int inet6_addr_del(struct net *net, int ifindex, u32 ifa_flags,
2979                           const struct in6_addr *pfx, unsigned int plen)
2980 {
2981         struct inet6_ifaddr *ifp;
2982         struct inet6_dev *idev;
2983         struct net_device *dev;
2984 
2985         if (plen > 128)
2986                 return -EINVAL;
2987 
2988         dev = __dev_get_by_index(net, ifindex);
2989         if (!dev)
2990                 return -ENODEV;
2991 
2992         idev = __in6_dev_get(dev);
2993         if (!idev)
2994                 return -ENXIO;
2995 
2996         read_lock_bh(&idev->lock);
2997         list_for_each_entry(ifp, &idev->addr_list, if_list) {
2998                 if (ifp->prefix_len == plen &&
2999                     ipv6_addr_equal(pfx, &ifp->addr)) {
3000                         in6_ifa_hold(ifp);
3001                         read_unlock_bh(&idev->lock);
3002 
3003                         if (!(ifp->flags & IFA_F_TEMPORARY) &&
3004                             (ifa_flags & IFA_F_MANAGETEMPADDR))
3005                                 manage_tempaddrs(idev, ifp, 0, 0, false,
3006                                                  jiffies);
3007                         ipv6_del_addr(ifp);
3008                         addrconf_verify_rtnl();
3009                         if (ipv6_addr_is_multicast(pfx)) {
3010                                 ipv6_mc_config(net->ipv6.mc_autojoin_sk,
3011                                                false, pfx, dev->ifindex);
3012                         }
3013                         return 0;
3014                 }
3015         }
3016         read_unlock_bh(&idev->lock);
3017         return -EADDRNOTAVAIL;
3018 }
3019 
3020 
3021 int addrconf_add_ifaddr(struct net *net, void __user *arg)
3022 {
3023         struct ifa6_config cfg = {
3024                 .ifa_flags = IFA_F_PERMANENT,
3025                 .preferred_lft = INFINITY_LIFE_TIME,
3026                 .valid_lft = INFINITY_LIFE_TIME,
3027         };
3028         struct in6_ifreq ireq;
3029         int err;
3030 
3031         if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
3032                 return -EPERM;
3033 
3034         if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
3035                 return -EFAULT;
3036 
3037         cfg.pfx = &ireq.ifr6_addr;
3038         cfg.plen = ireq.ifr6_prefixlen;
3039 
3040         rtnl_lock();
3041         err = inet6_addr_add(net, ireq.ifr6_ifindex, &cfg, NULL);
3042         rtnl_unlock();
3043         return err;
3044 }
3045 
3046 int addrconf_del_ifaddr(struct net *net, void __user *arg)
3047 {
3048         struct in6_ifreq ireq;
3049         int err;
3050 
3051         if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
3052                 return -EPERM;
3053 
3054         if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
3055                 return -EFAULT;
3056 
3057         rtnl_lock();
3058         err = inet6_addr_del(net, ireq.ifr6_ifindex, 0, &ireq.ifr6_addr,
3059                              ireq.ifr6_prefixlen);
3060         rtnl_unlock();
3061         return err;
3062 }
3063 
3064 static void add_addr(struct inet6_dev *idev, const struct in6_addr *addr,
3065                      int plen, int scope)
3066 {
3067         struct inet6_ifaddr *ifp;
3068         struct ifa6_config cfg = {
3069                 .pfx = addr,
3070                 .plen = plen,
3071                 .ifa_flags = IFA_F_PERMANENT,
3072                 .valid_lft = INFINITY_LIFE_TIME,
3073                 .preferred_lft = INFINITY_LIFE_TIME,
3074                 .scope = scope
3075         };
3076 
3077         ifp = ipv6_add_addr(idev, &cfg, true, NULL);
3078         if (!IS_ERR(ifp)) {
3079                 spin_lock_bh(&ifp->lock);
3080                 ifp->flags &= ~IFA_F_TENTATIVE;
3081                 spin_unlock_bh(&ifp->lock);
3082                 rt_genid_bump_ipv6(dev_net(idev->dev));
3083                 ipv6_ifa_notify(RTM_NEWADDR, ifp);
3084                 in6_ifa_put(ifp);
3085         }
3086 }
3087 
3088 #if IS_ENABLED(CONFIG_IPV6_SIT)
3089 static void sit_add_v4_addrs(struct inet6_dev *idev)
3090 {
3091         struct in6_addr addr;
3092         struct net_device *dev;
3093         struct net *net = dev_net(idev->dev);
3094         int scope, plen;
3095         u32 pflags = 0;
3096 
3097         ASSERT_RTNL();
3098 
3099         memset(&addr, 0, sizeof(struct in6_addr));
3100         memcpy(&addr.s6_addr32[3], idev->dev->dev_addr, 4);
3101 
3102         if (idev->dev->flags&IFF_POINTOPOINT) {
3103                 if (idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_NONE)
3104                         return;
3105 
3106                 addr.s6_addr32[0] = htonl(0xfe800000);
3107                 scope = IFA_LINK;
3108                 plen = 64;
3109         } else {
3110                 scope = IPV6_ADDR_COMPATv4;
3111                 plen = 96;
3112                 pflags |= RTF_NONEXTHOP;
3113         }
3114 
3115         if (addr.s6_addr32[3]) {
3116                 add_addr(idev, &addr, plen, scope);
3117                 addrconf_prefix_route(&addr, plen, 0, idev->dev, 0, pflags,
3118                                       GFP_KERNEL);
3119                 return;
3120         }
3121 
3122         for_each_netdev(net, dev) {
3123                 struct in_device *in_dev = __in_dev_get_rtnl(dev);
3124                 if (in_dev && (dev->flags & IFF_UP)) {
3125                         struct in_ifaddr *ifa;
3126                         int flag = scope;
3127 
3128                         in_dev_for_each_ifa_rtnl(ifa, in_dev) {
3129                                 addr.s6_addr32[3] = ifa->ifa_local;
3130 
3131                                 if (ifa->ifa_scope == RT_SCOPE_LINK)
3132                                         continue;
3133                                 if (ifa->ifa_scope >= RT_SCOPE_HOST) {
3134                                         if (idev->dev->flags&IFF_POINTOPOINT)
3135                                                 continue;
3136                                         flag |= IFA_HOST;
3137                                 }
3138 
3139                                 add_addr(idev, &addr, plen, flag);
3140                                 addrconf_prefix_route(&addr, plen, 0, idev->dev,
3141                                                       0, pflags, GFP_KERNEL);
3142                         }
3143                 }
3144         }
3145 }
3146 #endif
3147 
3148 static void init_loopback(struct net_device *dev)
3149 {
3150         struct inet6_dev  *idev;
3151 
3152         /* ::1 */
3153 
3154         ASSERT_RTNL();
3155 
3156         idev = ipv6_find_idev(dev);
3157         if (IS_ERR(idev)) {
3158                 pr_debug("%s: add_dev failed\n", __func__);
3159                 return;
3160         }
3161 
3162         add_addr(idev, &in6addr_loopback, 128, IFA_HOST);
3163 }
3164 
3165 void addrconf_add_linklocal(struct inet6_dev *idev,
3166                             const struct in6_addr *addr, u32 flags)
3167 {
3168         struct ifa6_config cfg = {
3169                 .pfx = addr,
3170                 .plen = 64,
3171                 .ifa_flags = flags | IFA_F_PERMANENT,
3172                 .valid_lft = INFINITY_LIFE_TIME,
3173                 .preferred_lft = INFINITY_LIFE_TIME,
3174                 .scope = IFA_LINK
3175         };
3176         struct inet6_ifaddr *ifp;
3177 
3178 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
3179         if ((dev_net(idev->dev)->ipv6.devconf_all->optimistic_dad ||
3180              idev->cnf.optimistic_dad) &&
3181             !dev_net(idev->dev)->ipv6.devconf_all->forwarding)
3182                 cfg.ifa_flags |= IFA_F_OPTIMISTIC;
3183 #endif
3184 
3185         ifp = ipv6_add_addr(idev, &cfg, true, NULL);
3186         if (!IS_ERR(ifp)) {
3187                 addrconf_prefix_route(&ifp->addr, ifp->prefix_len, 0, idev->dev,
3188                                       0, 0, GFP_ATOMIC);
3189                 addrconf_dad_start(ifp);
3190                 in6_ifa_put(ifp);
3191         }
3192 }
3193 EXPORT_SYMBOL_GPL(addrconf_add_linklocal);
3194 
3195 static bool ipv6_reserved_interfaceid(struct in6_addr address)
3196 {
3197         if ((address.s6_addr32[2] | address.s6_addr32[3]) == 0)
3198                 return true;
3199 
3200         if (address.s6_addr32[2] == htonl(0x02005eff) &&
3201             ((address.s6_addr32[3] & htonl(0xfe000000)) == htonl(0xfe000000)))
3202                 return true;
3203 
3204         if (address.s6_addr32[2] == htonl(0xfdffffff) &&
3205             ((address.s6_addr32[3] & htonl(0xffffff80)) == htonl(0xffffff80)))
3206                 return true;
3207 
3208         return false;
3209 }
3210 
3211 static int ipv6_generate_stable_address(struct in6_addr *address,
3212                                         u8 dad_count,
3213                                         const struct inet6_dev *idev)
3214 {
3215         static DEFINE_SPINLOCK(lock);
3216         static __u32 digest[SHA1_DIGEST_WORDS];
3217         static __u32 workspace[SHA1_WORKSPACE_WORDS];
3218 
3219         static union {
3220                 char __data[SHA1_BLOCK_SIZE];
3221                 struct {
3222                         struct in6_addr secret;
3223                         __be32 prefix[2];
3224                         unsigned char hwaddr[MAX_ADDR_LEN];
3225                         u8 dad_count;
3226                 } __packed;
3227         } data;
3228 
3229         struct in6_addr secret;
3230         struct in6_addr temp;
3231         struct net *net = dev_net(idev->dev);
3232 
3233         BUILD_BUG_ON(sizeof(data.__data) != sizeof(data));
3234 
3235         if (idev->cnf.stable_secret.initialized)
3236                 secret = idev->cnf.stable_secret.secret;
3237         else if (net->ipv6.devconf_dflt->stable_secret.initialized)
3238                 secret = net->ipv6.devconf_dflt->stable_secret.secret;
3239         else
3240                 return -1;
3241 
3242 retry:
3243         spin_lock_bh(&lock);
3244 
3245         sha1_init(digest);
3246         memset(&data, 0, sizeof(data));
3247         memset(workspace, 0, sizeof(workspace));
3248         memcpy(data.hwaddr, idev->dev->perm_addr, idev->dev->addr_len);
3249         data.prefix[0] = address->s6_addr32[0];
3250         data.prefix[1] = address->s6_addr32[1];
3251         data.secret = secret;
3252         data.dad_count = dad_count;
3253 
3254         sha1_transform(digest, data.__data, workspace);
3255 
3256         temp = *address;
3257         temp.s6_addr32[2] = (__force __be32)digest[0];
3258         temp.s6_addr32[3] = (__force __be32)digest[1];
3259 
3260         spin_unlock_bh(&lock);
3261 
3262         if (ipv6_reserved_interfaceid(temp)) {
3263                 dad_count++;
3264                 if (dad_count > dev_net(idev->dev)->ipv6.sysctl.idgen_retries)
3265                         return -1;
3266                 goto retry;
3267         }
3268 
3269         *address = temp;
3270         return 0;
3271 }
3272 
3273 static void ipv6_gen_mode_random_init(struct inet6_dev *idev)
3274 {
3275         struct ipv6_stable_secret *s = &idev->cnf.stable_secret;
3276 
3277         if (s->initialized)
3278                 return;
3279         s = &idev->cnf.stable_secret;
3280         get_random_bytes(&s->secret, sizeof(s->secret));
3281         s->initialized = true;
3282 }
3283 
3284 static void addrconf_addr_gen(struct inet6_dev *idev, bool prefix_route)
3285 {
3286         struct in6_addr addr;
3287 
3288         /* no link local addresses on L3 master devices */
3289         if (netif_is_l3_master(idev->dev))
3290                 return;
3291 
3292         /* no link local addresses on devices flagged as slaves */
3293         if (idev->dev->flags & IFF_SLAVE)
3294                 return;
3295 
3296         ipv6_addr_set(&addr, htonl(0xFE800000), 0, 0, 0);
3297 
3298         switch (idev->cnf.addr_gen_mode) {
3299         case IN6_ADDR_GEN_MODE_RANDOM:
3300                 ipv6_gen_mode_random_init(idev);
3301                 fallthrough;
3302         case IN6_ADDR_GEN_MODE_STABLE_PRIVACY:
3303                 if (!ipv6_generate_stable_address(&addr, 0, idev))
3304                         addrconf_add_linklocal(idev, &addr,
3305                                                IFA_F_STABLE_PRIVACY);
3306                 else if (prefix_route)
3307                         addrconf_prefix_route(&addr, 64, 0, idev->dev,
3308                                               0, 0, GFP_KERNEL);
3309                 break;
3310         case IN6_ADDR_GEN_MODE_EUI64:
3311                 /* addrconf_add_linklocal also adds a prefix_route and we
3312                  * only need to care about prefix routes if ipv6_generate_eui64
3313                  * couldn't generate one.
