net/ipv6/route.c

   1 /*
   2  *      Linux INET6 implementation
   3  *      FIB front-end.
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 /*      Changes:
  15  *
  16  *      YOSHIFUJI Hideaki @USAGI
  17  *              reworked default router selection.
  18  *              - respect outgoing interface
  19  *              - select from (probably) reachable routers (i.e.
  20  *              routers in REACHABLE, STALE, DELAY or PROBE states).
  21  *              - always select the same router if it is (probably)
  22  *              reachable.  otherwise, round-robin the list.
  23  *      Ville Nuorvala
  24  *              Fixed routing subtrees.
  25  */
  26
  27 #define pr_fmt(fmt) "IPv6: " fmt
  28
  29 #include <linux/capability.h>
  30 #include <linux/errno.h>
  31 #include <linux/export.h>
  32 #include <linux/types.h>
  33 #include <linux/times.h>
  34 #include <linux/socket.h>
  35 #include <linux/sockios.h>
  36 #include <linux/net.h>
  37 #include <linux/route.h>
  38 #include <linux/netdevice.h>
  39 #include <linux/in6.h>
  40 #include <linux/mroute6.h>
  41 #include <linux/init.h>
  42 #include <linux/if_arp.h>
  43 #include <linux/proc_fs.h>
  44 #include <linux/seq_file.h>
  45 #include <linux/nsproxy.h>
  46 #include <linux/slab.h>
  47 #include <linux/jhash.h>
  48 #include <net/net_namespace.h>
  49 #include <net/snmp.h>
  50 #include <net/ipv6.h>
  51 #include <net/ip6_fib.h>
  52 #include <net/ip6_route.h>
  53 #include <net/ndisc.h>
  54 #include <net/addrconf.h>
  55 #include <net/tcp.h>
  56 #include <linux/rtnetlink.h>
  57 #include <net/dst.h>
  58 #include <net/dst_metadata.h>
  59 #include <net/xfrm.h>
  60 #include <net/netevent.h>
  61 #include <net/netlink.h>
  62 #include <net/nexthop.h>
  63 #include <net/lwtunnel.h>
  64 #include <net/ip_tunnels.h>
  65 #include <net/l3mdev.h>
  66 #include <net/ip.h>
  67 #include <linux/uaccess.h>
  68
  69 #ifdef CONFIG_SYSCTL
  70 #include <linux/sysctl.h>
  71 #endif
  72
  73 static int ip6_rt_type_to_error(u8 fib6_type);
  74
  75 #define CREATE_TRACE_POINTS
  76 #include <trace/events/fib6.h>
  77 EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup);
  78 #undef CREATE_TRACE_POINTS
  79
  80 enum rt6_nud_state {
  81         RT6_NUD_FAIL_HARD = -3,
  82         RT6_NUD_FAIL_PROBE = -2,
  83         RT6_NUD_FAIL_DO_RR = -1,
  84         RT6_NUD_SUCCEED = 1
  85 };
  86
  87 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie);
  88 static unsigned int      ip6_default_advmss(const struct dst_entry *dst);
  89 static unsigned int      ip6_mtu(const struct dst_entry *dst);
  90 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
  91 static void             ip6_dst_destroy(struct dst_entry *);
  92 static void             ip6_dst_ifdown(struct dst_entry *,
  93                                        struct net_device *dev, int how);
  94 static int               ip6_dst_gc(struct dst_ops *ops);
  95
  96 static int              ip6_pkt_discard(struct sk_buff *skb);
  97 static int              ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
  98 static int              ip6_pkt_prohibit(struct sk_buff *skb);
  99 static int              ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 100 static void             ip6_link_failure(struct sk_buff *skb);
 101 static void             ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
 102                                            struct sk_buff *skb, u32 mtu);
 103 static void             rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
 104                                         struct sk_buff *skb);
 105 static int rt6_score_route(struct fib6_info *rt, int oif, int strict);
 106 static size_t rt6_nlmsg_size(struct fib6_info *rt);
 107 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
 108                          struct fib6_info *rt, struct dst_entry *dst,
 109                          struct in6_addr *dest, struct in6_addr *src,
 110                          int iif, int type, u32 portid, u32 seq,
 111                          unsigned int flags);
 112 static struct rt6_info *rt6_find_cached_rt(struct fib6_info *rt,
 113                                            struct in6_addr *daddr,
 114                                            struct in6_addr *saddr);
 115
 116 #ifdef CONFIG_IPV6_ROUTE_INFO
 117 static struct fib6_info *rt6_add_route_info(struct net *net,
 118                                            const struct in6_addr *prefix, int prefixlen,
 119                                            const struct in6_addr *gwaddr,
 120                                            struct net_device *dev,
 121                                            unsigned int pref);
 122 static struct fib6_info *rt6_get_route_info(struct net *net,
 123                                            const struct in6_addr *prefix, int prefixlen,
 124                                            const struct in6_addr *gwaddr,
 125                                            struct net_device *dev);
 126 #endif
 127
 128 struct uncached_list {
 129         spinlock_t              lock;
 130         struct list_head        head;
 131 };
 132
 133 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
 134
 135 void rt6_uncached_list_add(struct rt6_info *rt)
 136 {
 137         struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list);
 138
 139         rt->rt6i_uncached_list = ul;
 140
 141         spin_lock_bh(&ul->lock);
 142         list_add_tail(&rt->rt6i_uncached, &ul->head);
 143         spin_unlock_bh(&ul->lock);
 144 }
 145
 146 void rt6_uncached_list_del(struct rt6_info *rt)
 147 {
 148         if (!list_empty(&rt->rt6i_uncached)) {
 149                 struct uncached_list *ul = rt->rt6i_uncached_list;
 150                 struct net *net = dev_net(rt->dst.dev);
 151
 152                 spin_lock_bh(&ul->lock);
 153                 list_del(&rt->rt6i_uncached);
 154                 atomic_dec(&net->ipv6.rt6_stats->fib_rt_uncache);
 155                 spin_unlock_bh(&ul->lock);
 156         }
 157 }
 158
 159 static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev)
 160 {
 161         struct net_device *loopback_dev = net->loopback_dev;
 162         int cpu;
 163
 164         if (dev == loopback_dev)
 165                 return;
 166
 167         for_each_possible_cpu(cpu) {
 168                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
 169                 struct rt6_info *rt;
 170
 171                 spin_lock_bh(&ul->lock);
 172                 list_for_each_entry(rt, &ul->head, rt6i_uncached) {
 173                         struct inet6_dev *rt_idev = rt->rt6i_idev;
 174                         struct net_device *rt_dev = rt->dst.dev;
 175
 176                         if (rt_idev->dev == dev) {
 177                                 rt->rt6i_idev = in6_dev_get(loopback_dev);
 178                                 in6_dev_put(rt_idev);
 179                         }
 180
 181                         if (rt_dev == dev) {
 182                                 rt->dst.dev = loopback_dev;
 183                                 dev_hold(rt->dst.dev);
 184                                 dev_put(rt_dev);
 185                         }
 186                 }
 187                 spin_unlock_bh(&ul->lock);
 188         }
 189 }
 190
 191 static inline const void *choose_neigh_daddr(const struct in6_addr *p,
 192                                              struct sk_buff *skb,
 193                                              const void *daddr)
 194 {
 195         if (!ipv6_addr_any(p))
 196                 return (const void *) p;
 197         else if (skb)
 198                 return &ipv6_hdr(skb)->daddr;
 199         return daddr;
 200 }
 201
 202 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
 203                                    struct net_device *dev,
 204                                    struct sk_buff *skb,
 205                                    const void *daddr)
 206 {
 207         struct neighbour *n;
 208
 209         daddr = choose_neigh_daddr(gw, skb, daddr);
 210         n = __ipv6_neigh_lookup(dev, daddr);
 211         if (n)
 212                 return n;
 213         return neigh_create(&nd_tbl, daddr, dev);
 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(&rt->rt6i_gateway, dst->dev, skb, daddr);
 223 }
 224
 225 static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr)
 226 {
 227         struct net_device *dev = dst->dev;
 228         struct rt6_info *rt = (struct rt6_info *)dst;
 229
 230         daddr = choose_neigh_daddr(&rt->rt6i_gateway, NULL, daddr);
 231         if (!daddr)
 232                 return;
 233         if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
 234                 return;
 235         if (ipv6_addr_is_multicast((const struct in6_addr *)daddr))
 236                 return;
 237         __ipv6_confirm_neigh(dev, daddr);
 238 }
 239
 240 static struct dst_ops ip6_dst_ops_template = {
 241         .family                 =       AF_INET6,
 242         .gc                     =       ip6_dst_gc,
 243         .gc_thresh              =       1024,
 244         .check                  =       ip6_dst_check,
 245         .default_advmss         =       ip6_default_advmss,
 246         .mtu                    =       ip6_mtu,
 247         .cow_metrics            =       dst_cow_metrics_generic,
 248         .destroy                =       ip6_dst_destroy,
 249         .ifdown                 =       ip6_dst_ifdown,
 250         .negative_advice        =       ip6_negative_advice,
 251         .link_failure           =       ip6_link_failure,
 252         .update_pmtu            =       ip6_rt_update_pmtu,
 253         .redirect               =       rt6_do_redirect,
 254         .local_out              =       __ip6_local_out,
 255         .neigh_lookup           =       ip6_dst_neigh_lookup,
 256         .confirm_neigh          =       ip6_confirm_neigh,
 257 };
 258
 259 static unsigned int ip6_blackhole_mtu(const struct dst_entry *dst)
 260 {
 261         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
 262
