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         if (skb)
 427                 IP6CB(skb)->flags |= IP6SKB_MULTIPATH;
 428
 429         /* We might have already computed the hash for ICMPv6 errors. In such
 430          * case it will always be non-zero. Otherwise now is the time to do it.
 431          */
 432         if (!fl6->mp_hash &&
 433             (!match->nh || nexthop_is_multipath(match->nh)))
 434                 fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
 435
 436         if (unlikely(match->nh)) {
 437                 nexthop_path_fib6_result(res, fl6->mp_hash);
 438                 return;
 439         }
 440
 441         if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
 442                 goto out;
 443
 444         list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
 445                                  fib6_siblings) {
 446                 const struct fib6_nh *nh = sibling->fib6_nh;
 447                 int nh_upper_bound;
 448
 449                 nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
 450                 if (fl6->mp_hash > nh_upper_bound)
 451                         continue;
 452                 if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
 453                         break;
 454                 match = sibling;
 455                 break;
 456         }
 457
 458 out:
 459         res->f6i = match;
 460         res->nh = match->fib6_nh;
 461 }
 462
 463 /*
 464  *      Route lookup. rcu_read_lock() should be held.
 465  */
 466
 467 static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh,
 468                                const struct in6_addr *saddr, int oif, int flags)
 469 {
 470         const struct net_device *dev;
 471
 472         if (nh->fib_nh_flags & RTNH_F_DEAD)
 473                 return false;
 474
 475         dev = nh->fib_nh_dev;
 476         if (oif) {
 477                 if (dev->ifindex == oif)
 478                         return true;
 479         } else {
 480                 if (ipv6_chk_addr(net, saddr, dev,
 481                                   flags & RT6_LOOKUP_F_IFACE))
 482                         return true;
 483         }
 484
 485         return false;
 486 }
 487
 488 struct fib6_nh_dm_arg {
 489         struct net              *net;
 490         const struct in6_addr   *saddr;
 491         int                     oif;
 492         int                     flags;
 493         struct fib6_nh          *nh;
 494 };
 495
 496 static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg)
 497 {
 498         struct fib6_nh_dm_arg *arg = _arg;
 499
 500         arg->nh = nh;
 501         return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif,
 502                                   arg->flags);
 503 }
 504
 505 /* returns fib6_nh from nexthop or NULL */
 506 static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh,
 507                                         struct fib6_result *res,
 508                                         const struct in6_addr *saddr,
 509                                         int oif, int flags)
 510 {
 511         struct fib6_nh_dm_arg arg = {
 512                 .net   = net,
 513                 .saddr = saddr,
 514                 .oif   = oif,
 515                 .flags = flags,
 516         };
 517
 518         if (nexthop_is_blackhole(nh))
 519                 return NULL;
 520
 521         if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg))
 522                 return arg.nh;
 523
 524         return NULL;
 525 }
 526
 527 static void rt6_device_match(struct net *net, struct fib6_result *res,
 528                              const struct in6_addr *saddr, int oif, int flags)
 529 {
 530         struct fib6_info *f6i = res->f6i;
 531         struct fib6_info *spf6i;
 532         struct fib6_nh *nh;
 533
 534         if (!oif && ipv6_addr_any(saddr)) {
 535                 if (unlikely(f6i->nh)) {
 536                         nh = nexthop_fib6_nh(f6i->nh);
 537                         if (nexthop_is_blackhole(f6i->nh))
 538                                 goto out_blackhole;
 539                 } else {
 540                         nh = f6i->fib6_nh;
 541                 }
 542                 if (!(nh->fib_nh_flags & RTNH_F_DEAD))
 543                         goto out;
 544         }
 545
 546         for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
 547                 bool matched = false;
 548
 549                 if (unlikely(spf6i->nh)) {
 550                         nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr,
 551                                               oif, flags);
 552                         if (nh)
 553                                 matched = true;
 554                 } else {
 555                         nh = spf6i->fib6_nh;
 556                         if (__rt6_device_match(net, nh, saddr, oif, flags))
 557                                 matched = true;
 558                 }
 559                 if (matched) {
 560                         res->f6i = spf6i;
 561                         goto out;
 562                 }
 563         }
 564
 565         if (oif && flags & RT6_LOOKUP_F_IFACE) {
 566                 res->f6i = net->ipv6.fib6_null_entry;
 567                 nh = res->f6i->fib6_nh;
 568                 goto out;
 569         }
 570
 571         if (unlikely(f6i->nh)) {
 572                 nh = nexthop_fib6_nh(f6i->nh);
 573                 if (nexthop_is_blackhole(f6i->nh))
 574                         goto out_blackhole;
 575         } else {
 576                 nh = f6i->fib6_nh;
 577         }
 578
 579         if (nh->fib_nh_flags & RTNH_F_DEAD) {
 580                 res->f6i = net->ipv6.fib6_null_entry;
 581                 nh = res->f6i->fib6_nh;
 582         }
 583 out:
 584         res->nh = nh;
 585         res->fib6_type = res->f6i->fib6_type;
 586         res->fib6_flags = res->f6i->fib6_flags;
 587         return;
 588
 589 out_blackhole:
 590         res->fib6_flags |= RTF_REJECT;
 591         res->fib6_type = RTN_BLACKHOLE;
 592         res->nh = nh;
 593 }
 594
 595 #ifdef CONFIG_IPV6_ROUTER_PREF
 596 struct __rt6_probe_work {
 597         struct work_struct work;
 598         struct in6_addr target;
 599         struct net_device *dev;
 600         netdevice_tracker dev_tracker;
 601 };
 602
 603 static void rt6_probe_deferred(struct work_struct *w)
 604 {
 605         struct in6_addr mcaddr;
 606         struct __rt6_probe_work *work =
 607                 container_of(w, struct __rt6_probe_work, work);
 608
 609         addrconf_addr_solict_mult(&work->target, &mcaddr);
 610         ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
 611         netdev_put(work->dev, &work->dev_tracker);
 612         kfree(work);
 613 }
 614
 615 static void rt6_probe(struct fib6_nh *fib6_nh)
 616 {
 617         struct __rt6_probe_work *work = NULL;
 618         const struct in6_addr *nh_gw;
 619         unsigned long last_probe;
 620         struct neighbour *neigh;
 621         struct net_device *dev;
 622         struct inet6_dev *idev;
 623
 624         /*
 625          * Okay, this does not seem to be appropriate
 626          * for now, however, we need to check if it
 627          * is really so; aka Router Reachability Probing.
 628          *
 629          * Router Reachability Probe MUST be rate-limited
 630          * to no more than one per minute.
 631          */
 632         if (!fib6_nh->fib_nh_gw_family)
 633                 return;
 634
 635         nh_gw = &fib6_nh->fib_nh_gw6;
 636         dev = fib6_nh->fib_nh_dev;
 637         rcu_read_lock();
 638         last_probe = READ_ONCE(fib6_nh->last_probe);
 639         idev = __in6_dev_get(dev);
 640         neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
 641         if (neigh) {
 642                 if (READ_ONCE(neigh->nud_state) & NUD_VALID)
 643                         goto out;
 644
 645                 write_lock_bh(&neigh->lock);
 646                 if (!(neigh->nud_state & NUD_VALID) &&
 647                     time_after(jiffies,
 648                                neigh->updated + idev->cnf.rtr_probe_interval)) {
 649                         work = kmalloc(sizeof(*work), GFP_ATOMIC);
 650                         if (work)
 651                                 __neigh_set_probe_once(neigh);
 652                 }
 653                 write_unlock_bh(&neigh->lock);
 654         } else if (time_after(jiffies, last_probe +
 655                                        idev->cnf.rtr_probe_interval)) {
 656                 work = kmalloc(sizeof(*work), GFP_ATOMIC);
 657         }
 658
 659         if (!work || cmpxchg(&fib6_nh->last_probe,
 660                              last_probe, jiffies) != last_probe) {
 661                 kfree(work);
 662         } else {
 663                 INIT_WORK(&work->work, rt6_probe_deferred);
 664                 work->target = *nh_gw;
 665                 netdev_hold(dev, &work->dev_tracker, GFP_ATOMIC);
 666                 work->dev = dev;
 667                 schedule_work(&work->work);
 668         }
 669
 670 out:
 671         rcu_read_unlock();
 672 }
 673 #else
 674 static inline void rt6_probe(struct fib6_nh *fib6_nh)
 675 {
 676 }
 677 #endif
 678
 679 /*
 680  * Default Router Selection (RFC 2461 6.3.6)
 681  */
 682 static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh)
 683 {
 684         enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
 685         struct neighbour *neigh;
 686
 687         rcu_read_lock();
 688         neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev,
 689                                           &fib6_nh->fib_nh_gw6);
 690         if (neigh) {
 691                 u8 nud_state = READ_ONCE(neigh->nud_state);
 692
 693                 if (nud_state & NUD_VALID)
 694                         ret = RT6_NUD_SUCCEED;
 695 #ifdef CONFIG_IPV6_ROUTER_PREF
 696                 else if (!(nud_state & NUD_FAILED))
 697                         ret = RT6_NUD_SUCCEED;
 698                 else
 699                         ret = RT6_NUD_FAIL_PROBE;
 700 #endif
 701         } else {
 702                 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
 703                       RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
 704         }
 705         rcu_read_unlock();
 706
 707         return ret;
 708 }
 709
 710 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
 711                            int strict)
 712 {
 713         int m = 0;
 714
 715         if (!oif || nh->fib_nh_dev->ifindex == oif)
 716                 m = 2;
 717
 718         if (!m && (strict & RT6_LOOKUP_F_IFACE))
 719                 return RT6_NUD_FAIL_HARD;
 720 #ifdef CONFIG_IPV6_ROUTER_PREF
 721         m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2;
 722 #endif
 723         if ((strict & RT6_LOOKUP_F_REACHABLE) &&
 724             !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) {
 725                 int n = rt6_check_neigh(nh);
 726                 if (n < 0)
 727                         return n;
 728         }
 729         return m;
 730 }
 731
 732 static bool find_match(struct fib6_nh *nh, u32 fib6_flags,
 733                        int oif, int strict, int *mpri, bool *do_rr)
 734 {
 735         bool match_do_rr = false;
 736         bool rc = false;
 737         int m;
 738
 739         if (nh->fib_nh_flags & RTNH_F_DEAD)
 740                 goto out;
 741
 742         if (ip6_ignore_linkdown(nh->fib_nh_dev) &&
 743             nh->fib_nh_flags & RTNH_F_LINKDOWN &&
 744             !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
 745                 goto out;
 746
 747         m = rt6_score_route(nh, fib6_flags, oif, strict);
 748         if (m == RT6_NUD_FAIL_DO_RR) {
 749                 match_do_rr = true;
 750                 m = 0; /* lowest valid score */
 751         } else if (m == RT6_NUD_FAIL_HARD) {
 752                 goto out;
 753         }
 754
 755         if (strict & RT6_LOOKUP_F_REACHABLE)
 756                 rt6_probe(nh);
 757
 758         /* note that m can be RT6_NUD_FAIL_PROBE at this point */
 759         if (m > *mpri) {
 760                 *do_rr = match_do_rr;
 761                 *mpri = m;
 762                 rc = true;
 763         }
 764 out:
 765         return rc;
 766 }
 767
 768 struct fib6_nh_frl_arg {
 769         u32             flags;
 770         int             oif;
 771         int             strict;
 772         int             *mpri;
 773         bool            *do_rr;
 774         struct fib6_nh  *nh;
 775 };
 776
 777 static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg)
 778 {
 779         struct fib6_nh_frl_arg *arg = _arg;
 780
 781         arg->nh = nh;
 782         return find_match(nh, arg->flags, arg->oif, arg->strict,
 783                           arg->mpri, arg->do_rr);
 784 }
 785
 786 static void __find_rr_leaf(struct fib6_info *f6i_start,
 787                            struct fib6_info *nomatch, u32 metric,
 788                            struct fib6_result *res, struct fib6_info **cont,
 789                            int oif, int strict, bool *do_rr, int *mpri)
 790 {
 791         struct fib6_info *f6i;
 792
 793         for (f6i = f6i_start;
 794              f6i && f6i != nomatch;
 795              f6i = rcu_dereference(f6i->fib6_next)) {
 796                 bool matched = false;
 797                 struct fib6_nh *nh;
 798
 799                 if (cont && f6i->fib6_metric != metric) {
 800                         *cont = f6i;
 801                         return;
 802                 }
 803
 804                 if (fib6_check_expired(f6i))
 805                         continue;
 806
 807                 if (unlikely(f6i->nh)) {
 808                         struct fib6_nh_frl_arg arg = {
 809                                 .flags  = f6i->fib6_flags,
 810                                 .oif    = oif,
 811                                 .strict = strict,
 812                                 .mpri   = mpri,
 813                                 .do_rr  = do_rr
 814                         };
 815
 816                         if (nexthop_is_blackhole(f6i->nh)) {
 817                                 res->fib6_flags = RTF_REJECT;
 818                                 res->fib6_type = RTN_BLACKHOLE;
 819                                 res->f6i = f6i;
 820                                 res->nh = nexthop_fib6_nh(f6i->nh);
 821                                 return;
 822                         }
 823                         if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match,
 824                                                      &arg)) {
 825                                 matched = true;
 826                                 nh = arg.nh;
 827                         }
 828                 } else {
 829                         nh = f6i->fib6_nh;
 830                         if (find_match(nh, f6i->fib6_flags, oif, strict,
 831                                        mpri, do_rr))
 832                                 matched = true;
 833                 }
 834                 if (matched) {
 835                         res->f6i = f6i;
 836                         res->nh = nh;
 837                         res->fib6_flags = f6i->fib6_flags;
 838                         res->fib6_type = f6i->fib6_type;
 839                 }
 840         }
 841 }
 842
 843 static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf,
 844                          struct fib6_info *rr_head, int oif, int strict,
 845                          bool *do_rr, struct fib6_result *res)
 846 {
 847         u32 metric = rr_head->fib6_metric;
 848         struct fib6_info *cont = NULL;
 849         int mpri = -1;
 850
 851         __find_rr_leaf(rr_head, NULL, metric, res, &cont,
 852                        oif, strict, do_rr, &mpri);
 853
 854         __find_rr_leaf(leaf, rr_head, metric, res, &cont,
 855                        oif, strict, do_rr, &mpri);
 856
 857         if (res->f6i || !cont)
 858                 return;
 859
 860         __find_rr_leaf(cont, NULL, metric, res, NULL,
 861                        oif, strict, do_rr, &mpri);
 862 }
 863
 864 static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
 865                        struct fib6_result *res, int strict)
 866 {
 867         struct fib6_info *leaf = rcu_dereference(fn->leaf);
 868         struct fib6_info *rt0;
 869         bool do_rr = false;
 870         int key_plen;
 871
 872         /* make sure this function or its helpers sets f6i */
 873         res->f6i = NULL;
 874
 875         if (!leaf || leaf == net->ipv6.fib6_null_entry)
 876                 goto out;
 877
 878         rt0 = rcu_dereference(fn->rr_ptr);
 879         if (!rt0)
 880                 rt0 = leaf;
 881
 882         /* Double check to make sure fn is not an intermediate node
 883          * and fn->leaf does not points to its child's leaf
 884          * (This might happen if all routes under fn are deleted from
 885          * the tree and fib6_repair_tree() is called on the node.)
 886          */
 887         key_plen = rt0->fib6_dst.plen;
 888 #ifdef CONFIG_IPV6_SUBTREES
 889         if (rt0->fib6_src.plen)
 890                 key_plen = rt0->fib6_src.plen;
 891 #endif
 892         if (fn->fn_bit != key_plen)
 893                 goto out;
 894
 895         find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res);
 896         if (do_rr) {
 897                 struct fib6_info *next = rcu_dereference(rt0->fib6_next);
 898
 899                 /* no entries matched; do round-robin */
 900                 if (!next || next->fib6_metric != rt0->fib6_metric)
 901                         next = leaf;
 902
 903                 if (next != rt0) {
 904                         spin_lock_bh(&leaf->fib6_table->tb6_lock);
 905                         /* make sure next is not being deleted from the tree */
 906                         if (next->fib6_node)
 907                                 rcu_assign_pointer(fn->rr_ptr, next);
 908                         spin_unlock_bh(&leaf->fib6_table->tb6_lock);
 909                 }
 910         }
 911
 912 out:
 913         if (!res->f6i) {
 914                 res->f6i = net->ipv6.fib6_null_entry;
 915                 res->nh = res->f6i->fib6_nh;
 916                 res->fib6_flags = res->f6i->fib6_flags;
 917                 res->fib6_type = res->f6i->fib6_type;
 918         }
 919 }
 920
 921 static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res)
 922 {
 923         return (res->f6i->fib6_flags & RTF_NONEXTHOP) ||
 924                res->nh->fib_nh_gw_family;
 925 }
 926
 927 #ifdef CONFIG_IPV6_ROUTE_INFO
 928 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 929                   const struct in6_addr *gwaddr)
 930 {
 931         struct net *net = dev_net(dev);
 932         struct route_info *rinfo = (struct route_info *) opt;
 933         struct in6_addr prefix_buf, *prefix;
 934         unsigned int pref;
 935         unsigned long lifetime;
 936         struct fib6_info *rt;
 937
 938         if (len < sizeof(struct route_info)) {
 939                 return -EINVAL;
 940         }
 941
 942         /* Sanity check for prefix_len and length */
 943         if (rinfo->length > 3) {
 944                 return -EINVAL;
 945         } else if (rinfo->prefix_len > 128) {
 946                 return -EINVAL;
 947         } else if (rinfo->prefix_len > 64) {
 948                 if (rinfo->length < 2) {
 949                         return -EINVAL;
 950                 }
 951         } else if (rinfo->prefix_len > 0) {
 952                 if (rinfo->length < 1) {
 953                         return -EINVAL;
 954                 }
 955         }
 956
 957         pref = rinfo->route_pref;
 958         if (pref == ICMPV6_ROUTER_PREF_INVALID)
 959                 return -EINVAL;
 960
 961         lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
 962
 963         if (rinfo->length == 3)
 964                 prefix = (struct in6_addr *)rinfo->prefix;
 965         else {
 966                 /* this function is safe */
 967                 ipv6_addr_prefix(&prefix_buf,
 968                                  (struct in6_addr *)rinfo->prefix,
 969                                  rinfo->prefix_len);
 970                 prefix = &prefix_buf;
 971         }
 972
 973         if (rinfo->prefix_len == 0)
 974                 rt = rt6_get_dflt_router(net, gwaddr, dev);
 975         else
 976                 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
 977                                         gwaddr, dev);
 978
 979         if (rt && !lifetime) {
 980                 ip6_del_rt(net, rt, false);
 981                 rt = NULL;
 982         }
 983
 984         if (!rt && lifetime)
 985                 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
 986                                         dev, pref);
 987         else if (rt)
 988                 rt->fib6_flags = RTF_ROUTEINFO |
 989                                  (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 990
 991         if (rt) {
 992                 if (!addrconf_finite_timeout(lifetime))
 993                         fib6_clean_expires(rt);
 994                 else
 995                         fib6_set_expires(rt, jiffies + HZ * lifetime);
 996
 997                 fib6_info_release(rt);
 998         }
 999         return 0;
1000 }
1001 #endif
1002
1003 /*
1004  *      Misc support functions
1005  */
1006
1007 /* called with rcu_lock held */
1008 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
1009 {
1010         struct net_device *dev = res->nh->fib_nh_dev;
1011
1012         if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
1013                 /* for copies of local routes, dst->dev needs to be the
1014                  * device if it is a master device, the master device if
1015                  * device is enslaved, and the loopback as the default
1016                  */
1017                 if (netif_is_l3_slave(dev) &&
1018                     !rt6_need_strict(&res->f6i->fib6_dst.addr))
1019                         dev = l3mdev_master_dev_rcu(dev);
1020                 else if (!netif_is_l3_master(dev))
1021                         dev = dev_net(dev)->loopback_dev;
1022                 /* last case is netif_is_l3_master(dev) is true in which
1023                  * case we want dev returned to be dev
1024                  */
1025         }
1026
1027         return dev;
1028 }
1029
1030 static const int fib6_prop[RTN_MAX + 1] = {
1031         [RTN_UNSPEC]    = 0,
1032         [RTN_UNICAST]   = 0,
1033         [RTN_LOCAL]     = 0,
1034         [RTN_BROADCAST] = 0,
1035         [RTN_ANYCAST]   = 0,
1036         [RTN_MULTICAST] = 0,
1037         [RTN_BLACKHOLE] = -EINVAL,
1038         [RTN_UNREACHABLE] = -EHOSTUNREACH,
1039         [RTN_PROHIBIT]  = -EACCES,
1040         [RTN_THROW]     = -EAGAIN,
1041         [RTN_NAT]       = -EINVAL,
1042         [RTN_XRESOLVE]  = -EINVAL,
1043 };
1044
1045 static int ip6_rt_type_to_error(u8 fib6_type)
1046 {
1047         return fib6_prop[fib6_type];
1048 }
1049
1050 static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
1051 {
1052         unsigned short flags = 0;
1053
1054         if (rt->dst_nocount)
1055                 flags |= DST_NOCOUNT;
1056         if (rt->dst_nopolicy)
1057                 flags |= DST_NOPOLICY;
1058
1059         return flags;
1060 }
1061
1062 static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
1063 {
1064         rt->dst.error = ip6_rt_type_to_error(fib6_type);
1065
1066         switch (fib6_type) {
1067         case RTN_BLACKHOLE:
1068                 rt->dst.output = dst_discard_out;
1069                 rt->dst.input = dst_discard;
1070                 break;
1071         case RTN_PROHIBIT:
1072                 rt->dst.output = ip6_pkt_prohibit_out;
1073                 rt->dst.input = ip6_pkt_prohibit;
1074                 break;
1075         case RTN_THROW:
1076         case RTN_UNREACHABLE:
1077         default:
1078                 rt->dst.output = ip6_pkt_discard_out;
1079                 rt->dst.input = ip6_pkt_discard;
1080                 break;
1081         }
1082 }
1083
1084 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
1085 {
1086         struct fib6_info *f6i = res->f6i;
1087
1088         if (res->fib6_flags & RTF_REJECT) {
1089                 ip6_rt_init_dst_reject(rt, res->fib6_type);
1090                 return;
1091         }
1092
1093         rt->dst.error = 0;
1094         rt->dst.output = ip6_output;
1095
1096         if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
1097                 rt->dst.input = ip6_input;
1098         } else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
1099                 rt->dst.input = ip6_mc_input;
1100         } else {
1101                 rt->dst.input = ip6_forward;
1102         }
1103
1104         if (res->nh->fib_nh_lws) {
1105                 rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws);
1106                 lwtunnel_set_redirect(&rt->dst);
1107         }
1108
1109         rt->dst.lastuse = jiffies;
1110 }
1111
1112 /* Caller must already hold reference to @from */
1113 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
1114 {
1115         rt->rt6i_flags &= ~RTF_EXPIRES;
1116         rcu_assign_pointer(rt->from, from);
1117         ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
1118 }
1119
1120 /* Caller must already hold reference to f6i in result */
1121 static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
1122 {
1123         const struct fib6_nh *nh = res->nh;
1124         const struct net_device *dev = nh->fib_nh_dev;
1125         struct fib6_info *f6i = res->f6i;
1126
1127         ip6_rt_init_dst(rt, res);
1128
1129         rt->rt6i_dst = f6i->fib6_dst;
1130         rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
1131         rt->rt6i_flags = res->fib6_flags;
1132         if (nh->fib_nh_gw_family) {
1133                 rt->rt6i_gateway = nh->fib_nh_gw6;
1134                 rt->rt6i_flags |= RTF_GATEWAY;
1135         }
1136         rt6_set_from(rt, f6i);
1137 #ifdef CONFIG_IPV6_SUBTREES
1138         rt->rt6i_src = f6i->fib6_src;
1139 #endif
1140 }
1141
1142 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
1143                                         struct in6_addr *saddr)
1144 {
1145         struct fib6_node *pn, *sn;
1146         while (1) {
1147                 if (fn->fn_flags & RTN_TL_ROOT)
1148                         return NULL;
1149                 pn = rcu_dereference(fn->parent);
1150                 sn = FIB6_SUBTREE(pn);
1151                 if (sn && sn != fn)
1152                         fn = fib6_node_lookup(sn, NULL, saddr);
1153                 else
1154                         fn = pn;
1155                 if (fn->fn_flags & RTN_RTINFO)
1156                         return fn;
1157         }
1158 }
1159
1160 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt)
1161 {
1162         struct rt6_info *rt = *prt;
1163
1164         if (dst_hold_safe(&rt->dst))
1165                 return true;
1166         if (net) {
1167                 rt = net->ipv6.ip6_null_entry;
1168                 dst_hold(&rt->dst);
1169         } else {
1170                 rt = NULL;
1171         }
1172         *prt = rt;
1173         return false;
1174 }
1175
1176 /* called with rcu_lock held */
1177 static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res)
1178 {
1179         struct net_device *dev = res->nh->fib_nh_dev;
1180         struct fib6_info *f6i = res->f6i;
1181         unsigned short flags;
1182         struct rt6_info *nrt;
1183
1184         if (!fib6_info_hold_safe(f6i))
1185                 goto fallback;
1186
1187         flags = fib6_info_dst_flags(f6i);
1188         nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
1189         if (!nrt) {
1190                 fib6_info_release(f6i);
1191                 goto fallback;
1192         }
1193
1194         ip6_rt_copy_init(nrt, res);
1195         return nrt;
1196
1197 fallback:
1198         nrt = dev_net(dev)->ipv6.ip6_null_entry;
1199         dst_hold(&nrt->dst);
1200         return nrt;
1201 }
1202
1203 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net,
1204                                              struct fib6_table *table,
1205                                              struct flowi6 *fl6,
1206                                              const struct sk_buff *skb,
1207                                              int flags)
1208 {
1209         struct fib6_result res = {};
1210         struct fib6_node *fn;
1211         struct rt6_info *rt;
1212
1213         rcu_read_lock();
1214         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1215 restart:
1216         res.f6i = rcu_dereference(fn->leaf);
1217         if (!res.f6i)
1218                 res.f6i = net->ipv6.fib6_null_entry;
1219         else
1220                 rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif,
1221                                  flags);
1222
1223         if (res.f6i == net->ipv6.fib6_null_entry) {
1224                 fn = fib6_backtrack(fn, &fl6->saddr);
1225                 if (fn)
1226                         goto restart;
1227
1228                 rt = net->ipv6.ip6_null_entry;
1229                 dst_hold(&rt->dst);
1230                 goto out;
1231         } else if (res.fib6_flags & RTF_REJECT) {
1232                 goto do_create;
1233         }
1234
1235         fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
1236                          fl6->flowi6_oif != 0, skb, flags);
1237
1238         /* Search through exception table */
1239         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
1240         if (rt) {
1241                 if (ip6_hold_safe(net, &rt))
1242                         dst_use_noref(&rt->dst, jiffies);
1243         } else {
1244 do_create:
1245                 rt = ip6_create_rt_rcu(&res);
1246         }
1247
1248 out:
1249         trace_fib6_table_lookup(net, &res, table, fl6);
1250
1251         rcu_read_unlock();
1252
1253         return rt;
1254 }
1255
1256 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
1257                                    const struct sk_buff *skb, int flags)
1258 {
1259         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
1260 }
1261 EXPORT_SYMBOL_GPL(ip6_route_lookup);
1262
1263 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
1264                             const struct in6_addr *saddr, int oif,
1265                             const struct sk_buff *skb, int strict)
1266 {
1267         struct flowi6 fl6 = {
1268                 .flowi6_oif = oif,
1269                 .daddr = *daddr,
1270         };
1271         struct dst_entry *dst;
1272         int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
1273
1274         if (saddr) {
1275                 memcpy(&fl6.saddr, saddr, sizeof(*saddr));
1276                 flags |= RT6_LOOKUP_F_HAS_SADDR;
1277         }
1278
1279         dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
1280         if (dst->error == 0)
1281                 return (struct rt6_info *) dst;
1282
1283         dst_release(dst);
1284
1285         return NULL;
1286 }
1287 EXPORT_SYMBOL(rt6_lookup);
1288
1289 /* ip6_ins_rt is called with FREE table->tb6_lock.
