net/ipv6/route.c

   1 /*
   2  *      Linux INET6 implementation
   3  *      FIB front-end.
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <[email protected]>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 /*      Changes:
  15  *
  16  *      YOSHIFUJI Hideaki @USAGI
  17  *              reworked default router selection.
  18  *              - respect outgoing interface
  19  *              - select from (probably) reachable routers (i.e.
  20  *              routers in REACHABLE, STALE, DELAY or PROBE states).
  21  *              - always select the same router if it is (probably)
  22  *              reachable.  otherwise, round-robin the list.
  23  *      Ville Nuorvala
  24  *              Fixed routing subtrees.
  25  */
  26
  27 #define pr_fmt(fmt) "IPv6: " fmt
  28
  29 #include <linux/capability.h>
  30 #include <linux/errno.h>
  31 #include <linux/export.h>
  32 #include <linux/types.h>
  33 #include <linux/times.h>
  34 #include <linux/socket.h>
  35 #include <linux/sockios.h>
  36 #include <linux/net.h>
  37 #include <linux/route.h>
  38 #include <linux/netdevice.h>
  39 #include <linux/in6.h>
  40 #include <linux/mroute6.h>
  41 #include <linux/init.h>
  42 #include <linux/if_arp.h>
  43 #include <linux/proc_fs.h>
  44 #include <linux/seq_file.h>
  45 #include <linux/nsproxy.h>
  46 #include <linux/slab.h>
  47 #include <net/net_namespace.h>
  48 #include <net/snmp.h>
  49 #include <net/ipv6.h>
  50 #include <net/ip6_fib.h>
  51 #include <net/ip6_route.h>
  52 #include <net/ndisc.h>
  53 #include <net/addrconf.h>
  54 #include <net/tcp.h>
  55 #include <linux/rtnetlink.h>
  56 #include <net/dst.h>
  57 #include <net/dst_metadata.h>
  58 #include <net/xfrm.h>
  59 #include <net/netevent.h>
  60 #include <net/netlink.h>
  61 #include <net/nexthop.h>
  62 #include <net/lwtunnel.h>
  63 #include <net/ip_tunnels.h>
  64
  65 #include <asm/uaccess.h>
  66
  67 #ifdef CONFIG_SYSCTL
  68 #include <linux/sysctl.h>
  69 #endif
  70
  71 enum rt6_nud_state {
  72         RT6_NUD_FAIL_HARD = -3,
  73         RT6_NUD_FAIL_PROBE = -2,
  74         RT6_NUD_FAIL_DO_RR = -1,
  75         RT6_NUD_SUCCEED = 1
  76 };
  77
  78 static void ip6_rt_copy_init(struct rt6_info *rt, struct rt6_info *ort);
  79 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie);
  80 static unsigned int      ip6_default_advmss(const struct dst_entry *dst);
  81 static unsigned int      ip6_mtu(const struct dst_entry *dst);
  82 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
  83 static void             ip6_dst_destroy(struct dst_entry *);
  84 static void             ip6_dst_ifdown(struct dst_entry *,
  85                                        struct net_device *dev, int how);
  86 static int               ip6_dst_gc(struct dst_ops *ops);
  87
  88 static int              ip6_pkt_discard(struct sk_buff *skb);
  89 static int              ip6_pkt_discard_out(struct sock *sk, struct sk_buff *skb);
  90 static int              ip6_pkt_prohibit(struct sk_buff *skb);
  91 static int              ip6_pkt_prohibit_out(struct sock *sk, struct sk_buff *skb);
  92 static void             ip6_link_failure(struct sk_buff *skb);
  93 static void             ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
  94                                            struct sk_buff *skb, u32 mtu);
  95 static void             rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
  96                                         struct sk_buff *skb);
  97 static void             rt6_dst_from_metrics_check(struct rt6_info *rt);
  98 static int rt6_score_route(struct rt6_info *rt, int oif, int strict);
  99
 100 #ifdef CONFIG_IPV6_ROUTE_INFO
 101 static struct rt6_info *rt6_add_route_info(struct net *net,
 102                                            const struct in6_addr *prefix, int prefixlen,
 103                                            const struct in6_addr *gwaddr, int ifindex,
 104                                            unsigned int pref);
 105 static struct rt6_info *rt6_get_route_info(struct net *net,
 106                                            const struct in6_addr *prefix, int prefixlen,
 107                                            const struct in6_addr *gwaddr, int ifindex);
 108 #endif
 109
 110 struct uncached_list {
 111         spinlock_t              lock;
 112         struct list_head        head;
 113 };
 114
 115 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
 116
 117 static void rt6_uncached_list_add(struct rt6_info *rt)
 118 {
 119         struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list);
 120
 121         rt->dst.flags |= DST_NOCACHE;
 122         rt->rt6i_uncached_list = ul;
 123
 124         spin_lock_bh(&ul->lock);
 125         list_add_tail(&rt->rt6i_uncached, &ul->head);
 126         spin_unlock_bh(&ul->lock);
 127 }
 128
 129 static void rt6_uncached_list_del(struct rt6_info *rt)
 130 {
 131         if (!list_empty(&rt->rt6i_uncached)) {
 132                 struct uncached_list *ul = rt->rt6i_uncached_list;
 133
 134                 spin_lock_bh(&ul->lock);
 135                 list_del(&rt->rt6i_uncached);
 136                 spin_unlock_bh(&ul->lock);
 137         }
 138 }
 139
 140 static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev)
 141 {
 142         struct net_device *loopback_dev = net->loopback_dev;
 143         int cpu;
 144
 145         for_each_possible_cpu(cpu) {
 146                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
 147                 struct rt6_info *rt;
 148
 149                 spin_lock_bh(&ul->lock);
 150                 list_for_each_entry(rt, &ul->head, rt6i_uncached) {
 151                         struct inet6_dev *rt_idev = rt->rt6i_idev;
 152                         struct net_device *rt_dev = rt->dst.dev;
 153
 154                         if (rt_idev && (rt_idev->dev == dev || !dev) &&
 155                             rt_idev->dev != loopback_dev) {
 156                                 rt->rt6i_idev = in6_dev_get(loopback_dev);
 157                                 in6_dev_put(rt_idev);
 158                         }
 159
 160                         if (rt_dev && (rt_dev == dev || !dev) &&
 161                             rt_dev != loopback_dev) {
 162                                 rt->dst.dev = loopback_dev;
 163                                 dev_hold(rt->dst.dev);
 164                                 dev_put(rt_dev);
 165                         }
 166                 }
 167                 spin_unlock_bh(&ul->lock);
 168         }
 169 }
 170
 171 static u32 *rt6_pcpu_cow_metrics(struct rt6_info *rt)
 172 {
 173         return dst_metrics_write_ptr(rt->dst.from);
 174 }
 175
 176 static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old)
 177 {
 178         struct rt6_info *rt = (struct rt6_info *)dst;
 179
 180         if (rt->rt6i_flags & RTF_PCPU)
 181                 return rt6_pcpu_cow_metrics(rt);
 182         else if (rt->rt6i_flags & RTF_CACHE)
 183                 return NULL;
 184         else
 185                 return dst_cow_metrics_generic(dst, old);
 186 }
 187
 188 static inline const void *choose_neigh_daddr(struct rt6_info *rt,
 189                                              struct sk_buff *skb,
 190                                              const void *daddr)
 191 {
 192         struct in6_addr *p = &rt->rt6i_gateway;
 193
 194         if (!ipv6_addr_any(p))
 195                 return (const void *) p;
 196         else if (skb)
 197                 return &ipv6_hdr(skb)->daddr;
 198         return daddr;
 199 }
 200
 201 static struct neighbour *ip6_neigh_lookup(const struct dst_entry *dst,
 202                                           struct sk_buff *skb,
 203                                           const void *daddr)
 204 {
 205         struct rt6_info *rt = (struct rt6_info *) dst;
 206         struct neighbour *n;
 207
 208         daddr = choose_neigh_daddr(rt, skb, daddr);
 209         n = __ipv6_neigh_lookup(dst->dev, daddr);
 210         if (n)
 211                 return n;
 212         return neigh_create(&nd_tbl, daddr, dst->dev);
 213 }
 214
 215 static struct dst_ops ip6_dst_ops_template = {
 216         .family                 =       AF_INET6,
 217         .gc                     =       ip6_dst_gc,
 218         .gc_thresh              =       1024,
 219         .check                  =       ip6_dst_check,
 220         .default_advmss         =       ip6_default_advmss,
 221         .mtu                    =       ip6_mtu,
 222         .cow_metrics            =       ipv6_cow_metrics,
 223         .destroy                =       ip6_dst_destroy,
 224         .ifdown                 =       ip6_dst_ifdown,
 225         .negative_advice        =       ip6_negative_advice,
 226         .link_failure           =       ip6_link_failure,
 227         .update_pmtu            =       ip6_rt_update_pmtu,
 228         .redirect               =       rt6_do_redirect,
 229         .local_out              =       __ip6_local_out,
 230         .neigh_lookup           =       ip6_neigh_lookup,
 231 };
 232
 233 static unsigned int ip6_blackhole_mtu(const struct dst_entry *dst)
 234 {
 235         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
 236
 237         return mtu ? : dst->dev->mtu;
 238 }
 239
 240 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
 241                                          struct sk_buff *skb, u32 mtu)
 242 {
 243 }
 244
 245 static void ip6_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
 246                                       struct sk_buff *skb)
 247 {
 248 }
 249
 250 static u32 *ip6_rt_blackhole_cow_metrics(struct dst_entry *dst,
 251                                          unsigned long old)
 252 {
 253         return NULL;
 254 }
 255
 256 static struct dst_ops ip6_dst_blackhole_ops = {
 257         .family                 =       AF_INET6,
 258         .destroy                =       ip6_dst_destroy,
 259         .check                  =       ip6_dst_check,
 260         .mtu                    =       ip6_blackhole_mtu,
 261         .default_advmss         =       ip6_default_advmss,
 262         .update_pmtu            =       ip6_rt_blackhole_update_pmtu,
 263         .redirect               =       ip6_rt_blackhole_redirect,
 264         .cow_metrics            =       ip6_rt_blackhole_cow_metrics,
 265         .neigh_lookup           =       ip6_neigh_lookup,
 266 };
 267
 268 static const u32 ip6_template_metrics[RTAX_MAX] = {
 269         [RTAX_HOPLIMIT - 1] = 0,
 270 };
 271
 272 static const struct rt6_info ip6_null_entry_template = {
 273         .dst = {
 274                 .__refcnt       = ATOMIC_INIT(1),
 275                 .__use          = 1,
 276                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 277                 .error          = -ENETUNREACH,
 278                 .input          = ip6_pkt_discard,
 279                 .output         = ip6_pkt_discard_out,
 280         },
 281         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 282         .rt6i_protocol  = RTPROT_KERNEL,
 283         .rt6i_metric    = ~(u32) 0,
 284         .rt6i_ref       = ATOMIC_INIT(1),
 285 };
 286
 287 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 288
 289 static const struct rt6_info ip6_prohibit_entry_template = {
 290         .dst = {
 291                 .__refcnt       = ATOMIC_INIT(1),
 292                 .__use          = 1,
 293                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 294                 .error          = -EACCES,
 295                 .input          = ip6_pkt_prohibit,
 296                 .output         = ip6_pkt_prohibit_out,
 297         },
 298         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 299         .rt6i_protocol  = RTPROT_KERNEL,
 300         .rt6i_metric    = ~(u32) 0,
 301         .rt6i_ref       = ATOMIC_INIT(1),
 302 };
 303
 304 static const struct rt6_info ip6_blk_hole_entry_template = {
 305         .dst = {
 306                 .__refcnt       = ATOMIC_INIT(1),
 307                 .__use          = 1,
 308                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 309                 .error          = -EINVAL,
 310                 .input          = dst_discard,
 311                 .output         = dst_discard_sk,
 312         },
 313         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 314         .rt6i_protocol  = RTPROT_KERNEL,
 315         .rt6i_metric    = ~(u32) 0,
 316         .rt6i_ref       = ATOMIC_INIT(1),
 317 };
 318
 319 #endif
 320
 321 /* allocate dst with ip6_dst_ops */
 322 static struct rt6_info *__ip6_dst_alloc(struct net *net,
 323                                         struct net_device *dev,
 324                                         int flags)
 325 {
 326         struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
 327                                         0, DST_OBSOLETE_FORCE_CHK, flags);
 328
 329         if (rt) {
 330                 struct dst_entry *dst = &rt->dst;
 331
 332                 memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));
 333                 INIT_LIST_HEAD(&rt->rt6i_siblings);
 334                 INIT_LIST_HEAD(&rt->rt6i_uncached);
 335         }
 336         return rt;
 337 }
 338
 339 static struct rt6_info *ip6_dst_alloc(struct net *net,
 340                                       struct net_device *dev,
 341                                       int flags)
 342 {
 343         struct rt6_info *rt = __ip6_dst_alloc(net, dev, flags);
 344
 345         if (rt) {
 346                 rt->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, GFP_ATOMIC);
 347                 if (rt->rt6i_pcpu) {
 348                         int cpu;
 349
 350                         for_each_possible_cpu(cpu) {
 351                                 struct rt6_info **p;
 352
 353                                 p = per_cpu_ptr(rt->rt6i_pcpu, cpu);
 354                                 /* no one shares rt */
 355                                 *p =  NULL;
 356                         }
 357                 } else {
 358                         dst_destroy((struct dst_entry *)rt);
 359                         return NULL;
 360                 }
 361         }
 362
 363         return rt;
 364 }
 365
 366 static void ip6_dst_destroy(struct dst_entry *dst)
 367 {
 368         struct rt6_info *rt = (struct rt6_info *)dst;
 369         struct dst_entry *from = dst->from;
 370         struct inet6_dev *idev;
 371
 372         dst_destroy_metrics_generic(dst);
 373         free_percpu(rt->rt6i_pcpu);
 374         rt6_uncached_list_del(rt);
 375
 376         idev = rt->rt6i_idev;
 377         if (idev) {
 378                 rt->rt6i_idev = NULL;
 379                 in6_dev_put(idev);
 380         }
 381
 382         dst->from = NULL;
 383         dst_release(from);
 384 }
 385
 386 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 387                            int how)
 388 {
 389         struct rt6_info *rt = (struct rt6_info *)dst;
 390         struct inet6_dev *idev = rt->rt6i_idev;
 391         struct net_device *loopback_dev =
 392                 dev_net(dev)->loopback_dev;
 393
 394         if (dev != loopback_dev) {
 395                 if (idev && idev->dev == dev) {
 396                         struct inet6_dev *loopback_idev =
 397                                 in6_dev_get(loopback_dev);
 398                         if (loopback_idev) {
 399                                 rt->rt6i_idev = loopback_idev;
 400                                 in6_dev_put(idev);
 401                         }
 402                 }
 403         }
 404 }
 405
 406 static bool rt6_check_expired(const struct rt6_info *rt)
 407 {
 408         if (rt->rt6i_flags & RTF_EXPIRES) {
 409                 if (time_after(jiffies, rt->dst.expires))
 410                         return true;
 411         } else if (rt->dst.from) {
 412                 return rt6_check_expired((struct rt6_info *) rt->dst.from);
 413         }
 414         return false;
 415 }
 416
 417 /* Multipath route selection:
 418  *   Hash based function using packet header and flowlabel.