 263         return mtu ? : dst->dev->mtu;
 264 }
 265
 266 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
 267                                          struct sk_buff *skb, u32 mtu)
 268 {
 269 }
 270
 271 static void ip6_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
 272                                       struct sk_buff *skb)
 273 {
 274 }
 275
 276 static struct dst_ops ip6_dst_blackhole_ops = {
 277         .family                 =       AF_INET6,
 278         .destroy                =       ip6_dst_destroy,
 279         .check                  =       ip6_dst_check,
 280         .mtu                    =       ip6_blackhole_mtu,
 281         .default_advmss         =       ip6_default_advmss,
 282         .update_pmtu            =       ip6_rt_blackhole_update_pmtu,
 283         .redirect               =       ip6_rt_blackhole_redirect,
 284         .cow_metrics            =       dst_cow_metrics_generic,
 285         .neigh_lookup           =       ip6_dst_neigh_lookup,
 286 };
 287
 288 static const u32 ip6_template_metrics[RTAX_MAX] = {
 289         [RTAX_HOPLIMIT - 1] = 0,
 290 };
 291
 292 static const struct fib6_info fib6_null_entry_template = {
 293         .fib6_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 294         .fib6_protocol  = RTPROT_KERNEL,
 295         .fib6_metric    = ~(u32)0,
 296         .fib6_ref       = ATOMIC_INIT(1),
 297         .fib6_type      = RTN_UNREACHABLE,
 298         .fib6_metrics   = (struct dst_metrics *)&dst_default_metrics,
 299 };
 300
 301 static const struct rt6_info ip6_null_entry_template = {
 302         .dst = {
 303                 .__refcnt       = ATOMIC_INIT(1),
 304                 .__use          = 1,
 305                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 306                 .error          = -ENETUNREACH,
 307                 .input          = ip6_pkt_discard,
 308                 .output         = ip6_pkt_discard_out,
 309         },
 310         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 311 };
 312
 313 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 314
 315 static const struct rt6_info ip6_prohibit_entry_template = {
 316         .dst = {
 317                 .__refcnt       = ATOMIC_INIT(1),
 318                 .__use          = 1,
 319                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 320                 .error          = -EACCES,
 321                 .input          = ip6_pkt_prohibit,
 322                 .output         = ip6_pkt_prohibit_out,
 323         },
 324         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 325 };
 326
 327 static const struct rt6_info ip6_blk_hole_entry_template = {
 328         .dst = {
 329                 .__refcnt       = ATOMIC_INIT(1),
 330                 .__use          = 1,
 331                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
 332                 .error          = -EINVAL,
 333                 .input          = dst_discard,
 334                 .output         = dst_discard_out,
 335         },
 336         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
 337 };
 338
 339 #endif
 340
 341 static void rt6_info_init(struct rt6_info *rt)
 342 {
 343         struct dst_entry *dst = &rt->dst;
 344
 345         memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));
 346         INIT_LIST_HEAD(&rt->rt6i_uncached);
 347 }
 348
 349 /* allocate dst with ip6_dst_ops */
 350 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 351                                int flags)
 352 {
 353         struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
 354                                         1, DST_OBSOLETE_FORCE_CHK, flags);
 355
 356         if (rt) {
 357                 rt6_info_init(rt);
 358                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
 359         }
 360
 361         return rt;
 362 }
 363 EXPORT_SYMBOL(ip6_dst_alloc);
 364
 365 static void ip6_dst_destroy(struct dst_entry *dst)
 366 {
 367         struct rt6_info *rt = (struct rt6_info *)dst;
 368         struct fib6_info *from;
 369         struct inet6_dev *idev;
 370
 371         ip_dst_metrics_put(dst);
 372         rt6_uncached_list_del(rt);
 373
 374         idev = rt->rt6i_idev;
 375         if (idev) {
 376                 rt->rt6i_idev = NULL;
 377                 in6_dev_put(idev);
 378         }
 379
 380         rcu_read_lock();
 381         from = rcu_dereference(rt->from);
 382         rcu_assign_pointer(rt->from, NULL);
 383         fib6_info_release(from);
 384         rcu_read_unlock();
 385 }
 386
 387 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 388                            int how)
 389 {
 390         struct rt6_info *rt = (struct rt6_info *)dst;
 391         struct inet6_dev *idev = rt->rt6i_idev;
 392         struct net_device *loopback_dev =
 393                 dev_net(dev)->loopback_dev;
 394
 395         if (idev && idev->dev != loopback_dev) {
 396                 struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);
 397                 if (loopback_idev) {
 398                         rt->rt6i_idev = loopback_idev;
 399                         in6_dev_put(idev);
 400                 }
 401         }
 402 }
 403
 404 static bool __rt6_check_expired(const struct rt6_info *rt)
 405 {
 406         if (rt->rt6i_flags & RTF_EXPIRES)
 407                 return time_after(jiffies, rt->dst.expires);
 408         else
 409                 return false;
 410 }
 411
 412 static bool rt6_check_expired(const struct rt6_info *rt)
 413 {
 414         struct fib6_info *from;
 415
 416         from = rcu_dereference(rt->from);
 417
 418         if (rt->rt6i_flags & RTF_EXPIRES) {
 419                 if (time_after(jiffies, rt->dst.expires))
 420                         return true;
 421         } else if (from) {
 422                 return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
 423                         fib6_check_expired(from);
 424         }
 425         return false;
 426 }
 427
 428 struct fib6_info *fib6_multipath_select(const struct net *net,
 429                                         struct fib6_info *match,
 430                                         struct flowi6 *fl6, int oif,
 431                                         const struct sk_buff *skb,
 432                                         int strict)
 433 {
 434         struct fib6_info *sibling, *next_sibling;
 435
 436         /* We might have already computed the hash for ICMPv6 errors. In such
 437          * case it will always be non-zero. Otherwise now is the time to do it.
 438          */
 439         if (!fl6->mp_hash)
 440                 fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
 441
 442         if (fl6->mp_hash <= atomic_read(&match->fib6_nh.nh_upper_bound))
 443                 return match;
 444
 445         list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
 446                                  fib6_siblings) {
 447                 int nh_upper_bound;
 448
 449                 nh_upper_bound = atomic_read(&sibling->fib6_nh.nh_upper_bound);
 450                 if (fl6->mp_hash > nh_upper_bound)
 451                         continue;
 452                 if (rt6_score_route(sibling, oif, strict) < 0)
 453                         break;
 454                 match = sibling;
 455                 break;
 456         }
 457
 458         return match;
 459 }
 460
 461 /*
 462  *      Route lookup. rcu_read_lock() should be held.
 463  */
 464
 465 static inline struct fib6_info *rt6_device_match(struct net *net,
 466                                                  struct fib6_info *rt,
 467                                                     const struct in6_addr *saddr,
 468                                                     int oif,
 469                                                     int flags)
 470 {
 471         struct fib6_info *sprt;
 472
 473         if (!oif && ipv6_addr_any(saddr) &&
 474             !(rt->fib6_nh.nh_flags & RTNH_F_DEAD))
 475                 return rt;
 476
 477         for (sprt = rt; sprt; sprt = rcu_dereference(sprt->fib6_next)) {
 478                 const struct net_device *dev = sprt->fib6_nh.nh_dev;
 479
 480                 if (sprt->fib6_nh.nh_flags & RTNH_F_DEAD)
 481                         continue;
 482
 483                 if (oif) {
 484                         if (dev->ifindex == oif)
 485                                 return sprt;
 486                 } else {
 487                         if (ipv6_chk_addr(net, saddr, dev,
 488                                           flags & RT6_LOOKUP_F_IFACE))
 489                                 return sprt;
 490                 }
 491         }
 492
 493         if (oif && flags & RT6_LOOKUP_F_IFACE)
 494                 return net->ipv6.fib6_null_entry;
 495
 496         return rt->fib6_nh.nh_flags & RTNH_F_DEAD ? net->ipv6.fib6_null_entry : rt;
 497 }
 498
 499 #ifdef CONFIG_IPV6_ROUTER_PREF
 500 struct __rt6_probe_work {
 501         struct work_struct work;
 502         struct in6_addr target;
 503         struct net_device *dev;
 504 };
 505
 506 static void rt6_probe_deferred(struct work_struct *w)
 507 {
 508         struct in6_addr mcaddr;
 509         struct __rt6_probe_work *work =
 510                 container_of(w, struct __rt6_probe_work, work);
 511
 512         addrconf_addr_solict_mult(&work->target, &mcaddr);
 513         ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
 514         dev_put(work->dev);
 515         kfree(work);
 516 }
 517
 518 static void rt6_probe(struct fib6_info *rt)
 519 {
 520         struct __rt6_probe_work *work = NULL;
 521         const struct in6_addr *nh_gw;
 522         struct neighbour *neigh;
 523         struct net_device *dev;
 524         struct inet6_dev *idev;
 525
 526         /*
 527          * Okay, this does not seem to be appropriate
 528          * for now, however, we need to check if it
 529          * is really so; aka Router Reachability Probing.
 530          *
 531          * Router Reachability Probe MUST be rate-limited
 532          * to no more than one per minute.