1290  * It takes new route entry, the addition fails by any reason the
1291  * route is released.
1292  * Caller must hold dst before calling it.
1293  */
1294
1295 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
1296                         struct netlink_ext_ack *extack)
1297 {
1298         int err;
1299         struct fib6_table *table;
1300
1301         table = rt->fib6_table;
1302         spin_lock_bh(&table->tb6_lock);
1303         err = fib6_add(&table->tb6_root, rt, info, extack);
1304         spin_unlock_bh(&table->tb6_lock);
1305
1306         return err;
1307 }
1308
1309 int ip6_ins_rt(struct net *net, struct fib6_info *rt)
1310 {
1311         struct nl_info info = { .nl_net = net, };
1312
1313         return __ip6_ins_rt(rt, &info, NULL);
1314 }
1315
1316 static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res,
1317                                            const struct in6_addr *daddr,
1318                                            const struct in6_addr *saddr)
1319 {
1320         struct fib6_info *f6i = res->f6i;
1321         struct net_device *dev;
1322         struct rt6_info *rt;
1323
1324         /*
1325          *      Clone the route.
1326          */
1327
1328         if (!fib6_info_hold_safe(f6i))
1329                 return NULL;
1330
1331         dev = ip6_rt_get_dev_rcu(res);
1332         rt = ip6_dst_alloc(dev_net(dev), dev, 0);
1333         if (!rt) {
1334                 fib6_info_release(f6i);
1335                 return NULL;
1336         }
1337
1338         ip6_rt_copy_init(rt, res);
1339         rt->rt6i_flags |= RTF_CACHE;
1340         rt->rt6i_dst.addr = *daddr;
1341         rt->rt6i_dst.plen = 128;
1342
1343         if (!rt6_is_gw_or_nonexthop(res)) {
1344                 if (f6i->fib6_dst.plen != 128 &&
1345                     ipv6_addr_equal(&f6i->fib6_dst.addr, daddr))
1346                         rt->rt6i_flags |= RTF_ANYCAST;
1347 #ifdef CONFIG_IPV6_SUBTREES
1348                 if (rt->rt6i_src.plen && saddr) {
1349                         rt->rt6i_src.addr = *saddr;
1350                         rt->rt6i_src.plen = 128;
1351                 }
1352 #endif
1353         }
1354
1355         return rt;
1356 }
1357
1358 static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res)
1359 {
1360         struct fib6_info *f6i = res->f6i;
1361         unsigned short flags = fib6_info_dst_flags(f6i);
1362         struct net_device *dev;
1363         struct rt6_info *pcpu_rt;
1364
1365         if (!fib6_info_hold_safe(f6i))
1366                 return NULL;
1367
1368         rcu_read_lock();
1369         dev = ip6_rt_get_dev_rcu(res);
1370         pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT);
1371         rcu_read_unlock();
1372         if (!pcpu_rt) {
1373                 fib6_info_release(f6i);
1374                 return NULL;
1375         }
1376         ip6_rt_copy_init(pcpu_rt, res);
1377         pcpu_rt->rt6i_flags |= RTF_PCPU;
1378
1379         if (f6i->nh)
1380                 pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev));
1381
1382         return pcpu_rt;
1383 }
1384
1385 static bool rt6_is_valid(const struct rt6_info *rt6)
1386 {
1387         return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev));
1388 }
1389
1390 /* It should be called with rcu_read_lock() acquired */
1391 static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
1392 {
1393         struct rt6_info *pcpu_rt;
1394
1395         pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
1396
1397         if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) {
1398                 struct rt6_info *prev, **p;
1399
1400                 p = this_cpu_ptr(res->nh->rt6i_pcpu);
1401                 prev = xchg(p, NULL);
1402                 if (prev) {
1403                         dst_dev_put(&prev->dst);
1404                         dst_release(&prev->dst);
1405                 }
1406
1407                 pcpu_rt = NULL;
1408         }
1409
1410         return pcpu_rt;
1411 }
1412
1413 static struct rt6_info *rt6_make_pcpu_route(struct net *net,
1414                                             const struct fib6_result *res)
1415 {
1416         struct rt6_info *pcpu_rt, *prev, **p;
1417
1418         pcpu_rt = ip6_rt_pcpu_alloc(res);
1419         if (!pcpu_rt)
1420                 return NULL;
1421
1422         p = this_cpu_ptr(res->nh->rt6i_pcpu);
1423         prev = cmpxchg(p, NULL, pcpu_rt);
1424         BUG_ON(prev);
1425
1426         if (res->f6i->fib6_destroying) {
1427                 struct fib6_info *from;
1428
1429                 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
1430                 fib6_info_release(from);
1431         }
1432
1433         return pcpu_rt;
1434 }
1435
1436 /* exception hash table implementation
1437  */
1438 static DEFINE_SPINLOCK(rt6_exception_lock);
1439
1440 /* Remove rt6_ex from hash table and free the memory
1441  * Caller must hold rt6_exception_lock
1442  */
1443 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
1444                                  struct rt6_exception *rt6_ex)
1445 {
1446         struct fib6_info *from;
1447         struct net *net;
1448
1449         if (!bucket || !rt6_ex)
1450                 return;
1451
1452         net = dev_net(rt6_ex->rt6i->dst.dev);
1453         net->ipv6.rt6_stats->fib_rt_cache--;
1454
1455         /* purge completely the exception to allow releasing the held resources:
1456          * some [sk] cache may keep the dst around for unlimited time
1457          */
1458         from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL);
1459         fib6_info_release(from);
1460         dst_dev_put(&rt6_ex->rt6i->dst);
1461
1462         hlist_del_rcu(&rt6_ex->hlist);
1463         dst_release(&rt6_ex->rt6i->dst);
1464         kfree_rcu(rt6_ex, rcu);
1465         WARN_ON_ONCE(!bucket->depth);
1466         bucket->depth--;
1467 }
1468
1469 /* Remove oldest rt6_ex in bucket and free the memory
1470  * Caller must hold rt6_exception_lock
1471  */
1472 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
1473 {
1474         struct rt6_exception *rt6_ex, *oldest = NULL;
1475
1476         if (!bucket)
1477                 return;
1478
1479         hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
1480                 if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
1481                         oldest = rt6_ex;
1482         }
1483         rt6_remove_exception(bucket, oldest);
1484 }
1485
1486 static u32 rt6_exception_hash(const struct in6_addr *dst,
1487                               const struct in6_addr *src)
1488 {
1489         static siphash_aligned_key_t rt6_exception_key;
1490         struct {
1491                 struct in6_addr dst;
1492                 struct in6_addr src;
1493         } __aligned(SIPHASH_ALIGNMENT) combined = {
1494                 .dst = *dst,
1495         };
1496         u64 val;
1497
1498         net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key));
1499
1500 #ifdef CONFIG_IPV6_SUBTREES
1501         if (src)
1502                 combined.src = *src;
1503 #endif
1504         val = siphash(&combined, sizeof(combined), &rt6_exception_key);
1505
1506         return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
1507 }
1508
1509 /* Helper function to find the cached rt in the hash table
1510  * and update bucket pointer to point to the bucket for this
1511  * (daddr, saddr) pair
1512  * Caller must hold rt6_exception_lock
1513  */
1514 static struct rt6_exception *
1515 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
1516                               const struct in6_addr *daddr,
1517                               const struct in6_addr *saddr)
1518 {
1519         struct rt6_exception *rt6_ex;
1520         u32 hval;
1521
1522         if (!(*bucket) || !daddr)
1523                 return NULL;
1524
1525         hval = rt6_exception_hash(daddr, saddr);
1526         *bucket += hval;
1527
1528         hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
1529                 struct rt6_info *rt6 = rt6_ex->rt6i;
1530                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1531
1532 #ifdef CONFIG_IPV6_SUBTREES
1533                 if (matched && saddr)
1534                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1535 #endif
1536                 if (matched)
1537                         return rt6_ex;
1538         }
1539         return NULL;
1540 }
1541
1542 /* Helper function to find the cached rt in the hash table
1543  * and update bucket pointer to point to the bucket for this
1544  * (daddr, saddr) pair
1545  * Caller must hold rcu_read_lock()
1546  */
1547 static struct rt6_exception *
1548 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
1549                          const struct in6_addr *daddr,
1550                          const struct in6_addr *saddr)
1551 {
1552         struct rt6_exception *rt6_ex;
1553         u32 hval;
1554
1555         WARN_ON_ONCE(!rcu_read_lock_held());
1556
1557         if (!(*bucket) || !daddr)
1558                 return NULL;
1559
1560         hval = rt6_exception_hash(daddr, saddr);
1561         *bucket += hval;
1562
1563         hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
1564                 struct rt6_info *rt6 = rt6_ex->rt6i;
1565                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1566
1567 #ifdef CONFIG_IPV6_SUBTREES
1568                 if (matched && saddr)
1569                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1570 #endif
1571                 if (matched)
1572                         return rt6_ex;
1573         }
1574         return NULL;
1575 }
1576
1577 static unsigned int fib6_mtu(const struct fib6_result *res)
1578 {
1579         const struct fib6_nh *nh = res->nh;
1580         unsigned int mtu;
1581
1582         if (res->f6i->fib6_pmtu) {
1583                 mtu = res->f6i->fib6_pmtu;
1584         } else {
1585                 struct net_device *dev = nh->fib_nh_dev;
1586                 struct inet6_dev *idev;
1587
1588                 rcu_read_lock();
1589                 idev = __in6_dev_get(dev);
1590                 mtu = idev->cnf.mtu6;
1591                 rcu_read_unlock();
1592         }
1593
1594         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
1595
1596         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
1597 }
1598
1599 #define FIB6_EXCEPTION_BUCKET_FLUSHED  0x1UL
1600
1601 /* used when the flushed bit is not relevant, only access to the bucket
1602  * (ie., all bucket users except rt6_insert_exception);
1603  *
1604  * called under rcu lock; sometimes called with rt6_exception_lock held
1605  */
1606 static
1607 struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh,
1608                                                        spinlock_t *lock)
1609 {
1610         struct rt6_exception_bucket *bucket;
1611
1612         if (lock)
1613                 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1614                                                    lockdep_is_held(lock));
1615         else
1616                 bucket = rcu_dereference(nh->rt6i_exception_bucket);
1617
1618         /* remove bucket flushed bit if set */
1619         if (bucket) {
1620                 unsigned long p = (unsigned long)bucket;
1621
1622                 p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED;
1623                 bucket = (struct rt6_exception_bucket *)p;
1624         }
1625
1626         return bucket;
1627 }
1628
1629 static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket)
1630 {
1631         unsigned long p = (unsigned long)bucket;
1632
1633         return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED);
1634 }
1635
1636 /* called with rt6_exception_lock held */
1637 static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh,
1638                                               spinlock_t *lock)
1639 {
1640         struct rt6_exception_bucket *bucket;
1641         unsigned long p;
1642
1643         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1644                                            lockdep_is_held(lock));
1645
1646         p = (unsigned long)bucket;
1647         p |= FIB6_EXCEPTION_BUCKET_FLUSHED;
1648         bucket = (struct rt6_exception_bucket *)p;
1649         rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1650 }
1651
1652 static int rt6_insert_exception(struct rt6_info *nrt,
1653                                 const struct fib6_result *res)
1654 {
1655         struct net *net = dev_net(nrt->dst.dev);
1656         struct rt6_exception_bucket *bucket;
1657         struct fib6_info *f6i = res->f6i;
1658         struct in6_addr *src_key = NULL;
1659         struct rt6_exception *rt6_ex;
1660         struct fib6_nh *nh = res->nh;
1661         int max_depth;
1662         int err = 0;
1663
1664         spin_lock_bh(&rt6_exception_lock);
1665
1666         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1667                                           lockdep_is_held(&rt6_exception_lock));
1668         if (!bucket) {
1669                 bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
1670                                  GFP_ATOMIC);
1671                 if (!bucket) {
1672                         err = -ENOMEM;
1673                         goto out;
1674                 }
1675                 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1676         } else if (fib6_nh_excptn_bucket_flushed(bucket)) {
1677                 err = -EINVAL;
1678                 goto out;
1679         }
1680
1681 #ifdef CONFIG_IPV6_SUBTREES
1682         /* fib6_src.plen != 0 indicates f6i is in subtree
1683          * and exception table is indexed by a hash of
1684          * both fib6_dst and fib6_src.
1685          * Otherwise, the exception table is indexed by
1686          * a hash of only fib6_dst.
1687          */
1688         if (f6i->fib6_src.plen)
1689                 src_key = &nrt->rt6i_src.addr;
1690 #endif
1691         /* rt6_mtu_change() might lower mtu on f6i.
1692          * Only insert this exception route if its mtu
1693          * is less than f6i's mtu value.
1694          */
1695         if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) {
1696                 err = -EINVAL;
1697                 goto out;
1698         }
1699
1700         rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
1701                                                src_key);
1702         if (rt6_ex)
1703                 rt6_remove_exception(bucket, rt6_ex);
1704
1705         rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
1706         if (!rt6_ex) {
1707                 err = -ENOMEM;
1708                 goto out;
1709         }
1710         rt6_ex->rt6i = nrt;
1711         rt6_ex->stamp = jiffies;
1712         hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
1713         bucket->depth++;
1714         net->ipv6.rt6_stats->fib_rt_cache++;
1715
1716         /* Randomize max depth to avoid some side channels attacks. */
1717         max_depth = FIB6_MAX_DEPTH + get_random_u32_below(FIB6_MAX_DEPTH);
1718         while (bucket->depth > max_depth)
1719                 rt6_exception_remove_oldest(bucket);
1720
1721 out:
1722         spin_unlock_bh(&rt6_exception_lock);
1723
1724         /* Update fn->fn_sernum to invalidate all cached dst */
1725         if (!err) {
1726                 spin_lock_bh(&f6i->fib6_table->tb6_lock);
1727                 fib6_update_sernum(net, f6i);
1728                 spin_unlock_bh(&f6i->fib6_table->tb6_lock);
1729                 fib6_force_start_gc(net);
1730         }
1731
1732         return err;
1733 }
1734
1735 static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
1736 {
1737         struct rt6_exception_bucket *bucket;
1738         struct rt6_exception *rt6_ex;
1739         struct hlist_node *tmp;
1740         int i;
1741
1742         spin_lock_bh(&rt6_exception_lock);
1743
1744         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1745         if (!bucket)
1746                 goto out;
1747
1748         /* Prevent rt6_insert_exception() to recreate the bucket list */
1749         if (!from)
1750                 fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock);
1751
1752         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1753                 hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) {
1754                         if (!from ||
1755                             rcu_access_pointer(rt6_ex->rt6i->from) == from)
1756                                 rt6_remove_exception(bucket, rt6_ex);
1757                 }
1758                 WARN_ON_ONCE(!from && bucket->depth);
1759                 bucket++;
1760         }
1761 out:
1762         spin_unlock_bh(&rt6_exception_lock);
1763 }
1764
1765 static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg)
1766 {
1767         struct fib6_info *f6i = arg;
1768
1769         fib6_nh_flush_exceptions(nh, f6i);
1770
1771         return 0;
1772 }
1773
1774 void rt6_flush_exceptions(struct fib6_info *f6i)
1775 {
1776         if (f6i->nh)
1777                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions,
1778                                          f6i);
1779         else
1780                 fib6_nh_flush_exceptions(f6i->fib6_nh, f6i);
1781 }
1782
1783 /* Find cached rt in the hash table inside passed in rt
1784  * Caller has to hold rcu_read_lock()
1785  */
1786 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
1787                                            const struct in6_addr *daddr,
1788                                            const struct in6_addr *saddr)
1789 {
1790         const struct in6_addr *src_key = NULL;
1791         struct rt6_exception_bucket *bucket;
1792         struct rt6_exception *rt6_ex;
1793         struct rt6_info *ret = NULL;
1794
1795 #ifdef CONFIG_IPV6_SUBTREES
1796         /* fib6i_src.plen != 0 indicates f6i is in subtree
1797          * and exception table is indexed by a hash of
1798          * both fib6_dst and fib6_src.
1799          * However, the src addr used to create the hash
1800          * might not be exactly the passed in saddr which
1801          * is a /128 addr from the flow.
1802          * So we need to use f6i->fib6_src to redo lookup
1803          * if the passed in saddr does not find anything.
1804          * (See the logic in ip6_rt_cache_alloc() on how
1805          * rt->rt6i_src is updated.)
1806          */
1807         if (res->f6i->fib6_src.plen)
1808                 src_key = saddr;
1809 find_ex:
1810 #endif
1811         bucket = fib6_nh_get_excptn_bucket(res->nh, NULL);
1812         rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
1813
1814         if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
1815                 ret = rt6_ex->rt6i;
1816
1817 #ifdef CONFIG_IPV6_SUBTREES
1818         /* Use fib6_src as src_key and redo lookup */
1819         if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) {
1820                 src_key = &res->f6i->fib6_src.addr;
1821                 goto find_ex;
1822         }
1823 #endif
1824
1825         return ret;
1826 }
1827
1828 /* Remove the passed in cached rt from the hash table that contains it */
1829 static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen,
1830                                     const struct rt6_info *rt)
1831 {
1832         const struct in6_addr *src_key = NULL;
1833         struct rt6_exception_bucket *bucket;
1834         struct rt6_exception *rt6_ex;
1835         int err;
1836
1837         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
1838                 return -ENOENT;
1839
1840         spin_lock_bh(&rt6_exception_lock);
1841         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1842
1843 #ifdef CONFIG_IPV6_SUBTREES
1844         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1845          * and exception table is indexed by a hash of
1846          * both rt6i_dst and rt6i_src.
1847          * Otherwise, the exception table is indexed by
1848          * a hash of only rt6i_dst.
1849          */
1850         if (plen)
1851                 src_key = &rt->rt6i_src.addr;
1852 #endif
1853         rt6_ex = __rt6_find_exception_spinlock(&bucket,
1854                                                &rt->rt6i_dst.addr,
1855                                                src_key);
1856         if (rt6_ex) {
1857                 rt6_remove_exception(bucket, rt6_ex);
1858                 err = 0;
1859         } else {
1860                 err = -ENOENT;
1861         }
1862
1863         spin_unlock_bh(&rt6_exception_lock);
1864         return err;
1865 }
1866
1867 struct fib6_nh_excptn_arg {
1868         struct rt6_info *rt;
1869         int             plen;
1870 };
1871
1872 static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg)
1873 {
1874         struct fib6_nh_excptn_arg *arg = _arg;
1875         int err;
1876
1877         err = fib6_nh_remove_exception(nh, arg->plen, arg->rt);
1878         if (err == 0)
1879                 return 1;
1880
1881         return 0;
1882 }
1883
1884 static int rt6_remove_exception_rt(struct rt6_info *rt)
1885 {
1886         struct fib6_info *from;
1887
1888         from = rcu_dereference(rt->from);
1889         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1890                 return -EINVAL;
1891
1892         if (from->nh) {
1893                 struct fib6_nh_excptn_arg arg = {
1894                         .rt = rt,
1895                         .plen = from->fib6_src.plen
1896                 };
1897                 int rc;
1898
1899                 /* rc = 1 means an entry was found */
1900                 rc = nexthop_for_each_fib6_nh(from->nh,
1901                                               rt6_nh_remove_exception_rt,
1902                                               &arg);
1903                 return rc ? 0 : -ENOENT;
1904         }
1905
1906         return fib6_nh_remove_exception(from->fib6_nh,
1907                                         from->fib6_src.plen, rt);
1908 }
1909
1910 /* Find rt6_ex which contains the passed in rt cache and
1911  * refresh its stamp
1912  */
1913 static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen,
1914                                      const struct rt6_info *rt)
1915 {
1916         const struct in6_addr *src_key = NULL;
1917         struct rt6_exception_bucket *bucket;
1918         struct rt6_exception *rt6_ex;
1919
1920         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
1921 #ifdef CONFIG_IPV6_SUBTREES
1922         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1923          * and exception table is indexed by a hash of
1924          * both rt6i_dst and rt6i_src.
1925          * Otherwise, the exception table is indexed by
1926          * a hash of only rt6i_dst.
1927          */
1928         if (plen)
1929                 src_key = &rt->rt6i_src.addr;
1930 #endif
1931         rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
1932         if (rt6_ex)
1933                 rt6_ex->stamp = jiffies;
1934 }
1935
1936 struct fib6_nh_match_arg {
1937         const struct net_device *dev;
1938         const struct in6_addr   *gw;
1939         struct fib6_nh          *match;
1940 };
1941
1942 /* determine if fib6_nh has given device and gateway */
1943 static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg)
1944 {
1945         struct fib6_nh_match_arg *arg = _arg;
1946
1947         if (arg->dev != nh->fib_nh_dev ||
1948             (arg->gw && !nh->fib_nh_gw_family) ||
1949             (!arg->gw && nh->fib_nh_gw_family) ||
1950             (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6)))
1951                 return 0;
1952
1953         arg->match = nh;
1954
1955         /* found a match, break the loop */
1956         return 1;
1957 }
1958
1959 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
1960 {
1961         struct fib6_info *from;
1962         struct fib6_nh *fib6_nh;
1963
1964         rcu_read_lock();
1965
1966         from = rcu_dereference(rt->from);
1967         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1968                 goto unlock;
1969
1970         if (from->nh) {
1971                 struct fib6_nh_match_arg arg = {
1972                         .dev = rt->dst.dev,
1973                         .gw = &rt->rt6i_gateway,
1974                 };
1975
1976                 nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
1977
1978                 if (!arg.match)
1979                         goto unlock;
1980                 fib6_nh = arg.match;
1981         } else {
1982                 fib6_nh = from->fib6_nh;
1983         }
1984         fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt);
1985 unlock:
1986         rcu_read_unlock();
1987 }
1988
1989 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
1990                                          struct rt6_info *rt, int mtu)
1991 {
1992         /* If the new MTU is lower than the route PMTU, this new MTU will be the
1993          * lowest MTU in the path: always allow updating the route PMTU to
1994          * reflect PMTU decreases.
