net/ipv6/route.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Linux INET6 implementation
   4  *      FIB front-end.
   5  *
   6  *      Authors:
   7  *      Pedro Roque             <roque@di.fc.ul.pt>
   8  */
   9
  10 /*      Changes:
  11  *
  12  *      YOSHIFUJI Hideaki @USAGI
  13  *              reworked default router selection.
  14  *              - respect outgoing interface
  15  *              - select from (probably) reachable routers (i.e.
  16  *              routers in REACHABLE, STALE, DELAY or PROBE states).
  17  *              - always select the same router if it is (probably)
  18  *              reachable.  otherwise, round-robin the list.
  19  *      Ville Nuorvala
  20  *              Fixed routing subtrees.
  21  */
  22
  23 #define pr_fmt(fmt) "IPv6: " fmt
  24
  25 #include <linux/capability.h>
  26 #include <linux/errno.h>
  27 #include <linux/export.h>
  28 #include <linux/types.h>
  29 #include <linux/times.h>
  30 #include <linux/socket.h>
  31 #include <linux/sockios.h>
  32 #include <linux/net.h>
  33 #include <linux/route.h>
  34 #include <linux/netdevice.h>
  35 #include <linux/in6.h>
  36 #include <linux/mroute6.h>
  37 #include <linux/init.h>
  38 #include <linux/if_arp.h>
  39 #include <linux/proc_fs.h>
  40 #include <linux/seq_file.h>
  41 #include <linux/nsproxy.h>
  42 #include <linux/slab.h>
  43 #include <linux/jhash.h>
  44 #include <linux/siphash.h>
  45 #include <net/net_namespace.h>
  46 #include <net/snmp.h>
  47 #include <net/ipv6.h>
  48 #include <net/ip6_fib.h>
  49 #include <net/ip6_route.h>
  50 #include <net/ndisc.h>
  51 #include <net/addrconf.h>
  52 #include <net/tcp.h>
  53 #include <linux/rtnetlink.h>
  54 #include <net/dst.h>
  55 #include <net/dst_metadata.h>
  56 #include <net/xfrm.h>
  57 #include <net/netevent.h>
  58 #include <net/netlink.h>
  59 #include <net/rtnh.h>
  60 #include <net/lwtunnel.h>
  61 #include <net/ip_tunnels.h>
  62 #include <net/l3mdev.h>
  63 #include <net/ip.h>
  64 #include <linux/uaccess.h>
  65 #include <linux/btf_ids.h>
  66
  67 #ifdef CONFIG_SYSCTL
  68 #include <linux/sysctl.h>
  69 #endif
  70
  71 static int ip6_rt_type_to_error(u8 fib6_type);
  72
  73 #define CREATE_TRACE_POINTS
  74 #include <trace/events/fib6.h>
  75 EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup);
  76 #undef CREATE_TRACE_POINTS
  77
  78 enum rt6_nud_state {
  79         RT6_NUD_FAIL_HARD = -3,
  80         RT6_NUD_FAIL_PROBE = -2,
  81         RT6_NUD_FAIL_DO_RR = -1,
  82         RT6_NUD_SUCCEED = 1
  83 };
  84
  85 INDIRECT_CALLABLE_SCOPE
  86 struct dst_entry        *ip6_dst_check(struct dst_entry *dst, u32 cookie);
  87 static unsigned int      ip6_default_advmss(const struct dst_entry *dst);
  88 INDIRECT_CALLABLE_SCOPE
  89 unsigned int            ip6_mtu(const struct dst_entry *dst);
  90 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
  91 static void             ip6_dst_destroy(struct dst_entry *);
  92 static void             ip6_dst_ifdown(struct dst_entry *,
  93                                        struct net_device *dev);
  94 static void              ip6_dst_gc(struct dst_ops *ops);
  95
  96 static int              ip6_pkt_discard(struct sk_buff *skb);
  97 static int              ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
  98 static int              ip6_pkt_prohibit(struct sk_buff *skb);
  99 static int              ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 100 static void             ip6_link_failure(struct sk_buff *skb);
 101 static void             ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
 102                                            struct sk_buff *skb, u32 mtu,
 103                                            bool confirm_neigh);
 104 static void             rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
 105                                         struct sk_buff *skb);
 106 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
 107                            int strict);
 108 static size_t rt6_nlmsg_size(struct fib6_info *f6i);
 109 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
 110                          struct fib6_info *rt, struct dst_entry *dst,
 111                          struct in6_addr *dest, struct in6_addr *src,
 112                          int iif, int type, u32 portid, u32 seq,
 113                          unsigned int flags);
 114 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
 115                                            const struct in6_addr *daddr,
 116                                            const struct in6_addr *saddr);
 117
 118 #ifdef CONFIG_IPV6_ROUTE_INFO
 119 static struct fib6_info *rt6_add_route_info(struct net *net,
 120                                            const struct in6_addr *prefix, int prefixlen,
 121                                            const struct in6_addr *gwaddr,
 122                                            struct net_device *dev,
 123                                            unsigned int pref);
 124 static struct fib6_info *rt6_get_route_info(struct net *net,
 125                                            const struct in6_addr *prefix, int prefixlen,
 126                                            const struct in6_addr *gwaddr,
 127                                            struct net_device *dev);
 128 #endif
 129
 130 struct uncached_list {
 131         spinlock_t              lock;
 132         struct list_head        head;
 133         struct list_head        quarantine;
 134 };
 135
 136 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
 137
 138 void rt6_uncached_list_add(struct rt6_info *rt)
 139 {
 140         struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list);
 141
 142         rt->dst.rt_uncached_list = ul;
 143
 144         spin_lock_bh(&ul->lock);
 145         list_add_tail(&rt->dst.rt_uncached, &ul->head);
 146         spin_unlock_bh(&ul->lock);
 147 }
 148
 149 void rt6_uncached_list_del(struct rt6_info *rt)
 150 {
 151         if (!list_empty(&rt->dst.rt_uncached)) {
 152                 struct uncached_list *ul = rt->dst.rt_uncached_list;
 153
 154                 spin_lock_bh(&ul->lock);
 155                 list_del_init(&rt->dst.rt_uncached);
 156                 spin_unlock_bh(&ul->lock);
 157         }
 158 }
 159
 160 static void rt6_uncached_list_flush_dev(struct net_device *dev)
 161 {
 162         int cpu;
 163
 164         for_each_possible_cpu(cpu) {
 165                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
 166                 struct rt6_info *rt, *safe;
 167
 168                 if (list_empty(&ul->head))
 169                         continue;
 170
 171                 spin_lock_bh(&ul->lock);
 172                 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) {
 173                         struct inet6_dev *rt_idev = rt->rt6i_idev;
 174                         struct net_device *rt_dev = rt->dst.dev;
 175                         bool handled = false;
 176
 177                         if (rt_idev->dev == dev) {
 178                                 rt->rt6i_idev = in6_dev_get(blackhole_netdev);
 179                                 in6_dev_put(rt_idev);
 180                                 handled = true;
 181                         }
 182
 183                         if (rt_dev == dev) {
 184                                 rt->dst.dev = blackhole_netdev;
 185                                 netdev_ref_replace(rt_dev, blackhole_netdev,
 186                                                    &rt->dst.dev_tracker,
 187                                                    GFP_ATOMIC);
 188                                 handled = true;
 189                         }
 190                         if (handled)
 191                                 list_move(&rt->dst.rt_uncached,
 192                                           &ul->quarantine);
 193                 }
 194                 spin_unlock_bh(&ul->lock);
 195         }
 196 }
 197
 198 static inline const void *choose_neigh_daddr(const struct in6_addr *p,
 199                                              struct sk_buff *skb,
 200                                              const void *daddr)
 201 {
 202         if (!ipv6_addr_any(p))
 203                 return (const void *) p;
 204         else if (skb)
 205                 return &ipv6_hdr(skb)->daddr;
 206         return daddr;
 207 }
 208
 209 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
 210                                    struct net_device *dev,
 211                                    struct sk_buff *skb,
 212                                    const void *daddr)
 213 {
 214         struct neighbour *n;
 215
 216         daddr = choose_neigh_daddr(gw, skb, daddr);
 217         n = __ipv6_neigh_lookup(dev, daddr);
 218         if (n)
 219                 return n;
 220
 221         n = neigh_create(&nd_tbl, daddr, dev);
 222         return IS_ERR(n) ? NULL : n;
 223 }
 224
 225 static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst,
 226                                               struct sk_buff *skb,
 227                                               const void *daddr)
 228 {
 229         const struct rt6_info *rt = container_of(dst, struct rt6_info, dst);
 230
 231         return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any),
 232                                 dst->dev, skb, daddr);
 233 }
 234
 235 static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr)
 236 {
 237         struct net_device *dev = dst->dev;
 238         struct rt6_info *rt = (struct rt6_info *)dst;
 239
 240         daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr);
 241         if (!daddr)
 242                 return;
 243         if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
 244                 return;
 245         if (ipv6_addr_is_multicast((const struct in6_addr *)daddr))
 246                 return;
 247         __ipv6_confirm_neigh(dev, daddr);
 248 }
 249
 250 static struct dst_ops ip6_dst_ops_template = {
 251         .family                 =       AF_INET6,
 252         .gc                     =       ip6_dst_gc,
 253         .gc_thresh              =       1024,
 254         .check                  =       ip6_dst_check,
 255         .default_advmss         =       ip6_default_advmss,
 256         .mtu                    =       ip6_mtu,
 257         .cow_metrics            =       dst_cow_metrics_generic,
 258         .destroy                =       ip6_dst_destroy,
 259         .ifdown                 =       ip6_dst_ifdown,
 260         .negative_advice        =       ip6_negative_advice,
 261         .link_failure           =       ip6_link_failure,
 262         .update_pmtu            =       ip6_rt_update_pmtu,
 263         .redirect               =       rt6_do_redirect,
 264         .local_out              =       __ip6_local_out,
 265         .neigh_lookup           =       ip6_dst_neigh_lookup,
 266         .confirm_neigh          =       ip6_confirm_neigh,
 267 };
 268
 269 static struct dst_ops ip6_dst_blackhole_ops = {
 270         .family                 = AF_INET6,
 271         .default_advmss         = ip6_default_advmss,
 272         .neigh_lookup           = ip6_dst_neigh_lookup,
 273         .check                  = ip6_dst_check,
 274         .destroy                = ip6_dst_destroy,
 275         .cow_metrics            = dst_cow_metrics_generic,
 276         .update_pmtu            = dst_blackhole_update_pmtu,
 277         .redirect               = dst_blackhole_redirect,
 278         .mtu                    = dst_blackhole_mtu,
 279 };
 280
 281 static const u32 ip6_template_metrics[RTAX_MAX] = {
 282         [RTAX_HOPLIMIT - 1] = 0,
 283 };
 284
 285 static const struct fib6_info fib6_null_entry_template = {
 286         .fib6_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 287         .fib6_protocol  = RTPROT_KERNEL,
 288         .fib6_metric    = ~(u32)0,
 289         .fib6_ref       = REFCOUNT_INIT(1),
 290         .fib6_type      = RTN_UNREACHABLE,
 291         .fib6_metrics   = (struct dst_metrics *)&dst_default_metrics,
 292 };
 293
 294 static const struct rt6_info ip6_null_entry_template = {
 295         .dst = {
 296                 .__rcuref       = RCUREF_INIT(1),
 297                 .__use          = 1,
 298                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 299                 .error          = -ENETUNREACH,
 300                 .input          = ip6_pkt_discard,
 301                 .output         = ip6_pkt_discard_out,
 302         },
 303         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 304 };
 305
 306 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 307
 308 static const struct rt6_info ip6_prohibit_entry_template = {
 309         .dst = {
 310                 .__rcuref       = RCUREF_INIT(1),
 311                 .__use          = 1,
 312                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 313                 .error          = -EACCES,
 314                 .input          = ip6_pkt_prohibit,
 315                 .output         = ip6_pkt_prohibit_out,
 316         },
 317         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 318 };
 319
 320 static const struct rt6_info ip6_blk_hole_entry_template = {
 321         .dst = {
 322                 .__rcuref       = RCUREF_INIT(1),
 323                 .__use          = 1,
 324                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 325                 .error          = -EINVAL,
 326                 .input          = dst_discard,
 327                 .output         = dst_discard_out,
 328         },
 329         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 330 };
 331
 332 #endif
 333
 334 static void rt6_info_init(struct rt6_info *rt)
 335 {
 336         memset_after(rt, 0, dst);
 337 }
 338
 339 /* allocate dst with ip6_dst_ops */
 340 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 341                                int flags)
 342 {
 343         struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
 344                                         1, DST_OBSOLETE_FORCE_CHK, flags);
 345
 346         if (rt) {
 347                 rt6_info_init(rt);
 348                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
 349         }
 350
 351         return rt;
 352 }
 353 EXPORT_SYMBOL(ip6_dst_alloc);
 354
 355 static void ip6_dst_destroy(struct dst_entry *dst)
 356 {
 357         struct rt6_info *rt = (struct rt6_info *)dst;
 358         struct fib6_info *from;
 359         struct inet6_dev *idev;
 360
 361         ip_dst_metrics_put(dst);
 362         rt6_uncached_list_del(rt);
 363
 364         idev = rt->rt6i_idev;
 365         if (idev) {
 366                 rt->rt6i_idev = NULL;
 367                 in6_dev_put(idev);
 368         }
 369
 370         from = xchg((__force struct fib6_info **)&rt->from, NULL);
 371         fib6_info_release(from);
 372 }
 373
 374 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
 375 {
 376         struct rt6_info *rt = (struct rt6_info *)dst;
 377         struct inet6_dev *idev = rt->rt6i_idev;
 378
 379         if (idev && idev->dev != blackhole_netdev) {
 380                 struct inet6_dev *blackhole_idev = in6_dev_get(blackhole_netdev);
 381
 382                 if (blackhole_idev) {
 383                         rt->rt6i_idev = blackhole_idev;
 384                         in6_dev_put(idev);
 385                 }
 386         }
 387 }
 388
 389 static bool __rt6_check_expired(const struct rt6_info *rt)
 390 {
 391         if (rt->rt6i_flags & RTF_EXPIRES)
 392                 return time_after(jiffies, rt->dst.expires);
 393         else
 394                 return false;
 395 }
 396
 397 static bool rt6_check_expired(const struct rt6_info *rt)
 398 {
 399         struct fib6_info *from;
 400
 401         from = rcu_dereference(rt->from);
 402
 403         if (rt->rt6i_flags & RTF_EXPIRES) {
 404                 if (time_after(jiffies, rt->dst.expires))
 405                         return true;
 406         } else if (from) {
 407                 return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
 408                         fib6_check_expired(from);
 409         }
 410         return false;
 411 }
 412
 413 void fib6_select_path(const struct net *net, struct fib6_result *res,
 414                       struct flowi6 *fl6, int oif, bool have_oif_match,
 415                       const struct sk_buff *skb, int strict)
 416 {
 417         struct fib6_info *sibling, *next_sibling;
 418         struct fib6_info *match = res->f6i;
 419
 420         if (!match->nh && (!match->fib6_nsiblings || have_oif_match))
 421                 goto out;
 422
 423         if (match->nh && have_oif_match && res->nh)
 424                 return;
 425
 426         /* We might have already computed the hash for ICMPv6 errors. In such
 427          * case it will always be non-zero. Otherwise now is the time to do it.
 428          */
 429         if (!fl6->mp_hash &&
 430             (!match->nh || nexthop_is_multipath(match->nh)))
 431                 fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
 432
 433         if (unlikely(match->nh)) {
 434                 nexthop_path_fib6_result(res, fl6->mp_hash);
 435                 return;
 436         }
 437
 438         if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
 439                 goto out;
 440
 441         list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
 442                                  fib6_siblings) {
 443                 const struct fib6_nh *nh = sibling->fib6_nh;
 444                 int nh_upper_bound;
 445
 446                 nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
 447                 if (fl6->mp_hash > nh_upper_bound)
 448                         continue;
 449                 if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
 450                         break;
 451                 match = sibling;
 452                 break;
 453         }
 454
 455 out:
 456         res->f6i = match;
 457         res->nh = match->fib6_nh;
 458 }
 459
 460 /*
 461  *      Route lookup. rcu_read_lock() should be held.
 462  */
 463
 464 static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh,
 465                                const struct in6_addr *saddr, int oif, int flags)
 466 {
 467         const struct net_device *dev;
 468
 469         if (nh->fib_nh_flags & RTNH_F_DEAD)
 470                 return false;
 471
 472         dev = nh->fib_nh_dev;
 473         if (oif) {
 474                 if (dev->ifindex == oif)
 475                         return true;
 476         } else {
 477                 if (ipv6_chk_addr(net, saddr, dev,
 478                                   flags & RT6_LOOKUP_F_IFACE))
 479                         return true;
 480         }
 481
 482         return false;
 483 }
 484
 485 struct fib6_nh_dm_arg {
 486         struct net              *net;
 487         const struct in6_addr   *saddr;
 488         int                     oif;
 489         int                     flags;
 490         struct fib6_nh          *nh;
 491 };
 492
 493 static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg)
 494 {
 495         struct fib6_nh_dm_arg *arg = _arg;
 496
 497         arg->nh = nh;
 498         return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif,
 499                                   arg->flags);
 500 }
 501
 502 /* returns fib6_nh from nexthop or NULL */
 503 static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh,
 504                                         struct fib6_result *res,
 505                                         const struct in6_addr *saddr,
 506                                         int oif, int flags)
 507 {
 508         struct fib6_nh_dm_arg arg = {
 509                 .net   = net,
 510                 .saddr = saddr,
 511                 .oif   = oif,
 512                 .flags = flags,
 513         };
 514
 515         if (nexthop_is_blackhole(nh))
 516                 return NULL;
 517
 518         if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg))
 519                 return arg.nh;
 520
 521         return NULL;
 522 }
 523
 524 static void rt6_device_match(struct net *net, struct fib6_result *res,
 525                              const struct in6_addr *saddr, int oif, int flags)
 526 {
 527         struct fib6_info *f6i = res->f6i;
 528         struct fib6_info *spf6i;
 529         struct fib6_nh *nh;
 530
 531         if (!oif && ipv6_addr_any(saddr)) {
 532                 if (unlikely(f6i->nh)) {
 533                         nh = nexthop_fib6_nh(f6i->nh);
 534                         if (nexthop_is_blackhole(f6i->nh))
 535                                 goto out_blackhole;
 536                 } else {
 537                         nh = f6i->fib6_nh;
 538                 }
 539                 if (!(nh->fib_nh_flags & RTNH_F_DEAD))
 540                         goto out;
 541         }
 542
 543         for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
 544                 bool matched = false;
 545
 546                 if (unlikely(spf6i->nh)) {
 547                         nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr,
 548                                               oif, flags);
 549                         if (nh)
 550                                 matched = true;
 551                 } else {
 552                         nh = spf6i->fib6_nh;
 553                         if (__rt6_device_match(net, nh, saddr, oif, flags))
 554                                 matched = true;
 555                 }
 556                 if (matched) {
 557                         res->f6i = spf6i;
 558                         goto out;
 559                 }
 560         }
 561
 562         if (oif && flags & RT6_LOOKUP_F_IFACE) {
 563                 res->f6i = net->ipv6.fib6_null_entry;
 564                 nh = res->f6i->fib6_nh;
 565                 goto out;
 566         }
 567
 568         if (unlikely(f6i->nh)) {
 569                 nh = nexthop_fib6_nh(f6i->nh);
 570                 if (nexthop_is_blackhole(f6i->nh))
 571                         goto out_blackhole;
 572         } else {
 573                 nh = f6i->fib6_nh;
 574         }
 575
 576         if (nh->fib_nh_flags & RTNH_F_DEAD) {
 577                 res->f6i = net->ipv6.fib6_null_entry;
 578                 nh = res->f6i->fib6_nh;
 579         }
 580 out:
 581         res->nh = nh;
 582         res->fib6_type = res->f6i->fib6_type;
 583         res->fib6_flags = res->f6i->fib6_flags;
 584         return;
 585
 586 out_blackhole:
 587         res->fib6_flags |= RTF_REJECT;
 588         res->fib6_type = RTN_BLACKHOLE;
 589         res->nh = nh;
 590 }
 591
 592 #ifdef CONFIG_IPV6_ROUTER_PREF
 593 struct __rt6_probe_work {
 594         struct work_struct work;
 595         struct in6_addr target;
 596         struct net_device *dev;
 597         netdevice_tracker dev_tracker;
 598 };
 599
 600 static void rt6_probe_deferred(struct work_struct *w)
 601 {
 602         struct in6_addr mcaddr;
 603         struct __rt6_probe_work *work =
 604                 container_of(w, struct __rt6_probe_work, work);
 605
 606         addrconf_addr_solict_mult(&work->target, &mcaddr);
 607         ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
 608         netdev_put(work->dev, &work->dev_tracker);
 609         kfree(work);
 610 }
 611
 612 static void rt6_probe(struct fib6_nh *fib6_nh)
 613 {
 614         struct __rt6_probe_work *work = NULL;
 615         const struct in6_addr *nh_gw;
 616         unsigned long last_probe;
 617         struct neighbour *neigh;
 618         struct net_device *dev;
 619         struct inet6_dev *idev;
 620
 621         /*
 622          * Okay, this does not seem to be appropriate
 623          * for now, however, we need to check if it
 624          * is really so; aka Router Reachability Probing.
 625          *
 626          * Router Reachability Probe MUST be rate-limited
 627          * to no more than one per minute.
 628          */
 629         if (!fib6_nh->fib_nh_gw_family)
 630                 return;
 631
 632         nh_gw = &fib6_nh->fib_nh_gw6;
 633         dev = fib6_nh->fib_nh_dev;
 634         rcu_read_lock();
 635         last_probe = READ_ONCE(fib6_nh->last_probe);
 636         idev = __in6_dev_get(dev);
 637         neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
 638         if (neigh) {
 639                 if (READ_ONCE(neigh->nud_state) & NUD_VALID)
 640                         goto out;
 641
 642                 write_lock_bh(&neigh->lock);
 643                 if (!(neigh->nud_state & NUD_VALID) &&
 644                     time_after(jiffies,
 645                                neigh->updated + idev->cnf.rtr_probe_interval)) {
 646                         work = kmalloc(sizeof(*work), GFP_ATOMIC);
 647                         if (work)
 648                                 __neigh_set_probe_once(neigh);
 649                 }
 650                 write_unlock_bh(&neigh->lock);
 651         } else if (time_after(jiffies, last_probe +
 652                                        idev->cnf.rtr_probe_interval)) {
 653                 work = kmalloc(sizeof(*work), GFP_ATOMIC);
 654         }
 655
 656         if (!work || cmpxchg(&fib6_nh->last_probe,
 657                              last_probe, jiffies) != last_probe) {
 658                 kfree(work);
 659         } else {
 660                 INIT_WORK(&work->work, rt6_probe_deferred);
 661                 work->target = *nh_gw;
 662                 netdev_hold(dev, &work->dev_tracker, GFP_ATOMIC);
 663                 work->dev = dev;
 664                 schedule_work(&work->work);
 665         }
 666
 667 out:
 668         rcu_read_unlock();
 669 }
 670 #else
 671 static inline void rt6_probe(struct fib6_nh *fib6_nh)
 672 {
 673 }
 674 #endif
 675
 676 /*
 677  * Default Router Selection (RFC 2461 6.3.6)
 678  */
 679 static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh)
 680 {
 681         enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
 682         struct neighbour *neigh;
 683
 684         rcu_read_lock();
 685         neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev,
 686                                           &fib6_nh->fib_nh_gw6);
 687         if (neigh) {
 688                 u8 nud_state = READ_ONCE(neigh->nud_state);
 689
 690                 if (nud_state & NUD_VALID)
 691                         ret = RT6_NUD_SUCCEED;
 692 #ifdef CONFIG_IPV6_ROUTER_PREF
 693                 else if (!(nud_state & NUD_FAILED))
 694                         ret = RT6_NUD_SUCCEED;
 695                 else
 696                         ret = RT6_NUD_FAIL_PROBE;
 697 #endif
 698         } else {
 699                 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
 700                       RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
 701         }
 702         rcu_read_unlock();
 703
 704         return ret;
 705 }
 706
 707 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
 708                            int strict)
 709 {
 710         int m = 0;
 711
 712         if (!oif || nh->fib_nh_dev->ifindex == oif)
 713                 m = 2;
 714
 715         if (!m && (strict & RT6_LOOKUP_F_IFACE))
 716                 return RT6_NUD_FAIL_HARD;
 717 #ifdef CONFIG_IPV6_ROUTER_PREF
 718         m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2;
 719 #endif
 720         if ((strict & RT6_LOOKUP_F_REACHABLE) &&
 721             !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) {
 722                 int n = rt6_check_neigh(nh);
 723                 if (n < 0)
 724                         return n;
 725         }
 726         return m;
 727 }
 728
 729 static bool find_match(struct fib6_nh *nh, u32 fib6_flags,
 730                        int oif, int strict, int *mpri, bool *do_rr)
 731 {
 732         bool match_do_rr = false;
 733         bool rc = false;
 734         int m;
 735
 736         if (nh->fib_nh_flags & RTNH_F_DEAD)
 737                 goto out;
 738
 739         if (ip6_ignore_linkdown(nh->fib_nh_dev) &&
 740             nh->fib_nh_flags & RTNH_F_LINKDOWN &&
 741             !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
 742                 goto out;
 743
 744         m = rt6_score_route(nh, fib6_flags, oif, strict);
 745         if (m == RT6_NUD_FAIL_DO_RR) {
 746                 match_do_rr = true;
 747                 m = 0; /* lowest valid score */
 748         } else if (m == RT6_NUD_FAIL_HARD) {
 749                 goto out;
 750         }
 751
 752         if (strict & RT6_LOOKUP_F_REACHABLE)
 753                 rt6_probe(nh);
 754
 755         /* note that m can be RT6_NUD_FAIL_PROBE at this point */
 756         if (m > *mpri) {
 757                 *do_rr = match_do_rr;
 758                 *mpri = m;
 759                 rc = true;
 760         }
 761 out:
 762         return rc;
 763 }
 764
 765 struct fib6_nh_frl_arg {
 766         u32             flags;
 767         int             oif;
 768         int             strict;
 769         int             *mpri;
 770         bool            *do_rr;
 771         struct fib6_nh  *nh;
 772 };
 773
 774 static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg)
 775 {
 776         struct fib6_nh_frl_arg *arg = _arg;
 777
 778         arg->nh = nh;
 779         return find_match(nh, arg->flags, arg->oif, arg->strict,
 780                           arg->mpri, arg->do_rr);
 781 }
 782
 783 static void __find_rr_leaf(struct fib6_info *f6i_start,
 784                            struct fib6_info *nomatch, u32 metric,
 785                            struct fib6_result *res, struct fib6_info **cont,
 786                            int oif, int strict, bool *do_rr, int *mpri)
 787 {
 788         struct fib6_info *f6i;
 789
 790         for (f6i = f6i_start;
 791              f6i && f6i != nomatch;
 792              f6i = rcu_dereference(f6i->fib6_next)) {
 793                 bool matched = false;
 794                 struct fib6_nh *nh;
 795
 796                 if (cont && f6i->fib6_metric != metric) {
 797                         *cont = f6i;
 798                         return;
 799                 }
 800
 801                 if (fib6_check_expired(f6i))
 802                         continue;
 803
 804                 if (unlikely(f6i->nh)) {
 805                         struct fib6_nh_frl_arg arg = {
 806                                 .flags  = f6i->fib6_flags,
 807                                 .oif    = oif,
 808                                 .strict = strict,
 809                                 .mpri   = mpri,
 810                                 .do_rr  = do_rr
 811                         };
 812
 813                         if (nexthop_is_blackhole(f6i->nh)) {
 814                                 res->fib6_flags = RTF_REJECT;
 815                                 res->fib6_type = RTN_BLACKHOLE;
 816                                 res->f6i = f6i;
 817                                 res->nh = nexthop_fib6_nh(f6i->nh);
 818                                 return;
 819                         }
 820                         if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match,
 821                                                      &arg)) {
 822                                 matched = true;
 823                                 nh = arg.nh;
 824                         }
 825                 } else {
 826                         nh = f6i->fib6_nh;
 827                         if (find_match(nh, f6i->fib6_flags, oif, strict,
 828                                        mpri, do_rr))
 829                                 matched = true;
 830                 }
 831                 if (matched) {
 832                         res->f6i = f6i;
 833                         res->nh = nh;
 834                         res->fib6_flags = f6i->fib6_flags;
 835                         res->fib6_type = f6i->fib6_type;
 836                 }
 837         }
 838 }
 839
 840 static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf,
 841                          struct fib6_info *rr_head, int oif, int strict,
 842                          bool *do_rr, struct fib6_result *res)
 843 {
 844         u32 metric = rr_head->fib6_metric;
 845         struct fib6_info *cont = NULL;
 846         int mpri = -1;
 847
 848         __find_rr_leaf(rr_head, NULL, metric, res, &cont,
 849                        oif, strict, do_rr, &mpri);
 850
 851         __find_rr_leaf(leaf, rr_head, metric, res, &cont,
 852                        oif, strict, do_rr, &mpri);
 853
 854         if (res->f6i || !cont)
 855                 return;
 856
 857         __find_rr_leaf(cont, NULL, metric, res, NULL,
 858                        oif, strict, do_rr, &mpri);
 859 }
 860
 861 static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
 862                        struct fib6_result *res, int strict)
 863 {
 864         struct fib6_info *leaf = rcu_dereference(fn->leaf);
 865         struct fib6_info *rt0;
 866         bool do_rr = false;
 867         int key_plen;
 868
 869         /* make sure this function or its helpers sets f6i */
 870         res->f6i = NULL;
 871
 872         if (!leaf || leaf == net->ipv6.fib6_null_entry)
 873                 goto out;
 874
 875         rt0 = rcu_dereference(fn->rr_ptr);
 876         if (!rt0)
 877                 rt0 = leaf;
 878
 879         /* Double check to make sure fn is not an intermediate node
 880          * and fn->leaf does not points to its child's leaf
 881          * (This might happen if all routes under fn are deleted from
 882          * the tree and fib6_repair_tree() is called on the node.)