 533          */
 534         if (!rt || !(rt->fib6_flags & RTF_GATEWAY))
 535                 return;
 536
 537         nh_gw = &rt->fib6_nh.nh_gw;
 538         dev = rt->fib6_nh.nh_dev;
 539         rcu_read_lock_bh();
 540         idev = __in6_dev_get(dev);
 541         neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
 542         if (neigh) {
 543                 if (neigh->nud_state & NUD_VALID)
 544                         goto out;
 545
 546                 write_lock(&neigh->lock);
 547                 if (!(neigh->nud_state & NUD_VALID) &&
 548                     time_after(jiffies,
 549                                neigh->updated + idev->cnf.rtr_probe_interval)) {
 550                         work = kmalloc(sizeof(*work), GFP_ATOMIC);
 551                         if (work)
 552                                 __neigh_set_probe_once(neigh);
 553                 }
 554                 write_unlock(&neigh->lock);
 555         } else if (time_after(jiffies, rt->last_probe +
 556                                        idev->cnf.rtr_probe_interval)) {
 557                 work = kmalloc(sizeof(*work), GFP_ATOMIC);
 558         }
 559
 560         if (work) {
 561                 rt->last_probe = jiffies;
 562                 INIT_WORK(&work->work, rt6_probe_deferred);
 563                 work->target = *nh_gw;
 564                 dev_hold(dev);
 565                 work->dev = dev;
 566                 schedule_work(&work->work);
 567         }
 568
 569 out:
 570         rcu_read_unlock_bh();
 571 }
 572 #else
 573 static inline void rt6_probe(struct fib6_info *rt)
 574 {
 575 }
 576 #endif
 577
 578 /*
 579  * Default Router Selection (RFC 2461 6.3.6)
 580  */
 581 static inline int rt6_check_dev(struct fib6_info *rt, int oif)
 582 {
 583         const struct net_device *dev = rt->fib6_nh.nh_dev;
 584
 585         if (!oif || dev->ifindex == oif)
 586                 return 2;
 587         return 0;
 588 }
 589
 590 static inline enum rt6_nud_state rt6_check_neigh(struct fib6_info *rt)
 591 {
 592         enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
 593         struct neighbour *neigh;
 594
 595         if (rt->fib6_flags & RTF_NONEXTHOP ||
 596             !(rt->fib6_flags & RTF_GATEWAY))
 597                 return RT6_NUD_SUCCEED;
 598
 599         rcu_read_lock_bh();
 600         neigh = __ipv6_neigh_lookup_noref(rt->fib6_nh.nh_dev,
 601                                           &rt->fib6_nh.nh_gw);
 602         if (neigh) {
 603                 read_lock(&neigh->lock);
 604                 if (neigh->nud_state & NUD_VALID)
 605                         ret = RT6_NUD_SUCCEED;
 606 #ifdef CONFIG_IPV6_ROUTER_PREF
 607                 else if (!(neigh->nud_state & NUD_FAILED))
 608                         ret = RT6_NUD_SUCCEED;
 609                 else
 610                         ret = RT6_NUD_FAIL_PROBE;
 611 #endif
 612                 read_unlock(&neigh->lock);
 613         } else {
 614                 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
 615                       RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
 616         }
 617         rcu_read_unlock_bh();
 618
 619         return ret;
 620 }
 621
 622 static int rt6_score_route(struct fib6_info *rt, int oif, int strict)
 623 {
 624         int m;
 625
 626         m = rt6_check_dev(rt, oif);
 627         if (!m && (strict & RT6_LOOKUP_F_IFACE))
 628                 return RT6_NUD_FAIL_HARD;
 629 #ifdef CONFIG_IPV6_ROUTER_PREF
 630         m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->fib6_flags)) << 2;
 631 #endif
 632         if (strict & RT6_LOOKUP_F_REACHABLE) {
 633                 int n = rt6_check_neigh(rt);
 634                 if (n < 0)
 635                         return n;
 636         }
 637         return m;
 638 }
 639
 640 /* called with rc_read_lock held */
 641 static inline bool fib6_ignore_linkdown(const struct fib6_info *f6i)
 642 {
 643         const struct net_device *dev = fib6_info_nh_dev(f6i);
 644         bool rc = false;
 645
 646         if (dev) {
 647                 const struct inet6_dev *idev = __in6_dev_get(dev);
 648
 649                 rc = !!idev->cnf.ignore_routes_with_linkdown;
 650         }
 651
 652         return rc;
 653 }
 654
 655 static struct fib6_info *find_match(struct fib6_info *rt, int oif, int strict,
 656                                    int *mpri, struct fib6_info *match,
 657                                    bool *do_rr)
 658 {
 659         int m;
 660         bool match_do_rr = false;
 661
 662         if (rt->fib6_nh.nh_flags & RTNH_F_DEAD)
 663                 goto out;
 664
 665         if (fib6_ignore_linkdown(rt) &&
 666             rt->fib6_nh.nh_flags & RTNH_F_LINKDOWN &&
 667             !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
 668                 goto out;
 669
 670         if (fib6_check_expired(rt))
 671                 goto out;
 672
 673         m = rt6_score_route(rt, oif, strict);
 674         if (m == RT6_NUD_FAIL_DO_RR) {
 675                 match_do_rr = true;
 676                 m = 0; /* lowest valid score */
 677         } else if (m == RT6_NUD_FAIL_HARD) {
 678                 goto out;
 679         }
 680
 681         if (strict & RT6_LOOKUP_F_REACHABLE)
 682                 rt6_probe(rt);
 683
 684         /* note that m can be RT6_NUD_FAIL_PROBE at this point */
 685         if (m > *mpri) {
 686                 *do_rr = match_do_rr;
 687                 *mpri = m;
 688                 match = rt;
 689         }
 690 out:
 691         return match;
 692 }
 693
 694 static struct fib6_info *find_rr_leaf(struct fib6_node *fn,
 695                                      struct fib6_info *leaf,
 696                                      struct fib6_info *rr_head,
 697                                      u32 metric, int oif, int strict,
 698                                      bool *do_rr)
 699 {
 700         struct fib6_info *rt, *match, *cont;
 701         int mpri = -1;
 702
 703         match = NULL;
 704         cont = NULL;
 705         for (rt = rr_head; rt; rt = rcu_dereference(rt->fib6_next)) {
 706                 if (rt->fib6_metric != metric) {
 707                         cont = rt;
 708                         break;
 709                 }
 710
 711                 match = find_match(rt, oif, strict, &mpri, match, do_rr);
 712         }
 713
 714         for (rt = leaf; rt && rt != rr_head;
 715              rt = rcu_dereference(rt->fib6_next)) {
 716                 if (rt->fib6_metric != metric) {
 717                         cont = rt;
 718                         break;
 719                 }
 720
 721                 match = find_match(rt, oif, strict, &mpri, match, do_rr);
 722         }
 723
 724         if (match || !cont)
 725                 return match;
 726
 727         for (rt = cont; rt; rt = rcu_dereference(rt->fib6_next))
 728                 match = find_match(rt, oif, strict, &mpri, match, do_rr);
 729
 730         return match;
 731 }
 732
 733 static struct fib6_info *rt6_select(struct net *net, struct fib6_node *fn,
 734                                    int oif, int strict)
 735 {
 736         struct fib6_info *leaf = rcu_dereference(fn->leaf);
 737         struct fib6_info *match, *rt0;
 738         bool do_rr = false;
 739         int key_plen;
 740
 741         if (!leaf || leaf == net->ipv6.fib6_null_entry)
 742                 return net->ipv6.fib6_null_entry;
 743
 744         rt0 = rcu_dereference(fn->rr_ptr);
 745         if (!rt0)
 746                 rt0 = leaf;
 747
 748         /* Double check to make sure fn is not an intermediate node
 749          * and fn->leaf does not points to its child's leaf
 750          * (This might happen if all routes under fn are deleted from
 751          * the tree and fib6_repair_tree() is called on the node.)
