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             <[email protected]>
   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, int how);
  94 static int               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->rt6i_uncached_list = ul;
 143
 144         spin_lock_bh(&ul->lock);
 145         list_add_tail(&rt->rt6i_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->rt6i_uncached)) {
 152                 struct uncached_list *ul = rt->rt6i_uncached_list;
 153
 154                 spin_lock_bh(&ul->lock);
 155                 list_del_init(&rt->rt6i_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, rt6i_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                                 dev_replace_track(rt_dev, blackhole_netdev,
 186                                                   &rt->dst.dev_tracker,
 187                                                   GFP_ATOMIC);
 188                                 handled = true;
 189                         }
 190                         if (handled)
 191                                 list_move(&rt->rt6i_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                 .__refcnt       = ATOMIC_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                 .__refcnt       = ATOMIC_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                 .__refcnt       = ATOMIC_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         INIT_LIST_HEAD(&rt->rt6i_uncached);
 338 }
 339
 340 /* allocate dst with ip6_dst_ops */
 341 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 342                                int flags)
 343 {
 344         struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
 345                                         1, DST_OBSOLETE_FORCE_CHK, flags);
 346
 347         if (rt) {
 348                 rt6_info_init(rt);
 349                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
 350         }
 351
 352         return rt;
 353 }
 354 EXPORT_SYMBOL(ip6_dst_alloc);
 355
 356 static void ip6_dst_destroy(struct dst_entry *dst)
 357 {
 358         struct rt6_info *rt = (struct rt6_info *)dst;
 359         struct fib6_info *from;
 360         struct inet6_dev *idev;
 361
 362         ip_dst_metrics_put(dst);
 363         rt6_uncached_list_del(rt);
 364
 365         idev = rt->rt6i_idev;
 366         if (idev) {
 367                 rt->rt6i_idev = NULL;
 368                 in6_dev_put(idev);
 369         }
 370
 371         from = xchg((__force struct fib6_info **)&rt->from, NULL);
 372         fib6_info_release(from);
 373 }
 374
 375 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 376                            int how)
 377 {
 378         struct rt6_info *rt = (struct rt6_info *)dst;
 379         struct inet6_dev *idev = rt->rt6i_idev;
 380
 381         if (idev && idev->dev != blackhole_netdev) {
 382                 struct inet6_dev *blackhole_idev = in6_dev_get(blackhole_netdev);
 383
 384                 if (blackhole_idev) {
 385                         rt->rt6i_idev = blackhole_idev;
 386                         in6_dev_put(idev);
 387                 }
 388         }
 389 }
 390
 391 static bool __rt6_check_expired(const struct rt6_info *rt)
 392 {
 393         if (rt->rt6i_flags & RTF_EXPIRES)
 394                 return time_after(jiffies, rt->dst.expires);
 395         else
 396                 return false;
 397 }
 398
 399 static bool rt6_check_expired(const struct rt6_info *rt)
 400 {
 401         struct fib6_info *from;
 402
 403         from = rcu_dereference(rt->from);
 404
 405         if (rt->rt6i_flags & RTF_EXPIRES) {
 406                 if (time_after(jiffies, rt->dst.expires))
 407                         return true;
 408         } else if (from) {
 409                 return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
 410                         fib6_check_expired(from);
 411         }
 412         return false;
 413 }
 414
 415 void fib6_select_path(const struct net *net, struct fib6_result *res,
 416                       struct flowi6 *fl6, int oif, bool have_oif_match,
 417                       const struct sk_buff *skb, int strict)
 418 {
 419         struct fib6_info *sibling, *next_sibling;
 420         struct fib6_info *match = res->f6i;
 421
 422         if (!match->nh && (!match->fib6_nsiblings || have_oif_match))
 423                 goto out;
 424
 425         if (match->nh && have_oif_match && res->nh)
 426                 return;
 427
 428         /* We might have already computed the hash for ICMPv6 errors. In such
 429          * case it will always be non-zero. Otherwise now is the time to do it.
 430          */
 431         if (!fl6->mp_hash &&
 432             (!match->nh || nexthop_is_multipath(match->nh)))
 433                 fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
 434
 435         if (unlikely(match->nh)) {
 436                 nexthop_path_fib6_result(res, fl6->mp_hash);
 437                 return;
 438         }
 439
 440         if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
 441                 goto out;
 442
 443         list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
 444                                  fib6_siblings) {
 445                 const struct fib6_nh *nh = sibling->fib6_nh;
 446                 int nh_upper_bound;
 447
 448                 nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
 449                 if (fl6->mp_hash > nh_upper_bound)
 450                         continue;
 451                 if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
 452                         break;
 453                 match = sibling;
 454                 break;
 455         }
 456
 457 out:
 458         res->f6i = match;
 459         res->nh = match->fib6_nh;
 460 }
 461
 462 /*
 463  *      Route lookup. rcu_read_lock() should be held.
 464  */
 465
 466 static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh,
 467                                const struct in6_addr *saddr, int oif, int flags)
 468 {
 469         const struct net_device *dev;
 470
 471         if (nh->fib_nh_flags & RTNH_F_DEAD)
 472                 return false;
 473
 474         dev = nh->fib_nh_dev;
 475         if (oif) {
 476                 if (dev->ifindex == oif)
 477                         return true;
 478         } else {
 479                 if (ipv6_chk_addr(net, saddr, dev,
 480                                   flags & RT6_LOOKUP_F_IFACE))
 481                         return true;
 482         }
 483
 484         return false;
 485 }
 486
 487 struct fib6_nh_dm_arg {
 488         struct net              *net;
 489         const struct in6_addr   *saddr;
 490         int                     oif;
 491         int                     flags;
 492         struct fib6_nh          *nh;
 493 };
 494
 495 static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg)
 496 {
 497         struct fib6_nh_dm_arg *arg = _arg;
 498
 499         arg->nh = nh;
 500         return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif,
 501                                   arg->flags);
 502 }
 503
 504 /* returns fib6_nh from nexthop or NULL */
 505 static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh,
 506                                         struct fib6_result *res,
 507                                         const struct in6_addr *saddr,
 508                                         int oif, int flags)
 509 {
 510         struct fib6_nh_dm_arg arg = {
 511                 .net   = net,
 512                 .saddr = saddr,
 513                 .oif   = oif,
 514                 .flags = flags,
 515         };
 516
 517         if (nexthop_is_blackhole(nh))
 518                 return NULL;
 519
 520         if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg))
 521                 return arg.nh;
 522
 523         return NULL;
 524 }
 525
 526 static void rt6_device_match(struct net *net, struct fib6_result *res,
 527                              const struct in6_addr *saddr, int oif, int flags)
 528 {
 529         struct fib6_info *f6i = res->f6i;
 530         struct fib6_info *spf6i;
 531         struct fib6_nh *nh;
 532
 533         if (!oif && ipv6_addr_any(saddr)) {
 534                 if (unlikely(f6i->nh)) {
 535                         nh = nexthop_fib6_nh(f6i->nh);
 536                         if (nexthop_is_blackhole(f6i->nh))
 537                                 goto out_blackhole;
 538                 } else {
 539                         nh = f6i->fib6_nh;
 540                 }
 541                 if (!(nh->fib_nh_flags & RTNH_F_DEAD))
 542                         goto out;
 543         }
 544
 545         for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
 546                 bool matched = false;
 547
 548                 if (unlikely(spf6i->nh)) {
 549                         nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr,
 550                                               oif, flags);
 551                         if (nh)
 552                                 matched = true;
 553                 } else {
 554                         nh = spf6i->fib6_nh;
 555                         if (__rt6_device_match(net, nh, saddr, oif, flags))
 556                                 matched = true;
 557                 }
 558                 if (matched) {
 559                         res->f6i = spf6i;
 560                         goto out;
 561                 }
 562         }
 563
 564         if (oif && flags & RT6_LOOKUP_F_IFACE) {
 565                 res->f6i = net->ipv6.fib6_null_entry;
 566                 nh = res->f6i->fib6_nh;
 567                 goto out;
 568         }
 569
 570         if (unlikely(f6i->nh)) {
 571                 nh = nexthop_fib6_nh(f6i->nh);
 572                 if (nexthop_is_blackhole(f6i->nh))
 573                         goto out_blackhole;
 574         } else {
 575                 nh = f6i->fib6_nh;
 576         }
 577
 578         if (nh->fib_nh_flags & RTNH_F_DEAD) {
 579                 res->f6i = net->ipv6.fib6_null_entry;
 580                 nh = res->f6i->fib6_nh;
 581         }
 582 out:
 583         res->nh = nh;
 584         res->fib6_type = res->f6i->fib6_type;
 585         res->fib6_flags = res->f6i->fib6_flags;
 586         return;
 587
 588 out_blackhole:
 589         res->fib6_flags |= RTF_REJECT;
 590         res->fib6_type = RTN_BLACKHOLE;
 591         res->nh = nh;
 592 }
 593
 594 #ifdef CONFIG_IPV6_ROUTER_PREF
 595 struct __rt6_probe_work {
 596         struct work_struct work;
 597         struct in6_addr target;
 598         struct net_device *dev;
 599         netdevice_tracker dev_tracker;
 600 };
 601
 602 static void rt6_probe_deferred(struct work_struct *w)
 603 {
 604         struct in6_addr mcaddr;
 605         struct __rt6_probe_work *work =
 606                 container_of(w, struct __rt6_probe_work, work);
 607
 608         addrconf_addr_solict_mult(&work->target, &mcaddr);
 609         ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
 610         dev_put_track(work->dev, &work->dev_tracker);
 611         kfree(work);
 612 }
 613
 614 static void rt6_probe(struct fib6_nh *fib6_nh)
 615 {
 616         struct __rt6_probe_work *work = NULL;
 617         const struct in6_addr *nh_gw;
 618         unsigned long last_probe;
 619         struct neighbour *neigh;
 620         struct net_device *dev;
 621         struct inet6_dev *idev;
 622
 623         /*
 624          * Okay, this does not seem to be appropriate
 625          * for now, however, we need to check if it
 626          * is really so; aka Router Reachability Probing.
 627          *
 628          * Router Reachability Probe MUST be rate-limited
 629          * to no more than one per minute.
 630          */
 631         if (!fib6_nh->fib_nh_gw_family)
 632                 return;
 633
 634         nh_gw = &fib6_nh->fib_nh_gw6;
 635         dev = fib6_nh->fib_nh_dev;
 636         rcu_read_lock_bh();
 637         last_probe = READ_ONCE(fib6_nh->last_probe);
 638         idev = __in6_dev_get(dev);
 639         neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
 640         if (neigh) {
 641                 if (neigh->nud_state & NUD_VALID)
 642                         goto out;
 643
 644                 write_lock(&neigh->lock);
 645                 if (!(neigh->nud_state & NUD_VALID) &&
 646                     time_after(jiffies,
 647                                neigh->updated + idev->cnf.rtr_probe_interval)) {
 648                         work = kmalloc(sizeof(*work), GFP_ATOMIC);
 649                         if (work)
 650                                 __neigh_set_probe_once(neigh);
 651                 }
 652                 write_unlock(&neigh->lock);
 653         } else if (time_after(jiffies, last_probe +
 654                                        idev->cnf.rtr_probe_interval)) {
 655                 work = kmalloc(sizeof(*work), GFP_ATOMIC);
 656         }
 657
 658         if (!work || cmpxchg(&fib6_nh->last_probe,
 659                              last_probe, jiffies) != last_probe) {
 660                 kfree(work);
 661         } else {
 662                 INIT_WORK(&work->work, rt6_probe_deferred);
 663                 work->target = *nh_gw;
 664                 dev_hold_track(dev, &work->dev_tracker, GFP_ATOMIC);
 665                 work->dev = dev;
 666                 schedule_work(&work->work);
 667         }
 668
 669 out:
 670         rcu_read_unlock_bh();
 671 }
 672 #else
 673 static inline void rt6_probe(struct fib6_nh *fib6_nh)
 674 {
 675 }
 676 #endif
 677
 678 /*
 679  * Default Router Selection (RFC 2461 6.3.6)
 680  */
 681 static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh)
 682 {
 683         enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
 684         struct neighbour *neigh;
 685
 686         rcu_read_lock_bh();
 687         neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev,
 688                                           &fib6_nh->fib_nh_gw6);
 689         if (neigh) {
 690                 read_lock(&neigh->lock);
 691                 if (neigh->nud_state & NUD_VALID)
 692                         ret = RT6_NUD_SUCCEED;
 693 #ifdef CONFIG_IPV6_ROUTER_PREF
 694                 else if (!(neigh->nud_state & NUD_FAILED))
 695                         ret = RT6_NUD_SUCCEED;
 696                 else
 697                         ret = RT6_NUD_FAIL_PROBE;
 698 #endif
 699                 read_unlock(&neigh->lock);
 700         } else {
 701                 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
 702                       RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
 703         }
 704         rcu_read_unlock_bh();
 705
 706         return ret;
 707 }
 708
 709 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
 710                            int strict)
 711 {
 712         int m = 0;
 713
 714         if (!oif || nh->fib_nh_dev->ifindex == oif)
 715                 m = 2;
 716
 717         if (!m && (strict & RT6_LOOKUP_F_IFACE))
 718                 return RT6_NUD_FAIL_HARD;
 719 #ifdef CONFIG_IPV6_ROUTER_PREF
 720         m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2;
 721 #endif
 722         if ((strict & RT6_LOOKUP_F_REACHABLE) &&
 723             !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) {
 724                 int n = rt6_check_neigh(nh);
 725                 if (n < 0)
 726                         return n;
 727         }
 728         return m;
 729 }
 730
 731 static bool find_match(struct fib6_nh *nh, u32 fib6_flags,
 732                        int oif, int strict, int *mpri, bool *do_rr)
 733 {
 734         bool match_do_rr = false;
 735         bool rc = false;
 736         int m;
 737
 738         if (nh->fib_nh_flags & RTNH_F_DEAD)
 739                 goto out;
 740
 741         if (ip6_ignore_linkdown(nh->fib_nh_dev) &&
 742             nh->fib_nh_flags & RTNH_F_LINKDOWN &&
 743             !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
 744                 goto out;
 745
 746         m = rt6_score_route(nh, fib6_flags, oif, strict);
 747         if (m == RT6_NUD_FAIL_DO_RR) {
 748                 match_do_rr = true;
 749                 m = 0; /* lowest valid score */
 750         } else if (m == RT6_NUD_FAIL_HARD) {
 751                 goto out;
 752         }
 753
 754         if (strict & RT6_LOOKUP_F_REACHABLE)
 755                 rt6_probe(nh);
 756
 757         /* note that m can be RT6_NUD_FAIL_PROBE at this point */
 758         if (m > *mpri) {
 759                 *do_rr = match_do_rr;
 760                 *mpri = m;
 761                 rc = true;
 762         }
 763 out:
 764         return rc;
 765 }
 766
 767 struct fib6_nh_frl_arg {
 768         u32             flags;
 769         int             oif;
 770         int             strict;
 771         int             *mpri;
 772         bool            *do_rr;
 773         struct fib6_nh  *nh;
 774 };
 775
 776 static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg)
 777 {
 778         struct fib6_nh_frl_arg *arg = _arg;
 779
 780         arg->nh = nh;
 781         return find_match(nh, arg->flags, arg->oif, arg->strict,
 782                           arg->mpri, arg->do_rr);
 783 }
 784
 785 static void __find_rr_leaf(struct fib6_info *f6i_start,
 786                            struct fib6_info *nomatch, u32 metric,
 787                            struct fib6_result *res, struct fib6_info **cont,
 788                            int oif, int strict, bool *do_rr, int *mpri)
 789 {
 790         struct fib6_info *f6i;
 791
 792         for (f6i = f6i_start;
 793              f6i && f6i != nomatch;
 794              f6i = rcu_dereference(f6i->fib6_next)) {
 795                 bool matched = false;
 796                 struct fib6_nh *nh;
 797
 798                 if (cont && f6i->fib6_metric != metric) {
 799                         *cont = f6i;
 800                         return;
 801                 }
 802
 803                 if (fib6_check_expired(f6i))
 804                         continue;
 805
 806                 if (unlikely(f6i->nh)) {
 807                         struct fib6_nh_frl_arg arg = {
 808                                 .flags  = f6i->fib6_flags,
 809                                 .oif    = oif,
 810                                 .strict = strict,
 811                                 .mpri   = mpri,
 812                                 .do_rr  = do_rr
 813                         };
 814
 815                         if (nexthop_is_blackhole(f6i->nh)) {
 816                                 res->fib6_flags = RTF_REJECT;
 817                                 res->fib6_type = RTN_BLACKHOLE;
 818                                 res->f6i = f6i;
 819                                 res->nh = nexthop_fib6_nh(f6i->nh);
 820                                 return;
 821                         }
 822                         if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match,
 823                                                      &arg)) {
 824                                 matched = true;
 825                                 nh = arg.nh;
 826                         }
 827                 } else {
 828                         nh = f6i->fib6_nh;
 829                         if (find_match(nh, f6i->fib6_flags, oif, strict,
 830                                        mpri, do_rr))
 831                                 matched = true;
 832                 }
 833                 if (matched) {
 834                         res->f6i = f6i;
 835                         res->nh = nh;
 836                         res->fib6_flags = f6i->fib6_flags;
 837                         res->fib6_type = f6i->fib6_type;
 838                 }
 839         }
 840 }
 841
 842 static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf,
 843                          struct fib6_info *rr_head, int oif, int strict,
 844                          bool *do_rr, struct fib6_result *res)
 845 {
 846         u32 metric = rr_head->fib6_metric;
 847         struct fib6_info *cont = NULL;
 848         int mpri = -1;
 849
 850         __find_rr_leaf(rr_head, NULL, metric, res, &cont,
 851                        oif, strict, do_rr, &mpri);
 852
 853         __find_rr_leaf(leaf, rr_head, metric, res, &cont,
 854                        oif, strict, do_rr, &mpri);
 855
 856         if (res->f6i || !cont)
 857                 return;
 858
 859         __find_rr_leaf(cont, NULL, metric, res, NULL,
 860                        oif, strict, do_rr, &mpri);
 861 }
 862
 863 static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
 864                        struct fib6_result *res, int strict)
 865 {
 866         struct fib6_info *leaf = rcu_dereference(fn->leaf);
 867         struct fib6_info *rt0;
 868         bool do_rr = false;
 869         int key_plen;
 870
 871         /* make sure this function or its helpers sets f6i */
 872         res->f6i = NULL;
 873
 874         if (!leaf || leaf == net->ipv6.fib6_null_entry)
 875                 goto out;
 876
 877         rt0 = rcu_dereference(fn->rr_ptr);
 878         if (!rt0)
 879                 rt0 = leaf;
 880
 881         /* Double check to make sure fn is not an intermediate node
 882          * and fn->leaf does not points to its child's leaf
 883          * (This might happen if all routes under fn are deleted from
 884          * the tree and fib6_repair_tree() is called on the node.)
 885          */
 886         key_plen = rt0->fib6_dst.plen;
 887 #ifdef CONFIG_IPV6_SUBTREES
 888         if (rt0->fib6_src.plen)
 889                 key_plen = rt0->fib6_src.plen;
 890 #endif
 891         if (fn->fn_bit != key_plen)
 892                 goto out;
 893
 894         find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res);
 895         if (do_rr) {
 896                 struct fib6_info *next = rcu_dereference(rt0->fib6_next);
 897
 898                 /* no entries matched; do round-robin */
 899                 if (!next || next->fib6_metric != rt0->fib6_metric)
 900                         next = leaf;
 901
 902                 if (next != rt0) {
 903                         spin_lock_bh(&leaf->fib6_table->tb6_lock);
 904                         /* make sure next is not being deleted from the tree */
 905                         if (next->fib6_node)
 906                                 rcu_assign_pointer(fn->rr_ptr, next);
 907                         spin_unlock_bh(&leaf->fib6_table->tb6_lock);
 908                 }
 909         }
 910
 911 out:
 912         if (!res->f6i) {
 913                 res->f6i = net->ipv6.fib6_null_entry;
 914                 res->nh = res->f6i->fib6_nh;
 915                 res->fib6_flags = res->f6i->fib6_flags;
 916                 res->fib6_type = res->f6i->fib6_type;
 917         }
 918 }
 919
 920 static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res)
 921 {
 922         return (res->f6i->fib6_flags & RTF_NONEXTHOP) ||
 923                res->nh->fib_nh_gw_family;
 924 }
 925
 926 #ifdef CONFIG_IPV6_ROUTE_INFO
 927 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 928                   const struct in6_addr *gwaddr)
 929 {
 930         struct net *net = dev_net(dev);
 931         struct route_info *rinfo = (struct route_info *) opt;
 932         struct in6_addr prefix_buf, *prefix;
 933         unsigned int pref;
 934         unsigned long lifetime;
 935         struct fib6_info *rt;
 936
 937         if (len < sizeof(struct route_info)) {
 938                 return -EINVAL;
 939         }
 940
 941         /* Sanity check for prefix_len and length */
 942         if (rinfo->length > 3) {
 943                 return -EINVAL;
 944         } else if (rinfo->prefix_len > 128) {
 945                 return -EINVAL;
 946         } else if (rinfo->prefix_len > 64) {
 947                 if (rinfo->length < 2) {
 948                         return -EINVAL;
 949                 }
 950         } else if (rinfo->prefix_len > 0) {
 951                 if (rinfo->length < 1) {
 952                         return -EINVAL;
 953                 }
 954         }
 955
 956         pref = rinfo->route_pref;
 957         if (pref == ICMPV6_ROUTER_PREF_INVALID)
 958                 return -EINVAL;
 959
 960         lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
 961
 962         if (rinfo->length == 3)
 963                 prefix = (struct in6_addr *)rinfo->prefix;
 964         else {
 965                 /* this function is safe */
 966                 ipv6_addr_prefix(&prefix_buf,
 967                                  (struct in6_addr *)rinfo->prefix,
 968                                  rinfo->prefix_len);
 969                 prefix = &prefix_buf;
 970         }
 971
 972         if (rinfo->prefix_len == 0)
 973                 rt = rt6_get_dflt_router(net, gwaddr, dev);
 974         else
 975                 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
 976                                         gwaddr, dev);
 977
 978         if (rt && !lifetime) {
 979                 ip6_del_rt(net, rt, false);
 980                 rt = NULL;
 981         }
 982
 983         if (!rt && lifetime)
 984                 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
 985                                         dev, pref);
 986         else if (rt)
 987                 rt->fib6_flags = RTF_ROUTEINFO |
 988                                  (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 989
 990         if (rt) {
 991                 if (!addrconf_finite_timeout(lifetime))
 992                         fib6_clean_expires(rt);
 993                 else
 994                         fib6_set_expires(rt, jiffies + HZ * lifetime);
 995
 996                 fib6_info_release(rt);
 997         }
 998         return 0;
 999 }
1000 #endif
1001
1002 /*
1003  *      Misc support functions
1004  */
1005
1006 /* called with rcu_lock held */
1007 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
1008 {
1009         struct net_device *dev = res->nh->fib_nh_dev;
1010
1011         if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
1012                 /* for copies of local routes, dst->dev needs to be the
1013                  * device if it is a master device, the master device if
1014                  * device is enslaved, and the loopback as the default
1015                  */
1016                 if (netif_is_l3_slave(dev) &&
1017                     !rt6_need_strict(&res->f6i->fib6_dst.addr))
1018                         dev = l3mdev_master_dev_rcu(dev);
1019                 else if (!netif_is_l3_master(dev))
1020                         dev = dev_net(dev)->loopback_dev;
1021                 /* last case is netif_is_l3_master(dev) is true in which
1022                  * case we want dev returned to be dev
1023                  */
1024         }
1025
1026         return dev;
1027 }
1028
1029 static const int fib6_prop[RTN_MAX + 1] = {
1030         [RTN_UNSPEC]    = 0,
1031         [RTN_UNICAST]   = 0,
1032         [RTN_LOCAL]     = 0,
1033         [RTN_BROADCAST] = 0,
1034         [RTN_ANYCAST]   = 0,
1035         [RTN_MULTICAST] = 0,
1036         [RTN_BLACKHOLE] = -EINVAL,
1037         [RTN_UNREACHABLE] = -EHOSTUNREACH,
1038         [RTN_PROHIBIT]  = -EACCES,
1039         [RTN_THROW]     = -EAGAIN,
1040         [RTN_NAT]       = -EINVAL,
1041         [RTN_XRESOLVE]  = -EINVAL,
1042 };
1043
1044 static int ip6_rt_type_to_error(u8 fib6_type)
1045 {
1046         return fib6_prop[fib6_type];
1047 }
1048
1049 static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
1050 {
1051         unsigned short flags = 0;
1052
1053         if (rt->dst_nocount)
1054                 flags |= DST_NOCOUNT;
1055         if (rt->dst_nopolicy)
1056                 flags |= DST_NOPOLICY;
1057
1058         return flags;
1059 }
1060
1061 static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
1062 {
1063         rt->dst.error = ip6_rt_type_to_error(fib6_type);
1064
1065         switch (fib6_type) {
1066         case RTN_BLACKHOLE:
1067                 rt->dst.output = dst_discard_out;
1068                 rt->dst.input = dst_discard;
1069                 break;
1070         case RTN_PROHIBIT:
1071                 rt->dst.output = ip6_pkt_prohibit_out;
1072                 rt->dst.input = ip6_pkt_prohibit;
1073                 break;
1074         case RTN_THROW:
1075         case RTN_UNREACHABLE:
1076         default:
1077                 rt->dst.output = ip6_pkt_discard_out;
1078                 rt->dst.input = ip6_pkt_discard;
1079                 break;
1080         }
1081 }
1082
1083 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
1084 {
1085         struct fib6_info *f6i = res->f6i;
1086
1087         if (res->fib6_flags & RTF_REJECT) {
1088                 ip6_rt_init_dst_reject(rt, res->fib6_type);
1089                 return;
1090         }
1091
1092         rt->dst.error = 0;
1093         rt->dst.output = ip6_output;
1094
1095         if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
1096                 rt->dst.input = ip6_input;
1097         } else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
1098                 rt->dst.input = ip6_mc_input;
1099         } else {
1100                 rt->dst.input = ip6_forward;
1101         }
1102
1103         if (res->nh->fib_nh_lws) {
1104                 rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws);
1105                 lwtunnel_set_redirect(&rt->dst);
1106         }
1107
1108         rt->dst.lastuse = jiffies;
1109 }
1110
1111 /* Caller must already hold reference to @from */
1112 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
1113 {
1114         rt->rt6i_flags &= ~RTF_EXPIRES;
1115         rcu_assign_pointer(rt->from, from);
1116         ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
1117 }
1118
1119 /* Caller must already hold reference to f6i in result */
1120 static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
1121 {
1122         const struct fib6_nh *nh = res->nh;
1123         const struct net_device *dev = nh->fib_nh_dev;
1124         struct fib6_info *f6i = res->f6i;
1125
1126         ip6_rt_init_dst(rt, res);
1127
1128         rt->rt6i_dst = f6i->fib6_dst;
1129         rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
1130         rt->rt6i_flags = res->fib6_flags;
1131         if (nh->fib_nh_gw_family) {
1132                 rt->rt6i_gateway = nh->fib_nh_gw6;
1133                 rt->rt6i_flags |= RTF_GATEWAY;
1134         }
1135         rt6_set_from(rt, f6i);
1136 #ifdef CONFIG_IPV6_SUBTREES
1137         rt->rt6i_src = f6i->fib6_src;
1138 #endif
1139 }
1140
1141 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
1142                                         struct in6_addr *saddr)
1143 {
1144         struct fib6_node *pn, *sn;
1145         while (1) {
1146                 if (fn->fn_flags & RTN_TL_ROOT)
1147                         return NULL;
1148                 pn = rcu_dereference(fn->parent);
1149                 sn = FIB6_SUBTREE(pn);
1150                 if (sn && sn != fn)
1151                         fn = fib6_node_lookup(sn, NULL, saddr);
1152                 else
1153                         fn = pn;
1154                 if (fn->fn_flags & RTN_RTINFO)
1155                         return fn;
1156         }
1157 }
1158
1159 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt)
1160 {
1161         struct rt6_info *rt = *prt;
1162
1163         if (dst_hold_safe(&rt->dst))
1164                 return true;
1165         if (net) {
1166                 rt = net->ipv6.ip6_null_entry;
1167                 dst_hold(&rt->dst);
1168         } else {
1169                 rt = NULL;
1170         }
1171         *prt = rt;
1172         return false;
1173 }
1174
1175 /* called with rcu_lock held */
1176 static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res)
1177 {
1178         struct net_device *dev = res->nh->fib_nh_dev;
1179         struct fib6_info *f6i = res->f6i;
1180         unsigned short flags;
1181         struct rt6_info *nrt;
1182
1183         if (!fib6_info_hold_safe(f6i))
1184                 goto fallback;
1185
1186         flags = fib6_info_dst_flags(f6i);
1187         nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
1188         if (!nrt) {
1189                 fib6_info_release(f6i);
1190                 goto fallback;
1191         }
1192
1193         ip6_rt_copy_init(nrt, res);
1194         return nrt;
1195
1196 fallback:
1197         nrt = dev_net(dev)->ipv6.ip6_null_entry;
1198         dst_hold(&nrt->dst);
1199         return nrt;
1200 }
1201
1202 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net,
1203                                              struct fib6_table *table,
1204                                              struct flowi6 *fl6,
1205                                              const struct sk_buff *skb,
1206                                              int flags)
1207 {
1208         struct fib6_result res = {};
1209         struct fib6_node *fn;
1210         struct rt6_info *rt;
1211
1212         rcu_read_lock();
1213         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1214 restart:
1215         res.f6i = rcu_dereference(fn->leaf);
1216         if (!res.f6i)
1217                 res.f6i = net->ipv6.fib6_null_entry;
1218         else
1219                 rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif,
1220                                  flags);
1221
1222         if (res.f6i == net->ipv6.fib6_null_entry) {
1223                 fn = fib6_backtrack(fn, &fl6->saddr);
1224                 if (fn)
1225                         goto restart;
1226
1227                 rt = net->ipv6.ip6_null_entry;
1228                 dst_hold(&rt->dst);
1229                 goto out;
1230         } else if (res.fib6_flags & RTF_REJECT) {
1231                 goto do_create;
1232         }
1233
1234         fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
1235                          fl6->flowi6_oif != 0, skb, flags);
1236
1237         /* Search through exception table */
1238         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
1239         if (rt) {
1240                 if (ip6_hold_safe(net, &rt))
1241                         dst_use_noref(&rt->dst, jiffies);
1242         } else {
1243 do_create:
1244                 rt = ip6_create_rt_rcu(&res);
1245         }
1246
1247 out:
1248         trace_fib6_table_lookup(net, &res, table, fl6);
1249
1250         rcu_read_unlock();
1251
1252         return rt;
1253 }
1254
1255 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
1256                                    const struct sk_buff *skb, int flags)
1257 {
1258         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
1259 }
1260 EXPORT_SYMBOL_GPL(ip6_route_lookup);
1261
1262 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
1263                             const struct in6_addr *saddr, int oif,
1264                             const struct sk_buff *skb, int strict)
1265 {
1266         struct flowi6 fl6 = {
1267                 .flowi6_oif = oif,
1268                 .daddr = *daddr,
1269         };
1270         struct dst_entry *dst;
1271         int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
1272
1273         if (saddr) {
1274                 memcpy(&fl6.saddr, saddr, sizeof(*saddr));
1275                 flags |= RT6_LOOKUP_F_HAS_SADDR;
1276         }
1277
1278         dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
1279         if (dst->error == 0)
1280                 return (struct rt6_info *) dst;
1281
1282         dst_release(dst);
1283
1284         return NULL;
1285 }
1286 EXPORT_SYMBOL(rt6_lookup);
1287
1288 /* ip6_ins_rt is called with FREE table->tb6_lock.
