net/ipv6/route.c

   1 /*
   2  *      Linux INET6 implementation
   3  *      FIB front-end.
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   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 #include <net/l3mdev.h>
  65 #include <trace/events/fib6.h>
  66
  67 #include <asm/uaccess.h>
  68
  69 #ifdef CONFIG_SYSCTL
  70 #include <linux/sysctl.h>
  71 #endif
  72
  73 enum rt6_nud_state {
  74         RT6_NUD_FAIL_HARD = -3,
  75         RT6_NUD_FAIL_PROBE = -2,
  76         RT6_NUD_FAIL_DO_RR = -1,
  77         RT6_NUD_SUCCEED = 1
  78 };
  79
  80 static void ip6_rt_copy_init(struct rt6_info *rt, struct rt6_info *ort);
  81 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie);
  82 static unsigned int      ip6_default_advmss(const struct dst_entry *dst);
  83 static unsigned int      ip6_mtu(const struct dst_entry *dst);
  84 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
  85 static void             ip6_dst_destroy(struct dst_entry *);
  86 static void             ip6_dst_ifdown(struct dst_entry *,
  87                                        struct net_device *dev, int how);
  88 static int               ip6_dst_gc(struct dst_ops *ops);
  89
  90 static int              ip6_pkt_discard(struct sk_buff *skb);
  91 static int              ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
  92 static int              ip6_pkt_prohibit(struct sk_buff *skb);
  93 static int              ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb);
  94 static void             ip6_link_failure(struct sk_buff *skb);
  95 static void             ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
  96                                            struct sk_buff *skb, u32 mtu);
  97 static void             rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
  98                                         struct sk_buff *skb);
  99 static void             rt6_dst_from_metrics_check(struct rt6_info *rt);
 100 static int rt6_score_route(struct rt6_info *rt, int oif, int strict);
 101
 102 #ifdef CONFIG_IPV6_ROUTE_INFO
 103 static struct rt6_info *rt6_add_route_info(struct net *net,
 104                                            const struct in6_addr *prefix, int prefixlen,
 105                                            const struct in6_addr *gwaddr, int ifindex,
 106                                            unsigned int pref);
 107 static struct rt6_info *rt6_get_route_info(struct net *net,
 108                                            const struct in6_addr *prefix, int prefixlen,
 109                                            const struct in6_addr *gwaddr, int ifindex);
 110 #endif
 111
 112 struct uncached_list {
 113         spinlock_t              lock;
 114         struct list_head        head;
 115 };
 116
 117 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
 118
 119 static void rt6_uncached_list_add(struct rt6_info *rt)
 120 {
 121         struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list);
 122
 123         rt->dst.flags |= DST_NOCACHE;
 124         rt->rt6i_uncached_list = ul;
 125
 126         spin_lock_bh(&ul->lock);
 127         list_add_tail(&rt->rt6i_uncached, &ul->head);
 128         spin_unlock_bh(&ul->lock);
 129 }
 130
 131 static void rt6_uncached_list_del(struct rt6_info *rt)
 132 {
 133         if (!list_empty(&rt->rt6i_uncached)) {
 134                 struct uncached_list *ul = rt->rt6i_uncached_list;
 135
 136                 spin_lock_bh(&ul->lock);
 137                 list_del(&rt->rt6i_uncached);
 138                 spin_unlock_bh(&ul->lock);
 139         }
 140 }
 141
 142 static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev)
 143 {
 144         struct net_device *loopback_dev = net->loopback_dev;
 145         int cpu;
 146
 147         if (dev == loopback_dev)
 148                 return;
 149
 150         for_each_possible_cpu(cpu) {
 151                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
 152                 struct rt6_info *rt;
 153
 154                 spin_lock_bh(&ul->lock);
 155                 list_for_each_entry(rt, &ul->head, rt6i_uncached) {
 156                         struct inet6_dev *rt_idev = rt->rt6i_idev;
 157                         struct net_device *rt_dev = rt->dst.dev;
 158
 159                         if (rt_idev->dev == dev) {
 160                                 rt->rt6i_idev = in6_dev_get(loopback_dev);
 161                                 in6_dev_put(rt_idev);
 162                         }
 163
 164                         if (rt_dev == dev) {
 165                                 rt->dst.dev = loopback_dev;
 166                                 dev_hold(rt->dst.dev);
 167                                 dev_put(rt_dev);
 168                         }
 169                 }
 170                 spin_unlock_bh(&ul->lock);
 171         }
 172 }
 173
 174 static u32 *rt6_pcpu_cow_metrics(struct rt6_info *rt)
 175 {
 176         return dst_metrics_write_ptr(rt->dst.from);
 177 }
 178
 179 static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old)
 180 {
 181         struct rt6_info *rt = (struct rt6_info *)dst;
 182
 183         if (rt->rt6i_flags & RTF_PCPU)
 184                 return rt6_pcpu_cow_metrics(rt);
 185         else if (rt->rt6i_flags & RTF_CACHE)
 186                 return NULL;
 187         else
 188                 return dst_cow_metrics_generic(dst, old);
 189 }
 190
 191 static inline const void *choose_neigh_daddr(struct rt6_info *rt,
 192                                              struct sk_buff *skb,
 193                                              const void *daddr)
 194 {
 195         struct in6_addr *p = &rt->rt6i_gateway;
 196
 197         if (!ipv6_addr_any(p))
 198                 return (const void *) p;
 199         else if (skb)
 200                 return &ipv6_hdr(skb)->daddr;
 201         return daddr;
 202 }
 203
 204 static struct neighbour *ip6_neigh_lookup(const struct dst_entry *dst,
 205                                           struct sk_buff *skb,
 206                                           const void *daddr)
 207 {
 208         struct rt6_info *rt = (struct rt6_info *) dst;
 209         struct neighbour *n;
 210
 211         daddr = choose_neigh_daddr(rt, skb, daddr);
 212         n = __ipv6_neigh_lookup(dst->dev, daddr);
 213         if (n)
 214                 return n;
 215         return neigh_create(&nd_tbl, daddr, dst->dev);
 216 }
 217
 218 static struct dst_ops ip6_dst_ops_template = {
 219         .family                 =       AF_INET6,
 220         .gc                     =       ip6_dst_gc,
 221         .gc_thresh              =       1024,
 222         .check                  =       ip6_dst_check,
 223         .default_advmss         =       ip6_default_advmss,
 224         .mtu                    =       ip6_mtu,
 225         .cow_metrics            =       ipv6_cow_metrics,
 226         .destroy                =       ip6_dst_destroy,
 227         .ifdown                 =       ip6_dst_ifdown,
 228         .negative_advice        =       ip6_negative_advice,
 229         .link_failure           =       ip6_link_failure,
 230         .update_pmtu            =       ip6_rt_update_pmtu,
 231         .redirect               =       rt6_do_redirect,
 232         .local_out              =       __ip6_local_out,
 233         .neigh_lookup           =       ip6_neigh_lookup,
 234 };
 235
 236 static unsigned int ip6_blackhole_mtu(const struct dst_entry *dst)
 237 {
 238         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
 239
 240         return mtu ? : dst->dev->mtu;
 241 }
 242
 243 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
 244                                          struct sk_buff *skb, u32 mtu)
 245 {
 246 }
 247
 248 static void ip6_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
 249                                       struct sk_buff *skb)
 250 {
 251 }
 252
 253 static struct dst_ops ip6_dst_blackhole_ops = {
 254         .family                 =       AF_INET6,
 255         .destroy                =       ip6_dst_destroy,
 256         .check                  =       ip6_dst_check,
 257         .mtu                    =       ip6_blackhole_mtu,
 258         .default_advmss         =       ip6_default_advmss,
 259         .update_pmtu            =       ip6_rt_blackhole_update_pmtu,
 260         .redirect               =       ip6_rt_blackhole_redirect,
 261         .cow_metrics            =       dst_cow_metrics_generic,
 262         .neigh_lookup           =       ip6_neigh_lookup,
 263 };
 264
 265 static const u32 ip6_template_metrics[RTAX_MAX] = {
 266         [RTAX_HOPLIMIT - 1] = 0,
 267 };
 268
 269 static const struct rt6_info ip6_null_entry_template = {
 270         .dst = {
 271                 .__refcnt       = ATOMIC_INIT(1),
 272                 .__use          = 1,
 273                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 274                 .error          = -ENETUNREACH,
 275                 .input          = ip6_pkt_discard,
 276                 .output         = ip6_pkt_discard_out,
 277         },
 278         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 279         .rt6i_protocol  = RTPROT_KERNEL,
 280         .rt6i_metric    = ~(u32) 0,
 281         .rt6i_ref       = ATOMIC_INIT(1),
 282 };
 283
 284 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 285
 286 static const struct rt6_info ip6_prohibit_entry_template = {
 287         .dst = {
 288                 .__refcnt       = ATOMIC_INIT(1),
 289                 .__use          = 1,
 290                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 291                 .error          = -EACCES,
 292                 .input          = ip6_pkt_prohibit,
 293                 .output         = ip6_pkt_prohibit_out,
 294         },
 295         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 296         .rt6i_protocol  = RTPROT_KERNEL,
 297         .rt6i_metric    = ~(u32) 0,
 298         .rt6i_ref       = ATOMIC_INIT(1),
 299 };
 300
 301 static const struct rt6_info ip6_blk_hole_entry_template = {
 302         .dst = {
 303                 .__refcnt       = ATOMIC_INIT(1),
 304                 .__use          = 1,
 305                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 306                 .error          = -EINVAL,
 307                 .input          = dst_discard,
 308                 .output         = dst_discard_out,
 309         },
 310         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 311         .rt6i_protocol  = RTPROT_KERNEL,
 312         .rt6i_metric    = ~(u32) 0,
 313         .rt6i_ref       = ATOMIC_INIT(1),
 314 };
 315
 316 #endif
 317
 318 static void rt6_info_init(struct rt6_info *rt)
 319 {
 320         struct dst_entry *dst = &rt->dst;
 321
 322         memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));
 323         INIT_LIST_HEAD(&rt->rt6i_siblings);
 324         INIT_LIST_HEAD(&rt->rt6i_uncached);
 325 }
 326
 327 /* allocate dst with ip6_dst_ops */
 328 static struct rt6_info *__ip6_dst_alloc(struct net *net,
 329                                         struct net_device *dev,
 330                                         int flags)
 331 {
 332         struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
 333                                         0, DST_OBSOLETE_FORCE_CHK, flags);
 334
 335         if (rt)
 336                 rt6_info_init(rt);
 337
 338         return rt;
 339 }
 340
 341 struct rt6_info *ip6_dst_alloc(struct net *net,
 342                                struct net_device *dev,
 343                                int flags)
 344 {
 345         struct rt6_info *rt = __ip6_dst_alloc(net, dev, flags);
 346
 347         if (rt) {
 348                 rt->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, GFP_ATOMIC);
 349                 if (rt->rt6i_pcpu) {
 350                         int cpu;
 351
 352                         for_each_possible_cpu(cpu) {
 353                                 struct rt6_info **p;
 354
 355                                 p = per_cpu_ptr(rt->rt6i_pcpu, cpu);
 356                                 /* no one shares rt */
 357                                 *p =  NULL;
 358                         }
 359                 } else {
 360                         dst_destroy((struct dst_entry *)rt);
 361                         return NULL;
 362                 }
 363         }
 364
 365         return rt;
 366 }
 367 EXPORT_SYMBOL(ip6_dst_alloc);
 368
 369 static void ip6_dst_destroy(struct dst_entry *dst)
 370 {
 371         struct rt6_info *rt = (struct rt6_info *)dst;
 372         struct dst_entry *from = dst->from;
 373         struct inet6_dev *idev;
 374
 375         dst_destroy_metrics_generic(dst);
 376         free_percpu(rt->rt6i_pcpu);
 377         rt6_uncached_list_del(rt);
 378
 379         idev = rt->rt6i_idev;
 380         if (idev) {
 381                 rt->rt6i_idev = NULL;
 382                 in6_dev_put(idev);
 383         }
 384
 385         dst->from = NULL;
 386         dst_release(from);
 387 }
 388
 389 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 390                            int how)
 391 {
 392         struct rt6_info *rt = (struct rt6_info *)dst;
 393         struct inet6_dev *idev = rt->rt6i_idev;
 394         struct net_device *loopback_dev =
 395                 dev_net(dev)->loopback_dev;
 396
 397         if (dev != loopback_dev) {
 398                 if (idev && idev->dev == dev) {
 399                         struct inet6_dev *loopback_idev =
 400                                 in6_dev_get(loopback_dev);
 401                         if (loopback_idev) {
 402                                 rt->rt6i_idev = loopback_idev;
 403                                 in6_dev_put(idev);
 404                         }
 405                 }
 406         }
 407 }
 408
 409 static bool __rt6_check_expired(const struct rt6_info *rt)
 410 {
 411         if (rt->rt6i_flags & RTF_EXPIRES)
 412                 return time_after(jiffies, rt->dst.expires);
 413         else
 414                 return false;
 415 }
 416
 417 static bool rt6_check_expired(const struct rt6_info *rt)
 418 {
 419         if (rt->rt6i_flags & RTF_EXPIRES) {
 420                 if (time_after(jiffies, rt->dst.expires))
 421                         return true;
 422         } else if (rt->dst.from) {
 423                 return rt6_check_expired((struct rt6_info *) rt->dst.from);
 424         }
 425         return false;
 426 }
 427
 428 /* Multipath route selection:
 429  *   Hash based function using packet header and flowlabel.
 430  * Adapted from fib_info_hashfn()
 431  */
 432 static int rt6_info_hash_nhsfn(unsigned int candidate_count,
 433                                const struct flowi6 *fl6)
 434 {
 435         return get_hash_from_flowi6(fl6) % candidate_count;
 436 }
 437
 438 static struct rt6_info *rt6_multipath_select(struct rt6_info *match,
 439                                              struct flowi6 *fl6, int oif,
 440                                              int strict)
 441 {
 442         struct rt6_info *sibling, *next_sibling;
 443         int route_choosen;
 444
 445         route_choosen = rt6_info_hash_nhsfn(match->rt6i_nsiblings + 1, fl6);
 446         /* Don't change the route, if route_choosen == 0
 447          * (siblings does not include ourself)
 448          */
 449         if (route_choosen)
 450                 list_for_each_entry_safe(sibling, next_sibling,
 451                                 &match->rt6i_siblings, rt6i_siblings) {
 452                         route_choosen--;
 453                         if (route_choosen == 0) {
 454                                 if (rt6_score_route(sibling, oif, strict) < 0)
 455                                         break;
 456                                 match = sibling;
 457                                 break;
 458                         }
 459                 }
 460         return match;
 461 }
 462
 463 /*
 464  *      Route lookup. Any table->tb6_lock is implied.
 465  */
 466
 467 static inline struct rt6_info *rt6_device_match(struct net *net,
 468                                                     struct rt6_info *rt,
 469                                                     const struct in6_addr *saddr,
 470                                                     int oif,
 471                                                     int flags)
 472 {
 473         struct rt6_info *local = NULL;
 474         struct rt6_info *sprt;
 475
 476         if (!oif && ipv6_addr_any(saddr))
 477                 goto out;
 478
 479         for (sprt = rt; sprt; sprt = sprt->dst.rt6_next) {
 480                 struct net_device *dev = sprt->dst.dev;
 481
 482                 if (oif) {
 483                         if (dev->ifindex == oif)
 484                                 return sprt;
 485                         if (dev->flags & IFF_LOOPBACK) {
 486                                 if (!sprt->rt6i_idev ||
 487                                     sprt->rt6i_idev->dev->ifindex != oif) {
 488                                         if (flags & RT6_LOOKUP_F_IFACE)
 489                                                 continue;
 490                                         if (local &&
 491                                             local->rt6i_idev->dev->ifindex == oif)
 492                                                 continue;
 493                                 }
 494                                 local = sprt;
 495                         }
 496                 } else {
 497                         if (ipv6_chk_addr(net, saddr, dev,
 498                                           flags & RT6_LOOKUP_F_IFACE))
 499                                 return sprt;
 500                 }
 501         }
 502
 503         if (oif) {
 504                 if (local)
 505                         return local;
 506
 507                 if (flags & RT6_LOOKUP_F_IFACE)
 508                         return net->ipv6.ip6_null_entry;
 509         }
 510 out:
 511         return rt;
 512 }
 513
 514 #ifdef CONFIG_IPV6_ROUTER_PREF
 515 struct __rt6_probe_work {
 516         struct work_struct work;
 517         struct in6_addr target;
 518         struct net_device *dev;
 519 };
 520
 521 static void rt6_probe_deferred(struct work_struct *w)
 522 {
 523         struct in6_addr mcaddr;
 524         struct __rt6_probe_work *work =
 525                 container_of(w, struct __rt6_probe_work, work);
 526
 527         addrconf_addr_solict_mult(&work->target, &mcaddr);
 528         ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL);
 529         dev_put(work->dev);
 530         kfree(work);
 531 }
 532
 533 static void rt6_probe(struct rt6_info *rt)
 534 {
 535         struct __rt6_probe_work *work;
 536         struct neighbour *neigh;
 537         /*
 538          * Okay, this does not seem to be appropriate
 539          * for now, however, we need to check if it
 540          * is really so; aka Router Reachability Probing.
