net/ipv6/route.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Linux INET6 implementation
   4  *      FIB front-end.
   5  *
   6  *      Authors:
   7  *      Pedro Roque             <roque@di.fc.ul.pt>
   8  */
   9
  10 /*      Changes:
  11  *
  12  *      YOSHIFUJI Hideaki @USAGI
  13  *              reworked default router selection.
  14  *              - respect outgoing interface
  15  *              - select from (probably) reachable routers (i.e.
  16  *              routers in REACHABLE, STALE, DELAY or PROBE states).
  17  *              - always select the same router if it is (probably)
  18  *              reachable.  otherwise, round-robin the list.
  19  *      Ville Nuorvala
  20  *              Fixed routing subtrees.
  21  */
  22
  23 #define pr_fmt(fmt) "IPv6: " fmt
  24
  25 #include <linux/capability.h>
  26 #include <linux/errno.h>
  27 #include <linux/export.h>
  28 #include <linux/types.h>
  29 #include <linux/times.h>
  30 #include <linux/socket.h>
  31 #include <linux/sockios.h>
  32 #include <linux/net.h>
  33 #include <linux/route.h>
  34 #include <linux/netdevice.h>
  35 #include <linux/in6.h>
  36 #include <linux/mroute6.h>
  37 #include <linux/init.h>
  38 #include <linux/if_arp.h>
  39 #include <linux/proc_fs.h>
  40 #include <linux/seq_file.h>
  41 #include <linux/nsproxy.h>
  42 #include <linux/slab.h>
  43 #include <linux/jhash.h>
  44 #include <net/net_namespace.h>
  45 #include <net/snmp.h>
  46 #include <net/ipv6.h>
  47 #include <net/ip6_fib.h>
  48 #include <net/ip6_route.h>
  49 #include <net/ndisc.h>
  50 #include <net/addrconf.h>
  51 #include <net/tcp.h>
  52 #include <linux/rtnetlink.h>
  53 #include <net/dst.h>
  54 #include <net/dst_metadata.h>
  55 #include <net/xfrm.h>
  56 #include <net/netevent.h>
  57 #include <net/netlink.h>
  58 #include <net/rtnh.h>
  59 #include <net/lwtunnel.h>
  60 #include <net/ip_tunnels.h>
  61 #include <net/l3mdev.h>
  62 #include <net/ip.h>
  63 #include <linux/uaccess.h>
  64
  65 #ifdef CONFIG_SYSCTL
  66 #include <linux/sysctl.h>
  67 #endif
  68
  69 static int ip6_rt_type_to_error(u8 fib6_type);
  70
  71 #define CREATE_TRACE_POINTS
  72 #include <trace/events/fib6.h>
  73 EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup);
  74 #undef CREATE_TRACE_POINTS
  75
  76 enum rt6_nud_state {
  77         RT6_NUD_FAIL_HARD = -3,
  78         RT6_NUD_FAIL_PROBE = -2,
  79         RT6_NUD_FAIL_DO_RR = -1,
  80         RT6_NUD_SUCCEED = 1
  81 };
  82
  83 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie);
  84 static unsigned int      ip6_default_advmss(const struct dst_entry *dst);
  85 static unsigned int      ip6_mtu(const struct dst_entry *dst);
  86 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
  87 static void             ip6_dst_destroy(struct dst_entry *);
  88 static void             ip6_dst_ifdown(struct dst_entry *,
  89                                        struct net_device *dev, int how);
  90 static int               ip6_dst_gc(struct dst_ops *ops);
  91
  92 static int              ip6_pkt_discard(struct sk_buff *skb);
  93 static int              ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
  94 static int              ip6_pkt_prohibit(struct sk_buff *skb);
  95 static int              ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb);
  96 static void             ip6_link_failure(struct sk_buff *skb);
  97 static void             ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
  98                                            struct sk_buff *skb, u32 mtu,
  99                                            bool confirm_neigh);
 100 static void             rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
 101                                         struct sk_buff *skb);
 102 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
 103                            int strict);
 104 static size_t rt6_nlmsg_size(struct fib6_info *f6i);
 105 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
 106                          struct fib6_info *rt, struct dst_entry *dst,
 107                          struct in6_addr *dest, struct in6_addr *src,
 108                          int iif, int type, u32 portid, u32 seq,
 109                          unsigned int flags);
 110 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
 111                                            const struct in6_addr *daddr,
 112                                            const struct in6_addr *saddr);
 113
 114 #ifdef CONFIG_IPV6_ROUTE_INFO
 115 static struct fib6_info *rt6_add_route_info(struct net *net,
 116                                            const struct in6_addr *prefix, int prefixlen,
 117                                            const struct in6_addr *gwaddr,
 118                                            struct net_device *dev,
 119                                            unsigned int pref);
 120 static struct fib6_info *rt6_get_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 #endif
 125
 126 struct uncached_list {
 127         spinlock_t              lock;
 128         struct list_head        head;
 129 };
 130
 131 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
 132
 133 void rt6_uncached_list_add(struct rt6_info *rt)
 134 {
 135         struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list);
 136
 137         rt->rt6i_uncached_list = ul;
 138
 139         spin_lock_bh(&ul->lock);
 140         list_add_tail(&rt->rt6i_uncached, &ul->head);
 141         spin_unlock_bh(&ul->lock);
 142 }
 143
 144 void rt6_uncached_list_del(struct rt6_info *rt)
 145 {
 146         if (!list_empty(&rt->rt6i_uncached)) {
 147                 struct uncached_list *ul = rt->rt6i_uncached_list;
 148                 struct net *net = dev_net(rt->dst.dev);
 149
 150                 spin_lock_bh(&ul->lock);
 151                 list_del(&rt->rt6i_uncached);
 152                 atomic_dec(&net->ipv6.rt6_stats->fib_rt_uncache);
 153                 spin_unlock_bh(&ul->lock);
 154         }
 155 }
 156
 157 static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev)
 158 {
 159         struct net_device *loopback_dev = net->loopback_dev;
 160         int cpu;
 161
 162         if (dev == loopback_dev)
 163                 return;
 164
 165         for_each_possible_cpu(cpu) {
 166                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
 167                 struct rt6_info *rt;
 168
 169                 spin_lock_bh(&ul->lock);
 170                 list_for_each_entry(rt, &ul->head, rt6i_uncached) {
 171                         struct inet6_dev *rt_idev = rt->rt6i_idev;
 172                         struct net_device *rt_dev = rt->dst.dev;
 173
 174                         if (rt_idev->dev == dev) {
 175                                 rt->rt6i_idev = in6_dev_get(loopback_dev);
 176                                 in6_dev_put(rt_idev);
 177                         }
 178
 179                         if (rt_dev == dev) {
 180                                 rt->dst.dev = blackhole_netdev;
 181                                 dev_hold(rt->dst.dev);
 182                                 dev_put(rt_dev);
 183                         }
 184                 }
 185                 spin_unlock_bh(&ul->lock);
 186         }
 187 }
 188
 189 static inline const void *choose_neigh_daddr(const struct in6_addr *p,
 190                                              struct sk_buff *skb,
 191                                              const void *daddr)
 192 {
 193         if (!ipv6_addr_any(p))
 194                 return (const void *) p;
 195         else if (skb)
 196                 return &ipv6_hdr(skb)->daddr;
 197         return daddr;
 198 }
 199
 200 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
 201                                    struct net_device *dev,
 202                                    struct sk_buff *skb,
 203                                    const void *daddr)
 204 {
 205         struct neighbour *n;
 206
 207         daddr = choose_neigh_daddr(gw, skb, daddr);
 208         n = __ipv6_neigh_lookup(dev, daddr);
 209         if (n)
 210                 return n;
 211
 212         n = neigh_create(&nd_tbl, daddr, dev);
 213         return IS_ERR(n) ? NULL : n;
 214 }
 215
 216 static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst,
 217                                               struct sk_buff *skb,
 218                                               const void *daddr)
 219 {
 220         const struct rt6_info *rt = container_of(dst, struct rt6_info, dst);
 221
 222         return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any),
 223                                 dst->dev, skb, daddr);
 224 }
 225
 226 static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr)
 227 {
 228         struct net_device *dev = dst->dev;
 229         struct rt6_info *rt = (struct rt6_info *)dst;
 230
 231         daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr);
 232         if (!daddr)
 233                 return;
 234         if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
 235                 return;
 236         if (ipv6_addr_is_multicast((const struct in6_addr *)daddr))
 237                 return;
 238         __ipv6_confirm_neigh(dev, daddr);
 239 }
 240
 241 static struct dst_ops ip6_dst_ops_template = {
 242         .family                 =       AF_INET6,
 243         .gc                     =       ip6_dst_gc,
 244         .gc_thresh              =       1024,
 245         .check                  =       ip6_dst_check,
 246         .default_advmss         =       ip6_default_advmss,
 247         .mtu                    =       ip6_mtu,
 248         .cow_metrics            =       dst_cow_metrics_generic,
 249         .destroy                =       ip6_dst_destroy,
 250         .ifdown                 =       ip6_dst_ifdown,
 251         .negative_advice        =       ip6_negative_advice,
 252         .link_failure           =       ip6_link_failure,
 253         .update_pmtu            =       ip6_rt_update_pmtu,
 254         .redirect               =       rt6_do_redirect,
 255         .local_out              =       __ip6_local_out,
 256         .neigh_lookup           =       ip6_dst_neigh_lookup,
 257         .confirm_neigh          =       ip6_confirm_neigh,
 258 };
 259
 260 static unsigned int ip6_blackhole_mtu(const struct dst_entry *dst)
 261 {
 262         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
 263
 264         return mtu ? : dst->dev->mtu;
 265 }
 266
 267 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
 268                                          struct sk_buff *skb, u32 mtu,
 269                                          bool confirm_neigh)
 270 {
 271 }
 272
 273 static void ip6_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
 274                                       struct sk_buff *skb)
 275 {
 276 }
 277
 278 static struct dst_ops ip6_dst_blackhole_ops = {
 279         .family                 =       AF_INET6,
 280         .destroy                =       ip6_dst_destroy,
 281         .check                  =       ip6_dst_check,
 282         .mtu                    =       ip6_blackhole_mtu,
 283         .default_advmss         =       ip6_default_advmss,
 284         .update_pmtu            =       ip6_rt_blackhole_update_pmtu,
 285         .redirect               =       ip6_rt_blackhole_redirect,
 286         .cow_metrics            =       dst_cow_metrics_generic,
 287         .neigh_lookup           =       ip6_dst_neigh_lookup,
 288 };
 289
 290 static const u32 ip6_template_metrics[RTAX_MAX] = {
 291         [RTAX_HOPLIMIT - 1] = 0,
 292 };
 293
 294 static const struct fib6_info fib6_null_entry_template = {
 295         .fib6_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 296         .fib6_protocol  = RTPROT_KERNEL,
 297         .fib6_metric    = ~(u32)0,
 298         .fib6_ref       = REFCOUNT_INIT(1),
 299         .fib6_type      = RTN_UNREACHABLE,
 300         .fib6_metrics   = (struct dst_metrics *)&dst_default_metrics,
 301 };
 302
 303 static const struct rt6_info ip6_null_entry_template = {
 304         .dst = {
 305                 .__refcnt       = ATOMIC_INIT(1),
 306                 .__use          = 1,
 307                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 308                 .error          = -ENETUNREACH,
 309                 .input          = ip6_pkt_discard,
 310                 .output         = ip6_pkt_discard_out,
 311         },
 312         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 313 };
 314
 315 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 316
 317 static const struct rt6_info ip6_prohibit_entry_template = {
 318         .dst = {
 319                 .__refcnt       = ATOMIC_INIT(1),
 320                 .__use          = 1,
 321                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 322                 .error          = -EACCES,
 323                 .input          = ip6_pkt_prohibit,
 324                 .output         = ip6_pkt_prohibit_out,
 325         },
 326         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 327 };
 328
 329 static const struct rt6_info ip6_blk_hole_entry_template = {
 330         .dst = {
 331                 .__refcnt       = ATOMIC_INIT(1),
 332                 .__use          = 1,
 333                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 334                 .error          = -EINVAL,
 335                 .input          = dst_discard,
 336                 .output         = dst_discard_out,
 337         },
 338         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 339 };
 340
 341 #endif
 342
 343 static void rt6_info_init(struct rt6_info *rt)
 344 {
 345         struct dst_entry *dst = &rt->dst;
 346
 347         memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));
 348         INIT_LIST_HEAD(&rt->rt6i_uncached);
 349 }
 350
 351 /* allocate dst with ip6_dst_ops */
 352 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 353                                int flags)
 354 {
 355         struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
 356                                         1, DST_OBSOLETE_FORCE_CHK, flags);
 357
 358         if (rt) {
 359                 rt6_info_init(rt);
 360                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
 361         }
 362
 363         return rt;
 364 }
 365 EXPORT_SYMBOL(ip6_dst_alloc);
 366
 367 static void ip6_dst_destroy(struct dst_entry *dst)
 368 {
 369         struct rt6_info *rt = (struct rt6_info *)dst;
 370         struct fib6_info *from;
 371         struct inet6_dev *idev;
 372
 373         ip_dst_metrics_put(dst);
 374         rt6_uncached_list_del(rt);
 375
 376         idev = rt->rt6i_idev;
 377         if (idev) {
 378                 rt->rt6i_idev = NULL;
 379                 in6_dev_put(idev);
 380         }
 381
 382         from = xchg((__force struct fib6_info **)&rt->from, NULL);
 383         fib6_info_release(from);
 384 }
 385
 386 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 387                            int how)
 388 {
 389         struct rt6_info *rt = (struct rt6_info *)dst;
 390         struct inet6_dev *idev = rt->rt6i_idev;
 391         struct net_device *loopback_dev =
 392                 dev_net(dev)->loopback_dev;
 393
 394         if (idev && idev->dev != loopback_dev) {
 395                 struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);
 396                 if (loopback_idev) {
 397                         rt->rt6i_idev = loopback_idev;
 398                         in6_dev_put(idev);
 399                 }
 400         }
 401 }
 402
 403 static bool __rt6_check_expired(const struct rt6_info *rt)
 404 {
 405         if (rt->rt6i_flags & RTF_EXPIRES)
 406                 return time_after(jiffies, rt->dst.expires);
 407         else
 408                 return false;
 409 }
 410
 411 static bool rt6_check_expired(const struct rt6_info *rt)
 412 {
 413         struct fib6_info *from;
 414
 415         from = rcu_dereference(rt->from);
 416
 417         if (rt->rt6i_flags & RTF_EXPIRES) {
 418                 if (time_after(jiffies, rt->dst.expires))
 419                         return true;
 420         } else if (from) {
 421                 return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
 422                         fib6_check_expired(from);
 423         }
 424         return false;
 425 }
 426
 427 void fib6_select_path(const struct net *net, struct fib6_result *res,
 428                       struct flowi6 *fl6, int oif, bool have_oif_match,
 429                       const struct sk_buff *skb, int strict)
 430 {
 431         struct fib6_info *sibling, *next_sibling;
 432         struct fib6_info *match = res->f6i;
 433
 434         if ((!match->fib6_nsiblings && !match->nh) || have_oif_match)
 435                 goto out;
 436
 437         /* We might have already computed the hash for ICMPv6 errors. In such
 438          * case it will always be non-zero. Otherwise now is the time to do it.
 439          */
 440         if (!fl6->mp_hash &&
 441             (!match->nh || nexthop_is_multipath(match->nh)))
 442                 fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
 443
 444         if (unlikely(match->nh)) {
 445                 nexthop_path_fib6_result(res, fl6->mp_hash);
 446                 return;
 447         }
 448
 449         if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
 450                 goto out;
 451
 452         list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
 453                                  fib6_siblings) {
 454                 const struct fib6_nh *nh = sibling->fib6_nh;
 455                 int nh_upper_bound;
 456
 457                 nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
 458                 if (fl6->mp_hash > nh_upper_bound)
 459                         continue;
 460                 if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
 461                         break;
 462                 match = sibling;
 463                 break;
 464         }
 465
 466 out:
 467         res->f6i = match;
 468         res->nh = match->fib6_nh;
 469 }
 470
 471 /*
 472  *      Route lookup. rcu_read_lock() should be held.
 473  */
 474
 475 static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh,
 476                                const struct in6_addr *saddr, int oif, int flags)
 477 {
 478         const struct net_device *dev;
 479
 480         if (nh->fib_nh_flags & RTNH_F_DEAD)
 481                 return false;
 482
 483         dev = nh->fib_nh_dev;
 484         if (oif) {
 485                 if (dev->ifindex == oif)
 486                         return true;
 487         } else {
 488                 if (ipv6_chk_addr(net, saddr, dev,
 489                                   flags & RT6_LOOKUP_F_IFACE))
 490                         return true;
 491         }
 492
 493         return false;
 494 }
 495
 496 struct fib6_nh_dm_arg {
 497         struct net              *net;
 498         const struct in6_addr   *saddr;
 499         int                     oif;
 500         int                     flags;
 501         struct fib6_nh          *nh;
 502 };
 503
 504 static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg)
 505 {
 506         struct fib6_nh_dm_arg *arg = _arg;
 507
 508         arg->nh = nh;
 509         return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif,
 510                                   arg->flags);
 511 }
 512
 513 /* returns fib6_nh from nexthop or NULL */
 514 static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh,
 515                                         struct fib6_result *res,
 516                                         const struct in6_addr *saddr,
 517                                         int oif, int flags)
 518 {
 519         struct fib6_nh_dm_arg arg = {
 520                 .net   = net,
 521                 .saddr = saddr,
 522                 .oif   = oif,
 523                 .flags = flags,
 524         };
 525
 526         if (nexthop_is_blackhole(nh))
 527                 return NULL;
 528
 529         if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg))
 530                 return arg.nh;
 531
 532         return NULL;
 533 }
 534
 535 static void rt6_device_match(struct net *net, struct fib6_result *res,
 536                              const struct in6_addr *saddr, int oif, int flags)
 537 {
 538         struct fib6_info *f6i = res->f6i;
 539         struct fib6_info *spf6i;
 540         struct fib6_nh *nh;
 541
 542         if (!oif && ipv6_addr_any(saddr)) {
 543                 if (unlikely(f6i->nh)) {
 544                         nh = nexthop_fib6_nh(f6i->nh);
 545                         if (nexthop_is_blackhole(f6i->nh))
 546                                 goto out_blackhole;
 547                 } else {
 548                         nh = f6i->fib6_nh;
 549                 }
 550                 if (!(nh->fib_nh_flags & RTNH_F_DEAD))
 551                         goto out;
 552         }
 553
 554         for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
 555                 bool matched = false;
 556
 557                 if (unlikely(spf6i->nh)) {
 558                         nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr,
 559                                               oif, flags);
 560                         if (nh)
 561                                 matched = true;
 562                 } else {
 563                         nh = spf6i->fib6_nh;
 564                         if (__rt6_device_match(net, nh, saddr, oif, flags))
 565                                 matched = true;
 566                 }
 567                 if (matched) {
 568                         res->f6i = spf6i;
 569                         goto out;
 570                 }
 571         }
 572
 573         if (oif && flags & RT6_LOOKUP_F_IFACE) {
 574                 res->f6i = net->ipv6.fib6_null_entry;
 575                 nh = res->f6i->fib6_nh;
 576                 goto out;
 577         }
 578
 579         if (unlikely(f6i->nh)) {
 580                 nh = nexthop_fib6_nh(f6i->nh);
 581                 if (nexthop_is_blackhole(f6i->nh))
 582                         goto out_blackhole;
 583         } else {
 584                 nh = f6i->fib6_nh;
 585         }
 586
 587         if (nh->fib_nh_flags & RTNH_F_DEAD) {
 588                 res->f6i = net->ipv6.fib6_null_entry;
 589                 nh = res->f6i->fib6_nh;
 590         }
 591 out:
 592         res->nh = nh;
 593         res->fib6_type = res->f6i->fib6_type;
 594         res->fib6_flags = res->f6i->fib6_flags;
 595         return;
 596
 597 out_blackhole:
 598         res->fib6_flags |= RTF_REJECT;
 599         res->fib6_type = RTN_BLACKHOLE;
 600         res->nh = nh;
 601 }
 602
 603 #ifdef CONFIG_IPV6_ROUTER_PREF
 604 struct __rt6_probe_work {
 605         struct work_struct work;
 606         struct in6_addr target;
 607         struct net_device *dev;
 608 };
 609
 610 static void rt6_probe_deferred(struct work_struct *w)
 611 {
 612         struct in6_addr mcaddr;
 613         struct __rt6_probe_work *work =
 614                 container_of(w, struct __rt6_probe_work, work);
 615
 616         addrconf_addr_solict_mult(&work->target, &mcaddr);
 617         ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
 618         dev_put(work->dev);
 619         kfree(work);
 620 }
 621
 622 static void rt6_probe(struct fib6_nh *fib6_nh)
 623 {
 624         struct __rt6_probe_work *work = NULL;
 625         const struct in6_addr *nh_gw;
 626         unsigned long last_probe;
 627         struct neighbour *neigh;
 628         struct net_device *dev;
 629         struct inet6_dev *idev;
 630
 631         /*
 632          * Okay, this does not seem to be appropriate
 633          * for now, however, we need to check if it
 634          * is really so; aka Router Reachability Probing.
 635          *
 636          * Router Reachability Probe MUST be rate-limited
 637          * to no more than one per minute.
 638          */
 639         if (!fib6_nh->fib_nh_gw_family)
 640                 return;
 641
 642         nh_gw = &fib6_nh->fib_nh_gw6;
 643         dev = fib6_nh->fib_nh_dev;
 644         rcu_read_lock_bh();
 645         last_probe = READ_ONCE(fib6_nh->last_probe);
 646         idev = __in6_dev_get(dev);
 647         neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
 648         if (neigh) {
 649                 if (neigh->nud_state & NUD_VALID)
 650                         goto out;
 651
 652                 write_lock(&neigh->lock);
 653                 if (!(neigh->nud_state & NUD_VALID) &&
 654                     time_after(jiffies,
 655                                neigh->updated + idev->cnf.rtr_probe_interval)) {
 656                         work = kmalloc(sizeof(*work), GFP_ATOMIC);
 657                         if (work)
 658                                 __neigh_set_probe_once(neigh);
 659                 }
 660                 write_unlock(&neigh->lock);
 661         } else if (time_after(jiffies, last_probe +
 662                                        idev->cnf.rtr_probe_interval)) {
 663                 work = kmalloc(sizeof(*work), GFP_ATOMIC);
 664         }
 665
 666         if (!work || cmpxchg(&fib6_nh->last_probe,
 667                              last_probe, jiffies) != last_probe) {
 668                 kfree(work);
 669         } else {
 670                 INIT_WORK(&work->work, rt6_probe_deferred);
 671                 work->target = *nh_gw;
 672                 dev_hold(dev);
 673                 work->dev = dev;
 674                 schedule_work(&work->work);
 675         }
 676
 677 out:
 678         rcu_read_unlock_bh();
 679 }
 680 #else
 681 static inline void rt6_probe(struct fib6_nh *fib6_nh)
 682 {
 683 }
 684 #endif
 685
 686 /*
 687  * Default Router Selection (RFC 2461 6.3.6)
 688  */
 689 static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh)
 690 {
 691         enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
 692         struct neighbour *neigh;
 693
 694         rcu_read_lock_bh();
 695         neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev,
 696                                           &fib6_nh->fib_nh_gw6);
 697         if (neigh) {
 698                 read_lock(&neigh->lock);
 699                 if (neigh->nud_state & NUD_VALID)
 700                         ret = RT6_NUD_SUCCEED;
 701 #ifdef CONFIG_IPV6_ROUTER_PREF
 702                 else if (!(neigh->nud_state & NUD_FAILED))
 703                         ret = RT6_NUD_SUCCEED;
 704                 else
 705                         ret = RT6_NUD_FAIL_PROBE;
 706 #endif
 707                 read_unlock(&neigh->lock);
 708         } else {
 709                 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
 710                       RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
 711         }
 712         rcu_read_unlock_bh();
 713
 714         return ret;
 715 }
 716
 717 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
 718                            int strict)
 719 {
 720         int m = 0;
 721
 722         if (!oif || nh->fib_nh_dev->ifindex == oif)
 723                 m = 2;
 724
 725         if (!m && (strict & RT6_LOOKUP_F_IFACE))
 726                 return RT6_NUD_FAIL_HARD;
 727 #ifdef CONFIG_IPV6_ROUTER_PREF
 728         m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2;
 729 #endif
 730         if ((strict & RT6_LOOKUP_F_REACHABLE) &&
 731             !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) {
 732                 int n = rt6_check_neigh(nh);
 733                 if (n < 0)
 734                         return n;
 735         }
 736         return m;
 737 }
 738
 739 static bool find_match(struct fib6_nh *nh, u32 fib6_flags,
 740                        int oif, int strict, int *mpri, bool *do_rr)
 741 {
 742         bool match_do_rr = false;
 743         bool rc = false;
 744         int m;
 745
 746         if (nh->fib_nh_flags & RTNH_F_DEAD)
 747                 goto out;
 748
 749         if (ip6_ignore_linkdown(nh->fib_nh_dev) &&
 750             nh->fib_nh_flags & RTNH_F_LINKDOWN &&
 751             !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
 752                 goto out;
 753
 754         m = rt6_score_route(nh, fib6_flags, oif, strict);
 755         if (m == RT6_NUD_FAIL_DO_RR) {
 756                 match_do_rr = true;
 757                 m = 0; /* lowest valid score */
 758         } else if (m == RT6_NUD_FAIL_HARD) {
 759                 goto out;
 760         }
 761
 762         if (strict & RT6_LOOKUP_F_REACHABLE)
 763                 rt6_probe(nh);
 764
 765         /* note that m can be RT6_NUD_FAIL_PROBE at this point */
 766         if (m > *mpri) {
 767                 *do_rr = match_do_rr;
 768                 *mpri = m;
 769                 rc = true;
 770         }
 771 out:
 772         return rc;
 773 }
 774
 775 struct fib6_nh_frl_arg {
 776         u32             flags;
 777         int             oif;
 778         int             strict;
 779         int             *mpri;
 780         bool            *do_rr;
 781         struct fib6_nh  *nh;
 782 };
 783
 784 static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg)
 785 {
 786         struct fib6_nh_frl_arg *arg = _arg;
 787
 788         arg->nh = nh;
 789         return find_match(nh, arg->flags, arg->oif, arg->strict,
 790                           arg->mpri, arg->do_rr);
 791 }
 792
 793 static void __find_rr_leaf(struct fib6_info *f6i_start,
 794                            struct fib6_info *nomatch, u32 metric,
 795                            struct fib6_result *res, struct fib6_info **cont,
 796                            int oif, int strict, bool *do_rr, int *mpri)
 797 {
 798         struct fib6_info *f6i;
 799
 800         for (f6i = f6i_start;
 801              f6i && f6i != nomatch;
 802              f6i = rcu_dereference(f6i->fib6_next)) {
 803                 bool matched = false;
 804                 struct fib6_nh *nh;
 805
 806                 if (cont && f6i->fib6_metric != metric) {
 807                         *cont = f6i;
 808                         return;
 809                 }
 810
 811                 if (fib6_check_expired(f6i))
 812                         continue;
 813
 814                 if (unlikely(f6i->nh)) {
 815                         struct fib6_nh_frl_arg arg = {
 816                                 .flags  = f6i->fib6_flags,
 817                                 .oif    = oif,
 818                                 .strict = strict,
 819                                 .mpri   = mpri,
 820                                 .do_rr  = do_rr
 821                         };
 822
 823                         if (nexthop_is_blackhole(f6i->nh)) {
 824                                 res->fib6_flags = RTF_REJECT;
 825                                 res->fib6_type = RTN_BLACKHOLE;
 826                                 res->f6i = f6i;
 827                                 res->nh = nexthop_fib6_nh(f6i->nh);
 828                                 return;
 829                         }
 830                         if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match,
 831                                                      &arg)) {
 832                                 matched = true;
 833                                 nh = arg.nh;
 834                         }
 835                 } else {
 836                         nh = f6i->fib6_nh;
 837                         if (find_match(nh, f6i->fib6_flags, oif, strict,
 838                                        mpri, do_rr))
 839                                 matched = true;
 840                 }
 841                 if (matched) {
 842                         res->f6i = f6i;
 843                         res->nh = nh;
 844                         res->fib6_flags = f6i->fib6_flags;
 845                         res->fib6_type = f6i->fib6_type;
 846                 }
 847         }
 848 }
 849
 850 static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf,
 851                          struct fib6_info *rr_head, int oif, int strict,
 852                          bool *do_rr, struct fib6_result *res)
 853 {
 854         u32 metric = rr_head->fib6_metric;
 855         struct fib6_info *cont = NULL;
 856         int mpri = -1;
 857
 858         __find_rr_leaf(rr_head, NULL, metric, res, &cont,
 859                        oif, strict, do_rr, &mpri);
 860
 861         __find_rr_leaf(leaf, rr_head, metric, res, &cont,
 862                        oif, strict, do_rr, &mpri);
 863
 864         if (res->f6i || !cont)
 865                 return;
 866
 867         __find_rr_leaf(cont, NULL, metric, res, NULL,
 868                        oif, strict, do_rr, &mpri);
 869 }
 870
 871 static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
 872                        struct fib6_result *res, int strict)
 873 {
 874         struct fib6_info *leaf = rcu_dereference(fn->leaf);
 875         struct fib6_info *rt0;
 876         bool do_rr = false;
 877         int key_plen;
 878
 879         /* make sure this function or its helpers sets f6i */
 880         res->f6i = NULL;
 881
 882         if (!leaf || leaf == net->ipv6.fib6_null_entry)
 883                 goto out;
 884
 885         rt0 = rcu_dereference(fn->rr_ptr);
 886         if (!rt0)
 887                 rt0 = leaf;
 888
 889         /* Double check to make sure fn is not an intermediate node
 890          * and fn->leaf does not points to its child's leaf
 891          * (This might happen if all routes under fn are deleted from
 892          * the tree and fib6_repair_tree() is called on the node.)