1995          *
1996          * If the new MTU is higher, and the route PMTU is equal to the local
1997          * MTU, this means the old MTU is the lowest in the path, so allow
1998          * updating it: if other nodes now have lower MTUs, PMTU discovery will
1999          * handle this.
2000          */
2001
2002         if (dst_mtu(&rt->dst) >= mtu)
2003                 return true;
2004
2005         if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
2006                 return true;
2007
2008         return false;
2009 }
2010
2011 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
2012                                        const struct fib6_nh *nh, int mtu)
2013 {
2014         struct rt6_exception_bucket *bucket;
2015         struct rt6_exception *rt6_ex;
2016         int i;
2017
2018         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2019         if (!bucket)
2020                 return;
2021
2022         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2023                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
2024                         struct rt6_info *entry = rt6_ex->rt6i;
2025
2026                         /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
2027                          * route), the metrics of its rt->from have already
2028                          * been updated.
2029                          */
2030                         if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
2031                             rt6_mtu_change_route_allowed(idev, entry, mtu))
2032                                 dst_metric_set(&entry->dst, RTAX_MTU, mtu);
2033                 }
2034                 bucket++;
2035         }
2036 }
2037
2038 #define RTF_CACHE_GATEWAY       (RTF_GATEWAY | RTF_CACHE)
2039
2040 static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh,
2041                                             const struct in6_addr *gateway)
2042 {
2043         struct rt6_exception_bucket *bucket;
2044         struct rt6_exception *rt6_ex;
2045         struct hlist_node *tmp;
2046         int i;
2047
2048         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2049                 return;
2050
2051         spin_lock_bh(&rt6_exception_lock);
2052         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2053         if (bucket) {
2054                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2055                         hlist_for_each_entry_safe(rt6_ex, tmp,
2056                                                   &bucket->chain, hlist) {
2057                                 struct rt6_info *entry = rt6_ex->rt6i;
2058
2059                                 if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
2060                                     RTF_CACHE_GATEWAY &&
2061                                     ipv6_addr_equal(gateway,
2062                                                     &entry->rt6i_gateway)) {
2063                                         rt6_remove_exception(bucket, rt6_ex);
2064                                 }
2065                         }
2066                         bucket++;
2067                 }
2068         }
2069
2070         spin_unlock_bh(&rt6_exception_lock);
2071 }
2072
2073 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
2074                                       struct rt6_exception *rt6_ex,
2075                                       struct fib6_gc_args *gc_args,
2076                                       unsigned long now)
2077 {
2078         struct rt6_info *rt = rt6_ex->rt6i;
2079
2080         /* we are pruning and obsoleting aged-out and non gateway exceptions
2081          * even if others have still references to them, so that on next
2082          * dst_check() such references can be dropped.
2083          * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
2084          * expired, independently from their aging, as per RFC 8201 section 4
2085          */
2086         if (!(rt->rt6i_flags & RTF_EXPIRES)) {
2087                 if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
2088                         RT6_TRACE("aging clone %p\n", rt);
2089                         rt6_remove_exception(bucket, rt6_ex);
2090                         return;
2091                 }
2092         } else if (time_after(jiffies, rt->dst.expires)) {
2093                 RT6_TRACE("purging expired route %p\n", rt);
2094                 rt6_remove_exception(bucket, rt6_ex);
2095                 return;
2096         }
2097
2098         if (rt->rt6i_flags & RTF_GATEWAY) {
2099                 struct neighbour *neigh;
2100
2101                 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
2102
2103                 if (!(neigh && (neigh->flags & NTF_ROUTER))) {
2104                         RT6_TRACE("purging route %p via non-router but gateway\n",
2105                                   rt);
2106                         rt6_remove_exception(bucket, rt6_ex);
2107                         return;
2108                 }
2109         }
2110
2111         gc_args->more++;
2112 }
2113
2114 static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
2115                                    struct fib6_gc_args *gc_args,
2116                                    unsigned long now)
2117 {
2118         struct rt6_exception_bucket *bucket;
2119         struct rt6_exception *rt6_ex;
2120         struct hlist_node *tmp;
2121         int i;
2122
2123         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2124                 return;
2125
2126         rcu_read_lock_bh();
2127         spin_lock(&rt6_exception_lock);
2128         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2129         if (bucket) {
2130                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2131                         hlist_for_each_entry_safe(rt6_ex, tmp,
2132                                                   &bucket->chain, hlist) {
2133                                 rt6_age_examine_exception(bucket, rt6_ex,
2134                                                           gc_args, now);
2135                         }
2136                         bucket++;
2137                 }
2138         }
2139         spin_unlock(&rt6_exception_lock);
2140         rcu_read_unlock_bh();
2141 }
2142
2143 struct fib6_nh_age_excptn_arg {
2144         struct fib6_gc_args     *gc_args;
2145         unsigned long           now;
2146 };
2147
2148 static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg)
2149 {
2150         struct fib6_nh_age_excptn_arg *arg = _arg;
2151
2152         fib6_nh_age_exceptions(nh, arg->gc_args, arg->now);
2153         return 0;
2154 }
2155
2156 void rt6_age_exceptions(struct fib6_info *f6i,
2157                         struct fib6_gc_args *gc_args,
2158                         unsigned long now)
2159 {
2160         if (f6i->nh) {
2161                 struct fib6_nh_age_excptn_arg arg = {
2162                         .gc_args = gc_args,
2163                         .now = now
2164                 };
2165
2166                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions,
2167                                          &arg);
2168         } else {
2169                 fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now);
2170         }
2171 }
2172
2173 /* must be called with rcu lock held */
2174 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
2175                       struct flowi6 *fl6, struct fib6_result *res, int strict)
2176 {
2177         struct fib6_node *fn, *saved_fn;
2178
2179         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
2180         saved_fn = fn;
2181
2182 redo_rt6_select:
2183         rt6_select(net, fn, oif, res, strict);
2184         if (res->f6i == net->ipv6.fib6_null_entry) {
2185                 fn = fib6_backtrack(fn, &fl6->saddr);
2186                 if (fn)
2187                         goto redo_rt6_select;
2188                 else if (strict & RT6_LOOKUP_F_REACHABLE) {
2189                         /* also consider unreachable route */
2190                         strict &= ~RT6_LOOKUP_F_REACHABLE;
2191                         fn = saved_fn;
2192                         goto redo_rt6_select;
2193                 }
2194         }
2195
2196         trace_fib6_table_lookup(net, res, table, fl6);
2197
2198         return 0;
2199 }
2200
2201 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
2202                                int oif, struct flowi6 *fl6,
2203                                const struct sk_buff *skb, int flags)
2204 {
2205         struct fib6_result res = {};
2206         struct rt6_info *rt = NULL;
2207         int strict = 0;
2208
2209         WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
2210                      !rcu_read_lock_held());
2211
2212         strict |= flags & RT6_LOOKUP_F_IFACE;
2213         strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
2214         if (net->ipv6.devconf_all->forwarding == 0)
2215                 strict |= RT6_LOOKUP_F_REACHABLE;
2216
2217         rcu_read_lock();
2218
2219         fib6_table_lookup(net, table, oif, fl6, &res, strict);
2220         if (res.f6i == net->ipv6.fib6_null_entry)
2221                 goto out;
2222
2223         fib6_select_path(net, &res, fl6, oif, false, skb, strict);
2224
2225         /*Search through exception table */
2226         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
2227         if (rt) {
2228                 goto out;
2229         } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
2230                             !res.nh->fib_nh_gw_family)) {
2231                 /* Create a RTF_CACHE clone which will not be
2232                  * owned by the fib6 tree.  It is for the special case where
2233                  * the daddr in the skb during the neighbor look-up is different
2234                  * from the fl6->daddr used to look-up route here.
2235                  */
2236                 rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
2237
2238                 if (rt) {
2239                         /* 1 refcnt is taken during ip6_rt_cache_alloc().
2240                          * As rt6_uncached_list_add() does not consume refcnt,
2241                          * this refcnt is always returned to the caller even
2242                          * if caller sets RT6_LOOKUP_F_DST_NOREF flag.
2243                          */
2244                         rt6_uncached_list_add(rt);
2245                         rcu_read_unlock();
2246
2247                         return rt;
2248                 }
2249         } else {
2250                 /* Get a percpu copy */
2251                 local_bh_disable();
2252                 rt = rt6_get_pcpu_route(&res);
2253
2254                 if (!rt)
2255                         rt = rt6_make_pcpu_route(net, &res);
2256
2257                 local_bh_enable();
2258         }
2259 out:
2260         if (!rt)
2261                 rt = net->ipv6.ip6_null_entry;
2262         if (!(flags & RT6_LOOKUP_F_DST_NOREF))
2263                 ip6_hold_safe(net, &rt);
2264         rcu_read_unlock();
2265
2266         return rt;
2267 }
2268 EXPORT_SYMBOL_GPL(ip6_pol_route);
2269
2270 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net,
2271                                             struct fib6_table *table,
2272                                             struct flowi6 *fl6,
2273                                             const struct sk_buff *skb,
2274                                             int flags)
2275 {
2276         return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
2277 }
2278
2279 struct dst_entry *ip6_route_input_lookup(struct net *net,
2280                                          struct net_device *dev,
2281                                          struct flowi6 *fl6,
2282                                          const struct sk_buff *skb,
2283                                          int flags)
2284 {
2285         if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
2286                 flags |= RT6_LOOKUP_F_IFACE;
2287
2288         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
2289 }
2290 EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
2291
2292 static void ip6_multipath_l3_keys(const struct sk_buff *skb,
2293                                   struct flow_keys *keys,
2294                                   struct flow_keys *flkeys)
2295 {
2296         const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
2297         const struct ipv6hdr *key_iph = outer_iph;
2298         struct flow_keys *_flkeys = flkeys;
2299         const struct ipv6hdr *inner_iph;
2300         const struct icmp6hdr *icmph;
2301         struct ipv6hdr _inner_iph;
2302         struct icmp6hdr _icmph;
2303
2304         if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
2305                 goto out;
2306
2307         icmph = skb_header_pointer(skb, skb_transport_offset(skb),
2308                                    sizeof(_icmph), &_icmph);
2309         if (!icmph)
2310                 goto out;
2311
2312         if (!icmpv6_is_err(icmph->icmp6_type))
2313                 goto out;
2314
2315         inner_iph = skb_header_pointer(skb,
2316                                        skb_transport_offset(skb) + sizeof(*icmph),
2317                                        sizeof(_inner_iph), &_inner_iph);
2318         if (!inner_iph)
2319                 goto out;
2320
2321         key_iph = inner_iph;
2322         _flkeys = NULL;
2323 out:
2324         if (_flkeys) {
2325                 keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
2326                 keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
2327                 keys->tags.flow_label = _flkeys->tags.flow_label;
2328                 keys->basic.ip_proto = _flkeys->basic.ip_proto;
2329         } else {
2330                 keys->addrs.v6addrs.src = key_iph->saddr;
2331                 keys->addrs.v6addrs.dst = key_iph->daddr;
2332                 keys->tags.flow_label = ip6_flowlabel(key_iph);
2333                 keys->basic.ip_proto = key_iph->nexthdr;
2334         }
2335 }
2336
2337 static u32 rt6_multipath_custom_hash_outer(const struct net *net,
2338                                            const struct sk_buff *skb,
2339                                            bool *p_has_inner)
2340 {
2341         u32 hash_fields = ip6_multipath_hash_fields(net);
2342         struct flow_keys keys, hash_keys;
2343
2344         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2345                 return 0;
2346
2347         memset(&hash_keys, 0, sizeof(hash_keys));
2348         skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
2349
2350         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2351         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2352                 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2353         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2354                 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2355         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2356                 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2357         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2358                 hash_keys.tags.flow_label = keys.tags.flow_label;
2359         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2360                 hash_keys.ports.src = keys.ports.src;
2361         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2362                 hash_keys.ports.dst = keys.ports.dst;
2363
2364         *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
2365         return flow_hash_from_keys(&hash_keys);
2366 }
2367
2368 static u32 rt6_multipath_custom_hash_inner(const struct net *net,
2369                                            const struct sk_buff *skb,
2370                                            bool has_inner)
2371 {
2372         u32 hash_fields = ip6_multipath_hash_fields(net);
2373         struct flow_keys keys, hash_keys;
2374
2375         /* We assume the packet carries an encapsulation, but if none was
2376          * encountered during dissection of the outer flow, then there is no
2377          * point in calling the flow dissector again.
2378          */
2379         if (!has_inner)
2380                 return 0;
2381
2382         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
2383                 return 0;
2384
2385         memset(&hash_keys, 0, sizeof(hash_keys));
2386         skb_flow_dissect_flow_keys(skb, &keys, 0);
2387
2388         if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
2389                 return 0;
2390
2391         if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2392                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2393                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2394                         hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2395                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2396                         hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2397         } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2398                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2399                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2400                         hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2401                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2402                         hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2403                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
2404                         hash_keys.tags.flow_label = keys.tags.flow_label;
2405         }
2406
2407         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
2408                 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2409         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
2410                 hash_keys.ports.src = keys.ports.src;
2411         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
2412                 hash_keys.ports.dst = keys.ports.dst;
2413
2414         return flow_hash_from_keys(&hash_keys);
2415 }
2416
2417 static u32 rt6_multipath_custom_hash_skb(const struct net *net,
2418                                          const struct sk_buff *skb)
2419 {
2420         u32 mhash, mhash_inner;
2421         bool has_inner = true;
2422
2423         mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner);
2424         mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner);
2425
2426         return jhash_2words(mhash, mhash_inner, 0);
2427 }
2428
2429 static u32 rt6_multipath_custom_hash_fl6(const struct net *net,
2430                                          const struct flowi6 *fl6)
2431 {
2432         u32 hash_fields = ip6_multipath_hash_fields(net);
2433         struct flow_keys hash_keys;
2434
2435         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2436                 return 0;
2437
2438         memset(&hash_keys, 0, sizeof(hash_keys));
2439         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2440         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2441                 hash_keys.addrs.v6addrs.src = fl6->saddr;
2442         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2443                 hash_keys.addrs.v6addrs.dst = fl6->daddr;
2444         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2445                 hash_keys.basic.ip_proto = fl6->flowi6_proto;
2446         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2447                 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2448         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2449                 hash_keys.ports.src = fl6->fl6_sport;
2450         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2451                 hash_keys.ports.dst = fl6->fl6_dport;
2452
2453         return flow_hash_from_keys(&hash_keys);
2454 }
2455
2456 /* if skb is set it will be used and fl6 can be NULL */
2457 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
2458                        const struct sk_buff *skb, struct flow_keys *flkeys)
2459 {
2460         struct flow_keys hash_keys;
2461         u32 mhash = 0;
2462
2463         switch (ip6_multipath_hash_policy(net)) {
2464         case 0:
2465                 memset(&hash_keys, 0, sizeof(hash_keys));
2466                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2467                 if (skb) {
2468                         ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2469                 } else {
2470                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2471                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2472                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2473                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2474                 }
2475                 mhash = flow_hash_from_keys(&hash_keys);
2476                 break;
2477         case 1:
2478                 if (skb) {
2479                         unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2480                         struct flow_keys keys;
2481
2482                         /* short-circuit if we already have L4 hash present */
2483                         if (skb->l4_hash)
2484                                 return skb_get_hash_raw(skb) >> 1;
2485
2486                         memset(&hash_keys, 0, sizeof(hash_keys));
2487
2488                         if (!flkeys) {
2489                                 skb_flow_dissect_flow_keys(skb, &keys, flag);
2490                                 flkeys = &keys;
2491                         }
2492                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2493                         hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2494                         hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2495                         hash_keys.ports.src = flkeys->ports.src;
2496                         hash_keys.ports.dst = flkeys->ports.dst;
2497                         hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2498                 } else {
2499                         memset(&hash_keys, 0, sizeof(hash_keys));
2500                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2501                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2502                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2503                         hash_keys.ports.src = fl6->fl6_sport;
2504                         hash_keys.ports.dst = fl6->fl6_dport;
2505                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2506                 }
2507                 mhash = flow_hash_from_keys(&hash_keys);
2508                 break;
2509         case 2:
2510                 memset(&hash_keys, 0, sizeof(hash_keys));
2511                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2512                 if (skb) {
2513                         struct flow_keys keys;
2514
2515                         if (!flkeys) {
2516                                 skb_flow_dissect_flow_keys(skb, &keys, 0);
2517                                 flkeys = &keys;
2518                         }
2519
2520                         /* Inner can be v4 or v6 */
2521                         if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2522                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2523                                 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2524                                 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2525                         } else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2526                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2527                                 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2528                                 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2529                                 hash_keys.tags.flow_label = flkeys->tags.flow_label;
2530                                 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2531                         } else {
2532                                 /* Same as case 0 */
2533                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2534                                 ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2535                         }
2536                 } else {
2537                         /* Same as case 0 */
2538                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2539                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2540                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2541                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2542                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2543                 }
2544                 mhash = flow_hash_from_keys(&hash_keys);
2545                 break;
2546         case 3:
2547                 if (skb)
2548                         mhash = rt6_multipath_custom_hash_skb(net, skb);
2549                 else
2550                         mhash = rt6_multipath_custom_hash_fl6(net, fl6);
2551                 break;
2552         }
2553
2554         return mhash >> 1;
2555 }
2556
2557 /* Called with rcu held */
2558 void ip6_route_input(struct sk_buff *skb)
2559 {
2560         const struct ipv6hdr *iph = ipv6_hdr(skb);
2561         struct net *net = dev_net(skb->dev);
2562         int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF;
2563         struct ip_tunnel_info *tun_info;
2564         struct flowi6 fl6 = {
2565                 .flowi6_iif = skb->dev->ifindex,
2566                 .daddr = iph->daddr,
2567                 .saddr = iph->saddr,
2568                 .flowlabel = ip6_flowinfo(iph),
2569                 .flowi6_mark = skb->mark,
2570                 .flowi6_proto = iph->nexthdr,
2571         };
2572         struct flow_keys *flkeys = NULL, _flkeys;
2573
2574         tun_info = skb_tunnel_info(skb);
2575         if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2576                 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
2577
2578         if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
2579                 flkeys = &_flkeys;
2580
2581         if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
2582                 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
2583         skb_dst_drop(skb);
2584         skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev,
2585                                                       &fl6, skb, flags));
2586 }
2587
2588 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net,
2589                                              struct fib6_table *table,
2590                                              struct flowi6 *fl6,
2591                                              const struct sk_buff *skb,
2592                                              int flags)
2593 {
2594         return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
2595 }
2596
2597 static struct dst_entry *ip6_route_output_flags_noref(struct net *net,
2598                                                       const struct sock *sk,
2599                                                       struct flowi6 *fl6,
2600                                                       int flags)
2601 {
2602         bool any_src;
2603
2604         if (ipv6_addr_type(&fl6->daddr) &
2605             (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
2606                 struct dst_entry *dst;
2607
2608                 /* This function does not take refcnt on the dst */
2609                 dst = l3mdev_link_scope_lookup(net, fl6);
2610                 if (dst)
2611                         return dst;
2612         }
2613
2614         fl6->flowi6_iif = LOOPBACK_IFINDEX;
2615
2616         flags |= RT6_LOOKUP_F_DST_NOREF;
2617         any_src = ipv6_addr_any(&fl6->saddr);
2618         if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
2619             (fl6->flowi6_oif && any_src))
2620                 flags |= RT6_LOOKUP_F_IFACE;
2621
2622         if (!any_src)
2623                 flags |= RT6_LOOKUP_F_HAS_SADDR;
2624         else if (sk)
2625                 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
2626
2627         return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
2628 }
2629
2630 struct dst_entry *ip6_route_output_flags(struct net *net,
2631                                          const struct sock *sk,
2632                                          struct flowi6 *fl6,
2633                                          int flags)
2634 {
2635         struct dst_entry *dst;
2636         struct rt6_info *rt6;
2637
2638         rcu_read_lock();
2639         dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
2640         rt6 = (struct rt6_info *)dst;
2641         /* For dst cached in uncached_list, refcnt is already taken. */
2642         if (list_empty(&rt6->dst.rt_uncached) && !dst_hold_safe(dst)) {
2643                 dst = &net->ipv6.ip6_null_entry->dst;
2644                 dst_hold(dst);
2645         }
2646         rcu_read_unlock();
2647
2648         return dst;
2649 }
2650 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
2651
2652 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2653 {
2654         struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
2655         struct net_device *loopback_dev = net->loopback_dev;
2656         struct dst_entry *new = NULL;
2657
2658         rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
2659                        DST_OBSOLETE_DEAD, 0);
2660         if (rt) {
2661                 rt6_info_init(rt);
2662                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
2663
2664                 new = &rt->dst;
2665                 new->__use = 1;
2666                 new->input = dst_discard;
2667                 new->output = dst_discard_out;
2668
2669                 dst_copy_metrics(new, &ort->dst);
2670
2671                 rt->rt6i_idev = in6_dev_get(loopback_dev);
2672                 rt->rt6i_gateway = ort->rt6i_gateway;
2673                 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
2674
2675                 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
2676 #ifdef CONFIG_IPV6_SUBTREES
2677                 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
2678 #endif
2679         }
2680
2681         dst_release(dst_orig);
2682         return new ? new : ERR_PTR(-ENOMEM);
2683 }
2684
2685 /*
2686  *      Destination cache support functions
2687  */
2688
2689 static bool fib6_check(struct fib6_info *f6i, u32 cookie)
2690 {
2691         u32 rt_cookie = 0;
2692
2693         if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
2694                 return false;
2695
2696         if (fib6_check_expired(f6i))
2697                 return false;
2698
2699         return true;
2700 }
2701
2702 static struct dst_entry *rt6_check(struct rt6_info *rt,
2703                                    struct fib6_info *from,
2704                                    u32 cookie)
2705 {
2706         u32 rt_cookie = 0;
2707
2708         if (!from || !fib6_get_cookie_safe(from, &rt_cookie) ||
2709             rt_cookie != cookie)
2710                 return NULL;
2711
2712         if (rt6_check_expired(rt))
2713                 return NULL;
2714
2715         return &rt->dst;
2716 }
2717
2718 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
2719                                             struct fib6_info *from,
2720                                             u32 cookie)
2721 {
2722         if (!__rt6_check_expired(rt) &&
2723             rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
2724             fib6_check(from, cookie))
2725                 return &rt->dst;
2726         else
2727                 return NULL;
2728 }
2729
2730 INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst,
2731                                                         u32 cookie)
2732 {
2733         struct dst_entry *dst_ret;
2734         struct fib6_info *from;
2735         struct rt6_info *rt;
2736
2737         rt = container_of(dst, struct rt6_info, dst);
2738
2739         if (rt->sernum)
2740                 return rt6_is_valid(rt) ? dst : NULL;
2741
2742         rcu_read_lock();
2743
2744         /* All IPV6 dsts are created with ->obsolete set to the value
2745          * DST_OBSOLETE_FORCE_CHK which forces validation calls down
2746          * into this function always.
2747          */
2748
2749         from = rcu_dereference(rt->from);
2750
2751         if (from && (rt->rt6i_flags & RTF_PCPU ||
2752             unlikely(!list_empty(&rt->dst.rt_uncached))))
2753                 dst_ret = rt6_dst_from_check(rt, from, cookie);
2754         else
2755                 dst_ret = rt6_check(rt, from, cookie);
2756
2757         rcu_read_unlock();
2758
2759         return dst_ret;
2760 }
2761 EXPORT_INDIRECT_CALLABLE(ip6_dst_check);
2762
2763 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
2764 {
2765         struct rt6_info *rt = (struct rt6_info *) dst;
2766
2767         if (rt) {
2768                 if (rt->rt6i_flags & RTF_CACHE) {
2769                         rcu_read_lock();
2770                         if (rt6_check_expired(rt)) {
2771                                 rt6_remove_exception_rt(rt);
2772                                 dst = NULL;
2773                         }
2774                         rcu_read_unlock();
2775                 } else {
2776                         dst_release(dst);
2777                         dst = NULL;
2778                 }
2779         }
2780         return dst;
2781 }
2782
2783 static void ip6_link_failure(struct sk_buff *skb)
2784 {
2785         struct rt6_info *rt;
2786
2787         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
2788
2789         rt = (struct rt6_info *) skb_dst(skb);
2790         if (rt) {
2791                 rcu_read_lock();
2792                 if (rt->rt6i_flags & RTF_CACHE) {
2793                         rt6_remove_exception_rt(rt);
2794                 } else {
2795                         struct fib6_info *from;
2796                         struct fib6_node *fn;
2797
2798                         from = rcu_dereference(rt->from);
2799                         if (from) {
2800                                 fn = rcu_dereference(from->fib6_node);
2801                                 if (fn && (rt->rt6i_flags & RTF_DEFAULT))
2802                                         WRITE_ONCE(fn->fn_sernum, -1);
2803                         }
2804                 }
2805                 rcu_read_unlock();
2806         }
2807 }
2808
2809 static void rt6_update_expires(struct rt6_info *rt0, int timeout)
2810 {
2811         if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
2812                 struct fib6_info *from;
2813
2814                 rcu_read_lock();
2815                 from = rcu_dereference(rt0->from);
2816                 if (from)
2817                         rt0->dst.expires = from->expires;
2818                 rcu_read_unlock();
2819         }
2820
2821         dst_set_expires(&rt0->dst, timeout);
2822         rt0->rt6i_flags |= RTF_EXPIRES;
2823 }
2824
2825 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
2826 {
2827         struct net *net = dev_net(rt->dst.dev);
2828
2829         dst_metric_set(&rt->dst, RTAX_MTU, mtu);
2830         rt->rt6i_flags |= RTF_MODIFIED;
2831         rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
2832 }
2833
2834 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
2835 {
2836         return !(rt->rt6i_flags & RTF_CACHE) &&
2837                 (rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
2838 }
2839
2840 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
2841                                  const struct ipv6hdr *iph, u32 mtu,
2842                                  bool confirm_neigh)
2843 {
2844         const struct in6_addr *daddr, *saddr;
2845         struct rt6_info *rt6 = (struct rt6_info *)dst;
2846
2847         /* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU)
2848          * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it.
