net/ipv6/route.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Linux INET6 implementation
   4  *      FIB front-end.
   5  *
   6  *      Authors:
   7  *      Pedro Roque             <roque@di.fc.ul.pt>
   8  */
   9
  10 /*      Changes:
  11  *
  12  *      YOSHIFUJI Hideaki @USAGI
  13  *              reworked default router selection.
  14  *              - respect outgoing interface
  15  *              - select from (probably) reachable routers (i.e.
  16  *              routers in REACHABLE, STALE, DELAY or PROBE states).
  17  *              - always select the same router if it is (probably)
  18  *              reachable.  otherwise, round-robin the list.
  19  *      Ville Nuorvala
  20  *              Fixed routing subtrees.
  21  */
  22
  23 #define pr_fmt(fmt) "IPv6: " fmt
  24
  25 #include <linux/capability.h>
  26 #include <linux/errno.h>
  27 #include <linux/export.h>
  28 #include <linux/types.h>
  29 #include <linux/times.h>
  30 #include <linux/socket.h>
  31 #include <linux/sockios.h>
  32 #include <linux/net.h>
  33 #include <linux/route.h>
  34 #include <linux/netdevice.h>
  35 #include <linux/in6.h>
  36 #include <linux/mroute6.h>
  37 #include <linux/init.h>
  38 #include <linux/if_arp.h>
  39 #include <linux/proc_fs.h>
  40 #include <linux/seq_file.h>
  41 #include <linux/nsproxy.h>
  42 #include <linux/slab.h>
  43 #include <linux/jhash.h>
  44 #include <net/net_namespace.h>
  45 #include <net/snmp.h>
  46 #include <net/ipv6.h>
  47 #include <net/ip6_fib.h>
  48 #include <net/ip6_route.h>
  49 #include <net/ndisc.h>
  50 #include <net/addrconf.h>
  51 #include <net/tcp.h>
  52 #include <linux/rtnetlink.h>
  53 #include <net/dst.h>
  54 #include <net/dst_metadata.h>
  55 #include <net/xfrm.h>
  56 #include <net/netevent.h>
  57 #include <net/netlink.h>
  58 #include <net/rtnh.h>
  59 #include <net/lwtunnel.h>
  60 #include <net/ip_tunnels.h>
  61 #include <net/l3mdev.h>
  62 #include <net/ip.h>
  63 #include <linux/uaccess.h>
  64 #include <linux/btf_ids.h>
  65
  66 #ifdef CONFIG_SYSCTL
  67 #include <linux/sysctl.h>
  68 #endif
  69
  70 static int ip6_rt_type_to_error(u8 fib6_type);
  71
  72 #define CREATE_TRACE_POINTS
  73 #include <trace/events/fib6.h>
  74 EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup);
  75 #undef CREATE_TRACE_POINTS
  76
  77 enum rt6_nud_state {
  78         RT6_NUD_FAIL_HARD = -3,
  79         RT6_NUD_FAIL_PROBE = -2,
  80         RT6_NUD_FAIL_DO_RR = -1,
  81         RT6_NUD_SUCCEED = 1
  82 };
  83
  84 INDIRECT_CALLABLE_SCOPE
  85 struct dst_entry        *ip6_dst_check(struct dst_entry *dst, u32 cookie);
  86 static unsigned int      ip6_default_advmss(const struct dst_entry *dst);
  87 INDIRECT_CALLABLE_SCOPE
  88 unsigned int            ip6_mtu(const struct dst_entry *dst);
  89 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
  90 static void             ip6_dst_destroy(struct dst_entry *);
  91 static void             ip6_dst_ifdown(struct dst_entry *,
  92                                        struct net_device *dev, int how);
  93 static int               ip6_dst_gc(struct dst_ops *ops);
  94
  95 static int              ip6_pkt_discard(struct sk_buff *skb);
  96 static int              ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
  97 static int              ip6_pkt_prohibit(struct sk_buff *skb);
  98 static int              ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb);
  99 static void             ip6_link_failure(struct sk_buff *skb);
 100 static void             ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
 101                                            struct sk_buff *skb, u32 mtu,
 102                                            bool confirm_neigh);
 103 static void             rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
 104                                         struct sk_buff *skb);
 105 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
 106                            int strict);
 107 static size_t rt6_nlmsg_size(struct fib6_info *f6i);
 108 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
 109                          struct fib6_info *rt, struct dst_entry *dst,
 110                          struct in6_addr *dest, struct in6_addr *src,
 111                          int iif, int type, u32 portid, u32 seq,
 112                          unsigned int flags);
 113 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
 114                                            const struct in6_addr *daddr,
 115                                            const struct in6_addr *saddr);
 116
 117 #ifdef CONFIG_IPV6_ROUTE_INFO
 118 static struct fib6_info *rt6_add_route_info(struct net *net,
 119                                            const struct in6_addr *prefix, int prefixlen,
 120                                            const struct in6_addr *gwaddr,
 121                                            struct net_device *dev,
 122                                            unsigned int pref);
 123 static struct fib6_info *rt6_get_route_info(struct net *net,
 124                                            const struct in6_addr *prefix, int prefixlen,
 125                                            const struct in6_addr *gwaddr,
 126                                            struct net_device *dev);
 127 #endif
 128
 129 struct uncached_list {
 130         spinlock_t              lock;
 131         struct list_head        head;
 132 };
 133
 134 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
 135
 136 void rt6_uncached_list_add(struct rt6_info *rt)
 137 {
 138         struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list);
 139
 140         rt->rt6i_uncached_list = ul;
 141
 142         spin_lock_bh(&ul->lock);
 143         list_add_tail(&rt->rt6i_uncached, &ul->head);
 144         spin_unlock_bh(&ul->lock);
 145 }
 146
 147 void rt6_uncached_list_del(struct rt6_info *rt)
 148 {
 149         if (!list_empty(&rt->rt6i_uncached)) {
 150                 struct uncached_list *ul = rt->rt6i_uncached_list;
 151                 struct net *net = dev_net(rt->dst.dev);
 152
 153                 spin_lock_bh(&ul->lock);
 154                 list_del(&rt->rt6i_uncached);
 155                 atomic_dec(&net->ipv6.rt6_stats->fib_rt_uncache);
 156                 spin_unlock_bh(&ul->lock);
 157         }
 158 }
 159
 160 static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev)
 161 {
 162         struct net_device *loopback_dev = net->loopback_dev;
 163         int cpu;
 164
 165         if (dev == loopback_dev)
 166                 return;
 167
 168         for_each_possible_cpu(cpu) {
 169                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
 170                 struct rt6_info *rt;
 171
 172                 spin_lock_bh(&ul->lock);
 173                 list_for_each_entry(rt, &ul->head, rt6i_uncached) {
 174                         struct inet6_dev *rt_idev = rt->rt6i_idev;
 175                         struct net_device *rt_dev = rt->dst.dev;
 176
 177                         if (rt_idev->dev == dev) {
 178                                 rt->rt6i_idev = in6_dev_get(loopback_dev);
 179                                 in6_dev_put(rt_idev);
 180                         }
 181
 182                         if (rt_dev == dev) {
 183                                 rt->dst.dev = blackhole_netdev;
 184                                 dev_hold(rt->dst.dev);
 185                                 dev_put(rt_dev);
 186                         }
 187                 }
 188                 spin_unlock_bh(&ul->lock);
 189         }
 190 }
 191
 192 static inline const void *choose_neigh_daddr(const struct in6_addr *p,
 193                                              struct sk_buff *skb,
 194                                              const void *daddr)
 195 {
 196         if (!ipv6_addr_any(p))
 197                 return (const void *) p;
 198         else if (skb)
 199                 return &ipv6_hdr(skb)->daddr;
 200         return daddr;
 201 }
 202
 203 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
 204                                    struct net_device *dev,
 205                                    struct sk_buff *skb,
 206                                    const void *daddr)
 207 {
 208         struct neighbour *n;
 209
 210         daddr = choose_neigh_daddr(gw, skb, daddr);
 211         n = __ipv6_neigh_lookup(dev, daddr);
 212         if (n)
 213                 return n;
 214
 215         n = neigh_create(&nd_tbl, daddr, dev);
 216         return IS_ERR(n) ? NULL : n;
 217 }
 218
 219 static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst,
 220                                               struct sk_buff *skb,
 221                                               const void *daddr)
 222 {
 223         const struct rt6_info *rt = container_of(dst, struct rt6_info, dst);
 224
 225         return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any),
 226                                 dst->dev, skb, daddr);
 227 }
 228
 229 static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr)
 230 {
 231         struct net_device *dev = dst->dev;
 232         struct rt6_info *rt = (struct rt6_info *)dst;
 233
 234         daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr);
 235         if (!daddr)
 236                 return;
 237         if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
 238                 return;
 239         if (ipv6_addr_is_multicast((const struct in6_addr *)daddr))
 240                 return;
 241         __ipv6_confirm_neigh(dev, daddr);
 242 }
 243
 244 static struct dst_ops ip6_dst_ops_template = {
 245         .family                 =       AF_INET6,
 246         .gc                     =       ip6_dst_gc,
 247         .gc_thresh              =       1024,
 248         .check                  =       ip6_dst_check,
 249         .default_advmss         =       ip6_default_advmss,
 250         .mtu                    =       ip6_mtu,
 251         .cow_metrics            =       dst_cow_metrics_generic,
 252         .destroy                =       ip6_dst_destroy,
 253         .ifdown                 =       ip6_dst_ifdown,
 254         .negative_advice        =       ip6_negative_advice,
 255         .link_failure           =       ip6_link_failure,
 256         .update_pmtu            =       ip6_rt_update_pmtu,
 257         .redirect               =       rt6_do_redirect,
 258         .local_out              =       __ip6_local_out,
 259         .neigh_lookup           =       ip6_dst_neigh_lookup,
 260         .confirm_neigh          =       ip6_confirm_neigh,
 261 };
 262
 263 static struct dst_ops ip6_dst_blackhole_ops = {
 264         .family                 = AF_INET6,
 265         .default_advmss         = ip6_default_advmss,
 266         .neigh_lookup           = ip6_dst_neigh_lookup,
 267         .check                  = ip6_dst_check,
 268         .destroy                = ip6_dst_destroy,
 269         .cow_metrics            = dst_cow_metrics_generic,
 270         .update_pmtu            = dst_blackhole_update_pmtu,
 271         .redirect               = dst_blackhole_redirect,
 272         .mtu                    = dst_blackhole_mtu,
 273 };
 274
 275 static const u32 ip6_template_metrics[RTAX_MAX] = {
 276         [RTAX_HOPLIMIT - 1] = 0,
 277 };
 278
 279 static const struct fib6_info fib6_null_entry_template = {
 280         .fib6_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 281         .fib6_protocol  = RTPROT_KERNEL,
 282         .fib6_metric    = ~(u32)0,
 283         .fib6_ref       = REFCOUNT_INIT(1),
 284         .fib6_type      = RTN_UNREACHABLE,
 285         .fib6_metrics   = (struct dst_metrics *)&dst_default_metrics,
 286 };
 287
 288 static const struct rt6_info ip6_null_entry_template = {
 289         .dst = {
 290                 .__refcnt       = ATOMIC_INIT(1),
 291                 .__use          = 1,
 292                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 293                 .error          = -ENETUNREACH,
 294                 .input          = ip6_pkt_discard,
 295                 .output         = ip6_pkt_discard_out,
 296         },
 297         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 298 };
 299
 300 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 301
 302 static const struct rt6_info ip6_prohibit_entry_template = {
 303         .dst = {
 304                 .__refcnt       = ATOMIC_INIT(1),
 305                 .__use          = 1,
 306                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 307                 .error          = -EACCES,
 308                 .input          = ip6_pkt_prohibit,
 309                 .output         = ip6_pkt_prohibit_out,
 310         },
 311         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 312 };
 313
 314 static const struct rt6_info ip6_blk_hole_entry_template = {
 315         .dst = {
 316                 .__refcnt       = ATOMIC_INIT(1),
 317                 .__use          = 1,
 318                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 319                 .error          = -EINVAL,
 320                 .input          = dst_discard,
 321                 .output         = dst_discard_out,
 322         },
 323         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 324 };
 325
 326 #endif
 327
 328 static void rt6_info_init(struct rt6_info *rt)
 329 {
 330         struct dst_entry *dst = &rt->dst;
 331
 332         memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));
 333         INIT_LIST_HEAD(&rt->rt6i_uncached);
 334 }
 335
 336 /* allocate dst with ip6_dst_ops */
 337 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 338                                int flags)
 339 {
 340         struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
 341                                         1, DST_OBSOLETE_FORCE_CHK, flags);
 342
 343         if (rt) {
 344                 rt6_info_init(rt);
 345                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
 346         }
 347
 348         return rt;
 349 }
 350 EXPORT_SYMBOL(ip6_dst_alloc);
 351
 352 static void ip6_dst_destroy(struct dst_entry *dst)
 353 {
 354         struct rt6_info *rt = (struct rt6_info *)dst;
 355         struct fib6_info *from;
 356         struct inet6_dev *idev;
 357
 358         ip_dst_metrics_put(dst);
 359         rt6_uncached_list_del(rt);
 360
 361         idev = rt->rt6i_idev;
 362         if (idev) {
 363                 rt->rt6i_idev = NULL;
 364                 in6_dev_put(idev);
 365         }
 366
 367         from = xchg((__force struct fib6_info **)&rt->from, NULL);
 368         fib6_info_release(from);
 369 }
 370
 371 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 372                            int how)
 373 {
 374         struct rt6_info *rt = (struct rt6_info *)dst;
 375         struct inet6_dev *idev = rt->rt6i_idev;
 376         struct net_device *loopback_dev =
 377                 dev_net(dev)->loopback_dev;
 378
 379         if (idev && idev->dev != loopback_dev) {
 380                 struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);
 381                 if (loopback_idev) {
 382                         rt->rt6i_idev = loopback_idev;
 383                         in6_dev_put(idev);
 384                 }
 385         }
 386 }
 387
 388 static bool __rt6_check_expired(const struct rt6_info *rt)
 389 {
 390         if (rt->rt6i_flags & RTF_EXPIRES)
 391                 return time_after(jiffies, rt->dst.expires);
 392         else
 393                 return false;
 394 }
 395
 396 static bool rt6_check_expired(const struct rt6_info *rt)
 397 {
 398         struct fib6_info *from;
 399
 400         from = rcu_dereference(rt->from);
 401
 402         if (rt->rt6i_flags & RTF_EXPIRES) {
 403                 if (time_after(jiffies, rt->dst.expires))
 404                         return true;
 405         } else if (from) {
 406                 return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
 407                         fib6_check_expired(from);
 408         }
 409         return false;
 410 }
 411
 412 void fib6_select_path(const struct net *net, struct fib6_result *res,
 413                       struct flowi6 *fl6, int oif, bool have_oif_match,
 414                       const struct sk_buff *skb, int strict)
 415 {
 416         struct fib6_info *sibling, *next_sibling;
 417         struct fib6_info *match = res->f6i;
 418
 419         if (!match->nh && (!match->fib6_nsiblings || have_oif_match))
 420                 goto out;
 421
 422         if (match->nh && have_oif_match && res->nh)
 423                 return;
 424
 425         /* We might have already computed the hash for ICMPv6 errors. In such
 426          * case it will always be non-zero. Otherwise now is the time to do it.
 427          */
 428         if (!fl6->mp_hash &&
 429             (!match->nh || nexthop_is_multipath(match->nh)))
 430                 fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
 431
 432         if (unlikely(match->nh)) {
 433                 nexthop_path_fib6_result(res, fl6->mp_hash);
 434                 return;
 435         }
 436
 437         if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
 438                 goto out;
 439
 440         list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
 441                                  fib6_siblings) {
 442                 const struct fib6_nh *nh = sibling->fib6_nh;
 443                 int nh_upper_bound;
 444
 445                 nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
 446                 if (fl6->mp_hash > nh_upper_bound)
 447                         continue;
 448                 if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
 449                         break;
 450                 match = sibling;
 451                 break;
 452         }
 453
 454 out:
 455         res->f6i = match;
 456         res->nh = match->fib6_nh;
 457 }
 458
 459 /*
 460  *      Route lookup. rcu_read_lock() should be held.
 461  */
 462
 463 static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh,
 464                                const struct in6_addr *saddr, int oif, int flags)
 465 {
 466         const struct net_device *dev;
 467
 468         if (nh->fib_nh_flags & RTNH_F_DEAD)
 469                 return false;
 470
 471         dev = nh->fib_nh_dev;
 472         if (oif) {
 473                 if (dev->ifindex == oif)
 474                         return true;
 475         } else {
 476                 if (ipv6_chk_addr(net, saddr, dev,
 477                                   flags & RT6_LOOKUP_F_IFACE))
 478                         return true;
 479         }
 480
 481         return false;
 482 }
 483
 484 struct fib6_nh_dm_arg {
 485         struct net              *net;
 486         const struct in6_addr   *saddr;
 487         int                     oif;
 488         int                     flags;
 489         struct fib6_nh          *nh;
 490 };
 491
 492 static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg)
 493 {
 494         struct fib6_nh_dm_arg *arg = _arg;
 495
 496         arg->nh = nh;
 497         return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif,
 498                                   arg->flags);
 499 }
 500
 501 /* returns fib6_nh from nexthop or NULL */
 502 static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh,
 503                                         struct fib6_result *res,
 504                                         const struct in6_addr *saddr,
 505                                         int oif, int flags)
 506 {
 507         struct fib6_nh_dm_arg arg = {
 508                 .net   = net,
 509                 .saddr = saddr,
 510                 .oif   = oif,
 511                 .flags = flags,
 512         };
 513
 514         if (nexthop_is_blackhole(nh))
 515                 return NULL;
 516
 517         if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg))
 518                 return arg.nh;
 519
 520         return NULL;
 521 }
 522
 523 static void rt6_device_match(struct net *net, struct fib6_result *res,
 524                              const struct in6_addr *saddr, int oif, int flags)
 525 {
 526         struct fib6_info *f6i = res->f6i;
 527         struct fib6_info *spf6i;
 528         struct fib6_nh *nh;
 529
 530         if (!oif && ipv6_addr_any(saddr)) {
 531                 if (unlikely(f6i->nh)) {
 532                         nh = nexthop_fib6_nh(f6i->nh);
 533                         if (nexthop_is_blackhole(f6i->nh))
 534                                 goto out_blackhole;
 535                 } else {
 536                         nh = f6i->fib6_nh;
 537                 }
 538                 if (!(nh->fib_nh_flags & RTNH_F_DEAD))
 539                         goto out;
 540         }
 541
 542         for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
 543                 bool matched = false;
 544
 545                 if (unlikely(spf6i->nh)) {
 546                         nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr,
 547                                               oif, flags);
 548                         if (nh)
 549                                 matched = true;
 550                 } else {
 551                         nh = spf6i->fib6_nh;
 552                         if (__rt6_device_match(net, nh, saddr, oif, flags))
 553                                 matched = true;
 554                 }
 555                 if (matched) {
 556                         res->f6i = spf6i;
 557                         goto out;
 558                 }
 559         }
 560
 561         if (oif && flags & RT6_LOOKUP_F_IFACE) {
 562                 res->f6i = net->ipv6.fib6_null_entry;
 563                 nh = res->f6i->fib6_nh;
 564                 goto out;
 565         }
 566
 567         if (unlikely(f6i->nh)) {
 568                 nh = nexthop_fib6_nh(f6i->nh);
 569                 if (nexthop_is_blackhole(f6i->nh))
 570                         goto out_blackhole;
 571         } else {
 572                 nh = f6i->fib6_nh;
 573         }
 574
 575         if (nh->fib_nh_flags & RTNH_F_DEAD) {
 576                 res->f6i = net->ipv6.fib6_null_entry;
 577                 nh = res->f6i->fib6_nh;
 578         }
 579 out:
 580         res->nh = nh;
 581         res->fib6_type = res->f6i->fib6_type;
 582         res->fib6_flags = res->f6i->fib6_flags;
 583         return;
 584
 585 out_blackhole:
 586         res->fib6_flags |= RTF_REJECT;
 587         res->fib6_type = RTN_BLACKHOLE;
 588         res->nh = nh;
 589 }
 590
 591 #ifdef CONFIG_IPV6_ROUTER_PREF
 592 struct __rt6_probe_work {
 593         struct work_struct work;
 594         struct in6_addr target;
 595         struct net_device *dev;
 596 };
 597
 598 static void rt6_probe_deferred(struct work_struct *w)
 599 {
 600         struct in6_addr mcaddr;
 601         struct __rt6_probe_work *work =
 602                 container_of(w, struct __rt6_probe_work, work);
 603
 604         addrconf_addr_solict_mult(&work->target, &mcaddr);
 605         ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
 606         dev_put(work->dev);
 607         kfree(work);
 608 }
 609
 610 static void rt6_probe(struct fib6_nh *fib6_nh)
 611 {
 612         struct __rt6_probe_work *work = NULL;
 613         const struct in6_addr *nh_gw;
 614         unsigned long last_probe;
 615         struct neighbour *neigh;
 616         struct net_device *dev;
 617         struct inet6_dev *idev;
 618
 619         /*
 620          * Okay, this does not seem to be appropriate
 621          * for now, however, we need to check if it
 622          * is really so; aka Router Reachability Probing.
 623          *
 624          * Router Reachability Probe MUST be rate-limited
 625          * to no more than one per minute.
 626          */
 627         if (!fib6_nh->fib_nh_gw_family)
 628                 return;
 629
 630         nh_gw = &fib6_nh->fib_nh_gw6;
 631         dev = fib6_nh->fib_nh_dev;
 632         rcu_read_lock_bh();
 633         last_probe = READ_ONCE(fib6_nh->last_probe);
 634         idev = __in6_dev_get(dev);
 635         neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
 636         if (neigh) {
 637                 if (neigh->nud_state & NUD_VALID)
 638                         goto out;
 639
 640                 write_lock(&neigh->lock);
 641                 if (!(neigh->nud_state & NUD_VALID) &&
 642                     time_after(jiffies,
 643                                neigh->updated + idev->cnf.rtr_probe_interval)) {
 644                         work = kmalloc(sizeof(*work), GFP_ATOMIC);
 645                         if (work)
 646                                 __neigh_set_probe_once(neigh);
 647                 }
 648                 write_unlock(&neigh->lock);
 649         } else if (time_after(jiffies, last_probe +
 650                                        idev->cnf.rtr_probe_interval)) {
 651                 work = kmalloc(sizeof(*work), GFP_ATOMIC);
 652         }
 653
 654         if (!work || cmpxchg(&fib6_nh->last_probe,
 655                              last_probe, jiffies) != last_probe) {
 656                 kfree(work);
 657         } else {
 658                 INIT_WORK(&work->work, rt6_probe_deferred);
 659                 work->target = *nh_gw;
 660                 dev_hold(dev);
 661                 work->dev = dev;
 662                 schedule_work(&work->work);
 663         }
 664
 665 out:
 666         rcu_read_unlock_bh();
 667 }
 668 #else
 669 static inline void rt6_probe(struct fib6_nh *fib6_nh)
 670 {
 671 }
 672 #endif
 673
 674 /*
 675  * Default Router Selection (RFC 2461 6.3.6)
 676  */
 677 static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh)
 678 {
 679         enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
 680         struct neighbour *neigh;
 681
 682         rcu_read_lock_bh();
 683         neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev,
 684                                           &fib6_nh->fib_nh_gw6);
 685         if (neigh) {
 686                 read_lock(&neigh->lock);
 687                 if (neigh->nud_state & NUD_VALID)
 688                         ret = RT6_NUD_SUCCEED;
 689 #ifdef CONFIG_IPV6_ROUTER_PREF
 690                 else if (!(neigh->nud_state & NUD_FAILED))
 691                         ret = RT6_NUD_SUCCEED;
 692                 else
 693                         ret = RT6_NUD_FAIL_PROBE;
 694 #endif
 695                 read_unlock(&neigh->lock);
 696         } else {
 697                 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
 698                       RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
 699         }
 700         rcu_read_unlock_bh();
 701
 702         return ret;
 703 }
 704
 705 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
 706                            int strict)
 707 {
 708         int m = 0;
 709
 710         if (!oif || nh->fib_nh_dev->ifindex == oif)
 711                 m = 2;
 712
 713         if (!m && (strict & RT6_LOOKUP_F_IFACE))
 714                 return RT6_NUD_FAIL_HARD;
 715 #ifdef CONFIG_IPV6_ROUTER_PREF
 716         m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2;
 717 #endif
 718         if ((strict & RT6_LOOKUP_F_REACHABLE) &&
 719             !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) {
 720                 int n = rt6_check_neigh(nh);
 721                 if (n < 0)
 722                         return n;
 723         }
 724         return m;
 725 }
 726
 727 static bool find_match(struct fib6_nh *nh, u32 fib6_flags,
 728                        int oif, int strict, int *mpri, bool *do_rr)
 729 {
 730         bool match_do_rr = false;
 731         bool rc = false;
 732         int m;
 733
 734         if (nh->fib_nh_flags & RTNH_F_DEAD)
 735                 goto out;
 736
 737         if (ip6_ignore_linkdown(nh->fib_nh_dev) &&
 738             nh->fib_nh_flags & RTNH_F_LINKDOWN &&
 739             !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
 740                 goto out;
 741
 742         m = rt6_score_route(nh, fib6_flags, oif, strict);
 743         if (m == RT6_NUD_FAIL_DO_RR) {
 744                 match_do_rr = true;
 745                 m = 0; /* lowest valid score */
 746         } else if (m == RT6_NUD_FAIL_HARD) {
 747                 goto out;
 748         }
 749
 750         if (strict & RT6_LOOKUP_F_REACHABLE)
 751                 rt6_probe(nh);
 752
 753         /* note that m can be RT6_NUD_FAIL_PROBE at this point */
 754         if (m > *mpri) {
 755                 *do_rr = match_do_rr;
 756                 *mpri = m;
 757                 rc = true;
 758         }
 759 out:
 760         return rc;
 761 }
 762
 763 struct fib6_nh_frl_arg {
 764         u32             flags;
 765         int             oif;
 766         int             strict;
 767         int             *mpri;
 768         bool            *do_rr;
 769         struct fib6_nh  *nh;
 770 };
 771
 772 static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg)
 773 {
 774         struct fib6_nh_frl_arg *arg = _arg;
 775
 776         arg->nh = nh;
 777         return find_match(nh, arg->flags, arg->oif, arg->strict,
 778                           arg->mpri, arg->do_rr);
 779 }
 780
 781 static void __find_rr_leaf(struct fib6_info *f6i_start,
 782                            struct fib6_info *nomatch, u32 metric,
 783                            struct fib6_result *res, struct fib6_info **cont,
 784                            int oif, int strict, bool *do_rr, int *mpri)
 785 {
 786         struct fib6_info *f6i;
 787
 788         for (f6i = f6i_start;
 789              f6i && f6i != nomatch;
 790              f6i = rcu_dereference(f6i->fib6_next)) {
 791                 bool matched = false;
 792                 struct fib6_nh *nh;
 793
 794                 if (cont && f6i->fib6_metric != metric) {
 795                         *cont = f6i;
 796                         return;
 797                 }
 798
 799                 if (fib6_check_expired(f6i))
 800                         continue;
 801
 802                 if (unlikely(f6i->nh)) {
 803                         struct fib6_nh_frl_arg arg = {
 804                                 .flags  = f6i->fib6_flags,
 805                                 .oif    = oif,
 806                                 .strict = strict,
 807                                 .mpri   = mpri,
 808                                 .do_rr  = do_rr
 809                         };
 810
 811                         if (nexthop_is_blackhole(f6i->nh)) {
 812                                 res->fib6_flags = RTF_REJECT;
 813                                 res->fib6_type = RTN_BLACKHOLE;
 814                                 res->f6i = f6i;
 815                                 res->nh = nexthop_fib6_nh(f6i->nh);
 816                                 return;
 817                         }
 818                         if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match,
 819                                                      &arg)) {
 820                                 matched = true;
 821                                 nh = arg.nh;
 822                         }
 823                 } else {
 824                         nh = f6i->fib6_nh;
 825                         if (find_match(nh, f6i->fib6_flags, oif, strict,
 826                                        mpri, do_rr))
 827                                 matched = true;
 828                 }
 829                 if (matched) {
 830                         res->f6i = f6i;
 831                         res->nh = nh;
 832                         res->fib6_flags = f6i->fib6_flags;
 833                         res->fib6_type = f6i->fib6_type;
 834                 }
 835         }
 836 }
 837
 838 static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf,
 839                          struct fib6_info *rr_head, int oif, int strict,
 840                          bool *do_rr, struct fib6_result *res)
 841 {
 842         u32 metric = rr_head->fib6_metric;
 843         struct fib6_info *cont = NULL;
 844         int mpri = -1;
 845
 846         __find_rr_leaf(rr_head, NULL, metric, res, &cont,
 847                        oif, strict, do_rr, &mpri);
 848
 849         __find_rr_leaf(leaf, rr_head, metric, res, &cont,
 850                        oif, strict, do_rr, &mpri);
 851
 852         if (res->f6i || !cont)
 853                 return;
 854
 855         __find_rr_leaf(cont, NULL, metric, res, NULL,
 856                        oif, strict, do_rr, &mpri);
 857 }
 858
 859 static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
 860                        struct fib6_result *res, int strict)
 861 {
 862         struct fib6_info *leaf = rcu_dereference(fn->leaf);
 863         struct fib6_info *rt0;
 864         bool do_rr = false;
 865         int key_plen;
 866
 867         /* make sure this function or its helpers sets f6i */
 868         res->f6i = NULL;
 869
 870         if (!leaf || leaf == net->ipv6.fib6_null_entry)
 871                 goto out;
 872
 873         rt0 = rcu_dereference(fn->rr_ptr);
 874         if (!rt0)
 875                 rt0 = leaf;
 876
 877         /* Double check to make sure fn is not an intermediate node
 878          * and fn->leaf does not points to its child's leaf
 879          * (This might happen if all routes under fn are deleted from
 880          * the tree and fib6_repair_tree() is called on the node.)