 893          */
 894         key_plen = rt0->fib6_dst.plen;
 895 #ifdef CONFIG_IPV6_SUBTREES
 896         if (rt0->fib6_src.plen)
 897                 key_plen = rt0->fib6_src.plen;
 898 #endif
 899         if (fn->fn_bit != key_plen)
 900                 goto out;
 901
 902         find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res);
 903         if (do_rr) {
 904                 struct fib6_info *next = rcu_dereference(rt0->fib6_next);
 905
 906                 /* no entries matched; do round-robin */
 907                 if (!next || next->fib6_metric != rt0->fib6_metric)
 908                         next = leaf;
 909
 910                 if (next != rt0) {
 911                         spin_lock_bh(&leaf->fib6_table->tb6_lock);
 912                         /* make sure next is not being deleted from the tree */
 913                         if (next->fib6_node)
 914                                 rcu_assign_pointer(fn->rr_ptr, next);
 915                         spin_unlock_bh(&leaf->fib6_table->tb6_lock);
 916                 }
 917         }
 918
 919 out:
 920         if (!res->f6i) {
 921                 res->f6i = net->ipv6.fib6_null_entry;
 922                 res->nh = res->f6i->fib6_nh;
 923                 res->fib6_flags = res->f6i->fib6_flags;
 924                 res->fib6_type = res->f6i->fib6_type;
 925         }
 926 }
 927
 928 static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res)
 929 {
 930         return (res->f6i->fib6_flags & RTF_NONEXTHOP) ||
 931                res->nh->fib_nh_gw_family;
 932 }
 933
 934 #ifdef CONFIG_IPV6_ROUTE_INFO
 935 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 936                   const struct in6_addr *gwaddr)
 937 {
 938         struct net *net = dev_net(dev);
 939         struct route_info *rinfo = (struct route_info *) opt;
 940         struct in6_addr prefix_buf, *prefix;
 941         unsigned int pref;
 942         unsigned long lifetime;
 943         struct fib6_info *rt;
 944
 945         if (len < sizeof(struct route_info)) {
 946                 return -EINVAL;
 947         }
 948
 949         /* Sanity check for prefix_len and length */
 950         if (rinfo->length > 3) {
 951                 return -EINVAL;
 952         } else if (rinfo->prefix_len > 128) {
 953                 return -EINVAL;
 954         } else if (rinfo->prefix_len > 64) {
 955                 if (rinfo->length < 2) {
 956                         return -EINVAL;
 957                 }
 958         } else if (rinfo->prefix_len > 0) {
 959                 if (rinfo->length < 1) {
 960                         return -EINVAL;
 961                 }
 962         }
 963
 964         pref = rinfo->route_pref;
 965         if (pref == ICMPV6_ROUTER_PREF_INVALID)
 966                 return -EINVAL;
 967
 968         lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
 969
 970         if (rinfo->length == 3)
 971                 prefix = (struct in6_addr *)rinfo->prefix;
 972         else {
 973                 /* this function is safe */
 974                 ipv6_addr_prefix(&prefix_buf,
 975                                  (struct in6_addr *)rinfo->prefix,
 976                                  rinfo->prefix_len);
 977                 prefix = &prefix_buf;
 978         }
 979
 980         if (rinfo->prefix_len == 0)
 981                 rt = rt6_get_dflt_router(net, gwaddr, dev);
 982         else
 983                 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
 984                                         gwaddr, dev);
 985
 986         if (rt && !lifetime) {
 987                 ip6_del_rt(net, rt);
 988                 rt = NULL;
 989         }
 990
 991         if (!rt && lifetime)
 992                 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
 993                                         dev, pref);
 994         else if (rt)
 995                 rt->fib6_flags = RTF_ROUTEINFO |
 996                                  (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 997
 998         if (rt) {
 999                 if (!addrconf_finite_timeout(lifetime))
1000                         fib6_clean_expires(rt);
1001                 else
1002                         fib6_set_expires(rt, jiffies + HZ * lifetime);
1003
1004                 fib6_info_release(rt);
1005         }
1006         return 0;
1007 }
1008 #endif
1009
1010 /*
1011  *      Misc support functions
1012  */
1013
1014 /* called with rcu_lock held */
1015 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
1016 {
1017         struct net_device *dev = res->nh->fib_nh_dev;
1018
1019         if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
1020                 /* for copies of local routes, dst->dev needs to be the
1021                  * device if it is a master device, the master device if
1022                  * device is enslaved, and the loopback as the default
1023                  */
1024                 if (netif_is_l3_slave(dev) &&
1025                     !rt6_need_strict(&res->f6i->fib6_dst.addr))
1026                         dev = l3mdev_master_dev_rcu(dev);
1027                 else if (!netif_is_l3_master(dev))
1028                         dev = dev_net(dev)->loopback_dev;
1029                 /* last case is netif_is_l3_master(dev) is true in which
1030                  * case we want dev returned to be dev
1031                  */
1032         }
1033
1034         return dev;
1035 }
1036
1037 static const int fib6_prop[RTN_MAX + 1] = {
1038         [RTN_UNSPEC]    = 0,
1039         [RTN_UNICAST]   = 0,
1040         [RTN_LOCAL]     = 0,
1041         [RTN_BROADCAST] = 0,
1042         [RTN_ANYCAST]   = 0,
1043         [RTN_MULTICAST] = 0,
1044         [RTN_BLACKHOLE] = -EINVAL,
1045         [RTN_UNREACHABLE] = -EHOSTUNREACH,
1046         [RTN_PROHIBIT]  = -EACCES,
1047         [RTN_THROW]     = -EAGAIN,
1048         [RTN_NAT]       = -EINVAL,
1049         [RTN_XRESOLVE]  = -EINVAL,
1050 };
1051
1052 static int ip6_rt_type_to_error(u8 fib6_type)
1053 {
1054         return fib6_prop[fib6_type];
1055 }
1056
1057 static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
1058 {
1059         unsigned short flags = 0;
1060
1061         if (rt->dst_nocount)
1062                 flags |= DST_NOCOUNT;
1063         if (rt->dst_nopolicy)
1064                 flags |= DST_NOPOLICY;
1065         if (rt->dst_host)
1066                 flags |= DST_HOST;
1067
1068         return flags;
1069 }
1070
1071 static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
1072 {
1073         rt->dst.error = ip6_rt_type_to_error(fib6_type);
1074
1075         switch (fib6_type) {
1076         case RTN_BLACKHOLE:
1077                 rt->dst.output = dst_discard_out;
1078                 rt->dst.input = dst_discard;
1079                 break;
1080         case RTN_PROHIBIT:
1081                 rt->dst.output = ip6_pkt_prohibit_out;
1082                 rt->dst.input = ip6_pkt_prohibit;
1083                 break;
1084         case RTN_THROW:
1085         case RTN_UNREACHABLE:
1086         default:
1087                 rt->dst.output = ip6_pkt_discard_out;
1088                 rt->dst.input = ip6_pkt_discard;
1089                 break;
1090         }
1091 }
1092
1093 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
1094 {
1095         struct fib6_info *f6i = res->f6i;
1096
1097         if (res->fib6_flags & RTF_REJECT) {
1098                 ip6_rt_init_dst_reject(rt, res->fib6_type);
1099                 return;
1100         }
1101
1102         rt->dst.error = 0;
1103         rt->dst.output = ip6_output;
1104
1105         if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
1106                 rt->dst.input = ip6_input;
1107         } else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
1108                 rt->dst.input = ip6_mc_input;
1109         } else {
1110                 rt->dst.input = ip6_forward;
1111         }
1112
1113         if (res->nh->fib_nh_lws) {
1114                 rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws);
1115                 lwtunnel_set_redirect(&rt->dst);
1116         }
1117
1118         rt->dst.lastuse = jiffies;
1119 }
1120
1121 /* Caller must already hold reference to @from */
1122 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
1123 {
1124         rt->rt6i_flags &= ~RTF_EXPIRES;
1125         rcu_assign_pointer(rt->from, from);
1126         ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
1127 }
1128
1129 /* Caller must already hold reference to f6i in result */
1130 static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
1131 {
1132         const struct fib6_nh *nh = res->nh;
1133         const struct net_device *dev = nh->fib_nh_dev;
1134         struct fib6_info *f6i = res->f6i;
1135
1136         ip6_rt_init_dst(rt, res);
1137
1138         rt->rt6i_dst = f6i->fib6_dst;
1139         rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
1140         rt->rt6i_flags = res->fib6_flags;
1141         if (nh->fib_nh_gw_family) {
1142                 rt->rt6i_gateway = nh->fib_nh_gw6;
1143                 rt->rt6i_flags |= RTF_GATEWAY;
1144         }
1145         rt6_set_from(rt, f6i);
1146 #ifdef CONFIG_IPV6_SUBTREES
1147         rt->rt6i_src = f6i->fib6_src;
1148 #endif
1149 }
1150
1151 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
1152                                         struct in6_addr *saddr)
1153 {
1154         struct fib6_node *pn, *sn;
1155         while (1) {
1156                 if (fn->fn_flags & RTN_TL_ROOT)
1157                         return NULL;
1158                 pn = rcu_dereference(fn->parent);
1159                 sn = FIB6_SUBTREE(pn);
1160                 if (sn && sn != fn)
1161                         fn = fib6_node_lookup(sn, NULL, saddr);
1162                 else
1163                         fn = pn;
1164                 if (fn->fn_flags & RTN_RTINFO)
1165                         return fn;
1166         }
1167 }
1168
1169 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt)
1170 {
1171         struct rt6_info *rt = *prt;
1172
1173         if (dst_hold_safe(&rt->dst))
1174                 return true;
1175         if (net) {
1176                 rt = net->ipv6.ip6_null_entry;
1177                 dst_hold(&rt->dst);
1178         } else {
1179                 rt = NULL;
1180         }
1181         *prt = rt;
1182         return false;
1183 }
1184
1185 /* called with rcu_lock held */
1186 static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res)
1187 {
1188         struct net_device *dev = res->nh->fib_nh_dev;
1189         struct fib6_info *f6i = res->f6i;
1190         unsigned short flags;
1191         struct rt6_info *nrt;
1192
1193         if (!fib6_info_hold_safe(f6i))
1194                 goto fallback;
1195
1196         flags = fib6_info_dst_flags(f6i);
1197         nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
1198         if (!nrt) {
1199                 fib6_info_release(f6i);
1200                 goto fallback;
1201         }
1202
1203         ip6_rt_copy_init(nrt, res);
1204         return nrt;
1205
1206 fallback:
1207         nrt = dev_net(dev)->ipv6.ip6_null_entry;
1208         dst_hold(&nrt->dst);
1209         return nrt;
1210 }
1211
1212 static struct rt6_info *ip6_pol_route_lookup(struct net *net,
1213                                              struct fib6_table *table,
1214                                              struct flowi6 *fl6,
1215                                              const struct sk_buff *skb,
1216                                              int flags)
1217 {
1218         struct fib6_result res = {};
1219         struct fib6_node *fn;
1220         struct rt6_info *rt;
1221
1222         if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
1223                 flags &= ~RT6_LOOKUP_F_IFACE;
1224
1225         rcu_read_lock();
1226         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1227 restart:
1228         res.f6i = rcu_dereference(fn->leaf);
1229         if (!res.f6i)
1230                 res.f6i = net->ipv6.fib6_null_entry;
1231         else
1232                 rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif,
1233                                  flags);
1234
1235         if (res.f6i == net->ipv6.fib6_null_entry) {
1236                 fn = fib6_backtrack(fn, &fl6->saddr);
1237                 if (fn)
1238                         goto restart;
1239
1240                 rt = net->ipv6.ip6_null_entry;
1241                 dst_hold(&rt->dst);
1242                 goto out;
1243         } else if (res.fib6_flags & RTF_REJECT) {
1244                 goto do_create;
1245         }
1246
1247         fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
1248                          fl6->flowi6_oif != 0, skb, flags);
1249
1250         /* Search through exception table */
1251         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
1252         if (rt) {
1253                 if (ip6_hold_safe(net, &rt))
1254                         dst_use_noref(&rt->dst, jiffies);
1255         } else {
1256 do_create:
1257                 rt = ip6_create_rt_rcu(&res);
1258         }
1259
1260 out:
1261         trace_fib6_table_lookup(net, &res, table, fl6);
1262
1263         rcu_read_unlock();
1264
1265         return rt;
1266 }
1267
1268 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
1269                                    const struct sk_buff *skb, int flags)
1270 {
1271         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
1272 }
1273 EXPORT_SYMBOL_GPL(ip6_route_lookup);
1274
1275 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
1276                             const struct in6_addr *saddr, int oif,
1277                             const struct sk_buff *skb, int strict)
1278 {
1279         struct flowi6 fl6 = {
1280                 .flowi6_oif = oif,
1281                 .daddr = *daddr,
1282         };
1283         struct dst_entry *dst;
1284         int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
1285
1286         if (saddr) {
1287                 memcpy(&fl6.saddr, saddr, sizeof(*saddr));
1288                 flags |= RT6_LOOKUP_F_HAS_SADDR;
1289         }
1290
1291         dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
1292         if (dst->error == 0)
1293                 return (struct rt6_info *) dst;
1294
1295         dst_release(dst);
1296
1297         return NULL;
1298 }
1299 EXPORT_SYMBOL(rt6_lookup);
1300
1301 /* ip6_ins_rt is called with FREE table->tb6_lock.
1302  * It takes new route entry, the addition fails by any reason the
1303  * route is released.
1304  * Caller must hold dst before calling it.
1305  */
1306
1307 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
1308                         struct netlink_ext_ack *extack)
1309 {
1310         int err;
1311         struct fib6_table *table;
1312
1313         table = rt->fib6_table;
1314         spin_lock_bh(&table->tb6_lock);
1315         err = fib6_add(&table->tb6_root, rt, info, extack);
1316         spin_unlock_bh(&table->tb6_lock);
1317
1318         return err;
1319 }
1320
1321 int ip6_ins_rt(struct net *net, struct fib6_info *rt)
1322 {
1323         struct nl_info info = { .nl_net = net, };
1324
1325         return __ip6_ins_rt(rt, &info, NULL);
1326 }
1327
1328 static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res,
1329                                            const struct in6_addr *daddr,
1330                                            const struct in6_addr *saddr)
1331 {
1332         struct fib6_info *f6i = res->f6i;
1333         struct net_device *dev;
1334         struct rt6_info *rt;
1335
1336         /*
1337          *      Clone the route.
1338          */
1339
1340         if (!fib6_info_hold_safe(f6i))
1341                 return NULL;
1342
1343         dev = ip6_rt_get_dev_rcu(res);
1344         rt = ip6_dst_alloc(dev_net(dev), dev, 0);
1345         if (!rt) {
1346                 fib6_info_release(f6i);
1347                 return NULL;
1348         }
1349
1350         ip6_rt_copy_init(rt, res);
1351         rt->rt6i_flags |= RTF_CACHE;
1352         rt->dst.flags |= DST_HOST;
1353         rt->rt6i_dst.addr = *daddr;
1354         rt->rt6i_dst.plen = 128;
1355
1356         if (!rt6_is_gw_or_nonexthop(res)) {
1357                 if (f6i->fib6_dst.plen != 128 &&
1358                     ipv6_addr_equal(&f6i->fib6_dst.addr, daddr))
1359                         rt->rt6i_flags |= RTF_ANYCAST;
1360 #ifdef CONFIG_IPV6_SUBTREES
1361                 if (rt->rt6i_src.plen && saddr) {
1362                         rt->rt6i_src.addr = *saddr;
1363                         rt->rt6i_src.plen = 128;
1364                 }
1365 #endif
1366         }
1367
1368         return rt;
1369 }
1370
1371 static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res)
1372 {
1373         struct fib6_info *f6i = res->f6i;
1374         unsigned short flags = fib6_info_dst_flags(f6i);
1375         struct net_device *dev;
1376         struct rt6_info *pcpu_rt;
1377
1378         if (!fib6_info_hold_safe(f6i))
1379                 return NULL;
1380
1381         rcu_read_lock();
1382         dev = ip6_rt_get_dev_rcu(res);
1383         pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags);
1384         rcu_read_unlock();
1385         if (!pcpu_rt) {
1386                 fib6_info_release(f6i);
1387                 return NULL;
1388         }
1389         ip6_rt_copy_init(pcpu_rt, res);
1390         pcpu_rt->rt6i_flags |= RTF_PCPU;
1391         return pcpu_rt;
1392 }
1393
1394 /* It should be called with rcu_read_lock() acquired */
1395 static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
1396 {
1397         struct rt6_info *pcpu_rt;
1398
1399         pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
1400
1401         return pcpu_rt;
1402 }
1403
1404 static struct rt6_info *rt6_make_pcpu_route(struct net *net,
1405                                             const struct fib6_result *res)
1406 {
1407         struct rt6_info *pcpu_rt, *prev, **p;
1408
1409         pcpu_rt = ip6_rt_pcpu_alloc(res);
1410         if (!pcpu_rt)
1411                 return NULL;
1412
1413         p = this_cpu_ptr(res->nh->rt6i_pcpu);
1414         prev = cmpxchg(p, NULL, pcpu_rt);
1415         BUG_ON(prev);
1416
1417         if (res->f6i->fib6_destroying) {
1418                 struct fib6_info *from;
1419
1420                 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
1421                 fib6_info_release(from);
1422         }
1423
1424         return pcpu_rt;
1425 }
1426
1427 /* exception hash table implementation
1428  */
1429 static DEFINE_SPINLOCK(rt6_exception_lock);
1430
1431 /* Remove rt6_ex from hash table and free the memory
1432  * Caller must hold rt6_exception_lock
1433  */
1434 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
1435                                  struct rt6_exception *rt6_ex)
1436 {
1437         struct fib6_info *from;
1438         struct net *net;
1439
1440         if (!bucket || !rt6_ex)
1441                 return;
1442
1443         net = dev_net(rt6_ex->rt6i->dst.dev);
1444         net->ipv6.rt6_stats->fib_rt_cache--;
1445
1446         /* purge completely the exception to allow releasing the held resources:
1447          * some [sk] cache may keep the dst around for unlimited time
1448          */
1449         from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL);
1450         fib6_info_release(from);
1451         dst_dev_put(&rt6_ex->rt6i->dst);
1452
1453         hlist_del_rcu(&rt6_ex->hlist);
1454         dst_release(&rt6_ex->rt6i->dst);
1455         kfree_rcu(rt6_ex, rcu);
1456         WARN_ON_ONCE(!bucket->depth);
1457         bucket->depth--;
1458 }
1459
1460 /* Remove oldest rt6_ex in bucket and free the memory
1461  * Caller must hold rt6_exception_lock
1462  */
1463 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
1464 {
1465         struct rt6_exception *rt6_ex, *oldest = NULL;
1466
1467         if (!bucket)
1468                 return;
1469
1470         hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
1471                 if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
1472                         oldest = rt6_ex;
1473         }
1474         rt6_remove_exception(bucket, oldest);
1475 }
1476
1477 static u32 rt6_exception_hash(const struct in6_addr *dst,
1478                               const struct in6_addr *src)
1479 {
1480         static u32 seed __read_mostly;
1481         u32 val;
1482
1483         net_get_random_once(&seed, sizeof(seed));
1484         val = jhash2((const u32 *)dst, sizeof(*dst)/sizeof(u32), seed);
1485
1486 #ifdef CONFIG_IPV6_SUBTREES
1487         if (src)
1488                 val = jhash2((const u32 *)src, sizeof(*src)/sizeof(u32), val);
1489 #endif
1490         return hash_32(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
1491 }
1492
1493 /* Helper function to find the cached rt in the hash table
1494  * and update bucket pointer to point to the bucket for this
1495  * (daddr, saddr) pair
1496  * Caller must hold rt6_exception_lock
1497  */
1498 static struct rt6_exception *
1499 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
1500                               const struct in6_addr *daddr,
1501                               const struct in6_addr *saddr)
1502 {
1503         struct rt6_exception *rt6_ex;
1504         u32 hval;
1505
1506         if (!(*bucket) || !daddr)
1507                 return NULL;
1508
1509         hval = rt6_exception_hash(daddr, saddr);
1510         *bucket += hval;
1511
1512         hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
1513                 struct rt6_info *rt6 = rt6_ex->rt6i;
1514                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1515
1516 #ifdef CONFIG_IPV6_SUBTREES
1517                 if (matched && saddr)
1518                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1519 #endif
1520                 if (matched)
1521                         return rt6_ex;
1522         }
1523         return NULL;
1524 }
1525
1526 /* Helper function to find the cached rt in the hash table
1527  * and update bucket pointer to point to the bucket for this
1528  * (daddr, saddr) pair
1529  * Caller must hold rcu_read_lock()
1530  */
1531 static struct rt6_exception *
1532 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
1533                          const struct in6_addr *daddr,
1534                          const struct in6_addr *saddr)
1535 {
1536         struct rt6_exception *rt6_ex;
1537         u32 hval;
1538
1539         WARN_ON_ONCE(!rcu_read_lock_held());
1540
1541         if (!(*bucket) || !daddr)
1542                 return NULL;
1543
1544         hval = rt6_exception_hash(daddr, saddr);
1545         *bucket += hval;
1546
1547         hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
1548                 struct rt6_info *rt6 = rt6_ex->rt6i;
1549                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1550
1551 #ifdef CONFIG_IPV6_SUBTREES
1552                 if (matched && saddr)
1553                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1554 #endif
1555                 if (matched)
1556                         return rt6_ex;
1557         }
1558         return NULL;
1559 }
1560
1561 static unsigned int fib6_mtu(const struct fib6_result *res)
1562 {
1563         const struct fib6_nh *nh = res->nh;
1564         unsigned int mtu;
1565
1566         if (res->f6i->fib6_pmtu) {
1567                 mtu = res->f6i->fib6_pmtu;
1568         } else {
1569                 struct net_device *dev = nh->fib_nh_dev;
1570                 struct inet6_dev *idev;
1571
1572                 rcu_read_lock();
1573                 idev = __in6_dev_get(dev);
1574                 mtu = idev->cnf.mtu6;
1575                 rcu_read_unlock();
1576         }
1577
1578         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
1579
1580         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
1581 }
1582
1583 #define FIB6_EXCEPTION_BUCKET_FLUSHED  0x1UL
1584
1585 /* used when the flushed bit is not relevant, only access to the bucket
1586  * (ie., all bucket users except rt6_insert_exception);
1587  *
1588  * called under rcu lock; sometimes called with rt6_exception_lock held
1589  */
1590 static
1591 struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh,
1592                                                        spinlock_t *lock)
1593 {
1594         struct rt6_exception_bucket *bucket;
1595
1596         if (lock)
1597                 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1598                                                    lockdep_is_held(lock));
1599         else
1600                 bucket = rcu_dereference(nh->rt6i_exception_bucket);
1601
1602         /* remove bucket flushed bit if set */
1603         if (bucket) {
1604                 unsigned long p = (unsigned long)bucket;
1605
1606                 p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED;
1607                 bucket = (struct rt6_exception_bucket *)p;
1608         }
1609
1610         return bucket;
1611 }
1612
1613 static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket)
1614 {
1615         unsigned long p = (unsigned long)bucket;
1616
1617         return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED);
1618 }
1619
1620 /* called with rt6_exception_lock held */
1621 static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh,
1622                                               spinlock_t *lock)
1623 {
1624         struct rt6_exception_bucket *bucket;
1625         unsigned long p;
1626
1627         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1628                                            lockdep_is_held(lock));
1629
1630         p = (unsigned long)bucket;
1631         p |= FIB6_EXCEPTION_BUCKET_FLUSHED;
1632         bucket = (struct rt6_exception_bucket *)p;
1633         rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1634 }
1635
1636 static int rt6_insert_exception(struct rt6_info *nrt,
1637                                 const struct fib6_result *res)
1638 {
1639         struct net *net = dev_net(nrt->dst.dev);
1640         struct rt6_exception_bucket *bucket;
1641         struct fib6_info *f6i = res->f6i;
1642         struct in6_addr *src_key = NULL;
1643         struct rt6_exception *rt6_ex;
1644         struct fib6_nh *nh = res->nh;
1645         int err = 0;
1646
1647         spin_lock_bh(&rt6_exception_lock);
1648
1649         bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1650                                           lockdep_is_held(&rt6_exception_lock));
1651         if (!bucket) {
1652                 bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
1653                                  GFP_ATOMIC);
1654                 if (!bucket) {
1655                         err = -ENOMEM;
1656                         goto out;
1657                 }
1658                 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1659         } else if (fib6_nh_excptn_bucket_flushed(bucket)) {
1660                 err = -EINVAL;
1661                 goto out;
1662         }
1663
1664 #ifdef CONFIG_IPV6_SUBTREES
1665         /* fib6_src.plen != 0 indicates f6i is in subtree
1666          * and exception table is indexed by a hash of
1667          * both fib6_dst and fib6_src.