2849          * [see also comment in rt6_mtu_change_route()]
2850          */
2851
2852         if (iph) {
2853                 daddr = &iph->daddr;
2854                 saddr = &iph->saddr;
2855         } else if (sk) {
2856                 daddr = &sk->sk_v6_daddr;
2857                 saddr = &inet6_sk(sk)->saddr;
2858         } else {
2859                 daddr = NULL;
2860                 saddr = NULL;
2861         }
2862
2863         if (confirm_neigh)
2864                 dst_confirm_neigh(dst, daddr);
2865
2866         if (mtu < IPV6_MIN_MTU)
2867                 return;
2868         if (mtu >= dst_mtu(dst))
2869                 return;
2870
2871         if (!rt6_cache_allowed_for_pmtu(rt6)) {
2872                 rt6_do_update_pmtu(rt6, mtu);
2873                 /* update rt6_ex->stamp for cache */
2874                 if (rt6->rt6i_flags & RTF_CACHE)
2875                         rt6_update_exception_stamp_rt(rt6);
2876         } else if (daddr) {
2877                 struct fib6_result res = {};
2878                 struct rt6_info *nrt6;
2879
2880                 rcu_read_lock();
2881                 res.f6i = rcu_dereference(rt6->from);
2882                 if (!res.f6i)
2883                         goto out_unlock;
2884
2885                 res.fib6_flags = res.f6i->fib6_flags;
2886                 res.fib6_type = res.f6i->fib6_type;
2887
2888                 if (res.f6i->nh) {
2889                         struct fib6_nh_match_arg arg = {
2890                                 .dev = dst->dev,
2891                                 .gw = &rt6->rt6i_gateway,
2892                         };
2893
2894                         nexthop_for_each_fib6_nh(res.f6i->nh,
2895                                                  fib6_nh_find_match, &arg);
2896
2897                         /* fib6_info uses a nexthop that does not have fib6_nh
2898                          * using the dst->dev + gw. Should be impossible.
2899                          */
2900                         if (!arg.match)
2901                                 goto out_unlock;
2902
2903                         res.nh = arg.match;
2904                 } else {
2905                         res.nh = res.f6i->fib6_nh;
2906                 }
2907
2908                 nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
2909                 if (nrt6) {
2910                         rt6_do_update_pmtu(nrt6, mtu);
2911                         if (rt6_insert_exception(nrt6, &res))
2912                                 dst_release_immediate(&nrt6->dst);
2913                 }
2914 out_unlock:
2915                 rcu_read_unlock();
2916         }
2917 }
2918
2919 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
2920                                struct sk_buff *skb, u32 mtu,
2921                                bool confirm_neigh)
2922 {
2923         __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu,
2924                              confirm_neigh);
2925 }
2926
2927 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
2928                      int oif, u32 mark, kuid_t uid)
2929 {
2930         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2931         struct dst_entry *dst;
2932         struct flowi6 fl6 = {
2933                 .flowi6_oif = oif,
2934                 .flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
2935                 .daddr = iph->daddr,
2936                 .saddr = iph->saddr,
2937                 .flowlabel = ip6_flowinfo(iph),
2938                 .flowi6_uid = uid,
2939         };
2940
2941         dst = ip6_route_output(net, NULL, &fl6);
2942         if (!dst->error)
2943                 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true);
2944         dst_release(dst);
2945 }
2946 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
2947
2948 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
2949 {
2950         int oif = sk->sk_bound_dev_if;
2951         struct dst_entry *dst;
2952
2953         if (!oif && skb->dev)
2954                 oif = l3mdev_master_ifindex(skb->dev);
2955
2956         ip6_update_pmtu(skb, sock_net(sk), mtu, oif, READ_ONCE(sk->sk_mark),
2957                         sk->sk_uid);
2958
2959         dst = __sk_dst_get(sk);
2960         if (!dst || !dst->obsolete ||
2961             dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
2962                 return;
2963
2964         bh_lock_sock(sk);
2965         if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
2966                 ip6_datagram_dst_update(sk, false);
2967         bh_unlock_sock(sk);
2968 }
2969 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
2970
2971 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
2972                            const struct flowi6 *fl6)
2973 {
2974 #ifdef CONFIG_IPV6_SUBTREES
2975         struct ipv6_pinfo *np = inet6_sk(sk);
2976 #endif
2977
2978         ip6_dst_store(sk, dst,
2979                       ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
2980                       &sk->sk_v6_daddr : NULL,
2981 #ifdef CONFIG_IPV6_SUBTREES
2982                       ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
2983                       &np->saddr :
2984 #endif
2985                       NULL);
2986 }
2987
2988 static bool ip6_redirect_nh_match(const struct fib6_result *res,
2989                                   struct flowi6 *fl6,
2990                                   const struct in6_addr *gw,
2991                                   struct rt6_info **ret)
2992 {
2993         const struct fib6_nh *nh = res->nh;
2994
2995         if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family ||
2996             fl6->flowi6_oif != nh->fib_nh_dev->ifindex)
2997                 return false;
2998
2999         /* rt_cache's gateway might be different from its 'parent'
3000          * in the case of an ip redirect.
3001          * So we keep searching in the exception table if the gateway
3002          * is different.
3003          */
3004         if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) {
3005                 struct rt6_info *rt_cache;
3006
3007                 rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr);
3008                 if (rt_cache &&
3009                     ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) {
3010                         *ret = rt_cache;
3011                         return true;
3012                 }
3013                 return false;
3014         }
3015         return true;
3016 }
3017
3018 struct fib6_nh_rd_arg {
3019         struct fib6_result      *res;
3020         struct flowi6           *fl6;
3021         const struct in6_addr   *gw;
3022         struct rt6_info         **ret;
3023 };
3024
3025 static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg)
3026 {
3027         struct fib6_nh_rd_arg *arg = _arg;
3028
3029         arg->res->nh = nh;
3030         return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret);
3031 }
3032
3033 /* Handle redirects */
3034 struct ip6rd_flowi {
3035         struct flowi6 fl6;
3036         struct in6_addr gateway;
3037 };
3038
3039 INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net,
3040                                              struct fib6_table *table,
3041                                              struct flowi6 *fl6,
3042                                              const struct sk_buff *skb,
3043                                              int flags)
3044 {
3045         struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
3046         struct rt6_info *ret = NULL;
3047         struct fib6_result res = {};
3048         struct fib6_nh_rd_arg arg = {
3049                 .res = &res,
3050                 .fl6 = fl6,
3051                 .gw  = &rdfl->gateway,
3052                 .ret = &ret
3053         };
3054         struct fib6_info *rt;
3055         struct fib6_node *fn;
3056
3057         /* Get the "current" route for this destination and
3058          * check if the redirect has come from appropriate router.
3059          *
3060          * RFC 4861 specifies that redirects should only be
3061          * accepted if they come from the nexthop to the target.
3062          * Due to the way the routes are chosen, this notion
3063          * is a bit fuzzy and one might need to check all possible
3064          * routes.
3065          */
3066
3067         rcu_read_lock();
3068         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
3069 restart:
3070         for_each_fib6_node_rt_rcu(fn) {
3071                 res.f6i = rt;
3072                 if (fib6_check_expired(rt))
3073                         continue;
3074                 if (rt->fib6_flags & RTF_REJECT)
3075                         break;
3076                 if (unlikely(rt->nh)) {
3077                         if (nexthop_is_blackhole(rt->nh))
3078                                 continue;
3079                         /* on match, res->nh is filled in and potentially ret */
3080                         if (nexthop_for_each_fib6_nh(rt->nh,
3081                                                      fib6_nh_redirect_match,
3082                                                      &arg))
3083                                 goto out;
3084                 } else {
3085                         res.nh = rt->fib6_nh;
3086                         if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway,
3087                                                   &ret))
3088                                 goto out;
3089                 }
3090         }
3091
3092         if (!rt)
3093                 rt = net->ipv6.fib6_null_entry;
3094         else if (rt->fib6_flags & RTF_REJECT) {
3095                 ret = net->ipv6.ip6_null_entry;
3096                 goto out;
3097         }
3098
3099         if (rt == net->ipv6.fib6_null_entry) {
3100                 fn = fib6_backtrack(fn, &fl6->saddr);
3101                 if (fn)
3102                         goto restart;
3103         }
3104
3105         res.f6i = rt;
3106         res.nh = rt->fib6_nh;
3107 out:
3108         if (ret) {
3109                 ip6_hold_safe(net, &ret);
3110         } else {
3111                 res.fib6_flags = res.f6i->fib6_flags;
3112                 res.fib6_type = res.f6i->fib6_type;
3113                 ret = ip6_create_rt_rcu(&res);
3114         }
3115
3116         rcu_read_unlock();
3117
3118         trace_fib6_table_lookup(net, &res, table, fl6);
3119         return ret;
3120 };
3121
3122 static struct dst_entry *ip6_route_redirect(struct net *net,
3123                                             const struct flowi6 *fl6,
3124                                             const struct sk_buff *skb,
3125                                             const struct in6_addr *gateway)
3126 {
3127         int flags = RT6_LOOKUP_F_HAS_SADDR;
3128         struct ip6rd_flowi rdfl;
3129
3130         rdfl.fl6 = *fl6;
3131         rdfl.gateway = *gateway;
3132
3133         return fib6_rule_lookup(net, &rdfl.fl6, skb,
3134                                 flags, __ip6_route_redirect);
3135 }
3136
3137 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
3138                   kuid_t uid)
3139 {
3140         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
3141         struct dst_entry *dst;
3142         struct flowi6 fl6 = {
3143                 .flowi6_iif = LOOPBACK_IFINDEX,
3144                 .flowi6_oif = oif,
3145                 .flowi6_mark = mark,
3146                 .daddr = iph->daddr,
3147                 .saddr = iph->saddr,
3148                 .flowlabel = ip6_flowinfo(iph),
3149                 .flowi6_uid = uid,
3150         };
3151
3152         dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
3153         rt6_do_redirect(dst, NULL, skb);
3154         dst_release(dst);
3155 }
3156 EXPORT_SYMBOL_GPL(ip6_redirect);
3157
3158 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
3159 {
3160         const struct ipv6hdr *iph = ipv6_hdr(skb);
3161         const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
3162         struct dst_entry *dst;
3163         struct flowi6 fl6 = {
3164                 .flowi6_iif = LOOPBACK_IFINDEX,
3165                 .flowi6_oif = oif,
3166                 .daddr = msg->dest,
3167                 .saddr = iph->daddr,
3168                 .flowi6_uid = sock_net_uid(net, NULL),
3169         };
3170
3171         dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
3172         rt6_do_redirect(dst, NULL, skb);
3173         dst_release(dst);
3174 }
3175
3176 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
3177 {
3178         ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if,
3179                      READ_ONCE(sk->sk_mark), sk->sk_uid);
3180 }
3181 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
3182
3183 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
3184 {
3185         struct net_device *dev = dst->dev;
3186         unsigned int mtu = dst_mtu(dst);
3187         struct net *net = dev_net(dev);
3188
3189         mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
3190
3191         if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
3192                 mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
3193
3194         /*
3195          * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
3196          * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
3197          * IPV6_MAXPLEN is also valid and means: "any MSS,
3198          * rely only on pmtu discovery"
3199          */
3200         if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
3201                 mtu = IPV6_MAXPLEN;
3202         return mtu;
3203 }
3204
3205 INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst)
3206 {
3207         return ip6_dst_mtu_maybe_forward(dst, false);
3208 }
3209 EXPORT_INDIRECT_CALLABLE(ip6_mtu);
3210
3211 /* MTU selection:
3212  * 1. mtu on route is locked - use it
3213  * 2. mtu from nexthop exception
3214  * 3. mtu from egress device
3215  *
3216  * based on ip6_dst_mtu_forward and exception logic of
3217  * rt6_find_cached_rt; called with rcu_read_lock
3218  */
3219 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
3220                       const struct in6_addr *daddr,
3221                       const struct in6_addr *saddr)
3222 {
3223         const struct fib6_nh *nh = res->nh;
3224         struct fib6_info *f6i = res->f6i;
3225         struct inet6_dev *idev;
3226         struct rt6_info *rt;
3227         u32 mtu = 0;
3228
3229         if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
3230                 mtu = f6i->fib6_pmtu;
3231                 if (mtu)
3232                         goto out;
3233         }
3234
3235         rt = rt6_find_cached_rt(res, daddr, saddr);
3236         if (unlikely(rt)) {
3237                 mtu = dst_metric_raw(&rt->dst, RTAX_MTU);
3238         } else {
3239                 struct net_device *dev = nh->fib_nh_dev;
3240
3241                 mtu = IPV6_MIN_MTU;
3242                 idev = __in6_dev_get(dev);
3243                 if (idev && idev->cnf.mtu6 > mtu)
3244                         mtu = idev->cnf.mtu6;
3245         }
3246
3247         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
3248 out:
3249         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
3250 }
3251
3252 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
3253                                   struct flowi6 *fl6)
3254 {
3255         struct dst_entry *dst;
3256         struct rt6_info *rt;
3257         struct inet6_dev *idev = in6_dev_get(dev);
3258         struct net *net = dev_net(dev);
3259
3260         if (unlikely(!idev))
3261                 return ERR_PTR(-ENODEV);
3262
3263         rt = ip6_dst_alloc(net, dev, 0);
3264         if (unlikely(!rt)) {
3265                 in6_dev_put(idev);
3266                 dst = ERR_PTR(-ENOMEM);
3267                 goto out;
3268         }
3269
3270         rt->dst.input = ip6_input;
3271         rt->dst.output  = ip6_output;
3272         rt->rt6i_gateway  = fl6->daddr;
3273         rt->rt6i_dst.addr = fl6->daddr;
3274         rt->rt6i_dst.plen = 128;
3275         rt->rt6i_idev     = idev;
3276         dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
3277
3278         /* Add this dst into uncached_list so that rt6_disable_ip() can
3279          * do proper release of the net_device
3280          */
3281         rt6_uncached_list_add(rt);
3282
3283         dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
3284
3285 out:
3286         return dst;
3287 }
3288
3289 static void ip6_dst_gc(struct dst_ops *ops)
3290 {
3291         struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
3292         int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
3293         int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
3294         int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
3295         unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
3296         unsigned int val;
3297         int entries;
3298
3299         if (time_after(rt_last_gc + rt_min_interval, jiffies))
3300                 goto out;
3301
3302         fib6_run_gc(atomic_inc_return(&net->ipv6.ip6_rt_gc_expire), net, true);
3303         entries = dst_entries_get_slow(ops);
3304         if (entries < ops->gc_thresh)
3305                 atomic_set(&net->ipv6.ip6_rt_gc_expire, rt_gc_timeout >> 1);
3306 out:
3307         val = atomic_read(&net->ipv6.ip6_rt_gc_expire);
3308         atomic_set(&net->ipv6.ip6_rt_gc_expire, val - (val >> rt_elasticity));
3309 }
3310
3311 static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
3312                                const struct in6_addr *gw_addr, u32 tbid,
3313                                int flags, struct fib6_result *res)
3314 {
3315         struct flowi6 fl6 = {
3316                 .flowi6_oif = cfg->fc_ifindex,
3317                 .daddr = *gw_addr,
3318                 .saddr = cfg->fc_prefsrc,
3319         };
3320         struct fib6_table *table;
3321         int err;
3322
3323         table = fib6_get_table(net, tbid);
3324         if (!table)
3325                 return -EINVAL;
3326
3327         if (!ipv6_addr_any(&cfg->fc_prefsrc))
3328                 flags |= RT6_LOOKUP_F_HAS_SADDR;
3329
3330         flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
3331
3332         err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags);
3333         if (!err && res->f6i != net->ipv6.fib6_null_entry)
3334                 fib6_select_path(net, res, &fl6, cfg->fc_ifindex,
3335                                  cfg->fc_ifindex != 0, NULL, flags);
3336
3337         return err;
3338 }
3339
3340 static int ip6_route_check_nh_onlink(struct net *net,
3341                                      struct fib6_config *cfg,
3342                                      const struct net_device *dev,
3343                                      struct netlink_ext_ack *extack)
3344 {
3345         u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
3346         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3347         struct fib6_result res = {};
3348         int err;
3349
3350         err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res);
3351         if (!err && !(res.fib6_flags & RTF_REJECT) &&
3352             /* ignore match if it is the default route */
3353             !ipv6_addr_any(&res.f6i->fib6_dst.addr) &&
3354             (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) {
3355                 NL_SET_ERR_MSG(extack,
3356                                "Nexthop has invalid gateway or device mismatch");
3357                 err = -EINVAL;
3358         }
3359
3360         return err;
3361 }
3362
3363 static int ip6_route_check_nh(struct net *net,
3364                               struct fib6_config *cfg,
3365                               struct net_device **_dev,
3366                               netdevice_tracker *dev_tracker,
3367                               struct inet6_dev **idev)
3368 {
3369         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3370         struct net_device *dev = _dev ? *_dev : NULL;
3371         int flags = RT6_LOOKUP_F_IFACE;
3372         struct fib6_result res = {};
3373         int err = -EHOSTUNREACH;
3374
3375         if (cfg->fc_table) {
3376                 err = ip6_nh_lookup_table(net, cfg, gw_addr,
3377                                           cfg->fc_table, flags, &res);
3378                 /* gw_addr can not require a gateway or resolve to a reject
3379                  * route. If a device is given, it must match the result.
3380                  */
3381                 if (err || res.fib6_flags & RTF_REJECT ||
3382                     res.nh->fib_nh_gw_family ||
3383                     (dev && dev != res.nh->fib_nh_dev))
3384                         err = -EHOSTUNREACH;
3385         }
3386
3387         if (err < 0) {
3388                 struct flowi6 fl6 = {
3389                         .flowi6_oif = cfg->fc_ifindex,
3390                         .daddr = *gw_addr,
3391                 };
3392
3393                 err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags);
3394                 if (err || res.fib6_flags & RTF_REJECT ||
3395                     res.nh->fib_nh_gw_family)
3396                         err = -EHOSTUNREACH;
3397
3398                 if (err)
3399                         return err;
3400
3401                 fib6_select_path(net, &res, &fl6, cfg->fc_ifindex,
3402                                  cfg->fc_ifindex != 0, NULL, flags);
3403         }
3404
3405         err = 0;
3406         if (dev) {
3407                 if (dev != res.nh->fib_nh_dev)
3408                         err = -EHOSTUNREACH;
3409         } else {
3410                 *_dev = dev = res.nh->fib_nh_dev;
3411                 netdev_hold(dev, dev_tracker, GFP_ATOMIC);
3412                 *idev = in6_dev_get(dev);
3413         }
3414
3415         return err;
3416 }
3417
3418 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
3419                            struct net_device **_dev,
3420                            netdevice_tracker *dev_tracker,
3421                            struct inet6_dev **idev,
3422                            struct netlink_ext_ack *extack)
3423 {
3424         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3425         int gwa_type = ipv6_addr_type(gw_addr);
3426         bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
3427         const struct net_device *dev = *_dev;
3428         bool need_addr_check = !dev;
3429         int err = -EINVAL;
3430
3431         /* if gw_addr is local we will fail to detect this in case
3432          * address is still TENTATIVE (DAD in progress). rt6_lookup()
3433          * will return already-added prefix route via interface that
3434          * prefix route was assigned to, which might be non-loopback.
3435          */
3436         if (dev &&
3437             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3438                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3439                 goto out;
3440         }
3441
3442         if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
3443                 /* IPv6 strictly inhibits using not link-local
3444                  * addresses as nexthop address.
3445                  * Otherwise, router will not able to send redirects.
3446                  * It is very good, but in some (rare!) circumstances
3447                  * (SIT, PtP, NBMA NOARP links) it is handy to allow
3448                  * some exceptions. --ANK
3449                  * We allow IPv4-mapped nexthops to support RFC4798-type
3450                  * addressing
3451                  */
3452                 if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
3453                         NL_SET_ERR_MSG(extack, "Invalid gateway address");
3454                         goto out;
3455                 }
3456
3457                 rcu_read_lock();
3458
3459                 if (cfg->fc_flags & RTNH_F_ONLINK)
3460                         err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
3461                 else
3462                         err = ip6_route_check_nh(net, cfg, _dev, dev_tracker,
3463                                                  idev);
3464
3465                 rcu_read_unlock();
3466
3467                 if (err)
3468                         goto out;
3469         }
3470
3471         /* reload in case device was changed */
3472         dev = *_dev;
3473
3474         err = -EINVAL;
3475         if (!dev) {
3476                 NL_SET_ERR_MSG(extack, "Egress device not specified");
3477                 goto out;
3478         } else if (dev->flags & IFF_LOOPBACK) {
3479                 NL_SET_ERR_MSG(extack,
3480                                "Egress device can not be loopback device for this route");
3481                 goto out;
3482         }
3483
3484         /* if we did not check gw_addr above, do so now that the
3485          * egress device has been resolved.