1289  * It takes new route entry, the addition fails by any reason the
1290  * route is released.
1291  * Caller must hold dst before calling it.
1292  */
1293
1294 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
1295                         struct netlink_ext_ack *extack)
1296 {
1297         int err;
1298         struct fib6_table *table;
1299
1300         table = rt->fib6_table;
1301         spin_lock_bh(&table->tb6_lock);
1302         err = fib6_add(&table->tb6_root, rt, info, extack);
1303         spin_unlock_bh(&table->tb6_lock);
1304
1305         return err;
1306 }
1307
1308 int ip6_ins_rt(struct net *net, struct fib6_info *rt)
1309 {
1310         struct nl_info info = { .nl_net = net, };
1311
1312         return __ip6_ins_rt(rt, &info, NULL);
1313 }
1314
1315 static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res,
1316                                            const struct in6_addr *daddr,
1317                                            const struct in6_addr *saddr)
1318 {
1319         struct fib6_info *f6i = res->f6i;
1320         struct net_device *dev;
1321         struct rt6_info *rt;
1322
1323         /*
1324          *      Clone the route.
1325          */
1326
1327         if (!fib6_info_hold_safe(f6i))
1328                 return NULL;
1329
1330         dev = ip6_rt_get_dev_rcu(res);
1331         rt = ip6_dst_alloc(dev_net(dev), dev, 0);
1332         if (!rt) {
1333                 fib6_info_release(f6i);
1334                 return NULL;
1335         }
1336
1337         ip6_rt_copy_init(rt, res);
1338         rt->rt6i_flags |= RTF_CACHE;
1339         rt->rt6i_dst.addr = *daddr;
1340         rt->rt6i_dst.plen = 128;
1341
1342         if (!rt6_is_gw_or_nonexthop(res)) {
1343                 if (f6i->fib6_dst.plen != 128 &&
1344                     ipv6_addr_equal(&f6i->fib6_dst.addr, daddr))
1345                         rt->rt6i_flags |= RTF_ANYCAST;
1346 #ifdef CONFIG_IPV6_SUBTREES
1347                 if (rt->rt6i_src.plen && saddr) {
1348                         rt->rt6i_src.addr = *saddr;
1349                         rt->rt6i_src.plen = 128;
1350                 }
1351 #endif
1352         }
1353
1354         return rt;
1355 }
1356
1357 static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res)
1358 {
1359         struct fib6_info *f6i = res->f6i;
1360         unsigned short flags = fib6_info_dst_flags(f6i);
1361         struct net_device *dev;
1362         struct rt6_info *pcpu_rt;
1363
1364         if (!fib6_info_hold_safe(f6i))
1365                 return NULL;
1366
1367         rcu_read_lock();
1368         dev = ip6_rt_get_dev_rcu(res);
1369         pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT);
1370         rcu_read_unlock();
1371         if (!pcpu_rt) {
1372                 fib6_info_release(f6i);
1373                 return NULL;
1374         }
1375         ip6_rt_copy_init(pcpu_rt, res);
1376         pcpu_rt->rt6i_flags |= RTF_PCPU;
1377
1378         if (f6i->nh)
1379                 pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev));
1380
1381         return pcpu_rt;
1382 }
1383
1384 static bool rt6_is_valid(const struct rt6_info *rt6)
1385 {
1386         return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev));
1387 }
1388
1389 /* It should be called with rcu_read_lock() acquired */
1390 static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
1391 {
1392         struct rt6_info *pcpu_rt;
1393
1394         pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
1395
1396         if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) {
1397                 struct rt6_info *prev, **p;
1398
1399                 p = this_cpu_ptr(res->nh->rt6i_pcpu);
1400                 prev = xchg(p, NULL);
1401                 if (prev) {
1402                         dst_dev_put(&prev->dst);
1403                         dst_release(&prev->dst);
1404                 }
1405
1406                 pcpu_rt = NULL;
1407         }
1408
1409         return pcpu_rt;
1410 }
1411
1412 static struct rt6_info *rt6_make_pcpu_route(struct net *net,
1413                                             const struct fib6_result *res)
1414 {
1415         struct rt6_info *pcpu_rt, *prev, **p;
1416
1417         pcpu_rt = ip6_rt_pcpu_alloc(res);
1418         if (!pcpu_rt)
1419                 return NULL;
1420
1421         p = this_cpu_ptr(res->nh->rt6i_pcpu);
1422         prev = cmpxchg(p, NULL, pcpu_rt);
1423         BUG_ON(prev);
1424
1425         if (res->f6i->fib6_destroying) {
1426                 struct fib6_info *from;
1427
1428                 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
1429                 fib6_info_release(from);
1430         }
1431
1432         return pcpu_rt;
1433 }
1434
1435 /* exception hash table implementation
1436  */
1437 static DEFINE_SPINLOCK(rt6_exception_lock);
1438
1439 /* Remove rt6_ex from hash table and free the memory
1440  * Caller must hold rt6_exception_lock
1441  */
1442 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
1443                                  struct rt6_exception *rt6_ex)
1444 {
1445         struct fib6_info *from;
1446         struct net *net;
1447
1448         if (!bucket || !rt6_ex)
1449                 return;
1450
1451         net = dev_net(rt6_ex->rt6i->dst.dev);
1452         net->ipv6.rt6_stats->fib_rt_cache--;
1453
1454         /* purge completely the exception to allow releasing the held resources:
1455          * some [sk] cache may keep the dst around for unlimited time
1456          */
1457         from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL);
1458         fib6_info_release(from);
1459         dst_dev_put(&rt6_ex->rt6i->dst);
1460
1461         hlist_del_rcu(&rt6_ex->hlist);
1462         dst_release(&rt6_ex->rt6i->dst);
1463         kfree_rcu(rt6_ex, rcu);
1464         WARN_ON_ONCE(!bucket->depth);
1465         bucket->depth--;
1466 }
1467
1468 /* Remove oldest rt6_ex in bucket and free the memory
1469  * Caller must hold rt6_exception_lock
1470  */
1471 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
1472 {
1473         struct rt6_exception *rt6_ex, *oldest = NULL;
1474
1475         if (!bucket)
1476                 return;
1477
1478         hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
1479                 if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
1480                         oldest = rt6_ex;
1481         }
1482         rt6_remove_exception(bucket, oldest);
1483 }
1484
1485 static u32 rt6_exception_hash(const struct in6_addr *dst,
1486                               const struct in6_addr *src)
1487 {
1488         static siphash_aligned_key_t rt6_exception_key;
1489         struct {
1490                 struct in6_addr dst;
1491                 struct in6_addr src;
1492         } __aligned(SIPHASH_ALIGNMENT) combined = {
1493                 .dst = *dst,
1494         };
1495         u64 val;
1496
1497         net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key));
1498
1499 #ifdef CONFIG_IPV6_SUBTREES
1500         if (src)
1501                 combined.src = *src;
1502 #endif
1503         val = siphash(&combined, sizeof(combined), &rt6_exception_key);
1504
1505         return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
1506 }
1507
1508 /* Helper function to find the cached rt in the hash table
1509  * and update bucket pointer to point to the bucket for this
1510  * (daddr, saddr) pair
1511  * Caller must hold rt6_exception_lock
1512  */
1513 static struct rt6_exception *
1514 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
1515                               const struct in6_addr *daddr,
1516                               const struct in6_addr *saddr)
1517 {
1518         struct rt6_exception *rt6_ex;
1519         u32 hval;
1520
1521         if (!(*bucket) || !daddr)
1522                 return NULL;
1523
1524         hval = rt6_exception_hash(daddr, saddr);
1525         *bucket += hval;
1526
1527         hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
1528                 struct rt6_info *rt6 = rt6_ex->rt6i;
1529                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1530
1531 #ifdef CONFIG_IPV6_SUBTREES
1532                 if (matched && saddr)
1533                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1534 #endif
1535                 if (matched)
1536                         return rt6_ex;
1537         }
1538         return NULL;
1539 }
1540
1541 /* Helper function to find the cached rt in the hash table
1542  * and update bucket pointer to point to the bucket for this
1543  * (daddr, saddr) pair
1544  * Caller must hold rcu_read_lock()
1545  */
1546 static struct rt6_exception *
1547 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
1548                          const struct in6_addr *daddr,
1549                          const struct in6_addr *saddr)
1550 {
1551         struct rt6_exception *rt6_ex;
1552         u32 hval;
1553
1554         WARN_ON_ONCE(!rcu_read_lock_held());
1555
1556         if (!(*bucket) || !daddr)
1557                 return NULL;
1558
1559         hval = rt6_exception_hash(daddr, saddr);
1560         *bucket += hval;
1561
1562         hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
1563                 struct rt6_info *rt6 = rt6_ex->rt6i;
1564                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1565
1566 #ifdef CONFIG_IPV6_SUBTREES
1567                 if (matched && saddr)
1568                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1569 #endif
1570                 if (matched)
1571                         return rt6_ex;
1572         }
1573         return NULL;
1574 }
1575
1576 static unsigned int fib6_mtu(const struct fib6_result *res)
1577 {
1578         const struct fib6_nh *nh = res->nh;
1579         unsigned int mtu;
1580
1581         if (res->f6i->fib6_pmtu) {
1582                 mtu = res->f6i->fib6_pmtu;
1583         } else {
1584                 struct net_device *dev = nh->fib_nh_dev;
1585                 struct inet6_dev *idev;
1586
1587                 rcu_read_lock();
1588                 idev = __in6_dev_get(dev);
1589                 mtu = idev->cnf.mtu6;
1590                 rcu_read_unlock();
1591         }
1592
1593         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
1594
1595         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
1596 }
1597
1598 #define FIB6_EXCEPTION_BUCKET_FLUSHED  0x1UL
1599
1600 /* used when the flushed bit is not relevant, only access to the bucket
1601  * (ie., all bucket users except rt6_insert_exception);
1602  *
1603  * called under rcu lock; sometimes called with rt6_exception_lock held
1604  */
1605 static
1606 struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh,
1607                                                        spinlock_t *lock)
1608 {
1609         struct rt6_exception_bucket *bucket;
1610
1611         if (lock)
1612                 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1613                                                    lockdep_is_held(lock));
1614         else
1615                 bucket = rcu_dereference(nh->rt6i_exception_bucket);
1616
1617         /* remove bucket flushed bit if set */
1618         if (bucket) {
1619                 unsigned long p = (unsigned long)bucket;
1620
1621                 p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED;
1622                 bucket = (struct rt6_exception_bucket *)p;
1623         }
1624
1625         return bucket;
1626 }
1627
1628 static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket)
1629 {
1630         unsigned long p = (unsigned long)bucket;
1631
1632         return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED);
1633 }
1634
1635 /* called with rt6_exception_lock held */
1636 static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh,
1637                                               spinlock_t *lock)
1638 {
1639         struct rt6_exception_bucket *bucket;
1640         unsigned long p;
1641
1642         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1643                                            lockdep_is_held(lock));
1644
1645         p = (unsigned long)bucket;
1646         p |= FIB6_EXCEPTION_BUCKET_FLUSHED;
1647         bucket = (struct rt6_exception_bucket *)p;
1648         rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1649 }
1650
1651 static int rt6_insert_exception(struct rt6_info *nrt,
1652                                 const struct fib6_result *res)
1653 {
1654         struct net *net = dev_net(nrt->dst.dev);
1655         struct rt6_exception_bucket *bucket;
1656         struct fib6_info *f6i = res->f6i;
1657         struct in6_addr *src_key = NULL;
1658         struct rt6_exception *rt6_ex;
1659         struct fib6_nh *nh = res->nh;
1660         int max_depth;
1661         int err = 0;
1662
1663         spin_lock_bh(&rt6_exception_lock);
1664
1665         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1666                                           lockdep_is_held(&rt6_exception_lock));
1667         if (!bucket) {
1668                 bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
1669                                  GFP_ATOMIC);
1670                 if (!bucket) {
1671                         err = -ENOMEM;
1672                         goto out;
1673                 }
1674                 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1675         } else if (fib6_nh_excptn_bucket_flushed(bucket)) {
1676                 err = -EINVAL;
1677                 goto out;
1678         }
1679
1680 #ifdef CONFIG_IPV6_SUBTREES
1681         /* fib6_src.plen != 0 indicates f6i is in subtree
1682          * and exception table is indexed by a hash of
1683          * both fib6_dst and fib6_src.
1684          * Otherwise, the exception table is indexed by
1685          * a hash of only fib6_dst.
1686          */
1687         if (f6i->fib6_src.plen)
1688                 src_key = &nrt->rt6i_src.addr;
1689 #endif
1690         /* rt6_mtu_change() might lower mtu on f6i.
1691          * Only insert this exception route if its mtu
1692          * is less than f6i's mtu value.
1693          */
1694         if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) {
1695                 err = -EINVAL;
1696                 goto out;
1697         }
1698
1699         rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
1700                                                src_key);
1701         if (rt6_ex)
1702                 rt6_remove_exception(bucket, rt6_ex);
1703
1704         rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
1705         if (!rt6_ex) {
1706                 err = -ENOMEM;
1707                 goto out;
1708         }
1709         rt6_ex->rt6i = nrt;
1710         rt6_ex->stamp = jiffies;
1711         hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
1712         bucket->depth++;
1713         net->ipv6.rt6_stats->fib_rt_cache++;
1714
1715         /* Randomize max depth to avoid some side channels attacks. */
1716         max_depth = FIB6_MAX_DEPTH + prandom_u32_max(FIB6_MAX_DEPTH);
1717         while (bucket->depth > max_depth)
1718                 rt6_exception_remove_oldest(bucket);
1719
1720 out:
1721         spin_unlock_bh(&rt6_exception_lock);
1722
1723         /* Update fn->fn_sernum to invalidate all cached dst */
1724         if (!err) {
1725                 spin_lock_bh(&f6i->fib6_table->tb6_lock);
1726                 fib6_update_sernum(net, f6i);
1727                 spin_unlock_bh(&f6i->fib6_table->tb6_lock);
1728                 fib6_force_start_gc(net);
1729         }
1730
1731         return err;
1732 }
1733
1734 static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
1735 {
1736         struct rt6_exception_bucket *bucket;
1737         struct rt6_exception *rt6_ex;
1738         struct hlist_node *tmp;
1739         int i;
1740
1741         spin_lock_bh(&rt6_exception_lock);
1742
1743         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1744         if (!bucket)
1745                 goto out;
1746
1747         /* Prevent rt6_insert_exception() to recreate the bucket list */
1748         if (!from)
1749                 fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock);
1750
1751         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1752                 hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) {
1753                         if (!from ||
1754                             rcu_access_pointer(rt6_ex->rt6i->from) == from)
1755                                 rt6_remove_exception(bucket, rt6_ex);
1756                 }
1757                 WARN_ON_ONCE(!from && bucket->depth);
1758                 bucket++;
1759         }
1760 out:
1761         spin_unlock_bh(&rt6_exception_lock);
1762 }
1763
1764 static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg)
1765 {
1766         struct fib6_info *f6i = arg;
1767
1768         fib6_nh_flush_exceptions(nh, f6i);
1769
1770         return 0;
1771 }
1772
1773 void rt6_flush_exceptions(struct fib6_info *f6i)
1774 {
1775         if (f6i->nh)
1776                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions,
1777                                          f6i);
1778         else
1779                 fib6_nh_flush_exceptions(f6i->fib6_nh, f6i);
1780 }
1781
1782 /* Find cached rt in the hash table inside passed in rt
1783  * Caller has to hold rcu_read_lock()
1784  */
1785 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
1786                                            const struct in6_addr *daddr,
1787                                            const struct in6_addr *saddr)
1788 {
1789         const struct in6_addr *src_key = NULL;
1790         struct rt6_exception_bucket *bucket;
1791         struct rt6_exception *rt6_ex;
1792         struct rt6_info *ret = NULL;
1793
1794 #ifdef CONFIG_IPV6_SUBTREES
1795         /* fib6i_src.plen != 0 indicates f6i is in subtree
1796          * and exception table is indexed by a hash of
1797          * both fib6_dst and fib6_src.
1798          * However, the src addr used to create the hash
1799          * might not be exactly the passed in saddr which
1800          * is a /128 addr from the flow.
1801          * So we need to use f6i->fib6_src to redo lookup
1802          * if the passed in saddr does not find anything.
1803          * (See the logic in ip6_rt_cache_alloc() on how
1804          * rt->rt6i_src is updated.)
1805          */
1806         if (res->f6i->fib6_src.plen)
1807                 src_key = saddr;
1808 find_ex:
1809 #endif
1810         bucket = fib6_nh_get_excptn_bucket(res->nh, NULL);
1811         rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
1812
1813         if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
1814                 ret = rt6_ex->rt6i;
1815
1816 #ifdef CONFIG_IPV6_SUBTREES
1817         /* Use fib6_src as src_key and redo lookup */
1818         if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) {
1819                 src_key = &res->f6i->fib6_src.addr;
1820                 goto find_ex;
1821         }
1822 #endif
1823
1824         return ret;
1825 }
1826
1827 /* Remove the passed in cached rt from the hash table that contains it */
1828 static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen,
1829                                     const struct rt6_info *rt)
1830 {
1831         const struct in6_addr *src_key = NULL;
1832         struct rt6_exception_bucket *bucket;
1833         struct rt6_exception *rt6_ex;
1834         int err;
1835
1836         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
1837                 return -ENOENT;
1838
1839         spin_lock_bh(&rt6_exception_lock);
1840         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1841
1842 #ifdef CONFIG_IPV6_SUBTREES
1843         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1844          * and exception table is indexed by a hash of
1845          * both rt6i_dst and rt6i_src.
1846          * Otherwise, the exception table is indexed by
1847          * a hash of only rt6i_dst.
1848          */
1849         if (plen)
1850                 src_key = &rt->rt6i_src.addr;
1851 #endif
1852         rt6_ex = __rt6_find_exception_spinlock(&bucket,
1853                                                &rt->rt6i_dst.addr,
1854                                                src_key);
1855         if (rt6_ex) {
1856                 rt6_remove_exception(bucket, rt6_ex);
1857                 err = 0;
1858         } else {
1859                 err = -ENOENT;
1860         }
1861
1862         spin_unlock_bh(&rt6_exception_lock);
1863         return err;
1864 }
1865
1866 struct fib6_nh_excptn_arg {
1867         struct rt6_info *rt;
1868         int             plen;
1869 };
1870
1871 static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg)
1872 {
1873         struct fib6_nh_excptn_arg *arg = _arg;
1874         int err;
1875
1876         err = fib6_nh_remove_exception(nh, arg->plen, arg->rt);
1877         if (err == 0)
1878                 return 1;
1879
1880         return 0;
1881 }
1882
1883 static int rt6_remove_exception_rt(struct rt6_info *rt)
1884 {
1885         struct fib6_info *from;
1886
1887         from = rcu_dereference(rt->from);
1888         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1889                 return -EINVAL;
1890
1891         if (from->nh) {
1892                 struct fib6_nh_excptn_arg arg = {
1893                         .rt = rt,
1894                         .plen = from->fib6_src.plen
1895                 };
1896                 int rc;
1897
1898                 /* rc = 1 means an entry was found */
1899                 rc = nexthop_for_each_fib6_nh(from->nh,
1900                                               rt6_nh_remove_exception_rt,
1901                                               &arg);
1902                 return rc ? 0 : -ENOENT;
1903         }
1904
1905         return fib6_nh_remove_exception(from->fib6_nh,
1906                                         from->fib6_src.plen, rt);
1907 }
1908
1909 /* Find rt6_ex which contains the passed in rt cache and
1910  * refresh its stamp
1911  */
1912 static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen,
1913                                      const struct rt6_info *rt)
1914 {
1915         const struct in6_addr *src_key = NULL;
1916         struct rt6_exception_bucket *bucket;
1917         struct rt6_exception *rt6_ex;
1918
1919         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
1920 #ifdef CONFIG_IPV6_SUBTREES
1921         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1922          * and exception table is indexed by a hash of
1923          * both rt6i_dst and rt6i_src.