1668          * Otherwise, the exception table is indexed by
1669          * a hash of only fib6_dst.
1670          */
1671         if (f6i->fib6_src.plen)
1672                 src_key = &nrt->rt6i_src.addr;
1673 #endif
1674         /* rt6_mtu_change() might lower mtu on f6i.
1675          * Only insert this exception route if its mtu
1676          * is less than f6i's mtu value.
1677          */
1678         if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) {
1679                 err = -EINVAL;
1680                 goto out;
1681         }
1682
1683         rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
1684                                                src_key);
1685         if (rt6_ex)
1686                 rt6_remove_exception(bucket, rt6_ex);
1687
1688         rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
1689         if (!rt6_ex) {
1690                 err = -ENOMEM;
1691                 goto out;
1692         }
1693         rt6_ex->rt6i = nrt;
1694         rt6_ex->stamp = jiffies;
1695         hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
1696         bucket->depth++;
1697         net->ipv6.rt6_stats->fib_rt_cache++;
1698
1699         if (bucket->depth > FIB6_MAX_DEPTH)
1700                 rt6_exception_remove_oldest(bucket);
1701
1702 out:
1703         spin_unlock_bh(&rt6_exception_lock);
1704
1705         /* Update fn->fn_sernum to invalidate all cached dst */
1706         if (!err) {
1707                 spin_lock_bh(&f6i->fib6_table->tb6_lock);
1708                 fib6_update_sernum(net, f6i);
1709                 spin_unlock_bh(&f6i->fib6_table->tb6_lock);
1710                 fib6_force_start_gc(net);
1711         }
1712
1713         return err;
1714 }
1715
1716 static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
1717 {
1718         struct rt6_exception_bucket *bucket;
1719         struct rt6_exception *rt6_ex;
1720         struct hlist_node *tmp;
1721         int i;
1722
1723         spin_lock_bh(&rt6_exception_lock);
1724
1725         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1726         if (!bucket)
1727                 goto out;
1728
1729         /* Prevent rt6_insert_exception() to recreate the bucket list */
1730         if (!from)
1731                 fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock);
1732
1733         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1734                 hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) {
1735                         if (!from ||
1736                             rcu_access_pointer(rt6_ex->rt6i->from) == from)
1737                                 rt6_remove_exception(bucket, rt6_ex);
1738                 }
1739                 WARN_ON_ONCE(!from && bucket->depth);
1740                 bucket++;
1741         }
1742 out:
1743         spin_unlock_bh(&rt6_exception_lock);
1744 }
1745
1746 static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg)
1747 {
1748         struct fib6_info *f6i = arg;
1749
1750         fib6_nh_flush_exceptions(nh, f6i);
1751
1752         return 0;
1753 }
1754
1755 void rt6_flush_exceptions(struct fib6_info *f6i)
1756 {
1757         if (f6i->nh)
1758                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions,
1759                                          f6i);
1760         else
1761                 fib6_nh_flush_exceptions(f6i->fib6_nh, f6i);
1762 }
1763
1764 /* Find cached rt in the hash table inside passed in rt
1765  * Caller has to hold rcu_read_lock()
1766  */
1767 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
1768                                            const struct in6_addr *daddr,
1769                                            const struct in6_addr *saddr)
1770 {
1771         const struct in6_addr *src_key = NULL;
1772         struct rt6_exception_bucket *bucket;
1773         struct rt6_exception *rt6_ex;
1774         struct rt6_info *ret = NULL;
1775
1776 #ifdef CONFIG_IPV6_SUBTREES
1777         /* fib6i_src.plen != 0 indicates f6i is in subtree
1778          * and exception table is indexed by a hash of
1779          * both fib6_dst and fib6_src.
1780          * However, the src addr used to create the hash
1781          * might not be exactly the passed in saddr which
1782          * is a /128 addr from the flow.
1783          * So we need to use f6i->fib6_src to redo lookup
1784          * if the passed in saddr does not find anything.
1785          * (See the logic in ip6_rt_cache_alloc() on how
1786          * rt->rt6i_src is updated.)
1787          */
1788         if (res->f6i->fib6_src.plen)
1789                 src_key = saddr;
1790 find_ex:
1791 #endif
1792         bucket = fib6_nh_get_excptn_bucket(res->nh, NULL);
1793         rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
1794
1795         if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
1796                 ret = rt6_ex->rt6i;
1797
1798 #ifdef CONFIG_IPV6_SUBTREES
1799         /* Use fib6_src as src_key and redo lookup */
1800         if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) {
1801                 src_key = &res->f6i->fib6_src.addr;
1802                 goto find_ex;
1803         }
1804 #endif
1805
1806         return ret;
1807 }
1808
1809 /* Remove the passed in cached rt from the hash table that contains it */
1810 static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen,
1811                                     const struct rt6_info *rt)
1812 {
1813         const struct in6_addr *src_key = NULL;
1814         struct rt6_exception_bucket *bucket;
1815         struct rt6_exception *rt6_ex;
1816         int err;
1817
1818         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
1819                 return -ENOENT;
1820
1821         spin_lock_bh(&rt6_exception_lock);
1822         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1823
1824 #ifdef CONFIG_IPV6_SUBTREES
1825         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1826          * and exception table is indexed by a hash of
1827          * both rt6i_dst and rt6i_src.
1828          * Otherwise, the exception table is indexed by
1829          * a hash of only rt6i_dst.
1830          */
1831         if (plen)
1832                 src_key = &rt->rt6i_src.addr;
1833 #endif
1834         rt6_ex = __rt6_find_exception_spinlock(&bucket,
1835                                                &rt->rt6i_dst.addr,
1836                                                src_key);
1837         if (rt6_ex) {
1838                 rt6_remove_exception(bucket, rt6_ex);
1839                 err = 0;
1840         } else {
1841                 err = -ENOENT;
1842         }
1843
1844         spin_unlock_bh(&rt6_exception_lock);
1845         return err;
1846 }
1847
1848 struct fib6_nh_excptn_arg {
1849         struct rt6_info *rt;
1850         int             plen;
1851 };
1852
1853 static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg)
1854 {
1855         struct fib6_nh_excptn_arg *arg = _arg;
1856         int err;
1857
1858         err = fib6_nh_remove_exception(nh, arg->plen, arg->rt);
1859         if (err == 0)
1860                 return 1;
1861
1862         return 0;
1863 }
1864
1865 static int rt6_remove_exception_rt(struct rt6_info *rt)
1866 {
1867         struct fib6_info *from;
1868
1869         from = rcu_dereference(rt->from);
1870         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1871                 return -EINVAL;
1872
1873         if (from->nh) {
1874                 struct fib6_nh_excptn_arg arg = {
1875                         .rt = rt,
1876                         .plen = from->fib6_src.plen
1877                 };
1878                 int rc;
1879
1880                 /* rc = 1 means an entry was found */
1881                 rc = nexthop_for_each_fib6_nh(from->nh,
1882                                               rt6_nh_remove_exception_rt,
1883                                               &arg);
1884                 return rc ? 0 : -ENOENT;
1885         }
1886
1887         return fib6_nh_remove_exception(from->fib6_nh,
1888                                         from->fib6_src.plen, rt);
1889 }
1890
1891 /* Find rt6_ex which contains the passed in rt cache and
1892  * refresh its stamp
1893  */
1894 static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen,
1895                                      const struct rt6_info *rt)
1896 {
1897         const struct in6_addr *src_key = NULL;
1898         struct rt6_exception_bucket *bucket;
1899         struct rt6_exception *rt6_ex;
1900
1901         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
1902 #ifdef CONFIG_IPV6_SUBTREES
1903         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1904          * and exception table is indexed by a hash of
1905          * both rt6i_dst and rt6i_src.
1906          * Otherwise, the exception table is indexed by
1907          * a hash of only rt6i_dst.
1908          */
1909         if (plen)
1910                 src_key = &rt->rt6i_src.addr;
1911 #endif
1912         rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
1913         if (rt6_ex)
1914                 rt6_ex->stamp = jiffies;
1915 }
1916
1917 struct fib6_nh_match_arg {
1918         const struct net_device *dev;
1919         const struct in6_addr   *gw;
1920         struct fib6_nh          *match;
1921 };
1922
1923 /* determine if fib6_nh has given device and gateway */
1924 static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg)
1925 {
1926         struct fib6_nh_match_arg *arg = _arg;
1927
1928         if (arg->dev != nh->fib_nh_dev ||
1929             (arg->gw && !nh->fib_nh_gw_family) ||
1930             (!arg->gw && nh->fib_nh_gw_family) ||
1931             (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6)))
1932                 return 0;
1933
1934         arg->match = nh;
1935
1936         /* found a match, break the loop */
1937         return 1;
1938 }
1939
1940 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
1941 {
1942         struct fib6_info *from;
1943         struct fib6_nh *fib6_nh;
1944
1945         rcu_read_lock();
1946
1947         from = rcu_dereference(rt->from);
1948         if (!from || !(rt->rt6i_flags & RTF_CACHE))
1949                 goto unlock;
1950
1951         if (from->nh) {
1952                 struct fib6_nh_match_arg arg = {
1953                         .dev = rt->dst.dev,
1954                         .gw = &rt->rt6i_gateway,
1955                 };
1956
1957                 nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
1958
1959                 if (!arg.match)
1960                         goto unlock;
1961                 fib6_nh = arg.match;
1962         } else {
1963                 fib6_nh = from->fib6_nh;
1964         }
1965         fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt);
1966 unlock:
1967         rcu_read_unlock();
1968 }
1969
1970 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
1971                                          struct rt6_info *rt, int mtu)
1972 {
1973         /* If the new MTU is lower than the route PMTU, this new MTU will be the
1974          * lowest MTU in the path: always allow updating the route PMTU to
1975          * reflect PMTU decreases.
1976          *
1977          * If the new MTU is higher, and the route PMTU is equal to the local
1978          * MTU, this means the old MTU is the lowest in the path, so allow
1979          * updating it: if other nodes now have lower MTUs, PMTU discovery will
1980          * handle this.
1981          */
1982
1983         if (dst_mtu(&rt->dst) >= mtu)
1984                 return true;
1985
1986         if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
1987                 return true;
1988
1989         return false;
1990 }
1991
1992 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
1993                                        const struct fib6_nh *nh, int mtu)
1994 {
1995         struct rt6_exception_bucket *bucket;
1996         struct rt6_exception *rt6_ex;
1997         int i;
1998
1999         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2000         if (!bucket)
2001                 return;
2002
2003         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2004                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
2005                         struct rt6_info *entry = rt6_ex->rt6i;
2006
2007                         /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
2008                          * route), the metrics of its rt->from have already
2009                          * been updated.
2010                          */
2011                         if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
2012                             rt6_mtu_change_route_allowed(idev, entry, mtu))
2013                                 dst_metric_set(&entry->dst, RTAX_MTU, mtu);
2014                 }
2015                 bucket++;
2016         }
2017 }
2018
2019 #define RTF_CACHE_GATEWAY       (RTF_GATEWAY | RTF_CACHE)
2020
2021 static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh,
2022                                             const struct in6_addr *gateway)
2023 {
2024         struct rt6_exception_bucket *bucket;
2025         struct rt6_exception *rt6_ex;
2026         struct hlist_node *tmp;
2027         int i;
2028
2029         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2030                 return;
2031
2032         spin_lock_bh(&rt6_exception_lock);
2033         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2034         if (bucket) {
2035                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2036                         hlist_for_each_entry_safe(rt6_ex, tmp,
2037                                                   &bucket->chain, hlist) {
2038                                 struct rt6_info *entry = rt6_ex->rt6i;
2039
2040                                 if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
2041                                     RTF_CACHE_GATEWAY &&
2042                                     ipv6_addr_equal(gateway,
2043                                                     &entry->rt6i_gateway)) {
2044                                         rt6_remove_exception(bucket, rt6_ex);
2045                                 }
2046                         }
2047                         bucket++;
2048                 }
2049         }
2050
2051         spin_unlock_bh(&rt6_exception_lock);
2052 }
2053
2054 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
2055                                       struct rt6_exception *rt6_ex,
2056                                       struct fib6_gc_args *gc_args,
2057                                       unsigned long now)
2058 {
2059         struct rt6_info *rt = rt6_ex->rt6i;
2060
2061         /* we are pruning and obsoleting aged-out and non gateway exceptions
2062          * even if others have still references to them, so that on next
2063          * dst_check() such references can be dropped.
2064          * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
2065          * expired, independently from their aging, as per RFC 8201 section 4
2066          */
2067         if (!(rt->rt6i_flags & RTF_EXPIRES)) {
2068                 if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
2069                         RT6_TRACE("aging clone %p\n", rt);
2070                         rt6_remove_exception(bucket, rt6_ex);
2071                         return;
2072                 }
2073         } else if (time_after(jiffies, rt->dst.expires)) {
2074                 RT6_TRACE("purging expired route %p\n", rt);
2075                 rt6_remove_exception(bucket, rt6_ex);
2076                 return;
2077         }
2078
2079         if (rt->rt6i_flags & RTF_GATEWAY) {
2080                 struct neighbour *neigh;
2081                 __u8 neigh_flags = 0;
2082
2083                 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
2084                 if (neigh)
2085                         neigh_flags = neigh->flags;
2086
2087                 if (!(neigh_flags & NTF_ROUTER)) {
2088                         RT6_TRACE("purging route %p via non-router but gateway\n",
2089                                   rt);
2090                         rt6_remove_exception(bucket, rt6_ex);
2091                         return;
2092                 }
2093         }
2094
2095         gc_args->more++;
2096 }
2097
2098 static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
2099                                    struct fib6_gc_args *gc_args,
2100                                    unsigned long now)
2101 {
2102         struct rt6_exception_bucket *bucket;
2103         struct rt6_exception *rt6_ex;
2104         struct hlist_node *tmp;
2105         int i;
2106
2107         if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2108                 return;
2109
2110         rcu_read_lock_bh();
2111         spin_lock(&rt6_exception_lock);
2112         bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2113         if (bucket) {
2114                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2115                         hlist_for_each_entry_safe(rt6_ex, tmp,
2116                                                   &bucket->chain, hlist) {
2117                                 rt6_age_examine_exception(bucket, rt6_ex,
2118                                                           gc_args, now);
2119                         }
2120                         bucket++;
2121                 }
2122         }
2123         spin_unlock(&rt6_exception_lock);
2124         rcu_read_unlock_bh();
2125 }
2126
2127 struct fib6_nh_age_excptn_arg {
2128         struct fib6_gc_args     *gc_args;
2129         unsigned long           now;
2130 };
2131
2132 static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg)
2133 {
2134         struct fib6_nh_age_excptn_arg *arg = _arg;
2135
2136         fib6_nh_age_exceptions(nh, arg->gc_args, arg->now);
2137         return 0;
2138 }
2139
2140 void rt6_age_exceptions(struct fib6_info *f6i,
2141                         struct fib6_gc_args *gc_args,
2142                         unsigned long now)
2143 {
2144         if (f6i->nh) {
2145                 struct fib6_nh_age_excptn_arg arg = {
2146                         .gc_args = gc_args,
2147                         .now = now
2148                 };
2149
2150                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions,
2151                                          &arg);
2152         } else {
2153                 fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now);
2154         }
2155 }
2156
2157 /* must be called with rcu lock held */
2158 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
2159                       struct flowi6 *fl6, struct fib6_result *res, int strict)
2160 {
2161         struct fib6_node *fn, *saved_fn;
2162
2163         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
2164         saved_fn = fn;
2165
2166         if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
2167                 oif = 0;
2168
2169 redo_rt6_select:
2170         rt6_select(net, fn, oif, res, strict);
2171         if (res->f6i == net->ipv6.fib6_null_entry) {
2172                 fn = fib6_backtrack(fn, &fl6->saddr);
2173                 if (fn)
2174                         goto redo_rt6_select;
2175                 else if (strict & RT6_LOOKUP_F_REACHABLE) {
2176                         /* also consider unreachable route */
2177                         strict &= ~RT6_LOOKUP_F_REACHABLE;
2178                         fn = saved_fn;
2179                         goto redo_rt6_select;
2180                 }
2181         }
2182
2183         trace_fib6_table_lookup(net, res, table, fl6);
2184
2185         return 0;
2186 }
2187
2188 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
2189                                int oif, struct flowi6 *fl6,
2190                                const struct sk_buff *skb, int flags)
2191 {
2192         struct fib6_result res = {};
2193         struct rt6_info *rt = NULL;
2194         int strict = 0;
2195
2196         WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
2197                      !rcu_read_lock_held());
2198
2199         strict |= flags & RT6_LOOKUP_F_IFACE;
2200         strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
2201         if (net->ipv6.devconf_all->forwarding == 0)
2202                 strict |= RT6_LOOKUP_F_REACHABLE;
2203
2204         rcu_read_lock();
2205
2206         fib6_table_lookup(net, table, oif, fl6, &res, strict);
2207         if (res.f6i == net->ipv6.fib6_null_entry)
2208                 goto out;
2209
2210         fib6_select_path(net, &res, fl6, oif, false, skb, strict);
2211
2212         /*Search through exception table */
2213         rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
2214         if (rt) {
2215                 goto out;
2216         } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
2217                             !res.nh->fib_nh_gw_family)) {
2218                 /* Create a RTF_CACHE clone which will not be
2219                  * owned by the fib6 tree.  It is for the special case where
2220                  * the daddr in the skb during the neighbor look-up is different
2221                  * from the fl6->daddr used to look-up route here.
2222                  */
2223                 rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
2224
2225                 if (rt) {
2226                         /* 1 refcnt is taken during ip6_rt_cache_alloc().
2227                          * As rt6_uncached_list_add() does not consume refcnt,
2228                          * this refcnt is always returned to the caller even
2229                          * if caller sets RT6_LOOKUP_F_DST_NOREF flag.