3314                  */
3315                 if (ipv6_generate_eui64(addr.s6_addr + 8, idev->dev) == 0)
3316                         addrconf_add_linklocal(idev, &addr, 0);
3317                 else if (prefix_route)
3318                         addrconf_prefix_route(&addr, 64, 0, idev->dev,
3319                                               0, 0, GFP_KERNEL);
3320                 break;
3321         case IN6_ADDR_GEN_MODE_NONE:
3322         default:
3323                 /* will not add any link local address */
3324                 break;
3325         }
3326 }
3327 
3328 static void addrconf_dev_config(struct net_device *dev)
3329 {
3330         struct inet6_dev *idev;
3331 
3332         ASSERT_RTNL();
3333 
3334         if ((dev->type != ARPHRD_ETHER) &&
3335             (dev->type != ARPHRD_FDDI) &&
3336             (dev->type != ARPHRD_ARCNET) &&
3337             (dev->type != ARPHRD_INFINIBAND) &&
3338             (dev->type != ARPHRD_IEEE1394) &&
3339             (dev->type != ARPHRD_TUNNEL6) &&
3340             (dev->type != ARPHRD_6LOWPAN) &&
3341             (dev->type != ARPHRD_IP6GRE) &&
3342             (dev->type != ARPHRD_IPGRE) &&
3343             (dev->type != ARPHRD_TUNNEL) &&
3344             (dev->type != ARPHRD_NONE) &&
3345             (dev->type != ARPHRD_RAWIP)) {
3346                 /* Alas, we support only Ethernet autoconfiguration. */
3347                 idev = __in6_dev_get(dev);
3348                 if (!IS_ERR_OR_NULL(idev) && dev->flags & IFF_UP &&
3349                     dev->flags & IFF_MULTICAST)
3350                         ipv6_mc_up(idev);
3351                 return;
3352         }
3353 
3354         idev = addrconf_add_dev(dev);
3355         if (IS_ERR(idev))
3356                 return;
3357 
3358         /* this device type has no EUI support */
3359         if (dev->type == ARPHRD_NONE &&
3360             idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_EUI64)
3361                 idev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_RANDOM;
3362 
3363         addrconf_addr_gen(idev, false);
3364 }
3365 
3366 #if IS_ENABLED(CONFIG_IPV6_SIT)
3367 static void addrconf_sit_config(struct net_device *dev)
3368 {
3369         struct inet6_dev *idev;
3370 
3371         ASSERT_RTNL();
3372 
3373         /*
3374          * Configure the tunnel with one of our IPv4
3375          * addresses... we should configure all of
3376          * our v4 addrs in the tunnel
3377          */
3378 
3379         idev = ipv6_find_idev(dev);
3380         if (IS_ERR(idev)) {
3381                 pr_debug("%s: add_dev failed\n", __func__);
3382                 return;
3383         }
3384 
3385         if (dev->priv_flags & IFF_ISATAP) {
3386                 addrconf_addr_gen(idev, false);
3387                 return;
3388         }
3389 
3390         sit_add_v4_addrs(idev);
3391 
3392         if (dev->flags&IFF_POINTOPOINT)
3393                 addrconf_add_mroute(dev);
3394 }
3395 #endif
3396 
3397 #if IS_ENABLED(CONFIG_NET_IPGRE)
3398 static void addrconf_gre_config(struct net_device *dev)
3399 {
3400         struct inet6_dev *idev;
3401 
3402         ASSERT_RTNL();
3403 
3404         idev = ipv6_find_idev(dev);
3405         if (IS_ERR(idev)) {
3406                 pr_debug("%s: add_dev failed\n", __func__);
3407                 return;
3408         }
3409 
3410         addrconf_addr_gen(idev, true);
3411         if (dev->flags & IFF_POINTOPOINT)
3412                 addrconf_add_mroute(dev);
3413 }
3414 #endif
3415 
3416 static int fixup_permanent_addr(struct net *net,
3417                                 struct inet6_dev *idev,
3418                                 struct inet6_ifaddr *ifp)
3419 {
3420         /* !fib6_node means the host route was removed from the
3421          * FIB, for example, if 'lo' device is taken down. In that
3422          * case regenerate the host route.
3423          */
3424         if (!ifp->rt || !ifp->rt->fib6_node) {
3425                 struct fib6_info *f6i, *prev;
3426 
3427                 f6i = addrconf_f6i_alloc(net, idev, &ifp->addr, false,
3428                                          GFP_ATOMIC);
3429                 if (IS_ERR(f6i))
3430                         return PTR_ERR(f6i);
3431 
3432                 /* ifp->rt can be accessed outside of rtnl */
3433                 spin_lock(&ifp->lock);
3434                 prev = ifp->rt;
3435                 ifp->rt = f6i;
3436                 spin_unlock(&ifp->lock);
3437 
3438                 fib6_info_release(prev);
3439         }
3440 
3441         if (!(ifp->flags & IFA_F_NOPREFIXROUTE)) {
3442                 addrconf_prefix_route(&ifp->addr, ifp->prefix_len,
3443                                       ifp->rt_priority, idev->dev, 0, 0,
3444                                       GFP_ATOMIC);
3445         }
3446 
3447         if (ifp->state == INET6_IFADDR_STATE_PREDAD)
3448                 addrconf_dad_start(ifp);
3449 
3450         return 0;
3451 }
3452 
3453 static void addrconf_permanent_addr(struct net *net, struct net_device *dev)
3454 {
3455         struct inet6_ifaddr *ifp, *tmp;
3456         struct inet6_dev *idev;
3457 
3458         idev = __in6_dev_get(dev);
3459         if (!idev)
3460                 return;
3461 
3462         write_lock_bh(&idev->lock);
3463 
3464         list_for_each_entry_safe(ifp, tmp, &idev->addr_list, if_list) {
3465                 if ((ifp->flags & IFA_F_PERMANENT) &&
3466                     fixup_permanent_addr(net, idev, ifp) < 0) {
3467                         write_unlock_bh(&idev->lock);
3468                         in6_ifa_hold(ifp);
3469                         ipv6_del_addr(ifp);
3470                         write_lock_bh(&idev->lock);
3471 
3472                         net_info_ratelimited("%s: Failed to add prefix route for address %pI6c; dropping\n",
3473                                              idev->dev->name, &ifp->addr);
3474                 }
3475         }
3476 
3477         write_unlock_bh(&idev->lock);
3478 }
3479 
3480 static int addrconf_notify(struct notifier_block *this, unsigned long event,
3481                            void *ptr)
3482 {
3483         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3484         struct netdev_notifier_change_info *change_info;
3485         struct netdev_notifier_changeupper_info *info;
3486         struct inet6_dev *idev = __in6_dev_get(dev);
3487         struct net *net = dev_net(dev);
3488         int run_pending = 0;
3489         int err;
3490 
3491         switch (event) {
3492         case NETDEV_REGISTER:
3493                 if (!idev && dev->mtu >= IPV6_MIN_MTU) {
3494                         idev = ipv6_add_dev(dev);
3495                         if (IS_ERR(idev))
3496                                 return notifier_from_errno(PTR_ERR(idev));
3497                 }
3498                 break;
3499 
3500         case NETDEV_CHANGEMTU:
3501                 /* if MTU under IPV6_MIN_MTU stop IPv6 on this interface. */
3502                 if (dev->mtu < IPV6_MIN_MTU) {
3503                         addrconf_ifdown(dev, dev != net->loopback_dev);
3504                         break;
3505                 }
3506 
3507                 if (idev) {
3508                         rt6_mtu_change(dev, dev->mtu);
3509                         idev->cnf.mtu6 = dev->mtu;
3510                         break;
3511                 }
3512 
3513                 /* allocate new idev */
3514                 idev = ipv6_add_dev(dev);
3515                 if (IS_ERR(idev))
3516                         break;
3517 
3518                 /* device is still not ready */
3519                 if (!(idev->if_flags & IF_READY))
3520                         break;
3521 
3522                 run_pending = 1;
3523                 fallthrough;
3524         case NETDEV_UP:
3525         case NETDEV_CHANGE:
3526                 if (dev->flags & IFF_SLAVE)
3527                         break;
3528 
3529                 if (idev && idev->cnf.disable_ipv6)
3530                         break;
3531 
3532                 if (event == NETDEV_UP) {
3533                         /* restore routes for permanent addresses */
3534                         addrconf_permanent_addr(net, dev);
3535 
3536                         if (!addrconf_link_ready(dev)) {
3537                                 /* device is not ready yet. */
3538                                 pr_debug("ADDRCONF(NETDEV_UP): %s: link is not ready\n",
3539                                          dev->name);
3540                                 break;
3541                         }
3542 
3543                         if (!idev && dev->mtu >= IPV6_MIN_MTU)
3544                                 idev = ipv6_add_dev(dev);
3545 
3546                         if (!IS_ERR_OR_NULL(idev)) {
3547                                 idev->if_flags |= IF_READY;
3548                                 run_pending = 1;
3549                         }
3550                 } else if (event == NETDEV_CHANGE) {
3551                         if (!addrconf_link_ready(dev)) {
3552                                 /* device is still not ready. */
3553                                 rt6_sync_down_dev(dev, event);
3554                                 break;
3555                         }
3556 
3557                         if (!IS_ERR_OR_NULL(idev)) {
3558                                 if (idev->if_flags & IF_READY) {
3559                                         /* device is already configured -
3560                                          * but resend MLD reports, we might
3561                                          * have roamed and need to update
3562                                          * multicast snooping switches
3563                                          */
3564                                         ipv6_mc_up(idev);
3565                                         change_info = ptr;
3566                                         if (change_info->flags_changed & IFF_NOARP)
3567                                                 addrconf_dad_run(idev, true);
3568                                         rt6_sync_up(dev, RTNH_F_LINKDOWN);
3569                                         break;
3570                                 }
3571                                 idev->if_flags |= IF_READY;
3572                         }
3573 
3574                         pr_info("ADDRCONF(NETDEV_CHANGE): %s: link becomes ready\n",
3575                                 dev->name);
3576 
3577                         run_pending = 1;
3578                 }
3579 
3580                 switch (dev->type) {
3581 #if IS_ENABLED(CONFIG_IPV6_SIT)
3582                 case ARPHRD_SIT:
3583                         addrconf_sit_config(dev);
3584                         break;
3585 #endif
3586 #if IS_ENABLED(CONFIG_NET_IPGRE)
3587                 case ARPHRD_IPGRE:
3588                         addrconf_gre_config(dev);
3589                         break;
3590 #endif
3591                 case ARPHRD_LOOPBACK:
3592                         init_loopback(dev);
3593                         break;
3594 
3595                 default:
3596                         addrconf_dev_config(dev);
3597                         break;
3598                 }
3599 
3600                 if (!IS_ERR_OR_NULL(idev)) {
3601                         if (run_pending)
3602                                 addrconf_dad_run(idev, false);
3603 
3604                         /* Device has an address by now */
3605                         rt6_sync_up(dev, RTNH_F_DEAD);
3606 
3607                         /*
3608                          * If the MTU changed during the interface down,
3609                          * when the interface up, the changed MTU must be
3610                          * reflected in the idev as well as routers.
3611                          */
3612                         if (idev->cnf.mtu6 != dev->mtu &&
3613                             dev->mtu >= IPV6_MIN_MTU) {
3614                                 rt6_mtu_change(dev, dev->mtu);
3615                                 idev->cnf.mtu6 = dev->mtu;
3616                         }
3617                         idev->tstamp = jiffies;
3618                         inet6_ifinfo_notify(RTM_NEWLINK, idev);
3619 
3620                         /*
3621                          * If the changed mtu during down is lower than
3622                          * IPV6_MIN_MTU stop IPv6 on this interface.
3623                          */
3624                         if (dev->mtu < IPV6_MIN_MTU)
3625                                 addrconf_ifdown(dev, dev != net->loopback_dev);
3626                 }
3627                 break;
3628 
3629         case NETDEV_DOWN:
3630         case NETDEV_UNREGISTER:
3631                 /*
3632                  *      Remove all addresses from this interface.
3633                  */
3634                 addrconf_ifdown(dev, event != NETDEV_DOWN);
3635                 break;
3636 
3637         case NETDEV_CHANGENAME:
3638                 if (idev) {
3639                         snmp6_unregister_dev(idev);
3640                         addrconf_sysctl_unregister(idev);
3641                         err = addrconf_sysctl_register(idev);
3642                         if (err)
3643                                 return notifier_from_errno(err);
3644                         err = snmp6_register_dev(idev);
3645                         if (err) {
3646                                 addrconf_sysctl_unregister(idev);
3647                                 return notifier_from_errno(err);
3648                         }
3649                 }
3650                 break;
3651 
3652         case NETDEV_PRE_TYPE_CHANGE:
3653         case NETDEV_POST_TYPE_CHANGE:
3654                 if (idev)
3655                         addrconf_type_change(dev, event);
3656                 break;
3657 
3658         case NETDEV_CHANGEUPPER:
3659                 info = ptr;
3660 
3661                 /* flush all routes if dev is linked to or unlinked from
3662                  * an L3 master device (e.g., VRF)
3663                  */
3664                 if (info->upper_dev && netif_is_l3_master(info->upper_dev))
3665                         addrconf_ifdown(dev, false);
3666         }
3667 
3668         return NOTIFY_OK;
3669 }
3670 
3671 /*
3672  *      addrconf module should be notified of a device going up
3673  */
3674 static struct notifier_block ipv6_dev_notf = {
3675         .notifier_call = addrconf_notify,
3676         .priority = ADDRCONF_NOTIFY_PRIORITY,
3677 };
3678 
3679 static void addrconf_type_change(struct net_device *dev, unsigned long event)
3680 {
3681         struct inet6_dev *idev;
3682         ASSERT_RTNL();
3683 
3684         idev = __in6_dev_get(dev);
3685 
3686         if (event == NETDEV_POST_TYPE_CHANGE)
3687                 ipv6_mc_remap(idev);
3688         else if (event == NETDEV_PRE_TYPE_CHANGE)
3689                 ipv6_mc_unmap(idev);
3690 }
3691 
3692 static bool addr_is_local(const struct in6_addr *addr)
3693 {
3694         return ipv6_addr_type(addr) &
3695                 (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);
3696 }
3697 
3698 static int addrconf_ifdown(struct net_device *dev, bool unregister)
3699 {
3700         unsigned long event = unregister ? NETDEV_UNREGISTER : NETDEV_DOWN;
3701         struct net *net = dev_net(dev);
3702         struct inet6_dev *idev;
3703         struct inet6_ifaddr *ifa, *tmp;
3704         bool keep_addr = false;
3705         int state, i;
3706 
3707         ASSERT_RTNL();
3708 
3709         rt6_disable_ip(dev, event);
3710 
3711         idev = __in6_dev_get(dev);
3712         if (!idev)
3713                 return -ENODEV;
3714 
3715         /*
3716          * Step 1: remove reference to ipv6 device from parent device.
3717          *         Do not dev_put!