 883          */
 884         key_plen = rt0->fib6_dst.plen;
 885 #ifdef CONFIG_IPV6_SUBTREES
 886         if (rt0->fib6_src.plen)
 887                 key_plen = rt0->fib6_src.plen;
 888 #endif
 889         if (fn->fn_bit != key_plen)
 890                 goto out;
 891
 892         find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res);
 893         if (do_rr) {
 894                 struct fib6_info *next = rcu_dereference(rt0->fib6_next);
 895
 896                 /* no entries matched; do round-robin */
 897                 if (!next || next->fib6_metric != rt0->fib6_metric)
 898                         next = leaf;
 899
 900                 if (next != rt0) {
 901                         spin_lock_bh(&leaf->fib6_table->tb6_lock);
 902                         /* make sure next is not being deleted from the tree */
 903                         if (next->fib6_node)
 904                                 rcu_assign_pointer(fn->rr_ptr, next);
 905                         spin_unlock_bh(&leaf->fib6_table->tb6_lock);
 906                 }
 907         }
 908
 909 out:
 910         if (!res->f6i) {
 911                 res->f6i = net->ipv6.fib6_null_entry;
 912                 res->nh = res->f6i->fib6_nh;
 913                 res->fib6_flags = res->f6i->fib6_flags;
 914                 res->fib6_type = res->f6i->fib6_type;
 915         }
 916 }
 917
 918 static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res)
 919 {
 920         return (res->f6i->fib6_flags & RTF_NONEXTHOP) ||
 921                res->nh->fib_nh_gw_family;
 922 }
 923
 924 #ifdef CONFIG_IPV6_ROUTE_INFO
 925 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 926                   const struct in6_addr *gwaddr)
 927 {
 928         struct net *net = dev_net(dev);
 929         struct route_info *rinfo = (struct route_info *) opt;
 930         struct in6_addr prefix_buf, *prefix;
 931         unsigned int pref;
 932         unsigned long lifetime;
 933         struct fib6_info *rt;
 934
 935         if (len < sizeof(struct route_info)) {
 936                 return -EINVAL;
 937         }
 938
 939         /* Sanity check for prefix_len and length */
 940         if (rinfo->length > 3) {
 941                 return -EINVAL;
 942         } else if (rinfo->prefix_len > 128) {
 943                 return -EINVAL;
 944         } else if (rinfo->prefix_len > 64) {
 945                 if (rinfo->length < 2) {
 946                         return -EINVAL;
 947                 }
 948         } else if (rinfo->prefix_len > 0) {
 949                 if (rinfo->length < 1) {
 950                         return -EINVAL;
 951                 }
 952         }
 953
 954         pref = rinfo->route_pref;
 955         if (pref == ICMPV6_ROUTER_PREF_INVALID)
 956                 return -EINVAL;
 957
 958         lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
 959
 960         if (rinfo->length == 3)
 961                 prefix = (struct in6_addr *)rinfo->prefix;
 962         else {
 963                 /* this function is safe */
 964                 ipv6_addr_prefix(&prefix_buf,
 965                                  (struct in6_addr *)rinfo->prefix,
 966                                  rinfo->prefix_len);
 967                 prefix = &prefix_buf;
 968         }
 969
 970         if (rinfo->prefix_len == 0)
 971                 rt = rt6_get_dflt_router(net, gwaddr, dev);
 972         else
 973                 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
 974                                         gwaddr, dev);
 975
 976         if (rt && !lifetime) {
 977                 ip6_del_rt(net, rt, false);
 978                 rt = NULL;
 979         }
 980
 981         if (!rt && lifetime)
 982                 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
 983                                         dev, pref);
 984         else if (rt)
 985                 rt->fib6_flags = RTF_ROUTEINFO |
 986                                  (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 987
 988         if (rt) {
 989                 if (!addrconf_finite_timeout(lifetime))
 990                         fib6_clean_expires(rt);
 991                 else
 992                         fib6_set_expires(rt, jiffies + HZ * lifetime);
 993
 994                 fib6_info_release(rt);
 995         }
 996         return 0;
 997 }
 998 #endif
 999
1000 /*
1001  *      Misc support functions
1002  */
1003
1004 /* called with rcu_lock held */
1005 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
1006 {
1007         struct net_device *dev = res->nh->fib_nh_dev;
1008
1009         if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
1010                 /* for copies of local routes, dst->dev needs to be the
1011                  * device if it is a master device, the master device if
1012                  * device is enslaved, and the loopback as the default
1013                  */
1014                 if (netif_is_l3_slave(dev) &&
1015                     !rt6_need_strict(&res->f6i->fib6_dst.addr))
1016                         dev = l3mdev_master_dev_rcu(dev);
1017                 else if (!netif_is_l3_master(dev))
1018                         dev = dev_net(dev)->loopback_dev;
1019                 /* last case is netif_is_l3_master(dev) is true in which
1020                  * case we want dev returned to be dev
1021                  */
1022         }
1023
1024         return dev;
1025 }
1026
1027 static const int fib6_prop[RTN_MAX + 1] = {
1028         [RTN_UNSPEC]    = 0,
1029         [RTN_UNICAST]   = 0,
1030         [RTN_LOCAL]     = 0,
1031         [RTN_BROADCAST] = 0,
1032         [RTN_ANYCAST]   = 0,
1033         [RTN_MULTICAST] = 0,
1034         [RTN_BLACKHOLE] = -EINVAL,
1035         [RTN_UNREACHABLE] = -EHOSTUNREACH,
1036         [RTN_PROHIBIT]  = -EACCES,
1037         [RTN_THROW]     = -EAGAIN,
1038         [RTN_NAT]       = -EINVAL,
1039         [RTN_XRESOLVE]  = -EINVAL,
1040 };
1041
1042 static int ip6_rt_type_to_error(u8 fib6_type)
1043 {
1044         return fib6_prop[fib6_type];
1045 }
1046
1047 static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
1048 {
1049         unsigned short flags = 0;
1050
1051         if (rt->dst_nocount)
1052                 flags |= DST_NOCOUNT;
1053         if (rt->dst_nopolicy)
1054                 flags |= DST_NOPOLICY;
1055
1056         return flags;
1057 }
1058
1059 static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
1060 {
1061         rt->dst.error = ip6_rt_type_to_error(fib6_type);
1062
1063         switch (fib6_type) {
1064         case RTN_BLACKHOLE:
1065                 rt->dst.output = dst_discard_out;
1066                 rt->dst.input = dst_discard;
1067                 break;
1068         case RTN_PROHIBIT:
1069                 rt->dst.output = ip6_pkt_prohibit_out;
1070                 rt->dst.input = ip6_pkt_prohibit;
1071                 break;
1072         case RTN_THROW:
1073         case RTN_UNREACHABLE:
1074         default:
1075                 rt->dst.output = ip6_pkt_discard_out;
1076                 rt->dst.input = ip6_pkt_discard;
1077                 break;
1078         }
1079 }
1080
1081 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
1082 {
1083         struct fib6_info *f6i = res->f6i;
1084
1085         if (res->fib6_flags & RTF_REJECT) {
1086                 ip6_rt_init_dst_reject(rt, res->fib6_type);
1087                 return;
1088         }
1089
1090         rt->dst.error = 0;
1091         rt->dst.output = ip6_output;
1092
1093         if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
1094                 rt->dst.input = ip6_input;
1095         } else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
1096                 rt->dst.input = ip6_mc_input;
1097         } else {
1098                 rt->dst.input = ip6_forward;
1099         }
1100
1101         if (res->nh->fib_nh_lws) {
1102                 rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws);
1103                 lwtunnel_set_redirect(&rt->dst);
1104         }
1105
1106         rt->dst.lastuse = jiffies;
1107 }
1108
1109 /* Caller must already hold reference to @from */
1110 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
1111 {
1112         rt->rt6i_flags &= ~RTF_EXPIRES;
1113         rcu_assign_pointer(rt->from, from);
1114         ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
1115 }
1116
1117 /* Caller must already hold reference to f6i in result */
1118 static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
1119 {
1120         const struct fib6_nh *nh = res->nh;
1121         const struct net_device *dev = nh->fib_nh_dev;
1122         struct fib6_info *f6i = res->f6i;
1123
1124         ip6_rt_init_dst(rt, res);
1125
1126         rt->rt6i_dst = f6i->fib6_dst;
1127         rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
1128         rt->rt6i_flags = res->fib6_flags;
1129         if (nh->fib_nh_gw_family) {
1130                 rt->rt6i_gateway = nh->fib_nh_gw6;
1131                 rt->rt6i_flags |= RTF_GATEWAY;
1132         }
1133         rt6_set_from(rt, f6i);
1134 #ifdef CONFIG_IPV6_SUBTREES
1135         rt->rt6i_src = f6i->fib6_src;
1136 #endif
1137 }
1138
1139 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
1140                                         struct in6_addr *saddr)
1141 {
1142         struct fib6_node *pn, *sn;
1143         while (1) {
1144                 if (fn->fn_flags & RTN_TL_ROOT)
1145                         return NULL;
1146                 pn = rcu_dereference(fn->parent);
1147                 sn = FIB6_SUBTREE(pn);
1148                 if (sn && sn != fn)
1149                         fn = fib6_node_lookup(sn, NULL, saddr);
1150                 else
1151                         fn = pn;
1152                 if (fn->fn_flags & RTN_RTINFO)
1153                         return fn;
1154         }
1155 }
1156
1157 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt)
1158 {
1159         struct rt6_info *rt = *prt;
1160
1161         if (dst_hold_safe(&rt->dst))
1162                 return true;
1163         if (net) {
1164                 rt = net->ipv6.ip6_null_entry;
1165                 dst_hold(&rt->dst);
1166         } else {
1167                 rt = NULL;
1168         }
1169         *prt = rt;
1170         return false;
1171 }
1172
1173 /* called with rcu_lock held */
1174 static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res)
1175 {
1176         struct net_device *dev = res->nh->fib_nh_dev;
1177         struct fib6_info *f6i = res->f6i;
1178         unsigned short flags;
1179         struct rt6_info *nrt;
1180
1181         if (!fib6_info_hold_safe(f6i))
1182                 goto fallback;
1183
1184         flags = fib6_info_dst_flags(f6i);
1185         nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
1186         if (!nrt) {
1187                 fib6_info_release(f6i);
1188                 goto fallback;
1189         }
1190
1191         ip6_rt_copy_init(nrt, res);
1192         return nrt;
1193
1194 fallback:
1195         nrt = dev_net(dev)->ipv6.ip6_null_entry;
1196         dst_hold(&nrt->dst);
1197         return nrt;
1198 }
1199
1200 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net,
1201                                              struct fib6_table *table,
1202                                              struct flowi6 *fl6,
1203                                              const struct sk_buff *skb,
1204                                              int flags)
1205 {
1206         struct fib6_result res = {};
1207         struct fib6_node *fn;
1208         struct rt6_info *rt;
1209
1210         rcu_read_lock();
1211         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1212 restart:
1213         res.f6i = rcu_dereference(fn->leaf);
1214         if (!res.f6i)
1215                 res.f6i = net->ipv6.fib6_null_entry;
1216         else
1217                 rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif,
1218                                  flags);
1219
1220         if (res.f6i == net->ipv6.fib6_null_entry) {
1221                 fn = fib6_backtrack(fn, &fl6->saddr);
1222                 if (fn)
1223                         goto restart;
1224
1225                 rt = net->ipv6.ip6_null_entry;
1226                 dst_hold(&rt->dst);
1227                 goto out;
1228         } else if (res.fib6_flags & RTF_REJECT) {
1229                 goto do_create;
1230         }
1231
1232         fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
1233                          fl6->flowi6_oif != 0, skb, flags);
1234
1235         /* Search through exception table */
1236         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
1237         if (rt) {
1238                 if (ip6_hold_safe(net, &rt))
1239                         dst_use_noref(&rt->dst, jiffies);
1240         } else {
1241 do_create:
1242                 rt = ip6_create_rt_rcu(&res);
1243         }
1244
1245 out:
1246         trace_fib6_table_lookup(net, &res, table, fl6);
1247
1248         rcu_read_unlock();
1249
1250         return rt;
1251 }
1252
1253 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
1254                                    const struct sk_buff *skb, int flags)
1255 {
1256         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
1257 }
1258 EXPORT_SYMBOL_GPL(ip6_route_lookup);
1259
1260 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
1261                             const struct in6_addr *saddr, int oif,
1262                             const struct sk_buff *skb, int strict)
1263 {
1264         struct flowi6 fl6 = {
1265                 .flowi6_oif = oif,
1266                 .daddr = *daddr,
1267         };
1268         struct dst_entry *dst;
1269         int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
1270
1271         if (saddr) {
1272                 memcpy(&fl6.saddr, saddr, sizeof(*saddr));
1273                 flags |= RT6_LOOKUP_F_HAS_SADDR;
1274         }
1275
1276         dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
1277         if (dst->error == 0)
1278                 return (struct rt6_info *) dst;
1279
1280         dst_release(dst);
1281
1282         return NULL;
1283 }
1284 EXPORT_SYMBOL(rt6_lookup);
1285
1286 /* ip6_ins_rt is called with FREE table->tb6_lock.
1287  * It takes new route entry, the addition fails by any reason the
1288  * route is released.
1289  * Caller must hold dst before calling it.
1290  */
1291
1292 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
1293                         struct netlink_ext_ack *extack)
1294 {
1295         int err;
1296         struct fib6_table *table;
1297
1298         table = rt->fib6_table;
1299         spin_lock_bh(&table->tb6_lock);
1300         err = fib6_add(&table->tb6_root, rt, info, extack);
1301         spin_unlock_bh(&table->tb6_lock);
1302
1303         return err;
1304 }
1305
1306 int ip6_ins_rt(struct net *net, struct fib6_info *rt)
1307 {
1308         struct nl_info info = { .nl_net = net, };
1309
1310         return __ip6_ins_rt(rt, &info, NULL);
1311 }
1312
1313 static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res,
1314                                            const struct in6_addr *daddr,
1315                                            const struct in6_addr *saddr)
1316 {
1317         struct fib6_info *f6i = res->f6i;
1318         struct net_device *dev;
1319         struct rt6_info *rt;
1320
1321         /*
1322          *      Clone the route.
1323          */
1324
1325         if (!fib6_info_hold_safe(f6i))
1326                 return NULL;
1327
1328         dev = ip6_rt_get_dev_rcu(res);
1329         rt = ip6_dst_alloc(dev_net(dev), dev, 0);
1330         if (!rt) {
1331                 fib6_info_release(f6i);
1332                 return NULL;
1333         }
1334
1335         ip6_rt_copy_init(rt, res);
1336         rt->rt6i_flags |= RTF_CACHE;
1337         rt->rt6i_dst.addr = *daddr;
1338         rt->rt6i_dst.plen = 128;
1339
1340         if (!rt6_is_gw_or_nonexthop(res)) {
1341                 if (f6i->fib6_dst.plen != 128 &&
1342                     ipv6_addr_equal(&f6i->fib6_dst.addr, daddr))
1343                         rt->rt6i_flags |= RTF_ANYCAST;
1344 #ifdef CONFIG_IPV6_SUBTREES
1345                 if (rt->rt6i_src.plen && saddr) {
1346                         rt->rt6i_src.addr = *saddr;
1347                         rt->rt6i_src.plen = 128;
1348                 }
1349 #endif
1350         }
1351
1352         return rt;
1353 }
1354
1355 static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res)
1356 {
1357         struct fib6_info *f6i = res->f6i;
1358         unsigned short flags = fib6_info_dst_flags(f6i);
1359         struct net_device *dev;
1360         struct rt6_info *pcpu_rt;
1361
1362         if (!fib6_info_hold_safe(f6i))
1363                 return NULL;
1364
1365         rcu_read_lock();
1366         dev = ip6_rt_get_dev_rcu(res);
1367         pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT);
1368         rcu_read_unlock();
1369         if (!pcpu_rt) {
1370                 fib6_info_release(f6i);
1371                 return NULL;
1372         }
1373         ip6_rt_copy_init(pcpu_rt, res);
1374         pcpu_rt->rt6i_flags |= RTF_PCPU;
1375
1376         if (f6i->nh)
1377                 pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev));
1378
1379         return pcpu_rt;
1380 }
1381
1382 static bool rt6_is_valid(const struct rt6_info *rt6)
1383 {
1384         return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev));
1385 }
1386
1387 /* It should be called with rcu_read_lock() acquired */
1388 static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
1389 {
1390         struct rt6_info *pcpu_rt;
1391
1392         pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
1393
1394         if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) {
1395                 struct rt6_info *prev, **p;
1396
1397                 p = this_cpu_ptr(res->nh->rt6i_pcpu);
1398                 prev = xchg(p, NULL);
1399                 if (prev) {
1400                         dst_dev_put(&prev->dst);
1401                         dst_release(&prev->dst);
1402                 }
1403
1404                 pcpu_rt = NULL;
1405         }
1406
1407         return pcpu_rt;
1408 }
1409
1410 static struct rt6_info *rt6_make_pcpu_route(struct net *net,
1411                                             const struct fib6_result *res)
1412 {
1413         struct rt6_info *pcpu_rt, *prev, **p;
1414
1415         pcpu_rt = ip6_rt_pcpu_alloc(res);
1416         if (!pcpu_rt)
1417                 return NULL;
1418
1419         p = this_cpu_ptr(res->nh->rt6i_pcpu);
1420         prev = cmpxchg(p, NULL, pcpu_rt);
1421         BUG_ON(prev);
1422
1423         if (res->f6i->fib6_destroying) {
1424                 struct fib6_info *from;
1425
1426                 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
1427                 fib6_info_release(from);
1428         }
1429
1430         return pcpu_rt;
1431 }
1432
1433 /* exception hash table implementation
1434  */
1435 static DEFINE_SPINLOCK(rt6_exception_lock);
1436
1437 /* Remove rt6_ex from hash table and free the memory
1438  * Caller must hold rt6_exception_lock
1439  */
1440 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
1441                                  struct rt6_exception *rt6_ex)
1442 {
1443         struct fib6_info *from;
1444         struct net *net;
1445
1446         if (!bucket || !rt6_ex)
1447                 return;
1448
1449         net = dev_net(rt6_ex->rt6i->dst.dev);
1450         net->ipv6.rt6_stats->fib_rt_cache--;
1451
1452         /* purge completely the exception to allow releasing the held resources:
1453          * some [sk] cache may keep the dst around for unlimited time
1454          */
1455         from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL);
1456         fib6_info_release(from);
1457         dst_dev_put(&rt6_ex->rt6i->dst);
1458
1459         hlist_del_rcu(&rt6_ex->hlist);
1460         dst_release(&rt6_ex->rt6i->dst);
1461         kfree_rcu(rt6_ex, rcu);
1462         WARN_ON_ONCE(!bucket->depth);
1463         bucket->depth--;
1464 }
1465
1466 /* Remove oldest rt6_ex in bucket and free the memory
1467  * Caller must hold rt6_exception_lock
1468  */
1469 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
1470 {
1471         struct rt6_exception *rt6_ex, *oldest = NULL;
1472
1473         if (!bucket)
1474                 return;
1475
1476         hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
1477                 if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
1478                         oldest = rt6_ex;
1479         }
1480         rt6_remove_exception(bucket, oldest);
1481 }
1482
1483 static u32 rt6_exception_hash(const struct in6_addr *dst,
1484                               const struct in6_addr *src)
1485 {
1486         static siphash_aligned_key_t rt6_exception_key;
1487         struct {
1488                 struct in6_addr dst;
1489                 struct in6_addr src;
1490         } __aligned(SIPHASH_ALIGNMENT) combined = {
1491                 .dst = *dst,
1492         };
1493         u64 val;
1494
1495         net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key));
1496
1497 #ifdef CONFIG_IPV6_SUBTREES
1498         if (src)
1499                 combined.src = *src;
1500 #endif
1501         val = siphash(&combined, sizeof(combined), &rt6_exception_key);
1502
1503         return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
1504 }
1505
1506 /* Helper function to find the cached rt in the hash table
1507  * and update bucket pointer to point to the bucket for this
1508  * (daddr, saddr) pair
1509  * Caller must hold rt6_exception_lock
1510  */
1511 static struct rt6_exception *
1512 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
1513                               const struct in6_addr *daddr,
1514                               const struct in6_addr *saddr)
1515 {
1516         struct rt6_exception *rt6_ex;
1517         u32 hval;
1518
1519         if (!(*bucket) || !daddr)
1520                 return NULL;
1521
1522         hval = rt6_exception_hash(daddr, saddr);
1523         *bucket += hval;
1524
1525         hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
1526                 struct rt6_info *rt6 = rt6_ex->rt6i;
1527                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1528
1529 #ifdef CONFIG_IPV6_SUBTREES
1530                 if (matched && saddr)
1531                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1532 #endif
1533                 if (matched)
1534                         return rt6_ex;
1535         }
1536         return NULL;
1537 }
1538
1539 /* Helper function to find the cached rt in the hash table
1540  * and update bucket pointer to point to the bucket for this
1541  * (daddr, saddr) pair
1542  * Caller must hold rcu_read_lock()
1543  */
1544 static struct rt6_exception *
1545 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
1546                          const struct in6_addr *daddr,
1547                          const struct in6_addr *saddr)
1548 {
1549         struct rt6_exception *rt6_ex;
1550         u32 hval;
1551
1552         WARN_ON_ONCE(!rcu_read_lock_held());
1553
1554         if (!(*bucket) || !daddr)
1555                 return NULL;
1556
1557         hval = rt6_exception_hash(daddr, saddr);
1558         *bucket += hval;
1559
1560         hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
1561                 struct rt6_info *rt6 = rt6_ex->rt6i;
1562                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1563
1564 #ifdef CONFIG_IPV6_SUBTREES
1565                 if (matched && saddr)
1566                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1567 #endif
1568                 if (matched)
1569                         return rt6_ex;
1570         }
1571         return NULL;
1572 }
1573
1574 static unsigned int fib6_mtu(const struct fib6_result *res)
1575 {
1576         const struct fib6_nh *nh = res->nh;
1577         unsigned int mtu;
1578
1579         if (res->f6i->fib6_pmtu) {
1580                 mtu = res->f6i->fib6_pmtu;
1581         } else {
1582                 struct net_device *dev = nh->fib_nh_dev;
1583                 struct inet6_dev *idev;
1584
1585                 rcu_read_lock();
1586                 idev = __in6_dev_get(dev);
1587                 mtu = idev->cnf.mtu6;
1588                 rcu_read_unlock();
1589         }
1590
1591         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
1592
1593         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
1594 }
1595
1596 #define FIB6_EXCEPTION_BUCKET_FLUSHED  0x1UL
1597
1598 /* used when the flushed bit is not relevant, only access to the bucket
1599  * (ie., all bucket users except rt6_insert_exception);
1600  *
1601  * called under rcu lock; sometimes called with rt6_exception_lock held
1602  */
1603 static
1604 struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh,
1605                                                        spinlock_t *lock)
1606 {
1607         struct rt6_exception_bucket *bucket;
1608
1609         if (lock)
1610                 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1611                                                    lockdep_is_held(lock));
1612         else
1613                 bucket = rcu_dereference(nh->rt6i_exception_bucket);
1614
1615         /* remove bucket flushed bit if set */
1616         if (bucket) {
1617                 unsigned long p = (unsigned long)bucket;
1618
1619                 p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED;
1620                 bucket = (struct rt6_exception_bucket *)p;
1621         }
1622
1623         return bucket;
1624 }
1625
1626 static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket)
1627 {
1628         unsigned long p = (unsigned long)bucket;
1629
1630         return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED);
1631 }
1632
1633 /* called with rt6_exception_lock held */
1634 static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh,
1635                                               spinlock_t *lock)
1636 {
1637         struct rt6_exception_bucket *bucket;
1638         unsigned long p;
1639
1640         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1641                                            lockdep_is_held(lock));
1642
1643         p = (unsigned long)bucket;
1644         p |= FIB6_EXCEPTION_BUCKET_FLUSHED;
1645         bucket = (struct rt6_exception_bucket *)p;
1646         rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1647 }
1648
1649 static int rt6_insert_exception(struct rt6_info *nrt,
1650                                 const struct fib6_result *res)
1651 {
1652         struct net *net = dev_net(nrt->dst.dev);
1653         struct rt6_exception_bucket *bucket;
1654         struct fib6_info *f6i = res->f6i;
1655         struct in6_addr *src_key = NULL;
1656         struct rt6_exception *rt6_ex;
1657         struct fib6_nh *nh = res->nh;
1658         int max_depth;
1659         int err = 0;
1660
1661         spin_lock_bh(&rt6_exception_lock);
1662
1663         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1664                                           lockdep_is_held(&rt6_exception_lock));
1665         if (!bucket) {
1666                 bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
1667                                  GFP_ATOMIC);
1668                 if (!bucket) {
1669                         err = -ENOMEM;
1670                         goto out;
1671                 }
1672                 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1673         } else if (fib6_nh_excptn_bucket_flushed(bucket)) {
1674                 err = -EINVAL;
1675                 goto out;
1676         }
1677
1678 #ifdef CONFIG_IPV6_SUBTREES
1679         /* fib6_src.plen != 0 indicates f6i is in subtree
1680          * and exception table is indexed by a hash of
1681          * both fib6_dst and fib6_src.