 541          *
 542          * Router Reachability Probe MUST be rate-limited
 543          * to no more than one per minute.
 544          */
 545         if (!rt || !(rt->rt6i_flags & RTF_GATEWAY))
 546                 return;
 547         rcu_read_lock_bh();
 548         neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
 549         if (neigh) {
 550                 if (neigh->nud_state & NUD_VALID)
 551                         goto out;
 552
 553                 work = NULL;
 554                 write_lock(&neigh->lock);
 555                 if (!(neigh->nud_state & NUD_VALID) &&
 556                     time_after(jiffies,
 557                                neigh->updated +
 558                                rt->rt6i_idev->cnf.rtr_probe_interval)) {
 559                         work = kmalloc(sizeof(*work), GFP_ATOMIC);
 560                         if (work)
 561                                 __neigh_set_probe_once(neigh);
 562                 }
 563                 write_unlock(&neigh->lock);
 564         } else {
 565                 work = kmalloc(sizeof(*work), GFP_ATOMIC);
 566         }
 567
 568         if (work) {
 569                 INIT_WORK(&work->work, rt6_probe_deferred);
 570                 work->target = rt->rt6i_gateway;
 571                 dev_hold(rt->dst.dev);
 572                 work->dev = rt->dst.dev;
 573                 schedule_work(&work->work);
 574         }
 575
 576 out:
 577         rcu_read_unlock_bh();
 578 }
 579 #else
 580 static inline void rt6_probe(struct rt6_info *rt)
 581 {
 582 }
 583 #endif
 584
 585 /*
 586  * Default Router Selection (RFC 2461 6.3.6)
 587  */
 588 static inline int rt6_check_dev(struct rt6_info *rt, int oif)
 589 {
 590         struct net_device *dev = rt->dst.dev;
 591         if (!oif || dev->ifindex == oif)
 592                 return 2;
 593         if ((dev->flags & IFF_LOOPBACK) &&
 594             rt->rt6i_idev && rt->rt6i_idev->dev->ifindex == oif)
 595                 return 1;
 596         return 0;
 597 }
 598
 599 static inline enum rt6_nud_state rt6_check_neigh(struct rt6_info *rt)
 600 {
 601         struct neighbour *neigh;
 602         enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
 603
 604         if (rt->rt6i_flags & RTF_NONEXTHOP ||
 605             !(rt->rt6i_flags & RTF_GATEWAY))
 606                 return RT6_NUD_SUCCEED;
 607
 608         rcu_read_lock_bh();
 609         neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
 610         if (neigh) {
 611                 read_lock(&neigh->lock);
 612                 if (neigh->nud_state & NUD_VALID)
 613                         ret = RT6_NUD_SUCCEED;
 614 #ifdef CONFIG_IPV6_ROUTER_PREF
 615                 else if (!(neigh->nud_state & NUD_FAILED))
 616                         ret = RT6_NUD_SUCCEED;
 617                 else
 618                         ret = RT6_NUD_FAIL_PROBE;
 619 #endif
 620                 read_unlock(&neigh->lock);
 621         } else {
 622                 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
 623                       RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
 624         }
 625         rcu_read_unlock_bh();
 626
 627         return ret;
 628 }
 629
 630 static int rt6_score_route(struct rt6_info *rt, int oif,
 631                            int strict)
 632 {
 633         int m;
 634
 635         m = rt6_check_dev(rt, oif);
 636         if (!m && (strict & RT6_LOOKUP_F_IFACE))
 637                 return RT6_NUD_FAIL_HARD;
 638 #ifdef CONFIG_IPV6_ROUTER_PREF
 639         m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2;
 640 #endif
 641         if (strict & RT6_LOOKUP_F_REACHABLE) {
 642                 int n = rt6_check_neigh(rt);
 643                 if (n < 0)
 644                         return n;
 645         }
 646         return m;
 647 }
 648
 649 static struct rt6_info *find_match(struct rt6_info *rt, int oif, int strict,
 650                                    int *mpri, struct rt6_info *match,
 651                                    bool *do_rr)
 652 {
 653         int m;
 654         bool match_do_rr = false;
 655         struct inet6_dev *idev = rt->rt6i_idev;
 656         struct net_device *dev = rt->dst.dev;
 657
 658         if (dev && !netif_carrier_ok(dev) &&
 659             idev->cnf.ignore_routes_with_linkdown)
 660                 goto out;
 661
 662         if (rt6_check_expired(rt))
 663                 goto out;
 664
 665         m = rt6_score_route(rt, oif, strict);
 666         if (m == RT6_NUD_FAIL_DO_RR) {
 667                 match_do_rr = true;
 668                 m = 0; /* lowest valid score */
 669         } else if (m == RT6_NUD_FAIL_HARD) {
 670                 goto out;
 671         }
 672
 673         if (strict & RT6_LOOKUP_F_REACHABLE)
 674                 rt6_probe(rt);
 675
 676         /* note that m can be RT6_NUD_FAIL_PROBE at this point */
 677         if (m > *mpri) {
 678                 *do_rr = match_do_rr;
 679                 *mpri = m;
 680                 match = rt;
 681         }
 682 out:
 683         return match;
 684 }
 685
 686 static struct rt6_info *find_rr_leaf(struct fib6_node *fn,
 687                                      struct rt6_info *rr_head,
 688                                      u32 metric, int oif, int strict,
 689                                      bool *do_rr)
 690 {
 691         struct rt6_info *rt, *match, *cont;
 692         int mpri = -1;
 693
 694         match = NULL;
 695         cont = NULL;
 696         for (rt = rr_head; rt; rt = rt->dst.rt6_next) {
 697                 if (rt->rt6i_metric != metric) {
 698                         cont = rt;
 699                         break;
 700                 }
 701
 702                 match = find_match(rt, oif, strict, &mpri, match, do_rr);
 703         }
 704
 705         for (rt = fn->leaf; rt && rt != rr_head; rt = rt->dst.rt6_next) {
 706                 if (rt->rt6i_metric != metric) {
 707                         cont = rt;
 708                         break;
 709                 }
 710
 711                 match = find_match(rt, oif, strict, &mpri, match, do_rr);
 712         }
 713
 714         if (match || !cont)
 715                 return match;
 716
 717         for (rt = cont; rt; rt = rt->dst.rt6_next)
 718                 match = find_match(rt, oif, strict, &mpri, match, do_rr);
 719
 720         return match;
 721 }
 722
 723 static struct rt6_info *rt6_select(struct fib6_node *fn, int oif, int strict)
 724 {
 725         struct rt6_info *match, *rt0;
 726         struct net *net;
 727         bool do_rr = false;
 728
 729         rt0 = fn->rr_ptr;
 730         if (!rt0)
 731                 fn->rr_ptr = rt0 = fn->leaf;
 732
 733         match = find_rr_leaf(fn, rt0, rt0->rt6i_metric, oif, strict,
 734                              &do_rr);
 735
 736         if (do_rr) {
 737                 struct rt6_info *next = rt0->dst.rt6_next;
 738
 739                 /* no entries matched; do round-robin */
 740                 if (!next || next->rt6i_metric != rt0->rt6i_metric)
 741                         next = fn->leaf;
 742
 743                 if (next != rt0)
 744                         fn->rr_ptr = next;
 745         }
 746
 747         net = dev_net(rt0->dst.dev);
 748         return match ? match : net->ipv6.ip6_null_entry;
 749 }
 750
 751 static bool rt6_is_gw_or_nonexthop(const struct rt6_info *rt)
 752 {
 753         return (rt->rt6i_flags & (RTF_NONEXTHOP | RTF_GATEWAY));
 754 }
 755
 756 #ifdef CONFIG_IPV6_ROUTE_INFO
 757 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 758                   const struct in6_addr *gwaddr)
 759 {
 760         struct net *net = dev_net(dev);
 761         struct route_info *rinfo = (struct route_info *) opt;
 762         struct in6_addr prefix_buf, *prefix;
 763         unsigned int pref;
 764         unsigned long lifetime;
 765         struct rt6_info *rt;
 766
 767         if (len < sizeof(struct route_info)) {
 768                 return -EINVAL;
 769         }
 770
 771         /* Sanity check for prefix_len and length */
 772         if (rinfo->length > 3) {
 773                 return -EINVAL;
 774         } else if (rinfo->prefix_len > 128) {
 775                 return -EINVAL;
 776         } else if (rinfo->prefix_len > 64) {
 777                 if (rinfo->length < 2) {
 778                         return -EINVAL;
 779                 }
 780         } else if (rinfo->prefix_len > 0) {
 781                 if (rinfo->length < 1) {
 782                         return -EINVAL;
 783                 }
 784         }
 785
 786         pref = rinfo->route_pref;
 787         if (pref == ICMPV6_ROUTER_PREF_INVALID)
 788                 return -EINVAL;
 789
 790         lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
 791
 792         if (rinfo->length == 3)
 793                 prefix = (struct in6_addr *)rinfo->prefix;
 794         else {
 795                 /* this function is safe */
 796                 ipv6_addr_prefix(&prefix_buf,
 797                                  (struct in6_addr *)rinfo->prefix,
 798                                  rinfo->prefix_len);
 799                 prefix = &prefix_buf;
 800         }
 801
 802         if (rinfo->prefix_len == 0)
 803                 rt = rt6_get_dflt_router(gwaddr, dev);
 804         else
 805                 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
 806                                         gwaddr, dev->ifindex);
 807
 808         if (rt && !lifetime) {
 809                 ip6_del_rt(rt);
 810                 rt = NULL;
 811         }
 812
 813         if (!rt && lifetime)
 814                 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr, dev->ifindex,
 815                                         pref);
 816         else if (rt)
 817                 rt->rt6i_flags = RTF_ROUTEINFO |
 818                                  (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 819
 820         if (rt) {
 821                 if (!addrconf_finite_timeout(lifetime))
 822                         rt6_clean_expires(rt);
 823                 else
 824                         rt6_set_expires(rt, jiffies + HZ * lifetime);
 825
 826                 ip6_rt_put(rt);
 827         }
 828         return 0;
 829 }
 830 #endif
 831
 832 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
 833                                         struct in6_addr *saddr)
 834 {
 835         struct fib6_node *pn;
 836         while (1) {
 837                 if (fn->fn_flags & RTN_TL_ROOT)
 838                         return NULL;
 839                 pn = fn->parent;
 840                 if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn)
 841                         fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr);
 842                 else
 843                         fn = pn;
 844                 if (fn->fn_flags & RTN_RTINFO)
 845                         return fn;
 846         }
 847 }
 848
 849 static struct rt6_info *ip6_pol_route_lookup(struct net *net,
 850                                              struct fib6_table *table,
 851                                              struct flowi6 *fl6, int flags)
 852 {
 853         struct fib6_node *fn;
 854         struct rt6_info *rt;
 855
 856         read_lock_bh(&table->tb6_lock);
 857         fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
 858 restart:
 859         rt = fn->leaf;
 860         rt = rt6_device_match(net, rt, &fl6->saddr, fl6->flowi6_oif, flags);
 861         if (rt->rt6i_nsiblings && fl6->flowi6_oif == 0)
 862                 rt = rt6_multipath_select(rt, fl6, fl6->flowi6_oif, flags);
 863         if (rt == net->ipv6.ip6_null_entry) {
 864                 fn = fib6_backtrack(fn, &fl6->saddr);
 865                 if (fn)
 866                         goto restart;
 867         }
 868         dst_use(&rt->dst, jiffies);
 869         read_unlock_bh(&table->tb6_lock);
 870
 871         trace_fib6_table_lookup(net, rt, table->tb6_id, fl6);
 872
 873         return rt;
 874
 875 }
 876
 877 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
 878                                     int flags)
 879 {
 880         return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_lookup);
 881 }
 882 EXPORT_SYMBOL_GPL(ip6_route_lookup);
 883
 884 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
 885                             const struct in6_addr *saddr, int oif, int strict)
 886 {
 887         struct flowi6 fl6 = {
 888                 .flowi6_oif = oif,
 889                 .daddr = *daddr,
 890         };
 891         struct dst_entry *dst;
 892         int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
 893
 894         if (saddr) {
 895                 memcpy(&fl6.saddr, saddr, sizeof(*saddr));
 896                 flags |= RT6_LOOKUP_F_HAS_SADDR;
 897         }
 898
 899         dst = fib6_rule_lookup(net, &fl6, flags, ip6_pol_route_lookup);
 900         if (dst->error == 0)
 901                 return (struct rt6_info *) dst;
 902
 903         dst_release(dst);
 904
 905         return NULL;
 906 }
 907 EXPORT_SYMBOL(rt6_lookup);
 908
 909 /* ip6_ins_rt is called with FREE table->tb6_lock.
 910    It takes new route entry, the addition fails by any reason the
 911    route is freed. In any case, if caller does not hold it, it may
 912    be destroyed.
 913  */
 914
 915 static int __ip6_ins_rt(struct rt6_info *rt, struct nl_info *info,
 916                         struct mx6_config *mxc)
 917 {
 918         int err;
 919         struct fib6_table *table;
 920
 921         table = rt->rt6i_table;
 922         write_lock_bh(&table->tb6_lock);
 923         err = fib6_add(&table->tb6_root, rt, info, mxc);
 924         write_unlock_bh(&table->tb6_lock);
 925
 926         return err;
 927 }
 928
 929 int ip6_ins_rt(struct rt6_info *rt)
 930 {
 931         struct nl_info info = { .nl_net = dev_net(rt->dst.dev), };
 932         struct mx6_config mxc = { .mx = NULL, };
 933
 934         return __ip6_ins_rt(rt, &info, &mxc);
 935 }
 936
 937 static struct rt6_info *ip6_rt_cache_alloc(struct rt6_info *ort,
 938                                            const struct in6_addr *daddr,
 939                                            const struct in6_addr *saddr)
 940 {
 941         struct rt6_info *rt;
 942
 943         /*
 944          *      Clone the route.