 752          */
 753         key_plen = rt0->fib6_dst.plen;
 754 #ifdef CONFIG_IPV6_SUBTREES
 755         if (rt0->fib6_src.plen)
 756                 key_plen = rt0->fib6_src.plen;
 757 #endif
 758         if (fn->fn_bit != key_plen)
 759                 return net->ipv6.fib6_null_entry;
 760
 761         match = find_rr_leaf(fn, leaf, rt0, rt0->fib6_metric, oif, strict,
 762                              &do_rr);
 763
 764         if (do_rr) {
 765                 struct fib6_info *next = rcu_dereference(rt0->fib6_next);
 766
 767                 /* no entries matched; do round-robin */
 768                 if (!next || next->fib6_metric != rt0->fib6_metric)
 769                         next = leaf;
 770
 771                 if (next != rt0) {
 772                         spin_lock_bh(&leaf->fib6_table->tb6_lock);
 773                         /* make sure next is not being deleted from the tree */
 774                         if (next->fib6_node)
 775                                 rcu_assign_pointer(fn->rr_ptr, next);
 776                         spin_unlock_bh(&leaf->fib6_table->tb6_lock);
 777                 }
 778         }
 779
 780         return match ? match : net->ipv6.fib6_null_entry;
 781 }
 782
 783 static bool rt6_is_gw_or_nonexthop(const struct fib6_info *rt)
 784 {
 785         return (rt->fib6_flags & (RTF_NONEXTHOP | RTF_GATEWAY));
 786 }
 787
 788 #ifdef CONFIG_IPV6_ROUTE_INFO
 789 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
 790                   const struct in6_addr *gwaddr)
 791 {
 792         struct net *net = dev_net(dev);
 793         struct route_info *rinfo = (struct route_info *) opt;
 794         struct in6_addr prefix_buf, *prefix;
 795         unsigned int pref;
 796         unsigned long lifetime;
 797         struct fib6_info *rt;
 798
 799         if (len < sizeof(struct route_info)) {
 800                 return -EINVAL;
 801         }
 802
 803         /* Sanity check for prefix_len and length */
 804         if (rinfo->length > 3) {
 805                 return -EINVAL;
 806         } else if (rinfo->prefix_len > 128) {
 807                 return -EINVAL;
 808         } else if (rinfo->prefix_len > 64) {
 809                 if (rinfo->length < 2) {
 810                         return -EINVAL;
 811                 }
 812         } else if (rinfo->prefix_len > 0) {
 813                 if (rinfo->length < 1) {
 814                         return -EINVAL;
 815                 }
 816         }
 817
 818         pref = rinfo->route_pref;
 819         if (pref == ICMPV6_ROUTER_PREF_INVALID)
 820                 return -EINVAL;
 821
 822         lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
 823
 824         if (rinfo->length == 3)
 825                 prefix = (struct in6_addr *)rinfo->prefix;
 826         else {
 827                 /* this function is safe */
 828                 ipv6_addr_prefix(&prefix_buf,
 829                                  (struct in6_addr *)rinfo->prefix,
 830                                  rinfo->prefix_len);
 831                 prefix = &prefix_buf;
 832         }
 833
 834         if (rinfo->prefix_len == 0)
 835                 rt = rt6_get_dflt_router(net, gwaddr, dev);
 836         else
 837                 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
 838                                         gwaddr, dev);
 839
 840         if (rt && !lifetime) {
 841                 ip6_del_rt(net, rt);
 842                 rt = NULL;
 843         }
 844
 845         if (!rt && lifetime)
 846                 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
 847                                         dev, pref);
 848         else if (rt)
 849                 rt->fib6_flags = RTF_ROUTEINFO |
 850                                  (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 851
 852         if (rt) {
 853                 if (!addrconf_finite_timeout(lifetime))
 854                         fib6_clean_expires(rt);
 855                 else
 856                         fib6_set_expires(rt, jiffies + HZ * lifetime);
 857
 858                 fib6_info_release(rt);
 859         }
 860         return 0;
 861 }
 862 #endif
 863
 864 /*
 865  *      Misc support functions
 866  */
 867
 868 /* called with rcu_lock held */
 869 static struct net_device *ip6_rt_get_dev_rcu(struct fib6_info *rt)
 870 {
 871         struct net_device *dev = rt->fib6_nh.nh_dev;
 872
 873         if (rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
 874                 /* for copies of local routes, dst->dev needs to be the
 875                  * device if it is a master device, the master device if
 876                  * device is enslaved, and the loopback as the default
 877                  */
 878                 if (netif_is_l3_slave(dev) &&
 879                     !rt6_need_strict(&rt->fib6_dst.addr))
 880                         dev = l3mdev_master_dev_rcu(dev);
 881                 else if (!netif_is_l3_master(dev))
 882                         dev = dev_net(dev)->loopback_dev;
 883                 /* last case is netif_is_l3_master(dev) is true in which
 884                  * case we want dev returned to be dev
 885                  */
 886         }
 887
 888         return dev;
 889 }
 890
 891 static const int fib6_prop[RTN_MAX + 1] = {
 892         [RTN_UNSPEC]    = 0,
 893         [RTN_UNICAST]   = 0,
 894         [RTN_LOCAL]     = 0,
 895         [RTN_BROADCAST] = 0,
 896         [RTN_ANYCAST]   = 0,
 897         [RTN_MULTICAST] = 0,
 898         [RTN_BLACKHOLE] = -EINVAL,
 899         [RTN_UNREACHABLE] = -EHOSTUNREACH,
 900         [RTN_PROHIBIT]  = -EACCES,
 901         [RTN_THROW]     = -EAGAIN,
 902         [RTN_NAT]       = -EINVAL,
 903         [RTN_XRESOLVE]  = -EINVAL,
 904 };
 905
 906 static int ip6_rt_type_to_error(u8 fib6_type)
 907 {
 908         return fib6_prop[fib6_type];
 909 }
 910
 911 static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
 912 {
 913         unsigned short flags = 0;
 914
 915         if (rt->dst_nocount)
 916                 flags |= DST_NOCOUNT;
 917         if (rt->dst_nopolicy)
 918                 flags |= DST_NOPOLICY;
 919         if (rt->dst_host)
 920                 flags |= DST_HOST;
 921
 922         return flags;
 923 }
 924
 925 static void ip6_rt_init_dst_reject(struct rt6_info *rt, struct fib6_info *ort)
 926 {
 927         rt->dst.error = ip6_rt_type_to_error(ort->fib6_type);
 928
 929         switch (ort->fib6_type) {
 930         case RTN_BLACKHOLE:
 931                 rt->dst.output = dst_discard_out;
 932                 rt->dst.input = dst_discard;
 933                 break;
 934         case RTN_PROHIBIT:
 935                 rt->dst.output = ip6_pkt_prohibit_out;
 936                 rt->dst.input = ip6_pkt_prohibit;
 937                 break;
 938         case RTN_THROW:
 939         case RTN_UNREACHABLE:
 940         default:
 941                 rt->dst.output = ip6_pkt_discard_out;
 942                 rt->dst.input = ip6_pkt_discard;
 943                 break;
 944         }
 945 }
 946
 947 static void ip6_rt_init_dst(struct rt6_info *rt, struct fib6_info *ort)
 948 {
 949         if (ort->fib6_flags & RTF_REJECT) {
 950                 ip6_rt_init_dst_reject(rt, ort);
 951                 return;
 952         }
 953
 954         rt->dst.error = 0;
 955         rt->dst.output = ip6_output;
 956
 957         if (ort->fib6_type == RTN_LOCAL || ort->fib6_type == RTN_ANYCAST) {
 958                 rt->dst.input = ip6_input;
 959         } else if (ipv6_addr_type(&ort->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
 960                 rt->dst.input = ip6_mc_input;
 961         } else {
 962                 rt->dst.input = ip6_forward;
 963         }
 964
 965         if (ort->fib6_nh.nh_lwtstate) {
 966                 rt->dst.lwtstate = lwtstate_get(ort->fib6_nh.nh_lwtstate);
 967                 lwtunnel_set_redirect(&rt->dst);
 968         }
 969
 970         rt->dst.lastuse = jiffies;
 971 }
 972
 973 /* Caller must already hold reference to @from */
 974 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
 975 {
 976         rt->rt6i_flags &= ~RTF_EXPIRES;
 977         rcu_assign_pointer(rt->from, from);
 978         ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
 979 }
 980
 981 /* Caller must already hold reference to @ort */
 982 static void ip6_rt_copy_init(struct rt6_info *rt, struct fib6_info *ort)
 983 {
 984         struct net_device *dev = fib6_info_nh_dev(ort);
 985
 986         ip6_rt_init_dst(rt, ort);
 987
 988         rt->rt6i_dst = ort->fib6_dst;
 989         rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
 990         rt->rt6i_gateway = ort->fib6_nh.nh_gw;
 991         rt->rt6i_flags = ort->fib6_flags;
 992         rt6_set_from(rt, ort);
 993 #ifdef CONFIG_IPV6_SUBTREES
 994         rt->rt6i_src = ort->fib6_src;
 995 #endif
 996 }
 997
 998 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
 999                                         struct in6_addr *saddr)
1000 {
1001         struct fib6_node *pn, *sn;
1002         while (1) {
1003                 if (fn->fn_flags & RTN_TL_ROOT)
1004                         return NULL;
1005                 pn = rcu_dereference(fn->parent);
1006                 sn = FIB6_SUBTREE(pn);
1007                 if (sn && sn != fn)
1008                         fn = fib6_node_lookup(sn, NULL, saddr);
1009                 else
1010                         fn = pn;
1011                 if (fn->fn_flags & RTN_RTINFO)
1012                         return fn;
1013         }
1014 }
1015
1016 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt,
1017                           bool null_fallback)
1018 {
1019         struct rt6_info *rt = *prt;
1020
1021         if (dst_hold_safe(&rt->dst))
1022                 return true;
1023         if (null_fallback) {
1024                 rt = net->ipv6.ip6_null_entry;
1025                 dst_hold(&rt->dst);
1026         } else {
1027                 rt = NULL;
1028         }
1029         *prt = rt;
1030         return false;
1031 }
1032
1033 /* called with rcu_lock held */
1034 static struct rt6_info *ip6_create_rt_rcu(struct fib6_info *rt)
1035 {
1036         unsigned short flags = fib6_info_dst_flags(rt);
1037         struct net_device *dev = rt->fib6_nh.nh_dev;
1038         struct rt6_info *nrt;
1039
1040         if (!fib6_info_hold_safe(rt))
1041                 return NULL;
1042
1043         nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
1044         if (nrt)
1045                 ip6_rt_copy_init(nrt, rt);
1046         else
1047                 fib6_info_release(rt);
1048
1049         return nrt;
1050 }
1051
1052 static struct rt6_info *ip6_pol_route_lookup(struct net *net,
1053                                              struct fib6_table *table,
1054                                              struct flowi6 *fl6,
1055                                              const struct sk_buff *skb,
1056                                              int flags)
1057 {
1058         struct fib6_info *f6i;
1059         struct fib6_node *fn;
1060         struct rt6_info *rt;
1061
1062         if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
1063                 flags &= ~RT6_LOOKUP_F_IFACE;
1064
1065         rcu_read_lock();
1066         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1067 restart:
1068         f6i = rcu_dereference(fn->leaf);
1069         if (!f6i) {
1070                 f6i = net->ipv6.fib6_null_entry;
1071         } else {
1072                 f6i = rt6_device_match(net, f6i, &fl6->saddr,
1073                                       fl6->flowi6_oif, flags);
1074                 if (f6i->fib6_nsiblings && fl6->flowi6_oif == 0)
1075                         f6i = fib6_multipath_select(net, f6i, fl6,
1076                                                     fl6->flowi6_oif, skb,
1077                                                     flags);
1078         }
1079         if (f6i == net->ipv6.fib6_null_entry) {
1080                 fn = fib6_backtrack(fn, &fl6->saddr);
1081                 if (fn)
1082                         goto restart;
1083         }
1084
1085         trace_fib6_table_lookup(net, f6i, table, fl6);
1086
1087         /* Search through exception table */
1088         rt = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr);
1089         if (rt) {
1090                 if (ip6_hold_safe(net, &rt, true))
1091                         dst_use_noref(&rt->dst, jiffies);
1092         } else if (f6i == net->ipv6.fib6_null_entry) {
1093                 rt = net->ipv6.ip6_null_entry;
1094                 dst_hold(&rt->dst);
1095         } else {
1096                 rt = ip6_create_rt_rcu(f6i);
1097                 if (!rt) {
1098                         rt = net->ipv6.ip6_null_entry;
1099                         dst_hold(&rt->dst);
1100                 }
1101         }
1102
1103         rcu_read_unlock();
1104
1105         return rt;
1106 }
1107
1108 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
1109                                    const struct sk_buff *skb, int flags)
1110 {
1111         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
1112 }
1113 EXPORT_SYMBOL_GPL(ip6_route_lookup);
1114
1115 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
1116                             const struct in6_addr *saddr, int oif,
1117                             const struct sk_buff *skb, int strict)
1118 {
1119         struct flowi6 fl6 = {
1120                 .flowi6_oif = oif,
1121                 .daddr = *daddr,
1122         };
1123         struct dst_entry *dst;
1124         int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
1125
1126         if (saddr) {
1127                 memcpy(&fl6.saddr, saddr, sizeof(*saddr));
1128                 flags |= RT6_LOOKUP_F_HAS_SADDR;
1129         }
1130
1131         dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
1132         if (dst->error == 0)
1133                 return (struct rt6_info *) dst;
1134
1135         dst_release(dst);
1136
1137         return NULL;
1138 }
1139 EXPORT_SYMBOL(rt6_lookup);
1140
1141 /* ip6_ins_rt is called with FREE table->tb6_lock.