 881          */
 882         key_plen = rt0->fib6_dst.plen;
 883 #ifdef CONFIG_IPV6_SUBTREES
 884         if (rt0->fib6_src.plen)
 885                 key_plen = rt0->fib6_src.plen;
 886 #endif
 887         if (fn->fn_bit != key_plen)
 888                 goto out;
 889
 890         find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res);
 891         if (do_rr) {
 892                 struct fib6_info *next = rcu_dereference(rt0->fib6_next);
 893
 894                 /* no entries matched; do round-robin */
 895                 if (!next || next->fib6_metric != rt0->fib6_metric)
 896                         next = leaf;
 897
 898                 if (next != rt0) {
 899                         spin_lock_bh(&leaf->fib6_table->tb6_lock);
 900                         /* make sure next is not being deleted from the tree */
 901                         if (next->fib6_node)
 902                                 rcu_assign_pointer(fn->rr_ptr, next);
 903                         spin_unlock_bh(&leaf->fib6_table->tb6_lock);
 904                 }
 905         }
 906
 907 out:
 908         if (!res->f6i) {
 909                 res->f6i = net->ipv6.fib6_null_entry;
 910                 res->nh = res->f6i->fib6_nh;
 911                 res->fib6_flags = res->f6i->fib6_flags;
 912                 res->fib6_type = res->f6i->fib6_type;
 913         }
 914 }
 915
 916 static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res)
 917 {
 918         return (res->f6i->fib6_flags & RTF_NONEXTHOP) ||
 919                res->nh->fib_nh_gw_family;
 920 }
 921
 922 #ifdef CONFIG_IPV6_ROUTE_INFO
 923 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 924                   const struct in6_addr *gwaddr)
 925 {
 926         struct net *net = dev_net(dev);
 927         struct route_info *rinfo = (struct route_info *) opt;
 928         struct in6_addr prefix_buf, *prefix;
 929         unsigned int pref;
 930         unsigned long lifetime;
 931         struct fib6_info *rt;
 932
 933         if (len < sizeof(struct route_info)) {
 934                 return -EINVAL;
 935         }
 936
 937         /* Sanity check for prefix_len and length */
 938         if (rinfo->length > 3) {
 939                 return -EINVAL;
 940         } else if (rinfo->prefix_len > 128) {
 941                 return -EINVAL;
 942         } else if (rinfo->prefix_len > 64) {
 943                 if (rinfo->length < 2) {
 944                         return -EINVAL;
 945                 }
 946         } else if (rinfo->prefix_len > 0) {
 947                 if (rinfo->length < 1) {
 948                         return -EINVAL;
 949                 }
 950         }
 951
 952         pref = rinfo->route_pref;
 953         if (pref == ICMPV6_ROUTER_PREF_INVALID)
 954                 return -EINVAL;
 955
 956         lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
 957
 958         if (rinfo->length == 3)
 959                 prefix = (struct in6_addr *)rinfo->prefix;
 960         else {
 961                 /* this function is safe */
 962                 ipv6_addr_prefix(&prefix_buf,
 963                                  (struct in6_addr *)rinfo->prefix,
 964                                  rinfo->prefix_len);
 965                 prefix = &prefix_buf;
 966         }
 967
 968         if (rinfo->prefix_len == 0)
 969                 rt = rt6_get_dflt_router(net, gwaddr, dev);
 970         else
 971                 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
 972                                         gwaddr, dev);
 973
 974         if (rt && !lifetime) {
 975                 ip6_del_rt(net, rt, false);
 976                 rt = NULL;
 977         }
 978
 979         if (!rt && lifetime)
 980                 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
 981                                         dev, pref);
 982         else if (rt)
 983                 rt->fib6_flags = RTF_ROUTEINFO |
 984                                  (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 985
 986         if (rt) {
 987                 if (!addrconf_finite_timeout(lifetime))
 988                         fib6_clean_expires(rt);
 989                 else
 990                         fib6_set_expires(rt, jiffies + HZ * lifetime);
 991
 992                 fib6_info_release(rt);
 993         }
 994         return 0;
 995 }
 996 #endif
 997
 998 /*
 999  *      Misc support functions
1000  */
1001
1002 /* called with rcu_lock held */
1003 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
1004 {
1005         struct net_device *dev = res->nh->fib_nh_dev;
1006
1007         if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
1008                 /* for copies of local routes, dst->dev needs to be the
1009                  * device if it is a master device, the master device if
1010                  * device is enslaved, and the loopback as the default
1011                  */
1012                 if (netif_is_l3_slave(dev) &&
1013                     !rt6_need_strict(&res->f6i->fib6_dst.addr))
1014                         dev = l3mdev_master_dev_rcu(dev);
1015                 else if (!netif_is_l3_master(dev))
1016                         dev = dev_net(dev)->loopback_dev;
1017                 /* last case is netif_is_l3_master(dev) is true in which
1018                  * case we want dev returned to be dev
1019                  */
1020         }
1021
1022         return dev;
1023 }
1024
1025 static const int fib6_prop[RTN_MAX + 1] = {
1026         [RTN_UNSPEC]    = 0,
1027         [RTN_UNICAST]   = 0,
1028         [RTN_LOCAL]     = 0,
1029         [RTN_BROADCAST] = 0,
1030         [RTN_ANYCAST]   = 0,
1031         [RTN_MULTICAST] = 0,
1032         [RTN_BLACKHOLE] = -EINVAL,
1033         [RTN_UNREACHABLE] = -EHOSTUNREACH,
1034         [RTN_PROHIBIT]  = -EACCES,
1035         [RTN_THROW]     = -EAGAIN,
1036         [RTN_NAT]       = -EINVAL,
1037         [RTN_XRESOLVE]  = -EINVAL,
1038 };
1039
1040 static int ip6_rt_type_to_error(u8 fib6_type)
1041 {
1042         return fib6_prop[fib6_type];
1043 }
1044
1045 static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
1046 {
1047         unsigned short flags = 0;
1048
1049         if (rt->dst_nocount)
1050                 flags |= DST_NOCOUNT;
1051         if (rt->dst_nopolicy)
1052                 flags |= DST_NOPOLICY;
1053
1054         return flags;
1055 }
1056
1057 static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
1058 {
1059         rt->dst.error = ip6_rt_type_to_error(fib6_type);
1060
1061         switch (fib6_type) {
1062         case RTN_BLACKHOLE:
1063                 rt->dst.output = dst_discard_out;
1064                 rt->dst.input = dst_discard;
1065                 break;
1066         case RTN_PROHIBIT:
1067                 rt->dst.output = ip6_pkt_prohibit_out;
1068                 rt->dst.input = ip6_pkt_prohibit;
1069                 break;
1070         case RTN_THROW:
1071         case RTN_UNREACHABLE:
1072         default:
1073                 rt->dst.output = ip6_pkt_discard_out;
1074                 rt->dst.input = ip6_pkt_discard;
1075                 break;
1076         }
1077 }
1078
1079 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
1080 {
1081         struct fib6_info *f6i = res->f6i;
1082
1083         if (res->fib6_flags & RTF_REJECT) {
1084                 ip6_rt_init_dst_reject(rt, res->fib6_type);
1085                 return;
1086         }
1087
1088         rt->dst.error = 0;
1089         rt->dst.output = ip6_output;
1090
1091         if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
1092                 rt->dst.input = ip6_input;
1093         } else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
1094                 rt->dst.input = ip6_mc_input;
1095         } else {
1096                 rt->dst.input = ip6_forward;
1097         }
1098
1099         if (res->nh->fib_nh_lws) {
1100                 rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws);
1101                 lwtunnel_set_redirect(&rt->dst);
1102         }
1103
1104         rt->dst.lastuse = jiffies;
1105 }
1106
1107 /* Caller must already hold reference to @from */
1108 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
1109 {
1110         rt->rt6i_flags &= ~RTF_EXPIRES;
1111         rcu_assign_pointer(rt->from, from);
1112         ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
1113 }
1114
1115 /* Caller must already hold reference to f6i in result */
1116 static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
1117 {
1118         const struct fib6_nh *nh = res->nh;
1119         const struct net_device *dev = nh->fib_nh_dev;
1120         struct fib6_info *f6i = res->f6i;
1121
1122         ip6_rt_init_dst(rt, res);
1123
1124         rt->rt6i_dst = f6i->fib6_dst;
1125         rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
1126         rt->rt6i_flags = res->fib6_flags;
1127         if (nh->fib_nh_gw_family) {
1128                 rt->rt6i_gateway = nh->fib_nh_gw6;
1129                 rt->rt6i_flags |= RTF_GATEWAY;
1130         }
1131         rt6_set_from(rt, f6i);
1132 #ifdef CONFIG_IPV6_SUBTREES
1133         rt->rt6i_src = f6i->fib6_src;
1134 #endif
1135 }
1136
1137 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
1138                                         struct in6_addr *saddr)
1139 {
1140         struct fib6_node *pn, *sn;
1141         while (1) {
1142                 if (fn->fn_flags & RTN_TL_ROOT)
1143                         return NULL;
1144                 pn = rcu_dereference(fn->parent);
1145                 sn = FIB6_SUBTREE(pn);
1146                 if (sn && sn != fn)
1147                         fn = fib6_node_lookup(sn, NULL, saddr);
1148                 else
1149                         fn = pn;
1150                 if (fn->fn_flags & RTN_RTINFO)
1151                         return fn;
1152         }
1153 }
1154
1155 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt)
1156 {
1157         struct rt6_info *rt = *prt;
1158
1159         if (dst_hold_safe(&rt->dst))
1160                 return true;
1161         if (net) {
1162                 rt = net->ipv6.ip6_null_entry;
1163                 dst_hold(&rt->dst);
1164         } else {
1165                 rt = NULL;
1166         }
1167         *prt = rt;
1168         return false;
1169 }
1170
1171 /* called with rcu_lock held */
1172 static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res)
1173 {
1174         struct net_device *dev = res->nh->fib_nh_dev;
1175         struct fib6_info *f6i = res->f6i;
1176         unsigned short flags;
1177         struct rt6_info *nrt;
1178
1179         if (!fib6_info_hold_safe(f6i))
1180                 goto fallback;
1181
1182         flags = fib6_info_dst_flags(f6i);
1183         nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
1184         if (!nrt) {
1185                 fib6_info_release(f6i);
1186                 goto fallback;
1187         }
1188
1189         ip6_rt_copy_init(nrt, res);
1190         return nrt;
1191
1192 fallback:
1193         nrt = dev_net(dev)->ipv6.ip6_null_entry;
1194         dst_hold(&nrt->dst);
1195         return nrt;
1196 }
1197
1198 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net,
1199                                              struct fib6_table *table,
1200                                              struct flowi6 *fl6,
1201                                              const struct sk_buff *skb,
1202                                              int flags)
1203 {
1204         struct fib6_result res = {};
1205         struct fib6_node *fn;
1206         struct rt6_info *rt;
1207
1208         if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
1209                 flags &= ~RT6_LOOKUP_F_IFACE;
1210
1211         rcu_read_lock();
1212         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1213 restart:
1214         res.f6i = rcu_dereference(fn->leaf);
1215         if (!res.f6i)
1216                 res.f6i = net->ipv6.fib6_null_entry;
1217         else
1218                 rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif,
1219                                  flags);
1220
1221         if (res.f6i == net->ipv6.fib6_null_entry) {
1222                 fn = fib6_backtrack(fn, &fl6->saddr);
1223                 if (fn)
1224                         goto restart;
1225
1226                 rt = net->ipv6.ip6_null_entry;
1227                 dst_hold(&rt->dst);
1228                 goto out;
1229         } else if (res.fib6_flags & RTF_REJECT) {
1230                 goto do_create;
1231         }
1232
1233         fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
1234                          fl6->flowi6_oif != 0, skb, flags);
1235
1236         /* Search through exception table */
1237         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
1238         if (rt) {
1239                 if (ip6_hold_safe(net, &rt))
1240                         dst_use_noref(&rt->dst, jiffies);
1241         } else {
1242 do_create:
1243                 rt = ip6_create_rt_rcu(&res);
1244         }
1245
1246 out:
1247         trace_fib6_table_lookup(net, &res, table, fl6);
1248
1249         rcu_read_unlock();
1250
1251         return rt;
1252 }
1253
1254 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
1255                                    const struct sk_buff *skb, int flags)
1256 {
1257         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
1258 }
1259 EXPORT_SYMBOL_GPL(ip6_route_lookup);
1260
1261 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
1262                             const struct in6_addr *saddr, int oif,
1263                             const struct sk_buff *skb, int strict)
1264 {
1265         struct flowi6 fl6 = {
1266                 .flowi6_oif = oif,
1267                 .daddr = *daddr,
1268         };
1269         struct dst_entry *dst;
1270         int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
1271
1272         if (saddr) {
1273                 memcpy(&fl6.saddr, saddr, sizeof(*saddr));
1274                 flags |= RT6_LOOKUP_F_HAS_SADDR;
1275         }
1276
1277         dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
1278         if (dst->error == 0)
1279                 return (struct rt6_info *) dst;
1280
1281         dst_release(dst);
1282
1283         return NULL;
1284 }
1285 EXPORT_SYMBOL(rt6_lookup);
1286
1287 /* ip6_ins_rt is called with FREE table->tb6_lock.
1288  * It takes new route entry, the addition fails by any reason the
1289  * route is released.
1290  * Caller must hold dst before calling it.
1291  */
1292
1293 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
1294                         struct netlink_ext_ack *extack)
1295 {
1296         int err;
1297         struct fib6_table *table;
1298
1299         table = rt->fib6_table;
1300         spin_lock_bh(&table->tb6_lock);
1301         err = fib6_add(&table->tb6_root, rt, info, extack);
1302         spin_unlock_bh(&table->tb6_lock);
1303
1304         return err;
1305 }
1306
1307 int ip6_ins_rt(struct net *net, struct fib6_info *rt)
1308 {
1309         struct nl_info info = { .nl_net = net, };
1310
1311         return __ip6_ins_rt(rt, &info, NULL);
1312 }
1313
1314 static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res,
1315                                            const struct in6_addr *daddr,
1316                                            const struct in6_addr *saddr)
1317 {
1318         struct fib6_info *f6i = res->f6i;
1319         struct net_device *dev;
1320         struct rt6_info *rt;
1321
1322         /*
1323          *      Clone the route.
1324          */
1325
1326         if (!fib6_info_hold_safe(f6i))
1327                 return NULL;
1328
1329         dev = ip6_rt_get_dev_rcu(res);
1330         rt = ip6_dst_alloc(dev_net(dev), dev, 0);
1331         if (!rt) {
1332                 fib6_info_release(f6i);
1333                 return NULL;
1334         }
1335
1336         ip6_rt_copy_init(rt, res);
1337         rt->rt6i_flags |= RTF_CACHE;
1338         rt->rt6i_dst.addr = *daddr;
1339         rt->rt6i_dst.plen = 128;
1340
1341         if (!rt6_is_gw_or_nonexthop(res)) {
1342                 if (f6i->fib6_dst.plen != 128 &&
1343                     ipv6_addr_equal(&f6i->fib6_dst.addr, daddr))
1344                         rt->rt6i_flags |= RTF_ANYCAST;
1345 #ifdef CONFIG_IPV6_SUBTREES
1346                 if (rt->rt6i_src.plen && saddr) {
1347                         rt->rt6i_src.addr = *saddr;
1348                         rt->rt6i_src.plen = 128;
1349                 }
1350 #endif
1351         }
1352
1353         return rt;
1354 }
1355
1356 static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res)
1357 {
1358         struct fib6_info *f6i = res->f6i;
1359         unsigned short flags = fib6_info_dst_flags(f6i);
1360         struct net_device *dev;
1361         struct rt6_info *pcpu_rt;
1362
1363         if (!fib6_info_hold_safe(f6i))
1364                 return NULL;
1365
1366         rcu_read_lock();
1367         dev = ip6_rt_get_dev_rcu(res);
1368         pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT);
1369         rcu_read_unlock();
1370         if (!pcpu_rt) {
1371                 fib6_info_release(f6i);
1372                 return NULL;
1373         }
1374         ip6_rt_copy_init(pcpu_rt, res);
1375         pcpu_rt->rt6i_flags |= RTF_PCPU;
1376
1377         if (f6i->nh)
1378                 pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev));
1379
1380         return pcpu_rt;
1381 }
1382
1383 static bool rt6_is_valid(const struct rt6_info *rt6)
1384 {
1385         return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev));
1386 }
1387
1388 /* It should be called with rcu_read_lock() acquired */
1389 static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
1390 {
1391         struct rt6_info *pcpu_rt;
1392
1393         pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
1394
1395         if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) {
1396                 struct rt6_info *prev, **p;
1397
1398                 p = this_cpu_ptr(res->nh->rt6i_pcpu);
1399                 prev = xchg(p, NULL);
1400                 if (prev) {
1401                         dst_dev_put(&prev->dst);
1402                         dst_release(&prev->dst);
1403                 }
1404
1405                 pcpu_rt = NULL;
1406         }
1407
1408         return pcpu_rt;
1409 }
1410
1411 static struct rt6_info *rt6_make_pcpu_route(struct net *net,
1412                                             const struct fib6_result *res)
1413 {
1414         struct rt6_info *pcpu_rt, *prev, **p;
1415
1416         pcpu_rt = ip6_rt_pcpu_alloc(res);
1417         if (!pcpu_rt)
1418                 return NULL;
1419
1420         p = this_cpu_ptr(res->nh->rt6i_pcpu);
1421         prev = cmpxchg(p, NULL, pcpu_rt);
1422         BUG_ON(prev);
1423
1424         if (res->f6i->fib6_destroying) {
1425                 struct fib6_info *from;
1426
1427                 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
1428                 fib6_info_release(from);
1429         }
1430
1431         return pcpu_rt;
1432 }
1433
1434 /* exception hash table implementation
1435  */
1436 static DEFINE_SPINLOCK(rt6_exception_lock);
1437
1438 /* Remove rt6_ex from hash table and free the memory
1439  * Caller must hold rt6_exception_lock
1440  */
1441 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
1442                                  struct rt6_exception *rt6_ex)
1443 {
1444         struct fib6_info *from;
1445         struct net *net;
1446
1447         if (!bucket || !rt6_ex)
1448                 return;
1449
1450         net = dev_net(rt6_ex->rt6i->dst.dev);
1451         net->ipv6.rt6_stats->fib_rt_cache--;
1452
1453         /* purge completely the exception to allow releasing the held resources:
1454          * some [sk] cache may keep the dst around for unlimited time
1455          */
1456         from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL);
1457         fib6_info_release(from);
1458         dst_dev_put(&rt6_ex->rt6i->dst);
1459
1460         hlist_del_rcu(&rt6_ex->hlist);
1461         dst_release(&rt6_ex->rt6i->dst);
1462         kfree_rcu(rt6_ex, rcu);
1463         WARN_ON_ONCE(!bucket->depth);
1464         bucket->depth--;
1465 }
1466
1467 /* Remove oldest rt6_ex in bucket and free the memory
1468  * Caller must hold rt6_exception_lock
1469  */
1470 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
1471 {
1472         struct rt6_exception *rt6_ex, *oldest = NULL;
1473
1474         if (!bucket)
1475                 return;
1476
1477         hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
1478                 if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
1479                         oldest = rt6_ex;
1480         }
1481         rt6_remove_exception(bucket, oldest);
1482 }
1483
1484 static u32 rt6_exception_hash(const struct in6_addr *dst,
1485                               const struct in6_addr *src)
1486 {
1487         static u32 seed __read_mostly;
1488         u32 val;
1489
1490         net_get_random_once(&seed, sizeof(seed));
1491         val = jhash2((const u32 *)dst, sizeof(*dst)/sizeof(u32), seed);
1492
1493 #ifdef CONFIG_IPV6_SUBTREES
1494         if (src)
1495                 val = jhash2((const u32 *)src, sizeof(*src)/sizeof(u32), val);
1496 #endif
1497         return hash_32(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
1498 }
1499
1500 /* Helper function to find the cached rt in the hash table
1501  * and update bucket pointer to point to the bucket for this
1502  * (daddr, saddr) pair
1503  * Caller must hold rt6_exception_lock
1504  */
1505 static struct rt6_exception *
1506 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
1507                               const struct in6_addr *daddr,
1508                               const struct in6_addr *saddr)
1509 {
1510         struct rt6_exception *rt6_ex;
1511         u32 hval;
1512
1513         if (!(*bucket) || !daddr)
1514                 return NULL;
1515
1516         hval = rt6_exception_hash(daddr, saddr);
1517         *bucket += hval;
1518
1519         hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
1520                 struct rt6_info *rt6 = rt6_ex->rt6i;
1521                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1522
1523 #ifdef CONFIG_IPV6_SUBTREES
1524                 if (matched && saddr)
1525                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1526 #endif
1527                 if (matched)
1528                         return rt6_ex;
1529         }
1530         return NULL;
1531 }
1532
1533 /* Helper function to find the cached rt in the hash table
1534  * and update bucket pointer to point to the bucket for this
1535  * (daddr, saddr) pair
1536  * Caller must hold rcu_read_lock()
1537  */
1538 static struct rt6_exception *
1539 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
1540                          const struct in6_addr *daddr,
1541                          const struct in6_addr *saddr)
1542 {
1543         struct rt6_exception *rt6_ex;
1544         u32 hval;
1545
1546         WARN_ON_ONCE(!rcu_read_lock_held());
1547
1548         if (!(*bucket) || !daddr)
1549                 return NULL;
1550
1551         hval = rt6_exception_hash(daddr, saddr);
1552         *bucket += hval;
1553
1554         hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
1555                 struct rt6_info *rt6 = rt6_ex->rt6i;
1556                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1557
1558 #ifdef CONFIG_IPV6_SUBTREES
1559                 if (matched && saddr)
1560                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1561 #endif
1562                 if (matched)
1563                         return rt6_ex;
1564         }
1565         return NULL;
1566 }
1567
1568 static unsigned int fib6_mtu(const struct fib6_result *res)
1569 {
1570         const struct fib6_nh *nh = res->nh;
1571         unsigned int mtu;
1572
1573         if (res->f6i->fib6_pmtu) {
1574                 mtu = res->f6i->fib6_pmtu;
1575         } else {
1576                 struct net_device *dev = nh->fib_nh_dev;
1577                 struct inet6_dev *idev;
1578
1579                 rcu_read_lock();
1580                 idev = __in6_dev_get(dev);
1581                 mtu = idev->cnf.mtu6;
1582                 rcu_read_unlock();
1583         }
1584
1585         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
1586
1587         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
1588 }
1589
1590 #define FIB6_EXCEPTION_BUCKET_FLUSHED  0x1UL
1591
1592 /* used when the flushed bit is not relevant, only access to the bucket
1593  * (ie., all bucket users except rt6_insert_exception);
1594  *
1595  * called under rcu lock; sometimes called with rt6_exception_lock held
1596  */
1597 static
1598 struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh,
1599                                                        spinlock_t *lock)
1600 {
1601         struct rt6_exception_bucket *bucket;
1602
1603         if (lock)
1604                 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1605                                                    lockdep_is_held(lock));
1606         else
1607                 bucket = rcu_dereference(nh->rt6i_exception_bucket);
1608
1609         /* remove bucket flushed bit if set */
1610         if (bucket) {
1611                 unsigned long p = (unsigned long)bucket;
1612
1613                 p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED;
1614                 bucket = (struct rt6_exception_bucket *)p;
1615         }
1616
1617         return bucket;
1618 }
1619
1620 static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket)
1621 {
1622         unsigned long p = (unsigned long)bucket;
1623
1624         return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED);
1625 }
1626
1627 /* called with rt6_exception_lock held */
1628 static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh,
1629                                               spinlock_t *lock)
1630 {
1631         struct rt6_exception_bucket *bucket;
1632         unsigned long p;
1633
1634         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1635                                            lockdep_is_held(lock));
1636
1637         p = (unsigned long)bucket;
1638         p |= FIB6_EXCEPTION_BUCKET_FLUSHED;
1639         bucket = (struct rt6_exception_bucket *)p;
1640         rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1641 }
1642
1643 static int rt6_insert_exception(struct rt6_info *nrt,
1644                                 const struct fib6_result *res)
1645 {
1646         struct net *net = dev_net(nrt->dst.dev);
1647         struct rt6_exception_bucket *bucket;
1648         struct fib6_info *f6i = res->f6i;
1649         struct in6_addr *src_key = NULL;
1650         struct rt6_exception *rt6_ex;
1651         struct fib6_nh *nh = res->nh;
1652         int err = 0;
1653
1654         spin_lock_bh(&rt6_exception_lock);
1655
1656         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1657                                           lockdep_is_held(&rt6_exception_lock));
1658         if (!bucket) {
1659                 bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
1660                                  GFP_ATOMIC);
1661                 if (!bucket) {
1662                         err = -ENOMEM;
1663                         goto out;
1664                 }
1665                 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1666         } else if (fib6_nh_excptn_bucket_flushed(bucket)) {
1667                 err = -EINVAL;
1668                 goto out;
1669         }
1670
1671 #ifdef CONFIG_IPV6_SUBTREES
1672         /* fib6_src.plen != 0 indicates f6i is in subtree
1673          * and exception table is indexed by a hash of
1674          * both fib6_dst and fib6_src.