 945          */
 946
 947         if (ort->rt6i_flags & (RTF_CACHE | RTF_PCPU))
 948                 ort = (struct rt6_info *)ort->dst.from;
 949
 950         rt = __ip6_dst_alloc(dev_net(ort->dst.dev), ort->dst.dev, 0);
 951
 952         if (!rt)
 953                 return NULL;
 954
 955         ip6_rt_copy_init(rt, ort);
 956         rt->rt6i_flags |= RTF_CACHE;
 957         rt->rt6i_metric = 0;
 958         rt->dst.flags |= DST_HOST;
 959         rt->rt6i_dst.addr = *daddr;
 960         rt->rt6i_dst.plen = 128;
 961
 962         if (!rt6_is_gw_or_nonexthop(ort)) {
 963                 if (ort->rt6i_dst.plen != 128 &&
 964                     ipv6_addr_equal(&ort->rt6i_dst.addr, daddr))
 965                         rt->rt6i_flags |= RTF_ANYCAST;
 966 #ifdef CONFIG_IPV6_SUBTREES
 967                 if (rt->rt6i_src.plen && saddr) {
 968                         rt->rt6i_src.addr = *saddr;
 969                         rt->rt6i_src.plen = 128;
 970                 }
 971 #endif
 972         }
 973
 974         return rt;
 975 }
 976
 977 static struct rt6_info *ip6_rt_pcpu_alloc(struct rt6_info *rt)
 978 {
 979         struct rt6_info *pcpu_rt;
 980
 981         pcpu_rt = __ip6_dst_alloc(dev_net(rt->dst.dev),
 982                                   rt->dst.dev, rt->dst.flags);
 983
 984         if (!pcpu_rt)
 985                 return NULL;
 986         ip6_rt_copy_init(pcpu_rt, rt);
 987         pcpu_rt->rt6i_protocol = rt->rt6i_protocol;
 988         pcpu_rt->rt6i_flags |= RTF_PCPU;
 989         return pcpu_rt;
 990 }
 991
 992 /* It should be called with read_lock_bh(&tb6_lock) acquired */
 993 static struct rt6_info *rt6_get_pcpu_route(struct rt6_info *rt)
 994 {
 995         struct rt6_info *pcpu_rt, **p;
 996
 997         p = this_cpu_ptr(rt->rt6i_pcpu);
 998         pcpu_rt = *p;
 999
1000         if (pcpu_rt) {
1001                 dst_hold(&pcpu_rt->dst);
1002                 rt6_dst_from_metrics_check(pcpu_rt);
1003         }
1004         return pcpu_rt;
1005 }
1006
1007 static struct rt6_info *rt6_make_pcpu_route(struct rt6_info *rt)
1008 {
1009         struct fib6_table *table = rt->rt6i_table;
1010         struct rt6_info *pcpu_rt, *prev, **p;
1011
1012         pcpu_rt = ip6_rt_pcpu_alloc(rt);
1013         if (!pcpu_rt) {
1014                 struct net *net = dev_net(rt->dst.dev);
1015
1016                 dst_hold(&net->ipv6.ip6_null_entry->dst);
1017                 return net->ipv6.ip6_null_entry;
1018         }
1019
1020         read_lock_bh(&table->tb6_lock);
1021         if (rt->rt6i_pcpu) {
1022                 p = this_cpu_ptr(rt->rt6i_pcpu);
1023                 prev = cmpxchg(p, NULL, pcpu_rt);
1024                 if (prev) {
1025                         /* If someone did it before us, return prev instead */
1026                         dst_destroy(&pcpu_rt->dst);
1027                         pcpu_rt = prev;
1028                 }
1029         } else {
1030                 /* rt has been removed from the fib6 tree
1031                  * before we have a chance to acquire the read_lock.
1032                  * In this case, don't brother to create a pcpu rt
1033                  * since rt is going away anyway.  The next
1034                  * dst_check() will trigger a re-lookup.
1035                  */
1036                 dst_destroy(&pcpu_rt->dst);
1037                 pcpu_rt = rt;
1038         }
1039         dst_hold(&pcpu_rt->dst);
1040         rt6_dst_from_metrics_check(pcpu_rt);
1041         read_unlock_bh(&table->tb6_lock);
1042         return pcpu_rt;
1043 }
1044
1045 static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, int oif,
1046                                       struct flowi6 *fl6, int flags)
1047 {
1048         struct fib6_node *fn, *saved_fn;
1049         struct rt6_info *rt;
1050         int strict = 0;
1051
1052         strict |= flags & RT6_LOOKUP_F_IFACE;
1053         if (net->ipv6.devconf_all->forwarding == 0)
1054                 strict |= RT6_LOOKUP_F_REACHABLE;
1055
1056         read_lock_bh(&table->tb6_lock);
1057
1058         fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1059         saved_fn = fn;
1060
1061         if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
1062                 oif = 0;
1063
1064 redo_rt6_select:
1065         rt = rt6_select(fn, oif, strict);
1066         if (rt->rt6i_nsiblings)
1067                 rt = rt6_multipath_select(rt, fl6, oif, strict);
1068         if (rt == net->ipv6.ip6_null_entry) {
1069                 fn = fib6_backtrack(fn, &fl6->saddr);
1070                 if (fn)
1071                         goto redo_rt6_select;
1072                 else if (strict & RT6_LOOKUP_F_REACHABLE) {
1073                         /* also consider unreachable route */
1074                         strict &= ~RT6_LOOKUP_F_REACHABLE;
1075                         fn = saved_fn;
1076                         goto redo_rt6_select;
1077                 }
1078         }
1079
1080
1081         if (rt == net->ipv6.ip6_null_entry || (rt->rt6i_flags & RTF_CACHE)) {
1082                 dst_use(&rt->dst, jiffies);
1083                 read_unlock_bh(&table->tb6_lock);
1084
1085                 rt6_dst_from_metrics_check(rt);
1086
1087                 trace_fib6_table_lookup(net, rt, table->tb6_id, fl6);
1088                 return rt;
1089         } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
1090                             !(rt->rt6i_flags & RTF_GATEWAY))) {
1091                 /* Create a RTF_CACHE clone which will not be
1092                  * owned by the fib6 tree.  It is for the special case where
1093                  * the daddr in the skb during the neighbor look-up is different
1094                  * from the fl6->daddr used to look-up route here.
1095                  */
1096
1097                 struct rt6_info *uncached_rt;
1098
1099                 dst_use(&rt->dst, jiffies);
1100                 read_unlock_bh(&table->tb6_lock);
1101
1102                 uncached_rt = ip6_rt_cache_alloc(rt, &fl6->daddr, NULL);
1103                 dst_release(&rt->dst);
1104
1105                 if (uncached_rt)
1106                         rt6_uncached_list_add(uncached_rt);
1107                 else
1108                         uncached_rt = net->ipv6.ip6_null_entry;
1109
1110                 dst_hold(&uncached_rt->dst);
1111
1112                 trace_fib6_table_lookup(net, uncached_rt, table->tb6_id, fl6);
1113                 return uncached_rt;
1114
1115         } else {
1116                 /* Get a percpu copy */
1117
1118                 struct rt6_info *pcpu_rt;
1119
1120                 rt->dst.lastuse = jiffies;
1121                 rt->dst.__use++;
1122                 pcpu_rt = rt6_get_pcpu_route(rt);
1123
1124                 if (pcpu_rt) {
1125                         read_unlock_bh(&table->tb6_lock);
1126                 } else {
1127                         /* We have to do the read_unlock first
1128                          * because rt6_make_pcpu_route() may trigger
1129                          * ip6_dst_gc() which will take the write_lock.
1130                          */
1131                         dst_hold(&rt->dst);
1132                         read_unlock_bh(&table->tb6_lock);
1133                         pcpu_rt = rt6_make_pcpu_route(rt);
1134                         dst_release(&rt->dst);
1135                 }
1136
1137                 trace_fib6_table_lookup(net, pcpu_rt, table->tb6_id, fl6);
1138                 return pcpu_rt;
1139
1140         }
1141 }
1142
1143 static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *table,
1144                                             struct flowi6 *fl6, int flags)
1145 {
1146         return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, flags);
1147 }
1148
1149 static struct dst_entry *ip6_route_input_lookup(struct net *net,
1150                                                 struct net_device *dev,
1151                                                 struct flowi6 *fl6, int flags)
1152 {
1153         if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
1154                 flags |= RT6_LOOKUP_F_IFACE;
1155
1156         return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_input);
1157 }
1158
1159 void ip6_route_input(struct sk_buff *skb)
1160 {
1161         const struct ipv6hdr *iph = ipv6_hdr(skb);
1162         struct net *net = dev_net(skb->dev);
1163         int flags = RT6_LOOKUP_F_HAS_SADDR;
1164         struct ip_tunnel_info *tun_info;
1165         struct flowi6 fl6 = {
1166                 .flowi6_iif = l3mdev_fib_oif(skb->dev),
1167                 .daddr = iph->daddr,
1168                 .saddr = iph->saddr,
1169                 .flowlabel = ip6_flowinfo(iph),
1170                 .flowi6_mark = skb->mark,
1171                 .flowi6_proto = iph->nexthdr,
1172         };
1173
1174         tun_info = skb_tunnel_info(skb);
1175         if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1176                 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
1177         skb_dst_drop(skb);
1178         skb_dst_set(skb, ip6_route_input_lookup(net, skb->dev, &fl6, flags));
1179 }
1180
1181 static struct rt6_info *ip6_pol_route_output(struct net *net, struct fib6_table *table,
1182                                              struct flowi6 *fl6, int flags)
1183 {
1184         return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, flags);
1185 }
1186
1187 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
1188                                          struct flowi6 *fl6, int flags)
1189 {
1190         struct dst_entry *dst;
1191         bool any_src;
1192
1193         dst = l3mdev_rt6_dst_by_oif(net, fl6);
1194         if (dst)
1195                 return dst;
1196
1197         fl6->flowi6_iif = LOOPBACK_IFINDEX;
1198
1199         any_src = ipv6_addr_any(&fl6->saddr);
1200         if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
1201             (fl6->flowi6_oif && any_src))
1202                 flags |= RT6_LOOKUP_F_IFACE;
1203
1204         if (!any_src)
1205                 flags |= RT6_LOOKUP_F_HAS_SADDR;
1206         else if (sk)
1207                 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
1208
1209         return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_output);
1210 }
1211 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
1212
1213 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
1214 {
1215         struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
1216         struct dst_entry *new = NULL;
1217
1218         rt = dst_alloc(&ip6_dst_blackhole_ops, ort->dst.dev, 1, DST_OBSOLETE_NONE, 0);
1219         if (rt) {
1220                 rt6_info_init(rt);
1221
1222                 new = &rt->dst;
1223                 new->__use = 1;
1224                 new->input = dst_discard;
1225                 new->output = dst_discard_out;
1226
1227                 dst_copy_metrics(new, &ort->dst);
1228                 rt->rt6i_idev = ort->rt6i_idev;
1229                 if (rt->rt6i_idev)
1230                         in6_dev_hold(rt->rt6i_idev);
1231
1232                 rt->rt6i_gateway = ort->rt6i_gateway;
1233                 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
1234                 rt->rt6i_metric = 0;
1235
1236                 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
1237 #ifdef CONFIG_IPV6_SUBTREES
1238                 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
1239 #endif
1240
1241                 dst_free(new);
1242         }
1243
1244         dst_release(dst_orig);
1245         return new ? new : ERR_PTR(-ENOMEM);
1246 }
1247
1248 /*
1249  *      Destination cache support functions
1250  */
1251
1252 static void rt6_dst_from_metrics_check(struct rt6_info *rt)
1253 {
1254         if (rt->dst.from &&
1255             dst_metrics_ptr(&rt->dst) != dst_metrics_ptr(rt->dst.from))
1256                 dst_init_metrics(&rt->dst, dst_metrics_ptr(rt->dst.from), true);
1257 }
1258
1259 static struct dst_entry *rt6_check(struct rt6_info *rt, u32 cookie)
1260 {
1261         if (!rt->rt6i_node || (rt->rt6i_node->fn_sernum != cookie))
1262                 return NULL;
1263
1264         if (rt6_check_expired(rt))
1265                 return NULL;
1266
1267         return &rt->dst;
1268 }
1269
1270 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt, u32 cookie)
1271 {
1272         if (!__rt6_check_expired(rt) &&
1273             rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1274             rt6_check((struct rt6_info *)(rt->dst.from), cookie))
1275                 return &rt->dst;
1276         else
1277                 return NULL;
1278 }
1279
1280 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
1281 {
1282         struct rt6_info *rt;
1283
1284         rt = (struct rt6_info *) dst;
1285
1286         /* All IPV6 dsts are created with ->obsolete set to the value
1287          * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1288          * into this function always.
1289          */
1290
1291         rt6_dst_from_metrics_check(rt);
1292
1293         if (rt->rt6i_flags & RTF_PCPU ||
1294             (unlikely(dst->flags & DST_NOCACHE) && rt->dst.from))
1295                 return rt6_dst_from_check(rt, cookie);
1296         else
1297                 return rt6_check(rt, cookie);
1298 }
1299
1300 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
1301 {
1302         struct rt6_info *rt = (struct rt6_info *) dst;
1303
1304         if (rt) {
1305                 if (rt->rt6i_flags & RTF_CACHE) {
1306                         if (rt6_check_expired(rt)) {
1307                                 ip6_del_rt(rt);
1308                                 dst = NULL;
1309                         }
1310                 } else {
1311                         dst_release(dst);
1312                         dst = NULL;
1313                 }
1314         }
1315         return dst;
1316 }
1317
1318 static void ip6_link_failure(struct sk_buff *skb)
1319 {
1320         struct rt6_info *rt;
1321
1322         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
1323
1324         rt = (struct rt6_info *) skb_dst(skb);
1325         if (rt) {
1326                 if (rt->rt6i_flags & RTF_CACHE) {
1327                         dst_hold(&rt->dst);
1328                         ip6_del_rt(rt);
1329                 } else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT)) {
1330                         rt->rt6i_node->fn_sernum = -1;
1331                 }
1332         }
1333 }
1334
1335 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
1336 {
1337         struct net *net = dev_net(rt->dst.dev);
1338
1339         rt->rt6i_flags |= RTF_MODIFIED;
1340         rt->rt6i_pmtu = mtu;
1341         rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
1342 }
1343
1344 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
1345 {
1346         return !(rt->rt6i_flags & RTF_CACHE) &&
1347                 (rt->rt6i_flags & RTF_PCPU || rt->rt6i_node);
1348 }
1349
1350 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
1351                                  const struct ipv6hdr *iph, u32 mtu)
1352 {
1353         struct rt6_info *rt6 = (struct rt6_info *)dst;
1354
1355         if (rt6->rt6i_flags & RTF_LOCAL)
1356                 return;
1357
1358         dst_confirm(dst);
1359         mtu = max_t(u32, mtu, IPV6_MIN_MTU);
1360         if (mtu >= dst_mtu(dst))
1361                 return;
1362
1363         if (!rt6_cache_allowed_for_pmtu(rt6)) {
1364                 rt6_do_update_pmtu(rt6, mtu);
1365         } else {
1366                 const struct in6_addr *daddr, *saddr;
1367                 struct rt6_info *nrt6;
1368
1369                 if (iph) {
1370                         daddr = &iph->daddr;
1371                         saddr = &iph->saddr;
1372                 } else if (sk) {
1373                         daddr = &sk->sk_v6_daddr;
1374                         saddr = &inet6_sk(sk)->saddr;
1375                 } else {
1376                         return;
1377                 }
1378                 nrt6 = ip6_rt_cache_alloc(rt6, daddr, saddr);
1379                 if (nrt6) {
1380                         rt6_do_update_pmtu(nrt6, mtu);
1381
1382                         /* ip6_ins_rt(nrt6) will bump the
1383                          * rt6->rt6i_node->fn_sernum
1384                          * which will fail the next rt6_check() and
1385                          * invalidate the sk->sk_dst_cache.
1386                          */
1387                         ip6_ins_rt(nrt6);
1388                 }
1389         }
1390 }
1391
1392 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1393                                struct sk_buff *skb, u32 mtu)
1394 {
1395         __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu);
1396 }
1397
1398 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
1399                      int oif, u32 mark)
1400 {
1401         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
1402         struct dst_entry *dst;
1403         struct flowi6 fl6;
1404
1405         memset(&fl6, 0, sizeof(fl6));
1406         fl6.flowi6_oif = oif;
1407         fl6.flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark);
1408         fl6.daddr = iph->daddr;
1409         fl6.saddr = iph->saddr;
1410         fl6.flowlabel = ip6_flowinfo(iph);
1411
1412         dst = ip6_route_output(net, NULL, &fl6);
1413         if (!dst->error)
1414                 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu));
1415         dst_release(dst);
1416 }
1417 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
1418
1419 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
1420 {
1421         struct dst_entry *dst;
1422
1423         ip6_update_pmtu(skb, sock_net(sk), mtu,
1424                         sk->sk_bound_dev_if, sk->sk_mark);
1425
1426         dst = __sk_dst_get(sk);
1427         if (!dst || !dst->obsolete ||
1428             dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
1429                 return;
1430
1431         bh_lock_sock(sk);
1432         if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
1433                 ip6_datagram_dst_update(sk, false);
1434         bh_unlock_sock(sk);
1435 }
1436 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
1437
1438 /* Handle redirects */
1439 struct ip6rd_flowi {
1440         struct flowi6 fl6;
1441         struct in6_addr gateway;
1442 };
1443
1444 static struct rt6_info *__ip6_route_redirect(struct net *net,
1445                                              struct fib6_table *table,
1446                                              struct flowi6 *fl6,
1447                                              int flags)
1448 {
1449         struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
1450         struct rt6_info *rt;
1451         struct fib6_node *fn;
1452
1453         /* Get the "current" route for this destination and
1454          * check if the redirect has come from approriate router.