1142  * It takes new route entry, the addition fails by any reason the
1143  * route is released.
1144  * Caller must hold dst before calling it.
1145  */
1146
1147 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
1148                         struct netlink_ext_ack *extack)
1149 {
1150         int err;
1151         struct fib6_table *table;
1152
1153         table = rt->fib6_table;
1154         spin_lock_bh(&table->tb6_lock);
1155         err = fib6_add(&table->tb6_root, rt, info, extack);
1156         spin_unlock_bh(&table->tb6_lock);
1157
1158         return err;
1159 }
1160
1161 int ip6_ins_rt(struct net *net, struct fib6_info *rt)
1162 {
1163         struct nl_info info = { .nl_net = net, };
1164
1165         return __ip6_ins_rt(rt, &info, NULL);
1166 }
1167
1168 static struct rt6_info *ip6_rt_cache_alloc(struct fib6_info *ort,
1169                                            const struct in6_addr *daddr,
1170                                            const struct in6_addr *saddr)
1171 {
1172         struct net_device *dev;
1173         struct rt6_info *rt;
1174
1175         /*
1176          *      Clone the route.
1177          */
1178
1179         if (!fib6_info_hold_safe(ort))
1180                 return NULL;
1181
1182         dev = ip6_rt_get_dev_rcu(ort);
1183         rt = ip6_dst_alloc(dev_net(dev), dev, 0);
1184         if (!rt) {
1185                 fib6_info_release(ort);
1186                 return NULL;
1187         }
1188
1189         ip6_rt_copy_init(rt, ort);
1190         rt->rt6i_flags |= RTF_CACHE;
1191         rt->dst.flags |= DST_HOST;
1192         rt->rt6i_dst.addr = *daddr;
1193         rt->rt6i_dst.plen = 128;
1194
1195         if (!rt6_is_gw_or_nonexthop(ort)) {
1196                 if (ort->fib6_dst.plen != 128 &&
1197                     ipv6_addr_equal(&ort->fib6_dst.addr, daddr))
1198                         rt->rt6i_flags |= RTF_ANYCAST;
1199 #ifdef CONFIG_IPV6_SUBTREES
1200                 if (rt->rt6i_src.plen && saddr) {
1201                         rt->rt6i_src.addr = *saddr;
1202                         rt->rt6i_src.plen = 128;
1203                 }
1204 #endif
1205         }
1206
1207         return rt;
1208 }
1209
1210 static struct rt6_info *ip6_rt_pcpu_alloc(struct fib6_info *rt)
1211 {
1212         unsigned short flags = fib6_info_dst_flags(rt);
1213         struct net_device *dev;
1214         struct rt6_info *pcpu_rt;
1215
1216         if (!fib6_info_hold_safe(rt))
1217                 return NULL;
1218
1219         rcu_read_lock();
1220         dev = ip6_rt_get_dev_rcu(rt);
1221         pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags);
1222         rcu_read_unlock();
1223         if (!pcpu_rt) {
1224                 fib6_info_release(rt);
1225                 return NULL;
1226         }
1227         ip6_rt_copy_init(pcpu_rt, rt);
1228         pcpu_rt->rt6i_flags |= RTF_PCPU;
1229         return pcpu_rt;
1230 }
1231
1232 /* It should be called with rcu_read_lock() acquired */
1233 static struct rt6_info *rt6_get_pcpu_route(struct fib6_info *rt)
1234 {
1235         struct rt6_info *pcpu_rt, **p;
1236
1237         p = this_cpu_ptr(rt->rt6i_pcpu);
1238         pcpu_rt = *p;
1239
1240         if (pcpu_rt)
1241                 ip6_hold_safe(NULL, &pcpu_rt, false);
1242
1243         return pcpu_rt;
1244 }
1245
1246 static struct rt6_info *rt6_make_pcpu_route(struct net *net,
1247                                             struct fib6_info *rt)
1248 {
1249         struct rt6_info *pcpu_rt, *prev, **p;
1250
1251         pcpu_rt = ip6_rt_pcpu_alloc(rt);
1252         if (!pcpu_rt) {
1253                 dst_hold(&net->ipv6.ip6_null_entry->dst);
1254                 return net->ipv6.ip6_null_entry;
1255         }
1256
1257         dst_hold(&pcpu_rt->dst);
1258         p = this_cpu_ptr(rt->rt6i_pcpu);
1259         prev = cmpxchg(p, NULL, pcpu_rt);
1260         BUG_ON(prev);
1261
1262         return pcpu_rt;
1263 }
1264
1265 /* exception hash table implementation
1266  */
1267 static DEFINE_SPINLOCK(rt6_exception_lock);
1268
1269 /* Remove rt6_ex from hash table and free the memory
1270  * Caller must hold rt6_exception_lock
1271  */
1272 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
1273                                  struct rt6_exception *rt6_ex)
1274 {
1275         struct net *net;
1276
1277         if (!bucket || !rt6_ex)
1278                 return;
1279
1280         net = dev_net(rt6_ex->rt6i->dst.dev);
1281         hlist_del_rcu(&rt6_ex->hlist);
1282         dst_release(&rt6_ex->rt6i->dst);
1283         kfree_rcu(rt6_ex, rcu);
1284         WARN_ON_ONCE(!bucket->depth);
1285         bucket->depth--;
1286         net->ipv6.rt6_stats->fib_rt_cache--;
1287 }
1288
1289 /* Remove oldest rt6_ex in bucket and free the memory
1290  * Caller must hold rt6_exception_lock
1291  */
1292 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
1293 {
1294         struct rt6_exception *rt6_ex, *oldest = NULL;
1295
1296         if (!bucket)
1297                 return;
1298
1299         hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
1300                 if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
1301                         oldest = rt6_ex;
1302         }
1303         rt6_remove_exception(bucket, oldest);
1304 }
1305
1306 static u32 rt6_exception_hash(const struct in6_addr *dst,
1307                               const struct in6_addr *src)
1308 {
1309         static u32 seed __read_mostly;
1310         u32 val;
1311
1312         net_get_random_once(&seed, sizeof(seed));
1313         val = jhash(dst, sizeof(*dst), seed);
1314
1315 #ifdef CONFIG_IPV6_SUBTREES
1316         if (src)
1317                 val = jhash(src, sizeof(*src), val);
1318 #endif
1319         return hash_32(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
1320 }
1321
1322 /* Helper function to find the cached rt in the hash table
1323  * and update bucket pointer to point to the bucket for this
1324  * (daddr, saddr) pair
1325  * Caller must hold rt6_exception_lock
1326  */
1327 static struct rt6_exception *
1328 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
1329                               const struct in6_addr *daddr,
1330                               const struct in6_addr *saddr)
1331 {
1332         struct rt6_exception *rt6_ex;
1333         u32 hval;
1334
1335         if (!(*bucket) || !daddr)
1336                 return NULL;
1337
1338         hval = rt6_exception_hash(daddr, saddr);
1339         *bucket += hval;
1340
1341         hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
1342                 struct rt6_info *rt6 = rt6_ex->rt6i;
1343                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1344
1345 #ifdef CONFIG_IPV6_SUBTREES
1346                 if (matched && saddr)
1347                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1348 #endif
1349                 if (matched)
1350                         return rt6_ex;
1351         }
1352         return NULL;
1353 }
1354
1355 /* Helper function to find the cached rt in the hash table
1356  * and update bucket pointer to point to the bucket for this
1357  * (daddr, saddr) pair
1358  * Caller must hold rcu_read_lock()
1359  */
1360 static struct rt6_exception *
1361 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
1362                          const struct in6_addr *daddr,
1363                          const struct in6_addr *saddr)
1364 {
1365         struct rt6_exception *rt6_ex;
1366         u32 hval;
1367
1368         WARN_ON_ONCE(!rcu_read_lock_held());
1369
1370         if (!(*bucket) || !daddr)
1371                 return NULL;
1372
1373         hval = rt6_exception_hash(daddr, saddr);
1374         *bucket += hval;
1375
1376         hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
1377                 struct rt6_info *rt6 = rt6_ex->rt6i;
1378                 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1379
1380 #ifdef CONFIG_IPV6_SUBTREES
1381                 if (matched && saddr)
1382                         matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1383 #endif
1384                 if (matched)
1385                         return rt6_ex;
1386         }
1387         return NULL;
1388 }
1389
1390 static unsigned int fib6_mtu(const struct fib6_info *rt)
1391 {
1392         unsigned int mtu;