3486          */
3487         if (need_addr_check &&
3488             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3489                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3490                 goto out;
3491         }
3492
3493         err = 0;
3494 out:
3495         return err;
3496 }
3497
3498 static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
3499 {
3500         if ((flags & RTF_REJECT) ||
3501             (dev && (dev->flags & IFF_LOOPBACK) &&
3502              !(addr_type & IPV6_ADDR_LOOPBACK) &&
3503              !(flags & (RTF_ANYCAST | RTF_LOCAL))))
3504                 return true;
3505
3506         return false;
3507 }
3508
3509 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
3510                  struct fib6_config *cfg, gfp_t gfp_flags,
3511                  struct netlink_ext_ack *extack)
3512 {
3513         netdevice_tracker *dev_tracker = &fib6_nh->fib_nh_dev_tracker;
3514         struct net_device *dev = NULL;
3515         struct inet6_dev *idev = NULL;
3516         int addr_type;
3517         int err;
3518
3519         fib6_nh->fib_nh_family = AF_INET6;
3520 #ifdef CONFIG_IPV6_ROUTER_PREF
3521         fib6_nh->last_probe = jiffies;
3522 #endif
3523         if (cfg->fc_is_fdb) {
3524                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3525                 fib6_nh->fib_nh_gw_family = AF_INET6;
3526                 return 0;
3527         }
3528
3529         err = -ENODEV;
3530         if (cfg->fc_ifindex) {
3531                 dev = netdev_get_by_index(net, cfg->fc_ifindex,
3532                                           dev_tracker, gfp_flags);
3533                 if (!dev)
3534                         goto out;
3535                 idev = in6_dev_get(dev);
3536                 if (!idev)
3537                         goto out;
3538         }
3539
3540         if (cfg->fc_flags & RTNH_F_ONLINK) {
3541                 if (!dev) {
3542                         NL_SET_ERR_MSG(extack,
3543                                        "Nexthop device required for onlink");
3544                         goto out;
3545                 }
3546
3547                 if (!(dev->flags & IFF_UP)) {
3548                         NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3549                         err = -ENETDOWN;
3550                         goto out;
3551                 }
3552
3553                 fib6_nh->fib_nh_flags |= RTNH_F_ONLINK;
3554         }
3555
3556         fib6_nh->fib_nh_weight = 1;
3557
3558         /* We cannot add true routes via loopback here,
3559          * they would result in kernel looping; promote them to reject routes
3560          */
3561         addr_type = ipv6_addr_type(&cfg->fc_dst);
3562         if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) {
3563                 /* hold loopback dev/idev if we haven't done so. */
3564                 if (dev != net->loopback_dev) {
3565                         if (dev) {
3566                                 netdev_put(dev, dev_tracker);
3567                                 in6_dev_put(idev);
3568                         }
3569                         dev = net->loopback_dev;
3570                         netdev_hold(dev, dev_tracker, gfp_flags);
3571                         idev = in6_dev_get(dev);
3572                         if (!idev) {
3573                                 err = -ENODEV;
3574                                 goto out;
3575                         }
3576                 }
3577                 goto pcpu_alloc;
3578         }
3579
3580         if (cfg->fc_flags & RTF_GATEWAY) {
3581                 err = ip6_validate_gw(net, cfg, &dev, dev_tracker,
3582                                       &idev, extack);
3583                 if (err)
3584                         goto out;
3585
3586                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3587                 fib6_nh->fib_nh_gw_family = AF_INET6;
3588         }
3589
3590         err = -ENODEV;
3591         if (!dev)
3592                 goto out;
3593
3594         if (idev->cnf.disable_ipv6) {
3595                 NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
3596                 err = -EACCES;
3597                 goto out;
3598         }
3599
3600         if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
3601                 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3602                 err = -ENETDOWN;
3603                 goto out;
3604         }
3605
3606         if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
3607             !netif_carrier_ok(dev))
3608                 fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
3609
3610         err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap,
3611                                  cfg->fc_encap_type, cfg, gfp_flags, extack);
3612         if (err)
3613                 goto out;
3614
3615 pcpu_alloc:
3616         fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
3617         if (!fib6_nh->rt6i_pcpu) {
3618                 err = -ENOMEM;
3619                 goto out;
3620         }
3621
3622         fib6_nh->fib_nh_dev = dev;
3623         fib6_nh->fib_nh_oif = dev->ifindex;
3624         err = 0;
3625 out:
3626         if (idev)
3627                 in6_dev_put(idev);
3628
3629         if (err) {
3630                 lwtstate_put(fib6_nh->fib_nh_lws);
3631                 fib6_nh->fib_nh_lws = NULL;
3632                 netdev_put(dev, dev_tracker);
3633         }
3634
3635         return err;
3636 }
3637
3638 void fib6_nh_release(struct fib6_nh *fib6_nh)
3639 {
3640         struct rt6_exception_bucket *bucket;
3641
3642         rcu_read_lock();
3643
3644         fib6_nh_flush_exceptions(fib6_nh, NULL);
3645         bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL);
3646         if (bucket) {
3647                 rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL);
3648                 kfree(bucket);
3649         }
3650
3651         rcu_read_unlock();
3652
3653         fib6_nh_release_dsts(fib6_nh);
3654         free_percpu(fib6_nh->rt6i_pcpu);
3655
3656         fib_nh_common_release(&fib6_nh->nh_common);
3657 }
3658
3659 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh)
3660 {
3661         int cpu;
3662
3663         if (!fib6_nh->rt6i_pcpu)
3664                 return;
3665
3666         for_each_possible_cpu(cpu) {
3667                 struct rt6_info *pcpu_rt, **ppcpu_rt;
3668
3669                 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
3670                 pcpu_rt = xchg(ppcpu_rt, NULL);
3671                 if (pcpu_rt) {
3672                         dst_dev_put(&pcpu_rt->dst);
3673                         dst_release(&pcpu_rt->dst);
3674                 }
3675         }
3676 }
3677
3678 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
3679                                               gfp_t gfp_flags,
3680                                               struct netlink_ext_ack *extack)
3681 {
3682         struct net *net = cfg->fc_nlinfo.nl_net;
3683         struct fib6_info *rt = NULL;
3684         struct nexthop *nh = NULL;
3685         struct fib6_table *table;
3686         struct fib6_nh *fib6_nh;
3687         int err = -EINVAL;
3688         int addr_type;
3689
3690         /* RTF_PCPU is an internal flag; can not be set by userspace */
3691         if (cfg->fc_flags & RTF_PCPU) {
3692                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
3693                 goto out;
3694         }
3695
3696         /* RTF_CACHE is an internal flag; can not be set by userspace */
3697         if (cfg->fc_flags & RTF_CACHE) {
3698                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
3699                 goto out;
3700         }
3701
3702         if (cfg->fc_type > RTN_MAX) {
3703                 NL_SET_ERR_MSG(extack, "Invalid route type");
3704                 goto out;
3705         }
3706
3707         if (cfg->fc_dst_len > 128) {
3708                 NL_SET_ERR_MSG(extack, "Invalid prefix length");
3709                 goto out;
3710         }
3711         if (cfg->fc_src_len > 128) {
3712                 NL_SET_ERR_MSG(extack, "Invalid source address length");
3713                 goto out;
3714         }
3715 #ifndef CONFIG_IPV6_SUBTREES
3716         if (cfg->fc_src_len) {
3717                 NL_SET_ERR_MSG(extack,
3718                                "Specifying source address requires IPV6_SUBTREES to be enabled");
3719                 goto out;
3720         }
3721 #endif
3722         if (cfg->fc_nh_id) {
3723                 nh = nexthop_find_by_id(net, cfg->fc_nh_id);
3724                 if (!nh) {
3725                         NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
3726                         goto out;
3727                 }
3728                 err = fib6_check_nexthop(nh, cfg, extack);
3729                 if (err)
3730                         goto out;
3731         }
3732
3733         err = -ENOBUFS;
3734         if (cfg->fc_nlinfo.nlh &&
3735             !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
3736                 table = fib6_get_table(net, cfg->fc_table);
3737                 if (!table) {
3738                         pr_warn("NLM_F_CREATE should be specified when creating new route\n");
3739                         table = fib6_new_table(net, cfg->fc_table);
3740                 }
3741         } else {
3742                 table = fib6_new_table(net, cfg->fc_table);
3743         }
3744
3745         if (!table)
3746                 goto out;
3747
3748         err = -ENOMEM;
3749         rt = fib6_info_alloc(gfp_flags, !nh);
3750         if (!rt)
3751                 goto out;
3752
3753         rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len,
3754                                                extack);
3755         if (IS_ERR(rt->fib6_metrics)) {
3756                 err = PTR_ERR(rt->fib6_metrics);
3757                 /* Do not leave garbage there. */
3758                 rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
3759                 goto out_free;
3760         }
3761
3762         if (cfg->fc_flags & RTF_ADDRCONF)
3763                 rt->dst_nocount = true;
3764
3765         if (cfg->fc_flags & RTF_EXPIRES)
3766                 fib6_set_expires_locked(rt, jiffies +
3767                                         clock_t_to_jiffies(cfg->fc_expires));
3768         else
3769                 fib6_clean_expires_locked(rt);
3770
3771         if (cfg->fc_protocol == RTPROT_UNSPEC)
3772                 cfg->fc_protocol = RTPROT_BOOT;
3773         rt->fib6_protocol = cfg->fc_protocol;
3774
3775         rt->fib6_table = table;
3776         rt->fib6_metric = cfg->fc_metric;
3777         rt->fib6_type = cfg->fc_type ? : RTN_UNICAST;
3778         rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;
3779
3780         ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
3781         rt->fib6_dst.plen = cfg->fc_dst_len;
3782
3783 #ifdef CONFIG_IPV6_SUBTREES
3784         ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
3785         rt->fib6_src.plen = cfg->fc_src_len;
3786 #endif
3787         if (nh) {
3788                 if (rt->fib6_src.plen) {
3789                         NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
3790                         goto out_free;
3791                 }
3792                 if (!nexthop_get(nh)) {
3793                         NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
3794                         goto out_free;
3795                 }
3796                 rt->nh = nh;
3797                 fib6_nh = nexthop_fib6_nh(rt->nh);
3798         } else {
3799                 err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack);
3800                 if (err)
3801                         goto out;
3802
3803                 fib6_nh = rt->fib6_nh;
3804
3805                 /* We cannot add true routes via loopback here, they would
3806                  * result in kernel looping; promote them to reject routes
3807                  */
3808                 addr_type = ipv6_addr_type(&cfg->fc_dst);
3809                 if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev,
3810                                    addr_type))
3811                         rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
3812         }
3813
3814         if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
3815                 struct net_device *dev = fib6_nh->fib_nh_dev;
3816
3817                 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
3818                         NL_SET_ERR_MSG(extack, "Invalid source address");
3819                         err = -EINVAL;
3820                         goto out;
3821                 }
3822                 rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
3823                 rt->fib6_prefsrc.plen = 128;
3824         } else
3825                 rt->fib6_prefsrc.plen = 0;
3826
3827         return rt;
3828 out:
3829         fib6_info_release(rt);
3830         return ERR_PTR(err);
3831 out_free:
3832         ip_fib_metrics_put(rt->fib6_metrics);
3833         kfree(rt);
3834         return ERR_PTR(err);
3835 }
3836
3837 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
3838                   struct netlink_ext_ack *extack)
3839 {
3840         struct fib6_info *rt;
3841         int err;
3842
3843         rt = ip6_route_info_create(cfg, gfp_flags, extack);
3844         if (IS_ERR(rt))
3845                 return PTR_ERR(rt);
3846
3847         err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
3848         fib6_info_release(rt);
3849
3850         return err;
3851 }
3852
3853 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
3854 {
3855         struct net *net = info->nl_net;
3856         struct fib6_table *table;
3857         int err;
3858
3859         if (rt == net->ipv6.fib6_null_entry) {
3860                 err = -ENOENT;
3861                 goto out;
3862         }
3863
3864         table = rt->fib6_table;
3865         spin_lock_bh(&table->tb6_lock);
3866         err = fib6_del(rt, info);
3867         spin_unlock_bh(&table->tb6_lock);
3868
3869 out:
3870         fib6_info_release(rt);
3871         return err;
3872 }
3873
3874 int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify)
3875 {
3876         struct nl_info info = {
3877                 .nl_net = net,
3878                 .skip_notify = skip_notify
3879         };
3880
3881         return __ip6_del_rt(rt, &info);
3882 }
3883
3884 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
3885 {
3886         struct nl_info *info = &cfg->fc_nlinfo;
3887         struct net *net = info->nl_net;
3888         struct sk_buff *skb = NULL;
3889         struct fib6_table *table;
3890         int err = -ENOENT;
3891
3892         if (rt == net->ipv6.fib6_null_entry)
3893                 goto out_put;
3894         table = rt->fib6_table;
3895         spin_lock_bh(&table->tb6_lock);
3896
3897         if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
3898                 struct fib6_info *sibling, *next_sibling;
3899                 struct fib6_node *fn;
3900
3901                 /* prefer to send a single notification with all hops */
3902                 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3903                 if (skb) {
3904                         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3905
3906                         if (rt6_fill_node(net, skb, rt, NULL,
3907                                           NULL, NULL, 0, RTM_DELROUTE,
3908                                           info->portid, seq, 0) < 0) {
3909                                 kfree_skb(skb);
3910                                 skb = NULL;
3911                         } else
3912                                 info->skip_notify = 1;
3913                 }
3914
3915                 /* 'rt' points to the first sibling route. If it is not the
3916                  * leaf, then we do not need to send a notification. Otherwise,
3917                  * we need to check if the last sibling has a next route or not
3918                  * and emit a replace or delete notification, respectively.
3919                  */
3920                 info->skip_notify_kernel = 1;
3921                 fn = rcu_dereference_protected(rt->fib6_node,
3922                                             lockdep_is_held(&table->tb6_lock));
3923                 if (rcu_access_pointer(fn->leaf) == rt) {
3924                         struct fib6_info *last_sibling, *replace_rt;
3925
3926                         last_sibling = list_last_entry(&rt->fib6_siblings,
3927                                                        struct fib6_info,
3928                                                        fib6_siblings);
3929                         replace_rt = rcu_dereference_protected(
3930                                             last_sibling->fib6_next,
3931                                             lockdep_is_held(&table->tb6_lock));
3932                         if (replace_rt)
3933                                 call_fib6_entry_notifiers_replace(net,
3934                                                                   replace_rt);
3935                         else
3936                                 call_fib6_multipath_entry_notifiers(net,
3937                                                        FIB_EVENT_ENTRY_DEL,
3938                                                        rt, rt->fib6_nsiblings,
3939                                                        NULL);
3940                 }
3941                 list_for_each_entry_safe(sibling, next_sibling,
3942                                          &rt->fib6_siblings,
3943                                          fib6_siblings) {
3944                         err = fib6_del(sibling, info);
3945                         if (err)
3946                                 goto out_unlock;
3947                 }
3948         }
3949
3950         err = fib6_del(rt, info);
3951 out_unlock:
3952         spin_unlock_bh(&table->tb6_lock);
3953 out_put:
3954         fib6_info_release(rt);
3955
3956         if (skb) {
3957                 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3958                             info->nlh, gfp_any());
3959         }
3960         return err;
3961 }
3962
3963 static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
3964 {
3965         int rc = -ESRCH;
3966
3967         if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
3968                 goto out;
3969
3970         if (cfg->fc_flags & RTF_GATEWAY &&
3971             !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
3972                 goto out;
3973
3974         rc = rt6_remove_exception_rt(rt);
3975 out:
3976         return rc;
3977 }
3978
3979 static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt,
3980                              struct fib6_nh *nh)
3981 {
3982         struct fib6_result res = {
3983                 .f6i = rt,
3984                 .nh = nh,
3985         };
3986         struct rt6_info *rt_cache;
3987
3988         rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src);
3989         if (rt_cache)
3990                 return __ip6_del_cached_rt(rt_cache, cfg);
3991
3992         return 0;
3993 }
3994
3995 struct fib6_nh_del_cached_rt_arg {
3996         struct fib6_config *cfg;
3997         struct fib6_info *f6i;
3998 };
3999
4000 static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg)
4001 {
4002         struct fib6_nh_del_cached_rt_arg *arg = _arg;
4003         int rc;
4004
4005         rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh);
4006         return rc != -ESRCH ? rc : 0;
4007 }
4008
4009 static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i)
4010 {
4011         struct fib6_nh_del_cached_rt_arg arg = {
4012                 .cfg = cfg,
4013                 .f6i = f6i
4014         };
4015
4016         return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg);
4017 }
4018
4019 static int ip6_route_del(struct fib6_config *cfg,
4020                          struct netlink_ext_ack *extack)
4021 {
4022         struct fib6_table *table;
4023         struct fib6_info *rt;
4024         struct fib6_node *fn;
4025         int err = -ESRCH;
4026
4027         table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
4028         if (!table) {
4029                 NL_SET_ERR_MSG(extack, "FIB table does not exist");
4030                 return err;
4031         }
4032
4033         rcu_read_lock();
4034
4035         fn = fib6_locate(&table->tb6_root,
4036                          &cfg->fc_dst, cfg->fc_dst_len,
4037                          &cfg->fc_src, cfg->fc_src_len,
4038                          !(cfg->fc_flags & RTF_CACHE));
4039
4040         if (fn) {
4041                 for_each_fib6_node_rt_rcu(fn) {
4042                         struct fib6_nh *nh;
4043
4044                         if (rt->nh && cfg->fc_nh_id &&
4045                             rt->nh->id != cfg->fc_nh_id)
4046                                 continue;
4047
4048                         if (cfg->fc_flags & RTF_CACHE) {
4049                                 int rc = 0;
4050
4051                                 if (rt->nh) {
4052                                         rc = ip6_del_cached_rt_nh(cfg, rt);
4053                                 } else if (cfg->fc_nh_id) {
4054                                         continue;
4055                                 } else {
4056                                         nh = rt->fib6_nh;
4057                                         rc = ip6_del_cached_rt(cfg, rt, nh);
4058                                 }
4059                                 if (rc != -ESRCH) {
4060                                         rcu_read_unlock();
4061                                         return rc;
4062                                 }
4063                                 continue;
4064                         }
4065
4066                         if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
4067                                 continue;
4068                         if (cfg->fc_protocol &&
4069                             cfg->fc_protocol != rt->fib6_protocol)
4070                                 continue;
4071
4072                         if (rt->nh) {
4073                                 if (!fib6_info_hold_safe(rt))
4074                                         continue;
4075                                 rcu_read_unlock();
4076
4077                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4078                         }
4079                         if (cfg->fc_nh_id)
4080                                 continue;
4081
4082                         nh = rt->fib6_nh;
4083                         if (cfg->fc_ifindex &&
4084                             (!nh->fib_nh_dev ||
4085                              nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
4086                                 continue;
4087                         if (cfg->fc_flags & RTF_GATEWAY &&
4088                             !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6))
4089                                 continue;
4090                         if (!fib6_info_hold_safe(rt))
4091                                 continue;
4092                         rcu_read_unlock();
4093
4094                         /* if gateway was specified only delete the one hop */
4095                         if (cfg->fc_flags & RTF_GATEWAY)
4096                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4097
4098                         return __ip6_del_rt_siblings(rt, cfg);
4099                 }
4100         }
4101         rcu_read_unlock();
4102
4103         return err;
4104 }
4105
4106 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
4107 {
4108         struct netevent_redirect netevent;
4109         struct rt6_info *rt, *nrt = NULL;
4110         struct fib6_result res = {};
4111         struct ndisc_options ndopts;
4112         struct inet6_dev *in6_dev;
4113         struct neighbour *neigh;
4114         struct rd_msg *msg;
4115         int optlen, on_link;
4116         u8 *lladdr;
4117
4118         optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
4119         optlen -= sizeof(*msg);
4120
4121         if (optlen < 0) {
4122                 net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
4123                 return;
4124         }
4125
4126         msg = (struct rd_msg *)icmp6_hdr(skb);
4127
4128         if (ipv6_addr_is_multicast(&msg->dest)) {
4129                 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
4130                 return;
4131         }
4132
4133         on_link = 0;
4134         if (ipv6_addr_equal(&msg->dest, &msg->target)) {
4135                 on_link = 1;
4136         } else if (ipv6_addr_type(&msg->target) !=
4137                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
4138                 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
4139                 return;
4140         }
4141
4142         in6_dev = __in6_dev_get(skb->dev);
4143         if (!in6_dev)
4144                 return;
4145         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
4146                 return;
4147
4148         /* RFC2461 8.1:
4149          *      The IP source address of the Redirect MUST be the same as the current
4150          *      first-hop router for the specified ICMP Destination Address.
4151          */
4152
4153         if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
4154                 net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
4155                 return;
4156         }
4157
4158         lladdr = NULL;
4159         if (ndopts.nd_opts_tgt_lladdr) {
4160                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
4161                                              skb->dev);
4162                 if (!lladdr) {
4163                         net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
4164                         return;
4165                 }
4166         }
4167
4168         rt = (struct rt6_info *) dst;
4169         if (rt->rt6i_flags & RTF_REJECT) {
4170                 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
4171                 return;
4172         }
4173
4174         /* Redirect received -> path was valid.
4175          * Look, redirects are sent only in response to data packets,
4176          * so that this nexthop apparently is reachable. --ANK
4177          */
4178         dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
4179
4180         neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
4181         if (!neigh)
4182                 return;
4183
4184         /*
4185          *      We have finally decided to accept it.
4186          */
4187
4188         ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
4189                      NEIGH_UPDATE_F_WEAK_OVERRIDE|
4190                      NEIGH_UPDATE_F_OVERRIDE|
4191                      (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
4192                                      NEIGH_UPDATE_F_ISROUTER)),
4193                      NDISC_REDIRECT, &ndopts);
4194
4195         rcu_read_lock();
4196         res.f6i = rcu_dereference(rt->from);
4197         if (!res.f6i)
4198                 goto out;
4199
4200         if (res.f6i->nh) {
4201                 struct fib6_nh_match_arg arg = {
4202                         .dev = dst->dev,
4203                         .gw = &rt->rt6i_gateway,
4204                 };
4205
4206                 nexthop_for_each_fib6_nh(res.f6i->nh,
4207                                          fib6_nh_find_match, &arg);
4208
4209                 /* fib6_info uses a nexthop that does not have fib6_nh
4210                  * using the dst->dev. Should be impossible
4211                  */
4212                 if (!arg.match)
4213                         goto out;
4214                 res.nh = arg.match;
4215         } else {
4216                 res.nh = res.f6i->fib6_nh;
4217         }
4218
4219         res.fib6_flags = res.f6i->fib6_flags;
4220         res.fib6_type = res.f6i->fib6_type;
4221         nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL);
4222         if (!nrt)
4223                 goto out;
4224
4225         nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
4226         if (on_link)
4227                 nrt->rt6i_flags &= ~RTF_GATEWAY;
4228
4229         nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
4230
4231         /* rt6_insert_exception() will take care of duplicated exceptions */
4232         if (rt6_insert_exception(nrt, &res)) {
4233                 dst_release_immediate(&nrt->dst);
4234                 goto out;
4235         }
4236
4237         netevent.old = &rt->dst;
4238         netevent.new = &nrt->dst;
4239         netevent.daddr = &msg->dest;
4240         netevent.neigh = neigh;
4241         call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
4242
4243 out:
4244         rcu_read_unlock();
4245         neigh_release(neigh);
4246 }
4247
4248 #ifdef CONFIG_IPV6_ROUTE_INFO
4249 static struct fib6_info *rt6_get_route_info(struct net *net,
4250                                            const struct in6_addr *prefix, int prefixlen,
4251                                            const struct in6_addr *gwaddr,
4252                                            struct net_device *dev)
4253 {
4254         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4255         int ifindex = dev->ifindex;
4256         struct fib6_node *fn;
4257         struct fib6_info *rt = NULL;
4258         struct fib6_table *table;
4259
4260         table = fib6_get_table(net, tb_id);
4261         if (!table)
4262                 return NULL;
4263
4264         rcu_read_lock();
4265         fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
4266         if (!fn)
4267                 goto out;
4268
4269         for_each_fib6_node_rt_rcu(fn) {
4270                 /* these routes do not use nexthops */
4271                 if (rt->nh)
4272                         continue;
4273                 if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex)
4274                         continue;
4275                 if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
4276                     !rt->fib6_nh->fib_nh_gw_family)
4277                         continue;
4278                 if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr))
4279                         continue;
4280                 if (!fib6_info_hold_safe(rt))
4281                         continue;
4282                 break;
4283         }
4284 out:
4285         rcu_read_unlock();
4286         return rt;
4287 }
4288
4289 static struct fib6_info *rt6_add_route_info(struct net *net,
4290                                            const struct in6_addr *prefix, int prefixlen,
4291                                            const struct in6_addr *gwaddr,
4292                                            struct net_device *dev,
4293                                            unsigned int pref)
4294 {
4295         struct fib6_config cfg = {
4296                 .fc_metric      = IP6_RT_PRIO_USER,
4297                 .fc_ifindex     = dev->ifindex,
4298                 .fc_dst_len     = prefixlen,
4299                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
4300                                   RTF_UP | RTF_PREF(pref),
4301                 .fc_protocol = RTPROT_RA,
4302                 .fc_type = RTN_UNICAST,
4303                 .fc_nlinfo.portid = 0,
4304                 .fc_nlinfo.nlh = NULL,
4305                 .fc_nlinfo.nl_net = net,
4306         };
4307
4308         cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4309         cfg.fc_dst = *prefix;
4310         cfg.fc_gateway = *gwaddr;
4311
4312         /* We should treat it as a default route if prefix length is 0. */
4313         if (!prefixlen)
4314                 cfg.fc_flags |= RTF_DEFAULT;
4315
4316         ip6_route_add(&cfg, GFP_ATOMIC, NULL);
4317
4318         return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
4319 }
4320 #endif
4321
4322 struct fib6_info *rt6_get_dflt_router(struct net *net,
4323                                      const struct in6_addr *addr,
4324                                      struct net_device *dev)
4325 {
4326         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
4327         struct fib6_info *rt;
4328         struct fib6_table *table;
4329
4330         table = fib6_get_table(net, tb_id);
4331         if (!table)
4332                 return NULL;
4333
4334         rcu_read_lock();
4335         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4336                 struct fib6_nh *nh;
4337
4338                 /* RA routes do not use nexthops */
4339                 if (rt->nh)
4340                         continue;
4341
4342                 nh = rt->fib6_nh;
4343                 if (dev == nh->fib_nh_dev &&
4344                     ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
4345                     ipv6_addr_equal(&nh->fib_nh_gw6, addr))
4346                         break;
4347         }
4348         if (rt && !fib6_info_hold_safe(rt))
4349                 rt = NULL;
4350         rcu_read_unlock();
4351         return rt;
4352 }
4353
4354 struct fib6_info *rt6_add_dflt_router(struct net *net,
4355                                      const struct in6_addr *gwaddr,
4356                                      struct net_device *dev,
4357                                      unsigned int pref,
4358                                      u32 defrtr_usr_metric)
4359 {
4360         struct fib6_config cfg = {
4361                 .fc_table       = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
4362                 .fc_metric      = defrtr_usr_metric,
4363                 .fc_ifindex     = dev->ifindex,
4364                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
4365                                   RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
4366                 .fc_protocol = RTPROT_RA,
4367                 .fc_type = RTN_UNICAST,
4368                 .fc_nlinfo.portid = 0,
4369                 .fc_nlinfo.nlh = NULL,
4370                 .fc_nlinfo.nl_net = net,
4371         };
4372
4373         cfg.fc_gateway = *gwaddr;
4374
4375         if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
4376                 struct fib6_table *table;
4377
4378                 table = fib6_get_table(dev_net(dev), cfg.fc_table);
4379                 if (table)
4380                         table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
4381         }
4382
4383         return rt6_get_dflt_router(net, gwaddr, dev);
4384 }
4385
4386 static void __rt6_purge_dflt_routers(struct net *net,
4387                                      struct fib6_table *table)
4388 {
4389         struct fib6_info *rt;
4390
4391 restart:
4392         rcu_read_lock();
4393         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4394                 struct net_device *dev = fib6_info_nh_dev(rt);
4395                 struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
4396
4397                 if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
4398                     (!idev || idev->cnf.accept_ra != 2) &&
4399                     fib6_info_hold_safe(rt)) {
4400                         rcu_read_unlock();
4401                         ip6_del_rt(net, rt, false);
4402                         goto restart;
4403                 }
4404         }
4405         rcu_read_unlock();
4406
4407         table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
4408 }
4409
4410 void rt6_purge_dflt_routers(struct net *net)
4411 {
4412         struct fib6_table *table;
4413         struct hlist_head *head;
4414         unsigned int h;
4415
4416         rcu_read_lock();
4417
4418         for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
4419                 head = &net->ipv6.fib_table_hash[h];
4420                 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
4421                         if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
4422                                 __rt6_purge_dflt_routers(net, table);
4423                 }
4424         }
4425
4426         rcu_read_unlock();
4427 }
4428
4429 static void rtmsg_to_fib6_config(struct net *net,
4430                                  struct in6_rtmsg *rtmsg,
4431                                  struct fib6_config *cfg)
4432 {
4433         *cfg = (struct fib6_config){
4434                 .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
4435                          : RT6_TABLE_MAIN,
4436                 .fc_ifindex = rtmsg->rtmsg_ifindex,
4437                 .fc_metric = rtmsg->rtmsg_metric ? : IP6_RT_PRIO_USER,
4438                 .fc_expires = rtmsg->rtmsg_info,
4439                 .fc_dst_len = rtmsg->rtmsg_dst_len,
4440                 .fc_src_len = rtmsg->rtmsg_src_len,
4441                 .fc_flags = rtmsg->rtmsg_flags,
4442                 .fc_type = rtmsg->rtmsg_type,
4443
4444                 .fc_nlinfo.nl_net = net,
4445
4446                 .fc_dst = rtmsg->rtmsg_dst,
4447                 .fc_src = rtmsg->rtmsg_src,
4448                 .fc_gateway = rtmsg->rtmsg_gateway,
4449         };
4450 }
4451
4452 int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg)
4453 {
4454         struct fib6_config cfg;
4455         int err;
4456
4457         if (cmd != SIOCADDRT && cmd != SIOCDELRT)
4458                 return -EINVAL;
4459         if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
4460                 return -EPERM;
4461
4462         rtmsg_to_fib6_config(net, rtmsg, &cfg);
4463
4464         rtnl_lock();
4465         switch (cmd) {
4466         case SIOCADDRT:
4467                 err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
4468                 break;
4469         case SIOCDELRT:
4470                 err = ip6_route_del(&cfg, NULL);
4471                 break;
4472         }
4473         rtnl_unlock();
4474         return err;
4475 }
4476
4477 /*
4478  *      Drop the packet on the floor
4479  */
4480
4481 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
4482 {
4483         struct dst_entry *dst = skb_dst(skb);
4484         struct net *net = dev_net(dst->dev);
4485         struct inet6_dev *idev;
4486         SKB_DR(reason);
4487         int type;
4488
4489         if (netif_is_l3_master(skb->dev) ||
4490             dst->dev == net->loopback_dev)
4491                 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
4492         else
4493                 idev = ip6_dst_idev(dst);
4494
4495         switch (ipstats_mib_noroutes) {
4496         case IPSTATS_MIB_INNOROUTES:
4497                 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
4498                 if (type == IPV6_ADDR_ANY) {
4499                         SKB_DR_SET(reason, IP_INADDRERRORS);
4500                         IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
4501                         break;
4502                 }
4503                 SKB_DR_SET(reason, IP_INNOROUTES);
4504                 fallthrough;
4505         case IPSTATS_MIB_OUTNOROUTES:
4506                 SKB_DR_OR(reason, IP_OUTNOROUTES);
4507                 IP6_INC_STATS(net, idev, ipstats_mib_noroutes);
4508                 break;
4509         }
4510
4511         /* Start over by dropping the dst for l3mdev case */
4512         if (netif_is_l3_master(skb->dev))
4513                 skb_dst_drop(skb);
4514
4515         icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
4516         kfree_skb_reason(skb, reason);
4517         return 0;
4518 }
4519
4520 static int ip6_pkt_discard(struct sk_buff *skb)
4521 {
4522         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
4523 }
4524
4525 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4526 {
4527         skb->dev = skb_dst(skb)->dev;
4528         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
4529 }
4530
4531 static int ip6_pkt_prohibit(struct sk_buff *skb)
4532 {
4533         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
4534 }
4535
4536 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4537 {
4538         skb->dev = skb_dst(skb)->dev;
4539         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
4540 }
4541
4542 /*
4543  *      Allocate a dst for local (unicast / anycast) address.