1455          *
1456          * RFC 4861 specifies that redirects should only be
1457          * accepted if they come from the nexthop to the target.
1458          * Due to the way the routes are chosen, this notion
1459          * is a bit fuzzy and one might need to check all possible
1460          * routes.
1461          */
1462
1463         read_lock_bh(&table->tb6_lock);
1464         fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1465 restart:
1466         for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
1467                 if (rt6_check_expired(rt))
1468                         continue;
1469                 if (rt->dst.error)
1470                         break;
1471                 if (!(rt->rt6i_flags & RTF_GATEWAY))
1472                         continue;
1473                 if (fl6->flowi6_oif != rt->dst.dev->ifindex)
1474                         continue;
1475                 if (!ipv6_addr_equal(&rdfl->gateway, &rt->rt6i_gateway))
1476                         continue;
1477                 break;
1478         }
1479
1480         if (!rt)
1481                 rt = net->ipv6.ip6_null_entry;
1482         else if (rt->dst.error) {
1483                 rt = net->ipv6.ip6_null_entry;
1484                 goto out;
1485         }
1486
1487         if (rt == net->ipv6.ip6_null_entry) {
1488                 fn = fib6_backtrack(fn, &fl6->saddr);
1489                 if (fn)
1490                         goto restart;
1491         }
1492
1493 out:
1494         dst_hold(&rt->dst);
1495
1496         read_unlock_bh(&table->tb6_lock);
1497
1498         trace_fib6_table_lookup(net, rt, table->tb6_id, fl6);
1499         return rt;
1500 };
1501
1502 static struct dst_entry *ip6_route_redirect(struct net *net,
1503                                         const struct flowi6 *fl6,
1504                                         const struct in6_addr *gateway)
1505 {
1506         int flags = RT6_LOOKUP_F_HAS_SADDR;
1507         struct ip6rd_flowi rdfl;
1508
1509         rdfl.fl6 = *fl6;
1510         rdfl.gateway = *gateway;
1511
1512         return fib6_rule_lookup(net, &rdfl.fl6,
1513                                 flags, __ip6_route_redirect);
1514 }
1515
1516 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark)
1517 {
1518         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
1519         struct dst_entry *dst;
1520         struct flowi6 fl6;
1521
1522         memset(&fl6, 0, sizeof(fl6));
1523         fl6.flowi6_iif = LOOPBACK_IFINDEX;
1524         fl6.flowi6_oif = oif;
1525         fl6.flowi6_mark = mark;
1526         fl6.daddr = iph->daddr;
1527         fl6.saddr = iph->saddr;
1528         fl6.flowlabel = ip6_flowinfo(iph);
1529
1530         dst = ip6_route_redirect(net, &fl6, &ipv6_hdr(skb)->saddr);
1531         rt6_do_redirect(dst, NULL, skb);
1532         dst_release(dst);
1533 }
1534 EXPORT_SYMBOL_GPL(ip6_redirect);
1535
1536 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif,
1537                             u32 mark)
1538 {
1539         const struct ipv6hdr *iph = ipv6_hdr(skb);
1540         const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
1541         struct dst_entry *dst;
1542         struct flowi6 fl6;
1543
1544         memset(&fl6, 0, sizeof(fl6));
1545         fl6.flowi6_iif = LOOPBACK_IFINDEX;
1546         fl6.flowi6_oif = oif;
1547         fl6.flowi6_mark = mark;
1548         fl6.daddr = msg->dest;
1549         fl6.saddr = iph->daddr;
1550
1551         dst = ip6_route_redirect(net, &fl6, &iph->saddr);
1552         rt6_do_redirect(dst, NULL, skb);
1553         dst_release(dst);
1554 }
1555
1556 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
1557 {
1558         ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark);
1559 }
1560 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
1561
1562 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
1563 {
1564         struct net_device *dev = dst->dev;
1565         unsigned int mtu = dst_mtu(dst);
1566         struct net *net = dev_net(dev);
1567
1568         mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
1569
1570         if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
1571                 mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
1572
1573         /*
1574          * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
1575          * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
1576          * IPV6_MAXPLEN is also valid and means: "any MSS,
1577          * rely only on pmtu discovery"
1578          */
1579         if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
1580                 mtu = IPV6_MAXPLEN;
1581         return mtu;
1582 }
1583
1584 static unsigned int ip6_mtu(const struct dst_entry *dst)
1585 {
1586         const struct rt6_info *rt = (const struct rt6_info *)dst;
1587         unsigned int mtu = rt->rt6i_pmtu;
1588         struct inet6_dev *idev;
1589
1590         if (mtu)
1591                 goto out;
1592
1593         mtu = dst_metric_raw(dst, RTAX_MTU);
1594         if (mtu)
1595                 goto out;
1596
1597         mtu = IPV6_MIN_MTU;
1598
1599         rcu_read_lock();
1600         idev = __in6_dev_get(dst->dev);
1601         if (idev)
1602                 mtu = idev->cnf.mtu6;
1603         rcu_read_unlock();
1604
1605 out:
1606         return min_t(unsigned int, mtu, IP6_MAX_MTU);
1607 }
1608
1609 static struct dst_entry *icmp6_dst_gc_list;
1610 static DEFINE_SPINLOCK(icmp6_dst_lock);
1611
1612 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
1613                                   struct flowi6 *fl6)
1614 {
1615         struct dst_entry *dst;
1616         struct rt6_info *rt;
1617         struct inet6_dev *idev = in6_dev_get(dev);
1618         struct net *net = dev_net(dev);
1619
1620         if (unlikely(!idev))
1621                 return ERR_PTR(-ENODEV);
1622
1623         rt = ip6_dst_alloc(net, dev, 0);
1624         if (unlikely(!rt)) {
1625                 in6_dev_put(idev);
1626                 dst = ERR_PTR(-ENOMEM);
1627                 goto out;
1628         }
1629
1630         rt->dst.flags |= DST_HOST;
1631         rt->dst.output  = ip6_output;
1632         atomic_set(&rt->dst.__refcnt, 1);
1633         rt->rt6i_gateway  = fl6->daddr;
1634         rt->rt6i_dst.addr = fl6->daddr;
1635         rt->rt6i_dst.plen = 128;
1636         rt->rt6i_idev     = idev;
1637         dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
1638
1639         spin_lock_bh(&icmp6_dst_lock);
1640         rt->dst.next = icmp6_dst_gc_list;
1641         icmp6_dst_gc_list = &rt->dst;
1642         spin_unlock_bh(&icmp6_dst_lock);
1643
1644         fib6_force_start_gc(net);
1645
1646         dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
1647
1648 out:
1649         return dst;
1650 }
1651
1652 int icmp6_dst_gc(void)
1653 {
1654         struct dst_entry *dst, **pprev;
1655         int more = 0;
1656
1657         spin_lock_bh(&icmp6_dst_lock);
1658         pprev = &icmp6_dst_gc_list;
1659
1660         while ((dst = *pprev) != NULL) {
1661                 if (!atomic_read(&dst->__refcnt)) {
1662                         *pprev = dst->next;
1663                         dst_free(dst);
1664                 } else {
1665                         pprev = &dst->next;
1666                         ++more;
1667                 }
1668         }
1669
1670         spin_unlock_bh(&icmp6_dst_lock);
1671
1672         return more;
1673 }
1674
1675 static void icmp6_clean_all(int (*func)(struct rt6_info *rt, void *arg),
1676                             void *arg)
1677 {
1678         struct dst_entry *dst, **pprev;
1679
1680         spin_lock_bh(&icmp6_dst_lock);
1681         pprev = &icmp6_dst_gc_list;
1682         while ((dst = *pprev) != NULL) {
1683                 struct rt6_info *rt = (struct rt6_info *) dst;
1684                 if (func(rt, arg)) {
1685                         *pprev = dst->next;
1686                         dst_free(dst);
1687                 } else {
1688                         pprev = &dst->next;
1689                 }
1690         }
1691         spin_unlock_bh(&icmp6_dst_lock);
1692 }
1693
1694 static int ip6_dst_gc(struct dst_ops *ops)
1695 {
1696         struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
1697         int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
1698         int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
1699         int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
1700         int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
1701         unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
1702         int entries;
1703
1704         entries = dst_entries_get_fast(ops);
1705         if (time_after(rt_last_gc + rt_min_interval, jiffies) &&
1706             entries <= rt_max_size)
1707                 goto out;
1708
1709         net->ipv6.ip6_rt_gc_expire++;
1710         fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net, true);
1711         entries = dst_entries_get_slow(ops);
1712         if (entries < ops->gc_thresh)
1713                 net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;
1714 out:
1715         net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity;
1716         return entries > rt_max_size;
1717 }
1718
1719 static int ip6_convert_metrics(struct mx6_config *mxc,
1720                                const struct fib6_config *cfg)
1721 {
1722         bool ecn_ca = false;
1723         struct nlattr *nla;
1724         int remaining;
1725         u32 *mp;
1726
1727         if (!cfg->fc_mx)
1728                 return 0;
1729
1730         mp = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL);
1731         if (unlikely(!mp))
1732                 return -ENOMEM;
1733
1734         nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
1735                 int type = nla_type(nla);
1736                 u32 val;
1737
1738                 if (!type)
1739                         continue;
1740                 if (unlikely(type > RTAX_MAX))
1741                         goto err;
1742
1743                 if (type == RTAX_CC_ALGO) {
1744                         char tmp[TCP_CA_NAME_MAX];
1745
1746                         nla_strlcpy(tmp, nla, sizeof(tmp));
1747                         val = tcp_ca_get_key_by_name(tmp, &ecn_ca);
1748                         if (val == TCP_CA_UNSPEC)
1749                                 goto err;
1750                 } else {
1751                         val = nla_get_u32(nla);
1752                 }
1753                 if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK))
1754                         goto err;
1755
1756                 mp[type - 1] = val;
1757                 __set_bit(type - 1, mxc->mx_valid);
1758         }
1759
1760         if (ecn_ca) {
1761                 __set_bit(RTAX_FEATURES - 1, mxc->mx_valid);
1762                 mp[RTAX_FEATURES - 1] |= DST_FEATURE_ECN_CA;
1763         }
1764
1765         mxc->mx = mp;
1766         return 0;
1767  err:
1768         kfree(mp);
1769         return -EINVAL;
1770 }
1771
1772 static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg)
1773 {
1774         struct net *net = cfg->fc_nlinfo.nl_net;
1775         struct rt6_info *rt = NULL;
1776         struct net_device *dev = NULL;
1777         struct inet6_dev *idev = NULL;
1778         struct fib6_table *table;
1779         int addr_type;
1780         int err = -EINVAL;
1781
1782         if (cfg->fc_dst_len > 128 || cfg->fc_src_len > 128)
1783                 goto out;
1784 #ifndef CONFIG_IPV6_SUBTREES
1785         if (cfg->fc_src_len)
1786                 goto out;
1787 #endif
1788         if (cfg->fc_ifindex) {
1789                 err = -ENODEV;
1790                 dev = dev_get_by_index(net, cfg->fc_ifindex);
1791                 if (!dev)
1792                         goto out;
1793                 idev = in6_dev_get(dev);
1794                 if (!idev)
1795                         goto out;
1796         }
1797
1798         if (cfg->fc_metric == 0)
1799                 cfg->fc_metric = IP6_RT_PRIO_USER;
1800
1801         err = -ENOBUFS;
1802         if (cfg->fc_nlinfo.nlh &&
1803             !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
1804                 table = fib6_get_table(net, cfg->fc_table);
1805                 if (!table) {
1806                         pr_warn("NLM_F_CREATE should be specified when creating new route\n");
1807                         table = fib6_new_table(net, cfg->fc_table);
1808                 }
1809         } else {
1810                 table = fib6_new_table(net, cfg->fc_table);
1811         }
1812
1813         if (!table)
1814                 goto out;
1815
1816         rt = ip6_dst_alloc(net, NULL,
1817                            (cfg->fc_flags & RTF_ADDRCONF) ? 0 : DST_NOCOUNT);
1818
1819         if (!rt) {
1820                 err = -ENOMEM;
1821                 goto out;
1822         }
1823
1824         if (cfg->fc_flags & RTF_EXPIRES)
1825                 rt6_set_expires(rt, jiffies +
1826                                 clock_t_to_jiffies(cfg->fc_expires));
1827         else
1828                 rt6_clean_expires(rt);
1829
1830         if (cfg->fc_protocol == RTPROT_UNSPEC)
1831                 cfg->fc_protocol = RTPROT_BOOT;
1832         rt->rt6i_protocol = cfg->fc_protocol;
1833
1834         addr_type = ipv6_addr_type(&cfg->fc_dst);
1835
1836         if (addr_type & IPV6_ADDR_MULTICAST)
1837                 rt->dst.input = ip6_mc_input;
1838         else if (cfg->fc_flags & RTF_LOCAL)
1839                 rt->dst.input = ip6_input;
1840         else
1841                 rt->dst.input = ip6_forward;
1842
1843         rt->dst.output = ip6_output;
1844
1845         if (cfg->fc_encap) {
1846                 struct lwtunnel_state *lwtstate;
1847
1848                 err = lwtunnel_build_state(dev, cfg->fc_encap_type,
1849                                            cfg->fc_encap, AF_INET6, cfg,
1850                                            &lwtstate);
1851                 if (err)
1852                         goto out;
1853                 rt->dst.lwtstate = lwtstate_get(lwtstate);
1854                 if (lwtunnel_output_redirect(rt->dst.lwtstate)) {
1855                         rt->dst.lwtstate->orig_output = rt->dst.output;
1856                         rt->dst.output = lwtunnel_output;
1857                 }
1858                 if (lwtunnel_input_redirect(rt->dst.lwtstate)) {
1859                         rt->dst.lwtstate->orig_input = rt->dst.input;
1860                         rt->dst.input = lwtunnel_input;
1861                 }
1862         }
1863
1864         ipv6_addr_prefix(&rt->rt6i_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
1865         rt->rt6i_dst.plen = cfg->fc_dst_len;
1866         if (rt->rt6i_dst.plen == 128)
1867                 rt->dst.flags |= DST_HOST;
1868
1869 #ifdef CONFIG_IPV6_SUBTREES
1870         ipv6_addr_prefix(&rt->rt6i_src.addr, &cfg->fc_src, cfg->fc_src_len);
1871         rt->rt6i_src.plen = cfg->fc_src_len;
1872 #endif
1873
1874         rt->rt6i_metric = cfg->fc_metric;
1875
1876         /* We cannot add true routes via loopback here,
1877            they would result in kernel looping; promote them to reject routes
1878          */
1879         if ((cfg->fc_flags & RTF_REJECT) ||
1880             (dev && (dev->flags & IFF_LOOPBACK) &&
1881              !(addr_type & IPV6_ADDR_LOOPBACK) &&
1882              !(cfg->fc_flags & RTF_LOCAL))) {
1883                 /* hold loopback dev/idev if we haven't done so. */
1884                 if (dev != net->loopback_dev) {
1885                         if (dev) {
1886                                 dev_put(dev);
1887                                 in6_dev_put(idev);
1888                         }
1889                         dev = net->loopback_dev;
1890                         dev_hold(dev);
1891                         idev = in6_dev_get(dev);
1892                         if (!idev) {
1893                                 err = -ENODEV;
1894                                 goto out;
1895                         }
1896                 }
1897                 rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP;
1898                 switch (cfg->fc_type) {
1899                 case RTN_BLACKHOLE:
1900                         rt->dst.error = -EINVAL;
1901                         rt->dst.output = dst_discard_out;
1902                         rt->dst.input = dst_discard;
1903                         break;
1904                 case RTN_PROHIBIT:
1905                         rt->dst.error = -EACCES;
1906                         rt->dst.output = ip6_pkt_prohibit_out;
1907                         rt->dst.input = ip6_pkt_prohibit;
1908                         break;
1909                 case RTN_THROW:
1910                 case RTN_UNREACHABLE:
1911                 default:
1912                         rt->dst.error = (cfg->fc_type == RTN_THROW) ? -EAGAIN
1913                                         : (cfg->fc_type == RTN_UNREACHABLE)
1914                                         ? -EHOSTUNREACH : -ENETUNREACH;
1915                         rt->dst.output = ip6_pkt_discard_out;
1916                         rt->dst.input = ip6_pkt_discard;
1917                         break;
1918                 }
1919                 goto install_route;
1920         }
1921
1922         if (cfg->fc_flags & RTF_GATEWAY) {
1923                 const struct in6_addr *gw_addr;
1924                 int gwa_type;
1925
1926                 gw_addr = &cfg->fc_gateway;
1927                 gwa_type = ipv6_addr_type(gw_addr);
1928
1929                 /* if gw_addr is local we will fail to detect this in case
1930                  * address is still TENTATIVE (DAD in progress). rt6_lookup()
1931                  * will return already-added prefix route via interface that
1932                  * prefix route was assigned to, which might be non-loopback.
