net/ipv6/route.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Linux INET6 implementation
   4  *      FIB front-end.
   5  *
   6  *      Authors:
   7  *      Pedro Roque             <[email protected]>
   8  */
   9
  10 /*      Changes:
  11  *
  12  *      YOSHIFUJI Hideaki @USAGI
  13  *              reworked default router selection.
  14  *              - respect outgoing interface
  15  *              - select from (probably) reachable routers (i.e.
  16  *              routers in REACHABLE, STALE, DELAY or PROBE states).
  17  *              - always select the same router if it is (probably)
  18  *              reachable.  otherwise, round-robin the list.
  19  *      Ville Nuorvala
  20  *              Fixed routing subtrees.
  21  */
  22
  23 #define pr_fmt(fmt) "IPv6: " fmt
  24
  25 #include <linux/capability.h>
  26 #include <linux/errno.h>
  27 #include <linux/export.h>
  28 #include <linux/types.h>
  29 #include <linux/times.h>
  30 #include <linux/socket.h>
  31 #include <linux/sockios.h>
  32 #include <linux/net.h>
  33 #include <linux/route.h>
  34 #include <linux/netdevice.h>
  35 #include <linux/in6.h>
  36 #include <linux/mroute6.h>
  37 #include <linux/init.h>
  38 #include <linux/if_arp.h>
  39 #include <linux/proc_fs.h>
  40 #include <linux/seq_file.h>
  41 #include <linux/nsproxy.h>
  42 #include <linux/slab.h>
  43 #include <linux/jhash.h>
  44 #include <linux/siphash.h>
  45 #include <net/net_namespace.h>
  46 #include <net/snmp.h>
  47 #include <net/ipv6.h>
  48 #include <net/ip6_fib.h>
  49 #include <net/ip6_route.h>
  50 #include <net/ndisc.h>
  51 #include <net/addrconf.h>
  52 #include <net/tcp.h>
  53 #include <linux/rtnetlink.h>
  54 #include <net/dst.h>
  55 #include <net/dst_metadata.h>
  56 #include <net/xfrm.h>
  57 #include <net/netevent.h>
  58 #include <net/netlink.h>
  59 #include <net/rtnh.h>
  60 #include <net/lwtunnel.h>
  61 #include <net/ip_tunnels.h>
  62 #include <net/l3mdev.h>
  63 #include <net/ip.h>
  64 #include <linux/uaccess.h>
  65 #include <linux/btf_ids.h>
  66
  67 #ifdef CONFIG_SYSCTL
  68 #include <linux/sysctl.h>
  69 #endif
  70
  71 static int ip6_rt_type_to_error(u8 fib6_type);
  72
  73 #define CREATE_TRACE_POINTS
  74 #include <trace/events/fib6.h>
  75 EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup);
  76 #undef CREATE_TRACE_POINTS
  77
  78 enum rt6_nud_state {
  79         RT6_NUD_FAIL_HARD = -3,
  80         RT6_NUD_FAIL_PROBE = -2,
  81         RT6_NUD_FAIL_DO_RR = -1,
  82         RT6_NUD_SUCCEED = 1
  83 };
  84
  85 INDIRECT_CALLABLE_SCOPE
  86 struct dst_entry        *ip6_dst_check(struct dst_entry *dst, u32 cookie);
  87 static unsigned int      ip6_default_advmss(const struct dst_entry *dst);
  88 INDIRECT_CALLABLE_SCOPE
  89 unsigned int            ip6_mtu(const struct dst_entry *dst);
  90 static void             ip6_negative_advice(struct sock *sk,
  91                                             struct dst_entry *dst);
  92 static void             ip6_dst_destroy(struct dst_entry *);
  93 static void             ip6_dst_ifdown(struct dst_entry *,
  94                                        struct net_device *dev);
  95 static void              ip6_dst_gc(struct dst_ops *ops);
  96
  97 static int              ip6_pkt_discard(struct sk_buff *skb);
  98 static int              ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
  99 static int              ip6_pkt_prohibit(struct sk_buff *skb);
 100 static int              ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 101 static void             ip6_link_failure(struct sk_buff *skb);
 102 static void             ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
 103                                            struct sk_buff *skb, u32 mtu,
 104                                            bool confirm_neigh);
 105 static void             rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
 106                                         struct sk_buff *skb);
 107 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
 108                            int strict);
 109 static size_t rt6_nlmsg_size(struct fib6_info *f6i);
 110 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
 111                          struct fib6_info *rt, struct dst_entry *dst,
 112                          struct in6_addr *dest, struct in6_addr *src,
 113                          int iif, int type, u32 portid, u32 seq,
 114                          unsigned int flags);
 115 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
 116                                            const struct in6_addr *daddr,
 117                                            const struct in6_addr *saddr);
 118
 119 #ifdef CONFIG_IPV6_ROUTE_INFO
 120 static struct fib6_info *rt6_add_route_info(struct net *net,
 121                                            const struct in6_addr *prefix, int prefixlen,
 122                                            const struct in6_addr *gwaddr,
 123                                            struct net_device *dev,
 124                                            unsigned int pref);
 125 static struct fib6_info *rt6_get_route_info(struct net *net,
 126                                            const struct in6_addr *prefix, int prefixlen,
 127                                            const struct in6_addr *gwaddr,
 128                                            struct net_device *dev);
 129 #endif
 130
 131 struct uncached_list {
 132         spinlock_t              lock;
 133         struct list_head        head;
 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_del_init(&rt->dst.rt_uncached);
 192                 }
 193                 spin_unlock_bh(&ul->lock);
 194         }
 195 }
 196
 197 static inline const void *choose_neigh_daddr(const struct in6_addr *p,
 198                                              struct sk_buff *skb,
 199                                              const void *daddr)
 200 {
 201         if (!ipv6_addr_any(p))
 202                 return (const void *) p;
 203         else if (skb)
 204                 return &ipv6_hdr(skb)->daddr;
 205         return daddr;
 206 }
 207
 208 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
 209                                    struct net_device *dev,
 210                                    struct sk_buff *skb,
 211                                    const void *daddr)
 212 {
 213         struct neighbour *n;
 214
 215         daddr = choose_neigh_daddr(gw, skb, daddr);
 216         n = __ipv6_neigh_lookup(dev, daddr);
 217         if (n)
 218                 return n;
 219
 220         n = neigh_create(&nd_tbl, daddr, dev);
 221         return IS_ERR(n) ? NULL : n;
 222 }
 223
 224 static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst,
 225                                               struct sk_buff *skb,
 226                                               const void *daddr)
 227 {
 228         const struct rt6_info *rt = dst_rt6_info(dst);
 229
 230         return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any),
 231                                 dst->dev, skb, daddr);
 232 }
 233
 234 static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr)
 235 {
 236         const struct rt6_info *rt = dst_rt6_info(dst);
 237         struct net_device *dev = dst->dev;
 238
 239         daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr);
 240         if (!daddr)
 241                 return;
 242         if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
 243                 return;
 244         if (ipv6_addr_is_multicast((const struct in6_addr *)daddr))
 245                 return;
 246         __ipv6_confirm_neigh(dev, daddr);
 247 }
 248
 249 static struct dst_ops ip6_dst_ops_template = {
 250         .family                 =       AF_INET6,
 251         .gc                     =       ip6_dst_gc,
 252         .gc_thresh              =       1024,
 253         .check                  =       ip6_dst_check,
 254         .default_advmss         =       ip6_default_advmss,
 255         .mtu                    =       ip6_mtu,
 256         .cow_metrics            =       dst_cow_metrics_generic,
 257         .destroy                =       ip6_dst_destroy,
 258         .ifdown                 =       ip6_dst_ifdown,
 259         .negative_advice        =       ip6_negative_advice,
 260         .link_failure           =       ip6_link_failure,
 261         .update_pmtu            =       ip6_rt_update_pmtu,
 262         .redirect               =       rt6_do_redirect,
 263         .local_out              =       __ip6_local_out,
 264         .neigh_lookup           =       ip6_dst_neigh_lookup,
 265         .confirm_neigh          =       ip6_confirm_neigh,
 266 };
 267
 268 static struct dst_ops ip6_dst_blackhole_ops = {
 269         .family                 = AF_INET6,
 270         .default_advmss         = ip6_default_advmss,
 271         .neigh_lookup           = ip6_dst_neigh_lookup,
 272         .check                  = ip6_dst_check,
 273         .destroy                = ip6_dst_destroy,
 274         .cow_metrics            = dst_cow_metrics_generic,
 275         .update_pmtu            = dst_blackhole_update_pmtu,
 276         .redirect               = dst_blackhole_redirect,
 277         .mtu                    = dst_blackhole_mtu,
 278 };
 279
 280 static const u32 ip6_template_metrics[RTAX_MAX] = {
 281         [RTAX_HOPLIMIT - 1] = 0,
 282 };
 283
 284 static const struct fib6_info fib6_null_entry_template = {
 285         .fib6_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 286         .fib6_protocol  = RTPROT_KERNEL,
 287         .fib6_metric    = ~(u32)0,
 288         .fib6_ref       = REFCOUNT_INIT(1),
 289         .fib6_type      = RTN_UNREACHABLE,
 290         .fib6_metrics   = (struct dst_metrics *)&dst_default_metrics,
 291 };
 292
 293 static const struct rt6_info ip6_null_entry_template = {
 294         .dst = {
 295                 .__rcuref       = RCUREF_INIT(1),
 296                 .__use          = 1,
 297                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 298                 .error          = -ENETUNREACH,
 299                 .input          = ip6_pkt_discard,
 300                 .output         = ip6_pkt_discard_out,
 301         },
 302         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 303 };
 304
 305 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 306
 307 static const struct rt6_info ip6_prohibit_entry_template = {
 308         .dst = {
 309                 .__rcuref       = RCUREF_INIT(1),
 310                 .__use          = 1,
 311                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 312                 .error          = -EACCES,
 313                 .input          = ip6_pkt_prohibit,
 314                 .output         = ip6_pkt_prohibit_out,
 315         },
 316         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 317 };
 318
 319 static const struct rt6_info ip6_blk_hole_entry_template = {
 320         .dst = {
 321                 .__rcuref       = RCUREF_INIT(1),
 322                 .__use          = 1,
 323                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 324                 .error          = -EINVAL,
 325                 .input          = dst_discard,
 326                 .output         = dst_discard_out,
 327         },
 328         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 329 };
 330
 331 #endif
 332
 333 static void rt6_info_init(struct rt6_info *rt)
 334 {
 335         memset_after(rt, 0, dst);
 336 }
 337
 338 /* allocate dst with ip6_dst_ops */
 339 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 340                                int flags)
 341 {
 342         struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
 343                                         DST_OBSOLETE_FORCE_CHK, flags);
 344
 345         if (rt) {
 346                 rt6_info_init(rt);
 347                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
 348         }
 349
 350         return rt;
 351 }
 352 EXPORT_SYMBOL(ip6_dst_alloc);
 353
 354 static void ip6_dst_destroy(struct dst_entry *dst)
 355 {
 356         struct rt6_info *rt = dst_rt6_info(dst);
 357         struct fib6_info *from;
 358         struct inet6_dev *idev;
 359
 360         ip_dst_metrics_put(dst);
 361         rt6_uncached_list_del(rt);
 362
 363         idev = rt->rt6i_idev;
 364         if (idev) {
 365                 rt->rt6i_idev = NULL;
 366                 in6_dev_put(idev);
 367         }
 368
 369         from = unrcu_pointer(xchg(&rt->from, NULL));
 370         fib6_info_release(from);
 371 }
 372
 373 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
 374 {
 375         struct rt6_info *rt = dst_rt6_info(dst);
 376         struct inet6_dev *idev = rt->rt6i_idev;
 377
 378         if (idev && idev->dev != blackhole_netdev) {
 379                 struct inet6_dev *blackhole_idev = in6_dev_get(blackhole_netdev);
 380
 381                 if (blackhole_idev) {
 382                         rt->rt6i_idev = blackhole_idev;
 383                         in6_dev_put(idev);
 384                 }
 385         }
 386 }
 387
 388 static bool __rt6_check_expired(const struct rt6_info *rt)
 389 {
 390         if (rt->rt6i_flags & RTF_EXPIRES)
 391                 return time_after(jiffies, rt->dst.expires);
 392         else
 393                 return false;
 394 }
 395
 396 static bool rt6_check_expired(const struct rt6_info *rt)
 397 {
 398         struct fib6_info *from;
 399
 400         from = rcu_dereference(rt->from);
 401
 402         if (rt->rt6i_flags & RTF_EXPIRES) {
 403                 if (time_after(jiffies, rt->dst.expires))
 404                         return true;
 405         } else if (from) {
 406                 return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
 407                         fib6_check_expired(from);
 408         }
 409         return false;
 410 }
 411
 412 void fib6_select_path(const struct net *net, struct fib6_result *res,
 413                       struct flowi6 *fl6, int oif, bool have_oif_match,
 414                       const struct sk_buff *skb, int strict)
 415 {
 416         struct fib6_info *sibling, *next_sibling;
 417         struct fib6_info *match = res->f6i;
 418
 419         if (!match->nh && (!match->fib6_nsiblings || have_oif_match))
 420                 goto out;
 421
 422         if (match->nh && have_oif_match && res->nh)
 423                 return;
 424
 425         if (skb)
 426                 IP6CB(skb)->flags |= IP6SKB_MULTIPATH;
 427
 428         /* We might have already computed the hash for ICMPv6 errors. In such
 429          * case it will always be non-zero. Otherwise now is the time to do it.
 430          */
 431         if (!fl6->mp_hash &&
 432             (!match->nh || nexthop_is_multipath(match->nh)))
 433                 fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
 434
 435         if (unlikely(match->nh)) {
 436                 nexthop_path_fib6_result(res, fl6->mp_hash);
 437                 return;
 438         }
 439
 440         if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
 441                 goto out;
 442
 443         list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
 444                                  fib6_siblings) {
 445                 const struct fib6_nh *nh = sibling->fib6_nh;
 446                 int nh_upper_bound;
 447
 448                 nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
 449                 if (fl6->mp_hash > nh_upper_bound)
 450                         continue;
 451                 if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
 452                         break;
 453                 match = sibling;
 454                 break;
 455         }
 456
 457 out:
 458         res->f6i = match;
 459         res->nh = match->fib6_nh;
 460 }
 461
 462 /*
 463  *      Route lookup. rcu_read_lock() should be held.
 464  */
 465
 466 static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh,
 467                                const struct in6_addr *saddr, int oif, int flags)
 468 {
 469         const struct net_device *dev;
 470
 471         if (nh->fib_nh_flags & RTNH_F_DEAD)
 472                 return false;
 473
 474         dev = nh->fib_nh_dev;
 475         if (oif) {
 476                 if (dev->ifindex == oif)
 477                         return true;
 478         } else {
 479                 if (ipv6_chk_addr(net, saddr, dev,
 480                                   flags & RT6_LOOKUP_F_IFACE))
 481                         return true;
 482         }
 483
 484         return false;
 485 }
 486
 487 struct fib6_nh_dm_arg {
 488         struct net              *net;
 489         const struct in6_addr   *saddr;
 490         int                     oif;
 491         int                     flags;
 492         struct fib6_nh          *nh;
 493 };
 494
 495 static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg)
 496 {
 497         struct fib6_nh_dm_arg *arg = _arg;
 498
 499         arg->nh = nh;
 500         return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif,
 501                                   arg->flags);
 502 }
 503
 504 /* returns fib6_nh from nexthop or NULL */
 505 static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh,
 506                                         struct fib6_result *res,
 507                                         const struct in6_addr *saddr,
 508                                         int oif, int flags)
 509 {
 510         struct fib6_nh_dm_arg arg = {
 511                 .net   = net,
 512                 .saddr = saddr,
 513                 .oif   = oif,
 514                 .flags = flags,
 515         };
 516
 517         if (nexthop_is_blackhole(nh))
 518                 return NULL;
 519
 520         if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg))
 521                 return arg.nh;
 522
 523         return NULL;
 524 }
 525
 526 static void rt6_device_match(struct net *net, struct fib6_result *res,
 527                              const struct in6_addr *saddr, int oif, int flags)
 528 {
 529         struct fib6_info *f6i = res->f6i;
 530         struct fib6_info *spf6i;
 531         struct fib6_nh *nh;
 532
 533         if (!oif && ipv6_addr_any(saddr)) {
 534                 if (unlikely(f6i->nh)) {
 535                         nh = nexthop_fib6_nh(f6i->nh);
 536                         if (nexthop_is_blackhole(f6i->nh))
 537                                 goto out_blackhole;
 538                 } else {
 539                         nh = f6i->fib6_nh;
 540                 }
 541                 if (!(nh->fib_nh_flags & RTNH_F_DEAD))
 542                         goto out;
 543         }
 544
 545         for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
 546                 bool matched = false;
 547
 548                 if (unlikely(spf6i->nh)) {
 549                         nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr,
 550                                               oif, flags);
 551                         if (nh)
 552                                 matched = true;
 553                 } else {
 554                         nh = spf6i->fib6_nh;
 555                         if (__rt6_device_match(net, nh, saddr, oif, flags))
 556                                 matched = true;
 557                 }
 558                 if (matched) {
 559                         res->f6i = spf6i;
 560                         goto out;
 561                 }
 562         }
 563
 564         if (oif && flags & RT6_LOOKUP_F_IFACE) {
 565                 res->f6i = net->ipv6.fib6_null_entry;
 566                 nh = res->f6i->fib6_nh;
 567                 goto out;
 568         }
 569
 570         if (unlikely(f6i->nh)) {
 571                 nh = nexthop_fib6_nh(f6i->nh);
 572                 if (nexthop_is_blackhole(f6i->nh))
 573                         goto out_blackhole;
 574         } else {
 575                 nh = f6i->fib6_nh;
 576         }
 577
 578         if (nh->fib_nh_flags & RTNH_F_DEAD) {
 579                 res->f6i = net->ipv6.fib6_null_entry;
 580                 nh = res->f6i->fib6_nh;
 581         }
 582 out:
 583         res->nh = nh;
 584         res->fib6_type = res->f6i->fib6_type;
 585         res->fib6_flags = res->f6i->fib6_flags;
 586         return;
 587
 588 out_blackhole:
 589         res->fib6_flags |= RTF_REJECT;
 590         res->fib6_type = RTN_BLACKHOLE;
 591         res->nh = nh;
 592 }
 593
 594 #ifdef CONFIG_IPV6_ROUTER_PREF
 595 struct __rt6_probe_work {
 596         struct work_struct work;
 597         struct in6_addr target;
 598         struct net_device *dev;
 599         netdevice_tracker dev_tracker;
 600 };
 601
 602 static void rt6_probe_deferred(struct work_struct *w)
 603 {
 604         struct in6_addr mcaddr;
 605         struct __rt6_probe_work *work =
 606                 container_of(w, struct __rt6_probe_work, work);
 607
 608         addrconf_addr_solict_mult(&work->target, &mcaddr);
 609         ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
 610         netdev_put(work->dev, &work->dev_tracker);
 611         kfree(work);
 612 }
 613
 614 static void rt6_probe(struct fib6_nh *fib6_nh)
 615 {
 616         struct __rt6_probe_work *work = NULL;
 617         const struct in6_addr *nh_gw;
 618         unsigned long last_probe;
 619         struct neighbour *neigh;
 620         struct net_device *dev;
 621         struct inet6_dev *idev;
 622
 623         /*
 624          * Okay, this does not seem to be appropriate
 625          * for now, however, we need to check if it
 626          * is really so; aka Router Reachability Probing.
 627          *
 628          * Router Reachability Probe MUST be rate-limited
 629          * to no more than one per minute.
 630          */
 631         if (!fib6_nh->fib_nh_gw_family)
 632                 return;
 633
 634         nh_gw = &fib6_nh->fib_nh_gw6;
 635         dev = fib6_nh->fib_nh_dev;
 636         rcu_read_lock();
 637         last_probe = READ_ONCE(fib6_nh->last_probe);
 638         idev = __in6_dev_get(dev);
 639         if (!idev)
 640                 goto out;
 641         neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
 642         if (neigh) {
 643                 if (READ_ONCE(neigh->nud_state) & NUD_VALID)
 644                         goto out;
 645
 646                 write_lock_bh(&neigh->lock);
 647                 if (!(neigh->nud_state & NUD_VALID) &&
 648                     time_after(jiffies,
 649                                neigh->updated +
 650                                READ_ONCE(idev->cnf.rtr_probe_interval))) {
 651                         work = kmalloc(sizeof(*work), GFP_ATOMIC);
 652                         if (work)
 653                                 __neigh_set_probe_once(neigh);
 654                 }
 655                 write_unlock_bh(&neigh->lock);
 656         } else if (time_after(jiffies, last_probe +
 657                                        READ_ONCE(idev->cnf.rtr_probe_interval))) {
 658                 work = kmalloc(sizeof(*work), GFP_ATOMIC);
 659         }
 660
 661         if (!work || cmpxchg(&fib6_nh->last_probe,
 662                              last_probe, jiffies) != last_probe) {
 663                 kfree(work);
 664         } else {
 665                 INIT_WORK(&work->work, rt6_probe_deferred);
 666                 work->target = *nh_gw;
 667                 netdev_hold(dev, &work->dev_tracker, GFP_ATOMIC);
 668                 work->dev = dev;
 669                 schedule_work(&work->work);
 670         }
 671
 672 out:
 673         rcu_read_unlock();
 674 }
 675 #else
 676 static inline void rt6_probe(struct fib6_nh *fib6_nh)
 677 {
 678 }
 679 #endif
 680
 681 /*
 682  * Default Router Selection (RFC 2461 6.3.6)
 683  */
 684 static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh)
 685 {
 686         enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
 687         struct neighbour *neigh;
 688
 689         rcu_read_lock();
 690         neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev,
 691                                           &fib6_nh->fib_nh_gw6);
 692         if (neigh) {
 693                 u8 nud_state = READ_ONCE(neigh->nud_state);
 694
 695                 if (nud_state & NUD_VALID)
 696                         ret = RT6_NUD_SUCCEED;
 697 #ifdef CONFIG_IPV6_ROUTER_PREF
 698                 else if (!(nud_state & NUD_FAILED))
 699                         ret = RT6_NUD_SUCCEED;
 700                 else
 701                         ret = RT6_NUD_FAIL_PROBE;
 702 #endif
 703         } else {
 704                 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
 705                       RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
 706         }
 707         rcu_read_unlock();
 708
 709         return ret;
 710 }
 711
 712 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
 713                            int strict)
 714 {
 715         int m = 0;
 716
 717         if (!oif || nh->fib_nh_dev->ifindex == oif)
 718                 m = 2;
 719
 720         if (!m && (strict & RT6_LOOKUP_F_IFACE))
 721                 return RT6_NUD_FAIL_HARD;
 722 #ifdef CONFIG_IPV6_ROUTER_PREF
 723         m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2;
 724 #endif
 725         if ((strict & RT6_LOOKUP_F_REACHABLE) &&
 726             !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) {
 727                 int n = rt6_check_neigh(nh);
 728                 if (n < 0)
 729                         return n;
 730         }
 731         return m;
 732 }
 733
 734 static bool find_match(struct fib6_nh *nh, u32 fib6_flags,
 735                        int oif, int strict, int *mpri, bool *do_rr)
 736 {
 737         bool match_do_rr = false;
 738         bool rc = false;
 739         int m;
 740
 741         if (nh->fib_nh_flags & RTNH_F_DEAD)
 742                 goto out;
 743
 744         if (ip6_ignore_linkdown(nh->fib_nh_dev) &&
 745             nh->fib_nh_flags & RTNH_F_LINKDOWN &&
 746             !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
 747                 goto out;
 748
 749         m = rt6_score_route(nh, fib6_flags, oif, strict);
 750         if (m == RT6_NUD_FAIL_DO_RR) {
 751                 match_do_rr = true;
 752                 m = 0; /* lowest valid score */
 753         } else if (m == RT6_NUD_FAIL_HARD) {
 754                 goto out;
 755         }
 756
 757         if (strict & RT6_LOOKUP_F_REACHABLE)
 758                 rt6_probe(nh);
 759
 760         /* note that m can be RT6_NUD_FAIL_PROBE at this point */
 761         if (m > *mpri) {
 762                 *do_rr = match_do_rr;
 763                 *mpri = m;
 764                 rc = true;
 765         }
 766 out:
 767         return rc;
 768 }
 769
 770 struct fib6_nh_frl_arg {
 771         u32             flags;
 772         int             oif;
 773         int             strict;
 774         int             *mpri;
 775         bool            *do_rr;
 776         struct fib6_nh  *nh;
 777 };
 778
 779 static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg)
 780 {
 781         struct fib6_nh_frl_arg *arg = _arg;
 782
 783         arg->nh = nh;
 784         return find_match(nh, arg->flags, arg->oif, arg->strict,
 785                           arg->mpri, arg->do_rr);
 786 }
 787
 788 static void __find_rr_leaf(struct fib6_info *f6i_start,
 789                            struct fib6_info *nomatch, u32 metric,
 790                            struct fib6_result *res, struct fib6_info **cont,
 791                            int oif, int strict, bool *do_rr, int *mpri)
 792 {
 793         struct fib6_info *f6i;
 794
 795         for (f6i = f6i_start;
 796              f6i && f6i != nomatch;
 797              f6i = rcu_dereference(f6i->fib6_next)) {
 798                 bool matched = false;
 799                 struct fib6_nh *nh;
 800
 801                 if (cont && f6i->fib6_metric != metric) {
 802                         *cont = f6i;
 803                         return;
 804                 }
 805
 806                 if (fib6_check_expired(f6i))
 807                         continue;
 808
 809                 if (unlikely(f6i->nh)) {
 810                         struct fib6_nh_frl_arg arg = {
 811                                 .flags  = f6i->fib6_flags,
 812                                 .oif    = oif,
 813                                 .strict = strict,
 814                                 .mpri   = mpri,
 815                                 .do_rr  = do_rr
 816                         };
 817
 818                         if (nexthop_is_blackhole(f6i->nh)) {
 819                                 res->fib6_flags = RTF_REJECT;
 820                                 res->fib6_type = RTN_BLACKHOLE;
 821                                 res->f6i = f6i;
 822                                 res->nh = nexthop_fib6_nh(f6i->nh);
 823                                 return;
 824                         }
 825                         if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match,
 826                                                      &arg)) {
 827                                 matched = true;
 828                                 nh = arg.nh;
 829                         }
 830                 } else {
 831                         nh = f6i->fib6_nh;
 832                         if (find_match(nh, f6i->fib6_flags, oif, strict,
 833                                        mpri, do_rr))
 834                                 matched = true;
 835                 }
 836                 if (matched) {
 837                         res->f6i = f6i;
 838                         res->nh = nh;
 839                         res->fib6_flags = f6i->fib6_flags;
 840                         res->fib6_type = f6i->fib6_type;
 841                 }
 842         }
 843 }
 844
 845 static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf,
 846                          struct fib6_info *rr_head, int oif, int strict,
 847                          bool *do_rr, struct fib6_result *res)
 848 {
 849         u32 metric = rr_head->fib6_metric;
 850         struct fib6_info *cont = NULL;
 851         int mpri = -1;
 852
 853         __find_rr_leaf(rr_head, NULL, metric, res, &cont,
 854                        oif, strict, do_rr, &mpri);
 855
 856         __find_rr_leaf(leaf, rr_head, metric, res, &cont,
 857                        oif, strict, do_rr, &mpri);
 858
 859         if (res->f6i || !cont)
 860                 return;
 861
 862         __find_rr_leaf(cont, NULL, metric, res, NULL,
 863                        oif, strict, do_rr, &mpri);
 864 }
 865
 866 static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
 867                        struct fib6_result *res, int strict)
 868 {
 869         struct fib6_info *leaf = rcu_dereference(fn->leaf);
 870         struct fib6_info *rt0;
 871         bool do_rr = false;
 872         int key_plen;
 873
 874         /* make sure this function or its helpers sets f6i */
 875         res->f6i = NULL;
 876
 877         if (!leaf || leaf == net->ipv6.fib6_null_entry)
 878                 goto out;
 879
 880         rt0 = rcu_dereference(fn->rr_ptr);
 881         if (!rt0)
 882                 rt0 = leaf;
 883
 884         /* Double check to make sure fn is not an intermediate node
 885          * and fn->leaf does not points to its child's leaf
 886          * (This might happen if all routes under fn are deleted from
 887          * the tree and fib6_repair_tree() is called on the node.)