4544  */
4545
4546 struct fib6_info *addrconf_f6i_alloc(struct net *net,
4547                                      struct inet6_dev *idev,
4548                                      const struct in6_addr *addr,
4549                                      bool anycast, gfp_t gfp_flags,
4550                                      struct netlink_ext_ack *extack)
4551 {
4552         struct fib6_config cfg = {
4553                 .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
4554                 .fc_ifindex = idev->dev->ifindex,
4555                 .fc_flags = RTF_UP | RTF_NONEXTHOP,
4556                 .fc_dst = *addr,
4557                 .fc_dst_len = 128,
4558                 .fc_protocol = RTPROT_KERNEL,
4559                 .fc_nlinfo.nl_net = net,
4560                 .fc_ignore_dev_down = true,
4561         };
4562         struct fib6_info *f6i;
4563
4564         if (anycast) {
4565                 cfg.fc_type = RTN_ANYCAST;
4566                 cfg.fc_flags |= RTF_ANYCAST;
4567         } else {
4568                 cfg.fc_type = RTN_LOCAL;
4569                 cfg.fc_flags |= RTF_LOCAL;
4570         }
4571
4572         f6i = ip6_route_info_create(&cfg, gfp_flags, extack);
4573         if (!IS_ERR(f6i)) {
4574                 f6i->dst_nocount = true;
4575
4576                 if (!anycast &&
4577                     (net->ipv6.devconf_all->disable_policy ||
4578                      idev->cnf.disable_policy))
4579                         f6i->dst_nopolicy = true;
4580         }
4581
4582         return f6i;
4583 }
4584
4585 /* remove deleted ip from prefsrc entries */
4586 struct arg_dev_net_ip {
4587         struct net *net;
4588         struct in6_addr *addr;
4589 };
4590
4591 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
4592 {
4593         struct net *net = ((struct arg_dev_net_ip *)arg)->net;
4594         struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
4595
4596         if (!rt->nh &&
4597             rt != net->ipv6.fib6_null_entry &&
4598             ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr) &&
4599             !ipv6_chk_addr(net, addr, rt->fib6_nh->fib_nh_dev, 0)) {
4600                 spin_lock_bh(&rt6_exception_lock);
4601                 /* remove prefsrc entry */
4602                 rt->fib6_prefsrc.plen = 0;
4603                 spin_unlock_bh(&rt6_exception_lock);
4604         }
4605         return 0;
4606 }
4607
4608 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
4609 {
4610         struct net *net = dev_net(ifp->idev->dev);
4611         struct arg_dev_net_ip adni = {
4612                 .net = net,
4613                 .addr = &ifp->addr,
4614         };
4615         fib6_clean_all(net, fib6_remove_prefsrc, &adni);
4616 }
4617
4618 #define RTF_RA_ROUTER           (RTF_ADDRCONF | RTF_DEFAULT)
4619
4620 /* Remove routers and update dst entries when gateway turn into host. */
4621 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
4622 {
4623         struct in6_addr *gateway = (struct in6_addr *)arg;
4624         struct fib6_nh *nh;
4625
4626         /* RA routes do not use nexthops */
4627         if (rt->nh)
4628                 return 0;
4629
4630         nh = rt->fib6_nh;
4631         if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
4632             nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6))
4633                 return -1;
4634
4635         /* Further clean up cached routes in exception table.
4636          * This is needed because cached route may have a different
4637          * gateway than its 'parent' in the case of an ip redirect.
4638          */
4639         fib6_nh_exceptions_clean_tohost(nh, gateway);
4640
4641         return 0;
4642 }
4643
4644 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
4645 {
4646         fib6_clean_all(net, fib6_clean_tohost, gateway);
4647 }
4648
4649 struct arg_netdev_event {
4650         const struct net_device *dev;
4651         union {
4652                 unsigned char nh_flags;
4653                 unsigned long event;
4654         };
4655 };
4656
4657 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
4658 {
4659         struct fib6_info *iter;
4660         struct fib6_node *fn;
4661
4662         fn = rcu_dereference_protected(rt->fib6_node,
4663                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4664         iter = rcu_dereference_protected(fn->leaf,
4665                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4666         while (iter) {
4667                 if (iter->fib6_metric == rt->fib6_metric &&
4668                     rt6_qualify_for_ecmp(iter))
4669                         return iter;
4670                 iter = rcu_dereference_protected(iter->fib6_next,
4671                                 lockdep_is_held(&rt->fib6_table->tb6_lock));
4672         }
4673
4674         return NULL;
4675 }
4676
4677 /* only called for fib entries with builtin fib6_nh */
4678 static bool rt6_is_dead(const struct fib6_info *rt)
4679 {
4680         if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD ||
4681             (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN &&
4682              ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev)))
4683                 return true;
4684
4685         return false;
4686 }
4687
4688 static int rt6_multipath_total_weight(const struct fib6_info *rt)
4689 {
4690         struct fib6_info *iter;
4691         int total = 0;
4692
4693         if (!rt6_is_dead(rt))
4694                 total += rt->fib6_nh->fib_nh_weight;
4695
4696         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
4697                 if (!rt6_is_dead(iter))
4698                         total += iter->fib6_nh->fib_nh_weight;
4699         }
4700
4701         return total;
4702 }
4703
4704 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
4705 {
4706         int upper_bound = -1;
4707
4708         if (!rt6_is_dead(rt)) {
4709                 *weight += rt->fib6_nh->fib_nh_weight;
4710                 upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
4711                                                     total) - 1;
4712         }
4713         atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
4714 }
4715
4716 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
4717 {
4718         struct fib6_info *iter;
4719         int weight = 0;
4720
4721         rt6_upper_bound_set(rt, &weight, total);
4722
4723         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4724                 rt6_upper_bound_set(iter, &weight, total);
4725 }
4726
4727 void rt6_multipath_rebalance(struct fib6_info *rt)
4728 {
4729         struct fib6_info *first;
4730         int total;
4731
4732         /* In case the entire multipath route was marked for flushing,
4733          * then there is no need to rebalance upon the removal of every
4734          * sibling route.
4735          */
4736         if (!rt->fib6_nsiblings || rt->should_flush)
4737                 return;
4738
4739         /* During lookup routes are evaluated in order, so we need to
4740          * make sure upper bounds are assigned from the first sibling
4741          * onwards.
4742          */
4743         first = rt6_multipath_first_sibling(rt);
4744         if (WARN_ON_ONCE(!first))
4745                 return;
4746
4747         total = rt6_multipath_total_weight(first);
4748         rt6_multipath_upper_bound_set(first, total);
4749 }
4750
4751 static int fib6_ifup(struct fib6_info *rt, void *p_arg)
4752 {
4753         const struct arg_netdev_event *arg = p_arg;
4754         struct net *net = dev_net(arg->dev);
4755
4756         if (rt != net->ipv6.fib6_null_entry && !rt->nh &&
4757             rt->fib6_nh->fib_nh_dev == arg->dev) {
4758                 rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags;
4759                 fib6_update_sernum_upto_root(net, rt);
4760                 rt6_multipath_rebalance(rt);
4761         }
4762
4763         return 0;
4764 }
4765
4766 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags)
4767 {
4768         struct arg_netdev_event arg = {
4769                 .dev = dev,
4770                 {
4771                         .nh_flags = nh_flags,
4772                 },
4773         };
4774
4775         if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
4776                 arg.nh_flags |= RTNH_F_LINKDOWN;
4777
4778         fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
4779 }
4780
4781 /* only called for fib entries with inline fib6_nh */
4782 static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
4783                                    const struct net_device *dev)
4784 {
4785         struct fib6_info *iter;
4786
4787         if (rt->fib6_nh->fib_nh_dev == dev)
4788                 return true;
4789         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4790                 if (iter->fib6_nh->fib_nh_dev == dev)
4791                         return true;
4792
4793         return false;
4794 }
4795
4796 static void rt6_multipath_flush(struct fib6_info *rt)
4797 {
4798         struct fib6_info *iter;
4799
4800         rt->should_flush = 1;
4801         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4802                 iter->should_flush = 1;
4803 }
4804
4805 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
4806                                              const struct net_device *down_dev)
4807 {
4808         struct fib6_info *iter;
4809         unsigned int dead = 0;
4810
4811         if (rt->fib6_nh->fib_nh_dev == down_dev ||
4812             rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4813                 dead++;
4814         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4815                 if (iter->fib6_nh->fib_nh_dev == down_dev ||
4816                     iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4817                         dead++;
4818
4819         return dead;
4820 }
4821
4822 static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
4823                                        const struct net_device *dev,
4824                                        unsigned char nh_flags)
4825 {
4826         struct fib6_info *iter;
4827
4828         if (rt->fib6_nh->fib_nh_dev == dev)
4829                 rt->fib6_nh->fib_nh_flags |= nh_flags;
4830         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4831                 if (iter->fib6_nh->fib_nh_dev == dev)
4832                         iter->fib6_nh->fib_nh_flags |= nh_flags;
4833 }
4834
4835 /* called with write lock held for table with rt */
4836 static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
4837 {
4838         const struct arg_netdev_event *arg = p_arg;
4839         const struct net_device *dev = arg->dev;
4840         struct net *net = dev_net(dev);
4841
4842         if (rt == net->ipv6.fib6_null_entry || rt->nh)
4843                 return 0;
4844
4845         switch (arg->event) {
4846         case NETDEV_UNREGISTER:
4847                 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4848         case NETDEV_DOWN:
4849                 if (rt->should_flush)
4850                         return -1;
4851                 if (!rt->fib6_nsiblings)
4852                         return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4853                 if (rt6_multipath_uses_dev(rt, dev)) {
4854                         unsigned int count;
4855
4856                         count = rt6_multipath_dead_count(rt, dev);
4857                         if (rt->fib6_nsiblings + 1 == count) {
4858                                 rt6_multipath_flush(rt);
4859                                 return -1;
4860                         }
4861                         rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
4862                                                    RTNH_F_LINKDOWN);
4863                         fib6_update_sernum(net, rt);
4864                         rt6_multipath_rebalance(rt);
4865                 }
4866                 return -2;
4867         case NETDEV_CHANGE:
4868                 if (rt->fib6_nh->fib_nh_dev != dev ||
4869                     rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
4870                         break;
4871                 rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
4872                 rt6_multipath_rebalance(rt);
4873                 break;
4874         }
4875
4876         return 0;
4877 }
4878
4879 void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
4880 {
4881         struct arg_netdev_event arg = {
4882                 .dev = dev,
4883                 {
4884                         .event = event,
4885                 },
4886         };
4887         struct net *net = dev_net(dev);
4888
4889         if (net->ipv6.sysctl.skip_notify_on_dev_down)
4890                 fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
4891         else
4892                 fib6_clean_all(net, fib6_ifdown, &arg);
4893 }
4894
4895 void rt6_disable_ip(struct net_device *dev, unsigned long event)
4896 {
4897         rt6_sync_down_dev(dev, event);
4898         rt6_uncached_list_flush_dev(dev);
4899         neigh_ifdown(&nd_tbl, dev);
4900 }
4901
4902 struct rt6_mtu_change_arg {
4903         struct net_device *dev;
4904         unsigned int mtu;
4905         struct fib6_info *f6i;
4906 };
4907
4908 static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
4909 {
4910         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg;
4911         struct fib6_info *f6i = arg->f6i;
4912
4913         /* For administrative MTU increase, there is no way to discover
4914          * IPv6 PMTU increase, so PMTU increase should be updated here.
4915          * Since RFC 1981 doesn't include administrative MTU increase
4916          * update PMTU increase is a MUST. (i.e. jumbo frame)
4917          */
4918         if (nh->fib_nh_dev == arg->dev) {
4919                 struct inet6_dev *idev = __in6_dev_get(arg->dev);
4920                 u32 mtu = f6i->fib6_pmtu;
4921
4922                 if (mtu >= arg->mtu ||
4923                     (mtu < arg->mtu && mtu == idev->cnf.mtu6))
4924                         fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
4925
4926                 spin_lock_bh(&rt6_exception_lock);
4927                 rt6_exceptions_update_pmtu(idev, nh, arg->mtu);
4928                 spin_unlock_bh(&rt6_exception_lock);
4929         }
4930
4931         return 0;
4932 }
4933
4934 static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
4935 {
4936         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
4937         struct inet6_dev *idev;
4938
4939         /* In IPv6 pmtu discovery is not optional,
4940            so that RTAX_MTU lock cannot disable it.
4941            We still use this lock to block changes
4942            caused by addrconf/ndisc.
4943         */
4944
4945         idev = __in6_dev_get(arg->dev);
4946         if (!idev)
4947                 return 0;
4948
4949         if (fib6_metric_locked(f6i, RTAX_MTU))
4950                 return 0;
4951
4952         arg->f6i = f6i;
4953         if (f6i->nh) {
4954                 /* fib6_nh_mtu_change only returns 0, so this is safe */
4955                 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change,
4956                                                 arg);
4957         }
4958
4959         return fib6_nh_mtu_change(f6i->fib6_nh, arg);
4960 }
4961
4962 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
4963 {
4964         struct rt6_mtu_change_arg arg = {
4965                 .dev = dev,
4966                 .mtu = mtu,
4967         };
4968
4969         fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
4970 }
4971
4972 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
4973         [RTA_UNSPEC]            = { .strict_start_type = RTA_DPORT + 1 },
4974         [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
4975         [RTA_PREFSRC]           = { .len = sizeof(struct in6_addr) },
4976         [RTA_OIF]               = { .type = NLA_U32 },
4977         [RTA_IIF]               = { .type = NLA_U32 },
4978         [RTA_PRIORITY]          = { .type = NLA_U32 },
4979         [RTA_METRICS]           = { .type = NLA_NESTED },
4980         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
4981         [RTA_PREF]              = { .type = NLA_U8 },
4982         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
4983         [RTA_ENCAP]             = { .type = NLA_NESTED },
4984         [RTA_EXPIRES]           = { .type = NLA_U32 },
4985         [RTA_UID]               = { .type = NLA_U32 },
4986         [RTA_MARK]              = { .type = NLA_U32 },
4987         [RTA_TABLE]             = { .type = NLA_U32 },
4988         [RTA_IP_PROTO]          = { .type = NLA_U8 },
4989         [RTA_SPORT]             = { .type = NLA_U16 },
4990         [RTA_DPORT]             = { .type = NLA_U16 },
4991         [RTA_NH_ID]             = { .type = NLA_U32 },
4992 };
4993
4994 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
4995                               struct fib6_config *cfg,
4996                               struct netlink_ext_ack *extack)
4997 {
4998         struct rtmsg *rtm;
4999         struct nlattr *tb[RTA_MAX+1];
5000         unsigned int pref;
5001         int err;
5002
5003         err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5004                                      rtm_ipv6_policy, extack);
5005         if (err < 0)
5006                 goto errout;
5007
5008         err = -EINVAL;
5009         rtm = nlmsg_data(nlh);
5010
5011         if (rtm->rtm_tos) {
5012                 NL_SET_ERR_MSG(extack,
5013                                "Invalid dsfield (tos): option not available for IPv6");
5014                 goto errout;
5015         }
5016
5017         *cfg = (struct fib6_config){
5018                 .fc_table = rtm->rtm_table,
5019                 .fc_dst_len = rtm->rtm_dst_len,
5020                 .fc_src_len = rtm->rtm_src_len,
5021                 .fc_flags = RTF_UP,
5022                 .fc_protocol = rtm->rtm_protocol,
5023                 .fc_type = rtm->rtm_type,
5024
5025                 .fc_nlinfo.portid = NETLINK_CB(skb).portid,
5026                 .fc_nlinfo.nlh = nlh,
5027                 .fc_nlinfo.nl_net = sock_net(skb->sk),
5028         };
5029
5030         if (rtm->rtm_type == RTN_UNREACHABLE ||
5031             rtm->rtm_type == RTN_BLACKHOLE ||
5032             rtm->rtm_type == RTN_PROHIBIT ||
5033             rtm->rtm_type == RTN_THROW)
5034                 cfg->fc_flags |= RTF_REJECT;
5035
5036         if (rtm->rtm_type == RTN_LOCAL)
5037                 cfg->fc_flags |= RTF_LOCAL;
5038
5039         if (rtm->rtm_flags & RTM_F_CLONED)
5040                 cfg->fc_flags |= RTF_CACHE;
5041
5042         cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
5043
5044         if (tb[RTA_NH_ID]) {
5045                 if (tb[RTA_GATEWAY]   || tb[RTA_OIF] ||
5046                     tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {
5047                         NL_SET_ERR_MSG(extack,
5048                                        "Nexthop specification and nexthop id are mutually exclusive");
5049                         goto errout;
5050                 }
5051                 cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);
5052         }
5053
5054         if (tb[RTA_GATEWAY]) {
5055                 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
5056                 cfg->fc_flags |= RTF_GATEWAY;
5057         }
5058         if (tb[RTA_VIA]) {
5059                 NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
5060                 goto errout;
5061         }
5062
5063         if (tb[RTA_DST]) {
5064                 int plen = (rtm->rtm_dst_len + 7) >> 3;
5065
5066                 if (nla_len(tb[RTA_DST]) < plen)
5067                         goto errout;
5068
5069                 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
5070         }
5071
5072         if (tb[RTA_SRC]) {
5073                 int plen = (rtm->rtm_src_len + 7) >> 3;
5074
5075                 if (nla_len(tb[RTA_SRC]) < plen)
5076                         goto errout;
5077
5078                 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
5079         }
5080
5081         if (tb[RTA_PREFSRC])
5082                 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
5083
5084         if (tb[RTA_OIF])
5085                 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
5086
5087         if (tb[RTA_PRIORITY])
5088                 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
5089
5090         if (tb[RTA_METRICS]) {
5091                 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
5092                 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
5093         }
5094
5095         if (tb[RTA_TABLE])
5096                 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
5097
5098         if (tb[RTA_MULTIPATH]) {
5099                 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
5100                 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
5101
5102                 err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
5103                                                      cfg->fc_mp_len, extack);
5104                 if (err < 0)
5105                         goto errout;
5106         }
5107
5108         if (tb[RTA_PREF]) {
5109                 pref = nla_get_u8(tb[RTA_PREF]);
5110                 if (pref != ICMPV6_ROUTER_PREF_LOW &&
5111                     pref != ICMPV6_ROUTER_PREF_HIGH)
5112                         pref = ICMPV6_ROUTER_PREF_MEDIUM;
5113                 cfg->fc_flags |= RTF_PREF(pref);
5114         }
5115
5116         if (tb[RTA_ENCAP])
5117                 cfg->fc_encap = tb[RTA_ENCAP];
5118
5119         if (tb[RTA_ENCAP_TYPE]) {
5120                 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
5121
5122                 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
5123                 if (err < 0)
5124                         goto errout;
5125         }
5126
5127         if (tb[RTA_EXPIRES]) {
5128                 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
5129
5130                 if (addrconf_finite_timeout(timeout)) {
5131                         cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
5132                         cfg->fc_flags |= RTF_EXPIRES;
5133                 }
5134         }
5135
5136         err = 0;
5137 errout:
5138         return err;
5139 }
5140
5141 struct rt6_nh {
5142         struct fib6_info *fib6_info;
5143         struct fib6_config r_cfg;
5144         struct list_head next;
5145 };
5146
5147 static int ip6_route_info_append(struct net *net,
5148                                  struct list_head *rt6_nh_list,
5149                                  struct fib6_info *rt,
5150                                  struct fib6_config *r_cfg)
5151 {
5152         struct rt6_nh *nh;
5153         int err = -EEXIST;
5154
5155         list_for_each_entry(nh, rt6_nh_list, next) {
5156                 /* check if fib6_info already exists */
5157                 if (rt6_duplicate_nexthop(nh->fib6_info, rt))
5158                         return err;
5159         }
5160
5161         nh = kzalloc(sizeof(*nh), GFP_KERNEL);
5162         if (!nh)
5163                 return -ENOMEM;
5164         nh->fib6_info = rt;
5165         memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
5166         list_add_tail(&nh->next, rt6_nh_list);
5167
5168         return 0;
5169 }
5170
5171 static void ip6_route_mpath_notify(struct fib6_info *rt,
5172                                    struct fib6_info *rt_last,
5173                                    struct nl_info *info,
5174                                    __u16 nlflags)
5175 {
5176         /* if this is an APPEND route, then rt points to the first route
5177          * inserted and rt_last points to last route inserted. Userspace
5178          * wants a consistent dump of the route which starts at the first
5179          * nexthop. Since sibling routes are always added at the end of
5180          * the list, find the first sibling of the last route appended
5181          */
5182         if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
5183                 rt = list_first_entry(&rt_last->fib6_siblings,
5184                                       struct fib6_info,
5185                                       fib6_siblings);
5186         }
5187
5188         if (rt)
5189                 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
5190 }
5191
5192 static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
5193 {
5194         bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
5195         bool should_notify = false;
5196         struct fib6_info *leaf;
5197         struct fib6_node *fn;
5198
5199         rcu_read_lock();
5200         fn = rcu_dereference(rt->fib6_node);
5201         if (!fn)
5202                 goto out;
5203
5204         leaf = rcu_dereference(fn->leaf);
5205         if (!leaf)
5206                 goto out;
5207
5208         if (rt == leaf ||
5209             (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric &&
5210              rt6_qualify_for_ecmp(leaf)))
5211                 should_notify = true;
5212 out:
5213         rcu_read_unlock();
5214
5215         return should_notify;
5216 }
5217
5218 static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla,
5219                              struct netlink_ext_ack *extack)
5220 {
5221         if (nla_len(nla) < sizeof(*gw)) {
5222                 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY");
5223                 return -EINVAL;
5224         }
5225
5226         *gw = nla_get_in6_addr(nla);
5227
5228         return 0;
5229 }
5230
5231 static int ip6_route_multipath_add(struct fib6_config *cfg,
5232                                    struct netlink_ext_ack *extack)
5233 {
5234         struct fib6_info *rt_notif = NULL, *rt_last = NULL;
5235         struct nl_info *info = &cfg->fc_nlinfo;
5236         struct fib6_config r_cfg;
5237         struct rtnexthop *rtnh;
5238         struct fib6_info *rt;
5239         struct rt6_nh *err_nh;
5240         struct rt6_nh *nh, *nh_safe;
5241         __u16 nlflags;
5242         int remaining;
5243         int attrlen;
5244         int err = 1;
5245         int nhn = 0;
5246         int replace = (cfg->fc_nlinfo.nlh &&
5247                        (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
5248         LIST_HEAD(rt6_nh_list);
5249
5250         nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
5251         if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
5252                 nlflags |= NLM_F_APPEND;
5253
5254         remaining = cfg->fc_mp_len;
5255         rtnh = (struct rtnexthop *)cfg->fc_mp;
5256
5257         /* Parse a Multipath Entry and build a list (rt6_nh_list) of
5258          * fib6_info structs per nexthop
5259          */
5260         while (rtnh_ok(rtnh, remaining)) {
5261                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5262                 if (rtnh->rtnh_ifindex)
5263                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5264
5265                 attrlen = rtnh_attrlen(rtnh);
5266                 if (attrlen > 0) {
5267                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5268
5269                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5270                         if (nla) {
5271                                 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5272                                                         extack);
5273                                 if (err)
5274                                         goto cleanup;
5275
5276                                 r_cfg.fc_flags |= RTF_GATEWAY;
5277                         }
5278                         r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
5279
5280                         /* RTA_ENCAP_TYPE length checked in
5281                          * lwtunnel_valid_encap_type_attr
5282                          */
5283                         nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
5284                         if (nla)
5285                                 r_cfg.fc_encap_type = nla_get_u16(nla);
5286                 }
5287
5288                 r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
5289                 rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
5290                 if (IS_ERR(rt)) {
5291                         err = PTR_ERR(rt);
5292                         rt = NULL;
5293                         goto cleanup;
5294                 }
5295                 if (!rt6_qualify_for_ecmp(rt)) {
5296                         err = -EINVAL;
5297                         NL_SET_ERR_MSG(extack,
5298                                        "Device only routes can not be added for IPv6 using the multipath API.");
5299                         fib6_info_release(rt);
5300                         goto cleanup;
5301                 }
5302
5303                 rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
5304
5305                 err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
5306                                             rt, &r_cfg);
5307                 if (err) {
5308                         fib6_info_release(rt);
5309                         goto cleanup;
5310                 }
5311
5312                 rtnh = rtnh_next(rtnh, &remaining);
5313         }
5314
5315         if (list_empty(&rt6_nh_list)) {
5316                 NL_SET_ERR_MSG(extack,
5317                                "Invalid nexthop configuration - no valid nexthops");
5318                 return -EINVAL;
5319         }
5320
5321         /* for add and replace send one notification with all nexthops.