1682          * Otherwise, the exception table is indexed by
1683          * a hash of only fib6_dst.
1684          */
1685         if (f6i->fib6_src.plen)
1686                 src_key = &nrt->rt6i_src.addr;
1687 #endif
1688         /* rt6_mtu_change() might lower mtu on f6i.
1689          * Only insert this exception route if its mtu
1690          * is less than f6i's mtu value.
1691          */
1692         if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) {
1693                 err = -EINVAL;
1694                 goto out;
1695         }
1696
1697         rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
1698                                                src_key);
1699         if (rt6_ex)
1700                 rt6_remove_exception(bucket, rt6_ex);
1701
1702         rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
1703         if (!rt6_ex) {
1704                 err = -ENOMEM;
1705                 goto out;
1706         }
1707         rt6_ex->rt6i = nrt;
1708         rt6_ex->stamp = jiffies;
1709         hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
1710         bucket->depth++;
1711         net->ipv6.rt6_stats->fib_rt_cache++;
1712
1713         /* Randomize max depth to avoid some side channels attacks. */
1714         max_depth = FIB6_MAX_DEPTH + get_random_u32_below(FIB6_MAX_DEPTH);
1715         while (bucket->depth > max_depth)
1716                 rt6_exception_remove_oldest(bucket);
1717
1718 out:
1719         spin_unlock_bh(&rt6_exception_lock);
1720
1721         /* Update fn->fn_sernum to invalidate all cached dst */
1722         if (!err) {
1723                 spin_lock_bh(&f6i->fib6_table->tb6_lock);
1724                 fib6_update_sernum(net, f6i);
1725                 spin_unlock_bh(&f6i->fib6_table->tb6_lock);
1726                 fib6_force_start_gc(net);
1727         }
1728
1729         return err;
1730 }
1731
1732 static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
1733 {
1734         struct rt6_exception_bucket *bucket;
1735         struct rt6_exception *rt6_ex;
1736         struct hlist_node *tmp;
1737         int i;
1738
1739         spin_lock_bh(&rt6_exception_lock);
1740
1741         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1742         if (!bucket)
1743                 goto out;
1744
1745         /* Prevent rt6_insert_exception() to recreate the bucket list */
1746         if (!from)
1747                 fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock);
1748
1749         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1750                 hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) {
1751                         if (!from ||
1752                             rcu_access_pointer(rt6_ex->rt6i->from) == from)
1753                                 rt6_remove_exception(bucket, rt6_ex);
1754                 }
1755                 WARN_ON_ONCE(!from && bucket->depth);
1756                 bucket++;
1757         }
1758 out:
1759         spin_unlock_bh(&rt6_exception_lock);
1760 }
1761
1762 static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg)
1763 {
1764         struct fib6_info *f6i = arg;
1765
1766         fib6_nh_flush_exceptions(nh, f6i);
1767
1768         return 0;
1769 }
1770
1771 void rt6_flush_exceptions(struct fib6_info *f6i)
1772 {
1773         if (f6i->nh)
1774                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions,
1775                                          f6i);
1776         else
1777                 fib6_nh_flush_exceptions(f6i->fib6_nh, f6i);
1778 }
1779
1780 /* Find cached rt in the hash table inside passed in rt
1781  * Caller has to hold rcu_read_lock()
1782  */
1783 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
1784                                            const struct in6_addr *daddr,
1785                                            const struct in6_addr *saddr)
1786 {
1787         const struct in6_addr *src_key = NULL;
1788         struct rt6_exception_bucket *bucket;
1789         struct rt6_exception *rt6_ex;
1790         struct rt6_info *ret = NULL;
1791
1792 #ifdef CONFIG_IPV6_SUBTREES
1793         /* fib6i_src.plen != 0 indicates f6i is in subtree
1794          * and exception table is indexed by a hash of
1795          * both fib6_dst and fib6_src.
1796          * However, the src addr used to create the hash
1797          * might not be exactly the passed in saddr which
1798          * is a /128 addr from the flow.
1799          * So we need to use f6i->fib6_src to redo lookup
1800          * if the passed in saddr does not find anything.
1801          * (See the logic in ip6_rt_cache_alloc() on how
1802          * rt->rt6i_src is updated.)
1803          */
1804         if (res->f6i->fib6_src.plen)
1805                 src_key = saddr;
1806 find_ex:
1807 #endif
1808         bucket = fib6_nh_get_excptn_bucket(res->nh, NULL);
1809         rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
1810
1811         if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
1812                 ret = rt6_ex->rt6i;
1813
1814 #ifdef CONFIG_IPV6_SUBTREES
1815         /* Use fib6_src as src_key and redo lookup */
1816         if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) {
1817                 src_key = &res->f6i->fib6_src.addr;
1818                 goto find_ex;
1819         }
1820 #endif
1821
1822         return ret;
1823 }
1824
1825 /* Remove the passed in cached rt from the hash table that contains it */
1826 static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen,
1827                                     const struct rt6_info *rt)
1828 {
1829         const struct in6_addr *src_key = NULL;
1830         struct rt6_exception_bucket *bucket;
1831         struct rt6_exception *rt6_ex;
1832         int err;
1833
1834         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
1835                 return -ENOENT;
1836
1837         spin_lock_bh(&rt6_exception_lock);
1838         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1839
1840 #ifdef CONFIG_IPV6_SUBTREES
1841         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1842          * and exception table is indexed by a hash of
1843          * both rt6i_dst and rt6i_src.
1844          * Otherwise, the exception table is indexed by
1845          * a hash of only rt6i_dst.
1846          */
1847         if (plen)
1848                 src_key = &rt->rt6i_src.addr;
1849 #endif
1850         rt6_ex = __rt6_find_exception_spinlock(&bucket,
1851                                                &rt->rt6i_dst.addr,
1852                                                src_key);
1853         if (rt6_ex) {
1854                 rt6_remove_exception(bucket, rt6_ex);
1855                 err = 0;
1856         } else {
1857                 err = -ENOENT;
1858         }
1859
1860         spin_unlock_bh(&rt6_exception_lock);
1861         return err;
1862 }
1863
1864 struct fib6_nh_excptn_arg {
1865         struct rt6_info *rt;
1866         int             plen;
1867 };
1868
1869 static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg)
1870 {
1871         struct fib6_nh_excptn_arg *arg = _arg;
1872         int err;
1873
1874         err = fib6_nh_remove_exception(nh, arg->plen, arg->rt);
1875         if (err == 0)
1876                 return 1;
1877
1878         return 0;
1879 }
1880
1881 static int rt6_remove_exception_rt(struct rt6_info *rt)
1882 {
1883         struct fib6_info *from;
1884
1885         from = rcu_dereference(rt->from);
1886         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1887                 return -EINVAL;
1888
1889         if (from->nh) {
1890                 struct fib6_nh_excptn_arg arg = {
1891                         .rt = rt,
1892                         .plen = from->fib6_src.plen
1893                 };
1894                 int rc;
1895
1896                 /* rc = 1 means an entry was found */
1897                 rc = nexthop_for_each_fib6_nh(from->nh,
1898                                               rt6_nh_remove_exception_rt,
1899                                               &arg);
1900                 return rc ? 0 : -ENOENT;
1901         }
1902
1903         return fib6_nh_remove_exception(from->fib6_nh,
1904                                         from->fib6_src.plen, rt);
1905 }
1906
1907 /* Find rt6_ex which contains the passed in rt cache and
1908  * refresh its stamp
1909  */
1910 static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen,
1911                                      const struct rt6_info *rt)
1912 {
1913         const struct in6_addr *src_key = NULL;
1914         struct rt6_exception_bucket *bucket;
1915         struct rt6_exception *rt6_ex;
1916
1917         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
1918 #ifdef CONFIG_IPV6_SUBTREES
1919         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1920          * and exception table is indexed by a hash of
1921          * both rt6i_dst and rt6i_src.
1922          * Otherwise, the exception table is indexed by
1923          * a hash of only rt6i_dst.
1924          */
1925         if (plen)
1926                 src_key = &rt->rt6i_src.addr;
1927 #endif
1928         rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
1929         if (rt6_ex)
1930                 rt6_ex->stamp = jiffies;
1931 }
1932
1933 struct fib6_nh_match_arg {
1934         const struct net_device *dev;
1935         const struct in6_addr   *gw;
1936         struct fib6_nh          *match;
1937 };
1938
1939 /* determine if fib6_nh has given device and gateway */
1940 static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg)
1941 {
1942         struct fib6_nh_match_arg *arg = _arg;
1943
1944         if (arg->dev != nh->fib_nh_dev ||
1945             (arg->gw && !nh->fib_nh_gw_family) ||
1946             (!arg->gw && nh->fib_nh_gw_family) ||
1947             (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6)))
1948                 return 0;
1949
1950         arg->match = nh;
1951
1952         /* found a match, break the loop */
1953         return 1;
1954 }
1955
1956 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
1957 {
1958         struct fib6_info *from;
1959         struct fib6_nh *fib6_nh;
1960
1961         rcu_read_lock();
1962
1963         from = rcu_dereference(rt->from);
1964         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1965                 goto unlock;
1966
1967         if (from->nh) {
1968                 struct fib6_nh_match_arg arg = {
1969                         .dev = rt->dst.dev,
1970                         .gw = &rt->rt6i_gateway,
1971                 };
1972
1973                 nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
1974
1975                 if (!arg.match)
1976                         goto unlock;
1977                 fib6_nh = arg.match;
1978         } else {
1979                 fib6_nh = from->fib6_nh;
1980         }
1981         fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt);
1982 unlock:
1983         rcu_read_unlock();
1984 }
1985
1986 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
1987                                          struct rt6_info *rt, int mtu)
1988 {
1989         /* If the new MTU is lower than the route PMTU, this new MTU will be the
1990          * lowest MTU in the path: always allow updating the route PMTU to
1991          * reflect PMTU decreases.
1992          *
1993          * If the new MTU is higher, and the route PMTU is equal to the local
1994          * MTU, this means the old MTU is the lowest in the path, so allow
1995          * updating it: if other nodes now have lower MTUs, PMTU discovery will
1996          * handle this.
1997          */
1998
1999         if (dst_mtu(&rt->dst) >= mtu)
2000                 return true;
2001
2002         if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
2003                 return true;
2004
2005         return false;
2006 }
2007
2008 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
2009                                        const struct fib6_nh *nh, int mtu)
2010 {
2011         struct rt6_exception_bucket *bucket;
2012         struct rt6_exception *rt6_ex;
2013         int i;
2014
2015         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2016         if (!bucket)
2017                 return;
2018
2019         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2020                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
2021                         struct rt6_info *entry = rt6_ex->rt6i;
2022
2023                         /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
2024                          * route), the metrics of its rt->from have already
2025                          * been updated.
2026                          */
2027                         if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
2028                             rt6_mtu_change_route_allowed(idev, entry, mtu))
2029                                 dst_metric_set(&entry->dst, RTAX_MTU, mtu);
2030                 }
2031                 bucket++;
2032         }
2033 }
2034
2035 #define RTF_CACHE_GATEWAY       (RTF_GATEWAY | RTF_CACHE)
2036
2037 static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh,
2038                                             const struct in6_addr *gateway)
2039 {
2040         struct rt6_exception_bucket *bucket;
2041         struct rt6_exception *rt6_ex;
2042         struct hlist_node *tmp;
2043         int i;
2044
2045         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2046                 return;
2047
2048         spin_lock_bh(&rt6_exception_lock);
2049         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2050         if (bucket) {
2051                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2052                         hlist_for_each_entry_safe(rt6_ex, tmp,
2053                                                   &bucket->chain, hlist) {
2054                                 struct rt6_info *entry = rt6_ex->rt6i;
2055
2056                                 if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
2057                                     RTF_CACHE_GATEWAY &&
2058                                     ipv6_addr_equal(gateway,
2059                                                     &entry->rt6i_gateway)) {
2060                                         rt6_remove_exception(bucket, rt6_ex);
2061                                 }
2062                         }
2063                         bucket++;
2064                 }
2065         }
2066
2067         spin_unlock_bh(&rt6_exception_lock);
2068 }
2069
2070 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
2071                                       struct rt6_exception *rt6_ex,
2072                                       struct fib6_gc_args *gc_args,
2073                                       unsigned long now)
2074 {
2075         struct rt6_info *rt = rt6_ex->rt6i;
2076
2077         /* we are pruning and obsoleting aged-out and non gateway exceptions
2078          * even if others have still references to them, so that on next
2079          * dst_check() such references can be dropped.
2080          * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
2081          * expired, independently from their aging, as per RFC 8201 section 4
2082          */
2083         if (!(rt->rt6i_flags & RTF_EXPIRES)) {
2084                 if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
2085                         RT6_TRACE("aging clone %p\n", rt);
2086                         rt6_remove_exception(bucket, rt6_ex);
2087                         return;
2088                 }
2089         } else if (time_after(jiffies, rt->dst.expires)) {
2090                 RT6_TRACE("purging expired route %p\n", rt);
2091                 rt6_remove_exception(bucket, rt6_ex);
2092                 return;
2093         }
2094
2095         if (rt->rt6i_flags & RTF_GATEWAY) {
2096                 struct neighbour *neigh;
2097
2098                 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
2099
2100                 if (!(neigh && (neigh->flags & NTF_ROUTER))) {
2101                         RT6_TRACE("purging route %p via non-router but gateway\n",
2102                                   rt);
2103                         rt6_remove_exception(bucket, rt6_ex);
2104                         return;
2105                 }
2106         }
2107
2108         gc_args->more++;
2109 }
2110
2111 static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
2112                                    struct fib6_gc_args *gc_args,
2113                                    unsigned long now)
2114 {
2115         struct rt6_exception_bucket *bucket;
2116         struct rt6_exception *rt6_ex;
2117         struct hlist_node *tmp;
2118         int i;
2119
2120         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2121                 return;
2122
2123         rcu_read_lock_bh();
2124         spin_lock(&rt6_exception_lock);
2125         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2126         if (bucket) {
2127                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2128                         hlist_for_each_entry_safe(rt6_ex, tmp,
2129                                                   &bucket->chain, hlist) {
2130                                 rt6_age_examine_exception(bucket, rt6_ex,
2131                                                           gc_args, now);
2132                         }
2133                         bucket++;
2134                 }
2135         }
2136         spin_unlock(&rt6_exception_lock);
2137         rcu_read_unlock_bh();
2138 }
2139
2140 struct fib6_nh_age_excptn_arg {
2141         struct fib6_gc_args     *gc_args;
2142         unsigned long           now;
2143 };
2144
2145 static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg)
2146 {
2147         struct fib6_nh_age_excptn_arg *arg = _arg;
2148
2149         fib6_nh_age_exceptions(nh, arg->gc_args, arg->now);
2150         return 0;
2151 }
2152
2153 void rt6_age_exceptions(struct fib6_info *f6i,
2154                         struct fib6_gc_args *gc_args,
2155                         unsigned long now)
2156 {
2157         if (f6i->nh) {
2158                 struct fib6_nh_age_excptn_arg arg = {
2159                         .gc_args = gc_args,
2160                         .now = now
2161                 };
2162
2163                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions,
2164                                          &arg);
2165         } else {
2166                 fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now);
2167         }
2168 }
2169
2170 /* must be called with rcu lock held */
2171 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
2172                       struct flowi6 *fl6, struct fib6_result *res, int strict)
2173 {
2174         struct fib6_node *fn, *saved_fn;
2175
2176         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
2177         saved_fn = fn;
2178
2179 redo_rt6_select:
2180         rt6_select(net, fn, oif, res, strict);
2181         if (res->f6i == net->ipv6.fib6_null_entry) {
2182                 fn = fib6_backtrack(fn, &fl6->saddr);
2183                 if (fn)
2184                         goto redo_rt6_select;
2185                 else if (strict & RT6_LOOKUP_F_REACHABLE) {
2186                         /* also consider unreachable route */
2187                         strict &= ~RT6_LOOKUP_F_REACHABLE;
2188                         fn = saved_fn;
2189                         goto redo_rt6_select;
2190                 }
2191         }
2192
2193         trace_fib6_table_lookup(net, res, table, fl6);
2194
2195         return 0;
2196 }
2197
2198 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
2199                                int oif, struct flowi6 *fl6,
2200                                const struct sk_buff *skb, int flags)
2201 {
2202         struct fib6_result res = {};
2203         struct rt6_info *rt = NULL;
2204         int strict = 0;
2205
2206         WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
2207                      !rcu_read_lock_held());
2208
2209         strict |= flags & RT6_LOOKUP_F_IFACE;
2210         strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
2211         if (net->ipv6.devconf_all->forwarding == 0)
2212                 strict |= RT6_LOOKUP_F_REACHABLE;
2213
2214         rcu_read_lock();
2215
2216         fib6_table_lookup(net, table, oif, fl6, &res, strict);
2217         if (res.f6i == net->ipv6.fib6_null_entry)
2218                 goto out;
2219
2220         fib6_select_path(net, &res, fl6, oif, false, skb, strict);
2221
2222         /*Search through exception table */
2223         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
2224         if (rt) {
2225                 goto out;
2226         } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
2227                             !res.nh->fib_nh_gw_family)) {
2228                 /* Create a RTF_CACHE clone which will not be
2229                  * owned by the fib6 tree.  It is for the special case where
2230                  * the daddr in the skb during the neighbor look-up is different
2231                  * from the fl6->daddr used to look-up route here.
2232                  */
2233                 rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
2234
2235                 if (rt) {
2236                         /* 1 refcnt is taken during ip6_rt_cache_alloc().
2237                          * As rt6_uncached_list_add() does not consume refcnt,
2238                          * this refcnt is always returned to the caller even
2239                          * if caller sets RT6_LOOKUP_F_DST_NOREF flag.
2240                          */
2241                         rt6_uncached_list_add(rt);
2242                         rcu_read_unlock();
2243
2244                         return rt;
2245                 }
2246         } else {
2247                 /* Get a percpu copy */
2248                 local_bh_disable();
2249                 rt = rt6_get_pcpu_route(&res);
2250
2251                 if (!rt)
2252                         rt = rt6_make_pcpu_route(net, &res);
2253
2254                 local_bh_enable();
2255         }
2256 out:
2257         if (!rt)
2258                 rt = net->ipv6.ip6_null_entry;
2259         if (!(flags & RT6_LOOKUP_F_DST_NOREF))
2260                 ip6_hold_safe(net, &rt);
2261         rcu_read_unlock();
2262
2263         return rt;
2264 }
2265 EXPORT_SYMBOL_GPL(ip6_pol_route);
2266
2267 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net,
2268                                             struct fib6_table *table,
2269                                             struct flowi6 *fl6,
2270                                             const struct sk_buff *skb,
2271                                             int flags)
2272 {
2273         return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
2274 }
2275
2276 struct dst_entry *ip6_route_input_lookup(struct net *net,
2277                                          struct net_device *dev,
2278                                          struct flowi6 *fl6,
2279                                          const struct sk_buff *skb,
2280                                          int flags)
2281 {
2282         if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
2283                 flags |= RT6_LOOKUP_F_IFACE;
2284
2285         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
2286 }
2287 EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
2288
2289 static void ip6_multipath_l3_keys(const struct sk_buff *skb,
2290                                   struct flow_keys *keys,
2291                                   struct flow_keys *flkeys)
2292 {
2293         const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
2294         const struct ipv6hdr *key_iph = outer_iph;
2295         struct flow_keys *_flkeys = flkeys;
2296         const struct ipv6hdr *inner_iph;
2297         const struct icmp6hdr *icmph;
2298         struct ipv6hdr _inner_iph;
2299         struct icmp6hdr _icmph;
2300
2301         if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
2302                 goto out;
2303
2304         icmph = skb_header_pointer(skb, skb_transport_offset(skb),
2305                                    sizeof(_icmph), &_icmph);
2306         if (!icmph)
2307                 goto out;
2308
2309         if (!icmpv6_is_err(icmph->icmp6_type))
2310                 goto out;
2311
2312         inner_iph = skb_header_pointer(skb,
2313                                        skb_transport_offset(skb) + sizeof(*icmph),
2314                                        sizeof(_inner_iph), &_inner_iph);
2315         if (!inner_iph)
2316                 goto out;
2317
2318         key_iph = inner_iph;
2319         _flkeys = NULL;
2320 out:
2321         if (_flkeys) {
2322                 keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
2323                 keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
2324                 keys->tags.flow_label = _flkeys->tags.flow_label;
2325                 keys->basic.ip_proto = _flkeys->basic.ip_proto;
2326         } else {
2327                 keys->addrs.v6addrs.src = key_iph->saddr;
2328                 keys->addrs.v6addrs.dst = key_iph->daddr;
2329                 keys->tags.flow_label = ip6_flowlabel(key_iph);
2330                 keys->basic.ip_proto = key_iph->nexthdr;
2331         }
2332 }
2333
2334 static u32 rt6_multipath_custom_hash_outer(const struct net *net,
2335                                            const struct sk_buff *skb,
2336                                            bool *p_has_inner)
2337 {
2338         u32 hash_fields = ip6_multipath_hash_fields(net);
2339         struct flow_keys keys, hash_keys;
2340
2341         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2342                 return 0;
2343
2344         memset(&hash_keys, 0, sizeof(hash_keys));
2345         skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
2346
2347         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2348         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2349                 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2350         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2351                 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2352         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2353                 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2354         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2355                 hash_keys.tags.flow_label = keys.tags.flow_label;
2356         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2357                 hash_keys.ports.src = keys.ports.src;
2358         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2359                 hash_keys.ports.dst = keys.ports.dst;
2360
2361         *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
2362         return flow_hash_from_keys(&hash_keys);
2363 }
2364
2365 static u32 rt6_multipath_custom_hash_inner(const struct net *net,
2366                                            const struct sk_buff *skb,
2367                                            bool has_inner)
2368 {
2369         u32 hash_fields = ip6_multipath_hash_fields(net);
2370         struct flow_keys keys, hash_keys;
2371
2372         /* We assume the packet carries an encapsulation, but if none was
2373          * encountered during dissection of the outer flow, then there is no
2374          * point in calling the flow dissector again.