 419  * Adapted from fib_info_hashfn()
 420  */
 421 static int rt6_info_hash_nhsfn(unsigned int candidate_count,
 422                                const struct flowi6 *fl6)
 423 {
 424         unsigned int val = fl6->flowi6_proto;
 425
 426         val ^= ipv6_addr_hash(&fl6->daddr);
 427         val ^= ipv6_addr_hash(&fl6->saddr);
 428
 429         /* Work only if this not encapsulated */
 430         switch (fl6->flowi6_proto) {
 431         case IPPROTO_UDP:
 432         case IPPROTO_TCP:
 433         case IPPROTO_SCTP:
 434                 val ^= (__force u16)fl6->fl6_sport;
 435                 val ^= (__force u16)fl6->fl6_dport;
 436                 break;
 437
 438         case IPPROTO_ICMPV6:
 439                 val ^= (__force u16)fl6->fl6_icmp_type;
 440                 val ^= (__force u16)fl6->fl6_icmp_code;
 441                 break;
 442         }
 443         /* RFC6438 recommands to use flowlabel */
 444         val ^= (__force u32)fl6->flowlabel;
 445
 446         /* Perhaps, we need to tune, this function? */
 447         val = val ^ (val >> 7) ^ (val >> 12);
 448         return val % candidate_count;
 449 }
 450
 451 static struct rt6_info *rt6_multipath_select(struct rt6_info *match,
 452                                              struct flowi6 *fl6, int oif,
 453                                              int strict)
 454 {
 455         struct rt6_info *sibling, *next_sibling;
 456         int route_choosen;
 457
 458         route_choosen = rt6_info_hash_nhsfn(match->rt6i_nsiblings + 1, fl6);
 459         /* Don't change the route, if route_choosen == 0
 460          * (siblings does not include ourself)
 461          */
 462         if (route_choosen)
 463                 list_for_each_entry_safe(sibling, next_sibling,
 464                                 &match->rt6i_siblings, rt6i_siblings) {
 465                         route_choosen--;
 466                         if (route_choosen == 0) {
 467                                 if (rt6_score_route(sibling, oif, strict) < 0)
 468                                         break;
 469                                 match = sibling;
 470                                 break;
 471                         }
 472                 }
 473         return match;
 474 }
 475
 476 /*
 477  *      Route lookup. Any table->tb6_lock is implied.
 478  */
 479
 480 static inline struct rt6_info *rt6_device_match(struct net *net,
 481                                                     struct rt6_info *rt,
 482                                                     const struct in6_addr *saddr,
 483                                                     int oif,
 484                                                     int flags)
 485 {
 486         struct rt6_info *local = NULL;
 487         struct rt6_info *sprt;
 488
 489         if (!oif && ipv6_addr_any(saddr))
 490                 goto out;
 491
 492         for (sprt = rt; sprt; sprt = sprt->dst.rt6_next) {
 493                 struct net_device *dev = sprt->dst.dev;
 494
 495                 if (oif) {
 496                         if (dev->ifindex == oif)
 497                                 return sprt;
 498                         if (dev->flags & IFF_LOOPBACK) {
 499                                 if (!sprt->rt6i_idev ||
 500                                     sprt->rt6i_idev->dev->ifindex != oif) {
 501                                         if (flags & RT6_LOOKUP_F_IFACE && oif)
 502                                                 continue;
 503                                         if (local && (!oif ||
 504                                                       local->rt6i_idev->dev->ifindex == oif))
 505                                                 continue;
 506                                 }
 507                                 local = sprt;
 508                         }
 509                 } else {
 510                         if (ipv6_chk_addr(net, saddr, dev,
 511                                           flags & RT6_LOOKUP_F_IFACE))
 512                                 return sprt;
 513                 }
 514         }
 515
 516         if (oif) {
 517                 if (local)
 518                         return local;
 519
 520                 if (flags & RT6_LOOKUP_F_IFACE)
 521                         return net->ipv6.ip6_null_entry;
 522         }
 523 out:
 524         return rt;
 525 }
 526
 527 #ifdef CONFIG_IPV6_ROUTER_PREF
 528 struct __rt6_probe_work {
 529         struct work_struct work;
 530         struct in6_addr target;
 531         struct net_device *dev;
 532 };
 533
 534 static void rt6_probe_deferred(struct work_struct *w)
 535 {
 536         struct in6_addr mcaddr;
 537         struct __rt6_probe_work *work =
 538                 container_of(w, struct __rt6_probe_work, work);
 539
 540         addrconf_addr_solict_mult(&work->target, &mcaddr);
 541         ndisc_send_ns(work->dev, NULL, &work->target, &mcaddr, NULL, NULL);
 542         dev_put(work->dev);
 543         kfree(work);
 544 }
 545
 546 static void rt6_probe(struct rt6_info *rt)
 547 {
 548         struct __rt6_probe_work *work;
 549         struct neighbour *neigh;
 550         /*
 551          * Okay, this does not seem to be appropriate
 552          * for now, however, we need to check if it
 553          * is really so; aka Router Reachability Probing.
 554          *
 555          * Router Reachability Probe MUST be rate-limited
 556          * to no more than one per minute.
 557          */
 558         if (!rt || !(rt->rt6i_flags & RTF_GATEWAY))
 559                 return;
 560         rcu_read_lock_bh();
 561         neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
 562         if (neigh) {
 563                 if (neigh->nud_state & NUD_VALID)
 564                         goto out;
 565
 566                 work = NULL;
 567                 write_lock(&neigh->lock);
 568                 if (!(neigh->nud_state & NUD_VALID) &&
 569                     time_after(jiffies,
 570                                neigh->updated +
 571                                rt->rt6i_idev->cnf.rtr_probe_interval)) {
 572                         work = kmalloc(sizeof(*work), GFP_ATOMIC);
 573                         if (work)
 574                                 __neigh_set_probe_once(neigh);
 575                 }
 576                 write_unlock(&neigh->lock);
 577         } else {
 578                 work = kmalloc(sizeof(*work), GFP_ATOMIC);
 579         }
 580
 581         if (work) {
 582                 INIT_WORK(&work->work, rt6_probe_deferred);
 583                 work->target = rt->rt6i_gateway;
 584                 dev_hold(rt->dst.dev);
 585                 work->dev = rt->dst.dev;
 586                 schedule_work(&work->work);
 587         }
 588
 589 out:
 590         rcu_read_unlock_bh();
 591 }
 592 #else
 593 static inline void rt6_probe(struct rt6_info *rt)
 594 {
 595 }
 596 #endif
 597
 598 /*
 599  * Default Router Selection (RFC 2461 6.3.6)
 600  */
 601 static inline int rt6_check_dev(struct rt6_info *rt, int oif)
 602 {
 603         struct net_device *dev = rt->dst.dev;
 604         if (!oif || dev->ifindex == oif)
 605                 return 2;
 606         if ((dev->flags & IFF_LOOPBACK) &&
 607             rt->rt6i_idev && rt->rt6i_idev->dev->ifindex == oif)
 608                 return 1;
 609         return 0;
 610 }
 611
 612 static inline enum rt6_nud_state rt6_check_neigh(struct rt6_info *rt)
 613 {
 614         struct neighbour *neigh;
 615         enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
 616
 617         if (rt->rt6i_flags & RTF_NONEXTHOP ||
 618             !(rt->rt6i_flags & RTF_GATEWAY))
 619                 return RT6_NUD_SUCCEED;
 620
 621         rcu_read_lock_bh();
 622         neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
 623         if (neigh) {
 624                 read_lock(&neigh->lock);
 625                 if (neigh->nud_state & NUD_VALID)
 626                         ret = RT6_NUD_SUCCEED;
 627 #ifdef CONFIG_IPV6_ROUTER_PREF
 628                 else if (!(neigh->nud_state & NUD_FAILED))
 629                         ret = RT6_NUD_SUCCEED;
 630                 else
 631                         ret = RT6_NUD_FAIL_PROBE;
 632 #endif
 633                 read_unlock(&neigh->lock);
 634         } else {
 635                 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
 636                       RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
 637         }
 638         rcu_read_unlock_bh();
 639
 640         return ret;
 641 }
 642
 643 static int rt6_score_route(struct rt6_info *rt, int oif,
 644                            int strict)
 645 {
 646         int m;
 647
 648         m = rt6_check_dev(rt, oif);
 649         if (!m && (strict & RT6_LOOKUP_F_IFACE))
 650                 return RT6_NUD_FAIL_HARD;
 651 #ifdef CONFIG_IPV6_ROUTER_PREF
 652         m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2;
 653 #endif
 654         if (strict & RT6_LOOKUP_F_REACHABLE) {
 655                 int n = rt6_check_neigh(rt);
 656                 if (n < 0)
 657                         return n;
 658         }
 659         return m;
 660 }
 661
 662 static struct rt6_info *find_match(struct rt6_info *rt, int oif, int strict,
 663                                    int *mpri, struct rt6_info *match,
 664                                    bool *do_rr)
 665 {
 666         int m;
 667         bool match_do_rr = false;
 668         struct inet6_dev *idev = rt->rt6i_idev;
 669         struct net_device *dev = rt->dst.dev;
 670
 671         if (dev && !netif_carrier_ok(dev) &&
 672             idev->cnf.ignore_routes_with_linkdown)
 673                 goto out;
 674
 675         if (rt6_check_expired(rt))
 676                 goto out;
 677
 678         m = rt6_score_route(rt, oif, strict);
 679         if (m == RT6_NUD_FAIL_DO_RR) {
 680                 match_do_rr = true;
 681                 m = 0; /* lowest valid score */
 682         } else if (m == RT6_NUD_FAIL_HARD) {
 683                 goto out;
 684         }
 685
 686         if (strict & RT6_LOOKUP_F_REACHABLE)
 687                 rt6_probe(rt);
 688
 689         /* note that m can be RT6_NUD_FAIL_PROBE at this point */
 690         if (m > *mpri) {
 691                 *do_rr = match_do_rr;
 692                 *mpri = m;
 693                 match = rt;
 694         }
 695 out:
 696         return match;
 697 }
 698
 699 static struct rt6_info *find_rr_leaf(struct fib6_node *fn,
 700                                      struct rt6_info *rr_head,
 701                                      u32 metric, int oif, int strict,
 702                                      bool *do_rr)
 703 {
 704         struct rt6_info *rt, *match, *cont;
 705         int mpri = -1;
 706
 707         match = NULL;
 708         cont = NULL;
 709         for (rt = rr_head; rt; rt = rt->dst.rt6_next) {
 710                 if (rt->rt6i_metric != metric) {
 711                         cont = rt;
 712                         break;
 713                 }
 714
 715                 match = find_match(rt, oif, strict, &mpri, match, do_rr);
 716         }
 717
 718         for (rt = fn->leaf; rt && rt != rr_head; rt = rt->dst.rt6_next) {
 719                 if (rt->rt6i_metric != metric) {
 720                         cont = rt;
 721                         break;
 722                 }
 723
 724                 match = find_match(rt, oif, strict, &mpri, match, do_rr);
 725         }
 726
 727         if (match || !cont)
 728                 return match;
 729
 730         for (rt = cont; rt; rt = rt->dst.rt6_next)
 731                 match = find_match(rt, oif, strict, &mpri, match, do_rr);
 732
 733         return match;
 734 }
 735
 736 static struct rt6_info *rt6_select(struct fib6_node *fn, int oif, int strict)
 737 {
 738         struct rt6_info *match, *rt0;
 739         struct net *net;
 740         bool do_rr = false;
 741
 742         rt0 = fn->rr_ptr;
 743         if (!rt0)
 744                 fn->rr_ptr = rt0 = fn->leaf;
 745
 746         match = find_rr_leaf(fn, rt0, rt0->rt6i_metric, oif, strict,
 747                              &do_rr);
 748
 749         if (do_rr) {
 750                 struct rt6_info *next = rt0->dst.rt6_next;
 751
 752                 /* no entries matched; do round-robin */
 753                 if (!next || next->rt6i_metric != rt0->rt6i_metric)
 754                         next = fn->leaf;
 755
 756                 if (next != rt0)
 757                         fn->rr_ptr = next;
 758         }
 759
 760         net = dev_net(rt0->dst.dev);
 761         return match ? match : net->ipv6.ip6_null_entry;
 762 }
 763
 764 static bool rt6_is_gw_or_nonexthop(const struct rt6_info *rt)
 765 {
 766         return (rt->rt6i_flags & (RTF_NONEXTHOP | RTF_GATEWAY));
 767 }
 768
 769 #ifdef CONFIG_IPV6_ROUTE_INFO
 770 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 771                   const struct in6_addr *gwaddr)
 772 {
 773         struct net *net = dev_net(dev);
 774         struct route_info *rinfo = (struct route_info *) opt;
 775         struct in6_addr prefix_buf, *prefix;
 776         unsigned int pref;
 777         unsigned long lifetime;
 778         struct rt6_info *rt;
 779
 780         if (len < sizeof(struct route_info)) {
 781                 return -EINVAL;
 782         }
 783
 784         /* Sanity check for prefix_len and length */
 785         if (rinfo->length > 3) {
 786                 return -EINVAL;
 787         } else if (rinfo->prefix_len > 128) {
 788                 return -EINVAL;
 789         } else if (rinfo->prefix_len > 64) {
 790                 if (rinfo->length < 2) {
 791                         return -EINVAL;
 792                 }
 793         } else if (rinfo->prefix_len > 0) {
 794                 if (rinfo->length < 1) {
 795                         return -EINVAL;
 796                 }
 797         }
 798
 799         pref = rinfo->route_pref;
 800         if (pref == ICMPV6_ROUTER_PREF_INVALID)
 801                 return -EINVAL;
 802
 803         lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
 804
 805         if (rinfo->length == 3)
 806                 prefix = (struct in6_addr *)rinfo->prefix;
 807         else {
 808                 /* this function is safe */
 809                 ipv6_addr_prefix(&prefix_buf,
 810                                  (struct in6_addr *)rinfo->prefix,
 811                                  rinfo->prefix_len);
 812                 prefix = &prefix_buf;
 813         }
 814
 815         if (rinfo->prefix_len == 0)
 816                 rt = rt6_get_dflt_router(gwaddr, dev);
 817         else
 818                 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
 819                                         gwaddr, dev->ifindex);
 820
 821         if (rt && !lifetime) {
 822                 ip6_del_rt(rt);
 823                 rt = NULL;
 824         }
 825
 826         if (!rt && lifetime)
 827                 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr, dev->ifindex,
 828                                         pref);
 829         else if (rt)
 830                 rt->rt6i_flags = RTF_ROUTEINFO |
 831                                  (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 832
 833         if (rt) {
 834                 if (!addrconf_finite_timeout(lifetime))
 835                         rt6_clean_expires(rt);
 836                 else
 837                         rt6_set_expires(rt, jiffies + HZ * lifetime);
 838
 839                 ip6_rt_put(rt);
 840         }
 841         return 0;
 842 }
 843 #endif
 844
 845 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
 846                                         struct in6_addr *saddr)
 847 {
 848         struct fib6_node *pn;
 849         while (1) {
 850                 if (fn->fn_flags & RTN_TL_ROOT)
 851                         return NULL;
 852                 pn = fn->parent;
 853                 if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn)
 854                         fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr);
 855                 else
 856                         fn = pn;
 857                 if (fn->fn_flags & RTN_RTINFO)
 858                         return fn;
 859         }
 860 }
 861
 862 static struct rt6_info *ip6_pol_route_lookup(struct net *net,
 863                                              struct fib6_table *table,
 864                                              struct flowi6 *fl6, int flags)
 865 {
 866         struct fib6_node *fn;
 867         struct rt6_info *rt;
 868
 869         read_lock_bh(&table->tb6_lock);
 870         fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
 871 restart:
 872         rt = fn->leaf;
 873         rt = rt6_device_match(net, rt, &fl6->saddr, fl6->flowi6_oif, flags);
 874         if (rt->rt6i_nsiblings && fl6->flowi6_oif == 0)
 875                 rt = rt6_multipath_select(rt, fl6, fl6->flowi6_oif, flags);
 876         if (rt == net->ipv6.ip6_null_entry) {
 877                 fn = fib6_backtrack(fn, &fl6->saddr);
 878                 if (fn)
 879                         goto restart;
 880         }
 881         dst_use(&rt->dst, jiffies);
 882         read_unlock_bh(&table->tb6_lock);
 883         return rt;
 884
 885 }
 886
 887 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
 888                                     int flags)
 889 {
 890         return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_lookup);
 891 }
 892 EXPORT_SYMBOL_GPL(ip6_route_lookup);
 893
 894 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
 895                             const struct in6_addr *saddr, int oif, int strict)
 896 {
 897         struct flowi6 fl6 = {
 898                 .flowi6_oif = oif,
 899                 .daddr = *daddr,
 900         };
 901         struct dst_entry *dst;
 902         int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
 903
 904         if (saddr) {
 905                 memcpy(&fl6.saddr, saddr, sizeof(*saddr));
 906                 flags |= RT6_LOOKUP_F_HAS_SADDR;
 907         }
 908
 909         dst = fib6_rule_lookup(net, &fl6, flags, ip6_pol_route_lookup);
 910         if (dst->error == 0)
 911                 return (struct rt6_info *) dst;
 912
 913         dst_release(dst);
 914
 915         return NULL;
 916 }
 917 EXPORT_SYMBOL(rt6_lookup);
 918
 919 /* ip6_ins_rt is called with FREE table->tb6_lock.