1924          * Otherwise, the exception table is indexed by
1925          * a hash of only rt6i_dst.
1926          */
1927         if (plen)
1928                 src_key = &rt->rt6i_src.addr;
1929 #endif
1930         rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
1931         if (rt6_ex)
1932                 rt6_ex->stamp = jiffies;
1933 }
1934
1935 struct fib6_nh_match_arg {
1936         const struct net_device *dev;
1937         const struct in6_addr   *gw;
1938         struct fib6_nh          *match;
1939 };
1940
1941 /* determine if fib6_nh has given device and gateway */
1942 static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg)
1943 {
1944         struct fib6_nh_match_arg *arg = _arg;
1945
1946         if (arg->dev != nh->fib_nh_dev ||
1947             (arg->gw && !nh->fib_nh_gw_family) ||
1948             (!arg->gw && nh->fib_nh_gw_family) ||
1949             (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6)))
1950                 return 0;
1951
1952         arg->match = nh;
1953
1954         /* found a match, break the loop */
1955         return 1;
1956 }
1957
1958 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
1959 {
1960         struct fib6_info *from;
1961         struct fib6_nh *fib6_nh;
1962
1963         rcu_read_lock();
1964
1965         from = rcu_dereference(rt->from);
1966         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1967                 goto unlock;
1968
1969         if (from->nh) {
1970                 struct fib6_nh_match_arg arg = {
1971                         .dev = rt->dst.dev,
1972                         .gw = &rt->rt6i_gateway,
1973                 };
1974
1975                 nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
1976
1977                 if (!arg.match)
1978                         goto unlock;
1979                 fib6_nh = arg.match;
1980         } else {
1981                 fib6_nh = from->fib6_nh;
1982         }
1983         fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt);
1984 unlock:
1985         rcu_read_unlock();
1986 }
1987
1988 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
1989                                          struct rt6_info *rt, int mtu)
1990 {
1991         /* If the new MTU is lower than the route PMTU, this new MTU will be the
1992          * lowest MTU in the path: always allow updating the route PMTU to
1993          * reflect PMTU decreases.
1994          *
1995          * If the new MTU is higher, and the route PMTU is equal to the local
1996          * MTU, this means the old MTU is the lowest in the path, so allow
1997          * updating it: if other nodes now have lower MTUs, PMTU discovery will
1998          * handle this.
1999          */
2000
2001         if (dst_mtu(&rt->dst) >= mtu)
2002                 return true;
2003
2004         if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
2005                 return true;
2006
2007         return false;
2008 }
2009
2010 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
2011                                        const struct fib6_nh *nh, int mtu)
2012 {
2013         struct rt6_exception_bucket *bucket;
2014         struct rt6_exception *rt6_ex;
2015         int i;
2016
2017         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2018         if (!bucket)
2019                 return;
2020
2021         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2022                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
2023                         struct rt6_info *entry = rt6_ex->rt6i;
2024
2025                         /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
2026                          * route), the metrics of its rt->from have already
2027                          * been updated.
2028                          */
2029                         if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
2030                             rt6_mtu_change_route_allowed(idev, entry, mtu))
2031                                 dst_metric_set(&entry->dst, RTAX_MTU, mtu);
2032                 }
2033                 bucket++;
2034         }
2035 }
2036
2037 #define RTF_CACHE_GATEWAY       (RTF_GATEWAY | RTF_CACHE)
2038
2039 static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh,
2040                                             const struct in6_addr *gateway)
2041 {
2042         struct rt6_exception_bucket *bucket;
2043         struct rt6_exception *rt6_ex;
2044         struct hlist_node *tmp;
2045         int i;
2046
2047         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2048                 return;
2049
2050         spin_lock_bh(&rt6_exception_lock);
2051         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2052         if (bucket) {
2053                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2054                         hlist_for_each_entry_safe(rt6_ex, tmp,
2055                                                   &bucket->chain, hlist) {
2056                                 struct rt6_info *entry = rt6_ex->rt6i;
2057
2058                                 if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
2059                                     RTF_CACHE_GATEWAY &&
2060                                     ipv6_addr_equal(gateway,
2061                                                     &entry->rt6i_gateway)) {
2062                                         rt6_remove_exception(bucket, rt6_ex);
2063                                 }
2064                         }
2065                         bucket++;
2066                 }
2067         }
2068
2069         spin_unlock_bh(&rt6_exception_lock);
2070 }
2071
2072 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
2073                                       struct rt6_exception *rt6_ex,
2074                                       struct fib6_gc_args *gc_args,
2075                                       unsigned long now)
2076 {
2077         struct rt6_info *rt = rt6_ex->rt6i;
2078
2079         /* we are pruning and obsoleting aged-out and non gateway exceptions
2080          * even if others have still references to them, so that on next
2081          * dst_check() such references can be dropped.
2082          * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
2083          * expired, independently from their aging, as per RFC 8201 section 4
2084          */
2085         if (!(rt->rt6i_flags & RTF_EXPIRES)) {
2086                 if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
2087                         RT6_TRACE("aging clone %p\n", rt);
2088                         rt6_remove_exception(bucket, rt6_ex);
2089                         return;
2090                 }
2091         } else if (time_after(jiffies, rt->dst.expires)) {
2092                 RT6_TRACE("purging expired route %p\n", rt);
2093                 rt6_remove_exception(bucket, rt6_ex);
2094                 return;
2095         }
2096
2097         if (rt->rt6i_flags & RTF_GATEWAY) {
2098                 struct neighbour *neigh;
2099
2100                 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
2101
2102                 if (!(neigh && (neigh->flags & NTF_ROUTER))) {
2103                         RT6_TRACE("purging route %p via non-router but gateway\n",
2104                                   rt);
2105                         rt6_remove_exception(bucket, rt6_ex);
2106                         return;
2107                 }
2108         }
2109
2110         gc_args->more++;
2111 }
2112
2113 static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
2114                                    struct fib6_gc_args *gc_args,
2115                                    unsigned long now)
2116 {
2117         struct rt6_exception_bucket *bucket;
2118         struct rt6_exception *rt6_ex;
2119         struct hlist_node *tmp;
2120         int i;
2121
2122         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2123                 return;
2124
2125         rcu_read_lock_bh();
2126         spin_lock(&rt6_exception_lock);
2127         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2128         if (bucket) {
2129                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2130                         hlist_for_each_entry_safe(rt6_ex, tmp,
2131                                                   &bucket->chain, hlist) {
2132                                 rt6_age_examine_exception(bucket, rt6_ex,
2133                                                           gc_args, now);
2134                         }
2135                         bucket++;
2136                 }
2137         }
2138         spin_unlock(&rt6_exception_lock);
2139         rcu_read_unlock_bh();
2140 }
2141
2142 struct fib6_nh_age_excptn_arg {
2143         struct fib6_gc_args     *gc_args;
2144         unsigned long           now;
2145 };
2146
2147 static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg)
2148 {
2149         struct fib6_nh_age_excptn_arg *arg = _arg;
2150
2151         fib6_nh_age_exceptions(nh, arg->gc_args, arg->now);
2152         return 0;
2153 }
2154
2155 void rt6_age_exceptions(struct fib6_info *f6i,
2156                         struct fib6_gc_args *gc_args,
2157                         unsigned long now)
2158 {
2159         if (f6i->nh) {
2160                 struct fib6_nh_age_excptn_arg arg = {
2161                         .gc_args = gc_args,
2162                         .now = now
2163                 };
2164
2165                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions,
2166                                          &arg);
2167         } else {
2168                 fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now);
2169         }
2170 }
2171
2172 /* must be called with rcu lock held */
2173 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
2174                       struct flowi6 *fl6, struct fib6_result *res, int strict)
2175 {
2176         struct fib6_node *fn, *saved_fn;
2177
2178         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
2179         saved_fn = fn;
2180
2181 redo_rt6_select:
2182         rt6_select(net, fn, oif, res, strict);
2183         if (res->f6i == net->ipv6.fib6_null_entry) {
2184                 fn = fib6_backtrack(fn, &fl6->saddr);
2185                 if (fn)
2186                         goto redo_rt6_select;
2187                 else if (strict & RT6_LOOKUP_F_REACHABLE) {
2188                         /* also consider unreachable route */
2189                         strict &= ~RT6_LOOKUP_F_REACHABLE;
2190                         fn = saved_fn;
2191                         goto redo_rt6_select;
2192                 }
2193         }
2194
2195         trace_fib6_table_lookup(net, res, table, fl6);
2196
2197         return 0;
2198 }
2199
2200 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
2201                                int oif, struct flowi6 *fl6,
2202                                const struct sk_buff *skb, int flags)
2203 {
2204         struct fib6_result res = {};
2205         struct rt6_info *rt = NULL;
2206         int strict = 0;
2207
2208         WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
2209                      !rcu_read_lock_held());
2210
2211         strict |= flags & RT6_LOOKUP_F_IFACE;
2212         strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
2213         if (net->ipv6.devconf_all->forwarding == 0)
2214                 strict |= RT6_LOOKUP_F_REACHABLE;
2215
2216         rcu_read_lock();
2217
2218         fib6_table_lookup(net, table, oif, fl6, &res, strict);
2219         if (res.f6i == net->ipv6.fib6_null_entry)
2220                 goto out;
2221
2222         fib6_select_path(net, &res, fl6, oif, false, skb, strict);
2223
2224         /*Search through exception table */
2225         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
2226         if (rt) {
2227                 goto out;
2228         } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
2229                             !res.nh->fib_nh_gw_family)) {
2230                 /* Create a RTF_CACHE clone which will not be
2231                  * owned by the fib6 tree.  It is for the special case where
2232                  * the daddr in the skb during the neighbor look-up is different
2233                  * from the fl6->daddr used to look-up route here.
2234                  */
2235                 rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
2236
2237                 if (rt) {
2238                         /* 1 refcnt is taken during ip6_rt_cache_alloc().
2239                          * As rt6_uncached_list_add() does not consume refcnt,
2240                          * this refcnt is always returned to the caller even
2241                          * if caller sets RT6_LOOKUP_F_DST_NOREF flag.
2242                          */
2243                         rt6_uncached_list_add(rt);
2244                         rcu_read_unlock();
2245
2246                         return rt;
2247                 }
2248         } else {
2249                 /* Get a percpu copy */
2250                 local_bh_disable();
2251                 rt = rt6_get_pcpu_route(&res);
2252
2253                 if (!rt)
2254                         rt = rt6_make_pcpu_route(net, &res);
2255
2256                 local_bh_enable();
2257         }
2258 out:
2259         if (!rt)
2260                 rt = net->ipv6.ip6_null_entry;
2261         if (!(flags & RT6_LOOKUP_F_DST_NOREF))
2262                 ip6_hold_safe(net, &rt);
2263         rcu_read_unlock();
2264
2265         return rt;
2266 }
2267 EXPORT_SYMBOL_GPL(ip6_pol_route);
2268
2269 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net,
2270                                             struct fib6_table *table,
2271                                             struct flowi6 *fl6,
2272                                             const struct sk_buff *skb,
2273                                             int flags)
2274 {
2275         return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
2276 }
2277
2278 struct dst_entry *ip6_route_input_lookup(struct net *net,
2279                                          struct net_device *dev,
2280                                          struct flowi6 *fl6,
2281                                          const struct sk_buff *skb,
2282                                          int flags)
2283 {
2284         if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
2285                 flags |= RT6_LOOKUP_F_IFACE;
2286
2287         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
2288 }
2289 EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
2290
2291 static void ip6_multipath_l3_keys(const struct sk_buff *skb,
2292                                   struct flow_keys *keys,
2293                                   struct flow_keys *flkeys)
2294 {
2295         const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
2296         const struct ipv6hdr *key_iph = outer_iph;
2297         struct flow_keys *_flkeys = flkeys;
2298         const struct ipv6hdr *inner_iph;
2299         const struct icmp6hdr *icmph;
2300         struct ipv6hdr _inner_iph;
2301         struct icmp6hdr _icmph;
2302
2303         if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
2304                 goto out;
2305
2306         icmph = skb_header_pointer(skb, skb_transport_offset(skb),
2307                                    sizeof(_icmph), &_icmph);
2308         if (!icmph)
2309                 goto out;
2310
2311         if (!icmpv6_is_err(icmph->icmp6_type))
2312                 goto out;
2313
2314         inner_iph = skb_header_pointer(skb,
2315                                        skb_transport_offset(skb) + sizeof(*icmph),
2316                                        sizeof(_inner_iph), &_inner_iph);
2317         if (!inner_iph)
2318                 goto out;
2319
2320         key_iph = inner_iph;
2321         _flkeys = NULL;
2322 out:
2323         if (_flkeys) {
2324                 keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
2325                 keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
2326                 keys->tags.flow_label = _flkeys->tags.flow_label;
2327                 keys->basic.ip_proto = _flkeys->basic.ip_proto;
2328         } else {
2329                 keys->addrs.v6addrs.src = key_iph->saddr;
2330                 keys->addrs.v6addrs.dst = key_iph->daddr;
2331                 keys->tags.flow_label = ip6_flowlabel(key_iph);
2332                 keys->basic.ip_proto = key_iph->nexthdr;
2333         }
2334 }
2335
2336 static u32 rt6_multipath_custom_hash_outer(const struct net *net,
2337                                            const struct sk_buff *skb,
2338                                            bool *p_has_inner)
2339 {
2340         u32 hash_fields = ip6_multipath_hash_fields(net);
2341         struct flow_keys keys, hash_keys;
2342
2343         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2344                 return 0;
2345
2346         memset(&hash_keys, 0, sizeof(hash_keys));
2347         skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
2348
2349         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2350         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2351                 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2352         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2353                 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2354         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2355                 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2356         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2357                 hash_keys.tags.flow_label = keys.tags.flow_label;
2358         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2359                 hash_keys.ports.src = keys.ports.src;
2360         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2361                 hash_keys.ports.dst = keys.ports.dst;
2362
2363         *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
2364         return flow_hash_from_keys(&hash_keys);
2365 }
2366
2367 static u32 rt6_multipath_custom_hash_inner(const struct net *net,
2368                                            const struct sk_buff *skb,
2369                                            bool has_inner)
2370 {
2371         u32 hash_fields = ip6_multipath_hash_fields(net);
2372         struct flow_keys keys, hash_keys;
2373
2374         /* We assume the packet carries an encapsulation, but if none was
2375          * encountered during dissection of the outer flow, then there is no
2376          * point in calling the flow dissector again.
2377          */
2378         if (!has_inner)
2379                 return 0;
2380
2381         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
2382                 return 0;
2383
2384         memset(&hash_keys, 0, sizeof(hash_keys));
2385         skb_flow_dissect_flow_keys(skb, &keys, 0);
2386
2387         if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
2388                 return 0;
2389
2390         if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2391                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2392                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2393                         hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2394                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2395                         hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2396         } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2397                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2398                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2399                         hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2400                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2401                         hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2402                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
2403                         hash_keys.tags.flow_label = keys.tags.flow_label;
2404         }
2405
2406         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
2407                 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2408         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
2409                 hash_keys.ports.src = keys.ports.src;
2410         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
2411                 hash_keys.ports.dst = keys.ports.dst;
2412
2413         return flow_hash_from_keys(&hash_keys);
2414 }
2415
2416 static u32 rt6_multipath_custom_hash_skb(const struct net *net,
2417                                          const struct sk_buff *skb)
2418 {
2419         u32 mhash, mhash_inner;
2420         bool has_inner = true;
2421
2422         mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner);
2423         mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner);
2424
2425         return jhash_2words(mhash, mhash_inner, 0);
2426 }
2427
2428 static u32 rt6_multipath_custom_hash_fl6(const struct net *net,
2429                                          const struct flowi6 *fl6)
2430 {
2431         u32 hash_fields = ip6_multipath_hash_fields(net);
2432         struct flow_keys hash_keys;
2433
2434         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2435                 return 0;
2436
2437         memset(&hash_keys, 0, sizeof(hash_keys));
2438         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2439         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2440                 hash_keys.addrs.v6addrs.src = fl6->saddr;
2441         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2442                 hash_keys.addrs.v6addrs.dst = fl6->daddr;
2443         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2444                 hash_keys.basic.ip_proto = fl6->flowi6_proto;
2445         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2446                 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2447         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2448                 hash_keys.ports.src = fl6->fl6_sport;
2449         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2450                 hash_keys.ports.dst = fl6->fl6_dport;
2451
2452         return flow_hash_from_keys(&hash_keys);
2453 }
2454
2455 /* if skb is set it will be used and fl6 can be NULL */
2456 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
2457                        const struct sk_buff *skb, struct flow_keys *flkeys)
2458 {
2459         struct flow_keys hash_keys;
2460         u32 mhash = 0;
2461
2462         switch (ip6_multipath_hash_policy(net)) {
2463         case 0:
2464                 memset(&hash_keys, 0, sizeof(hash_keys));
2465                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2466                 if (skb) {
2467                         ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2468                 } else {
2469                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2470                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2471                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2472                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2473                 }
2474                 mhash = flow_hash_from_keys(&hash_keys);
2475                 break;
2476         case 1:
2477                 if (skb) {
2478                         unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2479                         struct flow_keys keys;
2480
2481                         /* short-circuit if we already have L4 hash present */
2482                         if (skb->l4_hash)
2483                                 return skb_get_hash_raw(skb) >> 1;
2484
2485                         memset(&hash_keys, 0, sizeof(hash_keys));
2486
2487                         if (!flkeys) {
2488                                 skb_flow_dissect_flow_keys(skb, &keys, flag);
2489                                 flkeys = &keys;
2490                         }
2491                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2492                         hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2493                         hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2494                         hash_keys.ports.src = flkeys->ports.src;
2495                         hash_keys.ports.dst = flkeys->ports.dst;
2496                         hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2497                 } else {
2498                         memset(&hash_keys, 0, sizeof(hash_keys));
2499                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2500                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2501                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2502                         hash_keys.ports.src = fl6->fl6_sport;
2503                         hash_keys.ports.dst = fl6->fl6_dport;
2504                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2505                 }
2506                 mhash = flow_hash_from_keys(&hash_keys);
2507                 break;
2508         case 2:
2509                 memset(&hash_keys, 0, sizeof(hash_keys));
2510                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2511                 if (skb) {
2512                         struct flow_keys keys;
2513
2514                         if (!flkeys) {
2515                                 skb_flow_dissect_flow_keys(skb, &keys, 0);
2516                                 flkeys = &keys;
2517                         }
2518
2519                         /* Inner can be v4 or v6 */
2520                         if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2521                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2522                                 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2523                                 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2524                         } else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2525                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2526                                 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2527                                 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2528                                 hash_keys.tags.flow_label = flkeys->tags.flow_label;
2529                                 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2530                         } else {
2531                                 /* Same as case 0 */
2532                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2533                                 ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2534                         }
2535                 } else {
2536                         /* Same as case 0 */
2537                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2538                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2539                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2540                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2541                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2542                 }
2543                 mhash = flow_hash_from_keys(&hash_keys);
2544                 break;
2545         case 3:
2546                 if (skb)
2547                         mhash = rt6_multipath_custom_hash_skb(net, skb);
2548                 else
2549                         mhash = rt6_multipath_custom_hash_fl6(net, fl6);
2550                 break;
2551         }
2552
2553         return mhash >> 1;
2554 }
2555
2556 /* Called with rcu held */
2557 void ip6_route_input(struct sk_buff *skb)
2558 {
2559         const struct ipv6hdr *iph = ipv6_hdr(skb);
2560         struct net *net = dev_net(skb->dev);
2561         int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF;
2562         struct ip_tunnel_info *tun_info;
2563         struct flowi6 fl6 = {
2564                 .flowi6_iif = skb->dev->ifindex,
2565                 .daddr = iph->daddr,
2566                 .saddr = iph->saddr,
2567                 .flowlabel = ip6_flowinfo(iph),
2568                 .flowi6_mark = skb->mark,
2569                 .flowi6_proto = iph->nexthdr,
2570         };
2571         struct flow_keys *flkeys = NULL, _flkeys;
2572
2573         tun_info = skb_tunnel_info(skb);
2574         if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2575                 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
2576
2577         if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
2578                 flkeys = &_flkeys;
2579
2580         if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
2581                 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
2582         skb_dst_drop(skb);
2583         skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev,
2584                                                       &fl6, skb, flags));
2585 }
2586
2587 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net,
2588                                              struct fib6_table *table,
2589                                              struct flowi6 *fl6,
2590                                              const struct sk_buff *skb,
2591                                              int flags)
2592 {
2593         return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
2594 }
2595
2596 struct dst_entry *ip6_route_output_flags_noref(struct net *net,
2597                                                const struct sock *sk,
2598                                                struct flowi6 *fl6, int flags)
2599 {
2600         bool any_src;
2601
2602         if (ipv6_addr_type(&fl6->daddr) &
2603             (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
2604                 struct dst_entry *dst;
2605
2606                 /* This function does not take refcnt on the dst */
2607                 dst = l3mdev_link_scope_lookup(net, fl6);
2608                 if (dst)
2609                         return dst;
2610         }
2611
2612         fl6->flowi6_iif = LOOPBACK_IFINDEX;
2613
2614         flags |= RT6_LOOKUP_F_DST_NOREF;
2615         any_src = ipv6_addr_any(&fl6->saddr);
2616         if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
2617             (fl6->flowi6_oif && any_src))
2618                 flags |= RT6_LOOKUP_F_IFACE;
2619
2620         if (!any_src)
2621                 flags |= RT6_LOOKUP_F_HAS_SADDR;
2622         else if (sk)
2623                 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
2624
2625         return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
2626 }
2627 EXPORT_SYMBOL_GPL(ip6_route_output_flags_noref);
2628
2629 struct dst_entry *ip6_route_output_flags(struct net *net,
2630                                          const struct sock *sk,
2631                                          struct flowi6 *fl6,
2632                                          int flags)
2633 {
2634         struct dst_entry *dst;
2635         struct rt6_info *rt6;
2636
2637         rcu_read_lock();
2638         dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
2639         rt6 = (struct rt6_info *)dst;
2640         /* For dst cached in uncached_list, refcnt is already taken. */
2641         if (list_empty(&rt6->rt6i_uncached) && !dst_hold_safe(dst)) {
2642                 dst = &net->ipv6.ip6_null_entry->dst;
2643                 dst_hold(dst);
2644         }
2645         rcu_read_unlock();
2646
2647         return dst;
2648 }
2649 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
2650
2651 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2652 {
2653         struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
2654         struct net_device *loopback_dev = net->loopback_dev;
2655         struct dst_entry *new = NULL;
2656
2657         rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
2658                        DST_OBSOLETE_DEAD, 0);
2659         if (rt) {
2660                 rt6_info_init(rt);
2661                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
2662
2663                 new = &rt->dst;
2664                 new->__use = 1;
2665                 new->input = dst_discard;
2666                 new->output = dst_discard_out;
2667
2668                 dst_copy_metrics(new, &ort->dst);
2669
2670                 rt->rt6i_idev = in6_dev_get(loopback_dev);
2671                 rt->rt6i_gateway = ort->rt6i_gateway;
2672                 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
2673
2674                 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
2675 #ifdef CONFIG_IPV6_SUBTREES
2676                 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
2677 #endif
2678         }
2679
2680         dst_release(dst_orig);
2681         return new ? new : ERR_PTR(-ENOMEM);
2682 }
2683
2684 /*
2685  *      Destination cache support functions
2686  */
2687
2688 static bool fib6_check(struct fib6_info *f6i, u32 cookie)
2689 {
2690         u32 rt_cookie = 0;
2691
2692         if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
2693                 return false;
2694
2695         if (fib6_check_expired(f6i))
2696                 return false;
2697
2698         return true;
2699 }
2700
2701 static struct dst_entry *rt6_check(struct rt6_info *rt,
2702                                    struct fib6_info *from,
2703                                    u32 cookie)
2704 {
2705         u32 rt_cookie = 0;
2706
2707         if (!from || !fib6_get_cookie_safe(from, &rt_cookie) ||
2708             rt_cookie != cookie)
2709                 return NULL;
2710
2711         if (rt6_check_expired(rt))
2712                 return NULL;
2713
2714         return &rt->dst;
2715 }
2716
2717 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
2718                                             struct fib6_info *from,
2719                                             u32 cookie)
2720 {
2721         if (!__rt6_check_expired(rt) &&
2722             rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
2723             fib6_check(from, cookie))
2724                 return &rt->dst;
2725         else
2726                 return NULL;
2727 }
2728
2729 INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst,
2730                                                         u32 cookie)
2731 {
2732         struct dst_entry *dst_ret;
2733         struct fib6_info *from;
2734         struct rt6_info *rt;
2735
2736         rt = container_of(dst, struct rt6_info, dst);
2737
2738         if (rt->sernum)
2739                 return rt6_is_valid(rt) ? dst : NULL;
2740
2741         rcu_read_lock();
2742
2743         /* All IPV6 dsts are created with ->obsolete set to the value
2744          * DST_OBSOLETE_FORCE_CHK which forces validation calls down
2745          * into this function always.