2230                          */
2231                         rt6_uncached_list_add(rt);
2232                         atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
2233                         rcu_read_unlock();
2234
2235                         return rt;
2236                 }
2237         } else {
2238                 /* Get a percpu copy */
2239                 local_bh_disable();
2240                 rt = rt6_get_pcpu_route(&res);
2241
2242                 if (!rt)
2243                         rt = rt6_make_pcpu_route(net, &res);
2244
2245                 local_bh_enable();
2246         }
2247 out:
2248         if (!rt)
2249                 rt = net->ipv6.ip6_null_entry;
2250         if (!(flags & RT6_LOOKUP_F_DST_NOREF))
2251                 ip6_hold_safe(net, &rt);
2252         rcu_read_unlock();
2253
2254         return rt;
2255 }
2256 EXPORT_SYMBOL_GPL(ip6_pol_route);
2257
2258 static struct rt6_info *ip6_pol_route_input(struct net *net,
2259                                             struct fib6_table *table,
2260                                             struct flowi6 *fl6,
2261                                             const struct sk_buff *skb,
2262                                             int flags)
2263 {
2264         return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
2265 }
2266
2267 struct dst_entry *ip6_route_input_lookup(struct net *net,
2268                                          struct net_device *dev,
2269                                          struct flowi6 *fl6,
2270                                          const struct sk_buff *skb,
2271                                          int flags)
2272 {
2273         if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
2274                 flags |= RT6_LOOKUP_F_IFACE;
2275
2276         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
2277 }
2278 EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
2279
2280 static void ip6_multipath_l3_keys(const struct sk_buff *skb,
2281                                   struct flow_keys *keys,
2282                                   struct flow_keys *flkeys)
2283 {
2284         const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
2285         const struct ipv6hdr *key_iph = outer_iph;
2286         struct flow_keys *_flkeys = flkeys;
2287         const struct ipv6hdr *inner_iph;
2288         const struct icmp6hdr *icmph;
2289         struct ipv6hdr _inner_iph;
2290         struct icmp6hdr _icmph;
2291
2292         if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
2293                 goto out;
2294
2295         icmph = skb_header_pointer(skb, skb_transport_offset(skb),
2296                                    sizeof(_icmph), &_icmph);
2297         if (!icmph)
2298                 goto out;
2299
2300         if (!icmpv6_is_err(icmph->icmp6_type))
2301                 goto out;
2302
2303         inner_iph = skb_header_pointer(skb,
2304                                        skb_transport_offset(skb) + sizeof(*icmph),
2305                                        sizeof(_inner_iph), &_inner_iph);
2306         if (!inner_iph)
2307                 goto out;
2308
2309         key_iph = inner_iph;
2310         _flkeys = NULL;
2311 out:
2312         if (_flkeys) {
2313                 keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
2314                 keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
2315                 keys->tags.flow_label = _flkeys->tags.flow_label;
2316                 keys->basic.ip_proto = _flkeys->basic.ip_proto;
2317         } else {
2318                 keys->addrs.v6addrs.src = key_iph->saddr;
2319                 keys->addrs.v6addrs.dst = key_iph->daddr;
2320                 keys->tags.flow_label = ip6_flowlabel(key_iph);
2321                 keys->basic.ip_proto = key_iph->nexthdr;
2322         }
2323 }
2324
2325 /* if skb is set it will be used and fl6 can be NULL */
2326 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
2327                        const struct sk_buff *skb, struct flow_keys *flkeys)
2328 {
2329         struct flow_keys hash_keys;
2330         u32 mhash;
2331
2332         switch (ip6_multipath_hash_policy(net)) {
2333         case 0:
2334                 memset(&hash_keys, 0, sizeof(hash_keys));
2335                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2336                 if (skb) {
2337                         ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2338                 } else {
2339                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2340                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2341                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2342                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2343                 }
2344                 break;
2345         case 1:
2346                 if (skb) {
2347                         unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2348                         struct flow_keys keys;
2349
2350                         /* short-circuit if we already have L4 hash present */
2351                         if (skb->l4_hash)
2352                                 return skb_get_hash_raw(skb) >> 1;
2353
2354                         memset(&hash_keys, 0, sizeof(hash_keys));
2355
2356                         if (!flkeys) {
2357                                 skb_flow_dissect_flow_keys(skb, &keys, flag);
2358                                 flkeys = &keys;
2359                         }
2360                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2361                         hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2362                         hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2363                         hash_keys.ports.src = flkeys->ports.src;
2364                         hash_keys.ports.dst = flkeys->ports.dst;
2365                         hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2366                 } else {
2367                         memset(&hash_keys, 0, sizeof(hash_keys));
2368                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2369                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2370                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2371                         hash_keys.ports.src = fl6->fl6_sport;
2372                         hash_keys.ports.dst = fl6->fl6_dport;
2373                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2374                 }
2375                 break;
2376         case 2:
2377                 memset(&hash_keys, 0, sizeof(hash_keys));
2378                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2379                 if (skb) {
2380                         struct flow_keys keys;
2381
2382                         if (!flkeys) {
2383                                 skb_flow_dissect_flow_keys(skb, &keys, 0);
2384                                 flkeys = &keys;
2385                         }
2386
2387                         /* Inner can be v4 or v6 */
2388                         if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2389                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2390                                 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2391                                 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2392                         } else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2393                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2394                                 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2395                                 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2396                                 hash_keys.tags.flow_label = flkeys->tags.flow_label;
2397                                 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2398                         } else {
2399                                 /* Same as case 0 */
2400                                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2401                                 ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2402                         }
2403                 } else {
2404                         /* Same as case 0 */
2405                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2406                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2407                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2408                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2409                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2410                 }
2411                 break;
2412         }
2413         mhash = flow_hash_from_keys(&hash_keys);
2414
2415         return mhash >> 1;
2416 }
2417
2418 /* Called with rcu held */
2419 void ip6_route_input(struct sk_buff *skb)
2420 {
2421         const struct ipv6hdr *iph = ipv6_hdr(skb);
2422         struct net *net = dev_net(skb->dev);
2423         int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF;
2424         struct ip_tunnel_info *tun_info;
2425         struct flowi6 fl6 = {
2426                 .flowi6_iif = skb->dev->ifindex,
2427                 .daddr = iph->daddr,
2428                 .saddr = iph->saddr,
2429                 .flowlabel = ip6_flowinfo(iph),
2430                 .flowi6_mark = skb->mark,
2431                 .flowi6_proto = iph->nexthdr,
2432         };
2433         struct flow_keys *flkeys = NULL, _flkeys;
2434
2435         tun_info = skb_tunnel_info(skb);
2436         if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2437                 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
2438
2439         if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
2440                 flkeys = &_flkeys;
2441
2442         if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
2443                 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
2444         skb_dst_drop(skb);
2445         skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev,
2446                                                       &fl6, skb, flags));
2447 }
2448
2449 static struct rt6_info *ip6_pol_route_output(struct net *net,
2450                                              struct fib6_table *table,
2451                                              struct flowi6 *fl6,
2452                                              const struct sk_buff *skb,
2453                                              int flags)
2454 {
2455         return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
2456 }
2457
2458 struct dst_entry *ip6_route_output_flags_noref(struct net *net,
2459                                                const struct sock *sk,
2460                                                struct flowi6 *fl6, int flags)
2461 {
2462         bool any_src;
2463
2464         if (ipv6_addr_type(&fl6->daddr) &
2465             (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
2466                 struct dst_entry *dst;
2467
2468                 /* This function does not take refcnt on the dst */
2469                 dst = l3mdev_link_scope_lookup(net, fl6);
2470                 if (dst)
2471                         return dst;
2472         }
2473
2474         fl6->flowi6_iif = LOOPBACK_IFINDEX;
2475
2476         flags |= RT6_LOOKUP_F_DST_NOREF;
2477         any_src = ipv6_addr_any(&fl6->saddr);
2478         if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
2479             (fl6->flowi6_oif && any_src))
2480                 flags |= RT6_LOOKUP_F_IFACE;
2481
2482         if (!any_src)
2483                 flags |= RT6_LOOKUP_F_HAS_SADDR;
2484         else if (sk)
2485                 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
2486
2487         return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
2488 }
2489 EXPORT_SYMBOL_GPL(ip6_route_output_flags_noref);
2490
2491 struct dst_entry *ip6_route_output_flags(struct net *net,
2492                                          const struct sock *sk,
2493                                          struct flowi6 *fl6,
2494                                          int flags)
2495 {
2496         struct dst_entry *dst;
2497         struct rt6_info *rt6;
2498
2499         rcu_read_lock();
2500         dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
2501         rt6 = (struct rt6_info *)dst;
2502         /* For dst cached in uncached_list, refcnt is already taken. */
2503         if (list_empty(&rt6->rt6i_uncached) && !dst_hold_safe(dst)) {
2504                 dst = &net->ipv6.ip6_null_entry->dst;
2505                 dst_hold(dst);
2506         }
2507         rcu_read_unlock();
2508
2509         return dst;
2510 }
2511 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
2512
2513 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2514 {
2515         struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
2516         struct net_device *loopback_dev = net->loopback_dev;
2517         struct dst_entry *new = NULL;
2518
2519         rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
2520                        DST_OBSOLETE_DEAD, 0);
2521         if (rt) {
2522                 rt6_info_init(rt);
2523                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
2524
2525                 new = &rt->dst;
2526                 new->__use = 1;
2527                 new->input = dst_discard;
2528                 new->output = dst_discard_out;
2529
2530                 dst_copy_metrics(new, &ort->dst);
2531
2532                 rt->rt6i_idev = in6_dev_get(loopback_dev);
2533                 rt->rt6i_gateway = ort->rt6i_gateway;
2534                 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
2535
2536                 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
2537 #ifdef CONFIG_IPV6_SUBTREES
2538                 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
2539 #endif
2540         }
2541
2542         dst_release(dst_orig);
2543         return new ? new : ERR_PTR(-ENOMEM);
2544 }
2545
2546 /*
2547  *      Destination cache support functions
2548  */
2549
2550 static bool fib6_check(struct fib6_info *f6i, u32 cookie)
2551 {
2552         u32 rt_cookie = 0;
2553
2554         if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
2555                 return false;
2556
2557         if (fib6_check_expired(f6i))
2558                 return false;
2559
2560         return true;
2561 }
2562
2563 static struct dst_entry *rt6_check(struct rt6_info *rt,
2564                                    struct fib6_info *from,
2565                                    u32 cookie)
2566 {
2567         u32 rt_cookie = 0;
2568
2569         if (!from || !fib6_get_cookie_safe(from, &rt_cookie) ||
2570             rt_cookie != cookie)
2571                 return NULL;
2572
2573         if (rt6_check_expired(rt))
2574                 return NULL;
2575
2576         return &rt->dst;
2577 }
2578
2579 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
2580                                             struct fib6_info *from,
2581                                             u32 cookie)
2582 {
2583         if (!__rt6_check_expired(rt) &&
2584             rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
2585             fib6_check(from, cookie))
2586                 return &rt->dst;
2587         else
2588                 return NULL;
2589 }
2590
2591 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
2592 {
2593         struct dst_entry *dst_ret;
2594         struct fib6_info *from;
2595         struct rt6_info *rt;
2596
2597         rt = container_of(dst, struct rt6_info, dst);
2598
2599         rcu_read_lock();
2600
2601         /* All IPV6 dsts are created with ->obsolete set to the value
2602          * DST_OBSOLETE_FORCE_CHK which forces validation calls down
2603          * into this function always.
2604          */
2605
2606         from = rcu_dereference(rt->from);
2607
2608         if (from && (rt->rt6i_flags & RTF_PCPU ||
2609             unlikely(!list_empty(&rt->rt6i_uncached))))
2610                 dst_ret = rt6_dst_from_check(rt, from, cookie);
2611         else
2612                 dst_ret = rt6_check(rt, from, cookie);
2613
2614         rcu_read_unlock();
2615
2616         return dst_ret;
2617 }
2618
2619 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
2620 {
2621         struct rt6_info *rt = (struct rt6_info *) dst;
2622
2623         if (rt) {
2624                 if (rt->rt6i_flags & RTF_CACHE) {
2625                         rcu_read_lock();
2626                         if (rt6_check_expired(rt)) {
2627                                 rt6_remove_exception_rt(rt);
2628                                 dst = NULL;
2629                         }
2630                         rcu_read_unlock();
2631                 } else {
2632                         dst_release(dst);
2633                         dst = NULL;
2634                 }
2635         }
2636         return dst;
2637 }
2638
2639 static void ip6_link_failure(struct sk_buff *skb)
2640 {
2641         struct rt6_info *rt;
2642
2643         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
2644
2645         rt = (struct rt6_info *) skb_dst(skb);
2646         if (rt) {
2647                 rcu_read_lock();
2648                 if (rt->rt6i_flags & RTF_CACHE) {
2649                         rt6_remove_exception_rt(rt);
2650                 } else {
2651                         struct fib6_info *from;
2652                         struct fib6_node *fn;
2653
2654                         from = rcu_dereference(rt->from);
2655                         if (from) {
2656                                 fn = rcu_dereference(from->fib6_node);
2657                                 if (fn && (rt->rt6i_flags & RTF_DEFAULT))
2658                                         fn->fn_sernum = -1;
2659                         }
2660                 }
2661                 rcu_read_unlock();
2662         }
2663 }
2664
2665 static void rt6_update_expires(struct rt6_info *rt0, int timeout)
2666 {
2667         if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
2668                 struct fib6_info *from;
2669
2670                 rcu_read_lock();
2671                 from = rcu_dereference(rt0->from);
2672                 if (from)
2673                         rt0->dst.expires = from->expires;
2674                 rcu_read_unlock();
2675         }
2676
2677         dst_set_expires(&rt0->dst, timeout);
2678         rt0->rt6i_flags |= RTF_EXPIRES;
2679 }
2680
2681 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
2682 {
2683         struct net *net = dev_net(rt->dst.dev);
2684
2685         dst_metric_set(&rt->dst, RTAX_MTU, mtu);
2686         rt->rt6i_flags |= RTF_MODIFIED;
2687         rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
2688 }
2689
2690 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
2691 {
2692         return !(rt->rt6i_flags & RTF_CACHE) &&
2693                 (rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
2694 }
2695
2696 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
2697                                  const struct ipv6hdr *iph, u32 mtu,
2698                                  bool confirm_neigh)
2699 {
2700         const struct in6_addr *daddr, *saddr;
2701         struct rt6_info *rt6 = (struct rt6_info *)dst;
2702
2703         if (dst_metric_locked(dst, RTAX_MTU))
2704                 return;
2705
2706         if (iph) {
2707                 daddr = &iph->daddr;
2708                 saddr = &iph->saddr;
2709         } else if (sk) {
2710                 daddr = &sk->sk_v6_daddr;
2711                 saddr = &inet6_sk(sk)->saddr;
2712         } else {
2713                 daddr = NULL;
2714                 saddr = NULL;
2715         }
2716
2717         if (confirm_neigh)
2718                 dst_confirm_neigh(dst, daddr);
2719
2720         mtu = max_t(u32, mtu, IPV6_MIN_MTU);
2721         if (mtu >= dst_mtu(dst))
2722                 return;
2723
2724         if (!rt6_cache_allowed_for_pmtu(rt6)) {
2725                 rt6_do_update_pmtu(rt6, mtu);
2726                 /* update rt6_ex->stamp for cache */
2727                 if (rt6->rt6i_flags & RTF_CACHE)
2728                         rt6_update_exception_stamp_rt(rt6);
2729         } else if (daddr) {
2730                 struct fib6_result res = {};
2731                 struct rt6_info *nrt6;
2732
2733                 rcu_read_lock();
2734                 res.f6i = rcu_dereference(rt6->from);
2735                 if (!res.f6i)
2736                         goto out_unlock;
2737
2738                 res.fib6_flags = res.f6i->fib6_flags;
2739                 res.fib6_type = res.f6i->fib6_type;
2740
2741                 if (res.f6i->nh) {
2742                         struct fib6_nh_match_arg arg = {
2743                                 .dev = dst->dev,
2744                                 .gw = &rt6->rt6i_gateway,
2745                         };
2746
2747                         nexthop_for_each_fib6_nh(res.f6i->nh,
2748                                                  fib6_nh_find_match, &arg);
2749
2750                         /* fib6_info uses a nexthop that does not have fib6_nh
2751                          * using the dst->dev + gw. Should be impossible.
2752                          */
2753                         if (!arg.match)
2754                                 goto out_unlock;
2755
2756                         res.nh = arg.match;
2757                 } else {
2758                         res.nh = res.f6i->fib6_nh;
2759                 }
2760
2761                 nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
2762                 if (nrt6) {
2763                         rt6_do_update_pmtu(nrt6, mtu);
2764                         if (rt6_insert_exception(nrt6, &res))
2765                                 dst_release_immediate(&nrt6->dst);
2766                 }
2767 out_unlock:
2768                 rcu_read_unlock();
2769         }
2770 }
2771
2772 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
2773                                struct sk_buff *skb, u32 mtu,
2774                                bool confirm_neigh)
2775 {
2776         __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu,
2777                              confirm_neigh);
2778 }
2779
2780 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
2781                      int oif, u32 mark, kuid_t uid)
2782 {
2783         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2784         struct dst_entry *dst;
2785         struct flowi6 fl6 = {
2786                 .flowi6_oif = oif,
2787                 .flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
2788                 .daddr = iph->daddr,
2789                 .saddr = iph->saddr,
2790                 .flowlabel = ip6_flowinfo(iph),
2791                 .flowi6_uid = uid,
2792         };
2793
2794         dst = ip6_route_output(net, NULL, &fl6);
2795         if (!dst->error)
2796                 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true);
2797         dst_release(dst);
2798 }
2799 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
2800
2801 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
2802 {
2803         int oif = sk->sk_bound_dev_if;
2804         struct dst_entry *dst;
2805
2806         if (!oif && skb->dev)
2807                 oif = l3mdev_master_ifindex(skb->dev);
2808
2809         ip6_update_pmtu(skb, sock_net(sk), mtu, oif, sk->sk_mark, sk->sk_uid);
2810
2811         dst = __sk_dst_get(sk);
2812         if (!dst || !dst->obsolete ||
2813             dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
2814                 return;
2815
2816         bh_lock_sock(sk);
2817         if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
2818                 ip6_datagram_dst_update(sk, false);
2819         bh_unlock_sock(sk);
2820 }
2821 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
2822
2823 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
2824                            const struct flowi6 *fl6)
2825 {
2826 #ifdef CONFIG_IPV6_SUBTREES
2827         struct ipv6_pinfo *np = inet6_sk(sk);
2828 #endif
2829
2830         ip6_dst_store(sk, dst,
2831                       ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
2832                       &sk->sk_v6_daddr : NULL,
2833 #ifdef CONFIG_IPV6_SUBTREES
2834                       ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
2835                       &np->saddr :
2836 #endif
2837                       NULL);
2838 }
2839
2840 static bool ip6_redirect_nh_match(const struct fib6_result *res,
2841                                   struct flowi6 *fl6,
2842                                   const struct in6_addr *gw,
2843                                   struct rt6_info **ret)
2844 {
2845         const struct fib6_nh *nh = res->nh;
2846
2847         if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family ||
2848             fl6->flowi6_oif != nh->fib_nh_dev->ifindex)
2849                 return false;
2850
2851         /* rt_cache's gateway might be different from its 'parent'
2852          * in the case of an ip redirect.
2853          * So we keep searching in the exception table if the gateway
2854          * is different.
2855          */
2856         if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) {
2857                 struct rt6_info *rt_cache;
2858
2859                 rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr);
2860                 if (rt_cache &&
2861                     ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) {
2862                         *ret = rt_cache;
2863                         return true;
2864                 }
2865                 return false;
2866         }
2867         return true;
2868 }
2869
2870 struct fib6_nh_rd_arg {
2871         struct fib6_result      *res;
2872         struct flowi6           *fl6;
2873         const struct in6_addr   *gw;
2874         struct rt6_info         **ret;
2875 };
2876
2877 static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg)
2878 {
2879         struct fib6_nh_rd_arg *arg = _arg;
2880
2881         arg->res->nh = nh;
2882         return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret);
2883 }
2884
2885 /* Handle redirects */
2886 struct ip6rd_flowi {
2887         struct flowi6 fl6;
2888         struct in6_addr gateway;
2889 };
2890
2891 static struct rt6_info *__ip6_route_redirect(struct net *net,
2892                                              struct fib6_table *table,
2893                                              struct flowi6 *fl6,
2894                                              const struct sk_buff *skb,
2895                                              int flags)
2896 {
2897         struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
2898         struct rt6_info *ret = NULL;
2899         struct fib6_result res = {};
2900         struct fib6_nh_rd_arg arg = {
2901                 .res = &res,
2902                 .fl6 = fl6,
2903                 .gw  = &rdfl->gateway,
2904                 .ret = &ret
2905         };
2906         struct fib6_info *rt;
2907         struct fib6_node *fn;
2908
2909         /* l3mdev_update_flow overrides oif if the device is enslaved; in
2910          * this case we must match on the real ingress device, so reset it
2911          */
2912         if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
2913                 fl6->flowi6_oif = skb->dev->ifindex;
2914
2915         /* Get the "current" route for this destination and
2916          * check if the redirect has come from appropriate router.
2917          *
2918          * RFC 4861 specifies that redirects should only be
2919          * accepted if they come from the nexthop to the target.
2920          * Due to the way the routes are chosen, this notion
2921          * is a bit fuzzy and one might need to check all possible
2922          * routes.
2923          */
2924
2925         rcu_read_lock();
2926         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
2927 restart:
2928         for_each_fib6_node_rt_rcu(fn) {
2929                 res.f6i = rt;
2930                 if (fib6_check_expired(rt))
2931                         continue;
2932                 if (rt->fib6_flags & RTF_REJECT)
2933                         break;
2934                 if (unlikely(rt->nh)) {
2935                         if (nexthop_is_blackhole(rt->nh))
2936                                 continue;
2937                         /* on match, res->nh is filled in and potentially ret */
2938                         if (nexthop_for_each_fib6_nh(rt->nh,
2939                                                      fib6_nh_redirect_match,
2940                                                      &arg))
2941                                 goto out;
2942                 } else {
2943                         res.nh = rt->fib6_nh;
2944                         if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway,
2945                                                   &ret))
2946                                 goto out;
2947                 }
2948         }
2949
2950         if (!rt)
2951                 rt = net->ipv6.fib6_null_entry;
2952         else if (rt->fib6_flags & RTF_REJECT) {
2953                 ret = net->ipv6.ip6_null_entry;
2954                 goto out;
2955         }
2956
2957         if (rt == net->ipv6.fib6_null_entry) {
2958                 fn = fib6_backtrack(fn, &fl6->saddr);
2959                 if (fn)
2960                         goto restart;
2961         }
2962
2963         res.f6i = rt;
2964         res.nh = rt->fib6_nh;
2965 out:
2966         if (ret) {
2967                 ip6_hold_safe(net, &ret);
2968         } else {
2969                 res.fib6_flags = res.f6i->fib6_flags;
2970                 res.fib6_type = res.f6i->fib6_type;
2971                 ret = ip6_create_rt_rcu(&res);
2972         }
2973
2974         rcu_read_unlock();
2975
2976         trace_fib6_table_lookup(net, &res, table, fl6);
2977         return ret;
2978 };
2979
2980 static struct dst_entry *ip6_route_redirect(struct net *net,
2981                                             const struct flowi6 *fl6,
2982                                             const struct sk_buff *skb,
2983                                             const struct in6_addr *gateway)
2984 {
2985         int flags = RT6_LOOKUP_F_HAS_SADDR;
2986         struct ip6rd_flowi rdfl;
2987
2988         rdfl.fl6 = *fl6;
2989         rdfl.gateway = *gateway;
2990
2991         return fib6_rule_lookup(net, &rdfl.fl6, skb,
2992                                 flags, __ip6_route_redirect);
2993 }
2994
2995 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
2996                   kuid_t uid)
2997 {
2998         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2999         struct dst_entry *dst;
3000         struct flowi6 fl6 = {
3001                 .flowi6_iif = LOOPBACK_IFINDEX,
3002                 .flowi6_oif = oif,
3003                 .flowi6_mark = mark,
3004                 .daddr = iph->daddr,
3005                 .saddr = iph->saddr,
3006                 .flowlabel = ip6_flowinfo(iph),
3007                 .flowi6_uid = uid,
3008         };
3009
3010         dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
3011         rt6_do_redirect(dst, NULL, skb);
3012         dst_release(dst);
3013 }
3014 EXPORT_SYMBOL_GPL(ip6_redirect);
3015
3016 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
3017 {
3018         const struct ipv6hdr *iph = ipv6_hdr(skb);
3019         const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
3020         struct dst_entry *dst;
3021         struct flowi6 fl6 = {
3022                 .flowi6_iif = LOOPBACK_IFINDEX,
3023                 .flowi6_oif = oif,
3024                 .daddr = msg->dest,
3025                 .saddr = iph->daddr,
3026                 .flowi6_uid = sock_net_uid(net, NULL),
3027         };
3028
3029         dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
3030         rt6_do_redirect(dst, NULL, skb);
3031         dst_release(dst);
3032 }
3033
3034 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
3035 {
3036         ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark,
3037                      sk->sk_uid);
3038 }
3039 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
3040
3041 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
3042 {
3043         struct net_device *dev = dst->dev;
3044         unsigned int mtu = dst_mtu(dst);
3045         struct net *net = dev_net(dev);
3046
3047         mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
3048
3049         if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
3050                 mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
3051
3052         /*
3053          * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
3054          * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
3055          * IPV6_MAXPLEN is also valid and means: "any MSS,
3056          * rely only on pmtu discovery"
3057          */
3058         if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
3059                 mtu = IPV6_MAXPLEN;
3060         return mtu;
3061 }
3062
3063 static unsigned int ip6_mtu(const struct dst_entry *dst)
3064 {
3065         struct inet6_dev *idev;
3066         unsigned int mtu;
3067
3068         mtu = dst_metric_raw(dst, RTAX_MTU);
3069         if (mtu)
3070                 goto out;
3071
3072         mtu = IPV6_MIN_MTU;
3073
3074         rcu_read_lock();
3075         idev = __in6_dev_get(dst->dev);
3076         if (idev)
3077                 mtu = idev->cnf.mtu6;
3078         rcu_read_unlock();
3079
3080 out:
3081         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
3082
3083         return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
3084 }
3085
3086 /* MTU selection:
3087  * 1. mtu on route is locked - use it
3088  * 2. mtu from nexthop exception
3089  * 3. mtu from egress device
3090  *
3091  * based on ip6_dst_mtu_forward and exception logic of
3092  * rt6_find_cached_rt; called with rcu_read_lock
3093  */
3094 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
3095                       const struct in6_addr *daddr,
3096                       const struct in6_addr *saddr)
3097 {
3098         const struct fib6_nh *nh = res->nh;
3099         struct fib6_info *f6i = res->f6i;
3100         struct inet6_dev *idev;
3101         struct rt6_info *rt;
3102         u32 mtu = 0;
3103
3104         if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
3105                 mtu = f6i->fib6_pmtu;
3106                 if (mtu)
3107                         goto out;
3108         }
3109
3110         rt = rt6_find_cached_rt(res, daddr, saddr);
3111         if (unlikely(rt)) {
3112                 mtu = dst_metric_raw(&rt->dst, RTAX_MTU);
3113         } else {
3114                 struct net_device *dev = nh->fib_nh_dev;
3115
3116                 mtu = IPV6_MIN_MTU;
3117                 idev = __in6_dev_get(dev);
3118                 if (idev && idev->cnf.mtu6 > mtu)
3119                         mtu = idev->cnf.mtu6;
3120         }
3121
3122         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
3123 out:
3124         return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
3125 }
3126
3127 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
3128                                   struct flowi6 *fl6)
3129 {
3130         struct dst_entry *dst;
3131         struct rt6_info *rt;
3132         struct inet6_dev *idev = in6_dev_get(dev);
3133         struct net *net = dev_net(dev);
3134
3135         if (unlikely(!idev))
3136                 return ERR_PTR(-ENODEV);
3137
3138         rt = ip6_dst_alloc(net, dev, 0);
3139         if (unlikely(!rt)) {
3140                 in6_dev_put(idev);
3141                 dst = ERR_PTR(-ENOMEM);
3142                 goto out;
3143         }
3144
3145         rt->dst.flags |= DST_HOST;
3146         rt->dst.input = ip6_input;
3147         rt->dst.output  = ip6_output;
3148         rt->rt6i_gateway  = fl6->daddr;
3149         rt->rt6i_dst.addr = fl6->daddr;
3150         rt->rt6i_dst.plen = 128;
3151         rt->rt6i_idev     = idev;
3152         dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
3153
3154         /* Add this dst into uncached_list so that rt6_disable_ip() can
3155          * do proper release of the net_device
3156          */
3157         rt6_uncached_list_add(rt);
3158         atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
3159
3160         dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
3161
3162 out:
3163         return dst;
3164 }
3165
3166 static int ip6_dst_gc(struct dst_ops *ops)
3167 {
3168         struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
3169         int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
3170         int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
3171         int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
3172         int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
3173         unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
3174         int entries;
3175
3176         entries = dst_entries_get_fast(ops);
3177         if (time_after(rt_last_gc + rt_min_interval, jiffies) &&
3178             entries <= rt_max_size)
3179                 goto out;
3180
3181         net->ipv6.ip6_rt_gc_expire++;
3182         fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net, true);
3183         entries = dst_entries_get_slow(ops);
3184         if (entries < ops->gc_thresh)
3185                 net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;
3186 out:
3187         net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity;
3188         return entries > rt_max_size;
3189 }
3190
3191 static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
3192                                const struct in6_addr *gw_addr, u32 tbid,
3193                                int flags, struct fib6_result *res)
3194 {
3195         struct flowi6 fl6 = {
3196                 .flowi6_oif = cfg->fc_ifindex,
3197                 .daddr = *gw_addr,
3198                 .saddr = cfg->fc_prefsrc,
3199         };
3200         struct fib6_table *table;
3201         int err;
3202
3203         table = fib6_get_table(net, tbid);
3204         if (!table)
3205                 return -EINVAL;
3206
3207         if (!ipv6_addr_any(&cfg->fc_prefsrc))
3208                 flags |= RT6_LOOKUP_F_HAS_SADDR;
3209
3210         flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
3211
3212         err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags);
3213         if (!err && res->f6i != net->ipv6.fib6_null_entry)
3214                 fib6_select_path(net, res, &fl6, cfg->fc_ifindex,
3215                                  cfg->fc_ifindex != 0, NULL, flags);
3216
3217         return err;
3218 }
3219
3220 static int ip6_route_check_nh_onlink(struct net *net,
3221                                      struct fib6_config *cfg,
3222                                      const struct net_device *dev,
3223                                      struct netlink_ext_ack *extack)
3224 {
3225         u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
3226         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3227         struct fib6_result res = {};
3228         int err;
3229
3230         err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res);
3231         if (!err && !(res.fib6_flags & RTF_REJECT) &&
3232             /* ignore match if it is the default route */
3233             !ipv6_addr_any(&res.f6i->fib6_dst.addr) &&
3234             (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) {
3235                 NL_SET_ERR_MSG(extack,
3236                                "Nexthop has invalid gateway or device mismatch");
3237                 err = -EINVAL;
3238         }
3239
3240         return err;
3241 }
3242
3243 static int ip6_route_check_nh(struct net *net,
3244                               struct fib6_config *cfg,
3245                               struct net_device **_dev,
3246                               struct inet6_dev **idev)
3247 {
3248         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3249         struct net_device *dev = _dev ? *_dev : NULL;
3250         int flags = RT6_LOOKUP_F_IFACE;
3251         struct fib6_result res = {};
3252         int err = -EHOSTUNREACH;
3253
3254         if (cfg->fc_table) {
3255                 err = ip6_nh_lookup_table(net, cfg, gw_addr,
3256                                           cfg->fc_table, flags, &res);
3257                 /* gw_addr can not require a gateway or resolve to a reject
3258                  * route. If a device is given, it must match the result.