1675          * Otherwise, the exception table is indexed by
1676          * a hash of only fib6_dst.
1677          */
1678         if (f6i->fib6_src.plen)
1679                 src_key = &nrt->rt6i_src.addr;
1680 #endif
1681         /* rt6_mtu_change() might lower mtu on f6i.
1682          * Only insert this exception route if its mtu
1683          * is less than f6i's mtu value.
1684          */
1685         if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) {
1686                 err = -EINVAL;
1687                 goto out;
1688         }
1689
1690         rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
1691                                                src_key);
1692         if (rt6_ex)
1693                 rt6_remove_exception(bucket, rt6_ex);
1694
1695         rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
1696         if (!rt6_ex) {
1697                 err = -ENOMEM;
1698                 goto out;
1699         }
1700         rt6_ex->rt6i = nrt;
1701         rt6_ex->stamp = jiffies;
1702         hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
1703         bucket->depth++;
1704         net->ipv6.rt6_stats->fib_rt_cache++;
1705
1706         if (bucket->depth > FIB6_MAX_DEPTH)
1707                 rt6_exception_remove_oldest(bucket);
1708
1709 out:
1710         spin_unlock_bh(&rt6_exception_lock);
1711
1712         /* Update fn->fn_sernum to invalidate all cached dst */
1713         if (!err) {
1714                 spin_lock_bh(&f6i->fib6_table->tb6_lock);
1715                 fib6_update_sernum(net, f6i);
1716                 spin_unlock_bh(&f6i->fib6_table->tb6_lock);
1717                 fib6_force_start_gc(net);
1718         }
1719
1720         return err;
1721 }
1722
1723 static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
1724 {
1725         struct rt6_exception_bucket *bucket;
1726         struct rt6_exception *rt6_ex;
1727         struct hlist_node *tmp;
1728         int i;
1729
1730         spin_lock_bh(&rt6_exception_lock);
1731
1732         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1733         if (!bucket)
1734                 goto out;
1735
1736         /* Prevent rt6_insert_exception() to recreate the bucket list */
1737         if (!from)
1738                 fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock);
1739
1740         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1741                 hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) {
1742                         if (!from ||
1743                             rcu_access_pointer(rt6_ex->rt6i->from) == from)
1744                                 rt6_remove_exception(bucket, rt6_ex);
1745                 }
1746                 WARN_ON_ONCE(!from && bucket->depth);
1747                 bucket++;
1748         }
1749 out:
1750         spin_unlock_bh(&rt6_exception_lock);
1751 }
1752
1753 static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg)
1754 {
1755         struct fib6_info *f6i = arg;
1756
1757         fib6_nh_flush_exceptions(nh, f6i);
1758
1759         return 0;
1760 }
1761
1762 void rt6_flush_exceptions(struct fib6_info *f6i)
1763 {
1764         if (f6i->nh)
1765                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions,
1766                                          f6i);
1767         else
1768                 fib6_nh_flush_exceptions(f6i->fib6_nh, f6i);
1769 }
1770
1771 /* Find cached rt in the hash table inside passed in rt
1772  * Caller has to hold rcu_read_lock()
1773  */
1774 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
1775                                            const struct in6_addr *daddr,
1776                                            const struct in6_addr *saddr)
1777 {
1778         const struct in6_addr *src_key = NULL;
1779         struct rt6_exception_bucket *bucket;
1780         struct rt6_exception *rt6_ex;
1781         struct rt6_info *ret = NULL;
1782
1783 #ifdef CONFIG_IPV6_SUBTREES
1784         /* fib6i_src.plen != 0 indicates f6i is in subtree
1785          * and exception table is indexed by a hash of
1786          * both fib6_dst and fib6_src.
1787          * However, the src addr used to create the hash
1788          * might not be exactly the passed in saddr which
1789          * is a /128 addr from the flow.
1790          * So we need to use f6i->fib6_src to redo lookup
1791          * if the passed in saddr does not find anything.
1792          * (See the logic in ip6_rt_cache_alloc() on how
1793          * rt->rt6i_src is updated.)
1794          */
1795         if (res->f6i->fib6_src.plen)
1796                 src_key = saddr;
1797 find_ex:
1798 #endif
1799         bucket = fib6_nh_get_excptn_bucket(res->nh, NULL);
1800         rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
1801
1802         if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
1803                 ret = rt6_ex->rt6i;
1804
1805 #ifdef CONFIG_IPV6_SUBTREES
1806         /* Use fib6_src as src_key and redo lookup */
1807         if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) {
1808                 src_key = &res->f6i->fib6_src.addr;
1809                 goto find_ex;
1810         }
1811 #endif
1812
1813         return ret;
1814 }
1815
1816 /* Remove the passed in cached rt from the hash table that contains it */
1817 static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen,
1818                                     const struct rt6_info *rt)
1819 {
1820         const struct in6_addr *src_key = NULL;
1821         struct rt6_exception_bucket *bucket;
1822         struct rt6_exception *rt6_ex;
1823         int err;
1824
1825         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
1826                 return -ENOENT;
1827
1828         spin_lock_bh(&rt6_exception_lock);
1829         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1830
1831 #ifdef CONFIG_IPV6_SUBTREES
1832         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1833          * and exception table is indexed by a hash of
1834          * both rt6i_dst and rt6i_src.
1835          * Otherwise, the exception table is indexed by
1836          * a hash of only rt6i_dst.
1837          */
1838         if (plen)
1839                 src_key = &rt->rt6i_src.addr;
1840 #endif
1841         rt6_ex = __rt6_find_exception_spinlock(&bucket,
1842                                                &rt->rt6i_dst.addr,
1843                                                src_key);
1844         if (rt6_ex) {
1845                 rt6_remove_exception(bucket, rt6_ex);
1846                 err = 0;
1847         } else {
1848                 err = -ENOENT;
1849         }
1850
1851         spin_unlock_bh(&rt6_exception_lock);
1852         return err;
1853 }
1854
1855 struct fib6_nh_excptn_arg {
1856         struct rt6_info *rt;
1857         int             plen;
1858 };
1859
1860 static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg)
1861 {
1862         struct fib6_nh_excptn_arg *arg = _arg;
1863         int err;
1864
1865         err = fib6_nh_remove_exception(nh, arg->plen, arg->rt);
1866         if (err == 0)
1867                 return 1;
1868
1869         return 0;
1870 }
1871
1872 static int rt6_remove_exception_rt(struct rt6_info *rt)
1873 {
1874         struct fib6_info *from;
1875
1876         from = rcu_dereference(rt->from);
1877         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1878                 return -EINVAL;
1879
1880         if (from->nh) {
1881                 struct fib6_nh_excptn_arg arg = {
1882                         .rt = rt,
1883                         .plen = from->fib6_src.plen
1884                 };
1885                 int rc;
1886
1887                 /* rc = 1 means an entry was found */
1888                 rc = nexthop_for_each_fib6_nh(from->nh,
1889                                               rt6_nh_remove_exception_rt,
1890                                               &arg);
1891                 return rc ? 0 : -ENOENT;
1892         }
1893
1894         return fib6_nh_remove_exception(from->fib6_nh,
1895                                         from->fib6_src.plen, rt);
1896 }
1897
1898 /* Find rt6_ex which contains the passed in rt cache and
1899  * refresh its stamp
1900  */
1901 static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen,
1902                                      const struct rt6_info *rt)
1903 {
1904         const struct in6_addr *src_key = NULL;
1905         struct rt6_exception_bucket *bucket;
1906         struct rt6_exception *rt6_ex;
1907
1908         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
1909 #ifdef CONFIG_IPV6_SUBTREES
1910         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1911          * and exception table is indexed by a hash of
1912          * both rt6i_dst and rt6i_src.
1913          * Otherwise, the exception table is indexed by
1914          * a hash of only rt6i_dst.
1915          */
1916         if (plen)
1917                 src_key = &rt->rt6i_src.addr;
1918 #endif
1919         rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
1920         if (rt6_ex)
1921                 rt6_ex->stamp = jiffies;
1922 }
1923
1924 struct fib6_nh_match_arg {
1925         const struct net_device *dev;
1926         const struct in6_addr   *gw;
1927         struct fib6_nh          *match;
1928 };
1929
1930 /* determine if fib6_nh has given device and gateway */
1931 static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg)
1932 {
1933         struct fib6_nh_match_arg *arg = _arg;
1934
1935         if (arg->dev != nh->fib_nh_dev ||
1936             (arg->gw && !nh->fib_nh_gw_family) ||
1937             (!arg->gw && nh->fib_nh_gw_family) ||
1938             (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6)))
1939                 return 0;
1940
1941         arg->match = nh;
1942
1943         /* found a match, break the loop */
1944         return 1;
1945 }
1946
1947 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
1948 {
1949         struct fib6_info *from;
1950         struct fib6_nh *fib6_nh;
1951
1952         rcu_read_lock();
1953
1954         from = rcu_dereference(rt->from);
1955         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1956                 goto unlock;
1957
1958         if (from->nh) {
1959                 struct fib6_nh_match_arg arg = {
1960                         .dev = rt->dst.dev,
1961                         .gw = &rt->rt6i_gateway,
1962                 };
1963
1964                 nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
1965
1966                 if (!arg.match)
1967                         goto unlock;
1968                 fib6_nh = arg.match;
1969         } else {
1970                 fib6_nh = from->fib6_nh;
1971         }
1972         fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt);
1973 unlock:
1974         rcu_read_unlock();
1975 }
1976
1977 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
1978                                          struct rt6_info *rt, int mtu)
1979 {
1980         /* If the new MTU is lower than the route PMTU, this new MTU will be the
1981          * lowest MTU in the path: always allow updating the route PMTU to
1982          * reflect PMTU decreases.
1983          *
1984          * If the new MTU is higher, and the route PMTU is equal to the local
1985          * MTU, this means the old MTU is the lowest in the path, so allow
1986          * updating it: if other nodes now have lower MTUs, PMTU discovery will
1987          * handle this.
1988          */
1989
1990         if (dst_mtu(&rt->dst) >= mtu)
1991                 return true;
1992
1993         if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
1994                 return true;
1995
1996         return false;
1997 }
1998
1999 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
2000                                        const struct fib6_nh *nh, int mtu)
2001 {
2002         struct rt6_exception_bucket *bucket;
2003         struct rt6_exception *rt6_ex;
2004         int i;
2005
2006         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2007         if (!bucket)
2008                 return;
2009
2010         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2011                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
2012                         struct rt6_info *entry = rt6_ex->rt6i;
2013
2014                         /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
2015                          * route), the metrics of its rt->from have already
2016                          * been updated.
2017                          */
2018                         if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
2019                             rt6_mtu_change_route_allowed(idev, entry, mtu))
2020                                 dst_metric_set(&entry->dst, RTAX_MTU, mtu);
2021                 }
2022                 bucket++;
2023         }
2024 }
2025
2026 #define RTF_CACHE_GATEWAY       (RTF_GATEWAY | RTF_CACHE)
2027
2028 static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh,
2029                                             const struct in6_addr *gateway)
2030 {
2031         struct rt6_exception_bucket *bucket;
2032         struct rt6_exception *rt6_ex;
2033         struct hlist_node *tmp;
2034         int i;
2035
2036         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2037                 return;
2038
2039         spin_lock_bh(&rt6_exception_lock);
2040         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2041         if (bucket) {
2042                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2043                         hlist_for_each_entry_safe(rt6_ex, tmp,
2044                                                   &bucket->chain, hlist) {
2045                                 struct rt6_info *entry = rt6_ex->rt6i;
2046
2047                                 if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
2048                                     RTF_CACHE_GATEWAY &&
2049                                     ipv6_addr_equal(gateway,
2050                                                     &entry->rt6i_gateway)) {
2051                                         rt6_remove_exception(bucket, rt6_ex);
2052                                 }
2053                         }
2054                         bucket++;
2055                 }
2056         }
2057
2058         spin_unlock_bh(&rt6_exception_lock);
2059 }
2060
2061 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
2062                                       struct rt6_exception *rt6_ex,
2063                                       struct fib6_gc_args *gc_args,
2064                                       unsigned long now)
2065 {
2066         struct rt6_info *rt = rt6_ex->rt6i;
2067
2068         /* we are pruning and obsoleting aged-out and non gateway exceptions
2069          * even if others have still references to them, so that on next
2070          * dst_check() such references can be dropped.
2071          * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
2072          * expired, independently from their aging, as per RFC 8201 section 4
2073          */
2074         if (!(rt->rt6i_flags & RTF_EXPIRES)) {
2075                 if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
2076                         RT6_TRACE("aging clone %p\n", rt);
2077                         rt6_remove_exception(bucket, rt6_ex);
2078                         return;
2079                 }
2080         } else if (time_after(jiffies, rt->dst.expires)) {
2081                 RT6_TRACE("purging expired route %p\n", rt);
2082                 rt6_remove_exception(bucket, rt6_ex);
2083                 return;
2084         }
2085
2086         if (rt->rt6i_flags & RTF_GATEWAY) {
2087                 struct neighbour *neigh;
2088
2089                 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
2090
2091                 if (!(neigh && (neigh->flags & NTF_ROUTER))) {
2092                         RT6_TRACE("purging route %p via non-router but gateway\n",
2093                                   rt);
2094                         rt6_remove_exception(bucket, rt6_ex);
2095                         return;
2096                 }
2097         }
2098
2099         gc_args->more++;
2100 }
2101
2102 static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
2103                                    struct fib6_gc_args *gc_args,
2104                                    unsigned long now)
2105 {
2106         struct rt6_exception_bucket *bucket;
2107         struct rt6_exception *rt6_ex;
2108         struct hlist_node *tmp;
2109         int i;
2110
2111         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2112                 return;
2113
2114         rcu_read_lock_bh();
2115         spin_lock(&rt6_exception_lock);
2116         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2117         if (bucket) {
2118                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2119                         hlist_for_each_entry_safe(rt6_ex, tmp,
2120                                                   &bucket->chain, hlist) {
2121                                 rt6_age_examine_exception(bucket, rt6_ex,
2122                                                           gc_args, now);
2123                         }
2124                         bucket++;
2125                 }
2126         }
2127         spin_unlock(&rt6_exception_lock);
2128         rcu_read_unlock_bh();
2129 }
2130
2131 struct fib6_nh_age_excptn_arg {
2132         struct fib6_gc_args     *gc_args;
2133         unsigned long           now;
2134 };
2135
2136 static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg)
2137 {
2138         struct fib6_nh_age_excptn_arg *arg = _arg;
2139
2140         fib6_nh_age_exceptions(nh, arg->gc_args, arg->now);
2141         return 0;
2142 }
2143
2144 void rt6_age_exceptions(struct fib6_info *f6i,
2145                         struct fib6_gc_args *gc_args,
2146                         unsigned long now)
2147 {
2148         if (f6i->nh) {
2149                 struct fib6_nh_age_excptn_arg arg = {
2150                         .gc_args = gc_args,
2151                         .now = now
2152                 };
2153
2154                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions,
2155                                          &arg);
2156         } else {
2157                 fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now);
2158         }
2159 }
2160
2161 /* must be called with rcu lock held */
2162 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
2163                       struct flowi6 *fl6, struct fib6_result *res, int strict)
2164 {
2165         struct fib6_node *fn, *saved_fn;
2166
2167         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
2168         saved_fn = fn;
2169
2170         if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
2171                 oif = 0;
2172
2173 redo_rt6_select:
2174         rt6_select(net, fn, oif, res, strict);
2175         if (res->f6i == net->ipv6.fib6_null_entry) {
2176                 fn = fib6_backtrack(fn, &fl6->saddr);
2177                 if (fn)
2178                         goto redo_rt6_select;
2179                 else if (strict & RT6_LOOKUP_F_REACHABLE) {
2180                         /* also consider unreachable route */
2181                         strict &= ~RT6_LOOKUP_F_REACHABLE;
2182                         fn = saved_fn;
2183                         goto redo_rt6_select;
2184                 }
2185         }
2186
2187         trace_fib6_table_lookup(net, res, table, fl6);
2188
2189         return 0;
2190 }
2191
2192 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
2193                                int oif, struct flowi6 *fl6,
2194                                const struct sk_buff *skb, int flags)
2195 {
2196         struct fib6_result res = {};
2197         struct rt6_info *rt = NULL;
2198         int strict = 0;
2199
2200         WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
2201                      !rcu_read_lock_held());
2202
2203         strict |= flags & RT6_LOOKUP_F_IFACE;
2204         strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
2205         if (net->ipv6.devconf_all->forwarding == 0)
2206                 strict |= RT6_LOOKUP_F_REACHABLE;
2207
2208         rcu_read_lock();
2209
2210         fib6_table_lookup(net, table, oif, fl6, &res, strict);
2211         if (res.f6i == net->ipv6.fib6_null_entry)
2212                 goto out;
2213
2214         fib6_select_path(net, &res, fl6, oif, false, skb, strict);
2215
2216         /*Search through exception table */
2217         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
2218         if (rt) {
2219                 goto out;
2220         } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
2221                             !res.nh->fib_nh_gw_family)) {
2222                 /* Create a RTF_CACHE clone which will not be
2223                  * owned by the fib6 tree.  It is for the special case where
2224                  * the daddr in the skb during the neighbor look-up is different
2225                  * from the fl6->daddr used to look-up route here.
2226                  */
2227                 rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
2228
2229                 if (rt) {
2230                         /* 1 refcnt is taken during ip6_rt_cache_alloc().
2231                          * As rt6_uncached_list_add() does not consume refcnt,
2232                          * this refcnt is always returned to the caller even
2233                          * if caller sets RT6_LOOKUP_F_DST_NOREF flag.
2234                          */
2235                         rt6_uncached_list_add(rt);
2236                         atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
2237                         rcu_read_unlock();
2238
2239                         return rt;
2240                 }
2241         } else {
2242                 /* Get a percpu copy */
2243                 local_bh_disable();
2244                 rt = rt6_get_pcpu_route(&res);
2245
2246                 if (!rt)
2247                         rt = rt6_make_pcpu_route(net, &res);
2248
2249                 local_bh_enable();
2250         }
2251 out:
2252         if (!rt)
2253                 rt = net->ipv6.ip6_null_entry;
2254         if (!(flags & RT6_LOOKUP_F_DST_NOREF))
2255                 ip6_hold_safe(net, &rt);
2256         rcu_read_unlock();
2257
2258         return rt;
2259 }
2260 EXPORT_SYMBOL_GPL(ip6_pol_route);
2261
2262 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net,
2263                                             struct fib6_table *table,
2264                                             struct flowi6 *fl6,
2265                                             const struct sk_buff *skb,
2266                                             int flags)
2267 {
2268         return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
2269 }
2270
2271 struct dst_entry *ip6_route_input_lookup(struct net *net,
2272                                          struct net_device *dev,
2273                                          struct flowi6 *fl6,
2274                                          const struct sk_buff *skb,
2275                                          int flags)
2276 {
2277         if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
2278                 flags |= RT6_LOOKUP_F_IFACE;
2279
2280         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
2281 }
2282 EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
2283
2284 static void ip6_multipath_l3_keys(const struct sk_buff *skb,
2285                                   struct flow_keys *keys,
2286                                   struct flow_keys *flkeys)
2287 {
2288         const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
2289         const struct ipv6hdr *key_iph = outer_iph;
2290         struct flow_keys *_flkeys = flkeys;
2291         const struct ipv6hdr *inner_iph;
2292         const struct icmp6hdr *icmph;
2293         struct ipv6hdr _inner_iph;
2294         struct icmp6hdr _icmph;
2295
2296         if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
2297                 goto out;
2298
2299         icmph = skb_header_pointer(skb, skb_transport_offset(skb),
2300                                    sizeof(_icmph), &_icmph);
2301         if (!icmph)
2302                 goto out;
2303
2304         if (!icmpv6_is_err(icmph->icmp6_type))
2305                 goto out;
2306
2307         inner_iph = skb_header_pointer(skb,
2308                                        skb_transport_offset(skb) + sizeof(*icmph),
2309                                        sizeof(_inner_iph), &_inner_iph);
2310         if (!inner_iph)
2311                 goto out;
2312
2313         key_iph = inner_iph;
2314         _flkeys = NULL;
2315 out:
2316         if (_flkeys) {
2317                 keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
2318                 keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
2319                 keys->tags.flow_label = _flkeys->tags.flow_label;
2320                 keys->basic.ip_proto = _flkeys->basic.ip_proto;
2321         } else {
2322                 keys->addrs.v6addrs.src = key_iph->saddr;
2323                 keys->addrs.v6addrs.dst = key_iph->daddr;
2324                 keys->tags.flow_label = ip6_flowlabel(key_iph);
2325                 keys->basic.ip_proto = key_iph->nexthdr;
2326         }
2327 }
2328
2329 static u32 rt6_multipath_custom_hash_outer(const struct net *net,
2330                                            const struct sk_buff *skb,
2331                                            bool *p_has_inner)
2332 {
2333         u32 hash_fields = ip6_multipath_hash_fields(net);
2334         struct flow_keys keys, hash_keys;
2335
2336         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2337                 return 0;
2338
2339         memset(&hash_keys, 0, sizeof(hash_keys));
2340         skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
2341
2342         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2343         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2344                 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2345         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2346                 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2347         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2348                 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2349         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2350                 hash_keys.tags.flow_label = keys.tags.flow_label;
2351         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2352                 hash_keys.ports.src = keys.ports.src;
2353         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2354                 hash_keys.ports.dst = keys.ports.dst;
2355
2356         *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
2357         return flow_hash_from_keys(&hash_keys);
2358 }
2359
2360 static u32 rt6_multipath_custom_hash_inner(const struct net *net,
2361                                            const struct sk_buff *skb,
2362                                            bool has_inner)
2363 {
2364         u32 hash_fields = ip6_multipath_hash_fields(net);
2365         struct flow_keys keys, hash_keys;
2366
2367         /* We assume the packet carries an encapsulation, but if none was
2368          * encountered during dissection of the outer flow, then there is no
2369          * point in calling the flow dissector again.