1393
1394         if (rt->fib6_pmtu) {
1395                 mtu = rt->fib6_pmtu;
1396         } else {
1397                 struct net_device *dev = fib6_info_nh_dev(rt);
1398                 struct inet6_dev *idev;
1399
1400                 rcu_read_lock();
1401                 idev = __in6_dev_get(dev);
1402                 mtu = idev->cnf.mtu6;
1403                 rcu_read_unlock();
1404         }
1405
1406         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
1407
1408         return mtu - lwtunnel_headroom(rt->fib6_nh.nh_lwtstate, mtu);
1409 }
1410
1411 static int rt6_insert_exception(struct rt6_info *nrt,
1412                                 struct fib6_info *ort)
1413 {
1414         struct net *net = dev_net(nrt->dst.dev);
1415         struct rt6_exception_bucket *bucket;
1416         struct in6_addr *src_key = NULL;
1417         struct rt6_exception *rt6_ex;
1418         int err = 0;
1419
1420         spin_lock_bh(&rt6_exception_lock);
1421
1422         if (ort->exception_bucket_flushed) {
1423                 err = -EINVAL;
1424                 goto out;
1425         }
1426
1427         bucket = rcu_dereference_protected(ort->rt6i_exception_bucket,
1428                                         lockdep_is_held(&rt6_exception_lock));
1429         if (!bucket) {
1430                 bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
1431                                  GFP_ATOMIC);
1432                 if (!bucket) {
1433                         err = -ENOMEM;
1434                         goto out;
1435                 }
1436                 rcu_assign_pointer(ort->rt6i_exception_bucket, bucket);
1437         }
1438
1439 #ifdef CONFIG_IPV6_SUBTREES
1440         /* rt6i_src.plen != 0 indicates ort is in subtree
1441          * and exception table is indexed by a hash of
1442          * both rt6i_dst and rt6i_src.
1443          * Otherwise, the exception table is indexed by
1444          * a hash of only rt6i_dst.
1445          */
1446         if (ort->fib6_src.plen)
1447                 src_key = &nrt->rt6i_src.addr;
1448 #endif
1449         /* rt6_mtu_change() might lower mtu on ort.
1450          * Only insert this exception route if its mtu
1451          * is less than ort's mtu value.
1452          */
1453         if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(ort)) {
1454                 err = -EINVAL;
1455                 goto out;
1456         }
1457
1458         rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
1459                                                src_key);
1460         if (rt6_ex)
1461                 rt6_remove_exception(bucket, rt6_ex);
1462
1463         rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
1464         if (!rt6_ex) {
1465                 err = -ENOMEM;
1466                 goto out;
1467         }
1468         rt6_ex->rt6i = nrt;
1469         rt6_ex->stamp = jiffies;
1470         hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
1471         bucket->depth++;
1472         net->ipv6.rt6_stats->fib_rt_cache++;
1473
1474         if (bucket->depth > FIB6_MAX_DEPTH)
1475                 rt6_exception_remove_oldest(bucket);
1476
1477 out:
1478         spin_unlock_bh(&rt6_exception_lock);
1479
1480         /* Update fn->fn_sernum to invalidate all cached dst */
1481         if (!err) {
1482                 spin_lock_bh(&ort->fib6_table->tb6_lock);
1483                 fib6_update_sernum(net, ort);
1484                 spin_unlock_bh(&ort->fib6_table->tb6_lock);
1485                 fib6_force_start_gc(net);
1486         }
1487
1488         return err;
1489 }
1490
1491 void rt6_flush_exceptions(struct fib6_info *rt)
1492 {
1493         struct rt6_exception_bucket *bucket;
1494         struct rt6_exception *rt6_ex;
1495         struct hlist_node *tmp;
1496         int i;
1497
1498         spin_lock_bh(&rt6_exception_lock);
1499         /* Prevent rt6_insert_exception() to recreate the bucket list */
1500         rt->exception_bucket_flushed = 1;
1501
1502         bucket = rcu_dereference_protected(rt->rt6i_exception_bucket,
1503                                     lockdep_is_held(&rt6_exception_lock));
1504         if (!bucket)
1505                 goto out;
1506
1507         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1508                 hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist)
1509                         rt6_remove_exception(bucket, rt6_ex);
1510                 WARN_ON_ONCE(bucket->depth);
1511                 bucket++;
1512         }
1513
1514 out:
1515         spin_unlock_bh(&rt6_exception_lock);
1516 }
1517
1518 /* Find cached rt in the hash table inside passed in rt
1519  * Caller has to hold rcu_read_lock()
1520  */
1521 static struct rt6_info *rt6_find_cached_rt(struct fib6_info *rt,
1522                                            struct in6_addr *daddr,
1523                                            struct in6_addr *saddr)
1524 {
1525         struct rt6_exception_bucket *bucket;
1526         struct in6_addr *src_key = NULL;
1527         struct rt6_exception *rt6_ex;
1528         struct rt6_info *res = NULL;
1529
1530         bucket = rcu_dereference(rt->rt6i_exception_bucket);
1531
1532 #ifdef CONFIG_IPV6_SUBTREES
1533         /* rt6i_src.plen != 0 indicates rt is in subtree
1534          * and exception table is indexed by a hash of
1535          * both rt6i_dst and rt6i_src.
1536          * Otherwise, the exception table is indexed by
1537          * a hash of only rt6i_dst.
1538          */
1539         if (rt->fib6_src.plen)
1540                 src_key = saddr;
1541 #endif
1542         rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
1543
1544         if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
1545                 res = rt6_ex->rt6i;
1546
1547         return res;
1548 }
1549
1550 /* Remove the passed in cached rt from the hash table that contains it */
1551 static int rt6_remove_exception_rt(struct rt6_info *rt)
1552 {
1553         struct rt6_exception_bucket *bucket;
1554         struct in6_addr *src_key = NULL;
1555         struct rt6_exception *rt6_ex;
1556         struct fib6_info *from;
1557         int err;
1558
1559         from = rcu_dereference(rt->from);
1560         if (!from ||
1561             !(rt->rt6i_flags & RTF_CACHE))
1562                 return -EINVAL;
1563
1564         if (!rcu_access_pointer(from->rt6i_exception_bucket))
1565                 return -ENOENT;
1566
1567         spin_lock_bh(&rt6_exception_lock);
1568         bucket = rcu_dereference_protected(from->rt6i_exception_bucket,
1569                                     lockdep_is_held(&rt6_exception_lock));
1570 #ifdef CONFIG_IPV6_SUBTREES
1571         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1572          * and exception table is indexed by a hash of
1573          * both rt6i_dst and rt6i_src.
1574          * Otherwise, the exception table is indexed by
1575          * a hash of only rt6i_dst.
1576          */
1577         if (from->fib6_src.plen)
1578                 src_key = &rt->rt6i_src.addr;
1579 #endif
1580         rt6_ex = __rt6_find_exception_spinlock(&bucket,
1581                                                &rt->rt6i_dst.addr,
1582                                                src_key);
1583         if (rt6_ex) {
1584                 rt6_remove_exception(bucket, rt6_ex);
1585                 err = 0;
1586         } else {
1587                 err = -ENOENT;
1588         }
1589
1590         spin_unlock_bh(&rt6_exception_lock);
1591         return err;
1592 }
1593
1594 /* Find rt6_ex which contains the passed in rt cache and
1595  * refresh its stamp
1596  */
1597 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
1598 {
1599         struct rt6_exception_bucket *bucket;
1600         struct fib6_info *from = rt->from;
1601         struct in6_addr *src_key = NULL;
1602         struct rt6_exception *rt6_ex;
1603
1604         if (!from ||
1605             !(rt->rt6i_flags & RTF_CACHE))
1606                 return;
1607
1608         rcu_read_lock();
1609         bucket = rcu_dereference(from->rt6i_exception_bucket);
1610
1611 #ifdef CONFIG_IPV6_SUBTREES
1612         /* rt6i_src.plen != 0 indicates 'from' is in subtree
1613          * and exception table is indexed by a hash of
1614          * both rt6i_dst and rt6i_src.