3718          */
3719         if (unregister) {
3720                 idev->dead = 1;
3721 
3722                 /* protected by rtnl_lock */
3723                 RCU_INIT_POINTER(dev->ip6_ptr, NULL);
3724 
3725                 /* Step 1.5: remove snmp6 entry */
3726                 snmp6_unregister_dev(idev);
3727 
3728         }
3729 
3730         /* combine the user config with event to determine if permanent
3731          * addresses are to be removed from address hash table
3732          */
3733         if (!unregister && !idev->cnf.disable_ipv6) {
3734                 /* aggregate the system setting and interface setting */
3735                 int _keep_addr = net->ipv6.devconf_all->keep_addr_on_down;
3736 
3737                 if (!_keep_addr)
3738                         _keep_addr = idev->cnf.keep_addr_on_down;
3739 
3740                 keep_addr = (_keep_addr > 0);
3741         }
3742 
3743         /* Step 2: clear hash table */
3744         for (i = 0; i < IN6_ADDR_HSIZE; i++) {
3745                 struct hlist_head *h = &inet6_addr_lst[i];
3746 
3747                 spin_lock_bh(&addrconf_hash_lock);
3748 restart:
3749                 hlist_for_each_entry_rcu(ifa, h, addr_lst) {
3750                         if (ifa->idev == idev) {
3751                                 addrconf_del_dad_work(ifa);
3752                                 /* combined flag + permanent flag decide if
3753                                  * address is retained on a down event
3754                                  */
3755                                 if (!keep_addr ||
3756                                     !(ifa->flags & IFA_F_PERMANENT) ||
3757                                     addr_is_local(&ifa->addr)) {
3758                                         hlist_del_init_rcu(&ifa->addr_lst);
3759                                         goto restart;
3760                                 }
3761                         }
3762                 }
3763                 spin_unlock_bh(&addrconf_hash_lock);
3764         }
3765 
3766         write_lock_bh(&idev->lock);
3767 
3768         addrconf_del_rs_timer(idev);
3769 
3770         /* Step 2: clear flags for stateless addrconf */
3771         if (!unregister)
3772                 idev->if_flags &= ~(IF_RS_SENT|IF_RA_RCVD|IF_READY);
3773 
3774         /* Step 3: clear tempaddr list */
3775         while (!list_empty(&idev->tempaddr_list)) {
3776                 ifa = list_first_entry(&idev->tempaddr_list,
3777                                        struct inet6_ifaddr, tmp_list);
3778                 list_del(&ifa->tmp_list);
3779                 write_unlock_bh(&idev->lock);
3780                 spin_lock_bh(&ifa->lock);
3781 
3782                 if (ifa->ifpub) {
3783                         in6_ifa_put(ifa->ifpub);
3784                         ifa->ifpub = NULL;
3785                 }
3786                 spin_unlock_bh(&ifa->lock);
3787                 in6_ifa_put(ifa);
3788                 write_lock_bh(&idev->lock);
3789         }
3790 
3791         list_for_each_entry_safe(ifa, tmp, &idev->addr_list, if_list) {
3792                 struct fib6_info *rt = NULL;
3793                 bool keep;
3794 
3795                 addrconf_del_dad_work(ifa);
3796 
3797                 keep = keep_addr && (ifa->flags & IFA_F_PERMANENT) &&
3798                         !addr_is_local(&ifa->addr);
3799 
3800                 write_unlock_bh(&idev->lock);
3801                 spin_lock_bh(&ifa->lock);
3802 
3803                 if (keep) {
3804                         /* set state to skip the notifier below */
3805                         state = INET6_IFADDR_STATE_DEAD;
3806                         ifa->state = INET6_IFADDR_STATE_PREDAD;
3807                         if (!(ifa->flags & IFA_F_NODAD))
3808                                 ifa->flags |= IFA_F_TENTATIVE;
3809 
3810                         rt = ifa->rt;
3811                         ifa->rt = NULL;
3812                 } else {
3813                         state = ifa->state;
3814                         ifa->state = INET6_IFADDR_STATE_DEAD;
3815                 }
3816 
3817                 spin_unlock_bh(&ifa->lock);
3818 
3819                 if (rt)
3820                         ip6_del_rt(net, rt, false);
3821 
3822                 if (state != INET6_IFADDR_STATE_DEAD) {
3823                         __ipv6_ifa_notify(RTM_DELADDR, ifa);
3824                         inet6addr_notifier_call_chain(NETDEV_DOWN, ifa);
3825                 } else {
3826                         if (idev->cnf.forwarding)
3827                                 addrconf_leave_anycast(ifa);
3828                         addrconf_leave_solict(ifa->idev, &ifa->addr);
3829                 }
3830 
3831                 write_lock_bh(&idev->lock);
3832                 if (!keep) {
3833                         list_del_rcu(&ifa->if_list);
3834                         in6_ifa_put(ifa);
3835                 }
3836         }
3837 
3838         write_unlock_bh(&idev->lock);
3839 
3840         /* Step 5: Discard anycast and multicast list */
3841         if (unregister) {
3842                 ipv6_ac_destroy_dev(idev);
3843                 ipv6_mc_destroy_dev(idev);
3844         } else {
3845                 ipv6_mc_down(idev);
3846         }
3847 
3848         idev->tstamp = jiffies;
3849 
3850         /* Last: Shot the device (if unregistered) */
3851         if (unregister) {
3852                 addrconf_sysctl_unregister(idev);
3853                 neigh_parms_release(&nd_tbl, idev->nd_parms);
3854                 neigh_ifdown(&nd_tbl, dev);
3855                 in6_dev_put(idev);
3856         }
3857         return 0;
3858 }
3859 
3860 static void addrconf_rs_timer(struct timer_list *t)
3861 {
3862         struct inet6_dev *idev = from_timer(idev, t, rs_timer);
3863         struct net_device *dev = idev->dev;
3864         struct in6_addr lladdr;
3865 
3866         write_lock(&idev->lock);
3867         if (idev->dead || !(idev->if_flags & IF_READY))
3868                 goto out;
3869 
3870         if (!ipv6_accept_ra(idev))
3871                 goto out;
3872 
3873         /* Announcement received after solicitation was sent */
3874         if (idev->if_flags & IF_RA_RCVD)
3875                 goto out;
3876 
3877         if (idev->rs_probes++ < idev->cnf.rtr_solicits || idev->cnf.rtr_solicits < 0) {
3878                 write_unlock(&idev->lock);
3879                 if (!ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE))
3880                         ndisc_send_rs(dev, &lladdr,
3881                                       &in6addr_linklocal_allrouters);
3882                 else
3883                         goto put;
3884 
3885                 write_lock(&idev->lock);
3886                 idev->rs_interval = rfc3315_s14_backoff_update(
3887                         idev->rs_interval, idev->cnf.rtr_solicit_max_interval);
3888                 /* The wait after the last probe can be shorter */
3889                 addrconf_mod_rs_timer(idev, (idev->rs_probes ==
3890                                              idev->cnf.rtr_solicits) ?
3891                                       idev->cnf.rtr_solicit_delay :
3892                                       idev->rs_interval);
3893         } else {
3894                 /*
3895                  * Note: we do not support deprecated "all on-link"
3896                  * assumption any longer.
3897                  */
3898                 pr_debug("%s: no IPv6 routers present\n", idev->dev->name);
3899         }
3900 
3901 out:
3902         write_unlock(&idev->lock);
3903 put:
3904         in6_dev_put(idev);
3905 }
3906 
3907 /*
3908  *      Duplicate Address Detection
3909  */
3910 static void addrconf_dad_kick(struct inet6_ifaddr *ifp)
3911 {
3912         unsigned long rand_num;
3913         struct inet6_dev *idev = ifp->idev;
3914         u64 nonce;
3915 
3916         if (ifp->flags & IFA_F_OPTIMISTIC)
3917                 rand_num = 0;
3918         else
3919                 rand_num = prandom_u32() % (idev->cnf.rtr_solicit_delay ? : 1);
3920 
3921         nonce = 0;
3922         if (idev->cnf.enhanced_dad ||
3923             dev_net(idev->dev)->ipv6.devconf_all->enhanced_dad) {
3924                 do
3925                         get_random_bytes(&nonce, 6);
3926                 while (nonce == 0);
3927         }
3928         ifp->dad_nonce = nonce;
3929         ifp->dad_probes = idev->cnf.dad_transmits;
3930         addrconf_mod_dad_work(ifp, rand_num);
3931 }
3932 
3933 static void addrconf_dad_begin(struct inet6_ifaddr *ifp)
3934 {
3935         struct inet6_dev *idev = ifp->idev;
3936         struct net_device *dev = idev->dev;
3937         bool bump_id, notify = false;
3938         struct net *net;
3939 
3940         addrconf_join_solict(dev, &ifp->addr);
3941 
3942         prandom_seed((__force u32) ifp->addr.s6_addr32[3]);
3943 
3944         read_lock_bh(&idev->lock);
3945         spin_lock(&ifp->lock);
3946         if (ifp->state == INET6_IFADDR_STATE_DEAD)
3947                 goto out;
3948 
3949         net = dev_net(dev);
3950         if (dev->flags&(IFF_NOARP|IFF_LOOPBACK) ||
3951             (net->ipv6.devconf_all->accept_dad < 1 &&
3952              idev->cnf.accept_dad < 1) ||
3953             !(ifp->flags&IFA_F_TENTATIVE) ||
3954             ifp->flags & IFA_F_NODAD) {
3955                 bool send_na = false;
3956 
3957                 if (ifp->flags & IFA_F_TENTATIVE &&
3958                     !(ifp->flags & IFA_F_OPTIMISTIC))
3959                         send_na = true;
3960                 bump_id = ifp->flags & IFA_F_TENTATIVE;
3961                 ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC|IFA_F_DADFAILED);
3962                 spin_unlock(&ifp->lock);
3963                 read_unlock_bh(&idev->lock);
3964 
3965                 addrconf_dad_completed(ifp, bump_id, send_na);
3966                 return;
3967         }
3968 
3969         if (!(idev->if_flags & IF_READY)) {
3970                 spin_unlock(&ifp->lock);
3971                 read_unlock_bh(&idev->lock);
3972                 /*
3973                  * If the device is not ready:
3974                  * - keep it tentative if it is a permanent address.
3975                  * - otherwise, kill it.
3976                  */
3977                 in6_ifa_hold(ifp);
3978                 addrconf_dad_stop(ifp, 0);
3979                 return;
3980         }
3981 
3982         /*
3983          * Optimistic nodes can start receiving
3984          * Frames right away
3985          */
3986         if (ifp->flags & IFA_F_OPTIMISTIC) {
3987                 ip6_ins_rt(net, ifp->rt);
3988                 if (ipv6_use_optimistic_addr(net, idev)) {
3989                         /* Because optimistic nodes can use this address,
3990                          * notify listeners. If DAD fails, RTM_DELADDR is sent.
3991                          */
3992                         notify = true;
3993                 }
3994         }
3995 
3996         addrconf_dad_kick(ifp);
3997 out:
3998         spin_unlock(&ifp->lock);
3999         read_unlock_bh(&idev->lock);
4000         if (notify)
4001                 ipv6_ifa_notify(RTM_NEWADDR, ifp);
4002 }
4003 
4004 static void addrconf_dad_start(struct inet6_ifaddr *ifp)
4005 {
4006         bool begin_dad = false;
4007 
4008         spin_lock_bh(&ifp->lock);
4009         if (ifp->state != INET6_IFADDR_STATE_DEAD) {
4010                 ifp->state = INET6_IFADDR_STATE_PREDAD;
4011                 begin_dad = true;
4012         }
4013         spin_unlock_bh(&ifp->lock);
4014 
4015         if (begin_dad)
4016                 addrconf_mod_dad_work(ifp, 0);
4017 }
4018 
4019 static void addrconf_dad_work(struct work_struct *w)
4020 {
4021         struct inet6_ifaddr *ifp = container_of(to_delayed_work(w),
4022                                                 struct inet6_ifaddr,
4023                                                 dad_work);
4024         struct inet6_dev *idev = ifp->idev;
4025         bool bump_id, disable_ipv6 = false;
4026         struct in6_addr mcaddr;
4027 
4028         enum {
4029                 DAD_PROCESS,
4030                 DAD_BEGIN,
4031                 DAD_ABORT,
4032         } action = DAD_PROCESS;
4033 
4034         rtnl_lock();
4035 
4036         spin_lock_bh(&ifp->lock);
4037         if (ifp->state == INET6_IFADDR_STATE_PREDAD) {
4038                 action = DAD_BEGIN;
4039                 ifp->state = INET6_IFADDR_STATE_DAD;
4040         } else if (ifp->state == INET6_IFADDR_STATE_ERRDAD) {
4041                 action = DAD_ABORT;
4042                 ifp->state = INET6_IFADDR_STATE_POSTDAD;
4043 
4044                 if ((dev_net(idev->dev)->ipv6.devconf_all->accept_dad > 1 ||
4045                      idev->cnf.accept_dad > 1) &&
4046                     !idev->cnf.disable_ipv6 &&
4047                     !(ifp->flags & IFA_F_STABLE_PRIVACY)) {
4048                         struct in6_addr addr;
4049 
4050                         addr.s6_addr32[0] = htonl(0xfe800000);
4051                         addr.s6_addr32[1] = 0;
4052 
4053                         if (!ipv6_generate_eui64(addr.s6_addr + 8, idev->dev) &&
4054                             ipv6_addr_equal(&ifp->addr, &addr)) {
4055                                 /* DAD failed for link-local based on MAC */
4056                                 idev->cnf.disable_ipv6 = 1;
4057 
4058                                 pr_info("%s: IPv6 being disabled!\n",
4059                                         ifp->idev->dev->name);
4060                                 disable_ipv6 = true;
4061                         }
4062                 }
4063         }
4064         spin_unlock_bh(&ifp->lock);
4065 
4066         if (action == DAD_BEGIN) {
4067                 addrconf_dad_begin(ifp);
4068                 goto out;
4069         } else if (action == DAD_ABORT) {
4070                 in6_ifa_hold(ifp);
4071                 addrconf_dad_stop(ifp, 1);
4072                 if (disable_ipv6)
4073                         addrconf_ifdown(idev->dev, false);
4074                 goto out;
4075         }
4076 
4077         if (!ifp->dad_probes && addrconf_dad_end(ifp))
4078                 goto out;
4079 
4080         write_lock_bh(&idev->lock);
4081         if (idev->dead || !(idev->if_flags & IF_READY)) {
4082                 write_unlock_bh(&idev->lock);
4083                 goto out;
4084         }
4085 
4086         spin_lock(&ifp->lock);
4087         if (ifp->state == INET6_IFADDR_STATE_DEAD) {
4088                 spin_unlock(&ifp->lock);
4089                 write_unlock_bh(&idev->lock);
4090                 goto out;
4091         }
4092 
4093         if (ifp->dad_probes == 0) {
4094                 bool send_na = false;
4095 
4096                 /*
4097                  * DAD was successful
4098                  */
4099 
4100                 if (ifp->flags & IFA_F_TENTATIVE &&
4101                     !(ifp->flags & IFA_F_OPTIMISTIC))
4102                         send_na = true;
4103                 bump_id = ifp->flags & IFA_F_TENTATIVE;
4104                 ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC|IFA_F_DADFAILED);
4105                 spin_unlock(&ifp->lock);
4106                 write_unlock_bh(&idev->lock);
4107 
4108                 addrconf_dad_completed(ifp, bump_id, send_na);
4109 
4110                 goto out;
4111         }
4112 
4113         ifp->dad_probes--;
4114         addrconf_mod_dad_work(ifp,
4115                               max(NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME),
4116                                   HZ/100));
4117         spin_unlock(&ifp->lock);
4118         write_unlock_bh(&idev->lock);
4119 
4120         /* send a neighbour solicitation for our addr */
4121         addrconf_addr_solict_mult(&ifp->addr, &mcaddr);
4122         ndisc_send_ns(ifp->idev->dev, &ifp->addr, &mcaddr, &in6addr_any,
4123                       ifp->dad_nonce);
4124 out:
4125         in6_ifa_put(ifp);
4126         rtnl_unlock();
4127 }
4128 
4129 /* ifp->idev must be at least read locked */
4130 static bool ipv6_lonely_lladdr(struct inet6_ifaddr *ifp)
4131 {
4132         struct inet6_ifaddr *ifpiter;
4133         struct inet6_dev *idev = ifp->idev;
4134 
4135         list_for_each_entry_reverse(ifpiter, &idev->addr_list, if_list) {
4136                 if (ifpiter->scope > IFA_LINK)
4137                         break;
4138                 if (ifp != ifpiter && ifpiter->scope == IFA_LINK &&
4139                     (ifpiter->flags & (IFA_F_PERMANENT|IFA_F_TENTATIVE|
4140                                        IFA_F_OPTIMISTIC|IFA_F_DADFAILED)) ==
4141                     IFA_F_PERMANENT)
4142                         return false;
4143         }
4144         return true;
4145 }
4146 
4147 static void addrconf_dad_completed(struct inet6_ifaddr *ifp, bool bump_id,
4148                                    bool send_na)
4149 {
4150         struct net_device *dev = ifp->idev->dev;
4151         struct in6_addr lladdr;
4152         bool send_rs, send_mld;
4153 
4154         addrconf_del_dad_work(ifp);
4155 
4156         /*
4157          *      Configure the address for reception. Now it is valid.