 920    It takes new route entry, the addition fails by any reason the
 921    route is freed. In any case, if caller does not hold it, it may
 922    be destroyed.
 923  */
 924
 925 static int __ip6_ins_rt(struct rt6_info *rt, struct nl_info *info,
 926                         struct mx6_config *mxc)
 927 {
 928         int err;
 929         struct fib6_table *table;
 930
 931         table = rt->rt6i_table;
 932         write_lock_bh(&table->tb6_lock);
 933         err = fib6_add(&table->tb6_root, rt, info, mxc);
 934         write_unlock_bh(&table->tb6_lock);
 935
 936         return err;
 937 }
 938
 939 int ip6_ins_rt(struct rt6_info *rt)
 940 {
 941         struct nl_info info = { .nl_net = dev_net(rt->dst.dev), };
 942         struct mx6_config mxc = { .mx = NULL, };
 943
 944         return __ip6_ins_rt(rt, &info, &mxc);
 945 }
 946
 947 static struct rt6_info *ip6_rt_cache_alloc(struct rt6_info *ort,
 948                                            const struct in6_addr *daddr,
 949                                            const struct in6_addr *saddr)
 950 {
 951         struct rt6_info *rt;
 952
 953         /*
 954          *      Clone the route.
 955          */
 956
 957         if (ort->rt6i_flags & (RTF_CACHE | RTF_PCPU))
 958                 ort = (struct rt6_info *)ort->dst.from;
 959
 960         rt = __ip6_dst_alloc(dev_net(ort->dst.dev), ort->dst.dev, 0);
 961
 962         if (!rt)
 963                 return NULL;
 964
 965         ip6_rt_copy_init(rt, ort);
 966         rt->rt6i_flags |= RTF_CACHE;
 967         rt->rt6i_metric = 0;
 968         rt->dst.flags |= DST_HOST;
 969         rt->rt6i_dst.addr = *daddr;
 970         rt->rt6i_dst.plen = 128;
 971
 972         if (!rt6_is_gw_or_nonexthop(ort)) {
 973                 if (ort->rt6i_dst.plen != 128 &&
 974                     ipv6_addr_equal(&ort->rt6i_dst.addr, daddr))
 975                         rt->rt6i_flags |= RTF_ANYCAST;
 976 #ifdef CONFIG_IPV6_SUBTREES
 977                 if (rt->rt6i_src.plen && saddr) {
 978                         rt->rt6i_src.addr = *saddr;
 979                         rt->rt6i_src.plen = 128;
 980                 }
 981 #endif
 982         }
 983
 984         return rt;
 985 }
 986
 987 static struct rt6_info *ip6_rt_pcpu_alloc(struct rt6_info *rt)
 988 {
 989         struct rt6_info *pcpu_rt;
 990
 991         pcpu_rt = __ip6_dst_alloc(dev_net(rt->dst.dev),
 992                                   rt->dst.dev, rt->dst.flags);
 993
 994         if (!pcpu_rt)
 995                 return NULL;
 996         ip6_rt_copy_init(pcpu_rt, rt);
 997         pcpu_rt->rt6i_protocol = rt->rt6i_protocol;
 998         pcpu_rt->rt6i_flags |= RTF_PCPU;
 999         return pcpu_rt;
1000 }
1001
1002 /* It should be called with read_lock_bh(&tb6_lock) acquired */
1003 static struct rt6_info *rt6_get_pcpu_route(struct rt6_info *rt)
1004 {
1005         struct rt6_info *pcpu_rt, **p;
1006
1007         p = this_cpu_ptr(rt->rt6i_pcpu);
1008         pcpu_rt = *p;
1009
1010         if (pcpu_rt) {
1011                 dst_hold(&pcpu_rt->dst);
1012                 rt6_dst_from_metrics_check(pcpu_rt);
1013         }
1014         return pcpu_rt;
1015 }
1016
1017 static struct rt6_info *rt6_make_pcpu_route(struct rt6_info *rt)
1018 {
1019         struct fib6_table *table = rt->rt6i_table;
1020         struct rt6_info *pcpu_rt, *prev, **p;
1021
1022         pcpu_rt = ip6_rt_pcpu_alloc(rt);
1023         if (!pcpu_rt) {
1024                 struct net *net = dev_net(rt->dst.dev);
1025
1026                 dst_hold(&net->ipv6.ip6_null_entry->dst);
1027                 return net->ipv6.ip6_null_entry;
1028         }
1029
1030         read_lock_bh(&table->tb6_lock);
1031         if (rt->rt6i_pcpu) {
1032                 p = this_cpu_ptr(rt->rt6i_pcpu);
1033                 prev = cmpxchg(p, NULL, pcpu_rt);
1034                 if (prev) {
1035                         /* If someone did it before us, return prev instead */
1036                         dst_destroy(&pcpu_rt->dst);
1037                         pcpu_rt = prev;
1038                 }
1039         } else {
1040                 /* rt has been removed from the fib6 tree
1041                  * before we have a chance to acquire the read_lock.
1042                  * In this case, don't brother to create a pcpu rt
1043                  * since rt is going away anyway.  The next
1044                  * dst_check() will trigger a re-lookup.
1045                  */
1046                 dst_destroy(&pcpu_rt->dst);
1047                 pcpu_rt = rt;
1048         }
1049         dst_hold(&pcpu_rt->dst);
1050         rt6_dst_from_metrics_check(pcpu_rt);
1051         read_unlock_bh(&table->tb6_lock);
1052         return pcpu_rt;
1053 }
1054
1055 static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, int oif,
1056                                       struct flowi6 *fl6, int flags)
1057 {
1058         struct fib6_node *fn, *saved_fn;
1059         struct rt6_info *rt;
1060         int strict = 0;
1061
1062         strict |= flags & RT6_LOOKUP_F_IFACE;
1063         if (net->ipv6.devconf_all->forwarding == 0)
1064                 strict |= RT6_LOOKUP_F_REACHABLE;
1065
1066         read_lock_bh(&table->tb6_lock);
1067
1068         fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1069         saved_fn = fn;
1070
1071 redo_rt6_select:
1072         rt = rt6_select(fn, oif, strict);
1073         if (rt->rt6i_nsiblings)
1074                 rt = rt6_multipath_select(rt, fl6, oif, strict);
1075         if (rt == net->ipv6.ip6_null_entry) {
1076                 fn = fib6_backtrack(fn, &fl6->saddr);
1077                 if (fn)
1078                         goto redo_rt6_select;
1079                 else if (strict & RT6_LOOKUP_F_REACHABLE) {
1080                         /* also consider unreachable route */
1081                         strict &= ~RT6_LOOKUP_F_REACHABLE;
1082                         fn = saved_fn;
1083                         goto redo_rt6_select;
1084                 }
1085         }
1086
1087
1088         if (rt == net->ipv6.ip6_null_entry || (rt->rt6i_flags & RTF_CACHE)) {
1089                 dst_use(&rt->dst, jiffies);
1090                 read_unlock_bh(&table->tb6_lock);
1091
1092                 rt6_dst_from_metrics_check(rt);
1093                 return rt;
1094         } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
1095                             !(rt->rt6i_flags & RTF_GATEWAY))) {
1096                 /* Create a RTF_CACHE clone which will not be
1097                  * owned by the fib6 tree.  It is for the special case where
1098                  * the daddr in the skb during the neighbor look-up is different
1099                  * from the fl6->daddr used to look-up route here.
1100                  */
1101
1102                 struct rt6_info *uncached_rt;
1103
1104                 dst_use(&rt->dst, jiffies);
1105                 read_unlock_bh(&table->tb6_lock);
1106
1107                 uncached_rt = ip6_rt_cache_alloc(rt, &fl6->daddr, NULL);
1108                 dst_release(&rt->dst);
1109
1110                 if (uncached_rt)
1111                         rt6_uncached_list_add(uncached_rt);
1112                 else
1113                         uncached_rt = net->ipv6.ip6_null_entry;
1114
1115                 dst_hold(&uncached_rt->dst);
1116                 return uncached_rt;
1117
1118         } else {
1119                 /* Get a percpu copy */
1120
1121                 struct rt6_info *pcpu_rt;
1122
1123                 rt->dst.lastuse = jiffies;
1124                 rt->dst.__use++;
1125                 pcpu_rt = rt6_get_pcpu_route(rt);
1126
1127                 if (pcpu_rt) {
1128                         read_unlock_bh(&table->tb6_lock);
1129                 } else {
1130                         /* We have to do the read_unlock first
1131                          * because rt6_make_pcpu_route() may trigger
1132                          * ip6_dst_gc() which will take the write_lock.
1133                          */
1134                         dst_hold(&rt->dst);
1135                         read_unlock_bh(&table->tb6_lock);
1136                         pcpu_rt = rt6_make_pcpu_route(rt);
1137                         dst_release(&rt->dst);
1138                 }
1139
1140                 return pcpu_rt;
1141
1142         }
1143 }
1144
1145 static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *table,
1146                                             struct flowi6 *fl6, int flags)
1147 {
1148         return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, flags);
1149 }
1150
1151 static struct dst_entry *ip6_route_input_lookup(struct net *net,
1152                                                 struct net_device *dev,
1153                                                 struct flowi6 *fl6, int flags)
1154 {
1155         if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
1156                 flags |= RT6_LOOKUP_F_IFACE;
1157
1158         return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_input);
1159 }
1160
1161 void ip6_route_input(struct sk_buff *skb)
1162 {
1163         const struct ipv6hdr *iph = ipv6_hdr(skb);
1164         struct net *net = dev_net(skb->dev);
1165         int flags = RT6_LOOKUP_F_HAS_SADDR;
1166         struct ip_tunnel_info *tun_info;
1167         struct flowi6 fl6 = {
1168                 .flowi6_iif = skb->dev->ifindex,
1169                 .daddr = iph->daddr,
1170                 .saddr = iph->saddr,
1171                 .flowlabel = ip6_flowinfo(iph),
1172                 .flowi6_mark = skb->mark,
1173                 .flowi6_proto = iph->nexthdr,
1174         };
1175
1176         tun_info = skb_tunnel_info(skb);
1177         if (tun_info && tun_info->mode == IP_TUNNEL_INFO_RX)
1178                 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
1179         skb_dst_drop(skb);
1180         skb_dst_set(skb, ip6_route_input_lookup(net, skb->dev, &fl6, flags));
1181 }
1182
1183 static struct rt6_info *ip6_pol_route_output(struct net *net, struct fib6_table *table,
1184                                              struct flowi6 *fl6, int flags)
1185 {
1186         return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, flags);
1187 }
1188
1189 struct dst_entry *ip6_route_output(struct net *net, const struct sock *sk,
1190                                     struct flowi6 *fl6)
1191 {
1192         int flags = 0;
1193
1194         fl6->flowi6_iif = LOOPBACK_IFINDEX;
1195
1196         if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr))
1197                 flags |= RT6_LOOKUP_F_IFACE;
1198
1199         if (!ipv6_addr_any(&fl6->saddr))
1200                 flags |= RT6_LOOKUP_F_HAS_SADDR;
1201         else if (sk)
1202                 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
1203
1204         return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_output);
1205 }
1206 EXPORT_SYMBOL(ip6_route_output);
1207
1208 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
1209 {
1210         struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
1211         struct dst_entry *new = NULL;
1212
1213         rt = dst_alloc(&ip6_dst_blackhole_ops, ort->dst.dev, 1, DST_OBSOLETE_NONE, 0);
1214         if (rt) {
1215                 new = &rt->dst;
1216
1217                 memset(new + 1, 0, sizeof(*rt) - sizeof(*new));
1218
1219                 new->__use = 1;
1220                 new->input = dst_discard;
1221                 new->output = dst_discard_sk;
1222
1223                 if (dst_metrics_read_only(&ort->dst))
1224                         new->_metrics = ort->dst._metrics;
1225                 else
1226                         dst_copy_metrics(new, &ort->dst);
1227                 rt->rt6i_idev = ort->rt6i_idev;
1228                 if (rt->rt6i_idev)
1229                         in6_dev_hold(rt->rt6i_idev);
1230
1231                 rt->rt6i_gateway = ort->rt6i_gateway;
1232                 rt->rt6i_flags = ort->rt6i_flags;
1233                 rt->rt6i_metric = 0;
1234
1235                 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
1236 #ifdef CONFIG_IPV6_SUBTREES
1237                 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
1238 #endif
1239
1240                 dst_free(new);
1241         }
1242
1243         dst_release(dst_orig);
1244         return new ? new : ERR_PTR(-ENOMEM);
1245 }
1246
1247 /*
1248  *      Destination cache support functions
1249  */
1250
1251 static void rt6_dst_from_metrics_check(struct rt6_info *rt)
1252 {
1253         if (rt->dst.from &&
1254             dst_metrics_ptr(&rt->dst) != dst_metrics_ptr(rt->dst.from))
1255                 dst_init_metrics(&rt->dst, dst_metrics_ptr(rt->dst.from), true);
1256 }
1257
1258 static struct dst_entry *rt6_check(struct rt6_info *rt, u32 cookie)
1259 {
1260         if (!rt->rt6i_node || (rt->rt6i_node->fn_sernum != cookie))
1261                 return NULL;
1262
1263         if (rt6_check_expired(rt))
1264                 return NULL;
1265
1266         return &rt->dst;
1267 }
1268
1269 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt, u32 cookie)
1270 {
1271         if (rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1272             rt6_check((struct rt6_info *)(rt->dst.from), cookie))
1273                 return &rt->dst;
1274         else
1275                 return NULL;
1276 }
1277
1278 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
1279 {
1280         struct rt6_info *rt;
1281
1282         rt = (struct rt6_info *) dst;
1283
1284         /* All IPV6 dsts are created with ->obsolete set to the value
1285          * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1286          * into this function always.