 888          */
 889         key_plen = rt0->fib6_dst.plen;
 890 #ifdef CONFIG_IPV6_SUBTREES
 891         if (rt0->fib6_src.plen)
 892                 key_plen = rt0->fib6_src.plen;
 893 #endif
 894         if (fn->fn_bit != key_plen)
 895                 goto out;
 896
 897         find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res);
 898         if (do_rr) {
 899                 struct fib6_info *next = rcu_dereference(rt0->fib6_next);
 900
 901                 /* no entries matched; do round-robin */
 902                 if (!next || next->fib6_metric != rt0->fib6_metric)
 903                         next = leaf;
 904
 905                 if (next != rt0) {
 906                         spin_lock_bh(&leaf->fib6_table->tb6_lock);
 907                         /* make sure next is not being deleted from the tree */
 908                         if (next->fib6_node)
 909                                 rcu_assign_pointer(fn->rr_ptr, next);
 910                         spin_unlock_bh(&leaf->fib6_table->tb6_lock);
 911                 }
 912         }
 913
 914 out:
 915         if (!res->f6i) {
 916                 res->f6i = net->ipv6.fib6_null_entry;
 917                 res->nh = res->f6i->fib6_nh;
 918                 res->fib6_flags = res->f6i->fib6_flags;
 919                 res->fib6_type = res->f6i->fib6_type;
 920         }
 921 }
 922
 923 static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res)
 924 {
 925         return (res->f6i->fib6_flags & RTF_NONEXTHOP) ||
 926                res->nh->fib_nh_gw_family;
 927 }
 928
 929 #ifdef CONFIG_IPV6_ROUTE_INFO
 930 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 931                   const struct in6_addr *gwaddr)
 932 {
 933         struct net *net = dev_net(dev);
 934         struct route_info *rinfo = (struct route_info *) opt;
 935         struct in6_addr prefix_buf, *prefix;
 936         struct fib6_table *table;
 937         unsigned int pref;
 938         unsigned long lifetime;
 939         struct fib6_info *rt;
 940
 941         if (len < sizeof(struct route_info)) {
 942                 return -EINVAL;
 943         }
 944
 945         /* Sanity check for prefix_len and length */
 946         if (rinfo->length > 3) {
 947                 return -EINVAL;
 948         } else if (rinfo->prefix_len > 128) {
 949                 return -EINVAL;
 950         } else if (rinfo->prefix_len > 64) {
 951                 if (rinfo->length < 2) {
 952                         return -EINVAL;
 953                 }
 954         } else if (rinfo->prefix_len > 0) {
 955                 if (rinfo->length < 1) {
 956                         return -EINVAL;
 957                 }
 958         }
 959
 960         pref = rinfo->route_pref;
 961         if (pref == ICMPV6_ROUTER_PREF_INVALID)
 962                 return -EINVAL;
 963
 964         lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
 965
 966         if (rinfo->length == 3)
 967                 prefix = (struct in6_addr *)rinfo->prefix;
 968         else {
 969                 /* this function is safe */
 970                 ipv6_addr_prefix(&prefix_buf,
 971                                  (struct in6_addr *)rinfo->prefix,
 972                                  rinfo->prefix_len);
 973                 prefix = &prefix_buf;
 974         }
 975
 976         if (rinfo->prefix_len == 0)
 977                 rt = rt6_get_dflt_router(net, gwaddr, dev);
 978         else
 979                 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
 980                                         gwaddr, dev);
 981
 982         if (rt && !lifetime) {
 983                 ip6_del_rt(net, rt, false);
 984                 rt = NULL;
 985         }
 986
 987         if (!rt && lifetime)
 988                 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
 989                                         dev, pref);
 990         else if (rt)
 991                 rt->fib6_flags = RTF_ROUTEINFO |
 992                                  (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 993
 994         if (rt) {
 995                 table = rt->fib6_table;
 996                 spin_lock_bh(&table->tb6_lock);
 997
 998                 if (!addrconf_finite_timeout(lifetime)) {
 999                         fib6_clean_expires(rt);
1000                         fib6_remove_gc_list(rt);
1001                 } else {
1002                         fib6_set_expires(rt, jiffies + HZ * lifetime);
1003                         fib6_add_gc_list(rt);
1004                 }
1005
1006                 spin_unlock_bh(&table->tb6_lock);
1007
1008                 fib6_info_release(rt);
1009         }
1010         return 0;
1011 }
1012 #endif
1013
1014 /*
1015  *      Misc support functions
1016  */
1017
1018 /* called with rcu_lock held */
1019 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
1020 {
1021         struct net_device *dev = res->nh->fib_nh_dev;
1022
1023         if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
1024                 /* for copies of local routes, dst->dev needs to be the
1025                  * device if it is a master device, the master device if
1026                  * device is enslaved, and the loopback as the default
1027                  */
1028                 if (netif_is_l3_slave(dev) &&
1029                     !rt6_need_strict(&res->f6i->fib6_dst.addr))
1030                         dev = l3mdev_master_dev_rcu(dev);
1031                 else if (!netif_is_l3_master(dev))
1032                         dev = dev_net(dev)->loopback_dev;
1033                 /* last case is netif_is_l3_master(dev) is true in which
1034                  * case we want dev returned to be dev
1035                  */
1036         }
1037
1038         return dev;
1039 }
1040
1041 static const int fib6_prop[RTN_MAX + 1] = {
1042         [RTN_UNSPEC]    = 0,
1043         [RTN_UNICAST]   = 0,
1044         [RTN_LOCAL]     = 0,
1045         [RTN_BROADCAST] = 0,
1046         [RTN_ANYCAST]   = 0,
1047         [RTN_MULTICAST] = 0,
1048         [RTN_BLACKHOLE] = -EINVAL,
1049         [RTN_UNREACHABLE] = -EHOSTUNREACH,
1050         [RTN_PROHIBIT]  = -EACCES,
1051         [RTN_THROW]     = -EAGAIN,
1052         [RTN_NAT]       = -EINVAL,
1053         [RTN_XRESOLVE]  = -EINVAL,
1054 };
1055
1056 static int ip6_rt_type_to_error(u8 fib6_type)
1057 {
1058         return fib6_prop[fib6_type];
1059 }
1060
1061 static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
1062 {
1063         unsigned short flags = 0;
1064
1065         if (rt->dst_nocount)
1066                 flags |= DST_NOCOUNT;
1067         if (rt->dst_nopolicy)
1068                 flags |= DST_NOPOLICY;
1069
1070         return flags;
1071 }
1072
1073 static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
1074 {
1075         rt->dst.error = ip6_rt_type_to_error(fib6_type);
1076
1077         switch (fib6_type) {
1078         case RTN_BLACKHOLE:
1079                 rt->dst.output = dst_discard_out;
1080                 rt->dst.input = dst_discard;
1081                 break;
1082         case RTN_PROHIBIT:
1083                 rt->dst.output = ip6_pkt_prohibit_out;
1084                 rt->dst.input = ip6_pkt_prohibit;
1085                 break;
1086         case RTN_THROW:
1087         case RTN_UNREACHABLE:
1088         default:
1089                 rt->dst.output = ip6_pkt_discard_out;
1090                 rt->dst.input = ip6_pkt_discard;
1091                 break;
1092         }
1093 }
1094
1095 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
1096 {
1097         struct fib6_info *f6i = res->f6i;
1098
1099         if (res->fib6_flags & RTF_REJECT) {
1100                 ip6_rt_init_dst_reject(rt, res->fib6_type);
1101                 return;
1102         }
1103
1104         rt->dst.error = 0;
1105         rt->dst.output = ip6_output;
1106
1107         if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
1108                 rt->dst.input = ip6_input;
1109         } else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
1110                 rt->dst.input = ip6_mc_input;
1111         } else {
1112                 rt->dst.input = ip6_forward;
1113         }
1114
1115         if (res->nh->fib_nh_lws) {
1116                 rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws);
1117                 lwtunnel_set_redirect(&rt->dst);
1118         }
1119
1120         rt->dst.lastuse = jiffies;
1121 }
1122
1123 /* Caller must already hold reference to @from */
1124 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
1125 {
1126         rt->rt6i_flags &= ~RTF_EXPIRES;
1127         rcu_assign_pointer(rt->from, from);
1128         ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
1129 }
1130
1131 /* Caller must already hold reference to f6i in result */
1132 static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
1133 {
1134         const struct fib6_nh *nh = res->nh;
1135         const struct net_device *dev = nh->fib_nh_dev;
1136         struct fib6_info *f6i = res->f6i;
1137
1138         ip6_rt_init_dst(rt, res);
1139
1140         rt->rt6i_dst = f6i->fib6_dst;
1141         rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
1142         rt->rt6i_flags = res->fib6_flags;
1143         if (nh->fib_nh_gw_family) {
1144                 rt->rt6i_gateway = nh->fib_nh_gw6;
1145                 rt->rt6i_flags |= RTF_GATEWAY;
1146         }
1147         rt6_set_from(rt, f6i);
1148 #ifdef CONFIG_IPV6_SUBTREES
1149         rt->rt6i_src = f6i->fib6_src;
1150 #endif
1151 }
1152
1153 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
1154                                         struct in6_addr *saddr)
1155 {
1156         struct fib6_node *pn, *sn;
1157         while (1) {
1158                 if (fn->fn_flags & RTN_TL_ROOT)
1159                         return NULL;
1160                 pn = rcu_dereference(fn->parent);
1161                 sn = FIB6_SUBTREE(pn);
1162                 if (sn && sn != fn)
1163                         fn = fib6_node_lookup(sn, NULL, saddr);
1164                 else
1165                         fn = pn;
1166                 if (fn->fn_flags & RTN_RTINFO)
1167                         return fn;
1168         }
1169 }
1170
1171 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt)
1172 {
1173         struct rt6_info *rt = *prt;
1174
1175         if (dst_hold_safe(&rt->dst))
1176                 return true;
1177         if (net) {
1178                 rt = net->ipv6.ip6_null_entry;
1179                 dst_hold(&rt->dst);
1180         } else {
1181                 rt = NULL;
1182         }
1183         *prt = rt;
1184         return false;
1185 }
1186
1187 /* called with rcu_lock held */
1188 static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res)
1189 {
1190         struct net_device *dev = res->nh->fib_nh_dev;
1191         struct fib6_info *f6i = res->f6i;
1192         unsigned short flags;
1193         struct rt6_info *nrt;
1194
1195         if (!fib6_info_hold_safe(f6i))
1196                 goto fallback;
1197
1198         flags = fib6_info_dst_flags(f6i);
1199         nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
1200         if (!nrt) {
1201                 fib6_info_release(f6i);
1202                 goto fallback;
1203         }
1204
1205         ip6_rt_copy_init(nrt, res);
1206         return nrt;
1207
1208 fallback:
1209         nrt = dev_net(dev)->ipv6.ip6_null_entry;
1210         dst_hold(&nrt->dst);
1211         return nrt;
1212 }
1213
1214 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net,
1215                                              struct fib6_table *table,
1216                                              struct flowi6 *fl6,
1217                                              const struct sk_buff *skb,
1218                                              int flags)
1219 {
1220         struct fib6_result res = {};
1221         struct fib6_node *fn;
1222         struct rt6_info *rt;
1223
1224         rcu_read_lock();
1225         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1226 restart:
1227         res.f6i = rcu_dereference(fn->leaf);
1228         if (!res.f6i)
1229                 res.f6i = net->ipv6.fib6_null_entry;
1230         else
1231                 rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif,
1232                                  flags);
1233
1234         if (res.f6i == net->ipv6.fib6_null_entry) {
1235                 fn = fib6_backtrack(fn, &fl6->saddr);
1236                 if (fn)
1237                         goto restart;
1238
1239                 rt = net->ipv6.ip6_null_entry;
1240                 dst_hold(&rt->dst);
1241                 goto out;
1242         } else if (res.fib6_flags & RTF_REJECT) {
1243                 goto do_create;
1244         }
1245
1246         fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
1247                          fl6->flowi6_oif != 0, skb, flags);
1248
1249         /* Search through exception table */
1250         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
1251         if (rt) {
1252                 if (ip6_hold_safe(net, &rt))
1253                         dst_use_noref(&rt->dst, jiffies);
1254         } else {
1255 do_create:
1256                 rt = ip6_create_rt_rcu(&res);
1257         }
1258
1259 out:
1260         trace_fib6_table_lookup(net, &res, table, fl6);
1261
1262         rcu_read_unlock();
1263
1264         return rt;
1265 }
1266
1267 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
1268                                    const struct sk_buff *skb, int flags)
1269 {
1270         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
1271 }
1272 EXPORT_SYMBOL_GPL(ip6_route_lookup);
1273
1274 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
1275                             const struct in6_addr *saddr, int oif,
1276                             const struct sk_buff *skb, int strict)
1277 {
1278         struct flowi6 fl6 = {
1279                 .flowi6_oif = oif,
1280                 .daddr = *daddr,
1281         };
1282         struct dst_entry *dst;
1283         int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
1284
1285         if (saddr) {
1286                 memcpy(&fl6.saddr, saddr, sizeof(*saddr));
1287                 flags |= RT6_LOOKUP_F_HAS_SADDR;
1288         }
1289
1290         dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
1291         if (dst->error == 0)
1292                 return dst_rt6_info(dst);
1293
1294         dst_release(dst);
1295
1296         return NULL;
1297 }
1298 EXPORT_SYMBOL(rt6_lookup);
1299
1300 /* ip6_ins_rt is called with FREE table->tb6_lock.
1301  * It takes new route entry, the addition fails by any reason the
1302  * route is released.
1303  * Caller must hold dst before calling it.
1304  */
1305
1306 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
1307                         struct netlink_ext_ack *extack)
1308 {
1309         int err;
1310         struct fib6_table *table;
1311
1312         table = rt->fib6_table;
1313         spin_lock_bh(&table->tb6_lock);
1314         err = fib6_add(&table->tb6_root, rt, info, extack);
1315         spin_unlock_bh(&table->tb6_lock);
1316
1317         return err;
1318 }
1319
1320 int ip6_ins_rt(struct net *net, struct fib6_info *rt)
1321 {
1322         struct nl_info info = { .nl_net = net, };
1323
1324         return __ip6_ins_rt(rt, &info, NULL);
1325 }
1326
1327 static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res,
1328                                            const struct in6_addr *daddr,
1329                                            const struct in6_addr *saddr)
1330 {
1331         struct fib6_info *f6i = res->f6i;
1332         struct net_device *dev;
1333         struct rt6_info *rt;
1334
1335         /*
1336          *      Clone the route.
1337          */
1338
1339         if (!fib6_info_hold_safe(f6i))
1340                 return NULL;
1341
1342         dev = ip6_rt_get_dev_rcu(res);
1343         rt = ip6_dst_alloc(dev_net(dev), dev, 0);
1344         if (!rt) {
1345                 fib6_info_release(f6i);
1346                 return NULL;
1347         }
1348
1349         ip6_rt_copy_init(rt, res);
1350         rt->rt6i_flags |= RTF_CACHE;
1351         rt->rt6i_dst.addr = *daddr;
1352         rt->rt6i_dst.plen = 128;
1353
1354         if (!rt6_is_gw_or_nonexthop(res)) {
1355                 if (f6i->fib6_dst.plen != 128 &&
1356                     ipv6_addr_equal(&f6i->fib6_dst.addr, daddr))
1357                         rt->rt6i_flags |= RTF_ANYCAST;
1358 #ifdef CONFIG_IPV6_SUBTREES
1359                 if (rt->rt6i_src.plen && saddr) {
1360                         rt->rt6i_src.addr = *saddr;
1361                         rt->rt6i_src.plen = 128;
1362                 }
1363 #endif
1364         }
1365
1366         return rt;
1367 }
1368
1369 static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res)
1370 {
1371         struct fib6_info *f6i = res->f6i;
1372         unsigned short flags = fib6_info_dst_flags(f6i);
1373         struct net_device *dev;
1374         struct rt6_info *pcpu_rt;
1375
1376         if (!fib6_info_hold_safe(f6i))
1377                 return NULL;
1378
1379         rcu_read_lock();
1380         dev = ip6_rt_get_dev_rcu(res);
1381         pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT);
1382         rcu_read_unlock();
1383         if (!pcpu_rt) {
1384                 fib6_info_release(f6i);
1385                 return NULL;
1386         }
1387         ip6_rt_copy_init(pcpu_rt, res);
1388         pcpu_rt->rt6i_flags |= RTF_PCPU;
1389
1390         if (f6i->nh)
1391                 pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev));
1392
1393         return pcpu_rt;
1394 }
1395
1396 static bool rt6_is_valid(const struct rt6_info *rt6)
1397 {
1398         return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev));
1399 }
1400
1401 /* It should be called with rcu_read_lock() acquired */
1402 static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
1403 {
1404         struct rt6_info *pcpu_rt;
1405
1406         pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
1407
1408         if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) {
1409                 struct rt6_info *prev, **p;
1410
1411                 p = this_cpu_ptr(res->nh->rt6i_pcpu);
1412                 /* Paired with READ_ONCE() in __fib6_drop_pcpu_from() */
1413                 prev = xchg(p, NULL);
1414                 if (prev) {
1415                         dst_dev_put(&prev->dst);
1416                         dst_release(&prev->dst);
1417                 }
1418
1419                 pcpu_rt = NULL;
1420         }
1421
1422         return pcpu_rt;
1423 }
1424
1425 static struct rt6_info *rt6_make_pcpu_route(struct net *net,
1426                                             const struct fib6_result *res)
1427 {
1428         struct rt6_info *pcpu_rt, *prev, **p;
1429
1430         pcpu_rt = ip6_rt_pcpu_alloc(res);
1431         if (!pcpu_rt)
1432                 return NULL;
1433
1434         p = this_cpu_ptr(res->nh->rt6i_pcpu);
1435         prev = cmpxchg(p, NULL, pcpu_rt);
1436         BUG_ON(prev);
1437
1438         if (res->f6i->fib6_destroying) {
1439                 struct fib6_info *from;
1440
1441                 from = unrcu_pointer(xchg(&pcpu_rt->from, NULL));
1442                 fib6_info_release(from);
1443         }
1444
1445         return pcpu_rt;
1446 }
1447
1448 /* exception hash table implementation
1449  */
1450 static DEFINE_SPINLOCK(rt6_exception_lock);
1451
1452 /* Remove rt6_ex from hash table and free the memory
1453  * Caller must hold rt6_exception_lock
1454  */
1455 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
1456                                  struct rt6_exception *rt6_ex)
1457 {
1458         struct fib6_info *from;
1459         struct net *net;
1460
1461         if (!bucket || !rt6_ex)
1462                 return;
1463
1464         net = dev_net(rt6_ex->rt6i->dst.dev);
1465         net->ipv6.rt6_stats->fib_rt_cache--;
1466
1467         /* purge completely the exception to allow releasing the held resources:
1468          * some [sk] cache may keep the dst around for unlimited time
1469          */
1470         from = unrcu_pointer(xchg(&rt6_ex->rt6i->from, NULL));
1471         fib6_info_release(from);
1472         dst_dev_put(&rt6_ex->rt6i->dst);
1473
1474         hlist_del_rcu(&rt6_ex->hlist);
1475         dst_release(&rt6_ex->rt6i->dst);
1476         kfree_rcu(rt6_ex, rcu);
1477         WARN_ON_ONCE(!bucket->depth);
1478         bucket->depth--;
1479 }
1480
1481 /* Remove oldest rt6_ex in bucket and free the memory
1482  * Caller must hold rt6_exception_lock
1483  */
1484 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
1485 {
1486         struct rt6_exception *rt6_ex, *oldest = NULL;
1487
1488         if (!bucket)
1489                 return;
1490
1491         hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
1492                 if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
1493                         oldest = rt6_ex;
1494         }
1495         rt6_remove_exception(bucket, oldest);
1496 }
1497
1498 static u32 rt6_exception_hash(const struct in6_addr *dst,
1499                               const struct in6_addr *src)
1500 {
1501         static siphash_aligned_key_t rt6_exception_key;
1502         struct {
1503                 struct in6_addr dst;
1504                 struct in6_addr src;
1505         } __aligned(SIPHASH_ALIGNMENT) combined = {
1506                 .dst = *dst,
1507         };
1508         u64 val;
1509
1510         net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key));
1511
1512 #ifdef CONFIG_IPV6_SUBTREES
1513         if (src)
1514                 combined.src = *src;
1515 #endif
1516         val = siphash(&combined, sizeof(combined), &rt6_exception_key);
1517
1518         return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
1519 }
1520
1521 /* Helper function to find the cached rt in the hash table
1522  * and update bucket pointer to point to the bucket for this
1523  * (daddr, saddr) pair
1524  * Caller must hold rt6_exception_lock
1525  */
1526 static struct rt6_exception *
1527 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
1528                               const struct in6_addr *daddr,
1529                               const struct in6_addr *saddr)
1530 {
1531         struct rt6_exception *rt6_ex;
1532         u32 hval;
1533
1534         if (!(*bucket) || !daddr)
1535                 return NULL;
1536
1537         hval = rt6_exception_hash(daddr, saddr);
1538         *bucket += hval;
1539
1540         hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
1541                 struct rt6_info *rt6 = rt6_ex->rt6i;
1542                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1543
1544 #ifdef CONFIG_IPV6_SUBTREES
1545                 if (matched && saddr)
1546                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1547 #endif
1548                 if (matched)
1549                         return rt6_ex;
1550         }
1551         return NULL;
1552 }
1553
1554 /* Helper function to find the cached rt in the hash table
1555  * and update bucket pointer to point to the bucket for this
1556  * (daddr, saddr) pair
1557  * Caller must hold rcu_read_lock()
1558  */
1559 static struct rt6_exception *
1560 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
1561                          const struct in6_addr *daddr,
1562                          const struct in6_addr *saddr)
1563 {
1564         struct rt6_exception *rt6_ex;
1565         u32 hval;
1566
1567         WARN_ON_ONCE(!rcu_read_lock_held());
1568
1569         if (!(*bucket) || !daddr)
1570                 return NULL;
1571
1572         hval = rt6_exception_hash(daddr, saddr);
1573         *bucket += hval;
1574
1575         hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
1576                 struct rt6_info *rt6 = rt6_ex->rt6i;
1577                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1578
1579 #ifdef CONFIG_IPV6_SUBTREES
1580                 if (matched && saddr)
1581                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1582 #endif
1583                 if (matched)
1584                         return rt6_ex;
1585         }
1586         return NULL;
1587 }
1588
1589 static unsigned int fib6_mtu(const struct fib6_result *res)
1590 {
1591         const struct fib6_nh *nh = res->nh;
1592         unsigned int mtu;
1593
1594         if (res->f6i->fib6_pmtu) {
1595                 mtu = res->f6i->fib6_pmtu;
1596         } else {
1597                 struct net_device *dev = nh->fib_nh_dev;
1598                 struct inet6_dev *idev;
1599
1600                 rcu_read_lock();
1601                 idev = __in6_dev_get(dev);
1602                 mtu = READ_ONCE(idev->cnf.mtu6);
1603                 rcu_read_unlock();
1604         }
1605
1606         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
1607
1608         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
1609 }
1610
1611 #define FIB6_EXCEPTION_BUCKET_FLUSHED  0x1UL
1612
1613 /* used when the flushed bit is not relevant, only access to the bucket
1614  * (ie., all bucket users except rt6_insert_exception);
1615  *
1616  * called under rcu lock; sometimes called with rt6_exception_lock held
1617  */
1618 static
1619 struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh,
1620                                                        spinlock_t *lock)
1621 {
1622         struct rt6_exception_bucket *bucket;
1623
1624         if (lock)
1625                 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1626                                                    lockdep_is_held(lock));
1627         else
1628                 bucket = rcu_dereference(nh->rt6i_exception_bucket);
1629
1630         /* remove bucket flushed bit if set */
1631         if (bucket) {
1632                 unsigned long p = (unsigned long)bucket;
1633
1634                 p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED;
1635                 bucket = (struct rt6_exception_bucket *)p;
1636         }
1637
1638         return bucket;
1639 }
1640
1641 static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket)
1642 {
1643         unsigned long p = (unsigned long)bucket;
1644
1645         return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED);
1646 }
1647
1648 /* called with rt6_exception_lock held */
1649 static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh,
1650                                               spinlock_t *lock)
1651 {
1652         struct rt6_exception_bucket *bucket;
1653         unsigned long p;
1654
1655         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1656                                            lockdep_is_held(lock));
1657
1658         p = (unsigned long)bucket;
1659         p |= FIB6_EXCEPTION_BUCKET_FLUSHED;
1660         bucket = (struct rt6_exception_bucket *)p;
1661         rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1662 }
1663
1664 static int rt6_insert_exception(struct rt6_info *nrt,
1665                                 const struct fib6_result *res)
1666 {
1667         struct net *net = dev_net(nrt->dst.dev);
1668         struct rt6_exception_bucket *bucket;
1669         struct fib6_info *f6i = res->f6i;
1670         struct in6_addr *src_key = NULL;
1671         struct rt6_exception *rt6_ex;
1672         struct fib6_nh *nh = res->nh;
1673         int max_depth;
1674         int err = 0;
1675
1676         spin_lock_bh(&rt6_exception_lock);
1677
1678         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1679                                           lockdep_is_held(&rt6_exception_lock));
1680         if (!bucket) {
1681                 bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
1682                                  GFP_ATOMIC);
1683                 if (!bucket) {
1684                         err = -ENOMEM;
1685                         goto out;
1686                 }
1687                 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1688         } else if (fib6_nh_excptn_bucket_flushed(bucket)) {
1689                 err = -EINVAL;
1690                 goto out;
1691         }
1692
1693 #ifdef CONFIG_IPV6_SUBTREES
1694         /* fib6_src.plen != 0 indicates f6i is in subtree
1695          * and exception table is indexed by a hash of
1696          * both fib6_dst and fib6_src.