2746          */
2747
2748         from = rcu_dereference(rt->from);
2749
2750         if (from && (rt->rt6i_flags & RTF_PCPU ||
2751             unlikely(!list_empty(&rt->rt6i_uncached))))
2752                 dst_ret = rt6_dst_from_check(rt, from, cookie);
2753         else
2754                 dst_ret = rt6_check(rt, from, cookie);
2755
2756         rcu_read_unlock();
2757
2758         return dst_ret;
2759 }
2760 EXPORT_INDIRECT_CALLABLE(ip6_dst_check);
2761
2762 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
2763 {
2764         struct rt6_info *rt = (struct rt6_info *) dst;
2765
2766         if (rt) {
2767                 if (rt->rt6i_flags & RTF_CACHE) {
2768                         rcu_read_lock();
2769                         if (rt6_check_expired(rt)) {
2770                                 rt6_remove_exception_rt(rt);
2771                                 dst = NULL;
2772                         }
2773                         rcu_read_unlock();
2774                 } else {
2775                         dst_release(dst);
2776                         dst = NULL;
2777                 }
2778         }
2779         return dst;
2780 }
2781
2782 static void ip6_link_failure(struct sk_buff *skb)
2783 {
2784         struct rt6_info *rt;
2785
2786         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
2787
2788         rt = (struct rt6_info *) skb_dst(skb);
2789         if (rt) {
2790                 rcu_read_lock();
2791                 if (rt->rt6i_flags & RTF_CACHE) {
2792                         rt6_remove_exception_rt(rt);
2793                 } else {
2794                         struct fib6_info *from;
2795                         struct fib6_node *fn;
2796
2797                         from = rcu_dereference(rt->from);
2798                         if (from) {
2799                                 fn = rcu_dereference(from->fib6_node);
2800                                 if (fn && (rt->rt6i_flags & RTF_DEFAULT))
2801                                         WRITE_ONCE(fn->fn_sernum, -1);
2802                         }
2803                 }
2804                 rcu_read_unlock();
2805         }
2806 }
2807
2808 static void rt6_update_expires(struct rt6_info *rt0, int timeout)
2809 {
2810         if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
2811                 struct fib6_info *from;
2812
2813                 rcu_read_lock();
2814                 from = rcu_dereference(rt0->from);
2815                 if (from)
2816                         rt0->dst.expires = from->expires;
2817                 rcu_read_unlock();
2818         }
2819
2820         dst_set_expires(&rt0->dst, timeout);
2821         rt0->rt6i_flags |= RTF_EXPIRES;
2822 }
2823
2824 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
2825 {
2826         struct net *net = dev_net(rt->dst.dev);
2827
2828         dst_metric_set(&rt->dst, RTAX_MTU, mtu);
2829         rt->rt6i_flags |= RTF_MODIFIED;
2830         rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
2831 }
2832
2833 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
2834 {
2835         return !(rt->rt6i_flags & RTF_CACHE) &&
2836                 (rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
2837 }
2838
2839 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
2840                                  const struct ipv6hdr *iph, u32 mtu,
2841                                  bool confirm_neigh)
2842 {
2843         const struct in6_addr *daddr, *saddr;
2844         struct rt6_info *rt6 = (struct rt6_info *)dst;
2845
2846         /* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU)
2847          * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it.
2848          * [see also comment in rt6_mtu_change_route()]
2849          */
2850
2851         if (iph) {
2852                 daddr = &iph->daddr;
2853                 saddr = &iph->saddr;
2854         } else if (sk) {
2855                 daddr = &sk->sk_v6_daddr;
2856                 saddr = &inet6_sk(sk)->saddr;
2857         } else {
2858                 daddr = NULL;
2859                 saddr = NULL;
2860         }
2861
2862         if (confirm_neigh)
2863                 dst_confirm_neigh(dst, daddr);
2864
2865         if (mtu < IPV6_MIN_MTU)
2866                 return;
2867         if (mtu >= dst_mtu(dst))
2868                 return;
2869
2870         if (!rt6_cache_allowed_for_pmtu(rt6)) {
2871                 rt6_do_update_pmtu(rt6, mtu);
2872                 /* update rt6_ex->stamp for cache */
2873                 if (rt6->rt6i_flags & RTF_CACHE)
2874                         rt6_update_exception_stamp_rt(rt6);
2875         } else if (daddr) {
2876                 struct fib6_result res = {};
2877                 struct rt6_info *nrt6;
2878
2879                 rcu_read_lock();
2880                 res.f6i = rcu_dereference(rt6->from);
2881                 if (!res.f6i)
2882                         goto out_unlock;
2883
2884                 res.fib6_flags = res.f6i->fib6_flags;
2885                 res.fib6_type = res.f6i->fib6_type;
2886
2887                 if (res.f6i->nh) {
2888                         struct fib6_nh_match_arg arg = {
2889                                 .dev = dst->dev,
2890                                 .gw = &rt6->rt6i_gateway,
2891                         };
2892
2893                         nexthop_for_each_fib6_nh(res.f6i->nh,
2894                                                  fib6_nh_find_match, &arg);
2895
2896                         /* fib6_info uses a nexthop that does not have fib6_nh
2897                          * using the dst->dev + gw. Should be impossible.
2898                          */
2899                         if (!arg.match)
2900                                 goto out_unlock;
2901
2902                         res.nh = arg.match;
2903                 } else {
2904                         res.nh = res.f6i->fib6_nh;
2905                 }
2906
2907                 nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
2908                 if (nrt6) {
2909                         rt6_do_update_pmtu(nrt6, mtu);
2910                         if (rt6_insert_exception(nrt6, &res))
2911                                 dst_release_immediate(&nrt6->dst);
2912                 }
2913 out_unlock:
2914                 rcu_read_unlock();
2915         }
2916 }
2917
2918 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
2919                                struct sk_buff *skb, u32 mtu,
2920                                bool confirm_neigh)
2921 {
2922         __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu,
2923                              confirm_neigh);
2924 }
2925
2926 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
2927                      int oif, u32 mark, kuid_t uid)
2928 {
2929         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2930         struct dst_entry *dst;
2931         struct flowi6 fl6 = {
2932                 .flowi6_oif = oif,
2933                 .flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
2934                 .daddr = iph->daddr,
2935                 .saddr = iph->saddr,
2936                 .flowlabel = ip6_flowinfo(iph),
2937                 .flowi6_uid = uid,
2938         };
2939
2940         dst = ip6_route_output(net, NULL, &fl6);
2941         if (!dst->error)
2942                 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true);
2943         dst_release(dst);
2944 }
2945 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
2946
2947 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
2948 {
2949         int oif = sk->sk_bound_dev_if;
2950         struct dst_entry *dst;
2951
2952         if (!oif && skb->dev)
2953                 oif = l3mdev_master_ifindex(skb->dev);
2954
2955         ip6_update_pmtu(skb, sock_net(sk), mtu, oif, sk->sk_mark, sk->sk_uid);
2956
2957         dst = __sk_dst_get(sk);
2958         if (!dst || !dst->obsolete ||
2959             dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
2960                 return;
2961
2962         bh_lock_sock(sk);
2963         if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
2964                 ip6_datagram_dst_update(sk, false);
2965         bh_unlock_sock(sk);
2966 }
2967 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
2968
2969 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
2970                            const struct flowi6 *fl6)
2971 {
2972 #ifdef CONFIG_IPV6_SUBTREES
2973         struct ipv6_pinfo *np = inet6_sk(sk);
2974 #endif
2975
2976         ip6_dst_store(sk, dst,
2977                       ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
2978                       &sk->sk_v6_daddr : NULL,
2979 #ifdef CONFIG_IPV6_SUBTREES
2980                       ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
2981                       &np->saddr :
2982 #endif
2983                       NULL);
2984 }
2985
2986 static bool ip6_redirect_nh_match(const struct fib6_result *res,
2987                                   struct flowi6 *fl6,
2988                                   const struct in6_addr *gw,
2989                                   struct rt6_info **ret)
2990 {
2991         const struct fib6_nh *nh = res->nh;
2992
2993         if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family ||
2994             fl6->flowi6_oif != nh->fib_nh_dev->ifindex)
2995                 return false;
2996
2997         /* rt_cache's gateway might be different from its 'parent'
2998          * in the case of an ip redirect.
2999          * So we keep searching in the exception table if the gateway
3000          * is different.
3001          */
3002         if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) {
3003                 struct rt6_info *rt_cache;
3004
3005                 rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr);
3006                 if (rt_cache &&
3007                     ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) {
3008                         *ret = rt_cache;
3009                         return true;
3010                 }
3011                 return false;
3012         }
3013         return true;
3014 }
3015
3016 struct fib6_nh_rd_arg {
3017         struct fib6_result      *res;
3018         struct flowi6           *fl6;
3019         const struct in6_addr   *gw;
3020         struct rt6_info         **ret;
3021 };
3022
3023 static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg)
3024 {
3025         struct fib6_nh_rd_arg *arg = _arg;
3026
3027         arg->res->nh = nh;
3028         return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret);
3029 }
3030
3031 /* Handle redirects */
3032 struct ip6rd_flowi {
3033         struct flowi6 fl6;
3034         struct in6_addr gateway;
3035 };
3036
3037 INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net,
3038                                              struct fib6_table *table,
3039                                              struct flowi6 *fl6,
3040                                              const struct sk_buff *skb,
3041                                              int flags)
3042 {
3043         struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
3044         struct rt6_info *ret = NULL;
3045         struct fib6_result res = {};
3046         struct fib6_nh_rd_arg arg = {
3047                 .res = &res,
3048                 .fl6 = fl6,
3049                 .gw  = &rdfl->gateway,
3050                 .ret = &ret
3051         };
3052         struct fib6_info *rt;
3053         struct fib6_node *fn;
3054
3055         /* Get the "current" route for this destination and
3056          * check if the redirect has come from appropriate router.
3057          *
3058          * RFC 4861 specifies that redirects should only be
3059          * accepted if they come from the nexthop to the target.
3060          * Due to the way the routes are chosen, this notion
3061          * is a bit fuzzy and one might need to check all possible
3062          * routes.
3063          */
3064
3065         rcu_read_lock();
3066         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
3067 restart:
3068         for_each_fib6_node_rt_rcu(fn) {
3069                 res.f6i = rt;
3070                 if (fib6_check_expired(rt))
3071                         continue;
3072                 if (rt->fib6_flags & RTF_REJECT)
3073                         break;
3074                 if (unlikely(rt->nh)) {
3075                         if (nexthop_is_blackhole(rt->nh))
3076                                 continue;
3077                         /* on match, res->nh is filled in and potentially ret */
3078                         if (nexthop_for_each_fib6_nh(rt->nh,
3079                                                      fib6_nh_redirect_match,
3080                                                      &arg))
3081                                 goto out;
3082                 } else {
3083                         res.nh = rt->fib6_nh;
3084                         if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway,
3085                                                   &ret))
3086                                 goto out;
3087                 }
3088         }
3089
3090         if (!rt)
3091                 rt = net->ipv6.fib6_null_entry;
3092         else if (rt->fib6_flags & RTF_REJECT) {
3093                 ret = net->ipv6.ip6_null_entry;
3094                 goto out;
3095         }
3096
3097         if (rt == net->ipv6.fib6_null_entry) {
3098                 fn = fib6_backtrack(fn, &fl6->saddr);
3099                 if (fn)
3100                         goto restart;
3101         }
3102
3103         res.f6i = rt;
3104         res.nh = rt->fib6_nh;
3105 out:
3106         if (ret) {
3107                 ip6_hold_safe(net, &ret);
3108         } else {
3109                 res.fib6_flags = res.f6i->fib6_flags;
3110                 res.fib6_type = res.f6i->fib6_type;
3111                 ret = ip6_create_rt_rcu(&res);
3112         }
3113
3114         rcu_read_unlock();
3115
3116         trace_fib6_table_lookup(net, &res, table, fl6);
3117         return ret;
3118 };
3119
3120 static struct dst_entry *ip6_route_redirect(struct net *net,
3121                                             const struct flowi6 *fl6,
3122                                             const struct sk_buff *skb,
3123                                             const struct in6_addr *gateway)
3124 {
3125         int flags = RT6_LOOKUP_F_HAS_SADDR;
3126         struct ip6rd_flowi rdfl;
3127
3128         rdfl.fl6 = *fl6;
3129         rdfl.gateway = *gateway;
3130
3131         return fib6_rule_lookup(net, &rdfl.fl6, skb,
3132                                 flags, __ip6_route_redirect);
3133 }
3134
3135 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
3136                   kuid_t uid)
3137 {
3138         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
3139         struct dst_entry *dst;
3140         struct flowi6 fl6 = {
3141                 .flowi6_iif = LOOPBACK_IFINDEX,
3142                 .flowi6_oif = oif,
3143                 .flowi6_mark = mark,
3144                 .daddr = iph->daddr,
3145                 .saddr = iph->saddr,
3146                 .flowlabel = ip6_flowinfo(iph),
3147                 .flowi6_uid = uid,
3148         };
3149
3150         dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
3151         rt6_do_redirect(dst, NULL, skb);
3152         dst_release(dst);
3153 }
3154 EXPORT_SYMBOL_GPL(ip6_redirect);
3155
3156 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
3157 {
3158         const struct ipv6hdr *iph = ipv6_hdr(skb);
3159         const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
3160         struct dst_entry *dst;
3161         struct flowi6 fl6 = {
3162                 .flowi6_iif = LOOPBACK_IFINDEX,
3163                 .flowi6_oif = oif,
3164                 .daddr = msg->dest,
3165                 .saddr = iph->daddr,
3166                 .flowi6_uid = sock_net_uid(net, NULL),
3167         };
3168
3169         dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
3170         rt6_do_redirect(dst, NULL, skb);
3171         dst_release(dst);
3172 }
3173
3174 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
3175 {
3176         ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark,
3177                      sk->sk_uid);
3178 }
3179 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
3180
3181 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
3182 {
3183         struct net_device *dev = dst->dev;
3184         unsigned int mtu = dst_mtu(dst);
3185         struct net *net = dev_net(dev);
3186
3187         mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
3188
3189         if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
3190                 mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
3191
3192         /*
3193          * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
3194          * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
3195          * IPV6_MAXPLEN is also valid and means: "any MSS,
3196          * rely only on pmtu discovery"
3197          */
3198         if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
3199                 mtu = IPV6_MAXPLEN;
3200         return mtu;
3201 }
3202
3203 INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst)
3204 {
3205         return ip6_dst_mtu_maybe_forward(dst, false);
3206 }
3207 EXPORT_INDIRECT_CALLABLE(ip6_mtu);
3208
3209 /* MTU selection:
3210  * 1. mtu on route is locked - use it
3211  * 2. mtu from nexthop exception
3212  * 3. mtu from egress device
3213  *
3214  * based on ip6_dst_mtu_forward and exception logic of
3215  * rt6_find_cached_rt; called with rcu_read_lock
3216  */
3217 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
3218                       const struct in6_addr *daddr,
3219                       const struct in6_addr *saddr)
3220 {
3221         const struct fib6_nh *nh = res->nh;
3222         struct fib6_info *f6i = res->f6i;
3223         struct inet6_dev *idev;
3224         struct rt6_info *rt;
3225         u32 mtu = 0;
3226
3227         if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
3228                 mtu = f6i->fib6_pmtu;
3229                 if (mtu)
3230                         goto out;
3231         }
3232
3233         rt = rt6_find_cached_rt(res, daddr, saddr);
3234         if (unlikely(rt)) {
3235                 mtu = dst_metric_raw(&rt->dst, RTAX_MTU);
3236         } else {
3237                 struct net_device *dev = nh->fib_nh_dev;
3238
3239                 mtu = IPV6_MIN_MTU;
3240                 idev = __in6_dev_get(dev);
3241                 if (idev && idev->cnf.mtu6 > mtu)
3242                         mtu = idev->cnf.mtu6;
3243         }
3244
3245         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
3246 out:
3247         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
3248 }
3249
3250 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
3251                                   struct flowi6 *fl6)
3252 {
3253         struct dst_entry *dst;
3254         struct rt6_info *rt;
3255         struct inet6_dev *idev = in6_dev_get(dev);
3256         struct net *net = dev_net(dev);
3257
3258         if (unlikely(!idev))
3259                 return ERR_PTR(-ENODEV);
3260
3261         rt = ip6_dst_alloc(net, dev, 0);
3262         if (unlikely(!rt)) {
3263                 in6_dev_put(idev);
3264                 dst = ERR_PTR(-ENOMEM);
3265                 goto out;
3266         }
3267
3268         rt->dst.input = ip6_input;
3269         rt->dst.output  = ip6_output;
3270         rt->rt6i_gateway  = fl6->daddr;
3271         rt->rt6i_dst.addr = fl6->daddr;
3272         rt->rt6i_dst.plen = 128;
3273         rt->rt6i_idev     = idev;
3274         dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
3275
3276         /* Add this dst into uncached_list so that rt6_disable_ip() can
3277          * do proper release of the net_device
3278          */
3279         rt6_uncached_list_add(rt);
3280
3281         dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
3282
3283 out:
3284         return dst;
3285 }
3286
3287 static int ip6_dst_gc(struct dst_ops *ops)
3288 {
3289         struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
3290         int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
3291         int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
3292         int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
3293         int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
3294         unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
3295         int entries;
3296
3297         entries = dst_entries_get_fast(ops);
3298         if (entries > rt_max_size)
3299                 entries = dst_entries_get_slow(ops);
3300
3301         if (time_after(rt_last_gc + rt_min_interval, jiffies) &&
3302             entries <= rt_max_size)
3303                 goto out;
3304
3305         net->ipv6.ip6_rt_gc_expire++;
3306         fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net, true);
3307         entries = dst_entries_get_slow(ops);
3308         if (entries < ops->gc_thresh)
3309                 net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;
3310 out:
3311         net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity;
3312         return entries > rt_max_size;
3313 }
3314
3315 static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
3316                                const struct in6_addr *gw_addr, u32 tbid,
3317                                int flags, struct fib6_result *res)
3318 {
3319         struct flowi6 fl6 = {
3320                 .flowi6_oif = cfg->fc_ifindex,
3321                 .daddr = *gw_addr,
3322                 .saddr = cfg->fc_prefsrc,
3323         };
3324         struct fib6_table *table;
3325         int err;
3326
3327         table = fib6_get_table(net, tbid);
3328         if (!table)
3329                 return -EINVAL;
3330
3331         if (!ipv6_addr_any(&cfg->fc_prefsrc))
3332                 flags |= RT6_LOOKUP_F_HAS_SADDR;
3333
3334         flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
3335
3336         err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags);
3337         if (!err && res->f6i != net->ipv6.fib6_null_entry)
3338                 fib6_select_path(net, res, &fl6, cfg->fc_ifindex,
3339                                  cfg->fc_ifindex != 0, NULL, flags);
3340
3341         return err;
3342 }
3343
3344 static int ip6_route_check_nh_onlink(struct net *net,
3345                                      struct fib6_config *cfg,
3346                                      const struct net_device *dev,
3347                                      struct netlink_ext_ack *extack)
3348 {
3349         u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
3350         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3351         struct fib6_result res = {};
3352         int err;
3353
3354         err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res);
3355         if (!err && !(res.fib6_flags & RTF_REJECT) &&
3356             /* ignore match if it is the default route */
3357             !ipv6_addr_any(&res.f6i->fib6_dst.addr) &&
3358             (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) {
3359                 NL_SET_ERR_MSG(extack,
3360                                "Nexthop has invalid gateway or device mismatch");
3361                 err = -EINVAL;
3362         }
3363
3364         return err;
3365 }
3366
3367 static int ip6_route_check_nh(struct net *net,
3368                               struct fib6_config *cfg,
3369                               struct net_device **_dev,
3370                               struct inet6_dev **idev)
3371 {
3372         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3373         struct net_device *dev = _dev ? *_dev : NULL;
3374         int flags = RT6_LOOKUP_F_IFACE;
3375         struct fib6_result res = {};
3376         int err = -EHOSTUNREACH;
3377
3378         if (cfg->fc_table) {
3379                 err = ip6_nh_lookup_table(net, cfg, gw_addr,
3380                                           cfg->fc_table, flags, &res);
3381                 /* gw_addr can not require a gateway or resolve to a reject
3382                  * route. If a device is given, it must match the result.
3383                  */
3384                 if (err || res.fib6_flags & RTF_REJECT ||
3385                     res.nh->fib_nh_gw_family ||
3386                     (dev && dev != res.nh->fib_nh_dev))
3387                         err = -EHOSTUNREACH;
3388         }
3389
3390         if (err < 0) {
3391                 struct flowi6 fl6 = {
3392                         .flowi6_oif = cfg->fc_ifindex,
3393                         .daddr = *gw_addr,
3394                 };
3395
3396                 err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags);
3397                 if (err || res.fib6_flags & RTF_REJECT ||
3398                     res.nh->fib_nh_gw_family)
3399                         err = -EHOSTUNREACH;
3400
3401                 if (err)
3402                         return err;
3403
3404                 fib6_select_path(net, &res, &fl6, cfg->fc_ifindex,
3405                                  cfg->fc_ifindex != 0, NULL, flags);
3406         }
3407
3408         err = 0;
3409         if (dev) {
3410                 if (dev != res.nh->fib_nh_dev)
3411                         err = -EHOSTUNREACH;
3412         } else {
3413                 *_dev = dev = res.nh->fib_nh_dev;
3414                 dev_hold(dev);
3415                 *idev = in6_dev_get(dev);
3416         }
3417
3418         return err;
3419 }
3420
3421 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
3422                            struct net_device **_dev, struct inet6_dev **idev,
3423                            struct netlink_ext_ack *extack)
3424 {
3425         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3426         int gwa_type = ipv6_addr_type(gw_addr);
3427         bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
3428         const struct net_device *dev = *_dev;
3429         bool need_addr_check = !dev;
3430         int err = -EINVAL;
3431
3432         /* if gw_addr is local we will fail to detect this in case
3433          * address is still TENTATIVE (DAD in progress). rt6_lookup()
3434          * will return already-added prefix route via interface that
3435          * prefix route was assigned to, which might be non-loopback.
3436          */
3437         if (dev &&
3438             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3439                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3440                 goto out;
3441         }
3442
3443         if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
3444                 /* IPv6 strictly inhibits using not link-local
3445                  * addresses as nexthop address.
3446                  * Otherwise, router will not able to send redirects.
3447                  * It is very good, but in some (rare!) circumstances
3448                  * (SIT, PtP, NBMA NOARP links) it is handy to allow
3449                  * some exceptions. --ANK
3450                  * We allow IPv4-mapped nexthops to support RFC4798-type
3451                  * addressing
3452                  */
3453                 if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
3454                         NL_SET_ERR_MSG(extack, "Invalid gateway address");
3455                         goto out;
3456                 }
3457
3458                 rcu_read_lock();
3459
3460                 if (cfg->fc_flags & RTNH_F_ONLINK)
3461                         err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
3462                 else
3463                         err = ip6_route_check_nh(net, cfg, _dev, idev);
3464
3465                 rcu_read_unlock();
3466
3467                 if (err)
3468                         goto out;
3469         }
3470
3471         /* reload in case device was changed */
3472         dev = *_dev;
3473
3474         err = -EINVAL;
3475         if (!dev) {
3476                 NL_SET_ERR_MSG(extack, "Egress device not specified");
3477                 goto out;
3478         } else if (dev->flags & IFF_LOOPBACK) {
3479                 NL_SET_ERR_MSG(extack,
3480                                "Egress device can not be loopback device for this route");
3481                 goto out;
3482         }
3483
3484         /* if we did not check gw_addr above, do so now that the
3485          * egress device has been resolved.