2375          */
2376         if (!has_inner)
2377                 return 0;
2378
2379         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
2380                 return 0;
2381
2382         memset(&hash_keys, 0, sizeof(hash_keys));
2383         skb_flow_dissect_flow_keys(skb, &keys, 0);
2384
2385         if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
2386                 return 0;
2387
2388         if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2389                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2390                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2391                         hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2392                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2393                         hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2394         } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2395                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2396                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2397                         hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2398                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2399                         hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2400                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
2401                         hash_keys.tags.flow_label = keys.tags.flow_label;
2402         }
2403
2404         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
2405                 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2406         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
2407                 hash_keys.ports.src = keys.ports.src;
2408         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
2409                 hash_keys.ports.dst = keys.ports.dst;
2410
2411         return flow_hash_from_keys(&hash_keys);
2412 }
2413
2414 static u32 rt6_multipath_custom_hash_skb(const struct net *net,
2415                                          const struct sk_buff *skb)
2416 {
2417         u32 mhash, mhash_inner;
2418         bool has_inner = true;
2419
2420         mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner);
2421         mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner);
2422
2423         return jhash_2words(mhash, mhash_inner, 0);
2424 }
2425
2426 static u32 rt6_multipath_custom_hash_fl6(const struct net *net,
2427                                          const struct flowi6 *fl6)
2428 {
2429         u32 hash_fields = ip6_multipath_hash_fields(net);
2430         struct flow_keys hash_keys;
2431
2432         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2433                 return 0;
2434
2435         memset(&hash_keys, 0, sizeof(hash_keys));
2436         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2437         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2438                 hash_keys.addrs.v6addrs.src = fl6->saddr;
2439         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2440                 hash_keys.addrs.v6addrs.dst = fl6->daddr;
2441         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2442                 hash_keys.basic.ip_proto = fl6->flowi6_proto;
2443         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2444                 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2445         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2446                 hash_keys.ports.src = fl6->fl6_sport;
2447         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2448                 hash_keys.ports.dst = fl6->fl6_dport;
2449
2450         return flow_hash_from_keys(&hash_keys);
2451 }
2452
2453 /* if skb is set it will be used and fl6 can be NULL */
2454 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
2455                        const struct sk_buff *skb, struct flow_keys *flkeys)
2456 {
2457         struct flow_keys hash_keys;
2458         u32 mhash = 0;
2459
2460         switch (ip6_multipath_hash_policy(net)) {
2461         case 0:
2462                 memset(&hash_keys, 0, sizeof(hash_keys));
2463                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2464                 if (skb) {
2465                         ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2466                 } else {
2467                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2468                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2469                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2470                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2471                 }
2472                 mhash = flow_hash_from_keys(&hash_keys);
2473                 break;
2474         case 1:
2475                 if (skb) {
2476                         unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2477                         struct flow_keys keys;
2478
2479                         /* short-circuit if we already have L4 hash present */
2480                         if (skb->l4_hash)
2481                                 return skb_get_hash_raw(skb) >> 1;
2482
2483                         memset(&hash_keys, 0, sizeof(hash_keys));
2484
2485                         if (!flkeys) {
2486                                 skb_flow_dissect_flow_keys(skb, &keys, flag);
2487                                 flkeys = &keys;
2488                         }
2489                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2490                         hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2491                         hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2492                         hash_keys.ports.src = flkeys->ports.src;
2493                         hash_keys.ports.dst = flkeys->ports.dst;
2494                         hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2495                 } else {
2496                         memset(&hash_keys, 0, sizeof(hash_keys));
2497                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2498                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2499                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2500                         hash_keys.ports.src = fl6->fl6_sport;
2501                         hash_keys.ports.dst = fl6->fl6_dport;
2502                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2503                 }
2504                 mhash = flow_hash_from_keys(&hash_keys);
2505                 break;
2506         case 2:
2507                 memset(&hash_keys, 0, sizeof(hash_keys));
2508                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2509                 if (skb) {
2510                         struct flow_keys keys;
2511
2512                         if (!flkeys) {
2513                                 skb_flow_dissect_flow_keys(skb, &keys, 0);
2514                                 flkeys = &keys;
2515                         }
2516
2517                         /* Inner can be v4 or v6 */
2518                         if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2519                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2520                                 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2521                                 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2522                         } else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2523                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2524                                 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2525                                 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2526                                 hash_keys.tags.flow_label = flkeys->tags.flow_label;
2527                                 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2528                         } else {
2529                                 /* Same as case 0 */
2530                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2531                                 ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2532                         }
2533                 } else {
2534                         /* Same as case 0 */
2535                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2536                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2537                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2538                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2539                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2540                 }
2541                 mhash = flow_hash_from_keys(&hash_keys);
2542                 break;
2543         case 3:
2544                 if (skb)
2545                         mhash = rt6_multipath_custom_hash_skb(net, skb);
2546                 else
2547                         mhash = rt6_multipath_custom_hash_fl6(net, fl6);
2548                 break;
2549         }
2550
2551         return mhash >> 1;
2552 }
2553
2554 /* Called with rcu held */
2555 void ip6_route_input(struct sk_buff *skb)
2556 {
2557         const struct ipv6hdr *iph = ipv6_hdr(skb);
2558         struct net *net = dev_net(skb->dev);
2559         int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF;
2560         struct ip_tunnel_info *tun_info;
2561         struct flowi6 fl6 = {
2562                 .flowi6_iif = skb->dev->ifindex,
2563                 .daddr = iph->daddr,
2564                 .saddr = iph->saddr,
2565                 .flowlabel = ip6_flowinfo(iph),
2566                 .flowi6_mark = skb->mark,
2567                 .flowi6_proto = iph->nexthdr,
2568         };
2569         struct flow_keys *flkeys = NULL, _flkeys;
2570
2571         tun_info = skb_tunnel_info(skb);
2572         if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2573                 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
2574
2575         if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
2576                 flkeys = &_flkeys;
2577
2578         if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
2579                 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
2580         skb_dst_drop(skb);
2581         skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev,
2582                                                       &fl6, skb, flags));
2583 }
2584
2585 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net,
2586                                              struct fib6_table *table,
2587                                              struct flowi6 *fl6,
2588                                              const struct sk_buff *skb,
2589                                              int flags)
2590 {
2591         return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
2592 }
2593
2594 static struct dst_entry *ip6_route_output_flags_noref(struct net *net,
2595                                                       const struct sock *sk,
2596                                                       struct flowi6 *fl6,
2597                                                       int flags)
2598 {
2599         bool any_src;
2600
2601         if (ipv6_addr_type(&fl6->daddr) &
2602             (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
2603                 struct dst_entry *dst;
2604
2605                 /* This function does not take refcnt on the dst */
2606                 dst = l3mdev_link_scope_lookup(net, fl6);
2607                 if (dst)
2608                         return dst;
2609         }
2610
2611         fl6->flowi6_iif = LOOPBACK_IFINDEX;
2612
2613         flags |= RT6_LOOKUP_F_DST_NOREF;
2614         any_src = ipv6_addr_any(&fl6->saddr);
2615         if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
2616             (fl6->flowi6_oif && any_src))
2617                 flags |= RT6_LOOKUP_F_IFACE;
2618
2619         if (!any_src)
2620                 flags |= RT6_LOOKUP_F_HAS_SADDR;
2621         else if (sk)
2622                 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
2623
2624         return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
2625 }
2626
2627 struct dst_entry *ip6_route_output_flags(struct net *net,
2628                                          const struct sock *sk,
2629                                          struct flowi6 *fl6,
2630                                          int flags)
2631 {
2632         struct dst_entry *dst;
2633         struct rt6_info *rt6;
2634
2635         rcu_read_lock();
2636         dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
2637         rt6 = (struct rt6_info *)dst;
2638         /* For dst cached in uncached_list, refcnt is already taken. */
2639         if (list_empty(&rt6->dst.rt_uncached) && !dst_hold_safe(dst)) {
2640                 dst = &net->ipv6.ip6_null_entry->dst;
2641                 dst_hold(dst);
2642         }
2643         rcu_read_unlock();
2644
2645         return dst;
2646 }
2647 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
2648
2649 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2650 {
2651         struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
2652         struct net_device *loopback_dev = net->loopback_dev;
2653         struct dst_entry *new = NULL;
2654
2655         rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
2656                        DST_OBSOLETE_DEAD, 0);
2657         if (rt) {
2658                 rt6_info_init(rt);
2659                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
2660
2661                 new = &rt->dst;
2662                 new->__use = 1;
2663                 new->input = dst_discard;
2664                 new->output = dst_discard_out;
2665
2666                 dst_copy_metrics(new, &ort->dst);
2667
2668                 rt->rt6i_idev = in6_dev_get(loopback_dev);
2669                 rt->rt6i_gateway = ort->rt6i_gateway;
2670                 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
2671
2672                 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
2673 #ifdef CONFIG_IPV6_SUBTREES
2674                 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
2675 #endif
2676         }
2677
2678         dst_release(dst_orig);
2679         return new ? new : ERR_PTR(-ENOMEM);
2680 }
2681
2682 /*
2683  *      Destination cache support functions
2684  */
2685
2686 static bool fib6_check(struct fib6_info *f6i, u32 cookie)
2687 {
2688         u32 rt_cookie = 0;
2689
2690         if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
2691                 return false;
2692
2693         if (fib6_check_expired(f6i))
2694                 return false;
2695
2696         return true;
2697 }
2698
2699 static struct dst_entry *rt6_check(struct rt6_info *rt,
2700                                    struct fib6_info *from,
2701                                    u32 cookie)
2702 {
2703         u32 rt_cookie = 0;
2704
2705         if (!from || !fib6_get_cookie_safe(from, &rt_cookie) ||
2706             rt_cookie != cookie)
2707                 return NULL;
2708
2709         if (rt6_check_expired(rt))
2710                 return NULL;
2711
2712         return &rt->dst;
2713 }
2714
2715 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
2716                                             struct fib6_info *from,
2717                                             u32 cookie)
2718 {
2719         if (!__rt6_check_expired(rt) &&
2720             rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
2721             fib6_check(from, cookie))
2722                 return &rt->dst;
2723         else
2724                 return NULL;
2725 }
2726
2727 INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst,
2728                                                         u32 cookie)
2729 {
2730         struct dst_entry *dst_ret;
2731         struct fib6_info *from;
2732         struct rt6_info *rt;
2733
2734         rt = container_of(dst, struct rt6_info, dst);
2735
2736         if (rt->sernum)
2737                 return rt6_is_valid(rt) ? dst : NULL;
2738
2739         rcu_read_lock();
2740
2741         /* All IPV6 dsts are created with ->obsolete set to the value
2742          * DST_OBSOLETE_FORCE_CHK which forces validation calls down
2743          * into this function always.
2744          */
2745
2746         from = rcu_dereference(rt->from);
2747
2748         if (from && (rt->rt6i_flags & RTF_PCPU ||
2749             unlikely(!list_empty(&rt->dst.rt_uncached))))
2750                 dst_ret = rt6_dst_from_check(rt, from, cookie);
2751         else
2752                 dst_ret = rt6_check(rt, from, cookie);
2753
2754         rcu_read_unlock();
2755
2756         return dst_ret;
2757 }
2758 EXPORT_INDIRECT_CALLABLE(ip6_dst_check);
2759
2760 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
2761 {
2762         struct rt6_info *rt = (struct rt6_info *) dst;
2763
2764         if (rt) {
2765                 if (rt->rt6i_flags & RTF_CACHE) {
2766                         rcu_read_lock();
2767                         if (rt6_check_expired(rt)) {
2768                                 rt6_remove_exception_rt(rt);
2769                                 dst = NULL;
2770                         }
2771                         rcu_read_unlock();
2772                 } else {
2773                         dst_release(dst);
2774                         dst = NULL;
2775                 }
2776         }
2777         return dst;
2778 }
2779
2780 static void ip6_link_failure(struct sk_buff *skb)
2781 {
2782         struct rt6_info *rt;
2783
2784         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
2785
2786         rt = (struct rt6_info *) skb_dst(skb);
2787         if (rt) {
2788                 rcu_read_lock();
2789                 if (rt->rt6i_flags & RTF_CACHE) {
2790                         rt6_remove_exception_rt(rt);
2791                 } else {
2792                         struct fib6_info *from;
2793                         struct fib6_node *fn;
2794
2795                         from = rcu_dereference(rt->from);
2796                         if (from) {
2797                                 fn = rcu_dereference(from->fib6_node);
2798                                 if (fn && (rt->rt6i_flags & RTF_DEFAULT))
2799                                         WRITE_ONCE(fn->fn_sernum, -1);
2800                         }
2801                 }
2802                 rcu_read_unlock();
2803         }
2804 }
2805
2806 static void rt6_update_expires(struct rt6_info *rt0, int timeout)
2807 {
2808         if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
2809                 struct fib6_info *from;
2810
2811                 rcu_read_lock();
2812                 from = rcu_dereference(rt0->from);
2813                 if (from)
2814                         rt0->dst.expires = from->expires;
2815                 rcu_read_unlock();
2816         }
2817
2818         dst_set_expires(&rt0->dst, timeout);
2819         rt0->rt6i_flags |= RTF_EXPIRES;
2820 }
2821
2822 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
2823 {
2824         struct net *net = dev_net(rt->dst.dev);
2825
2826         dst_metric_set(&rt->dst, RTAX_MTU, mtu);
2827         rt->rt6i_flags |= RTF_MODIFIED;
2828         rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
2829 }
2830
2831 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
2832 {
2833         return !(rt->rt6i_flags & RTF_CACHE) &&
2834                 (rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
2835 }
2836
2837 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
2838                                  const struct ipv6hdr *iph, u32 mtu,
2839                                  bool confirm_neigh)
2840 {
2841         const struct in6_addr *daddr, *saddr;
2842         struct rt6_info *rt6 = (struct rt6_info *)dst;
2843
2844         /* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU)
2845          * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it.
2846          * [see also comment in rt6_mtu_change_route()]
2847          */
2848
2849         if (iph) {
2850                 daddr = &iph->daddr;
2851                 saddr = &iph->saddr;
2852         } else if (sk) {
2853                 daddr = &sk->sk_v6_daddr;
2854                 saddr = &inet6_sk(sk)->saddr;
2855         } else {
2856                 daddr = NULL;
2857                 saddr = NULL;
2858         }
2859
2860         if (confirm_neigh)
2861                 dst_confirm_neigh(dst, daddr);
2862
2863         if (mtu < IPV6_MIN_MTU)
2864                 return;
2865         if (mtu >= dst_mtu(dst))
2866                 return;
2867
2868         if (!rt6_cache_allowed_for_pmtu(rt6)) {
2869                 rt6_do_update_pmtu(rt6, mtu);
2870                 /* update rt6_ex->stamp for cache */
2871                 if (rt6->rt6i_flags & RTF_CACHE)
2872                         rt6_update_exception_stamp_rt(rt6);
2873         } else if (daddr) {
2874                 struct fib6_result res = {};
2875                 struct rt6_info *nrt6;
2876
2877                 rcu_read_lock();
2878                 res.f6i = rcu_dereference(rt6->from);
2879                 if (!res.f6i)
2880                         goto out_unlock;
2881
2882                 res.fib6_flags = res.f6i->fib6_flags;
2883                 res.fib6_type = res.f6i->fib6_type;
2884
2885                 if (res.f6i->nh) {
2886                         struct fib6_nh_match_arg arg = {
2887                                 .dev = dst->dev,
2888                                 .gw = &rt6->rt6i_gateway,
2889                         };
2890
2891                         nexthop_for_each_fib6_nh(res.f6i->nh,
2892                                                  fib6_nh_find_match, &arg);
2893
2894                         /* fib6_info uses a nexthop that does not have fib6_nh
2895                          * using the dst->dev + gw. Should be impossible.
2896                          */
2897                         if (!arg.match)
2898                                 goto out_unlock;
2899
2900                         res.nh = arg.match;
2901                 } else {
2902                         res.nh = res.f6i->fib6_nh;
2903                 }
2904
2905                 nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
2906                 if (nrt6) {
2907                         rt6_do_update_pmtu(nrt6, mtu);
2908                         if (rt6_insert_exception(nrt6, &res))
2909                                 dst_release_immediate(&nrt6->dst);
2910                 }
2911 out_unlock:
2912                 rcu_read_unlock();
2913         }
2914 }
2915
2916 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
2917                                struct sk_buff *skb, u32 mtu,
2918                                bool confirm_neigh)
2919 {
2920         __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu,
2921                              confirm_neigh);
2922 }
2923
2924 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
2925                      int oif, u32 mark, kuid_t uid)
2926 {
2927         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2928         struct dst_entry *dst;
2929         struct flowi6 fl6 = {
2930                 .flowi6_oif = oif,
2931                 .flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
2932                 .daddr = iph->daddr,
2933                 .saddr = iph->saddr,
2934                 .flowlabel = ip6_flowinfo(iph),
2935                 .flowi6_uid = uid,
2936         };
2937
2938         dst = ip6_route_output(net, NULL, &fl6);
2939         if (!dst->error)
2940                 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true);
2941         dst_release(dst);
2942 }
2943 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
2944
2945 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
2946 {
2947         int oif = sk->sk_bound_dev_if;
2948         struct dst_entry *dst;
2949
2950         if (!oif && skb->dev)
2951                 oif = l3mdev_master_ifindex(skb->dev);
2952
2953         ip6_update_pmtu(skb, sock_net(sk), mtu, oif, READ_ONCE(sk->sk_mark),
2954                         sk->sk_uid);
2955
2956         dst = __sk_dst_get(sk);
2957         if (!dst || !dst->obsolete ||
2958             dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
2959                 return;
2960
2961         bh_lock_sock(sk);
2962         if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
2963                 ip6_datagram_dst_update(sk, false);
2964         bh_unlock_sock(sk);
2965 }
2966 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
2967
2968 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
2969                            const struct flowi6 *fl6)
2970 {
2971 #ifdef CONFIG_IPV6_SUBTREES
2972         struct ipv6_pinfo *np = inet6_sk(sk);
2973 #endif
2974
2975         ip6_dst_store(sk, dst,
2976                       ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
2977                       &sk->sk_v6_daddr : NULL,
2978 #ifdef CONFIG_IPV6_SUBTREES
2979                       ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
2980                       &np->saddr :
2981 #endif
2982                       NULL);
2983 }
2984
2985 static bool ip6_redirect_nh_match(const struct fib6_result *res,
2986                                   struct flowi6 *fl6,
2987                                   const struct in6_addr *gw,
2988                                   struct rt6_info **ret)
2989 {
2990         const struct fib6_nh *nh = res->nh;
2991
2992         if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family ||
2993             fl6->flowi6_oif != nh->fib_nh_dev->ifindex)
2994                 return false;
2995
2996         /* rt_cache's gateway might be different from its 'parent'
2997          * in the case of an ip redirect.
2998          * So we keep searching in the exception table if the gateway
2999          * is different.
3000          */
3001         if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) {
3002                 struct rt6_info *rt_cache;
3003
3004                 rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr);
3005                 if (rt_cache &&
3006                     ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) {
3007                         *ret = rt_cache;
3008                         return true;
3009                 }
3010                 return false;
3011         }
3012         return true;
3013 }
3014
3015 struct fib6_nh_rd_arg {
3016         struct fib6_result      *res;
3017         struct flowi6           *fl6;
3018         const struct in6_addr   *gw;
3019         struct rt6_info         **ret;
3020 };
3021
3022 static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg)
3023 {
3024         struct fib6_nh_rd_arg *arg = _arg;
3025
3026         arg->res->nh = nh;
3027         return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret);
3028 }
3029
3030 /* Handle redirects */
3031 struct ip6rd_flowi {
3032         struct flowi6 fl6;
3033         struct in6_addr gateway;
3034 };
3035
3036 INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net,
3037                                              struct fib6_table *table,
3038                                              struct flowi6 *fl6,
3039                                              const struct sk_buff *skb,
3040                                              int flags)
3041 {
3042         struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
3043         struct rt6_info *ret = NULL;
3044         struct fib6_result res = {};
3045         struct fib6_nh_rd_arg arg = {
3046                 .res = &res,
3047                 .fl6 = fl6,
3048                 .gw  = &rdfl->gateway,
3049                 .ret = &ret
3050         };
3051         struct fib6_info *rt;
3052         struct fib6_node *fn;
3053
3054         /* Get the "current" route for this destination and
3055          * check if the redirect has come from appropriate router.
3056          *
3057          * RFC 4861 specifies that redirects should only be
3058          * accepted if they come from the nexthop to the target.
3059          * Due to the way the routes are chosen, this notion
3060          * is a bit fuzzy and one might need to check all possible
3061          * routes.
3062          */
3063
3064         rcu_read_lock();
3065         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
3066 restart:
3067         for_each_fib6_node_rt_rcu(fn) {
3068                 res.f6i = rt;
3069                 if (fib6_check_expired(rt))
3070                         continue;
3071                 if (rt->fib6_flags & RTF_REJECT)
3072                         break;
3073                 if (unlikely(rt->nh)) {
3074                         if (nexthop_is_blackhole(rt->nh))
3075                                 continue;
3076                         /* on match, res->nh is filled in and potentially ret */
3077                         if (nexthop_for_each_fib6_nh(rt->nh,
3078                                                      fib6_nh_redirect_match,
3079                                                      &arg))
3080                                 goto out;
3081                 } else {
3082                         res.nh = rt->fib6_nh;
3083                         if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway,
3084                                                   &ret))
3085                                 goto out;
3086                 }
3087         }
3088
3089         if (!rt)
3090                 rt = net->ipv6.fib6_null_entry;
3091         else if (rt->fib6_flags & RTF_REJECT) {
3092                 ret = net->ipv6.ip6_null_entry;
3093                 goto out;
3094         }
3095
3096         if (rt == net->ipv6.fib6_null_entry) {
3097                 fn = fib6_backtrack(fn, &fl6->saddr);
3098                 if (fn)
3099                         goto restart;
3100         }
3101
3102         res.f6i = rt;
3103         res.nh = rt->fib6_nh;
3104 out:
3105         if (ret) {
3106                 ip6_hold_safe(net, &ret);
3107         } else {
3108                 res.fib6_flags = res.f6i->fib6_flags;
3109                 res.fib6_type = res.f6i->fib6_type;
3110                 ret = ip6_create_rt_rcu(&res);
3111         }
3112
3113         rcu_read_unlock();
3114
3115         trace_fib6_table_lookup(net, &res, table, fl6);
3116         return ret;
3117 };
3118
3119 static struct dst_entry *ip6_route_redirect(struct net *net,
3120                                             const struct flowi6 *fl6,
3121                                             const struct sk_buff *skb,
3122                                             const struct in6_addr *gateway)
3123 {
3124         int flags = RT6_LOOKUP_F_HAS_SADDR;
3125         struct ip6rd_flowi rdfl;
3126
3127         rdfl.fl6 = *fl6;
3128         rdfl.gateway = *gateway;
3129
3130         return fib6_rule_lookup(net, &rdfl.fl6, skb,
3131                                 flags, __ip6_route_redirect);
3132 }
3133
3134 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
3135                   kuid_t uid)
3136 {
3137         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
3138         struct dst_entry *dst;
3139         struct flowi6 fl6 = {
3140                 .flowi6_iif = LOOPBACK_IFINDEX,
3141                 .flowi6_oif = oif,
3142                 .flowi6_mark = mark,
3143                 .daddr = iph->daddr,
3144                 .saddr = iph->saddr,
3145                 .flowlabel = ip6_flowinfo(iph),
3146                 .flowi6_uid = uid,
3147         };
3148
3149         dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
3150         rt6_do_redirect(dst, NULL, skb);
3151         dst_release(dst);
3152 }
3153 EXPORT_SYMBOL_GPL(ip6_redirect);
3154
3155 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
3156 {
3157         const struct ipv6hdr *iph = ipv6_hdr(skb);
3158         const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
3159         struct dst_entry *dst;
3160         struct flowi6 fl6 = {
3161                 .flowi6_iif = LOOPBACK_IFINDEX,
3162                 .flowi6_oif = oif,
3163                 .daddr = msg->dest,
3164                 .saddr = iph->daddr,
3165                 .flowi6_uid = sock_net_uid(net, NULL),
3166         };
3167
3168         dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
3169         rt6_do_redirect(dst, NULL, skb);
3170         dst_release(dst);
3171 }
3172
3173 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
3174 {
3175         ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if,
3176                      READ_ONCE(sk->sk_mark), sk->sk_uid);
3177 }
3178 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
3179
3180 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
3181 {
3182         struct net_device *dev = dst->dev;
3183         unsigned int mtu = dst_mtu(dst);
3184         struct net *net = dev_net(dev);
3185
3186         mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
3187
3188         if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
3189                 mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
3190
3191         /*
3192          * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
3193          * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
3194          * IPV6_MAXPLEN is also valid and means: "any MSS,
3195          * rely only on pmtu discovery"
3196          */
3197         if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
3198                 mtu = IPV6_MAXPLEN;
3199         return mtu;
3200 }
3201
3202 INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst)
3203 {
3204         return ip6_dst_mtu_maybe_forward(dst, false);
3205 }
3206 EXPORT_INDIRECT_CALLABLE(ip6_mtu);
3207
3208 /* MTU selection:
3209  * 1. mtu on route is locked - use it
3210  * 2. mtu from nexthop exception
3211  * 3. mtu from egress device
3212  *
3213  * based on ip6_dst_mtu_forward and exception logic of
3214  * rt6_find_cached_rt; called with rcu_read_lock
3215  */
3216 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
3217                       const struct in6_addr *daddr,
3218                       const struct in6_addr *saddr)
3219 {
3220         const struct fib6_nh *nh = res->nh;
3221         struct fib6_info *f6i = res->f6i;
3222         struct inet6_dev *idev;
3223         struct rt6_info *rt;
3224         u32 mtu = 0;
3225
3226         if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
3227                 mtu = f6i->fib6_pmtu;
3228                 if (mtu)
3229                         goto out;
3230         }
3231
3232         rt = rt6_find_cached_rt(res, daddr, saddr);
3233         if (unlikely(rt)) {
3234                 mtu = dst_metric_raw(&rt->dst, RTAX_MTU);
3235         } else {
3236                 struct net_device *dev = nh->fib_nh_dev;
3237
3238                 mtu = IPV6_MIN_MTU;
3239                 idev = __in6_dev_get(dev);
3240                 if (idev && idev->cnf.mtu6 > mtu)
3241                         mtu = idev->cnf.mtu6;
3242         }
3243
3244         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
3245 out:
3246         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
3247 }
3248
3249 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
3250                                   struct flowi6 *fl6)
3251 {
3252         struct dst_entry *dst;
3253         struct rt6_info *rt;
3254         struct inet6_dev *idev = in6_dev_get(dev);
3255         struct net *net = dev_net(dev);
3256
3257         if (unlikely(!idev))
3258                 return ERR_PTR(-ENODEV);
3259
3260         rt = ip6_dst_alloc(net, dev, 0);
3261         if (unlikely(!rt)) {
3262                 in6_dev_put(idev);
3263                 dst = ERR_PTR(-ENOMEM);
3264                 goto out;
3265         }
3266
3267         rt->dst.input = ip6_input;
3268         rt->dst.output  = ip6_output;
3269         rt->rt6i_gateway  = fl6->daddr;
3270         rt->rt6i_dst.addr = fl6->daddr;
3271         rt->rt6i_dst.plen = 128;
3272         rt->rt6i_idev     = idev;
3273         dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
3274
3275         /* Add this dst into uncached_list so that rt6_disable_ip() can
3276          * do proper release of the net_device
3277          */
3278         rt6_uncached_list_add(rt);
3279
3280         dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
3281
3282 out:
3283         return dst;
3284 }
3285
3286 static void ip6_dst_gc(struct dst_ops *ops)
3287 {
3288         struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
3289         int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
3290         int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
3291         int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
3292         unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
3293         unsigned int val;
3294         int entries;
3295
3296         if (time_after(rt_last_gc + rt_min_interval, jiffies))
3297                 goto out;
3298
3299         fib6_run_gc(atomic_inc_return(&net->ipv6.ip6_rt_gc_expire), net, true);
3300         entries = dst_entries_get_slow(ops);
3301         if (entries < ops->gc_thresh)
3302                 atomic_set(&net->ipv6.ip6_rt_gc_expire, rt_gc_timeout >> 1);
3303 out:
3304         val = atomic_read(&net->ipv6.ip6_rt_gc_expire);
3305         atomic_set(&net->ipv6.ip6_rt_gc_expire, val - (val >> rt_elasticity));
3306 }
3307
3308 static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
3309                                const struct in6_addr *gw_addr, u32 tbid,
3310                                int flags, struct fib6_result *res)
3311 {
3312         struct flowi6 fl6 = {
3313                 .flowi6_oif = cfg->fc_ifindex,
3314                 .daddr = *gw_addr,
3315                 .saddr = cfg->fc_prefsrc,
3316         };
3317         struct fib6_table *table;
3318         int err;
3319
3320         table = fib6_get_table(net, tbid);
3321         if (!table)
3322                 return -EINVAL;
3323
3324         if (!ipv6_addr_any(&cfg->fc_prefsrc))
3325                 flags |= RT6_LOOKUP_F_HAS_SADDR;
3326
3327         flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
3328
3329         err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags);
3330         if (!err && res->f6i != net->ipv6.fib6_null_entry)
3331                 fib6_select_path(net, res, &fl6, cfg->fc_ifindex,
3332                                  cfg->fc_ifindex != 0, NULL, flags);
3333
3334         return err;
3335 }
3336
3337 static int ip6_route_check_nh_onlink(struct net *net,
3338                                      struct fib6_config *cfg,
3339                                      const struct net_device *dev,
3340                                      struct netlink_ext_ack *extack)
3341 {
3342         u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
3343         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3344         struct fib6_result res = {};
3345         int err;
3346
3347         err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res);
3348         if (!err && !(res.fib6_flags & RTF_REJECT) &&
3349             /* ignore match if it is the default route */
3350             !ipv6_addr_any(&res.f6i->fib6_dst.addr) &&
3351             (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) {
3352                 NL_SET_ERR_MSG(extack,
3353                                "Nexthop has invalid gateway or device mismatch");
3354                 err = -EINVAL;
3355         }
3356
3357         return err;
3358 }
3359
3360 static int ip6_route_check_nh(struct net *net,
3361                               struct fib6_config *cfg,
3362                               struct net_device **_dev,
3363                               netdevice_tracker *dev_tracker,
3364                               struct inet6_dev **idev)
3365 {
3366         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3367         struct net_device *dev = _dev ? *_dev : NULL;
3368         int flags = RT6_LOOKUP_F_IFACE;
3369         struct fib6_result res = {};
3370         int err = -EHOSTUNREACH;
3371
3372         if (cfg->fc_table) {
3373                 err = ip6_nh_lookup_table(net, cfg, gw_addr,
3374                                           cfg->fc_table, flags, &res);
3375                 /* gw_addr can not require a gateway or resolve to a reject
3376                  * route. If a device is given, it must match the result.