1697          * Otherwise, the exception table is indexed by
1698          * a hash of only fib6_dst.
1699          */
1700         if (f6i->fib6_src.plen)
1701                 src_key = &nrt->rt6i_src.addr;
1702 #endif
1703         /* rt6_mtu_change() might lower mtu on f6i.
1704          * Only insert this exception route if its mtu
1705          * is less than f6i's mtu value.
1706          */
1707         if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) {
1708                 err = -EINVAL;
1709                 goto out;
1710         }
1711
1712         rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
1713                                                src_key);
1714         if (rt6_ex)
1715                 rt6_remove_exception(bucket, rt6_ex);
1716
1717         rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
1718         if (!rt6_ex) {
1719                 err = -ENOMEM;
1720                 goto out;
1721         }
1722         rt6_ex->rt6i = nrt;
1723         rt6_ex->stamp = jiffies;
1724         hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
1725         bucket->depth++;
1726         net->ipv6.rt6_stats->fib_rt_cache++;
1727
1728         /* Randomize max depth to avoid some side channels attacks. */
1729         max_depth = FIB6_MAX_DEPTH + get_random_u32_below(FIB6_MAX_DEPTH);
1730         while (bucket->depth > max_depth)
1731                 rt6_exception_remove_oldest(bucket);
1732
1733 out:
1734         spin_unlock_bh(&rt6_exception_lock);
1735
1736         /* Update fn->fn_sernum to invalidate all cached dst */
1737         if (!err) {
1738                 spin_lock_bh(&f6i->fib6_table->tb6_lock);
1739                 fib6_update_sernum(net, f6i);
1740                 spin_unlock_bh(&f6i->fib6_table->tb6_lock);
1741                 fib6_force_start_gc(net);
1742         }
1743
1744         return err;
1745 }
1746
1747 static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
1748 {
1749         struct rt6_exception_bucket *bucket;
1750         struct rt6_exception *rt6_ex;
1751         struct hlist_node *tmp;
1752         int i;
1753
1754         spin_lock_bh(&rt6_exception_lock);
1755
1756         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1757         if (!bucket)
1758                 goto out;
1759
1760         /* Prevent rt6_insert_exception() to recreate the bucket list */
1761         if (!from)
1762                 fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock);
1763
1764         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1765                 hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) {
1766                         if (!from ||
1767                             rcu_access_pointer(rt6_ex->rt6i->from) == from)
1768                                 rt6_remove_exception(bucket, rt6_ex);
1769                 }
1770                 WARN_ON_ONCE(!from && bucket->depth);
1771                 bucket++;
1772         }
1773 out:
1774         spin_unlock_bh(&rt6_exception_lock);
1775 }
1776
1777 static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg)
1778 {
1779         struct fib6_info *f6i = arg;
1780
1781         fib6_nh_flush_exceptions(nh, f6i);
1782
1783         return 0;
1784 }
1785
1786 void rt6_flush_exceptions(struct fib6_info *f6i)
1787 {
1788         if (f6i->nh)
1789                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions,
1790                                          f6i);
1791         else
1792                 fib6_nh_flush_exceptions(f6i->fib6_nh, f6i);
1793 }
1794
1795 /* Find cached rt in the hash table inside passed in rt
1796  * Caller has to hold rcu_read_lock()
1797  */
1798 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
1799                                            const struct in6_addr *daddr,
1800                                            const struct in6_addr *saddr)
1801 {
1802         const struct in6_addr *src_key = NULL;
1803         struct rt6_exception_bucket *bucket;
1804         struct rt6_exception *rt6_ex;
1805         struct rt6_info *ret = NULL;
1806
1807 #ifdef CONFIG_IPV6_SUBTREES
1808         /* fib6i_src.plen != 0 indicates f6i is in subtree
1809          * and exception table is indexed by a hash of
1810          * both fib6_dst and fib6_src.
1811          * However, the src addr used to create the hash
1812          * might not be exactly the passed in saddr which
1813          * is a /128 addr from the flow.
1814          * So we need to use f6i->fib6_src to redo lookup
1815          * if the passed in saddr does not find anything.
1816          * (See the logic in ip6_rt_cache_alloc() on how
1817          * rt->rt6i_src is updated.)
1818          */
1819         if (res->f6i->fib6_src.plen)
1820                 src_key = saddr;
1821 find_ex:
1822 #endif
1823         bucket = fib6_nh_get_excptn_bucket(res->nh, NULL);
1824         rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
1825
1826         if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
1827                 ret = rt6_ex->rt6i;
1828
1829 #ifdef CONFIG_IPV6_SUBTREES
1830         /* Use fib6_src as src_key and redo lookup */
1831         if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) {
1832                 src_key = &res->f6i->fib6_src.addr;
1833                 goto find_ex;
1834         }
1835 #endif
1836
1837         return ret;
1838 }
1839
1840 /* Remove the passed in cached rt from the hash table that contains it */
1841 static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen,
1842                                     const struct rt6_info *rt)
1843 {
1844         const struct in6_addr *src_key = NULL;
1845         struct rt6_exception_bucket *bucket;
1846         struct rt6_exception *rt6_ex;
1847         int err;
1848
1849         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
1850                 return -ENOENT;
1851
1852         spin_lock_bh(&rt6_exception_lock);
1853         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1854
1855 #ifdef CONFIG_IPV6_SUBTREES
1856         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1857          * and exception table is indexed by a hash of
1858          * both rt6i_dst and rt6i_src.
1859          * Otherwise, the exception table is indexed by
1860          * a hash of only rt6i_dst.
1861          */
1862         if (plen)
1863                 src_key = &rt->rt6i_src.addr;
1864 #endif
1865         rt6_ex = __rt6_find_exception_spinlock(&bucket,
1866                                                &rt->rt6i_dst.addr,
1867                                                src_key);
1868         if (rt6_ex) {
1869                 rt6_remove_exception(bucket, rt6_ex);
1870                 err = 0;
1871         } else {
1872                 err = -ENOENT;
1873         }
1874
1875         spin_unlock_bh(&rt6_exception_lock);
1876         return err;
1877 }
1878
1879 struct fib6_nh_excptn_arg {
1880         struct rt6_info *rt;
1881         int             plen;
1882 };
1883
1884 static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg)
1885 {
1886         struct fib6_nh_excptn_arg *arg = _arg;
1887         int err;
1888
1889         err = fib6_nh_remove_exception(nh, arg->plen, arg->rt);
1890         if (err == 0)
1891                 return 1;
1892
1893         return 0;
1894 }
1895
1896 static int rt6_remove_exception_rt(struct rt6_info *rt)
1897 {
1898         struct fib6_info *from;
1899
1900         from = rcu_dereference(rt->from);
1901         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1902                 return -EINVAL;
1903
1904         if (from->nh) {
1905                 struct fib6_nh_excptn_arg arg = {
1906                         .rt = rt,
1907                         .plen = from->fib6_src.plen
1908                 };
1909                 int rc;
1910
1911                 /* rc = 1 means an entry was found */
1912                 rc = nexthop_for_each_fib6_nh(from->nh,
1913                                               rt6_nh_remove_exception_rt,
1914                                               &arg);
1915                 return rc ? 0 : -ENOENT;
1916         }
1917
1918         return fib6_nh_remove_exception(from->fib6_nh,
1919                                         from->fib6_src.plen, rt);
1920 }
1921
1922 /* Find rt6_ex which contains the passed in rt cache and
1923  * refresh its stamp
1924  */
1925 static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen,
1926                                      const struct rt6_info *rt)
1927 {
1928         const struct in6_addr *src_key = NULL;
1929         struct rt6_exception_bucket *bucket;
1930         struct rt6_exception *rt6_ex;
1931
1932         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
1933 #ifdef CONFIG_IPV6_SUBTREES
1934         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1935          * and exception table is indexed by a hash of
1936          * both rt6i_dst and rt6i_src.
1937          * Otherwise, the exception table is indexed by
1938          * a hash of only rt6i_dst.
1939          */
1940         if (plen)
1941                 src_key = &rt->rt6i_src.addr;
1942 #endif
1943         rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
1944         if (rt6_ex)
1945                 rt6_ex->stamp = jiffies;
1946 }
1947
1948 struct fib6_nh_match_arg {
1949         const struct net_device *dev;
1950         const struct in6_addr   *gw;
1951         struct fib6_nh          *match;
1952 };
1953
1954 /* determine if fib6_nh has given device and gateway */
1955 static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg)
1956 {
1957         struct fib6_nh_match_arg *arg = _arg;
1958
1959         if (arg->dev != nh->fib_nh_dev ||
1960             (arg->gw && !nh->fib_nh_gw_family) ||
1961             (!arg->gw && nh->fib_nh_gw_family) ||
1962             (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6)))
1963                 return 0;
1964
1965         arg->match = nh;
1966
1967         /* found a match, break the loop */
1968         return 1;
1969 }
1970
1971 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
1972 {
1973         struct fib6_info *from;
1974         struct fib6_nh *fib6_nh;
1975
1976         rcu_read_lock();
1977
1978         from = rcu_dereference(rt->from);
1979         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1980                 goto unlock;
1981
1982         if (from->nh) {
1983                 struct fib6_nh_match_arg arg = {
1984                         .dev = rt->dst.dev,
1985                         .gw = &rt->rt6i_gateway,
1986                 };
1987
1988                 nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
1989
1990                 if (!arg.match)
1991                         goto unlock;
1992                 fib6_nh = arg.match;
1993         } else {
1994                 fib6_nh = from->fib6_nh;
1995         }
1996         fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt);
1997 unlock:
1998         rcu_read_unlock();
1999 }
2000
2001 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
2002                                          struct rt6_info *rt, int mtu)
2003 {
2004         /* If the new MTU is lower than the route PMTU, this new MTU will be the
2005          * lowest MTU in the path: always allow updating the route PMTU to
2006          * reflect PMTU decreases.
2007          *
2008          * If the new MTU is higher, and the route PMTU is equal to the local
2009          * MTU, this means the old MTU is the lowest in the path, so allow
2010          * updating it: if other nodes now have lower MTUs, PMTU discovery will
2011          * handle this.
2012          */
2013
2014         if (dst_mtu(&rt->dst) >= mtu)
2015                 return true;
2016
2017         if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
2018                 return true;
2019
2020         return false;
2021 }
2022
2023 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
2024                                        const struct fib6_nh *nh, int mtu)
2025 {
2026         struct rt6_exception_bucket *bucket;
2027         struct rt6_exception *rt6_ex;
2028         int i;
2029
2030         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2031         if (!bucket)
2032                 return;
2033
2034         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2035                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
2036                         struct rt6_info *entry = rt6_ex->rt6i;
2037
2038                         /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
2039                          * route), the metrics of its rt->from have already
2040                          * been updated.
2041                          */
2042                         if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
2043                             rt6_mtu_change_route_allowed(idev, entry, mtu))
2044                                 dst_metric_set(&entry->dst, RTAX_MTU, mtu);
2045                 }
2046                 bucket++;
2047         }
2048 }
2049
2050 #define RTF_CACHE_GATEWAY       (RTF_GATEWAY | RTF_CACHE)
2051
2052 static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh,
2053                                             const struct in6_addr *gateway)
2054 {
2055         struct rt6_exception_bucket *bucket;
2056         struct rt6_exception *rt6_ex;
2057         struct hlist_node *tmp;
2058         int i;
2059
2060         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2061                 return;
2062
2063         spin_lock_bh(&rt6_exception_lock);
2064         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2065         if (bucket) {
2066                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2067                         hlist_for_each_entry_safe(rt6_ex, tmp,
2068                                                   &bucket->chain, hlist) {
2069                                 struct rt6_info *entry = rt6_ex->rt6i;
2070
2071                                 if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
2072                                     RTF_CACHE_GATEWAY &&
2073                                     ipv6_addr_equal(gateway,
2074                                                     &entry->rt6i_gateway)) {
2075                                         rt6_remove_exception(bucket, rt6_ex);
2076                                 }
2077                         }
2078                         bucket++;
2079                 }
2080         }
2081
2082         spin_unlock_bh(&rt6_exception_lock);
2083 }
2084
2085 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
2086                                       struct rt6_exception *rt6_ex,
2087                                       struct fib6_gc_args *gc_args,
2088                                       unsigned long now)
2089 {
2090         struct rt6_info *rt = rt6_ex->rt6i;
2091
2092         /* we are pruning and obsoleting aged-out and non gateway exceptions
2093          * even if others have still references to them, so that on next
2094          * dst_check() such references can be dropped.
2095          * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
2096          * expired, independently from their aging, as per RFC 8201 section 4
2097          */
2098         if (!(rt->rt6i_flags & RTF_EXPIRES)) {
2099                 if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
2100                         pr_debug("aging clone %p\n", rt);
2101                         rt6_remove_exception(bucket, rt6_ex);
2102                         return;
2103                 }
2104         } else if (time_after(jiffies, rt->dst.expires)) {
2105                 pr_debug("purging expired route %p\n", rt);
2106                 rt6_remove_exception(bucket, rt6_ex);
2107                 return;
2108         }
2109
2110         if (rt->rt6i_flags & RTF_GATEWAY) {
2111                 struct neighbour *neigh;
2112
2113                 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
2114
2115                 if (!(neigh && (neigh->flags & NTF_ROUTER))) {
2116                         pr_debug("purging route %p via non-router but gateway\n",
2117                                  rt);
2118                         rt6_remove_exception(bucket, rt6_ex);
2119                         return;
2120                 }
2121         }
2122
2123         gc_args->more++;
2124 }
2125
2126 static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
2127                                    struct fib6_gc_args *gc_args,
2128                                    unsigned long now)
2129 {
2130         struct rt6_exception_bucket *bucket;
2131         struct rt6_exception *rt6_ex;
2132         struct hlist_node *tmp;
2133         int i;
2134
2135         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2136                 return;
2137
2138         rcu_read_lock_bh();
2139         spin_lock(&rt6_exception_lock);
2140         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2141         if (bucket) {
2142                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2143                         hlist_for_each_entry_safe(rt6_ex, tmp,
2144                                                   &bucket->chain, hlist) {
2145                                 rt6_age_examine_exception(bucket, rt6_ex,
2146                                                           gc_args, now);
2147                         }
2148                         bucket++;
2149                 }
2150         }
2151         spin_unlock(&rt6_exception_lock);
2152         rcu_read_unlock_bh();
2153 }
2154
2155 struct fib6_nh_age_excptn_arg {
2156         struct fib6_gc_args     *gc_args;
2157         unsigned long           now;
2158 };
2159
2160 static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg)
2161 {
2162         struct fib6_nh_age_excptn_arg *arg = _arg;
2163
2164         fib6_nh_age_exceptions(nh, arg->gc_args, arg->now);
2165         return 0;
2166 }
2167
2168 void rt6_age_exceptions(struct fib6_info *f6i,
2169                         struct fib6_gc_args *gc_args,
2170                         unsigned long now)
2171 {
2172         if (f6i->nh) {
2173                 struct fib6_nh_age_excptn_arg arg = {
2174                         .gc_args = gc_args,
2175                         .now = now
2176                 };
2177
2178                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions,
2179                                          &arg);
2180         } else {
2181                 fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now);
2182         }
2183 }
2184
2185 /* must be called with rcu lock held */
2186 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
2187                       struct flowi6 *fl6, struct fib6_result *res, int strict)
2188 {
2189         struct fib6_node *fn, *saved_fn;
2190
2191         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
2192         saved_fn = fn;
2193
2194 redo_rt6_select:
2195         rt6_select(net, fn, oif, res, strict);
2196         if (res->f6i == net->ipv6.fib6_null_entry) {
2197                 fn = fib6_backtrack(fn, &fl6->saddr);
2198                 if (fn)
2199                         goto redo_rt6_select;
2200                 else if (strict & RT6_LOOKUP_F_REACHABLE) {
2201                         /* also consider unreachable route */
2202                         strict &= ~RT6_LOOKUP_F_REACHABLE;
2203                         fn = saved_fn;
2204                         goto redo_rt6_select;
2205                 }
2206         }
2207
2208         trace_fib6_table_lookup(net, res, table, fl6);
2209
2210         return 0;
2211 }
2212
2213 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
2214                                int oif, struct flowi6 *fl6,
2215                                const struct sk_buff *skb, int flags)
2216 {
2217         struct fib6_result res = {};
2218         struct rt6_info *rt = NULL;
2219         int strict = 0;
2220
2221         WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
2222                      !rcu_read_lock_held());
2223
2224         strict |= flags & RT6_LOOKUP_F_IFACE;
2225         strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
2226         if (READ_ONCE(net->ipv6.devconf_all->forwarding) == 0)
2227                 strict |= RT6_LOOKUP_F_REACHABLE;
2228
2229         rcu_read_lock();
2230
2231         fib6_table_lookup(net, table, oif, fl6, &res, strict);
2232         if (res.f6i == net->ipv6.fib6_null_entry)
2233                 goto out;
2234
2235         fib6_select_path(net, &res, fl6, oif, false, skb, strict);
2236
2237         /*Search through exception table */
2238         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
2239         if (rt) {
2240                 goto out;
2241         } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
2242                             !res.nh->fib_nh_gw_family)) {
2243                 /* Create a RTF_CACHE clone which will not be
2244                  * owned by the fib6 tree.  It is for the special case where
2245                  * the daddr in the skb during the neighbor look-up is different
2246                  * from the fl6->daddr used to look-up route here.
2247                  */
2248                 rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
2249
2250                 if (rt) {
2251                         /* 1 refcnt is taken during ip6_rt_cache_alloc().
2252                          * As rt6_uncached_list_add() does not consume refcnt,
2253                          * this refcnt is always returned to the caller even
2254                          * if caller sets RT6_LOOKUP_F_DST_NOREF flag.
2255                          */
2256                         rt6_uncached_list_add(rt);
2257                         rcu_read_unlock();
2258
2259                         return rt;
2260                 }
2261         } else {
2262                 /* Get a percpu copy */
2263                 local_bh_disable();
2264                 rt = rt6_get_pcpu_route(&res);
2265
2266                 if (!rt)
2267                         rt = rt6_make_pcpu_route(net, &res);
2268
2269                 local_bh_enable();
2270         }
2271 out:
2272         if (!rt)
2273                 rt = net->ipv6.ip6_null_entry;
2274         if (!(flags & RT6_LOOKUP_F_DST_NOREF))
2275                 ip6_hold_safe(net, &rt);
2276         rcu_read_unlock();
2277
2278         return rt;
2279 }
2280 EXPORT_SYMBOL_GPL(ip6_pol_route);
2281
2282 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net,
2283                                             struct fib6_table *table,
2284                                             struct flowi6 *fl6,
2285                                             const struct sk_buff *skb,
2286                                             int flags)
2287 {
2288         return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
2289 }
2290
2291 struct dst_entry *ip6_route_input_lookup(struct net *net,
2292                                          struct net_device *dev,
2293                                          struct flowi6 *fl6,
2294                                          const struct sk_buff *skb,
2295                                          int flags)
2296 {
2297         if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
2298                 flags |= RT6_LOOKUP_F_IFACE;
2299
2300         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
2301 }
2302 EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
2303
2304 static void ip6_multipath_l3_keys(const struct sk_buff *skb,
2305                                   struct flow_keys *keys,
2306                                   struct flow_keys *flkeys)
2307 {
2308         const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
2309         const struct ipv6hdr *key_iph = outer_iph;
2310         struct flow_keys *_flkeys = flkeys;
2311         const struct ipv6hdr *inner_iph;
2312         const struct icmp6hdr *icmph;
2313         struct ipv6hdr _inner_iph;
2314         struct icmp6hdr _icmph;
2315
2316         if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
2317                 goto out;
2318
2319         icmph = skb_header_pointer(skb, skb_transport_offset(skb),
2320                                    sizeof(_icmph), &_icmph);
2321         if (!icmph)
2322                 goto out;
2323
2324         if (!icmpv6_is_err(icmph->icmp6_type))
2325                 goto out;
2326
2327         inner_iph = skb_header_pointer(skb,
2328                                        skb_transport_offset(skb) + sizeof(*icmph),
2329                                        sizeof(_inner_iph), &_inner_iph);
2330         if (!inner_iph)
2331                 goto out;
2332
2333         key_iph = inner_iph;
2334         _flkeys = NULL;
2335 out:
2336         if (_flkeys) {
2337                 keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
2338                 keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
2339                 keys->tags.flow_label = _flkeys->tags.flow_label;
2340                 keys->basic.ip_proto = _flkeys->basic.ip_proto;
2341         } else {
2342                 keys->addrs.v6addrs.src = key_iph->saddr;
2343                 keys->addrs.v6addrs.dst = key_iph->daddr;
2344                 keys->tags.flow_label = ip6_flowlabel(key_iph);
2345                 keys->basic.ip_proto = key_iph->nexthdr;
2346         }
2347 }
2348
2349 static u32 rt6_multipath_custom_hash_outer(const struct net *net,
2350                                            const struct sk_buff *skb,
2351                                            bool *p_has_inner)
2352 {
2353         u32 hash_fields = ip6_multipath_hash_fields(net);
2354         struct flow_keys keys, hash_keys;
2355
2356         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2357                 return 0;
2358
2359         memset(&hash_keys, 0, sizeof(hash_keys));
2360         skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
2361
2362         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2363         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2364                 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2365         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2366                 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2367         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2368                 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2369         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2370                 hash_keys.tags.flow_label = keys.tags.flow_label;
2371         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2372                 hash_keys.ports.src = keys.ports.src;
2373         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2374                 hash_keys.ports.dst = keys.ports.dst;
2375
2376         *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
2377         return fib_multipath_hash_from_keys(net, &hash_keys);
2378 }
2379
2380 static u32 rt6_multipath_custom_hash_inner(const struct net *net,
2381                                            const struct sk_buff *skb,
2382                                            bool has_inner)
2383 {
2384         u32 hash_fields = ip6_multipath_hash_fields(net);
2385         struct flow_keys keys, hash_keys;
2386
2387         /* We assume the packet carries an encapsulation, but if none was
2388          * encountered during dissection of the outer flow, then there is no
2389          * point in calling the flow dissector again.