4158          */
4159 
4160         ipv6_ifa_notify(RTM_NEWADDR, ifp);
4161 
4162         /* If added prefix is link local and we are prepared to process
4163            router advertisements, start sending router solicitations.
4164          */
4165 
4166         read_lock_bh(&ifp->idev->lock);
4167         send_mld = ifp->scope == IFA_LINK && ipv6_lonely_lladdr(ifp);
4168         send_rs = send_mld &&
4169                   ipv6_accept_ra(ifp->idev) &&
4170                   ifp->idev->cnf.rtr_solicits != 0 &&
4171                   (dev->flags&IFF_LOOPBACK) == 0;
4172         read_unlock_bh(&ifp->idev->lock);
4173 
4174         /* While dad is in progress mld report's source address is in6_addrany.
4175          * Resend with proper ll now.
4176          */
4177         if (send_mld)
4178                 ipv6_mc_dad_complete(ifp->idev);
4179 
4180         /* send unsolicited NA if enabled */
4181         if (send_na &&
4182             (ifp->idev->cnf.ndisc_notify ||
4183              dev_net(dev)->ipv6.devconf_all->ndisc_notify)) {
4184                 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifp->addr,
4185                               /*router=*/ !!ifp->idev->cnf.forwarding,
4186                               /*solicited=*/ false, /*override=*/ true,
4187                               /*inc_opt=*/ true);
4188         }
4189 
4190         if (send_rs) {
4191                 /*
4192                  *      If a host as already performed a random delay
4193                  *      [...] as part of DAD [...] there is no need
4194                  *      to delay again before sending the first RS
4195                  */
4196                 if (ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE))
4197                         return;
4198                 ndisc_send_rs(dev, &lladdr, &in6addr_linklocal_allrouters);
4199 
4200                 write_lock_bh(&ifp->idev->lock);
4201                 spin_lock(&ifp->lock);
4202                 ifp->idev->rs_interval = rfc3315_s14_backoff_init(
4203                         ifp->idev->cnf.rtr_solicit_interval);
4204                 ifp->idev->rs_probes = 1;
4205                 ifp->idev->if_flags |= IF_RS_SENT;
4206                 addrconf_mod_rs_timer(ifp->idev, ifp->idev->rs_interval);
4207                 spin_unlock(&ifp->lock);
4208                 write_unlock_bh(&ifp->idev->lock);
4209         }
4210 
4211         if (bump_id)
4212                 rt_genid_bump_ipv6(dev_net(dev));
4213 
4214         /* Make sure that a new temporary address will be created
4215          * before this temporary address becomes deprecated.
4216          */
4217         if (ifp->flags & IFA_F_TEMPORARY)
4218                 addrconf_verify_rtnl();
4219 }
4220 
4221 static void addrconf_dad_run(struct inet6_dev *idev, bool restart)
4222 {
4223         struct inet6_ifaddr *ifp;
4224 
4225         read_lock_bh(&idev->lock);
4226         list_for_each_entry(ifp, &idev->addr_list, if_list) {
4227                 spin_lock(&ifp->lock);
4228                 if ((ifp->flags & IFA_F_TENTATIVE &&
4229                      ifp->state == INET6_IFADDR_STATE_DAD) || restart) {
4230                         if (restart)
4231                                 ifp->state = INET6_IFADDR_STATE_PREDAD;
4232                         addrconf_dad_kick(ifp);
4233                 }
4234                 spin_unlock(&ifp->lock);
4235         }
4236         read_unlock_bh(&idev->lock);
4237 }
4238 
4239 #ifdef CONFIG_PROC_FS
4240 struct if6_iter_state {
4241         struct seq_net_private p;
4242         int bucket;
4243         int offset;
4244 };
4245 
4246 static struct inet6_ifaddr *if6_get_first(struct seq_file *seq, loff_t pos)
4247 {
4248         struct if6_iter_state *state = seq->private;
4249         struct net *net = seq_file_net(seq);
4250         struct inet6_ifaddr *ifa = NULL;
4251         int p = 0;
4252 
4253         /* initial bucket if pos is 0 */
4254         if (pos == 0) {
4255                 state->bucket = 0;
4256                 state->offset = 0;
4257         }
4258 
4259         for (; state->bucket < IN6_ADDR_HSIZE; ++state->bucket) {
4260                 hlist_for_each_entry_rcu(ifa, &inet6_addr_lst[state->bucket],
4261                                          addr_lst) {
4262                         if (!net_eq(dev_net(ifa->idev->dev), net))
4263                                 continue;
4264                         /* sync with offset */
4265                         if (p < state->offset) {
4266                                 p++;
4267                                 continue;
4268                         }
4269                         return ifa;
4270                 }
4271 
4272                 /* prepare for next bucket */
4273                 state->offset = 0;
4274                 p = 0;
4275         }
4276         return NULL;
4277 }
4278 
4279 static struct inet6_ifaddr *if6_get_next(struct seq_file *seq,
4280                                          struct inet6_ifaddr *ifa)
4281 {
4282         struct if6_iter_state *state = seq->private;
4283         struct net *net = seq_file_net(seq);
4284 
4285         hlist_for_each_entry_continue_rcu(ifa, addr_lst) {
4286                 if (!net_eq(dev_net(ifa->idev->dev), net))
4287                         continue;
4288                 state->offset++;
4289                 return ifa;
4290         }
4291 
4292         state->offset = 0;
4293         while (++state->bucket < IN6_ADDR_HSIZE) {
4294                 hlist_for_each_entry_rcu(ifa,
4295                                      &inet6_addr_lst[state->bucket], addr_lst) {
4296                         if (!net_eq(dev_net(ifa->idev->dev), net))
4297                                 continue;
4298                         return ifa;
4299                 }
4300         }
4301 
4302         return NULL;
4303 }
4304 
4305 static void *if6_seq_start(struct seq_file *seq, loff_t *pos)
4306         __acquires(rcu)
4307 {
4308         rcu_read_lock();
4309         return if6_get_first(seq, *pos);
4310 }
4311 
4312 static void *if6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4313 {
4314         struct inet6_ifaddr *ifa;
4315 
4316         ifa = if6_get_next(seq, v);
4317         ++*pos;
4318         return ifa;
4319 }
4320 
4321 static void if6_seq_stop(struct seq_file *seq, void *v)
4322         __releases(rcu)
4323 {
4324         rcu_read_unlock();
4325 }
4326 
4327 static int if6_seq_show(struct seq_file *seq, void *v)
4328 {
4329         struct inet6_ifaddr *ifp = (struct inet6_ifaddr *)v;
4330         seq_printf(seq, "%pi6 %02x %02x %02x %02x %8s\n",
4331                    &ifp->addr,
4332                    ifp->idev->dev->ifindex,
4333                    ifp->prefix_len,
4334                    ifp->scope,
4335                    (u8) ifp->flags,
4336                    ifp->idev->dev->name);
4337         return 0;
4338 }
4339 
4340 static const struct seq_operations if6_seq_ops = {
4341         .start  = if6_seq_start,
4342         .next   = if6_seq_next,
4343         .show   = if6_seq_show,
4344         .stop   = if6_seq_stop,
4345 };
4346 
4347 static int __net_init if6_proc_net_init(struct net *net)
4348 {
4349         if (!proc_create_net("if_inet6", 0444, net->proc_net, &if6_seq_ops,
4350                         sizeof(struct if6_iter_state)))
4351                 return -ENOMEM;
4352         return 0;
4353 }
4354 
4355 static void __net_exit if6_proc_net_exit(struct net *net)
4356 {
4357         remove_proc_entry("if_inet6", net->proc_net);
4358 }
4359 
4360 static struct pernet_operations if6_proc_net_ops = {
4361         .init = if6_proc_net_init,
4362         .exit = if6_proc_net_exit,
4363 };
4364 
4365 int __init if6_proc_init(void)
4366 {
4367         return register_pernet_subsys(&if6_proc_net_ops);
4368 }
4369 
4370 void if6_proc_exit(void)
4371 {
4372         unregister_pernet_subsys(&if6_proc_net_ops);
4373 }
4374 #endif  /* CONFIG_PROC_FS */
4375 
4376 #if IS_ENABLED(CONFIG_IPV6_MIP6)
4377 /* Check if address is a home address configured on any interface. */
4378 int ipv6_chk_home_addr(struct net *net, const struct in6_addr *addr)
4379 {
4380         unsigned int hash = inet6_addr_hash(net, addr);
4381         struct inet6_ifaddr *ifp = NULL;
4382         int ret = 0;
4383 
4384         rcu_read_lock();
4385         hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) {
4386                 if (!net_eq(dev_net(ifp->idev->dev), net))
4387                         continue;
4388                 if (ipv6_addr_equal(&ifp->addr, addr) &&
4389                     (ifp->flags & IFA_F_HOMEADDRESS)) {
4390                         ret = 1;
4391                         break;
4392                 }
4393         }
4394         rcu_read_unlock();
4395         return ret;
4396 }
4397 #endif
4398 
4399 /* RFC6554 has some algorithm to avoid loops in segment routing by
4400  * checking if the segments contains any of a local interface address.
4401  *
4402  * Quote:
4403  *
4404  * To detect loops in the SRH, a router MUST determine if the SRH
4405  * includes multiple addresses assigned to any interface on that router.
4406  * If such addresses appear more than once and are separated by at least
4407  * one address not assigned to that router.
4408  */
4409 int ipv6_chk_rpl_srh_loop(struct net *net, const struct in6_addr *segs,
4410                           unsigned char nsegs)
4411 {
4412         const struct in6_addr *addr;
4413         int i, ret = 0, found = 0;
4414         struct inet6_ifaddr *ifp;
4415         bool separated = false;
4416         unsigned int hash;
4417         bool hash_found;
4418 
4419         rcu_read_lock();
4420         for (i = 0; i < nsegs; i++) {
4421                 addr = &segs[i];
4422                 hash = inet6_addr_hash(net, addr);
4423 
4424                 hash_found = false;
4425                 hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) {
4426                         if (!net_eq(dev_net(ifp->idev->dev), net))
4427                                 continue;
4428 
4429                         if (ipv6_addr_equal(&ifp->addr, addr)) {
4430                                 hash_found = true;
4431                                 break;
4432                         }
4433                 }
4434 
4435                 if (hash_found) {
4436                         if (found > 1 && separated) {
4437                                 ret = 1;
4438                                 break;
4439                         }
4440 
4441                         separated = false;
4442                         found++;
4443                 } else {
4444                         separated = true;
4445                 }
4446         }
4447         rcu_read_unlock();
4448 
4449         return ret;
4450 }
4451 
4452 /*
4453  *      Periodic address status verification
4454  */
4455 
4456 static void addrconf_verify_rtnl(void)
4457 {
4458         unsigned long now, next, next_sec, next_sched;
4459         struct inet6_ifaddr *ifp;
4460         int i;
4461 
4462         ASSERT_RTNL();
4463 
4464         rcu_read_lock_bh();
4465         now = jiffies;
4466         next = round_jiffies_up(now + ADDR_CHECK_FREQUENCY);
4467 
4468         cancel_delayed_work(&addr_chk_work);
4469 
4470         for (i = 0; i < IN6_ADDR_HSIZE; i++) {
4471 restart:
4472                 hlist_for_each_entry_rcu_bh(ifp, &inet6_addr_lst[i], addr_lst) {
4473                         unsigned long age;
4474 
4475                         /* When setting preferred_lft to a value not zero or
4476                          * infinity, while valid_lft is infinity
4477                          * IFA_F_PERMANENT has a non-infinity life time.