1933                  */
1934                 err = -EINVAL;
1935                 if (ipv6_chk_addr_and_flags(net, gw_addr,
1936                                             gwa_type & IPV6_ADDR_LINKLOCAL ?
1937                                             dev : NULL, 0, 0))
1938                         goto out;
1939
1940                 rt->rt6i_gateway = *gw_addr;
1941
1942                 if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {
1943                         struct rt6_info *grt;
1944
1945                         /* IPv6 strictly inhibits using not link-local
1946                            addresses as nexthop address.
1947                            Otherwise, router will not able to send redirects.
1948                            It is very good, but in some (rare!) circumstances
1949                            (SIT, PtP, NBMA NOARP links) it is handy to allow
1950                            some exceptions. --ANK
1951                          */
1952                         if (!(gwa_type & IPV6_ADDR_UNICAST))
1953                                 goto out;
1954
1955                         grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1);
1956
1957                         err = -EHOSTUNREACH;
1958                         if (!grt)
1959                                 goto out;
1960                         if (dev) {
1961                                 if (dev != grt->dst.dev) {
1962                                         ip6_rt_put(grt);
1963                                         goto out;
1964                                 }
1965                         } else {
1966                                 dev = grt->dst.dev;
1967                                 idev = grt->rt6i_idev;
1968                                 dev_hold(dev);
1969                                 in6_dev_hold(grt->rt6i_idev);
1970                         }
1971                         if (!(grt->rt6i_flags & RTF_GATEWAY))
1972                                 err = 0;
1973                         ip6_rt_put(grt);
1974
1975                         if (err)
1976                                 goto out;
1977                 }
1978                 err = -EINVAL;
1979                 if (!dev || (dev->flags & IFF_LOOPBACK))
1980                         goto out;
1981         }
1982
1983         err = -ENODEV;
1984         if (!dev)
1985                 goto out;
1986
1987         if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
1988                 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
1989                         err = -EINVAL;
1990                         goto out;
1991                 }
1992                 rt->rt6i_prefsrc.addr = cfg->fc_prefsrc;
1993                 rt->rt6i_prefsrc.plen = 128;
1994         } else
1995                 rt->rt6i_prefsrc.plen = 0;
1996
1997         rt->rt6i_flags = cfg->fc_flags;
1998
1999 install_route:
2000         rt->dst.dev = dev;
2001         rt->rt6i_idev = idev;
2002         rt->rt6i_table = table;
2003
2004         cfg->fc_nlinfo.nl_net = dev_net(dev);
2005
2006         return rt;
2007 out:
2008         if (dev)
2009                 dev_put(dev);
2010         if (idev)
2011                 in6_dev_put(idev);
2012         if (rt)
2013                 dst_free(&rt->dst);
2014
2015         return ERR_PTR(err);
2016 }
2017
2018 int ip6_route_add(struct fib6_config *cfg)
2019 {
2020         struct mx6_config mxc = { .mx = NULL, };
2021         struct rt6_info *rt;
2022         int err;
2023
2024         rt = ip6_route_info_create(cfg);
2025         if (IS_ERR(rt)) {
2026                 err = PTR_ERR(rt);
2027                 rt = NULL;
2028                 goto out;
2029         }
2030
2031         err = ip6_convert_metrics(&mxc, cfg);
2032         if (err)
2033                 goto out;
2034
2035         err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, &mxc);
2036
2037         kfree(mxc.mx);
2038
2039         return err;
2040 out:
2041         if (rt)
2042                 dst_free(&rt->dst);
2043
2044         return err;
2045 }
2046
2047 static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info)
2048 {
2049         int err;
2050         struct fib6_table *table;
2051         struct net *net = dev_net(rt->dst.dev);
2052
2053         if (rt == net->ipv6.ip6_null_entry ||
2054             rt->dst.flags & DST_NOCACHE) {
2055                 err = -ENOENT;
2056                 goto out;
2057         }
2058
2059         table = rt->rt6i_table;
2060         write_lock_bh(&table->tb6_lock);
2061         err = fib6_del(rt, info);
2062         write_unlock_bh(&table->tb6_lock);
2063
2064 out:
2065         ip6_rt_put(rt);
2066         return err;
2067 }
2068
2069 int ip6_del_rt(struct rt6_info *rt)
2070 {
2071         struct nl_info info = {
2072                 .nl_net = dev_net(rt->dst.dev),
2073         };
2074         return __ip6_del_rt(rt, &info);
2075 }
2076
2077 static int ip6_route_del(struct fib6_config *cfg)
2078 {
2079         struct fib6_table *table;
2080         struct fib6_node *fn;
2081         struct rt6_info *rt;
2082         int err = -ESRCH;
2083
2084         table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
2085         if (!table)
2086                 return err;
2087
2088         read_lock_bh(&table->tb6_lock);
2089
2090         fn = fib6_locate(&table->tb6_root,
2091                          &cfg->fc_dst, cfg->fc_dst_len,
2092                          &cfg->fc_src, cfg->fc_src_len);
2093
2094         if (fn) {
2095                 for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
2096                         if ((rt->rt6i_flags & RTF_CACHE) &&
2097                             !(cfg->fc_flags & RTF_CACHE))
2098                                 continue;
2099                         if (cfg->fc_ifindex &&
2100                             (!rt->dst.dev ||
2101                              rt->dst.dev->ifindex != cfg->fc_ifindex))
2102                                 continue;
2103                         if (cfg->fc_flags & RTF_GATEWAY &&
2104                             !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
2105                                 continue;
2106                         if (cfg->fc_metric && cfg->fc_metric != rt->rt6i_metric)
2107                                 continue;
2108                         dst_hold(&rt->dst);
2109                         read_unlock_bh(&table->tb6_lock);
2110
2111                         return __ip6_del_rt(rt, &cfg->fc_nlinfo);
2112                 }
2113         }
2114         read_unlock_bh(&table->tb6_lock);
2115
2116         return err;
2117 }
2118
2119 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
2120 {
2121         struct netevent_redirect netevent;
2122         struct rt6_info *rt, *nrt = NULL;
2123         struct ndisc_options ndopts;
2124         struct inet6_dev *in6_dev;
2125         struct neighbour *neigh;
2126         struct rd_msg *msg;
2127         int optlen, on_link;
2128         u8 *lladdr;
2129
2130         optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
2131         optlen -= sizeof(*msg);
2132
2133         if (optlen < 0) {
2134                 net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
2135                 return;
2136         }
2137
2138         msg = (struct rd_msg *)icmp6_hdr(skb);
2139
2140         if (ipv6_addr_is_multicast(&msg->dest)) {
2141                 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
2142                 return;
2143         }
2144
2145         on_link = 0;
2146         if (ipv6_addr_equal(&msg->dest, &msg->target)) {
2147                 on_link = 1;
2148         } else if (ipv6_addr_type(&msg->target) !=
2149                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
2150                 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
2151                 return;
2152         }
2153
2154         in6_dev = __in6_dev_get(skb->dev);
2155         if (!in6_dev)
2156                 return;
2157         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
2158                 return;
2159
2160         /* RFC2461 8.1:
2161          *      The IP source address of the Redirect MUST be the same as the current
2162          *      first-hop router for the specified ICMP Destination Address.
2163          */
2164
2165         if (!ndisc_parse_options(msg->opt, optlen, &ndopts)) {
2166                 net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
2167                 return;
2168         }
2169
2170         lladdr = NULL;
2171         if (ndopts.nd_opts_tgt_lladdr) {
2172                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
2173                                              skb->dev);
2174                 if (!lladdr) {
2175                         net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
2176                         return;
2177                 }
2178         }
2179
2180         rt = (struct rt6_info *) dst;
2181         if (rt->rt6i_flags & RTF_REJECT) {
2182                 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
2183                 return;
2184         }
2185
2186         /* Redirect received -> path was valid.
2187          * Look, redirects are sent only in response to data packets,
2188          * so that this nexthop apparently is reachable. --ANK
2189          */
2190         dst_confirm(&rt->dst);
2191
2192         neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
2193         if (!neigh)
2194                 return;
2195
2196         /*
2197          *      We have finally decided to accept it.
2198          */
2199
2200         neigh_update(neigh, lladdr, NUD_STALE,
2201                      NEIGH_UPDATE_F_WEAK_OVERRIDE|
2202                      NEIGH_UPDATE_F_OVERRIDE|
2203                      (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
2204                                      NEIGH_UPDATE_F_ISROUTER))
2205                      );
2206
2207         nrt = ip6_rt_cache_alloc(rt, &msg->dest, NULL);
2208         if (!nrt)
2209                 goto out;
2210
2211         nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
2212         if (on_link)
2213                 nrt->rt6i_flags &= ~RTF_GATEWAY;
2214
2215         nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
2216
2217         if (ip6_ins_rt(nrt))
2218                 goto out;
2219
2220         netevent.old = &rt->dst;
2221         netevent.new = &nrt->dst;
2222         netevent.daddr = &msg->dest;
2223         netevent.neigh = neigh;
2224         call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
2225
2226         if (rt->rt6i_flags & RTF_CACHE) {
2227                 rt = (struct rt6_info *) dst_clone(&rt->dst);
2228                 ip6_del_rt(rt);
2229         }
2230
2231 out:
2232         neigh_release(neigh);
2233 }
2234
2235 /*
2236  *      Misc support functions
2237  */
2238
2239 static void rt6_set_from(struct rt6_info *rt, struct rt6_info *from)
2240 {
2241         BUG_ON(from->dst.from);
2242
2243         rt->rt6i_flags &= ~RTF_EXPIRES;
2244         dst_hold(&from->dst);
2245         rt->dst.from = &from->dst;
2246         dst_init_metrics(&rt->dst, dst_metrics_ptr(&from->dst), true);
2247 }
2248
2249 static void ip6_rt_copy_init(struct rt6_info *rt, struct rt6_info *ort)
2250 {
2251         rt->dst.input = ort->dst.input;
2252         rt->dst.output = ort->dst.output;
2253         rt->rt6i_dst = ort->rt6i_dst;
2254         rt->dst.error = ort->dst.error;
2255         rt->rt6i_idev = ort->rt6i_idev;
2256         if (rt->rt6i_idev)
2257                 in6_dev_hold(rt->rt6i_idev);
2258         rt->dst.lastuse = jiffies;
2259         rt->rt6i_gateway = ort->rt6i_gateway;
2260         rt->rt6i_flags = ort->rt6i_flags;
2261         rt6_set_from(rt, ort);
2262         rt->rt6i_metric = ort->rt6i_metric;
2263 #ifdef CONFIG_IPV6_SUBTREES
2264         rt->rt6i_src = ort->rt6i_src;
2265 #endif
2266         rt->rt6i_prefsrc = ort->rt6i_prefsrc;
2267         rt->rt6i_table = ort->rt6i_table;
2268         rt->dst.lwtstate = lwtstate_get(ort->dst.lwtstate);
2269 }
2270
2271 #ifdef CONFIG_IPV6_ROUTE_INFO
2272 static struct rt6_info *rt6_get_route_info(struct net *net,
2273                                            const struct in6_addr *prefix, int prefixlen,
2274                                            const struct in6_addr *gwaddr, int ifindex)
2275 {
2276         struct fib6_node *fn;
2277         struct rt6_info *rt = NULL;
2278         struct fib6_table *table;
2279
2280         table = fib6_get_table(net, RT6_TABLE_INFO);
2281         if (!table)
2282                 return NULL;
2283
2284         read_lock_bh(&table->tb6_lock);
2285         fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0);
2286         if (!fn)
2287                 goto out;
2288
2289         for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
2290                 if (rt->dst.dev->ifindex != ifindex)
2291                         continue;
2292                 if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY))
2293                         continue;
2294                 if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr))
2295                         continue;
2296                 dst_hold(&rt->dst);
2297                 break;
2298         }
2299 out:
2300         read_unlock_bh(&table->tb6_lock);
2301         return rt;
2302 }
2303
2304 static struct rt6_info *rt6_add_route_info(struct net *net,
2305                                            const struct in6_addr *prefix, int prefixlen,
2306                                            const struct in6_addr *gwaddr, int ifindex,
2307                                            unsigned int pref)
2308 {
2309         struct fib6_config cfg = {
2310                 .fc_metric      = IP6_RT_PRIO_USER,
2311                 .fc_ifindex     = ifindex,
2312                 .fc_dst_len     = prefixlen,
2313                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
2314                                   RTF_UP | RTF_PREF(pref),
2315                 .fc_nlinfo.portid = 0,
2316                 .fc_nlinfo.nlh = NULL,
2317                 .fc_nlinfo.nl_net = net,
2318         };
2319
2320         cfg.fc_table = l3mdev_fib_table_by_index(net, ifindex) ? : RT6_TABLE_INFO;
2321         cfg.fc_dst = *prefix;
2322         cfg.fc_gateway = *gwaddr;
2323
2324         /* We should treat it as a default route if prefix length is 0. */
2325         if (!prefixlen)
2326                 cfg.fc_flags |= RTF_DEFAULT;
2327
2328         ip6_route_add(&cfg);
2329
2330         return rt6_get_route_info(net, prefix, prefixlen, gwaddr, ifindex);
2331 }
2332 #endif
2333
2334 struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr, struct net_device *dev)
2335 {
2336         struct rt6_info *rt;
2337         struct fib6_table *table;
2338
2339         table = fib6_get_table(dev_net(dev), RT6_TABLE_DFLT);
2340         if (!table)
2341                 return NULL;
2342
2343         read_lock_bh(&table->tb6_lock);
2344         for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) {
2345                 if (dev == rt->dst.dev &&
2346                     ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
2347                     ipv6_addr_equal(&rt->rt6i_gateway, addr))
2348                         break;
2349         }
2350         if (rt)
2351                 dst_hold(&rt->dst);
2352         read_unlock_bh(&table->tb6_lock);
2353         return rt;
2354 }
2355
2356 struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr,
2357                                      struct net_device *dev,
2358                                      unsigned int pref)
2359 {
2360         struct fib6_config cfg = {
2361                 .fc_table       = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
2362                 .fc_metric      = IP6_RT_PRIO_USER,
2363                 .fc_ifindex     = dev->ifindex,
2364                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
2365                                   RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
2366                 .fc_nlinfo.portid = 0,
2367                 .fc_nlinfo.nlh = NULL,
2368                 .fc_nlinfo.nl_net = dev_net(dev),
2369         };
2370
2371         cfg.fc_gateway = *gwaddr;
2372
2373         ip6_route_add(&cfg);
2374
2375         return rt6_get_dflt_router(gwaddr, dev);
2376 }
2377
2378 void rt6_purge_dflt_routers(struct net *net)
2379 {
2380         struct rt6_info *rt;
2381         struct fib6_table *table;
2382
2383         /* NOTE: Keep consistent with rt6_get_dflt_router */
2384         table = fib6_get_table(net, RT6_TABLE_DFLT);
2385         if (!table)
2386                 return;
2387
2388 restart:
2389         read_lock_bh(&table->tb6_lock);
2390         for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) {
2391                 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
2392                     (!rt->rt6i_idev || rt->rt6i_idev->cnf.accept_ra != 2)) {
2393                         dst_hold(&rt->dst);
2394                         read_unlock_bh(&table->tb6_lock);
2395                         ip6_del_rt(rt);
2396                         goto restart;
2397                 }
2398         }
2399         read_unlock_bh(&table->tb6_lock);
2400 }
2401
2402 static void rtmsg_to_fib6_config(struct net *net,
2403                                  struct in6_rtmsg *rtmsg,
2404                                  struct fib6_config *cfg)
2405 {
2406         memset(cfg, 0, sizeof(*cfg));
2407
2408         cfg->fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
2409                          : RT6_TABLE_MAIN;
2410         cfg->fc_ifindex = rtmsg->rtmsg_ifindex;
2411         cfg->fc_metric = rtmsg->rtmsg_metric;
2412         cfg->fc_expires = rtmsg->rtmsg_info;
2413         cfg->fc_dst_len = rtmsg->rtmsg_dst_len;
2414         cfg->fc_src_len = rtmsg->rtmsg_src_len;
2415         cfg->fc_flags = rtmsg->rtmsg_flags;
2416
2417         cfg->fc_nlinfo.nl_net = net;
2418
2419         cfg->fc_dst = rtmsg->rtmsg_dst;
2420         cfg->fc_src = rtmsg->rtmsg_src;
2421         cfg->fc_gateway = rtmsg->rtmsg_gateway;
2422 }
2423
2424 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg)
2425 {
2426         struct fib6_config cfg;
2427         struct in6_rtmsg rtmsg;
2428         int err;
2429
2430         switch (cmd) {
2431         case SIOCADDRT:         /* Add a route */
2432         case SIOCDELRT:         /* Delete a route */
2433                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2434                         return -EPERM;
2435                 err = copy_from_user(&rtmsg, arg,
2436                                      sizeof(struct in6_rtmsg));
2437                 if (err)
2438                         return -EFAULT;
2439
2440                 rtmsg_to_fib6_config(net, &rtmsg, &cfg);
2441
2442                 rtnl_lock();
2443                 switch (cmd) {
2444                 case SIOCADDRT:
2445                         err = ip6_route_add(&cfg);
2446                         break;
2447                 case SIOCDELRT:
2448                         err = ip6_route_del(&cfg);
2449                         break;
2450                 default:
2451                         err = -EINVAL;
2452                 }
2453                 rtnl_unlock();
2454
2455                 return err;
2456         }
2457
2458         return -EINVAL;
2459 }
2460
2461 /*
2462  *      Drop the packet on the floor
2463  */
2464
2465 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
2466 {
2467         int type;
2468         struct dst_entry *dst = skb_dst(skb);
2469         switch (ipstats_mib_noroutes) {
2470         case IPSTATS_MIB_INNOROUTES:
2471                 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
2472                 if (type == IPV6_ADDR_ANY) {
2473                         IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
2474                                       IPSTATS_MIB_INADDRERRORS);
2475                         break;
2476                 }
2477                 /* FALLTHROUGH */
2478         case IPSTATS_MIB_OUTNOROUTES:
2479                 IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
2480                               ipstats_mib_noroutes);
2481                 break;
2482         }
2483         icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
2484         kfree_skb(skb);
2485         return 0;
2486 }
2487
2488 static int ip6_pkt_discard(struct sk_buff *skb)
2489 {
2490         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
2491 }
2492
2493 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
2494 {
2495         skb->dev = skb_dst(skb)->dev;
2496         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
2497 }
2498
2499 static int ip6_pkt_prohibit(struct sk_buff *skb)
2500 {
2501         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
2502 }
2503
2504 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
2505 {
2506         skb->dev = skb_dst(skb)->dev;
2507         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
2508 }
2509
2510 /*
2511  *      Allocate a dst for local (unicast / anycast) address.