1287          */
1288
1289         rt6_dst_from_metrics_check(rt);
1290
1291         if ((rt->rt6i_flags & RTF_PCPU) || unlikely(dst->flags & DST_NOCACHE))
1292                 return rt6_dst_from_check(rt, cookie);
1293         else
1294                 return rt6_check(rt, cookie);
1295 }
1296
1297 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
1298 {
1299         struct rt6_info *rt = (struct rt6_info *) dst;
1300
1301         if (rt) {
1302                 if (rt->rt6i_flags & RTF_CACHE) {
1303                         if (rt6_check_expired(rt)) {
1304                                 ip6_del_rt(rt);
1305                                 dst = NULL;
1306                         }
1307                 } else {
1308                         dst_release(dst);
1309                         dst = NULL;
1310                 }
1311         }
1312         return dst;
1313 }
1314
1315 static void ip6_link_failure(struct sk_buff *skb)
1316 {
1317         struct rt6_info *rt;
1318
1319         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
1320
1321         rt = (struct rt6_info *) skb_dst(skb);
1322         if (rt) {
1323                 if (rt->rt6i_flags & RTF_CACHE) {
1324                         dst_hold(&rt->dst);
1325                         if (ip6_del_rt(rt))
1326                                 dst_free(&rt->dst);
1327                 } else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT)) {
1328                         rt->rt6i_node->fn_sernum = -1;
1329                 }
1330         }
1331 }
1332
1333 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
1334 {
1335         struct net *net = dev_net(rt->dst.dev);
1336
1337         rt->rt6i_flags |= RTF_MODIFIED;
1338         rt->rt6i_pmtu = mtu;
1339         rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
1340 }
1341
1342 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
1343                                  const struct ipv6hdr *iph, u32 mtu)
1344 {
1345         struct rt6_info *rt6 = (struct rt6_info *)dst;
1346
1347         if (rt6->rt6i_flags & RTF_LOCAL)
1348                 return;
1349
1350         dst_confirm(dst);
1351         mtu = max_t(u32, mtu, IPV6_MIN_MTU);
1352         if (mtu >= dst_mtu(dst))
1353                 return;
1354
1355         if (rt6->rt6i_flags & RTF_CACHE) {
1356                 rt6_do_update_pmtu(rt6, mtu);
1357         } else {
1358                 const struct in6_addr *daddr, *saddr;
1359                 struct rt6_info *nrt6;
1360
1361                 if (iph) {
1362                         daddr = &iph->daddr;
1363                         saddr = &iph->saddr;
1364                 } else if (sk) {
1365                         daddr = &sk->sk_v6_daddr;
1366                         saddr = &inet6_sk(sk)->saddr;
1367                 } else {
1368                         return;
1369                 }
1370                 nrt6 = ip6_rt_cache_alloc(rt6, daddr, saddr);
1371                 if (nrt6) {
1372                         rt6_do_update_pmtu(nrt6, mtu);
1373
1374                         /* ip6_ins_rt(nrt6) will bump the
1375                          * rt6->rt6i_node->fn_sernum
1376                          * which will fail the next rt6_check() and
1377                          * invalidate the sk->sk_dst_cache.
1378                          */
1379                         ip6_ins_rt(nrt6);
1380                 }
1381         }
1382 }
1383
1384 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1385                                struct sk_buff *skb, u32 mtu)
1386 {
1387         __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu);
1388 }
1389
1390 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
1391                      int oif, u32 mark)
1392 {
1393         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
1394         struct dst_entry *dst;
1395         struct flowi6 fl6;
1396
1397         memset(&fl6, 0, sizeof(fl6));
1398         fl6.flowi6_oif = oif;
1399         fl6.flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark);
1400         fl6.daddr = iph->daddr;
1401         fl6.saddr = iph->saddr;
1402         fl6.flowlabel = ip6_flowinfo(iph);
1403
1404         dst = ip6_route_output(net, NULL, &fl6);
1405         if (!dst->error)
1406                 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu));
1407         dst_release(dst);
1408 }
1409 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
1410
1411 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
1412 {
1413         ip6_update_pmtu(skb, sock_net(sk), mtu,
1414                         sk->sk_bound_dev_if, sk->sk_mark);
1415 }
1416 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
1417
1418 /* Handle redirects */
1419 struct ip6rd_flowi {
1420         struct flowi6 fl6;
1421         struct in6_addr gateway;
1422 };
1423
1424 static struct rt6_info *__ip6_route_redirect(struct net *net,
1425                                              struct fib6_table *table,
1426                                              struct flowi6 *fl6,
1427                                              int flags)
1428 {
1429         struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
1430         struct rt6_info *rt;
1431         struct fib6_node *fn;
1432
1433         /* Get the "current" route for this destination and
1434          * check if the redirect has come from approriate router.
1435          *
1436          * RFC 4861 specifies that redirects should only be
1437          * accepted if they come from the nexthop to the target.
1438          * Due to the way the routes are chosen, this notion
1439          * is a bit fuzzy and one might need to check all possible
1440          * routes.
1441          */
1442
1443         read_lock_bh(&table->tb6_lock);
1444         fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1445 restart:
1446         for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
1447                 if (rt6_check_expired(rt))
1448                         continue;
1449                 if (rt->dst.error)
1450                         break;
1451                 if (!(rt->rt6i_flags & RTF_GATEWAY))
1452                         continue;
1453                 if (fl6->flowi6_oif != rt->dst.dev->ifindex)
1454                         continue;
1455                 if (!ipv6_addr_equal(&rdfl->gateway, &rt->rt6i_gateway))
1456                         continue;
1457                 break;
1458         }
1459
1460         if (!rt)
1461                 rt = net->ipv6.ip6_null_entry;
1462         else if (rt->dst.error) {
1463                 rt = net->ipv6.ip6_null_entry;
1464                 goto out;
1465         }
1466
1467         if (rt == net->ipv6.ip6_null_entry) {
1468                 fn = fib6_backtrack(fn, &fl6->saddr);
1469                 if (fn)
1470                         goto restart;
1471         }
1472
1473 out:
1474         dst_hold(&rt->dst);
1475
1476         read_unlock_bh(&table->tb6_lock);
1477
1478         return rt;
1479 };
1480
1481 static struct dst_entry *ip6_route_redirect(struct net *net,
1482                                         const struct flowi6 *fl6,
1483                                         const struct in6_addr *gateway)
1484 {
1485         int flags = RT6_LOOKUP_F_HAS_SADDR;
1486         struct ip6rd_flowi rdfl;
1487
1488         rdfl.fl6 = *fl6;
1489         rdfl.gateway = *gateway;
1490
1491         return fib6_rule_lookup(net, &rdfl.fl6,
1492                                 flags, __ip6_route_redirect);
1493 }
1494
1495 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark)
1496 {
1497         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
1498         struct dst_entry *dst;
1499         struct flowi6 fl6;
1500
1501         memset(&fl6, 0, sizeof(fl6));
1502         fl6.flowi6_iif = LOOPBACK_IFINDEX;
1503         fl6.flowi6_oif = oif;
1504         fl6.flowi6_mark = mark;
1505         fl6.daddr = iph->daddr;
1506         fl6.saddr = iph->saddr;
1507         fl6.flowlabel = ip6_flowinfo(iph);
1508
1509         dst = ip6_route_redirect(net, &fl6, &ipv6_hdr(skb)->saddr);
1510         rt6_do_redirect(dst, NULL, skb);
1511         dst_release(dst);
1512 }
1513 EXPORT_SYMBOL_GPL(ip6_redirect);
1514
1515 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif,
1516                             u32 mark)
1517 {
1518         const struct ipv6hdr *iph = ipv6_hdr(skb);
1519         const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
1520         struct dst_entry *dst;
1521         struct flowi6 fl6;
1522
1523         memset(&fl6, 0, sizeof(fl6));
1524         fl6.flowi6_iif = LOOPBACK_IFINDEX;
1525         fl6.flowi6_oif = oif;
1526         fl6.flowi6_mark = mark;
1527         fl6.daddr = msg->dest;
1528         fl6.saddr = iph->daddr;
1529
1530         dst = ip6_route_redirect(net, &fl6, &iph->saddr);
1531         rt6_do_redirect(dst, NULL, skb);
1532         dst_release(dst);
1533 }
1534
1535 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
1536 {
1537         ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark);
1538 }
1539 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
1540
1541 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
1542 {
1543         struct net_device *dev = dst->dev;
1544         unsigned int mtu = dst_mtu(dst);
1545         struct net *net = dev_net(dev);
1546
1547         mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
1548
1549         if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
1550                 mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
1551
1552         /*
1553          * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
1554          * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
1555          * IPV6_MAXPLEN is also valid and means: "any MSS,
1556          * rely only on pmtu discovery"
1557          */
1558         if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
1559                 mtu = IPV6_MAXPLEN;
1560         return mtu;
1561 }
1562
1563 static unsigned int ip6_mtu(const struct dst_entry *dst)
1564 {
1565         const struct rt6_info *rt = (const struct rt6_info *)dst;
1566         unsigned int mtu = rt->rt6i_pmtu;
1567         struct inet6_dev *idev;
1568
1569         if (mtu)
1570                 goto out;
1571
1572         mtu = dst_metric_raw(dst, RTAX_MTU);
1573         if (mtu)
1574                 goto out;
1575
1576         mtu = IPV6_MIN_MTU;
1577
1578         rcu_read_lock();
1579         idev = __in6_dev_get(dst->dev);
1580         if (idev)
1581                 mtu = idev->cnf.mtu6;
1582         rcu_read_unlock();
1583
1584 out:
1585         return min_t(unsigned int, mtu, IP6_MAX_MTU);
1586 }
1587
1588 static struct dst_entry *icmp6_dst_gc_list;
1589 static DEFINE_SPINLOCK(icmp6_dst_lock);
1590
1591 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
1592                                   struct flowi6 *fl6)
1593 {
1594         struct dst_entry *dst;
1595         struct rt6_info *rt;
1596         struct inet6_dev *idev = in6_dev_get(dev);
1597         struct net *net = dev_net(dev);
1598
1599         if (unlikely(!idev))
1600                 return ERR_PTR(-ENODEV);
1601
1602         rt = ip6_dst_alloc(net, dev, 0);
1603         if (unlikely(!rt)) {
1604                 in6_dev_put(idev);
1605                 dst = ERR_PTR(-ENOMEM);
1606                 goto out;
1607         }
1608
1609         rt->dst.flags |= DST_HOST;
1610         rt->dst.output  = ip6_output;
1611         atomic_set(&rt->dst.__refcnt, 1);
1612         rt->rt6i_gateway  = fl6->daddr;
1613         rt->rt6i_dst.addr = fl6->daddr;
1614         rt->rt6i_dst.plen = 128;
1615         rt->rt6i_idev     = idev;
1616         dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
1617
1618         spin_lock_bh(&icmp6_dst_lock);
1619         rt->dst.next = icmp6_dst_gc_list;
1620         icmp6_dst_gc_list = &rt->dst;
1621         spin_unlock_bh(&icmp6_dst_lock);
1622
1623         fib6_force_start_gc(net);
1624
1625         dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
1626
1627 out:
1628         return dst;
1629 }
1630
1631 int icmp6_dst_gc(void)
1632 {
1633         struct dst_entry *dst, **pprev;
1634         int more = 0;
1635
1636         spin_lock_bh(&icmp6_dst_lock);
1637         pprev = &icmp6_dst_gc_list;
1638
1639         while ((dst = *pprev) != NULL) {
1640                 if (!atomic_read(&dst->__refcnt)) {
1641                         *pprev = dst->next;
1642                         dst_free(dst);
1643                 } else {
1644                         pprev = &dst->next;
1645                         ++more;
1646                 }
1647         }
1648
1649         spin_unlock_bh(&icmp6_dst_lock);
1650
1651         return more;
1652 }
1653
1654 static void icmp6_clean_all(int (*func)(struct rt6_info *rt, void *arg),
1655                             void *arg)
1656 {
1657         struct dst_entry *dst, **pprev;
1658
1659         spin_lock_bh(&icmp6_dst_lock);
1660         pprev = &icmp6_dst_gc_list;
1661         while ((dst = *pprev) != NULL) {
1662                 struct rt6_info *rt = (struct rt6_info *) dst;
1663                 if (func(rt, arg)) {
1664                         *pprev = dst->next;
1665                         dst_free(dst);
1666                 } else {
1667                         pprev = &dst->next;
1668                 }
1669         }
1670         spin_unlock_bh(&icmp6_dst_lock);
1671 }
1672
1673 static int ip6_dst_gc(struct dst_ops *ops)
1674 {
1675         struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
1676         int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
1677         int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
1678         int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
1679         int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
1680         unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
1681         int entries;
1682
1683         entries = dst_entries_get_fast(ops);
1684         if (time_after(rt_last_gc + rt_min_interval, jiffies) &&
1685             entries <= rt_max_size)
1686                 goto out;
1687
1688         net->ipv6.ip6_rt_gc_expire++;
1689         fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net, true);
1690         entries = dst_entries_get_slow(ops);
1691         if (entries < ops->gc_thresh)
1692                 net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;
1693 out:
1694         net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity;
1695         return entries > rt_max_size;
1696 }
1697
1698 static int ip6_convert_metrics(struct mx6_config *mxc,
1699                                const struct fib6_config *cfg)
1700 {
1701         struct nlattr *nla;
1702         int remaining;
1703         u32 *mp;
1704
1705         if (!cfg->fc_mx)
1706                 return 0;
1707
1708         mp = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL);
1709         if (unlikely(!mp))
1710                 return -ENOMEM;
1711
1712         nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
1713                 int type = nla_type(nla);
1714
1715                 if (type) {
1716                         u32 val;
1717
1718                         if (unlikely(type > RTAX_MAX))
1719                                 goto err;
1720                         if (type == RTAX_CC_ALGO) {
1721                                 char tmp[TCP_CA_NAME_MAX];
1722
1723                                 nla_strlcpy(tmp, nla, sizeof(tmp));
1724                                 val = tcp_ca_get_key_by_name(tmp);
1725                                 if (val == TCP_CA_UNSPEC)
1726                                         goto err;
1727                         } else {
1728                                 val = nla_get_u32(nla);
1729                         }
1730
1731                         mp[type - 1] = val;
1732                         __set_bit(type - 1, mxc->mx_valid);
1733                 }
1734         }
1735
1736         mxc->mx = mp;
1737
1738         return 0;
1739  err:
1740         kfree(mp);
1741         return -EINVAL;
1742 }
1743
1744 int ip6_route_add(struct fib6_config *cfg)
1745 {
1746         int err;
1747         struct net *net = cfg->fc_nlinfo.nl_net;
1748         struct rt6_info *rt = NULL;
1749         struct net_device *dev = NULL;
1750         struct inet6_dev *idev = NULL;
1751         struct fib6_table *table;
1752         struct mx6_config mxc = { .mx = NULL, };
1753         int addr_type;
1754
1755         if (cfg->fc_dst_len > 128 || cfg->fc_src_len > 128)
1756                 return -EINVAL;
1757 #ifndef CONFIG_IPV6_SUBTREES
1758         if (cfg->fc_src_len)
1759                 return -EINVAL;
1760 #endif
1761         if (cfg->fc_ifindex) {
1762                 err = -ENODEV;
1763                 dev = dev_get_by_index(net, cfg->fc_ifindex);
1764                 if (!dev)
1765                         goto out;
1766                 idev = in6_dev_get(dev);
1767                 if (!idev)
1768                         goto out;
1769         }
1770
1771         if (cfg->fc_metric == 0)
1772                 cfg->fc_metric = IP6_RT_PRIO_USER;
1773
1774         err = -ENOBUFS;
1775         if (cfg->fc_nlinfo.nlh &&
1776             !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
1777                 table = fib6_get_table(net, cfg->fc_table);
1778                 if (!table) {
1779                         pr_warn("NLM_F_CREATE should be specified when creating new route\n");
1780                         table = fib6_new_table(net, cfg->fc_table);
1781                 }
1782         } else {
1783                 table = fib6_new_table(net, cfg->fc_table);
1784         }
1785
1786         if (!table)
1787                 goto out;
1788
1789         rt = ip6_dst_alloc(net, NULL,
1790                            (cfg->fc_flags & RTF_ADDRCONF) ? 0 : DST_NOCOUNT);
1791
1792         if (!rt) {
1793                 err = -ENOMEM;
1794                 goto out;
1795         }
1796
1797         if (cfg->fc_flags & RTF_EXPIRES)
1798                 rt6_set_expires(rt, jiffies +
1799                                 clock_t_to_jiffies(cfg->fc_expires));
1800         else
1801                 rt6_clean_expires(rt);
1802
1803         if (cfg->fc_protocol == RTPROT_UNSPEC)
1804                 cfg->fc_protocol = RTPROT_BOOT;
1805         rt->rt6i_protocol = cfg->fc_protocol;
1806
1807         addr_type = ipv6_addr_type(&cfg->fc_dst);
1808
1809         if (addr_type & IPV6_ADDR_MULTICAST)
1810                 rt->dst.input = ip6_mc_input;
1811         else if (cfg->fc_flags & RTF_LOCAL)
1812                 rt->dst.input = ip6_input;
1813         else
1814                 rt->dst.input = ip6_forward;
1815
1816         rt->dst.output = ip6_output;
1817
1818         if (cfg->fc_encap) {
1819                 struct lwtunnel_state *lwtstate;
1820
1821                 err = lwtunnel_build_state(dev, cfg->fc_encap_type,
1822                                            cfg->fc_encap, AF_INET6, cfg,
1823                                            &lwtstate);
1824                 if (err)
1825                         goto out;
1826                 rt->dst.lwtstate = lwtstate_get(lwtstate);
1827                 if (lwtunnel_output_redirect(rt->dst.lwtstate)) {
1828                         rt->dst.lwtstate->orig_output = rt->dst.output;
1829                         rt->dst.output = lwtunnel_output;
1830                 }
1831                 if (lwtunnel_input_redirect(rt->dst.lwtstate)) {
1832                         rt->dst.lwtstate->orig_input = rt->dst.input;
1833                         rt->dst.input = lwtunnel_input;
1834                 }
1835         }
1836
1837         ipv6_addr_prefix(&rt->rt6i_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
1838         rt->rt6i_dst.plen = cfg->fc_dst_len;
1839         if (rt->rt6i_dst.plen == 128)
1840                 rt->dst.flags |= DST_HOST;
1841
1842 #ifdef CONFIG_IPV6_SUBTREES
1843         ipv6_addr_prefix(&rt->rt6i_src.addr, &cfg->fc_src, cfg->fc_src_len);
1844         rt->rt6i_src.plen = cfg->fc_src_len;
1845 #endif
1846
1847         rt->rt6i_metric = cfg->fc_metric;
1848
1849         /* We cannot add true routes via loopback here,
1850            they would result in kernel looping; promote them to reject routes
1851          */
1852         if ((cfg->fc_flags & RTF_REJECT) ||
1853             (dev && (dev->flags & IFF_LOOPBACK) &&
1854              !(addr_type & IPV6_ADDR_LOOPBACK) &&
1855              !(cfg->fc_flags & RTF_LOCAL))) {
1856                 /* hold loopback dev/idev if we haven't done so. */
1857                 if (dev != net->loopback_dev) {
1858                         if (dev) {
1859                                 dev_put(dev);
1860                                 in6_dev_put(idev);
1861                         }
1862                         dev = net->loopback_dev;
1863                         dev_hold(dev);
1864                         idev = in6_dev_get(dev);
1865                         if (!idev) {
1866                                 err = -ENODEV;
1867                                 goto out;
1868                         }
1869                 }
1870                 rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP;
1871                 switch (cfg->fc_type) {
1872                 case RTN_BLACKHOLE:
1873                         rt->dst.error = -EINVAL;
1874                         rt->dst.output = dst_discard_sk;
1875                         rt->dst.input = dst_discard;
1876                         break;
1877                 case RTN_PROHIBIT:
1878                         rt->dst.error = -EACCES;
1879                         rt->dst.output = ip6_pkt_prohibit_out;
1880                         rt->dst.input = ip6_pkt_prohibit;
1881                         break;
1882                 case RTN_THROW:
1883                 default:
1884                         rt->dst.error = (cfg->fc_type == RTN_THROW) ? -EAGAIN
1885                                         : -ENETUNREACH;
1886                         rt->dst.output = ip6_pkt_discard_out;
1887                         rt->dst.input = ip6_pkt_discard;
1888                         break;
1889                 }
1890                 goto install_route;
1891         }
1892
1893         if (cfg->fc_flags & RTF_GATEWAY) {
1894                 const struct in6_addr *gw_addr;
1895                 int gwa_type;
1896
1897                 gw_addr = &cfg->fc_gateway;
1898                 gwa_type = ipv6_addr_type(gw_addr);
1899
1900                 /* if gw_addr is local we will fail to detect this in case
1901                  * address is still TENTATIVE (DAD in progress). rt6_lookup()
1902                  * will return already-added prefix route via interface that
1903                  * prefix route was assigned to, which might be non-loopback.