3259                  */
3260                 if (err || res.fib6_flags & RTF_REJECT ||
3261                     res.nh->fib_nh_gw_family ||
3262                     (dev && dev != res.nh->fib_nh_dev))
3263                         err = -EHOSTUNREACH;
3264         }
3265
3266         if (err < 0) {
3267                 struct flowi6 fl6 = {
3268                         .flowi6_oif = cfg->fc_ifindex,
3269                         .daddr = *gw_addr,
3270                 };
3271
3272                 err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags);
3273                 if (err || res.fib6_flags & RTF_REJECT ||
3274                     res.nh->fib_nh_gw_family)
3275                         err = -EHOSTUNREACH;
3276
3277                 if (err)
3278                         return err;
3279
3280                 fib6_select_path(net, &res, &fl6, cfg->fc_ifindex,
3281                                  cfg->fc_ifindex != 0, NULL, flags);
3282         }
3283
3284         err = 0;
3285         if (dev) {
3286                 if (dev != res.nh->fib_nh_dev)
3287                         err = -EHOSTUNREACH;
3288         } else {
3289                 *_dev = dev = res.nh->fib_nh_dev;
3290                 dev_hold(dev);
3291                 *idev = in6_dev_get(dev);
3292         }
3293
3294         return err;
3295 }
3296
3297 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
3298                            struct net_device **_dev, struct inet6_dev **idev,
3299                            struct netlink_ext_ack *extack)
3300 {
3301         const struct in6_addr *gw_addr = &cfg->fc_gateway;
3302         int gwa_type = ipv6_addr_type(gw_addr);
3303         bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
3304         const struct net_device *dev = *_dev;
3305         bool need_addr_check = !dev;
3306         int err = -EINVAL;
3307
3308         /* if gw_addr is local we will fail to detect this in case
3309          * address is still TENTATIVE (DAD in progress). rt6_lookup()
3310          * will return already-added prefix route via interface that
3311          * prefix route was assigned to, which might be non-loopback.
3312          */
3313         if (dev &&
3314             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3315                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3316                 goto out;
3317         }
3318
3319         if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
3320                 /* IPv6 strictly inhibits using not link-local
3321                  * addresses as nexthop address.
3322                  * Otherwise, router will not able to send redirects.
3323                  * It is very good, but in some (rare!) circumstances
3324                  * (SIT, PtP, NBMA NOARP links) it is handy to allow
3325                  * some exceptions. --ANK
3326                  * We allow IPv4-mapped nexthops to support RFC4798-type
3327                  * addressing
3328                  */
3329                 if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
3330                         NL_SET_ERR_MSG(extack, "Invalid gateway address");
3331                         goto out;
3332                 }
3333
3334                 rcu_read_lock();
3335
3336                 if (cfg->fc_flags & RTNH_F_ONLINK)
3337                         err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
3338                 else
3339                         err = ip6_route_check_nh(net, cfg, _dev, idev);
3340
3341                 rcu_read_unlock();
3342
3343                 if (err)
3344                         goto out;
3345         }
3346
3347         /* reload in case device was changed */
3348         dev = *_dev;
3349
3350         err = -EINVAL;
3351         if (!dev) {
3352                 NL_SET_ERR_MSG(extack, "Egress device not specified");
3353                 goto out;
3354         } else if (dev->flags & IFF_LOOPBACK) {
3355                 NL_SET_ERR_MSG(extack,
3356                                "Egress device can not be loopback device for this route");
3357                 goto out;
3358         }
3359
3360         /* if we did not check gw_addr above, do so now that the
3361          * egress device has been resolved.
3362          */
3363         if (need_addr_check &&
3364             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3365                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3366                 goto out;
3367         }
3368
3369         err = 0;
3370 out:
3371         return err;
3372 }
3373
3374 static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
3375 {
3376         if ((flags & RTF_REJECT) ||
3377             (dev && (dev->flags & IFF_LOOPBACK) &&
3378              !(addr_type & IPV6_ADDR_LOOPBACK) &&
3379              !(flags & RTF_LOCAL)))
3380                 return true;
3381
3382         return false;
3383 }
3384
3385 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
3386                  struct fib6_config *cfg, gfp_t gfp_flags,
3387                  struct netlink_ext_ack *extack)
3388 {
3389         struct net_device *dev = NULL;
3390         struct inet6_dev *idev = NULL;
3391         int addr_type;
3392         int err;
3393
3394         fib6_nh->fib_nh_family = AF_INET6;
3395 #ifdef CONFIG_IPV6_ROUTER_PREF
3396         fib6_nh->last_probe = jiffies;
3397 #endif
3398
3399         err = -ENODEV;
3400         if (cfg->fc_ifindex) {
3401                 dev = dev_get_by_index(net, cfg->fc_ifindex);
3402                 if (!dev)
3403                         goto out;
3404                 idev = in6_dev_get(dev);
3405                 if (!idev)
3406                         goto out;
3407         }
3408
3409         if (cfg->fc_flags & RTNH_F_ONLINK) {
3410                 if (!dev) {
3411                         NL_SET_ERR_MSG(extack,
3412                                        "Nexthop device required for onlink");
3413                         goto out;
3414                 }
3415
3416                 if (!(dev->flags & IFF_UP)) {
3417                         NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3418                         err = -ENETDOWN;
3419                         goto out;
3420                 }
3421
3422                 fib6_nh->fib_nh_flags |= RTNH_F_ONLINK;
3423         }
3424
3425         fib6_nh->fib_nh_weight = 1;
3426
3427         /* We cannot add true routes via loopback here,
3428          * they would result in kernel looping; promote them to reject routes
3429          */
3430         addr_type = ipv6_addr_type(&cfg->fc_dst);
3431         if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) {
3432                 /* hold loopback dev/idev if we haven't done so. */
3433                 if (dev != net->loopback_dev) {
3434                         if (dev) {
3435                                 dev_put(dev);
3436                                 in6_dev_put(idev);
3437                         }
3438                         dev = net->loopback_dev;
3439                         dev_hold(dev);
3440                         idev = in6_dev_get(dev);
3441                         if (!idev) {
3442                                 err = -ENODEV;
3443                                 goto out;
3444                         }
3445                 }
3446                 goto pcpu_alloc;
3447         }
3448
3449         if (cfg->fc_flags & RTF_GATEWAY) {
3450                 err = ip6_validate_gw(net, cfg, &dev, &idev, extack);
3451                 if (err)
3452                         goto out;
3453
3454                 fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3455                 fib6_nh->fib_nh_gw_family = AF_INET6;
3456         }
3457
3458         err = -ENODEV;
3459         if (!dev)
3460                 goto out;
3461
3462         if (idev->cnf.disable_ipv6) {
3463                 NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
3464                 err = -EACCES;
3465                 goto out;
3466         }
3467
3468         if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
3469                 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3470                 err = -ENETDOWN;
3471                 goto out;
3472         }
3473
3474         if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
3475             !netif_carrier_ok(dev))
3476                 fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
3477
3478         err = fib_nh_common_init(&fib6_nh->nh_common, cfg->fc_encap,
3479                                  cfg->fc_encap_type, cfg, gfp_flags, extack);
3480         if (err)
3481                 goto out;
3482
3483 pcpu_alloc:
3484         fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
3485         if (!fib6_nh->rt6i_pcpu) {
3486                 err = -ENOMEM;
3487                 goto out;
3488         }
3489
3490         fib6_nh->fib_nh_dev = dev;
3491         fib6_nh->fib_nh_oif = dev->ifindex;
3492         err = 0;
3493 out:
3494         if (idev)
3495                 in6_dev_put(idev);
3496
3497         if (err) {
3498                 lwtstate_put(fib6_nh->fib_nh_lws);
3499                 fib6_nh->fib_nh_lws = NULL;
3500                 if (dev)
3501                         dev_put(dev);
3502         }
3503
3504         return err;
3505 }
3506
3507 void fib6_nh_release(struct fib6_nh *fib6_nh)
3508 {
3509         struct rt6_exception_bucket *bucket;
3510
3511         rcu_read_lock();
3512
3513         fib6_nh_flush_exceptions(fib6_nh, NULL);
3514         bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL);
3515         if (bucket) {
3516                 rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL);
3517                 kfree(bucket);
3518         }
3519
3520         rcu_read_unlock();
3521
3522         if (fib6_nh->rt6i_pcpu) {
3523                 int cpu;
3524
3525                 for_each_possible_cpu(cpu) {
3526                         struct rt6_info **ppcpu_rt;
3527                         struct rt6_info *pcpu_rt;
3528
3529                         ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
3530                         pcpu_rt = *ppcpu_rt;
3531                         if (pcpu_rt) {
3532                                 dst_dev_put(&pcpu_rt->dst);
3533                                 dst_release(&pcpu_rt->dst);
3534                                 *ppcpu_rt = NULL;
3535                         }
3536                 }
3537
3538                 free_percpu(fib6_nh->rt6i_pcpu);
3539         }
3540
3541         fib_nh_common_release(&fib6_nh->nh_common);
3542 }
3543
3544 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
3545                                               gfp_t gfp_flags,
3546                                               struct netlink_ext_ack *extack)
3547 {
3548         struct net *net = cfg->fc_nlinfo.nl_net;
3549         struct fib6_info *rt = NULL;
3550         struct nexthop *nh = NULL;
3551         struct fib6_table *table;
3552         struct fib6_nh *fib6_nh;
3553         int err = -EINVAL;
3554         int addr_type;
3555
3556         /* RTF_PCPU is an internal flag; can not be set by userspace */
3557         if (cfg->fc_flags & RTF_PCPU) {
3558                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
3559                 goto out;
3560         }
3561
3562         /* RTF_CACHE is an internal flag; can not be set by userspace */
3563         if (cfg->fc_flags & RTF_CACHE) {
3564                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
3565                 goto out;
3566         }
3567
3568         if (cfg->fc_type > RTN_MAX) {
3569                 NL_SET_ERR_MSG(extack, "Invalid route type");
3570                 goto out;
3571         }
3572
3573         if (cfg->fc_dst_len > 128) {
3574                 NL_SET_ERR_MSG(extack, "Invalid prefix length");
3575                 goto out;
3576         }
3577         if (cfg->fc_src_len > 128) {
3578                 NL_SET_ERR_MSG(extack, "Invalid source address length");
3579                 goto out;
3580         }
3581 #ifndef CONFIG_IPV6_SUBTREES
3582         if (cfg->fc_src_len) {
3583                 NL_SET_ERR_MSG(extack,
3584                                "Specifying source address requires IPV6_SUBTREES to be enabled");
3585                 goto out;
3586         }
3587 #endif
3588         if (cfg->fc_nh_id) {
3589                 nh = nexthop_find_by_id(net, cfg->fc_nh_id);
3590                 if (!nh) {
3591                         NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
3592                         goto out;
3593                 }
3594                 err = fib6_check_nexthop(nh, cfg, extack);
3595                 if (err)
3596                         goto out;
3597         }
3598
3599         err = -ENOBUFS;
3600         if (cfg->fc_nlinfo.nlh &&
3601             !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
3602                 table = fib6_get_table(net, cfg->fc_table);
3603                 if (!table) {
3604                         pr_warn("NLM_F_CREATE should be specified when creating new route\n");
3605                         table = fib6_new_table(net, cfg->fc_table);
3606                 }
3607         } else {
3608                 table = fib6_new_table(net, cfg->fc_table);
3609         }
3610
3611         if (!table)
3612                 goto out;
3613
3614         err = -ENOMEM;
3615         rt = fib6_info_alloc(gfp_flags, !nh);
3616         if (!rt)
3617                 goto out;
3618
3619         rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len,
3620                                                extack);
3621         if (IS_ERR(rt->fib6_metrics)) {
3622                 err = PTR_ERR(rt->fib6_metrics);
3623                 /* Do not leave garbage there. */
3624                 rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
3625                 goto out;
3626         }
3627
3628         if (cfg->fc_flags & RTF_ADDRCONF)
3629                 rt->dst_nocount = true;
3630
3631         if (cfg->fc_flags & RTF_EXPIRES)
3632                 fib6_set_expires(rt, jiffies +
3633                                 clock_t_to_jiffies(cfg->fc_expires));
3634         else
3635                 fib6_clean_expires(rt);
3636
3637         if (cfg->fc_protocol == RTPROT_UNSPEC)
3638                 cfg->fc_protocol = RTPROT_BOOT;
3639         rt->fib6_protocol = cfg->fc_protocol;
3640
3641         rt->fib6_table = table;
3642         rt->fib6_metric = cfg->fc_metric;
3643         rt->fib6_type = cfg->fc_type ? : RTN_UNICAST;
3644         rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;
3645
3646         ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
3647         rt->fib6_dst.plen = cfg->fc_dst_len;
3648         if (rt->fib6_dst.plen == 128)
3649                 rt->dst_host = true;
3650
3651 #ifdef CONFIG_IPV6_SUBTREES
3652         ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
3653         rt->fib6_src.plen = cfg->fc_src_len;
3654 #endif
3655         if (nh) {
3656                 if (!nexthop_get(nh)) {
3657                         NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
3658                         goto out;
3659                 }
3660                 if (rt->fib6_src.plen) {
3661                         NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
3662                         goto out;
3663                 }
3664                 rt->nh = nh;
3665                 fib6_nh = nexthop_fib6_nh(rt->nh);
3666         } else {
3667                 err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack);
3668                 if (err)
3669                         goto out;
3670
3671                 fib6_nh = rt->fib6_nh;
3672
3673                 /* We cannot add true routes via loopback here, they would
3674                  * result in kernel looping; promote them to reject routes
3675                  */
3676                 addr_type = ipv6_addr_type(&cfg->fc_dst);
3677                 if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev,
3678                                    addr_type))
3679                         rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
3680         }
3681
3682         if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
3683                 struct net_device *dev = fib6_nh->fib_nh_dev;
3684
3685                 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
3686                         NL_SET_ERR_MSG(extack, "Invalid source address");
3687                         err = -EINVAL;
3688                         goto out;
3689                 }
3690                 rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
3691                 rt->fib6_prefsrc.plen = 128;
3692         } else
3693                 rt->fib6_prefsrc.plen = 0;
3694
3695         return rt;
3696 out:
3697         fib6_info_release(rt);
3698         return ERR_PTR(err);
3699 }
3700
3701 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
3702                   struct netlink_ext_ack *extack)
3703 {
3704         struct fib6_info *rt;
3705         int err;
3706
3707         rt = ip6_route_info_create(cfg, gfp_flags, extack);
3708         if (IS_ERR(rt))
3709                 return PTR_ERR(rt);
3710
3711         err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
3712         fib6_info_release(rt);
3713
3714         return err;
3715 }
3716
3717 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
3718 {
3719         struct net *net = info->nl_net;
3720         struct fib6_table *table;
3721         int err;
3722
3723         if (rt == net->ipv6.fib6_null_entry) {
3724                 err = -ENOENT;
3725                 goto out;
3726         }
3727
3728         table = rt->fib6_table;
3729         spin_lock_bh(&table->tb6_lock);
3730         err = fib6_del(rt, info);
3731         spin_unlock_bh(&table->tb6_lock);
3732
3733 out:
3734         fib6_info_release(rt);
3735         return err;
3736 }
3737
3738 int ip6_del_rt(struct net *net, struct fib6_info *rt)
3739 {
3740         struct nl_info info = { .nl_net = net };
3741
3742         return __ip6_del_rt(rt, &info);
3743 }
3744
3745 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
3746 {
3747         struct nl_info *info = &cfg->fc_nlinfo;
3748         struct net *net = info->nl_net;
3749         struct sk_buff *skb = NULL;
3750         struct fib6_table *table;
3751         int err = -ENOENT;
3752
3753         if (rt == net->ipv6.fib6_null_entry)
3754                 goto out_put;
3755         table = rt->fib6_table;
3756         spin_lock_bh(&table->tb6_lock);
3757
3758         if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
3759                 struct fib6_info *sibling, *next_sibling;
3760                 struct fib6_node *fn;
3761
3762                 /* prefer to send a single notification with all hops */
3763                 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3764                 if (skb) {
3765                         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3766
3767                         if (rt6_fill_node(net, skb, rt, NULL,
3768                                           NULL, NULL, 0, RTM_DELROUTE,
3769                                           info->portid, seq, 0) < 0) {
3770                                 kfree_skb(skb);
3771                                 skb = NULL;
3772                         } else
3773                                 info->skip_notify = 1;
3774                 }
3775
3776                 /* 'rt' points to the first sibling route. If it is not the
3777                  * leaf, then we do not need to send a notification. Otherwise,
3778                  * we need to check if the last sibling has a next route or not
3779                  * and emit a replace or delete notification, respectively.
3780                  */
3781                 info->skip_notify_kernel = 1;
3782                 fn = rcu_dereference_protected(rt->fib6_node,
3783                                             lockdep_is_held(&table->tb6_lock));
3784                 if (rcu_access_pointer(fn->leaf) == rt) {
3785                         struct fib6_info *last_sibling, *replace_rt;
3786
3787                         last_sibling = list_last_entry(&rt->fib6_siblings,
3788                                                        struct fib6_info,
3789                                                        fib6_siblings);
3790                         replace_rt = rcu_dereference_protected(
3791                                             last_sibling->fib6_next,
3792                                             lockdep_is_held(&table->tb6_lock));
3793                         if (replace_rt)
3794                                 call_fib6_entry_notifiers_replace(net,
3795                                                                   replace_rt);
3796                         else
3797                                 call_fib6_multipath_entry_notifiers(net,
3798                                                        FIB_EVENT_ENTRY_DEL,
3799                                                        rt, rt->fib6_nsiblings,
3800                                                        NULL);
3801                 }
3802                 list_for_each_entry_safe(sibling, next_sibling,
3803                                          &rt->fib6_siblings,
3804                                          fib6_siblings) {
3805                         err = fib6_del(sibling, info);
3806                         if (err)
3807                                 goto out_unlock;
3808                 }
3809         }
3810
3811         err = fib6_del(rt, info);
3812 out_unlock:
3813         spin_unlock_bh(&table->tb6_lock);
3814 out_put:
3815         fib6_info_release(rt);
3816
3817         if (skb) {
3818                 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3819                             info->nlh, gfp_any());
3820         }
3821         return err;
3822 }
3823
3824 static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
3825 {
3826         int rc = -ESRCH;
3827
3828         if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
3829                 goto out;
3830
3831         if (cfg->fc_flags & RTF_GATEWAY &&
3832             !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
3833                 goto out;
3834
3835         rc = rt6_remove_exception_rt(rt);
3836 out:
3837         return rc;
3838 }
3839
3840 static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt,
3841                              struct fib6_nh *nh)
3842 {
3843         struct fib6_result res = {
3844                 .f6i = rt,
3845                 .nh = nh,
3846         };
3847         struct rt6_info *rt_cache;
3848
3849         rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src);
3850         if (rt_cache)
3851                 return __ip6_del_cached_rt(rt_cache, cfg);
3852
3853         return 0;
3854 }
3855
3856 struct fib6_nh_del_cached_rt_arg {
3857         struct fib6_config *cfg;
3858         struct fib6_info *f6i;
3859 };
3860
3861 static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg)
3862 {
3863         struct fib6_nh_del_cached_rt_arg *arg = _arg;
3864         int rc;
3865
3866         rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh);
3867         return rc != -ESRCH ? rc : 0;
3868 }
3869
3870 static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i)
3871 {
3872         struct fib6_nh_del_cached_rt_arg arg = {
3873                 .cfg = cfg,
3874                 .f6i = f6i
3875         };
3876
3877         return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg);
3878 }
3879
3880 static int ip6_route_del(struct fib6_config *cfg,
3881                          struct netlink_ext_ack *extack)
3882 {
3883         struct fib6_table *table;
3884         struct fib6_info *rt;
3885         struct fib6_node *fn;
3886         int err = -ESRCH;
3887
3888         table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
3889         if (!table) {
3890                 NL_SET_ERR_MSG(extack, "FIB table does not exist");
3891                 return err;
3892         }
3893
3894         rcu_read_lock();
3895
3896         fn = fib6_locate(&table->tb6_root,
3897                          &cfg->fc_dst, cfg->fc_dst_len,
3898                          &cfg->fc_src, cfg->fc_src_len,
3899                          !(cfg->fc_flags & RTF_CACHE));
3900
3901         if (fn) {
3902                 for_each_fib6_node_rt_rcu(fn) {
3903                         struct fib6_nh *nh;
3904
3905                         if (rt->nh && cfg->fc_nh_id &&
3906                             rt->nh->id != cfg->fc_nh_id)
3907                                 continue;
3908
3909                         if (cfg->fc_flags & RTF_CACHE) {
3910                                 int rc = 0;
3911
3912                                 if (rt->nh) {
3913                                         rc = ip6_del_cached_rt_nh(cfg, rt);
3914                                 } else if (cfg->fc_nh_id) {
3915                                         continue;
3916                                 } else {
3917                                         nh = rt->fib6_nh;
3918                                         rc = ip6_del_cached_rt(cfg, rt, nh);
3919                                 }
3920                                 if (rc != -ESRCH) {
3921                                         rcu_read_unlock();
3922                                         return rc;
3923                                 }
3924                                 continue;
3925                         }
3926
3927                         if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
3928                                 continue;
3929                         if (cfg->fc_protocol &&
3930                             cfg->fc_protocol != rt->fib6_protocol)
3931                                 continue;
3932
3933                         if (rt->nh) {
3934                                 if (!fib6_info_hold_safe(rt))
3935                                         continue;
3936                                 rcu_read_unlock();
3937
3938                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
3939                         }
3940                         if (cfg->fc_nh_id)
3941                                 continue;
3942
3943                         nh = rt->fib6_nh;
3944                         if (cfg->fc_ifindex &&
3945                             (!nh->fib_nh_dev ||
3946                              nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
3947                                 continue;
3948                         if (cfg->fc_flags & RTF_GATEWAY &&
3949                             !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6))
3950                                 continue;
3951                         if (!fib6_info_hold_safe(rt))
3952                                 continue;
3953                         rcu_read_unlock();
3954
3955                         /* if gateway was specified only delete the one hop */
3956                         if (cfg->fc_flags & RTF_GATEWAY)
3957                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
3958
3959                         return __ip6_del_rt_siblings(rt, cfg);
3960                 }
3961         }
3962         rcu_read_unlock();
3963
3964         return err;
3965 }
3966
3967 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
3968 {
3969         struct netevent_redirect netevent;
3970         struct rt6_info *rt, *nrt = NULL;
3971         struct fib6_result res = {};
3972         struct ndisc_options ndopts;
3973         struct inet6_dev *in6_dev;
3974         struct neighbour *neigh;
3975         struct rd_msg *msg;
3976         int optlen, on_link;
3977         u8 *lladdr;
3978
3979         optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
3980         optlen -= sizeof(*msg);
3981
3982         if (optlen < 0) {
3983                 net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
3984                 return;
3985         }
3986
3987         msg = (struct rd_msg *)icmp6_hdr(skb);
3988
3989         if (ipv6_addr_is_multicast(&msg->dest)) {
3990                 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
3991                 return;
3992         }
3993
3994         on_link = 0;
3995         if (ipv6_addr_equal(&msg->dest, &msg->target)) {
3996                 on_link = 1;
3997         } else if (ipv6_addr_type(&msg->target) !=
3998                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
3999                 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
4000                 return;
4001         }
4002
4003         in6_dev = __in6_dev_get(skb->dev);
4004         if (!in6_dev)
4005                 return;
4006         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
4007                 return;
4008
4009         /* RFC2461 8.1:
4010          *      The IP source address of the Redirect MUST be the same as the current
4011          *      first-hop router for the specified ICMP Destination Address.
4012          */
4013
4014         if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
4015                 net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
4016                 return;
4017         }
4018
4019         lladdr = NULL;
4020         if (ndopts.nd_opts_tgt_lladdr) {
4021                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
4022                                              skb->dev);
4023                 if (!lladdr) {
4024                         net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
4025                         return;
4026                 }
4027         }
4028
4029         rt = (struct rt6_info *) dst;
4030         if (rt->rt6i_flags & RTF_REJECT) {
4031                 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
4032                 return;
4033         }
4034
4035         /* Redirect received -> path was valid.
4036          * Look, redirects are sent only in response to data packets,
4037          * so that this nexthop apparently is reachable. --ANK
4038          */
4039         dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
4040
4041         neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
4042         if (!neigh)
4043                 return;
4044
4045         /*
4046          *      We have finally decided to accept it.