2370          */
2371         if (!has_inner)
2372                 return 0;
2373
2374         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
2375                 return 0;
2376
2377         memset(&hash_keys, 0, sizeof(hash_keys));
2378         skb_flow_dissect_flow_keys(skb, &keys, 0);
2379
2380         if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
2381                 return 0;
2382
2383         if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2384                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2385                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2386                         hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2387                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2388                         hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2389         } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2390                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2391                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2392                         hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2393                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2394                         hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2395                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
2396                         hash_keys.tags.flow_label = keys.tags.flow_label;
2397         }
2398
2399         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
2400                 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2401         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
2402                 hash_keys.ports.src = keys.ports.src;
2403         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
2404                 hash_keys.ports.dst = keys.ports.dst;
2405
2406         return flow_hash_from_keys(&hash_keys);
2407 }
2408
2409 static u32 rt6_multipath_custom_hash_skb(const struct net *net,
2410                                          const struct sk_buff *skb)
2411 {
2412         u32 mhash, mhash_inner;
2413         bool has_inner = true;
2414
2415         mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner);
2416         mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner);
2417
2418         return jhash_2words(mhash, mhash_inner, 0);
2419 }
2420
2421 static u32 rt6_multipath_custom_hash_fl6(const struct net *net,
2422                                          const struct flowi6 *fl6)
2423 {
2424         u32 hash_fields = ip6_multipath_hash_fields(net);
2425         struct flow_keys hash_keys;
2426
2427         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2428                 return 0;
2429
2430         memset(&hash_keys, 0, sizeof(hash_keys));
2431         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2432         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2433                 hash_keys.addrs.v6addrs.src = fl6->saddr;
2434         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2435                 hash_keys.addrs.v6addrs.dst = fl6->daddr;
2436         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2437                 hash_keys.basic.ip_proto = fl6->flowi6_proto;
2438         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2439                 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2440         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2441                 hash_keys.ports.src = fl6->fl6_sport;
2442         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2443                 hash_keys.ports.dst = fl6->fl6_dport;
2444
2445         return flow_hash_from_keys(&hash_keys);
2446 }
2447
2448 /* if skb is set it will be used and fl6 can be NULL */
2449 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
2450                        const struct sk_buff *skb, struct flow_keys *flkeys)
2451 {
2452         struct flow_keys hash_keys;
2453         u32 mhash = 0;
2454
2455         switch (ip6_multipath_hash_policy(net)) {
2456         case 0:
2457                 memset(&hash_keys, 0, sizeof(hash_keys));
2458                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2459                 if (skb) {
2460                         ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2461                 } else {
2462                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2463                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2464                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2465                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2466                 }
2467                 mhash = flow_hash_from_keys(&hash_keys);
2468                 break;
2469         case 1:
2470                 if (skb) {
2471                         unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2472                         struct flow_keys keys;
2473
2474                         /* short-circuit if we already have L4 hash present */
2475                         if (skb->l4_hash)
2476                                 return skb_get_hash_raw(skb) >> 1;
2477
2478                         memset(&hash_keys, 0, sizeof(hash_keys));
2479
2480                         if (!flkeys) {
2481                                 skb_flow_dissect_flow_keys(skb, &keys, flag);
2482                                 flkeys = &keys;
2483                         }
2484                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2485                         hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2486                         hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2487                         hash_keys.ports.src = flkeys->ports.src;
2488                         hash_keys.ports.dst = flkeys->ports.dst;
2489                         hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2490                 } else {
2491                         memset(&hash_keys, 0, sizeof(hash_keys));
2492                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2493                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2494                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2495                         hash_keys.ports.src = fl6->fl6_sport;
2496                         hash_keys.ports.dst = fl6->fl6_dport;
2497                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2498                 }
2499                 mhash = flow_hash_from_keys(&hash_keys);
2500                 break;
2501         case 2:
2502                 memset(&hash_keys, 0, sizeof(hash_keys));
2503                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2504                 if (skb) {
2505                         struct flow_keys keys;
2506
2507                         if (!flkeys) {
2508                                 skb_flow_dissect_flow_keys(skb, &keys, 0);
2509                                 flkeys = &keys;
2510                         }
2511
2512                         /* Inner can be v4 or v6 */
2513                         if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2514                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2515                                 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2516                                 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2517                         } else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2518                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2519                                 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2520                                 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2521                                 hash_keys.tags.flow_label = flkeys->tags.flow_label;
2522                                 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2523                         } else {
2524                                 /* Same as case 0 */
2525                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2526                                 ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2527                         }
2528                 } else {
2529                         /* Same as case 0 */
2530                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2531                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2532                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2533                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2534                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2535                 }
2536                 mhash = flow_hash_from_keys(&hash_keys);
2537                 break;
2538         case 3:
2539                 if (skb)
2540                         mhash = rt6_multipath_custom_hash_skb(net, skb);
2541                 else
2542                         mhash = rt6_multipath_custom_hash_fl6(net, fl6);
2543                 break;
2544         }
2545
2546         return mhash >> 1;
2547 }
2548
2549 /* Called with rcu held */
2550 void ip6_route_input(struct sk_buff *skb)
2551 {
2552         const struct ipv6hdr *iph = ipv6_hdr(skb);
2553         struct net *net = dev_net(skb->dev);
2554         int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF;
2555         struct ip_tunnel_info *tun_info;
2556         struct flowi6 fl6 = {
2557                 .flowi6_iif = skb->dev->ifindex,
2558                 .daddr = iph->daddr,
2559                 .saddr = iph->saddr,
2560                 .flowlabel = ip6_flowinfo(iph),
2561                 .flowi6_mark = skb->mark,
2562                 .flowi6_proto = iph->nexthdr,
2563         };
2564         struct flow_keys *flkeys = NULL, _flkeys;
2565
2566         tun_info = skb_tunnel_info(skb);
2567         if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2568                 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
2569
2570         if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
2571                 flkeys = &_flkeys;
2572
2573         if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
2574                 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
2575         skb_dst_drop(skb);
2576         skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev,
2577                                                       &fl6, skb, flags));
2578 }
2579
2580 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net,
2581                                              struct fib6_table *table,
2582                                              struct flowi6 *fl6,
2583                                              const struct sk_buff *skb,
2584                                              int flags)
2585 {
2586         return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
2587 }
2588
2589 struct dst_entry *ip6_route_output_flags_noref(struct net *net,
2590                                                const struct sock *sk,
2591                                                struct flowi6 *fl6, int flags)
2592 {
2593         bool any_src;
2594
2595         if (ipv6_addr_type(&fl6->daddr) &
2596             (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
2597                 struct dst_entry *dst;
2598
2599                 /* This function does not take refcnt on the dst */
2600                 dst = l3mdev_link_scope_lookup(net, fl6);
2601                 if (dst)
2602                         return dst;
2603         }
2604
2605         fl6->flowi6_iif = LOOPBACK_IFINDEX;
2606
2607         flags |= RT6_LOOKUP_F_DST_NOREF;
2608         any_src = ipv6_addr_any(&fl6->saddr);
2609         if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
2610             (fl6->flowi6_oif && any_src))
2611                 flags |= RT6_LOOKUP_F_IFACE;
2612
2613         if (!any_src)
2614                 flags |= RT6_LOOKUP_F_HAS_SADDR;
2615         else if (sk)
2616                 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
2617
2618         return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
2619 }
2620 EXPORT_SYMBOL_GPL(ip6_route_output_flags_noref);
2621
2622 struct dst_entry *ip6_route_output_flags(struct net *net,
2623                                          const struct sock *sk,
2624                                          struct flowi6 *fl6,
2625                                          int flags)
2626 {
2627         struct dst_entry *dst;
2628         struct rt6_info *rt6;
2629
2630         rcu_read_lock();
2631         dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
2632         rt6 = (struct rt6_info *)dst;
2633         /* For dst cached in uncached_list, refcnt is already taken. */
2634         if (list_empty(&rt6->rt6i_uncached) && !dst_hold_safe(dst)) {
2635                 dst = &net->ipv6.ip6_null_entry->dst;
2636                 dst_hold(dst);
2637         }
2638         rcu_read_unlock();
2639
2640         return dst;
2641 }
2642 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
2643
2644 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2645 {
2646         struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
2647         struct net_device *loopback_dev = net->loopback_dev;
2648         struct dst_entry *new = NULL;
2649
2650         rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
2651                        DST_OBSOLETE_DEAD, 0);
2652         if (rt) {
2653                 rt6_info_init(rt);
2654                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
2655
2656                 new = &rt->dst;
2657                 new->__use = 1;
2658                 new->input = dst_discard;
2659                 new->output = dst_discard_out;
2660
2661                 dst_copy_metrics(new, &ort->dst);
2662
2663                 rt->rt6i_idev = in6_dev_get(loopback_dev);
2664                 rt->rt6i_gateway = ort->rt6i_gateway;
2665                 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
2666
2667                 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
2668 #ifdef CONFIG_IPV6_SUBTREES
2669                 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
2670 #endif
2671         }
2672
2673         dst_release(dst_orig);
2674         return new ? new : ERR_PTR(-ENOMEM);
2675 }
2676
2677 /*
2678  *      Destination cache support functions
2679  */
2680
2681 static bool fib6_check(struct fib6_info *f6i, u32 cookie)
2682 {
2683         u32 rt_cookie = 0;
2684
2685         if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
2686                 return false;
2687
2688         if (fib6_check_expired(f6i))
2689                 return false;
2690
2691         return true;
2692 }
2693
2694 static struct dst_entry *rt6_check(struct rt6_info *rt,
2695                                    struct fib6_info *from,
2696                                    u32 cookie)
2697 {
2698         u32 rt_cookie = 0;
2699
2700         if (!from || !fib6_get_cookie_safe(from, &rt_cookie) ||
2701             rt_cookie != cookie)
2702                 return NULL;
2703
2704         if (rt6_check_expired(rt))
2705                 return NULL;
2706
2707         return &rt->dst;
2708 }
2709
2710 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
2711                                             struct fib6_info *from,
2712                                             u32 cookie)
2713 {
2714         if (!__rt6_check_expired(rt) &&
2715             rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
2716             fib6_check(from, cookie))
2717                 return &rt->dst;
2718         else
2719                 return NULL;
2720 }
2721
2722 INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst,
2723                                                         u32 cookie)
2724 {
2725         struct dst_entry *dst_ret;
2726         struct fib6_info *from;
2727         struct rt6_info *rt;
2728
2729         rt = container_of(dst, struct rt6_info, dst);
2730
2731         if (rt->sernum)
2732                 return rt6_is_valid(rt) ? dst : NULL;
2733
2734         rcu_read_lock();
2735
2736         /* All IPV6 dsts are created with ->obsolete set to the value
2737          * DST_OBSOLETE_FORCE_CHK which forces validation calls down
2738          * into this function always.
2739          */
2740
2741         from = rcu_dereference(rt->from);
2742
2743         if (from && (rt->rt6i_flags & RTF_PCPU ||
2744             unlikely(!list_empty(&rt->rt6i_uncached))))
2745                 dst_ret = rt6_dst_from_check(rt, from, cookie);
2746         else
2747                 dst_ret = rt6_check(rt, from, cookie);
2748
2749         rcu_read_unlock();
2750
2751         return dst_ret;
2752 }
2753 EXPORT_INDIRECT_CALLABLE(ip6_dst_check);
2754
2755 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
2756 {
2757         struct rt6_info *rt = (struct rt6_info *) dst;
2758
2759         if (rt) {
2760                 if (rt->rt6i_flags & RTF_CACHE) {
2761                         rcu_read_lock();
2762                         if (rt6_check_expired(rt)) {
2763                                 rt6_remove_exception_rt(rt);
2764                                 dst = NULL;
2765                         }
2766                         rcu_read_unlock();
2767                 } else {
2768                         dst_release(dst);
2769                         dst = NULL;
2770                 }
2771         }
2772         return dst;
2773 }
2774
2775 static void ip6_link_failure(struct sk_buff *skb)
2776 {
2777         struct rt6_info *rt;
2778
2779         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
2780
2781         rt = (struct rt6_info *) skb_dst(skb);
2782         if (rt) {
2783                 rcu_read_lock();
2784                 if (rt->rt6i_flags & RTF_CACHE) {
2785                         rt6_remove_exception_rt(rt);
2786                 } else {
2787                         struct fib6_info *from;
2788                         struct fib6_node *fn;
2789
2790                         from = rcu_dereference(rt->from);
2791                         if (from) {
2792                                 fn = rcu_dereference(from->fib6_node);
2793                                 if (fn && (rt->rt6i_flags & RTF_DEFAULT))
2794                                         fn->fn_sernum = -1;
2795                         }
2796                 }
2797                 rcu_read_unlock();
2798         }
2799 }
2800
2801 static void rt6_update_expires(struct rt6_info *rt0, int timeout)
2802 {
2803         if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
2804                 struct fib6_info *from;
2805
2806                 rcu_read_lock();
2807                 from = rcu_dereference(rt0->from);
2808                 if (from)
2809                         rt0->dst.expires = from->expires;
2810                 rcu_read_unlock();
2811         }
2812
2813         dst_set_expires(&rt0->dst, timeout);
2814         rt0->rt6i_flags |= RTF_EXPIRES;
2815 }
2816
2817 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
2818 {
2819         struct net *net = dev_net(rt->dst.dev);
2820
2821         dst_metric_set(&rt->dst, RTAX_MTU, mtu);
2822         rt->rt6i_flags |= RTF_MODIFIED;
2823         rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
2824 }
2825
2826 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
2827 {
2828         return !(rt->rt6i_flags & RTF_CACHE) &&
2829                 (rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
2830 }
2831
2832 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
2833                                  const struct ipv6hdr *iph, u32 mtu,
2834                                  bool confirm_neigh)
2835 {
2836         const struct in6_addr *daddr, *saddr;
2837         struct rt6_info *rt6 = (struct rt6_info *)dst;
2838
2839         /* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU)
2840          * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it.
2841          * [see also comment in rt6_mtu_change_route()]
2842          */
2843
2844         if (iph) {
2845                 daddr = &iph->daddr;
2846                 saddr = &iph->saddr;
2847         } else if (sk) {
2848                 daddr = &sk->sk_v6_daddr;
2849                 saddr = &inet6_sk(sk)->saddr;
2850         } else {
2851                 daddr = NULL;
2852                 saddr = NULL;
2853         }
2854
2855         if (confirm_neigh)
2856                 dst_confirm_neigh(dst, daddr);
2857
2858         if (mtu < IPV6_MIN_MTU)
2859                 return;
2860         if (mtu >= dst_mtu(dst))
2861                 return;
2862
2863         if (!rt6_cache_allowed_for_pmtu(rt6)) {
2864                 rt6_do_update_pmtu(rt6, mtu);
2865                 /* update rt6_ex->stamp for cache */
2866                 if (rt6->rt6i_flags & RTF_CACHE)
2867                         rt6_update_exception_stamp_rt(rt6);
2868         } else if (daddr) {
2869                 struct fib6_result res = {};
2870                 struct rt6_info *nrt6;
2871
2872                 rcu_read_lock();
2873                 res.f6i = rcu_dereference(rt6->from);
2874                 if (!res.f6i)
2875                         goto out_unlock;
2876
2877                 res.fib6_flags = res.f6i->fib6_flags;
2878                 res.fib6_type = res.f6i->fib6_type;
2879
2880                 if (res.f6i->nh) {
2881                         struct fib6_nh_match_arg arg = {
2882                                 .dev = dst->dev,
2883                                 .gw = &rt6->rt6i_gateway,
2884                         };
2885
2886                         nexthop_for_each_fib6_nh(res.f6i->nh,
2887                                                  fib6_nh_find_match, &arg);
2888
2889                         /* fib6_info uses a nexthop that does not have fib6_nh
2890                          * using the dst->dev + gw. Should be impossible.
2891                          */
2892                         if (!arg.match)
2893                                 goto out_unlock;
2894
2895                         res.nh = arg.match;
2896                 } else {
2897                         res.nh = res.f6i->fib6_nh;
2898                 }
2899
2900                 nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
2901                 if (nrt6) {
2902                         rt6_do_update_pmtu(nrt6, mtu);
2903                         if (rt6_insert_exception(nrt6, &res))
2904                                 dst_release_immediate(&nrt6->dst);
2905                 }
2906 out_unlock:
2907                 rcu_read_unlock();
2908         }
2909 }
2910
2911 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
2912                                struct sk_buff *skb, u32 mtu,
2913                                bool confirm_neigh)
2914 {
2915         __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu,
2916                              confirm_neigh);
2917 }
2918
2919 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
2920                      int oif, u32 mark, kuid_t uid)
2921 {
2922         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2923         struct dst_entry *dst;
2924         struct flowi6 fl6 = {
2925                 .flowi6_oif = oif,
2926                 .flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
2927                 .daddr = iph->daddr,
2928                 .saddr = iph->saddr,
2929                 .flowlabel = ip6_flowinfo(iph),
2930                 .flowi6_uid = uid,
2931         };
2932
2933         dst = ip6_route_output(net, NULL, &fl6);
2934         if (!dst->error)
2935                 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true);
2936         dst_release(dst);
2937 }
2938 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
2939
2940 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
2941 {
2942         int oif = sk->sk_bound_dev_if;
2943         struct dst_entry *dst;
2944
2945         if (!oif && skb->dev)
2946                 oif = l3mdev_master_ifindex(skb->dev);
2947
2948         ip6_update_pmtu(skb, sock_net(sk), mtu, oif, sk->sk_mark, sk->sk_uid);
2949
2950         dst = __sk_dst_get(sk);
2951         if (!dst || !dst->obsolete ||
2952             dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
2953                 return;
2954
2955         bh_lock_sock(sk);
2956         if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
2957                 ip6_datagram_dst_update(sk, false);
2958         bh_unlock_sock(sk);
2959 }
2960 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
2961
2962 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
2963                            const struct flowi6 *fl6)
2964 {
2965 #ifdef CONFIG_IPV6_SUBTREES
2966         struct ipv6_pinfo *np = inet6_sk(sk);
2967 #endif
2968
2969         ip6_dst_store(sk, dst,
2970                       ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
2971                       &sk->sk_v6_daddr : NULL,
2972 #ifdef CONFIG_IPV6_SUBTREES
2973                       ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
2974                       &np->saddr :
2975 #endif
2976                       NULL);
2977 }
2978
2979 static bool ip6_redirect_nh_match(const struct fib6_result *res,
2980                                   struct flowi6 *fl6,
2981                                   const struct in6_addr *gw,
2982                                   struct rt6_info **ret)
2983 {
2984         const struct fib6_nh *nh = res->nh;
2985
2986         if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family ||
2987             fl6->flowi6_oif != nh->fib_nh_dev->ifindex)
2988                 return false;
2989
2990         /* rt_cache's gateway might be different from its 'parent'
2991          * in the case of an ip redirect.
2992          * So we keep searching in the exception table if the gateway
2993          * is different.
2994          */
2995         if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) {
2996                 struct rt6_info *rt_cache;
2997
2998                 rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr);
2999                 if (rt_cache &&
3000                     ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) {
3001                         *ret = rt_cache;
3002                         return true;
3003                 }
3004                 return false;
3005         }
3006         return true;
3007 }
3008
3009 struct fib6_nh_rd_arg {
3010         struct fib6_result      *res;
3011         struct flowi6           *fl6;
3012         const struct in6_addr   *gw;
3013         struct rt6_info         **ret;
3014 };
3015
3016 static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg)
3017 {
3018         struct fib6_nh_rd_arg *arg = _arg;
3019
3020         arg->res->nh = nh;
3021         return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret);
3022 }
3023
3024 /* Handle redirects */
3025 struct ip6rd_flowi {
3026         struct flowi6 fl6;
3027         struct in6_addr gateway;
3028 };
3029
3030 INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net,
3031                                              struct fib6_table *table,
3032                                              struct flowi6 *fl6,
3033                                              const struct sk_buff *skb,
3034                                              int flags)
3035 {
3036         struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
3037         struct rt6_info *ret = NULL;
3038         struct fib6_result res = {};
3039         struct fib6_nh_rd_arg arg = {
3040                 .res = &res,
3041                 .fl6 = fl6,
3042                 .gw  = &rdfl->gateway,
3043                 .ret = &ret
3044         };
3045         struct fib6_info *rt;
3046         struct fib6_node *fn;
3047
3048         /* l3mdev_update_flow overrides oif if the device is enslaved; in
3049          * this case we must match on the real ingress device, so reset it
3050          */
3051         if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
3052                 fl6->flowi6_oif = skb->dev->ifindex;
3053
3054         /* Get the "current" route for this destination and
3055          * check if the redirect has come from appropriate router.
3056          *
3057          * RFC 4861 specifies that redirects should only be
3058          * accepted if they come from the nexthop to the target.
3059          * Due to the way the routes are chosen, this notion
3060          * is a bit fuzzy and one might need to check all possible
3061          * routes.
3062          */
3063
3064         rcu_read_lock();
3065         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
3066 restart:
3067         for_each_fib6_node_rt_rcu(fn) {
3068                 res.f6i = rt;
3069                 if (fib6_check_expired(rt))
3070                         continue;
3071                 if (rt->fib6_flags & RTF_REJECT)
3072                         break;
3073                 if (unlikely(rt->nh)) {
3074                         if (nexthop_is_blackhole(rt->nh))
3075                                 continue;
3076                         /* on match, res->nh is filled in and potentially ret */
3077                         if (nexthop_for_each_fib6_nh(rt->nh,
3078                                                      fib6_nh_redirect_match,
3079                                                      &arg))
3080                                 goto out;
3081                 } else {
3082                         res.nh = rt->fib6_nh;
3083                         if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway,
3084                                                   &ret))
3085                                 goto out;
3086                 }
3087         }
3088
3089         if (!rt)
3090                 rt = net->ipv6.fib6_null_entry;
3091         else if (rt->fib6_flags & RTF_REJECT) {
3092                 ret = net->ipv6.ip6_null_entry;
3093                 goto out;
3094         }
3095
3096         if (rt == net->ipv6.fib6_null_entry) {
3097                 fn = fib6_backtrack(fn, &fl6->saddr);
3098                 if (fn)
3099                         goto restart;
3100         }
3101
3102         res.f6i = rt;
3103         res.nh = rt->fib6_nh;
3104 out:
3105         if (ret) {
3106                 ip6_hold_safe(net, &ret);
3107         } else {
3108                 res.fib6_flags = res.f6i->fib6_flags;
3109                 res.fib6_type = res.f6i->fib6_type;
3110                 ret = ip6_create_rt_rcu(&res);
3111         }
3112
3113         rcu_read_unlock();
3114
3115         trace_fib6_table_lookup(net, &res, table, fl6);
3116         return ret;
3117 };
3118
3119 static struct dst_entry *ip6_route_redirect(struct net *net,
3120                                             const struct flowi6 *fl6,
3121                                             const struct sk_buff *skb,
3122                                             const struct in6_addr *gateway)
3123 {
3124         int flags = RT6_LOOKUP_F_HAS_SADDR;
3125         struct ip6rd_flowi rdfl;
3126
3127         rdfl.fl6 = *fl6;
3128         rdfl.gateway = *gateway;
3129
3130         return fib6_rule_lookup(net, &rdfl.fl6, skb,
3131                                 flags, __ip6_route_redirect);
3132 }
3133
3134 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
3135                   kuid_t uid)
3136 {
3137         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
3138         struct dst_entry *dst;
3139         struct flowi6 fl6 = {
3140                 .flowi6_iif = LOOPBACK_IFINDEX,
3141                 .flowi6_oif = oif,
3142                 .flowi6_mark = mark,
3143                 .daddr = iph->daddr,
3144                 .saddr = iph->saddr,
3145                 .flowlabel = ip6_flowinfo(iph),
3146                 .flowi6_uid = uid,
3147         };
3148
3149         dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
3150         rt6_do_redirect(dst, NULL, skb);
3151         dst_release(dst);
3152 }
3153 EXPORT_SYMBOL_GPL(ip6_redirect);
3154
3155 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
3156 {
3157         const struct ipv6hdr *iph = ipv6_hdr(skb);
3158         const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
3159         struct dst_entry *dst;
3160         struct flowi6 fl6 = {
3161                 .flowi6_iif = LOOPBACK_IFINDEX,
3162                 .flowi6_oif = oif,
3163                 .daddr = msg->dest,
3164                 .saddr = iph->daddr,
3165                 .flowi6_uid = sock_net_uid(net, NULL),
3166         };
3167
3168         dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
3169         rt6_do_redirect(dst, NULL, skb);
3170         dst_release(dst);
3171 }
3172
3173 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
3174 {
3175         ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark,
3176                      sk->sk_uid);
3177 }
3178 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
3179
3180 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
3181 {
3182         struct net_device *dev = dst->dev;
3183         unsigned int mtu = dst_mtu(dst);
3184         struct net *net = dev_net(dev);
3185
3186         mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
3187
3188         if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
3189                 mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
3190
3191         /*
3192          * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
3193          * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
3194          * IPV6_MAXPLEN is also valid and means: "any MSS,
3195          * rely only on pmtu discovery"
3196          */
3197         if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
3198                 mtu = IPV6_MAXPLEN;
3199         return mtu;
3200 }
3201
3202 INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst)
3203 {
3204         return ip6_dst_mtu_maybe_forward(dst, false);
3205 }
3206 EXPORT_INDIRECT_CALLABLE(ip6_mtu);
3207
3208 /* MTU selection:
3209  * 1. mtu on route is locked - use it
3210  * 2. mtu from nexthop exception
3211  * 3. mtu from egress device
3212  *
3213  * based on ip6_dst_mtu_forward and exception logic of
3214  * rt6_find_cached_rt; called with rcu_read_lock
3215  */
3216 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
3217                       const struct in6_addr *daddr,
3218                       const struct in6_addr *saddr)
3219 {
3220         const struct fib6_nh *nh = res->nh;
3221         struct fib6_info *f6i = res->f6i;
3222         struct inet6_dev *idev;
3223         struct rt6_info *rt;
3224         u32 mtu = 0;
3225
3226         if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
3227                 mtu = f6i->fib6_pmtu;
3228                 if (mtu)
3229                         goto out;
3230         }
3231
3232         rt = rt6_find_cached_rt(res, daddr, saddr);
3233         if (unlikely(rt)) {
3234                 mtu = dst_metric_raw(&rt->dst, RTAX_MTU);
3235         } else {
3236                 struct net_device *dev = nh->fib_nh_dev;
3237
3238                 mtu = IPV6_MIN_MTU;
3239                 idev = __in6_dev_get(dev);
3240                 if (idev && idev->cnf.mtu6 > mtu)
3241                         mtu = idev->cnf.mtu6;
3242         }
3243
3244         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
3245 out:
3246         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
3247 }
3248
3249 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
3250                                   struct flowi6 *fl6)
3251 {
3252         struct dst_entry *dst;
3253         struct rt6_info *rt;
3254         struct inet6_dev *idev = in6_dev_get(dev);
3255         struct net *net = dev_net(dev);
3256
3257         if (unlikely(!idev))
3258                 return ERR_PTR(-ENODEV);
3259
3260         rt = ip6_dst_alloc(net, dev, 0);
3261         if (unlikely(!rt)) {
3262                 in6_dev_put(idev);
3263                 dst = ERR_PTR(-ENOMEM);
3264                 goto out;
3265         }
3266
3267         rt->dst.input = ip6_input;
3268         rt->dst.output  = ip6_output;
3269         rt->rt6i_gateway  = fl6->daddr;
3270         rt->rt6i_dst.addr = fl6->daddr;
3271         rt->rt6i_dst.plen = 128;
3272         rt->rt6i_idev     = idev;
3273         dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
3274
3275         /* Add this dst into uncached_list so that rt6_disable_ip() can
3276          * do proper release of the net_device
3277          */
3278         rt6_uncached_list_add(rt);
3279         atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
3280
3281         dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
3282
3283 out:
3284         return dst;
3285 }
3286
3287 static int ip6_dst_gc(struct dst_ops *ops)
3288 {
3289         struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
3290         int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
3291         int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
3292         int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
3293         int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
3294         unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
3295         int entries;
3296
3297         entries = dst_entries_get_fast(ops);
3298         if (entries > rt_max_size)
3299                 entries = dst_entries_get_slow(ops);
3300
3301         if (time_after(rt_last_gc + rt_min_interval, jiffies) &&
3302             entries <= rt_max_size)
3303                 goto out;
3304
3305         net->ipv6.ip6_rt_gc_expire++;
3306         fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net, true);
3307         entries = dst_entries_get_slow(ops);
3308         if (entries < ops->gc_thresh)
3309                 net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;
3310 out:
3311         net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity;
3312         return entries > rt_max_size;
3313 }
3314
3315 static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
3316                                const struct in6_addr *gw_addr, u32 tbid,
3317                                int flags, struct fib6_result *res)
3318 {
3319         struct flowi6 fl6 = {
3320                 .flowi6_oif = cfg->fc_ifindex,
3321                 .daddr = *gw_addr,
3322                 .saddr = cfg->fc_prefsrc,
3323         };
3324         struct fib6_table *table;
3325         int err;
3326
3327         table = fib6_get_table(net, tbid);
3328         if (!table)
3329                 return -EINVAL;
3330
3331         if (!ipv6_addr_any(&cfg->fc_prefsrc))
3332                 flags |= RT6_LOOKUP_F_HAS_SADDR;
3333
3334         flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
3335
3336         err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags);
3337         if (!err && res->f6i != net->ipv6.fib6_null_entry)
3338                 fib6_select_path(net, res, &fl6, cfg->fc_ifindex,
3339                                  cfg->fc_ifindex != 0, NULL, flags);
3340
3341         return err;
3342 }
3343
3344 static int ip6_route_check_nh_onlink(struct net *net,
3345                                      struct fib6_config *cfg,
3346                                      const struct net_device *dev,
3347                                      struct netlink_ext_ack *extack)
3348 {
3349         u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
3350         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3351         struct fib6_result res = {};
3352         int err;
3353
3354         err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res);
3355         if (!err && !(res.fib6_flags & RTF_REJECT) &&
3356             /* ignore match if it is the default route */
3357             !ipv6_addr_any(&res.f6i->fib6_dst.addr) &&
3358             (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) {
3359                 NL_SET_ERR_MSG(extack,
3360                                "Nexthop has invalid gateway or device mismatch");
3361                 err = -EINVAL;
3362         }
3363
3364         return err;
3365 }
3366
3367 static int ip6_route_check_nh(struct net *net,
3368                               struct fib6_config *cfg,
3369                               struct net_device **_dev,
3370                               struct inet6_dev **idev)
3371 {
3372         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3373         struct net_device *dev = _dev ? *_dev : NULL;
3374         int flags = RT6_LOOKUP_F_IFACE;
3375         struct fib6_result res = {};
3376         int err = -EHOSTUNREACH;
3377
3378         if (cfg->fc_table) {
3379                 err = ip6_nh_lookup_table(net, cfg, gw_addr,
3380                                           cfg->fc_table, flags, &res);
3381                 /* gw_addr can not require a gateway or resolve to a reject
3382                  * route. If a device is given, it must match the result.