5322          * Skip the notification in fib6_add_rt2node and send one with
5323          * the full route when done
5324          */
5325         info->skip_notify = 1;
5326
5327         /* For add and replace, send one notification with all nexthops. For
5328          * append, send one notification with all appended nexthops.
5329          */
5330         info->skip_notify_kernel = 1;
5331
5332         err_nh = NULL;
5333         list_for_each_entry(nh, &rt6_nh_list, next) {
5334                 err = __ip6_ins_rt(nh->fib6_info, info, extack);
5335                 fib6_info_release(nh->fib6_info);
5336
5337                 if (!err) {
5338                         /* save reference to last route successfully inserted */
5339                         rt_last = nh->fib6_info;
5340
5341                         /* save reference to first route for notification */
5342                         if (!rt_notif)
5343                                 rt_notif = nh->fib6_info;
5344                 }
5345
5346                 /* nh->fib6_info is used or freed at this point, reset to NULL*/
5347                 nh->fib6_info = NULL;
5348                 if (err) {
5349                         if (replace && nhn)
5350                                 NL_SET_ERR_MSG_MOD(extack,
5351                                                    "multipath route replace failed (check consistency of installed routes)");
5352                         err_nh = nh;
5353                         goto add_errout;
5354                 }
5355
5356                 /* Because each route is added like a single route we remove
5357                  * these flags after the first nexthop: if there is a collision,
5358                  * we have already failed to add the first nexthop:
5359                  * fib6_add_rt2node() has rejected it; when replacing, old
5360                  * nexthops have been replaced by first new, the rest should
5361                  * be added to it.
5362                  */
5363                 if (cfg->fc_nlinfo.nlh) {
5364                         cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
5365                                                              NLM_F_REPLACE);
5366                         cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
5367                 }
5368                 nhn++;
5369         }
5370
5371         /* An in-kernel notification should only be sent in case the new
5372          * multipath route is added as the first route in the node, or if
5373          * it was appended to it. We pass 'rt_notif' since it is the first
5374          * sibling and might allow us to skip some checks in the replace case.
5375          */
5376         if (ip6_route_mpath_should_notify(rt_notif)) {
5377                 enum fib_event_type fib_event;
5378
5379                 if (rt_notif->fib6_nsiblings != nhn - 1)
5380                         fib_event = FIB_EVENT_ENTRY_APPEND;
5381                 else
5382                         fib_event = FIB_EVENT_ENTRY_REPLACE;
5383
5384                 err = call_fib6_multipath_entry_notifiers(info->nl_net,
5385                                                           fib_event, rt_notif,
5386                                                           nhn - 1, extack);
5387                 if (err) {
5388                         /* Delete all the siblings that were just added */
5389                         err_nh = NULL;
5390                         goto add_errout;
5391                 }
5392         }
5393
5394         /* success ... tell user about new route */
5395         ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5396         goto cleanup;
5397
5398 add_errout:
5399         /* send notification for routes that were added so that
5400          * the delete notifications sent by ip6_route_del are
5401          * coherent
5402          */
5403         if (rt_notif)
5404                 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5405
5406         /* Delete routes that were already added */
5407         list_for_each_entry(nh, &rt6_nh_list, next) {
5408                 if (err_nh == nh)
5409                         break;
5410                 ip6_route_del(&nh->r_cfg, extack);
5411         }
5412
5413 cleanup:
5414         list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
5415                 if (nh->fib6_info)
5416                         fib6_info_release(nh->fib6_info);
5417                 list_del(&nh->next);
5418                 kfree(nh);
5419         }
5420
5421         return err;
5422 }
5423
5424 static int ip6_route_multipath_del(struct fib6_config *cfg,
5425                                    struct netlink_ext_ack *extack)
5426 {
5427         struct fib6_config r_cfg;
5428         struct rtnexthop *rtnh;
5429         int last_err = 0;
5430         int remaining;
5431         int attrlen;
5432         int err;
5433
5434         remaining = cfg->fc_mp_len;
5435         rtnh = (struct rtnexthop *)cfg->fc_mp;
5436
5437         /* Parse a Multipath Entry */
5438         while (rtnh_ok(rtnh, remaining)) {
5439                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5440                 if (rtnh->rtnh_ifindex)
5441                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5442
5443                 attrlen = rtnh_attrlen(rtnh);
5444                 if (attrlen > 0) {
5445                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5446
5447                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5448                         if (nla) {
5449                                 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5450                                                         extack);
5451                                 if (err) {
5452                                         last_err = err;
5453                                         goto next_rtnh;
5454                                 }
5455
5456                                 r_cfg.fc_flags |= RTF_GATEWAY;
5457                         }
5458                 }
5459                 err = ip6_route_del(&r_cfg, extack);
5460                 if (err)
5461                         last_err = err;
5462
5463 next_rtnh:
5464                 rtnh = rtnh_next(rtnh, &remaining);
5465         }
5466
5467         return last_err;
5468 }
5469
5470 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5471                               struct netlink_ext_ack *extack)
5472 {
5473         struct fib6_config cfg;
5474         int err;
5475
5476         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5477         if (err < 0)
5478                 return err;
5479
5480         if (cfg.fc_nh_id &&
5481             !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {
5482                 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
5483                 return -EINVAL;
5484         }
5485
5486         if (cfg.fc_mp)
5487                 return ip6_route_multipath_del(&cfg, extack);
5488         else {
5489                 cfg.fc_delete_all_nh = 1;
5490                 return ip6_route_del(&cfg, extack);
5491         }
5492 }
5493
5494 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5495                               struct netlink_ext_ack *extack)
5496 {
5497         struct fib6_config cfg;
5498         int err;
5499
5500         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5501         if (err < 0)
5502                 return err;
5503
5504         if (cfg.fc_metric == 0)
5505                 cfg.fc_metric = IP6_RT_PRIO_USER;
5506
5507         if (cfg.fc_mp)
5508                 return ip6_route_multipath_add(&cfg, extack);
5509         else
5510                 return ip6_route_add(&cfg, GFP_KERNEL, extack);
5511 }
5512
5513 /* add the overhead of this fib6_nh to nexthop_len */
5514 static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg)
5515 {
5516         int *nexthop_len = arg;
5517
5518         *nexthop_len += nla_total_size(0)        /* RTA_MULTIPATH */
5519                      + NLA_ALIGN(sizeof(struct rtnexthop))
5520                      + nla_total_size(16); /* RTA_GATEWAY */
5521
5522         if (nh->fib_nh_lws) {
5523                 /* RTA_ENCAP_TYPE */
5524                 *nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5525                 /* RTA_ENCAP */
5526                 *nexthop_len += nla_total_size(2);
5527         }
5528
5529         return 0;
5530 }
5531
5532 static size_t rt6_nlmsg_size(struct fib6_info *f6i)
5533 {
5534         int nexthop_len;
5535
5536         if (f6i->nh) {
5537                 nexthop_len = nla_total_size(4); /* RTA_NH_ID */
5538                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
5539                                          &nexthop_len);
5540         } else {
5541                 struct fib6_info *sibling, *next_sibling;
5542                 struct fib6_nh *nh = f6i->fib6_nh;
5543
5544                 nexthop_len = 0;
5545                 if (f6i->fib6_nsiblings) {
5546                         rt6_nh_nlmsg_size(nh, &nexthop_len);
5547
5548                         list_for_each_entry_safe(sibling, next_sibling,
5549                                                  &f6i->fib6_siblings, fib6_siblings) {
5550                                 rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len);
5551                         }
5552                 }
5553                 nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5554         }
5555
5556         return NLMSG_ALIGN(sizeof(struct rtmsg))
5557                + nla_total_size(16) /* RTA_SRC */
5558                + nla_total_size(16) /* RTA_DST */
5559                + nla_total_size(16) /* RTA_GATEWAY */
5560                + nla_total_size(16) /* RTA_PREFSRC */
5561                + nla_total_size(4) /* RTA_TABLE */
5562                + nla_total_size(4) /* RTA_IIF */
5563                + nla_total_size(4) /* RTA_OIF */
5564                + nla_total_size(4) /* RTA_PRIORITY */
5565                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
5566                + nla_total_size(sizeof(struct rta_cacheinfo))
5567                + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
5568                + nla_total_size(1) /* RTA_PREF */
5569                + nexthop_len;
5570 }
5571
5572 static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh,
5573                                  unsigned char *flags)
5574 {
5575         if (nexthop_is_multipath(nh)) {
5576                 struct nlattr *mp;
5577
5578                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5579                 if (!mp)
5580                         goto nla_put_failure;
5581
5582                 if (nexthop_mpath_fill_node(skb, nh, AF_INET6))
5583                         goto nla_put_failure;
5584
5585                 nla_nest_end(skb, mp);
5586         } else {
5587                 struct fib6_nh *fib6_nh;
5588
5589                 fib6_nh = nexthop_fib6_nh(nh);
5590                 if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,
5591                                      flags, false) < 0)
5592                         goto nla_put_failure;
5593         }
5594
5595         return 0;
5596
5597 nla_put_failure:
5598         return -EMSGSIZE;
5599 }
5600
5601 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
5602                          struct fib6_info *rt, struct dst_entry *dst,
5603                          struct in6_addr *dest, struct in6_addr *src,
5604                          int iif, int type, u32 portid, u32 seq,
5605                          unsigned int flags)
5606 {
5607         struct rt6_info *rt6 = (struct rt6_info *)dst;
5608         struct rt6key *rt6_dst, *rt6_src;
5609         u32 *pmetrics, table, rt6_flags;
5610         unsigned char nh_flags = 0;
5611         struct nlmsghdr *nlh;
5612         struct rtmsg *rtm;
5613         long expires = 0;
5614
5615         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
5616         if (!nlh)
5617                 return -EMSGSIZE;
5618
5619         if (rt6) {
5620                 rt6_dst = &rt6->rt6i_dst;
5621                 rt6_src = &rt6->rt6i_src;
5622                 rt6_flags = rt6->rt6i_flags;
5623         } else {
5624                 rt6_dst = &rt->fib6_dst;
5625                 rt6_src = &rt->fib6_src;
5626                 rt6_flags = rt->fib6_flags;
5627         }
5628
5629         rtm = nlmsg_data(nlh);
5630         rtm->rtm_family = AF_INET6;
5631         rtm->rtm_dst_len = rt6_dst->plen;
5632         rtm->rtm_src_len = rt6_src->plen;
5633         rtm->rtm_tos = 0;
5634         if (rt->fib6_table)
5635                 table = rt->fib6_table->tb6_id;
5636         else
5637                 table = RT6_TABLE_UNSPEC;
5638         rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
5639         if (nla_put_u32(skb, RTA_TABLE, table))
5640                 goto nla_put_failure;
5641
5642         rtm->rtm_type = rt->fib6_type;
5643         rtm->rtm_flags = 0;
5644         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
5645         rtm->rtm_protocol = rt->fib6_protocol;
5646
5647         if (rt6_flags & RTF_CACHE)
5648                 rtm->rtm_flags |= RTM_F_CLONED;
5649
5650         if (dest) {
5651                 if (nla_put_in6_addr(skb, RTA_DST, dest))
5652                         goto nla_put_failure;
5653                 rtm->rtm_dst_len = 128;
5654         } else if (rtm->rtm_dst_len)
5655                 if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
5656                         goto nla_put_failure;
5657 #ifdef CONFIG_IPV6_SUBTREES
5658         if (src) {
5659                 if (nla_put_in6_addr(skb, RTA_SRC, src))
5660                         goto nla_put_failure;
5661                 rtm->rtm_src_len = 128;
5662         } else if (rtm->rtm_src_len &&
5663                    nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
5664                 goto nla_put_failure;
5665 #endif
5666         if (iif) {
5667 #ifdef CONFIG_IPV6_MROUTE
5668                 if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
5669                         int err = ip6mr_get_route(net, skb, rtm, portid);
5670
5671                         if (err == 0)
5672                                 return 0;
5673                         if (err < 0)
5674                                 goto nla_put_failure;
5675                 } else
5676 #endif
5677                         if (nla_put_u32(skb, RTA_IIF, iif))
5678                                 goto nla_put_failure;
5679         } else if (dest) {
5680                 struct in6_addr saddr_buf;
5681                 if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 &&
5682                     nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5683                         goto nla_put_failure;
5684         }
5685
5686         if (rt->fib6_prefsrc.plen) {
5687                 struct in6_addr saddr_buf;
5688                 saddr_buf = rt->fib6_prefsrc.addr;
5689                 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5690                         goto nla_put_failure;
5691         }
5692
5693         pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
5694         if (rtnetlink_put_metrics(skb, pmetrics) < 0)
5695                 goto nla_put_failure;
5696
5697         if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
5698                 goto nla_put_failure;
5699
5700         /* For multipath routes, walk the siblings list and add
5701          * each as a nexthop within RTA_MULTIPATH.
5702          */
5703         if (rt6) {
5704                 if (rt6_flags & RTF_GATEWAY &&
5705                     nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
5706                         goto nla_put_failure;
5707
5708                 if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
5709                         goto nla_put_failure;
5710
5711                 if (dst->lwtstate &&
5712                     lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
5713                         goto nla_put_failure;
5714         } else if (rt->fib6_nsiblings) {
5715                 struct fib6_info *sibling, *next_sibling;
5716                 struct nlattr *mp;
5717
5718                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5719                 if (!mp)
5720                         goto nla_put_failure;
5721
5722                 if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
5723                                     rt->fib6_nh->fib_nh_weight, AF_INET6,
5724                                     0) < 0)
5725                         goto nla_put_failure;
5726
5727                 list_for_each_entry_safe(sibling, next_sibling,
5728                                          &rt->fib6_siblings, fib6_siblings) {
5729                         if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
5730                                             sibling->fib6_nh->fib_nh_weight,
5731                                             AF_INET6, 0) < 0)
5732                                 goto nla_put_failure;
5733                 }
5734
5735                 nla_nest_end(skb, mp);
5736         } else if (rt->nh) {
5737                 if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
5738                         goto nla_put_failure;
5739
5740                 if (nexthop_is_blackhole(rt->nh))
5741                         rtm->rtm_type = RTN_BLACKHOLE;
5742
5743                 if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) &&
5744                     rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0)
5745                         goto nla_put_failure;
5746
5747                 rtm->rtm_flags |= nh_flags;
5748         } else {
5749                 if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,
5750                                      &nh_flags, false) < 0)
5751                         goto nla_put_failure;
5752
5753                 rtm->rtm_flags |= nh_flags;
5754         }
5755
5756         if (rt6_flags & RTF_EXPIRES) {
5757                 expires = dst ? dst->expires : rt->expires;
5758                 expires -= jiffies;
5759         }
5760
5761         if (!dst) {
5762                 if (READ_ONCE(rt->offload))
5763                         rtm->rtm_flags |= RTM_F_OFFLOAD;
5764                 if (READ_ONCE(rt->trap))
5765                         rtm->rtm_flags |= RTM_F_TRAP;
5766                 if (READ_ONCE(rt->offload_failed))
5767                         rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED;
5768         }
5769
5770         if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
5771                 goto nla_put_failure;
5772
5773         if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
5774                 goto nla_put_failure;
5775
5776
5777         nlmsg_end(skb, nlh);
5778         return 0;
5779
5780 nla_put_failure:
5781         nlmsg_cancel(skb, nlh);
5782         return -EMSGSIZE;
5783 }
5784
5785 static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg)
5786 {
5787         const struct net_device *dev = arg;
5788
5789         if (nh->fib_nh_dev == dev)
5790                 return 1;
5791
5792         return 0;
5793 }
5794
5795 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
5796                                const struct net_device *dev)
5797 {
5798         if (f6i->nh) {
5799                 struct net_device *_dev = (struct net_device *)dev;
5800
5801                 return !!nexthop_for_each_fib6_nh(f6i->nh,
5802                                                   fib6_info_nh_uses_dev,
5803                                                   _dev);
5804         }
5805
5806         if (f6i->fib6_nh->fib_nh_dev == dev)
5807                 return true;
5808
5809         if (f6i->fib6_nsiblings) {
5810                 struct fib6_info *sibling, *next_sibling;
5811
5812                 list_for_each_entry_safe(sibling, next_sibling,
5813                                          &f6i->fib6_siblings, fib6_siblings) {
5814                         if (sibling->fib6_nh->fib_nh_dev == dev)
5815                                 return true;
5816                 }
5817         }
5818
5819         return false;
5820 }
5821
5822 struct fib6_nh_exception_dump_walker {
5823         struct rt6_rtnl_dump_arg *dump;
5824         struct fib6_info *rt;
5825         unsigned int flags;
5826         unsigned int skip;
5827         unsigned int count;
5828 };
5829
5830 static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg)
5831 {
5832         struct fib6_nh_exception_dump_walker *w = arg;
5833         struct rt6_rtnl_dump_arg *dump = w->dump;
5834         struct rt6_exception_bucket *bucket;
5835         struct rt6_exception *rt6_ex;
5836         int i, err;
5837
5838         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
5839         if (!bucket)
5840                 return 0;
5841
5842         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
5843                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
5844                         if (w->skip) {
5845                                 w->skip--;
5846                                 continue;
5847                         }
5848
5849                         /* Expiration of entries doesn't bump sernum, insertion
5850                          * does. Removal is triggered by insertion, so we can
5851                          * rely on the fact that if entries change between two
5852                          * partial dumps, this node is scanned again completely,
5853                          * see rt6_insert_exception() and fib6_dump_table().
5854                          *
5855                          * Count expired entries we go through as handled
5856                          * entries that we'll skip next time, in case of partial
5857                          * node dump. Otherwise, if entries expire meanwhile,
5858                          * we'll skip the wrong amount.
