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 <linux/siphash.h>
  45 #include <net/net_namespace.h>
  46 #include <net/snmp.h>
  47 #include <net/ipv6.h>
  48 #include <net/ip6_fib.h>
  49 #include <net/ip6_route.h>
  50 #include <net/ndisc.h>
  51 #include <net/addrconf.h>
  52 #include <net/tcp.h>
  53 #include <linux/rtnetlink.h>
  54 #include <net/dst.h>
  55 #include <net/dst_metadata.h>
  56 #include <net/xfrm.h>
  57 #include <net/netevent.h>
  58 #include <net/netlink.h>
  59 #include <net/rtnh.h>
  60 #include <net/lwtunnel.h>
  61 #include <net/ip_tunnels.h>
  62 #include <net/l3mdev.h>
  63 #include <net/ip.h>
  64 #include <linux/uaccess.h>
  65 #include <linux/btf_ids.h>
  66
  67 #ifdef CONFIG_SYSCTL
  68 #include <linux/sysctl.h>
  69 #endif
  70
  71 static int ip6_rt_type_to_error(u8 fib6_type);
  72
  73 #define CREATE_TRACE_POINTS
  74 #include <trace/events/fib6.h>
  75 EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup);
  76 #undef CREATE_TRACE_POINTS
  77
  78 enum rt6_nud_state {
  79         RT6_NUD_FAIL_HARD = -3,
  80         RT6_NUD_FAIL_PROBE = -2,
  81         RT6_NUD_FAIL_DO_RR = -1,
  82         RT6_NUD_SUCCEED = 1
  83 };
  84
  85 INDIRECT_CALLABLE_SCOPE
  86 struct dst_entry        *ip6_dst_check(struct dst_entry *dst, u32 cookie);
  87 static unsigned int      ip6_default_advmss(const struct dst_entry *dst);
  88 INDIRECT_CALLABLE_SCOPE
  89 unsigned int            ip6_mtu(const struct dst_entry *dst);
  90 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
  91 static void             ip6_dst_destroy(struct dst_entry *);
  92 static void             ip6_dst_ifdown(struct dst_entry *,
  93                                        struct net_device *dev);
  94 static void              ip6_dst_gc(struct dst_ops *ops);
  95
  96 static int              ip6_pkt_discard(struct sk_buff *skb);
  97 static int              ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
  98 static int              ip6_pkt_prohibit(struct sk_buff *skb);
  99 static int              ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 100 static void             ip6_link_failure(struct sk_buff *skb);
 101 static void             ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
 102                                            struct sk_buff *skb, u32 mtu,
 103                                            bool confirm_neigh);
 104 static void             rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
 105                                         struct sk_buff *skb);
 106 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
 107                            int strict);
 108 static size_t rt6_nlmsg_size(struct fib6_info *f6i);
 109 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
 110                          struct fib6_info *rt, struct dst_entry *dst,
 111                          struct in6_addr *dest, struct in6_addr *src,
 112                          int iif, int type, u32 portid, u32 seq,
 113                          unsigned int flags);
 114 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
 115                                            const struct in6_addr *daddr,
 116                                            const struct in6_addr *saddr);
 117
 118 #ifdef CONFIG_IPV6_ROUTE_INFO
 119 static struct fib6_info *rt6_add_route_info(struct net *net,
 120                                            const struct in6_addr *prefix, int prefixlen,
 121                                            const struct in6_addr *gwaddr,
 122                                            struct net_device *dev,
 123                                            unsigned int pref);
 124 static struct fib6_info *rt6_get_route_info(struct net *net,
 125                                            const struct in6_addr *prefix, int prefixlen,
 126                                            const struct in6_addr *gwaddr,
 127                                            struct net_device *dev);
 128 #endif
 129
 130 struct uncached_list {
 131         spinlock_t              lock;
 132         struct list_head        head;
 133         struct list_head        quarantine;
 134 };
 135
 136 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
 137
 138 void rt6_uncached_list_add(struct rt6_info *rt)
 139 {
 140         struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list);
 141
 142         rt->dst.rt_uncached_list = ul;
 143
 144         spin_lock_bh(&ul->lock);
 145         list_add_tail(&rt->dst.rt_uncached, &ul->head);
 146         spin_unlock_bh(&ul->lock);
 147 }
 148
 149 void rt6_uncached_list_del(struct rt6_info *rt)
 150 {
 151         if (!list_empty(&rt->dst.rt_uncached)) {
 152                 struct uncached_list *ul = rt->dst.rt_uncached_list;
 153
 154                 spin_lock_bh(&ul->lock);
 155                 list_del_init(&rt->dst.rt_uncached);
 156                 spin_unlock_bh(&ul->lock);
 157         }
 158 }
 159
 160 static void rt6_uncached_list_flush_dev(struct net_device *dev)
 161 {
 162         int cpu;
 163
 164         for_each_possible_cpu(cpu) {
 165                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
 166                 struct rt6_info *rt, *safe;
 167
 168                 if (list_empty(&ul->head))
 169                         continue;
 170
 171                 spin_lock_bh(&ul->lock);
 172                 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) {
 173                         struct inet6_dev *rt_idev = rt->rt6i_idev;
 174                         struct net_device *rt_dev = rt->dst.dev;
 175                         bool handled = false;
 176
 177                         if (rt_idev->dev == dev) {
 178                                 rt->rt6i_idev = in6_dev_get(blackhole_netdev);
 179                                 in6_dev_put(rt_idev);
 180                                 handled = true;
 181                         }
 182
 183                         if (rt_dev == dev) {
 184                                 rt->dst.dev = blackhole_netdev;
 185                                 netdev_ref_replace(rt_dev, blackhole_netdev,
 186                                                    &rt->dst.dev_tracker,
 187                                                    GFP_ATOMIC);
 188                                 handled = true;
 189                         }
 190                         if (handled)
 191                                 list_move(&rt->dst.rt_uncached,
 192                                           &ul->quarantine);
 193                 }
 194                 spin_unlock_bh(&ul->lock);
 195         }
 196 }
 197
 198 static inline const void *choose_neigh_daddr(const struct in6_addr *p,
 199                                              struct sk_buff *skb,
 200                                              const void *daddr)
 201 {
 202         if (!ipv6_addr_any(p))
 203                 return (const void *) p;
 204         else if (skb)
 205                 return &ipv6_hdr(skb)->daddr;
 206         return daddr;
 207 }
 208
 209 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
 210                                    struct net_device *dev,
 211                                    struct sk_buff *skb,
 212                                    const void *daddr)
 213 {
 214         struct neighbour *n;
 215
 216         daddr = choose_neigh_daddr(gw, skb, daddr);
 217         n = __ipv6_neigh_lookup(dev, daddr);
 218         if (n)
 219                 return n;
 220
 221         n = neigh_create(&nd_tbl, daddr, dev);
 222         return IS_ERR(n) ? NULL : n;
 223 }
 224
 225 static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst,
 226                                               struct sk_buff *skb,
 227                                               const void *daddr)
 228 {
 229         const struct rt6_info *rt = container_of(dst, struct rt6_info, dst);
 230
 231         return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any),
 232                                 dst->dev, skb, daddr);
 233 }
 234
 235 static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr)
 236 {
 237         struct net_device *dev = dst->dev;
 238         struct rt6_info *rt = (struct rt6_info *)dst;
 239
 240         daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr);
 241         if (!daddr)
 242                 return;
 243         if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
 244                 return;
 245         if (ipv6_addr_is_multicast((const struct in6_addr *)daddr))
 246                 return;
 247         __ipv6_confirm_neigh(dev, daddr);
 248 }
 249
 250 static struct dst_ops ip6_dst_ops_template = {
 251         .family                 =       AF_INET6,
 252         .gc                     =       ip6_dst_gc,
 253         .gc_thresh              =       1024,
 254         .check                  =       ip6_dst_check,
 255         .default_advmss         =       ip6_default_advmss,
 256         .mtu                    =       ip6_mtu,
 257         .cow_metrics            =       dst_cow_metrics_generic,
 258         .destroy                =       ip6_dst_destroy,
 259         .ifdown                 =       ip6_dst_ifdown,
 260         .negative_advice        =       ip6_negative_advice,
 261         .link_failure           =       ip6_link_failure,
 262         .update_pmtu            =       ip6_rt_update_pmtu,
 263         .redirect               =       rt6_do_redirect,
 264         .local_out              =       __ip6_local_out,
 265         .neigh_lookup           =       ip6_dst_neigh_lookup,
 266         .confirm_neigh          =       ip6_confirm_neigh,
 267 };
 268
 269 static struct dst_ops ip6_dst_blackhole_ops = {
 270         .family                 = AF_INET6,
 271         .default_advmss         = ip6_default_advmss,
 272         .neigh_lookup           = ip6_dst_neigh_lookup,
 273         .check                  = ip6_dst_check,
 274         .destroy                = ip6_dst_destroy,
 275         .cow_metrics            = dst_cow_metrics_generic,
 276         .update_pmtu            = dst_blackhole_update_pmtu,
 277         .redirect               = dst_blackhole_redirect,
 278         .mtu                    = dst_blackhole_mtu,
 279 };
 280
 281 static const u32 ip6_template_metrics[RTAX_MAX] = {
 282         [RTAX_HOPLIMIT - 1] = 0,
 283 };
 284
 285 static const struct fib6_info fib6_null_entry_template = {
 286         .fib6_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 287         .fib6_protocol  = RTPROT_KERNEL,
 288         .fib6_metric    = ~(u32)0,
 289         .fib6_ref       = REFCOUNT_INIT(1),
 290         .fib6_type      = RTN_UNREACHABLE,
 291         .fib6_metrics   = (struct dst_metrics *)&dst_default_metrics,
 292 };
 293
 294 static const struct rt6_info ip6_null_entry_template = {
 295         .dst = {
 296                 .__rcuref       = RCUREF_INIT(1),
 297                 .__use          = 1,
 298                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 299                 .error          = -ENETUNREACH,
 300                 .input          = ip6_pkt_discard,
 301                 .output         = ip6_pkt_discard_out,
 302         },
 303         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 304 };
 305
 306 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 307
 308 static const struct rt6_info ip6_prohibit_entry_template = {
 309         .dst = {
 310                 .__rcuref       = RCUREF_INIT(1),
 311                 .__use          = 1,
 312                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 313                 .error          = -EACCES,
 314                 .input          = ip6_pkt_prohibit,
 315                 .output         = ip6_pkt_prohibit_out,
 316         },
 317         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 318 };
 319
 320 static const struct rt6_info ip6_blk_hole_entry_template = {
 321         .dst = {
 322                 .__rcuref       = RCUREF_INIT(1),
 323                 .__use          = 1,
 324                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 325                 .error          = -EINVAL,
 326                 .input          = dst_discard,
 327                 .output         = dst_discard_out,
 328         },
 329         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 330 };
 331
 332 #endif
 333
 334 static void rt6_info_init(struct rt6_info *rt)
 335 {
 336         memset_after(rt, 0, dst);
 337 }
 338
 339 /* allocate dst with ip6_dst_ops */
 340 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 341                                int flags)
 342 {
 343         struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
 344                                         DST_OBSOLETE_FORCE_CHK, flags);
 345
 346         if (rt) {
 347                 rt6_info_init(rt);
 348                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
 349         }
 350
 351         return rt;
 352 }
 353 EXPORT_SYMBOL(ip6_dst_alloc);
 354
 355 static void ip6_dst_destroy(struct dst_entry *dst)
 356 {
 357         struct rt6_info *rt = (struct rt6_info *)dst;
 358         struct fib6_info *from;
 359         struct inet6_dev *idev;
 360
 361         ip_dst_metrics_put(dst);
 362         rt6_uncached_list_del(rt);
 363
 364         idev = rt->rt6i_idev;
 365         if (idev) {
 366                 rt->rt6i_idev = NULL;
 367                 in6_dev_put(idev);
 368         }
 369
 370         from = xchg((__force struct fib6_info **)&rt->from, NULL);
 371         fib6_info_release(from);
 372 }
 373
 374 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
 375 {
 376         struct rt6_info *rt = (struct rt6_info *)dst;
 377         struct inet6_dev *idev = rt->rt6i_idev;
 378
 379         if (idev && idev->dev != blackhole_netdev) {
 380                 struct inet6_dev *blackhole_idev = in6_dev_get(blackhole_netdev);
 381
 382                 if (blackhole_idev) {
 383                         rt->rt6i_idev = blackhole_idev;
 384                         in6_dev_put(idev);
 385                 }
 386         }
 387 }
 388
 389 static bool __rt6_check_expired(const struct rt6_info *rt)
 390 {
 391         if (rt->rt6i_flags & RTF_EXPIRES)
 392                 return time_after(jiffies, rt->dst.expires);
 393         else
 394                 return false;
 395 }
 396
 397 static bool rt6_check_expired(const struct rt6_info *rt)
 398 {
 399         struct fib6_info *from;
 400
 401         from = rcu_dereference(rt->from);
 402
 403         if (rt->rt6i_flags & RTF_EXPIRES) {
 404                 if (time_after(jiffies, rt->dst.expires))
 405                         return true;
 406         } else if (from) {
 407                 return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
 408                         fib6_check_expired(from);
 409         }
 410         return false;
 411 }
 412
 413 void fib6_select_path(const struct net *net, struct fib6_result *res,
 414                       struct flowi6 *fl6, int oif, bool have_oif_match,
 415                       const struct sk_buff *skb, int strict)
 416 {
 417         struct fib6_info *sibling, *next_sibling;
 418         struct fib6_info *match = res->f6i;
 419
 420         if (!match->nh && (!match->fib6_nsiblings || have_oif_match))
 421                 goto out;
 422
 423         if (match->nh && have_oif_match && res->nh)
 424                 return;
 425
 426         if (skb)
 427                 IP6CB(skb)->flags |= IP6SKB_MULTIPATH;
 428
 429         /* We might have already computed the hash for ICMPv6 errors. In such
 430          * case it will always be non-zero. Otherwise now is the time to do it.
 431          */
 432         if (!fl6->mp_hash &&
 433             (!match->nh || nexthop_is_multipath(match->nh)))
 434                 fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
 435
 436         if (unlikely(match->nh)) {
 437                 nexthop_path_fib6_result(res, fl6->mp_hash);
 438                 return;
 439         }
 440
 441         if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
 442                 goto out;
 443
 444         list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
 445                                  fib6_siblings) {
 446                 const struct fib6_nh *nh = sibling->fib6_nh;
 447                 int nh_upper_bound;
 448
 449                 nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
 450                 if (fl6->mp_hash > nh_upper_bound)
 451                         continue;
 452                 if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
 453                         break;
 454                 match = sibling;
 455                 break;
 456         }
 457
 458 out:
 459         res->f6i = match;
 460         res->nh = match->fib6_nh;
 461 }
 462
 463 /*
 464  *      Route lookup. rcu_read_lock() should be held.
 465  */
 466
 467 static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh,
 468                                const struct in6_addr *saddr, int oif, int flags)
 469 {
 470         const struct net_device *dev;
 471
 472         if (nh->fib_nh_flags & RTNH_F_DEAD)
 473                 return false;
 474
 475         dev = nh->fib_nh_dev;
 476         if (oif) {
 477                 if (dev->ifindex == oif)
 478                         return true;
 479         } else {
 480                 if (ipv6_chk_addr(net, saddr, dev,
 481                                   flags & RT6_LOOKUP_F_IFACE))
 482                         return true;
 483         }
 484
 485         return false;
 486 }
 487
 488 struct fib6_nh_dm_arg {
 489         struct net              *net;
 490         const struct in6_addr   *saddr;
 491         int                     oif;
 492         int                     flags;
 493         struct fib6_nh          *nh;
 494 };
 495
 496 static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg)
 497 {
 498         struct fib6_nh_dm_arg *arg = _arg;
 499
 500         arg->nh = nh;
 501         return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif,
 502                                   arg->flags);
 503 }
 504
 505 /* returns fib6_nh from nexthop or NULL */
 506 static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh,
 507                                         struct fib6_result *res,
 508                                         const struct in6_addr *saddr,
 509                                         int oif, int flags)
 510 {
 511         struct fib6_nh_dm_arg arg = {
 512                 .net   = net,
 513                 .saddr = saddr,
 514                 .oif   = oif,
 515                 .flags = flags,
 516         };
 517
 518         if (nexthop_is_blackhole(nh))
 519                 return NULL;
 520
 521         if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg))
 522                 return arg.nh;
 523
 524         return NULL;
 525 }
 526
 527 static void rt6_device_match(struct net *net, struct fib6_result *res,
 528                              const struct in6_addr *saddr, int oif, int flags)
 529 {
 530         struct fib6_info *f6i = res->f6i;
 531         struct fib6_info *spf6i;
 532         struct fib6_nh *nh;
 533
 534         if (!oif && ipv6_addr_any(saddr)) {
 535                 if (unlikely(f6i->nh)) {
 536                         nh = nexthop_fib6_nh(f6i->nh);
 537                         if (nexthop_is_blackhole(f6i->nh))
 538                                 goto out_blackhole;
 539                 } else {
 540                         nh = f6i->fib6_nh;
 541                 }
 542                 if (!(nh->fib_nh_flags & RTNH_F_DEAD))
 543                         goto out;
 544         }
 545
 546         for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
 547                 bool matched = false;
 548
 549                 if (unlikely(spf6i->nh)) {
 550                         nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr,
 551                                               oif, flags);
 552                         if (nh)
 553                                 matched = true;
 554                 } else {
 555                         nh = spf6i->fib6_nh;
 556                         if (__rt6_device_match(net, nh, saddr, oif, flags))
 557                                 matched = true;
 558                 }
 559                 if (matched) {
 560                         res->f6i = spf6i;
 561                         goto out;
 562                 }
 563         }
 564
 565         if (oif && flags & RT6_LOOKUP_F_IFACE) {
 566                 res->f6i = net->ipv6.fib6_null_entry;
 567                 nh = res->f6i->fib6_nh;
 568                 goto out;
 569         }
 570
 571         if (unlikely(f6i->nh)) {
 572                 nh = nexthop_fib6_nh(f6i->nh);
 573                 if (nexthop_is_blackhole(f6i->nh))
 574                         goto out_blackhole;
 575         } else {
 576                 nh = f6i->fib6_nh;
 577         }
 578
 579         if (nh->fib_nh_flags & RTNH_F_DEAD) {
 580                 res->f6i = net->ipv6.fib6_null_entry;
 581                 nh = res->f6i->fib6_nh;
 582         }
 583 out:
 584         res->nh = nh;
 585         res->fib6_type = res->f6i->fib6_type;
 586         res->fib6_flags = res->f6i->fib6_flags;
 587         return;
 588
 589 out_blackhole:
 590         res->fib6_flags |= RTF_REJECT;
 591         res->fib6_type = RTN_BLACKHOLE;
 592         res->nh = nh;
 593 }
 594
 595 #ifdef CONFIG_IPV6_ROUTER_PREF
 596 struct __rt6_probe_work {
 597         struct work_struct work;
 598         struct in6_addr target;
 599         struct net_device *dev;
 600         netdevice_tracker dev_tracker;
 601 };
 602
 603 static void rt6_probe_deferred(struct work_struct *w)
 604 {
 605         struct in6_addr mcaddr;
 606         struct __rt6_probe_work *work =
 607                 container_of(w, struct __rt6_probe_work, work);
 608
 609         addrconf_addr_solict_mult(&work->target, &mcaddr);
 610         ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
 611         netdev_put(work->dev, &work->dev_tracker);
 612         kfree(work);
 613 }
 614
 615 static void rt6_probe(struct fib6_nh *fib6_nh)
 616 {
 617         struct __rt6_probe_work *work = NULL;
 618         const struct in6_addr *nh_gw;
 619         unsigned long last_probe;
 620         struct neighbour *neigh;
 621         struct net_device *dev;
 622         struct inet6_dev *idev;
 623
 624         /*
 625          * Okay, this does not seem to be appropriate
 626          * for now, however, we need to check if it
 627          * is really so; aka Router Reachability Probing.
 628          *
 629          * Router Reachability Probe MUST be rate-limited
 630          * to no more than one per minute.
 631          */
 632         if (!fib6_nh->fib_nh_gw_family)
 633                 return;
 634
 635         nh_gw = &fib6_nh->fib_nh_gw6;
 636         dev = fib6_nh->fib_nh_dev;
 637         rcu_read_lock();
 638         last_probe = READ_ONCE(fib6_nh->last_probe);
 639         idev = __in6_dev_get(dev);
 640         neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
 641         if (neigh) {
 642                 if (READ_ONCE(neigh->nud_state) & NUD_VALID)
 643                         goto out;
 644
 645                 write_lock_bh(&neigh->lock);
 646                 if (!(neigh->nud_state & NUD_VALID) &&
 647                     time_after(jiffies,
 648                                neigh->updated +
 649                                READ_ONCE(idev->cnf.rtr_probe_interval))) {
 650                         work = kmalloc(sizeof(*work), GFP_ATOMIC);
 651                         if (work)
 652                                 __neigh_set_probe_once(neigh);
 653                 }
 654                 write_unlock_bh(&neigh->lock);
 655         } else if (time_after(jiffies, last_probe +
 656                                        READ_ONCE(idev->cnf.rtr_probe_interval))) {
 657                 work = kmalloc(sizeof(*work), GFP_ATOMIC);
 658         }
 659
 660         if (!work || cmpxchg(&fib6_nh->last_probe,
 661                              last_probe, jiffies) != last_probe) {
 662                 kfree(work);
 663         } else {
 664                 INIT_WORK(&work->work, rt6_probe_deferred);
 665                 work->target = *nh_gw;
 666                 netdev_hold(dev, &work->dev_tracker, GFP_ATOMIC);
 667                 work->dev = dev;
 668                 schedule_work(&work->work);
 669         }
 670
 671 out:
 672         rcu_read_unlock();
 673 }
 674 #else
 675 static inline void rt6_probe(struct fib6_nh *fib6_nh)
 676 {
 677 }
 678 #endif
 679
 680 /*
 681  * Default Router Selection (RFC 2461 6.3.6)
 682  */
 683 static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh)
 684 {
 685         enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
 686         struct neighbour *neigh;
 687
 688         rcu_read_lock();
 689         neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev,
 690                                           &fib6_nh->fib_nh_gw6);
 691         if (neigh) {
 692                 u8 nud_state = READ_ONCE(neigh->nud_state);
 693
 694                 if (nud_state & NUD_VALID)
 695                         ret = RT6_NUD_SUCCEED;
 696 #ifdef CONFIG_IPV6_ROUTER_PREF
 697                 else if (!(nud_state & NUD_FAILED))
 698                         ret = RT6_NUD_SUCCEED;
 699                 else
 700                         ret = RT6_NUD_FAIL_PROBE;
 701 #endif
 702         } else {
 703                 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
 704                       RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
 705         }
 706         rcu_read_unlock();
 707
 708         return ret;
 709 }
 710
 711 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
 712                            int strict)
 713 {
 714         int m = 0;
 715
 716         if (!oif || nh->fib_nh_dev->ifindex == oif)
 717                 m = 2;
 718
 719         if (!m && (strict & RT6_LOOKUP_F_IFACE))
 720                 return RT6_NUD_FAIL_HARD;
 721 #ifdef CONFIG_IPV6_ROUTER_PREF
 722         m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2;
 723 #endif
 724         if ((strict & RT6_LOOKUP_F_REACHABLE) &&
 725             !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) {
 726                 int n = rt6_check_neigh(nh);
 727                 if (n < 0)
 728                         return n;
 729         }
 730         return m;
 731 }
 732
 733 static bool find_match(struct fib6_nh *nh, u32 fib6_flags,
 734                        int oif, int strict, int *mpri, bool *do_rr)
 735 {
 736         bool match_do_rr = false;
 737         bool rc = false;
 738         int m;
 739
 740         if (nh->fib_nh_flags & RTNH_F_DEAD)
 741                 goto out;
 742
 743         if (ip6_ignore_linkdown(nh->fib_nh_dev) &&
 744             nh->fib_nh_flags & RTNH_F_LINKDOWN &&
 745             !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
 746                 goto out;
 747
 748         m = rt6_score_route(nh, fib6_flags, oif, strict);
 749         if (m == RT6_NUD_FAIL_DO_RR) {
 750                 match_do_rr = true;
 751                 m = 0; /* lowest valid score */
 752         } else if (m == RT6_NUD_FAIL_HARD) {
 753                 goto out;
 754         }
 755
 756         if (strict & RT6_LOOKUP_F_REACHABLE)
 757                 rt6_probe(nh);
 758
 759         /* note that m can be RT6_NUD_FAIL_PROBE at this point */
 760         if (m > *mpri) {
 761                 *do_rr = match_do_rr;
 762                 *mpri = m;
 763                 rc = true;
 764         }
 765 out:
 766         return rc;
 767 }
 768
 769 struct fib6_nh_frl_arg {
 770         u32             flags;
 771         int             oif;
 772         int             strict;
 773         int             *mpri;
 774         bool            *do_rr;
 775         struct fib6_nh  *nh;
 776 };
 777
 778 static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg)
 779 {
 780         struct fib6_nh_frl_arg *arg = _arg;
 781
 782         arg->nh = nh;
 783         return find_match(nh, arg->flags, arg->oif, arg->strict,
 784                           arg->mpri, arg->do_rr);
 785 }
 786
 787 static void __find_rr_leaf(struct fib6_info *f6i_start,
 788                            struct fib6_info *nomatch, u32 metric,
 789                            struct fib6_result *res, struct fib6_info **cont,
 790                            int oif, int strict, bool *do_rr, int *mpri)
 791 {
 792         struct fib6_info *f6i;
 793
 794         for (f6i = f6i_start;
 795              f6i && f6i != nomatch;
 796              f6i = rcu_dereference(f6i->fib6_next)) {
 797                 bool matched = false;
 798                 struct fib6_nh *nh;
 799
 800                 if (cont && f6i->fib6_metric != metric) {
 801                         *cont = f6i;
 802                         return;
 803                 }
 804
 805                 if (fib6_check_expired(f6i))
 806                         continue;
 807
 808                 if (unlikely(f6i->nh)) {
 809                         struct fib6_nh_frl_arg arg = {
 810                                 .flags  = f6i->fib6_flags,
 811                                 .oif    = oif,
 812                                 .strict = strict,
 813                                 .mpri   = mpri,
 814                                 .do_rr  = do_rr
 815                         };
 816
 817                         if (nexthop_is_blackhole(f6i->nh)) {
 818                                 res->fib6_flags = RTF_REJECT;
 819                                 res->fib6_type = RTN_BLACKHOLE;
 820                                 res->f6i = f6i;
 821                                 res->nh = nexthop_fib6_nh(f6i->nh);
 822                                 return;
 823                         }
 824                         if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match,
 825                                                      &arg)) {
 826                                 matched = true;
 827                                 nh = arg.nh;
 828                         }
 829                 } else {
 830                         nh = f6i->fib6_nh;
 831                         if (find_match(nh, f6i->fib6_flags, oif, strict,
 832                                        mpri, do_rr))
 833                                 matched = true;
 834                 }
 835                 if (matched) {
 836                         res->f6i = f6i;
 837                         res->nh = nh;
 838                         res->fib6_flags = f6i->fib6_flags;
 839                         res->fib6_type = f6i->fib6_type;
 840                 }
 841         }
 842 }
 843
 844 static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf,
 845                          struct fib6_info *rr_head, int oif, int strict,
 846                          bool *do_rr, struct fib6_result *res)
 847 {
 848         u32 metric = rr_head->fib6_metric;
 849         struct fib6_info *cont = NULL;
 850         int mpri = -1;
 851
 852         __find_rr_leaf(rr_head, NULL, metric, res, &cont,
 853                        oif, strict, do_rr, &mpri);
 854
 855         __find_rr_leaf(leaf, rr_head, metric, res, &cont,
 856                        oif, strict, do_rr, &mpri);
 857
 858         if (res->f6i || !cont)
 859                 return;
 860
 861         __find_rr_leaf(cont, NULL, metric, res, NULL,
 862                        oif, strict, do_rr, &mpri);
 863 }
 864
 865 static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
 866                        struct fib6_result *res, int strict)
 867 {
 868         struct fib6_info *leaf = rcu_dereference(fn->leaf);
 869         struct fib6_info *rt0;
 870         bool do_rr = false;
 871         int key_plen;
 872
 873         /* make sure this function or its helpers sets f6i */
 874         res->f6i = NULL;
 875
 876         if (!leaf || leaf == net->ipv6.fib6_null_entry)
 877                 goto out;
 878
 879         rt0 = rcu_dereference(fn->rr_ptr);
 880         if (!rt0)
 881                 rt0 = leaf;
 882
 883         /* Double check to make sure fn is not an intermediate node
 884          * and fn->leaf does not points to its child's leaf
 885          * (This might happen if all routes under fn are deleted from
 886          * the tree and fib6_repair_tree() is called on the node.)