3383                  */
3384                 if (err || res.fib6_flags & RTF_REJECT ||
3385                     res.nh->fib_nh_gw_family ||
3386                     (dev && dev != res.nh->fib_nh_dev))
3387                         err = -EHOSTUNREACH;
3388         }
3389
3390         if (err < 0) {
3391                 struct flowi6 fl6 = {
3392                         .flowi6_oif = cfg->fc_ifindex,
3393                         .daddr = *gw_addr,
3394                 };
3395
3396                 err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags);
3397                 if (err || res.fib6_flags & RTF_REJECT ||
3398                     res.nh->fib_nh_gw_family)
3399                         err = -EHOSTUNREACH;
3400
3401                 if (err)
3402                         return err;
3403
3404                 fib6_select_path(net, &res, &fl6, cfg->fc_ifindex,
3405                                  cfg->fc_ifindex != 0, NULL, flags);
3406         }
3407
3408         err = 0;
3409         if (dev) {
3410                 if (dev != res.nh->fib_nh_dev)
3411                         err = -EHOSTUNREACH;
3412         } else {
3413                 *_dev = dev = res.nh->fib_nh_dev;
3414                 dev_hold(dev);
3415                 *idev = in6_dev_get(dev);
3416         }
3417
3418         return err;
3419 }
3420
3421 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
3422                            struct net_device **_dev, struct inet6_dev **idev,
3423                            struct netlink_ext_ack *extack)
3424 {
3425         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3426         int gwa_type = ipv6_addr_type(gw_addr);
3427         bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
3428         const struct net_device *dev = *_dev;
3429         bool need_addr_check = !dev;
3430         int err = -EINVAL;
3431
3432         /* if gw_addr is local we will fail to detect this in case
3433          * address is still TENTATIVE (DAD in progress). rt6_lookup()
3434          * will return already-added prefix route via interface that
3435          * prefix route was assigned to, which might be non-loopback.
3436          */
3437         if (dev &&
3438             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3439                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3440                 goto out;
3441         }
3442
3443         if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
3444                 /* IPv6 strictly inhibits using not link-local
3445                  * addresses as nexthop address.
3446                  * Otherwise, router will not able to send redirects.
3447                  * It is very good, but in some (rare!) circumstances
3448                  * (SIT, PtP, NBMA NOARP links) it is handy to allow
3449                  * some exceptions. --ANK
3450                  * We allow IPv4-mapped nexthops to support RFC4798-type
3451                  * addressing
3452                  */
3453                 if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
3454                         NL_SET_ERR_MSG(extack, "Invalid gateway address");
3455                         goto out;
3456                 }
3457
3458                 rcu_read_lock();
3459
3460                 if (cfg->fc_flags & RTNH_F_ONLINK)
3461                         err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
3462                 else
3463                         err = ip6_route_check_nh(net, cfg, _dev, idev);
3464
3465                 rcu_read_unlock();
3466
3467                 if (err)
3468                         goto out;
3469         }
3470
3471         /* reload in case device was changed */
3472         dev = *_dev;
3473
3474         err = -EINVAL;
3475         if (!dev) {
3476                 NL_SET_ERR_MSG(extack, "Egress device not specified");
3477                 goto out;
3478         } else if (dev->flags & IFF_LOOPBACK) {
3479                 NL_SET_ERR_MSG(extack,
3480                                "Egress device can not be loopback device for this route");
3481                 goto out;
3482         }
3483
3484         /* if we did not check gw_addr above, do so now that the
3485          * egress device has been resolved.
3486          */
3487         if (need_addr_check &&
3488             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3489                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3490                 goto out;
3491         }
3492
3493         err = 0;
3494 out:
3495         return err;
3496 }
3497
3498 static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
3499 {
3500         if ((flags & RTF_REJECT) ||
3501             (dev && (dev->flags & IFF_LOOPBACK) &&
3502              !(addr_type & IPV6_ADDR_LOOPBACK) &&
3503              !(flags & (RTF_ANYCAST | RTF_LOCAL))))
3504                 return true;
3505
3506         return false;
3507 }
3508
3509 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
3510                  struct fib6_config *cfg, gfp_t gfp_flags,
3511                  struct netlink_ext_ack *extack)
3512 {
3513         struct net_device *dev = NULL;
3514         struct inet6_dev *idev = NULL;
3515         int addr_type;
3516         int err;
3517
3518         fib6_nh->fib_nh_family = AF_INET6;
3519 #ifdef CONFIG_IPV6_ROUTER_PREF
3520         fib6_nh->last_probe = jiffies;
3521 #endif
3522         if (cfg->fc_is_fdb) {
3523                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3524                 fib6_nh->fib_nh_gw_family = AF_INET6;
3525                 return 0;
3526         }
3527
3528         err = -ENODEV;
3529         if (cfg->fc_ifindex) {
3530                 dev = dev_get_by_index(net, cfg->fc_ifindex);
3531                 if (!dev)
3532                         goto out;
3533                 idev = in6_dev_get(dev);
3534                 if (!idev)
3535                         goto out;
3536         }
3537
3538         if (cfg->fc_flags & RTNH_F_ONLINK) {
3539                 if (!dev) {
3540                         NL_SET_ERR_MSG(extack,
3541                                        "Nexthop device required for onlink");
3542                         goto out;
3543                 }
3544
3545                 if (!(dev->flags & IFF_UP)) {
3546                         NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3547                         err = -ENETDOWN;
3548                         goto out;
3549                 }
3550
3551                 fib6_nh->fib_nh_flags |= RTNH_F_ONLINK;
3552         }
3553
3554         fib6_nh->fib_nh_weight = 1;
3555
3556         /* We cannot add true routes via loopback here,
3557          * they would result in kernel looping; promote them to reject routes
3558          */
3559         addr_type = ipv6_addr_type(&cfg->fc_dst);
3560         if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) {
3561                 /* hold loopback dev/idev if we haven't done so. */
3562                 if (dev != net->loopback_dev) {
3563                         if (dev) {
3564                                 dev_put(dev);
3565                                 in6_dev_put(idev);
3566                         }
3567                         dev = net->loopback_dev;
3568                         dev_hold(dev);
3569                         idev = in6_dev_get(dev);
3570                         if (!idev) {
3571                                 err = -ENODEV;
3572                                 goto out;
3573                         }
3574                 }
3575                 goto pcpu_alloc;
3576         }
3577
3578         if (cfg->fc_flags & RTF_GATEWAY) {
3579                 err = ip6_validate_gw(net, cfg, &dev, &idev, extack);
3580                 if (err)
3581                         goto out;
3582
3583                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3584                 fib6_nh->fib_nh_gw_family = AF_INET6;
3585         }
3586
3587         err = -ENODEV;
3588         if (!dev)
3589                 goto out;
3590
3591         if (idev->cnf.disable_ipv6) {
3592                 NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
3593                 err = -EACCES;
3594                 goto out;
3595         }
3596
3597         if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
3598                 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3599                 err = -ENETDOWN;
3600                 goto out;
3601         }
3602
3603         if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
3604             !netif_carrier_ok(dev))
3605                 fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
3606
3607         err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap,
3608                                  cfg->fc_encap_type, cfg, gfp_flags, extack);
3609         if (err)
3610                 goto out;
3611
3612 pcpu_alloc:
3613         fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
3614         if (!fib6_nh->rt6i_pcpu) {
3615                 err = -ENOMEM;
3616                 goto out;
3617         }
3618
3619         fib6_nh->fib_nh_dev = dev;
3620         fib6_nh->fib_nh_oif = dev->ifindex;
3621         err = 0;
3622 out:
3623         if (idev)
3624                 in6_dev_put(idev);
3625
3626         if (err) {
3627                 lwtstate_put(fib6_nh->fib_nh_lws);
3628                 fib6_nh->fib_nh_lws = NULL;
3629                 dev_put(dev);
3630         }
3631
3632         return err;
3633 }
3634
3635 void fib6_nh_release(struct fib6_nh *fib6_nh)
3636 {
3637         struct rt6_exception_bucket *bucket;
3638
3639         rcu_read_lock();
3640
3641         fib6_nh_flush_exceptions(fib6_nh, NULL);
3642         bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL);
3643         if (bucket) {
3644                 rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL);
3645                 kfree(bucket);
3646         }
3647
3648         rcu_read_unlock();
3649
3650         if (fib6_nh->rt6i_pcpu) {
3651                 int cpu;
3652
3653                 for_each_possible_cpu(cpu) {
3654                         struct rt6_info **ppcpu_rt;
3655                         struct rt6_info *pcpu_rt;
3656
3657                         ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
3658                         pcpu_rt = *ppcpu_rt;
3659                         if (pcpu_rt) {
3660                                 dst_dev_put(&pcpu_rt->dst);
3661                                 dst_release(&pcpu_rt->dst);
3662                                 *ppcpu_rt = NULL;
3663                         }
3664                 }
3665
3666                 free_percpu(fib6_nh->rt6i_pcpu);
3667         }
3668
3669         fib_nh_common_release(&fib6_nh->nh_common);
3670 }
3671
3672 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
3673                                               gfp_t gfp_flags,
3674                                               struct netlink_ext_ack *extack)
3675 {
3676         struct net *net = cfg->fc_nlinfo.nl_net;
3677         struct fib6_info *rt = NULL;
3678         struct nexthop *nh = NULL;
3679         struct fib6_table *table;
3680         struct fib6_nh *fib6_nh;
3681         int err = -EINVAL;
3682         int addr_type;
3683
3684         /* RTF_PCPU is an internal flag; can not be set by userspace */
3685         if (cfg->fc_flags & RTF_PCPU) {
3686                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
3687                 goto out;
3688         }
3689
3690         /* RTF_CACHE is an internal flag; can not be set by userspace */
3691         if (cfg->fc_flags & RTF_CACHE) {
3692                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
3693                 goto out;
3694         }
3695
3696         if (cfg->fc_type > RTN_MAX) {
3697                 NL_SET_ERR_MSG(extack, "Invalid route type");
3698                 goto out;
3699         }
3700
3701         if (cfg->fc_dst_len > 128) {
3702                 NL_SET_ERR_MSG(extack, "Invalid prefix length");
3703                 goto out;
3704         }
3705         if (cfg->fc_src_len > 128) {
3706                 NL_SET_ERR_MSG(extack, "Invalid source address length");
3707                 goto out;
3708         }
3709 #ifndef CONFIG_IPV6_SUBTREES
3710         if (cfg->fc_src_len) {
3711                 NL_SET_ERR_MSG(extack,
3712                                "Specifying source address requires IPV6_SUBTREES to be enabled");
3713                 goto out;
3714         }
3715 #endif
3716         if (cfg->fc_nh_id) {
3717                 nh = nexthop_find_by_id(net, cfg->fc_nh_id);
3718                 if (!nh) {
3719                         NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
3720                         goto out;
3721                 }
3722                 err = fib6_check_nexthop(nh, cfg, extack);
3723                 if (err)
3724                         goto out;
3725         }
3726
3727         err = -ENOBUFS;
3728         if (cfg->fc_nlinfo.nlh &&
3729             !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
3730                 table = fib6_get_table(net, cfg->fc_table);
3731                 if (!table) {
3732                         pr_warn("NLM_F_CREATE should be specified when creating new route\n");
3733                         table = fib6_new_table(net, cfg->fc_table);
3734                 }
3735         } else {
3736                 table = fib6_new_table(net, cfg->fc_table);
3737         }
3738
3739         if (!table)
3740                 goto out;
3741
3742         err = -ENOMEM;
3743         rt = fib6_info_alloc(gfp_flags, !nh);
3744         if (!rt)
3745                 goto out;
3746
3747         rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len,
3748                                                extack);
3749         if (IS_ERR(rt->fib6_metrics)) {
3750                 err = PTR_ERR(rt->fib6_metrics);
3751                 /* Do not leave garbage there. */
3752                 rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
3753                 goto out_free;
3754         }
3755
3756         if (cfg->fc_flags & RTF_ADDRCONF)
3757                 rt->dst_nocount = true;
3758
3759         if (cfg->fc_flags & RTF_EXPIRES)
3760                 fib6_set_expires(rt, jiffies +
3761                                 clock_t_to_jiffies(cfg->fc_expires));
3762         else
3763                 fib6_clean_expires(rt);
3764
3765         if (cfg->fc_protocol == RTPROT_UNSPEC)
3766                 cfg->fc_protocol = RTPROT_BOOT;
3767         rt->fib6_protocol = cfg->fc_protocol;
3768
3769         rt->fib6_table = table;
3770         rt->fib6_metric = cfg->fc_metric;
3771         rt->fib6_type = cfg->fc_type ? : RTN_UNICAST;
3772         rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;
3773
3774         ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
3775         rt->fib6_dst.plen = cfg->fc_dst_len;
3776
3777 #ifdef CONFIG_IPV6_SUBTREES
3778         ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
3779         rt->fib6_src.plen = cfg->fc_src_len;
3780 #endif
3781         if (nh) {
3782                 if (rt->fib6_src.plen) {
3783                         NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
3784                         goto out_free;
3785                 }
3786                 if (!nexthop_get(nh)) {
3787                         NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
3788                         goto out_free;
3789                 }
3790                 rt->nh = nh;
3791                 fib6_nh = nexthop_fib6_nh(rt->nh);
3792         } else {
3793                 err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack);
3794                 if (err)
3795                         goto out;
3796
3797                 fib6_nh = rt->fib6_nh;
3798
3799                 /* We cannot add true routes via loopback here, they would
3800                  * result in kernel looping; promote them to reject routes
3801                  */
3802                 addr_type = ipv6_addr_type(&cfg->fc_dst);
3803                 if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev,
3804                                    addr_type))
3805                         rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
3806         }
3807
3808         if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
3809                 struct net_device *dev = fib6_nh->fib_nh_dev;
3810
3811                 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
3812                         NL_SET_ERR_MSG(extack, "Invalid source address");
3813                         err = -EINVAL;
3814                         goto out;
3815                 }
3816                 rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
3817                 rt->fib6_prefsrc.plen = 128;
3818         } else
3819                 rt->fib6_prefsrc.plen = 0;
3820
3821         return rt;
3822 out:
3823         fib6_info_release(rt);
3824         return ERR_PTR(err);
3825 out_free:
3826         ip_fib_metrics_put(rt->fib6_metrics);
3827         kfree(rt);
3828         return ERR_PTR(err);
3829 }
3830
3831 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
3832                   struct netlink_ext_ack *extack)
3833 {
3834         struct fib6_info *rt;
3835         int err;
3836
3837         rt = ip6_route_info_create(cfg, gfp_flags, extack);
3838         if (IS_ERR(rt))
3839                 return PTR_ERR(rt);
3840
3841         err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
3842         fib6_info_release(rt);
3843
3844         return err;
3845 }
3846
3847 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
3848 {
3849         struct net *net = info->nl_net;
3850         struct fib6_table *table;
3851         int err;
3852
3853         if (rt == net->ipv6.fib6_null_entry) {
3854                 err = -ENOENT;
3855                 goto out;
3856         }
3857
3858         table = rt->fib6_table;
3859         spin_lock_bh(&table->tb6_lock);
3860         err = fib6_del(rt, info);
3861         spin_unlock_bh(&table->tb6_lock);
3862
3863 out:
3864         fib6_info_release(rt);
3865         return err;
3866 }
3867
3868 int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify)
3869 {
3870         struct nl_info info = {
3871                 .nl_net = net,
3872                 .skip_notify = skip_notify
3873         };
3874
3875         return __ip6_del_rt(rt, &info);
3876 }
3877
3878 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
3879 {
3880         struct nl_info *info = &cfg->fc_nlinfo;
3881         struct net *net = info->nl_net;
3882         struct sk_buff *skb = NULL;
3883         struct fib6_table *table;
3884         int err = -ENOENT;
3885
3886         if (rt == net->ipv6.fib6_null_entry)
3887                 goto out_put;
3888         table = rt->fib6_table;
3889         spin_lock_bh(&table->tb6_lock);
3890
3891         if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
3892                 struct fib6_info *sibling, *next_sibling;
3893                 struct fib6_node *fn;
3894
3895                 /* prefer to send a single notification with all hops */
3896                 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3897                 if (skb) {
3898                         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3899
3900                         if (rt6_fill_node(net, skb, rt, NULL,
3901                                           NULL, NULL, 0, RTM_DELROUTE,
3902                                           info->portid, seq, 0) < 0) {
3903                                 kfree_skb(skb);
3904                                 skb = NULL;
3905                         } else
3906                                 info->skip_notify = 1;
3907                 }
3908
3909                 /* 'rt' points to the first sibling route. If it is not the
3910                  * leaf, then we do not need to send a notification. Otherwise,
3911                  * we need to check if the last sibling has a next route or not
3912                  * and emit a replace or delete notification, respectively.
3913                  */
3914                 info->skip_notify_kernel = 1;
3915                 fn = rcu_dereference_protected(rt->fib6_node,
3916                                             lockdep_is_held(&table->tb6_lock));
3917                 if (rcu_access_pointer(fn->leaf) == rt) {
3918                         struct fib6_info *last_sibling, *replace_rt;
3919
3920                         last_sibling = list_last_entry(&rt->fib6_siblings,
3921                                                        struct fib6_info,
3922                                                        fib6_siblings);
3923                         replace_rt = rcu_dereference_protected(
3924                                             last_sibling->fib6_next,
3925                                             lockdep_is_held(&table->tb6_lock));
3926                         if (replace_rt)
3927                                 call_fib6_entry_notifiers_replace(net,
3928                                                                   replace_rt);
3929                         else
3930                                 call_fib6_multipath_entry_notifiers(net,
3931                                                        FIB_EVENT_ENTRY_DEL,
3932                                                        rt, rt->fib6_nsiblings,
3933                                                        NULL);
3934                 }
3935                 list_for_each_entry_safe(sibling, next_sibling,
3936                                          &rt->fib6_siblings,
3937                                          fib6_siblings) {
3938                         err = fib6_del(sibling, info);
3939                         if (err)
3940                                 goto out_unlock;
3941                 }
3942         }
3943
3944         err = fib6_del(rt, info);
3945 out_unlock:
3946         spin_unlock_bh(&table->tb6_lock);
3947 out_put:
3948         fib6_info_release(rt);
3949
3950         if (skb) {
3951                 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3952                             info->nlh, gfp_any());
3953         }
3954         return err;
3955 }
3956
3957 static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
3958 {
3959         int rc = -ESRCH;
3960
3961         if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
3962                 goto out;
3963
3964         if (cfg->fc_flags & RTF_GATEWAY &&
3965             !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
3966                 goto out;
3967
3968         rc = rt6_remove_exception_rt(rt);
3969 out:
3970         return rc;
3971 }
3972
3973 static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt,
3974                              struct fib6_nh *nh)
3975 {
3976         struct fib6_result res = {
3977                 .f6i = rt,
3978                 .nh = nh,
3979         };
3980         struct rt6_info *rt_cache;
3981
3982         rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src);
3983         if (rt_cache)
3984                 return __ip6_del_cached_rt(rt_cache, cfg);
3985
3986         return 0;
3987 }
3988
3989 struct fib6_nh_del_cached_rt_arg {
3990         struct fib6_config *cfg;
3991         struct fib6_info *f6i;
3992 };
3993
3994 static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg)
3995 {
3996         struct fib6_nh_del_cached_rt_arg *arg = _arg;
3997         int rc;
3998
3999         rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh);
4000         return rc != -ESRCH ? rc : 0;
4001 }
4002
4003 static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i)
4004 {
4005         struct fib6_nh_del_cached_rt_arg arg = {
4006                 .cfg = cfg,
4007                 .f6i = f6i
4008         };
4009
4010         return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg);
4011 }
4012
4013 static int ip6_route_del(struct fib6_config *cfg,
4014                          struct netlink_ext_ack *extack)
4015 {
4016         struct fib6_table *table;
4017         struct fib6_info *rt;
4018         struct fib6_node *fn;
4019         int err = -ESRCH;
4020
4021         table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
4022         if (!table) {
4023                 NL_SET_ERR_MSG(extack, "FIB table does not exist");
4024                 return err;
4025         }
4026
4027         rcu_read_lock();
4028
4029         fn = fib6_locate(&table->tb6_root,
4030                          &cfg->fc_dst, cfg->fc_dst_len,
4031                          &cfg->fc_src, cfg->fc_src_len,
4032                          !(cfg->fc_flags & RTF_CACHE));
4033
4034         if (fn) {
4035                 for_each_fib6_node_rt_rcu(fn) {
4036                         struct fib6_nh *nh;
4037
4038                         if (rt->nh && cfg->fc_nh_id &&
4039                             rt->nh->id != cfg->fc_nh_id)
4040                                 continue;
4041
4042                         if (cfg->fc_flags & RTF_CACHE) {
4043                                 int rc = 0;
4044
4045                                 if (rt->nh) {
4046                                         rc = ip6_del_cached_rt_nh(cfg, rt);
4047                                 } else if (cfg->fc_nh_id) {
4048                                         continue;
4049                                 } else {
4050                                         nh = rt->fib6_nh;
4051                                         rc = ip6_del_cached_rt(cfg, rt, nh);
4052                                 }
4053                                 if (rc != -ESRCH) {
4054                                         rcu_read_unlock();
4055                                         return rc;
4056                                 }
4057                                 continue;
4058                         }
4059
4060                         if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
4061                                 continue;
4062                         if (cfg->fc_protocol &&
4063                             cfg->fc_protocol != rt->fib6_protocol)
4064                                 continue;
4065
4066                         if (rt->nh) {
4067                                 if (!fib6_info_hold_safe(rt))
4068                                         continue;
4069                                 rcu_read_unlock();
4070
4071                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4072                         }
4073                         if (cfg->fc_nh_id)
4074                                 continue;
4075
4076                         nh = rt->fib6_nh;
4077                         if (cfg->fc_ifindex &&
4078                             (!nh->fib_nh_dev ||
4079                              nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
4080                                 continue;
4081                         if (cfg->fc_flags & RTF_GATEWAY &&
4082                             !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6))
4083                                 continue;
4084                         if (!fib6_info_hold_safe(rt))
4085                                 continue;
4086                         rcu_read_unlock();
4087
4088                         /* if gateway was specified only delete the one hop */
4089                         if (cfg->fc_flags & RTF_GATEWAY)
4090                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4091
4092                         return __ip6_del_rt_siblings(rt, cfg);
4093                 }
4094         }
4095         rcu_read_unlock();
4096
4097         return err;
4098 }
4099
4100 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
4101 {
4102         struct netevent_redirect netevent;
4103         struct rt6_info *rt, *nrt = NULL;
4104         struct fib6_result res = {};
4105         struct ndisc_options ndopts;
4106         struct inet6_dev *in6_dev;
4107         struct neighbour *neigh;
4108         struct rd_msg *msg;
4109         int optlen, on_link;
4110         u8 *lladdr;
4111
4112         optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
4113         optlen -= sizeof(*msg);
4114
4115         if (optlen < 0) {
4116                 net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
4117                 return;
4118         }
4119
4120         msg = (struct rd_msg *)icmp6_hdr(skb);
4121
4122         if (ipv6_addr_is_multicast(&msg->dest)) {
4123                 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
4124                 return;
4125         }
4126
4127         on_link = 0;
4128         if (ipv6_addr_equal(&msg->dest, &msg->target)) {
4129                 on_link = 1;
4130         } else if (ipv6_addr_type(&msg->target) !=
4131                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
4132                 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
4133                 return;
4134         }
4135
4136         in6_dev = __in6_dev_get(skb->dev);
4137         if (!in6_dev)
4138                 return;
4139         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
4140                 return;
4141
4142         /* RFC2461 8.1:
4143          *      The IP source address of the Redirect MUST be the same as the current
4144          *      first-hop router for the specified ICMP Destination Address.
4145          */
4146
4147         if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
4148                 net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
4149                 return;
4150         }
4151
4152         lladdr = NULL;
4153         if (ndopts.nd_opts_tgt_lladdr) {
4154                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
4155                                              skb->dev);
4156                 if (!lladdr) {
4157                         net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
4158                         return;
4159                 }
4160         }
4161
4162         rt = (struct rt6_info *) dst;
4163         if (rt->rt6i_flags & RTF_REJECT) {
4164                 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
4165                 return;
4166         }
4167
4168         /* Redirect received -> path was valid.
4169          * Look, redirects are sent only in response to data packets,
4170          * so that this nexthop apparently is reachable. --ANK
4171          */
4172         dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
4173
4174         neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
4175         if (!neigh)
4176                 return;
4177
4178         /*
4179          *      We have finally decided to accept it.