4478                          */
4479                         if ((ifp->flags & IFA_F_PERMANENT) &&
4480                             (ifp->prefered_lft == INFINITY_LIFE_TIME))
4481                                 continue;
4482 
4483                         spin_lock(&ifp->lock);
4484                         /* We try to batch several events at once. */
4485                         age = (now - ifp->tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ;
4486 
4487                         if (ifp->valid_lft != INFINITY_LIFE_TIME &&
4488                             age >= ifp->valid_lft) {
4489                                 spin_unlock(&ifp->lock);
4490                                 in6_ifa_hold(ifp);
4491                                 rcu_read_unlock_bh();
4492                                 ipv6_del_addr(ifp);
4493                                 rcu_read_lock_bh();
4494                                 goto restart;
4495                         } else if (ifp->prefered_lft == INFINITY_LIFE_TIME) {
4496                                 spin_unlock(&ifp->lock);
4497                                 continue;
4498                         } else if (age >= ifp->prefered_lft) {
4499                                 /* jiffies - ifp->tstamp > age >= ifp->prefered_lft */
4500                                 int deprecate = 0;
4501 
4502                                 if (!(ifp->flags&IFA_F_DEPRECATED)) {
4503                                         deprecate = 1;
4504                                         ifp->flags |= IFA_F_DEPRECATED;
4505                                 }
4506 
4507                                 if ((ifp->valid_lft != INFINITY_LIFE_TIME) &&
4508                                     (time_before(ifp->tstamp + ifp->valid_lft * HZ, next)))
4509                                         next = ifp->tstamp + ifp->valid_lft * HZ;
4510 
4511                                 spin_unlock(&ifp->lock);
4512 
4513                                 if (deprecate) {
4514                                         in6_ifa_hold(ifp);
4515 
4516                                         ipv6_ifa_notify(0, ifp);
4517                                         in6_ifa_put(ifp);
4518                                         goto restart;
4519                                 }
4520                         } else if ((ifp->flags&IFA_F_TEMPORARY) &&
4521                                    !(ifp->flags&IFA_F_TENTATIVE)) {
4522                                 unsigned long regen_advance = ifp->idev->cnf.regen_max_retry *
4523                                         ifp->idev->cnf.dad_transmits *
4524                                         max(NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME), HZ/100) / HZ;
4525 
4526                                 if (age >= ifp->prefered_lft - regen_advance) {
4527                                         struct inet6_ifaddr *ifpub = ifp->ifpub;
4528                                         if (time_before(ifp->tstamp + ifp->prefered_lft * HZ, next))
4529                                                 next = ifp->tstamp + ifp->prefered_lft * HZ;
4530                                         if (!ifp->regen_count && ifpub) {
4531                                                 ifp->regen_count++;
4532                                                 in6_ifa_hold(ifp);
4533                                                 in6_ifa_hold(ifpub);
4534                                                 spin_unlock(&ifp->lock);
4535 
4536                                                 spin_lock(&ifpub->lock);
4537                                                 ifpub->regen_count = 0;
4538                                                 spin_unlock(&ifpub->lock);
4539                                                 rcu_read_unlock_bh();
4540                                                 ipv6_create_tempaddr(ifpub, true);
4541                                                 in6_ifa_put(ifpub);
4542                                                 in6_ifa_put(ifp);
4543                                                 rcu_read_lock_bh();
4544                                                 goto restart;
4545                                         }
4546                                 } else if (time_before(ifp->tstamp + ifp->prefered_lft * HZ - regen_advance * HZ, next))
4547                                         next = ifp->tstamp + ifp->prefered_lft * HZ - regen_advance * HZ;
4548                                 spin_unlock(&ifp->lock);
4549                         } else {
4550                                 /* ifp->prefered_lft <= ifp->valid_lft */
4551                                 if (time_before(ifp->tstamp + ifp->prefered_lft * HZ, next))
4552                                         next = ifp->tstamp + ifp->prefered_lft * HZ;
4553                                 spin_unlock(&ifp->lock);
4554                         }
4555                 }
4556         }
4557 
4558         next_sec = round_jiffies_up(next);
4559         next_sched = next;
4560 
4561         /* If rounded timeout is accurate enough, accept it. */
4562         if (time_before(next_sec, next + ADDRCONF_TIMER_FUZZ))
4563                 next_sched = next_sec;
4564 
4565         /* And minimum interval is ADDRCONF_TIMER_FUZZ_MAX. */
4566         if (time_before(next_sched, jiffies + ADDRCONF_TIMER_FUZZ_MAX))
4567                 next_sched = jiffies + ADDRCONF_TIMER_FUZZ_MAX;
4568 
4569         pr_debug("now = %lu, schedule = %lu, rounded schedule = %lu => %lu\n",
4570                  now, next, next_sec, next_sched);
4571         mod_delayed_work(addrconf_wq, &addr_chk_work, next_sched - now);
4572         rcu_read_unlock_bh();
4573 }
4574 
4575 static void addrconf_verify_work(struct work_struct *w)
4576 {
4577         rtnl_lock();
4578         addrconf_verify_rtnl();
4579         rtnl_unlock();
4580 }
4581 
4582 static void addrconf_verify(void)
4583 {
4584         mod_delayed_work(addrconf_wq, &addr_chk_work, 0);
4585 }
4586 
4587 static struct in6_addr *extract_addr(struct nlattr *addr, struct nlattr *local,
4588                                      struct in6_addr **peer_pfx)
4589 {
4590         struct in6_addr *pfx = NULL;
4591 
4592         *peer_pfx = NULL;
4593 
4594         if (addr)
4595                 pfx = nla_data(addr);
4596 
4597         if (local) {
4598                 if (pfx && nla_memcmp(local, pfx, sizeof(*pfx)))
4599                         *peer_pfx = pfx;
4600                 pfx = nla_data(local);
4601         }
4602 
4603         return pfx;
4604 }
4605 
4606 static const struct nla_policy ifa_ipv6_policy[IFA_MAX+1] = {
4607         [IFA_ADDRESS]           = { .len = sizeof(struct in6_addr) },
4608         [IFA_LOCAL]             = { .len = sizeof(struct in6_addr) },
4609         [IFA_CACHEINFO]         = { .len = sizeof(struct ifa_cacheinfo) },
4610         [IFA_FLAGS]             = { .len = sizeof(u32) },
4611         [IFA_RT_PRIORITY]       = { .len = sizeof(u32) },
4612         [IFA_TARGET_NETNSID]    = { .type = NLA_S32 },
4613 };
4614 
4615 static int
4616 inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh,
4617                   struct netlink_ext_ack *extack)
4618 {
4619         struct net *net = sock_net(skb->sk);
4620         struct ifaddrmsg *ifm;
4621         struct nlattr *tb[IFA_MAX+1];
4622         struct in6_addr *pfx, *peer_pfx;
4623         u32 ifa_flags;
4624         int err;
4625 
4626         err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFA_MAX,
4627                                      ifa_ipv6_policy, extack);
4628         if (err < 0)
4629                 return err;
4630 
4631         ifm = nlmsg_data(nlh);
4632         pfx = extract_addr(tb[IFA_ADDRESS], tb[IFA_LOCAL], &peer_pfx);
4633         if (!pfx)
4634                 return -EINVAL;
4635 
4636         ifa_flags = tb[IFA_FLAGS] ? nla_get_u32(tb[IFA_FLAGS]) : ifm->ifa_flags;
4637 
4638         /* We ignore other flags so far. */
4639         ifa_flags &= IFA_F_MANAGETEMPADDR;
4640 
4641         return inet6_addr_del(net, ifm->ifa_index, ifa_flags, pfx,
4642                               ifm->ifa_prefixlen);
4643 }
4644 
4645 static int modify_prefix_route(struct inet6_ifaddr *ifp,
4646                                unsigned long expires, u32 flags,
4647                                bool modify_peer)
4648 {
4649         struct fib6_info *f6i;
4650         u32 prio;
4651 
4652         f6i = addrconf_get_prefix_route(modify_peer ? &ifp->peer_addr : &ifp->addr,
4653                                         ifp->prefix_len,
4654                                         ifp->idev->dev, 0, RTF_DEFAULT, true);
4655         if (!f6i)
4656                 return -ENOENT;
4657 
4658         prio = ifp->rt_priority ? : IP6_RT_PRIO_ADDRCONF;
4659         if (f6i->fib6_metric != prio) {
4660                 /* delete old one */
4661                 ip6_del_rt(dev_net(ifp->idev->dev), f6i, false);
4662 
4663                 /* add new one */
4664                 addrconf_prefix_route(modify_peer ? &ifp->peer_addr : &ifp->addr,
4665                                       ifp->prefix_len,
4666                                       ifp->rt_priority, ifp->idev->dev,
4667                                       expires, flags, GFP_KERNEL);
4668         } else {
4669                 if (!expires)
4670                         fib6_clean_expires(f6i);
4671                 else
4672                         fib6_set_expires(f6i, expires);
4673 
4674                 fib6_info_release(f6i);
4675         }
4676 
4677         return 0;
4678 }
4679 
4680 static int inet6_addr_modify(struct inet6_ifaddr *ifp, struct ifa6_config *cfg)
4681 {
4682         u32 flags;
4683         clock_t expires;
4684         unsigned long timeout;
4685         bool was_managetempaddr;
4686         bool had_prefixroute;
4687         bool new_peer = false;
4688 
4689         ASSERT_RTNL();
4690 
4691         if (!cfg->valid_lft || cfg->preferred_lft > cfg->valid_lft)
4692                 return -EINVAL;
4693 
4694         if (cfg->ifa_flags & IFA_F_MANAGETEMPADDR &&
4695             (ifp->flags & IFA_F_TEMPORARY || ifp->prefix_len != 64))
4696                 return -EINVAL;
4697 
4698         if (!(ifp->flags & IFA_F_TENTATIVE) || ifp->flags & IFA_F_DADFAILED)
4699                 cfg->ifa_flags &= ~IFA_F_OPTIMISTIC;
4700 
4701         timeout = addrconf_timeout_fixup(cfg->valid_lft, HZ);
4702         if (addrconf_finite_timeout(timeout)) {
4703                 expires = jiffies_to_clock_t(timeout * HZ);
4704                 cfg->valid_lft = timeout;
4705                 flags = RTF_EXPIRES;
4706         } else {
4707                 expires = 0;
4708                 flags = 0;
4709                 cfg->ifa_flags |= IFA_F_PERMANENT;
4710         }
4711 
4712         timeout = addrconf_timeout_fixup(cfg->preferred_lft, HZ);
4713         if (addrconf_finite_timeout(timeout)) {
4714                 if (timeout == 0)
4715                         cfg->ifa_flags |= IFA_F_DEPRECATED;
4716                 cfg->preferred_lft = timeout;
4717         }
4718 
4719         if (cfg->peer_pfx &&
4720             memcmp(&ifp->peer_addr, cfg->peer_pfx, sizeof(struct in6_addr))) {
4721                 if (!ipv6_addr_any(&ifp->peer_addr))
4722                         cleanup_prefix_route(ifp, expires, true, true);
4723                 new_peer = true;
4724         }
4725 
4726         spin_lock_bh(&ifp->lock);
4727         was_managetempaddr = ifp->flags & IFA_F_MANAGETEMPADDR;
4728         had_prefixroute = ifp->flags & IFA_F_PERMANENT &&
4729                           !(ifp->flags & IFA_F_NOPREFIXROUTE);
4730         ifp->flags &= ~(IFA_F_DEPRECATED | IFA_F_PERMANENT | IFA_F_NODAD |
4731                         IFA_F_HOMEADDRESS | IFA_F_MANAGETEMPADDR |
4732                         IFA_F_NOPREFIXROUTE);
4733         ifp->flags |= cfg->ifa_flags;
4734         ifp->tstamp = jiffies;
4735         ifp->valid_lft = cfg->valid_lft;
4736         ifp->prefered_lft = cfg->preferred_lft;
4737 
4738         if (cfg->rt_priority && cfg->rt_priority != ifp->rt_priority)
4739                 ifp->rt_priority = cfg->rt_priority;
4740 
4741         if (new_peer)
4742                 ifp->peer_addr = *cfg->peer_pfx;
4743 
4744         spin_unlock_bh(&ifp->lock);
4745         if (!(ifp->flags&IFA_F_TENTATIVE))
4746                 ipv6_ifa_notify(0, ifp);
4747 
4748         if (!(cfg->ifa_flags & IFA_F_NOPREFIXROUTE)) {
4749                 int rc = -ENOENT;
4750 
4751                 if (had_prefixroute)
4752                         rc = modify_prefix_route(ifp, expires, flags, false);
4753 
4754                 /* prefix route could have been deleted; if so restore it */
4755                 if (rc == -ENOENT) {
4756                         addrconf_prefix_route(&ifp->addr, ifp->prefix_len,
4757                                               ifp->rt_priority, ifp->idev->dev,
4758                                               expires, flags, GFP_KERNEL);
4759                 }
4760 
4761                 if (had_prefixroute && !ipv6_addr_any(&ifp->peer_addr))
4762                         rc = modify_prefix_route(ifp, expires, flags, true);
4763 
4764                 if (rc == -ENOENT && !ipv6_addr_any(&ifp->peer_addr)) {
4765                         addrconf_prefix_route(&ifp->peer_addr, ifp->prefix_len,
4766                                               ifp->rt_priority, ifp->idev->dev,
4767                                               expires, flags, GFP_KERNEL);
4768                 }
4769         } else if (had_prefixroute) {
4770                 enum cleanup_prefix_rt_t action;
4771                 unsigned long rt_expires;
4772 
4773                 write_lock_bh(&ifp->idev->lock);
4774                 action = check_cleanup_prefix_route(ifp, &rt_expires);
4775                 write_unlock_bh(&ifp->idev->lock);
4776 
4777                 if (action != CLEANUP_PREFIX_RT_NOP) {
4778                         cleanup_prefix_route(ifp, rt_expires,
4779                                 action == CLEANUP_PREFIX_RT_DEL, false);
4780                 }
4781         }
4782 
4783         if (was_managetempaddr || ifp->flags & IFA_F_MANAGETEMPADDR) {
4784                 if (was_managetempaddr &&
4785                     !(ifp->flags & IFA_F_MANAGETEMPADDR)) {
4786                         cfg->valid_lft = 0;
4787                         cfg->preferred_lft = 0;
4788                 }
4789                 manage_tempaddrs(ifp->idev, ifp, cfg->valid_lft,
4790                                  cfg->preferred_lft, !was_managetempaddr,
4791                                  jiffies);
4792         }
4793 
4794         addrconf_verify_rtnl();
4795 
4796         return 0;
4797 }
4798 
4799 static int
4800 inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh,
4801                   struct netlink_ext_ack *extack)
4802 {
4803         struct net *net = sock_net(skb->sk);
4804         struct ifaddrmsg *ifm;
4805         struct nlattr *tb[IFA_MAX+1];
4806         struct in6_addr *peer_pfx;
4807         struct inet6_ifaddr *ifa;
4808         struct net_device *dev;
4809         struct inet6_dev *idev;
4810         struct ifa6_config cfg;
4811         int err;
4812 
4813         err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFA_MAX,
4814                                      ifa_ipv6_policy, extack);
4815         if (err < 0)
4816                 return err;
4817 
4818         memset(&cfg, 0, sizeof(cfg));
4819 
4820         ifm = nlmsg_data(nlh);
4821         cfg.pfx = extract_addr(tb[IFA_ADDRESS], tb[IFA_LOCAL], &peer_pfx);
4822         if (!cfg.pfx)
4823                 return -EINVAL;
4824 
4825         cfg.peer_pfx = peer_pfx;
4826         cfg.plen = ifm->ifa_prefixlen;
4827         if (tb[IFA_RT_PRIORITY])
4828                 cfg.rt_priority = nla_get_u32(tb[IFA_RT_PRIORITY]);
4829 
4830         cfg.valid_lft = INFINITY_LIFE_TIME;
4831         cfg.preferred_lft = INFINITY_LIFE_TIME;
4832 
4833         if (tb[IFA_CACHEINFO]) {
4834                 struct ifa_cacheinfo *ci;
4835 
4836                 ci = nla_data(tb[IFA_CACHEINFO]);
4837                 cfg.valid_lft = ci->ifa_valid;
4838                 cfg.preferred_lft = ci->ifa_prefered;
4839         }
4840 
4841         dev =  __dev_get_by_index(net, ifm->ifa_index);
4842         if (!dev)
4843                 return -ENODEV;
4844 
4845         if (tb[IFA_FLAGS])
4846                 cfg.ifa_flags = nla_get_u32(tb[IFA_FLAGS]);
4847         else
4848                 cfg.ifa_flags = ifm->ifa_flags;
4849 
4850         /* We ignore other flags so far. */
4851         cfg.ifa_flags &= IFA_F_NODAD | IFA_F_HOMEADDRESS |
4852                          IFA_F_MANAGETEMPADDR | IFA_F_NOPREFIXROUTE |
4853                          IFA_F_MCAUTOJOIN | IFA_F_OPTIMISTIC;
4854 
4855         idev = ipv6_find_idev(dev);
4856         if (IS_ERR(idev))
4857                 return PTR_ERR(idev);
4858 
4859         if (!ipv6_allow_optimistic_dad(net, idev))
4860                 cfg.ifa_flags &= ~IFA_F_OPTIMISTIC;
4861 
4862         if (cfg.ifa_flags & IFA_F_NODAD &&
4863             cfg.ifa_flags & IFA_F_OPTIMISTIC) {
4864                 NL_SET_ERR_MSG(extack, "IFA_F_NODAD and IFA_F_OPTIMISTIC are mutually exclusive");
4865                 return -EINVAL;
4866         }
4867 
4868         ifa = ipv6_get_ifaddr(net, cfg.pfx, dev, 1);
4869         if (!ifa) {
4870                 /*
4871                  * It would be best to check for !NLM_F_CREATE here but
4872                  * userspace already relies on not having to provide this.