2390          */
2391         if (!has_inner)
2392                 return 0;
2393
2394         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
2395                 return 0;
2396
2397         memset(&hash_keys, 0, sizeof(hash_keys));
2398         skb_flow_dissect_flow_keys(skb, &keys, 0);
2399
2400         if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
2401                 return 0;
2402
2403         if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2404                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2405                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2406                         hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2407                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2408                         hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2409         } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2410                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2411                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2412                         hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2413                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2414                         hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2415                 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
2416                         hash_keys.tags.flow_label = keys.tags.flow_label;
2417         }
2418
2419         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
2420                 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2421         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
2422                 hash_keys.ports.src = keys.ports.src;
2423         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
2424                 hash_keys.ports.dst = keys.ports.dst;
2425
2426         return fib_multipath_hash_from_keys(net, &hash_keys);
2427 }
2428
2429 static u32 rt6_multipath_custom_hash_skb(const struct net *net,
2430                                          const struct sk_buff *skb)
2431 {
2432         u32 mhash, mhash_inner;
2433         bool has_inner = true;
2434
2435         mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner);
2436         mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner);
2437
2438         return jhash_2words(mhash, mhash_inner, 0);
2439 }
2440
2441 static u32 rt6_multipath_custom_hash_fl6(const struct net *net,
2442                                          const struct flowi6 *fl6)
2443 {
2444         u32 hash_fields = ip6_multipath_hash_fields(net);
2445         struct flow_keys hash_keys;
2446
2447         if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2448                 return 0;
2449
2450         memset(&hash_keys, 0, sizeof(hash_keys));
2451         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2452         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2453                 hash_keys.addrs.v6addrs.src = fl6->saddr;
2454         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2455                 hash_keys.addrs.v6addrs.dst = fl6->daddr;
2456         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2457                 hash_keys.basic.ip_proto = fl6->flowi6_proto;
2458         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2459                 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2460         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2461                 hash_keys.ports.src = fl6->fl6_sport;
2462         if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2463                 hash_keys.ports.dst = fl6->fl6_dport;
2464
2465         return fib_multipath_hash_from_keys(net, &hash_keys);
2466 }
2467
2468 /* if skb is set it will be used and fl6 can be NULL */
2469 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
2470                        const struct sk_buff *skb, struct flow_keys *flkeys)
2471 {
2472         struct flow_keys hash_keys;
2473         u32 mhash = 0;
2474
2475         switch (ip6_multipath_hash_policy(net)) {
2476         case 0:
2477                 memset(&hash_keys, 0, sizeof(hash_keys));
2478                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2479                 if (skb) {
2480                         ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2481                 } else {
2482                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2483                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2484                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2485                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2486                 }
2487                 mhash = fib_multipath_hash_from_keys(net, &hash_keys);
2488                 break;
2489         case 1:
2490                 if (skb) {
2491                         unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2492                         struct flow_keys keys;
2493
2494                         /* short-circuit if we already have L4 hash present */
2495                         if (skb->l4_hash)
2496                                 return skb_get_hash_raw(skb) >> 1;
2497
2498                         memset(&hash_keys, 0, sizeof(hash_keys));
2499
2500                         if (!flkeys) {
2501                                 skb_flow_dissect_flow_keys(skb, &keys, flag);
2502                                 flkeys = &keys;
2503                         }
2504                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2505                         hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2506                         hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2507                         hash_keys.ports.src = flkeys->ports.src;
2508                         hash_keys.ports.dst = flkeys->ports.dst;
2509                         hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2510                 } else {
2511                         memset(&hash_keys, 0, sizeof(hash_keys));
2512                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2513                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2514                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2515                         hash_keys.ports.src = fl6->fl6_sport;
2516                         hash_keys.ports.dst = fl6->fl6_dport;
2517                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2518                 }
2519                 mhash = fib_multipath_hash_from_keys(net, &hash_keys);
2520                 break;
2521         case 2:
2522                 memset(&hash_keys, 0, sizeof(hash_keys));
2523                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2524                 if (skb) {
2525                         struct flow_keys keys;
2526
2527                         if (!flkeys) {
2528                                 skb_flow_dissect_flow_keys(skb, &keys, 0);
2529                                 flkeys = &keys;
2530                         }
2531
2532                         /* Inner can be v4 or v6 */
2533                         if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2534                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2535                                 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2536                                 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2537                         } else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2538                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2539                                 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2540                                 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2541                                 hash_keys.tags.flow_label = flkeys->tags.flow_label;
2542                                 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2543                         } else {
2544                                 /* Same as case 0 */
2545                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2546                                 ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2547                         }
2548                 } else {
2549                         /* Same as case 0 */
2550                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2551                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2552                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2553                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2554                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2555                 }
2556                 mhash = fib_multipath_hash_from_keys(net, &hash_keys);
2557                 break;
2558         case 3:
2559                 if (skb)
2560                         mhash = rt6_multipath_custom_hash_skb(net, skb);
2561                 else
2562                         mhash = rt6_multipath_custom_hash_fl6(net, fl6);
2563                 break;
2564         }
2565
2566         return mhash >> 1;
2567 }
2568
2569 /* Called with rcu held */
2570 void ip6_route_input(struct sk_buff *skb)
2571 {
2572         const struct ipv6hdr *iph = ipv6_hdr(skb);
2573         struct net *net = dev_net(skb->dev);
2574         int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF;
2575         struct ip_tunnel_info *tun_info;
2576         struct flowi6 fl6 = {
2577                 .flowi6_iif = skb->dev->ifindex,
2578                 .daddr = iph->daddr,
2579                 .saddr = iph->saddr,
2580                 .flowlabel = ip6_flowinfo(iph),
2581                 .flowi6_mark = skb->mark,
2582                 .flowi6_proto = iph->nexthdr,
2583         };
2584         struct flow_keys *flkeys = NULL, _flkeys;
2585
2586         tun_info = skb_tunnel_info(skb);
2587         if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2588                 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
2589
2590         if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
2591                 flkeys = &_flkeys;
2592
2593         if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
2594                 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
2595         skb_dst_drop(skb);
2596         skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev,
2597                                                       &fl6, skb, flags));
2598 }
2599
2600 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net,
2601                                              struct fib6_table *table,
2602                                              struct flowi6 *fl6,
2603                                              const struct sk_buff *skb,
2604                                              int flags)
2605 {
2606         return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
2607 }
2608
2609 static struct dst_entry *ip6_route_output_flags_noref(struct net *net,
2610                                                       const struct sock *sk,
2611                                                       struct flowi6 *fl6,
2612                                                       int flags)
2613 {
2614         bool any_src;
2615
2616         if (ipv6_addr_type(&fl6->daddr) &
2617             (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
2618                 struct dst_entry *dst;
2619
2620                 /* This function does not take refcnt on the dst */
2621                 dst = l3mdev_link_scope_lookup(net, fl6);
2622                 if (dst)
2623                         return dst;
2624         }
2625
2626         fl6->flowi6_iif = LOOPBACK_IFINDEX;
2627
2628         flags |= RT6_LOOKUP_F_DST_NOREF;
2629         any_src = ipv6_addr_any(&fl6->saddr);
2630         if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
2631             (fl6->flowi6_oif && any_src))
2632                 flags |= RT6_LOOKUP_F_IFACE;
2633
2634         if (!any_src)
2635                 flags |= RT6_LOOKUP_F_HAS_SADDR;
2636         else if (sk)
2637                 flags |= rt6_srcprefs2flags(READ_ONCE(inet6_sk(sk)->srcprefs));
2638
2639         return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
2640 }
2641
2642 struct dst_entry *ip6_route_output_flags(struct net *net,
2643                                          const struct sock *sk,
2644                                          struct flowi6 *fl6,
2645                                          int flags)
2646 {
2647         struct dst_entry *dst;
2648         struct rt6_info *rt6;
2649
2650         rcu_read_lock();
2651         dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
2652         rt6 = dst_rt6_info(dst);
2653         /* For dst cached in uncached_list, refcnt is already taken. */
2654         if (list_empty(&rt6->dst.rt_uncached) && !dst_hold_safe(dst)) {
2655                 dst = &net->ipv6.ip6_null_entry->dst;
2656                 dst_hold(dst);
2657         }
2658         rcu_read_unlock();
2659
2660         return dst;
2661 }
2662 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
2663
2664 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2665 {
2666         struct rt6_info *rt, *ort = dst_rt6_info(dst_orig);
2667         struct net_device *loopback_dev = net->loopback_dev;
2668         struct dst_entry *new = NULL;
2669
2670         rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev,
2671                        DST_OBSOLETE_DEAD, 0);
2672         if (rt) {
2673                 rt6_info_init(rt);
2674                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
2675
2676                 new = &rt->dst;
2677                 new->__use = 1;
2678                 new->input = dst_discard;
2679                 new->output = dst_discard_out;
2680
2681                 dst_copy_metrics(new, &ort->dst);
2682
2683                 rt->rt6i_idev = in6_dev_get(loopback_dev);
2684                 rt->rt6i_gateway = ort->rt6i_gateway;
2685                 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
2686
2687                 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
2688 #ifdef CONFIG_IPV6_SUBTREES
2689                 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
2690 #endif
2691         }
2692
2693         dst_release(dst_orig);
2694         return new ? new : ERR_PTR(-ENOMEM);
2695 }
2696
2697 /*
2698  *      Destination cache support functions
2699  */
2700
2701 static bool fib6_check(struct fib6_info *f6i, u32 cookie)
2702 {
2703         u32 rt_cookie = 0;
2704
2705         if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
2706                 return false;
2707
2708         if (fib6_check_expired(f6i))
2709                 return false;
2710
2711         return true;
2712 }
2713
2714 static struct dst_entry *rt6_check(struct rt6_info *rt,
2715                                    struct fib6_info *from,
2716                                    u32 cookie)
2717 {
2718         u32 rt_cookie = 0;
2719
2720         if (!from || !fib6_get_cookie_safe(from, &rt_cookie) ||
2721             rt_cookie != cookie)
2722                 return NULL;
2723
2724         if (rt6_check_expired(rt))
2725                 return NULL;
2726
2727         return &rt->dst;
2728 }
2729
2730 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
2731                                             struct fib6_info *from,
2732                                             u32 cookie)
2733 {
2734         if (!__rt6_check_expired(rt) &&
2735             rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
2736             fib6_check(from, cookie))
2737                 return &rt->dst;
2738         else
2739                 return NULL;
2740 }
2741
2742 INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst,
2743                                                         u32 cookie)
2744 {
2745         struct dst_entry *dst_ret;
2746         struct fib6_info *from;
2747         struct rt6_info *rt;
2748
2749         rt = dst_rt6_info(dst);
2750
2751         if (rt->sernum)
2752                 return rt6_is_valid(rt) ? dst : NULL;
2753
2754         rcu_read_lock();
2755
2756         /* All IPV6 dsts are created with ->obsolete set to the value
2757          * DST_OBSOLETE_FORCE_CHK which forces validation calls down
2758          * into this function always.
2759          */
2760
2761         from = rcu_dereference(rt->from);
2762
2763         if (from && (rt->rt6i_flags & RTF_PCPU ||
2764             unlikely(!list_empty(&rt->dst.rt_uncached))))
2765                 dst_ret = rt6_dst_from_check(rt, from, cookie);
2766         else
2767                 dst_ret = rt6_check(rt, from, cookie);
2768
2769         rcu_read_unlock();
2770
2771         return dst_ret;
2772 }
2773 EXPORT_INDIRECT_CALLABLE(ip6_dst_check);
2774
2775 static void ip6_negative_advice(struct sock *sk,
2776                                 struct dst_entry *dst)
2777 {
2778         struct rt6_info *rt = dst_rt6_info(dst);
2779
2780         if (rt->rt6i_flags & RTF_CACHE) {
2781                 rcu_read_lock();
2782                 if (rt6_check_expired(rt)) {
2783                         /* counteract the dst_release() in sk_dst_reset() */
2784                         dst_hold(dst);
2785                         sk_dst_reset(sk);
2786
2787                         rt6_remove_exception_rt(rt);
2788                 }
2789                 rcu_read_unlock();
2790                 return;
2791         }
2792         sk_dst_reset(sk);
2793 }
2794
2795 static void ip6_link_failure(struct sk_buff *skb)
2796 {
2797         struct rt6_info *rt;
2798
2799         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
2800
2801         rt = dst_rt6_info(skb_dst(skb));
2802         if (rt) {
2803                 rcu_read_lock();
2804                 if (rt->rt6i_flags & RTF_CACHE) {
2805                         rt6_remove_exception_rt(rt);
2806                 } else {
2807                         struct fib6_info *from;
2808                         struct fib6_node *fn;
2809
2810                         from = rcu_dereference(rt->from);
2811                         if (from) {
2812                                 fn = rcu_dereference(from->fib6_node);
2813                                 if (fn && (rt->rt6i_flags & RTF_DEFAULT))
2814                                         WRITE_ONCE(fn->fn_sernum, -1);
2815                         }
2816                 }
2817                 rcu_read_unlock();
2818         }
2819 }
2820
2821 static void rt6_update_expires(struct rt6_info *rt0, int timeout)
2822 {
2823         if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
2824                 struct fib6_info *from;
2825
2826                 rcu_read_lock();
2827                 from = rcu_dereference(rt0->from);
2828                 if (from)
2829                         rt0->dst.expires = from->expires;
2830                 rcu_read_unlock();
2831         }
2832
2833         dst_set_expires(&rt0->dst, timeout);
2834         rt0->rt6i_flags |= RTF_EXPIRES;
2835 }
2836
2837 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
2838 {
2839         struct net *net = dev_net(rt->dst.dev);
2840
2841         dst_metric_set(&rt->dst, RTAX_MTU, mtu);
2842         rt->rt6i_flags |= RTF_MODIFIED;
2843         rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
2844 }
2845
2846 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
2847 {
2848         return !(rt->rt6i_flags & RTF_CACHE) &&
2849                 (rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
2850 }
2851
2852 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
2853                                  const struct ipv6hdr *iph, u32 mtu,
2854                                  bool confirm_neigh)
2855 {
2856         const struct in6_addr *daddr, *saddr;
2857         struct rt6_info *rt6 = dst_rt6_info(dst);
2858
2859         /* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU)
2860          * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it.
2861          * [see also comment in rt6_mtu_change_route()]
2862          */
2863
2864         if (iph) {
2865                 daddr = &iph->daddr;
2866                 saddr = &iph->saddr;
2867         } else if (sk) {
2868                 daddr = &sk->sk_v6_daddr;
2869                 saddr = &inet6_sk(sk)->saddr;
2870         } else {
2871                 daddr = NULL;
2872                 saddr = NULL;
2873         }
2874
2875         if (confirm_neigh)
2876                 dst_confirm_neigh(dst, daddr);
2877
2878         if (mtu < IPV6_MIN_MTU)
2879                 return;
2880         if (mtu >= dst_mtu(dst))
2881                 return;
2882
2883         if (!rt6_cache_allowed_for_pmtu(rt6)) {
2884                 rt6_do_update_pmtu(rt6, mtu);
2885                 /* update rt6_ex->stamp for cache */
2886                 if (rt6->rt6i_flags & RTF_CACHE)
2887                         rt6_update_exception_stamp_rt(rt6);
2888         } else if (daddr) {
2889                 struct fib6_result res = {};
2890                 struct rt6_info *nrt6;
2891
2892                 rcu_read_lock();
2893                 res.f6i = rcu_dereference(rt6->from);
2894                 if (!res.f6i)
2895                         goto out_unlock;
2896
2897                 res.fib6_flags = res.f6i->fib6_flags;
2898                 res.fib6_type = res.f6i->fib6_type;
2899
2900                 if (res.f6i->nh) {
2901                         struct fib6_nh_match_arg arg = {
2902                                 .dev = dst->dev,
2903                                 .gw = &rt6->rt6i_gateway,
2904                         };
2905
2906                         nexthop_for_each_fib6_nh(res.f6i->nh,
2907                                                  fib6_nh_find_match, &arg);
2908
2909                         /* fib6_info uses a nexthop that does not have fib6_nh
2910                          * using the dst->dev + gw. Should be impossible.
2911                          */
2912                         if (!arg.match)
2913                                 goto out_unlock;
2914
2915                         res.nh = arg.match;
2916                 } else {
2917                         res.nh = res.f6i->fib6_nh;
2918                 }
2919
2920                 nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
2921                 if (nrt6) {
2922                         rt6_do_update_pmtu(nrt6, mtu);
2923                         if (rt6_insert_exception(nrt6, &res))
2924                                 dst_release_immediate(&nrt6->dst);
2925                 }
2926 out_unlock:
2927                 rcu_read_unlock();
2928         }
2929 }
2930
2931 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
2932                                struct sk_buff *skb, u32 mtu,
2933                                bool confirm_neigh)
2934 {
2935         __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu,
2936                              confirm_neigh);
2937 }
2938
2939 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
2940                      int oif, u32 mark, kuid_t uid)
2941 {
2942         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2943         struct dst_entry *dst;
2944         struct flowi6 fl6 = {
2945                 .flowi6_oif = oif,
2946                 .flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
2947                 .daddr = iph->daddr,
2948                 .saddr = iph->saddr,
2949                 .flowlabel = ip6_flowinfo(iph),
2950                 .flowi6_uid = uid,
2951         };
2952
2953         dst = ip6_route_output(net, NULL, &fl6);
2954         if (!dst->error)
2955                 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true);
2956         dst_release(dst);
2957 }
2958 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
2959
2960 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
2961 {
2962         int oif = sk->sk_bound_dev_if;
2963         struct dst_entry *dst;
2964
2965         if (!oif && skb->dev)
2966                 oif = l3mdev_master_ifindex(skb->dev);
2967
2968         ip6_update_pmtu(skb, sock_net(sk), mtu, oif, READ_ONCE(sk->sk_mark),
2969                         sk->sk_uid);
2970
2971         dst = __sk_dst_get(sk);
2972         if (!dst || !dst->obsolete ||
2973             dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
2974                 return;
2975
2976         bh_lock_sock(sk);
2977         if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
2978                 ip6_datagram_dst_update(sk, false);
2979         bh_unlock_sock(sk);
2980 }
2981 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
2982
2983 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
2984                            const struct flowi6 *fl6)
2985 {
2986 #ifdef CONFIG_IPV6_SUBTREES
2987         struct ipv6_pinfo *np = inet6_sk(sk);
2988 #endif
2989
2990         ip6_dst_store(sk, dst,
2991                       ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
2992                       &sk->sk_v6_daddr : NULL,
2993 #ifdef CONFIG_IPV6_SUBTREES
2994                       ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
2995                       &np->saddr :
2996 #endif
2997                       NULL);
2998 }
2999
3000 static bool ip6_redirect_nh_match(const struct fib6_result *res,
3001                                   struct flowi6 *fl6,
3002                                   const struct in6_addr *gw,
3003                                   struct rt6_info **ret)
3004 {
3005         const struct fib6_nh *nh = res->nh;
3006
3007         if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family ||
3008             fl6->flowi6_oif != nh->fib_nh_dev->ifindex)
3009                 return false;
3010
3011         /* rt_cache's gateway might be different from its 'parent'
3012          * in the case of an ip redirect.
3013          * So we keep searching in the exception table if the gateway
3014          * is different.
3015          */
3016         if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) {
3017                 struct rt6_info *rt_cache;
3018
3019                 rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr);
3020                 if (rt_cache &&
3021                     ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) {
3022                         *ret = rt_cache;
3023                         return true;
3024                 }
3025                 return false;
3026         }
3027         return true;
3028 }
3029
3030 struct fib6_nh_rd_arg {
3031         struct fib6_result      *res;
3032         struct flowi6           *fl6;
3033         const struct in6_addr   *gw;
3034         struct rt6_info         **ret;
3035 };
3036
3037 static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg)
3038 {
3039         struct fib6_nh_rd_arg *arg = _arg;
3040
3041         arg->res->nh = nh;
3042         return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret);
3043 }
3044
3045 /* Handle redirects */
3046 struct ip6rd_flowi {
3047         struct flowi6 fl6;
3048         struct in6_addr gateway;
3049 };
3050
3051 INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net,
3052                                              struct fib6_table *table,
3053                                              struct flowi6 *fl6,
3054                                              const struct sk_buff *skb,
3055                                              int flags)
3056 {
3057         struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
3058         struct rt6_info *ret = NULL;
3059         struct fib6_result res = {};
3060         struct fib6_nh_rd_arg arg = {
3061                 .res = &res,
3062                 .fl6 = fl6,
3063                 .gw  = &rdfl->gateway,
3064                 .ret = &ret
3065         };
3066         struct fib6_info *rt;
3067         struct fib6_node *fn;
3068
3069         /* Get the "current" route for this destination and
3070          * check if the redirect has come from appropriate router.
3071          *
3072          * RFC 4861 specifies that redirects should only be
3073          * accepted if they come from the nexthop to the target.
3074          * Due to the way the routes are chosen, this notion
3075          * is a bit fuzzy and one might need to check all possible
3076          * routes.
3077          */
3078
3079         rcu_read_lock();
3080         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
3081 restart:
3082         for_each_fib6_node_rt_rcu(fn) {
3083                 res.f6i = rt;
3084                 if (fib6_check_expired(rt))
3085                         continue;
3086                 if (rt->fib6_flags & RTF_REJECT)
3087                         break;
3088                 if (unlikely(rt->nh)) {
3089                         if (nexthop_is_blackhole(rt->nh))
3090                                 continue;
3091                         /* on match, res->nh is filled in and potentially ret */
3092                         if (nexthop_for_each_fib6_nh(rt->nh,
3093                                                      fib6_nh_redirect_match,
3094                                                      &arg))
3095                                 goto out;
3096                 } else {
3097                         res.nh = rt->fib6_nh;
3098                         if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway,
3099                                                   &ret))
3100                                 goto out;
3101                 }
3102         }
3103
3104         if (!rt)
3105                 rt = net->ipv6.fib6_null_entry;
3106         else if (rt->fib6_flags & RTF_REJECT) {
3107                 ret = net->ipv6.ip6_null_entry;
3108                 goto out;
3109         }
3110
3111         if (rt == net->ipv6.fib6_null_entry) {
3112                 fn = fib6_backtrack(fn, &fl6->saddr);
3113                 if (fn)
3114                         goto restart;
3115         }
3116
3117         res.f6i = rt;
3118         res.nh = rt->fib6_nh;
3119 out:
3120         if (ret) {
3121                 ip6_hold_safe(net, &ret);
3122         } else {
3123                 res.fib6_flags = res.f6i->fib6_flags;
3124                 res.fib6_type = res.f6i->fib6_type;
3125                 ret = ip6_create_rt_rcu(&res);
3126         }
3127
3128         rcu_read_unlock();
3129
3130         trace_fib6_table_lookup(net, &res, table, fl6);
3131         return ret;
3132 };
3133
3134 static struct dst_entry *ip6_route_redirect(struct net *net,
3135                                             const struct flowi6 *fl6,
3136                                             const struct sk_buff *skb,
3137                                             const struct in6_addr *gateway)
3138 {
3139         int flags = RT6_LOOKUP_F_HAS_SADDR;
3140         struct ip6rd_flowi rdfl;
3141
3142         rdfl.fl6 = *fl6;
3143         rdfl.gateway = *gateway;
3144
3145         return fib6_rule_lookup(net, &rdfl.fl6, skb,
3146                                 flags, __ip6_route_redirect);
3147 }
3148
3149 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
3150                   kuid_t uid)
3151 {
3152         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
3153         struct dst_entry *dst;
3154         struct flowi6 fl6 = {
3155                 .flowi6_iif = LOOPBACK_IFINDEX,
3156                 .flowi6_oif = oif,
3157                 .flowi6_mark = mark,
3158                 .daddr = iph->daddr,
3159                 .saddr = iph->saddr,
3160                 .flowlabel = ip6_flowinfo(iph),
3161                 .flowi6_uid = uid,
3162         };
3163
3164         dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
3165         rt6_do_redirect(dst, NULL, skb);
3166         dst_release(dst);
3167 }
3168 EXPORT_SYMBOL_GPL(ip6_redirect);
3169
3170 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
3171 {
3172         const struct ipv6hdr *iph = ipv6_hdr(skb);
3173         const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
3174         struct dst_entry *dst;
3175         struct flowi6 fl6 = {
3176                 .flowi6_iif = LOOPBACK_IFINDEX,
3177                 .flowi6_oif = oif,
3178                 .daddr = msg->dest,
3179                 .saddr = iph->daddr,
3180                 .flowi6_uid = sock_net_uid(net, NULL),
3181         };
3182
3183         dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
3184         rt6_do_redirect(dst, NULL, skb);
3185         dst_release(dst);
3186 }
3187
3188 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
3189 {
3190         ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if,
3191                      READ_ONCE(sk->sk_mark), sk->sk_uid);
3192 }
3193 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
3194
3195 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
3196 {
3197         struct net_device *dev = dst->dev;
3198         unsigned int mtu = dst_mtu(dst);
3199         struct net *net = dev_net(dev);
3200
3201         mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
3202
3203         if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
3204                 mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
3205
3206         /*
3207          * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
3208          * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
3209          * IPV6_MAXPLEN is also valid and means: "any MSS,
3210          * rely only on pmtu discovery"
3211          */
3212         if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
3213                 mtu = IPV6_MAXPLEN;
3214         return mtu;
3215 }
3216
3217 INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst)
3218 {
3219         return ip6_dst_mtu_maybe_forward(dst, false);
3220 }
3221 EXPORT_INDIRECT_CALLABLE(ip6_mtu);
3222
3223 /* MTU selection:
3224  * 1. mtu on route is locked - use it
3225  * 2. mtu from nexthop exception
3226  * 3. mtu from egress device
3227  *
3228  * based on ip6_dst_mtu_forward and exception logic of
3229  * rt6_find_cached_rt; called with rcu_read_lock
3230  */
3231 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
3232                       const struct in6_addr *daddr,
3233                       const struct in6_addr *saddr)
3234 {
3235         const struct fib6_nh *nh = res->nh;
3236         struct fib6_info *f6i = res->f6i;
3237         struct inet6_dev *idev;
3238         struct rt6_info *rt;
3239         u32 mtu = 0;
3240
3241         if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
3242                 mtu = f6i->fib6_pmtu;
3243                 if (mtu)
3244                         goto out;
3245         }
3246
3247         rt = rt6_find_cached_rt(res, daddr, saddr);
3248         if (unlikely(rt)) {
3249                 mtu = dst_metric_raw(&rt->dst, RTAX_MTU);
3250         } else {
3251                 struct net_device *dev = nh->fib_nh_dev;
3252
3253                 mtu = IPV6_MIN_MTU;
3254                 idev = __in6_dev_get(dev);
3255                 if (idev)
3256                         mtu = max_t(u32, mtu, READ_ONCE(idev->cnf.mtu6));
3257         }
3258
3259         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
3260 out:
3261         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
3262 }
3263
3264 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
3265                                   struct flowi6 *fl6)
3266 {
3267         struct dst_entry *dst;
3268         struct rt6_info *rt;
3269         struct inet6_dev *idev = in6_dev_get(dev);
3270         struct net *net = dev_net(dev);
3271
3272         if (unlikely(!idev))
3273                 return ERR_PTR(-ENODEV);
3274
3275         rt = ip6_dst_alloc(net, dev, 0);
3276         if (unlikely(!rt)) {
3277                 in6_dev_put(idev);
3278                 dst = ERR_PTR(-ENOMEM);
3279                 goto out;
3280         }
3281
3282         rt->dst.input = ip6_input;
3283         rt->dst.output  = ip6_output;
3284         rt->rt6i_gateway  = fl6->daddr;
3285         rt->rt6i_dst.addr = fl6->daddr;
3286         rt->rt6i_dst.plen = 128;
3287         rt->rt6i_idev     = idev;
3288         dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
3289
3290         /* Add this dst into uncached_list so that rt6_disable_ip() can
3291          * do proper release of the net_device
3292          */
3293         rt6_uncached_list_add(rt);
3294
3295         dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
3296
3297 out:
3298         return dst;
3299 }
3300
3301 static void ip6_dst_gc(struct dst_ops *ops)
3302 {
3303         struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
3304         int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
3305         int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
3306         int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
3307         unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
3308         unsigned int val;
3309         int entries;
3310
3311         if (time_after(rt_last_gc + rt_min_interval, jiffies))
3312                 goto out;
3313
3314         fib6_run_gc(atomic_inc_return(&net->ipv6.ip6_rt_gc_expire), net, true);
3315         entries = dst_entries_get_slow(ops);
3316         if (entries < ops->gc_thresh)
3317                 atomic_set(&net->ipv6.ip6_rt_gc_expire, rt_gc_timeout >> 1);
3318 out:
3319         val = atomic_read(&net->ipv6.ip6_rt_gc_expire);
3320         atomic_set(&net->ipv6.ip6_rt_gc_expire, val - (val >> rt_elasticity));
3321 }
3322
3323 static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
3324                                const struct in6_addr *gw_addr, u32 tbid,
3325                                int flags, struct fib6_result *res)
3326 {
3327         struct flowi6 fl6 = {
3328                 .flowi6_oif = cfg->fc_ifindex,
3329                 .daddr = *gw_addr,
3330                 .saddr = cfg->fc_prefsrc,
3331         };
3332         struct fib6_table *table;
3333         int err;
3334
3335         table = fib6_get_table(net, tbid);
3336         if (!table)
3337                 return -EINVAL;
3338
3339         if (!ipv6_addr_any(&cfg->fc_prefsrc))
3340                 flags |= RT6_LOOKUP_F_HAS_SADDR;
3341
3342         flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
3343
3344         err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags);
3345         if (!err && res->f6i != net->ipv6.fib6_null_entry)
3346                 fib6_select_path(net, res, &fl6, cfg->fc_ifindex,
3347                                  cfg->fc_ifindex != 0, NULL, flags);
3348
3349         return err;
3350 }
3351
3352 static int ip6_route_check_nh_onlink(struct net *net,
3353                                      struct fib6_config *cfg,
3354                                      const struct net_device *dev,
3355                                      struct netlink_ext_ack *extack)
3356 {
3357         u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
3358         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3359         struct fib6_result res = {};
3360         int err;
3361
3362         err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res);
3363         if (!err && !(res.fib6_flags & RTF_REJECT) &&
3364             /* ignore match if it is the default route */
3365             !ipv6_addr_any(&res.f6i->fib6_dst.addr) &&
3366             (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) {
3367                 NL_SET_ERR_MSG(extack,
3368                                "Nexthop has invalid gateway or device mismatch");
3369                 err = -EINVAL;
3370         }
3371
3372         return err;
3373 }
3374
3375 static int ip6_route_check_nh(struct net *net,
3376                               struct fib6_config *cfg,
3377                               struct net_device **_dev,
3378                               netdevice_tracker *dev_tracker,
3379                               struct inet6_dev **idev)
3380 {
3381         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3382         struct net_device *dev = _dev ? *_dev : NULL;
3383         int flags = RT6_LOOKUP_F_IFACE;
3384         struct fib6_result res = {};
3385         int err = -EHOSTUNREACH;
3386
3387         if (cfg->fc_table) {
3388                 err = ip6_nh_lookup_table(net, cfg, gw_addr,
3389                                           cfg->fc_table, flags, &res);
3390                 /* gw_addr can not require a gateway or resolve to a reject
3391                  * route. If a device is given, it must match the result.