3377                  */
3378                 if (err || res.fib6_flags & RTF_REJECT ||
3379                     res.nh->fib_nh_gw_family ||
3380                     (dev && dev != res.nh->fib_nh_dev))
3381                         err = -EHOSTUNREACH;
3382         }
3383
3384         if (err < 0) {
3385                 struct flowi6 fl6 = {
3386                         .flowi6_oif = cfg->fc_ifindex,
3387                         .daddr = *gw_addr,
3388                 };
3389
3390                 err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags);
3391                 if (err || res.fib6_flags & RTF_REJECT ||
3392                     res.nh->fib_nh_gw_family)
3393                         err = -EHOSTUNREACH;
3394
3395                 if (err)
3396                         return err;
3397
3398                 fib6_select_path(net, &res, &fl6, cfg->fc_ifindex,
3399                                  cfg->fc_ifindex != 0, NULL, flags);
3400         }
3401
3402         err = 0;
3403         if (dev) {
3404                 if (dev != res.nh->fib_nh_dev)
3405                         err = -EHOSTUNREACH;
3406         } else {
3407                 *_dev = dev = res.nh->fib_nh_dev;
3408                 netdev_hold(dev, dev_tracker, GFP_ATOMIC);
3409                 *idev = in6_dev_get(dev);
3410         }
3411
3412         return err;
3413 }
3414
3415 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
3416                            struct net_device **_dev,
3417                            netdevice_tracker *dev_tracker,
3418                            struct inet6_dev **idev,
3419                            struct netlink_ext_ack *extack)
3420 {
3421         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3422         int gwa_type = ipv6_addr_type(gw_addr);
3423         bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
3424         const struct net_device *dev = *_dev;
3425         bool need_addr_check = !dev;
3426         int err = -EINVAL;
3427
3428         /* if gw_addr is local we will fail to detect this in case
3429          * address is still TENTATIVE (DAD in progress). rt6_lookup()
3430          * will return already-added prefix route via interface that
3431          * prefix route was assigned to, which might be non-loopback.
3432          */
3433         if (dev &&
3434             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3435                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3436                 goto out;
3437         }
3438
3439         if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
3440                 /* IPv6 strictly inhibits using not link-local
3441                  * addresses as nexthop address.
3442                  * Otherwise, router will not able to send redirects.
3443                  * It is very good, but in some (rare!) circumstances
3444                  * (SIT, PtP, NBMA NOARP links) it is handy to allow
3445                  * some exceptions. --ANK
3446                  * We allow IPv4-mapped nexthops to support RFC4798-type
3447                  * addressing
3448                  */
3449                 if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
3450                         NL_SET_ERR_MSG(extack, "Invalid gateway address");
3451                         goto out;
3452                 }
3453
3454                 rcu_read_lock();
3455
3456                 if (cfg->fc_flags & RTNH_F_ONLINK)
3457                         err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
3458                 else
3459                         err = ip6_route_check_nh(net, cfg, _dev, dev_tracker,
3460                                                  idev);
3461
3462                 rcu_read_unlock();
3463
3464                 if (err)
3465                         goto out;
3466         }
3467
3468         /* reload in case device was changed */
3469         dev = *_dev;
3470
3471         err = -EINVAL;
3472         if (!dev) {
3473                 NL_SET_ERR_MSG(extack, "Egress device not specified");
3474                 goto out;
3475         } else if (dev->flags & IFF_LOOPBACK) {
3476                 NL_SET_ERR_MSG(extack,
3477                                "Egress device can not be loopback device for this route");
3478                 goto out;
3479         }
3480
3481         /* if we did not check gw_addr above, do so now that the
3482          * egress device has been resolved.
3483          */
3484         if (need_addr_check &&
3485             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3486                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3487                 goto out;
3488         }
3489
3490         err = 0;
3491 out:
3492         return err;
3493 }
3494
3495 static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
3496 {
3497         if ((flags & RTF_REJECT) ||
3498             (dev && (dev->flags & IFF_LOOPBACK) &&
3499              !(addr_type & IPV6_ADDR_LOOPBACK) &&
3500              !(flags & (RTF_ANYCAST | RTF_LOCAL))))
3501                 return true;
3502
3503         return false;
3504 }
3505
3506 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
3507                  struct fib6_config *cfg, gfp_t gfp_flags,
3508                  struct netlink_ext_ack *extack)
3509 {
3510         netdevice_tracker *dev_tracker = &fib6_nh->fib_nh_dev_tracker;
3511         struct net_device *dev = NULL;
3512         struct inet6_dev *idev = NULL;
3513         int addr_type;
3514         int err;
3515
3516         fib6_nh->fib_nh_family = AF_INET6;
3517 #ifdef CONFIG_IPV6_ROUTER_PREF
3518         fib6_nh->last_probe = jiffies;
3519 #endif
3520         if (cfg->fc_is_fdb) {
3521                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3522                 fib6_nh->fib_nh_gw_family = AF_INET6;
3523                 return 0;
3524         }
3525
3526         err = -ENODEV;
3527         if (cfg->fc_ifindex) {
3528                 dev = netdev_get_by_index(net, cfg->fc_ifindex,
3529                                           dev_tracker, gfp_flags);
3530                 if (!dev)
3531                         goto out;
3532                 idev = in6_dev_get(dev);
3533                 if (!idev)
3534                         goto out;
3535         }
3536
3537         if (cfg->fc_flags & RTNH_F_ONLINK) {
3538                 if (!dev) {
3539                         NL_SET_ERR_MSG(extack,
3540                                        "Nexthop device required for onlink");
3541                         goto out;
3542                 }
3543
3544                 if (!(dev->flags & IFF_UP)) {
3545                         NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3546                         err = -ENETDOWN;
3547                         goto out;
3548                 }
3549
3550                 fib6_nh->fib_nh_flags |= RTNH_F_ONLINK;
3551         }
3552
3553         fib6_nh->fib_nh_weight = 1;
3554
3555         /* We cannot add true routes via loopback here,
3556          * they would result in kernel looping; promote them to reject routes
3557          */
3558         addr_type = ipv6_addr_type(&cfg->fc_dst);
3559         if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) {
3560                 /* hold loopback dev/idev if we haven't done so. */
3561                 if (dev != net->loopback_dev) {
3562                         if (dev) {
3563                                 netdev_put(dev, dev_tracker);
3564                                 in6_dev_put(idev);
3565                         }
3566                         dev = net->loopback_dev;
3567                         netdev_hold(dev, dev_tracker, gfp_flags);
3568                         idev = in6_dev_get(dev);
3569                         if (!idev) {
3570                                 err = -ENODEV;
3571                                 goto out;
3572                         }
3573                 }
3574                 goto pcpu_alloc;
3575         }
3576
3577         if (cfg->fc_flags & RTF_GATEWAY) {
3578                 err = ip6_validate_gw(net, cfg, &dev, dev_tracker,
3579                                       &idev, extack);
3580                 if (err)
3581                         goto out;
3582
3583                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3584                 fib6_nh->fib_nh_gw_family = AF_INET6;
3585         }
3586
3587         err = -ENODEV;
3588         if (!dev)
3589                 goto out;
3590
3591         if (idev->cnf.disable_ipv6) {
3592                 NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
3593                 err = -EACCES;
3594                 goto out;
3595         }
3596
3597         if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
3598                 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3599                 err = -ENETDOWN;
3600                 goto out;
3601         }
3602
3603         if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
3604             !netif_carrier_ok(dev))
3605                 fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
3606
3607         err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap,
3608                                  cfg->fc_encap_type, cfg, gfp_flags, extack);
3609         if (err)
3610                 goto out;
3611
3612 pcpu_alloc:
3613         fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
3614         if (!fib6_nh->rt6i_pcpu) {
3615                 err = -ENOMEM;
3616                 goto out;
3617         }
3618
3619         fib6_nh->fib_nh_dev = dev;
3620         fib6_nh->fib_nh_oif = dev->ifindex;
3621         err = 0;
3622 out:
3623         if (idev)
3624                 in6_dev_put(idev);
3625
3626         if (err) {
3627                 lwtstate_put(fib6_nh->fib_nh_lws);
3628                 fib6_nh->fib_nh_lws = NULL;
3629                 netdev_put(dev, dev_tracker);
3630         }
3631
3632         return err;
3633 }
3634
3635 void fib6_nh_release(struct fib6_nh *fib6_nh)
3636 {
3637         struct rt6_exception_bucket *bucket;
3638
3639         rcu_read_lock();
3640
3641         fib6_nh_flush_exceptions(fib6_nh, NULL);
3642         bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL);
3643         if (bucket) {
3644                 rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL);
3645                 kfree(bucket);
3646         }
3647
3648         rcu_read_unlock();
3649
3650         fib6_nh_release_dsts(fib6_nh);
3651         free_percpu(fib6_nh->rt6i_pcpu);
3652
3653         fib_nh_common_release(&fib6_nh->nh_common);
3654 }
3655
3656 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh)
3657 {
3658         int cpu;
3659
3660         if (!fib6_nh->rt6i_pcpu)
3661                 return;
3662
3663         for_each_possible_cpu(cpu) {
3664                 struct rt6_info *pcpu_rt, **ppcpu_rt;
3665
3666                 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
3667                 pcpu_rt = xchg(ppcpu_rt, NULL);
3668                 if (pcpu_rt) {
3669                         dst_dev_put(&pcpu_rt->dst);
3670                         dst_release(&pcpu_rt->dst);
3671                 }
3672         }
3673 }
3674
3675 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
3676                                               gfp_t gfp_flags,
3677                                               struct netlink_ext_ack *extack)
3678 {
3679         struct net *net = cfg->fc_nlinfo.nl_net;
3680         struct fib6_info *rt = NULL;
3681         struct nexthop *nh = NULL;
3682         struct fib6_table *table;
3683         struct fib6_nh *fib6_nh;
3684         int err = -EINVAL;
3685         int addr_type;
3686
3687         /* RTF_PCPU is an internal flag; can not be set by userspace */
3688         if (cfg->fc_flags & RTF_PCPU) {
3689                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
3690                 goto out;
3691         }
3692
3693         /* RTF_CACHE is an internal flag; can not be set by userspace */
3694         if (cfg->fc_flags & RTF_CACHE) {
3695                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
3696                 goto out;
3697         }
3698
3699         if (cfg->fc_type > RTN_MAX) {
3700                 NL_SET_ERR_MSG(extack, "Invalid route type");
3701                 goto out;
3702         }
3703
3704         if (cfg->fc_dst_len > 128) {
3705                 NL_SET_ERR_MSG(extack, "Invalid prefix length");
3706                 goto out;
3707         }
3708         if (cfg->fc_src_len > 128) {
3709                 NL_SET_ERR_MSG(extack, "Invalid source address length");
3710                 goto out;
3711         }
3712 #ifndef CONFIG_IPV6_SUBTREES
3713         if (cfg->fc_src_len) {
3714                 NL_SET_ERR_MSG(extack,
3715                                "Specifying source address requires IPV6_SUBTREES to be enabled");
3716                 goto out;
3717         }
3718 #endif
3719         if (cfg->fc_nh_id) {
3720                 nh = nexthop_find_by_id(net, cfg->fc_nh_id);
3721                 if (!nh) {
3722                         NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
3723                         goto out;
3724                 }
3725                 err = fib6_check_nexthop(nh, cfg, extack);
3726                 if (err)
3727                         goto out;
3728         }
3729
3730         err = -ENOBUFS;
3731         if (cfg->fc_nlinfo.nlh &&
3732             !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
3733                 table = fib6_get_table(net, cfg->fc_table);
3734                 if (!table) {
3735                         pr_warn("NLM_F_CREATE should be specified when creating new route\n");
3736                         table = fib6_new_table(net, cfg->fc_table);
3737                 }
3738         } else {
3739                 table = fib6_new_table(net, cfg->fc_table);
3740         }
3741
3742         if (!table)
3743                 goto out;
3744
3745         err = -ENOMEM;
3746         rt = fib6_info_alloc(gfp_flags, !nh);
3747         if (!rt)
3748                 goto out;
3749
3750         rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len,
3751                                                extack);
3752         if (IS_ERR(rt->fib6_metrics)) {
3753                 err = PTR_ERR(rt->fib6_metrics);
3754                 /* Do not leave garbage there. */
3755                 rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
3756                 goto out_free;
3757         }
3758
3759         if (cfg->fc_flags & RTF_ADDRCONF)
3760                 rt->dst_nocount = true;
3761
3762         if (cfg->fc_flags & RTF_EXPIRES)
3763                 fib6_set_expires_locked(rt, jiffies +
3764                                         clock_t_to_jiffies(cfg->fc_expires));
3765         else
3766                 fib6_clean_expires_locked(rt);
3767
3768         if (cfg->fc_protocol == RTPROT_UNSPEC)
3769                 cfg->fc_protocol = RTPROT_BOOT;
3770         rt->fib6_protocol = cfg->fc_protocol;
3771
3772         rt->fib6_table = table;
3773         rt->fib6_metric = cfg->fc_metric;
3774         rt->fib6_type = cfg->fc_type ? : RTN_UNICAST;
3775         rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;
3776
3777         ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
3778         rt->fib6_dst.plen = cfg->fc_dst_len;
3779
3780 #ifdef CONFIG_IPV6_SUBTREES
3781         ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
3782         rt->fib6_src.plen = cfg->fc_src_len;
3783 #endif
3784         if (nh) {
3785                 if (rt->fib6_src.plen) {
3786                         NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
3787                         goto out_free;
3788                 }
3789                 if (!nexthop_get(nh)) {
3790                         NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
3791                         goto out_free;
3792                 }
3793                 rt->nh = nh;
3794                 fib6_nh = nexthop_fib6_nh(rt->nh);
3795         } else {
3796                 err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack);
3797                 if (err)
3798                         goto out;
3799
3800                 fib6_nh = rt->fib6_nh;
3801
3802                 /* We cannot add true routes via loopback here, they would
3803                  * result in kernel looping; promote them to reject routes
3804                  */
3805                 addr_type = ipv6_addr_type(&cfg->fc_dst);
3806                 if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev,
3807                                    addr_type))
3808                         rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
3809         }
3810
3811         if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
3812                 struct net_device *dev = fib6_nh->fib_nh_dev;
3813
3814                 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
3815                         NL_SET_ERR_MSG(extack, "Invalid source address");
3816                         err = -EINVAL;
3817                         goto out;
3818                 }
3819                 rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
3820                 rt->fib6_prefsrc.plen = 128;
3821         } else
3822                 rt->fib6_prefsrc.plen = 0;
3823
3824         return rt;
3825 out:
3826         fib6_info_release(rt);
3827         return ERR_PTR(err);
3828 out_free:
3829         ip_fib_metrics_put(rt->fib6_metrics);
3830         kfree(rt);
3831         return ERR_PTR(err);
3832 }
3833
3834 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
3835                   struct netlink_ext_ack *extack)
3836 {
3837         struct fib6_info *rt;
3838         int err;
3839
3840         rt = ip6_route_info_create(cfg, gfp_flags, extack);
3841         if (IS_ERR(rt))
3842                 return PTR_ERR(rt);
3843
3844         err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
3845         fib6_info_release(rt);
3846
3847         return err;
3848 }
3849
3850 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
3851 {
3852         struct net *net = info->nl_net;
3853         struct fib6_table *table;
3854         int err;
3855
3856         if (rt == net->ipv6.fib6_null_entry) {
3857                 err = -ENOENT;
3858                 goto out;
3859         }
3860
3861         table = rt->fib6_table;
3862         spin_lock_bh(&table->tb6_lock);
3863         err = fib6_del(rt, info);
3864         spin_unlock_bh(&table->tb6_lock);
3865
3866 out:
3867         fib6_info_release(rt);
3868         return err;
3869 }
3870
3871 int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify)
3872 {
3873         struct nl_info info = {
3874                 .nl_net = net,
3875                 .skip_notify = skip_notify
3876         };
3877
3878         return __ip6_del_rt(rt, &info);
3879 }
3880
3881 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
3882 {
3883         struct nl_info *info = &cfg->fc_nlinfo;
3884         struct net *net = info->nl_net;
3885         struct sk_buff *skb = NULL;
3886         struct fib6_table *table;
3887         int err = -ENOENT;
3888
3889         if (rt == net->ipv6.fib6_null_entry)
3890                 goto out_put;
3891         table = rt->fib6_table;
3892         spin_lock_bh(&table->tb6_lock);
3893
3894         if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
3895                 struct fib6_info *sibling, *next_sibling;
3896                 struct fib6_node *fn;
3897
3898                 /* prefer to send a single notification with all hops */
3899                 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3900                 if (skb) {
3901                         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3902
3903                         if (rt6_fill_node(net, skb, rt, NULL,
3904                                           NULL, NULL, 0, RTM_DELROUTE,
3905                                           info->portid, seq, 0) < 0) {
3906                                 kfree_skb(skb);
3907                                 skb = NULL;
3908                         } else
3909                                 info->skip_notify = 1;
3910                 }
3911
3912                 /* 'rt' points to the first sibling route. If it is not the
3913                  * leaf, then we do not need to send a notification. Otherwise,
3914                  * we need to check if the last sibling has a next route or not
3915                  * and emit a replace or delete notification, respectively.
3916                  */
3917                 info->skip_notify_kernel = 1;
3918                 fn = rcu_dereference_protected(rt->fib6_node,
3919                                             lockdep_is_held(&table->tb6_lock));
3920                 if (rcu_access_pointer(fn->leaf) == rt) {
3921                         struct fib6_info *last_sibling, *replace_rt;
3922
3923                         last_sibling = list_last_entry(&rt->fib6_siblings,
3924                                                        struct fib6_info,
3925                                                        fib6_siblings);
3926                         replace_rt = rcu_dereference_protected(
3927                                             last_sibling->fib6_next,
3928                                             lockdep_is_held(&table->tb6_lock));
3929                         if (replace_rt)
3930                                 call_fib6_entry_notifiers_replace(net,
3931                                                                   replace_rt);
3932                         else
3933                                 call_fib6_multipath_entry_notifiers(net,
3934                                                        FIB_EVENT_ENTRY_DEL,
3935                                                        rt, rt->fib6_nsiblings,
3936                                                        NULL);
3937                 }
3938                 list_for_each_entry_safe(sibling, next_sibling,
3939                                          &rt->fib6_siblings,
3940                                          fib6_siblings) {
3941                         err = fib6_del(sibling, info);
3942                         if (err)
3943                                 goto out_unlock;
3944                 }
3945         }
3946
3947         err = fib6_del(rt, info);
3948 out_unlock:
3949         spin_unlock_bh(&table->tb6_lock);
3950 out_put:
3951         fib6_info_release(rt);
3952
3953         if (skb) {
3954                 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3955                             info->nlh, gfp_any());
3956         }
3957         return err;
3958 }
3959
3960 static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
3961 {
3962         int rc = -ESRCH;
3963
3964         if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
3965                 goto out;
3966
3967         if (cfg->fc_flags & RTF_GATEWAY &&
3968             !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
3969                 goto out;
3970
3971         rc = rt6_remove_exception_rt(rt);
3972 out:
3973         return rc;
3974 }
3975
3976 static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt,
3977                              struct fib6_nh *nh)
3978 {
3979         struct fib6_result res = {
3980                 .f6i = rt,
3981                 .nh = nh,
3982         };
3983         struct rt6_info *rt_cache;
3984
3985         rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src);
3986         if (rt_cache)
3987                 return __ip6_del_cached_rt(rt_cache, cfg);
3988
3989         return 0;
3990 }
3991
3992 struct fib6_nh_del_cached_rt_arg {
3993         struct fib6_config *cfg;
3994         struct fib6_info *f6i;
3995 };
3996
3997 static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg)
3998 {
3999         struct fib6_nh_del_cached_rt_arg *arg = _arg;
4000         int rc;
4001
4002         rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh);
4003         return rc != -ESRCH ? rc : 0;
4004 }
4005
4006 static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i)
4007 {
4008         struct fib6_nh_del_cached_rt_arg arg = {
4009                 .cfg = cfg,
4010                 .f6i = f6i
4011         };
4012
4013         return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg);
4014 }
4015
4016 static int ip6_route_del(struct fib6_config *cfg,
4017                          struct netlink_ext_ack *extack)
4018 {
4019         struct fib6_table *table;
4020         struct fib6_info *rt;
4021         struct fib6_node *fn;
4022         int err = -ESRCH;
4023
4024         table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
4025         if (!table) {
4026                 NL_SET_ERR_MSG(extack, "FIB table does not exist");
4027                 return err;
4028         }
4029
4030         rcu_read_lock();
4031
4032         fn = fib6_locate(&table->tb6_root,
4033                          &cfg->fc_dst, cfg->fc_dst_len,
4034                          &cfg->fc_src, cfg->fc_src_len,
4035                          !(cfg->fc_flags & RTF_CACHE));
4036
4037         if (fn) {
4038                 for_each_fib6_node_rt_rcu(fn) {
4039                         struct fib6_nh *nh;
4040
4041                         if (rt->nh && cfg->fc_nh_id &&
4042                             rt->nh->id != cfg->fc_nh_id)
4043                                 continue;
4044
4045                         if (cfg->fc_flags & RTF_CACHE) {
4046                                 int rc = 0;
4047
4048                                 if (rt->nh) {
4049                                         rc = ip6_del_cached_rt_nh(cfg, rt);
4050                                 } else if (cfg->fc_nh_id) {
4051                                         continue;
4052                                 } else {
4053                                         nh = rt->fib6_nh;
4054                                         rc = ip6_del_cached_rt(cfg, rt, nh);
4055                                 }
4056                                 if (rc != -ESRCH) {
4057                                         rcu_read_unlock();
4058                                         return rc;
4059                                 }
4060                                 continue;
4061                         }
4062
4063                         if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
4064                                 continue;
4065                         if (cfg->fc_protocol &&
4066                             cfg->fc_protocol != rt->fib6_protocol)
4067                                 continue;
4068
4069                         if (rt->nh) {
4070                                 if (!fib6_info_hold_safe(rt))
4071                                         continue;
4072                                 rcu_read_unlock();
4073
4074                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4075                         }
4076                         if (cfg->fc_nh_id)
4077                                 continue;
4078
4079                         nh = rt->fib6_nh;
4080                         if (cfg->fc_ifindex &&
4081                             (!nh->fib_nh_dev ||
4082                              nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
4083                                 continue;
4084                         if (cfg->fc_flags & RTF_GATEWAY &&
4085                             !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6))
4086                                 continue;
4087                         if (!fib6_info_hold_safe(rt))
4088                                 continue;
4089                         rcu_read_unlock();
4090
4091                         /* if gateway was specified only delete the one hop */
4092                         if (cfg->fc_flags & RTF_GATEWAY)
4093                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4094
4095                         return __ip6_del_rt_siblings(rt, cfg);
4096                 }
4097         }
4098         rcu_read_unlock();
4099
4100         return err;
4101 }
4102
4103 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
4104 {
4105         struct netevent_redirect netevent;
4106         struct rt6_info *rt, *nrt = NULL;
4107         struct fib6_result res = {};
4108         struct ndisc_options ndopts;
4109         struct inet6_dev *in6_dev;
4110         struct neighbour *neigh;
4111         struct rd_msg *msg;
4112         int optlen, on_link;
4113         u8 *lladdr;
4114
4115         optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
4116         optlen -= sizeof(*msg);
4117
4118         if (optlen < 0) {
4119                 net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
4120                 return;
4121         }
4122
4123         msg = (struct rd_msg *)icmp6_hdr(skb);
4124
4125         if (ipv6_addr_is_multicast(&msg->dest)) {
4126                 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
4127                 return;
4128         }
4129
4130         on_link = 0;
4131         if (ipv6_addr_equal(&msg->dest, &msg->target)) {
4132                 on_link = 1;
4133         } else if (ipv6_addr_type(&msg->target) !=
4134                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
4135                 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
4136                 return;
4137         }
4138
4139         in6_dev = __in6_dev_get(skb->dev);
4140         if (!in6_dev)
4141                 return;
4142         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
4143                 return;
4144
4145         /* RFC2461 8.1:
4146          *      The IP source address of the Redirect MUST be the same as the current
4147          *      first-hop router for the specified ICMP Destination Address.
4148          */
4149
4150         if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
4151                 net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
4152                 return;
4153         }
4154
4155         lladdr = NULL;
4156         if (ndopts.nd_opts_tgt_lladdr) {
4157                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
4158                                              skb->dev);
4159                 if (!lladdr) {
4160                         net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
4161                         return;
4162                 }
4163         }
4164
4165         rt = (struct rt6_info *) dst;
4166         if (rt->rt6i_flags & RTF_REJECT) {
4167                 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
4168                 return;
4169         }
4170
4171         /* Redirect received -> path was valid.
4172          * Look, redirects are sent only in response to data packets,
4173          * so that this nexthop apparently is reachable. --ANK
4174          */
4175         dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
4176
4177         neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
4178         if (!neigh)
4179                 return;
4180
4181         /*
4182          *      We have finally decided to accept it.