 887          */
 888         key_plen = rt0->fib6_dst.plen;
 889 #ifdef CONFIG_IPV6_SUBTREES
 890         if (rt0->fib6_src.plen)
 891                 key_plen = rt0->fib6_src.plen;
 892 #endif
 893         if (fn->fn_bit != key_plen)
 894                 goto out;
 895
 896         find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res);
 897         if (do_rr) {
 898                 struct fib6_info *next = rcu_dereference(rt0->fib6_next);
 899
 900                 /* no entries matched; do round-robin */
 901                 if (!next || next->fib6_metric != rt0->fib6_metric)
 902                         next = leaf;
 903
 904                 if (next != rt0) {
 905                         spin_lock_bh(&leaf->fib6_table->tb6_lock);
 906                         /* make sure next is not being deleted from the tree */
 907                         if (next->fib6_node)
 908                                 rcu_assign_pointer(fn->rr_ptr, next);
 909                         spin_unlock_bh(&leaf->fib6_table->tb6_lock);
 910                 }
 911         }
 912
 913 out:
 914         if (!res->f6i) {
 915                 res->f6i = net->ipv6.fib6_null_entry;
 916                 res->nh = res->f6i->fib6_nh;
 917                 res->fib6_flags = res->f6i->fib6_flags;
 918                 res->fib6_type = res->f6i->fib6_type;
 919         }
 920 }
 921
 922 static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res)
 923 {
 924         return (res->f6i->fib6_flags & RTF_NONEXTHOP) ||
 925                res->nh->fib_nh_gw_family;
 926 }
 927
 928 #ifdef CONFIG_IPV6_ROUTE_INFO
 929 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 930                   const struct in6_addr *gwaddr)
 931 {
 932         struct net *net = dev_net(dev);
 933         struct route_info *rinfo = (struct route_info *) opt;
 934         struct in6_addr prefix_buf, *prefix;
 935         struct fib6_table *table;
 936         unsigned int pref;
 937         unsigned long lifetime;
 938         struct fib6_info *rt;
 939
 940         if (len < sizeof(struct route_info)) {
 941                 return -EINVAL;
 942         }
 943
 944         /* Sanity check for prefix_len and length */
 945         if (rinfo->length > 3) {
 946                 return -EINVAL;
 947         } else if (rinfo->prefix_len > 128) {
 948                 return -EINVAL;
 949         } else if (rinfo->prefix_len > 64) {
 950                 if (rinfo->length < 2) {
 951                         return -EINVAL;
 952                 }
 953         } else if (rinfo->prefix_len > 0) {
 954                 if (rinfo->length < 1) {
 955                         return -EINVAL;
 956                 }
 957         }
 958
 959         pref = rinfo->route_pref;
 960         if (pref == ICMPV6_ROUTER_PREF_INVALID)
 961                 return -EINVAL;
 962
 963         lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
 964
 965         if (rinfo->length == 3)
 966                 prefix = (struct in6_addr *)rinfo->prefix;
 967         else {
 968                 /* this function is safe */
 969                 ipv6_addr_prefix(&prefix_buf,
 970                                  (struct in6_addr *)rinfo->prefix,
 971                                  rinfo->prefix_len);
 972                 prefix = &prefix_buf;
 973         }
 974
 975         if (rinfo->prefix_len == 0)
 976                 rt = rt6_get_dflt_router(net, gwaddr, dev);
 977         else
 978                 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
 979                                         gwaddr, dev);
 980
 981         if (rt && !lifetime) {
 982                 ip6_del_rt(net, rt, false);
 983                 rt = NULL;
 984         }
 985
 986         if (!rt && lifetime)
 987                 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
 988                                         dev, pref);
 989         else if (rt)
 990                 rt->fib6_flags = RTF_ROUTEINFO |
 991                                  (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 992
 993         if (rt) {
 994                 table = rt->fib6_table;
 995                 spin_lock_bh(&table->tb6_lock);
 996
 997                 if (!addrconf_finite_timeout(lifetime)) {
 998                         fib6_clean_expires(rt);
 999                         fib6_remove_gc_list(rt);
1000                 } else {
1001                         fib6_set_expires(rt, jiffies + HZ * lifetime);
1002                         fib6_add_gc_list(rt);
1003                 }
1004
1005                 spin_unlock_bh(&table->tb6_lock);
1006
1007                 fib6_info_release(rt);
1008         }
1009         return 0;
1010 }
1011 #endif
1012
1013 /*
1014  *      Misc support functions
1015  */
1016
1017 /* called with rcu_lock held */
1018 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
1019 {
1020         struct net_device *dev = res->nh->fib_nh_dev;
1021
1022         if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
1023                 /* for copies of local routes, dst->dev needs to be the
1024                  * device if it is a master device, the master device if
1025                  * device is enslaved, and the loopback as the default
1026                  */
1027                 if (netif_is_l3_slave(dev) &&
1028                     !rt6_need_strict(&res->f6i->fib6_dst.addr))
1029                         dev = l3mdev_master_dev_rcu(dev);
1030                 else if (!netif_is_l3_master(dev))
1031                         dev = dev_net(dev)->loopback_dev;
1032                 /* last case is netif_is_l3_master(dev) is true in which
1033                  * case we want dev returned to be dev
1034                  */
1035         }
1036
1037         return dev;
1038 }
1039
1040 static const int fib6_prop[RTN_MAX + 1] = {
1041         [RTN_UNSPEC]    = 0,
1042         [RTN_UNICAST]   = 0,
1043         [RTN_LOCAL]     = 0,
1044         [RTN_BROADCAST] = 0,
1045         [RTN_ANYCAST]   = 0,
1046         [RTN_MULTICAST] = 0,
1047         [RTN_BLACKHOLE] = -EINVAL,
1048         [RTN_UNREACHABLE] = -EHOSTUNREACH,
1049         [RTN_PROHIBIT]  = -EACCES,
1050         [RTN_THROW]     = -EAGAIN,
1051         [RTN_NAT]       = -EINVAL,
1052         [RTN_XRESOLVE]  = -EINVAL,
1053 };
1054
1055 static int ip6_rt_type_to_error(u8 fib6_type)
1056 {
1057         return fib6_prop[fib6_type];
1058 }
1059
1060 static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
1061 {
1062         unsigned short flags = 0;
1063
1064         if (rt->dst_nocount)
1065                 flags |= DST_NOCOUNT;
1066         if (rt->dst_nopolicy)
1067                 flags |= DST_NOPOLICY;
1068
1069         return flags;
1070 }
1071
1072 static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
1073 {
1074         rt->dst.error = ip6_rt_type_to_error(fib6_type);
1075
1076         switch (fib6_type) {
1077         case RTN_BLACKHOLE:
1078                 rt->dst.output = dst_discard_out;
1079                 rt->dst.input = dst_discard;
1080                 break;
1081         case RTN_PROHIBIT:
1082                 rt->dst.output = ip6_pkt_prohibit_out;
1083                 rt->dst.input = ip6_pkt_prohibit;
1084                 break;
1085         case RTN_THROW:
1086         case RTN_UNREACHABLE:
1087         default:
1088                 rt->dst.output = ip6_pkt_discard_out;
1089                 rt->dst.input = ip6_pkt_discard;
1090                 break;
1091         }
1092 }
1093
1094 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
1095 {
1096         struct fib6_info *f6i = res->f6i;
1097
1098         if (res->fib6_flags & RTF_REJECT) {
1099                 ip6_rt_init_dst_reject(rt, res->fib6_type);
1100                 return;
1101         }
1102
1103         rt->dst.error = 0;
1104         rt->dst.output = ip6_output;
1105
1106         if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
1107                 rt->dst.input = ip6_input;
1108         } else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
1109                 rt->dst.input = ip6_mc_input;
1110         } else {
1111                 rt->dst.input = ip6_forward;
1112         }
1113
1114         if (res->nh->fib_nh_lws) {
1115                 rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws);
1116                 lwtunnel_set_redirect(&rt->dst);
1117         }
1118
1119         rt->dst.lastuse = jiffies;
1120 }
1121
1122 /* Caller must already hold reference to @from */
1123 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
1124 {
1125         rt->rt6i_flags &= ~RTF_EXPIRES;
1126         rcu_assign_pointer(rt->from, from);
1127         ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
1128 }
1129
1130 /* Caller must already hold reference to f6i in result */
1131 static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
1132 {
1133         const struct fib6_nh *nh = res->nh;
1134         const struct net_device *dev = nh->fib_nh_dev;
1135         struct fib6_info *f6i = res->f6i;
1136
1137         ip6_rt_init_dst(rt, res);
1138
1139         rt->rt6i_dst = f6i->fib6_dst;
1140         rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
1141         rt->rt6i_flags = res->fib6_flags;
1142         if (nh->fib_nh_gw_family) {
1143                 rt->rt6i_gateway = nh->fib_nh_gw6;
1144                 rt->rt6i_flags |= RTF_GATEWAY;
1145         }
1146         rt6_set_from(rt, f6i);
1147 #ifdef CONFIG_IPV6_SUBTREES
1148         rt->rt6i_src = f6i->fib6_src;
1149 #endif
1150 }
1151
1152 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
1153                                         struct in6_addr *saddr)
1154 {
1155         struct fib6_node *pn, *sn;
1156         while (1) {
1157                 if (fn->fn_flags & RTN_TL_ROOT)
1158                         return NULL;
1159                 pn = rcu_dereference(fn->parent);
1160                 sn = FIB6_SUBTREE(pn);
1161                 if (sn && sn != fn)
1162                         fn = fib6_node_lookup(sn, NULL, saddr);
1163                 else
1164                         fn = pn;
1165                 if (fn->fn_flags & RTN_RTINFO)
1166                         return fn;
1167         }
1168 }
1169
1170 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt)
1171 {
1172         struct rt6_info *rt = *prt;
1173
1174         if (dst_hold_safe(&rt->dst))
1175                 return true;
1176         if (net) {
1177                 rt = net->ipv6.ip6_null_entry;
1178                 dst_hold(&rt->dst);
1179         } else {
1180                 rt = NULL;
1181         }
1182         *prt = rt;
1183         return false;
1184 }
1185
1186 /* called with rcu_lock held */
1187 static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res)
1188 {
1189         struct net_device *dev = res->nh->fib_nh_dev;
1190         struct fib6_info *f6i = res->f6i;
1191         unsigned short flags;
1192         struct rt6_info *nrt;
1193
1194         if (!fib6_info_hold_safe(f6i))
1195                 goto fallback;
1196
1197         flags = fib6_info_dst_flags(f6i);
1198         nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
1199         if (!nrt) {
1200                 fib6_info_release(f6i);
1201                 goto fallback;
1202         }
1203
1204         ip6_rt_copy_init(nrt, res);
1205         return nrt;
1206
1207 fallback:
1208         nrt = dev_net(dev)->ipv6.ip6_null_entry;
1209         dst_hold(&nrt->dst);
1210         return nrt;
1211 }
1212
1213 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net,
1214                                              struct fib6_table *table,
1215                                              struct flowi6 *fl6,
1216                                              const struct sk_buff *skb,
1217                                              int flags)
1218 {
1219         struct fib6_result res = {};
1220         struct fib6_node *fn;
1221         struct rt6_info *rt;
1222
1223         rcu_read_lock();
1224         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1225 restart:
1226         res.f6i = rcu_dereference(fn->leaf);
1227         if (!res.f6i)
1228                 res.f6i = net->ipv6.fib6_null_entry;
1229         else
1230                 rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif,
1231                                  flags);
1232
1233         if (res.f6i == net->ipv6.fib6_null_entry) {
1234                 fn = fib6_backtrack(fn, &fl6->saddr);
1235                 if (fn)
1236                         goto restart;
1237
1238                 rt = net->ipv6.ip6_null_entry;
1239                 dst_hold(&rt->dst);
1240                 goto out;
1241         } else if (res.fib6_flags & RTF_REJECT) {
1242                 goto do_create;
1243         }
1244
1245         fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
1246                          fl6->flowi6_oif != 0, skb, flags);
1247
1248         /* Search through exception table */
1249         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
1250         if (rt) {
1251                 if (ip6_hold_safe(net, &rt))
1252                         dst_use_noref(&rt->dst, jiffies);
1253         } else {
1254 do_create:
1255                 rt = ip6_create_rt_rcu(&res);
1256         }
1257
1258 out:
1259         trace_fib6_table_lookup(net, &res, table, fl6);
1260
1261         rcu_read_unlock();
1262
1263         return rt;
1264 }
1265
1266 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
1267                                    const struct sk_buff *skb, int flags)
1268 {
1269         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
1270 }
1271 EXPORT_SYMBOL_GPL(ip6_route_lookup);
1272
1273 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
1274                             const struct in6_addr *saddr, int oif,
1275                             const struct sk_buff *skb, int strict)
1276 {
1277         struct flowi6 fl6 = {
1278                 .flowi6_oif = oif,
1279                 .daddr = *daddr,
1280         };
1281         struct dst_entry *dst;
1282         int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
1283
1284         if (saddr) {
1285                 memcpy(&fl6.saddr, saddr, sizeof(*saddr));
1286                 flags |= RT6_LOOKUP_F_HAS_SADDR;
1287         }
1288
1289         dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
1290         if (dst->error == 0)
1291                 return (struct rt6_info *) dst;
1292
1293         dst_release(dst);
1294
1295         return NULL;
1296 }
1297 EXPORT_SYMBOL(rt6_lookup);
1298
1299 /* ip6_ins_rt is called with FREE table->tb6_lock.
1300  * It takes new route entry, the addition fails by any reason the
1301  * route is released.
1302  * Caller must hold dst before calling it.
1303  */
1304
1305 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
1306                         struct netlink_ext_ack *extack)
1307 {
1308         int err;
1309         struct fib6_table *table;
1310
1311         table = rt->fib6_table;
1312         spin_lock_bh(&table->tb6_lock);
1313         err = fib6_add(&table->tb6_root, rt, info, extack);
1314         spin_unlock_bh(&table->tb6_lock);
1315
1316         return err;
1317 }
1318
1319 int ip6_ins_rt(struct net *net, struct fib6_info *rt)
1320 {
1321         struct nl_info info = { .nl_net = net, };
1322
1323         return __ip6_ins_rt(rt, &info, NULL);
1324 }
1325
1326 static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res,
1327                                            const struct in6_addr *daddr,
1328                                            const struct in6_addr *saddr)
1329 {
1330         struct fib6_info *f6i = res->f6i;
1331         struct net_device *dev;
1332         struct rt6_info *rt;
1333
1334         /*
1335          *      Clone the route.
1336          */
1337
1338         if (!fib6_info_hold_safe(f6i))
1339                 return NULL;
1340
1341         dev = ip6_rt_get_dev_rcu(res);
1342         rt = ip6_dst_alloc(dev_net(dev), dev, 0);
1343         if (!rt) {
1344                 fib6_info_release(f6i);
1345                 return NULL;
1346         }
1347
1348         ip6_rt_copy_init(rt, res);
1349         rt->rt6i_flags |= RTF_CACHE;
1350         rt->rt6i_dst.addr = *daddr;
1351         rt->rt6i_dst.plen = 128;
1352
1353         if (!rt6_is_gw_or_nonexthop(res)) {
1354                 if (f6i->fib6_dst.plen != 128 &&
1355                     ipv6_addr_equal(&f6i->fib6_dst.addr, daddr))
1356                         rt->rt6i_flags |= RTF_ANYCAST;
1357 #ifdef CONFIG_IPV6_SUBTREES
1358                 if (rt->rt6i_src.plen && saddr) {
1359                         rt->rt6i_src.addr = *saddr;
1360                         rt->rt6i_src.plen = 128;
1361                 }
1362 #endif
1363         }
1364
1365         return rt;
1366 }
1367
1368 static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res)
1369 {
1370         struct fib6_info *f6i = res->f6i;
1371         unsigned short flags = fib6_info_dst_flags(f6i);
1372         struct net_device *dev;
1373         struct rt6_info *pcpu_rt;
1374
1375         if (!fib6_info_hold_safe(f6i))
1376                 return NULL;
1377
1378         rcu_read_lock();
1379         dev = ip6_rt_get_dev_rcu(res);
1380         pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT);
1381         rcu_read_unlock();
1382         if (!pcpu_rt) {
1383                 fib6_info_release(f6i);
1384                 return NULL;
1385         }
1386         ip6_rt_copy_init(pcpu_rt, res);
1387         pcpu_rt->rt6i_flags |= RTF_PCPU;
1388
1389         if (f6i->nh)
1390                 pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev));
1391
1392         return pcpu_rt;
1393 }
1394
1395 static bool rt6_is_valid(const struct rt6_info *rt6)
1396 {
1397         return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev));
1398 }
1399
1400 /* It should be called with rcu_read_lock() acquired */
1401 static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
1402 {
1403         struct rt6_info *pcpu_rt;
1404
1405         pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
1406
1407         if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) {
1408                 struct rt6_info *prev, **p;
1409
1410                 p = this_cpu_ptr(res->nh->rt6i_pcpu);
1411                 prev = xchg(p, NULL);
1412                 if (prev) {
1413                         dst_dev_put(&prev->dst);
1414                         dst_release(&prev->dst);
1415                 }
1416
1417                 pcpu_rt = NULL;
1418         }
1419
1420         return pcpu_rt;
1421 }
1422
1423 static struct rt6_info *rt6_make_pcpu_route(struct net *net,
1424                                             const struct fib6_result *res)
1425 {
1426         struct rt6_info *pcpu_rt, *prev, **p;
1427
1428         pcpu_rt = ip6_rt_pcpu_alloc(res);
1429         if (!pcpu_rt)
1430                 return NULL;
1431
1432         p = this_cpu_ptr(res->nh->rt6i_pcpu);
1433         prev = cmpxchg(p, NULL, pcpu_rt);
1434         BUG_ON(prev);
1435
1436         if (res->f6i->fib6_destroying) {
1437                 struct fib6_info *from;
1438
1439                 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
1440                 fib6_info_release(from);
1441         }
1442
1443         return pcpu_rt;
1444 }
1445
1446 /* exception hash table implementation
1447  */
1448 static DEFINE_SPINLOCK(rt6_exception_lock);
1449
1450 /* Remove rt6_ex from hash table and free the memory
1451  * Caller must hold rt6_exception_lock
1452  */
1453 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
1454                                  struct rt6_exception *rt6_ex)
1455 {
1456         struct fib6_info *from;
1457         struct net *net;
1458
1459         if (!bucket || !rt6_ex)
1460                 return;
1461
1462         net = dev_net(rt6_ex->rt6i->dst.dev);
1463         net->ipv6.rt6_stats->fib_rt_cache--;
1464
1465         /* purge completely the exception to allow releasing the held resources:
1466          * some [sk] cache may keep the dst around for unlimited time
1467          */
1468         from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL);
1469         fib6_info_release(from);
1470         dst_dev_put(&rt6_ex->rt6i->dst);
1471
1472         hlist_del_rcu(&rt6_ex->hlist);
1473         dst_release(&rt6_ex->rt6i->dst);
1474         kfree_rcu(rt6_ex, rcu);
1475         WARN_ON_ONCE(!bucket->depth);
1476         bucket->depth--;
1477 }
1478
1479 /* Remove oldest rt6_ex in bucket and free the memory
1480  * Caller must hold rt6_exception_lock
1481  */
1482 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
1483 {
1484         struct rt6_exception *rt6_ex, *oldest = NULL;
1485
1486         if (!bucket)
1487                 return;
1488
1489         hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
1490                 if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
1491                         oldest = rt6_ex;
1492         }
1493         rt6_remove_exception(bucket, oldest);
1494 }
1495
1496 static u32 rt6_exception_hash(const struct in6_addr *dst,
1497                               const struct in6_addr *src)
1498 {
1499         static siphash_aligned_key_t rt6_exception_key;
1500         struct {
1501                 struct in6_addr dst;
1502                 struct in6_addr src;
1503         } __aligned(SIPHASH_ALIGNMENT) combined = {
1504                 .dst = *dst,
1505         };
1506         u64 val;
1507
1508         net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key));
1509
1510 #ifdef CONFIG_IPV6_SUBTREES
1511         if (src)
1512                 combined.src = *src;
1513 #endif
1514         val = siphash(&combined, sizeof(combined), &rt6_exception_key);
1515
1516         return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
1517 }
1518
1519 /* Helper function to find the cached rt in the hash table
1520  * and update bucket pointer to point to the bucket for this
1521  * (daddr, saddr) pair
1522  * Caller must hold rt6_exception_lock
1523  */
1524 static struct rt6_exception *
1525 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
1526                               const struct in6_addr *daddr,
1527                               const struct in6_addr *saddr)
1528 {
1529         struct rt6_exception *rt6_ex;
1530         u32 hval;
1531
1532         if (!(*bucket) || !daddr)
1533                 return NULL;
1534
1535         hval = rt6_exception_hash(daddr, saddr);
1536         *bucket += hval;
1537
1538         hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
1539                 struct rt6_info *rt6 = rt6_ex->rt6i;
1540                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1541
1542 #ifdef CONFIG_IPV6_SUBTREES
1543                 if (matched && saddr)
1544                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1545 #endif
1546                 if (matched)
1547                         return rt6_ex;
1548         }
1549         return NULL;
1550 }
1551
1552 /* Helper function to find the cached rt in the hash table
1553  * and update bucket pointer to point to the bucket for this
1554  * (daddr, saddr) pair
1555  * Caller must hold rcu_read_lock()
1556  */
1557 static struct rt6_exception *
1558 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
1559                          const struct in6_addr *daddr,
1560                          const struct in6_addr *saddr)
1561 {
1562         struct rt6_exception *rt6_ex;
1563         u32 hval;
1564
1565         WARN_ON_ONCE(!rcu_read_lock_held());
1566
1567         if (!(*bucket) || !daddr)
1568                 return NULL;
1569
1570         hval = rt6_exception_hash(daddr, saddr);
1571         *bucket += hval;
1572
1573         hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
1574                 struct rt6_info *rt6 = rt6_ex->rt6i;
1575                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1576
1577 #ifdef CONFIG_IPV6_SUBTREES
1578                 if (matched && saddr)
1579                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1580 #endif
1581                 if (matched)
1582                         return rt6_ex;
1583         }
1584         return NULL;
1585 }
1586
1587 static unsigned int fib6_mtu(const struct fib6_result *res)
1588 {
1589         const struct fib6_nh *nh = res->nh;
1590         unsigned int mtu;
1591
1592         if (res->f6i->fib6_pmtu) {
1593                 mtu = res->f6i->fib6_pmtu;
1594         } else {
1595                 struct net_device *dev = nh->fib_nh_dev;
1596                 struct inet6_dev *idev;
1597
1598                 rcu_read_lock();
1599                 idev = __in6_dev_get(dev);
1600                 mtu = READ_ONCE(idev->cnf.mtu6);
1601                 rcu_read_unlock();
1602         }
1603
1604         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
1605
1606         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
1607 }
1608
1609 #define FIB6_EXCEPTION_BUCKET_FLUSHED  0x1UL
1610
1611 /* used when the flushed bit is not relevant, only access to the bucket
1612  * (ie., all bucket users except rt6_insert_exception);
1613  *
1614  * called under rcu lock; sometimes called with rt6_exception_lock held
1615  */
1616 static
1617 struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh,
1618                                                        spinlock_t *lock)
1619 {
1620         struct rt6_exception_bucket *bucket;
1621
1622         if (lock)
1623                 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1624                                                    lockdep_is_held(lock));
1625         else
1626                 bucket = rcu_dereference(nh->rt6i_exception_bucket);
1627
1628         /* remove bucket flushed bit if set */
1629         if (bucket) {
1630                 unsigned long p = (unsigned long)bucket;
1631
1632                 p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED;
1633                 bucket = (struct rt6_exception_bucket *)p;
1634         }
1635
1636         return bucket;
1637 }
1638
1639 static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket)
1640 {
1641         unsigned long p = (unsigned long)bucket;
1642
1643         return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED);
1644 }
1645
1646 /* called with rt6_exception_lock held */
1647 static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh,
1648                                               spinlock_t *lock)
1649 {
1650         struct rt6_exception_bucket *bucket;
1651         unsigned long p;
1652
1653         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1654                                            lockdep_is_held(lock));
1655
1656         p = (unsigned long)bucket;
1657         p |= FIB6_EXCEPTION_BUCKET_FLUSHED;
1658         bucket = (struct rt6_exception_bucket *)p;
1659         rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1660 }
1661
1662 static int rt6_insert_exception(struct rt6_info *nrt,
1663                                 const struct fib6_result *res)
1664 {
1665         struct net *net = dev_net(nrt->dst.dev);
1666         struct rt6_exception_bucket *bucket;
1667         struct fib6_info *f6i = res->f6i;
1668         struct in6_addr *src_key = NULL;
1669         struct rt6_exception *rt6_ex;
1670         struct fib6_nh *nh = res->nh;
1671         int max_depth;
1672         int err = 0;
1673
1674         spin_lock_bh(&rt6_exception_lock);
1675
1676         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1677                                           lockdep_is_held(&rt6_exception_lock));
1678         if (!bucket) {
1679                 bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
1680                                  GFP_ATOMIC);
1681                 if (!bucket) {
1682                         err = -ENOMEM;
1683                         goto out;
1684                 }
1685                 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1686         } else if (fib6_nh_excptn_bucket_flushed(bucket)) {
1687                 err = -EINVAL;
1688                 goto out;
1689         }
1690
1691 #ifdef CONFIG_IPV6_SUBTREES
1692         /* fib6_src.plen != 0 indicates f6i is in subtree
1693          * and exception table is indexed by a hash of
1694          * both fib6_dst and fib6_src.