4180          */
4181
4182         ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
4183                      NEIGH_UPDATE_F_WEAK_OVERRIDE|
4184                      NEIGH_UPDATE_F_OVERRIDE|
4185                      (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
4186                                      NEIGH_UPDATE_F_ISROUTER)),
4187                      NDISC_REDIRECT, &ndopts);
4188
4189         rcu_read_lock();
4190         res.f6i = rcu_dereference(rt->from);
4191         if (!res.f6i)
4192                 goto out;
4193
4194         if (res.f6i->nh) {
4195                 struct fib6_nh_match_arg arg = {
4196                         .dev = dst->dev,
4197                         .gw = &rt->rt6i_gateway,
4198                 };
4199
4200                 nexthop_for_each_fib6_nh(res.f6i->nh,
4201                                          fib6_nh_find_match, &arg);
4202
4203                 /* fib6_info uses a nexthop that does not have fib6_nh
4204                  * using the dst->dev. Should be impossible
4205                  */
4206                 if (!arg.match)
4207                         goto out;
4208                 res.nh = arg.match;
4209         } else {
4210                 res.nh = res.f6i->fib6_nh;
4211         }
4212
4213         res.fib6_flags = res.f6i->fib6_flags;
4214         res.fib6_type = res.f6i->fib6_type;
4215         nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL);
4216         if (!nrt)
4217                 goto out;
4218
4219         nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
4220         if (on_link)
4221                 nrt->rt6i_flags &= ~RTF_GATEWAY;
4222
4223         nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
4224
4225         /* rt6_insert_exception() will take care of duplicated exceptions */
4226         if (rt6_insert_exception(nrt, &res)) {
4227                 dst_release_immediate(&nrt->dst);
4228                 goto out;
4229         }
4230
4231         netevent.old = &rt->dst;
4232         netevent.new = &nrt->dst;
4233         netevent.daddr = &msg->dest;
4234         netevent.neigh = neigh;
4235         call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
4236
4237 out:
4238         rcu_read_unlock();
4239         neigh_release(neigh);
4240 }
4241
4242 #ifdef CONFIG_IPV6_ROUTE_INFO
4243 static struct fib6_info *rt6_get_route_info(struct net *net,
4244                                            const struct in6_addr *prefix, int prefixlen,
4245                                            const struct in6_addr *gwaddr,
4246                                            struct net_device *dev)
4247 {
4248         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4249         int ifindex = dev->ifindex;
4250         struct fib6_node *fn;
4251         struct fib6_info *rt = NULL;
4252         struct fib6_table *table;
4253
4254         table = fib6_get_table(net, tb_id);
4255         if (!table)
4256                 return NULL;
4257
4258         rcu_read_lock();
4259         fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
4260         if (!fn)
4261                 goto out;
4262
4263         for_each_fib6_node_rt_rcu(fn) {
4264                 /* these routes do not use nexthops */
4265                 if (rt->nh)
4266                         continue;
4267                 if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex)
4268                         continue;
4269                 if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
4270                     !rt->fib6_nh->fib_nh_gw_family)
4271                         continue;
4272                 if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr))
4273                         continue;
4274                 if (!fib6_info_hold_safe(rt))
4275                         continue;
4276                 break;
4277         }
4278 out:
4279         rcu_read_unlock();
4280         return rt;
4281 }
4282
4283 static struct fib6_info *rt6_add_route_info(struct net *net,
4284                                            const struct in6_addr *prefix, int prefixlen,
4285                                            const struct in6_addr *gwaddr,
4286                                            struct net_device *dev,
4287                                            unsigned int pref)
4288 {
4289         struct fib6_config cfg = {
4290                 .fc_metric      = IP6_RT_PRIO_USER,
4291                 .fc_ifindex     = dev->ifindex,
4292                 .fc_dst_len     = prefixlen,
4293                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
4294                                   RTF_UP | RTF_PREF(pref),
4295                 .fc_protocol = RTPROT_RA,
4296                 .fc_type = RTN_UNICAST,
4297                 .fc_nlinfo.portid = 0,
4298                 .fc_nlinfo.nlh = NULL,
4299                 .fc_nlinfo.nl_net = net,
4300         };
4301
4302         cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4303         cfg.fc_dst = *prefix;
4304         cfg.fc_gateway = *gwaddr;
4305
4306         /* We should treat it as a default route if prefix length is 0. */
4307         if (!prefixlen)
4308                 cfg.fc_flags |= RTF_DEFAULT;
4309
4310         ip6_route_add(&cfg, GFP_ATOMIC, NULL);
4311
4312         return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
4313 }
4314 #endif
4315
4316 struct fib6_info *rt6_get_dflt_router(struct net *net,
4317                                      const struct in6_addr *addr,
4318                                      struct net_device *dev)
4319 {
4320         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
4321         struct fib6_info *rt;
4322         struct fib6_table *table;
4323
4324         table = fib6_get_table(net, tb_id);
4325         if (!table)
4326                 return NULL;
4327
4328         rcu_read_lock();
4329         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4330                 struct fib6_nh *nh;
4331
4332                 /* RA routes do not use nexthops */
4333                 if (rt->nh)
4334                         continue;
4335
4336                 nh = rt->fib6_nh;
4337                 if (dev == nh->fib_nh_dev &&
4338                     ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
4339                     ipv6_addr_equal(&nh->fib_nh_gw6, addr))
4340                         break;
4341         }
4342         if (rt && !fib6_info_hold_safe(rt))
4343                 rt = NULL;
4344         rcu_read_unlock();
4345         return rt;
4346 }
4347
4348 struct fib6_info *rt6_add_dflt_router(struct net *net,
4349                                      const struct in6_addr *gwaddr,
4350                                      struct net_device *dev,
4351                                      unsigned int pref,
4352                                      u32 defrtr_usr_metric)
4353 {
4354         struct fib6_config cfg = {
4355                 .fc_table       = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
4356                 .fc_metric      = defrtr_usr_metric,
4357                 .fc_ifindex     = dev->ifindex,
4358                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
4359                                   RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
4360                 .fc_protocol = RTPROT_RA,
4361                 .fc_type = RTN_UNICAST,
4362                 .fc_nlinfo.portid = 0,
4363                 .fc_nlinfo.nlh = NULL,
4364                 .fc_nlinfo.nl_net = net,
4365         };
4366
4367         cfg.fc_gateway = *gwaddr;
4368
4369         if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
4370                 struct fib6_table *table;
4371
4372                 table = fib6_get_table(dev_net(dev), cfg.fc_table);
4373                 if (table)
4374                         table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
4375         }
4376
4377         return rt6_get_dflt_router(net, gwaddr, dev);
4378 }
4379
4380 static void __rt6_purge_dflt_routers(struct net *net,
4381                                      struct fib6_table *table)
4382 {
4383         struct fib6_info *rt;
4384
4385 restart:
4386         rcu_read_lock();
4387         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4388                 struct net_device *dev = fib6_info_nh_dev(rt);
4389                 struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
4390
4391                 if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
4392                     (!idev || idev->cnf.accept_ra != 2) &&
4393                     fib6_info_hold_safe(rt)) {
4394                         rcu_read_unlock();
4395                         ip6_del_rt(net, rt, false);
4396                         goto restart;
4397                 }
4398         }
4399         rcu_read_unlock();
4400
4401         table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
4402 }
4403
4404 void rt6_purge_dflt_routers(struct net *net)
4405 {
4406         struct fib6_table *table;
4407         struct hlist_head *head;
4408         unsigned int h;
4409
4410         rcu_read_lock();
4411
4412         for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
4413                 head = &net->ipv6.fib_table_hash[h];
4414                 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
4415                         if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
4416                                 __rt6_purge_dflt_routers(net, table);
4417                 }
4418         }
4419
4420         rcu_read_unlock();
4421 }
4422
4423 static void rtmsg_to_fib6_config(struct net *net,
4424                                  struct in6_rtmsg *rtmsg,
4425                                  struct fib6_config *cfg)
4426 {
4427         *cfg = (struct fib6_config){
4428                 .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
4429                          : RT6_TABLE_MAIN,
4430                 .fc_ifindex = rtmsg->rtmsg_ifindex,
4431                 .fc_metric = rtmsg->rtmsg_metric ? : IP6_RT_PRIO_USER,
4432                 .fc_expires = rtmsg->rtmsg_info,
4433                 .fc_dst_len = rtmsg->rtmsg_dst_len,
4434                 .fc_src_len = rtmsg->rtmsg_src_len,
4435                 .fc_flags = rtmsg->rtmsg_flags,
4436                 .fc_type = rtmsg->rtmsg_type,
4437
4438                 .fc_nlinfo.nl_net = net,
4439
4440                 .fc_dst = rtmsg->rtmsg_dst,
4441                 .fc_src = rtmsg->rtmsg_src,
4442                 .fc_gateway = rtmsg->rtmsg_gateway,
4443         };
4444 }
4445
4446 int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg)
4447 {
4448         struct fib6_config cfg;
4449         int err;
4450
4451         if (cmd != SIOCADDRT && cmd != SIOCDELRT)
4452                 return -EINVAL;
4453         if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
4454                 return -EPERM;
4455
4456         rtmsg_to_fib6_config(net, rtmsg, &cfg);
4457
4458         rtnl_lock();
4459         switch (cmd) {
4460         case SIOCADDRT:
4461                 err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
4462                 break;
4463         case SIOCDELRT:
4464                 err = ip6_route_del(&cfg, NULL);
4465                 break;
4466         }
4467         rtnl_unlock();
4468         return err;
4469 }
4470
4471 /*
4472  *      Drop the packet on the floor
4473  */
4474
4475 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
4476 {
4477         struct dst_entry *dst = skb_dst(skb);
4478         struct net *net = dev_net(dst->dev);
4479         struct inet6_dev *idev;
4480         int type;
4481
4482         if (netif_is_l3_master(skb->dev) &&
4483             dst->dev == net->loopback_dev)
4484                 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
4485         else
4486                 idev = ip6_dst_idev(dst);
4487
4488         switch (ipstats_mib_noroutes) {
4489         case IPSTATS_MIB_INNOROUTES:
4490                 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
4491                 if (type == IPV6_ADDR_ANY) {
4492                         IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
4493                         break;
4494                 }
4495                 fallthrough;
4496         case IPSTATS_MIB_OUTNOROUTES:
4497                 IP6_INC_STATS(net, idev, ipstats_mib_noroutes);
4498                 break;
4499         }
4500
4501         /* Start over by dropping the dst for l3mdev case */
4502         if (netif_is_l3_master(skb->dev))
4503                 skb_dst_drop(skb);
4504
4505         icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
4506         kfree_skb(skb);
4507         return 0;
4508 }
4509
4510 static int ip6_pkt_discard(struct sk_buff *skb)
4511 {
4512         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
4513 }
4514
4515 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4516 {
4517         skb->dev = skb_dst(skb)->dev;
4518         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
4519 }
4520
4521 static int ip6_pkt_prohibit(struct sk_buff *skb)
4522 {
4523         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
4524 }
4525
4526 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4527 {
4528         skb->dev = skb_dst(skb)->dev;
4529         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
4530 }
4531
4532 /*
4533  *      Allocate a dst for local (unicast / anycast) address.
4534  */
4535
4536 struct fib6_info *addrconf_f6i_alloc(struct net *net,
4537                                      struct inet6_dev *idev,
4538                                      const struct in6_addr *addr,
4539                                      bool anycast, gfp_t gfp_flags)
4540 {
4541         struct fib6_config cfg = {
4542                 .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
4543                 .fc_ifindex = idev->dev->ifindex,
4544                 .fc_flags = RTF_UP | RTF_NONEXTHOP,
4545                 .fc_dst = *addr,
4546                 .fc_dst_len = 128,
4547                 .fc_protocol = RTPROT_KERNEL,
4548                 .fc_nlinfo.nl_net = net,
4549                 .fc_ignore_dev_down = true,
4550         };
4551         struct fib6_info *f6i;
4552
4553         if (anycast) {
4554                 cfg.fc_type = RTN_ANYCAST;
4555                 cfg.fc_flags |= RTF_ANYCAST;
4556         } else {
4557                 cfg.fc_type = RTN_LOCAL;
4558                 cfg.fc_flags |= RTF_LOCAL;
4559         }
4560
4561         f6i = ip6_route_info_create(&cfg, gfp_flags, NULL);
4562         if (!IS_ERR(f6i))
4563                 f6i->dst_nocount = true;
4564         return f6i;
4565 }
4566
4567 /* remove deleted ip from prefsrc entries */
4568 struct arg_dev_net_ip {
4569         struct net_device *dev;
4570         struct net *net;
4571         struct in6_addr *addr;
4572 };
4573
4574 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
4575 {
4576         struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev;
4577         struct net *net = ((struct arg_dev_net_ip *)arg)->net;
4578         struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
4579
4580         if (!rt->nh &&
4581             ((void *)rt->fib6_nh->fib_nh_dev == dev || !dev) &&
4582             rt != net->ipv6.fib6_null_entry &&
4583             ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr)) {
4584                 spin_lock_bh(&rt6_exception_lock);
4585                 /* remove prefsrc entry */
4586                 rt->fib6_prefsrc.plen = 0;
4587                 spin_unlock_bh(&rt6_exception_lock);
4588         }
4589         return 0;
4590 }
4591
4592 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
4593 {
4594         struct net *net = dev_net(ifp->idev->dev);
4595         struct arg_dev_net_ip adni = {
4596                 .dev = ifp->idev->dev,
4597                 .net = net,
4598                 .addr = &ifp->addr,
4599         };
4600         fib6_clean_all(net, fib6_remove_prefsrc, &adni);
4601 }
4602
4603 #define RTF_RA_ROUTER           (RTF_ADDRCONF | RTF_DEFAULT)
4604
4605 /* Remove routers and update dst entries when gateway turn into host. */
4606 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
4607 {
4608         struct in6_addr *gateway = (struct in6_addr *)arg;
4609         struct fib6_nh *nh;
4610
4611         /* RA routes do not use nexthops */
4612         if (rt->nh)
4613                 return 0;
4614
4615         nh = rt->fib6_nh;
4616         if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
4617             nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6))
4618                 return -1;
4619
4620         /* Further clean up cached routes in exception table.
4621          * This is needed because cached route may have a different
4622          * gateway than its 'parent' in the case of an ip redirect.
4623          */
4624         fib6_nh_exceptions_clean_tohost(nh, gateway);
4625
4626         return 0;
4627 }
4628
4629 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
4630 {
4631         fib6_clean_all(net, fib6_clean_tohost, gateway);
4632 }
4633
4634 struct arg_netdev_event {
4635         const struct net_device *dev;
4636         union {
4637                 unsigned char nh_flags;
4638                 unsigned long event;
4639         };
4640 };
4641
4642 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
4643 {
4644         struct fib6_info *iter;
4645         struct fib6_node *fn;
4646
4647         fn = rcu_dereference_protected(rt->fib6_node,
4648                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4649         iter = rcu_dereference_protected(fn->leaf,
4650                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4651         while (iter) {
4652                 if (iter->fib6_metric == rt->fib6_metric &&
4653                     rt6_qualify_for_ecmp(iter))
4654                         return iter;
4655                 iter = rcu_dereference_protected(iter->fib6_next,
4656                                 lockdep_is_held(&rt->fib6_table->tb6_lock));
4657         }
4658
4659         return NULL;
4660 }
4661
4662 /* only called for fib entries with builtin fib6_nh */
4663 static bool rt6_is_dead(const struct fib6_info *rt)
4664 {
4665         if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD ||
4666             (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN &&
4667              ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev)))
4668                 return true;
4669
4670         return false;
4671 }
4672
4673 static int rt6_multipath_total_weight(const struct fib6_info *rt)
4674 {
4675         struct fib6_info *iter;
4676         int total = 0;
4677
4678         if (!rt6_is_dead(rt))
4679                 total += rt->fib6_nh->fib_nh_weight;
4680
4681         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
4682                 if (!rt6_is_dead(iter))
4683                         total += iter->fib6_nh->fib_nh_weight;
4684         }
4685
4686         return total;
4687 }
4688
4689 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
4690 {
4691         int upper_bound = -1;
4692
4693         if (!rt6_is_dead(rt)) {
4694                 *weight += rt->fib6_nh->fib_nh_weight;
4695                 upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
4696                                                     total) - 1;
4697         }
4698         atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
4699 }
4700
4701 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
4702 {
4703         struct fib6_info *iter;
4704         int weight = 0;
4705
4706         rt6_upper_bound_set(rt, &weight, total);
4707
4708         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4709                 rt6_upper_bound_set(iter, &weight, total);
4710 }
4711
4712 void rt6_multipath_rebalance(struct fib6_info *rt)
4713 {
4714         struct fib6_info *first;
4715         int total;
4716
4717         /* In case the entire multipath route was marked for flushing,
4718          * then there is no need to rebalance upon the removal of every
4719          * sibling route.
4720          */
4721         if (!rt->fib6_nsiblings || rt->should_flush)
4722                 return;
4723
4724         /* During lookup routes are evaluated in order, so we need to
4725          * make sure upper bounds are assigned from the first sibling
4726          * onwards.
4727          */
4728         first = rt6_multipath_first_sibling(rt);
4729         if (WARN_ON_ONCE(!first))
4730                 return;
4731
4732         total = rt6_multipath_total_weight(first);
4733         rt6_multipath_upper_bound_set(first, total);
4734 }
4735
4736 static int fib6_ifup(struct fib6_info *rt, void *p_arg)
4737 {
4738         const struct arg_netdev_event *arg = p_arg;
4739         struct net *net = dev_net(arg->dev);
4740
4741         if (rt != net->ipv6.fib6_null_entry && !rt->nh &&
4742             rt->fib6_nh->fib_nh_dev == arg->dev) {
4743                 rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags;
4744                 fib6_update_sernum_upto_root(net, rt);
4745                 rt6_multipath_rebalance(rt);
4746         }
4747
4748         return 0;
4749 }
4750
4751 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags)
4752 {
4753         struct arg_netdev_event arg = {
4754                 .dev = dev,
4755                 {
4756                         .nh_flags = nh_flags,
4757                 },
4758         };
4759
4760         if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
4761                 arg.nh_flags |= RTNH_F_LINKDOWN;
4762
4763         fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
4764 }
4765
4766 /* only called for fib entries with inline fib6_nh */
4767 static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
4768                                    const struct net_device *dev)
4769 {
4770         struct fib6_info *iter;
4771
4772         if (rt->fib6_nh->fib_nh_dev == dev)
4773                 return true;
4774         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4775                 if (iter->fib6_nh->fib_nh_dev == dev)
4776                         return true;
4777
4778         return false;
4779 }
4780
4781 static void rt6_multipath_flush(struct fib6_info *rt)
4782 {
4783         struct fib6_info *iter;
4784
4785         rt->should_flush = 1;
4786         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4787                 iter->should_flush = 1;
4788 }
4789
4790 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
4791                                              const struct net_device *down_dev)
4792 {
4793         struct fib6_info *iter;
4794         unsigned int dead = 0;
4795
4796         if (rt->fib6_nh->fib_nh_dev == down_dev ||
4797             rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4798                 dead++;
4799         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4800                 if (iter->fib6_nh->fib_nh_dev == down_dev ||
4801                     iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4802                         dead++;
4803
4804         return dead;
4805 }
4806
4807 static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
4808                                        const struct net_device *dev,
4809                                        unsigned char nh_flags)
4810 {
4811         struct fib6_info *iter;
4812
4813         if (rt->fib6_nh->fib_nh_dev == dev)
4814                 rt->fib6_nh->fib_nh_flags |= nh_flags;
4815         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4816                 if (iter->fib6_nh->fib_nh_dev == dev)
4817                         iter->fib6_nh->fib_nh_flags |= nh_flags;
4818 }
4819
4820 /* called with write lock held for table with rt */
4821 static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
4822 {
4823         const struct arg_netdev_event *arg = p_arg;
4824         const struct net_device *dev = arg->dev;
4825         struct net *net = dev_net(dev);
4826
4827         if (rt == net->ipv6.fib6_null_entry || rt->nh)
4828                 return 0;
4829
4830         switch (arg->event) {
4831         case NETDEV_UNREGISTER:
4832                 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4833         case NETDEV_DOWN:
4834                 if (rt->should_flush)
4835                         return -1;
4836                 if (!rt->fib6_nsiblings)
4837                         return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4838                 if (rt6_multipath_uses_dev(rt, dev)) {
4839                         unsigned int count;
4840
4841                         count = rt6_multipath_dead_count(rt, dev);
4842                         if (rt->fib6_nsiblings + 1 == count) {
4843                                 rt6_multipath_flush(rt);
4844                                 return -1;
4845                         }
4846                         rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
4847                                                    RTNH_F_LINKDOWN);
4848                         fib6_update_sernum(net, rt);
4849                         rt6_multipath_rebalance(rt);
4850                 }
4851                 return -2;
4852         case NETDEV_CHANGE:
4853                 if (rt->fib6_nh->fib_nh_dev != dev ||
4854                     rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
4855                         break;
4856                 rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
4857                 rt6_multipath_rebalance(rt);
4858                 break;
4859         }
4860
4861         return 0;
4862 }
4863
4864 void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
4865 {
4866         struct arg_netdev_event arg = {
4867                 .dev = dev,
4868                 {
4869                         .event = event,
4870                 },
4871         };
4872         struct net *net = dev_net(dev);
4873
4874         if (net->ipv6.sysctl.skip_notify_on_dev_down)
4875                 fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
4876         else
4877                 fib6_clean_all(net, fib6_ifdown, &arg);
4878 }
4879
4880 void rt6_disable_ip(struct net_device *dev, unsigned long event)
4881 {
4882         rt6_sync_down_dev(dev, event);
4883         rt6_uncached_list_flush_dev(dev_net(dev), dev);
4884         neigh_ifdown(&nd_tbl, dev);
4885 }
4886
4887 struct rt6_mtu_change_arg {
4888         struct net_device *dev;
4889         unsigned int mtu;
4890         struct fib6_info *f6i;
4891 };
4892
4893 static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
4894 {
4895         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg;
4896         struct fib6_info *f6i = arg->f6i;
4897
4898         /* For administrative MTU increase, there is no way to discover
4899          * IPv6 PMTU increase, so PMTU increase should be updated here.
4900          * Since RFC 1981 doesn't include administrative MTU increase
4901          * update PMTU increase is a MUST. (i.e. jumbo frame)
4902          */
4903         if (nh->fib_nh_dev == arg->dev) {
4904                 struct inet6_dev *idev = __in6_dev_get(arg->dev);
4905                 u32 mtu = f6i->fib6_pmtu;
4906
4907                 if (mtu >= arg->mtu ||
4908                     (mtu < arg->mtu && mtu == idev->cnf.mtu6))
4909                         fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
4910
4911                 spin_lock_bh(&rt6_exception_lock);
4912                 rt6_exceptions_update_pmtu(idev, nh, arg->mtu);
4913                 spin_unlock_bh(&rt6_exception_lock);
4914         }
4915
4916         return 0;
4917 }
4918
4919 static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
4920 {
4921         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
4922         struct inet6_dev *idev;
4923
4924         /* In IPv6 pmtu discovery is not optional,
4925            so that RTAX_MTU lock cannot disable it.
4926            We still use this lock to block changes
4927            caused by addrconf/ndisc.