3486          */
3487         if (need_addr_check &&
3488             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3489                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3490                 goto out;
3491         }
3492
3493         err = 0;
3494 out:
3495         return err;
3496 }
3497
3498 static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
3499 {
3500         if ((flags & RTF_REJECT) ||
3501             (dev && (dev->flags & IFF_LOOPBACK) &&
3502              !(addr_type & IPV6_ADDR_LOOPBACK) &&
3503              !(flags & (RTF_ANYCAST | RTF_LOCAL))))
3504                 return true;
3505
3506         return false;
3507 }
3508
3509 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
3510                  struct fib6_config *cfg, gfp_t gfp_flags,
3511                  struct netlink_ext_ack *extack)
3512 {
3513         struct net_device *dev = NULL;
3514         struct inet6_dev *idev = NULL;
3515         int addr_type;
3516         int err;
3517
3518         fib6_nh->fib_nh_family = AF_INET6;
3519 #ifdef CONFIG_IPV6_ROUTER_PREF
3520         fib6_nh->last_probe = jiffies;
3521 #endif
3522         if (cfg->fc_is_fdb) {
3523                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3524                 fib6_nh->fib_nh_gw_family = AF_INET6;
3525                 return 0;
3526         }
3527
3528         err = -ENODEV;
3529         if (cfg->fc_ifindex) {
3530                 dev = dev_get_by_index(net, cfg->fc_ifindex);
3531                 if (!dev)
3532                         goto out;
3533                 idev = in6_dev_get(dev);
3534                 if (!idev)
3535                         goto out;
3536         }
3537
3538         if (cfg->fc_flags & RTNH_F_ONLINK) {
3539                 if (!dev) {
3540                         NL_SET_ERR_MSG(extack,
3541                                        "Nexthop device required for onlink");
3542                         goto out;
3543                 }
3544
3545                 if (!(dev->flags & IFF_UP)) {
3546                         NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3547                         err = -ENETDOWN;
3548                         goto out;
3549                 }
3550
3551                 fib6_nh->fib_nh_flags |= RTNH_F_ONLINK;
3552         }
3553
3554         fib6_nh->fib_nh_weight = 1;
3555
3556         /* We cannot add true routes via loopback here,
3557          * they would result in kernel looping; promote them to reject routes
3558          */
3559         addr_type = ipv6_addr_type(&cfg->fc_dst);
3560         if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) {
3561                 /* hold loopback dev/idev if we haven't done so. */
3562                 if (dev != net->loopback_dev) {
3563                         if (dev) {
3564                                 dev_put(dev);
3565                                 in6_dev_put(idev);
3566                         }
3567                         dev = net->loopback_dev;
3568                         dev_hold(dev);
3569                         idev = in6_dev_get(dev);
3570                         if (!idev) {
3571                                 err = -ENODEV;
3572                                 goto out;
3573                         }
3574                 }
3575                 goto pcpu_alloc;
3576         }
3577
3578         if (cfg->fc_flags & RTF_GATEWAY) {
3579                 err = ip6_validate_gw(net, cfg, &dev, &idev, extack);
3580                 if (err)
3581                         goto out;
3582
3583                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3584                 fib6_nh->fib_nh_gw_family = AF_INET6;
3585         }
3586
3587         err = -ENODEV;
3588         if (!dev)
3589                 goto out;
3590
3591         if (idev->cnf.disable_ipv6) {
3592                 NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
3593                 err = -EACCES;
3594                 goto out;
3595         }
3596
3597         if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
3598                 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3599                 err = -ENETDOWN;
3600                 goto out;
3601         }
3602
3603         if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
3604             !netif_carrier_ok(dev))
3605                 fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
3606
3607         err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap,
3608                                  cfg->fc_encap_type, cfg, gfp_flags, extack);
3609         if (err)
3610                 goto out;
3611
3612 pcpu_alloc:
3613         fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
3614         if (!fib6_nh->rt6i_pcpu) {
3615                 err = -ENOMEM;
3616                 goto out;
3617         }
3618
3619         fib6_nh->fib_nh_dev = dev;
3620         netdev_tracker_alloc(dev, &fib6_nh->fib_nh_dev_tracker, gfp_flags);
3621
3622         fib6_nh->fib_nh_oif = dev->ifindex;
3623         err = 0;
3624 out:
3625         if (idev)
3626                 in6_dev_put(idev);
3627
3628         if (err) {
3629                 lwtstate_put(fib6_nh->fib_nh_lws);
3630                 fib6_nh->fib_nh_lws = NULL;
3631                 dev_put(dev);
3632         }
3633
3634         return err;
3635 }
3636
3637 void fib6_nh_release(struct fib6_nh *fib6_nh)
3638 {
3639         struct rt6_exception_bucket *bucket;
3640
3641         rcu_read_lock();
3642
3643         fib6_nh_flush_exceptions(fib6_nh, NULL);
3644         bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL);
3645         if (bucket) {
3646                 rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL);
3647                 kfree(bucket);
3648         }
3649
3650         rcu_read_unlock();
3651
3652         fib6_nh_release_dsts(fib6_nh);
3653         free_percpu(fib6_nh->rt6i_pcpu);
3654
3655         fib_nh_common_release(&fib6_nh->nh_common);
3656 }
3657
3658 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh)
3659 {
3660         int cpu;
3661
3662         if (!fib6_nh->rt6i_pcpu)
3663                 return;
3664
3665         for_each_possible_cpu(cpu) {
3666                 struct rt6_info *pcpu_rt, **ppcpu_rt;
3667
3668                 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
3669                 pcpu_rt = xchg(ppcpu_rt, NULL);
3670                 if (pcpu_rt) {
3671                         dst_dev_put(&pcpu_rt->dst);
3672                         dst_release(&pcpu_rt->dst);
3673                 }
3674         }
3675 }
3676
3677 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
3678                                               gfp_t gfp_flags,
3679                                               struct netlink_ext_ack *extack)
3680 {
3681         struct net *net = cfg->fc_nlinfo.nl_net;
3682         struct fib6_info *rt = NULL;
3683         struct nexthop *nh = NULL;
3684         struct fib6_table *table;
3685         struct fib6_nh *fib6_nh;
3686         int err = -EINVAL;
3687         int addr_type;
3688
3689         /* RTF_PCPU is an internal flag; can not be set by userspace */
3690         if (cfg->fc_flags & RTF_PCPU) {
3691                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
3692                 goto out;
3693         }
3694
3695         /* RTF_CACHE is an internal flag; can not be set by userspace */
3696         if (cfg->fc_flags & RTF_CACHE) {
3697                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
3698                 goto out;
3699         }
3700
3701         if (cfg->fc_type > RTN_MAX) {
3702                 NL_SET_ERR_MSG(extack, "Invalid route type");
3703                 goto out;
3704         }
3705
3706         if (cfg->fc_dst_len > 128) {
3707                 NL_SET_ERR_MSG(extack, "Invalid prefix length");
3708                 goto out;
3709         }
3710         if (cfg->fc_src_len > 128) {
3711                 NL_SET_ERR_MSG(extack, "Invalid source address length");
3712                 goto out;
3713         }
3714 #ifndef CONFIG_IPV6_SUBTREES
3715         if (cfg->fc_src_len) {
3716                 NL_SET_ERR_MSG(extack,
3717                                "Specifying source address requires IPV6_SUBTREES to be enabled");
3718                 goto out;
3719         }
3720 #endif
3721         if (cfg->fc_nh_id) {
3722                 nh = nexthop_find_by_id(net, cfg->fc_nh_id);
3723                 if (!nh) {
3724                         NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
3725                         goto out;
3726                 }
3727                 err = fib6_check_nexthop(nh, cfg, extack);
3728                 if (err)
3729                         goto out;
3730         }
3731
3732         err = -ENOBUFS;
3733         if (cfg->fc_nlinfo.nlh &&
3734             !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
3735                 table = fib6_get_table(net, cfg->fc_table);
3736                 if (!table) {
3737                         pr_warn("NLM_F_CREATE should be specified when creating new route\n");
3738                         table = fib6_new_table(net, cfg->fc_table);
3739                 }
3740         } else {
3741                 table = fib6_new_table(net, cfg->fc_table);
3742         }
3743
3744         if (!table)
3745                 goto out;
3746
3747         err = -ENOMEM;
3748         rt = fib6_info_alloc(gfp_flags, !nh);
3749         if (!rt)
3750                 goto out;
3751
3752         rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len,
3753                                                extack);
3754         if (IS_ERR(rt->fib6_metrics)) {
3755                 err = PTR_ERR(rt->fib6_metrics);
3756                 /* Do not leave garbage there. */
3757                 rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
3758                 goto out_free;
3759         }
3760
3761         if (cfg->fc_flags & RTF_ADDRCONF)
3762                 rt->dst_nocount = true;
3763
3764         if (cfg->fc_flags & RTF_EXPIRES)
3765                 fib6_set_expires(rt, jiffies +
3766                                 clock_t_to_jiffies(cfg->fc_expires));
3767         else
3768                 fib6_clean_expires(rt);
3769
3770         if (cfg->fc_protocol == RTPROT_UNSPEC)
3771                 cfg->fc_protocol = RTPROT_BOOT;
3772         rt->fib6_protocol = cfg->fc_protocol;
3773
3774         rt->fib6_table = table;
3775         rt->fib6_metric = cfg->fc_metric;
3776         rt->fib6_type = cfg->fc_type ? : RTN_UNICAST;
3777         rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;
3778
3779         ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
3780         rt->fib6_dst.plen = cfg->fc_dst_len;
3781
3782 #ifdef CONFIG_IPV6_SUBTREES
3783         ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
3784         rt->fib6_src.plen = cfg->fc_src_len;
3785 #endif
3786         if (nh) {
3787                 if (rt->fib6_src.plen) {
3788                         NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
3789                         goto out_free;
3790                 }
3791                 if (!nexthop_get(nh)) {
3792                         NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
3793                         goto out_free;
3794                 }
3795                 rt->nh = nh;
3796                 fib6_nh = nexthop_fib6_nh(rt->nh);
3797         } else {
3798                 err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack);
3799                 if (err)
3800                         goto out;
3801
3802                 fib6_nh = rt->fib6_nh;
3803
3804                 /* We cannot add true routes via loopback here, they would
3805                  * result in kernel looping; promote them to reject routes
3806                  */
3807                 addr_type = ipv6_addr_type(&cfg->fc_dst);
3808                 if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev,
3809                                    addr_type))
3810                         rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
3811         }
3812
3813         if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
3814                 struct net_device *dev = fib6_nh->fib_nh_dev;
3815
3816                 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
3817                         NL_SET_ERR_MSG(extack, "Invalid source address");
3818                         err = -EINVAL;
3819                         goto out;
3820                 }
3821                 rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
3822                 rt->fib6_prefsrc.plen = 128;
3823         } else
3824                 rt->fib6_prefsrc.plen = 0;
3825
3826         return rt;
3827 out:
3828         fib6_info_release(rt);
3829         return ERR_PTR(err);
3830 out_free:
3831         ip_fib_metrics_put(rt->fib6_metrics);
3832         kfree(rt);
3833         return ERR_PTR(err);
3834 }
3835
3836 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
3837                   struct netlink_ext_ack *extack)
3838 {
3839         struct fib6_info *rt;
3840         int err;
3841
3842         rt = ip6_route_info_create(cfg, gfp_flags, extack);
3843         if (IS_ERR(rt))
3844                 return PTR_ERR(rt);
3845
3846         err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
3847         fib6_info_release(rt);
3848
3849         return err;
3850 }
3851
3852 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
3853 {
3854         struct net *net = info->nl_net;
3855         struct fib6_table *table;
3856         int err;
3857
3858         if (rt == net->ipv6.fib6_null_entry) {
3859                 err = -ENOENT;
3860                 goto out;
3861         }
3862
3863         table = rt->fib6_table;
3864         spin_lock_bh(&table->tb6_lock);
3865         err = fib6_del(rt, info);
3866         spin_unlock_bh(&table->tb6_lock);
3867
3868 out:
3869         fib6_info_release(rt);
3870         return err;
3871 }
3872
3873 int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify)
3874 {
3875         struct nl_info info = {
3876                 .nl_net = net,
3877                 .skip_notify = skip_notify
3878         };
3879
3880         return __ip6_del_rt(rt, &info);
3881 }
3882
3883 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
3884 {
3885         struct nl_info *info = &cfg->fc_nlinfo;
3886         struct net *net = info->nl_net;
3887         struct sk_buff *skb = NULL;
3888         struct fib6_table *table;
3889         int err = -ENOENT;
3890
3891         if (rt == net->ipv6.fib6_null_entry)
3892                 goto out_put;
3893         table = rt->fib6_table;
3894         spin_lock_bh(&table->tb6_lock);
3895
3896         if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
3897                 struct fib6_info *sibling, *next_sibling;
3898                 struct fib6_node *fn;
3899
3900                 /* prefer to send a single notification with all hops */
3901                 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3902                 if (skb) {
3903                         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3904
3905                         if (rt6_fill_node(net, skb, rt, NULL,
3906                                           NULL, NULL, 0, RTM_DELROUTE,
3907                                           info->portid, seq, 0) < 0) {
3908                                 kfree_skb(skb);
3909                                 skb = NULL;
3910                         } else
3911                                 info->skip_notify = 1;
3912                 }
3913
3914                 /* 'rt' points to the first sibling route. If it is not the
3915                  * leaf, then we do not need to send a notification. Otherwise,
3916                  * we need to check if the last sibling has a next route or not
3917                  * and emit a replace or delete notification, respectively.
3918                  */
3919                 info->skip_notify_kernel = 1;
3920                 fn = rcu_dereference_protected(rt->fib6_node,
3921                                             lockdep_is_held(&table->tb6_lock));
3922                 if (rcu_access_pointer(fn->leaf) == rt) {
3923                         struct fib6_info *last_sibling, *replace_rt;
3924
3925                         last_sibling = list_last_entry(&rt->fib6_siblings,
3926                                                        struct fib6_info,
3927                                                        fib6_siblings);
3928                         replace_rt = rcu_dereference_protected(
3929                                             last_sibling->fib6_next,
3930                                             lockdep_is_held(&table->tb6_lock));
3931                         if (replace_rt)
3932                                 call_fib6_entry_notifiers_replace(net,
3933                                                                   replace_rt);
3934                         else
3935                                 call_fib6_multipath_entry_notifiers(net,
3936                                                        FIB_EVENT_ENTRY_DEL,
3937                                                        rt, rt->fib6_nsiblings,
3938                                                        NULL);
3939                 }
3940                 list_for_each_entry_safe(sibling, next_sibling,
3941                                          &rt->fib6_siblings,
3942                                          fib6_siblings) {
3943                         err = fib6_del(sibling, info);
3944                         if (err)
3945                                 goto out_unlock;
3946                 }
3947         }
3948
3949         err = fib6_del(rt, info);
3950 out_unlock:
3951         spin_unlock_bh(&table->tb6_lock);
3952 out_put:
3953         fib6_info_release(rt);
3954
3955         if (skb) {
3956                 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3957                             info->nlh, gfp_any());
3958         }
3959         return err;
3960 }
3961
3962 static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
3963 {
3964         int rc = -ESRCH;
3965
3966         if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
3967                 goto out;
3968
3969         if (cfg->fc_flags & RTF_GATEWAY &&
3970             !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
3971                 goto out;
3972
3973         rc = rt6_remove_exception_rt(rt);
3974 out:
3975         return rc;
3976 }
3977
3978 static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt,
3979                              struct fib6_nh *nh)
3980 {
3981         struct fib6_result res = {
3982                 .f6i = rt,
3983                 .nh = nh,
3984         };
3985         struct rt6_info *rt_cache;
3986
3987         rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src);
3988         if (rt_cache)
3989                 return __ip6_del_cached_rt(rt_cache, cfg);
3990
3991         return 0;
3992 }
3993
3994 struct fib6_nh_del_cached_rt_arg {
3995         struct fib6_config *cfg;
3996         struct fib6_info *f6i;
3997 };
3998
3999 static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg)
4000 {
4001         struct fib6_nh_del_cached_rt_arg *arg = _arg;
4002         int rc;
4003
4004         rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh);
4005         return rc != -ESRCH ? rc : 0;
4006 }
4007
4008 static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i)
4009 {
4010         struct fib6_nh_del_cached_rt_arg arg = {
4011                 .cfg = cfg,
4012                 .f6i = f6i
4013         };
4014
4015         return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg);
4016 }
4017
4018 static int ip6_route_del(struct fib6_config *cfg,
4019                          struct netlink_ext_ack *extack)
4020 {
4021         struct fib6_table *table;
4022         struct fib6_info *rt;
4023         struct fib6_node *fn;
4024         int err = -ESRCH;
4025
4026         table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
4027         if (!table) {
4028                 NL_SET_ERR_MSG(extack, "FIB table does not exist");
4029                 return err;
4030         }
4031
4032         rcu_read_lock();
4033
4034         fn = fib6_locate(&table->tb6_root,
4035                          &cfg->fc_dst, cfg->fc_dst_len,
4036                          &cfg->fc_src, cfg->fc_src_len,
4037                          !(cfg->fc_flags & RTF_CACHE));
4038
4039         if (fn) {
4040                 for_each_fib6_node_rt_rcu(fn) {
4041                         struct fib6_nh *nh;
4042
4043                         if (rt->nh && cfg->fc_nh_id &&
4044                             rt->nh->id != cfg->fc_nh_id)
4045                                 continue;
4046
4047                         if (cfg->fc_flags & RTF_CACHE) {
4048                                 int rc = 0;
4049
4050                                 if (rt->nh) {
4051                                         rc = ip6_del_cached_rt_nh(cfg, rt);
4052                                 } else if (cfg->fc_nh_id) {
4053                                         continue;
4054                                 } else {
4055                                         nh = rt->fib6_nh;
4056                                         rc = ip6_del_cached_rt(cfg, rt, nh);
4057                                 }
4058                                 if (rc != -ESRCH) {
4059                                         rcu_read_unlock();
4060                                         return rc;
4061                                 }
4062                                 continue;
4063                         }
4064
4065                         if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
4066                                 continue;
4067                         if (cfg->fc_protocol &&
4068                             cfg->fc_protocol != rt->fib6_protocol)
4069                                 continue;
4070
4071                         if (rt->nh) {
4072                                 if (!fib6_info_hold_safe(rt))
4073                                         continue;
4074                                 rcu_read_unlock();
4075
4076                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4077                         }
4078                         if (cfg->fc_nh_id)
4079                                 continue;
4080
4081                         nh = rt->fib6_nh;
4082                         if (cfg->fc_ifindex &&
4083                             (!nh->fib_nh_dev ||
4084                              nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
4085                                 continue;
4086                         if (cfg->fc_flags & RTF_GATEWAY &&
4087                             !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6))
4088                                 continue;
4089                         if (!fib6_info_hold_safe(rt))
4090                                 continue;
4091                         rcu_read_unlock();
4092
4093                         /* if gateway was specified only delete the one hop */
4094                         if (cfg->fc_flags & RTF_GATEWAY)
4095                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4096
4097                         return __ip6_del_rt_siblings(rt, cfg);
4098                 }
4099         }
4100         rcu_read_unlock();
4101
4102         return err;
4103 }
4104
4105 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
4106 {
4107         struct netevent_redirect netevent;
4108         struct rt6_info *rt, *nrt = NULL;
4109         struct fib6_result res = {};
4110         struct ndisc_options ndopts;
4111         struct inet6_dev *in6_dev;
4112         struct neighbour *neigh;
4113         struct rd_msg *msg;
4114         int optlen, on_link;
4115         u8 *lladdr;
4116
4117         optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
4118         optlen -= sizeof(*msg);
4119
4120         if (optlen < 0) {
4121                 net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
4122                 return;
4123         }
4124
4125         msg = (struct rd_msg *)icmp6_hdr(skb);
4126
4127         if (ipv6_addr_is_multicast(&msg->dest)) {
4128                 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
4129                 return;
4130         }
4131
4132         on_link = 0;
4133         if (ipv6_addr_equal(&msg->dest, &msg->target)) {
4134                 on_link = 1;
4135         } else if (ipv6_addr_type(&msg->target) !=
4136                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
4137                 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
4138                 return;
4139         }
4140
4141         in6_dev = __in6_dev_get(skb->dev);
4142         if (!in6_dev)
4143                 return;
4144         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
4145                 return;
4146
4147         /* RFC2461 8.1:
4148          *      The IP source address of the Redirect MUST be the same as the current
4149          *      first-hop router for the specified ICMP Destination Address.
4150          */
4151
4152         if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
4153                 net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
4154                 return;
4155         }
4156
4157         lladdr = NULL;
4158         if (ndopts.nd_opts_tgt_lladdr) {
4159                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
4160                                              skb->dev);
4161                 if (!lladdr) {
4162                         net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
4163                         return;
4164                 }
4165         }
4166
4167         rt = (struct rt6_info *) dst;
4168         if (rt->rt6i_flags & RTF_REJECT) {
4169                 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
4170                 return;
4171         }
4172
4173         /* Redirect received -> path was valid.
4174          * Look, redirects are sent only in response to data packets,
4175          * so that this nexthop apparently is reachable. --ANK
4176          */
4177         dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
4178
4179         neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
4180         if (!neigh)
4181                 return;
4182
4183         /*
4184          *      We have finally decided to accept it.