3392                  */
3393                 if (err || res.fib6_flags & RTF_REJECT ||
3394                     res.nh->fib_nh_gw_family ||
3395                     (dev && dev != res.nh->fib_nh_dev))
3396                         err = -EHOSTUNREACH;
3397         }
3398
3399         if (err < 0) {
3400                 struct flowi6 fl6 = {
3401                         .flowi6_oif = cfg->fc_ifindex,
3402                         .daddr = *gw_addr,
3403                 };
3404
3405                 err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags);
3406                 if (err || res.fib6_flags & RTF_REJECT ||
3407                     res.nh->fib_nh_gw_family)
3408                         err = -EHOSTUNREACH;
3409
3410                 if (err)
3411                         return err;
3412
3413                 fib6_select_path(net, &res, &fl6, cfg->fc_ifindex,
3414                                  cfg->fc_ifindex != 0, NULL, flags);
3415         }
3416
3417         err = 0;
3418         if (dev) {
3419                 if (dev != res.nh->fib_nh_dev)
3420                         err = -EHOSTUNREACH;
3421         } else {
3422                 *_dev = dev = res.nh->fib_nh_dev;
3423                 netdev_hold(dev, dev_tracker, GFP_ATOMIC);
3424                 *idev = in6_dev_get(dev);
3425         }
3426
3427         return err;
3428 }
3429
3430 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
3431                            struct net_device **_dev,
3432                            netdevice_tracker *dev_tracker,
3433                            struct inet6_dev **idev,
3434                            struct netlink_ext_ack *extack)
3435 {
3436         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3437         int gwa_type = ipv6_addr_type(gw_addr);
3438         bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
3439         const struct net_device *dev = *_dev;
3440         bool need_addr_check = !dev;
3441         int err = -EINVAL;
3442
3443         /* if gw_addr is local we will fail to detect this in case
3444          * address is still TENTATIVE (DAD in progress). rt6_lookup()
3445          * will return already-added prefix route via interface that
3446          * prefix route was assigned to, which might be non-loopback.
3447          */
3448         if (dev &&
3449             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3450                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3451                 goto out;
3452         }
3453
3454         if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
3455                 /* IPv6 strictly inhibits using not link-local
3456                  * addresses as nexthop address.
3457                  * Otherwise, router will not able to send redirects.
3458                  * It is very good, but in some (rare!) circumstances
3459                  * (SIT, PtP, NBMA NOARP links) it is handy to allow
3460                  * some exceptions. --ANK
3461                  * We allow IPv4-mapped nexthops to support RFC4798-type
3462                  * addressing
3463                  */
3464                 if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
3465                         NL_SET_ERR_MSG(extack, "Invalid gateway address");
3466                         goto out;
3467                 }
3468
3469                 rcu_read_lock();
3470
3471                 if (cfg->fc_flags & RTNH_F_ONLINK)
3472                         err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
3473                 else
3474                         err = ip6_route_check_nh(net, cfg, _dev, dev_tracker,
3475                                                  idev);
3476
3477                 rcu_read_unlock();
3478
3479                 if (err)
3480                         goto out;
3481         }
3482
3483         /* reload in case device was changed */
3484         dev = *_dev;
3485
3486         err = -EINVAL;
3487         if (!dev) {
3488                 NL_SET_ERR_MSG(extack, "Egress device not specified");
3489                 goto out;
3490         } else if (dev->flags & IFF_LOOPBACK) {
3491                 NL_SET_ERR_MSG(extack,
3492                                "Egress device can not be loopback device for this route");
3493                 goto out;
3494         }
3495
3496         /* if we did not check gw_addr above, do so now that the
3497          * egress device has been resolved.
3498          */
3499         if (need_addr_check &&
3500             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3501                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3502                 goto out;
3503         }
3504
3505         err = 0;
3506 out:
3507         return err;
3508 }
3509
3510 static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
3511 {
3512         if ((flags & RTF_REJECT) ||
3513             (dev && (dev->flags & IFF_LOOPBACK) &&
3514              !(addr_type & IPV6_ADDR_LOOPBACK) &&
3515              !(flags & (RTF_ANYCAST | RTF_LOCAL))))
3516                 return true;
3517
3518         return false;
3519 }
3520
3521 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
3522                  struct fib6_config *cfg, gfp_t gfp_flags,
3523                  struct netlink_ext_ack *extack)
3524 {
3525         netdevice_tracker *dev_tracker = &fib6_nh->fib_nh_dev_tracker;
3526         struct net_device *dev = NULL;
3527         struct inet6_dev *idev = NULL;
3528         int addr_type;
3529         int err;
3530
3531         fib6_nh->fib_nh_family = AF_INET6;
3532 #ifdef CONFIG_IPV6_ROUTER_PREF
3533         fib6_nh->last_probe = jiffies;
3534 #endif
3535         if (cfg->fc_is_fdb) {
3536                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3537                 fib6_nh->fib_nh_gw_family = AF_INET6;
3538                 return 0;
3539         }
3540
3541         err = -ENODEV;
3542         if (cfg->fc_ifindex) {
3543                 dev = netdev_get_by_index(net, cfg->fc_ifindex,
3544                                           dev_tracker, gfp_flags);
3545                 if (!dev)
3546                         goto out;
3547                 idev = in6_dev_get(dev);
3548                 if (!idev)
3549                         goto out;
3550         }
3551
3552         if (cfg->fc_flags & RTNH_F_ONLINK) {
3553                 if (!dev) {
3554                         NL_SET_ERR_MSG(extack,
3555                                        "Nexthop device required for onlink");
3556                         goto out;
3557                 }
3558
3559                 if (!(dev->flags & IFF_UP)) {
3560                         NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3561                         err = -ENETDOWN;
3562                         goto out;
3563                 }
3564
3565                 fib6_nh->fib_nh_flags |= RTNH_F_ONLINK;
3566         }
3567
3568         fib6_nh->fib_nh_weight = 1;
3569
3570         /* We cannot add true routes via loopback here,
3571          * they would result in kernel looping; promote them to reject routes
3572          */
3573         addr_type = ipv6_addr_type(&cfg->fc_dst);
3574         if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) {
3575                 /* hold loopback dev/idev if we haven't done so. */
3576                 if (dev != net->loopback_dev) {
3577                         if (dev) {
3578                                 netdev_put(dev, dev_tracker);
3579                                 in6_dev_put(idev);
3580                         }
3581                         dev = net->loopback_dev;
3582                         netdev_hold(dev, dev_tracker, gfp_flags);
3583                         idev = in6_dev_get(dev);
3584                         if (!idev) {
3585                                 err = -ENODEV;
3586                                 goto out;
3587                         }
3588                 }
3589                 goto pcpu_alloc;
3590         }
3591
3592         if (cfg->fc_flags & RTF_GATEWAY) {
3593                 err = ip6_validate_gw(net, cfg, &dev, dev_tracker,
3594                                       &idev, extack);
3595                 if (err)
3596                         goto out;
3597
3598                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3599                 fib6_nh->fib_nh_gw_family = AF_INET6;
3600         }
3601
3602         err = -ENODEV;
3603         if (!dev)
3604                 goto out;
3605
3606         if (!idev || idev->cnf.disable_ipv6) {
3607                 NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
3608                 err = -EACCES;
3609                 goto out;
3610         }
3611
3612         if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
3613                 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3614                 err = -ENETDOWN;
3615                 goto out;
3616         }
3617
3618         if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
3619             !netif_carrier_ok(dev))
3620                 fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
3621
3622         err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap,
3623                                  cfg->fc_encap_type, cfg, gfp_flags, extack);
3624         if (err)
3625                 goto out;
3626
3627 pcpu_alloc:
3628         fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
3629         if (!fib6_nh->rt6i_pcpu) {
3630                 err = -ENOMEM;
3631                 goto out;
3632         }
3633
3634         fib6_nh->fib_nh_dev = dev;
3635         fib6_nh->fib_nh_oif = dev->ifindex;
3636         err = 0;
3637 out:
3638         if (idev)
3639                 in6_dev_put(idev);
3640
3641         if (err) {
3642                 lwtstate_put(fib6_nh->fib_nh_lws);
3643                 fib6_nh->fib_nh_lws = NULL;
3644                 netdev_put(dev, dev_tracker);
3645         }
3646
3647         return err;
3648 }
3649
3650 void fib6_nh_release(struct fib6_nh *fib6_nh)
3651 {
3652         struct rt6_exception_bucket *bucket;
3653
3654         rcu_read_lock();
3655
3656         fib6_nh_flush_exceptions(fib6_nh, NULL);
3657         bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL);
3658         if (bucket) {
3659                 rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL);
3660                 kfree(bucket);
3661         }
3662
3663         rcu_read_unlock();
3664
3665         fib6_nh_release_dsts(fib6_nh);
3666         free_percpu(fib6_nh->rt6i_pcpu);
3667
3668         fib_nh_common_release(&fib6_nh->nh_common);
3669 }
3670
3671 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh)
3672 {
3673         int cpu;
3674
3675         if (!fib6_nh->rt6i_pcpu)
3676                 return;
3677
3678         for_each_possible_cpu(cpu) {
3679                 struct rt6_info *pcpu_rt, **ppcpu_rt;
3680
3681                 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
3682                 pcpu_rt = xchg(ppcpu_rt, NULL);
3683                 if (pcpu_rt) {
3684                         dst_dev_put(&pcpu_rt->dst);
3685                         dst_release(&pcpu_rt->dst);
3686                 }
3687         }
3688 }
3689
3690 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
3691                                               gfp_t gfp_flags,
3692                                               struct netlink_ext_ack *extack)
3693 {
3694         struct net *net = cfg->fc_nlinfo.nl_net;
3695         struct fib6_info *rt = NULL;
3696         struct nexthop *nh = NULL;
3697         struct fib6_table *table;
3698         struct fib6_nh *fib6_nh;
3699         int err = -EINVAL;
3700         int addr_type;
3701
3702         /* RTF_PCPU is an internal flag; can not be set by userspace */
3703         if (cfg->fc_flags & RTF_PCPU) {
3704                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
3705                 goto out;
3706         }
3707
3708         /* RTF_CACHE is an internal flag; can not be set by userspace */
3709         if (cfg->fc_flags & RTF_CACHE) {
3710                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
3711                 goto out;
3712         }
3713
3714         if (cfg->fc_type > RTN_MAX) {
3715                 NL_SET_ERR_MSG(extack, "Invalid route type");
3716                 goto out;
3717         }
3718
3719         if (cfg->fc_dst_len > 128) {
3720                 NL_SET_ERR_MSG(extack, "Invalid prefix length");
3721                 goto out;
3722         }
3723         if (cfg->fc_src_len > 128) {
3724                 NL_SET_ERR_MSG(extack, "Invalid source address length");
3725                 goto out;
3726         }
3727 #ifndef CONFIG_IPV6_SUBTREES
3728         if (cfg->fc_src_len) {
3729                 NL_SET_ERR_MSG(extack,
3730                                "Specifying source address requires IPV6_SUBTREES to be enabled");
3731                 goto out;
3732         }
3733 #endif
3734         if (cfg->fc_nh_id) {
3735                 nh = nexthop_find_by_id(net, cfg->fc_nh_id);
3736                 if (!nh) {
3737                         NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
3738                         goto out;
3739                 }
3740                 err = fib6_check_nexthop(nh, cfg, extack);
3741                 if (err)
3742                         goto out;
3743         }
3744
3745         err = -ENOBUFS;
3746         if (cfg->fc_nlinfo.nlh &&
3747             !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
3748                 table = fib6_get_table(net, cfg->fc_table);
3749                 if (!table) {
3750                         pr_warn("NLM_F_CREATE should be specified when creating new route\n");
3751                         table = fib6_new_table(net, cfg->fc_table);
3752                 }
3753         } else {
3754                 table = fib6_new_table(net, cfg->fc_table);
3755         }
3756
3757         if (!table)
3758                 goto out;
3759
3760         err = -ENOMEM;
3761         rt = fib6_info_alloc(gfp_flags, !nh);
3762         if (!rt)
3763                 goto out;
3764
3765         rt->fib6_metrics = ip_fib_metrics_init(cfg->fc_mx, cfg->fc_mx_len,
3766                                                extack);
3767         if (IS_ERR(rt->fib6_metrics)) {
3768                 err = PTR_ERR(rt->fib6_metrics);
3769                 /* Do not leave garbage there. */
3770                 rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
3771                 goto out_free;
3772         }
3773
3774         if (cfg->fc_flags & RTF_ADDRCONF)
3775                 rt->dst_nocount = true;
3776
3777         if (cfg->fc_flags & RTF_EXPIRES)
3778                 fib6_set_expires(rt, jiffies +
3779                                 clock_t_to_jiffies(cfg->fc_expires));
3780
3781         if (cfg->fc_protocol == RTPROT_UNSPEC)
3782                 cfg->fc_protocol = RTPROT_BOOT;
3783         rt->fib6_protocol = cfg->fc_protocol;
3784
3785         rt->fib6_table = table;
3786         rt->fib6_metric = cfg->fc_metric;
3787         rt->fib6_type = cfg->fc_type ? : RTN_UNICAST;
3788         rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;
3789
3790         ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
3791         rt->fib6_dst.plen = cfg->fc_dst_len;
3792
3793 #ifdef CONFIG_IPV6_SUBTREES
3794         ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
3795         rt->fib6_src.plen = cfg->fc_src_len;
3796 #endif
3797         if (nh) {
3798                 if (rt->fib6_src.plen) {
3799                         NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
3800                         goto out_free;
3801                 }
3802                 if (!nexthop_get(nh)) {
3803                         NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
3804                         goto out_free;
3805                 }
3806                 rt->nh = nh;
3807                 fib6_nh = nexthop_fib6_nh(rt->nh);
3808         } else {
3809                 err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack);
3810                 if (err)
3811                         goto out;
3812
3813                 fib6_nh = rt->fib6_nh;
3814
3815                 /* We cannot add true routes via loopback here, they would
3816                  * result in kernel looping; promote them to reject routes
3817                  */
3818                 addr_type = ipv6_addr_type(&cfg->fc_dst);
3819                 if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev,
3820                                    addr_type))
3821                         rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
3822         }
3823
3824         if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
3825                 struct net_device *dev = fib6_nh->fib_nh_dev;
3826
3827                 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
3828                         NL_SET_ERR_MSG(extack, "Invalid source address");
3829                         err = -EINVAL;
3830                         goto out;
3831                 }
3832                 rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
3833                 rt->fib6_prefsrc.plen = 128;
3834         } else
3835                 rt->fib6_prefsrc.plen = 0;
3836
3837         return rt;
3838 out:
3839         fib6_info_release(rt);
3840         return ERR_PTR(err);
3841 out_free:
3842         ip_fib_metrics_put(rt->fib6_metrics);
3843         kfree(rt);
3844         return ERR_PTR(err);
3845 }
3846
3847 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
3848                   struct netlink_ext_ack *extack)
3849 {
3850         struct fib6_info *rt;
3851         int err;
3852
3853         rt = ip6_route_info_create(cfg, gfp_flags, extack);
3854         if (IS_ERR(rt))
3855                 return PTR_ERR(rt);
3856
3857         err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
3858         fib6_info_release(rt);
3859
3860         return err;
3861 }
3862
3863 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
3864 {
3865         struct net *net = info->nl_net;
3866         struct fib6_table *table;
3867         int err;
3868
3869         if (rt == net->ipv6.fib6_null_entry) {
3870                 err = -ENOENT;
3871                 goto out;
3872         }
3873
3874         table = rt->fib6_table;
3875         spin_lock_bh(&table->tb6_lock);
3876         err = fib6_del(rt, info);
3877         spin_unlock_bh(&table->tb6_lock);
3878
3879 out:
3880         fib6_info_release(rt);
3881         return err;
3882 }
3883
3884 int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify)
3885 {
3886         struct nl_info info = {
3887                 .nl_net = net,
3888                 .skip_notify = skip_notify
3889         };
3890
3891         return __ip6_del_rt(rt, &info);
3892 }
3893
3894 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
3895 {
3896         struct nl_info *info = &cfg->fc_nlinfo;
3897         struct net *net = info->nl_net;
3898         struct sk_buff *skb = NULL;
3899         struct fib6_table *table;
3900         int err = -ENOENT;
3901
3902         if (rt == net->ipv6.fib6_null_entry)
3903                 goto out_put;
3904         table = rt->fib6_table;
3905         spin_lock_bh(&table->tb6_lock);
3906
3907         if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
3908                 struct fib6_info *sibling, *next_sibling;
3909                 struct fib6_node *fn;
3910
3911                 /* prefer to send a single notification with all hops */
3912                 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3913                 if (skb) {
3914                         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3915
3916                         if (rt6_fill_node(net, skb, rt, NULL,
3917                                           NULL, NULL, 0, RTM_DELROUTE,
3918                                           info->portid, seq, 0) < 0) {
3919                                 kfree_skb(skb);
3920                                 skb = NULL;
3921                         } else
3922                                 info->skip_notify = 1;
3923                 }
3924
3925                 /* 'rt' points to the first sibling route. If it is not the
3926                  * leaf, then we do not need to send a notification. Otherwise,
3927                  * we need to check if the last sibling has a next route or not
3928                  * and emit a replace or delete notification, respectively.
3929                  */
3930                 info->skip_notify_kernel = 1;
3931                 fn = rcu_dereference_protected(rt->fib6_node,
3932                                             lockdep_is_held(&table->tb6_lock));
3933                 if (rcu_access_pointer(fn->leaf) == rt) {
3934                         struct fib6_info *last_sibling, *replace_rt;
3935
3936                         last_sibling = list_last_entry(&rt->fib6_siblings,
3937                                                        struct fib6_info,
3938                                                        fib6_siblings);
3939                         replace_rt = rcu_dereference_protected(
3940                                             last_sibling->fib6_next,
3941                                             lockdep_is_held(&table->tb6_lock));
3942                         if (replace_rt)
3943                                 call_fib6_entry_notifiers_replace(net,
3944                                                                   replace_rt);
3945                         else
3946                                 call_fib6_multipath_entry_notifiers(net,
3947                                                        FIB_EVENT_ENTRY_DEL,
3948                                                        rt, rt->fib6_nsiblings,
3949                                                        NULL);
3950                 }
3951                 list_for_each_entry_safe(sibling, next_sibling,
3952                                          &rt->fib6_siblings,
3953                                          fib6_siblings) {
3954                         err = fib6_del(sibling, info);
3955                         if (err)
3956                                 goto out_unlock;
3957                 }
3958         }
3959
3960         err = fib6_del(rt, info);
3961 out_unlock:
3962         spin_unlock_bh(&table->tb6_lock);
3963 out_put:
3964         fib6_info_release(rt);
3965
3966         if (skb) {
3967                 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3968                             info->nlh, gfp_any());
3969         }
3970         return err;
3971 }
3972
3973 static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
3974 {
3975         int rc = -ESRCH;
3976
3977         if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
3978                 goto out;
3979
3980         if (cfg->fc_flags & RTF_GATEWAY &&
3981             !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
3982                 goto out;
3983
3984         rc = rt6_remove_exception_rt(rt);
3985 out:
3986         return rc;
3987 }
3988
3989 static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt,
3990                              struct fib6_nh *nh)
3991 {
3992         struct fib6_result res = {
3993                 .f6i = rt,
3994                 .nh = nh,
3995         };
3996         struct rt6_info *rt_cache;
3997
3998         rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src);
3999         if (rt_cache)
4000                 return __ip6_del_cached_rt(rt_cache, cfg);
4001
4002         return 0;
4003 }
4004
4005 struct fib6_nh_del_cached_rt_arg {
4006         struct fib6_config *cfg;
4007         struct fib6_info *f6i;
4008 };
4009
4010 static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg)
4011 {
4012         struct fib6_nh_del_cached_rt_arg *arg = _arg;
4013         int rc;
4014
4015         rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh);
4016         return rc != -ESRCH ? rc : 0;
4017 }
4018
4019 static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i)
4020 {
4021         struct fib6_nh_del_cached_rt_arg arg = {
4022                 .cfg = cfg,
4023                 .f6i = f6i
4024         };
4025
4026         return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg);
4027 }
4028
4029 static int ip6_route_del(struct fib6_config *cfg,
4030                          struct netlink_ext_ack *extack)
4031 {
4032         struct fib6_table *table;
4033         struct fib6_info *rt;
4034         struct fib6_node *fn;
4035         int err = -ESRCH;
4036
4037         table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
4038         if (!table) {
4039                 NL_SET_ERR_MSG(extack, "FIB table does not exist");
4040                 return err;
4041         }
4042
4043         rcu_read_lock();
4044
4045         fn = fib6_locate(&table->tb6_root,
4046                          &cfg->fc_dst, cfg->fc_dst_len,
4047                          &cfg->fc_src, cfg->fc_src_len,
4048                          !(cfg->fc_flags & RTF_CACHE));
4049
4050         if (fn) {
4051                 for_each_fib6_node_rt_rcu(fn) {
4052                         struct fib6_nh *nh;
4053
4054                         if (rt->nh && cfg->fc_nh_id &&
4055                             rt->nh->id != cfg->fc_nh_id)
4056                                 continue;
4057
4058                         if (cfg->fc_flags & RTF_CACHE) {
4059                                 int rc = 0;
4060
4061                                 if (rt->nh) {
4062                                         rc = ip6_del_cached_rt_nh(cfg, rt);
4063                                 } else if (cfg->fc_nh_id) {
4064                                         continue;
4065                                 } else {
4066                                         nh = rt->fib6_nh;
4067                                         rc = ip6_del_cached_rt(cfg, rt, nh);
4068                                 }
4069                                 if (rc != -ESRCH) {
4070                                         rcu_read_unlock();
4071                                         return rc;
4072                                 }
4073                                 continue;
4074                         }
4075
4076                         if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
4077                                 continue;
4078                         if (cfg->fc_protocol &&
4079                             cfg->fc_protocol != rt->fib6_protocol)
4080                                 continue;
4081
4082                         if (rt->nh) {
4083                                 if (!fib6_info_hold_safe(rt))
4084                                         continue;
4085                                 rcu_read_unlock();
4086
4087                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4088                         }
4089                         if (cfg->fc_nh_id)
4090                                 continue;
4091
4092                         nh = rt->fib6_nh;
4093                         if (cfg->fc_ifindex &&
4094                             (!nh->fib_nh_dev ||
4095                              nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
4096                                 continue;
4097                         if (cfg->fc_flags & RTF_GATEWAY &&
4098                             !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6))
4099                                 continue;
4100                         if (!fib6_info_hold_safe(rt))
4101                                 continue;
4102                         rcu_read_unlock();
4103
4104                         /* if gateway was specified only delete the one hop */
4105                         if (cfg->fc_flags & RTF_GATEWAY)
4106                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4107
4108                         return __ip6_del_rt_siblings(rt, cfg);
4109                 }
4110         }
4111         rcu_read_unlock();
4112
4113         return err;
4114 }
4115
4116 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
4117 {
4118         struct netevent_redirect netevent;
4119         struct rt6_info *rt, *nrt = NULL;
4120         struct fib6_result res = {};
4121         struct ndisc_options ndopts;
4122         struct inet6_dev *in6_dev;
4123         struct neighbour *neigh;
4124         struct rd_msg *msg;
4125         int optlen, on_link;
4126         u8 *lladdr;
4127
4128         optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
4129         optlen -= sizeof(*msg);
4130
4131         if (optlen < 0) {
4132                 net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
4133                 return;
4134         }
4135
4136         msg = (struct rd_msg *)icmp6_hdr(skb);
4137
4138         if (ipv6_addr_is_multicast(&msg->dest)) {
4139                 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
4140                 return;
4141         }
4142
4143         on_link = 0;
4144         if (ipv6_addr_equal(&msg->dest, &msg->target)) {
4145                 on_link = 1;
4146         } else if (ipv6_addr_type(&msg->target) !=
4147                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
4148                 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
4149                 return;
4150         }
4151
4152         in6_dev = __in6_dev_get(skb->dev);
4153         if (!in6_dev)
4154                 return;
4155         if (READ_ONCE(in6_dev->cnf.forwarding) ||
4156             !READ_ONCE(in6_dev->cnf.accept_redirects))
4157                 return;
4158
4159         /* RFC2461 8.1:
4160          *      The IP source address of the Redirect MUST be the same as the current
4161          *      first-hop router for the specified ICMP Destination Address.
4162          */
4163
4164         if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
4165                 net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
4166                 return;
4167         }
4168
4169         lladdr = NULL;
4170         if (ndopts.nd_opts_tgt_lladdr) {
4171                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
4172                                              skb->dev);
4173                 if (!lladdr) {
4174                         net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
4175                         return;
4176                 }
4177         }
4178
4179         rt = dst_rt6_info(dst);
4180         if (rt->rt6i_flags & RTF_REJECT) {
4181                 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
4182                 return;
4183         }
4184
4185         /* Redirect received -> path was valid.
4186          * Look, redirects are sent only in response to data packets,
4187          * so that this nexthop apparently is reachable. --ANK
4188          */
4189         dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
4190
4191         neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
4192         if (!neigh)
4193                 return;
4194
4195         /*
4196          *      We have finally decided to accept it.