1904                  */
1905                 err = -EINVAL;
1906                 if (ipv6_chk_addr_and_flags(net, gw_addr,
1907                                             gwa_type & IPV6_ADDR_LINKLOCAL ?
1908                                             dev : NULL, 0, 0))
1909                         goto out;
1910
1911                 rt->rt6i_gateway = *gw_addr;
1912
1913                 if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {
1914                         struct rt6_info *grt;
1915
1916                         /* IPv6 strictly inhibits using not link-local
1917                            addresses as nexthop address.
1918                            Otherwise, router will not able to send redirects.
1919                            It is very good, but in some (rare!) circumstances
1920                            (SIT, PtP, NBMA NOARP links) it is handy to allow
1921                            some exceptions. --ANK
1922                          */
1923                         if (!(gwa_type & IPV6_ADDR_UNICAST))
1924                                 goto out;
1925
1926                         grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1);
1927
1928                         err = -EHOSTUNREACH;
1929                         if (!grt)
1930                                 goto out;
1931                         if (dev) {
1932                                 if (dev != grt->dst.dev) {
1933                                         ip6_rt_put(grt);
1934                                         goto out;
1935                                 }
1936                         } else {
1937                                 dev = grt->dst.dev;
1938                                 idev = grt->rt6i_idev;
1939                                 dev_hold(dev);
1940                                 in6_dev_hold(grt->rt6i_idev);
1941                         }
1942                         if (!(grt->rt6i_flags & RTF_GATEWAY))
1943                                 err = 0;
1944                         ip6_rt_put(grt);
1945
1946                         if (err)
1947                                 goto out;
1948                 }
1949                 err = -EINVAL;
1950                 if (!dev || (dev->flags & IFF_LOOPBACK))
1951                         goto out;
1952         }
1953
1954         err = -ENODEV;
1955         if (!dev)
1956                 goto out;
1957
1958         if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
1959                 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
1960                         err = -EINVAL;
1961                         goto out;
1962                 }
1963                 rt->rt6i_prefsrc.addr = cfg->fc_prefsrc;
1964                 rt->rt6i_prefsrc.plen = 128;
1965         } else
1966                 rt->rt6i_prefsrc.plen = 0;
1967
1968         rt->rt6i_flags = cfg->fc_flags;
1969
1970 install_route:
1971         rt->dst.dev = dev;
1972         rt->rt6i_idev = idev;
1973         rt->rt6i_table = table;
1974
1975         cfg->fc_nlinfo.nl_net = dev_net(dev);
1976
1977         err = ip6_convert_metrics(&mxc, cfg);
1978         if (err)
1979                 goto out;
1980
1981         err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, &mxc);
1982
1983         kfree(mxc.mx);
1984         return err;
1985 out:
1986         if (dev)
1987                 dev_put(dev);
1988         if (idev)
1989                 in6_dev_put(idev);
1990         if (rt)
1991                 dst_free(&rt->dst);
1992         return err;
1993 }
1994
1995 static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info)
1996 {
1997         int err;
1998         struct fib6_table *table;
1999         struct net *net = dev_net(rt->dst.dev);
2000
2001         if (rt == net->ipv6.ip6_null_entry) {
2002                 err = -ENOENT;
2003                 goto out;
2004         }
2005
2006         table = rt->rt6i_table;
2007         write_lock_bh(&table->tb6_lock);
2008         err = fib6_del(rt, info);
2009         write_unlock_bh(&table->tb6_lock);
2010
2011 out:
2012         ip6_rt_put(rt);
2013         return err;
2014 }
2015
2016 int ip6_del_rt(struct rt6_info *rt)
2017 {
2018         struct nl_info info = {
2019                 .nl_net = dev_net(rt->dst.dev),
2020         };
2021         return __ip6_del_rt(rt, &info);
2022 }
2023
2024 static int ip6_route_del(struct fib6_config *cfg)
2025 {
2026         struct fib6_table *table;
2027         struct fib6_node *fn;
2028         struct rt6_info *rt;
2029         int err = -ESRCH;
2030
2031         table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
2032         if (!table)
2033                 return err;
2034
2035         read_lock_bh(&table->tb6_lock);
2036
2037         fn = fib6_locate(&table->tb6_root,
2038                          &cfg->fc_dst, cfg->fc_dst_len,
2039                          &cfg->fc_src, cfg->fc_src_len);
2040
2041         if (fn) {
2042                 for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
2043                         if ((rt->rt6i_flags & RTF_CACHE) &&
2044                             !(cfg->fc_flags & RTF_CACHE))
2045                                 continue;
2046                         if (cfg->fc_ifindex &&
2047                             (!rt->dst.dev ||
2048                              rt->dst.dev->ifindex != cfg->fc_ifindex))
2049                                 continue;
2050                         if (cfg->fc_flags & RTF_GATEWAY &&
2051                             !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
2052                                 continue;
2053                         if (cfg->fc_metric && cfg->fc_metric != rt->rt6i_metric)
2054                                 continue;
2055                         dst_hold(&rt->dst);
2056                         read_unlock_bh(&table->tb6_lock);
2057
2058                         return __ip6_del_rt(rt, &cfg->fc_nlinfo);
2059                 }
2060         }
2061         read_unlock_bh(&table->tb6_lock);
2062
2063         return err;
2064 }
2065
2066 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
2067 {
2068         struct net *net = dev_net(skb->dev);
2069         struct netevent_redirect netevent;
2070         struct rt6_info *rt, *nrt = NULL;
2071         struct ndisc_options ndopts;
2072         struct inet6_dev *in6_dev;
2073         struct neighbour *neigh;
2074         struct rd_msg *msg;
2075         int optlen, on_link;
2076         u8 *lladdr;
2077
2078         optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
2079         optlen -= sizeof(*msg);
2080
2081         if (optlen < 0) {
2082                 net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
2083                 return;
2084         }
2085
2086         msg = (struct rd_msg *)icmp6_hdr(skb);
2087
2088         if (ipv6_addr_is_multicast(&msg->dest)) {
2089                 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
2090                 return;
2091         }
2092
2093         on_link = 0;
2094         if (ipv6_addr_equal(&msg->dest, &msg->target)) {
2095                 on_link = 1;
2096         } else if (ipv6_addr_type(&msg->target) !=
2097                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
2098                 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
2099                 return;
2100         }
2101
2102         in6_dev = __in6_dev_get(skb->dev);
2103         if (!in6_dev)
2104                 return;
2105         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
2106                 return;
2107
2108         /* RFC2461 8.1:
2109          *      The IP source address of the Redirect MUST be the same as the current
2110          *      first-hop router for the specified ICMP Destination Address.
2111          */
2112
2113         if (!ndisc_parse_options(msg->opt, optlen, &ndopts)) {
2114                 net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
2115                 return;
2116         }
2117
2118         lladdr = NULL;
2119         if (ndopts.nd_opts_tgt_lladdr) {
2120                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
2121                                              skb->dev);
2122                 if (!lladdr) {
2123                         net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
2124                         return;
2125                 }
2126         }
2127
2128         rt = (struct rt6_info *) dst;
2129         if (rt == net->ipv6.ip6_null_entry) {
2130                 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
2131                 return;
2132         }
2133
2134         /* Redirect received -> path was valid.
2135          * Look, redirects are sent only in response to data packets,
2136          * so that this nexthop apparently is reachable. --ANK
2137          */
2138         dst_confirm(&rt->dst);
2139
2140         neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
2141         if (!neigh)
2142                 return;
2143
2144         /*
2145          *      We have finally decided to accept it.