4928         */
4929
4930         idev = __in6_dev_get(arg->dev);
4931         if (!idev)
4932                 return 0;
4933
4934         if (fib6_metric_locked(f6i, RTAX_MTU))
4935                 return 0;
4936
4937         arg->f6i = f6i;
4938         if (f6i->nh) {
4939                 /* fib6_nh_mtu_change only returns 0, so this is safe */
4940                 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change,
4941                                                 arg);
4942         }
4943
4944         return fib6_nh_mtu_change(f6i->fib6_nh, arg);
4945 }
4946
4947 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
4948 {
4949         struct rt6_mtu_change_arg arg = {
4950                 .dev = dev,
4951                 .mtu = mtu,
4952         };
4953
4954         fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
4955 }
4956
4957 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
4958         [RTA_UNSPEC]            = { .strict_start_type = RTA_DPORT + 1 },
4959         [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
4960         [RTA_PREFSRC]           = { .len = sizeof(struct in6_addr) },
4961         [RTA_OIF]               = { .type = NLA_U32 },
4962         [RTA_IIF]               = { .type = NLA_U32 },
4963         [RTA_PRIORITY]          = { .type = NLA_U32 },
4964         [RTA_METRICS]           = { .type = NLA_NESTED },
4965         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
4966         [RTA_PREF]              = { .type = NLA_U8 },
4967         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
4968         [RTA_ENCAP]             = { .type = NLA_NESTED },
4969         [RTA_EXPIRES]           = { .type = NLA_U32 },
4970         [RTA_UID]               = { .type = NLA_U32 },
4971         [RTA_MARK]              = { .type = NLA_U32 },
4972         [RTA_TABLE]             = { .type = NLA_U32 },
4973         [RTA_IP_PROTO]          = { .type = NLA_U8 },
4974         [RTA_SPORT]             = { .type = NLA_U16 },
4975         [RTA_DPORT]             = { .type = NLA_U16 },
4976         [RTA_NH_ID]             = { .type = NLA_U32 },
4977 };
4978
4979 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
4980                               struct fib6_config *cfg,
4981                               struct netlink_ext_ack *extack)
4982 {
4983         struct rtmsg *rtm;
4984         struct nlattr *tb[RTA_MAX+1];
4985         unsigned int pref;
4986         int err;
4987
4988         err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
4989                                      rtm_ipv6_policy, extack);
4990         if (err < 0)
4991                 goto errout;
4992
4993         err = -EINVAL;
4994         rtm = nlmsg_data(nlh);
4995
4996         *cfg = (struct fib6_config){
4997                 .fc_table = rtm->rtm_table,
4998                 .fc_dst_len = rtm->rtm_dst_len,
4999                 .fc_src_len = rtm->rtm_src_len,
5000                 .fc_flags = RTF_UP,
5001                 .fc_protocol = rtm->rtm_protocol,
5002                 .fc_type = rtm->rtm_type,
5003
5004                 .fc_nlinfo.portid = NETLINK_CB(skb).portid,
5005                 .fc_nlinfo.nlh = nlh,
5006                 .fc_nlinfo.nl_net = sock_net(skb->sk),
5007         };
5008
5009         if (rtm->rtm_type == RTN_UNREACHABLE ||
5010             rtm->rtm_type == RTN_BLACKHOLE ||
5011             rtm->rtm_type == RTN_PROHIBIT ||
5012             rtm->rtm_type == RTN_THROW)
5013                 cfg->fc_flags |= RTF_REJECT;
5014
5015         if (rtm->rtm_type == RTN_LOCAL)
5016                 cfg->fc_flags |= RTF_LOCAL;
5017
5018         if (rtm->rtm_flags & RTM_F_CLONED)
5019                 cfg->fc_flags |= RTF_CACHE;
5020
5021         cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
5022
5023         if (tb[RTA_NH_ID]) {
5024                 if (tb[RTA_GATEWAY]   || tb[RTA_OIF] ||
5025                     tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {
5026                         NL_SET_ERR_MSG(extack,
5027                                        "Nexthop specification and nexthop id are mutually exclusive");
5028                         goto errout;
5029                 }
5030                 cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);
5031         }
5032
5033         if (tb[RTA_GATEWAY]) {
5034                 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
5035                 cfg->fc_flags |= RTF_GATEWAY;
5036         }
5037         if (tb[RTA_VIA]) {
5038                 NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
5039                 goto errout;
5040         }
5041
5042         if (tb[RTA_DST]) {
5043                 int plen = (rtm->rtm_dst_len + 7) >> 3;
5044
5045                 if (nla_len(tb[RTA_DST]) < plen)
5046                         goto errout;
5047
5048                 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
5049         }
5050
5051         if (tb[RTA_SRC]) {
5052                 int plen = (rtm->rtm_src_len + 7) >> 3;
5053
5054                 if (nla_len(tb[RTA_SRC]) < plen)
5055                         goto errout;
5056
5057                 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
5058         }
5059
5060         if (tb[RTA_PREFSRC])
5061                 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
5062
5063         if (tb[RTA_OIF])
5064                 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
5065
5066         if (tb[RTA_PRIORITY])
5067                 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
5068
5069         if (tb[RTA_METRICS]) {
5070                 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
5071                 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
5072         }
5073
5074         if (tb[RTA_TABLE])
5075                 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
5076
5077         if (tb[RTA_MULTIPATH]) {
5078                 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
5079                 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
5080
5081                 err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
5082                                                      cfg->fc_mp_len, extack);
5083                 if (err < 0)
5084                         goto errout;
5085         }
5086
5087         if (tb[RTA_PREF]) {
5088                 pref = nla_get_u8(tb[RTA_PREF]);
5089                 if (pref != ICMPV6_ROUTER_PREF_LOW &&
5090                     pref != ICMPV6_ROUTER_PREF_HIGH)
5091                         pref = ICMPV6_ROUTER_PREF_MEDIUM;
5092                 cfg->fc_flags |= RTF_PREF(pref);
5093         }
5094
5095         if (tb[RTA_ENCAP])
5096                 cfg->fc_encap = tb[RTA_ENCAP];
5097
5098         if (tb[RTA_ENCAP_TYPE]) {
5099                 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
5100
5101                 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
5102                 if (err < 0)
5103                         goto errout;
5104         }
5105
5106         if (tb[RTA_EXPIRES]) {
5107                 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
5108
5109                 if (addrconf_finite_timeout(timeout)) {
5110                         cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
5111                         cfg->fc_flags |= RTF_EXPIRES;
5112                 }
5113         }
5114
5115         err = 0;
5116 errout:
5117         return err;
5118 }
5119
5120 struct rt6_nh {
5121         struct fib6_info *fib6_info;
5122         struct fib6_config r_cfg;
5123         struct list_head next;
5124 };
5125
5126 static int ip6_route_info_append(struct net *net,
5127                                  struct list_head *rt6_nh_list,
5128                                  struct fib6_info *rt,
5129                                  struct fib6_config *r_cfg)
5130 {
5131         struct rt6_nh *nh;
5132         int err = -EEXIST;
5133
5134         list_for_each_entry(nh, rt6_nh_list, next) {
5135                 /* check if fib6_info already exists */
5136                 if (rt6_duplicate_nexthop(nh->fib6_info, rt))
5137                         return err;
5138         }
5139
5140         nh = kzalloc(sizeof(*nh), GFP_KERNEL);
5141         if (!nh)
5142                 return -ENOMEM;
5143         nh->fib6_info = rt;
5144         memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
5145         list_add_tail(&nh->next, rt6_nh_list);
5146
5147         return 0;
5148 }
5149
5150 static void ip6_route_mpath_notify(struct fib6_info *rt,
5151                                    struct fib6_info *rt_last,
5152                                    struct nl_info *info,
5153                                    __u16 nlflags)
5154 {
5155         /* if this is an APPEND route, then rt points to the first route
5156          * inserted and rt_last points to last route inserted. Userspace
5157          * wants a consistent dump of the route which starts at the first
5158          * nexthop. Since sibling routes are always added at the end of
5159          * the list, find the first sibling of the last route appended
5160          */
5161         if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
5162                 rt = list_first_entry(&rt_last->fib6_siblings,
5163                                       struct fib6_info,
5164                                       fib6_siblings);
5165         }
5166
5167         if (rt)
5168                 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
5169 }
5170
5171 static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
5172 {
5173         bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
5174         bool should_notify = false;
5175         struct fib6_info *leaf;
5176         struct fib6_node *fn;
5177
5178         rcu_read_lock();
5179         fn = rcu_dereference(rt->fib6_node);
5180         if (!fn)
5181                 goto out;
5182
5183         leaf = rcu_dereference(fn->leaf);
5184         if (!leaf)
5185                 goto out;
5186
5187         if (rt == leaf ||
5188             (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric &&
5189              rt6_qualify_for_ecmp(leaf)))
5190                 should_notify = true;
5191 out:
5192         rcu_read_unlock();
5193
5194         return should_notify;
5195 }
5196
5197 static int ip6_route_multipath_add(struct fib6_config *cfg,
5198                                    struct netlink_ext_ack *extack)
5199 {
5200         struct fib6_info *rt_notif = NULL, *rt_last = NULL;
5201         struct nl_info *info = &cfg->fc_nlinfo;
5202         struct fib6_config r_cfg;
5203         struct rtnexthop *rtnh;
5204         struct fib6_info *rt;
5205         struct rt6_nh *err_nh;
5206         struct rt6_nh *nh, *nh_safe;
5207         __u16 nlflags;
5208         int remaining;
5209         int attrlen;
5210         int err = 1;
5211         int nhn = 0;
5212         int replace = (cfg->fc_nlinfo.nlh &&
5213                        (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
5214         LIST_HEAD(rt6_nh_list);
5215
5216         nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
5217         if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
5218                 nlflags |= NLM_F_APPEND;
5219
5220         remaining = cfg->fc_mp_len;
5221         rtnh = (struct rtnexthop *)cfg->fc_mp;
5222
5223         /* Parse a Multipath Entry and build a list (rt6_nh_list) of
5224          * fib6_info structs per nexthop
5225          */
5226         while (rtnh_ok(rtnh, remaining)) {
5227                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5228                 if (rtnh->rtnh_ifindex)
5229                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5230
5231                 attrlen = rtnh_attrlen(rtnh);
5232                 if (attrlen > 0) {
5233                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5234
5235                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5236                         if (nla) {
5237                                 r_cfg.fc_gateway = nla_get_in6_addr(nla);
5238                                 r_cfg.fc_flags |= RTF_GATEWAY;
5239                         }
5240                         r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
5241                         nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
5242                         if (nla)
5243                                 r_cfg.fc_encap_type = nla_get_u16(nla);
5244                 }
5245
5246                 r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
5247                 rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
5248                 if (IS_ERR(rt)) {
5249                         err = PTR_ERR(rt);
5250                         rt = NULL;
5251                         goto cleanup;
5252                 }
5253                 if (!rt6_qualify_for_ecmp(rt)) {
5254                         err = -EINVAL;
5255                         NL_SET_ERR_MSG(extack,
5256                                        "Device only routes can not be added for IPv6 using the multipath API.");
5257                         fib6_info_release(rt);
5258                         goto cleanup;
5259                 }
5260
5261                 rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
5262
5263                 err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
5264                                             rt, &r_cfg);
5265                 if (err) {
5266                         fib6_info_release(rt);
5267                         goto cleanup;
5268                 }
5269
5270                 rtnh = rtnh_next(rtnh, &remaining);
5271         }
5272
5273         if (list_empty(&rt6_nh_list)) {
5274                 NL_SET_ERR_MSG(extack,
5275                                "Invalid nexthop configuration - no valid nexthops");
5276                 return -EINVAL;
5277         }
5278
5279         /* for add and replace send one notification with all nexthops.
5280          * Skip the notification in fib6_add_rt2node and send one with
5281          * the full route when done
5282          */
5283         info->skip_notify = 1;
5284
5285         /* For add and replace, send one notification with all nexthops. For
5286          * append, send one notification with all appended nexthops.
5287          */
5288         info->skip_notify_kernel = 1;
5289
5290         err_nh = NULL;
5291         list_for_each_entry(nh, &rt6_nh_list, next) {
5292                 err = __ip6_ins_rt(nh->fib6_info, info, extack);
5293                 fib6_info_release(nh->fib6_info);
5294
5295                 if (!err) {
5296                         /* save reference to last route successfully inserted */
5297                         rt_last = nh->fib6_info;
5298
5299                         /* save reference to first route for notification */
5300                         if (!rt_notif)
5301                                 rt_notif = nh->fib6_info;
5302                 }
5303
5304                 /* nh->fib6_info is used or freed at this point, reset to NULL*/
5305                 nh->fib6_info = NULL;
5306                 if (err) {
5307                         if (replace && nhn)
5308                                 NL_SET_ERR_MSG_MOD(extack,
5309                                                    "multipath route replace failed (check consistency of installed routes)");
5310                         err_nh = nh;
5311                         goto add_errout;
5312                 }
5313
5314                 /* Because each route is added like a single route we remove
5315                  * these flags after the first nexthop: if there is a collision,
5316                  * we have already failed to add the first nexthop:
5317                  * fib6_add_rt2node() has rejected it; when replacing, old
5318                  * nexthops have been replaced by first new, the rest should
5319                  * be added to it.
5320                  */
5321                 if (cfg->fc_nlinfo.nlh) {
5322                         cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
5323                                                              NLM_F_REPLACE);
5324                         cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
5325                 }
5326                 nhn++;
5327         }
5328
5329         /* An in-kernel notification should only be sent in case the new
5330          * multipath route is added as the first route in the node, or if
5331          * it was appended to it. We pass 'rt_notif' since it is the first
5332          * sibling and might allow us to skip some checks in the replace case.
5333          */
5334         if (ip6_route_mpath_should_notify(rt_notif)) {
5335                 enum fib_event_type fib_event;
5336
5337                 if (rt_notif->fib6_nsiblings != nhn - 1)
5338                         fib_event = FIB_EVENT_ENTRY_APPEND;
5339                 else
5340                         fib_event = FIB_EVENT_ENTRY_REPLACE;
5341
5342                 err = call_fib6_multipath_entry_notifiers(info->nl_net,
5343                                                           fib_event, rt_notif,
5344                                                           nhn - 1, extack);
5345                 if (err) {
5346                         /* Delete all the siblings that were just added */
5347                         err_nh = NULL;
5348                         goto add_errout;
5349                 }
5350         }
5351
5352         /* success ... tell user about new route */
5353         ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5354         goto cleanup;
5355
5356 add_errout:
5357         /* send notification for routes that were added so that
5358          * the delete notifications sent by ip6_route_del are
5359          * coherent
5360          */
5361         if (rt_notif)
5362                 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5363
5364         /* Delete routes that were already added */
5365         list_for_each_entry(nh, &rt6_nh_list, next) {
5366                 if (err_nh == nh)
5367                         break;
5368                 ip6_route_del(&nh->r_cfg, extack);
5369         }
5370
5371 cleanup:
5372         list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
5373                 if (nh->fib6_info)
5374                         fib6_info_release(nh->fib6_info);
5375                 list_del(&nh->next);
5376                 kfree(nh);
5377         }
5378
5379         return err;
5380 }
5381
5382 static int ip6_route_multipath_del(struct fib6_config *cfg,
5383                                    struct netlink_ext_ack *extack)
5384 {
5385         struct fib6_config r_cfg;
5386         struct rtnexthop *rtnh;
5387         int last_err = 0;
5388         int remaining;
5389         int attrlen;
5390         int err;
5391
5392         remaining = cfg->fc_mp_len;
5393         rtnh = (struct rtnexthop *)cfg->fc_mp;
5394
5395         /* Parse a Multipath Entry */
5396         while (rtnh_ok(rtnh, remaining)) {
5397                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5398                 if (rtnh->rtnh_ifindex)
5399                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5400
5401                 attrlen = rtnh_attrlen(rtnh);
5402                 if (attrlen > 0) {
5403                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5404
5405                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5406                         if (nla) {
5407                                 nla_memcpy(&r_cfg.fc_gateway, nla, 16);
5408                                 r_cfg.fc_flags |= RTF_GATEWAY;
5409                         }
5410                 }
5411                 err = ip6_route_del(&r_cfg, extack);
5412                 if (err)
5413                         last_err = err;
5414
5415                 rtnh = rtnh_next(rtnh, &remaining);
5416         }
5417
5418         return last_err;
5419 }
5420
5421 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5422                               struct netlink_ext_ack *extack)
5423 {
5424         struct fib6_config cfg;
5425         int err;
5426
5427         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5428         if (err < 0)
5429                 return err;
5430
5431         if (cfg.fc_nh_id &&
5432             !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {
5433                 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
5434                 return -EINVAL;
5435         }
5436
5437         if (cfg.fc_mp)
5438                 return ip6_route_multipath_del(&cfg, extack);
5439         else {
5440                 cfg.fc_delete_all_nh = 1;
5441                 return ip6_route_del(&cfg, extack);
5442         }
5443 }
5444
5445 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5446                               struct netlink_ext_ack *extack)
5447 {
5448         struct fib6_config cfg;
5449         int err;
5450
5451         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5452         if (err < 0)
5453                 return err;
5454
5455         if (cfg.fc_metric == 0)
5456                 cfg.fc_metric = IP6_RT_PRIO_USER;
5457
5458         if (cfg.fc_mp)
5459                 return ip6_route_multipath_add(&cfg, extack);
5460         else
5461                 return ip6_route_add(&cfg, GFP_KERNEL, extack);
5462 }
5463
5464 /* add the overhead of this fib6_nh to nexthop_len */
5465 static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg)
5466 {
5467         int *nexthop_len = arg;
5468
5469         *nexthop_len += nla_total_size(0)        /* RTA_MULTIPATH */
5470                      + NLA_ALIGN(sizeof(struct rtnexthop))
5471                      + nla_total_size(16); /* RTA_GATEWAY */
5472
5473         if (nh->fib_nh_lws) {
5474                 /* RTA_ENCAP_TYPE */
5475                 *nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5476                 /* RTA_ENCAP */
5477                 *nexthop_len += nla_total_size(2);
5478         }
5479
5480         return 0;
5481 }
5482
5483 static size_t rt6_nlmsg_size(struct fib6_info *f6i)
5484 {
5485         int nexthop_len;
5486
5487         if (f6i->nh) {
5488                 nexthop_len = nla_total_size(4); /* RTA_NH_ID */
5489                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
5490                                          &nexthop_len);
5491         } else {
5492                 struct fib6_nh *nh = f6i->fib6_nh;
5493
5494                 nexthop_len = 0;
5495                 if (f6i->fib6_nsiblings) {
5496                         nexthop_len = nla_total_size(0)  /* RTA_MULTIPATH */
5497                                     + NLA_ALIGN(sizeof(struct rtnexthop))
5498                                     + nla_total_size(16) /* RTA_GATEWAY */
5499                                     + lwtunnel_get_encap_size(nh->fib_nh_lws);
5500
5501                         nexthop_len *= f6i->fib6_nsiblings;
5502                 }
5503                 nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5504         }
5505
5506         return NLMSG_ALIGN(sizeof(struct rtmsg))
5507                + nla_total_size(16) /* RTA_SRC */
5508                + nla_total_size(16) /* RTA_DST */
5509                + nla_total_size(16) /* RTA_GATEWAY */
5510                + nla_total_size(16) /* RTA_PREFSRC */
5511                + nla_total_size(4) /* RTA_TABLE */
5512                + nla_total_size(4) /* RTA_IIF */
5513                + nla_total_size(4) /* RTA_OIF */
5514                + nla_total_size(4) /* RTA_PRIORITY */
5515                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
5516                + nla_total_size(sizeof(struct rta_cacheinfo))
5517                + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
5518                + nla_total_size(1) /* RTA_PREF */
5519                + nexthop_len;
5520 }
5521
5522 static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh,
5523                                  unsigned char *flags)
5524 {
5525         if (nexthop_is_multipath(nh)) {
5526                 struct nlattr *mp;
5527
5528                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5529                 if (!mp)
5530                         goto nla_put_failure;
5531
5532                 if (nexthop_mpath_fill_node(skb, nh, AF_INET6))
5533                         goto nla_put_failure;
5534
5535                 nla_nest_end(skb, mp);
5536         } else {
5537                 struct fib6_nh *fib6_nh;
5538
5539                 fib6_nh = nexthop_fib6_nh(nh);
5540                 if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,
5541                                      flags, false) < 0)
5542                         goto nla_put_failure;
5543         }
5544
5545         return 0;
5546
5547 nla_put_failure:
5548         return -EMSGSIZE;
5549 }
5550
5551 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
5552                          struct fib6_info *rt, struct dst_entry *dst,
5553                          struct in6_addr *dest, struct in6_addr *src,
5554                          int iif, int type, u32 portid, u32 seq,
5555                          unsigned int flags)
5556 {
5557         struct rt6_info *rt6 = (struct rt6_info *)dst;
5558         struct rt6key *rt6_dst, *rt6_src;
5559         u32 *pmetrics, table, rt6_flags;
5560         unsigned char nh_flags = 0;
5561         struct nlmsghdr *nlh;
5562         struct rtmsg *rtm;
5563         long expires = 0;
5564
5565         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
5566         if (!nlh)
5567                 return -EMSGSIZE;
5568
5569         if (rt6) {
5570                 rt6_dst = &rt6->rt6i_dst;
5571                 rt6_src = &rt6->rt6i_src;
5572                 rt6_flags = rt6->rt6i_flags;
5573         } else {
5574                 rt6_dst = &rt->fib6_dst;
5575                 rt6_src = &rt->fib6_src;
5576                 rt6_flags = rt->fib6_flags;
5577         }
5578
5579         rtm = nlmsg_data(nlh);
5580         rtm->rtm_family = AF_INET6;
5581         rtm->rtm_dst_len = rt6_dst->plen;
5582         rtm->rtm_src_len = rt6_src->plen;
5583         rtm->rtm_tos = 0;
5584         if (rt->fib6_table)
5585                 table = rt->fib6_table->tb6_id;
5586         else
5587                 table = RT6_TABLE_UNSPEC;
5588         rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
5589         if (nla_put_u32(skb, RTA_TABLE, table))
5590                 goto nla_put_failure;
5591
5592         rtm->rtm_type = rt->fib6_type;
5593         rtm->rtm_flags = 0;
5594         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
5595         rtm->rtm_protocol = rt->fib6_protocol;
5596
5597         if (rt6_flags & RTF_CACHE)
5598                 rtm->rtm_flags |= RTM_F_CLONED;
5599
5600         if (dest) {
5601                 if (nla_put_in6_addr(skb, RTA_DST, dest))
5602                         goto nla_put_failure;
5603                 rtm->rtm_dst_len = 128;
5604         } else if (rtm->rtm_dst_len)
5605                 if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
5606                         goto nla_put_failure;
5607 #ifdef CONFIG_IPV6_SUBTREES
5608         if (src) {
5609                 if (nla_put_in6_addr(skb, RTA_SRC, src))
5610                         goto nla_put_failure;
5611                 rtm->rtm_src_len = 128;
5612         } else if (rtm->rtm_src_len &&
5613                    nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
5614                 goto nla_put_failure;
5615 #endif
5616         if (iif) {
5617 #ifdef CONFIG_IPV6_MROUTE
5618                 if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
5619                         int err = ip6mr_get_route(net, skb, rtm, portid);
5620
5621                         if (err == 0)
5622                                 return 0;
5623                         if (err < 0)
5624                                 goto nla_put_failure;
5625                 } else
5626 #endif
5627                         if (nla_put_u32(skb, RTA_IIF, iif))
5628                                 goto nla_put_failure;
5629         } else if (dest) {
5630                 struct in6_addr saddr_buf;
5631                 if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 &&
5632                     nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5633                         goto nla_put_failure;
5634         }
5635
5636         if (rt->fib6_prefsrc.plen) {
5637                 struct in6_addr saddr_buf;
5638                 saddr_buf = rt->fib6_prefsrc.addr;
5639                 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5640                         goto nla_put_failure;
5641         }
5642
5643         pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
5644         if (rtnetlink_put_metrics(skb, pmetrics) < 0)
5645                 goto nla_put_failure;
5646
5647         if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
5648                 goto nla_put_failure;
5649
5650         /* For multipath routes, walk the siblings list and add
5651          * each as a nexthop within RTA_MULTIPATH.
5652          */
5653         if (rt6) {
5654                 if (rt6_flags & RTF_GATEWAY &&
5655                     nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
5656                         goto nla_put_failure;
5657
5658                 if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
5659                         goto nla_put_failure;
5660
5661                 if (dst->lwtstate &&
5662                     lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
5663                         goto nla_put_failure;
5664         } else if (rt->fib6_nsiblings) {
5665                 struct fib6_info *sibling, *next_sibling;
5666                 struct nlattr *mp;
5667
5668                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5669                 if (!mp)
5670                         goto nla_put_failure;
5671
5672                 if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
5673                                     rt->fib6_nh->fib_nh_weight, AF_INET6) < 0)
5674                         goto nla_put_failure;
5675
5676                 list_for_each_entry_safe(sibling, next_sibling,
5677                                          &rt->fib6_siblings, fib6_siblings) {
5678                         if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
5679                                             sibling->fib6_nh->fib_nh_weight,
5680                                             AF_INET6) < 0)
5681                                 goto nla_put_failure;
5682                 }
5683
5684                 nla_nest_end(skb, mp);
5685         } else if (rt->nh) {
5686                 if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
5687                         goto nla_put_failure;
5688
5689                 if (nexthop_is_blackhole(rt->nh))
5690                         rtm->rtm_type = RTN_BLACKHOLE;
5691
5692                 if (net->ipv4.sysctl_nexthop_compat_mode &&
5693                     rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0)
5694                         goto nla_put_failure;
5695
5696                 rtm->rtm_flags |= nh_flags;
5697         } else {
5698                 if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,
5699                                      &nh_flags, false) < 0)
5700                         goto nla_put_failure;
5701
5702                 rtm->rtm_flags |= nh_flags;
5703         }
5704
5705         if (rt6_flags & RTF_EXPIRES) {
5706                 expires = dst ? dst->expires : rt->expires;
5707                 expires -= jiffies;
5708         }
5709
5710         if (!dst) {
5711                 if (rt->offload)
5712                         rtm->rtm_flags |= RTM_F_OFFLOAD;
5713                 if (rt->trap)
5714                         rtm->rtm_flags |= RTM_F_TRAP;
5715                 if (rt->offload_failed)
5716                         rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED;
5717         }
5718
5719         if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
5720                 goto nla_put_failure;
5721
5722         if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
5723                 goto nla_put_failure;
5724
5725
5726         nlmsg_end(skb, nlh);
5727         return 0;
5728
5729 nla_put_failure:
5730         nlmsg_cancel(skb, nlh);
5731         return -EMSGSIZE;
5732 }
5733
5734 static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg)
5735 {
5736         const struct net_device *dev = arg;
5737
5738         if (nh->fib_nh_dev == dev)
5739                 return 1;
5740
5741         return 0;
5742 }
5743
5744 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
5745                                const struct net_device *dev)
5746 {
5747         if (f6i->nh) {
5748                 struct net_device *_dev = (struct net_device *)dev;
5749
5750                 return !!nexthop_for_each_fib6_nh(f6i->nh,
5751                                                   fib6_info_nh_uses_dev,
5752                                                   _dev);
5753         }
5754
5755         if (f6i->fib6_nh->fib_nh_dev == dev)
5756                 return true;
5757
5758         if (f6i->fib6_nsiblings) {
5759                 struct fib6_info *sibling, *next_sibling;
5760
5761                 list_for_each_entry_safe(sibling, next_sibling,
5762                                          &f6i->fib6_siblings, fib6_siblings) {
5763                         if (sibling->fib6_nh->fib_nh_dev == dev)
5764                                 return true;
5765                 }
5766         }
5767
5768         return false;
5769 }
5770
5771 struct fib6_nh_exception_dump_walker {
5772         struct rt6_rtnl_dump_arg *dump;
5773         struct fib6_info *rt;
5774         unsigned int flags;
5775         unsigned int skip;
5776         unsigned int count;
5777 };
5778
5779 static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg)
5780 {
5781         struct fib6_nh_exception_dump_walker *w = arg;
5782         struct rt6_rtnl_dump_arg *dump = w->dump;
5783         struct rt6_exception_bucket *bucket;
5784         struct rt6_exception *rt6_ex;
5785         int i, err;
5786
5787         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
5788         if (!bucket)
5789                 return 0;
5790
5791         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
5792                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
5793                         if (w->skip) {
5794                                 w->skip--;
5795                                 continue;
5796                         }
5797
5798                         /* Expiration of entries doesn't bump sernum, insertion
5799                          * does. Removal is triggered by insertion, so we can
5800                          * rely on the fact that if entries change between two
5801                          * partial dumps, this node is scanned again completely,
5802                          * see rt6_insert_exception() and fib6_dump_table().
5803                          *
5804                          * Count expired entries we go through as handled
5805                          * entries that we'll skip next time, in case of partial
5806                          * node dump. Otherwise, if entries expire meanwhile,
5807                          * we'll skip the wrong amount.