4197          */
4198
4199         ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
4200                      NEIGH_UPDATE_F_WEAK_OVERRIDE|
4201                      NEIGH_UPDATE_F_OVERRIDE|
4202                      (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
4203                                      NEIGH_UPDATE_F_ISROUTER)),
4204                      NDISC_REDIRECT, &ndopts);
4205
4206         rcu_read_lock();
4207         res.f6i = rcu_dereference(rt->from);
4208         if (!res.f6i)
4209                 goto out;
4210
4211         if (res.f6i->nh) {
4212                 struct fib6_nh_match_arg arg = {
4213                         .dev = dst->dev,
4214                         .gw = &rt->rt6i_gateway,
4215                 };
4216
4217                 nexthop_for_each_fib6_nh(res.f6i->nh,
4218                                          fib6_nh_find_match, &arg);
4219
4220                 /* fib6_info uses a nexthop that does not have fib6_nh
4221                  * using the dst->dev. Should be impossible
4222                  */
4223                 if (!arg.match)
4224                         goto out;
4225                 res.nh = arg.match;
4226         } else {
4227                 res.nh = res.f6i->fib6_nh;
4228         }
4229
4230         res.fib6_flags = res.f6i->fib6_flags;
4231         res.fib6_type = res.f6i->fib6_type;
4232         nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL);
4233         if (!nrt)
4234                 goto out;
4235
4236         nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
4237         if (on_link)
4238                 nrt->rt6i_flags &= ~RTF_GATEWAY;
4239
4240         nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
4241
4242         /* rt6_insert_exception() will take care of duplicated exceptions */
4243         if (rt6_insert_exception(nrt, &res)) {
4244                 dst_release_immediate(&nrt->dst);
4245                 goto out;
4246         }
4247
4248         netevent.old = &rt->dst;
4249         netevent.new = &nrt->dst;
4250         netevent.daddr = &msg->dest;
4251         netevent.neigh = neigh;
4252         call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
4253
4254 out:
4255         rcu_read_unlock();
4256         neigh_release(neigh);
4257 }
4258
4259 #ifdef CONFIG_IPV6_ROUTE_INFO
4260 static struct fib6_info *rt6_get_route_info(struct net *net,
4261                                            const struct in6_addr *prefix, int prefixlen,
4262                                            const struct in6_addr *gwaddr,
4263                                            struct net_device *dev)
4264 {
4265         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4266         int ifindex = dev->ifindex;
4267         struct fib6_node *fn;
4268         struct fib6_info *rt = NULL;
4269         struct fib6_table *table;
4270
4271         table = fib6_get_table(net, tb_id);
4272         if (!table)
4273                 return NULL;
4274
4275         rcu_read_lock();
4276         fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
4277         if (!fn)
4278                 goto out;
4279
4280         for_each_fib6_node_rt_rcu(fn) {
4281                 /* these routes do not use nexthops */
4282                 if (rt->nh)
4283                         continue;
4284                 if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex)
4285                         continue;
4286                 if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
4287                     !rt->fib6_nh->fib_nh_gw_family)
4288                         continue;
4289                 if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr))
4290                         continue;
4291                 if (!fib6_info_hold_safe(rt))
4292                         continue;
4293                 break;
4294         }
4295 out:
4296         rcu_read_unlock();
4297         return rt;
4298 }
4299
4300 static struct fib6_info *rt6_add_route_info(struct net *net,
4301                                            const struct in6_addr *prefix, int prefixlen,
4302                                            const struct in6_addr *gwaddr,
4303                                            struct net_device *dev,
4304                                            unsigned int pref)
4305 {
4306         struct fib6_config cfg = {
4307                 .fc_metric      = IP6_RT_PRIO_USER,
4308                 .fc_ifindex     = dev->ifindex,
4309                 .fc_dst_len     = prefixlen,
4310                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
4311                                   RTF_UP | RTF_PREF(pref),
4312                 .fc_protocol = RTPROT_RA,
4313                 .fc_type = RTN_UNICAST,
4314                 .fc_nlinfo.portid = 0,
4315                 .fc_nlinfo.nlh = NULL,
4316                 .fc_nlinfo.nl_net = net,
4317         };
4318
4319         cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4320         cfg.fc_dst = *prefix;
4321         cfg.fc_gateway = *gwaddr;
4322
4323         /* We should treat it as a default route if prefix length is 0. */
4324         if (!prefixlen)
4325                 cfg.fc_flags |= RTF_DEFAULT;
4326
4327         ip6_route_add(&cfg, GFP_ATOMIC, NULL);
4328
4329         return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
4330 }
4331 #endif
4332
4333 struct fib6_info *rt6_get_dflt_router(struct net *net,
4334                                      const struct in6_addr *addr,
4335                                      struct net_device *dev)
4336 {
4337         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
4338         struct fib6_info *rt;
4339         struct fib6_table *table;
4340
4341         table = fib6_get_table(net, tb_id);
4342         if (!table)
4343                 return NULL;
4344
4345         rcu_read_lock();
4346         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4347                 struct fib6_nh *nh;
4348
4349                 /* RA routes do not use nexthops */
4350                 if (rt->nh)
4351                         continue;
4352
4353                 nh = rt->fib6_nh;
4354                 if (dev == nh->fib_nh_dev &&
4355                     ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
4356                     ipv6_addr_equal(&nh->fib_nh_gw6, addr))
4357                         break;
4358         }
4359         if (rt && !fib6_info_hold_safe(rt))
4360                 rt = NULL;
4361         rcu_read_unlock();
4362         return rt;
4363 }
4364
4365 struct fib6_info *rt6_add_dflt_router(struct net *net,
4366                                      const struct in6_addr *gwaddr,
4367                                      struct net_device *dev,
4368                                      unsigned int pref,
4369                                      u32 defrtr_usr_metric,
4370                                      int lifetime)
4371 {
4372         struct fib6_config cfg = {
4373                 .fc_table       = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
4374                 .fc_metric      = defrtr_usr_metric,
4375                 .fc_ifindex     = dev->ifindex,
4376                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
4377                                   RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
4378                 .fc_protocol = RTPROT_RA,
4379                 .fc_type = RTN_UNICAST,
4380                 .fc_nlinfo.portid = 0,
4381                 .fc_nlinfo.nlh = NULL,
4382                 .fc_nlinfo.nl_net = net,
4383                 .fc_expires = jiffies_to_clock_t(lifetime * HZ),
4384         };
4385
4386         cfg.fc_gateway = *gwaddr;
4387
4388         if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
4389                 struct fib6_table *table;
4390
4391                 table = fib6_get_table(dev_net(dev), cfg.fc_table);
4392                 if (table)
4393                         table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
4394         }
4395
4396         return rt6_get_dflt_router(net, gwaddr, dev);
4397 }
4398
4399 static void __rt6_purge_dflt_routers(struct net *net,
4400                                      struct fib6_table *table)
4401 {
4402         struct fib6_info *rt;
4403
4404 restart:
4405         rcu_read_lock();
4406         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4407                 struct net_device *dev = fib6_info_nh_dev(rt);
4408                 struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
4409
4410                 if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
4411                     (!idev || idev->cnf.accept_ra != 2) &&
4412                     fib6_info_hold_safe(rt)) {
4413                         rcu_read_unlock();
4414                         ip6_del_rt(net, rt, false);
4415                         goto restart;
4416                 }
4417         }
4418         rcu_read_unlock();
4419
4420         table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
4421 }
4422
4423 void rt6_purge_dflt_routers(struct net *net)
4424 {
4425         struct fib6_table *table;
4426         struct hlist_head *head;
4427         unsigned int h;
4428
4429         rcu_read_lock();
4430
4431         for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
4432                 head = &net->ipv6.fib_table_hash[h];
4433                 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
4434                         if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
4435                                 __rt6_purge_dflt_routers(net, table);
4436                 }
4437         }
4438
4439         rcu_read_unlock();
4440 }
4441
4442 static void rtmsg_to_fib6_config(struct net *net,
4443                                  struct in6_rtmsg *rtmsg,
4444                                  struct fib6_config *cfg)
4445 {
4446         *cfg = (struct fib6_config){
4447                 .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
4448                          : RT6_TABLE_MAIN,
4449                 .fc_ifindex = rtmsg->rtmsg_ifindex,
4450                 .fc_metric = rtmsg->rtmsg_metric,
4451                 .fc_expires = rtmsg->rtmsg_info,
4452                 .fc_dst_len = rtmsg->rtmsg_dst_len,
4453                 .fc_src_len = rtmsg->rtmsg_src_len,
4454                 .fc_flags = rtmsg->rtmsg_flags,
4455                 .fc_type = rtmsg->rtmsg_type,
4456
4457                 .fc_nlinfo.nl_net = net,
4458
4459                 .fc_dst = rtmsg->rtmsg_dst,
4460                 .fc_src = rtmsg->rtmsg_src,
4461                 .fc_gateway = rtmsg->rtmsg_gateway,
4462         };
4463 }
4464
4465 int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg)
4466 {
4467         struct fib6_config cfg;
4468         int err;
4469
4470         if (cmd != SIOCADDRT && cmd != SIOCDELRT)
4471                 return -EINVAL;
4472         if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
4473                 return -EPERM;
4474
4475         rtmsg_to_fib6_config(net, rtmsg, &cfg);
4476
4477         rtnl_lock();
4478         switch (cmd) {
4479         case SIOCADDRT:
4480                 /* Only do the default setting of fc_metric in route adding */
4481                 if (cfg.fc_metric == 0)
4482                         cfg.fc_metric = IP6_RT_PRIO_USER;
4483                 err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
4484                 break;
4485         case SIOCDELRT:
4486                 err = ip6_route_del(&cfg, NULL);
4487                 break;
4488         }
4489         rtnl_unlock();
4490         return err;
4491 }
4492
4493 /*
4494  *      Drop the packet on the floor
4495  */
4496
4497 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
4498 {
4499         struct dst_entry *dst = skb_dst(skb);
4500         struct net *net = dev_net(dst->dev);
4501         struct inet6_dev *idev;
4502         SKB_DR(reason);
4503         int type;
4504
4505         if (netif_is_l3_master(skb->dev) ||
4506             dst->dev == net->loopback_dev)
4507                 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
4508         else
4509                 idev = ip6_dst_idev(dst);
4510
4511         switch (ipstats_mib_noroutes) {
4512         case IPSTATS_MIB_INNOROUTES:
4513                 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
4514                 if (type == IPV6_ADDR_ANY) {
4515                         SKB_DR_SET(reason, IP_INADDRERRORS);
4516                         IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
4517                         break;
4518                 }
4519                 SKB_DR_SET(reason, IP_INNOROUTES);
4520                 fallthrough;
4521         case IPSTATS_MIB_OUTNOROUTES:
4522                 SKB_DR_OR(reason, IP_OUTNOROUTES);
4523                 IP6_INC_STATS(net, idev, ipstats_mib_noroutes);
4524                 break;
4525         }
4526
4527         /* Start over by dropping the dst for l3mdev case */
4528         if (netif_is_l3_master(skb->dev))
4529                 skb_dst_drop(skb);
4530
4531         icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
4532         kfree_skb_reason(skb, reason);
4533         return 0;
4534 }
4535
4536 static int ip6_pkt_discard(struct sk_buff *skb)
4537 {
4538         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
4539 }
4540
4541 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4542 {
4543         skb->dev = skb_dst(skb)->dev;
4544         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
4545 }
4546
4547 static int ip6_pkt_prohibit(struct sk_buff *skb)
4548 {
4549         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
4550 }
4551
4552 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4553 {
4554         skb->dev = skb_dst(skb)->dev;
4555         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
4556 }
4557
4558 /*
4559  *      Allocate a dst for local (unicast / anycast) address.
4560  */
4561
4562 struct fib6_info *addrconf_f6i_alloc(struct net *net,
4563                                      struct inet6_dev *idev,
4564                                      const struct in6_addr *addr,
4565                                      bool anycast, gfp_t gfp_flags,
4566                                      struct netlink_ext_ack *extack)
4567 {
4568         struct fib6_config cfg = {
4569                 .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
4570                 .fc_ifindex = idev->dev->ifindex,
4571                 .fc_flags = RTF_UP | RTF_NONEXTHOP,
4572                 .fc_dst = *addr,
4573                 .fc_dst_len = 128,
4574                 .fc_protocol = RTPROT_KERNEL,
4575                 .fc_nlinfo.nl_net = net,
4576                 .fc_ignore_dev_down = true,
4577         };
4578         struct fib6_info *f6i;
4579
4580         if (anycast) {
4581                 cfg.fc_type = RTN_ANYCAST;
4582                 cfg.fc_flags |= RTF_ANYCAST;
4583         } else {
4584                 cfg.fc_type = RTN_LOCAL;
4585                 cfg.fc_flags |= RTF_LOCAL;
4586         }
4587
4588         f6i = ip6_route_info_create(&cfg, gfp_flags, extack);
4589         if (!IS_ERR(f6i)) {
4590                 f6i->dst_nocount = true;
4591
4592                 if (!anycast &&
4593                     (READ_ONCE(net->ipv6.devconf_all->disable_policy) ||
4594                      READ_ONCE(idev->cnf.disable_policy)))
4595                         f6i->dst_nopolicy = true;
4596         }
4597
4598         return f6i;
4599 }
4600
4601 /* remove deleted ip from prefsrc entries */
4602 struct arg_dev_net_ip {
4603         struct net *net;
4604         struct in6_addr *addr;
4605 };
4606
4607 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
4608 {
4609         struct net *net = ((struct arg_dev_net_ip *)arg)->net;
4610         struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
4611
4612         if (!rt->nh &&
4613             rt != net->ipv6.fib6_null_entry &&
4614             ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr) &&
4615             !ipv6_chk_addr(net, addr, rt->fib6_nh->fib_nh_dev, 0)) {
4616                 spin_lock_bh(&rt6_exception_lock);
4617                 /* remove prefsrc entry */
4618                 rt->fib6_prefsrc.plen = 0;
4619                 spin_unlock_bh(&rt6_exception_lock);
4620         }
4621         return 0;
4622 }
4623
4624 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
4625 {
4626         struct net *net = dev_net(ifp->idev->dev);
4627         struct arg_dev_net_ip adni = {
4628                 .net = net,
4629                 .addr = &ifp->addr,
4630         };
4631         fib6_clean_all(net, fib6_remove_prefsrc, &adni);
4632 }
4633
4634 #define RTF_RA_ROUTER           (RTF_ADDRCONF | RTF_DEFAULT)
4635
4636 /* Remove routers and update dst entries when gateway turn into host. */
4637 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
4638 {
4639         struct in6_addr *gateway = (struct in6_addr *)arg;
4640         struct fib6_nh *nh;
4641
4642         /* RA routes do not use nexthops */
4643         if (rt->nh)
4644                 return 0;
4645
4646         nh = rt->fib6_nh;
4647         if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
4648             nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6))
4649                 return -1;
4650
4651         /* Further clean up cached routes in exception table.
4652          * This is needed because cached route may have a different
4653          * gateway than its 'parent' in the case of an ip redirect.
4654          */
4655         fib6_nh_exceptions_clean_tohost(nh, gateway);
4656
4657         return 0;
4658 }
4659
4660 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
4661 {
4662         fib6_clean_all(net, fib6_clean_tohost, gateway);
4663 }
4664
4665 struct arg_netdev_event {
4666         const struct net_device *dev;
4667         union {
4668                 unsigned char nh_flags;
4669                 unsigned long event;
4670         };
4671 };
4672
4673 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
4674 {
4675         struct fib6_info *iter;
4676         struct fib6_node *fn;
4677
4678         fn = rcu_dereference_protected(rt->fib6_node,
4679                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4680         iter = rcu_dereference_protected(fn->leaf,
4681                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4682         while (iter) {
4683                 if (iter->fib6_metric == rt->fib6_metric &&
4684                     rt6_qualify_for_ecmp(iter))
4685                         return iter;
4686                 iter = rcu_dereference_protected(iter->fib6_next,
4687                                 lockdep_is_held(&rt->fib6_table->tb6_lock));
4688         }
4689
4690         return NULL;
4691 }
4692
4693 /* only called for fib entries with builtin fib6_nh */
4694 static bool rt6_is_dead(const struct fib6_info *rt)
4695 {
4696         if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD ||
4697             (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN &&
4698              ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev)))
4699                 return true;
4700
4701         return false;
4702 }
4703
4704 static int rt6_multipath_total_weight(const struct fib6_info *rt)
4705 {
4706         struct fib6_info *iter;
4707         int total = 0;
4708
4709         if (!rt6_is_dead(rt))
4710                 total += rt->fib6_nh->fib_nh_weight;
4711
4712         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
4713                 if (!rt6_is_dead(iter))
4714                         total += iter->fib6_nh->fib_nh_weight;
4715         }
4716
4717         return total;
4718 }
4719
4720 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
4721 {
4722         int upper_bound = -1;
4723
4724         if (!rt6_is_dead(rt)) {
4725                 *weight += rt->fib6_nh->fib_nh_weight;
4726                 upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
4727                                                     total) - 1;
4728         }
4729         atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
4730 }
4731
4732 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
4733 {
4734         struct fib6_info *iter;
4735         int weight = 0;
4736
4737         rt6_upper_bound_set(rt, &weight, total);
4738
4739         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4740                 rt6_upper_bound_set(iter, &weight, total);
4741 }
4742
4743 void rt6_multipath_rebalance(struct fib6_info *rt)
4744 {
4745         struct fib6_info *first;
4746         int total;
4747
4748         /* In case the entire multipath route was marked for flushing,
4749          * then there is no need to rebalance upon the removal of every
4750          * sibling route.
4751          */
4752         if (!rt->fib6_nsiblings || rt->should_flush)
4753                 return;
4754
4755         /* During lookup routes are evaluated in order, so we need to
4756          * make sure upper bounds are assigned from the first sibling
4757          * onwards.
4758          */
4759         first = rt6_multipath_first_sibling(rt);
4760         if (WARN_ON_ONCE(!first))
4761                 return;
4762
4763         total = rt6_multipath_total_weight(first);
4764         rt6_multipath_upper_bound_set(first, total);
4765 }
4766
4767 static int fib6_ifup(struct fib6_info *rt, void *p_arg)
4768 {
4769         const struct arg_netdev_event *arg = p_arg;
4770         struct net *net = dev_net(arg->dev);
4771
4772         if (rt != net->ipv6.fib6_null_entry && !rt->nh &&
4773             rt->fib6_nh->fib_nh_dev == arg->dev) {
4774                 rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags;
4775                 fib6_update_sernum_upto_root(net, rt);
4776                 rt6_multipath_rebalance(rt);
4777         }
4778
4779         return 0;
4780 }
4781
4782 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags)
4783 {
4784         struct arg_netdev_event arg = {
4785                 .dev = dev,
4786                 {
4787                         .nh_flags = nh_flags,
4788                 },
4789         };
4790
4791         if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
4792                 arg.nh_flags |= RTNH_F_LINKDOWN;
4793
4794         fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
4795 }
4796
4797 /* only called for fib entries with inline fib6_nh */
4798 static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
4799                                    const struct net_device *dev)
4800 {
4801         struct fib6_info *iter;
4802
4803         if (rt->fib6_nh->fib_nh_dev == dev)
4804                 return true;
4805         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4806                 if (iter->fib6_nh->fib_nh_dev == dev)
4807                         return true;
4808
4809         return false;
4810 }
4811
4812 static void rt6_multipath_flush(struct fib6_info *rt)
4813 {
4814         struct fib6_info *iter;
4815
4816         rt->should_flush = 1;
4817         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4818                 iter->should_flush = 1;
4819 }
4820
4821 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
4822                                              const struct net_device *down_dev)
4823 {
4824         struct fib6_info *iter;
4825         unsigned int dead = 0;
4826
4827         if (rt->fib6_nh->fib_nh_dev == down_dev ||
4828             rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4829                 dead++;
4830         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4831                 if (iter->fib6_nh->fib_nh_dev == down_dev ||
4832                     iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4833                         dead++;
4834
4835         return dead;
4836 }
4837
4838 static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
4839                                        const struct net_device *dev,
4840                                        unsigned char nh_flags)
4841 {
4842         struct fib6_info *iter;
4843
4844         if (rt->fib6_nh->fib_nh_dev == dev)
4845                 rt->fib6_nh->fib_nh_flags |= nh_flags;
4846         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4847                 if (iter->fib6_nh->fib_nh_dev == dev)
4848                         iter->fib6_nh->fib_nh_flags |= nh_flags;
4849 }
4850
4851 /* called with write lock held for table with rt */
4852 static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
4853 {
4854         const struct arg_netdev_event *arg = p_arg;
4855         const struct net_device *dev = arg->dev;
4856         struct net *net = dev_net(dev);
4857
4858         if (rt == net->ipv6.fib6_null_entry || rt->nh)
4859                 return 0;
4860
4861         switch (arg->event) {
4862         case NETDEV_UNREGISTER:
4863                 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4864         case NETDEV_DOWN:
4865                 if (rt->should_flush)
4866                         return -1;
4867                 if (!rt->fib6_nsiblings)
4868                         return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4869                 if (rt6_multipath_uses_dev(rt, dev)) {
4870                         unsigned int count;
4871
4872                         count = rt6_multipath_dead_count(rt, dev);
4873                         if (rt->fib6_nsiblings + 1 == count) {
4874                                 rt6_multipath_flush(rt);
4875                                 return -1;
4876                         }
4877                         rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
4878                                                    RTNH_F_LINKDOWN);
4879                         fib6_update_sernum(net, rt);
4880                         rt6_multipath_rebalance(rt);
4881                 }
4882                 return -2;
4883         case NETDEV_CHANGE:
4884                 if (rt->fib6_nh->fib_nh_dev != dev ||
4885                     rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
4886                         break;
4887                 rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
4888                 rt6_multipath_rebalance(rt);
4889                 break;
4890         }
4891
4892         return 0;
4893 }
4894
4895 void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
4896 {
4897         struct arg_netdev_event arg = {
4898                 .dev = dev,
4899                 {
4900                         .event = event,
4901                 },
4902         };
4903         struct net *net = dev_net(dev);
4904
4905         if (net->ipv6.sysctl.skip_notify_on_dev_down)
4906                 fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
4907         else
4908                 fib6_clean_all(net, fib6_ifdown, &arg);
4909 }
4910
4911 void rt6_disable_ip(struct net_device *dev, unsigned long event)
4912 {
4913         rt6_sync_down_dev(dev, event);
4914         rt6_uncached_list_flush_dev(dev);
4915         neigh_ifdown(&nd_tbl, dev);
4916 }
4917
4918 struct rt6_mtu_change_arg {
4919         struct net_device *dev;
4920         unsigned int mtu;
4921         struct fib6_info *f6i;
4922 };
4923
4924 static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
4925 {
4926         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg;
4927         struct fib6_info *f6i = arg->f6i;
4928
4929         /* For administrative MTU increase, there is no way to discover
4930          * IPv6 PMTU increase, so PMTU increase should be updated here.
4931          * Since RFC 1981 doesn't include administrative MTU increase
4932          * update PMTU increase is a MUST. (i.e. jumbo frame)
4933          */
4934         if (nh->fib_nh_dev == arg->dev) {
4935                 struct inet6_dev *idev = __in6_dev_get(arg->dev);
4936                 u32 mtu = f6i->fib6_pmtu;
4937
4938                 if (mtu >= arg->mtu ||
4939                     (mtu < arg->mtu && mtu == idev->cnf.mtu6))
4940                         fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
4941
4942                 spin_lock_bh(&rt6_exception_lock);
4943                 rt6_exceptions_update_pmtu(idev, nh, arg->mtu);
4944                 spin_unlock_bh(&rt6_exception_lock);
4945         }
4946
4947         return 0;
4948 }
4949
4950 static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
4951 {
4952         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
4953         struct inet6_dev *idev;
4954
4955         /* In IPv6 pmtu discovery is not optional,
4956            so that RTAX_MTU lock cannot disable it.
4957            We still use this lock to block changes
4958            caused by addrconf/ndisc.