4185          */
4186
4187         ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
4188                      NEIGH_UPDATE_F_WEAK_OVERRIDE|
4189                      NEIGH_UPDATE_F_OVERRIDE|
4190                      (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
4191                                      NEIGH_UPDATE_F_ISROUTER)),
4192                      NDISC_REDIRECT, &ndopts);
4193
4194         rcu_read_lock();
4195         res.f6i = rcu_dereference(rt->from);
4196         if (!res.f6i)
4197                 goto out;
4198
4199         if (res.f6i->nh) {
4200                 struct fib6_nh_match_arg arg = {
4201                         .dev = dst->dev,
4202                         .gw = &rt->rt6i_gateway,
4203                 };
4204
4205                 nexthop_for_each_fib6_nh(res.f6i->nh,
4206                                          fib6_nh_find_match, &arg);
4207
4208                 /* fib6_info uses a nexthop that does not have fib6_nh
4209                  * using the dst->dev. Should be impossible
4210                  */
4211                 if (!arg.match)
4212                         goto out;
4213                 res.nh = arg.match;
4214         } else {
4215                 res.nh = res.f6i->fib6_nh;
4216         }
4217
4218         res.fib6_flags = res.f6i->fib6_flags;
4219         res.fib6_type = res.f6i->fib6_type;
4220         nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL);
4221         if (!nrt)
4222                 goto out;
4223
4224         nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
4225         if (on_link)
4226                 nrt->rt6i_flags &= ~RTF_GATEWAY;
4227
4228         nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
4229
4230         /* rt6_insert_exception() will take care of duplicated exceptions */
4231         if (rt6_insert_exception(nrt, &res)) {
4232                 dst_release_immediate(&nrt->dst);
4233                 goto out;
4234         }
4235
4236         netevent.old = &rt->dst;
4237         netevent.new = &nrt->dst;
4238         netevent.daddr = &msg->dest;
4239         netevent.neigh = neigh;
4240         call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
4241
4242 out:
4243         rcu_read_unlock();
4244         neigh_release(neigh);
4245 }
4246
4247 #ifdef CONFIG_IPV6_ROUTE_INFO
4248 static struct fib6_info *rt6_get_route_info(struct net *net,
4249                                            const struct in6_addr *prefix, int prefixlen,
4250                                            const struct in6_addr *gwaddr,
4251                                            struct net_device *dev)
4252 {
4253         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4254         int ifindex = dev->ifindex;
4255         struct fib6_node *fn;
4256         struct fib6_info *rt = NULL;
4257         struct fib6_table *table;
4258
4259         table = fib6_get_table(net, tb_id);
4260         if (!table)
4261                 return NULL;
4262
4263         rcu_read_lock();
4264         fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
4265         if (!fn)
4266                 goto out;
4267
4268         for_each_fib6_node_rt_rcu(fn) {
4269                 /* these routes do not use nexthops */
4270                 if (rt->nh)
4271                         continue;
4272                 if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex)
4273                         continue;
4274                 if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
4275                     !rt->fib6_nh->fib_nh_gw_family)
4276                         continue;
4277                 if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr))
4278                         continue;
4279                 if (!fib6_info_hold_safe(rt))
4280                         continue;
4281                 break;
4282         }
4283 out:
4284         rcu_read_unlock();
4285         return rt;
4286 }
4287
4288 static struct fib6_info *rt6_add_route_info(struct net *net,
4289                                            const struct in6_addr *prefix, int prefixlen,
4290                                            const struct in6_addr *gwaddr,
4291                                            struct net_device *dev,
4292                                            unsigned int pref)
4293 {
4294         struct fib6_config cfg = {
4295                 .fc_metric      = IP6_RT_PRIO_USER,
4296                 .fc_ifindex     = dev->ifindex,
4297                 .fc_dst_len     = prefixlen,
4298                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
4299                                   RTF_UP | RTF_PREF(pref),
4300                 .fc_protocol = RTPROT_RA,
4301                 .fc_type = RTN_UNICAST,
4302                 .fc_nlinfo.portid = 0,
4303                 .fc_nlinfo.nlh = NULL,
4304                 .fc_nlinfo.nl_net = net,
4305         };
4306
4307         cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4308         cfg.fc_dst = *prefix;
4309         cfg.fc_gateway = *gwaddr;
4310
4311         /* We should treat it as a default route if prefix length is 0. */
4312         if (!prefixlen)
4313                 cfg.fc_flags |= RTF_DEFAULT;
4314
4315         ip6_route_add(&cfg, GFP_ATOMIC, NULL);
4316
4317         return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
4318 }
4319 #endif
4320
4321 struct fib6_info *rt6_get_dflt_router(struct net *net,
4322                                      const struct in6_addr *addr,
4323                                      struct net_device *dev)
4324 {
4325         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
4326         struct fib6_info *rt;
4327         struct fib6_table *table;
4328
4329         table = fib6_get_table(net, tb_id);
4330         if (!table)
4331                 return NULL;
4332
4333         rcu_read_lock();
4334         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4335                 struct fib6_nh *nh;
4336
4337                 /* RA routes do not use nexthops */
4338                 if (rt->nh)
4339                         continue;
4340
4341                 nh = rt->fib6_nh;
4342                 if (dev == nh->fib_nh_dev &&
4343                     ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
4344                     ipv6_addr_equal(&nh->fib_nh_gw6, addr))
4345                         break;
4346         }
4347         if (rt && !fib6_info_hold_safe(rt))
4348                 rt = NULL;
4349         rcu_read_unlock();
4350         return rt;
4351 }
4352
4353 struct fib6_info *rt6_add_dflt_router(struct net *net,
4354                                      const struct in6_addr *gwaddr,
4355                                      struct net_device *dev,
4356                                      unsigned int pref,
4357                                      u32 defrtr_usr_metric)
4358 {
4359         struct fib6_config cfg = {
4360                 .fc_table       = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
4361                 .fc_metric      = defrtr_usr_metric,
4362                 .fc_ifindex     = dev->ifindex,
4363                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
4364                                   RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
4365                 .fc_protocol = RTPROT_RA,
4366                 .fc_type = RTN_UNICAST,
4367                 .fc_nlinfo.portid = 0,
4368                 .fc_nlinfo.nlh = NULL,
4369                 .fc_nlinfo.nl_net = net,
4370         };
4371
4372         cfg.fc_gateway = *gwaddr;
4373
4374         if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
4375                 struct fib6_table *table;
4376
4377                 table = fib6_get_table(dev_net(dev), cfg.fc_table);
4378                 if (table)
4379                         table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
4380         }
4381
4382         return rt6_get_dflt_router(net, gwaddr, dev);
4383 }
4384
4385 static void __rt6_purge_dflt_routers(struct net *net,
4386                                      struct fib6_table *table)
4387 {
4388         struct fib6_info *rt;
4389
4390 restart:
4391         rcu_read_lock();
4392         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4393                 struct net_device *dev = fib6_info_nh_dev(rt);
4394                 struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
4395
4396                 if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
4397                     (!idev || idev->cnf.accept_ra != 2) &&
4398                     fib6_info_hold_safe(rt)) {
4399                         rcu_read_unlock();
4400                         ip6_del_rt(net, rt, false);
4401                         goto restart;
4402                 }
4403         }
4404         rcu_read_unlock();
4405
4406         table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
4407 }
4408
4409 void rt6_purge_dflt_routers(struct net *net)
4410 {
4411         struct fib6_table *table;
4412         struct hlist_head *head;
4413         unsigned int h;
4414
4415         rcu_read_lock();
4416
4417         for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
4418                 head = &net->ipv6.fib_table_hash[h];
4419                 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
4420                         if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
4421                                 __rt6_purge_dflt_routers(net, table);
4422                 }
4423         }
4424
4425         rcu_read_unlock();
4426 }
4427
4428 static void rtmsg_to_fib6_config(struct net *net,
4429                                  struct in6_rtmsg *rtmsg,
4430                                  struct fib6_config *cfg)
4431 {
4432         *cfg = (struct fib6_config){
4433                 .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
4434                          : RT6_TABLE_MAIN,
4435                 .fc_ifindex = rtmsg->rtmsg_ifindex,
4436                 .fc_metric = rtmsg->rtmsg_metric ? : IP6_RT_PRIO_USER,
4437                 .fc_expires = rtmsg->rtmsg_info,
4438                 .fc_dst_len = rtmsg->rtmsg_dst_len,
4439                 .fc_src_len = rtmsg->rtmsg_src_len,
4440                 .fc_flags = rtmsg->rtmsg_flags,
4441                 .fc_type = rtmsg->rtmsg_type,
4442
4443                 .fc_nlinfo.nl_net = net,
4444
4445                 .fc_dst = rtmsg->rtmsg_dst,
4446                 .fc_src = rtmsg->rtmsg_src,
4447                 .fc_gateway = rtmsg->rtmsg_gateway,
4448         };
4449 }
4450
4451 int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg)
4452 {
4453         struct fib6_config cfg;
4454         int err;
4455
4456         if (cmd != SIOCADDRT && cmd != SIOCDELRT)
4457                 return -EINVAL;
4458         if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
4459                 return -EPERM;
4460
4461         rtmsg_to_fib6_config(net, rtmsg, &cfg);
4462
4463         rtnl_lock();
4464         switch (cmd) {
4465         case SIOCADDRT:
4466                 err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
4467                 break;
4468         case SIOCDELRT:
4469                 err = ip6_route_del(&cfg, NULL);
4470                 break;
4471         }
4472         rtnl_unlock();
4473         return err;
4474 }
4475
4476 /*
4477  *      Drop the packet on the floor
4478  */
4479
4480 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
4481 {
4482         struct dst_entry *dst = skb_dst(skb);
4483         struct net *net = dev_net(dst->dev);
4484         struct inet6_dev *idev;
4485         int type;
4486
4487         if (netif_is_l3_master(skb->dev) &&
4488             dst->dev == net->loopback_dev)
4489                 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
4490         else
4491                 idev = ip6_dst_idev(dst);
4492
4493         switch (ipstats_mib_noroutes) {
4494         case IPSTATS_MIB_INNOROUTES:
4495                 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
4496                 if (type == IPV6_ADDR_ANY) {
4497                         IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
4498                         break;
4499                 }
4500                 fallthrough;
4501         case IPSTATS_MIB_OUTNOROUTES:
4502                 IP6_INC_STATS(net, idev, ipstats_mib_noroutes);
4503                 break;
4504         }
4505
4506         /* Start over by dropping the dst for l3mdev case */
4507         if (netif_is_l3_master(skb->dev))
4508                 skb_dst_drop(skb);
4509
4510         icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
4511         kfree_skb(skb);
4512         return 0;
4513 }
4514
4515 static int ip6_pkt_discard(struct sk_buff *skb)
4516 {
4517         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
4518 }
4519
4520 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4521 {
4522         skb->dev = skb_dst(skb)->dev;
4523         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
4524 }
4525
4526 static int ip6_pkt_prohibit(struct sk_buff *skb)
4527 {
4528         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
4529 }
4530
4531 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4532 {
4533         skb->dev = skb_dst(skb)->dev;
4534         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
4535 }
4536
4537 /*
4538  *      Allocate a dst for local (unicast / anycast) address.
4539  */
4540
4541 struct fib6_info *addrconf_f6i_alloc(struct net *net,
4542                                      struct inet6_dev *idev,
4543                                      const struct in6_addr *addr,
4544                                      bool anycast, gfp_t gfp_flags)
4545 {
4546         struct fib6_config cfg = {
4547                 .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
4548                 .fc_ifindex = idev->dev->ifindex,
4549                 .fc_flags = RTF_UP | RTF_NONEXTHOP,
4550                 .fc_dst = *addr,
4551                 .fc_dst_len = 128,
4552                 .fc_protocol = RTPROT_KERNEL,
4553                 .fc_nlinfo.nl_net = net,
4554                 .fc_ignore_dev_down = true,
4555         };
4556         struct fib6_info *f6i;
4557
4558         if (anycast) {
4559                 cfg.fc_type = RTN_ANYCAST;
4560                 cfg.fc_flags |= RTF_ANYCAST;
4561         } else {
4562                 cfg.fc_type = RTN_LOCAL;
4563                 cfg.fc_flags |= RTF_LOCAL;
4564         }
4565
4566         f6i = ip6_route_info_create(&cfg, gfp_flags, NULL);
4567         if (!IS_ERR(f6i))
4568                 f6i->dst_nocount = true;
4569         return f6i;
4570 }
4571
4572 /* remove deleted ip from prefsrc entries */
4573 struct arg_dev_net_ip {
4574         struct net_device *dev;
4575         struct net *net;
4576         struct in6_addr *addr;
4577 };
4578
4579 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
4580 {
4581         struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev;
4582         struct net *net = ((struct arg_dev_net_ip *)arg)->net;
4583         struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
4584
4585         if (!rt->nh &&
4586             ((void *)rt->fib6_nh->fib_nh_dev == dev || !dev) &&
4587             rt != net->ipv6.fib6_null_entry &&
4588             ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr)) {
4589                 spin_lock_bh(&rt6_exception_lock);
4590                 /* remove prefsrc entry */
4591                 rt->fib6_prefsrc.plen = 0;
4592                 spin_unlock_bh(&rt6_exception_lock);
4593         }
4594         return 0;
4595 }
4596
4597 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
4598 {
4599         struct net *net = dev_net(ifp->idev->dev);
4600         struct arg_dev_net_ip adni = {
4601                 .dev = ifp->idev->dev,
4602                 .net = net,
4603                 .addr = &ifp->addr,
4604         };
4605         fib6_clean_all(net, fib6_remove_prefsrc, &adni);
4606 }
4607
4608 #define RTF_RA_ROUTER           (RTF_ADDRCONF | RTF_DEFAULT)
4609
4610 /* Remove routers and update dst entries when gateway turn into host. */
4611 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
4612 {
4613         struct in6_addr *gateway = (struct in6_addr *)arg;
4614         struct fib6_nh *nh;
4615
4616         /* RA routes do not use nexthops */
4617         if (rt->nh)
4618                 return 0;
4619
4620         nh = rt->fib6_nh;
4621         if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
4622             nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6))
4623                 return -1;
4624
4625         /* Further clean up cached routes in exception table.
4626          * This is needed because cached route may have a different
4627          * gateway than its 'parent' in the case of an ip redirect.
4628          */
4629         fib6_nh_exceptions_clean_tohost(nh, gateway);
4630
4631         return 0;
4632 }
4633
4634 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
4635 {
4636         fib6_clean_all(net, fib6_clean_tohost, gateway);
4637 }
4638
4639 struct arg_netdev_event {
4640         const struct net_device *dev;
4641         union {
4642                 unsigned char nh_flags;
4643                 unsigned long event;
4644         };
4645 };
4646
4647 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
4648 {
4649         struct fib6_info *iter;
4650         struct fib6_node *fn;
4651
4652         fn = rcu_dereference_protected(rt->fib6_node,
4653                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4654         iter = rcu_dereference_protected(fn->leaf,
4655                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4656         while (iter) {
4657                 if (iter->fib6_metric == rt->fib6_metric &&
4658                     rt6_qualify_for_ecmp(iter))
4659                         return iter;
4660                 iter = rcu_dereference_protected(iter->fib6_next,
4661                                 lockdep_is_held(&rt->fib6_table->tb6_lock));
4662         }
4663
4664         return NULL;
4665 }
4666
4667 /* only called for fib entries with builtin fib6_nh */
4668 static bool rt6_is_dead(const struct fib6_info *rt)
4669 {
4670         if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD ||
4671             (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN &&
4672              ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev)))
4673                 return true;
4674
4675         return false;
4676 }
4677
4678 static int rt6_multipath_total_weight(const struct fib6_info *rt)
4679 {
4680         struct fib6_info *iter;
4681         int total = 0;
4682
4683         if (!rt6_is_dead(rt))
4684                 total += rt->fib6_nh->fib_nh_weight;
4685
4686         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
4687                 if (!rt6_is_dead(iter))
4688                         total += iter->fib6_nh->fib_nh_weight;
4689         }
4690
4691         return total;
4692 }
4693
4694 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
4695 {
4696         int upper_bound = -1;
4697
4698         if (!rt6_is_dead(rt)) {
4699                 *weight += rt->fib6_nh->fib_nh_weight;
4700                 upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
4701                                                     total) - 1;
4702         }
4703         atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
4704 }
4705
4706 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
4707 {
4708         struct fib6_info *iter;
4709         int weight = 0;
4710
4711         rt6_upper_bound_set(rt, &weight, total);
4712
4713         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4714                 rt6_upper_bound_set(iter, &weight, total);
4715 }
4716
4717 void rt6_multipath_rebalance(struct fib6_info *rt)
4718 {
4719         struct fib6_info *first;
4720         int total;
4721
4722         /* In case the entire multipath route was marked for flushing,
4723          * then there is no need to rebalance upon the removal of every
4724          * sibling route.
4725          */
4726         if (!rt->fib6_nsiblings || rt->should_flush)
4727                 return;
4728
4729         /* During lookup routes are evaluated in order, so we need to
4730          * make sure upper bounds are assigned from the first sibling
4731          * onwards.
4732          */
4733         first = rt6_multipath_first_sibling(rt);
4734         if (WARN_ON_ONCE(!first))
4735                 return;
4736
4737         total = rt6_multipath_total_weight(first);
4738         rt6_multipath_upper_bound_set(first, total);
4739 }
4740
4741 static int fib6_ifup(struct fib6_info *rt, void *p_arg)
4742 {
4743         const struct arg_netdev_event *arg = p_arg;
4744         struct net *net = dev_net(arg->dev);
4745
4746         if (rt != net->ipv6.fib6_null_entry && !rt->nh &&
4747             rt->fib6_nh->fib_nh_dev == arg->dev) {
4748                 rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags;
4749                 fib6_update_sernum_upto_root(net, rt);
4750                 rt6_multipath_rebalance(rt);
4751         }
4752
4753         return 0;
4754 }
4755
4756 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags)
4757 {
4758         struct arg_netdev_event arg = {
4759                 .dev = dev,
4760                 {
4761                         .nh_flags = nh_flags,
4762                 },
4763         };
4764
4765         if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
4766                 arg.nh_flags |= RTNH_F_LINKDOWN;
4767
4768         fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
4769 }
4770
4771 /* only called for fib entries with inline fib6_nh */
4772 static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
4773                                    const struct net_device *dev)
4774 {
4775         struct fib6_info *iter;
4776
4777         if (rt->fib6_nh->fib_nh_dev == dev)
4778                 return true;
4779         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4780                 if (iter->fib6_nh->fib_nh_dev == dev)
4781                         return true;
4782
4783         return false;
4784 }
4785
4786 static void rt6_multipath_flush(struct fib6_info *rt)
4787 {
4788         struct fib6_info *iter;
4789
4790         rt->should_flush = 1;
4791         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4792                 iter->should_flush = 1;
4793 }
4794
4795 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
4796                                              const struct net_device *down_dev)
4797 {
4798         struct fib6_info *iter;
4799         unsigned int dead = 0;
4800
4801         if (rt->fib6_nh->fib_nh_dev == down_dev ||
4802             rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4803                 dead++;
4804         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4805                 if (iter->fib6_nh->fib_nh_dev == down_dev ||
4806                     iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4807                         dead++;
4808
4809         return dead;
4810 }
4811
4812 static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
4813                                        const struct net_device *dev,
4814                                        unsigned char nh_flags)
4815 {
4816         struct fib6_info *iter;
4817
4818         if (rt->fib6_nh->fib_nh_dev == dev)
4819                 rt->fib6_nh->fib_nh_flags |= nh_flags;
4820         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4821                 if (iter->fib6_nh->fib_nh_dev == dev)
4822                         iter->fib6_nh->fib_nh_flags |= nh_flags;
4823 }
4824
4825 /* called with write lock held for table with rt */
4826 static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
4827 {
4828         const struct arg_netdev_event *arg = p_arg;
4829         const struct net_device *dev = arg->dev;
4830         struct net *net = dev_net(dev);
4831
4832         if (rt == net->ipv6.fib6_null_entry || rt->nh)
4833                 return 0;
4834
4835         switch (arg->event) {
4836         case NETDEV_UNREGISTER:
4837                 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4838         case NETDEV_DOWN:
4839                 if (rt->should_flush)
4840                         return -1;
4841                 if (!rt->fib6_nsiblings)
4842                         return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4843                 if (rt6_multipath_uses_dev(rt, dev)) {
4844                         unsigned int count;
4845
4846                         count = rt6_multipath_dead_count(rt, dev);
4847                         if (rt->fib6_nsiblings + 1 == count) {
4848                                 rt6_multipath_flush(rt);
4849                                 return -1;
4850                         }
4851                         rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
4852                                                    RTNH_F_LINKDOWN);
4853                         fib6_update_sernum(net, rt);
4854                         rt6_multipath_rebalance(rt);
4855                 }
4856                 return -2;
4857         case NETDEV_CHANGE:
4858                 if (rt->fib6_nh->fib_nh_dev != dev ||
4859                     rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
4860                         break;
4861                 rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
4862                 rt6_multipath_rebalance(rt);
4863                 break;
4864         }
4865
4866         return 0;
4867 }
4868
4869 void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
4870 {
4871         struct arg_netdev_event arg = {
4872                 .dev = dev,
4873                 {
4874                         .event = event,
4875                 },
4876         };
4877         struct net *net = dev_net(dev);
4878
4879         if (net->ipv6.sysctl.skip_notify_on_dev_down)
4880                 fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
4881         else
4882                 fib6_clean_all(net, fib6_ifdown, &arg);
4883 }
4884
4885 void rt6_disable_ip(struct net_device *dev, unsigned long event)
4886 {
4887         rt6_sync_down_dev(dev, event);
4888         rt6_uncached_list_flush_dev(dev);
4889         neigh_ifdown(&nd_tbl, dev);
4890 }
4891
4892 struct rt6_mtu_change_arg {
4893         struct net_device *dev;
4894         unsigned int mtu;
4895         struct fib6_info *f6i;
4896 };
4897
4898 static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
4899 {
4900         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg;
4901         struct fib6_info *f6i = arg->f6i;
4902
4903         /* For administrative MTU increase, there is no way to discover
4904          * IPv6 PMTU increase, so PMTU increase should be updated here.
4905          * Since RFC 1981 doesn't include administrative MTU increase
4906          * update PMTU increase is a MUST. (i.e. jumbo frame)
4907          */
4908         if (nh->fib_nh_dev == arg->dev) {
4909                 struct inet6_dev *idev = __in6_dev_get(arg->dev);
4910                 u32 mtu = f6i->fib6_pmtu;
4911
4912                 if (mtu >= arg->mtu ||
4913                     (mtu < arg->mtu && mtu == idev->cnf.mtu6))
4914                         fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
4915
4916                 spin_lock_bh(&rt6_exception_lock);
4917                 rt6_exceptions_update_pmtu(idev, nh, arg->mtu);
4918                 spin_unlock_bh(&rt6_exception_lock);
4919         }
4920
4921         return 0;
4922 }
4923
4924 static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
4925 {
4926         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
4927         struct inet6_dev *idev;
4928
4929         /* In IPv6 pmtu discovery is not optional,
4930            so that RTAX_MTU lock cannot disable it.
4931            We still use this lock to block changes
4932            caused by addrconf/ndisc.
4933         */
4934
4935         idev = __in6_dev_get(arg->dev);
4936         if (!idev)
4937                 return 0;
4938
4939         if (fib6_metric_locked(f6i, RTAX_MTU))
4940                 return 0;
4941
4942         arg->f6i = f6i;
4943         if (f6i->nh) {
4944                 /* fib6_nh_mtu_change only returns 0, so this is safe */
4945                 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change,
4946                                                 arg);
4947         }
4948
4949         return fib6_nh_mtu_change(f6i->fib6_nh, arg);
4950 }
4951
4952 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
4953 {
4954         struct rt6_mtu_change_arg arg = {
4955                 .dev = dev,
4956                 .mtu = mtu,
4957         };
4958
4959         fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
4960 }
4961
4962 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
4963         [RTA_UNSPEC]            = { .strict_start_type = RTA_DPORT + 1 },
4964         [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
4965         [RTA_PREFSRC]           = { .len = sizeof(struct in6_addr) },
4966         [RTA_OIF]               = { .type = NLA_U32 },
4967         [RTA_IIF]               = { .type = NLA_U32 },
4968         [RTA_PRIORITY]          = { .type = NLA_U32 },
4969         [RTA_METRICS]           = { .type = NLA_NESTED },
4970         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
4971         [RTA_PREF]              = { .type = NLA_U8 },
4972         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
4973         [RTA_ENCAP]             = { .type = NLA_NESTED },
4974         [RTA_EXPIRES]           = { .type = NLA_U32 },
4975         [RTA_UID]               = { .type = NLA_U32 },
4976         [RTA_MARK]              = { .type = NLA_U32 },
4977         [RTA_TABLE]             = { .type = NLA_U32 },
4978         [RTA_IP_PROTO]          = { .type = NLA_U8 },
4979         [RTA_SPORT]             = { .type = NLA_U16 },
4980         [RTA_DPORT]             = { .type = NLA_U16 },
4981         [RTA_NH_ID]             = { .type = NLA_U32 },
4982 };
4983
4984 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
4985                               struct fib6_config *cfg,
4986                               struct netlink_ext_ack *extack)
4987 {
4988         struct rtmsg *rtm;
4989         struct nlattr *tb[RTA_MAX+1];
4990         unsigned int pref;
4991         int err;
4992
4993         err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
4994                                      rtm_ipv6_policy, extack);
4995         if (err < 0)
4996                 goto errout;
4997
4998         err = -EINVAL;
4999         rtm = nlmsg_data(nlh);
5000
5001         if (rtm->rtm_tos) {
5002                 NL_SET_ERR_MSG(extack,
5003                                "Invalid dsfield (tos): option not available for IPv6");
5004                 goto errout;
5005         }
5006
5007         *cfg = (struct fib6_config){
5008                 .fc_table = rtm->rtm_table,
5009                 .fc_dst_len = rtm->rtm_dst_len,
5010                 .fc_src_len = rtm->rtm_src_len,
5011                 .fc_flags = RTF_UP,
5012                 .fc_protocol = rtm->rtm_protocol,
5013                 .fc_type = rtm->rtm_type,
5014
5015                 .fc_nlinfo.portid = NETLINK_CB(skb).portid,
5016                 .fc_nlinfo.nlh = nlh,
5017                 .fc_nlinfo.nl_net = sock_net(skb->sk),
5018         };
5019
5020         if (rtm->rtm_type == RTN_UNREACHABLE ||
5021             rtm->rtm_type == RTN_BLACKHOLE ||
5022             rtm->rtm_type == RTN_PROHIBIT ||
5023             rtm->rtm_type == RTN_THROW)
5024                 cfg->fc_flags |= RTF_REJECT;
5025
5026         if (rtm->rtm_type == RTN_LOCAL)
5027                 cfg->fc_flags |= RTF_LOCAL;
5028
5029         if (rtm->rtm_flags & RTM_F_CLONED)
5030                 cfg->fc_flags |= RTF_CACHE;
5031
5032         cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
5033
5034         if (tb[RTA_NH_ID]) {
5035                 if (tb[RTA_GATEWAY]   || tb[RTA_OIF] ||
5036                     tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {
5037                         NL_SET_ERR_MSG(extack,
5038                                        "Nexthop specification and nexthop id are mutually exclusive");
5039                         goto errout;
5040                 }
5041                 cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);
5042         }
5043
5044         if (tb[RTA_GATEWAY]) {
5045                 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
5046                 cfg->fc_flags |= RTF_GATEWAY;
5047         }
5048         if (tb[RTA_VIA]) {
5049                 NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
5050                 goto errout;
5051         }
5052
5053         if (tb[RTA_DST]) {
5054                 int plen = (rtm->rtm_dst_len + 7) >> 3;
5055
5056                 if (nla_len(tb[RTA_DST]) < plen)
5057                         goto errout;
5058
5059                 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
5060         }
5061
5062         if (tb[RTA_SRC]) {
5063                 int plen = (rtm->rtm_src_len + 7) >> 3;
5064
5065                 if (nla_len(tb[RTA_SRC]) < plen)
5066                         goto errout;
5067
5068                 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
5069         }
5070
5071         if (tb[RTA_PREFSRC])
5072                 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
5073
5074         if (tb[RTA_OIF])
5075                 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
5076
5077         if (tb[RTA_PRIORITY])
5078                 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
5079
5080         if (tb[RTA_METRICS]) {
5081                 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
5082                 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
5083         }
5084
5085         if (tb[RTA_TABLE])
5086                 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
5087
5088         if (tb[RTA_MULTIPATH]) {
5089                 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
5090                 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
5091
5092                 err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
5093                                                      cfg->fc_mp_len, extack);
5094                 if (err < 0)
5095                         goto errout;
5096         }
5097
5098         if (tb[RTA_PREF]) {
5099                 pref = nla_get_u8(tb[RTA_PREF]);
5100                 if (pref != ICMPV6_ROUTER_PREF_LOW &&
5101                     pref != ICMPV6_ROUTER_PREF_HIGH)
5102                         pref = ICMPV6_ROUTER_PREF_MEDIUM;
5103                 cfg->fc_flags |= RTF_PREF(pref);
5104         }
5105
5106         if (tb[RTA_ENCAP])
5107                 cfg->fc_encap = tb[RTA_ENCAP];
5108
5109         if (tb[RTA_ENCAP_TYPE]) {
5110                 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
5111
5112                 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
5113                 if (err < 0)
5114                         goto errout;
5115         }
5116
5117         if (tb[RTA_EXPIRES]) {
5118                 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
5119
5120                 if (addrconf_finite_timeout(timeout)) {
5121                         cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
5122                         cfg->fc_flags |= RTF_EXPIRES;
5123                 }
5124         }
5125
5126         err = 0;
5127 errout:
5128         return err;
5129 }
5130
5131 struct rt6_nh {
5132         struct fib6_info *fib6_info;
5133         struct fib6_config r_cfg;
5134         struct list_head next;
5135 };
5136
5137 static int ip6_route_info_append(struct net *net,
5138                                  struct list_head *rt6_nh_list,
5139                                  struct fib6_info *rt,
5140                                  struct fib6_config *r_cfg)
5141 {
5142         struct rt6_nh *nh;
5143         int err = -EEXIST;
5144
5145         list_for_each_entry(nh, rt6_nh_list, next) {
5146                 /* check if fib6_info already exists */
5147                 if (rt6_duplicate_nexthop(nh->fib6_info, rt))
5148                         return err;
5149         }
5150
5151         nh = kzalloc(sizeof(*nh), GFP_KERNEL);
5152         if (!nh)
5153                 return -ENOMEM;
5154         nh->fib6_info = rt;
5155         memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
5156         list_add_tail(&nh->next, rt6_nh_list);
5157
5158         return 0;
5159 }
5160
5161 static void ip6_route_mpath_notify(struct fib6_info *rt,
5162                                    struct fib6_info *rt_last,
5163                                    struct nl_info *info,
5164                                    __u16 nlflags)
5165 {
5166         /* if this is an APPEND route, then rt points to the first route
5167          * inserted and rt_last points to last route inserted. Userspace
5168          * wants a consistent dump of the route which starts at the first
5169          * nexthop. Since sibling routes are always added at the end of
5170          * the list, find the first sibling of the last route appended
5171          */
5172         if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
5173                 rt = list_first_entry(&rt_last->fib6_siblings,
5174                                       struct fib6_info,
5175                                       fib6_siblings);
5176         }
5177
5178         if (rt)
5179                 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
5180 }
5181
5182 static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
5183 {
5184         bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
5185         bool should_notify = false;
5186         struct fib6_info *leaf;
5187         struct fib6_node *fn;
5188
5189         rcu_read_lock();
5190         fn = rcu_dereference(rt->fib6_node);
5191         if (!fn)
5192                 goto out;
5193
5194         leaf = rcu_dereference(fn->leaf);
5195         if (!leaf)
5196                 goto out;
5197
5198         if (rt == leaf ||
5199             (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric &&
5200              rt6_qualify_for_ecmp(leaf)))
5201                 should_notify = true;
5202 out:
5203         rcu_read_unlock();
5204
5205         return should_notify;
5206 }
5207
5208 static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla,
5209                              struct netlink_ext_ack *extack)
5210 {
5211         if (nla_len(nla) < sizeof(*gw)) {
5212                 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY");
5213                 return -EINVAL;
5214         }
5215
5216         *gw = nla_get_in6_addr(nla);
5217
5218         return 0;
5219 }
5220
5221 static int ip6_route_multipath_add(struct fib6_config *cfg,
5222                                    struct netlink_ext_ack *extack)
5223 {
5224         struct fib6_info *rt_notif = NULL, *rt_last = NULL;
5225         struct nl_info *info = &cfg->fc_nlinfo;
5226         struct fib6_config r_cfg;
5227         struct rtnexthop *rtnh;
5228         struct fib6_info *rt;
5229         struct rt6_nh *err_nh;
5230         struct rt6_nh *nh, *nh_safe;
5231         __u16 nlflags;
5232         int remaining;
5233         int attrlen;
5234         int err = 1;
5235         int nhn = 0;
5236         int replace = (cfg->fc_nlinfo.nlh &&
5237                        (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
5238         LIST_HEAD(rt6_nh_list);
5239
5240         nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
5241         if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
5242                 nlflags |= NLM_F_APPEND;
5243
5244         remaining = cfg->fc_mp_len;
5245         rtnh = (struct rtnexthop *)cfg->fc_mp;
5246
5247         /* Parse a Multipath Entry and build a list (rt6_nh_list) of
5248          * fib6_info structs per nexthop
5249          */
5250         while (rtnh_ok(rtnh, remaining)) {
5251                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5252                 if (rtnh->rtnh_ifindex)
5253                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5254
5255                 attrlen = rtnh_attrlen(rtnh);
5256                 if (attrlen > 0) {
5257                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5258
5259                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5260                         if (nla) {
5261                                 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5262                                                         extack);
5263                                 if (err)
5264                                         goto cleanup;
5265
5266                                 r_cfg.fc_flags |= RTF_GATEWAY;
5267                         }
5268                         r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
5269
5270                         /* RTA_ENCAP_TYPE length checked in
5271                          * lwtunnel_valid_encap_type_attr
5272                          */
5273                         nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
5274                         if (nla)
5275                                 r_cfg.fc_encap_type = nla_get_u16(nla);
5276                 }
5277
5278                 r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
5279                 rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
5280                 if (IS_ERR(rt)) {
5281                         err = PTR_ERR(rt);
5282                         rt = NULL;
5283                         goto cleanup;
5284                 }
5285                 if (!rt6_qualify_for_ecmp(rt)) {
5286                         err = -EINVAL;
5287                         NL_SET_ERR_MSG(extack,
5288                                        "Device only routes can not be added for IPv6 using the multipath API.");
5289                         fib6_info_release(rt);
5290                         goto cleanup;
5291                 }
5292
5293                 rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
5294
5295                 err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
5296                                             rt, &r_cfg);
5297                 if (err) {
5298                         fib6_info_release(rt);
5299                         goto cleanup;
5300                 }
5301
5302                 rtnh = rtnh_next(rtnh, &remaining);
5303         }
5304
5305         if (list_empty(&rt6_nh_list)) {
5306                 NL_SET_ERR_MSG(extack,
5307                                "Invalid nexthop configuration - no valid nexthops");
5308                 return -EINVAL;
5309         }
5310
5311         /* for add and replace send one notification with all nexthops.