1695          * Otherwise, the exception table is indexed by
1696          * a hash of only fib6_dst.
1697          */
1698         if (f6i->fib6_src.plen)
1699                 src_key = &nrt->rt6i_src.addr;
1700 #endif
1701         /* rt6_mtu_change() might lower mtu on f6i.
1702          * Only insert this exception route if its mtu
1703          * is less than f6i's mtu value.
1704          */
1705         if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) {
1706                 err = -EINVAL;
1707                 goto out;
1708         }
1709
1710         rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
1711                                                src_key);
1712         if (rt6_ex)
1713                 rt6_remove_exception(bucket, rt6_ex);
1714
1715         rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
1716         if (!rt6_ex) {
1717                 err = -ENOMEM;
1718                 goto out;
1719         }
1720         rt6_ex->rt6i = nrt;
1721         rt6_ex->stamp = jiffies;
1722         hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
1723         bucket->depth++;
1724         net->ipv6.rt6_stats->fib_rt_cache++;
1725
1726         /* Randomize max depth to avoid some side channels attacks. */
1727         max_depth = FIB6_MAX_DEPTH + get_random_u32_below(FIB6_MAX_DEPTH);
1728         while (bucket->depth > max_depth)
1729                 rt6_exception_remove_oldest(bucket);
1730
1731 out:
1732         spin_unlock_bh(&rt6_exception_lock);
1733
1734         /* Update fn->fn_sernum to invalidate all cached dst */
1735         if (!err) {
1736                 spin_lock_bh(&f6i->fib6_table->tb6_lock);
1737                 fib6_update_sernum(net, f6i);
1738                 spin_unlock_bh(&f6i->fib6_table->tb6_lock);
1739                 fib6_force_start_gc(net);
1740         }
1741
1742         return err;
1743 }
1744
1745 static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
1746 {
1747         struct rt6_exception_bucket *bucket;
1748         struct rt6_exception *rt6_ex;
1749         struct hlist_node *tmp;
1750         int i;
1751
1752         spin_lock_bh(&rt6_exception_lock);
1753
1754         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1755         if (!bucket)
1756                 goto out;
1757
1758         /* Prevent rt6_insert_exception() to recreate the bucket list */
1759         if (!from)
1760                 fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock);
1761
1762         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1763                 hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) {
1764                         if (!from ||
1765                             rcu_access_pointer(rt6_ex->rt6i->from) == from)
1766                                 rt6_remove_exception(bucket, rt6_ex);
1767                 }
1768                 WARN_ON_ONCE(!from && bucket->depth);
1769                 bucket++;
1770         }
1771 out:
1772         spin_unlock_bh(&rt6_exception_lock);
1773 }
1774
1775 static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg)
1776 {
1777         struct fib6_info *f6i = arg;
1778
1779         fib6_nh_flush_exceptions(nh, f6i);
1780
1781         return 0;
1782 }
1783
1784 void rt6_flush_exceptions(struct fib6_info *f6i)
1785 {
1786         if (f6i->nh)
1787                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions,
1788                                          f6i);
1789         else
1790                 fib6_nh_flush_exceptions(f6i->fib6_nh, f6i);
1791 }
1792
1793 /* Find cached rt in the hash table inside passed in rt
1794  * Caller has to hold rcu_read_lock()
1795  */
1796 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
1797                                            const struct in6_addr *daddr,
1798                                            const struct in6_addr *saddr)
1799 {
1800         const struct in6_addr *src_key = NULL;
1801         struct rt6_exception_bucket *bucket;
1802         struct rt6_exception *rt6_ex;
1803         struct rt6_info *ret = NULL;
1804
1805 #ifdef CONFIG_IPV6_SUBTREES
1806         /* fib6i_src.plen != 0 indicates f6i is in subtree
1807          * and exception table is indexed by a hash of
1808          * both fib6_dst and fib6_src.
1809          * However, the src addr used to create the hash
1810          * might not be exactly the passed in saddr which
1811          * is a /128 addr from the flow.
1812          * So we need to use f6i->fib6_src to redo lookup
1813          * if the passed in saddr does not find anything.
1814          * (See the logic in ip6_rt_cache_alloc() on how
1815          * rt->rt6i_src is updated.)
1816          */
1817         if (res->f6i->fib6_src.plen)
1818                 src_key = saddr;
1819 find_ex:
1820 #endif
1821         bucket = fib6_nh_get_excptn_bucket(res->nh, NULL);
1822         rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
1823
1824         if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
1825                 ret = rt6_ex->rt6i;
1826
1827 #ifdef CONFIG_IPV6_SUBTREES
1828         /* Use fib6_src as src_key and redo lookup */
1829         if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) {
1830                 src_key = &res->f6i->fib6_src.addr;
1831                 goto find_ex;
1832         }
1833 #endif
1834
1835         return ret;
1836 }
1837
1838 /* Remove the passed in cached rt from the hash table that contains it */
1839 static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen,
1840                                     const struct rt6_info *rt)
1841 {
1842         const struct in6_addr *src_key = NULL;
1843         struct rt6_exception_bucket *bucket;
1844         struct rt6_exception *rt6_ex;
1845         int err;
1846
1847         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
1848                 return -ENOENT;
1849
1850         spin_lock_bh(&rt6_exception_lock);
1851         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1852
1853 #ifdef CONFIG_IPV6_SUBTREES
1854         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1855          * and exception table is indexed by a hash of
1856          * both rt6i_dst and rt6i_src.
1857          * Otherwise, the exception table is indexed by
1858          * a hash of only rt6i_dst.
1859          */
1860         if (plen)
1861                 src_key = &rt->rt6i_src.addr;
1862 #endif
1863         rt6_ex = __rt6_find_exception_spinlock(&bucket,
1864                                                &rt->rt6i_dst.addr,
1865                                                src_key);
1866         if (rt6_ex) {
1867                 rt6_remove_exception(bucket, rt6_ex);
1868                 err = 0;
1869         } else {
1870                 err = -ENOENT;
1871         }
1872
1873         spin_unlock_bh(&rt6_exception_lock);
1874         return err;
1875 }
1876
1877 struct fib6_nh_excptn_arg {
1878         struct rt6_info *rt;
1879         int             plen;
1880 };
1881
1882 static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg)
1883 {
1884         struct fib6_nh_excptn_arg *arg = _arg;
1885         int err;
1886
1887         err = fib6_nh_remove_exception(nh, arg->plen, arg->rt);
1888         if (err == 0)
1889                 return 1;
1890
1891         return 0;
1892 }
1893
1894 static int rt6_remove_exception_rt(struct rt6_info *rt)
1895 {
1896         struct fib6_info *from;
1897
1898         from = rcu_dereference(rt->from);
1899         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1900                 return -EINVAL;
1901
1902         if (from->nh) {
1903                 struct fib6_nh_excptn_arg arg = {
1904                         .rt = rt,
1905                         .plen = from->fib6_src.plen
1906                 };
1907                 int rc;
1908
1909                 /* rc = 1 means an entry was found */
1910                 rc = nexthop_for_each_fib6_nh(from->nh,
1911                                               rt6_nh_remove_exception_rt,
1912                                               &arg);
1913                 return rc ? 0 : -ENOENT;
1914         }
1915
1916         return fib6_nh_remove_exception(from->fib6_nh,
1917                                         from->fib6_src.plen, rt);
1918 }
1919
1920 /* Find rt6_ex which contains the passed in rt cache and
1921  * refresh its stamp
1922  */
1923 static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen,
1924                                      const struct rt6_info *rt)
1925 {
1926         const struct in6_addr *src_key = NULL;
1927         struct rt6_exception_bucket *bucket;
1928         struct rt6_exception *rt6_ex;
1929
1930         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
1931 #ifdef CONFIG_IPV6_SUBTREES
1932         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1933          * and exception table is indexed by a hash of
1934          * both rt6i_dst and rt6i_src.
1935          * Otherwise, the exception table is indexed by
1936          * a hash of only rt6i_dst.
1937          */
1938         if (plen)
1939                 src_key = &rt->rt6i_src.addr;
1940 #endif
1941         rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
1942         if (rt6_ex)
1943                 rt6_ex->stamp = jiffies;
1944 }
1945
1946 struct fib6_nh_match_arg {
1947         const struct net_device *dev;
1948         const struct in6_addr   *gw;
1949         struct fib6_nh          *match;
1950 };
1951
1952 /* determine if fib6_nh has given device and gateway */
1953 static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg)
1954 {
1955         struct fib6_nh_match_arg *arg = _arg;
1956
1957         if (arg->dev != nh->fib_nh_dev ||
1958             (arg->gw && !nh->fib_nh_gw_family) ||
1959             (!arg->gw && nh->fib_nh_gw_family) ||
1960             (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6)))
1961                 return 0;
1962
1963         arg->match = nh;
1964
1965         /* found a match, break the loop */
1966         return 1;
1967 }
1968
1969 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
1970 {
1971         struct fib6_info *from;
1972         struct fib6_nh *fib6_nh;
1973
1974         rcu_read_lock();
1975
1976         from = rcu_dereference(rt->from);
1977         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1978                 goto unlock;
1979
1980         if (from->nh) {
1981                 struct fib6_nh_match_arg arg = {
1982                         .dev = rt->dst.dev,
1983                         .gw = &rt->rt6i_gateway,
1984                 };
1985
1986                 nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
1987
1988                 if (!arg.match)
1989                         goto unlock;
1990                 fib6_nh = arg.match;
1991         } else {
1992                 fib6_nh = from->fib6_nh;
1993         }
1994         fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt);
1995 unlock:
1996         rcu_read_unlock();
1997 }
1998
1999 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
2000                                          struct rt6_info *rt, int mtu)
2001 {
2002         /* If the new MTU is lower than the route PMTU, this new MTU will be the
2003          * lowest MTU in the path: always allow updating the route PMTU to
2004          * reflect PMTU decreases.
2005          *
2006          * If the new MTU is higher, and the route PMTU is equal to the local
2007          * MTU, this means the old MTU is the lowest in the path, so allow
2008          * updating it: if other nodes now have lower MTUs, PMTU discovery will
2009          * handle this.
2010          */
2011
2012         if (dst_mtu(&rt->dst) >= mtu)
2013                 return true;
2014
2015         if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
2016                 return true;
2017
2018         return false;
2019 }
2020
2021 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
2022                                        const struct fib6_nh *nh, int mtu)
2023 {
2024         struct rt6_exception_bucket *bucket;
2025         struct rt6_exception *rt6_ex;
2026         int i;
2027
2028         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2029         if (!bucket)
2030                 return;
2031
2032         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2033                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
2034                         struct rt6_info *entry = rt6_ex->rt6i;
2035
2036                         /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
2037                          * route), the metrics of its rt->from have already
2038                          * been updated.
2039                          */
2040                         if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
2041                             rt6_mtu_change_route_allowed(idev, entry, mtu))
2042                                 dst_metric_set(&entry->dst, RTAX_MTU, mtu);
2043                 }
2044                 bucket++;
2045         }
2046 }
2047
2048 #define RTF_CACHE_GATEWAY       (RTF_GATEWAY | RTF_CACHE)
2049
2050 static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh,
2051                                             const struct in6_addr *gateway)
2052 {
2053         struct rt6_exception_bucket *bucket;
2054         struct rt6_exception *rt6_ex;
2055         struct hlist_node *tmp;
2056         int i;
2057
2058         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2059                 return;
2060
2061         spin_lock_bh(&rt6_exception_lock);
2062         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2063         if (bucket) {
2064                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2065                         hlist_for_each_entry_safe(rt6_ex, tmp,
2066                                                   &bucket->chain, hlist) {
2067                                 struct rt6_info *entry = rt6_ex->rt6i;
2068
2069                                 if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
2070                                     RTF_CACHE_GATEWAY &&
2071                                     ipv6_addr_equal(gateway,
2072                                                     &entry->rt6i_gateway)) {
2073                                         rt6_remove_exception(bucket, rt6_ex);
2074                                 }
2075                         }
2076                         bucket++;
2077                 }
2078         }
2079
2080         spin_unlock_bh(&rt6_exception_lock);
2081 }
2082
2083 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
2084                                       struct rt6_exception *rt6_ex,
2085                                       struct fib6_gc_args *gc_args,
2086                                       unsigned long now)
2087 {
2088         struct rt6_info *rt = rt6_ex->rt6i;
2089
2090         /* we are pruning and obsoleting aged-out and non gateway exceptions
2091          * even if others have still references to them, so that on next
2092          * dst_check() such references can be dropped.
2093          * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
2094          * expired, independently from their aging, as per RFC 8201 section 4
2095          */
2096         if (!(rt->rt6i_flags & RTF_EXPIRES)) {
2097                 if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
2098                         pr_debug("aging clone %p\n", rt);
2099                         rt6_remove_exception(bucket, rt6_ex);
2100                         return;
2101                 }
2102         } else if (time_after(jiffies, rt->dst.expires)) {
2103                 pr_debug("purging expired route %p\n", rt);
2104                 rt6_remove_exception(bucket, rt6_ex);
2105                 return;
2106         }
2107
2108         if (rt->rt6i_flags & RTF_GATEWAY) {
2109                 struct neighbour *neigh;
2110
2111                 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
2112
2113                 if (!(neigh && (neigh->flags & NTF_ROUTER))) {
2114                         pr_debug("purging route %p via non-router but gateway\n",
2115                                  rt);
2116                         rt6_remove_exception(bucket, rt6_ex);
2117                         return;
2118                 }
2119         }
2120
2121         gc_args->more++;
2122 }
2123
2124 static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
2125                                    struct fib6_gc_args *gc_args,
2126                                    unsigned long now)
2127 {
2128         struct rt6_exception_bucket *bucket;
2129         struct rt6_exception *rt6_ex;
2130         struct hlist_node *tmp;
2131         int i;
2132
2133         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2134                 return;
2135
2136         rcu_read_lock_bh();
2137         spin_lock(&rt6_exception_lock);
2138         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2139         if (bucket) {
2140                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2141                         hlist_for_each_entry_safe(rt6_ex, tmp,
2142                                                   &bucket->chain, hlist) {
2143                                 rt6_age_examine_exception(bucket, rt6_ex,
2144                                                           gc_args, now);
2145                         }
2146                         bucket++;
2147                 }
2148         }
2149         spin_unlock(&rt6_exception_lock);
2150         rcu_read_unlock_bh();
2151 }
2152
2153 struct fib6_nh_age_excptn_arg {
2154         struct fib6_gc_args     *gc_args;
2155         unsigned long           now;
2156 };
2157
2158 static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg)
2159 {
2160         struct fib6_nh_age_excptn_arg *arg = _arg;
2161
2162         fib6_nh_age_exceptions(nh, arg->gc_args, arg->now);
2163         return 0;
2164 }
2165
2166 void rt6_age_exceptions(struct fib6_info *f6i,
2167                         struct fib6_gc_args *gc_args,
2168                         unsigned long now)
2169 {
2170         if (f6i->nh) {
2171                 struct fib6_nh_age_excptn_arg arg = {
2172                         .gc_args = gc_args,
2173                         .now = now
2174                 };
2175
2176                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions,
2177                                          &arg);
2178         } else {
2179                 fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now);
2180         }
2181 }
2182
2183 /* must be called with rcu lock held */
2184 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
2185                       struct flowi6 *fl6, struct fib6_result *res, int strict)
2186 {
2187         struct fib6_node *fn, *saved_fn;
2188
2189         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
2190         saved_fn = fn;
2191
2192 redo_rt6_select:
2193         rt6_select(net, fn, oif, res, strict);
2194         if (res->f6i == net->ipv6.fib6_null_entry) {
2195                 fn = fib6_backtrack(fn, &fl6->saddr);
2196                 if (fn)
2197                         goto redo_rt6_select;
2198                 else if (strict & RT6_LOOKUP_F_REACHABLE) {
2199                         /* also consider unreachable route */
2200                         strict &= ~RT6_LOOKUP_F_REACHABLE;
2201                         fn = saved_fn;
2202                         goto redo_rt6_select;
2203                 }
2204         }
2205
2206         trace_fib6_table_lookup(net, res, table, fl6);
2207
2208         return 0;
2209 }
2210
2211 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
2212                                int oif, struct flowi6 *fl6,
2213                                const struct sk_buff *skb, int flags)
2214 {
2215         struct fib6_result res = {};
2216         struct rt6_info *rt = NULL;
2217         int strict = 0;
2218
2219         WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
2220                      !rcu_read_lock_held());
2221
2222         strict |= flags & RT6_LOOKUP_F_IFACE;
2223         strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
2224         if (READ_ONCE(net->ipv6.devconf_all->forwarding) == 0)
2225                 strict |= RT6_LOOKUP_F_REACHABLE;
2226
2227         rcu_read_lock();
2228
2229         fib6_table_lookup(net, table, oif, fl6, &res, strict);
2230         if (res.f6i == net->ipv6.fib6_null_entry)
2231                 goto out;
2232
2233         fib6_select_path(net, &res, fl6, oif, false, skb, strict);
2234
2235         /*Search through exception table */
2236         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
2237         if (rt) {
2238                 goto out;
2239         } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
2240                             !res.nh->fib_nh_gw_family)) {
2241                 /* Create a RTF_CACHE clone which will not be
2242                  * owned by the fib6 tree.  It is for the special case where
2243                  * the daddr in the skb during the neighbor look-up is different
2244                  * from the fl6->daddr used to look-up route here.
2245                  */
2246                 rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
2247
2248                 if (rt) {
2249                         /* 1 refcnt is taken during ip6_rt_cache_alloc().
2250                          * As rt6_uncached_list_add() does not consume refcnt,
2251                          * this refcnt is always returned to the caller even
2252                          * if caller sets RT6_LOOKUP_F_DST_NOREF flag.
2253                          */
2254                         rt6_uncached_list_add(rt);
2255                         rcu_read_unlock();
2256
2257                         return rt;
2258                 }
2259         } else {
2260                 /* Get a percpu copy */
2261                 local_bh_disable();
2262                 rt = rt6_get_pcpu_route(&res);
2263
2264                 if (!rt)
2265                         rt = rt6_make_pcpu_route(net, &res);
2266
2267                 local_bh_enable();
2268         }
2269 out:
2270         if (!rt)
2271                 rt = net->ipv6.ip6_null_entry;
2272         if (!(flags & RT6_LOOKUP_F_DST_NOREF))
2273                 ip6_hold_safe(net, &rt);
2274         rcu_read_unlock();
2275
2276         return rt;
2277 }
2278 EXPORT_SYMBOL_GPL(ip6_pol_route);
2279
2280 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net,
2281                                             struct fib6_table *table,
2282                                             struct flowi6 *fl6,
2283                                             const struct sk_buff *skb,
2284                                             int flags)
2285 {
2286         return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
2287 }
2288
2289 struct dst_entry *ip6_route_input_lookup(struct net *net,
2290                                          struct net_device *dev,
2291                                          struct flowi6 *fl6,
2292                                          const struct sk_buff *skb,
2293                                          int flags)
2294 {
2295         if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
2296                 flags |= RT6_LOOKUP_F_IFACE;
2297
2298         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
2299 }
2300 EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
2301
2302 static void ip6_multipath_l3_keys(const struct sk_buff *skb,
2303                                   struct flow_keys *keys,
2304                                   struct flow_keys *flkeys)
2305 {
2306         const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
2307         const struct ipv6hdr *key_iph = outer_iph;
2308         struct flow_keys *_flkeys = flkeys;
2309         const struct ipv6hdr *inner_iph;
2310         const struct icmp6hdr *icmph;
2311         struct ipv6hdr _inner_iph;
2312         struct icmp6hdr _icmph;
2313
2314         if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
2315                 goto out;
2316
2317         icmph = skb_header_pointer(skb, skb_transport_offset(skb),
2318                                    sizeof(_icmph), &_icmph);
2319         if (!icmph)
2320                 goto out;
2321
2322         if (!icmpv6_is_err(icmph->icmp6_type))
2323                 goto out;
2324
2325         inner_iph = skb_header_pointer(skb,
2326                                        skb_transport_offset(skb) + sizeof(*icmph),
2327                                        sizeof(_inner_iph), &_inner_iph);
2328         if (!inner_iph)
2329                 goto out;
2330
2331         key_iph = inner_iph;
2332         _flkeys = NULL;
2333 out:
2334         if (_flkeys) {
2335                 keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
2336                 keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
2337                 keys->tags.flow_label = _flkeys->tags.flow_label;
2338                 keys->basic.ip_proto = _flkeys->basic.ip_proto;
2339         } else {
2340                 keys->addrs.v6addrs.src = key_iph->saddr;
2341                 keys->addrs.v6addrs.dst = key_iph->daddr;
2342                 keys->tags.flow_label = ip6_flowlabel(key_iph);
2343                 keys->basic.ip_proto = key_iph->nexthdr;
2344         }
2345 }
2346
2347 static u32 rt6_multipath_custom_hash_outer(const struct net *net,
2348                                            const struct sk_buff *skb,
2349                                            bool *p_has_inner)
2350 {
2351         u32 hash_fields = ip6_multipath_hash_fields(net);
2352         struct flow_keys keys, hash_keys;
2353
2354         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2355                 return 0;
2356
2357         memset(&hash_keys, 0, sizeof(hash_keys));
2358         skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
2359
2360         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2361         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2362                 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2363         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2364                 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2365         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2366                 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2367         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2368                 hash_keys.tags.flow_label = keys.tags.flow_label;
2369         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2370                 hash_keys.ports.src = keys.ports.src;
2371         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2372                 hash_keys.ports.dst = keys.ports.dst;
2373
2374         *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
2375         return flow_hash_from_keys(&hash_keys);
2376 }
2377
2378 static u32 rt6_multipath_custom_hash_inner(const struct net *net,
2379                                            const struct sk_buff *skb,
2380                                            bool has_inner)
2381 {
2382         u32 hash_fields = ip6_multipath_hash_fields(net);
2383         struct flow_keys keys, hash_keys;
2384
2385         /* We assume the packet carries an encapsulation, but if none was
2386          * encountered during dissection of the outer flow, then there is no
2387          * point in calling the flow dissector again.