4873                  */
4874                 return inet6_addr_add(net, ifm->ifa_index, &cfg, extack);
4875         }
4876 
4877         if (nlh->nlmsg_flags & NLM_F_EXCL ||
4878             !(nlh->nlmsg_flags & NLM_F_REPLACE))
4879                 err = -EEXIST;
4880         else
4881                 err = inet6_addr_modify(ifa, &cfg);
4882 
4883         in6_ifa_put(ifa);
4884 
4885         return err;
4886 }
4887 
4888 static void put_ifaddrmsg(struct nlmsghdr *nlh, u8 prefixlen, u32 flags,
4889                           u8 scope, int ifindex)
4890 {
4891         struct ifaddrmsg *ifm;
4892 
4893         ifm = nlmsg_data(nlh);
4894         ifm->ifa_family = AF_INET6;
4895         ifm->ifa_prefixlen = prefixlen;
4896         ifm->ifa_flags = flags;
4897         ifm->ifa_scope = scope;
4898         ifm->ifa_index = ifindex;
4899 }
4900 
4901 static int put_cacheinfo(struct sk_buff *skb, unsigned long cstamp,
4902                          unsigned long tstamp, u32 preferred, u32 valid)
4903 {
4904         struct ifa_cacheinfo ci;
4905 
4906         ci.cstamp = cstamp_delta(cstamp);
4907         ci.tstamp = cstamp_delta(tstamp);
4908         ci.ifa_prefered = preferred;
4909         ci.ifa_valid = valid;
4910 
4911         return nla_put(skb, IFA_CACHEINFO, sizeof(ci), &ci);
4912 }
4913 
4914 static inline int rt_scope(int ifa_scope)
4915 {
4916         if (ifa_scope & IFA_HOST)
4917                 return RT_SCOPE_HOST;
4918         else if (ifa_scope & IFA_LINK)
4919                 return RT_SCOPE_LINK;
4920         else if (ifa_scope & IFA_SITE)
4921                 return RT_SCOPE_SITE;
4922         else
4923                 return RT_SCOPE_UNIVERSE;
4924 }
4925 
4926 static inline int inet6_ifaddr_msgsize(void)
4927 {
4928         return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
4929                + nla_total_size(16) /* IFA_LOCAL */
4930                + nla_total_size(16) /* IFA_ADDRESS */
4931                + nla_total_size(sizeof(struct ifa_cacheinfo))
4932                + nla_total_size(4)  /* IFA_FLAGS */
4933                + nla_total_size(4)  /* IFA_RT_PRIORITY */;
4934 }
4935 
4936 enum addr_type_t {
4937         UNICAST_ADDR,
4938         MULTICAST_ADDR,
4939         ANYCAST_ADDR,
4940 };
4941 
4942 struct inet6_fill_args {
4943         u32 portid;
4944         u32 seq;
4945         int event;
4946         unsigned int flags;
4947         int netnsid;
4948         int ifindex;
4949         enum addr_type_t type;
4950 };
4951 
4952 static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
4953                              struct inet6_fill_args *args)
4954 {
4955         struct nlmsghdr  *nlh;
4956         u32 preferred, valid;
4957 
4958         nlh = nlmsg_put(skb, args->portid, args->seq, args->event,
4959                         sizeof(struct ifaddrmsg), args->flags);
4960         if (!nlh)
4961                 return -EMSGSIZE;
4962 
4963         put_ifaddrmsg(nlh, ifa->prefix_len, ifa->flags, rt_scope(ifa->scope),
4964                       ifa->idev->dev->ifindex);
4965 
4966         if (args->netnsid >= 0 &&
4967             nla_put_s32(skb, IFA_TARGET_NETNSID, args->netnsid))
4968                 goto error;
4969 
4970         if (!((ifa->flags&IFA_F_PERMANENT) &&
4971               (ifa->prefered_lft == INFINITY_LIFE_TIME))) {
4972                 preferred = ifa->prefered_lft;
4973                 valid = ifa->valid_lft;
4974                 if (preferred != INFINITY_LIFE_TIME) {
4975                         long tval = (jiffies - ifa->tstamp)/HZ;
4976                         if (preferred > tval)
4977                                 preferred -= tval;
4978                         else
4979                                 preferred = 0;
4980                         if (valid != INFINITY_LIFE_TIME) {
4981                                 if (valid > tval)
4982                                         valid -= tval;
4983                                 else
4984                                         valid = 0;
4985                         }
4986                 }
4987         } else {
4988                 preferred = INFINITY_LIFE_TIME;
4989                 valid = INFINITY_LIFE_TIME;
4990         }
4991 
4992         if (!ipv6_addr_any(&ifa->peer_addr)) {
4993                 if (nla_put_in6_addr(skb, IFA_LOCAL, &ifa->addr) < 0 ||
4994                     nla_put_in6_addr(skb, IFA_ADDRESS, &ifa->peer_addr) < 0)
4995                         goto error;
4996         } else
4997                 if (nla_put_in6_addr(skb, IFA_ADDRESS, &ifa->addr) < 0)
4998                         goto error;
4999 
5000         if (ifa->rt_priority &&
5001             nla_put_u32(skb, IFA_RT_PRIORITY, ifa->rt_priority))
5002                 goto error;
5003 
5004         if (put_cacheinfo(skb, ifa->cstamp, ifa->tstamp, preferred, valid) < 0)
5005                 goto error;
5006 
5007         if (nla_put_u32(skb, IFA_FLAGS, ifa->flags) < 0)
5008                 goto error;
5009 
5010         nlmsg_end(skb, nlh);
5011         return 0;
5012 
5013 error:
5014         nlmsg_cancel(skb, nlh);
5015         return -EMSGSIZE;
5016 }
5017 
5018 static int inet6_fill_ifmcaddr(struct sk_buff *skb, struct ifmcaddr6 *ifmca,
5019                                struct inet6_fill_args *args)
5020 {
5021         struct nlmsghdr  *nlh;
5022         u8 scope = RT_SCOPE_UNIVERSE;
5023         int ifindex = ifmca->idev->dev->ifindex;
5024 
5025         if (ipv6_addr_scope(&ifmca->mca_addr) & IFA_SITE)
5026                 scope = RT_SCOPE_SITE;
5027 
5028         nlh = nlmsg_put(skb, args->portid, args->seq, args->event,
5029                         sizeof(struct ifaddrmsg), args->flags);
5030         if (!nlh)
5031                 return -EMSGSIZE;
5032 
5033         if (args->netnsid >= 0 &&
5034             nla_put_s32(skb, IFA_TARGET_NETNSID, args->netnsid)) {
5035                 nlmsg_cancel(skb, nlh);
5036                 return -EMSGSIZE;
5037         }
5038 
5039         put_ifaddrmsg(nlh, 128, IFA_F_PERMANENT, scope, ifindex);
5040         if (nla_put_in6_addr(skb, IFA_MULTICAST, &ifmca->mca_addr) < 0 ||
5041             put_cacheinfo(skb, ifmca->mca_cstamp, ifmca->mca_tstamp,
5042                           INFINITY_LIFE_TIME, INFINITY_LIFE_TIME) < 0) {
5043                 nlmsg_cancel(skb, nlh);
5044                 return -EMSGSIZE;
5045         }
5046 
5047         nlmsg_end(skb, nlh);
5048         return 0;
5049 }
5050 
5051 static int inet6_fill_ifacaddr(struct sk_buff *skb, struct ifacaddr6 *ifaca,
5052                                struct inet6_fill_args *args)
5053 {
5054         struct net_device *dev = fib6_info_nh_dev(ifaca->aca_rt);
5055         int ifindex = dev ? dev->ifindex : 1;
5056         struct nlmsghdr  *nlh;
5057         u8 scope = RT_SCOPE_UNIVERSE;
5058 
5059         if (ipv6_addr_scope(&ifaca->aca_addr) & IFA_SITE)
5060                 scope = RT_SCOPE_SITE;
5061 
5062         nlh = nlmsg_put(skb, args->portid, args->seq, args->event,
5063                         sizeof(struct ifaddrmsg), args->flags);
5064         if (!nlh)
5065                 return -EMSGSIZE;
5066 
5067         if (args->netnsid >= 0 &&
5068             nla_put_s32(skb, IFA_TARGET_NETNSID, args->netnsid)) {
5069                 nlmsg_cancel(skb, nlh);
5070                 return -EMSGSIZE;
5071         }
5072 
5073         put_ifaddrmsg(nlh, 128, IFA_F_PERMANENT, scope, ifindex);
5074         if (nla_put_in6_addr(skb, IFA_ANYCAST, &ifaca->aca_addr) < 0 ||
5075             put_cacheinfo(skb, ifaca->aca_cstamp, ifaca->aca_tstamp,
5076                           INFINITY_LIFE_TIME, INFINITY_LIFE_TIME) < 0) {
5077                 nlmsg_cancel(skb, nlh);
5078                 return -EMSGSIZE;
5079         }
5080 
5081         nlmsg_end(skb, nlh);
5082         return 0;
5083 }
5084 
5085 /* called with rcu_read_lock() */
5086 static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb,
5087                           struct netlink_callback *cb, int s_ip_idx,
5088                           struct inet6_fill_args *fillargs)
5089 {
5090         struct ifmcaddr6 *ifmca;
5091         struct ifacaddr6 *ifaca;
5092         int ip_idx = 0;
5093         int err = 1;
5094 
5095         read_lock_bh(&idev->lock);
5096         switch (fillargs->type) {
5097         case UNICAST_ADDR: {
5098                 struct inet6_ifaddr *ifa;
5099                 fillargs->event = RTM_NEWADDR;
5100 
5101                 /* unicast address incl. temp addr */
5102                 list_for_each_entry(ifa, &idev->addr_list, if_list) {
5103                         if (ip_idx < s_ip_idx)
5104                                 goto next;
5105                         err = inet6_fill_ifaddr(skb, ifa, fillargs);
5106                         if (err < 0)
5107                                 break;
5108                         nl_dump_check_consistent(cb, nlmsg_hdr(skb));
5109 next:
5110                         ip_idx++;
5111                 }
5112                 break;
5113         }
5114         case MULTICAST_ADDR:
5115                 read_unlock_bh(&idev->lock);
5116                 fillargs->event = RTM_GETMULTICAST;
5117 
5118                 /* multicast address */
5119                 for (ifmca = rcu_dereference(idev->mc_list);
5120                      ifmca;
5121                      ifmca = rcu_dereference(ifmca->next), ip_idx++) {
5122                         if (ip_idx < s_ip_idx)
5123                                 continue;
5124                         err = inet6_fill_ifmcaddr(skb, ifmca, fillargs);
5125                         if (err < 0)
5126                                 break;
5127                 }
5128                 read_lock_bh(&idev->lock);
5129                 break;
5130         case ANYCAST_ADDR:
5131                 fillargs->event = RTM_GETANYCAST;
5132                 /* anycast address */
5133                 for (ifaca = idev->ac_list; ifaca;
5134                      ifaca = ifaca->aca_next, ip_idx++) {
5135                         if (ip_idx < s_ip_idx)
5136                                 continue;
5137                         err = inet6_fill_ifacaddr(skb, ifaca, fillargs);
5138                         if (err < 0)
5139                                 break;
5140                 }
5141                 break;
5142         default:
5143                 break;
5144         }
5145         read_unlock_bh(&idev->lock);
5146         cb->args[2] = ip_idx;
5147         return err;
5148 }
5149 
5150 static int inet6_valid_dump_ifaddr_req(const struct nlmsghdr *nlh,
5151                                        struct inet6_fill_args *fillargs,
5152                                        struct net **tgt_net, struct sock *sk,
5153                                        struct netlink_callback *cb)
5154 {
5155         struct netlink_ext_ack *extack = cb->extack;
5156         struct nlattr *tb[IFA_MAX+1];
5157         struct ifaddrmsg *ifm;
5158         int err, i;
5159 
5160         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
5161                 NL_SET_ERR_MSG_MOD(extack, "Invalid header for address dump request");
5162                 return -EINVAL;
5163         }
5164 
5165         ifm = nlmsg_data(nlh);
5166         if (ifm->ifa_prefixlen || ifm->ifa_flags || ifm->ifa_scope) {
5167                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for address dump request");
5168                 return -EINVAL;
5169         }
5170 
5171         fillargs->ifindex = ifm->ifa_index;
5172         if (fillargs->ifindex) {
5173                 cb->answer_flags |= NLM_F_DUMP_FILTERED;
5174                 fillargs->flags |= NLM_F_DUMP_FILTERED;
5175         }
5176 
5177         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*ifm), tb, IFA_MAX,
5178                                             ifa_ipv6_policy, extack);
5179         if (err < 0)
5180                 return err;
5181 
5182         for (i = 0; i <= IFA_MAX; ++i) {
5183                 if (!tb[i])
5184                         continue;
5185 
5186                 if (i == IFA_TARGET_NETNSID) {
5187                         struct net *net;
5188 
5189                         fillargs->netnsid = nla_get_s32(tb[i]);
5190                         net = rtnl_get_net_ns_capable(sk, fillargs->netnsid);
5191                         if (IS_ERR(net)) {
5192                                 fillargs->netnsid = -1;
5193                                 NL_SET_ERR_MSG_MOD(extack, "Invalid target network namespace id");
5194                                 return PTR_ERR(net);
5195                         }
5196                         *tgt_net = net;
5197                 } else {
5198                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in dump request");
5199                         return -EINVAL;
5200                 }
5201         }
5202 
5203         return 0;
5204 }
5205 
5206 static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb,
5207                            enum addr_type_t type)
5208 {
5209         const struct nlmsghdr *nlh = cb->nlh;
5210         struct inet6_fill_args fillargs = {
5211                 .portid = NETLINK_CB(cb->skb).portid,
5212                 .seq = cb->nlh->nlmsg_seq,
5213                 .flags = NLM_F_MULTI,
5214                 .netnsid = -1,
5215                 .type = type,
5216         };
5217         struct net *net = sock_net(skb->sk);
5218         struct net *tgt_net = net;
5219         int idx, s_idx, s_ip_idx;
5220         int h, s_h;
5221         struct net_device *dev;
5222         struct inet6_dev *idev;
5223         struct hlist_head *head;
5224         int err = 0;
5225 
5226         s_h = cb->args[0];
5227         s_idx = idx = cb->args[1];
5228         s_ip_idx = cb->args[2];
5229 
5230         if (cb->strict_check) {
5231                 err = inet6_valid_dump_ifaddr_req(nlh, &fillargs, &tgt_net,
5232                                                   skb->sk, cb);
5233                 if (err < 0)
5234                         goto put_tgt_net;
5235 
5236                 err = 0;
5237                 if (fillargs.ifindex) {
5238                         dev = __dev_get_by_index(tgt_net, fillargs.ifindex);
5239                         if (!dev) {
5240                                 err = -ENODEV;