4047          */
4048
4049         ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
4050                      NEIGH_UPDATE_F_WEAK_OVERRIDE|
4051                      NEIGH_UPDATE_F_OVERRIDE|
4052                      (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
4053                                      NEIGH_UPDATE_F_ISROUTER)),
4054                      NDISC_REDIRECT, &ndopts);
4055
4056         rcu_read_lock();
4057         res.f6i = rcu_dereference(rt->from);
4058         if (!res.f6i)
4059                 goto out;
4060
4061         if (res.f6i->nh) {
4062                 struct fib6_nh_match_arg arg = {
4063                         .dev = dst->dev,
4064                         .gw = &rt->rt6i_gateway,
4065                 };
4066
4067                 nexthop_for_each_fib6_nh(res.f6i->nh,
4068                                          fib6_nh_find_match, &arg);
4069
4070                 /* fib6_info uses a nexthop that does not have fib6_nh
4071                  * using the dst->dev. Should be impossible
4072                  */
4073                 if (!arg.match)
4074                         goto out;
4075                 res.nh = arg.match;
4076         } else {
4077                 res.nh = res.f6i->fib6_nh;
4078         }
4079
4080         res.fib6_flags = res.f6i->fib6_flags;
4081         res.fib6_type = res.f6i->fib6_type;
4082         nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL);
4083         if (!nrt)
4084                 goto out;
4085
4086         nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
4087         if (on_link)
4088                 nrt->rt6i_flags &= ~RTF_GATEWAY;
4089
4090         nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
4091
4092         /* rt6_insert_exception() will take care of duplicated exceptions */
4093         if (rt6_insert_exception(nrt, &res)) {
4094                 dst_release_immediate(&nrt->dst);
4095                 goto out;
4096         }
4097
4098         netevent.old = &rt->dst;
4099         netevent.new = &nrt->dst;
4100         netevent.daddr = &msg->dest;
4101         netevent.neigh = neigh;
4102         call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
4103
4104 out:
4105         rcu_read_unlock();
4106         neigh_release(neigh);
4107 }
4108
4109 #ifdef CONFIG_IPV6_ROUTE_INFO
4110 static struct fib6_info *rt6_get_route_info(struct net *net,
4111                                            const struct in6_addr *prefix, int prefixlen,
4112                                            const struct in6_addr *gwaddr,
4113                                            struct net_device *dev)
4114 {
4115         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4116         int ifindex = dev->ifindex;
4117         struct fib6_node *fn;
4118         struct fib6_info *rt = NULL;
4119         struct fib6_table *table;
4120
4121         table = fib6_get_table(net, tb_id);
4122         if (!table)
4123                 return NULL;
4124
4125         rcu_read_lock();
4126         fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
4127         if (!fn)
4128                 goto out;
4129
4130         for_each_fib6_node_rt_rcu(fn) {
4131                 /* these routes do not use nexthops */
4132                 if (rt->nh)
4133                         continue;
4134                 if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex)
4135                         continue;
4136                 if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
4137                     !rt->fib6_nh->fib_nh_gw_family)
4138                         continue;
4139                 if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr))
4140                         continue;
4141                 if (!fib6_info_hold_safe(rt))
4142                         continue;
4143                 break;
4144         }
4145 out:
4146         rcu_read_unlock();
4147         return rt;
4148 }
4149
4150 static struct fib6_info *rt6_add_route_info(struct net *net,
4151                                            const struct in6_addr *prefix, int prefixlen,
4152                                            const struct in6_addr *gwaddr,
4153                                            struct net_device *dev,
4154                                            unsigned int pref)
4155 {
4156         struct fib6_config cfg = {
4157                 .fc_metric      = IP6_RT_PRIO_USER,
4158                 .fc_ifindex     = dev->ifindex,
4159                 .fc_dst_len     = prefixlen,
4160                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
4161                                   RTF_UP | RTF_PREF(pref),
4162                 .fc_protocol = RTPROT_RA,
4163                 .fc_type = RTN_UNICAST,
4164                 .fc_nlinfo.portid = 0,
4165                 .fc_nlinfo.nlh = NULL,
4166                 .fc_nlinfo.nl_net = net,
4167         };
4168
4169         cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO,
4170         cfg.fc_dst = *prefix;
4171         cfg.fc_gateway = *gwaddr;
4172
4173         /* We should treat it as a default route if prefix length is 0. */
4174         if (!prefixlen)
4175                 cfg.fc_flags |= RTF_DEFAULT;
4176
4177         ip6_route_add(&cfg, GFP_ATOMIC, NULL);
4178
4179         return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
4180 }
4181 #endif
4182
4183 struct fib6_info *rt6_get_dflt_router(struct net *net,
4184                                      const struct in6_addr *addr,
4185                                      struct net_device *dev)
4186 {
4187         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
4188         struct fib6_info *rt;
4189         struct fib6_table *table;
4190
4191         table = fib6_get_table(net, tb_id);
4192         if (!table)
4193                 return NULL;
4194
4195         rcu_read_lock();
4196         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4197                 struct fib6_nh *nh;
4198
4199                 /* RA routes do not use nexthops */
4200                 if (rt->nh)
4201                         continue;
4202
4203                 nh = rt->fib6_nh;
4204                 if (dev == nh->fib_nh_dev &&
4205                     ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
4206                     ipv6_addr_equal(&nh->fib_nh_gw6, addr))
4207                         break;
4208         }
4209         if (rt && !fib6_info_hold_safe(rt))
4210                 rt = NULL;
4211         rcu_read_unlock();
4212         return rt;
4213 }
4214
4215 struct fib6_info *rt6_add_dflt_router(struct net *net,
4216                                      const struct in6_addr *gwaddr,
4217                                      struct net_device *dev,
4218                                      unsigned int pref)
4219 {
4220         struct fib6_config cfg = {
4221                 .fc_table       = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
4222                 .fc_metric      = IP6_RT_PRIO_USER,
4223                 .fc_ifindex     = dev->ifindex,
4224                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
4225                                   RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
4226                 .fc_protocol = RTPROT_RA,
4227                 .fc_type = RTN_UNICAST,
4228                 .fc_nlinfo.portid = 0,
4229                 .fc_nlinfo.nlh = NULL,
4230                 .fc_nlinfo.nl_net = net,
4231         };
4232
4233         cfg.fc_gateway = *gwaddr;
4234
4235         if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
4236                 struct fib6_table *table;
4237
4238                 table = fib6_get_table(dev_net(dev), cfg.fc_table);
4239                 if (table)
4240                         table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
4241         }
4242
4243         return rt6_get_dflt_router(net, gwaddr, dev);
4244 }
4245
4246 static void __rt6_purge_dflt_routers(struct net *net,
4247                                      struct fib6_table *table)
4248 {
4249         struct fib6_info *rt;
4250
4251 restart:
4252         rcu_read_lock();
4253         for_each_fib6_node_rt_rcu(&table->tb6_root) {
4254                 struct net_device *dev = fib6_info_nh_dev(rt);
4255                 struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
4256
4257                 if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
4258                     (!idev || idev->cnf.accept_ra != 2) &&
4259                     fib6_info_hold_safe(rt)) {
4260                         rcu_read_unlock();
4261                         ip6_del_rt(net, rt);
4262                         goto restart;
4263                 }
4264         }
4265         rcu_read_unlock();
4266
4267         table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
4268 }
4269
4270 void rt6_purge_dflt_routers(struct net *net)
4271 {
4272         struct fib6_table *table;
4273         struct hlist_head *head;
4274         unsigned int h;
4275
4276         rcu_read_lock();
4277
4278         for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
4279                 head = &net->ipv6.fib_table_hash[h];
4280                 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
4281                         if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
4282                                 __rt6_purge_dflt_routers(net, table);
4283                 }
4284         }
4285
4286         rcu_read_unlock();
4287 }
4288
4289 static void rtmsg_to_fib6_config(struct net *net,
4290                                  struct in6_rtmsg *rtmsg,
4291                                  struct fib6_config *cfg)
4292 {
4293         *cfg = (struct fib6_config){
4294                 .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
4295                          : RT6_TABLE_MAIN,
4296                 .fc_ifindex = rtmsg->rtmsg_ifindex,
4297                 .fc_metric = rtmsg->rtmsg_metric ? : IP6_RT_PRIO_USER,
4298                 .fc_expires = rtmsg->rtmsg_info,
4299                 .fc_dst_len = rtmsg->rtmsg_dst_len,
4300                 .fc_src_len = rtmsg->rtmsg_src_len,
4301                 .fc_flags = rtmsg->rtmsg_flags,
4302                 .fc_type = rtmsg->rtmsg_type,
4303
4304                 .fc_nlinfo.nl_net = net,
4305
4306                 .fc_dst = rtmsg->rtmsg_dst,
4307                 .fc_src = rtmsg->rtmsg_src,
4308                 .fc_gateway = rtmsg->rtmsg_gateway,
4309         };
4310 }
4311
4312 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg)
4313 {
4314         struct fib6_config cfg;
4315         struct in6_rtmsg rtmsg;
4316         int err;
4317
4318         switch (cmd) {
4319         case SIOCADDRT:         /* Add a route */
4320         case SIOCDELRT:         /* Delete a route */
4321                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
4322                         return -EPERM;
4323                 err = copy_from_user(&rtmsg, arg,
4324                                      sizeof(struct in6_rtmsg));
4325                 if (err)
4326                         return -EFAULT;
4327
4328                 rtmsg_to_fib6_config(net, &rtmsg, &cfg);
4329
4330                 rtnl_lock();
4331                 switch (cmd) {
4332                 case SIOCADDRT:
4333                         err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
4334                         break;
4335                 case SIOCDELRT:
4336                         err = ip6_route_del(&cfg, NULL);
4337                         break;
4338                 default:
4339                         err = -EINVAL;
4340                 }
4341                 rtnl_unlock();
4342
4343                 return err;
4344         }
4345
4346         return -EINVAL;
4347 }
4348
4349 /*
4350  *      Drop the packet on the floor
4351  */
4352
4353 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
4354 {
4355         struct dst_entry *dst = skb_dst(skb);
4356         struct net *net = dev_net(dst->dev);
4357         struct inet6_dev *idev;
4358         int type;
4359
4360         if (netif_is_l3_master(skb->dev) &&
4361             dst->dev == net->loopback_dev)
4362                 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
4363         else
4364                 idev = ip6_dst_idev(dst);
4365
4366         switch (ipstats_mib_noroutes) {
4367         case IPSTATS_MIB_INNOROUTES:
4368                 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
4369                 if (type == IPV6_ADDR_ANY) {
4370                         IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
4371                         break;
4372                 }
4373                 /* FALLTHROUGH */
4374         case IPSTATS_MIB_OUTNOROUTES:
4375                 IP6_INC_STATS(net, idev, ipstats_mib_noroutes);
4376                 break;
4377         }
4378
4379         /* Start over by dropping the dst for l3mdev case */
4380         if (netif_is_l3_master(skb->dev))
4381                 skb_dst_drop(skb);
4382
4383         icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
4384         kfree_skb(skb);
4385         return 0;
4386 }
4387
4388 static int ip6_pkt_discard(struct sk_buff *skb)
4389 {
4390         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
4391 }
4392
4393 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4394 {
4395         skb->dev = skb_dst(skb)->dev;
4396         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
4397 }
4398
4399 static int ip6_pkt_prohibit(struct sk_buff *skb)
4400 {
4401         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
4402 }
4403
4404 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4405 {
4406         skb->dev = skb_dst(skb)->dev;
4407         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
4408 }
4409
4410 /*
4411  *      Allocate a dst for local (unicast / anycast) address.
4412  */
4413
4414 struct fib6_info *addrconf_f6i_alloc(struct net *net,
4415                                      struct inet6_dev *idev,
4416                                      const struct in6_addr *addr,
4417                                      bool anycast, gfp_t gfp_flags)
4418 {
4419         struct fib6_config cfg = {
4420                 .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
4421                 .fc_ifindex = idev->dev->ifindex,
4422                 .fc_flags = RTF_UP | RTF_NONEXTHOP,
4423                 .fc_dst = *addr,
4424                 .fc_dst_len = 128,
4425                 .fc_protocol = RTPROT_KERNEL,
4426                 .fc_nlinfo.nl_net = net,
4427                 .fc_ignore_dev_down = true,
4428         };
4429         struct fib6_info *f6i;
4430
4431         if (anycast) {
4432                 cfg.fc_type = RTN_ANYCAST;
4433                 cfg.fc_flags |= RTF_ANYCAST;
4434         } else {
4435                 cfg.fc_type = RTN_LOCAL;
4436                 cfg.fc_flags |= RTF_LOCAL;
4437         }
4438
4439         f6i = ip6_route_info_create(&cfg, gfp_flags, NULL);
4440         if (!IS_ERR(f6i))
4441                 f6i->dst_nocount = true;
4442         return f6i;
4443 }
4444
4445 /* remove deleted ip from prefsrc entries */
4446 struct arg_dev_net_ip {
4447         struct net_device *dev;
4448         struct net *net;
4449         struct in6_addr *addr;
4450 };
4451
4452 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
4453 {
4454         struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev;
4455         struct net *net = ((struct arg_dev_net_ip *)arg)->net;
4456         struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
4457
4458         if (!rt->nh &&
4459             ((void *)rt->fib6_nh->fib_nh_dev == dev || !dev) &&
4460             rt != net->ipv6.fib6_null_entry &&
4461             ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr)) {
4462                 spin_lock_bh(&rt6_exception_lock);
4463                 /* remove prefsrc entry */
4464                 rt->fib6_prefsrc.plen = 0;
4465                 spin_unlock_bh(&rt6_exception_lock);
4466         }
4467         return 0;
4468 }
4469
4470 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
4471 {
4472         struct net *net = dev_net(ifp->idev->dev);
4473         struct arg_dev_net_ip adni = {
4474                 .dev = ifp->idev->dev,
4475                 .net = net,
4476                 .addr = &ifp->addr,
4477         };
4478         fib6_clean_all(net, fib6_remove_prefsrc, &adni);
4479 }
4480
4481 #define RTF_RA_ROUTER           (RTF_ADDRCONF | RTF_DEFAULT)
4482
4483 /* Remove routers and update dst entries when gateway turn into host. */
4484 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
4485 {
4486         struct in6_addr *gateway = (struct in6_addr *)arg;
4487         struct fib6_nh *nh;
4488
4489         /* RA routes do not use nexthops */
4490         if (rt->nh)
4491                 return 0;
4492
4493         nh = rt->fib6_nh;
4494         if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
4495             nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6))
4496                 return -1;
4497
4498         /* Further clean up cached routes in exception table.
4499          * This is needed because cached route may have a different
4500          * gateway than its 'parent' in the case of an ip redirect.
4501          */
4502         fib6_nh_exceptions_clean_tohost(nh, gateway);
4503
4504         return 0;
4505 }
4506
4507 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
4508 {
4509         fib6_clean_all(net, fib6_clean_tohost, gateway);
4510 }
4511
4512 struct arg_netdev_event {
4513         const struct net_device *dev;
4514         union {
4515                 unsigned char nh_flags;
4516                 unsigned long event;
4517         };
4518 };
4519
4520 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
4521 {
4522         struct fib6_info *iter;
4523         struct fib6_node *fn;
4524
4525         fn = rcu_dereference_protected(rt->fib6_node,
4526                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4527         iter = rcu_dereference_protected(fn->leaf,
4528                         lockdep_is_held(&rt->fib6_table->tb6_lock));
4529         while (iter) {
4530                 if (iter->fib6_metric == rt->fib6_metric &&
4531                     rt6_qualify_for_ecmp(iter))
4532                         return iter;
4533                 iter = rcu_dereference_protected(iter->fib6_next,
4534                                 lockdep_is_held(&rt->fib6_table->tb6_lock));
4535         }
4536
4537         return NULL;
4538 }
4539
4540 /* only called for fib entries with builtin fib6_nh */
4541 static bool rt6_is_dead(const struct fib6_info *rt)
4542 {
4543         if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD ||
4544             (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN &&
4545              ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev)))
4546                 return true;
4547
4548         return false;
4549 }
4550
4551 static int rt6_multipath_total_weight(const struct fib6_info *rt)
4552 {
4553         struct fib6_info *iter;
4554         int total = 0;
4555
4556         if (!rt6_is_dead(rt))
4557                 total += rt->fib6_nh->fib_nh_weight;
4558
4559         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
4560                 if (!rt6_is_dead(iter))
4561                         total += iter->fib6_nh->fib_nh_weight;
4562         }
4563
4564         return total;
4565 }
4566
4567 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
4568 {
4569         int upper_bound = -1;
4570
4571         if (!rt6_is_dead(rt)) {
4572                 *weight += rt->fib6_nh->fib_nh_weight;
4573                 upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
4574                                                     total) - 1;
4575         }
4576         atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
4577 }
4578
4579 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
4580 {
4581         struct fib6_info *iter;
4582         int weight = 0;
4583
4584         rt6_upper_bound_set(rt, &weight, total);
4585
4586         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4587                 rt6_upper_bound_set(iter, &weight, total);
4588 }
4589
4590 void rt6_multipath_rebalance(struct fib6_info *rt)
4591 {
4592         struct fib6_info *first;
4593         int total;
4594
4595         /* In case the entire multipath route was marked for flushing,
4596          * then there is no need to rebalance upon the removal of every
4597          * sibling route.
4598          */
4599         if (!rt->fib6_nsiblings || rt->should_flush)
4600                 return;
4601
4602         /* During lookup routes are evaluated in order, so we need to
4603          * make sure upper bounds are assigned from the first sibling
4604          * onwards.
4605          */
4606         first = rt6_multipath_first_sibling(rt);
4607         if (WARN_ON_ONCE(!first))
4608                 return;
4609
4610         total = rt6_multipath_total_weight(first);
4611         rt6_multipath_upper_bound_set(first, total);
4612 }
4613
4614 static int fib6_ifup(struct fib6_info *rt, void *p_arg)
4615 {
4616         const struct arg_netdev_event *arg = p_arg;
4617         struct net *net = dev_net(arg->dev);
4618
4619         if (rt != net->ipv6.fib6_null_entry && !rt->nh &&
4620             rt->fib6_nh->fib_nh_dev == arg->dev) {
4621                 rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags;
4622                 fib6_update_sernum_upto_root(net, rt);
4623                 rt6_multipath_rebalance(rt);
4624         }
4625
4626         return 0;
4627 }
4628
4629 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags)
4630 {
4631         struct arg_netdev_event arg = {
4632                 .dev = dev,
4633                 {
4634                         .nh_flags = nh_flags,
4635                 },
4636         };
4637
4638         if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
4639                 arg.nh_flags |= RTNH_F_LINKDOWN;
4640
4641         fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
4642 }
4643
4644 /* only called for fib entries with inline fib6_nh */
4645 static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
4646                                    const struct net_device *dev)
4647 {
4648         struct fib6_info *iter;
4649
4650         if (rt->fib6_nh->fib_nh_dev == dev)
4651                 return true;
4652         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4653                 if (iter->fib6_nh->fib_nh_dev == dev)
4654                         return true;
4655
4656         return false;
4657 }
4658
4659 static void rt6_multipath_flush(struct fib6_info *rt)
4660 {
4661         struct fib6_info *iter;
4662
4663         rt->should_flush = 1;
4664         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4665                 iter->should_flush = 1;
4666 }
4667
4668 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
4669                                              const struct net_device *down_dev)
4670 {
4671         struct fib6_info *iter;
4672         unsigned int dead = 0;
4673
4674         if (rt->fib6_nh->fib_nh_dev == down_dev ||
4675             rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4676                 dead++;
4677         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4678                 if (iter->fib6_nh->fib_nh_dev == down_dev ||
4679                     iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4680                         dead++;
4681
4682         return dead;
4683 }
4684
4685 static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
4686                                        const struct net_device *dev,
4687                                        unsigned char nh_flags)
4688 {
4689         struct fib6_info *iter;
4690
4691         if (rt->fib6_nh->fib_nh_dev == dev)
4692                 rt->fib6_nh->fib_nh_flags |= nh_flags;
4693         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4694                 if (iter->fib6_nh->fib_nh_dev == dev)
4695                         iter->fib6_nh->fib_nh_flags |= nh_flags;
4696 }
4697
4698 /* called with write lock held for table with rt */
4699 static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
4700 {
4701         const struct arg_netdev_event *arg = p_arg;
4702         const struct net_device *dev = arg->dev;
4703         struct net *net = dev_net(dev);
4704
4705         if (rt == net->ipv6.fib6_null_entry || rt->nh)
4706                 return 0;
4707
4708         switch (arg->event) {
4709         case NETDEV_UNREGISTER:
4710                 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4711         case NETDEV_DOWN:
4712                 if (rt->should_flush)
4713                         return -1;
4714                 if (!rt->fib6_nsiblings)
4715                         return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4716                 if (rt6_multipath_uses_dev(rt, dev)) {
4717                         unsigned int count;
4718
4719                         count = rt6_multipath_dead_count(rt, dev);
4720                         if (rt->fib6_nsiblings + 1 == count) {
4721                                 rt6_multipath_flush(rt);
4722                                 return -1;
4723                         }
4724                         rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
4725                                                    RTNH_F_LINKDOWN);
4726                         fib6_update_sernum(net, rt);
4727                         rt6_multipath_rebalance(rt);
4728                 }
4729                 return -2;
4730         case NETDEV_CHANGE:
4731                 if (rt->fib6_nh->fib_nh_dev != dev ||
4732                     rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
4733                         break;
4734                 rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
4735                 rt6_multipath_rebalance(rt);
4736                 break;
4737         }
4738
4739         return 0;
4740 }
4741
4742 void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
4743 {
4744         struct arg_netdev_event arg = {
4745                 .dev = dev,
4746                 {
4747                         .event = event,
4748                 },
4749         };
4750         struct net *net = dev_net(dev);
4751
4752         if (net->ipv6.sysctl.skip_notify_on_dev_down)
4753                 fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
4754         else
4755                 fib6_clean_all(net, fib6_ifdown, &arg);
4756 }
4757
4758 void rt6_disable_ip(struct net_device *dev, unsigned long event)
4759 {
4760         rt6_sync_down_dev(dev, event);
4761         rt6_uncached_list_flush_dev(dev_net(dev), dev);
4762         neigh_ifdown(&nd_tbl, dev);
4763 }
4764
4765 struct rt6_mtu_change_arg {
4766         struct net_device *dev;
4767         unsigned int mtu;
4768         struct fib6_info *f6i;
4769 };
4770
4771 static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
4772 {
4773         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg;
4774         struct fib6_info *f6i = arg->f6i;
4775
4776         /* For administrative MTU increase, there is no way to discover
4777          * IPv6 PMTU increase, so PMTU increase should be updated here.
4778          * Since RFC 1981 doesn't include administrative MTU increase
4779          * update PMTU increase is a MUST. (i.e. jumbo frame)
4780          */
4781         if (nh->fib_nh_dev == arg->dev) {
4782                 struct inet6_dev *idev = __in6_dev_get(arg->dev);
4783                 u32 mtu = f6i->fib6_pmtu;
4784
4785                 if (mtu >= arg->mtu ||
4786                     (mtu < arg->mtu && mtu == idev->cnf.mtu6))
4787                         fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
4788
4789                 spin_lock_bh(&rt6_exception_lock);
4790                 rt6_exceptions_update_pmtu(idev, nh, arg->mtu);
4791                 spin_unlock_bh(&rt6_exception_lock);
4792         }
4793
4794         return 0;
4795 }
4796
4797 static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
4798 {
4799         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
4800         struct inet6_dev *idev;
4801
4802         /* In IPv6 pmtu discovery is not optional,
4803            so that RTAX_MTU lock cannot disable it.
4804            We still use this lock to block changes
4805            caused by addrconf/ndisc.