4183          */
4184
4185         ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
4186                      NEIGH_UPDATE_F_WEAK_OVERRIDE|
4187                      NEIGH_UPDATE_F_OVERRIDE|
4188                      (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
4189                                      NEIGH_UPDATE_F_ISROUTER)),
4190                      NDISC_REDIRECT, &ndopts);
4191
4192         rcu_read_lock();
4193         res.f6i = rcu_dereference(rt->from);
4194         if (!res.f6i)
4195                 goto out;
4196
4197         if (res.f6i->nh) {
4198                 struct fib6_nh_match_arg arg = {
4199                         .dev = dst->dev,
4200                         .gw = &rt->rt6i_gateway,
4201                 };
4202
4203                 nexthop_for_each_fib6_nh(res.f6i->nh,
4204                                          fib6_nh_find_match, &arg);
4205
4206                 /* fib6_info uses a nexthop that does not have fib6_nh
4207                  * using the dst->dev. Should be impossible
4208                  */
4209                 if (!arg.match)
4210                         goto out;
4211                 res.nh = arg.match;
4212         } else {
4213                 res.nh = res.f6i->fib6_nh;
4214         }
4215
4216         res.fib6_flags = res.f6i->fib6_flags;
4217         res.fib6_type = res.f6i->fib6_type;
4218         nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL);
4219         if (!nrt)
4220                 goto out;
4221
4222         nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
4223         if (on_link)
4224                 nrt->rt6i_flags &= ~RTF_GATEWAY;
4225
4226         nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
4227
4228         /* rt6_insert_exception() will take care of duplicated exceptions */
4229         if (rt6_insert_exception(nrt, &res)) {
4230                 dst_release_immediate(&nrt->dst);
4231                 goto out;
4232         }
4233
4234         netevent.old = &rt->dst;
4235         netevent.new = &nrt->dst;
4236         netevent.daddr = &msg->dest;
4237         netevent.neigh = neigh;
4238         call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
4239
4240 out:
4241         rcu_read_unlock();
4242         neigh_release(neigh);
4243 }
4244
4245 #ifdef CONFIG_IPV6_ROUTE_INFO
4246 static struct fib6_info *rt6_get_route_info(struct net *net,
4247                                            const struct in6_addr *prefix, int prefixlen,
4248                                            const struct in6_addr *gwaddr,
4249                                            struct net_device *dev)
4250 {
4251         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4252         int ifindex = dev->ifindex;
4253         struct fib6_node *fn;
4254         struct fib6_info *rt = NULL;
4255         struct fib6_table *table;
4256
4257         table = fib6_get_table(net, tb_id);
4258         if (!table)
4259                 return NULL;
4260
4261         rcu_read_lock();
4262         fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
4263         if (!fn)
4264                 goto out;
4265
4266         for_each_fib6_node_rt_rcu(fn) {
4267                 /* these routes do not use nexthops */
4268                 if (rt->nh)
4269                         continue;
4270                 if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex)
4271                         continue;
4272                 if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
4273                     !rt->fib6_nh->fib_nh_gw_family)
4274                         continue;
4275                 if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr))
4276                         continue;
4277                 if (!fib6_info_hold_safe(rt))
4278                         continue;
4279                 break;
4280         }
4281 out:
4282         rcu_read_unlock();
4283         return rt;
4284 }
4285
4286 static struct fib6_info *rt6_add_route_info(struct net *net,
4287                                            const struct in6_addr *prefix, int prefixlen,
4288                                            const struct in6_addr *gwaddr,
4289                                            struct net_device *dev,
4290                                            unsigned int pref)
4291 {
4292         struct fib6_config cfg = {
4293                 .fc_metric      = IP6_RT_PRIO_USER,
4294                 .fc_ifindex     = dev->ifindex,
4295                 .fc_dst_len     = prefixlen,
4296                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
4297                                   RTF_UP | RTF_PREF(pref),
4298                 .fc_protocol = RTPROT_RA,
4299                 .fc_type = RTN_UNICAST,
4300                 .fc_nlinfo.portid = 0,
4301                 .fc_nlinfo.nlh = NULL,
4302                 .fc_nlinfo.nl_net = net,
4303         };
4304
4305         cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4306         cfg.fc_dst = *prefix;
4307         cfg.fc_gateway = *gwaddr;
4308
4309         /* We should treat it as a default route if prefix length is 0. */
4310         if (!prefixlen)
4311                 cfg.fc_flags |= RTF_DEFAULT;
4312
4313         ip6_route_add(&cfg, GFP_ATOMIC, NULL);
4314
4315         return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
4316 }
4317 #endif
4318
4319 struct fib6_info *rt6_get_dflt_router(struct net *net,
4320                                      const struct in6_addr *addr,
4321                                      struct net_device *dev)
4322 {
4323         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
4324         struct fib6_info *rt;
4325         struct fib6_table *table;
4326
4327         table = fib6_get_table(net, tb_id);
4328         if (!table)
4329                 return NULL;
4330
4331         rcu_read_lock();
4332         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4333                 struct fib6_nh *nh;
4334
4335                 /* RA routes do not use nexthops */
4336                 if (rt->nh)
4337                         continue;
4338
4339                 nh = rt->fib6_nh;
4340                 if (dev == nh->fib_nh_dev &&
4341                     ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
4342                     ipv6_addr_equal(&nh->fib_nh_gw6, addr))
4343                         break;
4344         }
4345         if (rt && !fib6_info_hold_safe(rt))
4346                 rt = NULL;
4347         rcu_read_unlock();
4348         return rt;
4349 }
4350
4351 struct fib6_info *rt6_add_dflt_router(struct net *net,
4352                                      const struct in6_addr *gwaddr,
4353                                      struct net_device *dev,
4354                                      unsigned int pref,
4355                                      u32 defrtr_usr_metric)
4356 {
4357         struct fib6_config cfg = {
4358                 .fc_table       = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
4359                 .fc_metric      = defrtr_usr_metric,
4360                 .fc_ifindex     = dev->ifindex,
4361                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
4362                                   RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
4363                 .fc_protocol = RTPROT_RA,
4364                 .fc_type = RTN_UNICAST,
4365                 .fc_nlinfo.portid = 0,
4366                 .fc_nlinfo.nlh = NULL,
4367                 .fc_nlinfo.nl_net = net,
4368         };
4369
4370         cfg.fc_gateway = *gwaddr;
4371
4372         if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
4373                 struct fib6_table *table;
4374
4375                 table = fib6_get_table(dev_net(dev), cfg.fc_table);
4376                 if (table)
4377                         table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
4378         }
4379
4380         return rt6_get_dflt_router(net, gwaddr, dev);
4381 }
4382
4383 static void __rt6_purge_dflt_routers(struct net *net,
4384                                      struct fib6_table *table)
4385 {
4386         struct fib6_info *rt;
4387
4388 restart:
4389         rcu_read_lock();
4390         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4391                 struct net_device *dev = fib6_info_nh_dev(rt);
4392                 struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
4393
4394                 if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
4395                     (!idev || idev->cnf.accept_ra != 2) &&
4396                     fib6_info_hold_safe(rt)) {
4397                         rcu_read_unlock();
4398                         ip6_del_rt(net, rt, false);
4399                         goto restart;
4400                 }
4401         }
4402         rcu_read_unlock();
4403
4404         table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
4405 }
4406
4407 void rt6_purge_dflt_routers(struct net *net)
4408 {
4409         struct fib6_table *table;
4410         struct hlist_head *head;
4411         unsigned int h;
4412
4413         rcu_read_lock();
4414
4415         for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
4416                 head = &net->ipv6.fib_table_hash[h];
4417                 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
4418                         if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
4419                                 __rt6_purge_dflt_routers(net, table);
4420                 }
4421         }
4422
4423         rcu_read_unlock();
4424 }
4425
4426 static void rtmsg_to_fib6_config(struct net *net,
4427                                  struct in6_rtmsg *rtmsg,
4428                                  struct fib6_config *cfg)
4429 {
4430         *cfg = (struct fib6_config){
4431                 .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
4432                          : RT6_TABLE_MAIN,
4433                 .fc_ifindex = rtmsg->rtmsg_ifindex,
4434                 .fc_metric = rtmsg->rtmsg_metric ? : IP6_RT_PRIO_USER,
4435                 .fc_expires = rtmsg->rtmsg_info,
4436                 .fc_dst_len = rtmsg->rtmsg_dst_len,
4437                 .fc_src_len = rtmsg->rtmsg_src_len,
4438                 .fc_flags = rtmsg->rtmsg_flags,
4439                 .fc_type = rtmsg->rtmsg_type,
4440
4441                 .fc_nlinfo.nl_net = net,
4442
4443                 .fc_dst = rtmsg->rtmsg_dst,
4444                 .fc_src = rtmsg->rtmsg_src,
4445                 .fc_gateway = rtmsg->rtmsg_gateway,
4446         };
4447 }
4448
4449 int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg)
4450 {
4451         struct fib6_config cfg;
4452         int err;
4453
4454         if (cmd != SIOCADDRT && cmd != SIOCDELRT)
4455                 return -EINVAL;
4456         if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
4457                 return -EPERM;
4458
4459         rtmsg_to_fib6_config(net, rtmsg, &cfg);
4460
4461         rtnl_lock();
4462         switch (cmd) {
4463         case SIOCADDRT:
4464                 err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
4465                 break;
4466         case SIOCDELRT:
4467                 err = ip6_route_del(&cfg, NULL);
4468                 break;
4469         }
4470         rtnl_unlock();
4471         return err;
4472 }
4473
4474 /*
4475  *      Drop the packet on the floor
4476  */
4477
4478 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
4479 {
4480         struct dst_entry *dst = skb_dst(skb);
4481         struct net *net = dev_net(dst->dev);
4482         struct inet6_dev *idev;
4483         SKB_DR(reason);
4484         int type;
4485
4486         if (netif_is_l3_master(skb->dev) ||
4487             dst->dev == net->loopback_dev)
4488                 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
4489         else
4490                 idev = ip6_dst_idev(dst);
4491
4492         switch (ipstats_mib_noroutes) {
4493         case IPSTATS_MIB_INNOROUTES:
4494                 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
4495                 if (type == IPV6_ADDR_ANY) {
4496                         SKB_DR_SET(reason, IP_INADDRERRORS);
4497                         IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
4498                         break;
4499                 }
4500                 SKB_DR_SET(reason, IP_INNOROUTES);
4501                 fallthrough;
4502         case IPSTATS_MIB_OUTNOROUTES:
4503                 SKB_DR_OR(reason, IP_OUTNOROUTES);
4504                 IP6_INC_STATS(net, idev, ipstats_mib_noroutes);
4505                 break;
4506         }
4507
4508         /* Start over by dropping the dst for l3mdev case */
4509         if (netif_is_l3_master(skb->dev))
4510                 skb_dst_drop(skb);
4511
4512         icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
4513         kfree_skb_reason(skb, reason);
4514         return 0;
4515 }
4516
4517 static int ip6_pkt_discard(struct sk_buff *skb)
4518 {
4519         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
4520 }
4521
4522 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4523 {
4524         skb->dev = skb_dst(skb)->dev;
4525         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
4526 }
4527
4528 static int ip6_pkt_prohibit(struct sk_buff *skb)
4529 {
4530         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
4531 }
4532
4533 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4534 {
4535         skb->dev = skb_dst(skb)->dev;
4536         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
4537 }
4538
4539 /*
4540  *      Allocate a dst for local (unicast / anycast) address.
4541  */
4542
4543 struct fib6_info *addrconf_f6i_alloc(struct net *net,
4544                                      struct inet6_dev *idev,
4545                                      const struct in6_addr *addr,
4546                                      bool anycast, gfp_t gfp_flags,
4547                                      struct netlink_ext_ack *extack)
4548 {
4549         struct fib6_config cfg = {
4550                 .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
4551                 .fc_ifindex = idev->dev->ifindex,
4552                 .fc_flags = RTF_UP | RTF_NONEXTHOP,
4553                 .fc_dst = *addr,
4554                 .fc_dst_len = 128,
4555                 .fc_protocol = RTPROT_KERNEL,
4556                 .fc_nlinfo.nl_net = net,
4557                 .fc_ignore_dev_down = true,
4558         };
4559         struct fib6_info *f6i;
4560
4561         if (anycast) {
4562                 cfg.fc_type = RTN_ANYCAST;
4563                 cfg.fc_flags |= RTF_ANYCAST;
4564         } else {
4565                 cfg.fc_type = RTN_LOCAL;
4566                 cfg.fc_flags |= RTF_LOCAL;
4567         }
4568
4569         f6i = ip6_route_info_create(&cfg, gfp_flags, extack);
4570         if (!IS_ERR(f6i)) {
4571                 f6i->dst_nocount = true;
4572
4573                 if (!anycast &&
4574                     (net->ipv6.devconf_all->disable_policy ||
4575                      idev->cnf.disable_policy))
4576                         f6i->dst_nopolicy = true;
4577         }
4578
4579         return f6i;
4580 }
4581
4582 /* remove deleted ip from prefsrc entries */
4583 struct arg_dev_net_ip {
4584         struct net *net;
4585         struct in6_addr *addr;
4586 };
4587
4588 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
4589 {
4590         struct net *net = ((struct arg_dev_net_ip *)arg)->net;
4591         struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
4592
4593         if (!rt->nh &&
4594             rt != net->ipv6.fib6_null_entry &&
4595             ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr) &&
4596             !ipv6_chk_addr(net, addr, rt->fib6_nh->fib_nh_dev, 0)) {
4597                 spin_lock_bh(&rt6_exception_lock);
4598                 /* remove prefsrc entry */
4599                 rt->fib6_prefsrc.plen = 0;
4600                 spin_unlock_bh(&rt6_exception_lock);
4601         }
4602         return 0;
4603 }
4604
4605 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
4606 {
4607         struct net *net = dev_net(ifp->idev->dev);
4608         struct arg_dev_net_ip adni = {
4609                 .net = net,
4610                 .addr = &ifp->addr,
4611         };
4612         fib6_clean_all(net, fib6_remove_prefsrc, &adni);
4613 }
4614
4615 #define RTF_RA_ROUTER           (RTF_ADDRCONF | RTF_DEFAULT)
4616
4617 /* Remove routers and update dst entries when gateway turn into host. */
4618 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
4619 {
4620         struct in6_addr *gateway = (struct in6_addr *)arg;
4621         struct fib6_nh *nh;
4622
4623         /* RA routes do not use nexthops */
4624         if (rt->nh)
4625                 return 0;
4626
4627         nh = rt->fib6_nh;
4628         if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
4629             nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6))
4630                 return -1;
4631
4632         /* Further clean up cached routes in exception table.
4633          * This is needed because cached route may have a different
4634          * gateway than its 'parent' in the case of an ip redirect.
4635          */
4636         fib6_nh_exceptions_clean_tohost(nh, gateway);
4637
4638         return 0;
4639 }
4640
4641 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
4642 {
4643         fib6_clean_all(net, fib6_clean_tohost, gateway);
4644 }
4645
4646 struct arg_netdev_event {
4647         const struct net_device *dev;
4648         union {
4649                 unsigned char nh_flags;
4650                 unsigned long event;
4651         };
4652 };
4653
4654 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
4655 {
4656         struct fib6_info *iter;
4657         struct fib6_node *fn;
4658
4659         fn = rcu_dereference_protected(rt->fib6_node,
4660                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4661         iter = rcu_dereference_protected(fn->leaf,
4662                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4663         while (iter) {
4664                 if (iter->fib6_metric == rt->fib6_metric &&
4665                     rt6_qualify_for_ecmp(iter))
4666                         return iter;
4667                 iter = rcu_dereference_protected(iter->fib6_next,
4668                                 lockdep_is_held(&rt->fib6_table->tb6_lock));
4669         }
4670
4671         return NULL;
4672 }
4673
4674 /* only called for fib entries with builtin fib6_nh */
4675 static bool rt6_is_dead(const struct fib6_info *rt)
4676 {
4677         if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD ||
4678             (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN &&
4679              ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev)))
4680                 return true;
4681
4682         return false;
4683 }
4684
4685 static int rt6_multipath_total_weight(const struct fib6_info *rt)
4686 {
4687         struct fib6_info *iter;
4688         int total = 0;
4689
4690         if (!rt6_is_dead(rt))
4691                 total += rt->fib6_nh->fib_nh_weight;
4692
4693         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
4694                 if (!rt6_is_dead(iter))
4695                         total += iter->fib6_nh->fib_nh_weight;
4696         }
4697
4698         return total;
4699 }
4700
4701 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
4702 {
4703         int upper_bound = -1;
4704
4705         if (!rt6_is_dead(rt)) {
4706                 *weight += rt->fib6_nh->fib_nh_weight;
4707                 upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
4708                                                     total) - 1;
4709         }
4710         atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
4711 }
4712
4713 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
4714 {
4715         struct fib6_info *iter;
4716         int weight = 0;
4717
4718         rt6_upper_bound_set(rt, &weight, total);
4719
4720         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4721                 rt6_upper_bound_set(iter, &weight, total);
4722 }
4723
4724 void rt6_multipath_rebalance(struct fib6_info *rt)
4725 {
4726         struct fib6_info *first;
4727         int total;
4728
4729         /* In case the entire multipath route was marked for flushing,
4730          * then there is no need to rebalance upon the removal of every
4731          * sibling route.
4732          */
4733         if (!rt->fib6_nsiblings || rt->should_flush)
4734                 return;
4735
4736         /* During lookup routes are evaluated in order, so we need to
4737          * make sure upper bounds are assigned from the first sibling
4738          * onwards.
4739          */
4740         first = rt6_multipath_first_sibling(rt);
4741         if (WARN_ON_ONCE(!first))
4742                 return;
4743
4744         total = rt6_multipath_total_weight(first);
4745         rt6_multipath_upper_bound_set(first, total);
4746 }
4747
4748 static int fib6_ifup(struct fib6_info *rt, void *p_arg)
4749 {
4750         const struct arg_netdev_event *arg = p_arg;
4751         struct net *net = dev_net(arg->dev);
4752
4753         if (rt != net->ipv6.fib6_null_entry && !rt->nh &&
4754             rt->fib6_nh->fib_nh_dev == arg->dev) {
4755                 rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags;
4756                 fib6_update_sernum_upto_root(net, rt);
4757                 rt6_multipath_rebalance(rt);
4758         }
4759
4760         return 0;
4761 }
4762
4763 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags)
4764 {
4765         struct arg_netdev_event arg = {
4766                 .dev = dev,
4767                 {
4768                         .nh_flags = nh_flags,
4769                 },
4770         };
4771
4772         if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
4773                 arg.nh_flags |= RTNH_F_LINKDOWN;
4774
4775         fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
4776 }
4777
4778 /* only called for fib entries with inline fib6_nh */
4779 static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
4780                                    const struct net_device *dev)
4781 {
4782         struct fib6_info *iter;
4783
4784         if (rt->fib6_nh->fib_nh_dev == dev)
4785                 return true;
4786         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4787                 if (iter->fib6_nh->fib_nh_dev == dev)
4788                         return true;
4789
4790         return false;
4791 }
4792
4793 static void rt6_multipath_flush(struct fib6_info *rt)
4794 {
4795         struct fib6_info *iter;
4796
4797         rt->should_flush = 1;
4798         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4799                 iter->should_flush = 1;
4800 }
4801
4802 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
4803                                              const struct net_device *down_dev)
4804 {
4805         struct fib6_info *iter;
4806         unsigned int dead = 0;
4807
4808         if (rt->fib6_nh->fib_nh_dev == down_dev ||
4809             rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4810                 dead++;
4811         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4812                 if (iter->fib6_nh->fib_nh_dev == down_dev ||
4813                     iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4814                         dead++;
4815
4816         return dead;
4817 }
4818
4819 static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
4820                                        const struct net_device *dev,
4821                                        unsigned char nh_flags)
4822 {
4823         struct fib6_info *iter;
4824
4825         if (rt->fib6_nh->fib_nh_dev == dev)
4826                 rt->fib6_nh->fib_nh_flags |= nh_flags;
4827         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4828                 if (iter->fib6_nh->fib_nh_dev == dev)
4829                         iter->fib6_nh->fib_nh_flags |= nh_flags;
4830 }
4831
4832 /* called with write lock held for table with rt */
4833 static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
4834 {
4835         const struct arg_netdev_event *arg = p_arg;
4836         const struct net_device *dev = arg->dev;
4837         struct net *net = dev_net(dev);
4838
4839         if (rt == net->ipv6.fib6_null_entry || rt->nh)
4840                 return 0;
4841
4842         switch (arg->event) {
4843         case NETDEV_UNREGISTER:
4844                 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4845         case NETDEV_DOWN:
4846                 if (rt->should_flush)
4847                         return -1;
4848                 if (!rt->fib6_nsiblings)
4849                         return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4850                 if (rt6_multipath_uses_dev(rt, dev)) {
4851                         unsigned int count;
4852
4853                         count = rt6_multipath_dead_count(rt, dev);
4854                         if (rt->fib6_nsiblings + 1 == count) {
4855                                 rt6_multipath_flush(rt);
4856                                 return -1;
4857                         }
4858                         rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
4859                                                    RTNH_F_LINKDOWN);
4860                         fib6_update_sernum(net, rt);
4861                         rt6_multipath_rebalance(rt);
4862                 }
4863                 return -2;
4864         case NETDEV_CHANGE:
4865                 if (rt->fib6_nh->fib_nh_dev != dev ||
4866                     rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
4867                         break;
4868                 rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
4869                 rt6_multipath_rebalance(rt);
4870                 break;
4871         }
4872
4873         return 0;
4874 }
4875
4876 void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
4877 {
4878         struct arg_netdev_event arg = {
4879                 .dev = dev,
4880                 {
4881                         .event = event,
4882                 },
4883         };
4884         struct net *net = dev_net(dev);
4885
4886         if (net->ipv6.sysctl.skip_notify_on_dev_down)
4887                 fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
4888         else
4889                 fib6_clean_all(net, fib6_ifdown, &arg);
4890 }
4891
4892 void rt6_disable_ip(struct net_device *dev, unsigned long event)
4893 {
4894         rt6_sync_down_dev(dev, event);
4895         rt6_uncached_list_flush_dev(dev);
4896         neigh_ifdown(&nd_tbl, dev);
4897 }
4898
4899 struct rt6_mtu_change_arg {
4900         struct net_device *dev;
4901         unsigned int mtu;
4902         struct fib6_info *f6i;
4903 };
4904
4905 static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
4906 {
4907         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg;
4908         struct fib6_info *f6i = arg->f6i;
4909
4910         /* For administrative MTU increase, there is no way to discover
4911          * IPv6 PMTU increase, so PMTU increase should be updated here.
4912          * Since RFC 1981 doesn't include administrative MTU increase
4913          * update PMTU increase is a MUST. (i.e. jumbo frame)
4914          */
4915         if (nh->fib_nh_dev == arg->dev) {
4916                 struct inet6_dev *idev = __in6_dev_get(arg->dev);
4917                 u32 mtu = f6i->fib6_pmtu;
4918
4919                 if (mtu >= arg->mtu ||
4920                     (mtu < arg->mtu && mtu == idev->cnf.mtu6))
4921                         fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
4922
4923                 spin_lock_bh(&rt6_exception_lock);
4924                 rt6_exceptions_update_pmtu(idev, nh, arg->mtu);
4925                 spin_unlock_bh(&rt6_exception_lock);
4926         }
4927
4928         return 0;
4929 }
4930
4931 static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
4932 {
4933         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
4934         struct inet6_dev *idev;
4935
4936         /* In IPv6 pmtu discovery is not optional,
4937            so that RTAX_MTU lock cannot disable it.
4938            We still use this lock to block changes
4939            caused by addrconf/ndisc.