2146          */
2147
2148         neigh_update(neigh, lladdr, NUD_STALE,
2149                      NEIGH_UPDATE_F_WEAK_OVERRIDE|
2150                      NEIGH_UPDATE_F_OVERRIDE|
2151                      (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
2152                                      NEIGH_UPDATE_F_ISROUTER))
2153                      );
2154
2155         nrt = ip6_rt_cache_alloc(rt, &msg->dest, NULL);
2156         if (!nrt)
2157                 goto out;
2158
2159         nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
2160         if (on_link)
2161                 nrt->rt6i_flags &= ~RTF_GATEWAY;
2162
2163         nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
2164
2165         if (ip6_ins_rt(nrt))
2166                 goto out;
2167
2168         netevent.old = &rt->dst;
2169         netevent.new = &nrt->dst;
2170         netevent.daddr = &msg->dest;
2171         netevent.neigh = neigh;
2172         call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
2173
2174         if (rt->rt6i_flags & RTF_CACHE) {
2175                 rt = (struct rt6_info *) dst_clone(&rt->dst);
2176                 ip6_del_rt(rt);
2177         }
2178
2179 out:
2180         neigh_release(neigh);
2181 }
2182
2183 /*
2184  *      Misc support functions
2185  */
2186
2187 static void rt6_set_from(struct rt6_info *rt, struct rt6_info *from)
2188 {
2189         BUG_ON(from->dst.from);
2190
2191         rt->rt6i_flags &= ~RTF_EXPIRES;
2192         dst_hold(&from->dst);
2193         rt->dst.from = &from->dst;
2194         dst_init_metrics(&rt->dst, dst_metrics_ptr(&from->dst), true);
2195 }
2196
2197 static void ip6_rt_copy_init(struct rt6_info *rt, struct rt6_info *ort)
2198 {
2199         rt->dst.input = ort->dst.input;
2200         rt->dst.output = ort->dst.output;
2201         rt->rt6i_dst = ort->rt6i_dst;
2202         rt->dst.error = ort->dst.error;
2203         rt->rt6i_idev = ort->rt6i_idev;
2204         if (rt->rt6i_idev)
2205                 in6_dev_hold(rt->rt6i_idev);
2206         rt->dst.lastuse = jiffies;
2207         rt->rt6i_gateway = ort->rt6i_gateway;
2208         rt->rt6i_flags = ort->rt6i_flags;
2209         rt6_set_from(rt, ort);
2210         rt->rt6i_metric = ort->rt6i_metric;
2211 #ifdef CONFIG_IPV6_SUBTREES
2212         rt->rt6i_src = ort->rt6i_src;
2213 #endif
2214         rt->rt6i_prefsrc = ort->rt6i_prefsrc;
2215         rt->rt6i_table = ort->rt6i_table;
2216         rt->dst.lwtstate = lwtstate_get(ort->dst.lwtstate);
2217 }
2218
2219 #ifdef CONFIG_IPV6_ROUTE_INFO
2220 static struct rt6_info *rt6_get_route_info(struct net *net,
2221                                            const struct in6_addr *prefix, int prefixlen,
2222                                            const struct in6_addr *gwaddr, int ifindex)
2223 {
2224         struct fib6_node *fn;
2225         struct rt6_info *rt = NULL;
2226         struct fib6_table *table;
2227
2228         table = fib6_get_table(net, RT6_TABLE_INFO);
2229         if (!table)
2230                 return NULL;
2231
2232         read_lock_bh(&table->tb6_lock);
2233         fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0);
2234         if (!fn)
2235                 goto out;
2236
2237         for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
2238                 if (rt->dst.dev->ifindex != ifindex)
2239                         continue;
2240                 if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY))
2241                         continue;
2242                 if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr))
2243                         continue;
2244                 dst_hold(&rt->dst);
2245                 break;
2246         }
2247 out:
2248         read_unlock_bh(&table->tb6_lock);
2249         return rt;
2250 }
2251
2252 static struct rt6_info *rt6_add_route_info(struct net *net,
2253                                            const struct in6_addr *prefix, int prefixlen,
2254                                            const struct in6_addr *gwaddr, int ifindex,
2255                                            unsigned int pref)
2256 {
2257         struct fib6_config cfg = {
2258                 .fc_table       = RT6_TABLE_INFO,
2259                 .fc_metric      = IP6_RT_PRIO_USER,
2260                 .fc_ifindex     = ifindex,
2261                 .fc_dst_len     = prefixlen,
2262                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
2263                                   RTF_UP | RTF_PREF(pref),
2264                 .fc_nlinfo.portid = 0,
2265                 .fc_nlinfo.nlh = NULL,
2266                 .fc_nlinfo.nl_net = net,
2267         };
2268
2269         cfg.fc_dst = *prefix;
2270         cfg.fc_gateway = *gwaddr;
2271
2272         /* We should treat it as a default route if prefix length is 0. */
2273         if (!prefixlen)
2274                 cfg.fc_flags |= RTF_DEFAULT;
2275
2276         ip6_route_add(&cfg);
2277
2278         return rt6_get_route_info(net, prefix, prefixlen, gwaddr, ifindex);
2279 }
2280 #endif
2281
2282 struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr, struct net_device *dev)
2283 {
2284         struct rt6_info *rt;
2285         struct fib6_table *table;
2286
2287         table = fib6_get_table(dev_net(dev), RT6_TABLE_DFLT);
2288         if (!table)
2289                 return NULL;
2290
2291         read_lock_bh(&table->tb6_lock);
2292         for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) {
2293                 if (dev == rt->dst.dev &&
2294                     ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
2295                     ipv6_addr_equal(&rt->rt6i_gateway, addr))
2296                         break;
2297         }
2298         if (rt)
2299                 dst_hold(&rt->dst);
2300         read_unlock_bh(&table->tb6_lock);
2301         return rt;
2302 }
2303
2304 struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr,
2305                                      struct net_device *dev,
2306                                      unsigned int pref)
2307 {
2308         struct fib6_config cfg = {
2309                 .fc_table       = RT6_TABLE_DFLT,
2310                 .fc_metric      = IP6_RT_PRIO_USER,
2311                 .fc_ifindex     = dev->ifindex,
2312                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
2313                                   RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
2314                 .fc_nlinfo.portid = 0,
2315                 .fc_nlinfo.nlh = NULL,
2316                 .fc_nlinfo.nl_net = dev_net(dev),
2317         };
2318
2319         cfg.fc_gateway = *gwaddr;
2320
2321         ip6_route_add(&cfg);
2322
2323         return rt6_get_dflt_router(gwaddr, dev);
2324 }
2325
2326 void rt6_purge_dflt_routers(struct net *net)
2327 {
2328         struct rt6_info *rt;
2329         struct fib6_table *table;
2330
2331         /* NOTE: Keep consistent with rt6_get_dflt_router */
2332         table = fib6_get_table(net, RT6_TABLE_DFLT);
2333         if (!table)
2334                 return;
2335
2336 restart:
2337         read_lock_bh(&table->tb6_lock);
2338         for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) {
2339                 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
2340                     (!rt->rt6i_idev || rt->rt6i_idev->cnf.accept_ra != 2)) {
2341                         dst_hold(&rt->dst);
2342                         read_unlock_bh(&table->tb6_lock);
2343                         ip6_del_rt(rt);
2344                         goto restart;
2345                 }
2346         }
2347         read_unlock_bh(&table->tb6_lock);
2348 }
2349
2350 static void rtmsg_to_fib6_config(struct net *net,
2351                                  struct in6_rtmsg *rtmsg,
2352                                  struct fib6_config *cfg)
2353 {
2354         memset(cfg, 0, sizeof(*cfg));
2355
2356         cfg->fc_table = RT6_TABLE_MAIN;
2357         cfg->fc_ifindex = rtmsg->rtmsg_ifindex;
2358         cfg->fc_metric = rtmsg->rtmsg_metric;
2359         cfg->fc_expires = rtmsg->rtmsg_info;
2360         cfg->fc_dst_len = rtmsg->rtmsg_dst_len;
2361         cfg->fc_src_len = rtmsg->rtmsg_src_len;
2362         cfg->fc_flags = rtmsg->rtmsg_flags;
2363
2364         cfg->fc_nlinfo.nl_net = net;
2365
2366         cfg->fc_dst = rtmsg->rtmsg_dst;
2367         cfg->fc_src = rtmsg->rtmsg_src;
2368         cfg->fc_gateway = rtmsg->rtmsg_gateway;
2369 }
2370
2371 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg)
2372 {
2373         struct fib6_config cfg;
2374         struct in6_rtmsg rtmsg;
2375         int err;
2376
2377         switch (cmd) {
2378         case SIOCADDRT:         /* Add a route */
2379         case SIOCDELRT:         /* Delete a route */
2380                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2381                         return -EPERM;
2382                 err = copy_from_user(&rtmsg, arg,
2383                                      sizeof(struct in6_rtmsg));
2384                 if (err)
2385                         return -EFAULT;
2386
2387                 rtmsg_to_fib6_config(net, &rtmsg, &cfg);
2388
2389                 rtnl_lock();
2390                 switch (cmd) {
2391                 case SIOCADDRT:
2392                         err = ip6_route_add(&cfg);
2393                         break;
2394                 case SIOCDELRT:
2395                         err = ip6_route_del(&cfg);
2396                         break;
2397                 default:
2398                         err = -EINVAL;
2399                 }
2400                 rtnl_unlock();
2401
2402                 return err;
2403         }
2404
2405         return -EINVAL;
2406 }
2407
2408 /*
2409  *      Drop the packet on the floor
2410  */
2411
2412 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
2413 {
2414         int type;
2415         struct dst_entry *dst = skb_dst(skb);
2416         switch (ipstats_mib_noroutes) {
2417         case IPSTATS_MIB_INNOROUTES:
2418                 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
2419                 if (type == IPV6_ADDR_ANY) {
2420                         IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
2421                                       IPSTATS_MIB_INADDRERRORS);
2422                         break;
2423                 }
2424                 /* FALLTHROUGH */
2425         case IPSTATS_MIB_OUTNOROUTES:
2426                 IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
2427                               ipstats_mib_noroutes);
2428                 break;
2429         }
2430         icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
2431         kfree_skb(skb);
2432         return 0;
2433 }
2434
2435 static int ip6_pkt_discard(struct sk_buff *skb)
2436 {
2437         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
2438 }
2439
2440 static int ip6_pkt_discard_out(struct sock *sk, struct sk_buff *skb)
2441 {
2442         skb->dev = skb_dst(skb)->dev;
2443         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
2444 }
2445
2446 static int ip6_pkt_prohibit(struct sk_buff *skb)
2447 {
2448         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
2449 }
2450
2451 static int ip6_pkt_prohibit_out(struct sock *sk, struct sk_buff *skb)
2452 {
2453         skb->dev = skb_dst(skb)->dev;
2454         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
2455 }
2456
2457 /*
2458  *      Allocate a dst for local (unicast / anycast) address.
2459  */
2460
2461 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
2462                                     const struct in6_addr *addr,
2463                                     bool anycast)
2464 {
2465         struct net *net = dev_net(idev->dev);
2466         struct rt6_info *rt = ip6_dst_alloc(net, net->loopback_dev,
2467                                             DST_NOCOUNT);
2468         if (!rt)
2469                 return ERR_PTR(-ENOMEM);
2470
2471         in6_dev_hold(idev);
2472
2473         rt->dst.flags |= DST_HOST;
2474         rt->dst.input = ip6_input;
2475         rt->dst.output = ip6_output;
2476         rt->rt6i_idev = idev;
2477
2478         rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP;
2479         if (anycast)
2480                 rt->rt6i_flags |= RTF_ANYCAST;
2481         else
2482                 rt->rt6i_flags |= RTF_LOCAL;
2483
2484         rt->rt6i_gateway  = *addr;
2485         rt->rt6i_dst.addr = *addr;
2486         rt->rt6i_dst.plen = 128;
2487         rt->rt6i_table = fib6_get_table(net, RT6_TABLE_LOCAL);
2488
2489         atomic_set(&rt->dst.__refcnt, 1);
2490
2491         return rt;
2492 }
2493
2494 int ip6_route_get_saddr(struct net *net,
2495                         struct rt6_info *rt,
2496                         const struct in6_addr *daddr,
2497                         unsigned int prefs,
2498                         struct in6_addr *saddr)
2499 {
2500         struct inet6_dev *idev =
2501                 rt ? ip6_dst_idev((struct dst_entry *)rt) : NULL;
2502         int err = 0;
2503         if (rt && rt->rt6i_prefsrc.plen)
2504                 *saddr = rt->rt6i_prefsrc.addr;
2505         else
2506                 err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,
2507                                          daddr, prefs, saddr);
2508         return err;
2509 }
2510
2511 /* remove deleted ip from prefsrc entries */
2512 struct arg_dev_net_ip {
2513         struct net_device *dev;
2514         struct net *net;
2515         struct in6_addr *addr;
2516 };
2517
2518 static int fib6_remove_prefsrc(struct rt6_info *rt, void *arg)
2519 {
2520         struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev;
2521         struct net *net = ((struct arg_dev_net_ip *)arg)->net;
2522         struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
2523
2524         if (((void *)rt->dst.dev == dev || !dev) &&
2525             rt != net->ipv6.ip6_null_entry &&
2526             ipv6_addr_equal(addr, &rt->rt6i_prefsrc.addr)) {
2527                 /* remove prefsrc entry */
2528                 rt->rt6i_prefsrc.plen = 0;
2529         }
2530         return 0;
2531 }
2532
2533 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
2534 {
2535         struct net *net = dev_net(ifp->idev->dev);
2536         struct arg_dev_net_ip adni = {
2537                 .dev = ifp->idev->dev,
2538                 .net = net,
2539                 .addr = &ifp->addr,
2540         };
2541         fib6_clean_all(net, fib6_remove_prefsrc, &adni);
2542 }
2543
2544 #define RTF_RA_ROUTER           (RTF_ADDRCONF | RTF_DEFAULT | RTF_GATEWAY)
2545 #define RTF_CACHE_GATEWAY       (RTF_GATEWAY | RTF_CACHE)
2546
2547 /* Remove routers and update dst entries when gateway turn into host. */
2548 static int fib6_clean_tohost(struct rt6_info *rt, void *arg)
2549 {
2550         struct in6_addr *gateway = (struct in6_addr *)arg;
2551
2552         if ((((rt->rt6i_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) ||
2553              ((rt->rt6i_flags & RTF_CACHE_GATEWAY) == RTF_CACHE_GATEWAY)) &&
2554              ipv6_addr_equal(gateway, &rt->rt6i_gateway)) {
2555                 return -1;
2556         }
2557         return 0;
2558 }
2559
2560 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
2561 {
2562         fib6_clean_all(net, fib6_clean_tohost, gateway);
2563 }
2564
2565 struct arg_dev_net {
2566         struct net_device *dev;
2567         struct net *net;
2568 };
2569
2570 static int fib6_ifdown(struct rt6_info *rt, void *arg)
2571 {
2572         const struct arg_dev_net *adn = arg;
2573         const struct net_device *dev = adn->dev;
2574
2575         if ((rt->dst.dev == dev || !dev) &&
2576             rt != adn->net->ipv6.ip6_null_entry)
2577                 return -1;
2578
2579         return 0;
2580 }
2581
2582 void rt6_ifdown(struct net *net, struct net_device *dev)
2583 {
2584         struct arg_dev_net adn = {
2585                 .dev = dev,
2586                 .net = net,
2587         };
2588
2589         fib6_clean_all(net, fib6_ifdown, &adn);
2590         icmp6_clean_all(fib6_ifdown, &adn);
2591         rt6_uncached_list_flush_dev(net, dev);
2592 }
2593
2594 struct rt6_mtu_change_arg {
2595         struct net_device *dev;
2596         unsigned int mtu;
2597 };
2598
2599 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg)
2600 {
2601         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
2602         struct inet6_dev *idev;
2603
2604         /* In IPv6 pmtu discovery is not optional,
2605            so that RTAX_MTU lock cannot disable it.
2606            We still use this lock to block changes
2607            caused by addrconf/ndisc.
2608         */
2609
2610         idev = __in6_dev_get(arg->dev);
2611         if (!idev)
2612                 return 0;
2613
2614         /* For administrative MTU increase, there is no way to discover
2615            IPv6 PMTU increase, so PMTU increase should be updated here.
2616            Since RFC 1981 doesn't include administrative MTU increase
2617            update PMTU increase is a MUST. (i.e. jumbo frame)
2618          */
2619         /*
2620            If new MTU is less than route PMTU, this new MTU will be the
2621            lowest MTU in the path, update the route PMTU to reflect PMTU
2622            decreases; if new MTU is greater than route PMTU, and the
2623            old MTU is the lowest MTU in the path, update the route PMTU
2624            to reflect the increase. In this case if the other nodes' MTU
2625            also have the lowest MTU, TOO BIG MESSAGE will be lead to
2626            PMTU discouvery.
2627          */
2628         if (rt->dst.dev == arg->dev &&
2629             !dst_metric_locked(&rt->dst, RTAX_MTU)) {
2630                 if (rt->rt6i_flags & RTF_CACHE) {
2631                         /* For RTF_CACHE with rt6i_pmtu == 0
2632                          * (i.e. a redirected route),
2633                          * the metrics of its rt->dst.from has already
2634                          * been updated.