1615          * Otherwise, the exception table is indexed by
1616          * a hash of only rt6i_dst.
1617          */
1618         if (from->fib6_src.plen)
1619                 src_key = &rt->rt6i_src.addr;
1620 #endif
1621         rt6_ex = __rt6_find_exception_rcu(&bucket,
1622                                           &rt->rt6i_dst.addr,
1623                                           src_key);
1624         if (rt6_ex)
1625                 rt6_ex->stamp = jiffies;
1626
1627         rcu_read_unlock();
1628 }
1629
1630 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
1631                                          struct rt6_info *rt, int mtu)
1632 {
1633         /* If the new MTU is lower than the route PMTU, this new MTU will be the
1634          * lowest MTU in the path: always allow updating the route PMTU to
1635          * reflect PMTU decreases.
1636          *
1637          * If the new MTU is higher, and the route PMTU is equal to the local
1638          * MTU, this means the old MTU is the lowest in the path, so allow
1639          * updating it: if other nodes now have lower MTUs, PMTU discovery will
1640          * handle this.
1641          */
1642
1643         if (dst_mtu(&rt->dst) >= mtu)
1644                 return true;
1645
1646         if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
1647                 return true;
1648
1649         return false;
1650 }
1651
1652 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
1653                                        struct fib6_info *rt, int mtu)
1654 {
1655         struct rt6_exception_bucket *bucket;
1656         struct rt6_exception *rt6_ex;
1657         int i;
1658
1659         bucket = rcu_dereference_protected(rt->rt6i_exception_bucket,
1660                                         lockdep_is_held(&rt6_exception_lock));
1661
1662         if (!bucket)
1663                 return;
1664
1665         for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1666                 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
1667                         struct rt6_info *entry = rt6_ex->rt6i;
1668
1669                         /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
1670                          * route), the metrics of its rt->from have already
1671                          * been updated.
1672                          */
1673                         if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
1674                             rt6_mtu_change_route_allowed(idev, entry, mtu))
1675                                 dst_metric_set(&entry->dst, RTAX_MTU, mtu);
1676                 }
1677                 bucket++;
1678         }
1679 }
1680
1681 #define RTF_CACHE_GATEWAY       (RTF_GATEWAY | RTF_CACHE)
1682
1683 static void rt6_exceptions_clean_tohost(struct fib6_info *rt,
1684                                         struct in6_addr *gateway)
1685 {
1686         struct rt6_exception_bucket *bucket;
1687         struct rt6_exception *rt6_ex;
1688         struct hlist_node *tmp;
1689         int i;
1690
1691         if (!rcu_access_pointer(rt->rt6i_exception_bucket))
1692                 return;
1693
1694         spin_lock_bh(&rt6_exception_lock);
1695         bucket = rcu_dereference_protected(rt->rt6i_exception_bucket,
1696                                      lockdep_is_held(&rt6_exception_lock));
1697
1698         if (bucket) {
1699                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1700                         hlist_for_each_entry_safe(rt6_ex, tmp,
1701                                                   &bucket->chain, hlist) {
1702                                 struct rt6_info *entry = rt6_ex->rt6i;
1703
1704                                 if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
1705                                     RTF_CACHE_GATEWAY &&
1706                                     ipv6_addr_equal(gateway,
1707                                                     &entry->rt6i_gateway)) {
1708                                         rt6_remove_exception(bucket, rt6_ex);
1709                                 }
1710                         }
1711                         bucket++;
1712                 }
1713         }
1714
1715         spin_unlock_bh(&rt6_exception_lock);
1716 }
1717
1718 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
1719                                       struct rt6_exception *rt6_ex,
1720                                       struct fib6_gc_args *gc_args,
1721                                       unsigned long now)
1722 {
1723         struct rt6_info *rt = rt6_ex->rt6i;
1724
1725         /* we are pruning and obsoleting aged-out and non gateway exceptions
1726          * even if others have still references to them, so that on next
1727          * dst_check() such references can be dropped.
1728          * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
1729          * expired, independently from their aging, as per RFC 8201 section 4
1730          */
1731         if (!(rt->rt6i_flags & RTF_EXPIRES)) {
1732                 if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
1733                         RT6_TRACE("aging clone %p\n", rt);
1734                         rt6_remove_exception(bucket, rt6_ex);
1735                         return;
1736                 }
1737         } else if (time_after(jiffies, rt->dst.expires)) {
1738                 RT6_TRACE("purging expired route %p\n", rt);
1739                 rt6_remove_exception(bucket, rt6_ex);
1740                 return;
1741         }
1742
1743         if (rt->rt6i_flags & RTF_GATEWAY) {
1744                 struct neighbour *neigh;
1745                 __u8 neigh_flags = 0;
1746
1747                 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
1748                 if (neigh)
1749                         neigh_flags = neigh->flags;
1750
1751                 if (!(neigh_flags & NTF_ROUTER)) {
1752                         RT6_TRACE("purging route %p via non-router but gateway\n",
1753                                   rt);
1754                         rt6_remove_exception(bucket, rt6_ex);
1755                         return;
1756                 }
1757         }
1758
1759         gc_args->more++;
1760 }
1761
1762 void rt6_age_exceptions(struct fib6_info *rt,
1763                         struct fib6_gc_args *gc_args,
1764                         unsigned long now)
1765 {
1766         struct rt6_exception_bucket *bucket;
1767         struct rt6_exception *rt6_ex;
1768         struct hlist_node *tmp;
1769         int i;
1770
1771         if (!rcu_access_pointer(rt->rt6i_exception_bucket))
1772                 return;
1773
1774         rcu_read_lock_bh();
1775         spin_lock(&rt6_exception_lock);
1776         bucket = rcu_dereference_protected(rt->rt6i_exception_bucket,
1777                                     lockdep_is_held(&rt6_exception_lock));
1778
1779         if (bucket) {
1780                 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1781                         hlist_for_each_entry_safe(rt6_ex, tmp,
1782                                                   &bucket->chain, hlist) {
1783                                 rt6_age_examine_exception(bucket, rt6_ex,
1784                                                           gc_args, now);
1785                         }
1786                         bucket++;
1787                 }
1788         }
1789         spin_unlock(&rt6_exception_lock);
1790         rcu_read_unlock_bh();
1791 }
1792
1793 /* must be called with rcu lock held */
1794 struct fib6_info *fib6_table_lookup(struct net *net, struct fib6_table *table,
1795                                     int oif, struct flowi6 *fl6, int strict)
1796 {
1797         struct fib6_node *fn, *saved_fn;
1798         struct fib6_info *f6i;
1799
1800         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1801         saved_fn = fn;
1802
1803         if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
1804                 oif = 0;
1805
1806 redo_rt6_select:
1807         f6i = rt6_select(net, fn, oif, strict);
1808         if (f6i == net->ipv6.fib6_null_entry) {
1809                 fn = fib6_backtrack(fn, &fl6->saddr);
1810                 if (fn)
1811                         goto redo_rt6_select;
1812                 else if (strict & RT6_LOOKUP_F_REACHABLE) {
1813                         /* also consider unreachable route */
1814                         strict &= ~RT6_LOOKUP_F_REACHABLE;
1815                         fn = saved_fn;
1816                         goto redo_rt6_select;
1817                 }
1818         }
1819
1820         trace_fib6_table_lookup(net, f6i, table, fl6);
1821
1822         return f6i;
1823 }
1824
1825 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
1826                                int oif, struct flowi6 *fl6,
1827                                const struct sk_buff *skb, int flags)
1828 {
1829         struct fib6_info *f6i;
1830         struct rt6_info *rt;
1831         int strict = 0;
1832
1833         strict |= flags & RT6_LOOKUP_F_IFACE;
1834         strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
1835         if (net->ipv6.devconf_all->forwarding == 0)
1836                 strict |= RT6_LOOKUP_F_REACHABLE;
1837
1838         rcu_read_lock();
1839
1840         f6i = fib6_table_lookup(net, table, oif, fl6, strict);
1841         if (f6i->fib6_nsiblings)
1842                 f6i = fib6_multipath_select(net, f6i, fl6, oif, skb, strict);
1843
1844         if (f6i == net->ipv6.fib6_null_entry) {
1845                 rt = net->ipv6.ip6_null_entry;
1846                 rcu_read_unlock();
1847                 dst_hold(&rt->dst);
1848                 return rt;
1849         }
1850
1851         /*Search through exception table */
1852         rt = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr);
1853         if (rt) {
1854                 if (ip6_hold_safe(net, &rt, true))
1855                         dst_use_noref(&rt->dst, jiffies);
1856
1857                 rcu_read_unlock();
1858                 return rt;
1859         } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
1860                             !(f6i->fib6_flags & RTF_GATEWAY))) {
1861                 /* Create a RTF_CACHE clone which will not be
1862                  * owned by the fib6 tree.  It is for the special case where
1863                  * the daddr in the skb during the neighbor look-up is different
1864                  * from the fl6->daddr used to look-up route here.