5312          * Skip the notification in fib6_add_rt2node and send one with
5313          * the full route when done
5314          */
5315         info->skip_notify = 1;
5316
5317         /* For add and replace, send one notification with all nexthops. For
5318          * append, send one notification with all appended nexthops.
5319          */
5320         info->skip_notify_kernel = 1;
5321
5322         err_nh = NULL;
5323         list_for_each_entry(nh, &rt6_nh_list, next) {
5324                 err = __ip6_ins_rt(nh->fib6_info, info, extack);
5325                 fib6_info_release(nh->fib6_info);
5326
5327                 if (!err) {
5328                         /* save reference to last route successfully inserted */
5329                         rt_last = nh->fib6_info;
5330
5331                         /* save reference to first route for notification */
5332                         if (!rt_notif)
5333                                 rt_notif = nh->fib6_info;
5334                 }
5335
5336                 /* nh->fib6_info is used or freed at this point, reset to NULL*/
5337                 nh->fib6_info = NULL;
5338                 if (err) {
5339                         if (replace && nhn)
5340                                 NL_SET_ERR_MSG_MOD(extack,
5341                                                    "multipath route replace failed (check consistency of installed routes)");
5342                         err_nh = nh;
5343                         goto add_errout;
5344                 }
5345
5346                 /* Because each route is added like a single route we remove
5347                  * these flags after the first nexthop: if there is a collision,
5348                  * we have already failed to add the first nexthop:
5349                  * fib6_add_rt2node() has rejected it; when replacing, old
5350                  * nexthops have been replaced by first new, the rest should
5351                  * be added to it.
5352                  */
5353                 if (cfg->fc_nlinfo.nlh) {
5354                         cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
5355                                                              NLM_F_REPLACE);
5356                         cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
5357                 }
5358                 nhn++;
5359         }
5360
5361         /* An in-kernel notification should only be sent in case the new
5362          * multipath route is added as the first route in the node, or if
5363          * it was appended to it. We pass 'rt_notif' since it is the first
5364          * sibling and might allow us to skip some checks in the replace case.
5365          */
5366         if (ip6_route_mpath_should_notify(rt_notif)) {
5367                 enum fib_event_type fib_event;
5368
5369                 if (rt_notif->fib6_nsiblings != nhn - 1)
5370                         fib_event = FIB_EVENT_ENTRY_APPEND;
5371                 else
5372                         fib_event = FIB_EVENT_ENTRY_REPLACE;
5373
5374                 err = call_fib6_multipath_entry_notifiers(info->nl_net,
5375                                                           fib_event, rt_notif,
5376                                                           nhn - 1, extack);
5377                 if (err) {
5378                         /* Delete all the siblings that were just added */
5379                         err_nh = NULL;
5380                         goto add_errout;
5381                 }
5382         }
5383
5384         /* success ... tell user about new route */
5385         ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5386         goto cleanup;
5387
5388 add_errout:
5389         /* send notification for routes that were added so that
5390          * the delete notifications sent by ip6_route_del are
5391          * coherent
5392          */
5393         if (rt_notif)
5394                 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5395
5396         /* Delete routes that were already added */
5397         list_for_each_entry(nh, &rt6_nh_list, next) {
5398                 if (err_nh == nh)
5399                         break;
5400                 ip6_route_del(&nh->r_cfg, extack);
5401         }
5402
5403 cleanup:
5404         list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
5405                 if (nh->fib6_info)
5406                         fib6_info_release(nh->fib6_info);
5407                 list_del(&nh->next);
5408                 kfree(nh);
5409         }
5410
5411         return err;
5412 }
5413
5414 static int ip6_route_multipath_del(struct fib6_config *cfg,
5415                                    struct netlink_ext_ack *extack)
5416 {
5417         struct fib6_config r_cfg;
5418         struct rtnexthop *rtnh;
5419         int last_err = 0;
5420         int remaining;
5421         int attrlen;
5422         int err;
5423
5424         remaining = cfg->fc_mp_len;
5425         rtnh = (struct rtnexthop *)cfg->fc_mp;
5426
5427         /* Parse a Multipath Entry */
5428         while (rtnh_ok(rtnh, remaining)) {
5429                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5430                 if (rtnh->rtnh_ifindex)
5431                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5432
5433                 attrlen = rtnh_attrlen(rtnh);
5434                 if (attrlen > 0) {
5435                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5436
5437                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5438                         if (nla) {
5439                                 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5440                                                         extack);
5441                                 if (err) {
5442                                         last_err = err;
5443                                         goto next_rtnh;
5444                                 }
5445
5446                                 r_cfg.fc_flags |= RTF_GATEWAY;
5447                         }
5448                 }
5449                 err = ip6_route_del(&r_cfg, extack);
5450                 if (err)
5451                         last_err = err;
5452
5453 next_rtnh:
5454                 rtnh = rtnh_next(rtnh, &remaining);
5455         }
5456
5457         return last_err;
5458 }
5459
5460 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5461                               struct netlink_ext_ack *extack)
5462 {
5463         struct fib6_config cfg;
5464         int err;
5465
5466         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5467         if (err < 0)
5468                 return err;
5469
5470         if (cfg.fc_nh_id &&
5471             !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {
5472                 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
5473                 return -EINVAL;
5474         }
5475
5476         if (cfg.fc_mp)
5477                 return ip6_route_multipath_del(&cfg, extack);
5478         else {
5479                 cfg.fc_delete_all_nh = 1;
5480                 return ip6_route_del(&cfg, extack);
5481         }
5482 }
5483
5484 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5485                               struct netlink_ext_ack *extack)
5486 {
5487         struct fib6_config cfg;
5488         int err;
5489
5490         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5491         if (err < 0)
5492                 return err;
5493
5494         if (cfg.fc_metric == 0)
5495                 cfg.fc_metric = IP6_RT_PRIO_USER;
5496
5497         if (cfg.fc_mp)
5498                 return ip6_route_multipath_add(&cfg, extack);
5499         else
5500                 return ip6_route_add(&cfg, GFP_KERNEL, extack);
5501 }
5502
5503 /* add the overhead of this fib6_nh to nexthop_len */
5504 static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg)
5505 {
5506         int *nexthop_len = arg;
5507
5508         *nexthop_len += nla_total_size(0)        /* RTA_MULTIPATH */
5509                      + NLA_ALIGN(sizeof(struct rtnexthop))
5510                      + nla_total_size(16); /* RTA_GATEWAY */
5511
5512         if (nh->fib_nh_lws) {
5513                 /* RTA_ENCAP_TYPE */
5514                 *nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5515                 /* RTA_ENCAP */
5516                 *nexthop_len += nla_total_size(2);
5517         }
5518
5519         return 0;
5520 }
5521
5522 static size_t rt6_nlmsg_size(struct fib6_info *f6i)
5523 {
5524         int nexthop_len;
5525
5526         if (f6i->nh) {
5527                 nexthop_len = nla_total_size(4); /* RTA_NH_ID */
5528                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
5529                                          &nexthop_len);
5530         } else {
5531                 struct fib6_nh *nh = f6i->fib6_nh;
5532
5533                 nexthop_len = 0;
5534                 if (f6i->fib6_nsiblings) {
5535                         nexthop_len = nla_total_size(0)  /* RTA_MULTIPATH */
5536                                     + NLA_ALIGN(sizeof(struct rtnexthop))
5537                                     + nla_total_size(16) /* RTA_GATEWAY */
5538                                     + lwtunnel_get_encap_size(nh->fib_nh_lws);
5539
5540                         nexthop_len *= f6i->fib6_nsiblings;
5541                 }
5542                 nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5543         }
5544
5545         return NLMSG_ALIGN(sizeof(struct rtmsg))
5546                + nla_total_size(16) /* RTA_SRC */
5547                + nla_total_size(16) /* RTA_DST */
5548                + nla_total_size(16) /* RTA_GATEWAY */
5549                + nla_total_size(16) /* RTA_PREFSRC */
5550                + nla_total_size(4) /* RTA_TABLE */
5551                + nla_total_size(4) /* RTA_IIF */
5552                + nla_total_size(4) /* RTA_OIF */
5553                + nla_total_size(4) /* RTA_PRIORITY */
5554                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
5555                + nla_total_size(sizeof(struct rta_cacheinfo))
5556                + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
5557                + nla_total_size(1) /* RTA_PREF */
5558                + nexthop_len;
5559 }
5560
5561 static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh,
5562                                  unsigned char *flags)
5563 {
5564         if (nexthop_is_multipath(nh)) {
5565                 struct nlattr *mp;
5566
5567                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5568                 if (!mp)
5569                         goto nla_put_failure;
5570
5571                 if (nexthop_mpath_fill_node(skb, nh, AF_INET6))
5572                         goto nla_put_failure;
5573
5574                 nla_nest_end(skb, mp);
5575         } else {
5576                 struct fib6_nh *fib6_nh;
5577
5578                 fib6_nh = nexthop_fib6_nh(nh);
5579                 if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,
5580                                      flags, false) < 0)
5581                         goto nla_put_failure;
5582         }
5583
5584         return 0;
5585
5586 nla_put_failure:
5587         return -EMSGSIZE;
5588 }
5589
5590 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
5591                          struct fib6_info *rt, struct dst_entry *dst,
5592                          struct in6_addr *dest, struct in6_addr *src,
5593                          int iif, int type, u32 portid, u32 seq,
5594                          unsigned int flags)
5595 {
5596         struct rt6_info *rt6 = (struct rt6_info *)dst;
5597         struct rt6key *rt6_dst, *rt6_src;
5598         u32 *pmetrics, table, rt6_flags;
5599         unsigned char nh_flags = 0;
5600         struct nlmsghdr *nlh;
5601         struct rtmsg *rtm;
5602         long expires = 0;
5603
5604         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
5605         if (!nlh)
5606                 return -EMSGSIZE;
5607
5608         if (rt6) {
5609                 rt6_dst = &rt6->rt6i_dst;
5610                 rt6_src = &rt6->rt6i_src;
5611                 rt6_flags = rt6->rt6i_flags;
5612         } else {
5613                 rt6_dst = &rt->fib6_dst;
5614                 rt6_src = &rt->fib6_src;
5615                 rt6_flags = rt->fib6_flags;
5616         }
5617
5618         rtm = nlmsg_data(nlh);
5619         rtm->rtm_family = AF_INET6;
5620         rtm->rtm_dst_len = rt6_dst->plen;
5621         rtm->rtm_src_len = rt6_src->plen;
5622         rtm->rtm_tos = 0;
5623         if (rt->fib6_table)
5624                 table = rt->fib6_table->tb6_id;
5625         else
5626                 table = RT6_TABLE_UNSPEC;
5627         rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
5628         if (nla_put_u32(skb, RTA_TABLE, table))
5629                 goto nla_put_failure;
5630
5631         rtm->rtm_type = rt->fib6_type;
5632         rtm->rtm_flags = 0;
5633         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
5634         rtm->rtm_protocol = rt->fib6_protocol;
5635
5636         if (rt6_flags & RTF_CACHE)
5637                 rtm->rtm_flags |= RTM_F_CLONED;
5638
5639         if (dest) {
5640                 if (nla_put_in6_addr(skb, RTA_DST, dest))
5641                         goto nla_put_failure;
5642                 rtm->rtm_dst_len = 128;
5643         } else if (rtm->rtm_dst_len)
5644                 if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
5645                         goto nla_put_failure;
5646 #ifdef CONFIG_IPV6_SUBTREES
5647         if (src) {
5648                 if (nla_put_in6_addr(skb, RTA_SRC, src))
5649                         goto nla_put_failure;
5650                 rtm->rtm_src_len = 128;
5651         } else if (rtm->rtm_src_len &&
5652                    nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
5653                 goto nla_put_failure;
5654 #endif
5655         if (iif) {
5656 #ifdef CONFIG_IPV6_MROUTE
5657                 if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
5658                         int err = ip6mr_get_route(net, skb, rtm, portid);
5659
5660                         if (err == 0)
5661                                 return 0;
5662                         if (err < 0)
5663                                 goto nla_put_failure;
5664                 } else
5665 #endif
5666                         if (nla_put_u32(skb, RTA_IIF, iif))
5667                                 goto nla_put_failure;
5668         } else if (dest) {
5669                 struct in6_addr saddr_buf;
5670                 if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 &&
5671                     nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5672                         goto nla_put_failure;
5673         }
5674
5675         if (rt->fib6_prefsrc.plen) {
5676                 struct in6_addr saddr_buf;
5677                 saddr_buf = rt->fib6_prefsrc.addr;
5678                 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5679                         goto nla_put_failure;
5680         }
5681
5682         pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
5683         if (rtnetlink_put_metrics(skb, pmetrics) < 0)
5684                 goto nla_put_failure;
5685
5686         if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
5687                 goto nla_put_failure;
5688
5689         /* For multipath routes, walk the siblings list and add
5690          * each as a nexthop within RTA_MULTIPATH.
5691          */
5692         if (rt6) {
5693                 if (rt6_flags & RTF_GATEWAY &&
5694                     nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
5695                         goto nla_put_failure;
5696
5697                 if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
5698                         goto nla_put_failure;
5699
5700                 if (dst->lwtstate &&
5701                     lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
5702                         goto nla_put_failure;
5703         } else if (rt->fib6_nsiblings) {
5704                 struct fib6_info *sibling, *next_sibling;
5705                 struct nlattr *mp;
5706
5707                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5708                 if (!mp)
5709                         goto nla_put_failure;
5710
5711                 if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
5712                                     rt->fib6_nh->fib_nh_weight, AF_INET6,
5713                                     0) < 0)
5714                         goto nla_put_failure;
5715
5716                 list_for_each_entry_safe(sibling, next_sibling,
5717                                          &rt->fib6_siblings, fib6_siblings) {
5718                         if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
5719                                             sibling->fib6_nh->fib_nh_weight,
5720                                             AF_INET6, 0) < 0)
5721                                 goto nla_put_failure;
5722                 }
5723
5724                 nla_nest_end(skb, mp);
5725         } else if (rt->nh) {
5726                 if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
5727                         goto nla_put_failure;
5728
5729                 if (nexthop_is_blackhole(rt->nh))
5730                         rtm->rtm_type = RTN_BLACKHOLE;
5731
5732                 if (net->ipv4.sysctl_nexthop_compat_mode &&
5733                     rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0)
5734                         goto nla_put_failure;
5735
5736                 rtm->rtm_flags |= nh_flags;
5737         } else {
5738                 if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,
5739                                      &nh_flags, false) < 0)
5740                         goto nla_put_failure;
5741
5742                 rtm->rtm_flags |= nh_flags;
5743         }
5744
5745         if (rt6_flags & RTF_EXPIRES) {
5746                 expires = dst ? dst->expires : rt->expires;
5747                 expires -= jiffies;
5748         }
5749
5750         if (!dst) {
5751                 if (READ_ONCE(rt->offload))
5752                         rtm->rtm_flags |= RTM_F_OFFLOAD;
5753                 if (READ_ONCE(rt->trap))
5754                         rtm->rtm_flags |= RTM_F_TRAP;
5755                 if (READ_ONCE(rt->offload_failed))
5756                         rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED;
5757         }
5758
5759         if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
5760                 goto nla_put_failure;
5761
5762         if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
5763                 goto nla_put_failure;
5764
5765
5766         nlmsg_end(skb, nlh);
5767         return 0;
5768
5769 nla_put_failure:
5770         nlmsg_cancel(skb, nlh);
5771         return -EMSGSIZE;
5772 }
5773
5774 static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg)
5775 {
5776         const struct net_device *dev = arg;
5777
5778         if (nh->fib_nh_dev == dev)
5779                 return 1;
5780
5781         return 0;
5782 }
5783
5784 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
5785                                const struct net_device *dev)
5786 {
5787         if (f6i->nh) {
5788                 struct net_device *_dev = (struct net_device *)dev;
5789
5790                 return !!nexthop_for_each_fib6_nh(f6i->nh,
5791                                                   fib6_info_nh_uses_dev,
5792                                                   _dev);
5793         }
5794
5795         if (f6i->fib6_nh->fib_nh_dev == dev)
5796                 return true;
5797
5798         if (f6i->fib6_nsiblings) {
5799                 struct fib6_info *sibling, *next_sibling;
5800
5801                 list_for_each_entry_safe(sibling, next_sibling,
5802                                          &f6i->fib6_siblings, fib6_siblings) {
5803                         if (sibling->fib6_nh->fib_nh_dev == dev)
5804                                 return true;
5805                 }
5806         }
5807
5808         return false;
5809 }
5810
5811 struct fib6_nh_exception_dump_walker {
5812         struct rt6_rtnl_dump_arg *dump;
5813         struct fib6_info *rt;
5814         unsigned int flags;
5815         unsigned int skip;
5816         unsigned int count;
5817 };
5818
5819 static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg)
5820 {
5821         struct fib6_nh_exception_dump_walker *w = arg;
5822         struct rt6_rtnl_dump_arg *dump = w->dump;
5823         struct rt6_exception_bucket *bucket;
5824         struct rt6_exception *rt6_ex;
5825         int i, err;
5826
5827         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
5828         if (!bucket)
5829                 return 0;
5830
5831         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
5832                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
5833                         if (w->skip) {
5834                                 w->skip--;
5835                                 continue;
5836                         }
5837
5838                         /* Expiration of entries doesn't bump sernum, insertion
5839                          * does. Removal is triggered by insertion, so we can
5840                          * rely on the fact that if entries change between two
5841                          * partial dumps, this node is scanned again completely,
5842                          * see rt6_insert_exception() and fib6_dump_table().
5843                          *
5844                          * Count expired entries we go through as handled
5845                          * entries that we'll skip next time, in case of partial
5846                          * node dump. Otherwise, if entries expire meanwhile,
5847                          * we'll skip the wrong amount.