2388          */
2389         if (!has_inner)
2390                 return 0;
2391
2392         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
2393                 return 0;
2394
2395         memset(&hash_keys, 0, sizeof(hash_keys));
2396         skb_flow_dissect_flow_keys(skb, &keys, 0);
2397
2398         if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
2399                 return 0;
2400
2401         if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2402                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2403                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2404                         hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2405                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2406                         hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2407         } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2408                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2409                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2410                         hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2411                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2412                         hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2413                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
2414                         hash_keys.tags.flow_label = keys.tags.flow_label;
2415         }
2416
2417         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
2418                 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2419         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
2420                 hash_keys.ports.src = keys.ports.src;
2421         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
2422                 hash_keys.ports.dst = keys.ports.dst;
2423
2424         return flow_hash_from_keys(&hash_keys);
2425 }
2426
2427 static u32 rt6_multipath_custom_hash_skb(const struct net *net,
2428                                          const struct sk_buff *skb)
2429 {
2430         u32 mhash, mhash_inner;
2431         bool has_inner = true;
2432
2433         mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner);
2434         mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner);
2435
2436         return jhash_2words(mhash, mhash_inner, 0);
2437 }
2438
2439 static u32 rt6_multipath_custom_hash_fl6(const struct net *net,
2440                                          const struct flowi6 *fl6)
2441 {
2442         u32 hash_fields = ip6_multipath_hash_fields(net);
2443         struct flow_keys hash_keys;
2444
2445         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2446                 return 0;
2447
2448         memset(&hash_keys, 0, sizeof(hash_keys));
2449         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2450         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2451                 hash_keys.addrs.v6addrs.src = fl6->saddr;
2452         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2453                 hash_keys.addrs.v6addrs.dst = fl6->daddr;
2454         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2455                 hash_keys.basic.ip_proto = fl6->flowi6_proto;
2456         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2457                 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2458         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2459                 hash_keys.ports.src = fl6->fl6_sport;
2460         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2461                 hash_keys.ports.dst = fl6->fl6_dport;
2462
2463         return flow_hash_from_keys(&hash_keys);
2464 }
2465
2466 /* if skb is set it will be used and fl6 can be NULL */
2467 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
2468                        const struct sk_buff *skb, struct flow_keys *flkeys)
2469 {
2470         struct flow_keys hash_keys;
2471         u32 mhash = 0;
2472
2473         switch (ip6_multipath_hash_policy(net)) {
2474         case 0:
2475                 memset(&hash_keys, 0, sizeof(hash_keys));
2476                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2477                 if (skb) {
2478                         ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2479                 } else {
2480                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2481                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2482                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2483                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2484                 }
2485                 mhash = flow_hash_from_keys(&hash_keys);
2486                 break;
2487         case 1:
2488                 if (skb) {
2489                         unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2490                         struct flow_keys keys;
2491
2492                         /* short-circuit if we already have L4 hash present */
2493                         if (skb->l4_hash)
2494                                 return skb_get_hash_raw(skb) >> 1;
2495
2496                         memset(&hash_keys, 0, sizeof(hash_keys));
2497
2498                         if (!flkeys) {
2499                                 skb_flow_dissect_flow_keys(skb, &keys, flag);
2500                                 flkeys = &keys;
2501                         }
2502                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2503                         hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2504                         hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2505                         hash_keys.ports.src = flkeys->ports.src;
2506                         hash_keys.ports.dst = flkeys->ports.dst;
2507                         hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2508                 } else {
2509                         memset(&hash_keys, 0, sizeof(hash_keys));
2510                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2511                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2512                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2513                         hash_keys.ports.src = fl6->fl6_sport;
2514                         hash_keys.ports.dst = fl6->fl6_dport;
2515                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2516                 }
2517                 mhash = flow_hash_from_keys(&hash_keys);
2518                 break;
2519         case 2:
2520                 memset(&hash_keys, 0, sizeof(hash_keys));
2521                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2522                 if (skb) {
2523                         struct flow_keys keys;
2524
2525                         if (!flkeys) {
2526                                 skb_flow_dissect_flow_keys(skb, &keys, 0);
2527                                 flkeys = &keys;
2528                         }
2529
2530                         /* Inner can be v4 or v6 */
2531                         if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2532                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2533                                 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2534                                 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2535                         } else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2536                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2537                                 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2538                                 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2539                                 hash_keys.tags.flow_label = flkeys->tags.flow_label;
2540                                 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2541                         } else {
2542                                 /* Same as case 0 */
2543                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2544                                 ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2545                         }
2546                 } else {
2547                         /* Same as case 0 */
2548                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2549                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2550                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2551                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2552                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2553                 }
2554                 mhash = flow_hash_from_keys(&hash_keys);
2555                 break;
2556         case 3:
2557                 if (skb)
2558                         mhash = rt6_multipath_custom_hash_skb(net, skb);
2559                 else
2560                         mhash = rt6_multipath_custom_hash_fl6(net, fl6);
2561                 break;
2562         }
2563
2564         return mhash >> 1;
2565 }
2566
2567 /* Called with rcu held */
2568 void ip6_route_input(struct sk_buff *skb)
2569 {
2570         const struct ipv6hdr *iph = ipv6_hdr(skb);
2571         struct net *net = dev_net(skb->dev);
2572         int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF;
2573         struct ip_tunnel_info *tun_info;
2574         struct flowi6 fl6 = {
2575                 .flowi6_iif = skb->dev->ifindex,
2576                 .daddr = iph->daddr,
2577                 .saddr = iph->saddr,
2578                 .flowlabel = ip6_flowinfo(iph),
2579                 .flowi6_mark = skb->mark,
2580                 .flowi6_proto = iph->nexthdr,
2581         };
2582         struct flow_keys *flkeys = NULL, _flkeys;
2583
2584         tun_info = skb_tunnel_info(skb);
2585         if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2586                 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
2587
2588         if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
2589                 flkeys = &_flkeys;
2590
2591         if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
2592                 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
2593         skb_dst_drop(skb);
2594         skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev,
2595                                                       &fl6, skb, flags));
2596 }
2597
2598 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net,
2599                                              struct fib6_table *table,
2600                                              struct flowi6 *fl6,
2601                                              const struct sk_buff *skb,
2602                                              int flags)
2603 {
2604         return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
2605 }
2606
2607 static struct dst_entry *ip6_route_output_flags_noref(struct net *net,
2608                                                       const struct sock *sk,
2609                                                       struct flowi6 *fl6,
2610                                                       int flags)
2611 {
2612         bool any_src;
2613
2614         if (ipv6_addr_type(&fl6->daddr) &
2615             (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
2616                 struct dst_entry *dst;
2617
2618                 /* This function does not take refcnt on the dst */
2619                 dst = l3mdev_link_scope_lookup(net, fl6);
2620                 if (dst)
2621                         return dst;
2622         }
2623
2624         fl6->flowi6_iif = LOOPBACK_IFINDEX;
2625
2626         flags |= RT6_LOOKUP_F_DST_NOREF;
2627         any_src = ipv6_addr_any(&fl6->saddr);
2628         if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
2629             (fl6->flowi6_oif && any_src))
2630                 flags |= RT6_LOOKUP_F_IFACE;
2631
2632         if (!any_src)
2633                 flags |= RT6_LOOKUP_F_HAS_SADDR;
2634         else if (sk)
2635                 flags |= rt6_srcprefs2flags(READ_ONCE(inet6_sk(sk)->srcprefs));
2636
2637         return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
2638 }
2639
2640 struct dst_entry *ip6_route_output_flags(struct net *net,
2641                                          const struct sock *sk,
2642                                          struct flowi6 *fl6,
2643                                          int flags)
2644 {
2645         struct dst_entry *dst;
2646         struct rt6_info *rt6;
2647
2648         rcu_read_lock();
2649         dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
2650         rt6 = (struct rt6_info *)dst;
2651         /* For dst cached in uncached_list, refcnt is already taken. */
2652         if (list_empty(&rt6->dst.rt_uncached) && !dst_hold_safe(dst)) {
2653                 dst = &net->ipv6.ip6_null_entry->dst;
2654                 dst_hold(dst);
2655         }
2656         rcu_read_unlock();
2657
2658         return dst;
2659 }
2660 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
2661
2662 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2663 {
2664         struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
2665         struct net_device *loopback_dev = net->loopback_dev;
2666         struct dst_entry *new = NULL;
2667
2668         rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev,
2669                        DST_OBSOLETE_DEAD, 0);
2670         if (rt) {
2671                 rt6_info_init(rt);
2672                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
2673
2674                 new = &rt->dst;
2675                 new->__use = 1;
2676                 new->input = dst_discard;
2677                 new->output = dst_discard_out;
2678
2679                 dst_copy_metrics(new, &ort->dst);
2680
2681                 rt->rt6i_idev = in6_dev_get(loopback_dev);
2682                 rt->rt6i_gateway = ort->rt6i_gateway;
2683                 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
2684
2685                 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
2686 #ifdef CONFIG_IPV6_SUBTREES
2687                 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
2688 #endif
2689         }
2690
2691         dst_release(dst_orig);
2692         return new ? new : ERR_PTR(-ENOMEM);
2693 }
2694
2695 /*
2696  *      Destination cache support functions
2697  */
2698
2699 static bool fib6_check(struct fib6_info *f6i, u32 cookie)
2700 {
2701         u32 rt_cookie = 0;
2702
2703         if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
2704                 return false;
2705
2706         if (fib6_check_expired(f6i))
2707                 return false;
2708
2709         return true;
2710 }
2711
2712 static struct dst_entry *rt6_check(struct rt6_info *rt,
2713                                    struct fib6_info *from,
2714                                    u32 cookie)
2715 {
2716         u32 rt_cookie = 0;
2717
2718         if (!from || !fib6_get_cookie_safe(from, &rt_cookie) ||
2719             rt_cookie != cookie)
2720                 return NULL;
2721
2722         if (rt6_check_expired(rt))
2723                 return NULL;
2724
2725         return &rt->dst;
2726 }
2727
2728 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
2729                                             struct fib6_info *from,
2730                                             u32 cookie)
2731 {
2732         if (!__rt6_check_expired(rt) &&
2733             rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
2734             fib6_check(from, cookie))
2735                 return &rt->dst;
2736         else
2737                 return NULL;
2738 }
2739
2740 INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst,
2741                                                         u32 cookie)
2742 {
2743         struct dst_entry *dst_ret;
2744         struct fib6_info *from;
2745         struct rt6_info *rt;
2746
2747         rt = container_of(dst, struct rt6_info, dst);
2748
2749         if (rt->sernum)
2750                 return rt6_is_valid(rt) ? dst : NULL;
2751
2752         rcu_read_lock();
2753
2754         /* All IPV6 dsts are created with ->obsolete set to the value
2755          * DST_OBSOLETE_FORCE_CHK which forces validation calls down
2756          * into this function always.
2757          */
2758
2759         from = rcu_dereference(rt->from);
2760
2761         if (from && (rt->rt6i_flags & RTF_PCPU ||
2762             unlikely(!list_empty(&rt->dst.rt_uncached))))
2763                 dst_ret = rt6_dst_from_check(rt, from, cookie);
2764         else
2765                 dst_ret = rt6_check(rt, from, cookie);
2766
2767         rcu_read_unlock();
2768
2769         return dst_ret;
2770 }
2771 EXPORT_INDIRECT_CALLABLE(ip6_dst_check);
2772
2773 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
2774 {
2775         struct rt6_info *rt = (struct rt6_info *) dst;
2776
2777         if (rt) {
2778                 if (rt->rt6i_flags & RTF_CACHE) {
2779                         rcu_read_lock();
2780                         if (rt6_check_expired(rt)) {
2781                                 rt6_remove_exception_rt(rt);
2782                                 dst = NULL;
2783                         }
2784                         rcu_read_unlock();
2785                 } else {
2786                         dst_release(dst);
2787                         dst = NULL;
2788                 }
2789         }
2790         return dst;
2791 }
2792
2793 static void ip6_link_failure(struct sk_buff *skb)
2794 {
2795         struct rt6_info *rt;
2796
2797         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
2798
2799         rt = (struct rt6_info *) skb_dst(skb);
2800         if (rt) {
2801                 rcu_read_lock();
2802                 if (rt->rt6i_flags & RTF_CACHE) {
2803                         rt6_remove_exception_rt(rt);
2804                 } else {
2805                         struct fib6_info *from;
2806                         struct fib6_node *fn;
2807
2808                         from = rcu_dereference(rt->from);
2809                         if (from) {
2810                                 fn = rcu_dereference(from->fib6_node);
2811                                 if (fn && (rt->rt6i_flags & RTF_DEFAULT))
2812                                         WRITE_ONCE(fn->fn_sernum, -1);
2813                         }
2814                 }
2815                 rcu_read_unlock();
2816         }
2817 }
2818
2819 static void rt6_update_expires(struct rt6_info *rt0, int timeout)
2820 {
2821         if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
2822                 struct fib6_info *from;
2823
2824                 rcu_read_lock();
2825                 from = rcu_dereference(rt0->from);
2826                 if (from)
2827                         rt0->dst.expires = from->expires;
2828                 rcu_read_unlock();
2829         }
2830
2831         dst_set_expires(&rt0->dst, timeout);
2832         rt0->rt6i_flags |= RTF_EXPIRES;
2833 }
2834
2835 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
2836 {
2837         struct net *net = dev_net(rt->dst.dev);
2838
2839         dst_metric_set(&rt->dst, RTAX_MTU, mtu);
2840         rt->rt6i_flags |= RTF_MODIFIED;
2841         rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
2842 }
2843
2844 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
2845 {
2846         return !(rt->rt6i_flags & RTF_CACHE) &&
2847                 (rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
2848 }
2849
2850 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
2851                                  const struct ipv6hdr *iph, u32 mtu,
2852                                  bool confirm_neigh)
2853 {
2854         const struct in6_addr *daddr, *saddr;
2855         struct rt6_info *rt6 = (struct rt6_info *)dst;
2856
2857         /* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU)
2858          * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it.
2859          * [see also comment in rt6_mtu_change_route()]
2860          */
2861
2862         if (iph) {
2863                 daddr = &iph->daddr;
2864                 saddr = &iph->saddr;
2865         } else if (sk) {
2866                 daddr = &sk->sk_v6_daddr;
2867                 saddr = &inet6_sk(sk)->saddr;
2868         } else {
2869                 daddr = NULL;
2870                 saddr = NULL;
2871         }
2872
2873         if (confirm_neigh)
2874                 dst_confirm_neigh(dst, daddr);
2875
2876         if (mtu < IPV6_MIN_MTU)
2877                 return;
2878         if (mtu >= dst_mtu(dst))
2879                 return;
2880
2881         if (!rt6_cache_allowed_for_pmtu(rt6)) {
2882                 rt6_do_update_pmtu(rt6, mtu);
2883                 /* update rt6_ex->stamp for cache */
2884                 if (rt6->rt6i_flags & RTF_CACHE)
2885                         rt6_update_exception_stamp_rt(rt6);
2886         } else if (daddr) {
2887                 struct fib6_result res = {};
2888                 struct rt6_info *nrt6;
2889
2890                 rcu_read_lock();
2891                 res.f6i = rcu_dereference(rt6->from);
2892                 if (!res.f6i)
2893                         goto out_unlock;
2894
2895                 res.fib6_flags = res.f6i->fib6_flags;
2896                 res.fib6_type = res.f6i->fib6_type;
2897
2898                 if (res.f6i->nh) {
2899                         struct fib6_nh_match_arg arg = {
2900                                 .dev = dst->dev,
2901                                 .gw = &rt6->rt6i_gateway,
2902                         };
2903
2904                         nexthop_for_each_fib6_nh(res.f6i->nh,
2905                                                  fib6_nh_find_match, &arg);
2906
2907                         /* fib6_info uses a nexthop that does not have fib6_nh
2908                          * using the dst->dev + gw. Should be impossible.
2909                          */
2910                         if (!arg.match)
2911                                 goto out_unlock;
2912
2913                         res.nh = arg.match;
2914                 } else {
2915                         res.nh = res.f6i->fib6_nh;
2916                 }
2917
2918                 nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
2919                 if (nrt6) {
2920                         rt6_do_update_pmtu(nrt6, mtu);
2921                         if (rt6_insert_exception(nrt6, &res))
2922                                 dst_release_immediate(&nrt6->dst);
2923                 }
2924 out_unlock:
2925                 rcu_read_unlock();
2926         }
2927 }
2928
2929 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
2930                                struct sk_buff *skb, u32 mtu,
2931                                bool confirm_neigh)
2932 {
2933         __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu,
2934                              confirm_neigh);
2935 }
2936
2937 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
2938                      int oif, u32 mark, kuid_t uid)
2939 {
2940         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2941         struct dst_entry *dst;
2942         struct flowi6 fl6 = {
2943                 .flowi6_oif = oif,
2944                 .flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
2945                 .daddr = iph->daddr,
2946                 .saddr = iph->saddr,
2947                 .flowlabel = ip6_flowinfo(iph),
2948                 .flowi6_uid = uid,
2949         };
2950
2951         dst = ip6_route_output(net, NULL, &fl6);
2952         if (!dst->error)
2953                 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true);
2954         dst_release(dst);
2955 }
2956 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
2957
2958 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
2959 {
2960         int oif = sk->sk_bound_dev_if;
2961         struct dst_entry *dst;
2962
2963         if (!oif && skb->dev)
2964                 oif = l3mdev_master_ifindex(skb->dev);
2965
2966         ip6_update_pmtu(skb, sock_net(sk), mtu, oif, READ_ONCE(sk->sk_mark),
2967                         sk->sk_uid);
2968
2969         dst = __sk_dst_get(sk);
2970         if (!dst || !dst->obsolete ||
2971             dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
2972                 return;
2973
2974         bh_lock_sock(sk);
2975         if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
2976                 ip6_datagram_dst_update(sk, false);
2977         bh_unlock_sock(sk);
2978 }
2979 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
2980
2981 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
2982                            const struct flowi6 *fl6)
2983 {
2984 #ifdef CONFIG_IPV6_SUBTREES
2985         struct ipv6_pinfo *np = inet6_sk(sk);
2986 #endif
2987
2988         ip6_dst_store(sk, dst,
2989                       ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
2990                       &sk->sk_v6_daddr : NULL,
2991 #ifdef CONFIG_IPV6_SUBTREES
2992                       ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
2993                       &np->saddr :
2994 #endif
2995                       NULL);
2996 }
2997
2998 static bool ip6_redirect_nh_match(const struct fib6_result *res,
2999                                   struct flowi6 *fl6,
3000                                   const struct in6_addr *gw,
3001                                   struct rt6_info **ret)
3002 {
3003         const struct fib6_nh *nh = res->nh;
3004
3005         if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family ||
3006             fl6->flowi6_oif != nh->fib_nh_dev->ifindex)
3007                 return false;
3008
3009         /* rt_cache's gateway might be different from its 'parent'
3010          * in the case of an ip redirect.
3011          * So we keep searching in the exception table if the gateway
3012          * is different.
3013          */
3014         if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) {
3015                 struct rt6_info *rt_cache;
3016
3017                 rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr);
3018                 if (rt_cache &&
3019                     ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) {
3020                         *ret = rt_cache;
3021                         return true;
3022                 }
3023                 return false;
3024         }
3025         return true;
3026 }
3027
3028 struct fib6_nh_rd_arg {
3029         struct fib6_result      *res;
3030         struct flowi6           *fl6;
3031         const struct in6_addr   *gw;
3032         struct rt6_info         **ret;
3033 };
3034
3035 static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg)
3036 {
3037         struct fib6_nh_rd_arg *arg = _arg;
3038
3039         arg->res->nh = nh;
3040         return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret);
3041 }
3042
3043 /* Handle redirects */
3044 struct ip6rd_flowi {
3045         struct flowi6 fl6;
3046         struct in6_addr gateway;
3047 };
3048
3049 INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net,
3050                                              struct fib6_table *table,
3051                                              struct flowi6 *fl6,
3052                                              const struct sk_buff *skb,
3053                                              int flags)
3054 {
3055         struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
3056         struct rt6_info *ret = NULL;
3057         struct fib6_result res = {};
3058         struct fib6_nh_rd_arg arg = {
3059                 .res = &res,
3060                 .fl6 = fl6,
3061                 .gw  = &rdfl->gateway,
3062                 .ret = &ret
3063         };
3064         struct fib6_info *rt;
3065         struct fib6_node *fn;
3066
3067         /* Get the "current" route for this destination and
3068          * check if the redirect has come from appropriate router.
3069          *
3070          * RFC 4861 specifies that redirects should only be
3071          * accepted if they come from the nexthop to the target.
3072          * Due to the way the routes are chosen, this notion
3073          * is a bit fuzzy and one might need to check all possible
3074          * routes.
3075          */
3076
3077         rcu_read_lock();
3078         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
3079 restart:
3080         for_each_fib6_node_rt_rcu(fn) {
3081                 res.f6i = rt;
3082                 if (fib6_check_expired(rt))
3083                         continue;
3084                 if (rt->fib6_flags & RTF_REJECT)
3085                         break;
3086                 if (unlikely(rt->nh)) {
3087                         if (nexthop_is_blackhole(rt->nh))
3088                                 continue;
3089                         /* on match, res->nh is filled in and potentially ret */
3090                         if (nexthop_for_each_fib6_nh(rt->nh,
3091                                                      fib6_nh_redirect_match,
3092                                                      &arg))
3093                                 goto out;
3094                 } else {
3095                         res.nh = rt->fib6_nh;
3096                         if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway,
3097                                                   &ret))
3098                                 goto out;
3099                 }
3100         }
3101
3102         if (!rt)
3103                 rt = net->ipv6.fib6_null_entry;
3104         else if (rt->fib6_flags & RTF_REJECT) {
3105                 ret = net->ipv6.ip6_null_entry;
3106                 goto out;
3107         }
3108
3109         if (rt == net->ipv6.fib6_null_entry) {
3110                 fn = fib6_backtrack(fn, &fl6->saddr);
3111                 if (fn)
3112                         goto restart;
3113         }
3114
3115         res.f6i = rt;
3116         res.nh = rt->fib6_nh;
3117 out:
3118         if (ret) {
3119                 ip6_hold_safe(net, &ret);
3120         } else {
3121                 res.fib6_flags = res.f6i->fib6_flags;
3122                 res.fib6_type = res.f6i->fib6_type;
3123                 ret = ip6_create_rt_rcu(&res);
3124         }
3125
3126         rcu_read_unlock();
3127
3128         trace_fib6_table_lookup(net, &res, table, fl6);
3129         return ret;
3130 };
3131
3132 static struct dst_entry *ip6_route_redirect(struct net *net,
3133                                             const struct flowi6 *fl6,
3134                                             const struct sk_buff *skb,
3135                                             const struct in6_addr *gateway)
3136 {
3137         int flags = RT6_LOOKUP_F_HAS_SADDR;
3138         struct ip6rd_flowi rdfl;
3139
3140         rdfl.fl6 = *fl6;
3141         rdfl.gateway = *gateway;
3142
3143         return fib6_rule_lookup(net, &rdfl.fl6, skb,
3144                                 flags, __ip6_route_redirect);
3145 }
3146
3147 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
3148                   kuid_t uid)
3149 {
3150         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
3151         struct dst_entry *dst;
3152         struct flowi6 fl6 = {
3153                 .flowi6_iif = LOOPBACK_IFINDEX,
3154                 .flowi6_oif = oif,
3155                 .flowi6_mark = mark,
3156                 .daddr = iph->daddr,
3157                 .saddr = iph->saddr,
3158                 .flowlabel = ip6_flowinfo(iph),
3159                 .flowi6_uid = uid,
3160         };
3161
3162         dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
3163         rt6_do_redirect(dst, NULL, skb);
3164         dst_release(dst);
3165 }
3166 EXPORT_SYMBOL_GPL(ip6_redirect);
3167
3168 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
3169 {
3170         const struct ipv6hdr *iph = ipv6_hdr(skb);
3171         const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
3172         struct dst_entry *dst;
3173         struct flowi6 fl6 = {
3174                 .flowi6_iif = LOOPBACK_IFINDEX,
3175                 .flowi6_oif = oif,
3176                 .daddr = msg->dest,
3177                 .saddr = iph->daddr,
3178                 .flowi6_uid = sock_net_uid(net, NULL),
3179         };
3180
3181         dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
3182         rt6_do_redirect(dst, NULL, skb);
3183         dst_release(dst);
3184 }
3185
3186 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
3187 {
3188         ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if,
3189                      READ_ONCE(sk->sk_mark), sk->sk_uid);
3190 }
3191 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
3192
3193 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
3194 {
3195         struct net_device *dev = dst->dev;
3196         unsigned int mtu = dst_mtu(dst);
3197         struct net *net = dev_net(dev);
3198
3199         mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
3200
3201         if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
3202                 mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
3203
3204         /*
3205          * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
3206          * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
3207          * IPV6_MAXPLEN is also valid and means: "any MSS,
3208          * rely only on pmtu discovery"
3209          */
3210         if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
3211                 mtu = IPV6_MAXPLEN;
3212         return mtu;
3213 }
3214
3215 INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst)
3216 {
3217         return ip6_dst_mtu_maybe_forward(dst, false);
3218 }
3219 EXPORT_INDIRECT_CALLABLE(ip6_mtu);
3220
3221 /* MTU selection:
3222  * 1. mtu on route is locked - use it
3223  * 2. mtu from nexthop exception
3224  * 3. mtu from egress device
3225  *
3226  * based on ip6_dst_mtu_forward and exception logic of
3227  * rt6_find_cached_rt; called with rcu_read_lock
3228  */
3229 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
3230                       const struct in6_addr *daddr,
3231                       const struct in6_addr *saddr)
3232 {
3233         const struct fib6_nh *nh = res->nh;
3234         struct fib6_info *f6i = res->f6i;
3235         struct inet6_dev *idev;
3236         struct rt6_info *rt;
3237         u32 mtu = 0;
3238
3239         if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
3240                 mtu = f6i->fib6_pmtu;
3241                 if (mtu)
3242                         goto out;
3243         }
3244
3245         rt = rt6_find_cached_rt(res, daddr, saddr);
3246         if (unlikely(rt)) {
3247                 mtu = dst_metric_raw(&rt->dst, RTAX_MTU);
3248         } else {
3249                 struct net_device *dev = nh->fib_nh_dev;
3250
3251                 mtu = IPV6_MIN_MTU;
3252                 idev = __in6_dev_get(dev);
3253                 if (idev)
3254                         mtu = max_t(u32, mtu, READ_ONCE(idev->cnf.mtu6));
3255         }
3256
3257         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
3258 out:
3259         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
3260 }
3261
3262 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
3263                                   struct flowi6 *fl6)
3264 {
3265         struct dst_entry *dst;
3266         struct rt6_info *rt;
3267         struct inet6_dev *idev = in6_dev_get(dev);
3268         struct net *net = dev_net(dev);
3269
3270         if (unlikely(!idev))
3271                 return ERR_PTR(-ENODEV);
3272
3273         rt = ip6_dst_alloc(net, dev, 0);
3274         if (unlikely(!rt)) {
3275                 in6_dev_put(idev);
3276                 dst = ERR_PTR(-ENOMEM);
3277                 goto out;
3278         }
3279
3280         rt->dst.input = ip6_input;
3281         rt->dst.output  = ip6_output;
3282         rt->rt6i_gateway  = fl6->daddr;
3283         rt->rt6i_dst.addr = fl6->daddr;
3284         rt->rt6i_dst.plen = 128;
3285         rt->rt6i_idev     = idev;
3286         dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
3287
3288         /* Add this dst into uncached_list so that rt6_disable_ip() can
3289          * do proper release of the net_device
3290          */
3291         rt6_uncached_list_add(rt);
3292
3293         dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
3294
3295 out:
3296         return dst;
3297 }
3298
3299 static void ip6_dst_gc(struct dst_ops *ops)
3300 {
3301         struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
3302         int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
3303         int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
3304         int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
3305         unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
3306         unsigned int val;
3307         int entries;
3308
3309         if (time_after(rt_last_gc + rt_min_interval, jiffies))
3310                 goto out;
3311
3312         fib6_run_gc(atomic_inc_return(&net->ipv6.ip6_rt_gc_expire), net, true);
3313         entries = dst_entries_get_slow(ops);
3314         if (entries < ops->gc_thresh)
3315                 atomic_set(&net->ipv6.ip6_rt_gc_expire, rt_gc_timeout >> 1);
3316 out:
3317         val = atomic_read(&net->ipv6.ip6_rt_gc_expire);
3318         atomic_set(&net->ipv6.ip6_rt_gc_expire, val - (val >> rt_elasticity));
3319 }
3320
3321 static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
3322                                const struct in6_addr *gw_addr, u32 tbid,
3323                                int flags, struct fib6_result *res)
3324 {
3325         struct flowi6 fl6 = {
3326                 .flowi6_oif = cfg->fc_ifindex,
3327                 .daddr = *gw_addr,
3328                 .saddr = cfg->fc_prefsrc,
3329         };
3330         struct fib6_table *table;
3331         int err;
3332
3333         table = fib6_get_table(net, tbid);
3334         if (!table)
3335                 return -EINVAL;
3336
3337         if (!ipv6_addr_any(&cfg->fc_prefsrc))
3338                 flags |= RT6_LOOKUP_F_HAS_SADDR;
3339
3340         flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
3341
3342         err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags);
3343         if (!err && res->f6i != net->ipv6.fib6_null_entry)
3344                 fib6_select_path(net, res, &fl6, cfg->fc_ifindex,
3345                                  cfg->fc_ifindex != 0, NULL, flags);
3346
3347         return err;
3348 }
3349
3350 static int ip6_route_check_nh_onlink(struct net *net,
3351                                      struct fib6_config *cfg,
3352                                      const struct net_device *dev,
3353                                      struct netlink_ext_ack *extack)
3354 {
3355         u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
3356         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3357         struct fib6_result res = {};
3358         int err;
3359
3360         err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res);
3361         if (!err && !(res.fib6_flags & RTF_REJECT) &&
3362             /* ignore match if it is the default route */
3363             !ipv6_addr_any(&res.f6i->fib6_dst.addr) &&
3364             (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) {
3365                 NL_SET_ERR_MSG(extack,
3366                                "Nexthop has invalid gateway or device mismatch");
3367                 err = -EINVAL;
3368         }
3369
3370         return err;
3371 }
3372
3373 static int ip6_route_check_nh(struct net *net,
3374                               struct fib6_config *cfg,
3375                               struct net_device **_dev,
3376                               netdevice_tracker *dev_tracker,
3377                               struct inet6_dev **idev)
3378 {
3379         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3380         struct net_device *dev = _dev ? *_dev : NULL;
3381         int flags = RT6_LOOKUP_F_IFACE;
3382         struct fib6_result res = {};
3383         int err = -EHOSTUNREACH;
3384
3385         if (cfg->fc_table) {
3386                 err = ip6_nh_lookup_table(net, cfg, gw_addr,
3387                                           cfg->fc_table, flags, &res);
3388                 /* gw_addr can not require a gateway or resolve to a reject
3389                  * route. If a device is given, it must match the result.