5241                                 goto put_tgt_net;
5242                         }
5243                         idev = __in6_dev_get(dev);
5244                         if (idev) {
5245                                 err = in6_dump_addrs(idev, skb, cb, s_ip_idx,
5246                                                      &fillargs);
5247                                 if (err > 0)
5248                                         err = 0;
5249                         }
5250                         goto put_tgt_net;
5251                 }
5252         }
5253 
5254         rcu_read_lock();
5255         cb->seq = atomic_read(&tgt_net->ipv6.dev_addr_genid) ^ tgt_net->dev_base_seq;
5256         for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
5257                 idx = 0;
5258                 head = &tgt_net->dev_index_head[h];
5259                 hlist_for_each_entry_rcu(dev, head, index_hlist) {
5260                         if (idx < s_idx)
5261                                 goto cont;
5262                         if (h > s_h || idx > s_idx)
5263                                 s_ip_idx = 0;
5264                         idev = __in6_dev_get(dev);
5265                         if (!idev)
5266                                 goto cont;
5267 
5268                         if (in6_dump_addrs(idev, skb, cb, s_ip_idx,
5269                                            &fillargs) < 0)
5270                                 goto done;
5271 cont:
5272                         idx++;
5273                 }
5274         }
5275 done:
5276         rcu_read_unlock();
5277         cb->args[0] = h;
5278         cb->args[1] = idx;
5279 put_tgt_net:
5280         if (fillargs.netnsid >= 0)
5281                 put_net(tgt_net);
5282 
5283         return skb->len ? : err;
5284 }
5285 
5286 static int inet6_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
5287 {
5288         enum addr_type_t type = UNICAST_ADDR;
5289 
5290         return inet6_dump_addr(skb, cb, type);
5291 }
5292 
5293 static int inet6_dump_ifmcaddr(struct sk_buff *skb, struct netlink_callback *cb)
5294 {
5295         enum addr_type_t type = MULTICAST_ADDR;
5296 
5297         return inet6_dump_addr(skb, cb, type);
5298 }
5299 
5300 
5301 static int inet6_dump_ifacaddr(struct sk_buff *skb, struct netlink_callback *cb)
5302 {
5303         enum addr_type_t type = ANYCAST_ADDR;
5304 
5305         return inet6_dump_addr(skb, cb, type);
5306 }
5307 
5308 static int inet6_rtm_valid_getaddr_req(struct sk_buff *skb,
5309                                        const struct nlmsghdr *nlh,
5310                                        struct nlattr **tb,
5311                                        struct netlink_ext_ack *extack)
5312 {
5313         struct ifaddrmsg *ifm;
5314         int i, err;
5315 
5316         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
5317                 NL_SET_ERR_MSG_MOD(extack, "Invalid header for get address request");
5318                 return -EINVAL;
5319         }
5320 
5321         if (!netlink_strict_get_check(skb))
5322                 return nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFA_MAX,
5323                                               ifa_ipv6_policy, extack);
5324 
5325         ifm = nlmsg_data(nlh);
5326         if (ifm->ifa_prefixlen || ifm->ifa_flags || ifm->ifa_scope) {
5327                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get address request");
5328                 return -EINVAL;
5329         }
5330 
5331         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*ifm), tb, IFA_MAX,
5332                                             ifa_ipv6_policy, extack);
5333         if (err)
5334                 return err;
5335 
5336         for (i = 0; i <= IFA_MAX; i++) {
5337                 if (!tb[i])
5338                         continue;
5339 
5340                 switch (i) {
5341                 case IFA_TARGET_NETNSID:
5342                 case IFA_ADDRESS:
5343                 case IFA_LOCAL:
5344                         break;
5345                 default:
5346                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get address request");
5347                         return -EINVAL;
5348                 }
5349         }
5350 
5351         return 0;
5352 }
5353 
5354 static int inet6_rtm_getaddr(struct sk_buff *in_skb, struct nlmsghdr *nlh,
5355                              struct netlink_ext_ack *extack)
5356 {
5357         struct net *net = sock_net(in_skb->sk);
5358         struct inet6_fill_args fillargs = {
5359                 .portid = NETLINK_CB(in_skb).portid,
5360                 .seq = nlh->nlmsg_seq,
5361                 .event = RTM_NEWADDR,
5362                 .flags = 0,
5363                 .netnsid = -1,
5364         };
5365         struct net *tgt_net = net;
5366         struct ifaddrmsg *ifm;
5367         struct nlattr *tb[IFA_MAX+1];
5368         struct in6_addr *addr = NULL, *peer;
5369         struct net_device *dev = NULL;
5370         struct inet6_ifaddr *ifa;
5371         struct sk_buff *skb;
5372         int err;
5373 
5374         err = inet6_rtm_valid_getaddr_req(in_skb, nlh, tb, extack);
5375         if (err < 0)
5376                 return err;
5377 
5378         if (tb[IFA_TARGET_NETNSID]) {
5379                 fillargs.netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]);
5380 
5381                 tgt_net = rtnl_get_net_ns_capable(NETLINK_CB(in_skb).sk,
5382                                                   fillargs.netnsid);
5383                 if (IS_ERR(tgt_net))
5384                         return PTR_ERR(tgt_net);
5385         }
5386 
5387         addr = extract_addr(tb[IFA_ADDRESS], tb[IFA_LOCAL], &peer);
5388         if (!addr)
5389                 return -EINVAL;
5390 
5391         ifm = nlmsg_data(nlh);
5392         if (ifm->ifa_index)
5393                 dev = dev_get_by_index(tgt_net, ifm->ifa_index);
5394 
5395         ifa = ipv6_get_ifaddr(tgt_net, addr, dev, 1);
5396         if (!ifa) {
5397                 err = -EADDRNOTAVAIL;
5398                 goto errout;
5399         }
5400 
5401         skb = nlmsg_new(inet6_ifaddr_msgsize(), GFP_KERNEL);
5402         if (!skb) {
5403                 err = -ENOBUFS;
5404                 goto errout_ifa;
5405         }
5406 
5407         err = inet6_fill_ifaddr(skb, ifa, &fillargs);
5408         if (err < 0) {
5409                 /* -EMSGSIZE implies BUG in inet6_ifaddr_msgsize() */
5410                 WARN_ON(err == -EMSGSIZE);
5411                 kfree_skb(skb);
5412                 goto errout_ifa;
5413         }
5414         err = rtnl_unicast(skb, tgt_net, NETLINK_CB(in_skb).portid);
5415 errout_ifa:
5416         in6_ifa_put(ifa);
5417 errout:
5418         if (dev)
5419                 dev_put(dev);
5420         if (fillargs.netnsid >= 0)
5421                 put_net(tgt_net);
5422 
5423         return err;
5424 }
5425 
5426 static void inet6_ifa_notify(int event, struct inet6_ifaddr *ifa)
5427 {
5428         struct sk_buff *skb;
5429         struct net *net = dev_net(ifa->idev->dev);
5430         struct inet6_fill_args fillargs = {
5431                 .portid = 0,
5432                 .seq = 0,
5433                 .event = event,
5434                 .flags = 0,
5435                 .netnsid = -1,
5436         };
5437         int err = -ENOBUFS;
5438 
5439         skb = nlmsg_new(inet6_ifaddr_msgsize(), GFP_ATOMIC);
5440         if (!skb)
5441                 goto errout;
5442 
5443         err = inet6_fill_ifaddr(skb, ifa, &fillargs);
5444         if (err < 0) {
5445                 /* -EMSGSIZE implies BUG in inet6_ifaddr_msgsize() */
5446                 WARN_ON(err == -EMSGSIZE);
5447                 kfree_skb(skb);
5448                 goto errout;
5449         }
5450         rtnl_notify(skb, net, 0, RTNLGRP_IPV6_IFADDR, NULL, GFP_ATOMIC);
5451         return;
5452 errout:
5453         if (err < 0)
5454                 rtnl_set_sk_err(net, RTNLGRP_IPV6_IFADDR, err);
5455 }
5456 
5457 static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
5458                                 __s32 *array, int bytes)
5459 {
5460         BUG_ON(bytes < (DEVCONF_MAX * 4));
5461 
5462         memset(array, 0, bytes);
5463         array[DEVCONF_FORWARDING] = cnf->forwarding;
5464         array[DEVCONF_HOPLIMIT] = cnf->hop_limit;
5465         array[DEVCONF_MTU6] = cnf->mtu6;
5466         array[DEVCONF_ACCEPT_RA] = cnf->accept_ra;
5467         array[DEVCONF_ACCEPT_REDIRECTS] = cnf->accept_redirects;
5468         array[DEVCONF_AUTOCONF] = cnf->autoconf;
5469         array[DEVCONF_DAD_TRANSMITS] = cnf->dad_transmits;
5470         array[DEVCONF_RTR_SOLICITS] = cnf->rtr_solicits;
5471         array[DEVCONF_RTR_SOLICIT_INTERVAL] =
5472                 jiffies_to_msecs(cnf->rtr_solicit_interval);
5473         array[DEVCONF_RTR_SOLICIT_MAX_INTERVAL] =
5474                 jiffies_to_msecs(cnf->rtr_solicit_max_interval);
5475         array[DEVCONF_RTR_SOLICIT_DELAY] =
5476                 jiffies_to_msecs(cnf->rtr_solicit_delay);
5477         array[DEVCONF_FORCE_MLD_VERSION] = cnf->force_mld_version;
5478         array[DEVCONF_MLDV1_UNSOLICITED_REPORT_INTERVAL] =
5479                 jiffies_to_msecs(cnf->mldv1_unsolicited_report_interval);
5480         array[DEVCONF_MLDV2_UNSOLICITED_REPORT_INTERVAL] =
5481                 jiffies_to_msecs(cnf->mldv2_unsolicited_report_interval);
5482         array[DEVCONF_USE_TEMPADDR] = cnf->use_tempaddr;
5483         array[DEVCONF_TEMP_VALID_LFT] = cnf->temp_valid_lft;
5484         array[DEVCONF_TEMP_PREFERED_LFT] = cnf->temp_prefered_lft;
5485         array[DEVCONF_REGEN_MAX_RETRY] = cnf->regen_max_retry;
5486         array[DEVCONF_MAX_DESYNC_FACTOR] = cnf->max_desync_factor;
5487         array[DEVCONF_MAX_ADDRESSES] = cnf->max_addresses;
5488         array[DEVCONF_ACCEPT_RA_DEFRTR] = cnf->accept_ra_defrtr;
5489         array[DEVCONF_RA_DEFRTR_METRIC] = cnf->ra_defrtr_metric;
5490         array[DEVCONF_ACCEPT_RA_MIN_HOP_LIMIT] = cnf->accept_ra_min_hop_limit;
5491         array[DEVCONF_ACCEPT_RA_PINFO] = cnf->accept_ra_pinfo;
5492 #ifdef CONFIG_IPV6_ROUTER_PREF
5493         array[DEVCONF_ACCEPT_RA_RTR_PREF] = cnf->accept_ra_rtr_pref;
5494         array[DEVCONF_RTR_PROBE_INTERVAL] =
5495                 jiffies_to_msecs(cnf->rtr_probe_interval);
5496 #ifdef CONFIG_IPV6_ROUTE_INFO
5497         array[DEVCONF_ACCEPT_RA_RT_INFO_MIN_PLEN] = cnf->accept_ra_rt_info_min_plen;
5498         array[DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN] = cnf->accept_ra_rt_info_max_plen;
5499 #endif
5500 #endif
5501         array[DEVCONF_PROXY_NDP] = cnf->proxy_ndp;
5502         array[DEVCONF_ACCEPT_SOURCE_ROUTE] = cnf->accept_source_route;
5503 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
5504         array[DEVCONF_OPTIMISTIC_DAD] = cnf->optimistic_dad;
5505         array[DEVCONF_USE_OPTIMISTIC] = cnf->use_optimistic;
5506 #endif
5507 #ifdef CONFIG_IPV6_MROUTE
5508         array[DEVCONF_MC_FORWARDING] = cnf->mc_forwarding;
5509 #endif
5510         array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6;
5511         array[DEVCONF_ACCEPT_DAD] = cnf->accept_dad;
5512         array[DEVCONF_FORCE_TLLAO] = cnf->force_tllao;
5513         array[DEVCONF_NDISC_NOTIFY] = cnf->ndisc_notify;
5514         array[DEVCONF_SUPPRESS_FRAG_NDISC] = cnf->suppress_frag_ndisc;
5515         array[DEVCONF_ACCEPT_RA_FROM_LOCAL] = cnf->accept_ra_from_local;
5516         array[DEVCONF_ACCEPT_RA_MTU] = cnf->accept_ra_mtu;
5517         array[DEVCONF_IGNORE_ROUTES_WITH_LINKDOWN] = cnf->ignore_routes_with_linkdown;
5518         /* we omit DEVCONF_STABLE_SECRET for now */
5519         array[DEVCONF_USE_OIF_ADDRS_ONLY] = cnf->use_oif_addrs_only;
5520         array[DEVCONF_DROP_UNICAST_IN_L2_MULTICAST] = cnf->drop_unicast_in_l2_multicast;
5521         array[DEVCONF_DROP_UNSOLICITED_NA] = cnf->drop_unsolicited_na;
5522         array[DEVCONF_KEEP_ADDR_ON_DOWN] = cnf->keep_addr_on_down;
5523         array[DEVCONF_SEG6_ENABLED] = cnf->seg6_enabled;
5524 #ifdef CONFIG_IPV6_SEG6_HMAC
5525         array[DEVCONF_SEG6_REQUIRE_HMAC] = cnf->seg6_require_hmac;
5526 #endif
5527         array[DEVCONF_ENHANCED_DAD] = cnf->enhanced_dad;
5528         array[DEVCONF_ADDR_GEN_MODE] = cnf->addr_gen_mode;
5529         array[DEVCONF_DISABLE_POLICY] = cnf->disable_policy;
5530         array[DEVCONF_NDISC_TCLASS] = cnf->ndisc_tclass;
5531         array[DEVCONF_RPL_SEG_ENABLED] = cnf->rpl_seg_enabled;
5532 }
5533 
5534 static inline size_t inet6_ifla6_size(void)
5535 {
5536         return nla_total_size(4) /* IFLA_INET6_FLAGS */
5537              + nla_total_size(sizeof(struct ifla_cacheinfo))
5538              + nla_total_size(DEVCONF_MAX * 4) /* IFLA_INET6_CONF */
5539              + nla_total_size(IPSTATS_MIB_MAX * 8) /* IFLA_INET6_STATS */
5540              + nla_total_size(ICMP6_MIB_MAX * 8) /* IFLA_INET6_ICMP6STATS */
5541              + nla_total_size(sizeof(struct in6_addr)) /* IFLA_INET6_TOKEN */
5542              + nla_total_size(1) /* IFLA_INET6_ADDR_GEN_MODE */
5543              + 0;
5544 }
5545 
5546 static inline size_t inet6_if_nlmsg_size(void)
5547 {
5548         return NLMSG_ALIGN(sizeof(struct ifinfomsg))
5549                + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
5550                + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
5551                + nla_total_size(4) /* IFLA_MTU */
5552                + nla_total_size(4) /* IFLA_LINK */
5553                + nla_total_size(1) /* IFLA_OPERSTATE */
5554                + nla_total_size(inet6_ifla6_size()); /* IFLA_PROTINFO */
5555 }
5556 
5557 static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
5558                                         int bytes)
5559 {
5560         int i;
5561         int pad = bytes - sizeof(u64) * ICMP6_MIB_MAX;
5562         BUG_ON(pad < 0);
5563 
5564         /* Use put_unaligned() because stats may not be aligned for u64. */
5565         put_unaligned(ICMP6_MIB_MAX, &stats[0]);
5566         for (i = 1; i < ICMP6_MIB_MAX; i++)
5567                 put_unaligned(atomic_long_read(&mib[i]), &stats[i]);
5568 
5569         memset(&stats[ICMP6_MIB_MAX], 0, pad);
5570 }
5571 
5572 static inline void __snmp6_fill_stats64(u64 *stats, void __percpu *mib,
5573                                         int bytes, size_t syncpoff)