5848                          */
5849                         if (rt6_check_expired(rt6_ex->rt6i)) {
5850                                 w->count++;
5851                                 continue;
5852                         }
5853
5854                         err = rt6_fill_node(dump->net, dump->skb, w->rt,
5855                                             &rt6_ex->rt6i->dst, NULL, NULL, 0,
5856                                             RTM_NEWROUTE,
5857                                             NETLINK_CB(dump->cb->skb).portid,
5858                                             dump->cb->nlh->nlmsg_seq, w->flags);
5859                         if (err)
5860                                 return err;
5861
5862                         w->count++;
5863                 }
5864                 bucket++;
5865         }
5866
5867         return 0;
5868 }
5869
5870 /* Return -1 if done with node, number of handled routes on partial dump */
5871 int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip)
5872 {
5873         struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
5874         struct fib_dump_filter *filter = &arg->filter;
5875         unsigned int flags = NLM_F_MULTI;
5876         struct net *net = arg->net;
5877         int count = 0;
5878
5879         if (rt == net->ipv6.fib6_null_entry)
5880                 return -1;
5881
5882         if ((filter->flags & RTM_F_PREFIX) &&
5883             !(rt->fib6_flags & RTF_PREFIX_RT)) {
5884                 /* success since this is not a prefix route */
5885                 return -1;
5886         }
5887         if (filter->filter_set &&
5888             ((filter->rt_type  && rt->fib6_type != filter->rt_type) ||
5889              (filter->dev      && !fib6_info_uses_dev(rt, filter->dev)) ||
5890              (filter->protocol && rt->fib6_protocol != filter->protocol))) {
5891                 return -1;
5892         }
5893
5894         if (filter->filter_set ||
5895             !filter->dump_routes || !filter->dump_exceptions) {
5896                 flags |= NLM_F_DUMP_FILTERED;
5897         }
5898
5899         if (filter->dump_routes) {
5900                 if (skip) {
5901                         skip--;
5902                 } else {
5903                         if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL,
5904                                           0, RTM_NEWROUTE,
5905                                           NETLINK_CB(arg->cb->skb).portid,
5906                                           arg->cb->nlh->nlmsg_seq, flags)) {
5907                                 return 0;
5908                         }
5909                         count++;
5910                 }
5911         }
5912
5913         if (filter->dump_exceptions) {
5914                 struct fib6_nh_exception_dump_walker w = { .dump = arg,
5915                                                            .rt = rt,
5916                                                            .flags = flags,
5917                                                            .skip = skip,
5918                                                            .count = 0 };
5919                 int err;
5920
5921                 rcu_read_lock();
5922                 if (rt->nh) {
5923                         err = nexthop_for_each_fib6_nh(rt->nh,
5924                                                        rt6_nh_dump_exceptions,
5925                                                        &w);
5926                 } else {
5927                         err = rt6_nh_dump_exceptions(rt->fib6_nh, &w);
5928                 }
5929                 rcu_read_unlock();
5930
5931                 if (err)
5932                         return count += w.count;
5933         }
5934
5935         return -1;
5936 }
5937
5938 static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
5939                                         const struct nlmsghdr *nlh,
5940                                         struct nlattr **tb,
5941                                         struct netlink_ext_ack *extack)
5942 {
5943         struct rtmsg *rtm;
5944         int i, err;
5945
5946         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
5947                 NL_SET_ERR_MSG_MOD(extack,
5948                                    "Invalid header for get route request");
5949                 return -EINVAL;
5950         }
5951
5952         if (!netlink_strict_get_check(skb))
5953                 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5954                                               rtm_ipv6_policy, extack);
5955
5956         rtm = nlmsg_data(nlh);
5957         if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
5958             (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
5959             rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
5960             rtm->rtm_type) {
5961                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
5962                 return -EINVAL;
5963         }
5964         if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
5965                 NL_SET_ERR_MSG_MOD(extack,
5966                                    "Invalid flags for get route request");
5967                 return -EINVAL;
5968         }
5969
5970         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
5971                                             rtm_ipv6_policy, extack);
5972         if (err)
5973                 return err;
5974
5975         if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
5976             (tb[RTA_DST] && !rtm->rtm_dst_len)) {
5977                 NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
5978                 return -EINVAL;
5979         }
5980
5981         for (i = 0; i <= RTA_MAX; i++) {
5982                 if (!tb[i])
5983                         continue;
5984
5985                 switch (i) {
5986                 case RTA_SRC:
5987                 case RTA_DST:
5988                 case RTA_IIF:
5989                 case RTA_OIF:
5990                 case RTA_MARK:
5991                 case RTA_UID:
5992                 case RTA_SPORT:
5993                 case RTA_DPORT:
5994                 case RTA_IP_PROTO:
5995                         break;
5996                 default:
5997                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
5998                         return -EINVAL;
5999                 }
6000         }
6001
6002         return 0;
6003 }
6004
6005 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
6006                               struct netlink_ext_ack *extack)
6007 {
6008         struct net *net = sock_net(in_skb->sk);
6009         struct nlattr *tb[RTA_MAX+1];
6010         int err, iif = 0, oif = 0;
6011         struct fib6_info *from;
6012         struct dst_entry *dst;
6013         struct rt6_info *rt;
6014         struct sk_buff *skb;
6015         struct rtmsg *rtm;
6016         struct flowi6 fl6 = {};
6017         bool fibmatch;
6018
6019         err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
6020         if (err < 0)
6021                 goto errout;
6022
6023         err = -EINVAL;
6024         rtm = nlmsg_data(nlh);
6025         fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
6026         fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
6027
6028         if (tb[RTA_SRC]) {
6029                 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
6030                         goto errout;
6031
6032                 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
6033         }
6034
6035         if (tb[RTA_DST]) {
6036                 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
6037                         goto errout;
6038
6039                 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
6040         }
6041
6042         if (tb[RTA_IIF])
6043                 iif = nla_get_u32(tb[RTA_IIF]);
6044
6045         if (tb[RTA_OIF])
6046                 oif = nla_get_u32(tb[RTA_OIF]);
6047
6048         if (tb[RTA_MARK])
6049                 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
6050
6051         if (tb[RTA_UID])
6052                 fl6.flowi6_uid = make_kuid(current_user_ns(),
6053                                            nla_get_u32(tb[RTA_UID]));
6054         else
6055                 fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
6056
6057         if (tb[RTA_SPORT])
6058                 fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
6059
6060         if (tb[RTA_DPORT])
6061                 fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
6062
6063         if (tb[RTA_IP_PROTO]) {
6064                 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
6065                                                   &fl6.flowi6_proto, AF_INET6,
6066                                                   extack);
6067                 if (err)
6068                         goto errout;
6069         }
6070
6071         if (iif) {
6072                 struct net_device *dev;
6073                 int flags = 0;
6074
6075                 rcu_read_lock();
6076
6077                 dev = dev_get_by_index_rcu(net, iif);
6078                 if (!dev) {
6079                         rcu_read_unlock();
6080                         err = -ENODEV;
6081                         goto errout;
6082                 }
6083
6084                 fl6.flowi6_iif = iif;
6085
6086                 if (!ipv6_addr_any(&fl6.saddr))
6087                         flags |= RT6_LOOKUP_F_HAS_SADDR;
6088
6089                 dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
6090
6091                 rcu_read_unlock();
6092         } else {
6093                 fl6.flowi6_oif = oif;
6094
6095                 dst = ip6_route_output(net, NULL, &fl6);
6096         }
6097
6098
6099         rt = container_of(dst, struct rt6_info, dst);
6100         if (rt->dst.error) {
6101                 err = rt->dst.error;
6102                 ip6_rt_put(rt);
6103                 goto errout;
6104         }
6105
6106         if (rt == net->ipv6.ip6_null_entry) {
6107                 err = rt->dst.error;
6108                 ip6_rt_put(rt);
6109                 goto errout;
6110         }
6111
6112         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
6113         if (!skb) {
6114                 ip6_rt_put(rt);
6115                 err = -ENOBUFS;
6116                 goto errout;
6117         }
6118
6119         skb_dst_set(skb, &rt->dst);
6120
6121         rcu_read_lock();
6122         from = rcu_dereference(rt->from);
6123         if (from) {
6124                 if (fibmatch)
6125                         err = rt6_fill_node(net, skb, from, NULL, NULL, NULL,
6126                                             iif, RTM_NEWROUTE,
6127                                             NETLINK_CB(in_skb).portid,
6128                                             nlh->nlmsg_seq, 0);
6129                 else
6130                         err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
6131                                             &fl6.saddr, iif, RTM_NEWROUTE,
6132                                             NETLINK_CB(in_skb).portid,
6133                                             nlh->nlmsg_seq, 0);
6134         } else {
6135                 err = -ENETUNREACH;
6136         }
6137         rcu_read_unlock();
6138
6139         if (err < 0) {
6140                 kfree_skb(skb);
6141                 goto errout;
6142         }
6143
6144         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
6145 errout:
6146         return err;
6147 }
6148
6149 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
6150                      unsigned int nlm_flags)
6151 {
6152         struct sk_buff *skb;
6153         struct net *net = info->nl_net;
6154         u32 seq;
6155         int err;
6156
6157         err = -ENOBUFS;
6158         seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6159
6160         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6161         if (!skb)
6162                 goto errout;
6163
6164         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6165                             event, info->portid, seq, nlm_flags);
6166         if (err < 0) {
6167                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6168                 WARN_ON(err == -EMSGSIZE);
6169                 kfree_skb(skb);
6170                 goto errout;
6171         }
6172         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6173                     info->nlh, gfp_any());
6174         return;
6175 errout:
6176         if (err < 0)
6177                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6178 }
6179
6180 void fib6_rt_update(struct net *net, struct fib6_info *rt,
6181                     struct nl_info *info)
6182 {
6183         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6184         struct sk_buff *skb;
6185         int err = -ENOBUFS;
6186
6187         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6188         if (!skb)
6189                 goto errout;
6190
6191         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6192                             RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
6193         if (err < 0) {
6194                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6195                 WARN_ON(err == -EMSGSIZE);
6196                 kfree_skb(skb);
6197                 goto errout;
6198         }
6199         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6200                     info->nlh, gfp_any());
6201         return;
6202 errout:
6203         if (err < 0)
6204                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6205 }
6206
6207 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
6208                             bool offload, bool trap, bool offload_failed)
6209 {
6210         struct sk_buff *skb;
6211         int err;
6212
6213         if (READ_ONCE(f6i->offload) == offload &&
6214             READ_ONCE(f6i->trap) == trap &&
6215             READ_ONCE(f6i->offload_failed) == offload_failed)
6216                 return;
6217
6218         WRITE_ONCE(f6i->offload, offload);
6219         WRITE_ONCE(f6i->trap, trap);
6220
6221         /* 2 means send notifications only if offload_failed was changed. */
6222         if (net->ipv6.sysctl.fib_notify_on_flag_change == 2 &&
6223             READ_ONCE(f6i->offload_failed) == offload_failed)
6224                 return;
6225
6226         WRITE_ONCE(f6i->offload_failed, offload_failed);
6227
6228         if (!rcu_access_pointer(f6i->fib6_node))
6229                 /* The route was removed from the tree, do not send
6230                  * notification.
6231                  */
6232                 return;
6233
6234         if (!net->ipv6.sysctl.fib_notify_on_flag_change)
6235                 return;
6236
6237         skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL);
6238         if (!skb) {
6239                 err = -ENOBUFS;
6240                 goto errout;
6241         }
6242
6243         err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0,
6244                             0, 0);
6245         if (err < 0) {
6246                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6247                 WARN_ON(err == -EMSGSIZE);
6248                 kfree_skb(skb);
6249                 goto errout;
6250         }
6251
6252         rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL);
6253         return;
6254
6255 errout:
6256         rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6257 }
6258 EXPORT_SYMBOL(fib6_info_hw_flags_set);
6259
6260 static int ip6_route_dev_notify(struct notifier_block *this,
6261                                 unsigned long event, void *ptr)
6262 {
6263         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
6264         struct net *net = dev_net(dev);
6265
6266         if (!(dev->flags & IFF_LOOPBACK))
6267                 return NOTIFY_OK;
6268
6269         if (event == NETDEV_REGISTER) {
6270                 net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev;
6271                 net->ipv6.ip6_null_entry->dst.dev = dev;
6272                 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
6273 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6274                 net->ipv6.ip6_prohibit_entry->dst.dev = dev;
6275                 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
6276                 net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
6277                 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
6278 #endif
6279          } else if (event == NETDEV_UNREGISTER &&
6280                     dev->reg_state != NETREG_UNREGISTERED) {
6281                 /* NETDEV_UNREGISTER could be fired for multiple times by
6282                  * netdev_wait_allrefs(). Make sure we only call this once.
6283                  */
6284                 in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
6285 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6286                 in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
6287                 in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
6288 #endif
6289         }
6290
6291         return NOTIFY_OK;
6292 }
6293
6294 /*
6295  *      /proc
6296  */
6297
6298 #ifdef CONFIG_PROC_FS
6299 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
6300 {
6301         struct net *net = (struct net *)seq->private;
6302         seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
6303                    net->ipv6.rt6_stats->fib_nodes,
6304                    net->ipv6.rt6_stats->fib_route_nodes,
6305                    atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
6306                    net->ipv6.rt6_stats->fib_rt_entries,
6307                    net->ipv6.rt6_stats->fib_rt_cache,
6308                    dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
6309                    net->ipv6.rt6_stats->fib_discarded_routes);
6310
6311         return 0;
6312 }
6313 #endif  /* CONFIG_PROC_FS */
6314
6315 #ifdef CONFIG_SYSCTL
6316
6317 static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
6318                               void *buffer, size_t *lenp, loff_t *ppos)
6319 {
6320         struct net *net;
6321         int delay;
6322         int ret;
6323         if (!write)
6324                 return -EINVAL;
6325
6326         net = (struct net *)ctl->extra1;
6327         delay = net->ipv6.sysctl.flush_delay;
6328         ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
6329         if (ret)
6330                 return ret;
6331
6332         fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
6333         return 0;
6334 }
6335
6336 static struct ctl_table ipv6_route_table_template[] = {
6337         {
6338                 .procname       =       "max_size",
6339                 .data           =       &init_net.ipv6.sysctl.ip6_rt_max_size,
6340                 .maxlen         =       sizeof(int),
6341                 .mode           =       0644,
6342                 .proc_handler   =       proc_dointvec,
6343         },
6344         {
6345                 .procname       =       "gc_thresh",
6346                 .data           =       &ip6_dst_ops_template.gc_thresh,
6347                 .maxlen         =       sizeof(int),
6348                 .mode           =       0644,
6349                 .proc_handler   =       proc_dointvec,
6350         },
6351         {
6352                 .procname       =       "flush",
6353                 .data           =       &init_net.ipv6.sysctl.flush_delay,
6354                 .maxlen         =       sizeof(int),
6355                 .mode           =       0200,
6356                 .proc_handler   =       ipv6_sysctl_rtcache_flush
6357         },
6358         {
6359                 .procname       =       "gc_min_interval",
6360                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6361                 .maxlen         =       sizeof(int),
6362                 .mode           =       0644,
6363                 .proc_handler   =       proc_dointvec_jiffies,
6364         },
6365         {
6366                 .procname       =       "gc_timeout",
6367                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
6368                 .maxlen         =       sizeof(int),
6369                 .mode           =       0644,
6370                 .proc_handler   =       proc_dointvec_jiffies,
6371         },
6372         {
6373                 .procname       =       "gc_interval",
6374                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_interval,
6375                 .maxlen         =       sizeof(int),
6376                 .mode           =       0644,
6377                 .proc_handler   =       proc_dointvec_jiffies,
6378         },
6379         {
6380                 .procname       =       "gc_elasticity",
6381                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
6382                 .maxlen         =       sizeof(int),
6383                 .mode           =       0644,
6384                 .proc_handler   =       proc_dointvec,
6385         },
6386         {
6387                 .procname       =       "mtu_expires",
6388                 .data           =       &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
6389                 .maxlen         =       sizeof(int),
6390                 .mode           =       0644,
6391                 .proc_handler   =       proc_dointvec_jiffies,
6392         },
6393         {
6394                 .procname       =       "min_adv_mss",
6395                 .data           =       &init_net.ipv6.sysctl.ip6_rt_min_advmss,
6396                 .maxlen         =       sizeof(int),
6397                 .mode           =       0644,
6398                 .proc_handler   =       proc_dointvec,
6399         },
6400         {
6401                 .procname       =       "gc_min_interval_ms",
6402                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6403                 .maxlen         =       sizeof(int),
6404                 .mode           =       0644,
6405                 .proc_handler   =       proc_dointvec_ms_jiffies,
6406         },
6407         {
6408                 .procname       =       "skip_notify_on_dev_down",
6409                 .data           =       &init_net.ipv6.sysctl.skip_notify_on_dev_down,
6410                 .maxlen         =       sizeof(int),
6411                 .mode           =       0644,
6412                 .proc_handler   =       proc_dointvec_minmax,
6413                 .extra1         =       SYSCTL_ZERO,
6414                 .extra2         =       SYSCTL_ONE,
6415         },
6416         { }
6417 };
6418
6419 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
6420 {
6421         struct ctl_table *table;
6422
6423         table = kmemdup(ipv6_route_table_template,
6424                         sizeof(ipv6_route_table_template),
6425                         GFP_KERNEL);
6426
6427         if (table) {
6428                 table[0].data = &net->ipv6.sysctl.ip6_rt_max_size;
6429                 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
6430                 table[2].data = &net->ipv6.sysctl.flush_delay;
6431                 table[2].extra1 = net;
6432                 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6433                 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
6434                 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
6435                 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
6436                 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
6437                 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
6438                 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6439                 table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
6440
6441                 /* Don't export sysctls to unprivileged users */
6442                 if (net->user_ns != &init_user_ns)
6443                         table[1].procname = NULL;
6444         }
6445
6446         return table;
6447 }
6448 #endif
6449
6450 static int __net_init ip6_route_net_init(struct net *net)
6451 {
6452         int ret = -ENOMEM;
6453
6454         memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
6455                sizeof(net->ipv6.ip6_dst_ops));
6456
6457         if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
6458                 goto out_ip6_dst_ops;
6459
6460         net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true);
6461         if (!net->ipv6.fib6_null_entry)
6462                 goto out_ip6_dst_entries;
6463         memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template,
6464                sizeof(*net->ipv6.fib6_null_entry));
6465
6466         net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
6467                                            sizeof(*net->ipv6.ip6_null_entry),
6468                                            GFP_KERNEL);
6469         if (!net->ipv6.ip6_null_entry)
6470                 goto out_fib6_null_entry;
6471         net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6472         dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
6473                          ip6_template_metrics, true);
6474         INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->rt6i_uncached);
6475
6476 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6477         net->ipv6.fib6_has_custom_rules = false;
6478         net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
6479                                                sizeof(*net->ipv6.ip6_prohibit_entry),
6480                                                GFP_KERNEL);
6481         if (!net->ipv6.ip6_prohibit_entry)
6482                 goto out_ip6_null_entry;
6483         net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6484         dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
6485                          ip6_template_metrics, true);
6486         INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->rt6i_uncached);
6487
6488         net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
6489                                                sizeof(*net->ipv6.ip6_blk_hole_entry),
6490                                                GFP_KERNEL);
6491         if (!net->ipv6.ip6_blk_hole_entry)
6492                 goto out_ip6_prohibit_entry;
6493         net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6494         dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
6495                          ip6_template_metrics, true);
6496         INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->rt6i_uncached);
6497 #ifdef CONFIG_IPV6_SUBTREES
6498         net->ipv6.fib6_routes_require_src = 0;
6499 #endif
6500 #endif
6501
6502         net->ipv6.sysctl.flush_delay = 0;
6503         net->ipv6.sysctl.ip6_rt_max_size = 4096;
6504         net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
6505         net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
6506         net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
6507         net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
6508         net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
6509         net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
6510         net->ipv6.sysctl.skip_notify_on_dev_down = 0;
6511
6512         net->ipv6.ip6_rt_gc_expire = 30*HZ;
6513
6514         ret = 0;
6515 out:
6516         return ret;
6517
6518 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6519 out_ip6_prohibit_entry:
6520         kfree(net->ipv6.ip6_prohibit_entry);
6521 out_ip6_null_entry:
6522         kfree(net->ipv6.ip6_null_entry);
6523 #endif
6524 out_fib6_null_entry:
6525         kfree(net->ipv6.fib6_null_entry);
6526 out_ip6_dst_entries:
6527         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6528 out_ip6_dst_ops:
6529         goto out;
6530 }
6531
6532 static void __net_exit ip6_route_net_exit(struct net *net)
6533 {
6534         kfree(net->ipv6.fib6_null_entry);
6535         kfree(net->ipv6.ip6_null_entry);
6536 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6537         kfree(net->ipv6.ip6_prohibit_entry);
6538         kfree(net->ipv6.ip6_blk_hole_entry);
6539 #endif
6540         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6541 }
6542
6543 static int __net_init ip6_route_net_init_late(struct net *net)
6544 {
6545 #ifdef CONFIG_PROC_FS
6546         proc_create_net("ipv6_route", 0, net->proc_net, &ipv6_route_seq_ops,
6547                         sizeof(struct ipv6_route_iter));
6548         proc_create_net_single("rt6_stats", 0444, net->proc_net,
6549                         rt6_stats_seq_show, NULL);
6550 #endif
6551         return 0;
6552 }
6553
6554 static void __net_exit ip6_route_net_exit_late(struct net *net)
6555 {
6556 #ifdef CONFIG_PROC_FS
6557         remove_proc_entry("ipv6_route", net->proc_net);
6558         remove_proc_entry("rt6_stats", net->proc_net);
6559 #endif
6560 }
6561
6562 static struct pernet_operations ip6_route_net_ops = {
6563         .init = ip6_route_net_init,
6564         .exit = ip6_route_net_exit,
6565 };
6566
6567 static int __net_init ipv6_inetpeer_init(struct net *net)
6568 {
6569         struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
6570
6571         if (!bp)
6572                 return -ENOMEM;
6573         inet_peer_base_init(bp);
6574         net->ipv6.peers = bp;
6575         return 0;
6576 }
6577
6578 static void __net_exit ipv6_inetpeer_exit(struct net *net)
6579 {
6580         struct inet_peer_base *bp = net->ipv6.peers;
6581
6582         net->ipv6.peers = NULL;
6583         inetpeer_invalidate_tree(bp);
6584         kfree(bp);
6585 }
6586
6587 static struct pernet_operations ipv6_inetpeer_ops = {
6588         .init   =       ipv6_inetpeer_init,
6589         .exit   =       ipv6_inetpeer_exit,
6590 };
6591
6592 static struct pernet_operations ip6_route_net_late_ops = {
6593         .init = ip6_route_net_init_late,
6594         .exit = ip6_route_net_exit_late,
6595 };
6596
6597 static struct notifier_block ip6_route_dev_notifier = {
6598         .notifier_call = ip6_route_dev_notify,
6599         .priority = ADDRCONF_NOTIFY_PRIORITY - 10,
6600 };
6601
6602 void __init ip6_route_init_special_entries(void)
6603 {
6604         /* Registering of the loopback is done before this portion of code,
6605          * the loopback reference in rt6_info will not be taken, do it
6606          * manually for init_net */
6607         init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev;
6608         init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
6609         init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6610   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6611         init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
6612         init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6613         init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
6614         init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6615   #endif
6616 }
6617
6618 #if IS_BUILTIN(CONFIG_IPV6)
6619 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6620 DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt)
6621
6622 BTF_ID_LIST(btf_fib6_info_id)
6623 BTF_ID(struct, fib6_info)
6624
6625 static const struct bpf_iter_seq_info ipv6_route_seq_info = {
6626         .seq_ops                = &ipv6_route_seq_ops,
6627         .init_seq_private       = bpf_iter_init_seq_net,
6628         .fini_seq_private       = bpf_iter_fini_seq_net,
6629         .seq_priv_size          = sizeof(struct ipv6_route_iter),
6630 };
6631
6632 static struct bpf_iter_reg ipv6_route_reg_info = {
6633         .target                 = "ipv6_route",
6634         .ctx_arg_info_size      = 1,
6635         .ctx_arg_info           = {
6636                 { offsetof(struct bpf_iter__ipv6_route, rt),
6637                   PTR_TO_BTF_ID_OR_NULL },
6638         },
6639         .seq_info               = &ipv6_route_seq_info,
6640 };
6641
6642 static int __init bpf_iter_register(void)
6643 {
6644         ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id;
6645         return bpf_iter_reg_target(&ipv6_route_reg_info);
6646 }
6647
6648 static void bpf_iter_unregister(void)
6649 {
6650         bpf_iter_unreg_target(&ipv6_route_reg_info);
6651 }
6652 #endif
6653 #endif
6654
6655 int __init ip6_route_init(void)
6656 {
6657         int ret;
6658         int cpu;
6659
6660         ret = -ENOMEM;
6661         ip6_dst_ops_template.kmem_cachep =
6662                 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
6663                                   SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
6664         if (!ip6_dst_ops_template.kmem_cachep)
6665                 goto out;
6666
6667         ret = dst_entries_init(&ip6_dst_blackhole_ops);
6668         if (ret)
6669                 goto out_kmem_cache;
6670
6671         ret = register_pernet_subsys(&ipv6_inetpeer_ops);
6672         if (ret)
6673                 goto out_dst_entries;
6674
6675         ret = register_pernet_subsys(&ip6_route_net_ops);
6676         if (ret)
6677                 goto out_register_inetpeer;
6678
6679         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
6680
6681         ret = fib6_init();
6682         if (ret)
6683                 goto out_register_subsys;
6684
6685         ret = xfrm6_init();
6686         if (ret)
6687                 goto out_fib6_init;
6688
6689         ret = fib6_rules_init();
6690         if (ret)
6691                 goto xfrm6_init;
6692
6693         ret = register_pernet_subsys(&ip6_route_net_late_ops);
6694         if (ret)
6695                 goto fib6_rules_init;
6696
6697         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
6698                                    inet6_rtm_newroute, NULL, 0);
6699         if (ret < 0)
6700                 goto out_register_late_subsys;
6701
6702         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
6703                                    inet6_rtm_delroute, NULL, 0);
6704         if (ret < 0)
6705                 goto out_register_late_subsys;
6706
6707         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
6708                                    inet6_rtm_getroute, NULL,
6709                                    RTNL_FLAG_DOIT_UNLOCKED);
6710         if (ret < 0)
6711                 goto out_register_late_subsys;
6712
6713         ret = register_netdevice_notifier(&ip6_route_dev_notifier);
6714         if (ret)
6715                 goto out_register_late_subsys;
6716
6717 #if IS_BUILTIN(CONFIG_IPV6)
6718 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6719         ret = bpf_iter_register();
6720         if (ret)
6721                 goto out_register_late_subsys;
6722 #endif
6723 #endif
6724
6725         for_each_possible_cpu(cpu) {
6726                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
6727
6728                 INIT_LIST_HEAD(&ul->head);
6729                 INIT_LIST_HEAD(&ul->quarantine);
6730                 spin_lock_init(&ul->lock);
6731         }
6732
6733 out:
6734         return ret;
6735
6736 out_register_late_subsys:
6737         rtnl_unregister_all(PF_INET6);
6738         unregister_pernet_subsys(&ip6_route_net_late_ops);
6739 fib6_rules_init:
6740         fib6_rules_cleanup();
6741 xfrm6_init:
6742         xfrm6_fini();
6743 out_fib6_init:
6744         fib6_gc_cleanup();
6745 out_register_subsys:
6746         unregister_pernet_subsys(&ip6_route_net_ops);
6747 out_register_inetpeer:
6748         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6749 out_dst_entries:
6750         dst_entries_destroy(&ip6_dst_blackhole_ops);
6751 out_kmem_cache:
6752         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6753         goto out;
6754 }
6755
6756 void ip6_route_cleanup(void)
6757 {
6758 #if IS_BUILTIN(CONFIG_IPV6)
6759 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6760         bpf_iter_unregister();
6761 #endif
6762 #endif
6763         unregister_netdevice_notifier(&ip6_route_dev_notifier);
6764         unregister_pernet_subsys(&ip6_route_net_late_ops);
6765         fib6_rules_cleanup();
6766         xfrm6_fini();
6767         fib6_gc_cleanup();
6768         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6769         unregister_pernet_subsys(&ip6_route_net_ops);
6770         dst_entries_destroy(&ip6_dst_blackhole_ops);
6771         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6772 }