3390                  */
3391                 if (err || res.fib6_flags & RTF_REJECT ||
3392                     res.nh->fib_nh_gw_family ||
3393                     (dev && dev != res.nh->fib_nh_dev))
3394                         err = -EHOSTUNREACH;
3395         }
3396
3397         if (err < 0) {
3398                 struct flowi6 fl6 = {
3399                         .flowi6_oif = cfg->fc_ifindex,
3400                         .daddr = *gw_addr,
3401                 };
3402
3403                 err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags);
3404                 if (err || res.fib6_flags & RTF_REJECT ||
3405                     res.nh->fib_nh_gw_family)
3406                         err = -EHOSTUNREACH;
3407
3408                 if (err)
3409                         return err;
3410
3411                 fib6_select_path(net, &res, &fl6, cfg->fc_ifindex,
3412                                  cfg->fc_ifindex != 0, NULL, flags);
3413         }
3414
3415         err = 0;
3416         if (dev) {
3417                 if (dev != res.nh->fib_nh_dev)
3418                         err = -EHOSTUNREACH;
3419         } else {
3420                 *_dev = dev = res.nh->fib_nh_dev;
3421                 netdev_hold(dev, dev_tracker, GFP_ATOMIC);
3422                 *idev = in6_dev_get(dev);
3423         }
3424
3425         return err;
3426 }
3427
3428 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
3429                            struct net_device **_dev,
3430                            netdevice_tracker *dev_tracker,
3431                            struct inet6_dev **idev,
3432                            struct netlink_ext_ack *extack)
3433 {
3434         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3435         int gwa_type = ipv6_addr_type(gw_addr);
3436         bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
3437         const struct net_device *dev = *_dev;
3438         bool need_addr_check = !dev;
3439         int err = -EINVAL;
3440
3441         /* if gw_addr is local we will fail to detect this in case
3442          * address is still TENTATIVE (DAD in progress). rt6_lookup()
3443          * will return already-added prefix route via interface that
3444          * prefix route was assigned to, which might be non-loopback.
3445          */
3446         if (dev &&
3447             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3448                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3449                 goto out;
3450         }
3451
3452         if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
3453                 /* IPv6 strictly inhibits using not link-local
3454                  * addresses as nexthop address.
3455                  * Otherwise, router will not able to send redirects.
3456                  * It is very good, but in some (rare!) circumstances
3457                  * (SIT, PtP, NBMA NOARP links) it is handy to allow
3458                  * some exceptions. --ANK
3459                  * We allow IPv4-mapped nexthops to support RFC4798-type
3460                  * addressing
3461                  */
3462                 if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
3463                         NL_SET_ERR_MSG(extack, "Invalid gateway address");
3464                         goto out;
3465                 }
3466
3467                 rcu_read_lock();
3468
3469                 if (cfg->fc_flags & RTNH_F_ONLINK)
3470                         err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
3471                 else
3472                         err = ip6_route_check_nh(net, cfg, _dev, dev_tracker,
3473                                                  idev);
3474
3475                 rcu_read_unlock();
3476
3477                 if (err)
3478                         goto out;
3479         }
3480
3481         /* reload in case device was changed */
3482         dev = *_dev;
3483
3484         err = -EINVAL;
3485         if (!dev) {
3486                 NL_SET_ERR_MSG(extack, "Egress device not specified");
3487                 goto out;
3488         } else if (dev->flags & IFF_LOOPBACK) {
3489                 NL_SET_ERR_MSG(extack,
3490                                "Egress device can not be loopback device for this route");
3491                 goto out;
3492         }
3493
3494         /* if we did not check gw_addr above, do so now that the
3495          * egress device has been resolved.
3496          */
3497         if (need_addr_check &&
3498             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3499                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3500                 goto out;
3501         }
3502
3503         err = 0;
3504 out:
3505         return err;
3506 }
3507
3508 static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
3509 {
3510         if ((flags & RTF_REJECT) ||
3511             (dev && (dev->flags & IFF_LOOPBACK) &&
3512              !(addr_type & IPV6_ADDR_LOOPBACK) &&
3513              !(flags & (RTF_ANYCAST | RTF_LOCAL))))
3514                 return true;
3515
3516         return false;
3517 }
3518
3519 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
3520                  struct fib6_config *cfg, gfp_t gfp_flags,
3521                  struct netlink_ext_ack *extack)
3522 {
3523         netdevice_tracker *dev_tracker = &fib6_nh->fib_nh_dev_tracker;
3524         struct net_device *dev = NULL;
3525         struct inet6_dev *idev = NULL;
3526         int addr_type;
3527         int err;
3528
3529         fib6_nh->fib_nh_family = AF_INET6;
3530 #ifdef CONFIG_IPV6_ROUTER_PREF
3531         fib6_nh->last_probe = jiffies;
3532 #endif
3533         if (cfg->fc_is_fdb) {
3534                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3535                 fib6_nh->fib_nh_gw_family = AF_INET6;
3536                 return 0;
3537         }
3538
3539         err = -ENODEV;
3540         if (cfg->fc_ifindex) {
3541                 dev = netdev_get_by_index(net, cfg->fc_ifindex,
3542                                           dev_tracker, gfp_flags);
3543                 if (!dev)
3544                         goto out;
3545                 idev = in6_dev_get(dev);
3546                 if (!idev)
3547                         goto out;
3548         }
3549
3550         if (cfg->fc_flags & RTNH_F_ONLINK) {
3551                 if (!dev) {
3552                         NL_SET_ERR_MSG(extack,
3553                                        "Nexthop device required for onlink");
3554                         goto out;
3555                 }
3556
3557                 if (!(dev->flags & IFF_UP)) {
3558                         NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3559                         err = -ENETDOWN;
3560                         goto out;
3561                 }
3562
3563                 fib6_nh->fib_nh_flags |= RTNH_F_ONLINK;
3564         }
3565
3566         fib6_nh->fib_nh_weight = 1;
3567
3568         /* We cannot add true routes via loopback here,
3569          * they would result in kernel looping; promote them to reject routes
3570          */
3571         addr_type = ipv6_addr_type(&cfg->fc_dst);
3572         if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) {
3573                 /* hold loopback dev/idev if we haven't done so. */
3574                 if (dev != net->loopback_dev) {
3575                         if (dev) {
3576                                 netdev_put(dev, dev_tracker);
3577                                 in6_dev_put(idev);
3578                         }
3579                         dev = net->loopback_dev;
3580                         netdev_hold(dev, dev_tracker, gfp_flags);
3581                         idev = in6_dev_get(dev);
3582                         if (!idev) {
3583                                 err = -ENODEV;
3584                                 goto out;
3585                         }
3586                 }
3587                 goto pcpu_alloc;
3588         }
3589
3590         if (cfg->fc_flags & RTF_GATEWAY) {
3591                 err = ip6_validate_gw(net, cfg, &dev, dev_tracker,
3592                                       &idev, extack);
3593                 if (err)
3594                         goto out;
3595
3596                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3597                 fib6_nh->fib_nh_gw_family = AF_INET6;
3598         }
3599
3600         err = -ENODEV;
3601         if (!dev)
3602                 goto out;
3603
3604         if (idev->cnf.disable_ipv6) {
3605                 NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
3606                 err = -EACCES;
3607                 goto out;
3608         }
3609
3610         if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
3611                 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3612                 err = -ENETDOWN;
3613                 goto out;
3614         }
3615
3616         if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
3617             !netif_carrier_ok(dev))
3618                 fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
3619
3620         err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap,
3621                                  cfg->fc_encap_type, cfg, gfp_flags, extack);
3622         if (err)
3623                 goto out;
3624
3625 pcpu_alloc:
3626         fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
3627         if (!fib6_nh->rt6i_pcpu) {
3628                 err = -ENOMEM;
3629                 goto out;
3630         }
3631
3632         fib6_nh->fib_nh_dev = dev;
3633         fib6_nh->fib_nh_oif = dev->ifindex;
3634         err = 0;
3635 out:
3636         if (idev)
3637                 in6_dev_put(idev);
3638
3639         if (err) {
3640                 lwtstate_put(fib6_nh->fib_nh_lws);
3641                 fib6_nh->fib_nh_lws = NULL;
3642                 netdev_put(dev, dev_tracker);
3643         }
3644
3645         return err;
3646 }
3647
3648 void fib6_nh_release(struct fib6_nh *fib6_nh)
3649 {
3650         struct rt6_exception_bucket *bucket;
3651
3652         rcu_read_lock();
3653
3654         fib6_nh_flush_exceptions(fib6_nh, NULL);
3655         bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL);
3656         if (bucket) {
3657                 rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL);
3658                 kfree(bucket);
3659         }
3660
3661         rcu_read_unlock();
3662
3663         fib6_nh_release_dsts(fib6_nh);
3664         free_percpu(fib6_nh->rt6i_pcpu);
3665
3666         fib_nh_common_release(&fib6_nh->nh_common);
3667 }
3668
3669 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh)
3670 {
3671         int cpu;
3672
3673         if (!fib6_nh->rt6i_pcpu)
3674                 return;
3675
3676         for_each_possible_cpu(cpu) {
3677                 struct rt6_info *pcpu_rt, **ppcpu_rt;
3678
3679                 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
3680                 pcpu_rt = xchg(ppcpu_rt, NULL);
3681                 if (pcpu_rt) {
3682                         dst_dev_put(&pcpu_rt->dst);
3683                         dst_release(&pcpu_rt->dst);
3684                 }
3685         }
3686 }
3687
3688 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
3689                                               gfp_t gfp_flags,
3690                                               struct netlink_ext_ack *extack)
3691 {
3692         struct net *net = cfg->fc_nlinfo.nl_net;
3693         struct fib6_info *rt = NULL;
3694         struct nexthop *nh = NULL;
3695         struct fib6_table *table;
3696         struct fib6_nh *fib6_nh;
3697         int err = -EINVAL;
3698         int addr_type;
3699
3700         /* RTF_PCPU is an internal flag; can not be set by userspace */
3701         if (cfg->fc_flags & RTF_PCPU) {
3702                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
3703                 goto out;
3704         }
3705
3706         /* RTF_CACHE is an internal flag; can not be set by userspace */
3707         if (cfg->fc_flags & RTF_CACHE) {
3708                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
3709                 goto out;
3710         }
3711
3712         if (cfg->fc_type > RTN_MAX) {
3713                 NL_SET_ERR_MSG(extack, "Invalid route type");
3714                 goto out;
3715         }
3716
3717         if (cfg->fc_dst_len > 128) {
3718                 NL_SET_ERR_MSG(extack, "Invalid prefix length");
3719                 goto out;
3720         }
3721         if (cfg->fc_src_len > 128) {
3722                 NL_SET_ERR_MSG(extack, "Invalid source address length");
3723                 goto out;
3724         }
3725 #ifndef CONFIG_IPV6_SUBTREES
3726         if (cfg->fc_src_len) {
3727                 NL_SET_ERR_MSG(extack,
3728                                "Specifying source address requires IPV6_SUBTREES to be enabled");
3729                 goto out;
3730         }
3731 #endif
3732         if (cfg->fc_nh_id) {
3733                 nh = nexthop_find_by_id(net, cfg->fc_nh_id);
3734                 if (!nh) {
3735                         NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
3736                         goto out;
3737                 }
3738                 err = fib6_check_nexthop(nh, cfg, extack);
3739                 if (err)
3740                         goto out;
3741         }
3742
3743         err = -ENOBUFS;
3744         if (cfg->fc_nlinfo.nlh &&
3745             !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
3746                 table = fib6_get_table(net, cfg->fc_table);
3747                 if (!table) {
3748                         pr_warn("NLM_F_CREATE should be specified when creating new route\n");
3749                         table = fib6_new_table(net, cfg->fc_table);
3750                 }
3751         } else {
3752                 table = fib6_new_table(net, cfg->fc_table);
3753         }
3754
3755         if (!table)
3756                 goto out;
3757
3758         err = -ENOMEM;
3759         rt = fib6_info_alloc(gfp_flags, !nh);
3760         if (!rt)
3761                 goto out;
3762
3763         rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len,
3764                                                extack);
3765         if (IS_ERR(rt->fib6_metrics)) {
3766                 err = PTR_ERR(rt->fib6_metrics);
3767                 /* Do not leave garbage there. */
3768                 rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
3769                 goto out_free;
3770         }
3771
3772         if (cfg->fc_flags & RTF_ADDRCONF)
3773                 rt->dst_nocount = true;
3774
3775         if (cfg->fc_flags & RTF_EXPIRES)
3776                 fib6_set_expires(rt, jiffies +
3777                                 clock_t_to_jiffies(cfg->fc_expires));
3778
3779         if (cfg->fc_protocol == RTPROT_UNSPEC)
3780                 cfg->fc_protocol = RTPROT_BOOT;
3781         rt->fib6_protocol = cfg->fc_protocol;
3782
3783         rt->fib6_table = table;
3784         rt->fib6_metric = cfg->fc_metric;
3785         rt->fib6_type = cfg->fc_type ? : RTN_UNICAST;
3786         rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;
3787
3788         ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
3789         rt->fib6_dst.plen = cfg->fc_dst_len;
3790
3791 #ifdef CONFIG_IPV6_SUBTREES
3792         ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
3793         rt->fib6_src.plen = cfg->fc_src_len;
3794 #endif
3795         if (nh) {
3796                 if (rt->fib6_src.plen) {
3797                         NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
3798                         goto out_free;
3799                 }
3800                 if (!nexthop_get(nh)) {
3801                         NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
3802                         goto out_free;
3803                 }
3804                 rt->nh = nh;
3805                 fib6_nh = nexthop_fib6_nh(rt->nh);
3806         } else {
3807                 err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack);
3808                 if (err)
3809                         goto out;
3810
3811                 fib6_nh = rt->fib6_nh;
3812
3813                 /* We cannot add true routes via loopback here, they would
3814                  * result in kernel looping; promote them to reject routes
3815                  */
3816                 addr_type = ipv6_addr_type(&cfg->fc_dst);
3817                 if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev,
3818                                    addr_type))
3819                         rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
3820         }
3821
3822         if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
3823                 struct net_device *dev = fib6_nh->fib_nh_dev;
3824
3825                 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
3826                         NL_SET_ERR_MSG(extack, "Invalid source address");
3827                         err = -EINVAL;
3828                         goto out;
3829                 }
3830                 rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
3831                 rt->fib6_prefsrc.plen = 128;
3832         } else
3833                 rt->fib6_prefsrc.plen = 0;
3834
3835         return rt;
3836 out:
3837         fib6_info_release(rt);
3838         return ERR_PTR(err);
3839 out_free:
3840         ip_fib_metrics_put(rt->fib6_metrics);
3841         kfree(rt);
3842         return ERR_PTR(err);
3843 }
3844
3845 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
3846                   struct netlink_ext_ack *extack)
3847 {
3848         struct fib6_info *rt;
3849         int err;
3850
3851         rt = ip6_route_info_create(cfg, gfp_flags, extack);
3852         if (IS_ERR(rt))
3853                 return PTR_ERR(rt);
3854
3855         err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
3856         fib6_info_release(rt);
3857
3858         return err;
3859 }
3860
3861 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
3862 {
3863         struct net *net = info->nl_net;
3864         struct fib6_table *table;
3865         int err;
3866
3867         if (rt == net->ipv6.fib6_null_entry) {
3868                 err = -ENOENT;
3869                 goto out;
3870         }
3871
3872         table = rt->fib6_table;
3873         spin_lock_bh(&table->tb6_lock);
3874         err = fib6_del(rt, info);
3875         spin_unlock_bh(&table->tb6_lock);
3876
3877 out:
3878         fib6_info_release(rt);
3879         return err;
3880 }
3881
3882 int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify)
3883 {
3884         struct nl_info info = {
3885                 .nl_net = net,
3886                 .skip_notify = skip_notify
3887         };
3888
3889         return __ip6_del_rt(rt, &info);
3890 }
3891
3892 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
3893 {
3894         struct nl_info *info = &cfg->fc_nlinfo;
3895         struct net *net = info->nl_net;
3896         struct sk_buff *skb = NULL;
3897         struct fib6_table *table;
3898         int err = -ENOENT;
3899
3900         if (rt == net->ipv6.fib6_null_entry)
3901                 goto out_put;
3902         table = rt->fib6_table;
3903         spin_lock_bh(&table->tb6_lock);
3904
3905         if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
3906                 struct fib6_info *sibling, *next_sibling;
3907                 struct fib6_node *fn;
3908
3909                 /* prefer to send a single notification with all hops */
3910                 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3911                 if (skb) {
3912                         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3913
3914                         if (rt6_fill_node(net, skb, rt, NULL,
3915                                           NULL, NULL, 0, RTM_DELROUTE,
3916                                           info->portid, seq, 0) < 0) {
3917                                 kfree_skb(skb);
3918                                 skb = NULL;
3919                         } else
3920                                 info->skip_notify = 1;
3921                 }
3922
3923                 /* 'rt' points to the first sibling route. If it is not the
3924                  * leaf, then we do not need to send a notification. Otherwise,
3925                  * we need to check if the last sibling has a next route or not
3926                  * and emit a replace or delete notification, respectively.
3927                  */
3928                 info->skip_notify_kernel = 1;
3929                 fn = rcu_dereference_protected(rt->fib6_node,
3930                                             lockdep_is_held(&table->tb6_lock));
3931                 if (rcu_access_pointer(fn->leaf) == rt) {
3932                         struct fib6_info *last_sibling, *replace_rt;
3933
3934                         last_sibling = list_last_entry(&rt->fib6_siblings,
3935                                                        struct fib6_info,
3936                                                        fib6_siblings);
3937                         replace_rt = rcu_dereference_protected(
3938                                             last_sibling->fib6_next,
3939                                             lockdep_is_held(&table->tb6_lock));
3940                         if (replace_rt)
3941                                 call_fib6_entry_notifiers_replace(net,
3942                                                                   replace_rt);
3943                         else
3944                                 call_fib6_multipath_entry_notifiers(net,
3945                                                        FIB_EVENT_ENTRY_DEL,
3946                                                        rt, rt->fib6_nsiblings,
3947                                                        NULL);
3948                 }
3949                 list_for_each_entry_safe(sibling, next_sibling,
3950                                          &rt->fib6_siblings,
3951                                          fib6_siblings) {
3952                         err = fib6_del(sibling, info);
3953                         if (err)
3954                                 goto out_unlock;
3955                 }
3956         }
3957
3958         err = fib6_del(rt, info);
3959 out_unlock:
3960         spin_unlock_bh(&table->tb6_lock);
3961 out_put:
3962         fib6_info_release(rt);
3963
3964         if (skb) {
3965                 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3966                             info->nlh, gfp_any());
3967         }
3968         return err;
3969 }
3970
3971 static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
3972 {
3973         int rc = -ESRCH;
3974
3975         if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
3976                 goto out;
3977
3978         if (cfg->fc_flags & RTF_GATEWAY &&
3979             !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
3980                 goto out;
3981
3982         rc = rt6_remove_exception_rt(rt);
3983 out:
3984         return rc;
3985 }
3986
3987 static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt,
3988                              struct fib6_nh *nh)
3989 {
3990         struct fib6_result res = {
3991                 .f6i = rt,
3992                 .nh = nh,
3993         };
3994         struct rt6_info *rt_cache;
3995
3996         rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src);
3997         if (rt_cache)
3998                 return __ip6_del_cached_rt(rt_cache, cfg);
3999
4000         return 0;
4001 }
4002
4003 struct fib6_nh_del_cached_rt_arg {
4004         struct fib6_config *cfg;
4005         struct fib6_info *f6i;
4006 };
4007
4008 static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg)
4009 {
4010         struct fib6_nh_del_cached_rt_arg *arg = _arg;
4011         int rc;
4012
4013         rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh);
4014         return rc != -ESRCH ? rc : 0;
4015 }
4016
4017 static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i)
4018 {
4019         struct fib6_nh_del_cached_rt_arg arg = {
4020                 .cfg = cfg,
4021                 .f6i = f6i
4022         };
4023
4024         return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg);
4025 }
4026
4027 static int ip6_route_del(struct fib6_config *cfg,
4028                          struct netlink_ext_ack *extack)
4029 {
4030         struct fib6_table *table;
4031         struct fib6_info *rt;
4032         struct fib6_node *fn;
4033         int err = -ESRCH;
4034
4035         table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
4036         if (!table) {
4037                 NL_SET_ERR_MSG(extack, "FIB table does not exist");
4038                 return err;
4039         }
4040
4041         rcu_read_lock();
4042
4043         fn = fib6_locate(&table->tb6_root,
4044                          &cfg->fc_dst, cfg->fc_dst_len,
4045                          &cfg->fc_src, cfg->fc_src_len,
4046                          !(cfg->fc_flags & RTF_CACHE));
4047
4048         if (fn) {
4049                 for_each_fib6_node_rt_rcu(fn) {
4050                         struct fib6_nh *nh;
4051
4052                         if (rt->nh && cfg->fc_nh_id &&
4053                             rt->nh->id != cfg->fc_nh_id)
4054                                 continue;
4055
4056                         if (cfg->fc_flags & RTF_CACHE) {
4057                                 int rc = 0;
4058
4059                                 if (rt->nh) {
4060                                         rc = ip6_del_cached_rt_nh(cfg, rt);
4061                                 } else if (cfg->fc_nh_id) {
4062                                         continue;
4063                                 } else {
4064                                         nh = rt->fib6_nh;
4065                                         rc = ip6_del_cached_rt(cfg, rt, nh);
4066                                 }
4067                                 if (rc != -ESRCH) {
4068                                         rcu_read_unlock();
4069                                         return rc;
4070                                 }
4071                                 continue;
4072                         }
4073
4074                         if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
4075                                 continue;
4076                         if (cfg->fc_protocol &&
4077                             cfg->fc_protocol != rt->fib6_protocol)
4078                                 continue;
4079
4080                         if (rt->nh) {
4081                                 if (!fib6_info_hold_safe(rt))
4082                                         continue;
4083                                 rcu_read_unlock();
4084
4085                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4086                         }
4087                         if (cfg->fc_nh_id)
4088                                 continue;
4089
4090                         nh = rt->fib6_nh;
4091                         if (cfg->fc_ifindex &&
4092                             (!nh->fib_nh_dev ||
4093                              nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
4094                                 continue;
4095                         if (cfg->fc_flags & RTF_GATEWAY &&
4096                             !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6))
4097                                 continue;
4098                         if (!fib6_info_hold_safe(rt))
4099                                 continue;
4100                         rcu_read_unlock();
4101
4102                         /* if gateway was specified only delete the one hop */
4103                         if (cfg->fc_flags & RTF_GATEWAY)
4104                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4105
4106                         return __ip6_del_rt_siblings(rt, cfg);
4107                 }
4108         }
4109         rcu_read_unlock();
4110
4111         return err;
4112 }
4113
4114 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
4115 {
4116         struct netevent_redirect netevent;
4117         struct rt6_info *rt, *nrt = NULL;
4118         struct fib6_result res = {};
4119         struct ndisc_options ndopts;
4120         struct inet6_dev *in6_dev;
4121         struct neighbour *neigh;
4122         struct rd_msg *msg;
4123         int optlen, on_link;
4124         u8 *lladdr;
4125
4126         optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
4127         optlen -= sizeof(*msg);
4128
4129         if (optlen < 0) {
4130                 net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
4131                 return;
4132         }
4133
4134         msg = (struct rd_msg *)icmp6_hdr(skb);
4135
4136         if (ipv6_addr_is_multicast(&msg->dest)) {
4137                 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
4138                 return;
4139         }
4140
4141         on_link = 0;
4142         if (ipv6_addr_equal(&msg->dest, &msg->target)) {
4143                 on_link = 1;
4144         } else if (ipv6_addr_type(&msg->target) !=
4145                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
4146                 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
4147                 return;
4148         }
4149
4150         in6_dev = __in6_dev_get(skb->dev);
4151         if (!in6_dev)
4152                 return;
4153         if (READ_ONCE(in6_dev->cnf.forwarding) ||
4154             !READ_ONCE(in6_dev->cnf.accept_redirects))
4155                 return;
4156
4157         /* RFC2461 8.1:
4158          *      The IP source address of the Redirect MUST be the same as the current
4159          *      first-hop router for the specified ICMP Destination Address.
4160          */
4161
4162         if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
4163                 net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
4164                 return;
4165         }
4166
4167         lladdr = NULL;
4168         if (ndopts.nd_opts_tgt_lladdr) {
4169                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
4170                                              skb->dev);
4171                 if (!lladdr) {
4172                         net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
4173                         return;
4174                 }
4175         }
4176
4177         rt = (struct rt6_info *) dst;
4178         if (rt->rt6i_flags & RTF_REJECT) {
4179                 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
4180                 return;
4181         }
4182
4183         /* Redirect received -> path was valid.
4184          * Look, redirects are sent only in response to data packets,
4185          * so that this nexthop apparently is reachable. --ANK
4186          */
4187         dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
4188
4189         neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
4190         if (!neigh)
4191                 return;
4192
4193         /*
4194          *      We have finally decided to accept it.