4940         */
4941
4942         idev = __in6_dev_get(arg->dev);
4943         if (!idev)
4944                 return 0;
4945
4946         if (fib6_metric_locked(f6i, RTAX_MTU))
4947                 return 0;
4948
4949         arg->f6i = f6i;
4950         if (f6i->nh) {
4951                 /* fib6_nh_mtu_change only returns 0, so this is safe */
4952                 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change,
4953                                                 arg);
4954         }
4955
4956         return fib6_nh_mtu_change(f6i->fib6_nh, arg);
4957 }
4958
4959 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
4960 {
4961         struct rt6_mtu_change_arg arg = {
4962                 .dev = dev,
4963                 .mtu = mtu,
4964         };
4965
4966         fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
4967 }
4968
4969 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
4970         [RTA_UNSPEC]            = { .strict_start_type = RTA_DPORT + 1 },
4971         [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
4972         [RTA_PREFSRC]           = { .len = sizeof(struct in6_addr) },
4973         [RTA_OIF]               = { .type = NLA_U32 },
4974         [RTA_IIF]               = { .type = NLA_U32 },
4975         [RTA_PRIORITY]          = { .type = NLA_U32 },
4976         [RTA_METRICS]           = { .type = NLA_NESTED },
4977         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
4978         [RTA_PREF]              = { .type = NLA_U8 },
4979         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
4980         [RTA_ENCAP]             = { .type = NLA_NESTED },
4981         [RTA_EXPIRES]           = { .type = NLA_U32 },
4982         [RTA_UID]               = { .type = NLA_U32 },
4983         [RTA_MARK]              = { .type = NLA_U32 },
4984         [RTA_TABLE]             = { .type = NLA_U32 },
4985         [RTA_IP_PROTO]          = { .type = NLA_U8 },
4986         [RTA_SPORT]             = { .type = NLA_U16 },
4987         [RTA_DPORT]             = { .type = NLA_U16 },
4988         [RTA_NH_ID]             = { .type = NLA_U32 },
4989 };
4990
4991 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
4992                               struct fib6_config *cfg,
4993                               struct netlink_ext_ack *extack)
4994 {
4995         struct rtmsg *rtm;
4996         struct nlattr *tb[RTA_MAX+1];
4997         unsigned int pref;
4998         int err;
4999
5000         err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5001                                      rtm_ipv6_policy, extack);
5002         if (err < 0)
5003                 goto errout;
5004
5005         err = -EINVAL;
5006         rtm = nlmsg_data(nlh);
5007
5008         if (rtm->rtm_tos) {
5009                 NL_SET_ERR_MSG(extack,
5010                                "Invalid dsfield (tos): option not available for IPv6");
5011                 goto errout;
5012         }
5013
5014         *cfg = (struct fib6_config){
5015                 .fc_table = rtm->rtm_table,
5016                 .fc_dst_len = rtm->rtm_dst_len,
5017                 .fc_src_len = rtm->rtm_src_len,
5018                 .fc_flags = RTF_UP,
5019                 .fc_protocol = rtm->rtm_protocol,
5020                 .fc_type = rtm->rtm_type,
5021
5022                 .fc_nlinfo.portid = NETLINK_CB(skb).portid,
5023                 .fc_nlinfo.nlh = nlh,
5024                 .fc_nlinfo.nl_net = sock_net(skb->sk),
5025         };
5026
5027         if (rtm->rtm_type == RTN_UNREACHABLE ||
5028             rtm->rtm_type == RTN_BLACKHOLE ||
5029             rtm->rtm_type == RTN_PROHIBIT ||
5030             rtm->rtm_type == RTN_THROW)
5031                 cfg->fc_flags |= RTF_REJECT;
5032
5033         if (rtm->rtm_type == RTN_LOCAL)
5034                 cfg->fc_flags |= RTF_LOCAL;
5035
5036         if (rtm->rtm_flags & RTM_F_CLONED)
5037                 cfg->fc_flags |= RTF_CACHE;
5038
5039         cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
5040
5041         if (tb[RTA_NH_ID]) {
5042                 if (tb[RTA_GATEWAY]   || tb[RTA_OIF] ||
5043                     tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {
5044                         NL_SET_ERR_MSG(extack,
5045                                        "Nexthop specification and nexthop id are mutually exclusive");
5046                         goto errout;
5047                 }
5048                 cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);
5049         }
5050
5051         if (tb[RTA_GATEWAY]) {
5052                 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
5053                 cfg->fc_flags |= RTF_GATEWAY;
5054         }
5055         if (tb[RTA_VIA]) {
5056                 NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
5057                 goto errout;
5058         }
5059
5060         if (tb[RTA_DST]) {
5061                 int plen = (rtm->rtm_dst_len + 7) >> 3;
5062
5063                 if (nla_len(tb[RTA_DST]) < plen)
5064                         goto errout;
5065
5066                 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
5067         }
5068
5069         if (tb[RTA_SRC]) {
5070                 int plen = (rtm->rtm_src_len + 7) >> 3;
5071
5072                 if (nla_len(tb[RTA_SRC]) < plen)
5073                         goto errout;
5074
5075                 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
5076         }
5077
5078         if (tb[RTA_PREFSRC])
5079                 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
5080
5081         if (tb[RTA_OIF])
5082                 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
5083
5084         if (tb[RTA_PRIORITY])
5085                 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
5086
5087         if (tb[RTA_METRICS]) {
5088                 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
5089                 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
5090         }
5091
5092         if (tb[RTA_TABLE])
5093                 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
5094
5095         if (tb[RTA_MULTIPATH]) {
5096                 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
5097                 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
5098
5099                 err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
5100                                                      cfg->fc_mp_len, extack);
5101                 if (err < 0)
5102                         goto errout;
5103         }
5104
5105         if (tb[RTA_PREF]) {
5106                 pref = nla_get_u8(tb[RTA_PREF]);
5107                 if (pref != ICMPV6_ROUTER_PREF_LOW &&
5108                     pref != ICMPV6_ROUTER_PREF_HIGH)
5109                         pref = ICMPV6_ROUTER_PREF_MEDIUM;
5110                 cfg->fc_flags |= RTF_PREF(pref);
5111         }
5112
5113         if (tb[RTA_ENCAP])
5114                 cfg->fc_encap = tb[RTA_ENCAP];
5115
5116         if (tb[RTA_ENCAP_TYPE]) {
5117                 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
5118
5119                 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
5120                 if (err < 0)
5121                         goto errout;
5122         }
5123
5124         if (tb[RTA_EXPIRES]) {
5125                 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
5126
5127                 if (addrconf_finite_timeout(timeout)) {
5128                         cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
5129                         cfg->fc_flags |= RTF_EXPIRES;
5130                 }
5131         }
5132
5133         err = 0;
5134 errout:
5135         return err;
5136 }
5137
5138 struct rt6_nh {
5139         struct fib6_info *fib6_info;
5140         struct fib6_config r_cfg;
5141         struct list_head next;
5142 };
5143
5144 static int ip6_route_info_append(struct net *net,
5145                                  struct list_head *rt6_nh_list,
5146                                  struct fib6_info *rt,
5147                                  struct fib6_config *r_cfg)
5148 {
5149         struct rt6_nh *nh;
5150         int err = -EEXIST;
5151
5152         list_for_each_entry(nh, rt6_nh_list, next) {
5153                 /* check if fib6_info already exists */
5154                 if (rt6_duplicate_nexthop(nh->fib6_info, rt))
5155                         return err;
5156         }
5157
5158         nh = kzalloc(sizeof(*nh), GFP_KERNEL);
5159         if (!nh)
5160                 return -ENOMEM;
5161         nh->fib6_info = rt;
5162         memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
5163         list_add_tail(&nh->next, rt6_nh_list);
5164
5165         return 0;
5166 }
5167
5168 static void ip6_route_mpath_notify(struct fib6_info *rt,
5169                                    struct fib6_info *rt_last,
5170                                    struct nl_info *info,
5171                                    __u16 nlflags)
5172 {
5173         /* if this is an APPEND route, then rt points to the first route
5174          * inserted and rt_last points to last route inserted. Userspace
5175          * wants a consistent dump of the route which starts at the first
5176          * nexthop. Since sibling routes are always added at the end of
5177          * the list, find the first sibling of the last route appended
5178          */
5179         if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
5180                 rt = list_first_entry(&rt_last->fib6_siblings,
5181                                       struct fib6_info,
5182                                       fib6_siblings);
5183         }
5184
5185         if (rt)
5186                 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
5187 }
5188
5189 static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
5190 {
5191         bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
5192         bool should_notify = false;
5193         struct fib6_info *leaf;
5194         struct fib6_node *fn;
5195
5196         rcu_read_lock();
5197         fn = rcu_dereference(rt->fib6_node);
5198         if (!fn)
5199                 goto out;
5200
5201         leaf = rcu_dereference(fn->leaf);
5202         if (!leaf)
5203                 goto out;
5204
5205         if (rt == leaf ||
5206             (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric &&
5207              rt6_qualify_for_ecmp(leaf)))
5208                 should_notify = true;
5209 out:
5210         rcu_read_unlock();
5211
5212         return should_notify;
5213 }
5214
5215 static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla,
5216                              struct netlink_ext_ack *extack)
5217 {
5218         if (nla_len(nla) < sizeof(*gw)) {
5219                 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY");
5220                 return -EINVAL;
5221         }
5222
5223         *gw = nla_get_in6_addr(nla);
5224
5225         return 0;
5226 }
5227
5228 static int ip6_route_multipath_add(struct fib6_config *cfg,
5229                                    struct netlink_ext_ack *extack)
5230 {
5231         struct fib6_info *rt_notif = NULL, *rt_last = NULL;
5232         struct nl_info *info = &cfg->fc_nlinfo;
5233         struct fib6_config r_cfg;
5234         struct rtnexthop *rtnh;
5235         struct fib6_info *rt;
5236         struct rt6_nh *err_nh;
5237         struct rt6_nh *nh, *nh_safe;
5238         __u16 nlflags;
5239         int remaining;
5240         int attrlen;
5241         int err = 1;
5242         int nhn = 0;
5243         int replace = (cfg->fc_nlinfo.nlh &&
5244                        (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
5245         LIST_HEAD(rt6_nh_list);
5246
5247         nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
5248         if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
5249                 nlflags |= NLM_F_APPEND;
5250
5251         remaining = cfg->fc_mp_len;
5252         rtnh = (struct rtnexthop *)cfg->fc_mp;
5253
5254         /* Parse a Multipath Entry and build a list (rt6_nh_list) of
5255          * fib6_info structs per nexthop
5256          */
5257         while (rtnh_ok(rtnh, remaining)) {
5258                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5259                 if (rtnh->rtnh_ifindex)
5260                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5261
5262                 attrlen = rtnh_attrlen(rtnh);
5263                 if (attrlen > 0) {
5264                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5265
5266                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5267                         if (nla) {
5268                                 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5269                                                         extack);
5270                                 if (err)
5271                                         goto cleanup;
5272
5273                                 r_cfg.fc_flags |= RTF_GATEWAY;
5274                         }
5275                         r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
5276
5277                         /* RTA_ENCAP_TYPE length checked in
5278                          * lwtunnel_valid_encap_type_attr
5279                          */
5280                         nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
5281                         if (nla)
5282                                 r_cfg.fc_encap_type = nla_get_u16(nla);
5283                 }
5284
5285                 r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
5286                 rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
5287                 if (IS_ERR(rt)) {
5288                         err = PTR_ERR(rt);
5289                         rt = NULL;
5290                         goto cleanup;
5291                 }
5292                 if (!rt6_qualify_for_ecmp(rt)) {
5293                         err = -EINVAL;
5294                         NL_SET_ERR_MSG(extack,
5295                                        "Device only routes can not be added for IPv6 using the multipath API.");
5296                         fib6_info_release(rt);
5297                         goto cleanup;
5298                 }
5299
5300                 rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
5301
5302                 err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
5303                                             rt, &r_cfg);
5304                 if (err) {
5305                         fib6_info_release(rt);
5306                         goto cleanup;
5307                 }
5308
5309                 rtnh = rtnh_next(rtnh, &remaining);
5310         }
5311
5312         if (list_empty(&rt6_nh_list)) {
5313                 NL_SET_ERR_MSG(extack,
5314                                "Invalid nexthop configuration - no valid nexthops");
5315                 return -EINVAL;
5316         }
5317
5318         /* for add and replace send one notification with all nexthops.
5319          * Skip the notification in fib6_add_rt2node and send one with
5320          * the full route when done
5321          */
5322         info->skip_notify = 1;
5323
5324         /* For add and replace, send one notification with all nexthops. For
5325          * append, send one notification with all appended nexthops.
5326          */
5327         info->skip_notify_kernel = 1;
5328
5329         err_nh = NULL;
5330         list_for_each_entry(nh, &rt6_nh_list, next) {
5331                 err = __ip6_ins_rt(nh->fib6_info, info, extack);
5332                 fib6_info_release(nh->fib6_info);
5333
5334                 if (!err) {
5335                         /* save reference to last route successfully inserted */
5336                         rt_last = nh->fib6_info;
5337
5338                         /* save reference to first route for notification */
5339                         if (!rt_notif)
5340                                 rt_notif = nh->fib6_info;
5341                 }
5342
5343                 /* nh->fib6_info is used or freed at this point, reset to NULL*/
5344                 nh->fib6_info = NULL;
5345                 if (err) {
5346                         if (replace && nhn)
5347                                 NL_SET_ERR_MSG_MOD(extack,
5348                                                    "multipath route replace failed (check consistency of installed routes)");
5349                         err_nh = nh;
5350                         goto add_errout;
5351                 }
5352
5353                 /* Because each route is added like a single route we remove
5354                  * these flags after the first nexthop: if there is a collision,
5355                  * we have already failed to add the first nexthop:
5356                  * fib6_add_rt2node() has rejected it; when replacing, old
5357                  * nexthops have been replaced by first new, the rest should
5358                  * be added to it.
5359                  */
5360                 if (cfg->fc_nlinfo.nlh) {
5361                         cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
5362                                                              NLM_F_REPLACE);
5363                         cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
5364                 }
5365                 nhn++;
5366         }
5367
5368         /* An in-kernel notification should only be sent in case the new
5369          * multipath route is added as the first route in the node, or if
5370          * it was appended to it. We pass 'rt_notif' since it is the first
5371          * sibling and might allow us to skip some checks in the replace case.
5372          */
5373         if (ip6_route_mpath_should_notify(rt_notif)) {
5374                 enum fib_event_type fib_event;
5375
5376                 if (rt_notif->fib6_nsiblings != nhn - 1)
5377                         fib_event = FIB_EVENT_ENTRY_APPEND;
5378                 else
5379                         fib_event = FIB_EVENT_ENTRY_REPLACE;
5380
5381                 err = call_fib6_multipath_entry_notifiers(info->nl_net,
5382                                                           fib_event, rt_notif,
5383                                                           nhn - 1, extack);
5384                 if (err) {
5385                         /* Delete all the siblings that were just added */
5386                         err_nh = NULL;
5387                         goto add_errout;
5388                 }
5389         }
5390
5391         /* success ... tell user about new route */
5392         ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5393         goto cleanup;
5394
5395 add_errout:
5396         /* send notification for routes that were added so that
5397          * the delete notifications sent by ip6_route_del are
5398          * coherent
5399          */
5400         if (rt_notif)
5401                 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5402
5403         /* Delete routes that were already added */
5404         list_for_each_entry(nh, &rt6_nh_list, next) {
5405                 if (err_nh == nh)
5406                         break;
5407                 ip6_route_del(&nh->r_cfg, extack);
5408         }
5409
5410 cleanup:
5411         list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
5412                 if (nh->fib6_info)
5413                         fib6_info_release(nh->fib6_info);
5414                 list_del(&nh->next);
5415                 kfree(nh);
5416         }
5417
5418         return err;
5419 }
5420
5421 static int ip6_route_multipath_del(struct fib6_config *cfg,
5422                                    struct netlink_ext_ack *extack)
5423 {
5424         struct fib6_config r_cfg;
5425         struct rtnexthop *rtnh;
5426         int last_err = 0;
5427         int remaining;
5428         int attrlen;
5429         int err;
5430
5431         remaining = cfg->fc_mp_len;
5432         rtnh = (struct rtnexthop *)cfg->fc_mp;
5433
5434         /* Parse a Multipath Entry */
5435         while (rtnh_ok(rtnh, remaining)) {
5436                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5437                 if (rtnh->rtnh_ifindex)
5438                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5439
5440                 attrlen = rtnh_attrlen(rtnh);
5441                 if (attrlen > 0) {
5442                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5443
5444                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5445                         if (nla) {
5446                                 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5447                                                         extack);
5448                                 if (err) {
5449                                         last_err = err;
5450                                         goto next_rtnh;
5451                                 }
5452
5453                                 r_cfg.fc_flags |= RTF_GATEWAY;
5454                         }
5455                 }
5456                 err = ip6_route_del(&r_cfg, extack);
5457                 if (err)
5458                         last_err = err;
5459
5460 next_rtnh:
5461                 rtnh = rtnh_next(rtnh, &remaining);
5462         }
5463
5464         return last_err;
5465 }
5466
5467 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5468                               struct netlink_ext_ack *extack)
5469 {
5470         struct fib6_config cfg;
5471         int err;
5472
5473         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5474         if (err < 0)
5475                 return err;
5476
5477         if (cfg.fc_nh_id &&
5478             !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {
5479                 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
5480                 return -EINVAL;
5481         }
5482
5483         if (cfg.fc_mp)
5484                 return ip6_route_multipath_del(&cfg, extack);
5485         else {
5486                 cfg.fc_delete_all_nh = 1;
5487                 return ip6_route_del(&cfg, extack);
5488         }
5489 }
5490
5491 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5492                               struct netlink_ext_ack *extack)
5493 {
5494         struct fib6_config cfg;
5495         int err;
5496
5497         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5498         if (err < 0)
5499                 return err;
5500
5501         if (cfg.fc_metric == 0)
5502                 cfg.fc_metric = IP6_RT_PRIO_USER;
5503
5504         if (cfg.fc_mp)
5505                 return ip6_route_multipath_add(&cfg, extack);
5506         else
5507                 return ip6_route_add(&cfg, GFP_KERNEL, extack);
5508 }
5509
5510 /* add the overhead of this fib6_nh to nexthop_len */
5511 static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg)
5512 {
5513         int *nexthop_len = arg;
5514
5515         *nexthop_len += nla_total_size(0)        /* RTA_MULTIPATH */
5516                      + NLA_ALIGN(sizeof(struct rtnexthop))
5517                      + nla_total_size(16); /* RTA_GATEWAY */
5518
5519         if (nh->fib_nh_lws) {
5520                 /* RTA_ENCAP_TYPE */
5521                 *nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5522                 /* RTA_ENCAP */
5523                 *nexthop_len += nla_total_size(2);
5524         }
5525
5526         return 0;
5527 }
5528
5529 static size_t rt6_nlmsg_size(struct fib6_info *f6i)
5530 {
5531         int nexthop_len;
5532
5533         if (f6i->nh) {
5534                 nexthop_len = nla_total_size(4); /* RTA_NH_ID */
5535                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
5536                                          &nexthop_len);
5537         } else {
5538                 struct fib6_info *sibling, *next_sibling;
5539                 struct fib6_nh *nh = f6i->fib6_nh;
5540
5541                 nexthop_len = 0;
5542                 if (f6i->fib6_nsiblings) {
5543                         rt6_nh_nlmsg_size(nh, &nexthop_len);
5544
5545                         list_for_each_entry_safe(sibling, next_sibling,
5546                                                  &f6i->fib6_siblings, fib6_siblings) {
5547                                 rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len);
5548                         }
5549                 }
5550                 nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5551         }
5552
5553         return NLMSG_ALIGN(sizeof(struct rtmsg))
5554                + nla_total_size(16) /* RTA_SRC */
5555                + nla_total_size(16) /* RTA_DST */
5556                + nla_total_size(16) /* RTA_GATEWAY */
5557                + nla_total_size(16) /* RTA_PREFSRC */
5558                + nla_total_size(4) /* RTA_TABLE */
5559                + nla_total_size(4) /* RTA_IIF */
5560                + nla_total_size(4) /* RTA_OIF */
5561                + nla_total_size(4) /* RTA_PRIORITY */
5562                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
5563                + nla_total_size(sizeof(struct rta_cacheinfo))
5564                + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
5565                + nla_total_size(1) /* RTA_PREF */
5566                + nexthop_len;
5567 }
5568
5569 static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh,
5570                                  unsigned char *flags)
5571 {
5572         if (nexthop_is_multipath(nh)) {
5573                 struct nlattr *mp;
5574
5575                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5576                 if (!mp)
5577                         goto nla_put_failure;
5578
5579                 if (nexthop_mpath_fill_node(skb, nh, AF_INET6))
5580                         goto nla_put_failure;
5581
5582                 nla_nest_end(skb, mp);
5583         } else {
5584                 struct fib6_nh *fib6_nh;
5585
5586                 fib6_nh = nexthop_fib6_nh(nh);
5587                 if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,
5588                                      flags, false) < 0)
5589                         goto nla_put_failure;
5590         }
5591
5592         return 0;
5593
5594 nla_put_failure:
5595         return -EMSGSIZE;
5596 }
5597
5598 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
5599                          struct fib6_info *rt, struct dst_entry *dst,
5600                          struct in6_addr *dest, struct in6_addr *src,
5601                          int iif, int type, u32 portid, u32 seq,
5602                          unsigned int flags)
5603 {
5604         struct rt6_info *rt6 = (struct rt6_info *)dst;
5605         struct rt6key *rt6_dst, *rt6_src;
5606         u32 *pmetrics, table, rt6_flags;
5607         unsigned char nh_flags = 0;
5608         struct nlmsghdr *nlh;
5609         struct rtmsg *rtm;
5610         long expires = 0;
5611
5612         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
5613         if (!nlh)
5614                 return -EMSGSIZE;
5615
5616         if (rt6) {
5617                 rt6_dst = &rt6->rt6i_dst;
5618                 rt6_src = &rt6->rt6i_src;
5619                 rt6_flags = rt6->rt6i_flags;
5620         } else {
5621                 rt6_dst = &rt->fib6_dst;
5622                 rt6_src = &rt->fib6_src;
5623                 rt6_flags = rt->fib6_flags;
5624         }
5625
5626         rtm = nlmsg_data(nlh);
5627         rtm->rtm_family = AF_INET6;
5628         rtm->rtm_dst_len = rt6_dst->plen;
5629         rtm->rtm_src_len = rt6_src->plen;
5630         rtm->rtm_tos = 0;
5631         if (rt->fib6_table)
5632                 table = rt->fib6_table->tb6_id;
5633         else
5634                 table = RT6_TABLE_UNSPEC;
5635         rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
5636         if (nla_put_u32(skb, RTA_TABLE, table))
5637                 goto nla_put_failure;
5638
5639         rtm->rtm_type = rt->fib6_type;
5640         rtm->rtm_flags = 0;
5641         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
5642         rtm->rtm_protocol = rt->fib6_protocol;
5643
5644         if (rt6_flags & RTF_CACHE)
5645                 rtm->rtm_flags |= RTM_F_CLONED;
5646
5647         if (dest) {
5648                 if (nla_put_in6_addr(skb, RTA_DST, dest))
5649                         goto nla_put_failure;
5650                 rtm->rtm_dst_len = 128;
5651         } else if (rtm->rtm_dst_len)
5652                 if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
5653                         goto nla_put_failure;
5654 #ifdef CONFIG_IPV6_SUBTREES
5655         if (src) {
5656                 if (nla_put_in6_addr(skb, RTA_SRC, src))
5657                         goto nla_put_failure;
5658                 rtm->rtm_src_len = 128;
5659         } else if (rtm->rtm_src_len &&
5660                    nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
5661                 goto nla_put_failure;
5662 #endif
5663         if (iif) {
5664 #ifdef CONFIG_IPV6_MROUTE
5665                 if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
5666                         int err = ip6mr_get_route(net, skb, rtm, portid);
5667
5668                         if (err == 0)
5669                                 return 0;
5670                         if (err < 0)
5671                                 goto nla_put_failure;
5672                 } else
5673 #endif
5674                         if (nla_put_u32(skb, RTA_IIF, iif))
5675                                 goto nla_put_failure;
5676         } else if (dest) {
5677                 struct in6_addr saddr_buf;
5678                 if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 &&
5679                     nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5680                         goto nla_put_failure;
5681         }
5682
5683         if (rt->fib6_prefsrc.plen) {
5684                 struct in6_addr saddr_buf;
5685                 saddr_buf = rt->fib6_prefsrc.addr;
5686                 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5687                         goto nla_put_failure;
5688         }
5689
5690         pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
5691         if (rtnetlink_put_metrics(skb, pmetrics) < 0)
5692                 goto nla_put_failure;
5693
5694         if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
5695                 goto nla_put_failure;
5696
5697         /* For multipath routes, walk the siblings list and add
5698          * each as a nexthop within RTA_MULTIPATH.
5699          */
5700         if (rt6) {
5701                 if (rt6_flags & RTF_GATEWAY &&
5702                     nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
5703                         goto nla_put_failure;
5704
5705                 if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
5706                         goto nla_put_failure;
5707
5708                 if (dst->lwtstate &&
5709                     lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
5710                         goto nla_put_failure;
5711         } else if (rt->fib6_nsiblings) {
5712                 struct fib6_info *sibling, *next_sibling;
5713                 struct nlattr *mp;
5714
5715                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5716                 if (!mp)
5717                         goto nla_put_failure;
5718
5719                 if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
5720                                     rt->fib6_nh->fib_nh_weight, AF_INET6,
5721                                     0) < 0)
5722                         goto nla_put_failure;
5723
5724                 list_for_each_entry_safe(sibling, next_sibling,
5725                                          &rt->fib6_siblings, fib6_siblings) {
5726                         if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
5727                                             sibling->fib6_nh->fib_nh_weight,
5728                                             AF_INET6, 0) < 0)
5729                                 goto nla_put_failure;
5730                 }
5731
5732                 nla_nest_end(skb, mp);
5733         } else if (rt->nh) {
5734                 if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
5735                         goto nla_put_failure;
5736
5737                 if (nexthop_is_blackhole(rt->nh))
5738                         rtm->rtm_type = RTN_BLACKHOLE;
5739
5740                 if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) &&
5741                     rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0)
5742                         goto nla_put_failure;
5743
5744                 rtm->rtm_flags |= nh_flags;
5745         } else {
5746                 if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,
5747                                      &nh_flags, false) < 0)
5748                         goto nla_put_failure;
5749
5750                 rtm->rtm_flags |= nh_flags;
5751         }
5752
5753         if (rt6_flags & RTF_EXPIRES) {
5754                 expires = dst ? dst->expires : rt->expires;
5755                 expires -= jiffies;
5756         }
5757
5758         if (!dst) {
5759                 if (READ_ONCE(rt->offload))
5760                         rtm->rtm_flags |= RTM_F_OFFLOAD;
5761                 if (READ_ONCE(rt->trap))
5762                         rtm->rtm_flags |= RTM_F_TRAP;
5763                 if (READ_ONCE(rt->offload_failed))
5764                         rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED;
5765         }
5766
5767         if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
5768                 goto nla_put_failure;
5769
5770         if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
5771                 goto nla_put_failure;
5772
5773
5774         nlmsg_end(skb, nlh);
5775         return 0;
5776
5777 nla_put_failure:
5778         nlmsg_cancel(skb, nlh);
5779         return -EMSGSIZE;
5780 }
5781
5782 static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg)
5783 {
5784         const struct net_device *dev = arg;
5785
5786         if (nh->fib_nh_dev == dev)
5787                 return 1;
5788
5789         return 0;
5790 }
5791
5792 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
5793                                const struct net_device *dev)
5794 {
5795         if (f6i->nh) {
5796                 struct net_device *_dev = (struct net_device *)dev;
5797
5798                 return !!nexthop_for_each_fib6_nh(f6i->nh,
5799                                                   fib6_info_nh_uses_dev,
5800                                                   _dev);
5801         }
5802
5803         if (f6i->fib6_nh->fib_nh_dev == dev)
5804                 return true;
5805
5806         if (f6i->fib6_nsiblings) {
5807                 struct fib6_info *sibling, *next_sibling;
5808
5809                 list_for_each_entry_safe(sibling, next_sibling,
5810                                          &f6i->fib6_siblings, fib6_siblings) {
5811                         if (sibling->fib6_nh->fib_nh_dev == dev)
5812                                 return true;
5813                 }
5814         }
5815
5816         return false;
5817 }
5818
5819 struct fib6_nh_exception_dump_walker {
5820         struct rt6_rtnl_dump_arg *dump;
5821         struct fib6_info *rt;
5822         unsigned int flags;
5823         unsigned int skip;
5824         unsigned int count;
5825 };
5826
5827 static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg)
5828 {
5829         struct fib6_nh_exception_dump_walker *w = arg;
5830         struct rt6_rtnl_dump_arg *dump = w->dump;
5831         struct rt6_exception_bucket *bucket;
5832         struct rt6_exception *rt6_ex;
5833         int i, err;
5834
5835         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
5836         if (!bucket)
5837                 return 0;
5838
5839         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
5840                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
5841                         if (w->skip) {
5842                                 w->skip--;
5843                                 continue;
5844                         }
5845
5846                         /* Expiration of entries doesn't bump sernum, insertion
5847                          * does. Removal is triggered by insertion, so we can
5848                          * rely on the fact that if entries change between two
5849                          * partial dumps, this node is scanned again completely,
5850                          * see rt6_insert_exception() and fib6_dump_table().
5851                          *
5852                          * Count expired entries we go through as handled
5853                          * entries that we'll skip next time, in case of partial
5854                          * node dump. Otherwise, if entries expire meanwhile,
5855                          * we'll skip the wrong amount.