2635                          */
2636                         if (rt->rt6i_pmtu && rt->rt6i_pmtu > arg->mtu)
2637                                 rt->rt6i_pmtu = arg->mtu;
2638                 } else if (dst_mtu(&rt->dst) >= arg->mtu ||
2639                            (dst_mtu(&rt->dst) < arg->mtu &&
2640                             dst_mtu(&rt->dst) == idev->cnf.mtu6)) {
2641                         dst_metric_set(&rt->dst, RTAX_MTU, arg->mtu);
2642                 }
2643         }
2644         return 0;
2645 }
2646
2647 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
2648 {
2649         struct rt6_mtu_change_arg arg = {
2650                 .dev = dev,
2651                 .mtu = mtu,
2652         };
2653
2654         fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
2655 }
2656
2657 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
2658         [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
2659         [RTA_OIF]               = { .type = NLA_U32 },
2660         [RTA_IIF]               = { .type = NLA_U32 },
2661         [RTA_PRIORITY]          = { .type = NLA_U32 },
2662         [RTA_METRICS]           = { .type = NLA_NESTED },
2663         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
2664         [RTA_PREF]              = { .type = NLA_U8 },
2665         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
2666         [RTA_ENCAP]             = { .type = NLA_NESTED },
2667 };
2668
2669 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
2670                               struct fib6_config *cfg)
2671 {
2672         struct rtmsg *rtm;
2673         struct nlattr *tb[RTA_MAX+1];
2674         unsigned int pref;
2675         int err;
2676
2677         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
2678         if (err < 0)
2679                 goto errout;
2680
2681         err = -EINVAL;
2682         rtm = nlmsg_data(nlh);
2683         memset(cfg, 0, sizeof(*cfg));
2684
2685         cfg->fc_table = rtm->rtm_table;
2686         cfg->fc_dst_len = rtm->rtm_dst_len;
2687         cfg->fc_src_len = rtm->rtm_src_len;
2688         cfg->fc_flags = RTF_UP;
2689         cfg->fc_protocol = rtm->rtm_protocol;
2690         cfg->fc_type = rtm->rtm_type;
2691
2692         if (rtm->rtm_type == RTN_UNREACHABLE ||
2693             rtm->rtm_type == RTN_BLACKHOLE ||
2694             rtm->rtm_type == RTN_PROHIBIT ||
2695             rtm->rtm_type == RTN_THROW)
2696                 cfg->fc_flags |= RTF_REJECT;
2697
2698         if (rtm->rtm_type == RTN_LOCAL)
2699                 cfg->fc_flags |= RTF_LOCAL;
2700
2701         if (rtm->rtm_flags & RTM_F_CLONED)
2702                 cfg->fc_flags |= RTF_CACHE;
2703
2704         cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
2705         cfg->fc_nlinfo.nlh = nlh;
2706         cfg->fc_nlinfo.nl_net = sock_net(skb->sk);
2707
2708         if (tb[RTA_GATEWAY]) {
2709                 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
2710                 cfg->fc_flags |= RTF_GATEWAY;
2711         }
2712
2713         if (tb[RTA_DST]) {
2714                 int plen = (rtm->rtm_dst_len + 7) >> 3;
2715
2716                 if (nla_len(tb[RTA_DST]) < plen)
2717                         goto errout;
2718
2719                 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
2720         }
2721
2722         if (tb[RTA_SRC]) {
2723                 int plen = (rtm->rtm_src_len + 7) >> 3;
2724
2725                 if (nla_len(tb[RTA_SRC]) < plen)
2726                         goto errout;
2727
2728                 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
2729         }
2730
2731         if (tb[RTA_PREFSRC])
2732                 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
2733
2734         if (tb[RTA_OIF])
2735                 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
2736
2737         if (tb[RTA_PRIORITY])
2738                 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
2739
2740         if (tb[RTA_METRICS]) {
2741                 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
2742                 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
2743         }
2744
2745         if (tb[RTA_TABLE])
2746                 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
2747
2748         if (tb[RTA_MULTIPATH]) {
2749                 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
2750                 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
2751         }
2752
2753         if (tb[RTA_PREF]) {
2754                 pref = nla_get_u8(tb[RTA_PREF]);
2755                 if (pref != ICMPV6_ROUTER_PREF_LOW &&
2756                     pref != ICMPV6_ROUTER_PREF_HIGH)
2757                         pref = ICMPV6_ROUTER_PREF_MEDIUM;
2758                 cfg->fc_flags |= RTF_PREF(pref);
2759         }
2760
2761         if (tb[RTA_ENCAP])
2762                 cfg->fc_encap = tb[RTA_ENCAP];
2763
2764         if (tb[RTA_ENCAP_TYPE])
2765                 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
2766
2767         err = 0;
2768 errout:
2769         return err;
2770 }
2771
2772 static int ip6_route_multipath(struct fib6_config *cfg, int add)
2773 {
2774         struct fib6_config r_cfg;
2775         struct rtnexthop *rtnh;
2776         int remaining;
2777         int attrlen;
2778         int err = 0, last_err = 0;
2779
2780         remaining = cfg->fc_mp_len;
2781 beginning:
2782         rtnh = (struct rtnexthop *)cfg->fc_mp;
2783
2784         /* Parse a Multipath Entry */
2785         while (rtnh_ok(rtnh, remaining)) {
2786                 memcpy(&r_cfg, cfg, sizeof(*cfg));
2787                 if (rtnh->rtnh_ifindex)
2788                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
2789
2790                 attrlen = rtnh_attrlen(rtnh);
2791                 if (attrlen > 0) {
2792                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
2793
2794                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
2795                         if (nla) {
2796                                 r_cfg.fc_gateway = nla_get_in6_addr(nla);
2797                                 r_cfg.fc_flags |= RTF_GATEWAY;
2798                         }
2799                         r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
2800                         nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
2801                         if (nla)
2802                                 r_cfg.fc_encap_type = nla_get_u16(nla);
2803                 }
2804                 err = add ? ip6_route_add(&r_cfg) : ip6_route_del(&r_cfg);
2805                 if (err) {
2806                         last_err = err;
2807                         /* If we are trying to remove a route, do not stop the
2808                          * loop when ip6_route_del() fails (because next hop is
2809                          * already gone), we should try to remove all next hops.
2810                          */
2811                         if (add) {
2812                                 /* If add fails, we should try to delete all
2813                                  * next hops that have been already added.
2814                                  */
2815                                 add = 0;
2816                                 remaining = cfg->fc_mp_len - remaining;
2817                                 goto beginning;
2818                         }
2819                 }
2820                 /* Because each route is added like a single route we remove
2821                  * these flags after the first nexthop: if there is a collision,
2822                  * we have already failed to add the first nexthop:
2823                  * fib6_add_rt2node() has rejected it; when replacing, old
2824                  * nexthops have been replaced by first new, the rest should
2825                  * be added to it.
2826                  */
2827                 cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
2828                                                      NLM_F_REPLACE);
2829                 rtnh = rtnh_next(rtnh, &remaining);
2830         }
2831
2832         return last_err;
2833 }
2834
2835 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
2836 {
2837         struct fib6_config cfg;
2838         int err;
2839
2840         err = rtm_to_fib6_config(skb, nlh, &cfg);
2841         if (err < 0)
2842                 return err;
2843
2844         if (cfg.fc_mp)
2845                 return ip6_route_multipath(&cfg, 0);
2846         else
2847                 return ip6_route_del(&cfg);
2848 }
2849
2850 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
2851 {
2852         struct fib6_config cfg;
2853         int err;
2854
2855         err = rtm_to_fib6_config(skb, nlh, &cfg);
2856         if (err < 0)
2857                 return err;
2858
2859         if (cfg.fc_mp)
2860                 return ip6_route_multipath(&cfg, 1);
2861         else
2862                 return ip6_route_add(&cfg);
2863 }
2864
2865 static inline size_t rt6_nlmsg_size(struct rt6_info *rt)
2866 {
2867         return NLMSG_ALIGN(sizeof(struct rtmsg))
2868                + nla_total_size(16) /* RTA_SRC */
2869                + nla_total_size(16) /* RTA_DST */
2870                + nla_total_size(16) /* RTA_GATEWAY */
2871                + nla_total_size(16) /* RTA_PREFSRC */
2872                + nla_total_size(4) /* RTA_TABLE */
2873                + nla_total_size(4) /* RTA_IIF */
2874                + nla_total_size(4) /* RTA_OIF */
2875                + nla_total_size(4) /* RTA_PRIORITY */
2876                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
2877                + nla_total_size(sizeof(struct rta_cacheinfo))
2878                + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
2879                + nla_total_size(1) /* RTA_PREF */
2880                + lwtunnel_get_encap_size(rt->dst.lwtstate);
2881 }
2882
2883 static int rt6_fill_node(struct net *net,
2884                          struct sk_buff *skb, struct rt6_info *rt,
2885                          struct in6_addr *dst, struct in6_addr *src,
2886                          int iif, int type, u32 portid, u32 seq,
2887                          int prefix, int nowait, unsigned int flags)
2888 {
2889         u32 metrics[RTAX_MAX];
2890         struct rtmsg *rtm;
2891         struct nlmsghdr *nlh;
2892         long expires;
2893         u32 table;
2894
2895         if (prefix) {   /* user wants prefix routes only */
2896                 if (!(rt->rt6i_flags & RTF_PREFIX_RT)) {
2897                         /* success since this is not a prefix route */
2898                         return 1;
2899                 }
2900         }
2901
2902         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
2903         if (!nlh)
2904                 return -EMSGSIZE;
2905
2906         rtm = nlmsg_data(nlh);
2907         rtm->rtm_family = AF_INET6;
2908         rtm->rtm_dst_len = rt->rt6i_dst.plen;
2909         rtm->rtm_src_len = rt->rt6i_src.plen;
2910         rtm->rtm_tos = 0;
2911         if (rt->rt6i_table)
2912                 table = rt->rt6i_table->tb6_id;
2913         else
2914                 table = RT6_TABLE_UNSPEC;
2915         rtm->rtm_table = table;
2916         if (nla_put_u32(skb, RTA_TABLE, table))
2917                 goto nla_put_failure;
2918         if (rt->rt6i_flags & RTF_REJECT) {
2919                 switch (rt->dst.error) {
2920                 case -EINVAL:
2921                         rtm->rtm_type = RTN_BLACKHOLE;
2922                         break;
2923                 case -EACCES:
2924                         rtm->rtm_type = RTN_PROHIBIT;
2925                         break;
2926                 case -EAGAIN:
2927                         rtm->rtm_type = RTN_THROW;
2928                         break;
2929                 default:
2930                         rtm->rtm_type = RTN_UNREACHABLE;
2931                         break;
2932                 }
2933         }
2934         else if (rt->rt6i_flags & RTF_LOCAL)
2935                 rtm->rtm_type = RTN_LOCAL;
2936         else if (rt->dst.dev && (rt->dst.dev->flags & IFF_LOOPBACK))
2937                 rtm->rtm_type = RTN_LOCAL;
2938         else
2939                 rtm->rtm_type = RTN_UNICAST;
2940         rtm->rtm_flags = 0;
2941         if (!netif_carrier_ok(rt->dst.dev)) {
2942                 rtm->rtm_flags |= RTNH_F_LINKDOWN;
2943                 if (rt->rt6i_idev->cnf.ignore_routes_with_linkdown)
2944                         rtm->rtm_flags |= RTNH_F_DEAD;
2945         }
2946         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
2947         rtm->rtm_protocol = rt->rt6i_protocol;
2948         if (rt->rt6i_flags & RTF_DYNAMIC)
2949                 rtm->rtm_protocol = RTPROT_REDIRECT;
2950         else if (rt->rt6i_flags & RTF_ADDRCONF) {
2951                 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ROUTEINFO))
2952                         rtm->rtm_protocol = RTPROT_RA;
2953                 else
2954                         rtm->rtm_protocol = RTPROT_KERNEL;
2955         }
2956
2957         if (rt->rt6i_flags & RTF_CACHE)
2958                 rtm->rtm_flags |= RTM_F_CLONED;
2959
2960         if (dst) {
2961                 if (nla_put_in6_addr(skb, RTA_DST, dst))
2962                         goto nla_put_failure;
2963                 rtm->rtm_dst_len = 128;
2964         } else if (rtm->rtm_dst_len)
2965                 if (nla_put_in6_addr(skb, RTA_DST, &rt->rt6i_dst.addr))
2966                         goto nla_put_failure;
2967 #ifdef CONFIG_IPV6_SUBTREES
2968         if (src) {
2969                 if (nla_put_in6_addr(skb, RTA_SRC, src))
2970                         goto nla_put_failure;
2971                 rtm->rtm_src_len = 128;
2972         } else if (rtm->rtm_src_len &&
2973                    nla_put_in6_addr(skb, RTA_SRC, &rt->rt6i_src.addr))
2974                 goto nla_put_failure;
2975 #endif
2976         if (iif) {
2977 #ifdef CONFIG_IPV6_MROUTE
2978                 if (ipv6_addr_is_multicast(&rt->rt6i_dst.addr)) {
2979                         int err = ip6mr_get_route(net, skb, rtm, nowait);
2980                         if (err <= 0) {
2981                                 if (!nowait) {
2982                                         if (err == 0)
2983                                                 return 0;
2984                                         goto nla_put_failure;
2985                                 } else {
2986                                         if (err == -EMSGSIZE)
2987                                                 goto nla_put_failure;
2988                                 }
2989                         }
2990                 } else
2991 #endif
2992                         if (nla_put_u32(skb, RTA_IIF, iif))
2993                                 goto nla_put_failure;
2994         } else if (dst) {
2995                 struct in6_addr saddr_buf;
2996                 if (ip6_route_get_saddr(net, rt, dst, 0, &saddr_buf) == 0 &&
2997                     nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
2998                         goto nla_put_failure;
2999         }
3000
3001         if (rt->rt6i_prefsrc.plen) {
3002                 struct in6_addr saddr_buf;
3003                 saddr_buf = rt->rt6i_prefsrc.addr;
3004                 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
3005                         goto nla_put_failure;
3006         }
3007
3008         memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
3009         if (rt->rt6i_pmtu)
3010                 metrics[RTAX_MTU - 1] = rt->rt6i_pmtu;
3011         if (rtnetlink_put_metrics(skb, metrics) < 0)
3012                 goto nla_put_failure;
3013
3014         if (rt->rt6i_flags & RTF_GATEWAY) {
3015                 if (nla_put_in6_addr(skb, RTA_GATEWAY, &rt->rt6i_gateway) < 0)
3016                         goto nla_put_failure;
3017         }
3018
3019         if (rt->dst.dev &&
3020             nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
3021                 goto nla_put_failure;
3022         if (nla_put_u32(skb, RTA_PRIORITY, rt->rt6i_metric))
3023                 goto nla_put_failure;
3024
3025         expires = (rt->rt6i_flags & RTF_EXPIRES) ? rt->dst.expires - jiffies : 0;
3026
3027         if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, rt->dst.error) < 0)
3028                 goto nla_put_failure;
3029
3030         if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt->rt6i_flags)))
3031                 goto nla_put_failure;
3032
3033         lwtunnel_fill_encap(skb, rt->dst.lwtstate);
3034
3035         nlmsg_end(skb, nlh);
3036         return 0;
3037
3038 nla_put_failure:
3039         nlmsg_cancel(skb, nlh);
3040         return -EMSGSIZE;
3041 }
3042
3043 int rt6_dump_route(struct rt6_info *rt, void *p_arg)
3044 {
3045         struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
3046         int prefix;
3047
3048         if (nlmsg_len(arg->cb->nlh) >= sizeof(struct rtmsg)) {
3049                 struct rtmsg *rtm = nlmsg_data(arg->cb->nlh);
3050                 prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0;
3051         } else
3052                 prefix = 0;
3053
3054         return rt6_fill_node(arg->net,
3055                      arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE,
3056                      NETLINK_CB(arg->cb->skb).portid, arg->cb->nlh->nlmsg_seq,
3057                      prefix, 0, NLM_F_MULTI);
3058 }
3059
3060 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
3061 {
3062         struct net *net = sock_net(in_skb->sk);
3063         struct nlattr *tb[RTA_MAX+1];
3064         struct rt6_info *rt;
3065         struct sk_buff *skb;
3066         struct rtmsg *rtm;
3067         struct flowi6 fl6;
3068         int err, iif = 0, oif = 0;
3069
3070         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
3071         if (err < 0)
3072                 goto errout;
3073
3074         err = -EINVAL;
3075         memset(&fl6, 0, sizeof(fl6));
3076
3077         if (tb[RTA_SRC]) {
3078                 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
3079                         goto errout;
3080
3081                 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
3082         }
3083
3084         if (tb[RTA_DST]) {
3085                 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
3086                         goto errout;
3087
3088                 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
3089         }
3090
3091         if (tb[RTA_IIF])
3092                 iif = nla_get_u32(tb[RTA_IIF]);
3093
3094         if (tb[RTA_OIF])
3095                 oif = nla_get_u32(tb[RTA_OIF]);
3096
3097         if (tb[RTA_MARK])
3098                 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
3099
3100         if (iif) {
3101                 struct net_device *dev;
3102                 int flags = 0;
3103
3104                 dev = __dev_get_by_index(net, iif);
3105                 if (!dev) {
3106                         err = -ENODEV;
3107                         goto errout;
3108                 }
3109
3110                 fl6.flowi6_iif = iif;
3111
3112                 if (!ipv6_addr_any(&fl6.saddr))
3113                         flags |= RT6_LOOKUP_F_HAS_SADDR;
3114
3115                 rt = (struct rt6_info *)ip6_route_input_lookup(net, dev, &fl6,
3116                                                                flags);
3117         } else {
3118                 fl6.flowi6_oif = oif;
3119
3120                 rt = (struct rt6_info *)ip6_route_output(net, NULL, &fl6);
3121         }
3122
3123         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3124         if (!skb) {
3125                 ip6_rt_put(rt);
3126                 err = -ENOBUFS;
3127                 goto errout;
3128         }
3129
3130         /* Reserve room for dummy headers, this skb can pass
3131            through good chunk of routing engine.