4195          */
4196
4197         ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
4198                      NEIGH_UPDATE_F_WEAK_OVERRIDE|
4199                      NEIGH_UPDATE_F_OVERRIDE|
4200                      (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
4201                                      NEIGH_UPDATE_F_ISROUTER)),
4202                      NDISC_REDIRECT, &ndopts);
4203
4204         rcu_read_lock();
4205         res.f6i = rcu_dereference(rt->from);
4206         if (!res.f6i)
4207                 goto out;
4208
4209         if (res.f6i->nh) {
4210                 struct fib6_nh_match_arg arg = {
4211                         .dev = dst->dev,
4212                         .gw = &rt->rt6i_gateway,
4213                 };
4214
4215                 nexthop_for_each_fib6_nh(res.f6i->nh,
4216                                          fib6_nh_find_match, &arg);
4217
4218                 /* fib6_info uses a nexthop that does not have fib6_nh
4219                  * using the dst->dev. Should be impossible
4220                  */
4221                 if (!arg.match)
4222                         goto out;
4223                 res.nh = arg.match;
4224         } else {
4225                 res.nh = res.f6i->fib6_nh;
4226         }
4227
4228         res.fib6_flags = res.f6i->fib6_flags;
4229         res.fib6_type = res.f6i->fib6_type;
4230         nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL);
4231         if (!nrt)
4232                 goto out;
4233
4234         nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
4235         if (on_link)
4236                 nrt->rt6i_flags &= ~RTF_GATEWAY;
4237
4238         nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
4239
4240         /* rt6_insert_exception() will take care of duplicated exceptions */
4241         if (rt6_insert_exception(nrt, &res)) {
4242                 dst_release_immediate(&nrt->dst);
4243                 goto out;
4244         }
4245
4246         netevent.old = &rt->dst;
4247         netevent.new = &nrt->dst;
4248         netevent.daddr = &msg->dest;
4249         netevent.neigh = neigh;
4250         call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
4251
4252 out:
4253         rcu_read_unlock();
4254         neigh_release(neigh);
4255 }
4256
4257 #ifdef CONFIG_IPV6_ROUTE_INFO
4258 static struct fib6_info *rt6_get_route_info(struct net *net,
4259                                            const struct in6_addr *prefix, int prefixlen,
4260                                            const struct in6_addr *gwaddr,
4261                                            struct net_device *dev)
4262 {
4263         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4264         int ifindex = dev->ifindex;
4265         struct fib6_node *fn;
4266         struct fib6_info *rt = NULL;
4267         struct fib6_table *table;
4268
4269         table = fib6_get_table(net, tb_id);
4270         if (!table)
4271                 return NULL;
4272
4273         rcu_read_lock();
4274         fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
4275         if (!fn)
4276                 goto out;
4277
4278         for_each_fib6_node_rt_rcu(fn) {
4279                 /* these routes do not use nexthops */
4280                 if (rt->nh)
4281                         continue;
4282                 if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex)
4283                         continue;
4284                 if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
4285                     !rt->fib6_nh->fib_nh_gw_family)
4286                         continue;
4287                 if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr))
4288                         continue;
4289                 if (!fib6_info_hold_safe(rt))
4290                         continue;
4291                 break;
4292         }
4293 out:
4294         rcu_read_unlock();
4295         return rt;
4296 }
4297
4298 static struct fib6_info *rt6_add_route_info(struct net *net,
4299                                            const struct in6_addr *prefix, int prefixlen,
4300                                            const struct in6_addr *gwaddr,
4301                                            struct net_device *dev,
4302                                            unsigned int pref)
4303 {
4304         struct fib6_config cfg = {
4305                 .fc_metric      = IP6_RT_PRIO_USER,
4306                 .fc_ifindex     = dev->ifindex,
4307                 .fc_dst_len     = prefixlen,
4308                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
4309                                   RTF_UP | RTF_PREF(pref),
4310                 .fc_protocol = RTPROT_RA,
4311                 .fc_type = RTN_UNICAST,
4312                 .fc_nlinfo.portid = 0,
4313                 .fc_nlinfo.nlh = NULL,
4314                 .fc_nlinfo.nl_net = net,
4315         };
4316
4317         cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4318         cfg.fc_dst = *prefix;
4319         cfg.fc_gateway = *gwaddr;
4320
4321         /* We should treat it as a default route if prefix length is 0. */
4322         if (!prefixlen)
4323                 cfg.fc_flags |= RTF_DEFAULT;
4324
4325         ip6_route_add(&cfg, GFP_ATOMIC, NULL);
4326
4327         return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
4328 }
4329 #endif
4330
4331 struct fib6_info *rt6_get_dflt_router(struct net *net,
4332                                      const struct in6_addr *addr,
4333                                      struct net_device *dev)
4334 {
4335         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
4336         struct fib6_info *rt;
4337         struct fib6_table *table;
4338
4339         table = fib6_get_table(net, tb_id);
4340         if (!table)
4341                 return NULL;
4342
4343         rcu_read_lock();
4344         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4345                 struct fib6_nh *nh;
4346
4347                 /* RA routes do not use nexthops */
4348                 if (rt->nh)
4349                         continue;
4350
4351                 nh = rt->fib6_nh;
4352                 if (dev == nh->fib_nh_dev &&
4353                     ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
4354                     ipv6_addr_equal(&nh->fib_nh_gw6, addr))
4355                         break;
4356         }
4357         if (rt && !fib6_info_hold_safe(rt))
4358                 rt = NULL;
4359         rcu_read_unlock();
4360         return rt;
4361 }
4362
4363 struct fib6_info *rt6_add_dflt_router(struct net *net,
4364                                      const struct in6_addr *gwaddr,
4365                                      struct net_device *dev,
4366                                      unsigned int pref,
4367                                      u32 defrtr_usr_metric,
4368                                      int lifetime)
4369 {
4370         struct fib6_config cfg = {
4371                 .fc_table       = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
4372                 .fc_metric      = defrtr_usr_metric,
4373                 .fc_ifindex     = dev->ifindex,
4374                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
4375                                   RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
4376                 .fc_protocol = RTPROT_RA,
4377                 .fc_type = RTN_UNICAST,
4378                 .fc_nlinfo.portid = 0,
4379                 .fc_nlinfo.nlh = NULL,
4380                 .fc_nlinfo.nl_net = net,
4381                 .fc_expires = jiffies_to_clock_t(lifetime * HZ),
4382         };
4383
4384         cfg.fc_gateway = *gwaddr;
4385
4386         if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
4387                 struct fib6_table *table;
4388
4389                 table = fib6_get_table(dev_net(dev), cfg.fc_table);
4390                 if (table)
4391                         table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
4392         }
4393
4394         return rt6_get_dflt_router(net, gwaddr, dev);
4395 }
4396
4397 static void __rt6_purge_dflt_routers(struct net *net,
4398                                      struct fib6_table *table)
4399 {
4400         struct fib6_info *rt;
4401
4402 restart:
4403         rcu_read_lock();
4404         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4405                 struct net_device *dev = fib6_info_nh_dev(rt);
4406                 struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
4407
4408                 if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
4409                     (!idev || idev->cnf.accept_ra != 2) &&
4410                     fib6_info_hold_safe(rt)) {
4411                         rcu_read_unlock();
4412                         ip6_del_rt(net, rt, false);
4413                         goto restart;
4414                 }
4415         }
4416         rcu_read_unlock();
4417
4418         table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
4419 }
4420
4421 void rt6_purge_dflt_routers(struct net *net)
4422 {
4423         struct fib6_table *table;
4424         struct hlist_head *head;
4425         unsigned int h;
4426
4427         rcu_read_lock();
4428
4429         for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
4430                 head = &net->ipv6.fib_table_hash[h];
4431                 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
4432                         if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
4433                                 __rt6_purge_dflt_routers(net, table);
4434                 }
4435         }
4436
4437         rcu_read_unlock();
4438 }
4439
4440 static void rtmsg_to_fib6_config(struct net *net,
4441                                  struct in6_rtmsg *rtmsg,
4442                                  struct fib6_config *cfg)
4443 {
4444         *cfg = (struct fib6_config){
4445                 .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
4446                          : RT6_TABLE_MAIN,
4447                 .fc_ifindex = rtmsg->rtmsg_ifindex,
4448                 .fc_metric = rtmsg->rtmsg_metric ? : IP6_RT_PRIO_USER,
4449                 .fc_expires = rtmsg->rtmsg_info,
4450                 .fc_dst_len = rtmsg->rtmsg_dst_len,
4451                 .fc_src_len = rtmsg->rtmsg_src_len,
4452                 .fc_flags = rtmsg->rtmsg_flags,
4453                 .fc_type = rtmsg->rtmsg_type,
4454
4455                 .fc_nlinfo.nl_net = net,
4456
4457                 .fc_dst = rtmsg->rtmsg_dst,
4458                 .fc_src = rtmsg->rtmsg_src,
4459                 .fc_gateway = rtmsg->rtmsg_gateway,
4460         };
4461 }
4462
4463 int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg)
4464 {
4465         struct fib6_config cfg;
4466         int err;
4467
4468         if (cmd != SIOCADDRT && cmd != SIOCDELRT)
4469                 return -EINVAL;
4470         if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
4471                 return -EPERM;
4472
4473         rtmsg_to_fib6_config(net, rtmsg, &cfg);
4474
4475         rtnl_lock();
4476         switch (cmd) {
4477         case SIOCADDRT:
4478                 err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
4479                 break;
4480         case SIOCDELRT:
4481                 err = ip6_route_del(&cfg, NULL);
4482                 break;
4483         }
4484         rtnl_unlock();
4485         return err;
4486 }
4487
4488 /*
4489  *      Drop the packet on the floor
4490  */
4491
4492 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
4493 {
4494         struct dst_entry *dst = skb_dst(skb);
4495         struct net *net = dev_net(dst->dev);
4496         struct inet6_dev *idev;
4497         SKB_DR(reason);
4498         int type;
4499
4500         if (netif_is_l3_master(skb->dev) ||
4501             dst->dev == net->loopback_dev)
4502                 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
4503         else
4504                 idev = ip6_dst_idev(dst);
4505
4506         switch (ipstats_mib_noroutes) {
4507         case IPSTATS_MIB_INNOROUTES:
4508                 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
4509                 if (type == IPV6_ADDR_ANY) {
4510                         SKB_DR_SET(reason, IP_INADDRERRORS);
4511                         IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
4512                         break;
4513                 }
4514                 SKB_DR_SET(reason, IP_INNOROUTES);
4515                 fallthrough;
4516         case IPSTATS_MIB_OUTNOROUTES:
4517                 SKB_DR_OR(reason, IP_OUTNOROUTES);
4518                 IP6_INC_STATS(net, idev, ipstats_mib_noroutes);
4519                 break;
4520         }
4521
4522         /* Start over by dropping the dst for l3mdev case */
4523         if (netif_is_l3_master(skb->dev))
4524                 skb_dst_drop(skb);
4525
4526         icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
4527         kfree_skb_reason(skb, reason);
4528         return 0;
4529 }
4530
4531 static int ip6_pkt_discard(struct sk_buff *skb)
4532 {
4533         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
4534 }
4535
4536 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4537 {
4538         skb->dev = skb_dst(skb)->dev;
4539         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
4540 }
4541
4542 static int ip6_pkt_prohibit(struct sk_buff *skb)
4543 {
4544         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
4545 }
4546
4547 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4548 {
4549         skb->dev = skb_dst(skb)->dev;
4550         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
4551 }
4552
4553 /*
4554  *      Allocate a dst for local (unicast / anycast) address.
4555  */
4556
4557 struct fib6_info *addrconf_f6i_alloc(struct net *net,
4558                                      struct inet6_dev *idev,
4559                                      const struct in6_addr *addr,
4560                                      bool anycast, gfp_t gfp_flags,
4561                                      struct netlink_ext_ack *extack)
4562 {
4563         struct fib6_config cfg = {
4564                 .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
4565                 .fc_ifindex = idev->dev->ifindex,
4566                 .fc_flags = RTF_UP | RTF_NONEXTHOP,
4567                 .fc_dst = *addr,
4568                 .fc_dst_len = 128,
4569                 .fc_protocol = RTPROT_KERNEL,
4570                 .fc_nlinfo.nl_net = net,
4571                 .fc_ignore_dev_down = true,
4572         };
4573         struct fib6_info *f6i;
4574
4575         if (anycast) {
4576                 cfg.fc_type = RTN_ANYCAST;
4577                 cfg.fc_flags |= RTF_ANYCAST;
4578         } else {
4579                 cfg.fc_type = RTN_LOCAL;
4580                 cfg.fc_flags |= RTF_LOCAL;
4581         }
4582
4583         f6i = ip6_route_info_create(&cfg, gfp_flags, extack);
4584         if (!IS_ERR(f6i)) {
4585                 f6i->dst_nocount = true;
4586
4587                 if (!anycast &&
4588                     (READ_ONCE(net->ipv6.devconf_all->disable_policy) ||
4589                      READ_ONCE(idev->cnf.disable_policy)))
4590                         f6i->dst_nopolicy = true;
4591         }
4592
4593         return f6i;
4594 }
4595
4596 /* remove deleted ip from prefsrc entries */
4597 struct arg_dev_net_ip {
4598         struct net *net;
4599         struct in6_addr *addr;
4600 };
4601
4602 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
4603 {
4604         struct net *net = ((struct arg_dev_net_ip *)arg)->net;
4605         struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
4606
4607         if (!rt->nh &&
4608             rt != net->ipv6.fib6_null_entry &&
4609             ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr) &&
4610             !ipv6_chk_addr(net, addr, rt->fib6_nh->fib_nh_dev, 0)) {
4611                 spin_lock_bh(&rt6_exception_lock);
4612                 /* remove prefsrc entry */
4613                 rt->fib6_prefsrc.plen = 0;
4614                 spin_unlock_bh(&rt6_exception_lock);
4615         }
4616         return 0;
4617 }
4618
4619 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
4620 {
4621         struct net *net = dev_net(ifp->idev->dev);
4622         struct arg_dev_net_ip adni = {
4623                 .net = net,
4624                 .addr = &ifp->addr,
4625         };
4626         fib6_clean_all(net, fib6_remove_prefsrc, &adni);
4627 }
4628
4629 #define RTF_RA_ROUTER           (RTF_ADDRCONF | RTF_DEFAULT)
4630
4631 /* Remove routers and update dst entries when gateway turn into host. */
4632 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
4633 {
4634         struct in6_addr *gateway = (struct in6_addr *)arg;
4635         struct fib6_nh *nh;
4636
4637         /* RA routes do not use nexthops */
4638         if (rt->nh)
4639                 return 0;
4640
4641         nh = rt->fib6_nh;
4642         if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
4643             nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6))
4644                 return -1;
4645
4646         /* Further clean up cached routes in exception table.
4647          * This is needed because cached route may have a different
4648          * gateway than its 'parent' in the case of an ip redirect.
4649          */
4650         fib6_nh_exceptions_clean_tohost(nh, gateway);
4651
4652         return 0;
4653 }
4654
4655 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
4656 {
4657         fib6_clean_all(net, fib6_clean_tohost, gateway);
4658 }
4659
4660 struct arg_netdev_event {
4661         const struct net_device *dev;
4662         union {
4663                 unsigned char nh_flags;
4664                 unsigned long event;
4665         };
4666 };
4667
4668 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
4669 {
4670         struct fib6_info *iter;
4671         struct fib6_node *fn;
4672
4673         fn = rcu_dereference_protected(rt->fib6_node,
4674                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4675         iter = rcu_dereference_protected(fn->leaf,
4676                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4677         while (iter) {
4678                 if (iter->fib6_metric == rt->fib6_metric &&
4679                     rt6_qualify_for_ecmp(iter))
4680                         return iter;
4681                 iter = rcu_dereference_protected(iter->fib6_next,
4682                                 lockdep_is_held(&rt->fib6_table->tb6_lock));
4683         }
4684
4685         return NULL;
4686 }
4687
4688 /* only called for fib entries with builtin fib6_nh */
4689 static bool rt6_is_dead(const struct fib6_info *rt)
4690 {
4691         if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD ||
4692             (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN &&
4693              ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev)))
4694                 return true;
4695
4696         return false;
4697 }
4698
4699 static int rt6_multipath_total_weight(const struct fib6_info *rt)
4700 {
4701         struct fib6_info *iter;
4702         int total = 0;
4703
4704         if (!rt6_is_dead(rt))
4705                 total += rt->fib6_nh->fib_nh_weight;
4706
4707         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
4708                 if (!rt6_is_dead(iter))
4709                         total += iter->fib6_nh->fib_nh_weight;
4710         }
4711
4712         return total;
4713 }
4714
4715 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
4716 {
4717         int upper_bound = -1;
4718
4719         if (!rt6_is_dead(rt)) {
4720                 *weight += rt->fib6_nh->fib_nh_weight;
4721                 upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
4722                                                     total) - 1;
4723         }
4724         atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
4725 }
4726
4727 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
4728 {
4729         struct fib6_info *iter;
4730         int weight = 0;
4731
4732         rt6_upper_bound_set(rt, &weight, total);
4733
4734         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4735                 rt6_upper_bound_set(iter, &weight, total);
4736 }
4737
4738 void rt6_multipath_rebalance(struct fib6_info *rt)
4739 {
4740         struct fib6_info *first;
4741         int total;
4742
4743         /* In case the entire multipath route was marked for flushing,
4744          * then there is no need to rebalance upon the removal of every
4745          * sibling route.
4746          */
4747         if (!rt->fib6_nsiblings || rt->should_flush)
4748                 return;
4749
4750         /* During lookup routes are evaluated in order, so we need to
4751          * make sure upper bounds are assigned from the first sibling
4752          * onwards.
4753          */
4754         first = rt6_multipath_first_sibling(rt);
4755         if (WARN_ON_ONCE(!first))
4756                 return;
4757
4758         total = rt6_multipath_total_weight(first);
4759         rt6_multipath_upper_bound_set(first, total);
4760 }
4761
4762 static int fib6_ifup(struct fib6_info *rt, void *p_arg)
4763 {
4764         const struct arg_netdev_event *arg = p_arg;
4765         struct net *net = dev_net(arg->dev);
4766
4767         if (rt != net->ipv6.fib6_null_entry && !rt->nh &&
4768             rt->fib6_nh->fib_nh_dev == arg->dev) {
4769                 rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags;
4770                 fib6_update_sernum_upto_root(net, rt);
4771                 rt6_multipath_rebalance(rt);
4772         }
4773
4774         return 0;
4775 }
4776
4777 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags)
4778 {
4779         struct arg_netdev_event arg = {
4780                 .dev = dev,
4781                 {
4782                         .nh_flags = nh_flags,
4783                 },
4784         };
4785
4786         if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
4787                 arg.nh_flags |= RTNH_F_LINKDOWN;
4788
4789         fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
4790 }
4791
4792 /* only called for fib entries with inline fib6_nh */
4793 static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
4794                                    const struct net_device *dev)
4795 {
4796         struct fib6_info *iter;
4797
4798         if (rt->fib6_nh->fib_nh_dev == dev)
4799                 return true;
4800         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4801                 if (iter->fib6_nh->fib_nh_dev == dev)
4802                         return true;
4803
4804         return false;
4805 }
4806
4807 static void rt6_multipath_flush(struct fib6_info *rt)
4808 {
4809         struct fib6_info *iter;
4810
4811         rt->should_flush = 1;
4812         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4813                 iter->should_flush = 1;
4814 }
4815
4816 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
4817                                              const struct net_device *down_dev)
4818 {
4819         struct fib6_info *iter;
4820         unsigned int dead = 0;
4821
4822         if (rt->fib6_nh->fib_nh_dev == down_dev ||
4823             rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4824                 dead++;
4825         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4826                 if (iter->fib6_nh->fib_nh_dev == down_dev ||
4827                     iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4828                         dead++;
4829
4830         return dead;
4831 }
4832
4833 static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
4834                                        const struct net_device *dev,
4835                                        unsigned char nh_flags)
4836 {
4837         struct fib6_info *iter;
4838
4839         if (rt->fib6_nh->fib_nh_dev == dev)
4840                 rt->fib6_nh->fib_nh_flags |= nh_flags;
4841         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4842                 if (iter->fib6_nh->fib_nh_dev == dev)
4843                         iter->fib6_nh->fib_nh_flags |= nh_flags;
4844 }
4845
4846 /* called with write lock held for table with rt */
4847 static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
4848 {
4849         const struct arg_netdev_event *arg = p_arg;
4850         const struct net_device *dev = arg->dev;
4851         struct net *net = dev_net(dev);
4852
4853         if (rt == net->ipv6.fib6_null_entry || rt->nh)
4854                 return 0;
4855
4856         switch (arg->event) {
4857         case NETDEV_UNREGISTER:
4858                 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4859         case NETDEV_DOWN:
4860                 if (rt->should_flush)
4861                         return -1;
4862                 if (!rt->fib6_nsiblings)
4863                         return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4864                 if (rt6_multipath_uses_dev(rt, dev)) {
4865                         unsigned int count;
4866
4867                         count = rt6_multipath_dead_count(rt, dev);
4868                         if (rt->fib6_nsiblings + 1 == count) {
4869                                 rt6_multipath_flush(rt);
4870                                 return -1;
4871                         }
4872                         rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
4873                                                    RTNH_F_LINKDOWN);
4874                         fib6_update_sernum(net, rt);
4875                         rt6_multipath_rebalance(rt);
4876                 }
4877                 return -2;
4878         case NETDEV_CHANGE:
4879                 if (rt->fib6_nh->fib_nh_dev != dev ||
4880                     rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
4881                         break;
4882                 rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
4883                 rt6_multipath_rebalance(rt);
4884                 break;
4885         }
4886
4887         return 0;
4888 }
4889
4890 void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
4891 {
4892         struct arg_netdev_event arg = {
4893                 .dev = dev,
4894                 {
4895                         .event = event,
4896                 },
4897         };
4898         struct net *net = dev_net(dev);
4899
4900         if (net->ipv6.sysctl.skip_notify_on_dev_down)
4901                 fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
4902         else
4903                 fib6_clean_all(net, fib6_ifdown, &arg);
4904 }
4905
4906 void rt6_disable_ip(struct net_device *dev, unsigned long event)
4907 {
4908         rt6_sync_down_dev(dev, event);
4909         rt6_uncached_list_flush_dev(dev);
4910         neigh_ifdown(&nd_tbl, dev);
4911 }
4912
4913 struct rt6_mtu_change_arg {
4914         struct net_device *dev;
4915         unsigned int mtu;
4916         struct fib6_info *f6i;
4917 };
4918
4919 static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
4920 {
4921         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg;
4922         struct fib6_info *f6i = arg->f6i;
4923
4924         /* For administrative MTU increase, there is no way to discover
4925          * IPv6 PMTU increase, so PMTU increase should be updated here.
4926          * Since RFC 1981 doesn't include administrative MTU increase
4927          * update PMTU increase is a MUST. (i.e. jumbo frame)
4928          */
4929         if (nh->fib_nh_dev == arg->dev) {
4930                 struct inet6_dev *idev = __in6_dev_get(arg->dev);
4931                 u32 mtu = f6i->fib6_pmtu;
4932
4933                 if (mtu >= arg->mtu ||
4934                     (mtu < arg->mtu && mtu == idev->cnf.mtu6))
4935                         fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
4936
4937                 spin_lock_bh(&rt6_exception_lock);
4938                 rt6_exceptions_update_pmtu(idev, nh, arg->mtu);
4939                 spin_unlock_bh(&rt6_exception_lock);
4940         }
4941
4942         return 0;
4943 }
4944
4945 static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
4946 {
4947         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
4948         struct inet6_dev *idev;
4949
4950         /* In IPv6 pmtu discovery is not optional,
4951            so that RTAX_MTU lock cannot disable it.
4952            We still use this lock to block changes
4953            caused by addrconf/ndisc.