5859                          */
5860                         if (rt6_check_expired(rt6_ex->rt6i)) {
5861                                 w->count++;
5862                                 continue;
5863                         }
5864
5865                         err = rt6_fill_node(dump->net, dump->skb, w->rt,
5866                                             &rt6_ex->rt6i->dst, NULL, NULL, 0,
5867                                             RTM_NEWROUTE,
5868                                             NETLINK_CB(dump->cb->skb).portid,
5869                                             dump->cb->nlh->nlmsg_seq, w->flags);
5870                         if (err)
5871                                 return err;
5872
5873                         w->count++;
5874                 }
5875                 bucket++;
5876         }
5877
5878         return 0;
5879 }
5880
5881 /* Return -1 if done with node, number of handled routes on partial dump */
5882 int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip)
5883 {
5884         struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
5885         struct fib_dump_filter *filter = &arg->filter;
5886         unsigned int flags = NLM_F_MULTI;
5887         struct net *net = arg->net;
5888         int count = 0;
5889
5890         if (rt == net->ipv6.fib6_null_entry)
5891                 return -1;
5892
5893         if ((filter->flags & RTM_F_PREFIX) &&
5894             !(rt->fib6_flags & RTF_PREFIX_RT)) {
5895                 /* success since this is not a prefix route */
5896                 return -1;
5897         }
5898         if (filter->filter_set &&
5899             ((filter->rt_type  && rt->fib6_type != filter->rt_type) ||
5900              (filter->dev      && !fib6_info_uses_dev(rt, filter->dev)) ||
5901              (filter->protocol && rt->fib6_protocol != filter->protocol))) {
5902                 return -1;
5903         }
5904
5905         if (filter->filter_set ||
5906             !filter->dump_routes || !filter->dump_exceptions) {
5907                 flags |= NLM_F_DUMP_FILTERED;
5908         }
5909
5910         if (filter->dump_routes) {
5911                 if (skip) {
5912                         skip--;
5913                 } else {
5914                         if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL,
5915                                           0, RTM_NEWROUTE,
5916                                           NETLINK_CB(arg->cb->skb).portid,
5917                                           arg->cb->nlh->nlmsg_seq, flags)) {
5918                                 return 0;
5919                         }
5920                         count++;
5921                 }
5922         }
5923
5924         if (filter->dump_exceptions) {
5925                 struct fib6_nh_exception_dump_walker w = { .dump = arg,
5926                                                            .rt = rt,
5927                                                            .flags = flags,
5928                                                            .skip = skip,
5929                                                            .count = 0 };
5930                 int err;
5931
5932                 rcu_read_lock();
5933                 if (rt->nh) {
5934                         err = nexthop_for_each_fib6_nh(rt->nh,
5935                                                        rt6_nh_dump_exceptions,
5936                                                        &w);
5937                 } else {
5938                         err = rt6_nh_dump_exceptions(rt->fib6_nh, &w);
5939                 }
5940                 rcu_read_unlock();
5941
5942                 if (err)
5943                         return count + w.count;
5944         }
5945
5946         return -1;
5947 }
5948
5949 static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
5950                                         const struct nlmsghdr *nlh,
5951                                         struct nlattr **tb,
5952                                         struct netlink_ext_ack *extack)
5953 {
5954         struct rtmsg *rtm;
5955         int i, err;
5956
5957         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
5958                 NL_SET_ERR_MSG_MOD(extack,
5959                                    "Invalid header for get route request");
5960                 return -EINVAL;
5961         }
5962
5963         if (!netlink_strict_get_check(skb))
5964                 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5965                                               rtm_ipv6_policy, extack);
5966
5967         rtm = nlmsg_data(nlh);
5968         if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
5969             (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
5970             rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
5971             rtm->rtm_type) {
5972                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
5973                 return -EINVAL;
5974         }
5975         if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
5976                 NL_SET_ERR_MSG_MOD(extack,
5977                                    "Invalid flags for get route request");
5978                 return -EINVAL;
5979         }
5980
5981         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
5982                                             rtm_ipv6_policy, extack);
5983         if (err)
5984                 return err;
5985
5986         if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
5987             (tb[RTA_DST] && !rtm->rtm_dst_len)) {
5988                 NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
5989                 return -EINVAL;
5990         }
5991
5992         for (i = 0; i <= RTA_MAX; i++) {
5993                 if (!tb[i])
5994                         continue;
5995
5996                 switch (i) {
5997                 case RTA_SRC:
5998                 case RTA_DST:
5999                 case RTA_IIF:
6000                 case RTA_OIF:
6001                 case RTA_MARK:
6002                 case RTA_UID:
6003                 case RTA_SPORT:
6004                 case RTA_DPORT:
6005                 case RTA_IP_PROTO:
6006                         break;
6007                 default:
6008                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
6009                         return -EINVAL;
6010                 }
6011         }
6012
6013         return 0;
6014 }
6015
6016 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
6017                               struct netlink_ext_ack *extack)
6018 {
6019         struct net *net = sock_net(in_skb->sk);
6020         struct nlattr *tb[RTA_MAX+1];
6021         int err, iif = 0, oif = 0;
6022         struct fib6_info *from;
6023         struct dst_entry *dst;
6024         struct rt6_info *rt;
6025         struct sk_buff *skb;
6026         struct rtmsg *rtm;
6027         struct flowi6 fl6 = {};
6028         bool fibmatch;
6029
6030         err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
6031         if (err < 0)
6032                 goto errout;
6033
6034         err = -EINVAL;
6035         rtm = nlmsg_data(nlh);
6036         fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
6037         fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
6038
6039         if (tb[RTA_SRC]) {
6040                 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
6041                         goto errout;
6042
6043                 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
6044         }
6045
6046         if (tb[RTA_DST]) {
6047                 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
6048                         goto errout;
6049
6050                 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
6051         }
6052
6053         if (tb[RTA_IIF])
6054                 iif = nla_get_u32(tb[RTA_IIF]);
6055
6056         if (tb[RTA_OIF])
6057                 oif = nla_get_u32(tb[RTA_OIF]);
6058
6059         if (tb[RTA_MARK])
6060                 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
6061
6062         if (tb[RTA_UID])
6063                 fl6.flowi6_uid = make_kuid(current_user_ns(),
6064                                            nla_get_u32(tb[RTA_UID]));
6065         else
6066                 fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
6067
6068         if (tb[RTA_SPORT])
6069                 fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
6070
6071         if (tb[RTA_DPORT])
6072                 fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
6073
6074         if (tb[RTA_IP_PROTO]) {
6075                 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
6076                                                   &fl6.flowi6_proto, AF_INET6,
6077                                                   extack);
6078                 if (err)
6079                         goto errout;
6080         }
6081
6082         if (iif) {
6083                 struct net_device *dev;
6084                 int flags = 0;
6085
6086                 rcu_read_lock();
6087
6088                 dev = dev_get_by_index_rcu(net, iif);
6089                 if (!dev) {
6090                         rcu_read_unlock();
6091                         err = -ENODEV;
6092                         goto errout;
6093                 }
6094
6095                 fl6.flowi6_iif = iif;
6096
6097                 if (!ipv6_addr_any(&fl6.saddr))
6098                         flags |= RT6_LOOKUP_F_HAS_SADDR;
6099
6100                 dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
6101
6102                 rcu_read_unlock();
6103         } else {
6104                 fl6.flowi6_oif = oif;
6105
6106                 dst = ip6_route_output(net, NULL, &fl6);
6107         }
6108
6109
6110         rt = container_of(dst, struct rt6_info, dst);
6111         if (rt->dst.error) {
6112                 err = rt->dst.error;
6113                 ip6_rt_put(rt);
6114                 goto errout;
6115         }
6116
6117         if (rt == net->ipv6.ip6_null_entry) {
6118                 err = rt->dst.error;
6119                 ip6_rt_put(rt);
6120                 goto errout;
6121         }
6122
6123         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
6124         if (!skb) {
6125                 ip6_rt_put(rt);
6126                 err = -ENOBUFS;
6127                 goto errout;
6128         }
6129
6130         skb_dst_set(skb, &rt->dst);
6131
6132         rcu_read_lock();
6133         from = rcu_dereference(rt->from);
6134         if (from) {
6135                 if (fibmatch)
6136                         err = rt6_fill_node(net, skb, from, NULL, NULL, NULL,
6137                                             iif, RTM_NEWROUTE,
6138                                             NETLINK_CB(in_skb).portid,
6139                                             nlh->nlmsg_seq, 0);
6140                 else
6141                         err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
6142                                             &fl6.saddr, iif, RTM_NEWROUTE,
6143                                             NETLINK_CB(in_skb).portid,
6144                                             nlh->nlmsg_seq, 0);
6145         } else {
6146                 err = -ENETUNREACH;
6147         }
6148         rcu_read_unlock();
6149
6150         if (err < 0) {
6151                 kfree_skb(skb);
6152                 goto errout;
6153         }
6154
6155         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
6156 errout:
6157         return err;
6158 }
6159
6160 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
6161                      unsigned int nlm_flags)
6162 {
6163         struct sk_buff *skb;
6164         struct net *net = info->nl_net;
6165         u32 seq;
6166         int err;
6167
6168         err = -ENOBUFS;
6169         seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6170
6171         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6172         if (!skb)
6173                 goto errout;
6174
6175         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6176                             event, info->portid, seq, nlm_flags);
6177         if (err < 0) {
6178                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6179                 WARN_ON(err == -EMSGSIZE);
6180                 kfree_skb(skb);
6181                 goto errout;
6182         }
6183         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6184                     info->nlh, gfp_any());
6185         return;
6186 errout:
6187         if (err < 0)
6188                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6189 }
6190
6191 void fib6_rt_update(struct net *net, struct fib6_info *rt,
6192                     struct nl_info *info)
6193 {
6194         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6195         struct sk_buff *skb;
6196         int err = -ENOBUFS;
6197
6198         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6199         if (!skb)
6200                 goto errout;
6201
6202         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6203                             RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
6204         if (err < 0) {
6205                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6206                 WARN_ON(err == -EMSGSIZE);
6207                 kfree_skb(skb);
6208                 goto errout;
6209         }
6210         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6211                     info->nlh, gfp_any());
6212         return;
6213 errout:
6214         if (err < 0)
6215                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6216 }
6217
6218 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
6219                             bool offload, bool trap, bool offload_failed)
6220 {
6221         struct sk_buff *skb;
6222         int err;
6223
6224         if (READ_ONCE(f6i->offload) == offload &&
6225             READ_ONCE(f6i->trap) == trap &&
6226             READ_ONCE(f6i->offload_failed) == offload_failed)
6227                 return;
6228
6229         WRITE_ONCE(f6i->offload, offload);
6230         WRITE_ONCE(f6i->trap, trap);
6231
6232         /* 2 means send notifications only if offload_failed was changed. */
6233         if (net->ipv6.sysctl.fib_notify_on_flag_change == 2 &&
6234             READ_ONCE(f6i->offload_failed) == offload_failed)
6235                 return;
6236
6237         WRITE_ONCE(f6i->offload_failed, offload_failed);
6238
6239         if (!rcu_access_pointer(f6i->fib6_node))
6240                 /* The route was removed from the tree, do not send
6241                  * notification.
6242                  */
6243                 return;
6244
6245         if (!net->ipv6.sysctl.fib_notify_on_flag_change)
6246                 return;
6247
6248         skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL);
6249         if (!skb) {
6250                 err = -ENOBUFS;
6251                 goto errout;
6252         }
6253
6254         err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0,
6255                             0, 0);
6256         if (err < 0) {
6257                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6258                 WARN_ON(err == -EMSGSIZE);
6259                 kfree_skb(skb);
6260                 goto errout;
6261         }
6262
6263         rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL);
6264         return;
6265
6266 errout:
6267         rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6268 }
6269 EXPORT_SYMBOL(fib6_info_hw_flags_set);
6270
6271 static int ip6_route_dev_notify(struct notifier_block *this,
6272                                 unsigned long event, void *ptr)
6273 {
6274         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
6275         struct net *net = dev_net(dev);
6276
6277         if (!(dev->flags & IFF_LOOPBACK))
6278                 return NOTIFY_OK;
6279
6280         if (event == NETDEV_REGISTER) {
6281                 net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev;
6282                 net->ipv6.ip6_null_entry->dst.dev = dev;
6283                 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
6284 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6285                 net->ipv6.ip6_prohibit_entry->dst.dev = dev;
6286                 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
6287                 net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
6288                 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
6289 #endif
6290          } else if (event == NETDEV_UNREGISTER &&
6291                     dev->reg_state != NETREG_UNREGISTERED) {
6292                 /* NETDEV_UNREGISTER could be fired for multiple times by
6293                  * netdev_wait_allrefs(). Make sure we only call this once.
6294                  */
6295                 in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
6296 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6297                 in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
6298                 in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
6299 #endif
6300         }
6301
6302         return NOTIFY_OK;
6303 }
6304
6305 /*
6306  *      /proc
6307  */
6308
6309 #ifdef CONFIG_PROC_FS
6310 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
6311 {
6312         struct net *net = (struct net *)seq->private;
6313         seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
6314                    net->ipv6.rt6_stats->fib_nodes,
6315                    net->ipv6.rt6_stats->fib_route_nodes,
6316                    atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
6317                    net->ipv6.rt6_stats->fib_rt_entries,
6318                    net->ipv6.rt6_stats->fib_rt_cache,
6319                    dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
6320                    net->ipv6.rt6_stats->fib_discarded_routes);
6321
6322         return 0;
6323 }
6324 #endif  /* CONFIG_PROC_FS */
6325
6326 #ifdef CONFIG_SYSCTL
6327
6328 static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
6329                               void *buffer, size_t *lenp, loff_t *ppos)
6330 {
6331         struct net *net;
6332         int delay;
6333         int ret;
6334         if (!write)
6335                 return -EINVAL;
6336
6337         net = (struct net *)ctl->extra1;
6338         delay = net->ipv6.sysctl.flush_delay;
6339         ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
6340         if (ret)
6341                 return ret;
6342
6343         fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
6344         return 0;
6345 }
6346
6347 static struct ctl_table ipv6_route_table_template[] = {
6348         {
6349                 .procname       =       "max_size",
6350                 .data           =       &init_net.ipv6.sysctl.ip6_rt_max_size,
6351                 .maxlen         =       sizeof(int),
6352                 .mode           =       0644,
6353                 .proc_handler   =       proc_dointvec,
6354         },
6355         {
6356                 .procname       =       "gc_thresh",
6357                 .data           =       &ip6_dst_ops_template.gc_thresh,
6358                 .maxlen         =       sizeof(int),
6359                 .mode           =       0644,
6360                 .proc_handler   =       proc_dointvec,
6361         },
6362         {
6363                 .procname       =       "flush",
6364                 .data           =       &init_net.ipv6.sysctl.flush_delay,
6365                 .maxlen         =       sizeof(int),
6366                 .mode           =       0200,
6367                 .proc_handler   =       ipv6_sysctl_rtcache_flush
6368         },
6369         {
6370                 .procname       =       "gc_min_interval",
6371                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6372                 .maxlen         =       sizeof(int),
6373                 .mode           =       0644,
6374                 .proc_handler   =       proc_dointvec_jiffies,
6375         },
6376         {
6377                 .procname       =       "gc_timeout",
6378                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
6379                 .maxlen         =       sizeof(int),
6380                 .mode           =       0644,
6381                 .proc_handler   =       proc_dointvec_jiffies,
6382         },
6383         {
6384                 .procname       =       "gc_interval",
6385                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_interval,
6386                 .maxlen         =       sizeof(int),
6387                 .mode           =       0644,
6388                 .proc_handler   =       proc_dointvec_jiffies,
6389         },
6390         {
6391                 .procname       =       "gc_elasticity",
6392                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
6393                 .maxlen         =       sizeof(int),
6394                 .mode           =       0644,
6395                 .proc_handler   =       proc_dointvec,
6396         },
6397         {
6398                 .procname       =       "mtu_expires",
6399                 .data           =       &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
6400                 .maxlen         =       sizeof(int),
6401                 .mode           =       0644,
6402                 .proc_handler   =       proc_dointvec_jiffies,
6403         },
6404         {
6405                 .procname       =       "min_adv_mss",
6406                 .data           =       &init_net.ipv6.sysctl.ip6_rt_min_advmss,
6407                 .maxlen         =       sizeof(int),
6408                 .mode           =       0644,
6409                 .proc_handler   =       proc_dointvec,
6410         },
6411         {
6412                 .procname       =       "gc_min_interval_ms",
6413                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6414                 .maxlen         =       sizeof(int),
6415                 .mode           =       0644,
6416                 .proc_handler   =       proc_dointvec_ms_jiffies,
6417         },
6418         {
6419                 .procname       =       "skip_notify_on_dev_down",
6420                 .data           =       &init_net.ipv6.sysctl.skip_notify_on_dev_down,
6421                 .maxlen         =       sizeof(u8),
6422                 .mode           =       0644,
6423                 .proc_handler   =       proc_dou8vec_minmax,
6424                 .extra1         =       SYSCTL_ZERO,
6425                 .extra2         =       SYSCTL_ONE,
6426         },
6427         { }
6428 };
6429
6430 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
6431 {
6432         struct ctl_table *table;
6433
6434         table = kmemdup(ipv6_route_table_template,
6435                         sizeof(ipv6_route_table_template),
6436                         GFP_KERNEL);
6437
6438         if (table) {
6439                 table[0].data = &net->ipv6.sysctl.ip6_rt_max_size;
6440                 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
6441                 table[2].data = &net->ipv6.sysctl.flush_delay;
6442                 table[2].extra1 = net;
6443                 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6444                 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
6445                 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
6446                 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
6447                 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
6448                 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
6449                 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6450                 table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
6451
6452                 /* Don't export sysctls to unprivileged users */
6453                 if (net->user_ns != &init_user_ns)
6454                         table[1].procname = NULL;
6455         }
6456
6457         return table;
6458 }
6459
6460 size_t ipv6_route_sysctl_table_size(struct net *net)
6461 {
6462         /* Don't export sysctls to unprivileged users */
6463         if (net->user_ns != &init_user_ns)
6464                 return 1;
6465
6466         return ARRAY_SIZE(ipv6_route_table_template);
6467 }
6468 #endif
6469
6470 static int __net_init ip6_route_net_init(struct net *net)
6471 {
6472         int ret = -ENOMEM;
6473
6474         memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
6475                sizeof(net->ipv6.ip6_dst_ops));
6476
6477         if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
6478                 goto out_ip6_dst_ops;
6479
6480         net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true);
6481         if (!net->ipv6.fib6_null_entry)
6482                 goto out_ip6_dst_entries;
6483         memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template,
6484                sizeof(*net->ipv6.fib6_null_entry));
6485
6486         net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
6487                                            sizeof(*net->ipv6.ip6_null_entry),
6488                                            GFP_KERNEL);
6489         if (!net->ipv6.ip6_null_entry)
6490                 goto out_fib6_null_entry;
6491         net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6492         dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
6493                          ip6_template_metrics, true);
6494         INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->dst.rt_uncached);
6495
6496 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6497         net->ipv6.fib6_has_custom_rules = false;
6498         net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
6499                                                sizeof(*net->ipv6.ip6_prohibit_entry),
6500                                                GFP_KERNEL);
6501         if (!net->ipv6.ip6_prohibit_entry)
6502                 goto out_ip6_null_entry;
6503         net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6504         dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
6505                          ip6_template_metrics, true);
6506         INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->dst.rt_uncached);
6507
6508         net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
6509                                                sizeof(*net->ipv6.ip6_blk_hole_entry),
6510                                                GFP_KERNEL);
6511         if (!net->ipv6.ip6_blk_hole_entry)
6512                 goto out_ip6_prohibit_entry;
6513         net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6514         dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
6515                          ip6_template_metrics, true);
6516         INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->dst.rt_uncached);
6517 #ifdef CONFIG_IPV6_SUBTREES
6518         net->ipv6.fib6_routes_require_src = 0;
6519 #endif
6520 #endif
6521
6522         net->ipv6.sysctl.flush_delay = 0;
6523         net->ipv6.sysctl.ip6_rt_max_size = INT_MAX;
6524         net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
6525         net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
6526         net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
6527         net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
6528         net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
6529         net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
6530         net->ipv6.sysctl.skip_notify_on_dev_down = 0;
6531
6532         atomic_set(&net->ipv6.ip6_rt_gc_expire, 30*HZ);
6533
6534         ret = 0;
6535 out:
6536         return ret;
6537
6538 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6539 out_ip6_prohibit_entry:
6540         kfree(net->ipv6.ip6_prohibit_entry);
6541 out_ip6_null_entry:
6542         kfree(net->ipv6.ip6_null_entry);
6543 #endif
6544 out_fib6_null_entry:
6545         kfree(net->ipv6.fib6_null_entry);
6546 out_ip6_dst_entries:
6547         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6548 out_ip6_dst_ops:
6549         goto out;
6550 }
6551
6552 static void __net_exit ip6_route_net_exit(struct net *net)
6553 {
6554         kfree(net->ipv6.fib6_null_entry);
6555         kfree(net->ipv6.ip6_null_entry);
6556 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6557         kfree(net->ipv6.ip6_prohibit_entry);
6558         kfree(net->ipv6.ip6_blk_hole_entry);
6559 #endif
6560         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6561 }
6562
6563 static int __net_init ip6_route_net_init_late(struct net *net)
6564 {
6565 #ifdef CONFIG_PROC_FS
6566         if (!proc_create_net("ipv6_route", 0, net->proc_net,
6567                              &ipv6_route_seq_ops,
6568                              sizeof(struct ipv6_route_iter)))
6569                 return -ENOMEM;
6570
6571         if (!proc_create_net_single("rt6_stats", 0444, net->proc_net,
6572                                     rt6_stats_seq_show, NULL)) {
6573                 remove_proc_entry("ipv6_route", net->proc_net);
6574                 return -ENOMEM;
6575         }
6576 #endif
6577         return 0;
6578 }
6579
6580 static void __net_exit ip6_route_net_exit_late(struct net *net)
6581 {
6582 #ifdef CONFIG_PROC_FS
6583         remove_proc_entry("ipv6_route", net->proc_net);
6584         remove_proc_entry("rt6_stats", net->proc_net);
6585 #endif
6586 }
6587
6588 static struct pernet_operations ip6_route_net_ops = {
6589         .init = ip6_route_net_init,
6590         .exit = ip6_route_net_exit,
6591 };
6592
6593 static int __net_init ipv6_inetpeer_init(struct net *net)
6594 {
6595         struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
6596
6597         if (!bp)
6598                 return -ENOMEM;
6599         inet_peer_base_init(bp);
6600         net->ipv6.peers = bp;
6601         return 0;
6602 }
6603
6604 static void __net_exit ipv6_inetpeer_exit(struct net *net)
6605 {
6606         struct inet_peer_base *bp = net->ipv6.peers;
6607
6608         net->ipv6.peers = NULL;
6609         inetpeer_invalidate_tree(bp);
6610         kfree(bp);
6611 }
6612
6613 static struct pernet_operations ipv6_inetpeer_ops = {
6614         .init   =       ipv6_inetpeer_init,
6615         .exit   =       ipv6_inetpeer_exit,
6616 };
6617
6618 static struct pernet_operations ip6_route_net_late_ops = {
6619         .init = ip6_route_net_init_late,
6620         .exit = ip6_route_net_exit_late,
6621 };
6622
6623 static struct notifier_block ip6_route_dev_notifier = {
6624         .notifier_call = ip6_route_dev_notify,
6625         .priority = ADDRCONF_NOTIFY_PRIORITY - 10,
6626 };
6627
6628 void __init ip6_route_init_special_entries(void)
6629 {
6630         /* Registering of the loopback is done before this portion of code,
6631          * the loopback reference in rt6_info will not be taken, do it
6632          * manually for init_net */
6633         init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev;
6634         init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
6635         init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6636   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6637         init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
6638         init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6639         init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
6640         init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6641   #endif
6642 }
6643
6644 #if IS_BUILTIN(CONFIG_IPV6)
6645 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6646 DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt)
6647
6648 BTF_ID_LIST(btf_fib6_info_id)
6649 BTF_ID(struct, fib6_info)
6650
6651 static const struct bpf_iter_seq_info ipv6_route_seq_info = {
6652         .seq_ops                = &ipv6_route_seq_ops,
6653         .init_seq_private       = bpf_iter_init_seq_net,
6654         .fini_seq_private       = bpf_iter_fini_seq_net,
6655         .seq_priv_size          = sizeof(struct ipv6_route_iter),
6656 };
6657
6658 static struct bpf_iter_reg ipv6_route_reg_info = {
6659         .target                 = "ipv6_route",
6660         .ctx_arg_info_size      = 1,
6661         .ctx_arg_info           = {
6662                 { offsetof(struct bpf_iter__ipv6_route, rt),
6663                   PTR_TO_BTF_ID_OR_NULL },
6664         },
6665         .seq_info               = &ipv6_route_seq_info,
6666 };
6667
6668 static int __init bpf_iter_register(void)
6669 {
6670         ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id;
6671         return bpf_iter_reg_target(&ipv6_route_reg_info);
6672 }
6673
6674 static void bpf_iter_unregister(void)
6675 {
6676         bpf_iter_unreg_target(&ipv6_route_reg_info);
6677 }
6678 #endif
6679 #endif
6680
6681 int __init ip6_route_init(void)
6682 {
6683         int ret;
6684         int cpu;
6685
6686         ret = -ENOMEM;
6687         ip6_dst_ops_template.kmem_cachep =
6688                 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
6689                                   SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
6690         if (!ip6_dst_ops_template.kmem_cachep)
6691                 goto out;
6692
6693         ret = dst_entries_init(&ip6_dst_blackhole_ops);
6694         if (ret)
6695                 goto out_kmem_cache;
6696
6697         ret = register_pernet_subsys(&ipv6_inetpeer_ops);
6698         if (ret)
6699                 goto out_dst_entries;
6700
6701         ret = register_pernet_subsys(&ip6_route_net_ops);
6702         if (ret)
6703                 goto out_register_inetpeer;
6704
6705         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
6706
6707         ret = fib6_init();
6708         if (ret)
6709                 goto out_register_subsys;
6710
6711         ret = xfrm6_init();
6712         if (ret)
6713                 goto out_fib6_init;
6714
6715         ret = fib6_rules_init();
6716         if (ret)
6717                 goto xfrm6_init;
6718
6719         ret = register_pernet_subsys(&ip6_route_net_late_ops);
6720         if (ret)
6721                 goto fib6_rules_init;
6722
6723         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
6724                                    inet6_rtm_newroute, NULL, 0);
6725         if (ret < 0)
6726                 goto out_register_late_subsys;
6727
6728         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
6729                                    inet6_rtm_delroute, NULL, 0);
6730         if (ret < 0)
6731                 goto out_register_late_subsys;
6732
6733         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
6734                                    inet6_rtm_getroute, NULL,
6735                                    RTNL_FLAG_DOIT_UNLOCKED);
6736         if (ret < 0)
6737                 goto out_register_late_subsys;
6738
6739         ret = register_netdevice_notifier(&ip6_route_dev_notifier);
6740         if (ret)
6741                 goto out_register_late_subsys;
6742
6743 #if IS_BUILTIN(CONFIG_IPV6)
6744 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6745         ret = bpf_iter_register();
6746         if (ret)
6747                 goto out_register_late_subsys;
6748 #endif
6749 #endif
6750
6751         for_each_possible_cpu(cpu) {
6752                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
6753
6754                 INIT_LIST_HEAD(&ul->head);
6755                 INIT_LIST_HEAD(&ul->quarantine);
6756                 spin_lock_init(&ul->lock);
6757         }
6758
6759 out:
6760         return ret;
6761
6762 out_register_late_subsys:
6763         rtnl_unregister_all(PF_INET6);
6764         unregister_pernet_subsys(&ip6_route_net_late_ops);
6765 fib6_rules_init:
6766         fib6_rules_cleanup();
6767 xfrm6_init:
6768         xfrm6_fini();
6769 out_fib6_init:
6770         fib6_gc_cleanup();
6771 out_register_subsys:
6772         unregister_pernet_subsys(&ip6_route_net_ops);
6773 out_register_inetpeer:
6774         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6775 out_dst_entries:
6776         dst_entries_destroy(&ip6_dst_blackhole_ops);
6777 out_kmem_cache:
6778         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6779         goto out;
6780 }
6781
6782 void ip6_route_cleanup(void)
6783 {
6784 #if IS_BUILTIN(CONFIG_IPV6)
6785 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6786         bpf_iter_unregister();
6787 #endif
6788 #endif
6789         unregister_netdevice_notifier(&ip6_route_dev_notifier);
6790         unregister_pernet_subsys(&ip6_route_net_late_ops);
6791         fib6_rules_cleanup();
6792         xfrm6_fini();
6793         fib6_gc_cleanup();
6794         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6795         unregister_pernet_subsys(&ip6_route_net_ops);
6796         dst_entries_destroy(&ip6_dst_blackhole_ops);
6797         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6798 }