4959         */
4960
4961         idev = __in6_dev_get(arg->dev);
4962         if (!idev)
4963                 return 0;
4964
4965         if (fib6_metric_locked(f6i, RTAX_MTU))
4966                 return 0;
4967
4968         arg->f6i = f6i;
4969         if (f6i->nh) {
4970                 /* fib6_nh_mtu_change only returns 0, so this is safe */
4971                 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change,
4972                                                 arg);
4973         }
4974
4975         return fib6_nh_mtu_change(f6i->fib6_nh, arg);
4976 }
4977
4978 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
4979 {
4980         struct rt6_mtu_change_arg arg = {
4981                 .dev = dev,
4982                 .mtu = mtu,
4983         };
4984
4985         fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
4986 }
4987
4988 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
4989         [RTA_UNSPEC]            = { .strict_start_type = RTA_DPORT + 1 },
4990         [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
4991         [RTA_PREFSRC]           = { .len = sizeof(struct in6_addr) },
4992         [RTA_OIF]               = { .type = NLA_U32 },
4993         [RTA_IIF]               = { .type = NLA_U32 },
4994         [RTA_PRIORITY]          = { .type = NLA_U32 },
4995         [RTA_METRICS]           = { .type = NLA_NESTED },
4996         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
4997         [RTA_PREF]              = { .type = NLA_U8 },
4998         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
4999         [RTA_ENCAP]             = { .type = NLA_NESTED },
5000         [RTA_EXPIRES]           = { .type = NLA_U32 },
5001         [RTA_UID]               = { .type = NLA_U32 },
5002         [RTA_MARK]              = { .type = NLA_U32 },
5003         [RTA_TABLE]             = { .type = NLA_U32 },
5004         [RTA_IP_PROTO]          = { .type = NLA_U8 },
5005         [RTA_SPORT]             = { .type = NLA_U16 },
5006         [RTA_DPORT]             = { .type = NLA_U16 },
5007         [RTA_NH_ID]             = { .type = NLA_U32 },
5008 };
5009
5010 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
5011                               struct fib6_config *cfg,
5012                               struct netlink_ext_ack *extack)
5013 {
5014         struct rtmsg *rtm;
5015         struct nlattr *tb[RTA_MAX+1];
5016         unsigned int pref;
5017         int err;
5018
5019         err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5020                                      rtm_ipv6_policy, extack);
5021         if (err < 0)
5022                 goto errout;
5023
5024         err = -EINVAL;
5025         rtm = nlmsg_data(nlh);
5026
5027         if (rtm->rtm_tos) {
5028                 NL_SET_ERR_MSG(extack,
5029                                "Invalid dsfield (tos): option not available for IPv6");
5030                 goto errout;
5031         }
5032
5033         *cfg = (struct fib6_config){
5034                 .fc_table = rtm->rtm_table,
5035                 .fc_dst_len = rtm->rtm_dst_len,
5036                 .fc_src_len = rtm->rtm_src_len,
5037                 .fc_flags = RTF_UP,
5038                 .fc_protocol = rtm->rtm_protocol,
5039                 .fc_type = rtm->rtm_type,
5040
5041                 .fc_nlinfo.portid = NETLINK_CB(skb).portid,
5042                 .fc_nlinfo.nlh = nlh,
5043                 .fc_nlinfo.nl_net = sock_net(skb->sk),
5044         };
5045
5046         if (rtm->rtm_type == RTN_UNREACHABLE ||
5047             rtm->rtm_type == RTN_BLACKHOLE ||
5048             rtm->rtm_type == RTN_PROHIBIT ||
5049             rtm->rtm_type == RTN_THROW)
5050                 cfg->fc_flags |= RTF_REJECT;
5051
5052         if (rtm->rtm_type == RTN_LOCAL)
5053                 cfg->fc_flags |= RTF_LOCAL;
5054
5055         if (rtm->rtm_flags & RTM_F_CLONED)
5056                 cfg->fc_flags |= RTF_CACHE;
5057
5058         cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
5059
5060         if (tb[RTA_NH_ID]) {
5061                 if (tb[RTA_GATEWAY]   || tb[RTA_OIF] ||
5062                     tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {
5063                         NL_SET_ERR_MSG(extack,
5064                                        "Nexthop specification and nexthop id are mutually exclusive");
5065                         goto errout;
5066                 }
5067                 cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);
5068         }
5069
5070         if (tb[RTA_GATEWAY]) {
5071                 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
5072                 cfg->fc_flags |= RTF_GATEWAY;
5073         }
5074         if (tb[RTA_VIA]) {
5075                 NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
5076                 goto errout;
5077         }
5078
5079         if (tb[RTA_DST]) {
5080                 int plen = (rtm->rtm_dst_len + 7) >> 3;
5081
5082                 if (nla_len(tb[RTA_DST]) < plen)
5083                         goto errout;
5084
5085                 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
5086         }
5087
5088         if (tb[RTA_SRC]) {
5089                 int plen = (rtm->rtm_src_len + 7) >> 3;
5090
5091                 if (nla_len(tb[RTA_SRC]) < plen)
5092                         goto errout;
5093
5094                 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
5095         }
5096
5097         if (tb[RTA_PREFSRC])
5098                 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
5099
5100         if (tb[RTA_OIF])
5101                 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
5102
5103         if (tb[RTA_PRIORITY])
5104                 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
5105
5106         if (tb[RTA_METRICS]) {
5107                 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
5108                 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
5109         }
5110
5111         if (tb[RTA_TABLE])
5112                 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
5113
5114         if (tb[RTA_MULTIPATH]) {
5115                 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
5116                 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
5117
5118                 err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
5119                                                      cfg->fc_mp_len, extack);
5120                 if (err < 0)
5121                         goto errout;
5122         }
5123
5124         if (tb[RTA_PREF]) {
5125                 pref = nla_get_u8(tb[RTA_PREF]);
5126                 if (pref != ICMPV6_ROUTER_PREF_LOW &&
5127                     pref != ICMPV6_ROUTER_PREF_HIGH)
5128                         pref = ICMPV6_ROUTER_PREF_MEDIUM;
5129                 cfg->fc_flags |= RTF_PREF(pref);
5130         }
5131
5132         if (tb[RTA_ENCAP])
5133                 cfg->fc_encap = tb[RTA_ENCAP];
5134
5135         if (tb[RTA_ENCAP_TYPE]) {
5136                 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
5137
5138                 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
5139                 if (err < 0)
5140                         goto errout;
5141         }
5142
5143         if (tb[RTA_EXPIRES]) {
5144                 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
5145
5146                 if (addrconf_finite_timeout(timeout)) {
5147                         cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
5148                         cfg->fc_flags |= RTF_EXPIRES;
5149                 }
5150         }
5151
5152         err = 0;
5153 errout:
5154         return err;
5155 }
5156
5157 struct rt6_nh {
5158         struct fib6_info *fib6_info;
5159         struct fib6_config r_cfg;
5160         struct list_head next;
5161 };
5162
5163 static int ip6_route_info_append(struct net *net,
5164                                  struct list_head *rt6_nh_list,
5165                                  struct fib6_info *rt,
5166                                  struct fib6_config *r_cfg)
5167 {
5168         struct rt6_nh *nh;
5169         int err = -EEXIST;
5170
5171         list_for_each_entry(nh, rt6_nh_list, next) {
5172                 /* check if fib6_info already exists */
5173                 if (rt6_duplicate_nexthop(nh->fib6_info, rt))
5174                         return err;
5175         }
5176
5177         nh = kzalloc(sizeof(*nh), GFP_KERNEL);
5178         if (!nh)
5179                 return -ENOMEM;
5180         nh->fib6_info = rt;
5181         memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
5182         list_add_tail(&nh->next, rt6_nh_list);
5183
5184         return 0;
5185 }
5186
5187 static void ip6_route_mpath_notify(struct fib6_info *rt,
5188                                    struct fib6_info *rt_last,
5189                                    struct nl_info *info,
5190                                    __u16 nlflags)
5191 {
5192         /* if this is an APPEND route, then rt points to the first route
5193          * inserted and rt_last points to last route inserted. Userspace
5194          * wants a consistent dump of the route which starts at the first
5195          * nexthop. Since sibling routes are always added at the end of
5196          * the list, find the first sibling of the last route appended
5197          */
5198         if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
5199                 rt = list_first_entry(&rt_last->fib6_siblings,
5200                                       struct fib6_info,
5201                                       fib6_siblings);
5202         }
5203
5204         if (rt)
5205                 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
5206 }
5207
5208 static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
5209 {
5210         bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
5211         bool should_notify = false;
5212         struct fib6_info *leaf;
5213         struct fib6_node *fn;
5214
5215         rcu_read_lock();
5216         fn = rcu_dereference(rt->fib6_node);
5217         if (!fn)
5218                 goto out;
5219
5220         leaf = rcu_dereference(fn->leaf);
5221         if (!leaf)
5222                 goto out;
5223
5224         if (rt == leaf ||
5225             (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric &&
5226              rt6_qualify_for_ecmp(leaf)))
5227                 should_notify = true;
5228 out:
5229         rcu_read_unlock();
5230
5231         return should_notify;
5232 }
5233
5234 static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla,
5235                              struct netlink_ext_ack *extack)
5236 {
5237         if (nla_len(nla) < sizeof(*gw)) {
5238                 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY");
5239                 return -EINVAL;
5240         }
5241
5242         *gw = nla_get_in6_addr(nla);
5243
5244         return 0;
5245 }
5246
5247 static int ip6_route_multipath_add(struct fib6_config *cfg,
5248                                    struct netlink_ext_ack *extack)
5249 {
5250         struct fib6_info *rt_notif = NULL, *rt_last = NULL;
5251         struct nl_info *info = &cfg->fc_nlinfo;
5252         struct fib6_config r_cfg;
5253         struct rtnexthop *rtnh;
5254         struct fib6_info *rt;
5255         struct rt6_nh *err_nh;
5256         struct rt6_nh *nh, *nh_safe;
5257         __u16 nlflags;
5258         int remaining;
5259         int attrlen;
5260         int err = 1;
5261         int nhn = 0;
5262         int replace = (cfg->fc_nlinfo.nlh &&
5263                        (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
5264         LIST_HEAD(rt6_nh_list);
5265
5266         nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
5267         if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
5268                 nlflags |= NLM_F_APPEND;
5269
5270         remaining = cfg->fc_mp_len;
5271         rtnh = (struct rtnexthop *)cfg->fc_mp;
5272
5273         /* Parse a Multipath Entry and build a list (rt6_nh_list) of
5274          * fib6_info structs per nexthop
5275          */
5276         while (rtnh_ok(rtnh, remaining)) {
5277                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5278                 if (rtnh->rtnh_ifindex)
5279                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5280
5281                 attrlen = rtnh_attrlen(rtnh);
5282                 if (attrlen > 0) {
5283                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5284
5285                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5286                         if (nla) {
5287                                 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5288                                                         extack);
5289                                 if (err)
5290                                         goto cleanup;
5291
5292                                 r_cfg.fc_flags |= RTF_GATEWAY;
5293                         }
5294                         r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
5295
5296                         /* RTA_ENCAP_TYPE length checked in
5297                          * lwtunnel_valid_encap_type_attr
5298                          */
5299                         nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
5300                         if (nla)
5301                                 r_cfg.fc_encap_type = nla_get_u16(nla);
5302                 }
5303
5304                 r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
5305                 rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
5306                 if (IS_ERR(rt)) {
5307                         err = PTR_ERR(rt);
5308                         rt = NULL;
5309                         goto cleanup;
5310                 }
5311                 if (!rt6_qualify_for_ecmp(rt)) {
5312                         err = -EINVAL;
5313                         NL_SET_ERR_MSG(extack,
5314                                        "Device only routes can not be added for IPv6 using the multipath API.");
5315                         fib6_info_release(rt);
5316                         goto cleanup;
5317                 }
5318
5319                 rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
5320
5321                 err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
5322                                             rt, &r_cfg);
5323                 if (err) {
5324                         fib6_info_release(rt);
5325                         goto cleanup;
5326                 }
5327
5328                 rtnh = rtnh_next(rtnh, &remaining);
5329         }
5330
5331         if (list_empty(&rt6_nh_list)) {
5332                 NL_SET_ERR_MSG(extack,
5333                                "Invalid nexthop configuration - no valid nexthops");
5334                 return -EINVAL;
5335         }
5336
5337         /* for add and replace send one notification with all nexthops.
5338          * Skip the notification in fib6_add_rt2node and send one with
5339          * the full route when done
5340          */
5341         info->skip_notify = 1;
5342
5343         /* For add and replace, send one notification with all nexthops. For
5344          * append, send one notification with all appended nexthops.
5345          */
5346         info->skip_notify_kernel = 1;
5347
5348         err_nh = NULL;
5349         list_for_each_entry(nh, &rt6_nh_list, next) {
5350                 err = __ip6_ins_rt(nh->fib6_info, info, extack);
5351
5352                 if (err) {
5353                         if (replace && nhn)
5354                                 NL_SET_ERR_MSG_MOD(extack,
5355                                                    "multipath route replace failed (check consistency of installed routes)");
5356                         err_nh = nh;
5357                         goto add_errout;
5358                 }
5359                 /* save reference to last route successfully inserted */
5360                 rt_last = nh->fib6_info;
5361
5362                 /* save reference to first route for notification */
5363                 if (!rt_notif)
5364                         rt_notif = nh->fib6_info;
5365
5366                 /* Because each route is added like a single route we remove
5367                  * these flags after the first nexthop: if there is a collision,
5368                  * we have already failed to add the first nexthop:
5369                  * fib6_add_rt2node() has rejected it; when replacing, old
5370                  * nexthops have been replaced by first new, the rest should
5371                  * be added to it.
5372                  */
5373                 if (cfg->fc_nlinfo.nlh) {
5374                         cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
5375                                                              NLM_F_REPLACE);
5376                         cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
5377                 }
5378                 nhn++;
5379         }
5380
5381         /* An in-kernel notification should only be sent in case the new
5382          * multipath route is added as the first route in the node, or if
5383          * it was appended to it. We pass 'rt_notif' since it is the first
5384          * sibling and might allow us to skip some checks in the replace case.
5385          */
5386         if (ip6_route_mpath_should_notify(rt_notif)) {
5387                 enum fib_event_type fib_event;
5388
5389                 if (rt_notif->fib6_nsiblings != nhn - 1)
5390                         fib_event = FIB_EVENT_ENTRY_APPEND;
5391                 else
5392                         fib_event = FIB_EVENT_ENTRY_REPLACE;
5393
5394                 err = call_fib6_multipath_entry_notifiers(info->nl_net,
5395                                                           fib_event, rt_notif,
5396                                                           nhn - 1, extack);
5397                 if (err) {
5398                         /* Delete all the siblings that were just added */
5399                         err_nh = NULL;
5400                         goto add_errout;
5401                 }
5402         }
5403
5404         /* success ... tell user about new route */
5405         ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5406         goto cleanup;
5407
5408 add_errout:
5409         /* send notification for routes that were added so that
5410          * the delete notifications sent by ip6_route_del are
5411          * coherent
5412          */
5413         if (rt_notif)
5414                 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5415
5416         /* Delete routes that were already added */
5417         list_for_each_entry(nh, &rt6_nh_list, next) {
5418                 if (err_nh == nh)
5419                         break;
5420                 ip6_route_del(&nh->r_cfg, extack);
5421         }
5422
5423 cleanup:
5424         list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
5425                 fib6_info_release(nh->fib6_info);
5426                 list_del(&nh->next);
5427                 kfree(nh);
5428         }
5429
5430         return err;
5431 }
5432
5433 static int ip6_route_multipath_del(struct fib6_config *cfg,
5434                                    struct netlink_ext_ack *extack)
5435 {
5436         struct fib6_config r_cfg;
5437         struct rtnexthop *rtnh;
5438         int last_err = 0;
5439         int remaining;
5440         int attrlen;
5441         int err;
5442
5443         remaining = cfg->fc_mp_len;
5444         rtnh = (struct rtnexthop *)cfg->fc_mp;
5445
5446         /* Parse a Multipath Entry */
5447         while (rtnh_ok(rtnh, remaining)) {
5448                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5449                 if (rtnh->rtnh_ifindex)
5450                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5451
5452                 attrlen = rtnh_attrlen(rtnh);
5453                 if (attrlen > 0) {
5454                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5455
5456                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5457                         if (nla) {
5458                                 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5459                                                         extack);
5460                                 if (err) {
5461                                         last_err = err;
5462                                         goto next_rtnh;
5463                                 }
5464
5465                                 r_cfg.fc_flags |= RTF_GATEWAY;
5466                         }
5467                 }
5468                 err = ip6_route_del(&r_cfg, extack);
5469                 if (err)
5470                         last_err = err;
5471
5472 next_rtnh:
5473                 rtnh = rtnh_next(rtnh, &remaining);
5474         }
5475
5476         return last_err;
5477 }
5478
5479 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5480                               struct netlink_ext_ack *extack)
5481 {
5482         struct fib6_config cfg;
5483         int err;
5484
5485         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5486         if (err < 0)
5487                 return err;
5488
5489         if (cfg.fc_nh_id &&
5490             !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {
5491                 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
5492                 return -EINVAL;
5493         }
5494
5495         if (cfg.fc_mp)
5496                 return ip6_route_multipath_del(&cfg, extack);
5497         else {
5498                 cfg.fc_delete_all_nh = 1;
5499                 return ip6_route_del(&cfg, extack);
5500         }
5501 }
5502
5503 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5504                               struct netlink_ext_ack *extack)
5505 {
5506         struct fib6_config cfg;
5507         int err;
5508
5509         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5510         if (err < 0)
5511                 return err;
5512
5513         if (cfg.fc_metric == 0)
5514                 cfg.fc_metric = IP6_RT_PRIO_USER;
5515
5516         if (cfg.fc_mp)
5517                 return ip6_route_multipath_add(&cfg, extack);
5518         else
5519                 return ip6_route_add(&cfg, GFP_KERNEL, extack);
5520 }
5521
5522 /* add the overhead of this fib6_nh to nexthop_len */
5523 static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg)
5524 {
5525         int *nexthop_len = arg;
5526
5527         *nexthop_len += nla_total_size(0)        /* RTA_MULTIPATH */
5528                      + NLA_ALIGN(sizeof(struct rtnexthop))
5529                      + nla_total_size(16); /* RTA_GATEWAY */
5530
5531         if (nh->fib_nh_lws) {
5532                 /* RTA_ENCAP_TYPE */
5533                 *nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5534                 /* RTA_ENCAP */
5535                 *nexthop_len += nla_total_size(2);
5536         }
5537
5538         return 0;
5539 }
5540
5541 static size_t rt6_nlmsg_size(struct fib6_info *f6i)
5542 {
5543         int nexthop_len;
5544
5545         if (f6i->nh) {
5546                 nexthop_len = nla_total_size(4); /* RTA_NH_ID */
5547                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
5548                                          &nexthop_len);
5549         } else {
5550                 struct fib6_info *sibling, *next_sibling;
5551                 struct fib6_nh *nh = f6i->fib6_nh;
5552
5553                 nexthop_len = 0;
5554                 if (f6i->fib6_nsiblings) {
5555                         rt6_nh_nlmsg_size(nh, &nexthop_len);
5556
5557                         list_for_each_entry_safe(sibling, next_sibling,
5558                                                  &f6i->fib6_siblings, fib6_siblings) {
5559                                 rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len);
5560                         }
5561                 }
5562                 nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5563         }
5564
5565         return NLMSG_ALIGN(sizeof(struct rtmsg))
5566                + nla_total_size(16) /* RTA_SRC */
5567                + nla_total_size(16) /* RTA_DST */
5568                + nla_total_size(16) /* RTA_GATEWAY */
5569                + nla_total_size(16) /* RTA_PREFSRC */
5570                + nla_total_size(4) /* RTA_TABLE */
5571                + nla_total_size(4) /* RTA_IIF */
5572                + nla_total_size(4) /* RTA_OIF */
5573                + nla_total_size(4) /* RTA_PRIORITY */
5574                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
5575                + nla_total_size(sizeof(struct rta_cacheinfo))
5576                + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
5577                + nla_total_size(1) /* RTA_PREF */
5578                + nexthop_len;
5579 }
5580
5581 static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh,
5582                                  unsigned char *flags)
5583 {
5584         if (nexthop_is_multipath(nh)) {
5585                 struct nlattr *mp;
5586
5587                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5588                 if (!mp)
5589                         goto nla_put_failure;
5590
5591                 if (nexthop_mpath_fill_node(skb, nh, AF_INET6))
5592                         goto nla_put_failure;
5593
5594                 nla_nest_end(skb, mp);
5595         } else {
5596                 struct fib6_nh *fib6_nh;
5597
5598                 fib6_nh = nexthop_fib6_nh(nh);
5599                 if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,
5600                                      flags, false) < 0)
5601                         goto nla_put_failure;
5602         }
5603
5604         return 0;
5605
5606 nla_put_failure:
5607         return -EMSGSIZE;
5608 }
5609
5610 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
5611                          struct fib6_info *rt, struct dst_entry *dst,
5612                          struct in6_addr *dest, struct in6_addr *src,
5613                          int iif, int type, u32 portid, u32 seq,
5614                          unsigned int flags)
5615 {
5616         struct rt6_info *rt6 = dst_rt6_info(dst);
5617         struct rt6key *rt6_dst, *rt6_src;
5618         u32 *pmetrics, table, rt6_flags;
5619         unsigned char nh_flags = 0;
5620         struct nlmsghdr *nlh;
5621         struct rtmsg *rtm;
5622         long expires = 0;
5623
5624         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
5625         if (!nlh)
5626                 return -EMSGSIZE;
5627
5628         if (rt6) {
5629                 rt6_dst = &rt6->rt6i_dst;
5630                 rt6_src = &rt6->rt6i_src;
5631                 rt6_flags = rt6->rt6i_flags;
5632         } else {
5633                 rt6_dst = &rt->fib6_dst;
5634                 rt6_src = &rt->fib6_src;
5635                 rt6_flags = rt->fib6_flags;
5636         }
5637
5638         rtm = nlmsg_data(nlh);
5639         rtm->rtm_family = AF_INET6;
5640         rtm->rtm_dst_len = rt6_dst->plen;
5641         rtm->rtm_src_len = rt6_src->plen;
5642         rtm->rtm_tos = 0;
5643         if (rt->fib6_table)
5644                 table = rt->fib6_table->tb6_id;
5645         else
5646                 table = RT6_TABLE_UNSPEC;
5647         rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
5648         if (nla_put_u32(skb, RTA_TABLE, table))
5649                 goto nla_put_failure;
5650
5651         rtm->rtm_type = rt->fib6_type;
5652         rtm->rtm_flags = 0;
5653         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
5654         rtm->rtm_protocol = rt->fib6_protocol;
5655
5656         if (rt6_flags & RTF_CACHE)
5657                 rtm->rtm_flags |= RTM_F_CLONED;
5658
5659         if (dest) {
5660                 if (nla_put_in6_addr(skb, RTA_DST, dest))
5661                         goto nla_put_failure;
5662                 rtm->rtm_dst_len = 128;
5663         } else if (rtm->rtm_dst_len)
5664                 if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
5665                         goto nla_put_failure;
5666 #ifdef CONFIG_IPV6_SUBTREES
5667         if (src) {
5668                 if (nla_put_in6_addr(skb, RTA_SRC, src))
5669                         goto nla_put_failure;
5670                 rtm->rtm_src_len = 128;
5671         } else if (rtm->rtm_src_len &&
5672                    nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
5673                 goto nla_put_failure;
5674 #endif
5675         if (iif) {
5676 #ifdef CONFIG_IPV6_MROUTE
5677                 if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
5678                         int err = ip6mr_get_route(net, skb, rtm, portid);
5679
5680                         if (err == 0)
5681                                 return 0;
5682                         if (err < 0)
5683                                 goto nla_put_failure;
5684                 } else
5685 #endif
5686                         if (nla_put_u32(skb, RTA_IIF, iif))
5687                                 goto nla_put_failure;
5688         } else if (dest) {
5689                 struct in6_addr saddr_buf;
5690                 if (ip6_route_get_saddr(net, rt, dest, 0, 0, &saddr_buf) == 0 &&
5691                     nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5692                         goto nla_put_failure;
5693         }
5694
5695         if (rt->fib6_prefsrc.plen) {
5696                 struct in6_addr saddr_buf;
5697                 saddr_buf = rt->fib6_prefsrc.addr;
5698                 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5699                         goto nla_put_failure;
5700         }
5701
5702         pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
5703         if (rtnetlink_put_metrics(skb, pmetrics) < 0)
5704                 goto nla_put_failure;
5705
5706         if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
5707                 goto nla_put_failure;
5708
5709         /* For multipath routes, walk the siblings list and add
5710          * each as a nexthop within RTA_MULTIPATH.
5711          */
5712         if (rt6) {
5713                 if (rt6_flags & RTF_GATEWAY &&
5714                     nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
5715                         goto nla_put_failure;
5716
5717                 if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
5718                         goto nla_put_failure;
5719
5720                 if (dst->lwtstate &&
5721                     lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
5722                         goto nla_put_failure;
5723         } else if (rt->fib6_nsiblings) {
5724                 struct fib6_info *sibling, *next_sibling;
5725                 struct nlattr *mp;
5726
5727                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5728                 if (!mp)
5729                         goto nla_put_failure;
5730
5731                 if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
5732                                     rt->fib6_nh->fib_nh_weight, AF_INET6,
5733                                     0) < 0)
5734                         goto nla_put_failure;
5735
5736                 list_for_each_entry_safe(sibling, next_sibling,
5737                                          &rt->fib6_siblings, fib6_siblings) {
5738                         if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
5739                                             sibling->fib6_nh->fib_nh_weight,
5740                                             AF_INET6, 0) < 0)
5741                                 goto nla_put_failure;
5742                 }
5743
5744                 nla_nest_end(skb, mp);
5745         } else if (rt->nh) {
5746                 if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
5747                         goto nla_put_failure;
5748
5749                 if (nexthop_is_blackhole(rt->nh))
5750                         rtm->rtm_type = RTN_BLACKHOLE;
5751
5752                 if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) &&
5753                     rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0)
5754                         goto nla_put_failure;
5755
5756                 rtm->rtm_flags |= nh_flags;
5757         } else {
5758                 if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,
5759                                      &nh_flags, false) < 0)
5760                         goto nla_put_failure;
5761
5762                 rtm->rtm_flags |= nh_flags;
5763         }
5764
5765         if (rt6_flags & RTF_EXPIRES) {
5766                 expires = dst ? dst->expires : rt->expires;
5767                 expires -= jiffies;
5768         }
5769
5770         if (!dst) {
5771                 if (READ_ONCE(rt->offload))
5772                         rtm->rtm_flags |= RTM_F_OFFLOAD;
5773                 if (READ_ONCE(rt->trap))
5774                         rtm->rtm_flags |= RTM_F_TRAP;
5775                 if (READ_ONCE(rt->offload_failed))
5776                         rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED;
5777         }
5778
5779         if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
5780                 goto nla_put_failure;
5781
5782         if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
5783                 goto nla_put_failure;
5784
5785
5786         nlmsg_end(skb, nlh);
5787         return 0;
5788
5789 nla_put_failure:
5790         nlmsg_cancel(skb, nlh);
5791         return -EMSGSIZE;
5792 }
5793
5794 static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg)
5795 {
5796         const struct net_device *dev = arg;
5797
5798         if (nh->fib_nh_dev == dev)
5799                 return 1;
5800
5801         return 0;
5802 }
5803
5804 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
5805                                const struct net_device *dev)
5806 {
5807         if (f6i->nh) {
5808                 struct net_device *_dev = (struct net_device *)dev;
5809
5810                 return !!nexthop_for_each_fib6_nh(f6i->nh,
5811                                                   fib6_info_nh_uses_dev,
5812                                                   _dev);
5813         }
5814
5815         if (f6i->fib6_nh->fib_nh_dev == dev)
5816                 return true;
5817
5818         if (f6i->fib6_nsiblings) {
5819                 struct fib6_info *sibling, *next_sibling;
5820
5821                 list_for_each_entry_safe(sibling, next_sibling,
5822                                          &f6i->fib6_siblings, fib6_siblings) {
5823                         if (sibling->fib6_nh->fib_nh_dev == dev)
5824                                 return true;
5825                 }
5826         }
5827
5828         return false;
5829 }
5830
5831 struct fib6_nh_exception_dump_walker {
5832         struct rt6_rtnl_dump_arg *dump;
5833         struct fib6_info *rt;
5834         unsigned int flags;
5835         unsigned int skip;
5836         unsigned int count;
5837 };
5838
5839 static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg)
5840 {
5841         struct fib6_nh_exception_dump_walker *w = arg;
5842         struct rt6_rtnl_dump_arg *dump = w->dump;
5843         struct rt6_exception_bucket *bucket;
5844         struct rt6_exception *rt6_ex;
5845         int i, err;
5846
5847         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
5848         if (!bucket)
5849                 return 0;
5850
5851         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
5852                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
5853                         if (w->skip) {
5854                                 w->skip--;
5855                                 continue;
5856                         }
5857
5858                         /* Expiration of entries doesn't bump sernum, insertion
5859                          * does. Removal is triggered by insertion, so we can
5860                          * rely on the fact that if entries change between two
5861                          * partial dumps, this node is scanned again completely,
5862                          * see rt6_insert_exception() and fib6_dump_table().
5863                          *
5864                          * Count expired entries we go through as handled
5865                          * entries that we'll skip next time, in case of partial
5866                          * node dump. Otherwise, if entries expire meanwhile,
5867                          * we'll skip the wrong amount.