4954         */
4955
4956         idev = __in6_dev_get(arg->dev);
4957         if (!idev)
4958                 return 0;
4959
4960         if (fib6_metric_locked(f6i, RTAX_MTU))
4961                 return 0;
4962
4963         arg->f6i = f6i;
4964         if (f6i->nh) {
4965                 /* fib6_nh_mtu_change only returns 0, so this is safe */
4966                 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change,
4967                                                 arg);
4968         }
4969
4970         return fib6_nh_mtu_change(f6i->fib6_nh, arg);
4971 }
4972
4973 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
4974 {
4975         struct rt6_mtu_change_arg arg = {
4976                 .dev = dev,
4977                 .mtu = mtu,
4978         };
4979
4980         fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
4981 }
4982
4983 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
4984         [RTA_UNSPEC]            = { .strict_start_type = RTA_DPORT + 1 },
4985         [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
4986         [RTA_PREFSRC]           = { .len = sizeof(struct in6_addr) },
4987         [RTA_OIF]               = { .type = NLA_U32 },
4988         [RTA_IIF]               = { .type = NLA_U32 },
4989         [RTA_PRIORITY]          = { .type = NLA_U32 },
4990         [RTA_METRICS]           = { .type = NLA_NESTED },
4991         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
4992         [RTA_PREF]              = { .type = NLA_U8 },
4993         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
4994         [RTA_ENCAP]             = { .type = NLA_NESTED },
4995         [RTA_EXPIRES]           = { .type = NLA_U32 },
4996         [RTA_UID]               = { .type = NLA_U32 },
4997         [RTA_MARK]              = { .type = NLA_U32 },
4998         [RTA_TABLE]             = { .type = NLA_U32 },
4999         [RTA_IP_PROTO]          = { .type = NLA_U8 },
5000         [RTA_SPORT]             = { .type = NLA_U16 },
5001         [RTA_DPORT]             = { .type = NLA_U16 },
5002         [RTA_NH_ID]             = { .type = NLA_U32 },
5003 };
5004
5005 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
5006                               struct fib6_config *cfg,
5007                               struct netlink_ext_ack *extack)
5008 {
5009         struct rtmsg *rtm;
5010         struct nlattr *tb[RTA_MAX+1];
5011         unsigned int pref;
5012         int err;
5013
5014         err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5015                                      rtm_ipv6_policy, extack);
5016         if (err < 0)
5017                 goto errout;
5018
5019         err = -EINVAL;
5020         rtm = nlmsg_data(nlh);
5021
5022         if (rtm->rtm_tos) {
5023                 NL_SET_ERR_MSG(extack,
5024                                "Invalid dsfield (tos): option not available for IPv6");
5025                 goto errout;
5026         }
5027
5028         *cfg = (struct fib6_config){
5029                 .fc_table = rtm->rtm_table,
5030                 .fc_dst_len = rtm->rtm_dst_len,
5031                 .fc_src_len = rtm->rtm_src_len,
5032                 .fc_flags = RTF_UP,
5033                 .fc_protocol = rtm->rtm_protocol,
5034                 .fc_type = rtm->rtm_type,
5035
5036                 .fc_nlinfo.portid = NETLINK_CB(skb).portid,
5037                 .fc_nlinfo.nlh = nlh,
5038                 .fc_nlinfo.nl_net = sock_net(skb->sk),
5039         };
5040
5041         if (rtm->rtm_type == RTN_UNREACHABLE ||
5042             rtm->rtm_type == RTN_BLACKHOLE ||
5043             rtm->rtm_type == RTN_PROHIBIT ||
5044             rtm->rtm_type == RTN_THROW)
5045                 cfg->fc_flags |= RTF_REJECT;
5046
5047         if (rtm->rtm_type == RTN_LOCAL)
5048                 cfg->fc_flags |= RTF_LOCAL;
5049
5050         if (rtm->rtm_flags & RTM_F_CLONED)
5051                 cfg->fc_flags |= RTF_CACHE;
5052
5053         cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
5054
5055         if (tb[RTA_NH_ID]) {
5056                 if (tb[RTA_GATEWAY]   || tb[RTA_OIF] ||
5057                     tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {
5058                         NL_SET_ERR_MSG(extack,
5059                                        "Nexthop specification and nexthop id are mutually exclusive");
5060                         goto errout;
5061                 }
5062                 cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);
5063         }
5064
5065         if (tb[RTA_GATEWAY]) {
5066                 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
5067                 cfg->fc_flags |= RTF_GATEWAY;
5068         }
5069         if (tb[RTA_VIA]) {
5070                 NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
5071                 goto errout;
5072         }
5073
5074         if (tb[RTA_DST]) {
5075                 int plen = (rtm->rtm_dst_len + 7) >> 3;
5076
5077                 if (nla_len(tb[RTA_DST]) < plen)
5078                         goto errout;
5079
5080                 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
5081         }
5082
5083         if (tb[RTA_SRC]) {
5084                 int plen = (rtm->rtm_src_len + 7) >> 3;
5085
5086                 if (nla_len(tb[RTA_SRC]) < plen)
5087                         goto errout;
5088
5089                 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
5090         }
5091
5092         if (tb[RTA_PREFSRC])
5093                 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
5094
5095         if (tb[RTA_OIF])
5096                 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
5097
5098         if (tb[RTA_PRIORITY])
5099                 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
5100
5101         if (tb[RTA_METRICS]) {
5102                 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
5103                 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
5104         }
5105
5106         if (tb[RTA_TABLE])
5107                 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
5108
5109         if (tb[RTA_MULTIPATH]) {
5110                 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
5111                 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
5112
5113                 err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
5114                                                      cfg->fc_mp_len, extack);
5115                 if (err < 0)
5116                         goto errout;
5117         }
5118
5119         if (tb[RTA_PREF]) {
5120                 pref = nla_get_u8(tb[RTA_PREF]);
5121                 if (pref != ICMPV6_ROUTER_PREF_LOW &&
5122                     pref != ICMPV6_ROUTER_PREF_HIGH)
5123                         pref = ICMPV6_ROUTER_PREF_MEDIUM;
5124                 cfg->fc_flags |= RTF_PREF(pref);
5125         }
5126
5127         if (tb[RTA_ENCAP])
5128                 cfg->fc_encap = tb[RTA_ENCAP];
5129
5130         if (tb[RTA_ENCAP_TYPE]) {
5131                 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
5132
5133                 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
5134                 if (err < 0)
5135                         goto errout;
5136         }
5137
5138         if (tb[RTA_EXPIRES]) {
5139                 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
5140
5141                 if (addrconf_finite_timeout(timeout)) {
5142                         cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
5143                         cfg->fc_flags |= RTF_EXPIRES;
5144                 }
5145         }
5146
5147         err = 0;
5148 errout:
5149         return err;
5150 }
5151
5152 struct rt6_nh {
5153         struct fib6_info *fib6_info;
5154         struct fib6_config r_cfg;
5155         struct list_head next;
5156 };
5157
5158 static int ip6_route_info_append(struct net *net,
5159                                  struct list_head *rt6_nh_list,
5160                                  struct fib6_info *rt,
5161                                  struct fib6_config *r_cfg)
5162 {
5163         struct rt6_nh *nh;
5164         int err = -EEXIST;
5165
5166         list_for_each_entry(nh, rt6_nh_list, next) {
5167                 /* check if fib6_info already exists */
5168                 if (rt6_duplicate_nexthop(nh->fib6_info, rt))
5169                         return err;
5170         }
5171
5172         nh = kzalloc(sizeof(*nh), GFP_KERNEL);
5173         if (!nh)
5174                 return -ENOMEM;
5175         nh->fib6_info = rt;
5176         memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
5177         list_add_tail(&nh->next, rt6_nh_list);
5178
5179         return 0;
5180 }
5181
5182 static void ip6_route_mpath_notify(struct fib6_info *rt,
5183                                    struct fib6_info *rt_last,
5184                                    struct nl_info *info,
5185                                    __u16 nlflags)
5186 {
5187         /* if this is an APPEND route, then rt points to the first route
5188          * inserted and rt_last points to last route inserted. Userspace
5189          * wants a consistent dump of the route which starts at the first
5190          * nexthop. Since sibling routes are always added at the end of
5191          * the list, find the first sibling of the last route appended
5192          */
5193         if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
5194                 rt = list_first_entry(&rt_last->fib6_siblings,
5195                                       struct fib6_info,
5196                                       fib6_siblings);
5197         }
5198
5199         if (rt)
5200                 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
5201 }
5202
5203 static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
5204 {
5205         bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
5206         bool should_notify = false;
5207         struct fib6_info *leaf;
5208         struct fib6_node *fn;
5209
5210         rcu_read_lock();
5211         fn = rcu_dereference(rt->fib6_node);
5212         if (!fn)
5213                 goto out;
5214
5215         leaf = rcu_dereference(fn->leaf);
5216         if (!leaf)
5217                 goto out;
5218
5219         if (rt == leaf ||
5220             (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric &&
5221              rt6_qualify_for_ecmp(leaf)))
5222                 should_notify = true;
5223 out:
5224         rcu_read_unlock();
5225
5226         return should_notify;
5227 }
5228
5229 static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla,
5230                              struct netlink_ext_ack *extack)
5231 {
5232         if (nla_len(nla) < sizeof(*gw)) {
5233                 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY");
5234                 return -EINVAL;
5235         }
5236
5237         *gw = nla_get_in6_addr(nla);
5238
5239         return 0;
5240 }
5241
5242 static int ip6_route_multipath_add(struct fib6_config *cfg,
5243                                    struct netlink_ext_ack *extack)
5244 {
5245         struct fib6_info *rt_notif = NULL, *rt_last = NULL;
5246         struct nl_info *info = &cfg->fc_nlinfo;
5247         struct fib6_config r_cfg;
5248         struct rtnexthop *rtnh;
5249         struct fib6_info *rt;
5250         struct rt6_nh *err_nh;
5251         struct rt6_nh *nh, *nh_safe;
5252         __u16 nlflags;
5253         int remaining;
5254         int attrlen;
5255         int err = 1;
5256         int nhn = 0;
5257         int replace = (cfg->fc_nlinfo.nlh &&
5258                        (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
5259         LIST_HEAD(rt6_nh_list);
5260
5261         nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
5262         if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
5263                 nlflags |= NLM_F_APPEND;
5264
5265         remaining = cfg->fc_mp_len;
5266         rtnh = (struct rtnexthop *)cfg->fc_mp;
5267
5268         /* Parse a Multipath Entry and build a list (rt6_nh_list) of
5269          * fib6_info structs per nexthop
5270          */
5271         while (rtnh_ok(rtnh, remaining)) {
5272                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5273                 if (rtnh->rtnh_ifindex)
5274                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5275
5276                 attrlen = rtnh_attrlen(rtnh);
5277                 if (attrlen > 0) {
5278                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5279
5280                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5281                         if (nla) {
5282                                 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5283                                                         extack);
5284                                 if (err)
5285                                         goto cleanup;
5286
5287                                 r_cfg.fc_flags |= RTF_GATEWAY;
5288                         }
5289                         r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
5290
5291                         /* RTA_ENCAP_TYPE length checked in
5292                          * lwtunnel_valid_encap_type_attr
5293                          */
5294                         nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
5295                         if (nla)
5296                                 r_cfg.fc_encap_type = nla_get_u16(nla);
5297                 }
5298
5299                 r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
5300                 rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
5301                 if (IS_ERR(rt)) {
5302                         err = PTR_ERR(rt);
5303                         rt = NULL;
5304                         goto cleanup;
5305                 }
5306                 if (!rt6_qualify_for_ecmp(rt)) {
5307                         err = -EINVAL;
5308                         NL_SET_ERR_MSG(extack,
5309                                        "Device only routes can not be added for IPv6 using the multipath API.");
5310                         fib6_info_release(rt);
5311                         goto cleanup;
5312                 }
5313
5314                 rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
5315
5316                 err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
5317                                             rt, &r_cfg);
5318                 if (err) {
5319                         fib6_info_release(rt);
5320                         goto cleanup;
5321                 }
5322
5323                 rtnh = rtnh_next(rtnh, &remaining);
5324         }
5325
5326         if (list_empty(&rt6_nh_list)) {
5327                 NL_SET_ERR_MSG(extack,
5328                                "Invalid nexthop configuration - no valid nexthops");
5329                 return -EINVAL;
5330         }
5331
5332         /* for add and replace send one notification with all nexthops.
5333          * Skip the notification in fib6_add_rt2node and send one with
5334          * the full route when done
5335          */
5336         info->skip_notify = 1;
5337
5338         /* For add and replace, send one notification with all nexthops. For
5339          * append, send one notification with all appended nexthops.
5340          */
5341         info->skip_notify_kernel = 1;
5342
5343         err_nh = NULL;
5344         list_for_each_entry(nh, &rt6_nh_list, next) {
5345                 err = __ip6_ins_rt(nh->fib6_info, info, extack);
5346
5347                 if (err) {
5348                         if (replace && nhn)
5349                                 NL_SET_ERR_MSG_MOD(extack,
5350                                                    "multipath route replace failed (check consistency of installed routes)");
5351                         err_nh = nh;
5352                         goto add_errout;
5353                 }
5354                 /* save reference to last route successfully inserted */
5355                 rt_last = nh->fib6_info;
5356
5357                 /* save reference to first route for notification */
5358                 if (!rt_notif)
5359                         rt_notif = nh->fib6_info;
5360
5361                 /* Because each route is added like a single route we remove
5362                  * these flags after the first nexthop: if there is a collision,
5363                  * we have already failed to add the first nexthop:
5364                  * fib6_add_rt2node() has rejected it; when replacing, old
5365                  * nexthops have been replaced by first new, the rest should
5366                  * be added to it.
5367                  */
5368                 if (cfg->fc_nlinfo.nlh) {
5369                         cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
5370                                                              NLM_F_REPLACE);
5371                         cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
5372                 }
5373                 nhn++;
5374         }
5375
5376         /* An in-kernel notification should only be sent in case the new
5377          * multipath route is added as the first route in the node, or if
5378          * it was appended to it. We pass 'rt_notif' since it is the first
5379          * sibling and might allow us to skip some checks in the replace case.
5380          */
5381         if (ip6_route_mpath_should_notify(rt_notif)) {
5382                 enum fib_event_type fib_event;
5383
5384                 if (rt_notif->fib6_nsiblings != nhn - 1)
5385                         fib_event = FIB_EVENT_ENTRY_APPEND;
5386                 else
5387                         fib_event = FIB_EVENT_ENTRY_REPLACE;
5388
5389                 err = call_fib6_multipath_entry_notifiers(info->nl_net,
5390                                                           fib_event, rt_notif,
5391                                                           nhn - 1, extack);
5392                 if (err) {
5393                         /* Delete all the siblings that were just added */
5394                         err_nh = NULL;
5395                         goto add_errout;
5396                 }
5397         }
5398
5399         /* success ... tell user about new route */
5400         ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5401         goto cleanup;
5402
5403 add_errout:
5404         /* send notification for routes that were added so that
5405          * the delete notifications sent by ip6_route_del are
5406          * coherent
5407          */
5408         if (rt_notif)
5409                 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5410
5411         /* Delete routes that were already added */
5412         list_for_each_entry(nh, &rt6_nh_list, next) {
5413                 if (err_nh == nh)
5414                         break;
5415                 ip6_route_del(&nh->r_cfg, extack);
5416         }
5417
5418 cleanup:
5419         list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
5420                 fib6_info_release(nh->fib6_info);
5421                 list_del(&nh->next);
5422                 kfree(nh);
5423         }
5424
5425         return err;
5426 }
5427
5428 static int ip6_route_multipath_del(struct fib6_config *cfg,
5429                                    struct netlink_ext_ack *extack)
5430 {
5431         struct fib6_config r_cfg;
5432         struct rtnexthop *rtnh;
5433         int last_err = 0;
5434         int remaining;
5435         int attrlen;
5436         int err;
5437
5438         remaining = cfg->fc_mp_len;
5439         rtnh = (struct rtnexthop *)cfg->fc_mp;
5440
5441         /* Parse a Multipath Entry */
5442         while (rtnh_ok(rtnh, remaining)) {
5443                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5444                 if (rtnh->rtnh_ifindex)
5445                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5446
5447                 attrlen = rtnh_attrlen(rtnh);
5448                 if (attrlen > 0) {
5449                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5450
5451                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5452                         if (nla) {
5453                                 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5454                                                         extack);
5455                                 if (err) {
5456                                         last_err = err;
5457                                         goto next_rtnh;
5458                                 }
5459
5460                                 r_cfg.fc_flags |= RTF_GATEWAY;
5461                         }
5462                 }
5463                 err = ip6_route_del(&r_cfg, extack);
5464                 if (err)
5465                         last_err = err;
5466
5467 next_rtnh:
5468                 rtnh = rtnh_next(rtnh, &remaining);
5469         }
5470
5471         return last_err;
5472 }
5473
5474 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5475                               struct netlink_ext_ack *extack)
5476 {
5477         struct fib6_config cfg;
5478         int err;
5479
5480         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5481         if (err < 0)
5482                 return err;
5483
5484         if (cfg.fc_nh_id &&
5485             !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {
5486                 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
5487                 return -EINVAL;
5488         }
5489
5490         if (cfg.fc_mp)
5491                 return ip6_route_multipath_del(&cfg, extack);
5492         else {
5493                 cfg.fc_delete_all_nh = 1;
5494                 return ip6_route_del(&cfg, extack);
5495         }
5496 }
5497
5498 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5499                               struct netlink_ext_ack *extack)
5500 {
5501         struct fib6_config cfg;
5502         int err;
5503
5504         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5505         if (err < 0)
5506                 return err;
5507
5508         if (cfg.fc_metric == 0)
5509                 cfg.fc_metric = IP6_RT_PRIO_USER;
5510
5511         if (cfg.fc_mp)
5512                 return ip6_route_multipath_add(&cfg, extack);
5513         else
5514                 return ip6_route_add(&cfg, GFP_KERNEL, extack);
5515 }
5516
5517 /* add the overhead of this fib6_nh to nexthop_len */
5518 static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg)
5519 {
5520         int *nexthop_len = arg;
5521
5522         *nexthop_len += nla_total_size(0)        /* RTA_MULTIPATH */
5523                      + NLA_ALIGN(sizeof(struct rtnexthop))
5524                      + nla_total_size(16); /* RTA_GATEWAY */
5525
5526         if (nh->fib_nh_lws) {
5527                 /* RTA_ENCAP_TYPE */
5528                 *nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5529                 /* RTA_ENCAP */
5530                 *nexthop_len += nla_total_size(2);
5531         }
5532
5533         return 0;
5534 }
5535
5536 static size_t rt6_nlmsg_size(struct fib6_info *f6i)
5537 {
5538         int nexthop_len;
5539
5540         if (f6i->nh) {
5541                 nexthop_len = nla_total_size(4); /* RTA_NH_ID */
5542                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
5543                                          &nexthop_len);
5544         } else {
5545                 struct fib6_info *sibling, *next_sibling;
5546                 struct fib6_nh *nh = f6i->fib6_nh;
5547
5548                 nexthop_len = 0;
5549                 if (f6i->fib6_nsiblings) {
5550                         rt6_nh_nlmsg_size(nh, &nexthop_len);
5551
5552                         list_for_each_entry_safe(sibling, next_sibling,
5553                                                  &f6i->fib6_siblings, fib6_siblings) {
5554                                 rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len);
5555                         }
5556                 }
5557                 nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5558         }
5559
5560         return NLMSG_ALIGN(sizeof(struct rtmsg))
5561                + nla_total_size(16) /* RTA_SRC */
5562                + nla_total_size(16) /* RTA_DST */
5563                + nla_total_size(16) /* RTA_GATEWAY */
5564                + nla_total_size(16) /* RTA_PREFSRC */
5565                + nla_total_size(4) /* RTA_TABLE */
5566                + nla_total_size(4) /* RTA_IIF */
5567                + nla_total_size(4) /* RTA_OIF */
5568                + nla_total_size(4) /* RTA_PRIORITY */
5569                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
5570                + nla_total_size(sizeof(struct rta_cacheinfo))
5571                + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
5572                + nla_total_size(1) /* RTA_PREF */
5573                + nexthop_len;
5574 }
5575
5576 static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh,
5577                                  unsigned char *flags)
5578 {
5579         if (nexthop_is_multipath(nh)) {
5580                 struct nlattr *mp;
5581
5582                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5583                 if (!mp)
5584                         goto nla_put_failure;
5585
5586                 if (nexthop_mpath_fill_node(skb, nh, AF_INET6))
5587                         goto nla_put_failure;
5588
5589                 nla_nest_end(skb, mp);
5590         } else {
5591                 struct fib6_nh *fib6_nh;
5592
5593                 fib6_nh = nexthop_fib6_nh(nh);
5594                 if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,
5595                                      flags, false) < 0)
5596                         goto nla_put_failure;
5597         }
5598
5599         return 0;
5600
5601 nla_put_failure:
5602         return -EMSGSIZE;
5603 }
5604
5605 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
5606                          struct fib6_info *rt, struct dst_entry *dst,
5607                          struct in6_addr *dest, struct in6_addr *src,
5608                          int iif, int type, u32 portid, u32 seq,
5609                          unsigned int flags)
5610 {
5611         struct rt6_info *rt6 = (struct rt6_info *)dst;
5612         struct rt6key *rt6_dst, *rt6_src;
5613         u32 *pmetrics, table, rt6_flags;
5614         unsigned char nh_flags = 0;
5615         struct nlmsghdr *nlh;
5616         struct rtmsg *rtm;
5617         long expires = 0;
5618
5619         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
5620         if (!nlh)
5621                 return -EMSGSIZE;
5622
5623         if (rt6) {
5624                 rt6_dst = &rt6->rt6i_dst;
5625                 rt6_src = &rt6->rt6i_src;
5626                 rt6_flags = rt6->rt6i_flags;
5627         } else {
5628                 rt6_dst = &rt->fib6_dst;
5629                 rt6_src = &rt->fib6_src;
5630                 rt6_flags = rt->fib6_flags;
5631         }
5632
5633         rtm = nlmsg_data(nlh);
5634         rtm->rtm_family = AF_INET6;
5635         rtm->rtm_dst_len = rt6_dst->plen;
5636         rtm->rtm_src_len = rt6_src->plen;
5637         rtm->rtm_tos = 0;
5638         if (rt->fib6_table)
5639                 table = rt->fib6_table->tb6_id;
5640         else
5641                 table = RT6_TABLE_UNSPEC;
5642         rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
5643         if (nla_put_u32(skb, RTA_TABLE, table))
5644                 goto nla_put_failure;
5645
5646         rtm->rtm_type = rt->fib6_type;
5647         rtm->rtm_flags = 0;
5648         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
5649         rtm->rtm_protocol = rt->fib6_protocol;
5650
5651         if (rt6_flags & RTF_CACHE)
5652                 rtm->rtm_flags |= RTM_F_CLONED;
5653
5654         if (dest) {
5655                 if (nla_put_in6_addr(skb, RTA_DST, dest))
5656                         goto nla_put_failure;
5657                 rtm->rtm_dst_len = 128;
5658         } else if (rtm->rtm_dst_len)
5659                 if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
5660                         goto nla_put_failure;
5661 #ifdef CONFIG_IPV6_SUBTREES
5662         if (src) {
5663                 if (nla_put_in6_addr(skb, RTA_SRC, src))
5664                         goto nla_put_failure;
5665                 rtm->rtm_src_len = 128;
5666         } else if (rtm->rtm_src_len &&
5667                    nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
5668                 goto nla_put_failure;
5669 #endif
5670         if (iif) {
5671 #ifdef CONFIG_IPV6_MROUTE
5672                 if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
5673                         int err = ip6mr_get_route(net, skb, rtm, portid);
5674
5675                         if (err == 0)
5676                                 return 0;
5677                         if (err < 0)
5678                                 goto nla_put_failure;
5679                 } else
5680 #endif
5681                         if (nla_put_u32(skb, RTA_IIF, iif))
5682                                 goto nla_put_failure;
5683         } else if (dest) {
5684                 struct in6_addr saddr_buf;
5685                 if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 &&
5686                     nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5687                         goto nla_put_failure;
5688         }
5689
5690         if (rt->fib6_prefsrc.plen) {
5691                 struct in6_addr saddr_buf;
5692                 saddr_buf = rt->fib6_prefsrc.addr;
5693                 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5694                         goto nla_put_failure;
5695         }
5696
5697         pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
5698         if (rtnetlink_put_metrics(skb, pmetrics) < 0)
5699                 goto nla_put_failure;
5700
5701         if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
5702                 goto nla_put_failure;
5703
5704         /* For multipath routes, walk the siblings list and add
5705          * each as a nexthop within RTA_MULTIPATH.
5706          */
5707         if (rt6) {
5708                 if (rt6_flags & RTF_GATEWAY &&
5709                     nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
5710                         goto nla_put_failure;
5711
5712                 if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
5713                         goto nla_put_failure;
5714
5715                 if (dst->lwtstate &&
5716                     lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
5717                         goto nla_put_failure;
5718         } else if (rt->fib6_nsiblings) {
5719                 struct fib6_info *sibling, *next_sibling;
5720                 struct nlattr *mp;
5721
5722                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5723                 if (!mp)
5724                         goto nla_put_failure;
5725
5726                 if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
5727                                     rt->fib6_nh->fib_nh_weight, AF_INET6,
5728                                     0) < 0)
5729                         goto nla_put_failure;
5730
5731                 list_for_each_entry_safe(sibling, next_sibling,
5732                                          &rt->fib6_siblings, fib6_siblings) {
5733                         if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
5734                                             sibling->fib6_nh->fib_nh_weight,
5735                                             AF_INET6, 0) < 0)
5736                                 goto nla_put_failure;
5737                 }
5738
5739                 nla_nest_end(skb, mp);
5740         } else if (rt->nh) {
5741                 if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
5742                         goto nla_put_failure;
5743
5744                 if (nexthop_is_blackhole(rt->nh))
5745                         rtm->rtm_type = RTN_BLACKHOLE;
5746
5747                 if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) &&
5748                     rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0)
5749                         goto nla_put_failure;
5750
5751                 rtm->rtm_flags |= nh_flags;
5752         } else {
5753                 if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,
5754                                      &nh_flags, false) < 0)
5755                         goto nla_put_failure;
5756
5757                 rtm->rtm_flags |= nh_flags;
5758         }
5759
5760         if (rt6_flags & RTF_EXPIRES) {
5761                 expires = dst ? dst->expires : rt->expires;
5762                 expires -= jiffies;
5763         }
5764
5765         if (!dst) {
5766                 if (READ_ONCE(rt->offload))
5767                         rtm->rtm_flags |= RTM_F_OFFLOAD;
5768                 if (READ_ONCE(rt->trap))
5769                         rtm->rtm_flags |= RTM_F_TRAP;
5770                 if (READ_ONCE(rt->offload_failed))
5771                         rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED;
5772         }
5773
5774         if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
5775                 goto nla_put_failure;
5776
5777         if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
5778                 goto nla_put_failure;
5779
5780
5781         nlmsg_end(skb, nlh);
5782         return 0;
5783
5784 nla_put_failure:
5785         nlmsg_cancel(skb, nlh);
5786         return -EMSGSIZE;
5787 }
5788
5789 static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg)
5790 {
5791         const struct net_device *dev = arg;
5792
5793         if (nh->fib_nh_dev == dev)
5794                 return 1;
5795
5796         return 0;
5797 }
5798
5799 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
5800                                const struct net_device *dev)
5801 {
5802         if (f6i->nh) {
5803                 struct net_device *_dev = (struct net_device *)dev;
5804
5805                 return !!nexthop_for_each_fib6_nh(f6i->nh,
5806                                                   fib6_info_nh_uses_dev,
5807                                                   _dev);
5808         }
5809
5810         if (f6i->fib6_nh->fib_nh_dev == dev)
5811                 return true;
5812
5813         if (f6i->fib6_nsiblings) {
5814                 struct fib6_info *sibling, *next_sibling;
5815
5816                 list_for_each_entry_safe(sibling, next_sibling,
5817                                          &f6i->fib6_siblings, fib6_siblings) {
5818                         if (sibling->fib6_nh->fib_nh_dev == dev)
5819                                 return true;
5820                 }
5821         }
5822
5823         return false;
5824 }
5825
5826 struct fib6_nh_exception_dump_walker {
5827         struct rt6_rtnl_dump_arg *dump;
5828         struct fib6_info *rt;
5829         unsigned int flags;
5830         unsigned int skip;
5831         unsigned int count;
5832 };
5833
5834 static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg)
5835 {
5836         struct fib6_nh_exception_dump_walker *w = arg;
5837         struct rt6_rtnl_dump_arg *dump = w->dump;
5838         struct rt6_exception_bucket *bucket;
5839         struct rt6_exception *rt6_ex;
5840         int i, err;
5841
5842         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
5843         if (!bucket)
5844                 return 0;
5845
5846         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
5847                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
5848                         if (w->skip) {
5849                                 w->skip--;
5850                                 continue;
5851                         }
5852
5853                         /* Expiration of entries doesn't bump sernum, insertion
5854                          * does. Removal is triggered by insertion, so we can
5855                          * rely on the fact that if entries change between two
5856                          * partial dumps, this node is scanned again completely,
5857                          * see rt6_insert_exception() and fib6_dump_table().
5858                          *
5859                          * Count expired entries we go through as handled
5860                          * entries that we'll skip next time, in case of partial
5861                          * node dump. Otherwise, if entries expire meanwhile,
5862                          * we'll skip the wrong amount.