3132          */
3133         skb_reset_mac_header(skb);
3134         skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr));
3135
3136         skb_dst_set(skb, &rt->dst);
3137
3138         err = rt6_fill_node(net, skb, rt, &fl6.daddr, &fl6.saddr, iif,
3139                             RTM_NEWROUTE, NETLINK_CB(in_skb).portid,
3140                             nlh->nlmsg_seq, 0, 0, 0);
3141         if (err < 0) {
3142                 kfree_skb(skb);
3143                 goto errout;
3144         }
3145
3146         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3147 errout:
3148         return err;
3149 }
3150
3151 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info)
3152 {
3153         struct sk_buff *skb;
3154         struct net *net = info->nl_net;
3155         u32 seq;
3156         int err;
3157
3158         err = -ENOBUFS;
3159         seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3160
3161         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3162         if (!skb)
3163                 goto errout;
3164
3165         err = rt6_fill_node(net, skb, rt, NULL, NULL, 0,
3166                                 event, info->portid, seq, 0, 0, 0);
3167         if (err < 0) {
3168                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
3169                 WARN_ON(err == -EMSGSIZE);
3170                 kfree_skb(skb);
3171                 goto errout;
3172         }
3173         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3174                     info->nlh, gfp_any());
3175         return;
3176 errout:
3177         if (err < 0)
3178                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
3179 }
3180
3181 static int ip6_route_dev_notify(struct notifier_block *this,
3182                                 unsigned long event, void *ptr)
3183 {
3184         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3185         struct net *net = dev_net(dev);
3186
3187         if (event == NETDEV_REGISTER && (dev->flags & IFF_LOOPBACK)) {
3188                 net->ipv6.ip6_null_entry->dst.dev = dev;
3189                 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
3190 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3191                 net->ipv6.ip6_prohibit_entry->dst.dev = dev;
3192                 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
3193                 net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
3194                 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
3195 #endif
3196         }
3197
3198         return NOTIFY_OK;
3199 }
3200
3201 /*
3202  *      /proc
3203  */
3204
3205 #ifdef CONFIG_PROC_FS
3206
3207 static const struct file_operations ipv6_route_proc_fops = {
3208         .owner          = THIS_MODULE,
3209         .open           = ipv6_route_open,
3210         .read           = seq_read,
3211         .llseek         = seq_lseek,
3212         .release        = seq_release_net,
3213 };
3214
3215 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
3216 {
3217         struct net *net = (struct net *)seq->private;
3218         seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
3219                    net->ipv6.rt6_stats->fib_nodes,
3220                    net->ipv6.rt6_stats->fib_route_nodes,
3221                    net->ipv6.rt6_stats->fib_rt_alloc,
3222                    net->ipv6.rt6_stats->fib_rt_entries,
3223                    net->ipv6.rt6_stats->fib_rt_cache,
3224                    dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
3225                    net->ipv6.rt6_stats->fib_discarded_routes);
3226
3227         return 0;
3228 }
3229
3230 static int rt6_stats_seq_open(struct inode *inode, struct file *file)
3231 {
3232         return single_open_net(inode, file, rt6_stats_seq_show);
3233 }
3234
3235 static const struct file_operations rt6_stats_seq_fops = {
3236         .owner   = THIS_MODULE,
3237         .open    = rt6_stats_seq_open,
3238         .read    = seq_read,
3239         .llseek  = seq_lseek,
3240         .release = single_release_net,
3241 };
3242 #endif  /* CONFIG_PROC_FS */
3243
3244 #ifdef CONFIG_SYSCTL
3245
3246 static
3247 int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
3248                               void __user *buffer, size_t *lenp, loff_t *ppos)
3249 {
3250         struct net *net;
3251         int delay;
3252         if (!write)
3253                 return -EINVAL;
3254
3255         net = (struct net *)ctl->extra1;
3256         delay = net->ipv6.sysctl.flush_delay;
3257         proc_dointvec(ctl, write, buffer, lenp, ppos);
3258         fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
3259         return 0;
3260 }
3261
3262 struct ctl_table ipv6_route_table_template[] = {
3263         {
3264                 .procname       =       "flush",
3265                 .data           =       &init_net.ipv6.sysctl.flush_delay,
3266                 .maxlen         =       sizeof(int),
3267                 .mode           =       0200,
3268                 .proc_handler   =       ipv6_sysctl_rtcache_flush
3269         },
3270         {
3271                 .procname       =       "gc_thresh",
3272                 .data           =       &ip6_dst_ops_template.gc_thresh,
3273                 .maxlen         =       sizeof(int),
3274                 .mode           =       0644,
3275                 .proc_handler   =       proc_dointvec,
3276         },
3277         {
3278                 .procname       =       "max_size",
3279                 .data           =       &init_net.ipv6.sysctl.ip6_rt_max_size,
3280                 .maxlen         =       sizeof(int),
3281                 .mode           =       0644,
3282                 .proc_handler   =       proc_dointvec,
3283         },
3284         {
3285                 .procname       =       "gc_min_interval",
3286                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
3287                 .maxlen         =       sizeof(int),
3288                 .mode           =       0644,
3289                 .proc_handler   =       proc_dointvec_jiffies,
3290         },
3291         {
3292                 .procname       =       "gc_timeout",
3293                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
3294                 .maxlen         =       sizeof(int),
3295                 .mode           =       0644,
3296                 .proc_handler   =       proc_dointvec_jiffies,
3297         },
3298         {
3299                 .procname       =       "gc_interval",
3300                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_interval,
3301                 .maxlen         =       sizeof(int),
3302                 .mode           =       0644,
3303                 .proc_handler   =       proc_dointvec_jiffies,
3304         },
3305         {
3306                 .procname       =       "gc_elasticity",
3307                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
3308                 .maxlen         =       sizeof(int),
3309                 .mode           =       0644,
3310                 .proc_handler   =       proc_dointvec,
3311         },
3312         {
3313                 .procname       =       "mtu_expires",
3314                 .data           =       &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
3315                 .maxlen         =       sizeof(int),
3316                 .mode           =       0644,
3317                 .proc_handler   =       proc_dointvec_jiffies,
3318         },
3319         {
3320                 .procname       =       "min_adv_mss",
3321                 .data           =       &init_net.ipv6.sysctl.ip6_rt_min_advmss,
3322                 .maxlen         =       sizeof(int),
3323                 .mode           =       0644,
3324                 .proc_handler   =       proc_dointvec,
3325         },
3326         {
3327                 .procname       =       "gc_min_interval_ms",
3328                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
3329                 .maxlen         =       sizeof(int),
3330                 .mode           =       0644,
3331                 .proc_handler   =       proc_dointvec_ms_jiffies,
3332         },
3333         { }
3334 };
3335
3336 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
3337 {
3338         struct ctl_table *table;
3339
3340         table = kmemdup(ipv6_route_table_template,
3341                         sizeof(ipv6_route_table_template),
3342                         GFP_KERNEL);
3343
3344         if (table) {
3345                 table[0].data = &net->ipv6.sysctl.flush_delay;
3346                 table[0].extra1 = net;
3347                 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
3348                 table[2].data = &net->ipv6.sysctl.ip6_rt_max_size;
3349                 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
3350                 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
3351                 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
3352                 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
3353                 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
3354                 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
3355                 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
3356
3357                 /* Don't export sysctls to unprivileged users */
3358                 if (net->user_ns != &init_user_ns)
3359                         table[0].procname = NULL;
3360         }
3361
3362         return table;
3363 }
3364 #endif
3365
3366 static int __net_init ip6_route_net_init(struct net *net)
3367 {
3368         int ret = -ENOMEM;
3369
3370         memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
3371                sizeof(net->ipv6.ip6_dst_ops));
3372
3373         if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
3374                 goto out_ip6_dst_ops;
3375
3376         net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
3377                                            sizeof(*net->ipv6.ip6_null_entry),
3378                                            GFP_KERNEL);
3379         if (!net->ipv6.ip6_null_entry)
3380                 goto out_ip6_dst_entries;
3381         net->ipv6.ip6_null_entry->dst.path =
3382                 (struct dst_entry *)net->ipv6.ip6_null_entry;
3383         net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
3384         dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
3385                          ip6_template_metrics, true);
3386
3387 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3388         net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
3389                                                sizeof(*net->ipv6.ip6_prohibit_entry),
3390                                                GFP_KERNEL);
3391         if (!net->ipv6.ip6_prohibit_entry)
3392                 goto out_ip6_null_entry;
3393         net->ipv6.ip6_prohibit_entry->dst.path =
3394                 (struct dst_entry *)net->ipv6.ip6_prohibit_entry;
3395         net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
3396         dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
3397                          ip6_template_metrics, true);
3398
3399         net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
3400                                                sizeof(*net->ipv6.ip6_blk_hole_entry),
3401                                                GFP_KERNEL);
3402         if (!net->ipv6.ip6_blk_hole_entry)
3403                 goto out_ip6_prohibit_entry;
3404         net->ipv6.ip6_blk_hole_entry->dst.path =
3405                 (struct dst_entry *)net->ipv6.ip6_blk_hole_entry;
3406         net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
3407         dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
3408                          ip6_template_metrics, true);
3409 #endif
3410
3411         net->ipv6.sysctl.flush_delay = 0;
3412         net->ipv6.sysctl.ip6_rt_max_size = 4096;
3413         net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
3414         net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
3415         net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
3416         net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
3417         net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
3418         net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
3419
3420         net->ipv6.ip6_rt_gc_expire = 30*HZ;
3421
3422         ret = 0;
3423 out:
3424         return ret;
3425
3426 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3427 out_ip6_prohibit_entry:
3428         kfree(net->ipv6.ip6_prohibit_entry);
3429 out_ip6_null_entry:
3430         kfree(net->ipv6.ip6_null_entry);
3431 #endif
3432 out_ip6_dst_entries:
3433         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
3434 out_ip6_dst_ops:
3435         goto out;
3436 }
3437
3438 static void __net_exit ip6_route_net_exit(struct net *net)
3439 {
3440         kfree(net->ipv6.ip6_null_entry);
3441 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3442         kfree(net->ipv6.ip6_prohibit_entry);
3443         kfree(net->ipv6.ip6_blk_hole_entry);
3444 #endif
3445         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
3446 }
3447
3448 static int __net_init ip6_route_net_init_late(struct net *net)
3449 {
3450 #ifdef CONFIG_PROC_FS
3451         proc_create("ipv6_route", 0, net->proc_net, &ipv6_route_proc_fops);
3452         proc_create("rt6_stats", S_IRUGO, net->proc_net, &rt6_stats_seq_fops);
3453 #endif
3454         return 0;
3455 }
3456
3457 static void __net_exit ip6_route_net_exit_late(struct net *net)
3458 {
3459 #ifdef CONFIG_PROC_FS
3460         remove_proc_entry("ipv6_route", net->proc_net);
3461         remove_proc_entry("rt6_stats", net->proc_net);
3462 #endif
3463 }
3464
3465 static struct pernet_operations ip6_route_net_ops = {
3466         .init = ip6_route_net_init,
3467         .exit = ip6_route_net_exit,
3468 };
3469
3470 static int __net_init ipv6_inetpeer_init(struct net *net)
3471 {
3472         struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3473
3474         if (!bp)
3475                 return -ENOMEM;
3476         inet_peer_base_init(bp);
3477         net->ipv6.peers = bp;
3478         return 0;
3479 }
3480
3481 static void __net_exit ipv6_inetpeer_exit(struct net *net)
3482 {
3483         struct inet_peer_base *bp = net->ipv6.peers;
3484
3485         net->ipv6.peers = NULL;
3486         inetpeer_invalidate_tree(bp);
3487         kfree(bp);
3488 }
3489
3490 static struct pernet_operations ipv6_inetpeer_ops = {
3491         .init   =       ipv6_inetpeer_init,
3492         .exit   =       ipv6_inetpeer_exit,
3493 };
3494
3495 static struct pernet_operations ip6_route_net_late_ops = {
3496         .init = ip6_route_net_init_late,
3497         .exit = ip6_route_net_exit_late,
3498 };
3499
3500 static struct notifier_block ip6_route_dev_notifier = {
3501         .notifier_call = ip6_route_dev_notify,
3502         .priority = 0,
3503 };
3504
3505 int __init ip6_route_init(void)
3506 {
3507         int ret;
3508         int cpu;
3509
3510         ret = -ENOMEM;
3511         ip6_dst_ops_template.kmem_cachep =
3512                 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
3513                                   SLAB_HWCACHE_ALIGN, NULL);
3514         if (!ip6_dst_ops_template.kmem_cachep)
3515                 goto out;
3516
3517         ret = dst_entries_init(&ip6_dst_blackhole_ops);
3518         if (ret)
3519                 goto out_kmem_cache;
3520
3521         ret = register_pernet_subsys(&ipv6_inetpeer_ops);
3522         if (ret)
3523                 goto out_dst_entries;
3524
3525         ret = register_pernet_subsys(&ip6_route_net_ops);
3526         if (ret)
3527                 goto out_register_inetpeer;
3528
3529         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
3530
3531         /* Registering of the loopback is done before this portion of code,
3532          * the loopback reference in rt6_info will not be taken, do it
3533          * manually for init_net */
3534         init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
3535         init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
3536   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3537         init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
3538         init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
3539         init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
3540         init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
3541   #endif
3542         ret = fib6_init();
3543         if (ret)
3544                 goto out_register_subsys;
3545
3546         ret = xfrm6_init();
3547         if (ret)
3548                 goto out_fib6_init;
3549
3550         ret = fib6_rules_init();
3551         if (ret)
3552                 goto xfrm6_init;
3553
3554         ret = register_pernet_subsys(&ip6_route_net_late_ops);
3555         if (ret)
3556                 goto fib6_rules_init;
3557
3558         ret = -ENOBUFS;
3559         if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL, NULL) ||
3560             __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL, NULL) ||
3561             __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL, NULL))
3562                 goto out_register_late_subsys;
3563
3564         ret = register_netdevice_notifier(&ip6_route_dev_notifier);
3565         if (ret)
3566                 goto out_register_late_subsys;
3567
3568         for_each_possible_cpu(cpu) {
3569                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
3570
3571                 INIT_LIST_HEAD(&ul->head);
3572                 spin_lock_init(&ul->lock);
3573         }
3574
3575 out:
3576         return ret;
3577
3578 out_register_late_subsys:
3579         unregister_pernet_subsys(&ip6_route_net_late_ops);
3580 fib6_rules_init:
3581         fib6_rules_cleanup();
3582 xfrm6_init:
3583         xfrm6_fini();
3584 out_fib6_init:
3585         fib6_gc_cleanup();
3586 out_register_subsys:
3587         unregister_pernet_subsys(&ip6_route_net_ops);
3588 out_register_inetpeer:
3589         unregister_pernet_subsys(&ipv6_inetpeer_ops);
3590 out_dst_entries:
3591         dst_entries_destroy(&ip6_dst_blackhole_ops);
3592 out_kmem_cache:
3593         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
3594         goto out;
3595 }
3596
3597 void ip6_route_cleanup(void)
3598 {
3599         unregister_netdevice_notifier(&ip6_route_dev_notifier);
3600         unregister_pernet_subsys(&ip6_route_net_late_ops);
3601         fib6_rules_cleanup();
3602         xfrm6_fini();
3603         fib6_gc_cleanup();
3604         unregister_pernet_subsys(&ipv6_inetpeer_ops);
3605         unregister_pernet_subsys(&ip6_route_net_ops);
3606         dst_entries_destroy(&ip6_dst_blackhole_ops);
3607         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
3608 }