2512  */
2513
2514 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
2515                                     const struct in6_addr *addr,
2516                                     bool anycast)
2517 {
2518         u32 tb_id;
2519         struct net *net = dev_net(idev->dev);
2520         struct rt6_info *rt = ip6_dst_alloc(net, net->loopback_dev,
2521                                             DST_NOCOUNT);
2522         if (!rt)
2523                 return ERR_PTR(-ENOMEM);
2524
2525         in6_dev_hold(idev);
2526
2527         rt->dst.flags |= DST_HOST;
2528         rt->dst.input = ip6_input;
2529         rt->dst.output = ip6_output;
2530         rt->rt6i_idev = idev;
2531
2532         rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP;
2533         if (anycast)
2534                 rt->rt6i_flags |= RTF_ANYCAST;
2535         else
2536                 rt->rt6i_flags |= RTF_LOCAL;
2537
2538         rt->rt6i_gateway  = *addr;
2539         rt->rt6i_dst.addr = *addr;
2540         rt->rt6i_dst.plen = 128;
2541         tb_id = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL;
2542         rt->rt6i_table = fib6_get_table(net, tb_id);
2543         rt->dst.flags |= DST_NOCACHE;
2544
2545         atomic_set(&rt->dst.__refcnt, 1);
2546
2547         return rt;
2548 }
2549
2550 int ip6_route_get_saddr(struct net *net,
2551                         struct rt6_info *rt,
2552                         const struct in6_addr *daddr,
2553                         unsigned int prefs,
2554                         struct in6_addr *saddr)
2555 {
2556         struct inet6_dev *idev =
2557                 rt ? ip6_dst_idev((struct dst_entry *)rt) : NULL;
2558         int err = 0;
2559         if (rt && rt->rt6i_prefsrc.plen)
2560                 *saddr = rt->rt6i_prefsrc.addr;
2561         else
2562                 err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,
2563                                          daddr, prefs, saddr);
2564         return err;
2565 }
2566
2567 /* remove deleted ip from prefsrc entries */
2568 struct arg_dev_net_ip {
2569         struct net_device *dev;
2570         struct net *net;
2571         struct in6_addr *addr;
2572 };
2573
2574 static int fib6_remove_prefsrc(struct rt6_info *rt, void *arg)
2575 {
2576         struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev;
2577         struct net *net = ((struct arg_dev_net_ip *)arg)->net;
2578         struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
2579
2580         if (((void *)rt->dst.dev == dev || !dev) &&
2581             rt != net->ipv6.ip6_null_entry &&
2582             ipv6_addr_equal(addr, &rt->rt6i_prefsrc.addr)) {
2583                 /* remove prefsrc entry */
2584                 rt->rt6i_prefsrc.plen = 0;
2585         }
2586         return 0;
2587 }
2588
2589 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
2590 {
2591         struct net *net = dev_net(ifp->idev->dev);
2592         struct arg_dev_net_ip adni = {
2593                 .dev = ifp->idev->dev,
2594                 .net = net,
2595                 .addr = &ifp->addr,
2596         };
2597         fib6_clean_all(net, fib6_remove_prefsrc, &adni);
2598 }
2599
2600 #define RTF_RA_ROUTER           (RTF_ADDRCONF | RTF_DEFAULT | RTF_GATEWAY)
2601 #define RTF_CACHE_GATEWAY       (RTF_GATEWAY | RTF_CACHE)
2602
2603 /* Remove routers and update dst entries when gateway turn into host. */
2604 static int fib6_clean_tohost(struct rt6_info *rt, void *arg)
2605 {
2606         struct in6_addr *gateway = (struct in6_addr *)arg;
2607
2608         if ((((rt->rt6i_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) ||
2609              ((rt->rt6i_flags & RTF_CACHE_GATEWAY) == RTF_CACHE_GATEWAY)) &&
2610              ipv6_addr_equal(gateway, &rt->rt6i_gateway)) {
2611                 return -1;
2612         }
2613         return 0;
2614 }
2615
2616 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
2617 {
2618         fib6_clean_all(net, fib6_clean_tohost, gateway);
2619 }
2620
2621 struct arg_dev_net {
2622         struct net_device *dev;
2623         struct net *net;
2624 };
2625
2626 static int fib6_ifdown(struct rt6_info *rt, void *arg)
2627 {
2628         const struct arg_dev_net *adn = arg;
2629         const struct net_device *dev = adn->dev;
2630
2631         if ((rt->dst.dev == dev || !dev) &&
2632             rt != adn->net->ipv6.ip6_null_entry)
2633                 return -1;
2634
2635         return 0;
2636 }
2637
2638 void rt6_ifdown(struct net *net, struct net_device *dev)
2639 {
2640         struct arg_dev_net adn = {
2641                 .dev = dev,
2642                 .net = net,
2643         };
2644
2645         fib6_clean_all(net, fib6_ifdown, &adn);
2646         icmp6_clean_all(fib6_ifdown, &adn);
2647         if (dev)
2648                 rt6_uncached_list_flush_dev(net, dev);
2649 }
2650
2651 struct rt6_mtu_change_arg {
2652         struct net_device *dev;
2653         unsigned int mtu;
2654 };
2655
2656 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg)
2657 {
2658         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
2659         struct inet6_dev *idev;
2660
2661         /* In IPv6 pmtu discovery is not optional,
2662            so that RTAX_MTU lock cannot disable it.
2663            We still use this lock to block changes
2664            caused by addrconf/ndisc.
2665         */
2666
2667         idev = __in6_dev_get(arg->dev);
2668         if (!idev)
2669                 return 0;
2670
2671         /* For administrative MTU increase, there is no way to discover
2672            IPv6 PMTU increase, so PMTU increase should be updated here.
2673            Since RFC 1981 doesn't include administrative MTU increase
2674            update PMTU increase is a MUST. (i.e. jumbo frame)
2675          */
2676         /*
2677            If new MTU is less than route PMTU, this new MTU will be the
2678            lowest MTU in the path, update the route PMTU to reflect PMTU
2679            decreases; if new MTU is greater than route PMTU, and the
2680            old MTU is the lowest MTU in the path, update the route PMTU
2681            to reflect the increase. In this case if the other nodes' MTU
2682            also have the lowest MTU, TOO BIG MESSAGE will be lead to
2683            PMTU discouvery.
2684          */
2685         if (rt->dst.dev == arg->dev &&
2686             !dst_metric_locked(&rt->dst, RTAX_MTU)) {
2687                 if (rt->rt6i_flags & RTF_CACHE) {
2688                         /* For RTF_CACHE with rt6i_pmtu == 0
2689                          * (i.e. a redirected route),
2690                          * the metrics of its rt->dst.from has already
2691                          * been updated.
2692                          */
2693                         if (rt->rt6i_pmtu && rt->rt6i_pmtu > arg->mtu)
2694                                 rt->rt6i_pmtu = arg->mtu;
2695                 } else if (dst_mtu(&rt->dst) >= arg->mtu ||
2696                            (dst_mtu(&rt->dst) < arg->mtu &&
2697                             dst_mtu(&rt->dst) == idev->cnf.mtu6)) {
2698                         dst_metric_set(&rt->dst, RTAX_MTU, arg->mtu);
2699                 }
2700         }
2701         return 0;
2702 }
2703
2704 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
2705 {
2706         struct rt6_mtu_change_arg arg = {
2707                 .dev = dev,
2708                 .mtu = mtu,
2709         };
2710
2711         fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
2712 }
2713
2714 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
2715         [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
2716         [RTA_OIF]               = { .type = NLA_U32 },
2717         [RTA_IIF]               = { .type = NLA_U32 },
2718         [RTA_PRIORITY]          = { .type = NLA_U32 },
2719         [RTA_METRICS]           = { .type = NLA_NESTED },
2720         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
2721         [RTA_PREF]              = { .type = NLA_U8 },
2722         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
2723         [RTA_ENCAP]             = { .type = NLA_NESTED },
2724         [RTA_EXPIRES]           = { .type = NLA_U32 },
2725 };
2726
2727 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
2728                               struct fib6_config *cfg)
2729 {
2730         struct rtmsg *rtm;
2731         struct nlattr *tb[RTA_MAX+1];
2732         unsigned int pref;
2733         int err;
2734
2735         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
2736         if (err < 0)
2737                 goto errout;
2738
2739         err = -EINVAL;
2740         rtm = nlmsg_data(nlh);
2741         memset(cfg, 0, sizeof(*cfg));
2742
2743         cfg->fc_table = rtm->rtm_table;
2744         cfg->fc_dst_len = rtm->rtm_dst_len;
2745         cfg->fc_src_len = rtm->rtm_src_len;
2746         cfg->fc_flags = RTF_UP;
2747         cfg->fc_protocol = rtm->rtm_protocol;
2748         cfg->fc_type = rtm->rtm_type;
2749
2750         if (rtm->rtm_type == RTN_UNREACHABLE ||
2751             rtm->rtm_type == RTN_BLACKHOLE ||
2752             rtm->rtm_type == RTN_PROHIBIT ||
2753             rtm->rtm_type == RTN_THROW)
2754                 cfg->fc_flags |= RTF_REJECT;
2755
2756         if (rtm->rtm_type == RTN_LOCAL)
2757                 cfg->fc_flags |= RTF_LOCAL;
2758
2759         if (rtm->rtm_flags & RTM_F_CLONED)
2760                 cfg->fc_flags |= RTF_CACHE;
2761
2762         cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
2763         cfg->fc_nlinfo.nlh = nlh;
2764         cfg->fc_nlinfo.nl_net = sock_net(skb->sk);
2765
2766         if (tb[RTA_GATEWAY]) {
2767                 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
2768                 cfg->fc_flags |= RTF_GATEWAY;
2769         }
2770
2771         if (tb[RTA_DST]) {
2772                 int plen = (rtm->rtm_dst_len + 7) >> 3;
2773
2774                 if (nla_len(tb[RTA_DST]) < plen)
2775                         goto errout;
2776
2777                 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
2778         }
2779
2780         if (tb[RTA_SRC]) {
2781                 int plen = (rtm->rtm_src_len + 7) >> 3;
2782
2783                 if (nla_len(tb[RTA_SRC]) < plen)
2784                         goto errout;
2785
2786                 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
2787         }
2788
2789         if (tb[RTA_PREFSRC])
2790                 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
2791
2792         if (tb[RTA_OIF])
2793                 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
2794
2795         if (tb[RTA_PRIORITY])
2796                 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
2797
2798         if (tb[RTA_METRICS]) {
2799                 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
2800                 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
2801         }
2802
2803         if (tb[RTA_TABLE])
2804                 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
2805
2806         if (tb[RTA_MULTIPATH]) {
2807                 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
2808                 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
2809         }
2810
2811         if (tb[RTA_PREF]) {
2812                 pref = nla_get_u8(tb[RTA_PREF]);
2813                 if (pref != ICMPV6_ROUTER_PREF_LOW &&
2814                     pref != ICMPV6_ROUTER_PREF_HIGH)
2815                         pref = ICMPV6_ROUTER_PREF_MEDIUM;
2816                 cfg->fc_flags |= RTF_PREF(pref);
2817         }
2818
2819         if (tb[RTA_ENCAP])
2820                 cfg->fc_encap = tb[RTA_ENCAP];
2821
2822         if (tb[RTA_ENCAP_TYPE])
2823                 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
2824
2825         if (tb[RTA_EXPIRES]) {
2826                 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
2827
2828                 if (addrconf_finite_timeout(timeout)) {
2829                         cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
2830                         cfg->fc_flags |= RTF_EXPIRES;
2831                 }
2832         }
2833
2834         err = 0;
2835 errout:
2836         return err;
2837 }
2838
2839 struct rt6_nh {
2840         struct rt6_info *rt6_info;
2841         struct fib6_config r_cfg;
2842         struct mx6_config mxc;
2843         struct list_head next;
2844 };
2845
2846 static void ip6_print_replace_route_err(struct list_head *rt6_nh_list)
2847 {
2848         struct rt6_nh *nh;
2849
2850         list_for_each_entry(nh, rt6_nh_list, next) {
2851                 pr_warn("IPV6: multipath route replace failed (check consistency of installed routes): %pI6 nexthop %pI6 ifi %d\n",
2852                         &nh->r_cfg.fc_dst, &nh->r_cfg.fc_gateway,
2853                         nh->r_cfg.fc_ifindex);
2854         }
2855 }
2856
2857 static int ip6_route_info_append(struct list_head *rt6_nh_list,
2858                                  struct rt6_info *rt, struct fib6_config *r_cfg)
2859 {
2860         struct rt6_nh *nh;
2861         struct rt6_info *rtnh;
2862         int err = -EEXIST;
2863
2864         list_for_each_entry(nh, rt6_nh_list, next) {
2865                 /* check if rt6_info already exists */
2866                 rtnh = nh->rt6_info;
2867
2868                 if (rtnh->dst.dev == rt->dst.dev &&
2869                     rtnh->rt6i_idev == rt->rt6i_idev &&
2870                     ipv6_addr_equal(&rtnh->rt6i_gateway,
2871                                     &rt->rt6i_gateway))
2872                         return err;
2873         }
2874
2875         nh = kzalloc(sizeof(*nh), GFP_KERNEL);
2876         if (!nh)
2877                 return -ENOMEM;
2878         nh->rt6_info = rt;
2879         err = ip6_convert_metrics(&nh->mxc, r_cfg);
2880         if (err) {
2881                 kfree(nh);
2882                 return err;
2883         }
2884         memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
2885         list_add_tail(&nh->next, rt6_nh_list);
2886
2887         return 0;
2888 }
2889
2890 static int ip6_route_multipath_add(struct fib6_config *cfg)
2891 {
2892         struct fib6_config r_cfg;
2893         struct rtnexthop *rtnh;
2894         struct rt6_info *rt;
2895         struct rt6_nh *err_nh;
2896         struct rt6_nh *nh, *nh_safe;
2897         int remaining;
2898         int attrlen;
2899         int err = 1;
2900         int nhn = 0;
2901         int replace = (cfg->fc_nlinfo.nlh &&
2902                        (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
2903         LIST_HEAD(rt6_nh_list);
2904
2905         remaining = cfg->fc_mp_len;
2906         rtnh = (struct rtnexthop *)cfg->fc_mp;
2907
2908         /* Parse a Multipath Entry and build a list (rt6_nh_list) of
2909          * rt6_info structs per nexthop
2910          */
2911         while (rtnh_ok(rtnh, remaining)) {
2912                 memcpy(&r_cfg, cfg, sizeof(*cfg));
2913                 if (rtnh->rtnh_ifindex)
2914                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
2915
2916                 attrlen = rtnh_attrlen(rtnh);
2917                 if (attrlen > 0) {
2918                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
2919
2920                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
2921                         if (nla) {
2922                                 r_cfg.fc_gateway = nla_get_in6_addr(nla);
2923                                 r_cfg.fc_flags |= RTF_GATEWAY;
2924                         }
2925                         r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
2926                         nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
2927                         if (nla)
2928                                 r_cfg.fc_encap_type = nla_get_u16(nla);
2929                 }
2930
2931                 rt = ip6_route_info_create(&r_cfg);
2932                 if (IS_ERR(rt)) {
2933                         err = PTR_ERR(rt);
2934                         rt = NULL;
2935                         goto cleanup;
2936                 }
2937
2938                 err = ip6_route_info_append(&rt6_nh_list, rt, &r_cfg);
2939                 if (err) {
2940                         dst_free(&rt->dst);
2941                         goto cleanup;
2942                 }
2943
2944                 rtnh = rtnh_next(rtnh, &remaining);
2945         }
2946
2947         err_nh = NULL;
2948         list_for_each_entry(nh, &rt6_nh_list, next) {
2949                 err = __ip6_ins_rt(nh->rt6_info, &cfg->fc_nlinfo, &nh->mxc);
2950                 /* nh->rt6_info is used or freed at this point, reset to NULL*/
2951                 nh->rt6_info = NULL;
2952                 if (err) {
2953                         if (replace && nhn)
2954                                 ip6_print_replace_route_err(&rt6_nh_list);
2955                         err_nh = nh;
2956                         goto add_errout;
2957                 }
2958
2959                 /* Because each route is added like a single route we remove
2960                  * these flags after the first nexthop: if there is a collision,
2961                  * we have already failed to add the first nexthop:
2962                  * fib6_add_rt2node() has rejected it; when replacing, old
2963                  * nexthops have been replaced by first new, the rest should
2964                  * be added to it.