5863                          */
5864                         if (rt6_check_expired(rt6_ex->rt6i)) {
5865                                 w->count++;
5866                                 continue;
5867                         }
5868
5869                         err = rt6_fill_node(dump->net, dump->skb, w->rt,
5870                                             &rt6_ex->rt6i->dst, NULL, NULL, 0,
5871                                             RTM_NEWROUTE,
5872                                             NETLINK_CB(dump->cb->skb).portid,
5873                                             dump->cb->nlh->nlmsg_seq, w->flags);
5874                         if (err)
5875                                 return err;
5876
5877                         w->count++;
5878                 }
5879                 bucket++;
5880         }
5881
5882         return 0;
5883 }
5884
5885 /* Return -1 if done with node, number of handled routes on partial dump */
5886 int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip)
5887 {
5888         struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
5889         struct fib_dump_filter *filter = &arg->filter;
5890         unsigned int flags = NLM_F_MULTI;
5891         struct net *net = arg->net;
5892         int count = 0;
5893
5894         if (rt == net->ipv6.fib6_null_entry)
5895                 return -1;
5896
5897         if ((filter->flags & RTM_F_PREFIX) &&
5898             !(rt->fib6_flags & RTF_PREFIX_RT)) {
5899                 /* success since this is not a prefix route */
5900                 return -1;
5901         }
5902         if (filter->filter_set &&
5903             ((filter->rt_type  && rt->fib6_type != filter->rt_type) ||
5904              (filter->dev      && !fib6_info_uses_dev(rt, filter->dev)) ||
5905              (filter->protocol && rt->fib6_protocol != filter->protocol))) {
5906                 return -1;
5907         }
5908
5909         if (filter->filter_set ||
5910             !filter->dump_routes || !filter->dump_exceptions) {
5911                 flags |= NLM_F_DUMP_FILTERED;
5912         }
5913
5914         if (filter->dump_routes) {
5915                 if (skip) {
5916                         skip--;
5917                 } else {
5918                         if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL,
5919                                           0, RTM_NEWROUTE,
5920                                           NETLINK_CB(arg->cb->skb).portid,
5921                                           arg->cb->nlh->nlmsg_seq, flags)) {
5922                                 return 0;
5923                         }
5924                         count++;
5925                 }
5926         }
5927
5928         if (filter->dump_exceptions) {
5929                 struct fib6_nh_exception_dump_walker w = { .dump = arg,
5930                                                            .rt = rt,
5931                                                            .flags = flags,
5932                                                            .skip = skip,
5933                                                            .count = 0 };
5934                 int err;
5935
5936                 rcu_read_lock();
5937                 if (rt->nh) {
5938                         err = nexthop_for_each_fib6_nh(rt->nh,
5939                                                        rt6_nh_dump_exceptions,
5940                                                        &w);
5941                 } else {
5942                         err = rt6_nh_dump_exceptions(rt->fib6_nh, &w);
5943                 }
5944                 rcu_read_unlock();
5945
5946                 if (err)
5947                         return count + w.count;
5948         }
5949
5950         return -1;
5951 }
5952
5953 static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
5954                                         const struct nlmsghdr *nlh,
5955                                         struct nlattr **tb,
5956                                         struct netlink_ext_ack *extack)
5957 {
5958         struct rtmsg *rtm;
5959         int i, err;
5960
5961         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
5962                 NL_SET_ERR_MSG_MOD(extack,
5963                                    "Invalid header for get route request");
5964                 return -EINVAL;
5965         }
5966
5967         if (!netlink_strict_get_check(skb))
5968                 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5969                                               rtm_ipv6_policy, extack);
5970
5971         rtm = nlmsg_data(nlh);
5972         if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
5973             (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
5974             rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
5975             rtm->rtm_type) {
5976                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
5977                 return -EINVAL;
5978         }
5979         if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
5980                 NL_SET_ERR_MSG_MOD(extack,
5981                                    "Invalid flags for get route request");
5982                 return -EINVAL;
5983         }
5984
5985         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
5986                                             rtm_ipv6_policy, extack);
5987         if (err)
5988                 return err;
5989
5990         if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
5991             (tb[RTA_DST] && !rtm->rtm_dst_len)) {
5992                 NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
5993                 return -EINVAL;
5994         }
5995
5996         for (i = 0; i <= RTA_MAX; i++) {
5997                 if (!tb[i])
5998                         continue;
5999
6000                 switch (i) {
6001                 case RTA_SRC:
6002                 case RTA_DST:
6003                 case RTA_IIF:
6004                 case RTA_OIF:
6005                 case RTA_MARK:
6006                 case RTA_UID:
6007                 case RTA_SPORT:
6008                 case RTA_DPORT:
6009                 case RTA_IP_PROTO:
6010                         break;
6011                 default:
6012                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
6013                         return -EINVAL;
6014                 }
6015         }
6016
6017         return 0;
6018 }
6019
6020 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
6021                               struct netlink_ext_ack *extack)
6022 {
6023         struct net *net = sock_net(in_skb->sk);
6024         struct nlattr *tb[RTA_MAX+1];
6025         int err, iif = 0, oif = 0;
6026         struct fib6_info *from;
6027         struct dst_entry *dst;
6028         struct rt6_info *rt;
6029         struct sk_buff *skb;
6030         struct rtmsg *rtm;
6031         struct flowi6 fl6 = {};
6032         bool fibmatch;
6033
6034         err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
6035         if (err < 0)
6036                 goto errout;
6037
6038         err = -EINVAL;
6039         rtm = nlmsg_data(nlh);
6040         fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
6041         fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
6042
6043         if (tb[RTA_SRC]) {
6044                 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
6045                         goto errout;
6046
6047                 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
6048         }
6049
6050         if (tb[RTA_DST]) {
6051                 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
6052                         goto errout;
6053
6054                 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
6055         }
6056
6057         if (tb[RTA_IIF])
6058                 iif = nla_get_u32(tb[RTA_IIF]);
6059
6060         if (tb[RTA_OIF])
6061                 oif = nla_get_u32(tb[RTA_OIF]);
6062
6063         if (tb[RTA_MARK])
6064                 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
6065
6066         if (tb[RTA_UID])
6067                 fl6.flowi6_uid = make_kuid(current_user_ns(),
6068                                            nla_get_u32(tb[RTA_UID]));
6069         else
6070                 fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
6071
6072         if (tb[RTA_SPORT])
6073                 fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
6074
6075         if (tb[RTA_DPORT])
6076                 fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
6077
6078         if (tb[RTA_IP_PROTO]) {
6079                 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
6080                                                   &fl6.flowi6_proto, AF_INET6,
6081                                                   extack);
6082                 if (err)
6083                         goto errout;
6084         }
6085
6086         if (iif) {
6087                 struct net_device *dev;
6088                 int flags = 0;
6089
6090                 rcu_read_lock();
6091
6092                 dev = dev_get_by_index_rcu(net, iif);
6093                 if (!dev) {
6094                         rcu_read_unlock();
6095                         err = -ENODEV;
6096                         goto errout;
6097                 }
6098
6099                 fl6.flowi6_iif = iif;
6100
6101                 if (!ipv6_addr_any(&fl6.saddr))
6102                         flags |= RT6_LOOKUP_F_HAS_SADDR;
6103
6104                 dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
6105
6106                 rcu_read_unlock();
6107         } else {
6108                 fl6.flowi6_oif = oif;
6109
6110                 dst = ip6_route_output(net, NULL, &fl6);
6111         }
6112
6113
6114         rt = container_of(dst, struct rt6_info, dst);
6115         if (rt->dst.error) {
6116                 err = rt->dst.error;
6117                 ip6_rt_put(rt);
6118                 goto errout;
6119         }
6120
6121         if (rt == net->ipv6.ip6_null_entry) {
6122                 err = rt->dst.error;
6123                 ip6_rt_put(rt);
6124                 goto errout;
6125         }
6126
6127         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
6128         if (!skb) {
6129                 ip6_rt_put(rt);
6130                 err = -ENOBUFS;
6131                 goto errout;
6132         }
6133
6134         skb_dst_set(skb, &rt->dst);
6135
6136         rcu_read_lock();
6137         from = rcu_dereference(rt->from);
6138         if (from) {
6139                 if (fibmatch)
6140                         err = rt6_fill_node(net, skb, from, NULL, NULL, NULL,
6141                                             iif, RTM_NEWROUTE,
6142                                             NETLINK_CB(in_skb).portid,
6143                                             nlh->nlmsg_seq, 0);
6144                 else
6145                         err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
6146                                             &fl6.saddr, iif, RTM_NEWROUTE,
6147                                             NETLINK_CB(in_skb).portid,
6148                                             nlh->nlmsg_seq, 0);
6149         } else {
6150                 err = -ENETUNREACH;
6151         }
6152         rcu_read_unlock();
6153
6154         if (err < 0) {
6155                 kfree_skb(skb);
6156                 goto errout;
6157         }
6158
6159         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
6160 errout:
6161         return err;
6162 }
6163
6164 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
6165                      unsigned int nlm_flags)
6166 {
6167         struct sk_buff *skb;
6168         struct net *net = info->nl_net;
6169         u32 seq;
6170         int err;
6171
6172         err = -ENOBUFS;
6173         seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6174
6175         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6176         if (!skb)
6177                 goto errout;
6178
6179         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6180                             event, info->portid, seq, nlm_flags);
6181         if (err < 0) {
6182                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6183                 WARN_ON(err == -EMSGSIZE);
6184                 kfree_skb(skb);
6185                 goto errout;
6186         }
6187         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6188                     info->nlh, gfp_any());
6189         return;
6190 errout:
6191         if (err < 0)
6192                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6193 }
6194
6195 void fib6_rt_update(struct net *net, struct fib6_info *rt,
6196                     struct nl_info *info)
6197 {
6198         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6199         struct sk_buff *skb;
6200         int err = -ENOBUFS;
6201
6202         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6203         if (!skb)
6204                 goto errout;
6205
6206         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6207                             RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
6208         if (err < 0) {
6209                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6210                 WARN_ON(err == -EMSGSIZE);
6211                 kfree_skb(skb);
6212                 goto errout;
6213         }
6214         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6215                     info->nlh, gfp_any());
6216         return;
6217 errout:
6218         if (err < 0)
6219                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6220 }
6221
6222 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
6223                             bool offload, bool trap, bool offload_failed)
6224 {
6225         struct sk_buff *skb;
6226         int err;
6227
6228         if (READ_ONCE(f6i->offload) == offload &&
6229             READ_ONCE(f6i->trap) == trap &&
6230             READ_ONCE(f6i->offload_failed) == offload_failed)
6231                 return;
6232
6233         WRITE_ONCE(f6i->offload, offload);
6234         WRITE_ONCE(f6i->trap, trap);
6235
6236         /* 2 means send notifications only if offload_failed was changed. */
6237         if (net->ipv6.sysctl.fib_notify_on_flag_change == 2 &&
6238             READ_ONCE(f6i->offload_failed) == offload_failed)
6239                 return;
6240
6241         WRITE_ONCE(f6i->offload_failed, offload_failed);
6242
6243         if (!rcu_access_pointer(f6i->fib6_node))
6244                 /* The route was removed from the tree, do not send
6245                  * notification.
6246                  */
6247                 return;
6248
6249         if (!net->ipv6.sysctl.fib_notify_on_flag_change)
6250                 return;
6251
6252         skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL);
6253         if (!skb) {
6254                 err = -ENOBUFS;
6255                 goto errout;
6256         }
6257
6258         err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0,
6259                             0, 0);
6260         if (err < 0) {
6261                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6262                 WARN_ON(err == -EMSGSIZE);
6263                 kfree_skb(skb);
6264                 goto errout;
6265         }
6266
6267         rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL);
6268         return;
6269
6270 errout:
6271         rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6272 }
6273 EXPORT_SYMBOL(fib6_info_hw_flags_set);
6274
6275 static int ip6_route_dev_notify(struct notifier_block *this,
6276                                 unsigned long event, void *ptr)
6277 {
6278         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
6279         struct net *net = dev_net(dev);
6280
6281         if (!(dev->flags & IFF_LOOPBACK))
6282                 return NOTIFY_OK;
6283
6284         if (event == NETDEV_REGISTER) {
6285                 net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev;
6286                 net->ipv6.ip6_null_entry->dst.dev = dev;
6287                 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
6288 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6289                 net->ipv6.ip6_prohibit_entry->dst.dev = dev;
6290                 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
6291                 net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
6292                 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
6293 #endif
6294          } else if (event == NETDEV_UNREGISTER &&
6295                     dev->reg_state != NETREG_UNREGISTERED) {
6296                 /* NETDEV_UNREGISTER could be fired for multiple times by
6297                  * netdev_wait_allrefs(). Make sure we only call this once.
6298                  */
6299                 in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
6300 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6301                 in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
6302                 in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
6303 #endif
6304         }
6305
6306         return NOTIFY_OK;
6307 }
6308
6309 /*
6310  *      /proc
6311  */
6312
6313 #ifdef CONFIG_PROC_FS
6314 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
6315 {
6316         struct net *net = (struct net *)seq->private;
6317         seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
6318                    net->ipv6.rt6_stats->fib_nodes,
6319                    net->ipv6.rt6_stats->fib_route_nodes,
6320                    atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
6321                    net->ipv6.rt6_stats->fib_rt_entries,
6322                    net->ipv6.rt6_stats->fib_rt_cache,
6323                    dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
6324                    net->ipv6.rt6_stats->fib_discarded_routes);
6325
6326         return 0;
6327 }
6328 #endif  /* CONFIG_PROC_FS */
6329
6330 #ifdef CONFIG_SYSCTL
6331
6332 static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
6333                               void *buffer, size_t *lenp, loff_t *ppos)
6334 {
6335         struct net *net;
6336         int delay;
6337         int ret;
6338         if (!write)
6339                 return -EINVAL;
6340
6341         net = (struct net *)ctl->extra1;
6342         delay = net->ipv6.sysctl.flush_delay;
6343         ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
6344         if (ret)
6345                 return ret;
6346
6347         fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
6348         return 0;
6349 }
6350
6351 static struct ctl_table ipv6_route_table_template[] = {
6352         {
6353                 .procname       =       "max_size",
6354                 .data           =       &init_net.ipv6.sysctl.ip6_rt_max_size,
6355                 .maxlen         =       sizeof(int),
6356                 .mode           =       0644,
6357                 .proc_handler   =       proc_dointvec,
6358         },
6359         {
6360                 .procname       =       "gc_thresh",
6361                 .data           =       &ip6_dst_ops_template.gc_thresh,
6362                 .maxlen         =       sizeof(int),
6363                 .mode           =       0644,
6364                 .proc_handler   =       proc_dointvec,
6365         },
6366         {
6367                 .procname       =       "flush",
6368                 .data           =       &init_net.ipv6.sysctl.flush_delay,
6369                 .maxlen         =       sizeof(int),
6370                 .mode           =       0200,
6371                 .proc_handler   =       ipv6_sysctl_rtcache_flush
6372         },
6373         {
6374                 .procname       =       "gc_min_interval",
6375                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6376                 .maxlen         =       sizeof(int),
6377                 .mode           =       0644,
6378                 .proc_handler   =       proc_dointvec_jiffies,
6379         },
6380         {
6381                 .procname       =       "gc_timeout",
6382                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
6383                 .maxlen         =       sizeof(int),
6384                 .mode           =       0644,
6385                 .proc_handler   =       proc_dointvec_jiffies,
6386         },
6387         {
6388                 .procname       =       "gc_interval",
6389                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_interval,
6390                 .maxlen         =       sizeof(int),
6391                 .mode           =       0644,
6392                 .proc_handler   =       proc_dointvec_jiffies,
6393         },
6394         {
6395                 .procname       =       "gc_elasticity",
6396                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
6397                 .maxlen         =       sizeof(int),
6398                 .mode           =       0644,
6399                 .proc_handler   =       proc_dointvec,
6400         },
6401         {
6402                 .procname       =       "mtu_expires",
6403                 .data           =       &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
6404                 .maxlen         =       sizeof(int),
6405                 .mode           =       0644,
6406                 .proc_handler   =       proc_dointvec_jiffies,
6407         },
6408         {
6409                 .procname       =       "min_adv_mss",
6410                 .data           =       &init_net.ipv6.sysctl.ip6_rt_min_advmss,
6411                 .maxlen         =       sizeof(int),
6412                 .mode           =       0644,
6413                 .proc_handler   =       proc_dointvec,
6414         },
6415         {
6416                 .procname       =       "gc_min_interval_ms",
6417                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6418                 .maxlen         =       sizeof(int),
6419                 .mode           =       0644,
6420                 .proc_handler   =       proc_dointvec_ms_jiffies,
6421         },
6422         {
6423                 .procname       =       "skip_notify_on_dev_down",
6424                 .data           =       &init_net.ipv6.sysctl.skip_notify_on_dev_down,
6425                 .maxlen         =       sizeof(u8),
6426                 .mode           =       0644,
6427                 .proc_handler   =       proc_dou8vec_minmax,
6428                 .extra1         =       SYSCTL_ZERO,
6429                 .extra2         =       SYSCTL_ONE,
6430         },
6431         { }
6432 };
6433
6434 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
6435 {
6436         struct ctl_table *table;
6437
6438         table = kmemdup(ipv6_route_table_template,
6439                         sizeof(ipv6_route_table_template),
6440                         GFP_KERNEL);
6441
6442         if (table) {
6443                 table[0].data = &net->ipv6.sysctl.ip6_rt_max_size;
6444                 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
6445                 table[2].data = &net->ipv6.sysctl.flush_delay;
6446                 table[2].extra1 = net;
6447                 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6448                 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
6449                 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
6450                 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
6451                 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
6452                 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
6453                 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6454                 table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
6455
6456                 /* Don't export sysctls to unprivileged users */
6457                 if (net->user_ns != &init_user_ns)
6458                         table[1].procname = NULL;
6459         }
6460
6461         return table;
6462 }
6463
6464 size_t ipv6_route_sysctl_table_size(struct net *net)
6465 {
6466         /* Don't export sysctls to unprivileged users */
6467         if (net->user_ns != &init_user_ns)
6468                 return 1;
6469
6470         return ARRAY_SIZE(ipv6_route_table_template);
6471 }
6472 #endif
6473
6474 static int __net_init ip6_route_net_init(struct net *net)
6475 {
6476         int ret = -ENOMEM;
6477
6478         memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
6479                sizeof(net->ipv6.ip6_dst_ops));
6480
6481         if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
6482                 goto out_ip6_dst_ops;
6483
6484         net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true);
6485         if (!net->ipv6.fib6_null_entry)
6486                 goto out_ip6_dst_entries;
6487         memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template,
6488                sizeof(*net->ipv6.fib6_null_entry));
6489
6490         net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
6491                                            sizeof(*net->ipv6.ip6_null_entry),
6492                                            GFP_KERNEL);
6493         if (!net->ipv6.ip6_null_entry)
6494                 goto out_fib6_null_entry;
6495         net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6496         dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
6497                          ip6_template_metrics, true);
6498         INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->dst.rt_uncached);
6499
6500 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6501         net->ipv6.fib6_has_custom_rules = false;
6502         net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
6503                                                sizeof(*net->ipv6.ip6_prohibit_entry),
6504                                                GFP_KERNEL);
6505         if (!net->ipv6.ip6_prohibit_entry)
6506                 goto out_ip6_null_entry;
6507         net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6508         dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
6509                          ip6_template_metrics, true);
6510         INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->dst.rt_uncached);
6511
6512         net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
6513                                                sizeof(*net->ipv6.ip6_blk_hole_entry),
6514                                                GFP_KERNEL);
6515         if (!net->ipv6.ip6_blk_hole_entry)
6516                 goto out_ip6_prohibit_entry;
6517         net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6518         dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
6519                          ip6_template_metrics, true);
6520         INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->dst.rt_uncached);
6521 #ifdef CONFIG_IPV6_SUBTREES
6522         net->ipv6.fib6_routes_require_src = 0;
6523 #endif
6524 #endif
6525
6526         net->ipv6.sysctl.flush_delay = 0;
6527         net->ipv6.sysctl.ip6_rt_max_size = INT_MAX;
6528         net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
6529         net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
6530         net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
6531         net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
6532         net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
6533         net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
6534         net->ipv6.sysctl.skip_notify_on_dev_down = 0;
6535
6536         atomic_set(&net->ipv6.ip6_rt_gc_expire, 30*HZ);
6537
6538         ret = 0;
6539 out:
6540         return ret;
6541
6542 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6543 out_ip6_prohibit_entry:
6544         kfree(net->ipv6.ip6_prohibit_entry);
6545 out_ip6_null_entry:
6546         kfree(net->ipv6.ip6_null_entry);
6547 #endif
6548 out_fib6_null_entry:
6549         kfree(net->ipv6.fib6_null_entry);
6550 out_ip6_dst_entries:
6551         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6552 out_ip6_dst_ops:
6553         goto out;
6554 }
6555
6556 static void __net_exit ip6_route_net_exit(struct net *net)
6557 {
6558         kfree(net->ipv6.fib6_null_entry);
6559         kfree(net->ipv6.ip6_null_entry);
6560 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6561         kfree(net->ipv6.ip6_prohibit_entry);
6562         kfree(net->ipv6.ip6_blk_hole_entry);
6563 #endif
6564         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6565 }
6566
6567 static int __net_init ip6_route_net_init_late(struct net *net)
6568 {
6569 #ifdef CONFIG_PROC_FS
6570         if (!proc_create_net("ipv6_route", 0, net->proc_net,
6571                              &ipv6_route_seq_ops,
6572                              sizeof(struct ipv6_route_iter)))
6573                 return -ENOMEM;
6574
6575         if (!proc_create_net_single("rt6_stats", 0444, net->proc_net,
6576                                     rt6_stats_seq_show, NULL)) {
6577                 remove_proc_entry("ipv6_route", net->proc_net);
6578                 return -ENOMEM;
6579         }
6580 #endif
6581         return 0;
6582 }
6583
6584 static void __net_exit ip6_route_net_exit_late(struct net *net)
6585 {
6586 #ifdef CONFIG_PROC_FS
6587         remove_proc_entry("ipv6_route", net->proc_net);
6588         remove_proc_entry("rt6_stats", net->proc_net);
6589 #endif
6590 }
6591
6592 static struct pernet_operations ip6_route_net_ops = {
6593         .init = ip6_route_net_init,
6594         .exit = ip6_route_net_exit,
6595 };
6596
6597 static int __net_init ipv6_inetpeer_init(struct net *net)
6598 {
6599         struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
6600
6601         if (!bp)
6602                 return -ENOMEM;
6603         inet_peer_base_init(bp);
6604         net->ipv6.peers = bp;
6605         return 0;
6606 }
6607
6608 static void __net_exit ipv6_inetpeer_exit(struct net *net)
6609 {
6610         struct inet_peer_base *bp = net->ipv6.peers;
6611
6612         net->ipv6.peers = NULL;
6613         inetpeer_invalidate_tree(bp);
6614         kfree(bp);
6615 }
6616
6617 static struct pernet_operations ipv6_inetpeer_ops = {
6618         .init   =       ipv6_inetpeer_init,
6619         .exit   =       ipv6_inetpeer_exit,
6620 };
6621
6622 static struct pernet_operations ip6_route_net_late_ops = {
6623         .init = ip6_route_net_init_late,
6624         .exit = ip6_route_net_exit_late,
6625 };
6626
6627 static struct notifier_block ip6_route_dev_notifier = {
6628         .notifier_call = ip6_route_dev_notify,
6629         .priority = ADDRCONF_NOTIFY_PRIORITY - 10,
6630 };
6631
6632 void __init ip6_route_init_special_entries(void)
6633 {
6634         /* Registering of the loopback is done before this portion of code,
6635          * the loopback reference in rt6_info will not be taken, do it
6636          * manually for init_net */
6637         init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev;
6638         init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
6639         init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6640   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6641         init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
6642         init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6643         init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
6644         init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6645   #endif
6646 }
6647
6648 #if IS_BUILTIN(CONFIG_IPV6)
6649 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6650 DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt)
6651
6652 BTF_ID_LIST(btf_fib6_info_id)
6653 BTF_ID(struct, fib6_info)
6654
6655 static const struct bpf_iter_seq_info ipv6_route_seq_info = {
6656         .seq_ops                = &ipv6_route_seq_ops,
6657         .init_seq_private       = bpf_iter_init_seq_net,
6658         .fini_seq_private       = bpf_iter_fini_seq_net,
6659         .seq_priv_size          = sizeof(struct ipv6_route_iter),
6660 };
6661
6662 static struct bpf_iter_reg ipv6_route_reg_info = {
6663         .target                 = "ipv6_route",
6664         .ctx_arg_info_size      = 1,
6665         .ctx_arg_info           = {
6666                 { offsetof(struct bpf_iter__ipv6_route, rt),
6667                   PTR_TO_BTF_ID_OR_NULL },
6668         },
6669         .seq_info               = &ipv6_route_seq_info,
6670 };
6671
6672 static int __init bpf_iter_register(void)
6673 {
6674         ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id;
6675         return bpf_iter_reg_target(&ipv6_route_reg_info);
6676 }
6677
6678 static void bpf_iter_unregister(void)
6679 {
6680         bpf_iter_unreg_target(&ipv6_route_reg_info);
6681 }
6682 #endif
6683 #endif
6684
6685 int __init ip6_route_init(void)
6686 {
6687         int ret;
6688         int cpu;
6689
6690         ret = -ENOMEM;
6691         ip6_dst_ops_template.kmem_cachep =
6692                 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
6693                                   SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
6694         if (!ip6_dst_ops_template.kmem_cachep)
6695                 goto out;
6696
6697         ret = dst_entries_init(&ip6_dst_blackhole_ops);
6698         if (ret)
6699                 goto out_kmem_cache;
6700
6701         ret = register_pernet_subsys(&ipv6_inetpeer_ops);
6702         if (ret)
6703                 goto out_dst_entries;
6704
6705         ret = register_pernet_subsys(&ip6_route_net_ops);
6706         if (ret)
6707                 goto out_register_inetpeer;
6708
6709         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
6710
6711         ret = fib6_init();
6712         if (ret)
6713                 goto out_register_subsys;
6714
6715         ret = xfrm6_init();
6716         if (ret)
6717                 goto out_fib6_init;
6718
6719         ret = fib6_rules_init();
6720         if (ret)
6721                 goto xfrm6_init;
6722
6723         ret = register_pernet_subsys(&ip6_route_net_late_ops);
6724         if (ret)
6725                 goto fib6_rules_init;
6726
6727         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
6728                                    inet6_rtm_newroute, NULL, 0);
6729         if (ret < 0)
6730                 goto out_register_late_subsys;
6731
6732         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
6733                                    inet6_rtm_delroute, NULL, 0);
6734         if (ret < 0)
6735                 goto out_register_late_subsys;
6736
6737         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
6738                                    inet6_rtm_getroute, NULL,
6739                                    RTNL_FLAG_DOIT_UNLOCKED);
6740         if (ret < 0)
6741                 goto out_register_late_subsys;
6742
6743         ret = register_netdevice_notifier(&ip6_route_dev_notifier);
6744         if (ret)
6745                 goto out_register_late_subsys;
6746
6747 #if IS_BUILTIN(CONFIG_IPV6)
6748 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6749         ret = bpf_iter_register();
6750         if (ret)
6751                 goto out_register_late_subsys;
6752 #endif
6753 #endif
6754
6755         for_each_possible_cpu(cpu) {
6756                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
6757
6758                 INIT_LIST_HEAD(&ul->head);
6759                 INIT_LIST_HEAD(&ul->quarantine);
6760                 spin_lock_init(&ul->lock);
6761         }
6762
6763 out:
6764         return ret;
6765
6766 out_register_late_subsys:
6767         rtnl_unregister_all(PF_INET6);
6768         unregister_pernet_subsys(&ip6_route_net_late_ops);
6769 fib6_rules_init:
6770         fib6_rules_cleanup();
6771 xfrm6_init:
6772         xfrm6_fini();
6773 out_fib6_init:
6774         fib6_gc_cleanup();
6775 out_register_subsys:
6776         unregister_pernet_subsys(&ip6_route_net_ops);
6777 out_register_inetpeer:
6778         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6779 out_dst_entries:
6780         dst_entries_destroy(&ip6_dst_blackhole_ops);
6781 out_kmem_cache:
6782         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6783         goto out;
6784 }
6785
6786 void ip6_route_cleanup(void)
6787 {
6788 #if IS_BUILTIN(CONFIG_IPV6)
6789 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6790         bpf_iter_unregister();
6791 #endif
6792 #endif
6793         unregister_netdevice_notifier(&ip6_route_dev_notifier);
6794         unregister_pernet_subsys(&ip6_route_net_late_ops);
6795         fib6_rules_cleanup();
6796         xfrm6_fini();
6797         fib6_gc_cleanup();
6798         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6799         unregister_pernet_subsys(&ip6_route_net_ops);
6800         dst_entries_destroy(&ip6_dst_blackhole_ops);
6801         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6802 }