4806         */
4807
4808         idev = __in6_dev_get(arg->dev);
4809         if (!idev)
4810                 return 0;
4811
4812         if (fib6_metric_locked(f6i, RTAX_MTU))
4813                 return 0;
4814
4815         arg->f6i = f6i;
4816         if (f6i->nh) {
4817                 /* fib6_nh_mtu_change only returns 0, so this is safe */
4818                 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change,
4819                                                 arg);
4820         }
4821
4822         return fib6_nh_mtu_change(f6i->fib6_nh, arg);
4823 }
4824
4825 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
4826 {
4827         struct rt6_mtu_change_arg arg = {
4828                 .dev = dev,
4829                 .mtu = mtu,
4830         };
4831
4832         fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
4833 }
4834
4835 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
4836         [RTA_UNSPEC]            = { .strict_start_type = RTA_DPORT + 1 },
4837         [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
4838         [RTA_PREFSRC]           = { .len = sizeof(struct in6_addr) },
4839         [RTA_OIF]               = { .type = NLA_U32 },
4840         [RTA_IIF]               = { .type = NLA_U32 },
4841         [RTA_PRIORITY]          = { .type = NLA_U32 },
4842         [RTA_METRICS]           = { .type = NLA_NESTED },
4843         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
4844         [RTA_PREF]              = { .type = NLA_U8 },
4845         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
4846         [RTA_ENCAP]             = { .type = NLA_NESTED },
4847         [RTA_EXPIRES]           = { .type = NLA_U32 },
4848         [RTA_UID]               = { .type = NLA_U32 },
4849         [RTA_MARK]              = { .type = NLA_U32 },
4850         [RTA_TABLE]             = { .type = NLA_U32 },
4851         [RTA_IP_PROTO]          = { .type = NLA_U8 },
4852         [RTA_SPORT]             = { .type = NLA_U16 },
4853         [RTA_DPORT]             = { .type = NLA_U16 },
4854         [RTA_NH_ID]             = { .type = NLA_U32 },
4855 };
4856
4857 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
4858                               struct fib6_config *cfg,
4859                               struct netlink_ext_ack *extack)
4860 {
4861         struct rtmsg *rtm;
4862         struct nlattr *tb[RTA_MAX+1];
4863         unsigned int pref;
4864         int err;
4865
4866         err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
4867                                      rtm_ipv6_policy, extack);
4868         if (err < 0)
4869                 goto errout;
4870
4871         err = -EINVAL;
4872         rtm = nlmsg_data(nlh);
4873
4874         *cfg = (struct fib6_config){
4875                 .fc_table = rtm->rtm_table,
4876                 .fc_dst_len = rtm->rtm_dst_len,
4877                 .fc_src_len = rtm->rtm_src_len,
4878                 .fc_flags = RTF_UP,
4879                 .fc_protocol = rtm->rtm_protocol,
4880                 .fc_type = rtm->rtm_type,
4881
4882                 .fc_nlinfo.portid = NETLINK_CB(skb).portid,
4883                 .fc_nlinfo.nlh = nlh,
4884                 .fc_nlinfo.nl_net = sock_net(skb->sk),
4885         };
4886
4887         if (rtm->rtm_type == RTN_UNREACHABLE ||
4888             rtm->rtm_type == RTN_BLACKHOLE ||
4889             rtm->rtm_type == RTN_PROHIBIT ||
4890             rtm->rtm_type == RTN_THROW)
4891                 cfg->fc_flags |= RTF_REJECT;
4892
4893         if (rtm->rtm_type == RTN_LOCAL)
4894                 cfg->fc_flags |= RTF_LOCAL;
4895
4896         if (rtm->rtm_flags & RTM_F_CLONED)
4897                 cfg->fc_flags |= RTF_CACHE;
4898
4899         cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
4900
4901         if (tb[RTA_NH_ID]) {
4902                 if (tb[RTA_GATEWAY]   || tb[RTA_OIF] ||
4903                     tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {
4904                         NL_SET_ERR_MSG(extack,
4905                                        "Nexthop specification and nexthop id are mutually exclusive");
4906                         goto errout;
4907                 }
4908                 cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);
4909         }
4910
4911         if (tb[RTA_GATEWAY]) {
4912                 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
4913                 cfg->fc_flags |= RTF_GATEWAY;
4914         }
4915         if (tb[RTA_VIA]) {
4916                 NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
4917                 goto errout;
4918         }
4919
4920         if (tb[RTA_DST]) {
4921                 int plen = (rtm->rtm_dst_len + 7) >> 3;
4922
4923                 if (nla_len(tb[RTA_DST]) < plen)
4924                         goto errout;
4925
4926                 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
4927         }
4928
4929         if (tb[RTA_SRC]) {
4930                 int plen = (rtm->rtm_src_len + 7) >> 3;
4931
4932                 if (nla_len(tb[RTA_SRC]) < plen)
4933                         goto errout;
4934
4935                 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
4936         }
4937
4938         if (tb[RTA_PREFSRC])
4939                 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
4940
4941         if (tb[RTA_OIF])
4942                 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
4943
4944         if (tb[RTA_PRIORITY])
4945                 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
4946
4947         if (tb[RTA_METRICS]) {
4948                 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
4949                 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
4950         }
4951
4952         if (tb[RTA_TABLE])
4953                 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
4954
4955         if (tb[RTA_MULTIPATH]) {
4956                 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
4957                 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
4958
4959                 err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
4960                                                      cfg->fc_mp_len, extack);
4961                 if (err < 0)
4962                         goto errout;
4963         }
4964
4965         if (tb[RTA_PREF]) {
4966                 pref = nla_get_u8(tb[RTA_PREF]);
4967                 if (pref != ICMPV6_ROUTER_PREF_LOW &&
4968                     pref != ICMPV6_ROUTER_PREF_HIGH)
4969                         pref = ICMPV6_ROUTER_PREF_MEDIUM;
4970                 cfg->fc_flags |= RTF_PREF(pref);
4971         }
4972
4973         if (tb[RTA_ENCAP])
4974                 cfg->fc_encap = tb[RTA_ENCAP];
4975
4976         if (tb[RTA_ENCAP_TYPE]) {
4977                 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
4978
4979                 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
4980                 if (err < 0)
4981                         goto errout;
4982         }
4983
4984         if (tb[RTA_EXPIRES]) {
4985                 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
4986
4987                 if (addrconf_finite_timeout(timeout)) {
4988                         cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
4989                         cfg->fc_flags |= RTF_EXPIRES;
4990                 }
4991         }
4992
4993         err = 0;
4994 errout:
4995         return err;
4996 }
4997
4998 struct rt6_nh {
4999         struct fib6_info *fib6_info;
5000         struct fib6_config r_cfg;
5001         struct list_head next;
5002 };
5003
5004 static int ip6_route_info_append(struct net *net,
5005                                  struct list_head *rt6_nh_list,
5006                                  struct fib6_info *rt,
5007                                  struct fib6_config *r_cfg)
5008 {
5009         struct rt6_nh *nh;
5010         int err = -EEXIST;
5011
5012         list_for_each_entry(nh, rt6_nh_list, next) {
5013                 /* check if fib6_info already exists */
5014                 if (rt6_duplicate_nexthop(nh->fib6_info, rt))
5015                         return err;
5016         }
5017
5018         nh = kzalloc(sizeof(*nh), GFP_KERNEL);
5019         if (!nh)
5020                 return -ENOMEM;
5021         nh->fib6_info = rt;
5022         memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
5023         list_add_tail(&nh->next, rt6_nh_list);
5024
5025         return 0;
5026 }
5027
5028 static void ip6_route_mpath_notify(struct fib6_info *rt,
5029                                    struct fib6_info *rt_last,
5030                                    struct nl_info *info,
5031                                    __u16 nlflags)
5032 {
5033         /* if this is an APPEND route, then rt points to the first route
5034          * inserted and rt_last points to last route inserted. Userspace
5035          * wants a consistent dump of the route which starts at the first
5036          * nexthop. Since sibling routes are always added at the end of
5037          * the list, find the first sibling of the last route appended
5038          */
5039         if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
5040                 rt = list_first_entry(&rt_last->fib6_siblings,
5041                                       struct fib6_info,
5042                                       fib6_siblings);
5043         }
5044
5045         if (rt)
5046                 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
5047 }
5048
5049 static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
5050 {
5051         bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
5052         bool should_notify = false;
5053         struct fib6_info *leaf;
5054         struct fib6_node *fn;
5055
5056         rcu_read_lock();
5057         fn = rcu_dereference(rt->fib6_node);
5058         if (!fn)
5059                 goto out;
5060
5061         leaf = rcu_dereference(fn->leaf);
5062         if (!leaf)
5063                 goto out;
5064
5065         if (rt == leaf ||
5066             (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric &&
5067              rt6_qualify_for_ecmp(leaf)))
5068                 should_notify = true;
5069 out:
5070         rcu_read_unlock();
5071
5072         return should_notify;
5073 }
5074
5075 static int ip6_route_multipath_add(struct fib6_config *cfg,
5076                                    struct netlink_ext_ack *extack)
5077 {
5078         struct fib6_info *rt_notif = NULL, *rt_last = NULL;
5079         struct nl_info *info = &cfg->fc_nlinfo;
5080         struct fib6_config r_cfg;
5081         struct rtnexthop *rtnh;
5082         struct fib6_info *rt;
5083         struct rt6_nh *err_nh;
5084         struct rt6_nh *nh, *nh_safe;
5085         __u16 nlflags;
5086         int remaining;
5087         int attrlen;
5088         int err = 1;
5089         int nhn = 0;
5090         int replace = (cfg->fc_nlinfo.nlh &&
5091                        (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
5092         LIST_HEAD(rt6_nh_list);
5093
5094         nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
5095         if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
5096                 nlflags |= NLM_F_APPEND;
5097
5098         remaining = cfg->fc_mp_len;
5099         rtnh = (struct rtnexthop *)cfg->fc_mp;
5100
5101         /* Parse a Multipath Entry and build a list (rt6_nh_list) of
5102          * fib6_info structs per nexthop
5103          */
5104         while (rtnh_ok(rtnh, remaining)) {
5105                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5106                 if (rtnh->rtnh_ifindex)
5107                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5108
5109                 attrlen = rtnh_attrlen(rtnh);
5110                 if (attrlen > 0) {
5111                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5112
5113                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5114                         if (nla) {
5115                                 r_cfg.fc_gateway = nla_get_in6_addr(nla);
5116                                 r_cfg.fc_flags |= RTF_GATEWAY;
5117                         }
5118                         r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
5119                         nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
5120                         if (nla)
5121                                 r_cfg.fc_encap_type = nla_get_u16(nla);
5122                 }
5123
5124                 r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
5125                 rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
5126                 if (IS_ERR(rt)) {
5127                         err = PTR_ERR(rt);
5128                         rt = NULL;
5129                         goto cleanup;
5130                 }
5131                 if (!rt6_qualify_for_ecmp(rt)) {
5132                         err = -EINVAL;
5133                         NL_SET_ERR_MSG(extack,
5134                                        "Device only routes can not be added for IPv6 using the multipath API.");
5135                         fib6_info_release(rt);
5136                         goto cleanup;
5137                 }
5138
5139                 rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
5140
5141                 err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
5142                                             rt, &r_cfg);
5143                 if (err) {
5144                         fib6_info_release(rt);
5145                         goto cleanup;
5146                 }
5147
5148                 rtnh = rtnh_next(rtnh, &remaining);
5149         }
5150
5151         if (list_empty(&rt6_nh_list)) {
5152                 NL_SET_ERR_MSG(extack,
5153                                "Invalid nexthop configuration - no valid nexthops");
5154                 return -EINVAL;
5155         }
5156
5157         /* for add and replace send one notification with all nexthops.
5158          * Skip the notification in fib6_add_rt2node and send one with
5159          * the full route when done
5160          */
5161         info->skip_notify = 1;
5162
5163         /* For add and replace, send one notification with all nexthops. For
5164          * append, send one notification with all appended nexthops.
5165          */
5166         info->skip_notify_kernel = 1;
5167
5168         err_nh = NULL;
5169         list_for_each_entry(nh, &rt6_nh_list, next) {
5170                 err = __ip6_ins_rt(nh->fib6_info, info, extack);
5171                 fib6_info_release(nh->fib6_info);
5172
5173                 if (!err) {
5174                         /* save reference to last route successfully inserted */
5175                         rt_last = nh->fib6_info;
5176
5177                         /* save reference to first route for notification */
5178                         if (!rt_notif)
5179                                 rt_notif = nh->fib6_info;
5180                 }
5181
5182                 /* nh->fib6_info is used or freed at this point, reset to NULL*/
5183                 nh->fib6_info = NULL;
5184                 if (err) {
5185                         if (replace && nhn)
5186                                 NL_SET_ERR_MSG_MOD(extack,
5187                                                    "multipath route replace failed (check consistency of installed routes)");
5188                         err_nh = nh;
5189                         goto add_errout;
5190                 }
5191
5192                 /* Because each route is added like a single route we remove
5193                  * these flags after the first nexthop: if there is a collision,
5194                  * we have already failed to add the first nexthop:
5195                  * fib6_add_rt2node() has rejected it; when replacing, old
5196                  * nexthops have been replaced by first new, the rest should
5197                  * be added to it.
5198                  */
5199                 cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
5200                                                      NLM_F_REPLACE);
5201                 nhn++;
5202         }
5203
5204         /* An in-kernel notification should only be sent in case the new
5205          * multipath route is added as the first route in the node, or if
5206          * it was appended to it. We pass 'rt_notif' since it is the first
5207          * sibling and might allow us to skip some checks in the replace case.
5208          */
5209         if (ip6_route_mpath_should_notify(rt_notif)) {
5210                 enum fib_event_type fib_event;
5211
5212                 if (rt_notif->fib6_nsiblings != nhn - 1)
5213                         fib_event = FIB_EVENT_ENTRY_APPEND;
5214                 else
5215                         fib_event = FIB_EVENT_ENTRY_REPLACE;
5216
5217                 err = call_fib6_multipath_entry_notifiers(info->nl_net,
5218                                                           fib_event, rt_notif,
5219                                                           nhn - 1, extack);
5220                 if (err) {
5221                         /* Delete all the siblings that were just added */
5222                         err_nh = NULL;
5223                         goto add_errout;
5224                 }
5225         }
5226
5227         /* success ... tell user about new route */
5228         ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5229         goto cleanup;
5230
5231 add_errout:
5232         /* send notification for routes that were added so that
5233          * the delete notifications sent by ip6_route_del are
5234          * coherent
5235          */
5236         if (rt_notif)
5237                 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5238
5239         /* Delete routes that were already added */
5240         list_for_each_entry(nh, &rt6_nh_list, next) {
5241                 if (err_nh == nh)
5242                         break;
5243                 ip6_route_del(&nh->r_cfg, extack);
5244         }
5245
5246 cleanup:
5247         list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
5248                 if (nh->fib6_info)
5249                         fib6_info_release(nh->fib6_info);
5250                 list_del(&nh->next);
5251                 kfree(nh);
5252         }
5253
5254         return err;
5255 }
5256
5257 static int ip6_route_multipath_del(struct fib6_config *cfg,
5258                                    struct netlink_ext_ack *extack)
5259 {
5260         struct fib6_config r_cfg;
5261         struct rtnexthop *rtnh;
5262         int remaining;
5263         int attrlen;
5264         int err = 1, last_err = 0;
5265
5266         remaining = cfg->fc_mp_len;
5267         rtnh = (struct rtnexthop *)cfg->fc_mp;
5268
5269         /* Parse a Multipath Entry */
5270         while (rtnh_ok(rtnh, remaining)) {
5271                 memcpy(&r_cfg, cfg, sizeof(*cfg));
5272                 if (rtnh->rtnh_ifindex)
5273                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5274
5275                 attrlen = rtnh_attrlen(rtnh);
5276                 if (attrlen > 0) {
5277                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5278
5279                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5280                         if (nla) {
5281                                 nla_memcpy(&r_cfg.fc_gateway, nla, 16);
5282                                 r_cfg.fc_flags |= RTF_GATEWAY;
5283                         }
5284                 }
5285                 err = ip6_route_del(&r_cfg, extack);
5286                 if (err)
5287                         last_err = err;
5288
5289                 rtnh = rtnh_next(rtnh, &remaining);
5290         }
5291
5292         return last_err;
5293 }
5294
5295 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5296                               struct netlink_ext_ack *extack)
5297 {
5298         struct fib6_config cfg;
5299         int err;
5300
5301         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5302         if (err < 0)
5303                 return err;
5304
5305         if (cfg.fc_nh_id &&
5306             !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {
5307                 NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
5308                 return -EINVAL;
5309         }
5310
5311         if (cfg.fc_mp)
5312                 return ip6_route_multipath_del(&cfg, extack);
5313         else {
5314                 cfg.fc_delete_all_nh = 1;
5315                 return ip6_route_del(&cfg, extack);
5316         }
5317 }
5318
5319 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5320                               struct netlink_ext_ack *extack)
5321 {
5322         struct fib6_config cfg;
5323         int err;
5324
5325         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5326         if (err < 0)
5327                 return err;
5328
5329         if (cfg.fc_metric == 0)
5330                 cfg.fc_metric = IP6_RT_PRIO_USER;
5331
5332         if (cfg.fc_mp)
5333                 return ip6_route_multipath_add(&cfg, extack);
5334         else
5335                 return ip6_route_add(&cfg, GFP_KERNEL, extack);
5336 }
5337
5338 /* add the overhead of this fib6_nh to nexthop_len */
5339 static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg)
5340 {
5341         int *nexthop_len = arg;
5342
5343         *nexthop_len += nla_total_size(0)        /* RTA_MULTIPATH */
5344                      + NLA_ALIGN(sizeof(struct rtnexthop))
5345                      + nla_total_size(16); /* RTA_GATEWAY */
5346
5347         if (nh->fib_nh_lws) {
5348                 /* RTA_ENCAP_TYPE */
5349                 *nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5350                 /* RTA_ENCAP */
5351                 *nexthop_len += nla_total_size(2);
5352         }
5353
5354         return 0;
5355 }
5356
5357 static size_t rt6_nlmsg_size(struct fib6_info *f6i)
5358 {
5359         int nexthop_len;
5360
5361         if (f6i->nh) {
5362                 nexthop_len = nla_total_size(4); /* RTA_NH_ID */
5363                 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
5364                                          &nexthop_len);
5365         } else {
5366                 struct fib6_nh *nh = f6i->fib6_nh;
5367
5368                 nexthop_len = 0;
5369                 if (f6i->fib6_nsiblings) {
5370                         nexthop_len = nla_total_size(0)  /* RTA_MULTIPATH */
5371                                     + NLA_ALIGN(sizeof(struct rtnexthop))
5372                                     + nla_total_size(16) /* RTA_GATEWAY */
5373                                     + lwtunnel_get_encap_size(nh->fib_nh_lws);
5374
5375                         nexthop_len *= f6i->fib6_nsiblings;
5376                 }
5377                 nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5378         }
5379
5380         return NLMSG_ALIGN(sizeof(struct rtmsg))
5381                + nla_total_size(16) /* RTA_SRC */
5382                + nla_total_size(16) /* RTA_DST */
5383                + nla_total_size(16) /* RTA_GATEWAY */
5384                + nla_total_size(16) /* RTA_PREFSRC */
5385                + nla_total_size(4) /* RTA_TABLE */
5386                + nla_total_size(4) /* RTA_IIF */
5387                + nla_total_size(4) /* RTA_OIF */
5388                + nla_total_size(4) /* RTA_PRIORITY */
5389                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
5390                + nla_total_size(sizeof(struct rta_cacheinfo))
5391                + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
5392                + nla_total_size(1) /* RTA_PREF */
5393                + nexthop_len;
5394 }
5395
5396 static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh,
5397                                  unsigned char *flags)
5398 {
5399         if (nexthop_is_multipath(nh)) {
5400                 struct nlattr *mp;
5401
5402                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5403                 if (!mp)
5404                         goto nla_put_failure;
5405
5406                 if (nexthop_mpath_fill_node(skb, nh, AF_INET6))
5407                         goto nla_put_failure;
5408
5409                 nla_nest_end(skb, mp);
5410         } else {
5411                 struct fib6_nh *fib6_nh;
5412
5413                 fib6_nh = nexthop_fib6_nh(nh);
5414                 if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,
5415                                      flags, false) < 0)
5416                         goto nla_put_failure;
5417         }
5418
5419         return 0;
5420
5421 nla_put_failure:
5422         return -EMSGSIZE;
5423 }
5424
5425 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
5426                          struct fib6_info *rt, struct dst_entry *dst,
5427                          struct in6_addr *dest, struct in6_addr *src,
5428                          int iif, int type, u32 portid, u32 seq,
5429                          unsigned int flags)
5430 {
5431         struct rt6_info *rt6 = (struct rt6_info *)dst;
5432         struct rt6key *rt6_dst, *rt6_src;
5433         u32 *pmetrics, table, rt6_flags;
5434         unsigned char nh_flags = 0;
5435         struct nlmsghdr *nlh;
5436         struct rtmsg *rtm;
5437         long expires = 0;
5438
5439         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
5440         if (!nlh)
5441                 return -EMSGSIZE;
5442
5443         if (rt6) {
5444                 rt6_dst = &rt6->rt6i_dst;
5445                 rt6_src = &rt6->rt6i_src;
5446                 rt6_flags = rt6->rt6i_flags;
5447         } else {
5448                 rt6_dst = &rt->fib6_dst;
5449                 rt6_src = &rt->fib6_src;
5450                 rt6_flags = rt->fib6_flags;
5451         }
5452
5453         rtm = nlmsg_data(nlh);
5454         rtm->rtm_family = AF_INET6;
5455         rtm->rtm_dst_len = rt6_dst->plen;
5456         rtm->rtm_src_len = rt6_src->plen;
5457         rtm->rtm_tos = 0;
5458         if (rt->fib6_table)
5459                 table = rt->fib6_table->tb6_id;
5460         else
5461                 table = RT6_TABLE_UNSPEC;
5462         rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
5463         if (nla_put_u32(skb, RTA_TABLE, table))
5464                 goto nla_put_failure;
5465
5466         rtm->rtm_type = rt->fib6_type;
5467         rtm->rtm_flags = 0;
5468         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
5469         rtm->rtm_protocol = rt->fib6_protocol;
5470
5471         if (rt6_flags & RTF_CACHE)
5472                 rtm->rtm_flags |= RTM_F_CLONED;
5473
5474         if (dest) {
5475                 if (nla_put_in6_addr(skb, RTA_DST, dest))
5476                         goto nla_put_failure;
5477                 rtm->rtm_dst_len = 128;
5478         } else if (rtm->rtm_dst_len)
5479                 if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
5480                         goto nla_put_failure;
5481 #ifdef CONFIG_IPV6_SUBTREES
5482         if (src) {
5483                 if (nla_put_in6_addr(skb, RTA_SRC, src))
5484                         goto nla_put_failure;
5485                 rtm->rtm_src_len = 128;
5486         } else if (rtm->rtm_src_len &&
5487                    nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
5488                 goto nla_put_failure;
5489 #endif
5490         if (iif) {
5491 #ifdef CONFIG_IPV6_MROUTE
5492                 if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
5493                         int err = ip6mr_get_route(net, skb, rtm, portid);
5494
5495                         if (err == 0)
5496                                 return 0;
5497                         if (err < 0)
5498                                 goto nla_put_failure;
5499                 } else
5500 #endif
5501                         if (nla_put_u32(skb, RTA_IIF, iif))
5502                                 goto nla_put_failure;
5503         } else if (dest) {
5504                 struct in6_addr saddr_buf;
5505                 if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 &&
5506                     nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5507                         goto nla_put_failure;
5508         }
5509
5510         if (rt->fib6_prefsrc.plen) {
5511                 struct in6_addr saddr_buf;
5512                 saddr_buf = rt->fib6_prefsrc.addr;
5513                 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5514                         goto nla_put_failure;
5515         }
5516
5517         pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
5518         if (rtnetlink_put_metrics(skb, pmetrics) < 0)
5519                 goto nla_put_failure;
5520
5521         if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
5522                 goto nla_put_failure;
5523
5524         /* For multipath routes, walk the siblings list and add
5525          * each as a nexthop within RTA_MULTIPATH.
5526          */
5527         if (rt6) {
5528                 if (rt6_flags & RTF_GATEWAY &&
5529                     nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
5530                         goto nla_put_failure;
5531
5532                 if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
5533                         goto nla_put_failure;
5534         } else if (rt->fib6_nsiblings) {
5535                 struct fib6_info *sibling, *next_sibling;
5536                 struct nlattr *mp;
5537
5538                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5539                 if (!mp)
5540                         goto nla_put_failure;
5541
5542                 if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
5543                                     rt->fib6_nh->fib_nh_weight, AF_INET6) < 0)
5544                         goto nla_put_failure;
5545
5546                 list_for_each_entry_safe(sibling, next_sibling,
5547                                          &rt->fib6_siblings, fib6_siblings) {
5548                         if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
5549                                             sibling->fib6_nh->fib_nh_weight,
5550                                             AF_INET6) < 0)
5551                                 goto nla_put_failure;
5552                 }
5553
5554                 nla_nest_end(skb, mp);
5555         } else if (rt->nh) {
5556                 if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
5557                         goto nla_put_failure;
5558
5559                 if (nexthop_is_blackhole(rt->nh))
5560                         rtm->rtm_type = RTN_BLACKHOLE;
5561
5562                 if (rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0)
5563                         goto nla_put_failure;
5564
5565                 rtm->rtm_flags |= nh_flags;
5566         } else {
5567                 if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,
5568                                      &nh_flags, false) < 0)
5569                         goto nla_put_failure;
5570
5571                 rtm->rtm_flags |= nh_flags;
5572         }
5573
5574         if (rt6_flags & RTF_EXPIRES) {
5575                 expires = dst ? dst->expires : rt->expires;
5576                 expires -= jiffies;
5577         }
5578
5579         if (!dst) {
5580                 if (rt->offload)
5581                         rtm->rtm_flags |= RTM_F_OFFLOAD;
5582                 if (rt->trap)
5583                         rtm->rtm_flags |= RTM_F_TRAP;
5584         }
5585
5586         if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
5587                 goto nla_put_failure;
5588
5589         if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
5590                 goto nla_put_failure;
5591
5592
5593         nlmsg_end(skb, nlh);
5594         return 0;
5595
5596 nla_put_failure:
5597         nlmsg_cancel(skb, nlh);
5598         return -EMSGSIZE;
5599 }
5600
5601 static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg)
5602 {
5603         const struct net_device *dev = arg;
5604
5605         if (nh->fib_nh_dev == dev)
5606                 return 1;
5607
5608         return 0;
5609 }
5610
5611 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
5612                                const struct net_device *dev)
5613 {
5614         if (f6i->nh) {
5615                 struct net_device *_dev = (struct net_device *)dev;
5616
5617                 return !!nexthop_for_each_fib6_nh(f6i->nh,
5618                                                   fib6_info_nh_uses_dev,
5619                                                   _dev);
5620         }
5621
5622         if (f6i->fib6_nh->fib_nh_dev == dev)
5623                 return true;
5624
5625         if (f6i->fib6_nsiblings) {
5626                 struct fib6_info *sibling, *next_sibling;
5627
5628                 list_for_each_entry_safe(sibling, next_sibling,
5629                                          &f6i->fib6_siblings, fib6_siblings) {
5630                         if (sibling->fib6_nh->fib_nh_dev == dev)
5631                                 return true;
5632                 }
5633         }
5634
5635         return false;
5636 }
5637
5638 struct fib6_nh_exception_dump_walker {
5639         struct rt6_rtnl_dump_arg *dump;
5640         struct fib6_info *rt;
5641         unsigned int flags;
5642         unsigned int skip;
5643         unsigned int count;
5644 };
5645
5646 static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg)
5647 {
5648         struct fib6_nh_exception_dump_walker *w = arg;
5649         struct rt6_rtnl_dump_arg *dump = w->dump;
5650         struct rt6_exception_bucket *bucket;
5651         struct rt6_exception *rt6_ex;
5652         int i, err;
5653
5654         bucket = fib6_nh_get_excptn_bucket(nh, NULL);
5655         if (!bucket)
5656                 return 0;
5657
5658         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
5659                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
5660                         if (w->skip) {
5661                                 w->skip--;
5662                                 continue;
5663                         }
5664
5665                         /* Expiration of entries doesn't bump sernum, insertion
5666                          * does. Removal is triggered by insertion, so we can
5667                          * rely on the fact that if entries change between two
5668                          * partial dumps, this node is scanned again completely,
5669                          * see rt6_insert_exception() and fib6_dump_table().