5574 {
5575         int i, c;
5576         u64 buff[IPSTATS_MIB_MAX];
5577         int pad = bytes - sizeof(u64) * IPSTATS_MIB_MAX;
5578 
5579         BUG_ON(pad < 0);
5580 
5581         memset(buff, 0, sizeof(buff));
5582         buff[0] = IPSTATS_MIB_MAX;
5583 
5584         for_each_possible_cpu(c) {
5585                 for (i = 1; i < IPSTATS_MIB_MAX; i++)
5586                         buff[i] += snmp_get_cpu_field64(mib, c, i, syncpoff);
5587         }
5588 
5589         memcpy(stats, buff, IPSTATS_MIB_MAX * sizeof(u64));
5590         memset(&stats[IPSTATS_MIB_MAX], 0, pad);
5591 }
5592 
5593 static void snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int attrtype,
5594                              int bytes)
5595 {
5596         switch (attrtype) {
5597         case IFLA_INET6_STATS:
5598                 __snmp6_fill_stats64(stats, idev->stats.ipv6, bytes,
5599                                      offsetof(struct ipstats_mib, syncp));
5600                 break;
5601         case IFLA_INET6_ICMP6STATS:
5602                 __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs, bytes);
5603                 break;
5604         }
5605 }
5606 
5607 static int inet6_fill_ifla6_attrs(struct sk_buff *skb, struct inet6_dev *idev,
5608                                   u32 ext_filter_mask)
5609 {
5610         struct nlattr *nla;
5611         struct ifla_cacheinfo ci;
5612 
5613         if (nla_put_u32(skb, IFLA_INET6_FLAGS, idev->if_flags))
5614                 goto nla_put_failure;
5615         ci.max_reasm_len = IPV6_MAXPLEN;
5616         ci.tstamp = cstamp_delta(idev->tstamp);
5617         ci.reachable_time = jiffies_to_msecs(idev->nd_parms->reachable_time);
5618         ci.retrans_time = jiffies_to_msecs(NEIGH_VAR(idev->nd_parms, RETRANS_TIME));
5619         if (nla_put(skb, IFLA_INET6_CACHEINFO, sizeof(ci), &ci))
5620                 goto nla_put_failure;
5621         nla = nla_reserve(skb, IFLA_INET6_CONF, DEVCONF_MAX * sizeof(s32));
5622         if (!nla)
5623                 goto nla_put_failure;
5624         ipv6_store_devconf(&idev->cnf, nla_data(nla), nla_len(nla));
5625 
5626         /* XXX - MC not implemented */
5627 
5628         if (ext_filter_mask & RTEXT_FILTER_SKIP_STATS)
5629                 return 0;
5630 
5631         nla = nla_reserve(skb, IFLA_INET6_STATS, IPSTATS_MIB_MAX * sizeof(u64));
5632         if (!nla)
5633                 goto nla_put_failure;
5634         snmp6_fill_stats(nla_data(nla), idev, IFLA_INET6_STATS, nla_len(nla));
5635 
5636         nla = nla_reserve(skb, IFLA_INET6_ICMP6STATS, ICMP6_MIB_MAX * sizeof(u64));
5637         if (!nla)
5638                 goto nla_put_failure;
5639         snmp6_fill_stats(nla_data(nla), idev, IFLA_INET6_ICMP6STATS, nla_len(nla));
5640 
5641         nla = nla_reserve(skb, IFLA_INET6_TOKEN, sizeof(struct in6_addr));
5642         if (!nla)
5643                 goto nla_put_failure;
5644         read_lock_bh(&idev->lock);
5645         memcpy(nla_data(nla), idev->token.s6_addr, nla_len(nla));
5646         read_unlock_bh(&idev->lock);
5647 
5648         if (nla_put_u8(skb, IFLA_INET6_ADDR_GEN_MODE, idev->cnf.addr_gen_mode))
5649                 goto nla_put_failure;
5650 
5651         return 0;
5652 
5653 nla_put_failure:
5654         return -EMSGSIZE;
5655 }
5656 
5657 static size_t inet6_get_link_af_size(const struct net_device *dev,
5658                                      u32 ext_filter_mask)
5659 {
5660         if (!__in6_dev_get(dev))
5661                 return 0;
5662 
5663         return inet6_ifla6_size();
5664 }
5665 
5666 static int inet6_fill_link_af(struct sk_buff *skb, const struct net_device *dev,
5667                               u32 ext_filter_mask)
5668 {
5669         struct inet6_dev *idev = __in6_dev_get(dev);
5670 
5671         if (!idev)
5672                 return -ENODATA;
5673 
5674         if (inet6_fill_ifla6_attrs(skb, idev, ext_filter_mask) < 0)
5675                 return -EMSGSIZE;
5676 
5677         return 0;
5678 }
5679 
5680 static int inet6_set_iftoken(struct inet6_dev *idev, struct in6_addr *token,
5681                              struct netlink_ext_ack *extack)
5682 {
5683         struct inet6_ifaddr *ifp;
5684         struct net_device *dev = idev->dev;
5685         bool clear_token, update_rs = false;
5686         struct in6_addr ll_addr;
5687 
5688         ASSERT_RTNL();
5689 
5690         if (!token)
5691                 return -EINVAL;
5692 
5693         if (dev->flags & IFF_LOOPBACK) {
5694                 NL_SET_ERR_MSG_MOD(extack, "Device is loopback");
5695                 return -EINVAL;
5696         }
5697 
5698         if (dev->flags & IFF_NOARP) {
5699                 NL_SET_ERR_MSG_MOD(extack,
5700                                    "Device does not do neighbour discovery");
5701                 return -EINVAL;
5702         }
5703 
5704         if (!ipv6_accept_ra(idev)) {
5705                 NL_SET_ERR_MSG_MOD(extack,
5706                                    "Router advertisement is disabled on device");
5707                 return -EINVAL;
5708         }
5709 
5710         if (idev->cnf.rtr_solicits == 0) {
5711                 NL_SET_ERR_MSG(extack,
5712                                "Router solicitation is disabled on device");
5713                 return -EINVAL;
5714         }
5715 
5716         write_lock_bh(&idev->lock);
5717 
5718         BUILD_BUG_ON(sizeof(token->s6_addr) != 16);
5719         memcpy(idev->token.s6_addr + 8, token->s6_addr + 8, 8);
5720 
5721         write_unlock_bh(&idev->lock);
5722 
5723         clear_token = ipv6_addr_any(token);
5724         if (clear_token)
5725                 goto update_lft;
5726 
5727         if (!idev->dead && (idev->if_flags & IF_READY) &&
5728             !ipv6_get_lladdr(dev, &ll_addr, IFA_F_TENTATIVE |
5729                              IFA_F_OPTIMISTIC)) {
5730                 /* If we're not ready, then normal ifup will take care
5731                  * of this. Otherwise, we need to request our rs here.
5732                  */
5733                 ndisc_send_rs(dev, &ll_addr, &in6addr_linklocal_allrouters);
5734                 update_rs = true;
5735         }
5736 
5737 update_lft:
5738         write_lock_bh(&idev->lock);
5739 
5740         if (update_rs) {
5741                 idev->if_flags |= IF_RS_SENT;
5742                 idev->rs_interval = rfc3315_s14_backoff_init(
5743                         idev->cnf.rtr_solicit_interval);
5744                 idev->rs_probes = 1;
5745                 addrconf_mod_rs_timer(idev, idev->rs_interval);
5746         }
5747 
5748         /* Well, that's kinda nasty ... */
5749         list_for_each_entry(ifp, &idev->addr_list, if_list) {
5750                 spin_lock(&ifp->lock);
5751                 if (ifp->tokenized) {
5752                         ifp->valid_lft = 0;
5753                         ifp->prefered_lft = 0;
5754                 }
5755                 spin_unlock(&ifp->lock);
5756         }
5757 
5758         write_unlock_bh(&idev->lock);
5759         inet6_ifinfo_notify(RTM_NEWLINK, idev);
5760         addrconf_verify_rtnl();
5761         return 0;
5762 }
5763 
5764 static const struct nla_policy inet6_af_policy[IFLA_INET6_MAX + 1] = {
5765         [IFLA_INET6_ADDR_GEN_MODE]      = { .type = NLA_U8 },
5766         [IFLA_INET6_TOKEN]              = { .len = sizeof(struct in6_addr) },
5767 };
5768 
5769 static int check_addr_gen_mode(int mode)
5770 {
5771         if (mode != IN6_ADDR_GEN_MODE_EUI64 &&
5772             mode != IN6_ADDR_GEN_MODE_NONE &&
5773             mode != IN6_ADDR_GEN_MODE_STABLE_PRIVACY &&
5774             mode != IN6_ADDR_GEN_MODE_RANDOM)
5775                 return -EINVAL;
5776         return 1;
5777 }
5778 
5779 static int check_stable_privacy(struct inet6_dev *idev, struct net *net,
5780                                 int mode)
5781 {
5782         if (mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY &&
5783             !idev->cnf.stable_secret.initialized &&
5784             !net->ipv6.devconf_dflt->stable_secret.initialized)
5785                 return -EINVAL;
5786         return 1;
5787 }
5788 
5789 static int inet6_validate_link_af(const struct net_device *dev,
5790                                   const struct nlattr *nla)
5791 {
5792         struct nlattr *tb[IFLA_INET6_MAX + 1];
5793         struct inet6_dev *idev = NULL;
5794         int err;
5795 
5796         if (dev) {
5797                 idev = __in6_dev_get(dev);
5798                 if (!idev)
5799                         return -EAFNOSUPPORT;
5800         }
5801 
5802         err = nla_parse_nested_deprecated(tb, IFLA_INET6_MAX, nla,
5803                                           inet6_af_policy, NULL);
5804         if (err)
5805                 return err;
5806 
5807         if (!tb[IFLA_INET6_TOKEN] && !tb[IFLA_INET6_ADDR_GEN_MODE])
5808                 return -EINVAL;
5809 
5810         if (tb[IFLA_INET6_ADDR_GEN_MODE]) {
5811                 u8 mode = nla_get_u8(tb[IFLA_INET6_ADDR_GEN_MODE]);
5812 
5813                 if (check_addr_gen_mode(mode) < 0)
5814                         return -EINVAL;
5815                 if (dev && check_stable_privacy(idev, dev_net(dev), mode) < 0)
5816                         return -EINVAL;
5817         }
5818 
5819         return 0;
5820 }
5821 
5822 static int inet6_set_link_af(struct net_device *dev, const struct nlattr *nla,
5823                              struct netlink_ext_ack *extack)
5824 {
5825         struct inet6_dev *idev = __in6_dev_get(dev);
5826         struct nlattr *tb[IFLA_INET6_MAX + 1];
5827         int err;
5828 
5829         if (!idev)
5830                 return -EAFNOSUPPORT;
5831 
5832         if (nla_parse_nested_deprecated(tb, IFLA_INET6_MAX, nla, NULL, NULL) < 0)
5833                 return -EINVAL;
5834 
5835         if (tb[IFLA_INET6_TOKEN]) {
5836                 err = inet6_set_iftoken(idev, nla_data(tb[IFLA_INET6_TOKEN]),
5837                                         extack);
5838                 if (err)
5839                         return err;
5840         }
5841 
5842         if (tb[IFLA_INET6_ADDR_GEN_MODE]) {
5843                 u8 mode = nla_get_u8(tb[IFLA_INET6_ADDR_GEN_MODE]);
5844 
5845                 idev->cnf.addr_gen_mode = mode;
5846         }
5847 
5848         return 0;
5849 }
5850 
5851 static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev,
5852                              u32 portid, u32 seq, int event, unsigned int flags)
5853 {
5854         struct net_device *dev = idev->dev;
5855         struct ifinfomsg *hdr;
5856         struct nlmsghdr *nlh;
5857         void *protoinfo;
5858 
5859         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*hdr), flags);
5860         if (!nlh)
5861                 return -EMSGSIZE;
5862 
5863         hdr = nlmsg_data(nlh);
5864         hdr->ifi_family = AF_INET6;
5865         hdr->__ifi_pad = 0;
5866         hdr->ifi_type = dev->type;
5867         hdr->ifi_index = dev->ifindex;
5868         hdr->ifi_flags = dev_get_flags(dev);
5869         hdr->ifi_change = 0;
5870 
5871         if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
5872             (dev->addr_len &&
5873              nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) ||
5874             nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
5875             (dev->ifindex != dev_get_iflink(dev) &&
5876              nla_put_u32(skb, IFLA_LINK, dev_get_iflink(dev))) ||
5877             nla_put_u8(skb, IFLA_OPERSTATE,
5878                        netif_running(dev) ? dev->operstate : IF_OPER_DOWN))
5879                 goto nla_put_failure;
5880         protoinfo = nla_nest_start_noflag(skb, IFLA_PROTINFO);
5881         if (!protoinfo)
5882                 goto nla_put_failure;
5883 
5884         if (inet6_fill_ifla6_attrs(skb, idev, 0) < 0)
5885                 goto nla_put_failure;
5886 
5887         nla_nest_end(skb, protoinfo);
5888         nlmsg_end(skb, nlh);
5889         return 0;
5890 
5891 nla_put_failure:
5892         nlmsg_cancel(skb, nlh);
5893         return -EMSGSIZE;
5894 }
5895 
5896 static int inet6_valid_dump_ifinfo(const struct nlmsghdr *nlh,
5897                                    struct netlink_ext_ack *extack)
5898 {
5899         struct ifinfomsg *ifm;
5900 
5901         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
5902                 NL_SET_ERR_MSG_MOD(extack, "Invalid header for link dump request");
5903                 return -EINVAL;
5904         }
5905 
5906         if (nlmsg_attrlen(nlh, sizeof(*ifm))) {
5907                 NL_SET_ERR_MSG_MOD(extack, "Invalid data after header");
5908                 return -EINVAL;
5909         }
5910 
5911         ifm = nlmsg_data(nlh);
5912         if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
5913             ifm->ifi_change || ifm->ifi_index) {
5914                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for dump request");
5915                 return -EINVAL;
5916         }
5917 
5918         return 0;
5919 }
5920 
5921 static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
5922 {
5923         struct net *net = sock_net(skb->sk);
5924         int h, s_h;
5925         int idx = 0, s_idx;
5926         struct net_device *dev;
5927         struct inet6_dev *idev;
5928         struct hlist_head *head;
5929 
5930         /* only requests using strict checking can pass data to
5931          * influence the dump
5932          */
5933         if (cb->strict_check) {
5934                 int err = inet6_valid_dump_ifinfo(cb->nlh, cb->extack);
5935 
5936                 if (err < 0)
5937                         return err;
5938         }
5939 
5940         s_h = cb->args[0];
5941         s_idx = cb->args[1];
5942 
5943         rcu_read_lock();
5944         for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
5945                 idx = 0;
5946                 head = &net->dev_index_head[h];
5947                 hlist_for_each_entry_rcu(dev, head, index_hlist) {
5948                         if (idx < s_idx)
5949                                 goto cont;
5950                         idev = __in6_dev_get(dev);
5951                         if (!idev)
5952                                 goto cont;
5953                         if (inet6_fill_ifinfo(skb, idev,
5954