5808                          */
5809                         if (rt6_check_expired(rt6_ex->rt6i)) {
5810                                 w->count++;
5811                                 continue;
5812                         }
5813
5814                         err = rt6_fill_node(dump->net, dump->skb, w->rt,
5815                                             &rt6_ex->rt6i->dst, NULL, NULL, 0,
5816                                             RTM_NEWROUTE,
5817                                             NETLINK_CB(dump->cb->skb).portid,
5818                                             dump->cb->nlh->nlmsg_seq, w->flags);
5819                         if (err)
5820                                 return err;
5821
5822                         w->count++;
5823                 }
5824                 bucket++;
5825         }
5826
5827         return 0;
5828 }
5829
5830 /* Return -1 if done with node, number of handled routes on partial dump */
5831 int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip)
5832 {
5833         struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
5834         struct fib_dump_filter *filter = &arg->filter;
5835         unsigned int flags = NLM_F_MULTI;
5836         struct net *net = arg->net;
5837         int count = 0;
5838
5839         if (rt == net->ipv6.fib6_null_entry)
5840                 return -1;
5841
5842         if ((filter->flags & RTM_F_PREFIX) &&
5843             !(rt->fib6_flags & RTF_PREFIX_RT)) {
5844                 /* success since this is not a prefix route */
5845                 return -1;
5846         }
5847         if (filter->filter_set &&
5848             ((filter->rt_type  && rt->fib6_type != filter->rt_type) ||
5849              (filter->dev      && !fib6_info_uses_dev(rt, filter->dev)) ||
5850              (filter->protocol && rt->fib6_protocol != filter->protocol))) {
5851                 return -1;
5852         }
5853
5854         if (filter->filter_set ||
5855             !filter->dump_routes || !filter->dump_exceptions) {
5856                 flags |= NLM_F_DUMP_FILTERED;
5857         }
5858
5859         if (filter->dump_routes) {
5860                 if (skip) {
5861                         skip--;
5862                 } else {
5863                         if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL,
5864                                           0, RTM_NEWROUTE,
5865                                           NETLINK_CB(arg->cb->skb).portid,
5866                                           arg->cb->nlh->nlmsg_seq, flags)) {
5867                                 return 0;
5868                         }
5869                         count++;
5870                 }
5871         }
5872
5873         if (filter->dump_exceptions) {
5874                 struct fib6_nh_exception_dump_walker w = { .dump = arg,
5875                                                            .rt = rt,
5876                                                            .flags = flags,
5877                                                            .skip = skip,
5878                                                            .count = 0 };
5879                 int err;
5880
5881                 rcu_read_lock();
5882                 if (rt->nh) {
5883                         err = nexthop_for_each_fib6_nh(rt->nh,
5884                                                        rt6_nh_dump_exceptions,
5885                                                        &w);
5886                 } else {
5887                         err = rt6_nh_dump_exceptions(rt->fib6_nh, &w);
5888                 }
5889                 rcu_read_unlock();
5890
5891                 if (err)
5892                         return count += w.count;
5893         }
5894
5895         return -1;
5896 }
5897
5898 static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
5899                                         const struct nlmsghdr *nlh,
5900                                         struct nlattr **tb,
5901                                         struct netlink_ext_ack *extack)
5902 {
5903         struct rtmsg *rtm;
5904         int i, err;
5905
5906         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
5907                 NL_SET_ERR_MSG_MOD(extack,
5908                                    "Invalid header for get route request");
5909                 return -EINVAL;
5910         }
5911
5912         if (!netlink_strict_get_check(skb))
5913                 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5914                                               rtm_ipv6_policy, extack);
5915
5916         rtm = nlmsg_data(nlh);
5917         if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
5918             (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
5919             rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
5920             rtm->rtm_type) {
5921                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
5922                 return -EINVAL;
5923         }
5924         if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
5925                 NL_SET_ERR_MSG_MOD(extack,
5926                                    "Invalid flags for get route request");
5927                 return -EINVAL;
5928         }
5929
5930         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
5931                                             rtm_ipv6_policy, extack);
5932         if (err)
5933                 return err;
5934
5935         if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
5936             (tb[RTA_DST] && !rtm->rtm_dst_len)) {
5937                 NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
5938                 return -EINVAL;
5939         }
5940
5941         for (i = 0; i <= RTA_MAX; i++) {
5942                 if (!tb[i])
5943                         continue;
5944
5945                 switch (i) {
5946                 case RTA_SRC:
5947                 case RTA_DST:
5948                 case RTA_IIF:
5949                 case RTA_OIF:
5950                 case RTA_MARK:
5951                 case RTA_UID:
5952                 case RTA_SPORT:
5953                 case RTA_DPORT:
5954                 case RTA_IP_PROTO:
5955                         break;
5956                 default:
5957                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
5958                         return -EINVAL;
5959                 }
5960         }
5961
5962         return 0;
5963 }
5964
5965 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
5966                               struct netlink_ext_ack *extack)
5967 {
5968         struct net *net = sock_net(in_skb->sk);
5969         struct nlattr *tb[RTA_MAX+1];
5970         int err, iif = 0, oif = 0;
5971         struct fib6_info *from;
5972         struct dst_entry *dst;
5973         struct rt6_info *rt;
5974         struct sk_buff *skb;
5975         struct rtmsg *rtm;
5976         struct flowi6 fl6 = {};
5977         bool fibmatch;
5978
5979         err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
5980         if (err < 0)
5981                 goto errout;
5982
5983         err = -EINVAL;
5984         rtm = nlmsg_data(nlh);
5985         fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
5986         fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
5987
5988         if (tb[RTA_SRC]) {
5989                 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
5990                         goto errout;
5991
5992                 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
5993         }
5994
5995         if (tb[RTA_DST]) {
5996                 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
5997                         goto errout;
5998
5999                 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
6000         }
6001
6002         if (tb[RTA_IIF])
6003                 iif = nla_get_u32(tb[RTA_IIF]);
6004
6005         if (tb[RTA_OIF])
6006                 oif = nla_get_u32(tb[RTA_OIF]);
6007
6008         if (tb[RTA_MARK])
6009                 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
6010
6011         if (tb[RTA_UID])
6012                 fl6.flowi6_uid = make_kuid(current_user_ns(),
6013                                            nla_get_u32(tb[RTA_UID]));
6014         else
6015                 fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
6016
6017         if (tb[RTA_SPORT])
6018                 fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
6019
6020         if (tb[RTA_DPORT])
6021                 fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
6022
6023         if (tb[RTA_IP_PROTO]) {
6024                 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
6025                                                   &fl6.flowi6_proto, AF_INET6,
6026                                                   extack);
6027                 if (err)
6028                         goto errout;
6029         }
6030
6031         if (iif) {
6032                 struct net_device *dev;
6033                 int flags = 0;
6034
6035                 rcu_read_lock();
6036
6037                 dev = dev_get_by_index_rcu(net, iif);
6038                 if (!dev) {
6039                         rcu_read_unlock();
6040                         err = -ENODEV;
6041                         goto errout;
6042                 }
6043
6044                 fl6.flowi6_iif = iif;
6045
6046                 if (!ipv6_addr_any(&fl6.saddr))
6047                         flags |= RT6_LOOKUP_F_HAS_SADDR;
6048
6049                 dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
6050
6051                 rcu_read_unlock();
6052         } else {
6053                 fl6.flowi6_oif = oif;
6054
6055                 dst = ip6_route_output(net, NULL, &fl6);
6056         }
6057
6058
6059         rt = container_of(dst, struct rt6_info, dst);
6060         if (rt->dst.error) {
6061                 err = rt->dst.error;
6062                 ip6_rt_put(rt);
6063                 goto errout;
6064         }
6065
6066         if (rt == net->ipv6.ip6_null_entry) {
6067                 err = rt->dst.error;
6068                 ip6_rt_put(rt);
6069                 goto errout;
6070         }
6071
6072         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
6073         if (!skb) {
6074                 ip6_rt_put(rt);
6075                 err = -ENOBUFS;
6076                 goto errout;
6077         }
6078
6079         skb_dst_set(skb, &rt->dst);
6080
6081         rcu_read_lock();
6082         from = rcu_dereference(rt->from);
6083         if (from) {
6084                 if (fibmatch)
6085                         err = rt6_fill_node(net, skb, from, NULL, NULL, NULL,
6086                                             iif, RTM_NEWROUTE,
6087                                             NETLINK_CB(in_skb).portid,
6088                                             nlh->nlmsg_seq, 0);
6089                 else
6090                         err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
6091                                             &fl6.saddr, iif, RTM_NEWROUTE,
6092                                             NETLINK_CB(in_skb).portid,
6093                                             nlh->nlmsg_seq, 0);
6094         } else {
6095                 err = -ENETUNREACH;
6096         }
6097         rcu_read_unlock();
6098
6099         if (err < 0) {
6100                 kfree_skb(skb);
6101                 goto errout;
6102         }
6103
6104         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
6105 errout:
6106         return err;
6107 }
6108
6109 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
6110                      unsigned int nlm_flags)
6111 {
6112         struct sk_buff *skb;
6113         struct net *net = info->nl_net;
6114         u32 seq;
6115         int err;
6116
6117         err = -ENOBUFS;
6118         seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6119
6120         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6121         if (!skb)
6122                 goto errout;
6123
6124         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6125                             event, info->portid, seq, nlm_flags);
6126         if (err < 0) {
6127                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6128                 WARN_ON(err == -EMSGSIZE);
6129                 kfree_skb(skb);
6130                 goto errout;
6131         }
6132         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6133                     info->nlh, gfp_any());
6134         return;
6135 errout:
6136         if (err < 0)
6137                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6138 }
6139
6140 void fib6_rt_update(struct net *net, struct fib6_info *rt,
6141                     struct nl_info *info)
6142 {
6143         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6144         struct sk_buff *skb;
6145         int err = -ENOBUFS;
6146
6147         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6148         if (!skb)
6149                 goto errout;
6150
6151         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6152                             RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
6153         if (err < 0) {
6154                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6155                 WARN_ON(err == -EMSGSIZE);
6156                 kfree_skb(skb);
6157                 goto errout;
6158         }
6159         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6160                     info->nlh, gfp_any());
6161         return;
6162 errout:
6163         if (err < 0)
6164                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6165 }
6166
6167 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
6168                             bool offload, bool trap, bool offload_failed)
6169 {
6170         struct sk_buff *skb;
6171         int err;
6172
6173         if (f6i->offload == offload && f6i->trap == trap &&
6174             f6i->offload_failed == offload_failed)
6175                 return;
6176
6177         f6i->offload = offload;
6178         f6i->trap = trap;
6179
6180         /* 2 means send notifications only if offload_failed was changed. */
6181         if (net->ipv6.sysctl.fib_notify_on_flag_change == 2 &&
6182             f6i->offload_failed == offload_failed)
6183                 return;
6184
6185         f6i->offload_failed = offload_failed;
6186
6187         if (!rcu_access_pointer(f6i->fib6_node))
6188                 /* The route was removed from the tree, do not send
6189                  * notification.
6190                  */
6191                 return;
6192
6193         if (!net->ipv6.sysctl.fib_notify_on_flag_change)
6194                 return;
6195
6196         skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL);
6197         if (!skb) {
6198                 err = -ENOBUFS;
6199                 goto errout;
6200         }
6201
6202         err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0,
6203                             0, 0);
6204         if (err < 0) {
6205                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6206                 WARN_ON(err == -EMSGSIZE);
6207                 kfree_skb(skb);
6208                 goto errout;
6209         }
6210
6211         rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL);
6212         return;
6213
6214 errout:
6215         rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6216 }
6217 EXPORT_SYMBOL(fib6_info_hw_flags_set);
6218
6219 static int ip6_route_dev_notify(struct notifier_block *this,
6220                                 unsigned long event, void *ptr)
6221 {
6222         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
6223         struct net *net = dev_net(dev);
6224
6225         if (!(dev->flags & IFF_LOOPBACK))
6226                 return NOTIFY_OK;
6227
6228         if (event == NETDEV_REGISTER) {
6229                 net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev;
6230                 net->ipv6.ip6_null_entry->dst.dev = dev;
6231                 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
6232 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6233                 net->ipv6.ip6_prohibit_entry->dst.dev = dev;
6234                 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
6235                 net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
6236                 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
6237 #endif
6238          } else if (event == NETDEV_UNREGISTER &&
6239                     dev->reg_state != NETREG_UNREGISTERED) {
6240                 /* NETDEV_UNREGISTER could be fired for multiple times by
6241                  * netdev_wait_allrefs(). Make sure we only call this once.
6242                  */
6243                 in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
6244 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6245                 in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
6246                 in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
6247 #endif
6248         }
6249
6250         return NOTIFY_OK;
6251 }
6252
6253 /*
6254  *      /proc
6255  */
6256
6257 #ifdef CONFIG_PROC_FS
6258 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
6259 {
6260         struct net *net = (struct net *)seq->private;
6261         seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
6262                    net->ipv6.rt6_stats->fib_nodes,
6263                    net->ipv6.rt6_stats->fib_route_nodes,
6264                    atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
6265                    net->ipv6.rt6_stats->fib_rt_entries,
6266                    net->ipv6.rt6_stats->fib_rt_cache,
6267                    dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
6268                    net->ipv6.rt6_stats->fib_discarded_routes);
6269
6270         return 0;
6271 }
6272 #endif  /* CONFIG_PROC_FS */
6273
6274 #ifdef CONFIG_SYSCTL
6275
6276 static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
6277                               void *buffer, size_t *lenp, loff_t *ppos)
6278 {
6279         struct net *net;
6280         int delay;
6281         int ret;
6282         if (!write)
6283                 return -EINVAL;
6284
6285         net = (struct net *)ctl->extra1;
6286         delay = net->ipv6.sysctl.flush_delay;
6287         ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
6288         if (ret)
6289                 return ret;
6290
6291         fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
6292         return 0;
6293 }
6294
6295 static struct ctl_table ipv6_route_table_template[] = {
6296         {
6297                 .procname       =       "flush",
6298                 .data           =       &init_net.ipv6.sysctl.flush_delay,
6299                 .maxlen         =       sizeof(int),
6300                 .mode           =       0200,
6301                 .proc_handler   =       ipv6_sysctl_rtcache_flush
6302         },
6303         {
6304                 .procname       =       "gc_thresh",
6305                 .data           =       &ip6_dst_ops_template.gc_thresh,
6306                 .maxlen         =       sizeof(int),
6307                 .mode           =       0644,
6308                 .proc_handler   =       proc_dointvec,
6309         },
6310         {
6311                 .procname       =       "max_size",
6312                 .data           =       &init_net.ipv6.sysctl.ip6_rt_max_size,
6313                 .maxlen         =       sizeof(int),
6314                 .mode           =       0644,
6315                 .proc_handler   =       proc_dointvec,
6316         },
6317         {
6318                 .procname       =       "gc_min_interval",
6319                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6320                 .maxlen         =       sizeof(int),
6321                 .mode           =       0644,
6322                 .proc_handler   =       proc_dointvec_jiffies,
6323         },
6324         {
6325                 .procname       =       "gc_timeout",
6326                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
6327                 .maxlen         =       sizeof(int),
6328                 .mode           =       0644,
6329                 .proc_handler   =       proc_dointvec_jiffies,
6330         },
6331         {
6332                 .procname       =       "gc_interval",
6333                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_interval,
6334                 .maxlen         =       sizeof(int),
6335                 .mode           =       0644,
6336                 .proc_handler   =       proc_dointvec_jiffies,
6337         },
6338         {
6339                 .procname       =       "gc_elasticity",
6340                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
6341                 .maxlen         =       sizeof(int),
6342                 .mode           =       0644,
6343                 .proc_handler   =       proc_dointvec,
6344         },
6345         {
6346                 .procname       =       "mtu_expires",
6347                 .data           =       &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
6348                 .maxlen         =       sizeof(int),
6349                 .mode           =       0644,
6350                 .proc_handler   =       proc_dointvec_jiffies,
6351         },
6352         {
6353                 .procname       =       "min_adv_mss",
6354                 .data           =       &init_net.ipv6.sysctl.ip6_rt_min_advmss,
6355                 .maxlen         =       sizeof(int),
6356                 .mode           =       0644,
6357                 .proc_handler   =       proc_dointvec,
6358         },
6359         {
6360                 .procname       =       "gc_min_interval_ms",
6361                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6362                 .maxlen         =       sizeof(int),
6363                 .mode           =       0644,
6364                 .proc_handler   =       proc_dointvec_ms_jiffies,
6365         },
6366         {
6367                 .procname       =       "skip_notify_on_dev_down",
6368                 .data           =       &init_net.ipv6.sysctl.skip_notify_on_dev_down,
6369                 .maxlen         =       sizeof(int),
6370                 .mode           =       0644,
6371                 .proc_handler   =       proc_dointvec_minmax,
6372                 .extra1         =       SYSCTL_ZERO,
6373                 .extra2         =       SYSCTL_ONE,
6374         },
6375         { }
6376 };
6377
6378 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
6379 {
6380         struct ctl_table *table;
6381
6382         table = kmemdup(ipv6_route_table_template,
6383                         sizeof(ipv6_route_table_template),
6384                         GFP_KERNEL);
6385
6386         if (table) {
6387                 table[0].data = &net->ipv6.sysctl.flush_delay;
6388                 table[0].extra1 = net;
6389                 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
6390                 table[2].data = &net->ipv6.sysctl.ip6_rt_max_size;
6391                 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6392                 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
6393                 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
6394                 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
6395                 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
6396                 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
6397                 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6398                 table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
6399
6400                 /* Don't export sysctls to unprivileged users */
6401                 if (net->user_ns != &init_user_ns)
6402                         table[0].procname = NULL;
6403         }
6404
6405         return table;
6406 }
6407 #endif
6408
6409 static int __net_init ip6_route_net_init(struct net *net)
6410 {
6411         int ret = -ENOMEM;
6412
6413         memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
6414                sizeof(net->ipv6.ip6_dst_ops));
6415
6416         if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
6417                 goto out_ip6_dst_ops;
6418
6419         net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true);
6420         if (!net->ipv6.fib6_null_entry)
6421                 goto out_ip6_dst_entries;
6422         memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template,
6423                sizeof(*net->ipv6.fib6_null_entry));
6424
6425         net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
6426                                            sizeof(*net->ipv6.ip6_null_entry),
6427                                            GFP_KERNEL);
6428         if (!net->ipv6.ip6_null_entry)
6429                 goto out_fib6_null_entry;
6430         net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6431         dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
6432                          ip6_template_metrics, true);
6433         INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->rt6i_uncached);
6434
6435 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6436         net->ipv6.fib6_has_custom_rules = false;
6437         net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
6438                                                sizeof(*net->ipv6.ip6_prohibit_entry),
6439                                                GFP_KERNEL);
6440         if (!net->ipv6.ip6_prohibit_entry)
6441                 goto out_ip6_null_entry;
6442         net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6443         dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
6444                          ip6_template_metrics, true);
6445         INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->rt6i_uncached);
6446
6447         net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
6448                                                sizeof(*net->ipv6.ip6_blk_hole_entry),
6449                                                GFP_KERNEL);
6450         if (!net->ipv6.ip6_blk_hole_entry)
6451                 goto out_ip6_prohibit_entry;
6452         net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6453         dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
6454                          ip6_template_metrics, true);
6455         INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->rt6i_uncached);
6456 #ifdef CONFIG_IPV6_SUBTREES
6457         net->ipv6.fib6_routes_require_src = 0;
6458 #endif
6459 #endif
6460
6461         net->ipv6.sysctl.flush_delay = 0;
6462         net->ipv6.sysctl.ip6_rt_max_size = 4096;
6463         net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
6464         net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
6465         net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
6466         net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
6467         net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
6468         net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
6469         net->ipv6.sysctl.skip_notify_on_dev_down = 0;
6470
6471         net->ipv6.ip6_rt_gc_expire = 30*HZ;
6472
6473         ret = 0;
6474 out:
6475         return ret;
6476
6477 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6478 out_ip6_prohibit_entry:
6479         kfree(net->ipv6.ip6_prohibit_entry);
6480 out_ip6_null_entry:
6481         kfree(net->ipv6.ip6_null_entry);
6482 #endif
6483 out_fib6_null_entry:
6484         kfree(net->ipv6.fib6_null_entry);
6485 out_ip6_dst_entries:
6486         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6487 out_ip6_dst_ops:
6488         goto out;
6489 }
6490
6491 static void __net_exit ip6_route_net_exit(struct net *net)
6492 {
6493         kfree(net->ipv6.fib6_null_entry);
6494         kfree(net->ipv6.ip6_null_entry);
6495 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6496         kfree(net->ipv6.ip6_prohibit_entry);
6497         kfree(net->ipv6.ip6_blk_hole_entry);
6498 #endif
6499         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6500 }
6501
6502 static int __net_init ip6_route_net_init_late(struct net *net)
6503 {
6504 #ifdef CONFIG_PROC_FS
6505         proc_create_net("ipv6_route", 0, net->proc_net, &ipv6_route_seq_ops,
6506                         sizeof(struct ipv6_route_iter));
6507         proc_create_net_single("rt6_stats", 0444, net->proc_net,
6508                         rt6_stats_seq_show, NULL);
6509 #endif
6510         return 0;
6511 }
6512
6513 static void __net_exit ip6_route_net_exit_late(struct net *net)
6514 {
6515 #ifdef CONFIG_PROC_FS
6516         remove_proc_entry("ipv6_route", net->proc_net);
6517         remove_proc_entry("rt6_stats", net->proc_net);
6518 #endif
6519 }
6520
6521 static struct pernet_operations ip6_route_net_ops = {
6522         .init = ip6_route_net_init,
6523         .exit = ip6_route_net_exit,
6524 };
6525
6526 static int __net_init ipv6_inetpeer_init(struct net *net)
6527 {
6528         struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
6529
6530         if (!bp)
6531                 return -ENOMEM;
6532         inet_peer_base_init(bp);
6533         net->ipv6.peers = bp;
6534         return 0;
6535 }
6536
6537 static void __net_exit ipv6_inetpeer_exit(struct net *net)
6538 {
6539         struct inet_peer_base *bp = net->ipv6.peers;
6540
6541         net->ipv6.peers = NULL;
6542         inetpeer_invalidate_tree(bp);
6543         kfree(bp);
6544 }
6545
6546 static struct pernet_operations ipv6_inetpeer_ops = {
6547         .init   =       ipv6_inetpeer_init,
6548         .exit   =       ipv6_inetpeer_exit,
6549 };
6550
6551 static struct pernet_operations ip6_route_net_late_ops = {
6552         .init = ip6_route_net_init_late,
6553         .exit = ip6_route_net_exit_late,
6554 };
6555
6556 static struct notifier_block ip6_route_dev_notifier = {
6557         .notifier_call = ip6_route_dev_notify,
6558         .priority = ADDRCONF_NOTIFY_PRIORITY - 10,
6559 };
6560
6561 void __init ip6_route_init_special_entries(void)
6562 {
6563         /* Registering of the loopback is done before this portion of code,
6564          * the loopback reference in rt6_info will not be taken, do it
6565          * manually for init_net */
6566         init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev;
6567         init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
6568         init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6569   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6570         init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
6571         init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6572         init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
6573         init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6574   #endif
6575 }
6576
6577 #if IS_BUILTIN(CONFIG_IPV6)
6578 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6579 DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt)
6580
6581 BTF_ID_LIST(btf_fib6_info_id)
6582 BTF_ID(struct, fib6_info)
6583
6584 static const struct bpf_iter_seq_info ipv6_route_seq_info = {
6585         .seq_ops                = &ipv6_route_seq_ops,
6586         .init_seq_private       = bpf_iter_init_seq_net,
6587         .fini_seq_private       = bpf_iter_fini_seq_net,
6588         .seq_priv_size          = sizeof(struct ipv6_route_iter),
6589 };
6590
6591 static struct bpf_iter_reg ipv6_route_reg_info = {
6592         .target                 = "ipv6_route",
6593         .ctx_arg_info_size      = 1,
6594         .ctx_arg_info           = {
6595                 { offsetof(struct bpf_iter__ipv6_route, rt),
6596                   PTR_TO_BTF_ID_OR_NULL },
6597         },
6598         .seq_info               = &ipv6_route_seq_info,
6599 };
6600
6601 static int __init bpf_iter_register(void)
6602 {
6603         ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id;
6604         return bpf_iter_reg_target(&ipv6_route_reg_info);
6605 }
6606
6607 static void bpf_iter_unregister(void)
6608 {
6609         bpf_iter_unreg_target(&ipv6_route_reg_info);
6610 }
6611 #endif
6612 #endif
6613
6614 int __init ip6_route_init(void)
6615 {
6616         int ret;
6617         int cpu;
6618
6619         ret = -ENOMEM;
6620         ip6_dst_ops_template.kmem_cachep =
6621                 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
6622                                   SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
6623         if (!ip6_dst_ops_template.kmem_cachep)
6624                 goto out;
6625
6626         ret = dst_entries_init(&ip6_dst_blackhole_ops);
6627         if (ret)
6628                 goto out_kmem_cache;
6629
6630         ret = register_pernet_subsys(&ipv6_inetpeer_ops);
6631         if (ret)
6632                 goto out_dst_entries;
6633
6634         ret = register_pernet_subsys(&ip6_route_net_ops);
6635         if (ret)
6636                 goto out_register_inetpeer;
6637
6638         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
6639
6640         ret = fib6_init();
6641         if (ret)
6642                 goto out_register_subsys;
6643
6644         ret = xfrm6_init();
6645         if (ret)
6646                 goto out_fib6_init;
6647
6648         ret = fib6_rules_init();
6649         if (ret)
6650                 goto xfrm6_init;
6651
6652         ret = register_pernet_subsys(&ip6_route_net_late_ops);
6653         if (ret)
6654                 goto fib6_rules_init;
6655
6656         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
6657                                    inet6_rtm_newroute, NULL, 0);
6658         if (ret < 0)
6659                 goto out_register_late_subsys;
6660
6661         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
6662                                    inet6_rtm_delroute, NULL, 0);
6663         if (ret < 0)
6664                 goto out_register_late_subsys;
6665
6666         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
6667                                    inet6_rtm_getroute, NULL,
6668                                    RTNL_FLAG_DOIT_UNLOCKED);
6669         if (ret < 0)
6670                 goto out_register_late_subsys;
6671
6672         ret = register_netdevice_notifier(&ip6_route_dev_notifier);
6673         if (ret)
6674                 goto out_register_late_subsys;
6675
6676 #if IS_BUILTIN(CONFIG_IPV6)
6677 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6678         ret = bpf_iter_register();
6679         if (ret)
6680                 goto out_register_late_subsys;
6681 #endif
6682 #endif
6683
6684         for_each_possible_cpu(cpu) {
6685                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
6686
6687                 INIT_LIST_HEAD(&ul->head);
6688                 spin_lock_init(&ul->lock);
6689         }
6690
6691 out:
6692         return ret;
6693
6694 out_register_late_subsys:
6695         rtnl_unregister_all(PF_INET6);
6696         unregister_pernet_subsys(&ip6_route_net_late_ops);
6697 fib6_rules_init:
6698         fib6_rules_cleanup();
6699 xfrm6_init:
6700         xfrm6_fini();
6701 out_fib6_init:
6702         fib6_gc_cleanup();
6703 out_register_subsys:
6704         unregister_pernet_subsys(&ip6_route_net_ops);
6705 out_register_inetpeer:
6706         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6707 out_dst_entries:
6708         dst_entries_destroy(&ip6_dst_blackhole_ops);
6709 out_kmem_cache:
6710         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6711         goto out;
6712 }
6713
6714 void ip6_route_cleanup(void)
6715 {
6716 #if IS_BUILTIN(CONFIG_IPV6)
6717 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6718         bpf_iter_unregister();
6719 #endif
6720 #endif
6721         unregister_netdevice_notifier(&ip6_route_dev_notifier);
6722         unregister_pernet_subsys(&ip6_route_net_late_ops);
6723         fib6_rules_cleanup();
6724         xfrm6_fini();
6725         fib6_gc_cleanup();
6726         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6727         unregister_pernet_subsys(&ip6_route_net_ops);
6728         dst_entries_destroy(&ip6_dst_blackhole_ops);
6729         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6730 }