5670                          *
5671                          * Count expired entries we go through as handled
5672                          * entries that we'll skip next time, in case of partial
5673                          * node dump. Otherwise, if entries expire meanwhile,
5674                          * we'll skip the wrong amount.
5675                          */
5676                         if (rt6_check_expired(rt6_ex->rt6i)) {
5677                                 w->count++;
5678                                 continue;
5679                         }
5680
5681                         err = rt6_fill_node(dump->net, dump->skb, w->rt,
5682                                             &rt6_ex->rt6i->dst, NULL, NULL, 0,
5683                                             RTM_NEWROUTE,
5684                                             NETLINK_CB(dump->cb->skb).portid,
5685                                             dump->cb->nlh->nlmsg_seq, w->flags);
5686                         if (err)
5687                                 return err;
5688
5689                         w->count++;
5690                 }
5691                 bucket++;
5692         }
5693
5694         return 0;
5695 }
5696
5697 /* Return -1 if done with node, number of handled routes on partial dump */
5698 int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip)
5699 {
5700         struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
5701         struct fib_dump_filter *filter = &arg->filter;
5702         unsigned int flags = NLM_F_MULTI;
5703         struct net *net = arg->net;
5704         int count = 0;
5705
5706         if (rt == net->ipv6.fib6_null_entry)
5707                 return -1;
5708
5709         if ((filter->flags & RTM_F_PREFIX) &&
5710             !(rt->fib6_flags & RTF_PREFIX_RT)) {
5711                 /* success since this is not a prefix route */
5712                 return -1;
5713         }
5714         if (filter->filter_set &&
5715             ((filter->rt_type  && rt->fib6_type != filter->rt_type) ||
5716              (filter->dev      && !fib6_info_uses_dev(rt, filter->dev)) ||
5717              (filter->protocol && rt->fib6_protocol != filter->protocol))) {
5718                 return -1;
5719         }
5720
5721         if (filter->filter_set ||
5722             !filter->dump_routes || !filter->dump_exceptions) {
5723                 flags |= NLM_F_DUMP_FILTERED;
5724         }
5725
5726         if (filter->dump_routes) {
5727                 if (skip) {
5728                         skip--;
5729                 } else {
5730                         if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL,
5731                                           0, RTM_NEWROUTE,
5732                                           NETLINK_CB(arg->cb->skb).portid,
5733                                           arg->cb->nlh->nlmsg_seq, flags)) {
5734                                 return 0;
5735                         }
5736                         count++;
5737                 }
5738         }
5739
5740         if (filter->dump_exceptions) {
5741                 struct fib6_nh_exception_dump_walker w = { .dump = arg,
5742                                                            .rt = rt,
5743                                                            .flags = flags,
5744                                                            .skip = skip,
5745                                                            .count = 0 };
5746                 int err;
5747
5748                 rcu_read_lock();
5749                 if (rt->nh) {
5750                         err = nexthop_for_each_fib6_nh(rt->nh,
5751                                                        rt6_nh_dump_exceptions,
5752                                                        &w);
5753                 } else {
5754                         err = rt6_nh_dump_exceptions(rt->fib6_nh, &w);
5755                 }
5756                 rcu_read_unlock();
5757
5758                 if (err)
5759                         return count += w.count;
5760         }
5761
5762         return -1;
5763 }
5764
5765 static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
5766                                         const struct nlmsghdr *nlh,
5767                                         struct nlattr **tb,
5768                                         struct netlink_ext_ack *extack)
5769 {
5770         struct rtmsg *rtm;
5771         int i, err;
5772
5773         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
5774                 NL_SET_ERR_MSG_MOD(extack,
5775                                    "Invalid header for get route request");
5776                 return -EINVAL;
5777         }
5778
5779         if (!netlink_strict_get_check(skb))
5780                 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5781                                               rtm_ipv6_policy, extack);
5782
5783         rtm = nlmsg_data(nlh);
5784         if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
5785             (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
5786             rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
5787             rtm->rtm_type) {
5788                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
5789                 return -EINVAL;
5790         }
5791         if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
5792                 NL_SET_ERR_MSG_MOD(extack,
5793                                    "Invalid flags for get route request");
5794                 return -EINVAL;
5795         }
5796
5797         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
5798                                             rtm_ipv6_policy, extack);
5799         if (err)
5800                 return err;
5801
5802         if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
5803             (tb[RTA_DST] && !rtm->rtm_dst_len)) {
5804                 NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
5805                 return -EINVAL;
5806         }
5807
5808         for (i = 0; i <= RTA_MAX; i++) {
5809                 if (!tb[i])
5810                         continue;
5811
5812                 switch (i) {
5813                 case RTA_SRC:
5814                 case RTA_DST:
5815                 case RTA_IIF:
5816                 case RTA_OIF:
5817                 case RTA_MARK:
5818                 case RTA_UID:
5819                 case RTA_SPORT:
5820                 case RTA_DPORT:
5821                 case RTA_IP_PROTO:
5822                         break;
5823                 default:
5824                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
5825                         return -EINVAL;
5826                 }
5827         }
5828
5829         return 0;
5830 }
5831
5832 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
5833                               struct netlink_ext_ack *extack)
5834 {
5835         struct net *net = sock_net(in_skb->sk);
5836         struct nlattr *tb[RTA_MAX+1];
5837         int err, iif = 0, oif = 0;
5838         struct fib6_info *from;
5839         struct dst_entry *dst;
5840         struct rt6_info *rt;
5841         struct sk_buff *skb;
5842         struct rtmsg *rtm;
5843         struct flowi6 fl6 = {};
5844         bool fibmatch;
5845
5846         err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
5847         if (err < 0)
5848                 goto errout;
5849
5850         err = -EINVAL;
5851         rtm = nlmsg_data(nlh);
5852         fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
5853         fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
5854
5855         if (tb[RTA_SRC]) {
5856                 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
5857                         goto errout;
5858
5859                 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
5860         }
5861
5862         if (tb[RTA_DST]) {
5863                 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
5864                         goto errout;
5865
5866                 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
5867         }
5868
5869         if (tb[RTA_IIF])
5870                 iif = nla_get_u32(tb[RTA_IIF]);
5871
5872         if (tb[RTA_OIF])
5873                 oif = nla_get_u32(tb[RTA_OIF]);
5874
5875         if (tb[RTA_MARK])
5876                 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
5877
5878         if (tb[RTA_UID])
5879                 fl6.flowi6_uid = make_kuid(current_user_ns(),
5880                                            nla_get_u32(tb[RTA_UID]));
5881         else
5882                 fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
5883
5884         if (tb[RTA_SPORT])
5885                 fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
5886
5887         if (tb[RTA_DPORT])
5888                 fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
5889
5890         if (tb[RTA_IP_PROTO]) {
5891                 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
5892                                                   &fl6.flowi6_proto, AF_INET6,
5893                                                   extack);
5894                 if (err)
5895                         goto errout;
5896         }
5897
5898         if (iif) {
5899                 struct net_device *dev;
5900                 int flags = 0;
5901
5902                 rcu_read_lock();
5903
5904                 dev = dev_get_by_index_rcu(net, iif);
5905                 if (!dev) {
5906                         rcu_read_unlock();
5907                         err = -ENODEV;
5908                         goto errout;
5909                 }
5910
5911                 fl6.flowi6_iif = iif;
5912
5913                 if (!ipv6_addr_any(&fl6.saddr))
5914                         flags |= RT6_LOOKUP_F_HAS_SADDR;
5915
5916                 dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
5917
5918                 rcu_read_unlock();
5919         } else {
5920                 fl6.flowi6_oif = oif;
5921
5922                 dst = ip6_route_output(net, NULL, &fl6);
5923         }
5924
5925
5926         rt = container_of(dst, struct rt6_info, dst);
5927         if (rt->dst.error) {
5928                 err = rt->dst.error;
5929                 ip6_rt_put(rt);
5930                 goto errout;
5931         }
5932
5933         if (rt == net->ipv6.ip6_null_entry) {
5934                 err = rt->dst.error;
5935                 ip6_rt_put(rt);
5936                 goto errout;
5937         }
5938
5939         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
5940         if (!skb) {
5941                 ip6_rt_put(rt);
5942                 err = -ENOBUFS;
5943                 goto errout;
5944         }
5945
5946         skb_dst_set(skb, &rt->dst);
5947
5948         rcu_read_lock();
5949         from = rcu_dereference(rt->from);
5950         if (from) {
5951                 if (fibmatch)
5952                         err = rt6_fill_node(net, skb, from, NULL, NULL, NULL,
5953                                             iif, RTM_NEWROUTE,
5954                                             NETLINK_CB(in_skb).portid,
5955                                             nlh->nlmsg_seq, 0);
5956                 else
5957                         err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
5958                                             &fl6.saddr, iif, RTM_NEWROUTE,
5959                                             NETLINK_CB(in_skb).portid,
5960                                             nlh->nlmsg_seq, 0);
5961         } else {
5962                 err = -ENETUNREACH;
5963         }
5964         rcu_read_unlock();
5965
5966         if (err < 0) {
5967                 kfree_skb(skb);
5968                 goto errout;
5969         }
5970
5971         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
5972 errout:
5973         return err;
5974 }
5975
5976 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
5977                      unsigned int nlm_flags)
5978 {
5979         struct sk_buff *skb;
5980         struct net *net = info->nl_net;
5981         u32 seq;
5982         int err;
5983
5984         err = -ENOBUFS;
5985         seq = info->nlh ? info->nlh->nlmsg_seq : 0;
5986
5987         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
5988         if (!skb)
5989                 goto errout;
5990
5991         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
5992                             event, info->portid, seq, nlm_flags);
5993         if (err < 0) {
5994                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
5995                 WARN_ON(err == -EMSGSIZE);
5996                 kfree_skb(skb);
5997                 goto errout;
5998         }
5999         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6000                     info->nlh, gfp_any());
6001         return;
6002 errout:
6003         if (err < 0)
6004                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6005 }
6006
6007 void fib6_rt_update(struct net *net, struct fib6_info *rt,
6008                     struct nl_info *info)
6009 {
6010         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6011         struct sk_buff *skb;
6012         int err = -ENOBUFS;
6013
6014         /* call_fib6_entry_notifiers will be removed when in-kernel notifier
6015          * is implemented and supported for nexthop objects
6016          */
6017         call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, rt, NULL);
6018
6019         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6020         if (!skb)
6021                 goto errout;
6022
6023         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6024                             RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
6025         if (err < 0) {
6026                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6027                 WARN_ON(err == -EMSGSIZE);
6028                 kfree_skb(skb);
6029                 goto errout;
6030         }
6031         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6032                     info->nlh, gfp_any());
6033         return;
6034 errout:
6035         if (err < 0)
6036                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6037 }
6038
6039 static int ip6_route_dev_notify(struct notifier_block *this,
6040                                 unsigned long event, void *ptr)
6041 {
6042         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
6043         struct net *net = dev_net(dev);
6044
6045         if (!(dev->flags & IFF_LOOPBACK))
6046                 return NOTIFY_OK;
6047
6048         if (event == NETDEV_REGISTER) {
6049                 net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev;
6050                 net->ipv6.ip6_null_entry->dst.dev = dev;
6051                 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
6052 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6053                 net->ipv6.ip6_prohibit_entry->dst.dev = dev;
6054                 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
6055                 net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
6056                 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
6057 #endif
6058          } else if (event == NETDEV_UNREGISTER &&
6059                     dev->reg_state != NETREG_UNREGISTERED) {
6060                 /* NETDEV_UNREGISTER could be fired for multiple times by
6061                  * netdev_wait_allrefs(). Make sure we only call this once.
6062                  */
6063                 in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
6064 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6065                 in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
6066                 in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
6067 #endif
6068         }
6069
6070         return NOTIFY_OK;
6071 }
6072
6073 /*
6074  *      /proc
6075  */
6076
6077 #ifdef CONFIG_PROC_FS
6078 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
6079 {
6080         struct net *net = (struct net *)seq->private;
6081         seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
6082                    net->ipv6.rt6_stats->fib_nodes,
6083                    net->ipv6.rt6_stats->fib_route_nodes,
6084                    atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
6085                    net->ipv6.rt6_stats->fib_rt_entries,
6086                    net->ipv6.rt6_stats->fib_rt_cache,
6087                    dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
6088                    net->ipv6.rt6_stats->fib_discarded_routes);
6089
6090         return 0;
6091 }
6092 #endif  /* CONFIG_PROC_FS */
6093
6094 #ifdef CONFIG_SYSCTL
6095
6096 static
6097 int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
6098                               void __user *buffer, size_t *lenp, loff_t *ppos)
6099 {
6100         struct net *net;
6101         int delay;
6102         int ret;
6103         if (!write)
6104                 return -EINVAL;
6105
6106         net = (struct net *)ctl->extra1;
6107         delay = net->ipv6.sysctl.flush_delay;
6108         ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
6109         if (ret)
6110                 return ret;
6111
6112         fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
6113         return 0;
6114 }
6115
6116 static struct ctl_table ipv6_route_table_template[] = {
6117         {
6118                 .procname       =       "flush",
6119                 .data           =       &init_net.ipv6.sysctl.flush_delay,
6120                 .maxlen         =       sizeof(int),
6121                 .mode           =       0200,
6122                 .proc_handler   =       ipv6_sysctl_rtcache_flush
6123         },
6124         {
6125                 .procname       =       "gc_thresh",
6126                 .data           =       &ip6_dst_ops_template.gc_thresh,
6127                 .maxlen         =       sizeof(int),
6128                 .mode           =       0644,
6129                 .proc_handler   =       proc_dointvec,
6130         },
6131         {
6132                 .procname       =       "max_size",
6133                 .data           =       &init_net.ipv6.sysctl.ip6_rt_max_size,
6134                 .maxlen         =       sizeof(int),
6135                 .mode           =       0644,
6136                 .proc_handler   =       proc_dointvec,
6137         },
6138         {
6139                 .procname       =       "gc_min_interval",
6140                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6141                 .maxlen         =       sizeof(int),
6142                 .mode           =       0644,
6143                 .proc_handler   =       proc_dointvec_jiffies,
6144         },
6145         {
6146                 .procname       =       "gc_timeout",
6147                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
6148                 .maxlen         =       sizeof(int),
6149                 .mode           =       0644,
6150                 .proc_handler   =       proc_dointvec_jiffies,
6151         },
6152         {
6153                 .procname       =       "gc_interval",
6154                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_interval,
6155                 .maxlen         =       sizeof(int),
6156                 .mode           =       0644,
6157                 .proc_handler   =       proc_dointvec_jiffies,
6158         },
6159         {
6160                 .procname       =       "gc_elasticity",
6161                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
6162                 .maxlen         =       sizeof(int),
6163                 .mode           =       0644,
6164                 .proc_handler   =       proc_dointvec,
6165         },
6166         {
6167                 .procname       =       "mtu_expires",
6168                 .data           =       &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
6169                 .maxlen         =       sizeof(int),
6170                 .mode           =       0644,
6171                 .proc_handler   =       proc_dointvec_jiffies,
6172         },
6173         {
6174                 .procname       =       "min_adv_mss",
6175                 .data           =       &init_net.ipv6.sysctl.ip6_rt_min_advmss,
6176                 .maxlen         =       sizeof(int),
6177                 .mode           =       0644,
6178                 .proc_handler   =       proc_dointvec,
6179         },
6180         {
6181                 .procname       =       "gc_min_interval_ms",
6182                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6183                 .maxlen         =       sizeof(int),
6184                 .mode           =       0644,
6185                 .proc_handler   =       proc_dointvec_ms_jiffies,
6186         },
6187         {
6188                 .procname       =       "skip_notify_on_dev_down",
6189                 .data           =       &init_net.ipv6.sysctl.skip_notify_on_dev_down,
6190                 .maxlen         =       sizeof(int),
6191                 .mode           =       0644,
6192                 .proc_handler   =       proc_dointvec_minmax,
6193                 .extra1         =       SYSCTL_ZERO,
6194                 .extra2         =       SYSCTL_ONE,
6195         },
6196         { }
6197 };
6198
6199 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
6200 {
6201         struct ctl_table *table;
6202
6203         table = kmemdup(ipv6_route_table_template,
6204                         sizeof(ipv6_route_table_template),
6205                         GFP_KERNEL);
6206
6207         if (table) {
6208                 table[0].data = &net->ipv6.sysctl.flush_delay;
6209                 table[0].extra1 = net;
6210                 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
6211                 table[2].data = &net->ipv6.sysctl.ip6_rt_max_size;
6212                 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6213                 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
6214                 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
6215                 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
6216                 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
6217                 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
6218                 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6219                 table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
6220
6221                 /* Don't export sysctls to unprivileged users */
6222                 if (net->user_ns != &init_user_ns)
6223                         table[0].procname = NULL;
6224         }
6225
6226         return table;
6227 }
6228 #endif
6229
6230 static int __net_init ip6_route_net_init(struct net *net)
6231 {
6232         int ret = -ENOMEM;
6233
6234         memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
6235                sizeof(net->ipv6.ip6_dst_ops));
6236
6237         if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
6238                 goto out_ip6_dst_ops;
6239
6240         net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true);
6241         if (!net->ipv6.fib6_null_entry)
6242                 goto out_ip6_dst_entries;
6243         memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template,
6244                sizeof(*net->ipv6.fib6_null_entry));
6245
6246         net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
6247                                            sizeof(*net->ipv6.ip6_null_entry),
6248                                            GFP_KERNEL);
6249         if (!net->ipv6.ip6_null_entry)
6250                 goto out_fib6_null_entry;
6251         net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6252         dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
6253                          ip6_template_metrics, true);
6254         INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->rt6i_uncached);
6255
6256 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6257         net->ipv6.fib6_has_custom_rules = false;
6258         net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
6259                                                sizeof(*net->ipv6.ip6_prohibit_entry),
6260                                                GFP_KERNEL);
6261         if (!net->ipv6.ip6_prohibit_entry)
6262                 goto out_ip6_null_entry;
6263         net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6264         dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
6265                          ip6_template_metrics, true);
6266         INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->rt6i_uncached);
6267
6268         net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
6269                                                sizeof(*net->ipv6.ip6_blk_hole_entry),
6270                                                GFP_KERNEL);
6271         if (!net->ipv6.ip6_blk_hole_entry)
6272                 goto out_ip6_prohibit_entry;
6273         net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6274         dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
6275                          ip6_template_metrics, true);
6276         INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->rt6i_uncached);
6277 #ifdef CONFIG_IPV6_SUBTREES
6278         net->ipv6.fib6_routes_require_src = 0;
6279 #endif
6280 #endif
6281
6282         net->ipv6.sysctl.flush_delay = 0;
6283         net->ipv6.sysctl.ip6_rt_max_size = 4096;
6284         net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
6285         net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
6286         net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
6287         net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
6288         net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
6289         net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
6290         net->ipv6.sysctl.skip_notify_on_dev_down = 0;
6291
6292         net->ipv6.ip6_rt_gc_expire = 30*HZ;
6293
6294         ret = 0;
6295 out:
6296         return ret;
6297
6298 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6299 out_ip6_prohibit_entry:
6300         kfree(net->ipv6.ip6_prohibit_entry);
6301 out_ip6_null_entry:
6302         kfree(net->ipv6.ip6_null_entry);
6303 #endif
6304 out_fib6_null_entry:
6305         kfree(net->ipv6.fib6_null_entry);
6306 out_ip6_dst_entries:
6307         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6308 out_ip6_dst_ops:
6309         goto out;
6310 }
6311
6312 static void __net_exit ip6_route_net_exit(struct net *net)
6313 {
6314         kfree(net->ipv6.fib6_null_entry);
6315         kfree(net->ipv6.ip6_null_entry);
6316 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6317         kfree(net->ipv6.ip6_prohibit_entry);
6318         kfree(net->ipv6.ip6_blk_hole_entry);
6319 #endif
6320         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6321 }
6322
6323 static int __net_init ip6_route_net_init_late(struct net *net)
6324 {
6325 #ifdef CONFIG_PROC_FS
6326         proc_create_net("ipv6_route", 0, net->proc_net, &ipv6_route_seq_ops,
6327                         sizeof(struct ipv6_route_iter));
6328         proc_create_net_single("rt6_stats", 0444, net->proc_net,
6329                         rt6_stats_seq_show, NULL);
6330 #endif
6331         return 0;
6332 }
6333
6334 static void __net_exit ip6_route_net_exit_late(struct net *net)
6335 {
6336 #ifdef CONFIG_PROC_FS
6337         remove_proc_entry("ipv6_route", net->proc_net);
6338         remove_proc_entry("rt6_stats", net->proc_net);
6339 #endif
6340 }
6341
6342 static struct pernet_operations ip6_route_net_ops = {
6343         .init = ip6_route_net_init,
6344         .exit = ip6_route_net_exit,
6345 };
6346
6347 static int __net_init ipv6_inetpeer_init(struct net *net)
6348 {
6349         struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
6350
6351         if (!bp)
6352                 return -ENOMEM;
6353         inet_peer_base_init(bp);
6354         net->ipv6.peers = bp;
6355         return 0;
6356 }
6357
6358 static void __net_exit ipv6_inetpeer_exit(struct net *net)
6359 {
6360         struct inet_peer_base *bp = net->ipv6.peers;
6361
6362         net->ipv6.peers = NULL;
6363         inetpeer_invalidate_tree(bp);
6364         kfree(bp);
6365 }
6366
6367 static struct pernet_operations ipv6_inetpeer_ops = {
6368         .init   =       ipv6_inetpeer_init,
6369         .exit   =       ipv6_inetpeer_exit,
6370 };
6371
6372 static struct pernet_operations ip6_route_net_late_ops = {
6373         .init = ip6_route_net_init_late,
6374         .exit = ip6_route_net_exit_late,
6375 };
6376
6377 static struct notifier_block ip6_route_dev_notifier = {
6378         .notifier_call = ip6_route_dev_notify,
6379         .priority = ADDRCONF_NOTIFY_PRIORITY - 10,
6380 };
6381
6382 void __init ip6_route_init_special_entries(void)
6383 {
6384         /* Registering of the loopback is done before this portion of code,
6385          * the loopback reference in rt6_info will not be taken, do it
6386          * manually for init_net */
6387         init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev;
6388         init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
6389         init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6390   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6391         init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
6392         init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6393         init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
6394         init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6395   #endif
6396 }
6397
6398 int __init ip6_route_init(void)
6399 {
6400         int ret;
6401         int cpu;
6402
6403         ret = -ENOMEM;
6404         ip6_dst_ops_template.kmem_cachep =
6405                 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
6406                                   SLAB_HWCACHE_ALIGN, NULL);
6407         if (!ip6_dst_ops_template.kmem_cachep)
6408                 goto out;
6409
6410         ret = dst_entries_init(&ip6_dst_blackhole_ops);
6411         if (ret)
6412                 goto out_kmem_cache;
6413
6414         ret = register_pernet_subsys(&ipv6_inetpeer_ops);
6415         if (ret)
6416                 goto out_dst_entries;
6417
6418         ret = register_pernet_subsys(&ip6_route_net_ops);
6419         if (ret)
6420                 goto out_register_inetpeer;
6421
6422         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
6423
6424         ret = fib6_init();
6425         if (ret)
6426                 goto out_register_subsys;
6427
6428         ret = xfrm6_init();
6429         if (ret)
6430                 goto out_fib6_init;
6431
6432         ret = fib6_rules_init();
6433         if (ret)
6434                 goto xfrm6_init;
6435
6436         ret = register_pernet_subsys(&ip6_route_net_late_ops);
6437         if (ret)
6438                 goto fib6_rules_init;
6439
6440         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
6441                                    inet6_rtm_newroute, NULL, 0);
6442         if (ret < 0)
6443                 goto out_register_late_subsys;
6444
6445         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
6446                                    inet6_rtm_delroute, NULL, 0);
6447         if (ret < 0)
6448                 goto out_register_late_subsys;
6449
6450         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
6451                                    inet6_rtm_getroute, NULL,
6452                                    RTNL_FLAG_DOIT_UNLOCKED);
6453         if (ret < 0)
6454                 goto out_register_late_subsys;
6455
6456         ret = register_netdevice_notifier(&ip6_route_dev_notifier);
6457         if (ret)
6458                 goto out_register_late_subsys;
6459
6460         for_each_possible_cpu(cpu) {
6461                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
6462
6463                 INIT_LIST_HEAD(&ul->head);
6464                 spin_lock_init(&ul->lock);
6465         }
6466
6467 out:
6468         return ret;
6469
6470 out_register_late_subsys:
6471         rtnl_unregister_all(PF_INET6);
6472         unregister_pernet_subsys(&ip6_route_net_late_ops);
6473 fib6_rules_init:
6474         fib6_rules_cleanup();
6475 xfrm6_init:
6476         xfrm6_fini();
6477 out_fib6_init:
6478         fib6_gc_cleanup();
6479 out_register_subsys:
6480         unregister_pernet_subsys(&ip6_route_net_ops);
6481 out_register_inetpeer:
6482         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6483 out_dst_entries:
6484         dst_entries_destroy(&ip6_dst_blackhole_ops);
6485 out_kmem_cache:
6486         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6487         goto out;
6488 }
6489
6490 void ip6_route_cleanup(void)
6491 {
6492         unregister_netdevice_notifier(&ip6_route_dev_notifier);
6493         unregister_pernet_subsys(&ip6_route_net_late_ops);
6494         fib6_rules_cleanup();
6495         xfrm6_fini();
6496         fib6_gc_cleanup();
6497         unregister_pernet_subsys(&ipv6_inetpeer_ops);
6498         unregister_pernet_subsys(&ip6_route_net_ops);
6499         dst_entries_destroy(&ip6_dst_blackhole_ops);
6500         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6501 }