5856                          */
5857                         if (rt6_check_expired(rt6_ex->rt6i)) {
5858                                 w->count++;
5859                                 continue;
5860                         }
5861
5862                         err = rt6_fill_node(dump->net, dump->skb, w->rt,
5863                                             &rt6_ex->rt6i->dst, NULL, NULL, 0,
5864                                             RTM_NEWROUTE,
5865                                             NETLINK_CB(dump->cb->skb).portid,
5866                                             dump->cb->nlh->nlmsg_seq, w->flags);
5867                         if (err)
5868                                 return err;
5869
5870                         w->count++;
5871                 }
5872                 bucket++;
5873         }
5874
5875         return 0;
5876 }
5877
5878 /* Return -1 if done with node, number of handled routes on partial dump */
5879 int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip)
5880 {
5881         struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
5882         struct fib_dump_filter *filter = &arg->filter;
5883         unsigned int flags = NLM_F_MULTI;
5884         struct net *net = arg->net;
5885         int count = 0;
5886
5887         if (rt == net->ipv6.fib6_null_entry)
5888                 return -1;
5889
5890         if ((filter->flags & RTM_F_PREFIX) &&
5891             !(rt->fib6_flags & RTF_PREFIX_RT)) {
5892                 /* success since this is not a prefix route */
5893                 return -1;
5894         }
5895         if (filter->filter_set &&
5896             ((filter->rt_type  && rt->fib6_type != filter->rt_type) ||
5897              (filter->dev      && !fib6_info_uses_dev(rt, filter->dev)) ||
5898              (filter->protocol && rt->fib6_protocol != filter->protocol))) {
5899                 return -1;
5900         }
5901
5902         if (filter->filter_set ||
5903             !filter->dump_routes || !filter->dump_exceptions) {
5904                 flags |= NLM_F_DUMP_FILTERED;
5905         }
5906
5907         if (filter->dump_routes) {
5908                 if (skip) {
5909                         skip--;
5910                 } else {
5911                         if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL,
5912                                           0, RTM_NEWROUTE,
5913                                           NETLINK_CB(arg->cb->skb).portid,
5914                                           arg->cb->nlh->nlmsg_seq, flags)) {
5915                                 return 0;
5916                         }
5917                         count++;
5918                 }
5919         }
5920
5921         if (filter->dump_exceptions) {
5922                 struct fib6_nh_exception_dump_walker w = { .dump = arg,
5923                                                            .rt = rt,
5924                                                            .flags = flags,
5925                                                            .skip = skip,
5926                                                            .count = 0 };
5927                 int err;
5928
5929                 rcu_read_lock();
5930                 if (rt->nh) {
5931                         err = nexthop_for_each_fib6_nh(rt->nh,
5932                                                        rt6_nh_dump_exceptions,
5933                                                        &w);
5934                 } else {
5935                         err = rt6_nh_dump_exceptions(rt->fib6_nh, &w);
5936                 }
5937                 rcu_read_unlock();
5938
5939                 if (err)
5940                         return count + w.count;
5941         }
5942
5943         return -1;
5944 }
5945
5946 static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
5947                                         const struct nlmsghdr *nlh,
5948                                         struct nlattr **tb,
5949                                         struct netlink_ext_ack *extack)
5950 {
5951         struct rtmsg *rtm;
5952         int i, err;
5953
5954         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
5955                 NL_SET_ERR_MSG_MOD(extack,
5956                                    "Invalid header for get route request");
5957                 return -EINVAL;
5958         }
5959
5960         if (!netlink_strict_get_check(skb))
5961                 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5962                                               rtm_ipv6_policy, extack);
5963
5964         rtm = nlmsg_data(nlh);
5965         if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
5966             (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
5967             rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
5968             rtm->rtm_type) {
5969                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
5970                 return -EINVAL;
5971         }
5972         if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
5973                 NL_SET_ERR_MSG_MOD(extack,
5974                                    "Invalid flags for get route request");
5975                 return -EINVAL;
5976         }
5977
5978         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
5979                                             rtm_ipv6_policy, extack);
5980         if (err)
5981                 return err;
5982
5983         if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
5984             (tb[RTA_DST] && !rtm->rtm_dst_len)) {
5985                 NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
5986                 return -EINVAL;
5987         }
5988
5989         for (i = 0; i <= RTA_MAX; i++) {
5990                 if (!tb[i])
5991                         continue;
5992
5993                 switch (i) {
5994                 case RTA_SRC:
5995                 case RTA_DST:
5996                 case RTA_IIF:
5997                 case RTA_OIF:
5998                 case RTA_MARK:
5999                 case RTA_UID:
6000                 case RTA_SPORT:
6001                 case RTA_DPORT:
6002                 case RTA_IP_PROTO:
6003                         break;
6004                 default:
6005                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
6006                         return -EINVAL;
6007                 }
6008         }
6009
6010         return 0;
6011 }
6012
6013 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
6014                               struct netlink_ext_ack *extack)
6015 {
6016         struct net *net = sock_net(in_skb->sk);
6017         struct nlattr *tb[RTA_MAX+1];
6018         int err, iif = 0, oif = 0;
6019         struct fib6_info *from;
6020         struct dst_entry *dst;
6021         struct rt6_info *rt;
6022         struct sk_buff *skb;
6023         struct rtmsg *rtm;
6024         struct flowi6 fl6 = {};
6025         bool fibmatch;
6026
6027         err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
6028         if (err < 0)
6029                 goto errout;
6030
6031         err = -EINVAL;
6032         rtm = nlmsg_data(nlh);
6033         fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
6034         fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
6035
6036         if (tb[RTA_SRC]) {
6037                 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
6038                         goto errout;
6039
6040                 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
6041         }
6042
6043         if (tb[RTA_DST]) {
6044                 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
6045                         goto errout;
6046
6047                 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
6048         }
6049
6050         if (tb[RTA_IIF])
6051                 iif = nla_get_u32(tb[RTA_IIF]);
6052
6053         if (tb[RTA_OIF])
6054                 oif = nla_get_u32(tb[RTA_OIF]);
6055
6056         if (tb[RTA_MARK])
6057                 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
6058
6059         if (tb[RTA_UID])
6060                 fl6.flowi6_uid = make_kuid(current_user_ns(),
6061                                            nla_get_u32(tb[RTA_UID]));
6062         else
6063                 fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
6064
6065         if (tb[RTA_SPORT])
6066                 fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
6067
6068         if (tb[RTA_DPORT])
6069                 fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
6070
6071         if (tb[RTA_IP_PROTO]) {
6072                 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
6073                                                   &fl6.flowi6_proto, AF_INET6,
6074                                                   extack);
6075                 if (err)
6076                         goto errout;
6077         }
6078
6079         if (iif) {
6080                 struct net_device *dev;
6081                 int flags = 0;
6082
6083                 rcu_read_lock();
6084
6085                 dev = dev_get_by_index_rcu(net, iif);
6086                 if (!dev) {
6087                         rcu_read_unlock();
6088                         err = -ENODEV;
6089                         goto errout;
6090                 }
6091
6092                 fl6.flowi6_iif = iif;
6093
6094                 if (!ipv6_addr_any(&fl6.saddr))
6095                         flags |= RT6_LOOKUP_F_HAS_SADDR;
6096
6097                 dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
6098
6099                 rcu_read_unlock();
6100         } else {
6101                 fl6.flowi6_oif = oif;
6102
6103                 dst = ip6_route_output(net, NULL, &fl6);
6104         }
6105
6106
6107         rt = container_of(dst, struct rt6_info, dst);
6108         if (rt->dst.error) {
6109                 err = rt->dst.error;
6110                 ip6_rt_put(rt);
6111                 goto errout;
6112         }
6113
6114         if (rt == net->ipv6.ip6_null_entry) {
6115                 err = rt->dst.error;
6116                 ip6_rt_put(rt);
6117                 goto errout;
6118         }
6119
6120         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
6121         if (!skb) {
6122                 ip6_rt_put(rt);
6123                 err = -ENOBUFS;
6124                 goto errout;
6125         }
6126
6127         skb_dst_set(skb, &rt->dst);
6128
6129         rcu_read_lock();
6130         from = rcu_dereference(rt->from);
6131         if (from) {
6132                 if (fibmatch)
6133                         err = rt6_fill_node(net, skb, from, NULL, NULL, NULL,
6134                                             iif, RTM_NEWROUTE,
6135                                             NETLINK_CB(in_skb).portid,
6136                                             nlh->nlmsg_seq, 0);
6137                 else
6138                         err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
6139                                             &fl6.saddr, iif, RTM_NEWROUTE,
6140                                             NETLINK_CB(in_skb).portid,
6141                                             nlh->nlmsg_seq, 0);
6142         } else {
6143                 err = -ENETUNREACH;
6144         }
6145         rcu_read_unlock();
6146
6147         if (err < 0) {
6148                 kfree_skb(skb);
6149                 goto errout;
6150         }
6151
6152         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
6153 errout:
6154         return err;
6155 }
6156
6157 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
6158                      unsigned int nlm_flags)
6159 {
6160         struct sk_buff *skb;
6161         struct net *net = info->nl_net;
6162         u32 seq;
6163         int err;
6164
6165         err = -ENOBUFS;
6166         seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6167
6168         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6169         if (!skb)
6170                 goto errout;
6171
6172         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6173                             event, info->portid, seq, nlm_flags);
6174         if (err < 0) {
6175                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6176                 WARN_ON(err == -EMSGSIZE);
6177                 kfree_skb(skb);
6178                 goto errout;
6179         }
6180         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6181                     info->nlh, gfp_any());
6182         return;
6183 errout:
6184         if (err < 0)
6185                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6186 }
6187
6188 void fib6_rt_update(struct net *net, struct fib6_info *rt,
6189                     struct nl_info *info)
6190 {
6191         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6192         struct sk_buff *skb;
6193         int err = -ENOBUFS;
6194
6195         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6196         if (!skb)
6197                 goto errout;
6198
6199         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6200                             RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
6201         if (err < 0) {
6202                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6203                 WARN_ON(err == -EMSGSIZE);
6204                 kfree_skb(skb);
6205                 goto errout;
6206         }
6207         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6208                     info->nlh, gfp_any());
6209         return;
6210 errout:
6211         if (err < 0)
6212                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6213 }
6214
6215 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
6216                             bool offload, bool trap, bool offload_failed)
6217 {
6218         struct sk_buff *skb;
6219         int err;
6220
6221         if (READ_ONCE(f6i->offload) == offload &&
6222             READ_ONCE(f6i->trap) == trap &&
6223             READ_ONCE(f6i->offload_failed) == offload_failed)
6224                 return;
6225
6226         WRITE_ONCE(f6i->offload, offload);
6227         WRITE_ONCE(f6i->trap, trap);
6228
6229         /* 2 means send notifications only if offload_failed was changed. */
6230         if (net->ipv6.sysctl.fib_notify_on_flag_change == 2 &&
6231             READ_ONCE(f6i->offload_failed) == offload_failed)
6232                 return;
6233
6234         WRITE_ONCE(f6i->offload_failed, offload_failed);
6235
6236         if (!rcu_access_pointer(f6i->fib6_node))
6237                 /* The route was removed from the tree, do not send
6238                  * notification.
6239                  */
6240                 return;
6241
6242         if (!net->ipv6.sysctl.fib_notify_on_flag_change)
6243                 return;
6244
6245         skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL);
6246         if (!skb) {
6247                 err = -ENOBUFS;
6248                 goto errout;
6249         }
6250
6251         err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0,
6252                             0, 0);
6253         if (err < 0) {
6254                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6255                 WARN_ON(err == -EMSGSIZE);
6256                 kfree_skb(skb);
6257                 goto errout;
6258         }
6259
6260         rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL);
6261         return;
6262
6263 errout:
6264         rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6265 }
6266 EXPORT_SYMBOL(fib6_info_hw_flags_set);
6267
6268 static int ip6_route_dev_notify(struct notifier_block *this,
6269                                 unsigned long event, void *ptr)
6270 {
6271         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
6272         struct net *net = dev_net(dev);
6273
6274         if (!(dev->flags & IFF_LOOPBACK))
6275                 return NOTIFY_OK;
6276
6277         if (event == NETDEV_REGISTER) {
6278                 net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev;
6279                 net->ipv6.ip6_null_entry->dst.dev = dev;
6280                 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
6281 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6282                 net->ipv6.ip6_prohibit_entry->dst.dev = dev;
6283                 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
6284                 net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
6285                 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
6286 #endif
6287          } else if (event == NETDEV_UNREGISTER &&
6288                     dev->reg_state != NETREG_UNREGISTERED) {
6289                 /* NETDEV_UNREGISTER could be fired for multiple times by
6290                  * netdev_wait_allrefs(). Make sure we only call this once.
6291                  */
6292                 in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
6293 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6294                 in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
6295                 in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
6296 #endif
6297         }
6298
6299         return NOTIFY_OK;
6300 }
6301
6302 /*
6303  *      /proc
6304  */
6305
6306 #ifdef CONFIG_PROC_FS
6307 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
6308 {
6309         struct net *net = (struct net *)seq->private;
6310         seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
6311                    net->ipv6.rt6_stats->fib_nodes,
6312                    net->ipv6.rt6_stats->fib_route_nodes,
6313                    atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
6314                    net->ipv6.rt6_stats->fib_rt_entries,
6315                    net->ipv6.rt6_stats->fib_rt_cache,
6316                    dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
6317                    net->ipv6.rt6_stats->fib_discarded_routes);
6318
6319         return 0;
6320 }
6321 #endif  /* CONFIG_PROC_FS */
6322
6323 #ifdef CONFIG_SYSCTL
6324
6325 static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
6326                               void *buffer, size_t *lenp, loff_t *ppos)
6327 {
6328         struct net *net;
6329         int delay;
6330         int ret;
6331         if (!write)
6332                 return -EINVAL;
6333
6334         net = (struct net *)ctl->extra1;
6335         delay = net->ipv6.sysctl.flush_delay;
6336         ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
6337         if (ret)
6338                 return ret;
6339
6340         fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
6341         return 0;
6342 }
6343
6344 static struct ctl_table ipv6_route_table_template[] = {
6345         {
6346                 .procname       =       "max_size",
6347                 .data           =       &init_net.ipv6.sysctl.ip6_rt_max_size,
6348                 .maxlen         =       sizeof(int),
6349                 .mode           =       0644,
6350                 .proc_handler   =       proc_dointvec,
6351         },
6352         {
6353                 .procname       =       "gc_thresh",
6354                 .data           =       &ip6_dst_ops_template.gc_thresh,
6355                 .maxlen         =       sizeof(int),
6356                 .mode           =       0644,
6357                 .proc_handler   =       proc_dointvec,
6358         },
6359         {
6360                 .procname       =       "flush",
6361                 .data           =       &init_net.ipv6.sysctl.flush_delay,
6362                 .maxlen         =       sizeof(int),
6363                 .mode           =       0200,
6364                 .proc_handler   =       ipv6_sysctl_rtcache_flush
6365         },
6366         {
6367                 .procname       =       "gc_min_interval",
6368                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6369                 .maxlen         =       sizeof(int),
6370                 .mode           =       0644,
6371                 .proc_handler   =       proc_dointvec_jiffies,
6372         },
6373         {
6374                 .procname       =       "gc_timeout",
6375                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
6376                 .maxlen         =       sizeof(int),
6377                 .mode           =       0644,
6378                 .proc_handler   =       proc_dointvec_jiffies,
6379         },
6380         {
6381                 .procname       =       "gc_interval",
6382                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_interval,
6383                 .maxlen         =       sizeof(int),
6384                 .mode           =       0644,
6385                 .proc_handler   =       proc_dointvec_jiffies,
6386         },
6387         {
6388                 .procname       =       "gc_elasticity",
6389                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
6390                 .maxlen         =       sizeof(int),
6391                 .mode           =       0644,
6392                 .proc_handler   =       proc_dointvec,
6393         },
6394         {
6395                 .procname       =       "mtu_expires",
6396                 .data           =       &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
6397                 .maxlen         =       sizeof(int),
6398                 .mode           =       0644,
6399                 .proc_handler   =       proc_dointvec_jiffies,
6400         },
6401         {
6402                 .procname       =       "min_adv_mss",
6403                 .data           =       &init_net.ipv6.sysctl.ip6_rt_min_advmss,
6404                 .maxlen         =       sizeof(int),
6405                 .mode           =       0644,
6406                 .proc_handler   =       proc_dointvec,
6407         },
6408         {
6409                 .procname       =       "gc_min_interval_ms",
6410                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6411                 .maxlen         =       sizeof(int),
6412                 .mode           =       0644,
6413                 .proc_handler   =       proc_dointvec_ms_jiffies,
6414         },
6415         {
6416                 .procname       =       "skip_notify_on_dev_down",
6417                 .data           =       &init_net.ipv6.sysctl.skip_notify_on_dev_down,
6418                 .maxlen         =       sizeof(u8),
6419                 .mode           =       0644,
6420                 .proc_handler   =       proc_dou8vec_minmax,
6421                 .extra1         =       SYSCTL_ZERO,
6422                 .extra2         =       SYSCTL_ONE,
6423         },
6424         { }
6425 };
6426
6427 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
6428 {
6429         struct ctl_table *table;
6430
6431         table = kmemdup(ipv6_route_table_template,
6432                         sizeof(ipv6_route_table_template),
6433                         GFP_KERNEL);
6434
6435         if (table) {
6436                 table[0].data = &net->ipv6.sysctl.ip6_rt_max_size;
6437                 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
6438                 table[2].data = &net->ipv6.sysctl.flush_delay;
6439                 table[2].extra1 = net;
6440                 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6441                 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
6442                 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
6443                 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
6444                 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
6445                 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
6446                 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6447                 table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
6448
6449                 /* Don't export sysctls to unprivileged users */
6450                 if (net->user_ns != &init_user_ns)
6451                         table[1].procname = NULL;
6452         }
6453
6454         return table;
6455 }
6456
6457 size_t ipv6_route_sysctl_table_size(struct net *net)
6458 {
6459         /* Don't export sysctls to unprivileged users */
6460         if (net->user_ns != &init_user_ns)
6461                 return 1;
6462
6463         return ARRAY_SIZE(ipv6_route_table_template);
6464 }
6465 #endif
6466
6467 static int __net_init ip6_route_net_init(struct net *net)
6468 {
6469         int ret = -ENOMEM;
6470
6471         memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
6472                sizeof(net->ipv6.ip6_dst_ops));
6473
6474         if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
6475                 goto out_ip6_dst_ops;
6476
6477         net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true);
6478         if (!net->ipv6.fib6_null_entry)
6479                 goto out_ip6_dst_entries;
6480         memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template,
6481                sizeof(*net->ipv6.fib6_null_entry));
6482
6483         net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
6484                                            sizeof(*net->ipv6.ip6_null_entry),
6485                                            GFP_KERNEL);
6486         if (!net->ipv6.ip6_null_entry)
6487                 goto out_fib6_null_entry;
6488         net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6489         dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
6490                          ip6_template_metrics, true);
6491         INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->dst.rt_uncached);
6492
6493 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6494         net->ipv6.fib6_has_custom_rules = false;
6495         net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
6496                                                sizeof(*net->ipv6.ip6_prohibit_entry),
6497                                                GFP_KERNEL);
6498         if (!net->ipv6.ip6_prohibit_entry)
6499                 goto out_ip6_null_entry;
6500         net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6501         dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
6502                          ip6_template_metrics, true);
6503         INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->dst.rt_uncached);
6504
6505         net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
6506                                                sizeof(*net->ipv6.ip6_blk_hole_entry),
6507                                                GFP_KERNEL);
6508         if (!net->ipv6.ip6_blk_hole_entry)
6509                 goto out_ip6_prohibit_entry;
6510         net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6511         dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
6512                          ip6_template_metrics, true);
6513         INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->dst.rt_uncached);
6514 #ifdef CONFIG_IPV6_SUBTREES
6515         net->ipv6.fib6_routes_require_src = 0;
6516 #endif
6517 #endif
6518
6519         net->ipv6.sysctl.flush_delay = 0;
6520         net->ipv6.sysctl.ip6_rt_max_size = INT_MAX;
6521         net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
6522         net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
6523         net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
6524         net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
6525         net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
6526         net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
6527         net->ipv6.sysctl.skip_notify_on_dev_down = 0;
6528
6529         atomic_set(&net->ipv6.ip6_rt_gc_expire, 30*HZ);
6530
6531         ret = 0;
6532 out:
6533         return ret;
6534
6535 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6536 out_ip6_prohibit_entry:
6537         kfree(net->ipv6.ip6_prohibit_entry);
6538 out_ip6_null_entry:
6539         kfree(net->ipv6.ip6_null_entry);
6540 #endif
6541 out_fib6_null_entry:
6542         kfree(net->ipv6.fib6_null_entry);
6543 out_ip6_dst_entries:
6544         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6545 out_ip6_dst_ops:
6546         goto out;
6547 }
6548
6549 static void __net_exit ip6_route_net_exit(struct net *net)
6550 {
6551         kfree(net->ipv6.fib6_null_entry);
6552         kfree(net->ipv6.ip6_null_entry);
6553 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6554         kfree(net->ipv6.ip6_prohibit_entry);
6555         kfree(net->ipv6.ip6_blk_hole_entry);
6556 #endif
6557         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6558 }
6559
6560 static int __net_init ip6_route_net_init_late(struct net *net)
6561 {
6562 #ifdef CONFIG_PROC_FS
6563         if (!proc_create_net("ipv6_route", 0, net->proc_net,
6564                              &ipv6_route_seq_ops,
6565                              sizeof(struct ipv6_route_iter)))
6566                 return -ENOMEM;
6567
6568         if (!proc_create_net_single("rt6_stats", 0444, net->proc_net,
6569                                     rt6_stats_seq_show, NULL)) {
6570                 remove_proc_entry("ipv6_route", net->proc_net);
6571                 return -ENOMEM;
6572         }
6573 #endif
6574         return 0;
6575 }
6576
6577 static void __net_exit ip6_route_net_exit_late(struct net *net)
6578 {
6579 #ifdef CONFIG_PROC_FS
6580         remove_proc_entry("ipv6_route", net->proc_net);
6581         remove_proc_entry("rt6_stats", net->proc_net);
6582 #endif
6583 }
6584
6585 static struct pernet_operations ip6_route_net_ops = {
6586         .init = ip6_route_net_init,
6587         .exit = ip6_route_net_exit,
6588 };
6589
6590 static int __net_init ipv6_inetpeer_init(struct net *net)
6591 {
6592         struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
6593
6594         if (!bp)
6595                 return -ENOMEM;
6596         inet_peer_base_init(bp);
6597         net->ipv6.peers = bp;
6598         return 0;
6599 }
6600
6601 static void __net_exit ipv6_inetpeer_exit(struct net *net)
6602 {
6603         struct inet_peer_base *bp = net->ipv6.peers;
6604
6605         net->ipv6.peers = NULL;
6606         inetpeer_invalidate_tree(bp);
6607         kfree(bp);
6608 }
6609
6610 static struct pernet_operations ipv6_inetpeer_ops = {
6611         .init   =       ipv6_inetpeer_init,
6612         .exit   =       ipv6_inetpeer_exit,
6613 };
6614
6615 static struct pernet_operations ip6_route_net_late_ops = {
6616         .init = ip6_route_net_init_late,
6617         .exit = ip6_route_net_exit_late,
6618 };
6619
6620 static struct notifier_block ip6_route_dev_notifier = {
6621         .notifier_call = ip6_route_dev_notify,
6622         .priority = ADDRCONF_NOTIFY_PRIORITY - 10,
6623 };
6624
6625 void __init ip6_route_init_special_entries(void)
6626 {
6627         /* Registering of the loopback is done before this portion of code,
6628          * the loopback reference in rt6_info will not be taken, do it
6629          * manually for init_net */
6630         init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev;
6631         init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
6632         init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6633   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6634         init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
6635         init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6636         init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
6637         init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6638   #endif
6639 }
6640
6641 #if IS_BUILTIN(CONFIG_IPV6)
6642 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6643 DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt)
6644
6645 BTF_ID_LIST(btf_fib6_info_id)
6646 BTF_ID(struct, fib6_info)
6647
6648 static const struct bpf_iter_seq_info ipv6_route_seq_info = {
6649         .seq_ops                = &ipv6_route_seq_ops,
6650         .init_seq_private       = bpf_iter_init_seq_net,
6651         .fini_seq_private       = bpf_iter_fini_seq_net,
6652         .seq_priv_size          = sizeof(struct ipv6_route_iter),
6653 };
6654
6655 static struct bpf_iter_reg ipv6_route_reg_info = {
6656         .target                 = "ipv6_route",
6657         .ctx_arg_info_size      = 1,
6658         .ctx_arg_info           = {
6659                 { offsetof(struct bpf_iter__ipv6_route, rt),
6660                   PTR_TO_BTF_ID_OR_NULL },
6661         },
6662         .seq_info               = &ipv6_route_seq_info,
6663 };
6664
6665 static int __init bpf_iter_register(void)
6666 {
6667         ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id;
6668         return bpf_iter_reg_target(&ipv6_route_reg_info);
6669 }
6670
6671 static void bpf_iter_unregister(void)
6672 {
6673         bpf_iter_unreg_target(&ipv6_route_reg_info);
6674 }
6675 #endif
6676 #endif
6677
6678 int __init ip6_route_init(void)
6679 {
6680         int ret;
6681         int cpu;
6682
6683         ret = -ENOMEM;
6684         ip6_dst_ops_template.kmem_cachep =
6685                 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
6686                                   SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
6687         if (!ip6_dst_ops_template.kmem_cachep)
6688                 goto out;
6689
6690         ret = dst_entries_init(&ip6_dst_blackhole_ops);
6691         if (ret)
6692                 goto out_kmem_cache;
6693
6694         ret = register_pernet_subsys(&ipv6_inetpeer_ops);
6695         if (ret)
6696                 goto out_dst_entries;
6697
6698         ret = register_pernet_subsys(&ip6_route_net_ops);
6699         if (ret)
6700                 goto out_register_inetpeer;
6701
6702         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
6703
6704         ret = fib6_init();
6705         if (ret)
6706                 goto out_register_subsys;
6707
6708         ret = xfrm6_init();
6709         if (ret)
6710                 goto out_fib6_init;
6711
6712         ret = fib6_rules_init();
6713         if (ret)
6714                 goto xfrm6_init;
6715
6716         ret = register_pernet_subsys(&ip6_route_net_late_ops);
6717         if (ret)
6718                 goto fib6_rules_init;
6719
6720         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
6721                                    inet6_rtm_newroute, NULL, 0);
6722         if (ret < 0)
6723                 goto out_register_late_subsys;
6724
6725         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
6726                                    inet6_rtm_delroute, NULL, 0);
6727         if (ret < 0)
6728                 goto out_register_late_subsys;
6729
6730         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
6731                                    inet6_rtm_getroute, NULL,
6732                                    RTNL_FLAG_DOIT_UNLOCKED);
6733         if (ret < 0)
6734                 goto out_register_late_subsys;
6735
6736         ret = register_netdevice_notifier(&ip6_route_dev_notifier);
6737         if (ret)
6738                 goto out_register_late_subsys;
6739
6740 #if IS_BUILTIN(CONFIG_IPV6)
6741 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6742         ret = bpf_iter_register();
6743         if (ret)
6744                 goto out_register_late_subsys;
6745 #endif
6746 #endif
6747
6748         for_each_possible_cpu(cpu) {
6749                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
6750
6751                 INIT_LIST_HEAD(&ul->head);
6752                 INIT_LIST_HEAD(&ul->quarantine);
6753                 spin_lock_init(&ul->lock);
6754         }
6755
6756 out:
6757         return ret;
6758
6759 out_register_late_subsys:
6760         rtnl_unregister_all(PF_INET6);
6761         unregister_pernet_subsys(&ip6_route_net_late_ops);
6762 fib6_rules_init:
6763         fib6_rules_cleanup();
6764 xfrm6_init:
6765         xfrm6_fini();
6766 out_fib6_init:
6767         fib6_gc_cleanup();
6768 out_register_subsys:
6769         unregister_pernet_subsys(&ip6_route_net_ops);
6770 out_register_inetpeer:
6771         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6772 out_dst_entries:
6773         dst_entries_destroy(&ip6_dst_blackhole_ops);
6774 out_kmem_cache:
6775         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6776         goto out;
6777 }
6778
6779 void ip6_route_cleanup(void)
6780 {
6781 #if IS_BUILTIN(CONFIG_IPV6)
6782 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6783         bpf_iter_unregister();
6784 #endif
6785 #endif
6786         unregister_netdevice_notifier(&ip6_route_dev_notifier);
6787         unregister_pernet_subsys(&ip6_route_net_late_ops);
6788         fib6_rules_cleanup();
6789         xfrm6_fini();
6790         fib6_gc_cleanup();
6791         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6792         unregister_pernet_subsys(&ip6_route_net_ops);
6793         dst_entries_destroy(&ip6_dst_blackhole_ops);
6794         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6795 }