2965                  */
2966                 cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
2967                                                      NLM_F_REPLACE);
2968                 nhn++;
2969         }
2970
2971         goto cleanup;
2972
2973 add_errout:
2974         /* Delete routes that were already added */
2975         list_for_each_entry(nh, &rt6_nh_list, next) {
2976                 if (err_nh == nh)
2977                         break;
2978                 ip6_route_del(&nh->r_cfg);
2979         }
2980
2981 cleanup:
2982         list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
2983                 if (nh->rt6_info)
2984                         dst_free(&nh->rt6_info->dst);
2985                 kfree(nh->mxc.mx);
2986                 list_del(&nh->next);
2987                 kfree(nh);
2988         }
2989
2990         return err;
2991 }
2992
2993 static int ip6_route_multipath_del(struct fib6_config *cfg)
2994 {
2995         struct fib6_config r_cfg;
2996         struct rtnexthop *rtnh;
2997         int remaining;
2998         int attrlen;
2999         int err = 1, last_err = 0;
3000
3001         remaining = cfg->fc_mp_len;
3002         rtnh = (struct rtnexthop *)cfg->fc_mp;
3003
3004         /* Parse a Multipath Entry */
3005         while (rtnh_ok(rtnh, remaining)) {
3006                 memcpy(&r_cfg, cfg, sizeof(*cfg));
3007                 if (rtnh->rtnh_ifindex)
3008                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
3009
3010                 attrlen = rtnh_attrlen(rtnh);
3011                 if (attrlen > 0) {
3012                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
3013
3014                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
3015                         if (nla) {
3016                                 nla_memcpy(&r_cfg.fc_gateway, nla, 16);
3017                                 r_cfg.fc_flags |= RTF_GATEWAY;
3018                         }
3019                 }
3020                 err = ip6_route_del(&r_cfg);
3021                 if (err)
3022                         last_err = err;
3023
3024                 rtnh = rtnh_next(rtnh, &remaining);
3025         }
3026
3027         return last_err;
3028 }
3029
3030 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
3031 {
3032         struct fib6_config cfg;
3033         int err;
3034
3035         err = rtm_to_fib6_config(skb, nlh, &cfg);
3036         if (err < 0)
3037                 return err;
3038
3039         if (cfg.fc_mp)
3040                 return ip6_route_multipath_del(&cfg);
3041         else
3042                 return ip6_route_del(&cfg);
3043 }
3044
3045 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
3046 {
3047         struct fib6_config cfg;
3048         int err;
3049
3050         err = rtm_to_fib6_config(skb, nlh, &cfg);
3051         if (err < 0)
3052                 return err;
3053
3054         if (cfg.fc_mp)
3055                 return ip6_route_multipath_add(&cfg);
3056         else
3057                 return ip6_route_add(&cfg);
3058 }
3059
3060 static inline size_t rt6_nlmsg_size(struct rt6_info *rt)
3061 {
3062         return NLMSG_ALIGN(sizeof(struct rtmsg))
3063                + nla_total_size(16) /* RTA_SRC */
3064                + nla_total_size(16) /* RTA_DST */
3065                + nla_total_size(16) /* RTA_GATEWAY */
3066                + nla_total_size(16) /* RTA_PREFSRC */
3067                + nla_total_size(4) /* RTA_TABLE */
3068                + nla_total_size(4) /* RTA_IIF */
3069                + nla_total_size(4) /* RTA_OIF */
3070                + nla_total_size(4) /* RTA_PRIORITY */
3071                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
3072                + nla_total_size(sizeof(struct rta_cacheinfo))
3073                + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
3074                + nla_total_size(1) /* RTA_PREF */
3075                + lwtunnel_get_encap_size(rt->dst.lwtstate);
3076 }
3077
3078 static int rt6_fill_node(struct net *net,
3079                          struct sk_buff *skb, struct rt6_info *rt,
3080                          struct in6_addr *dst, struct in6_addr *src,
3081                          int iif, int type, u32 portid, u32 seq,
3082                          int prefix, int nowait, unsigned int flags)
3083 {
3084         u32 metrics[RTAX_MAX];
3085         struct rtmsg *rtm;
3086         struct nlmsghdr *nlh;
3087         long expires;
3088         u32 table;
3089
3090         if (prefix) {   /* user wants prefix routes only */
3091                 if (!(rt->rt6i_flags & RTF_PREFIX_RT)) {
3092                         /* success since this is not a prefix route */
3093                         return 1;
3094                 }
3095         }
3096
3097         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
3098         if (!nlh)
3099                 return -EMSGSIZE;
3100
3101         rtm = nlmsg_data(nlh);
3102         rtm->rtm_family = AF_INET6;
3103         rtm->rtm_dst_len = rt->rt6i_dst.plen;
3104         rtm->rtm_src_len = rt->rt6i_src.plen;
3105         rtm->rtm_tos = 0;
3106         if (rt->rt6i_table)
3107                 table = rt->rt6i_table->tb6_id;
3108         else
3109                 table = RT6_TABLE_UNSPEC;
3110         rtm->rtm_table = table;
3111         if (nla_put_u32(skb, RTA_TABLE, table))
3112                 goto nla_put_failure;
3113         if (rt->rt6i_flags & RTF_REJECT) {
3114                 switch (rt->dst.error) {
3115                 case -EINVAL:
3116                         rtm->rtm_type = RTN_BLACKHOLE;
3117                         break;
3118                 case -EACCES:
3119                         rtm->rtm_type = RTN_PROHIBIT;
3120                         break;
3121                 case -EAGAIN:
3122                         rtm->rtm_type = RTN_THROW;
3123                         break;
3124                 default:
3125                         rtm->rtm_type = RTN_UNREACHABLE;
3126                         break;
3127                 }
3128         }
3129         else if (rt->rt6i_flags & RTF_LOCAL)
3130                 rtm->rtm_type = RTN_LOCAL;
3131         else if (rt->dst.dev && (rt->dst.dev->flags & IFF_LOOPBACK))
3132                 rtm->rtm_type = RTN_LOCAL;
3133         else
3134                 rtm->rtm_type = RTN_UNICAST;
3135         rtm->rtm_flags = 0;
3136         if (!netif_carrier_ok(rt->dst.dev)) {
3137                 rtm->rtm_flags |= RTNH_F_LINKDOWN;
3138                 if (rt->rt6i_idev->cnf.ignore_routes_with_linkdown)
3139                         rtm->rtm_flags |= RTNH_F_DEAD;
3140         }
3141         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
3142         rtm->rtm_protocol = rt->rt6i_protocol;
3143         if (rt->rt6i_flags & RTF_DYNAMIC)
3144                 rtm->rtm_protocol = RTPROT_REDIRECT;
3145         else if (rt->rt6i_flags & RTF_ADDRCONF) {
3146                 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ROUTEINFO))
3147                         rtm->rtm_protocol = RTPROT_RA;
3148                 else
3149                         rtm->rtm_protocol = RTPROT_KERNEL;
3150         }
3151
3152         if (rt->rt6i_flags & RTF_CACHE)
3153                 rtm->rtm_flags |= RTM_F_CLONED;
3154
3155         if (dst) {
3156                 if (nla_put_in6_addr(skb, RTA_DST, dst))
3157                         goto nla_put_failure;
3158                 rtm->rtm_dst_len = 128;
3159         } else if (rtm->rtm_dst_len)
3160                 if (nla_put_in6_addr(skb, RTA_DST, &rt->rt6i_dst.addr))
3161                         goto nla_put_failure;
3162 #ifdef CONFIG_IPV6_SUBTREES
3163         if (src) {
3164                 if (nla_put_in6_addr(skb, RTA_SRC, src))
3165                         goto nla_put_failure;
3166                 rtm->rtm_src_len = 128;
3167         } else if (rtm->rtm_src_len &&
3168                    nla_put_in6_addr(skb, RTA_SRC, &rt->rt6i_src.addr))
3169                 goto nla_put_failure;
3170 #endif
3171         if (iif) {
3172 #ifdef CONFIG_IPV6_MROUTE
3173                 if (ipv6_addr_is_multicast(&rt->rt6i_dst.addr)) {
3174                         int err = ip6mr_get_route(net, skb, rtm, nowait);
3175                         if (err <= 0) {
3176                                 if (!nowait) {
3177                                         if (err == 0)
3178                                                 return 0;
3179                                         goto nla_put_failure;
3180                                 } else {
3181                                         if (err == -EMSGSIZE)
3182                                                 goto nla_put_failure;
3183                                 }
3184                         }
3185                 } else
3186 #endif
3187                         if (nla_put_u32(skb, RTA_IIF, iif))
3188                                 goto nla_put_failure;
3189         } else if (dst) {
3190                 struct in6_addr saddr_buf;
3191                 if (ip6_route_get_saddr(net, rt, dst, 0, &saddr_buf) == 0 &&
3192                     nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
3193                         goto nla_put_failure;
3194         }
3195
3196         if (rt->rt6i_prefsrc.plen) {
3197                 struct in6_addr saddr_buf;
3198                 saddr_buf = rt->rt6i_prefsrc.addr;
3199                 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
3200                         goto nla_put_failure;
3201         }
3202
3203         memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
3204         if (rt->rt6i_pmtu)
3205                 metrics[RTAX_MTU - 1] = rt->rt6i_pmtu;
3206         if (rtnetlink_put_metrics(skb, metrics) < 0)
3207                 goto nla_put_failure;
3208
3209         if (rt->rt6i_flags & RTF_GATEWAY) {
3210                 if (nla_put_in6_addr(skb, RTA_GATEWAY, &rt->rt6i_gateway) < 0)
3211                         goto nla_put_failure;
3212         }
3213
3214         if (rt->dst.dev &&
3215             nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
3216                 goto nla_put_failure;
3217         if (nla_put_u32(skb, RTA_PRIORITY, rt->rt6i_metric))
3218                 goto nla_put_failure;
3219
3220         expires = (rt->rt6i_flags & RTF_EXPIRES) ? rt->dst.expires - jiffies : 0;
3221
3222         if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, rt->dst.error) < 0)
3223                 goto nla_put_failure;
3224
3225         if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt->rt6i_flags)))
3226                 goto nla_put_failure;
3227
3228         lwtunnel_fill_encap(skb, rt->dst.lwtstate);
3229
3230         nlmsg_end(skb, nlh);
3231         return 0;
3232
3233 nla_put_failure:
3234         nlmsg_cancel(skb, nlh);
3235         return -EMSGSIZE;
3236 }
3237
3238 int rt6_dump_route(struct rt6_info *rt, void *p_arg)
3239 {
3240         struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
3241         int prefix;
3242
3243         if (nlmsg_len(arg->cb->nlh) >= sizeof(struct rtmsg)) {
3244                 struct rtmsg *rtm = nlmsg_data(arg->cb->nlh);
3245                 prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0;
3246         } else
3247                 prefix = 0;
3248
3249         return rt6_fill_node(arg->net,
3250                      arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE,
3251                      NETLINK_CB(arg->cb->skb).portid, arg->cb->nlh->nlmsg_seq,
3252                      prefix, 0, NLM_F_MULTI);
3253 }
3254
3255 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
3256 {
3257         struct net *net = sock_net(in_skb->sk);
3258         struct nlattr *tb[RTA_MAX+1];
3259         struct rt6_info *rt;
3260         struct sk_buff *skb;
3261         struct rtmsg *rtm;
3262         struct flowi6 fl6;
3263         int err, iif = 0, oif = 0;
3264
3265         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
3266         if (err < 0)
3267                 goto errout;
3268
3269         err = -EINVAL;
3270         memset(&fl6, 0, sizeof(fl6));
3271
3272         if (tb[RTA_SRC]) {
3273                 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
3274                         goto errout;
3275
3276                 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
3277         }
3278
3279         if (tb[RTA_DST]) {
3280                 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
3281                         goto errout;
3282
3283                 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
3284         }
3285
3286         if (tb[RTA_IIF])
3287                 iif = nla_get_u32(tb[RTA_IIF]);
3288
3289         if (tb[RTA_OIF])
3290                 oif = nla_get_u32(tb[RTA_OIF]);
3291
3292         if (tb[RTA_MARK])
3293                 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
3294
3295         if (iif) {
3296                 struct net_device *dev;
3297                 int flags = 0;
3298
3299                 dev = __dev_get_by_index(net, iif);
3300                 if (!dev) {
3301                         err = -ENODEV;
3302                         goto errout;
3303                 }
3304
3305                 fl6.flowi6_iif = iif;
3306
3307                 if (!ipv6_addr_any(&fl6.saddr))
3308                         flags |= RT6_LOOKUP_F_HAS_SADDR;
3309
3310                 rt = (struct rt6_info *)ip6_route_input_lookup(net, dev, &fl6,
3311                                                                flags);
3312         } else {
3313                 fl6.flowi6_oif = oif;
3314
3315                 if (netif_index_is_l3_master(net, oif)) {
3316                         fl6.flowi6_flags = FLOWI_FLAG_L3MDEV_SRC |
3317                                            FLOWI_FLAG_SKIP_NH_OIF;
3318                 }
3319
3320                 rt = (struct rt6_info *)ip6_route_output(net, NULL, &fl6);
3321         }
3322
3323         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3324         if (!skb) {
3325                 ip6_rt_put(rt);
3326                 err = -ENOBUFS;
3327                 goto errout;
3328         }
3329
3330         /* Reserve room for dummy headers, this skb can pass
3331            through good chunk of routing engine.