5868                          */
5869                         if (rt6_check_expired(rt6_ex->rt6i)) {
5870                                 w->count++;
5871                                 continue;
5872                         }
5873
5874                         err = rt6_fill_node(dump->net, dump->skb, w->rt,
5875                                             &rt6_ex->rt6i->dst, NULL, NULL, 0,
5876                                             RTM_NEWROUTE,
5877                                             NETLINK_CB(dump->cb->skb).portid,
5878                                             dump->cb->nlh->nlmsg_seq, w->flags);
5879                         if (err)
5880                                 return err;
5881
5882                         w->count++;
5883                 }
5884                 bucket++;
5885         }
5886
5887         return 0;
5888 }
5889
5890 /* Return -1 if done with node, number of handled routes on partial dump */
5891 int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip)
5892 {
5893         struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
5894         struct fib_dump_filter *filter = &arg->filter;
5895         unsigned int flags = NLM_F_MULTI;
5896         struct net *net = arg->net;
5897         int count = 0;
5898
5899         if (rt == net->ipv6.fib6_null_entry)
5900                 return -1;
5901
5902         if ((filter->flags & RTM_F_PREFIX) &&
5903             !(rt->fib6_flags & RTF_PREFIX_RT)) {
5904                 /* success since this is not a prefix route */
5905                 return -1;
5906         }
5907         if (filter->filter_set &&
5908             ((filter->rt_type  && rt->fib6_type != filter->rt_type) ||
5909              (filter->dev      && !fib6_info_uses_dev(rt, filter->dev)) ||
5910              (filter->protocol && rt->fib6_protocol != filter->protocol))) {
5911                 return -1;
5912         }
5913
5914         if (filter->filter_set ||
5915             !filter->dump_routes || !filter->dump_exceptions) {
5916                 flags |= NLM_F_DUMP_FILTERED;
5917         }
5918
5919         if (filter->dump_routes) {
5920                 if (skip) {
5921                         skip--;
5922                 } else {
5923                         if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL,
5924                                           0, RTM_NEWROUTE,
5925                                           NETLINK_CB(arg->cb->skb).portid,
5926                                           arg->cb->nlh->nlmsg_seq, flags)) {
5927                                 return 0;
5928                         }
5929                         count++;
5930                 }
5931         }
5932
5933         if (filter->dump_exceptions) {
5934                 struct fib6_nh_exception_dump_walker w = { .dump = arg,
5935                                                            .rt = rt,
5936                                                            .flags = flags,
5937                                                            .skip = skip,
5938                                                            .count = 0 };
5939                 int err;
5940
5941                 rcu_read_lock();
5942                 if (rt->nh) {
5943                         err = nexthop_for_each_fib6_nh(rt->nh,
5944                                                        rt6_nh_dump_exceptions,
5945                                                        &w);
5946                 } else {
5947                         err = rt6_nh_dump_exceptions(rt->fib6_nh, &w);
5948                 }
5949                 rcu_read_unlock();
5950
5951                 if (err)
5952                         return count + w.count;
5953         }
5954
5955         return -1;
5956 }
5957
5958 static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
5959                                         const struct nlmsghdr *nlh,
5960                                         struct nlattr **tb,
5961                                         struct netlink_ext_ack *extack)
5962 {
5963         struct rtmsg *rtm;
5964         int i, err;
5965
5966         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
5967                 NL_SET_ERR_MSG_MOD(extack,
5968                                    "Invalid header for get route request");
5969                 return -EINVAL;
5970         }
5971
5972         if (!netlink_strict_get_check(skb))
5973                 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5974                                               rtm_ipv6_policy, extack);
5975
5976         rtm = nlmsg_data(nlh);
5977         if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
5978             (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
5979             rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
5980             rtm->rtm_type) {
5981                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
5982                 return -EINVAL;
5983         }
5984         if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
5985                 NL_SET_ERR_MSG_MOD(extack,
5986                                    "Invalid flags for get route request");
5987                 return -EINVAL;
5988         }
5989
5990         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
5991                                             rtm_ipv6_policy, extack);
5992         if (err)
5993                 return err;
5994
5995         if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
5996             (tb[RTA_DST] && !rtm->rtm_dst_len)) {
5997                 NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
5998                 return -EINVAL;
5999         }
6000
6001         for (i = 0; i <= RTA_MAX; i++) {
6002                 if (!tb[i])
6003                         continue;
6004
6005                 switch (i) {
6006                 case RTA_SRC:
6007                 case RTA_DST:
6008                 case RTA_IIF:
6009                 case RTA_OIF:
6010                 case RTA_MARK:
6011                 case RTA_UID:
6012                 case RTA_SPORT:
6013                 case RTA_DPORT:
6014                 case RTA_IP_PROTO:
6015                         break;
6016                 default:
6017                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
6018                         return -EINVAL;
6019                 }
6020         }
6021
6022         return 0;
6023 }
6024
6025 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
6026                               struct netlink_ext_ack *extack)
6027 {
6028         struct net *net = sock_net(in_skb->sk);
6029         struct nlattr *tb[RTA_MAX+1];
6030         int err, iif = 0, oif = 0;
6031         struct fib6_info *from;
6032         struct dst_entry *dst;
6033         struct rt6_info *rt;
6034         struct sk_buff *skb;
6035         struct rtmsg *rtm;
6036         struct flowi6 fl6 = {};
6037         bool fibmatch;
6038
6039         err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
6040         if (err < 0)
6041                 goto errout;
6042
6043         err = -EINVAL;
6044         rtm = nlmsg_data(nlh);
6045         fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
6046         fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
6047
6048         if (tb[RTA_SRC]) {
6049                 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
6050                         goto errout;
6051
6052                 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
6053         }
6054
6055         if (tb[RTA_DST]) {
6056                 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
6057                         goto errout;
6058
6059                 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
6060         }
6061
6062         if (tb[RTA_IIF])
6063                 iif = nla_get_u32(tb[RTA_IIF]);
6064
6065         if (tb[RTA_OIF])
6066                 oif = nla_get_u32(tb[RTA_OIF]);
6067
6068         if (tb[RTA_MARK])
6069                 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
6070
6071         if (tb[RTA_UID])
6072                 fl6.flowi6_uid = make_kuid(current_user_ns(),
6073                                            nla_get_u32(tb[RTA_UID]));
6074         else
6075                 fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
6076
6077         if (tb[RTA_SPORT])
6078                 fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
6079
6080         if (tb[RTA_DPORT])
6081                 fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
6082
6083         if (tb[RTA_IP_PROTO]) {
6084                 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
6085                                                   &fl6.flowi6_proto, AF_INET6,
6086                                                   extack);
6087                 if (err)
6088                         goto errout;
6089         }
6090
6091         if (iif) {
6092                 struct net_device *dev;
6093                 int flags = 0;
6094
6095                 rcu_read_lock();
6096
6097                 dev = dev_get_by_index_rcu(net, iif);
6098                 if (!dev) {
6099                         rcu_read_unlock();
6100                         err = -ENODEV;
6101                         goto errout;
6102                 }
6103
6104                 fl6.flowi6_iif = iif;
6105
6106                 if (!ipv6_addr_any(&fl6.saddr))
6107                         flags |= RT6_LOOKUP_F_HAS_SADDR;
6108
6109                 dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
6110
6111                 rcu_read_unlock();
6112         } else {
6113                 fl6.flowi6_oif = oif;
6114
6115                 dst = ip6_route_output(net, NULL, &fl6);
6116         }
6117
6118
6119         rt = dst_rt6_info(dst);
6120         if (rt->dst.error) {
6121                 err = rt->dst.error;
6122                 ip6_rt_put(rt);
6123                 goto errout;
6124         }
6125
6126         if (rt == net->ipv6.ip6_null_entry) {
6127                 err = rt->dst.error;
6128                 ip6_rt_put(rt);
6129                 goto errout;
6130         }
6131
6132         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
6133         if (!skb) {
6134                 ip6_rt_put(rt);
6135                 err = -ENOBUFS;
6136                 goto errout;
6137         }
6138
6139         skb_dst_set(skb, &rt->dst);
6140
6141         rcu_read_lock();
6142         from = rcu_dereference(rt->from);
6143         if (from) {
6144                 if (fibmatch)
6145                         err = rt6_fill_node(net, skb, from, NULL, NULL, NULL,
6146                                             iif, RTM_NEWROUTE,
6147                                             NETLINK_CB(in_skb).portid,
6148                                             nlh->nlmsg_seq, 0);
6149                 else
6150                         err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
6151                                             &fl6.saddr, iif, RTM_NEWROUTE,
6152                                             NETLINK_CB(in_skb).portid,
6153                                             nlh->nlmsg_seq, 0);
6154         } else {
6155                 err = -ENETUNREACH;
6156         }
6157         rcu_read_unlock();
6158
6159         if (err < 0) {
6160                 kfree_skb(skb);
6161                 goto errout;
6162         }
6163
6164         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
6165 errout:
6166         return err;
6167 }
6168
6169 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
6170                      unsigned int nlm_flags)
6171 {
6172         struct sk_buff *skb;
6173         struct net *net = info->nl_net;
6174         u32 seq;
6175         int err;
6176
6177         err = -ENOBUFS;
6178         seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6179
6180         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6181         if (!skb)
6182                 goto errout;
6183
6184         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6185                             event, info->portid, seq, nlm_flags);
6186         if (err < 0) {
6187                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6188                 WARN_ON(err == -EMSGSIZE);
6189                 kfree_skb(skb);
6190                 goto errout;
6191         }
6192         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6193                     info->nlh, gfp_any());
6194         return;
6195 errout:
6196         if (err < 0)
6197                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6198 }
6199
6200 void fib6_rt_update(struct net *net, struct fib6_info *rt,
6201                     struct nl_info *info)
6202 {
6203         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6204         struct sk_buff *skb;
6205         int err = -ENOBUFS;
6206
6207         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6208         if (!skb)
6209                 goto errout;
6210
6211         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6212                             RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
6213         if (err < 0) {
6214                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6215                 WARN_ON(err == -EMSGSIZE);
6216                 kfree_skb(skb);
6217                 goto errout;
6218         }
6219         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6220                     info->nlh, gfp_any());
6221         return;
6222 errout:
6223         if (err < 0)
6224                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6225 }
6226
6227 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
6228                             bool offload, bool trap, bool offload_failed)
6229 {
6230         struct sk_buff *skb;
6231         int err;
6232
6233         if (READ_ONCE(f6i->offload) == offload &&
6234             READ_ONCE(f6i->trap) == trap &&
6235             READ_ONCE(f6i->offload_failed) == offload_failed)
6236                 return;
6237
6238         WRITE_ONCE(f6i->offload, offload);
6239         WRITE_ONCE(f6i->trap, trap);
6240
6241         /* 2 means send notifications only if offload_failed was changed. */
6242         if (net->ipv6.sysctl.fib_notify_on_flag_change == 2 &&
6243             READ_ONCE(f6i->offload_failed) == offload_failed)
6244                 return;
6245
6246         WRITE_ONCE(f6i->offload_failed, offload_failed);
6247
6248         if (!rcu_access_pointer(f6i->fib6_node))
6249                 /* The route was removed from the tree, do not send
6250                  * notification.
6251                  */
6252                 return;
6253
6254         if (!net->ipv6.sysctl.fib_notify_on_flag_change)
6255                 return;
6256
6257         skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL);
6258         if (!skb) {
6259                 err = -ENOBUFS;
6260                 goto errout;
6261         }
6262
6263         err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0,
6264                             0, 0);
6265         if (err < 0) {
6266                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6267                 WARN_ON(err == -EMSGSIZE);
6268                 kfree_skb(skb);
6269                 goto errout;
6270         }
6271
6272         rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL);
6273         return;
6274
6275 errout:
6276         rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6277 }
6278 EXPORT_SYMBOL(fib6_info_hw_flags_set);
6279
6280 static int ip6_route_dev_notify(struct notifier_block *this,
6281                                 unsigned long event, void *ptr)
6282 {
6283         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
6284         struct net *net = dev_net(dev);
6285
6286         if (!(dev->flags & IFF_LOOPBACK))
6287                 return NOTIFY_OK;
6288
6289         if (event == NETDEV_REGISTER) {
6290                 net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev;
6291                 net->ipv6.ip6_null_entry->dst.dev = dev;
6292                 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
6293 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6294                 net->ipv6.ip6_prohibit_entry->dst.dev = dev;
6295                 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
6296                 net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
6297                 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
6298 #endif
6299          } else if (event == NETDEV_UNREGISTER &&
6300                     dev->reg_state != NETREG_UNREGISTERED) {
6301                 /* NETDEV_UNREGISTER could be fired for multiple times by
6302                  * netdev_wait_allrefs(). Make sure we only call this once.
6303                  */
6304                 in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
6305 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6306                 in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
6307                 in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
6308 #endif
6309         }
6310
6311         return NOTIFY_OK;
6312 }
6313
6314 /*
6315  *      /proc
6316  */
6317
6318 #ifdef CONFIG_PROC_FS
6319 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
6320 {
6321         struct net *net = (struct net *)seq->private;
6322         seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
6323                    net->ipv6.rt6_stats->fib_nodes,
6324                    net->ipv6.rt6_stats->fib_route_nodes,
6325                    atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
6326                    net->ipv6.rt6_stats->fib_rt_entries,
6327                    net->ipv6.rt6_stats->fib_rt_cache,
6328                    dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
6329                    net->ipv6.rt6_stats->fib_discarded_routes);
6330
6331         return 0;
6332 }
6333 #endif  /* CONFIG_PROC_FS */
6334
6335 #ifdef CONFIG_SYSCTL
6336
6337 static int ipv6_sysctl_rtcache_flush(const struct ctl_table *ctl, int write,
6338                               void *buffer, size_t *lenp, loff_t *ppos)
6339 {
6340         struct net *net;
6341         int delay;
6342         int ret;
6343         if (!write)
6344                 return -EINVAL;
6345
6346         ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
6347         if (ret)
6348                 return ret;
6349
6350         net = (struct net *)ctl->extra1;
6351         delay = net->ipv6.sysctl.flush_delay;
6352         fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
6353         return 0;
6354 }
6355
6356 static struct ctl_table ipv6_route_table_template[] = {
6357         {
6358                 .procname       =       "max_size",
6359                 .data           =       &init_net.ipv6.sysctl.ip6_rt_max_size,
6360                 .maxlen         =       sizeof(int),
6361                 .mode           =       0644,
6362                 .proc_handler   =       proc_dointvec,
6363         },
6364         {
6365                 .procname       =       "gc_thresh",
6366                 .data           =       &ip6_dst_ops_template.gc_thresh,
6367                 .maxlen         =       sizeof(int),
6368                 .mode           =       0644,
6369                 .proc_handler   =       proc_dointvec,
6370         },
6371         {
6372                 .procname       =       "flush",
6373                 .data           =       &init_net.ipv6.sysctl.flush_delay,
6374                 .maxlen         =       sizeof(int),
6375                 .mode           =       0200,
6376                 .proc_handler   =       ipv6_sysctl_rtcache_flush
6377         },
6378         {
6379                 .procname       =       "gc_min_interval",
6380                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6381                 .maxlen         =       sizeof(int),
6382                 .mode           =       0644,
6383                 .proc_handler   =       proc_dointvec_jiffies,
6384         },
6385         {
6386                 .procname       =       "gc_timeout",
6387                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
6388                 .maxlen         =       sizeof(int),
6389                 .mode           =       0644,
6390                 .proc_handler   =       proc_dointvec_jiffies,
6391         },
6392         {
6393                 .procname       =       "gc_interval",
6394                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_interval,
6395                 .maxlen         =       sizeof(int),
6396                 .mode           =       0644,
6397                 .proc_handler   =       proc_dointvec_jiffies,
6398         },
6399         {
6400                 .procname       =       "gc_elasticity",
6401                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
6402                 .maxlen         =       sizeof(int),
6403                 .mode           =       0644,
6404                 .proc_handler   =       proc_dointvec,
6405         },
6406         {
6407                 .procname       =       "mtu_expires",
6408                 .data           =       &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
6409                 .maxlen         =       sizeof(int),
6410                 .mode           =       0644,
6411                 .proc_handler   =       proc_dointvec_jiffies,
6412         },
6413         {
6414                 .procname       =       "min_adv_mss",
6415                 .data           =       &init_net.ipv6.sysctl.ip6_rt_min_advmss,
6416                 .maxlen         =       sizeof(int),
6417                 .mode           =       0644,
6418                 .proc_handler   =       proc_dointvec,
6419         },
6420         {
6421                 .procname       =       "gc_min_interval_ms",
6422                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6423                 .maxlen         =       sizeof(int),
6424                 .mode           =       0644,
6425                 .proc_handler   =       proc_dointvec_ms_jiffies,
6426         },
6427         {
6428                 .procname       =       "skip_notify_on_dev_down",
6429                 .data           =       &init_net.ipv6.sysctl.skip_notify_on_dev_down,
6430                 .maxlen         =       sizeof(u8),
6431                 .mode           =       0644,
6432                 .proc_handler   =       proc_dou8vec_minmax,
6433                 .extra1         =       SYSCTL_ZERO,
6434                 .extra2         =       SYSCTL_ONE,
6435         },
6436 };
6437
6438 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
6439 {
6440         struct ctl_table *table;
6441
6442         table = kmemdup(ipv6_route_table_template,
6443                         sizeof(ipv6_route_table_template),
6444                         GFP_KERNEL);
6445
6446         if (table) {
6447                 table[0].data = &net->ipv6.sysctl.ip6_rt_max_size;
6448                 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
6449                 table[2].data = &net->ipv6.sysctl.flush_delay;
6450                 table[2].extra1 = net;
6451                 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6452                 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
6453                 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
6454                 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
6455                 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
6456                 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
6457                 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6458                 table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
6459         }
6460
6461         return table;
6462 }
6463
6464 size_t ipv6_route_sysctl_table_size(struct net *net)
6465 {
6466         /* Don't export sysctls to unprivileged users */
6467         if (net->user_ns != &init_user_ns)
6468                 return 1;
6469
6470         return ARRAY_SIZE(ipv6_route_table_template);
6471 }
6472 #endif
6473
6474 static int __net_init ip6_route_net_init(struct net *net)
6475 {
6476         int ret = -ENOMEM;
6477
6478         memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
6479                sizeof(net->ipv6.ip6_dst_ops));
6480
6481         if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
6482                 goto out_ip6_dst_ops;
6483
6484         net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true);
6485         if (!net->ipv6.fib6_null_entry)
6486                 goto out_ip6_dst_entries;
6487         memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template,
6488                sizeof(*net->ipv6.fib6_null_entry));
6489
6490         net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
6491                                            sizeof(*net->ipv6.ip6_null_entry),
6492                                            GFP_KERNEL);
6493         if (!net->ipv6.ip6_null_entry)
6494                 goto out_fib6_null_entry;
6495         net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6496         dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
6497                          ip6_template_metrics, true);
6498         INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->dst.rt_uncached);
6499
6500 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6501         net->ipv6.fib6_has_custom_rules = false;
6502         net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
6503                                                sizeof(*net->ipv6.ip6_prohibit_entry),
6504                                                GFP_KERNEL);
6505         if (!net->ipv6.ip6_prohibit_entry)
6506                 goto out_ip6_null_entry;
6507         net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6508         dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
6509                          ip6_template_metrics, true);
6510         INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->dst.rt_uncached);
6511
6512         net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
6513                                                sizeof(*net->ipv6.ip6_blk_hole_entry),
6514                                                GFP_KERNEL);
6515         if (!net->ipv6.ip6_blk_hole_entry)
6516                 goto out_ip6_prohibit_entry;
6517         net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6518         dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
6519                          ip6_template_metrics, true);
6520         INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->dst.rt_uncached);
6521 #ifdef CONFIG_IPV6_SUBTREES
6522         net->ipv6.fib6_routes_require_src = 0;
6523 #endif
6524 #endif
6525
6526         net->ipv6.sysctl.flush_delay = 0;
6527         net->ipv6.sysctl.ip6_rt_max_size = INT_MAX;
6528         net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
6529         net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
6530         net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
6531         net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
6532         net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
6533         net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
6534         net->ipv6.sysctl.skip_notify_on_dev_down = 0;
6535
6536         atomic_set(&net->ipv6.ip6_rt_gc_expire, 30*HZ);
6537
6538         ret = 0;
6539 out:
6540         return ret;
6541
6542 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6543 out_ip6_prohibit_entry:
6544         kfree(net->ipv6.ip6_prohibit_entry);
6545 out_ip6_null_entry:
6546         kfree(net->ipv6.ip6_null_entry);
6547 #endif
6548 out_fib6_null_entry:
6549         kfree(net->ipv6.fib6_null_entry);
6550 out_ip6_dst_entries:
6551         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6552 out_ip6_dst_ops:
6553         goto out;
6554 }
6555
6556 static void __net_exit ip6_route_net_exit(struct net *net)
6557 {
6558         kfree(net->ipv6.fib6_null_entry);
6559         kfree(net->ipv6.ip6_null_entry);
6560 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6561         kfree(net->ipv6.ip6_prohibit_entry);
6562         kfree(net->ipv6.ip6_blk_hole_entry);
6563 #endif
6564         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6565 }
6566
6567 static int __net_init ip6_route_net_init_late(struct net *net)
6568 {
6569 #ifdef CONFIG_PROC_FS
6570         if (!proc_create_net("ipv6_route", 0, net->proc_net,
6571                              &ipv6_route_seq_ops,
6572                              sizeof(struct ipv6_route_iter)))
6573                 return -ENOMEM;
6574
6575         if (!proc_create_net_single("rt6_stats", 0444, net->proc_net,
6576                                     rt6_stats_seq_show, NULL)) {
6577                 remove_proc_entry("ipv6_route", net->proc_net);
6578                 return -ENOMEM;
6579         }
6580 #endif
6581         return 0;
6582 }
6583
6584 static void __net_exit ip6_route_net_exit_late(struct net *net)
6585 {
6586 #ifdef CONFIG_PROC_FS
6587         remove_proc_entry("ipv6_route", net->proc_net);
6588         remove_proc_entry("rt6_stats", net->proc_net);
6589 #endif
6590 }
6591
6592 static struct pernet_operations ip6_route_net_ops = {
6593         .init = ip6_route_net_init,
6594         .exit = ip6_route_net_exit,
6595 };
6596
6597 static int __net_init ipv6_inetpeer_init(struct net *net)
6598 {
6599         struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
6600
6601         if (!bp)
6602                 return -ENOMEM;
6603         inet_peer_base_init(bp);
6604         net->ipv6.peers = bp;
6605         return 0;
6606 }
6607
6608 static void __net_exit ipv6_inetpeer_exit(struct net *net)
6609 {
6610         struct inet_peer_base *bp = net->ipv6.peers;
6611
6612         net->ipv6.peers = NULL;
6613         inetpeer_invalidate_tree(bp);
6614         kfree(bp);
6615 }
6616
6617 static struct pernet_operations ipv6_inetpeer_ops = {
6618         .init   =       ipv6_inetpeer_init,
6619         .exit   =       ipv6_inetpeer_exit,
6620 };
6621
6622 static struct pernet_operations ip6_route_net_late_ops = {
6623         .init = ip6_route_net_init_late,
6624         .exit = ip6_route_net_exit_late,
6625 };
6626
6627 static struct notifier_block ip6_route_dev_notifier = {
6628         .notifier_call = ip6_route_dev_notify,
6629         .priority = ADDRCONF_NOTIFY_PRIORITY - 10,
6630 };
6631
6632 void __init ip6_route_init_special_entries(void)
6633 {
6634         /* Registering of the loopback is done before this portion of code,
6635          * the loopback reference in rt6_info will not be taken, do it
6636          * manually for init_net */
6637         init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev;
6638         init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
6639         init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6640   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6641         init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
6642         init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6643         init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
6644         init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6645   #endif
6646 }
6647
6648 #if IS_BUILTIN(CONFIG_IPV6)
6649 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6650 DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt)
6651
6652 BTF_ID_LIST(btf_fib6_info_id)
6653 BTF_ID(struct, fib6_info)
6654
6655 static const struct bpf_iter_seq_info ipv6_route_seq_info = {
6656         .seq_ops                = &ipv6_route_seq_ops,
6657         .init_seq_private       = bpf_iter_init_seq_net,
6658         .fini_seq_private       = bpf_iter_fini_seq_net,
6659         .seq_priv_size          = sizeof(struct ipv6_route_iter),
6660 };
6661
6662 static struct bpf_iter_reg ipv6_route_reg_info = {
6663         .target                 = "ipv6_route",
6664         .ctx_arg_info_size      = 1,
6665         .ctx_arg_info           = {
6666                 { offsetof(struct bpf_iter__ipv6_route, rt),
6667                   PTR_TO_BTF_ID_OR_NULL },
6668         },
6669         .seq_info               = &ipv6_route_seq_info,
6670 };
6671
6672 static int __init bpf_iter_register(void)
6673 {
6674         ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id;
6675         return bpf_iter_reg_target(&ipv6_route_reg_info);
6676 }
6677
6678 static void bpf_iter_unregister(void)
6679 {
6680         bpf_iter_unreg_target(&ipv6_route_reg_info);
6681 }
6682 #endif
6683 #endif
6684
6685 int __init ip6_route_init(void)
6686 {
6687         int ret;
6688         int cpu;
6689
6690         ret = -ENOMEM;
6691         ip6_dst_ops_template.kmem_cachep =
6692                 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
6693                                   SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
6694         if (!ip6_dst_ops_template.kmem_cachep)
6695                 goto out;
6696
6697         ret = dst_entries_init(&ip6_dst_blackhole_ops);
6698         if (ret)
6699                 goto out_kmem_cache;
6700
6701         ret = register_pernet_subsys(&ipv6_inetpeer_ops);
6702         if (ret)
6703                 goto out_dst_entries;
6704
6705         ret = register_pernet_subsys(&ip6_route_net_ops);
6706         if (ret)
6707                 goto out_register_inetpeer;
6708
6709         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
6710
6711         ret = fib6_init();
6712         if (ret)
6713                 goto out_register_subsys;
6714
6715         ret = xfrm6_init();
6716         if (ret)
6717                 goto out_fib6_init;
6718
6719         ret = fib6_rules_init();
6720         if (ret)
6721                 goto xfrm6_init;
6722
6723         ret = register_pernet_subsys(&ip6_route_net_late_ops);
6724         if (ret)
6725                 goto fib6_rules_init;
6726
6727         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
6728                                    inet6_rtm_newroute, NULL, 0);
6729         if (ret < 0)
6730                 goto out_register_late_subsys;
6731
6732         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
6733                                    inet6_rtm_delroute, NULL, 0);
6734         if (ret < 0)
6735                 goto out_register_late_subsys;
6736
6737         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
6738                                    inet6_rtm_getroute, NULL,
6739                                    RTNL_FLAG_DOIT_UNLOCKED);
6740         if (ret < 0)
6741                 goto out_register_late_subsys;
6742
6743         ret = register_netdevice_notifier(&ip6_route_dev_notifier);
6744         if (ret)
6745                 goto out_register_late_subsys;
6746
6747 #if IS_BUILTIN(CONFIG_IPV6)
6748 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6749         ret = bpf_iter_register();
6750         if (ret)
6751                 goto out_register_late_subsys;
6752 #endif
6753 #endif
6754
6755         for_each_possible_cpu(cpu) {
6756                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
6757
6758                 INIT_LIST_HEAD(&ul->head);
6759                 spin_lock_init(&ul->lock);
6760         }
6761
6762 out:
6763         return ret;
6764
6765 out_register_late_subsys:
6766         rtnl_unregister_all(PF_INET6);
6767         unregister_pernet_subsys(&ip6_route_net_late_ops);
6768 fib6_rules_init:
6769         fib6_rules_cleanup();
6770 xfrm6_init:
6771         xfrm6_fini();
6772 out_fib6_init:
6773         fib6_gc_cleanup();
6774 out_register_subsys:
6775         unregister_pernet_subsys(&ip6_route_net_ops);
6776 out_register_inetpeer:
6777         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6778 out_dst_entries:
6779         dst_entries_destroy(&ip6_dst_blackhole_ops);
6780 out_kmem_cache:
6781         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6782         goto out;
6783 }
6784
6785 void ip6_route_cleanup(void)
6786 {
6787 #if IS_BUILTIN(CONFIG_IPV6)
6788 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6789         bpf_iter_unregister();
6790 #endif
6791 #endif
6792         unregister_netdevice_notifier(&ip6_route_dev_notifier);
6793         unregister_pernet_subsys(&ip6_route_net_late_ops);
6794         fib6_rules_cleanup();
6795         xfrm6_fini();
6796         fib6_gc_cleanup();
6797         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6798         unregister_pernet_subsys(&ip6_route_net_ops);
6799         dst_entries_destroy(&ip6_dst_blackhole_ops);
6800         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6801 }