3332          */
3333         skb_reset_mac_header(skb);
3334         skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr));
3335
3336         skb_dst_set(skb, &rt->dst);
3337
3338         err = rt6_fill_node(net, skb, rt, &fl6.daddr, &fl6.saddr, iif,
3339                             RTM_NEWROUTE, NETLINK_CB(in_skb).portid,
3340                             nlh->nlmsg_seq, 0, 0, 0);
3341         if (err < 0) {
3342                 kfree_skb(skb);
3343                 goto errout;
3344         }
3345
3346         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3347 errout:
3348         return err;
3349 }
3350
3351 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info,
3352                      unsigned int nlm_flags)
3353 {
3354         struct sk_buff *skb;
3355         struct net *net = info->nl_net;
3356         u32 seq;
3357         int err;
3358
3359         err = -ENOBUFS;
3360         seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3361
3362         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3363         if (!skb)
3364                 goto errout;
3365
3366         err = rt6_fill_node(net, skb, rt, NULL, NULL, 0,
3367                                 event, info->portid, seq, 0, 0, nlm_flags);
3368         if (err < 0) {
3369                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
3370                 WARN_ON(err == -EMSGSIZE);
3371                 kfree_skb(skb);
3372                 goto errout;
3373         }
3374         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3375                     info->nlh, gfp_any());
3376         return;
3377 errout:
3378         if (err < 0)
3379                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
3380 }
3381
3382 static int ip6_route_dev_notify(struct notifier_block *this,
3383                                 unsigned long event, void *ptr)
3384 {
3385         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3386         struct net *net = dev_net(dev);
3387
3388         if (event == NETDEV_REGISTER && (dev->flags & IFF_LOOPBACK)) {
3389                 net->ipv6.ip6_null_entry->dst.dev = dev;
3390                 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
3391 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3392                 net->ipv6.ip6_prohibit_entry->dst.dev = dev;
3393                 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
3394                 net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
3395                 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
3396 #endif
3397         }
3398
3399         return NOTIFY_OK;
3400 }
3401
3402 /*
3403  *      /proc
3404  */
3405
3406 #ifdef CONFIG_PROC_FS
3407
3408 static const struct file_operations ipv6_route_proc_fops = {
3409         .owner          = THIS_MODULE,
3410         .open           = ipv6_route_open,
3411         .read           = seq_read,
3412         .llseek         = seq_lseek,
3413         .release        = seq_release_net,
3414 };
3415
3416 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
3417 {
3418         struct net *net = (struct net *)seq->private;
3419         seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
3420                    net->ipv6.rt6_stats->fib_nodes,
3421                    net->ipv6.rt6_stats->fib_route_nodes,
3422                    net->ipv6.rt6_stats->fib_rt_alloc,
3423                    net->ipv6.rt6_stats->fib_rt_entries,
3424                    net->ipv6.rt6_stats->fib_rt_cache,
3425                    dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
3426                    net->ipv6.rt6_stats->fib_discarded_routes);
3427
3428         return 0;
3429 }
3430
3431 static int rt6_stats_seq_open(struct inode *inode, struct file *file)
3432 {
3433         return single_open_net(inode, file, rt6_stats_seq_show);
3434 }
3435
3436 static const struct file_operations rt6_stats_seq_fops = {
3437         .owner   = THIS_MODULE,
3438         .open    = rt6_stats_seq_open,
3439         .read    = seq_read,
3440         .llseek  = seq_lseek,
3441         .release = single_release_net,
3442 };
3443 #endif  /* CONFIG_PROC_FS */
3444
3445 #ifdef CONFIG_SYSCTL
3446
3447 static
3448 int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
3449                               void __user *buffer, size_t *lenp, loff_t *ppos)
3450 {
3451         struct net *net;
3452         int delay;
3453         if (!write)
3454                 return -EINVAL;
3455
3456         net = (struct net *)ctl->extra1;
3457         delay = net->ipv6.sysctl.flush_delay;
3458         proc_dointvec(ctl, write, buffer, lenp, ppos);
3459         fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
3460         return 0;
3461 }
3462
3463 struct ctl_table ipv6_route_table_template[] = {
3464         {
3465                 .procname       =       "flush",
3466                 .data           =       &init_net.ipv6.sysctl.flush_delay,
3467                 .maxlen         =       sizeof(int),
3468                 .mode           =       0200,
3469                 .proc_handler   =       ipv6_sysctl_rtcache_flush
3470         },
3471         {
3472                 .procname       =       "gc_thresh",
3473                 .data           =       &ip6_dst_ops_template.gc_thresh,
3474                 .maxlen         =       sizeof(int),
3475                 .mode           =       0644,
3476                 .proc_handler   =       proc_dointvec,
3477         },
3478         {
3479                 .procname       =       "max_size",
3480                 .data           =       &init_net.ipv6.sysctl.ip6_rt_max_size,
3481                 .maxlen         =       sizeof(int),
3482                 .mode           =       0644,
3483                 .proc_handler   =       proc_dointvec,
3484         },
3485         {
3486                 .procname       =       "gc_min_interval",
3487                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
3488                 .maxlen         =       sizeof(int),
3489                 .mode           =       0644,
3490                 .proc_handler   =       proc_dointvec_jiffies,
3491         },
3492         {
3493                 .procname       =       "gc_timeout",
3494                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
3495                 .maxlen         =       sizeof(int),
3496                 .mode           =       0644,
3497                 .proc_handler   =       proc_dointvec_jiffies,
3498         },
3499         {
3500                 .procname       =       "gc_interval",
3501                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_interval,
3502                 .maxlen         =       sizeof(int),
3503                 .mode           =       0644,
3504                 .proc_handler   =       proc_dointvec_jiffies,
3505         },
3506         {
3507                 .procname       =       "gc_elasticity",
3508                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
3509                 .maxlen         =       sizeof(int),
3510                 .mode           =       0644,
3511                 .proc_handler   =       proc_dointvec,
3512         },
3513         {
3514                 .procname       =       "mtu_expires",
3515                 .data           =       &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
3516                 .maxlen         =       sizeof(int),
3517                 .mode           =       0644,
3518                 .proc_handler   =       proc_dointvec_jiffies,
3519         },
3520         {
3521                 .procname       =       "min_adv_mss",
3522                 .data           =       &init_net.ipv6.sysctl.ip6_rt_min_advmss,
3523                 .maxlen         =       sizeof(int),
3524                 .mode           =       0644,
3525                 .proc_handler   =       proc_dointvec,
3526         },
3527         {
3528                 .procname       =       "gc_min_interval_ms",
3529                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
3530                 .maxlen         =       sizeof(int),
3531                 .mode           =       0644,
3532                 .proc_handler   =       proc_dointvec_ms_jiffies,
3533         },
3534         { }
3535 };
3536
3537 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
3538 {
3539         struct ctl_table *table;
3540
3541         table = kmemdup(ipv6_route_table_template,
3542                         sizeof(ipv6_route_table_template),
3543                         GFP_KERNEL);
3544
3545         if (table) {
3546                 table[0].data = &net->ipv6.sysctl.flush_delay;
3547                 table[0].extra1 = net;
3548                 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
3549                 table[2].data = &net->ipv6.sysctl.ip6_rt_max_size;
3550                 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
3551                 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
3552                 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
3553                 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
3554                 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
3555                 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
3556                 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
3557
3558                 /* Don't export sysctls to unprivileged users */
3559                 if (net->user_ns != &init_user_ns)
3560                         table[0].procname = NULL;
3561         }
3562
3563         return table;
3564 }
3565 #endif
3566
3567 static int __net_init ip6_route_net_init(struct net *net)
3568 {
3569         int ret = -ENOMEM;
3570
3571         memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
3572                sizeof(net->ipv6.ip6_dst_ops));
3573
3574         if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
3575                 goto out_ip6_dst_ops;
3576
3577         net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
3578                                            sizeof(*net->ipv6.ip6_null_entry),
3579                                            GFP_KERNEL);
3580         if (!net->ipv6.ip6_null_entry)
3581                 goto out_ip6_dst_entries;
3582         net->ipv6.ip6_null_entry->dst.path =
3583                 (struct dst_entry *)net->ipv6.ip6_null_entry;
3584         net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
3585         dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
3586                          ip6_template_metrics, true);
3587
3588 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3589         net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
3590                                                sizeof(*net->ipv6.ip6_prohibit_entry),
3591                                                GFP_KERNEL);
3592         if (!net->ipv6.ip6_prohibit_entry)
3593                 goto out_ip6_null_entry;
3594         net->ipv6.ip6_prohibit_entry->dst.path =
3595                 (struct dst_entry *)net->ipv6.ip6_prohibit_entry;
3596         net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
3597         dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
3598                          ip6_template_metrics, true);
3599
3600         net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
3601                                                sizeof(*net->ipv6.ip6_blk_hole_entry),
3602                                                GFP_KERNEL);
3603         if (!net->ipv6.ip6_blk_hole_entry)
3604                 goto out_ip6_prohibit_entry;
3605         net->ipv6.ip6_blk_hole_entry->dst.path =
3606                 (struct dst_entry *)net->ipv6.ip6_blk_hole_entry;
3607         net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
3608         dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
3609                          ip6_template_metrics, true);
3610 #endif
3611
3612         net->ipv6.sysctl.flush_delay = 0;
3613         net->ipv6.sysctl.ip6_rt_max_size = 4096;
3614         net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
3615         net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
3616         net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
3617         net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
3618         net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
3619         net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
3620
3621         net->ipv6.ip6_rt_gc_expire = 30*HZ;
3622
3623         ret = 0;
3624 out:
3625         return ret;
3626
3627 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3628 out_ip6_prohibit_entry:
3629         kfree(net->ipv6.ip6_prohibit_entry);
3630 out_ip6_null_entry:
3631         kfree(net->ipv6.ip6_null_entry);
3632 #endif
3633 out_ip6_dst_entries:
3634         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
3635 out_ip6_dst_ops:
3636         goto out;
3637 }
3638
3639 static void __net_exit ip6_route_net_exit(struct net *net)
3640 {
3641         kfree(net->ipv6.ip6_null_entry);
3642 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3643         kfree(net->ipv6.ip6_prohibit_entry);
3644         kfree(net->ipv6.ip6_blk_hole_entry);
3645 #endif
3646         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
3647 }
3648
3649 static int __net_init ip6_route_net_init_late(struct net *net)
3650 {
3651 #ifdef CONFIG_PROC_FS
3652         proc_create("ipv6_route", 0, net->proc_net, &ipv6_route_proc_fops);
3653         proc_create("rt6_stats", S_IRUGO, net->proc_net, &rt6_stats_seq_fops);
3654 #endif
3655         return 0;
3656 }
3657
3658 static void __net_exit ip6_route_net_exit_late(struct net *net)
3659 {
3660 #ifdef CONFIG_PROC_FS
3661         remove_proc_entry("ipv6_route", net->proc_net);
3662         remove_proc_entry("rt6_stats", net->proc_net);
3663 #endif
3664 }
3665
3666 static struct pernet_operations ip6_route_net_ops = {
3667         .init = ip6_route_net_init,
3668         .exit = ip6_route_net_exit,
3669 };
3670
3671 static int __net_init ipv6_inetpeer_init(struct net *net)
3672 {
3673         struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3674
3675         if (!bp)
3676                 return -ENOMEM;
3677         inet_peer_base_init(bp);
3678         net->ipv6.peers = bp;
3679         return 0;
3680 }
3681
3682 static void __net_exit ipv6_inetpeer_exit(struct net *net)
3683 {
3684         struct inet_peer_base *bp = net->ipv6.peers;
3685
3686         net->ipv6.peers = NULL;
3687         inetpeer_invalidate_tree(bp);
3688         kfree(bp);
3689 }
3690
3691 static struct pernet_operations ipv6_inetpeer_ops = {
3692         .init   =       ipv6_inetpeer_init,
3693         .exit   =       ipv6_inetpeer_exit,
3694 };
3695
3696 static struct pernet_operations ip6_route_net_late_ops = {
3697         .init = ip6_route_net_init_late,
3698         .exit = ip6_route_net_exit_late,
3699 };
3700
3701 static struct notifier_block ip6_route_dev_notifier = {
3702         .notifier_call = ip6_route_dev_notify,
3703         .priority = 0,
3704 };
3705
3706 int __init ip6_route_init(void)
3707 {
3708         int ret;
3709         int cpu;
3710
3711         ret = -ENOMEM;
3712         ip6_dst_ops_template.kmem_cachep =
3713                 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
3714                                   SLAB_HWCACHE_ALIGN, NULL);
3715         if (!ip6_dst_ops_template.kmem_cachep)
3716                 goto out;
3717
3718         ret = dst_entries_init(&ip6_dst_blackhole_ops);
3719         if (ret)
3720                 goto out_kmem_cache;
3721
3722         ret = register_pernet_subsys(&ipv6_inetpeer_ops);
3723         if (ret)
3724                 goto out_dst_entries;
3725
3726         ret = register_pernet_subsys(&ip6_route_net_ops);
3727         if (ret)
3728                 goto out_register_inetpeer;
3729
3730         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
3731
3732         /* Registering of the loopback is done before this portion of code,
3733          * the loopback reference in rt6_info will not be taken, do it
3734          * manually for init_net */
3735         init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
3736         init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
3737   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3738         init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
3739         init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
3740         init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
3741         init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
3742   #endif
3743         ret = fib6_init();
3744         if (ret)
3745                 goto out_register_subsys;
3746
3747         ret = xfrm6_init();
3748         if (ret)
3749                 goto out_fib6_init;
3750
3751         ret = fib6_rules_init();
3752         if (ret)
3753                 goto xfrm6_init;
3754
3755         ret = register_pernet_subsys(&ip6_route_net_late_ops);
3756         if (ret)
3757                 goto fib6_rules_init;
3758
3759         ret = -ENOBUFS;
3760         if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL, NULL) ||
3761             __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL, NULL) ||
3762             __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL, NULL))
3763                 goto out_register_late_subsys;
3764
3765         ret = register_netdevice_notifier(&ip6_route_dev_notifier);
3766         if (ret)
3767                 goto out_register_late_subsys;
3768
3769         for_each_possible_cpu(cpu) {
3770                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
3771
3772                 INIT_LIST_HEAD(&ul->head);
3773                 spin_lock_init(&ul->lock);
3774         }
3775
3776 out:
3777         return ret;
3778
3779 out_register_late_subsys:
3780         unregister_pernet_subsys(&ip6_route_net_late_ops);
3781 fib6_rules_init:
3782         fib6_rules_cleanup();
3783 xfrm6_init:
3784         xfrm6_fini();
3785 out_fib6_init:
3786         fib6_gc_cleanup();
3787 out_register_subsys:
3788         unregister_pernet_subsys(&ip6_route_net_ops);
3789 out_register_inetpeer:
3790         unregister_pernet_subsys(&ipv6_inetpeer_ops);
3791 out_dst_entries:
3792         dst_entries_destroy(&ip6_dst_blackhole_ops);
3793 out_kmem_cache:
3794         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
3795         goto out;
3796 }
3797
3798 void ip6_route_cleanup(void)
3799 {
3800         unregister_netdevice_notifier(&ip6_route_dev_notifier);
3801         unregister_pernet_subsys(&ip6_route_net_late_ops);
3802         fib6_rules_cleanup();
3803         xfrm6_fini();
3804         fib6_gc_cleanup();
3805         unregister_pernet_subsys(&ipv6_inetpeer_ops);
3806         unregister_pernet_subsys(&ip6_route_net_ops);
3807         dst_entries_destroy(&ip6_dst_blackhole_ops);
3808         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
3809 }