1865                  */
1866                 struct rt6_info *uncached_rt;
1867
1868                 uncached_rt = ip6_rt_cache_alloc(f6i, &fl6->daddr, NULL);
1869
1870                 rcu_read_unlock();
1871
1872                 if (uncached_rt) {
1873                         /* Uncached_rt's refcnt is taken during ip6_rt_cache_alloc()
1874                          * No need for another dst_hold()
1875                          */
1876                         rt6_uncached_list_add(uncached_rt);
1877                         atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
1878                 } else {
1879                         uncached_rt = net->ipv6.ip6_null_entry;
1880                         dst_hold(&uncached_rt->dst);
1881                 }
1882
1883                 return uncached_rt;
1884         } else {
1885                 /* Get a percpu copy */
1886
1887                 struct rt6_info *pcpu_rt;
1888
1889                 local_bh_disable();
1890                 pcpu_rt = rt6_get_pcpu_route(f6i);
1891
1892                 if (!pcpu_rt)
1893                         pcpu_rt = rt6_make_pcpu_route(net, f6i);
1894
1895                 local_bh_enable();
1896                 rcu_read_unlock();
1897
1898                 return pcpu_rt;
1899         }
1900 }
1901 EXPORT_SYMBOL_GPL(ip6_pol_route);
1902
1903 static struct rt6_info *ip6_pol_route_input(struct net *net,
1904                                             struct fib6_table *table,
1905                                             struct flowi6 *fl6,
1906                                             const struct sk_buff *skb,
1907                                             int flags)
1908 {
1909         return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
1910 }
1911
1912 struct dst_entry *ip6_route_input_lookup(struct net *net,
1913                                          struct net_device *dev,
1914                                          struct flowi6 *fl6,
1915                                          const struct sk_buff *skb,
1916                                          int flags)
1917 {
1918         if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
1919                 flags |= RT6_LOOKUP_F_IFACE;
1920
1921         return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
1922 }
1923 EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
1924
1925 static void ip6_multipath_l3_keys(const struct sk_buff *skb,
1926                                   struct flow_keys *keys,
1927                                   struct flow_keys *flkeys)
1928 {
1929         const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
1930         const struct ipv6hdr *key_iph = outer_iph;
1931         struct flow_keys *_flkeys = flkeys;
1932         const struct ipv6hdr *inner_iph;
1933         const struct icmp6hdr *icmph;
1934         struct ipv6hdr _inner_iph;
1935         struct icmp6hdr _icmph;
1936
1937         if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
1938                 goto out;
1939
1940         icmph = skb_header_pointer(skb, skb_transport_offset(skb),
1941                                    sizeof(_icmph), &_icmph);
1942         if (!icmph)
1943                 goto out;
1944
1945         if (icmph->icmp6_type != ICMPV6_DEST_UNREACH &&
1946             icmph->icmp6_type != ICMPV6_PKT_TOOBIG &&
1947             icmph->icmp6_type != ICMPV6_TIME_EXCEED &&
1948             icmph->icmp6_type != ICMPV6_PARAMPROB)
1949                 goto out;
1950
1951         inner_iph = skb_header_pointer(skb,
1952                                        skb_transport_offset(skb) + sizeof(*icmph),
1953                                        sizeof(_inner_iph), &_inner_iph);
1954         if (!inner_iph)
1955                 goto out;
1956
1957         key_iph = inner_iph;
1958         _flkeys = NULL;
1959 out:
1960         if (_flkeys) {
1961                 keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
1962                 keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
1963                 keys->tags.flow_label = _flkeys->tags.flow_label;
1964                 keys->basic.ip_proto = _flkeys->basic.ip_proto;
1965         } else {
1966                 keys->addrs.v6addrs.src = key_iph->saddr;
1967                 keys->addrs.v6addrs.dst = key_iph->daddr;
1968                 keys->tags.flow_label = ip6_flowlabel(key_iph);
1969                 keys->basic.ip_proto = key_iph->nexthdr;
1970         }
1971 }
1972
1973 /* if skb is set it will be used and fl6 can be NULL */
1974 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
1975                        const struct sk_buff *skb, struct flow_keys *flkeys)
1976 {
1977         struct flow_keys hash_keys;
1978         u32 mhash;
1979
1980         switch (ip6_multipath_hash_policy(net)) {
1981         case 0:
1982                 memset(&hash_keys, 0, sizeof(hash_keys));
1983                 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1984                 if (skb) {
1985                         ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
1986                 } else {
1987                         hash_keys.addrs.v6addrs.src = fl6->saddr;
1988                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
1989                         hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1990                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
1991                 }
1992                 break;
1993         case 1:
1994                 if (skb) {
1995                         unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
1996                         struct flow_keys keys;
1997
1998                         /* short-circuit if we already have L4 hash present */
1999                         if (skb->l4_hash)
2000                                 return skb_get_hash_raw(skb) >> 1;
2001
2002                         memset(&hash_keys, 0, sizeof(hash_keys));
2003
2004                         if (!flkeys) {
2005                                 skb_flow_dissect_flow_keys(skb, &keys, flag);
2006                                 flkeys = &keys;
2007                         }
2008                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2009                         hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2010                         hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2011                         hash_keys.ports.src = flkeys->ports.src;
2012                         hash_keys.ports.dst = flkeys->ports.dst;
2013                         hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2014                 } else {
2015                         memset(&hash_keys, 0, sizeof(hash_keys));
2016                         hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2017                         hash_keys.addrs.v6addrs.src = fl6->saddr;
2018                         hash_keys.addrs.v6addrs.dst = fl6->daddr;
2019                         hash_keys.ports.src = fl6->fl6_sport;
2020                         hash_keys.ports.dst = fl6->fl6_dport;
2021                         hash_keys.basic.ip_proto = fl6->flowi6_proto;
2022                 }
2023                 break;
2024         }
2025         mhash = flow_hash_from_keys(&hash_keys);
2026
2027         return mhash >> 1;
2028 }
2029
2030 void ip6_route_input(struct sk_buff *skb)
2031 {
2032         const struct ipv6hdr *iph = ipv6_hdr(skb);
2033         struct net *net = dev_net(skb->dev);
2034         int flags = RT6_LOOKUP_F_HAS_SADDR;
2035         struct ip_tunnel_info *tun_info;
2036         struct flowi6 fl6 = {
2037                 .flowi6_iif = skb->dev->ifindex,
2038                 .daddr = iph->daddr,
2039                 .saddr = iph->saddr,
2040                 .flowlabel = ip6_flowinfo(iph),
2041                 .flowi6_mark = skb->mark,
2042                 .flowi6_proto = iph->nexthdr,
2043         };
2044         struct flow_keys *flkeys = NULL, _flkeys;
2045
2046         tun_info = skb_tunnel_info(skb);
2047         if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2048                 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
2049
2050         if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
2051                 flkeys = &_flkeys;
2052
2053         if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
2054                 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
2055         skb_dst_drop(skb);
2056         skb_dst_set(skb,
2057                     ip6_route_input_lookup(net, skb->dev, &fl6, skb, flags));
2058 }
2059
2060 static struct rt6_info *ip6_pol_route_output(struct net *net,
2061                                              struct fib6_table *table,
2062                                              struct flowi6 *fl6,
2063                                              const struct sk_buff *skb,
2064                                              int flags)
2065 {
2066         return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
2067 }
2068
2069 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
2070                                          struct flowi6 *fl6, int flags)
2071 {
2072         bool any_src;
2073
2074         if (ipv6_addr_type(&fl6->daddr) &
2075             (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
2076                 struct dst_entry *dst;
2077
2078                 dst = l3mdev_link_scope_lookup(net, fl6);
2079                 if (dst)
2080                         return dst;
2081         }
2082
2083         fl6->flowi6_iif = LOOPBACK_IFINDEX;
2084
2085         any_src = ipv6_addr_any(&fl6->saddr);
2086         if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
2087             (fl6->flowi6_oif && any_src))
2088                 flags |= RT6_LOOKUP_F_IFACE;
2089
2090         if (!any_src)
2091                 flags |= RT6_LOOKUP_F_HAS_SADDR;
2092         else if (sk)
2093                 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
2094
2095         return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
2096 }
2097 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
2098
2099 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2100 {
2101         struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
2102         struct net_device *loopback_dev = net->loopback_dev;
2103         struct dst_entry *new = NULL;
2104
2105         rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
2106                        DST_OBSOLETE_DEAD, 0);
2107         if (rt) {
2108                 rt6_info_init(rt);
2109                 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
2110
2111                 new = &rt->dst;
2112                 new->__use = 1;
2113                 new->input = dst_discard;
2114                 new->output = dst_discard_out;
2115
2116                 dst_copy_metrics(new, &ort->dst);
2117
2118                 rt->rt6i_idev = in6_dev_get(loopback_dev);
2119                 rt->rt6i_gateway = ort->rt6i_gateway;
2120                 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
2121
2122                 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
2123 #ifdef CONFIG_IPV6_SUBTREES
2124                 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
2125 #endif
2126         }
2127
2128         dst_release(dst_orig);
2129         return new ? new : ERR_PTR(-ENOMEM);
2130 }
2131
2132 /*
2133  *      Destination cache support functions
2134  */
2135
2136 static bool fib6_check(struct fib6_info *f6i, u32 cookie)
2137 {
2138         u32 rt_cookie = 0;
2139
2140         if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
2141                 return false;
2142
2143         if (fib6_check_expired(f6i))
2144                 return false;
2145
2146         return true;
2147 }
2148
2149 static struct dst_entry *rt6_check(struct rt6_info *rt,
2150                                    struct fib6_info *from,
2151                                    u32 cookie)
2152 {
2153         u32 rt_cookie = 0;
2154
2155         if ((from && !fib6_get_cookie_safe(from, &rt_cookie)) ||
2156             rt_cookie != cookie)
2157                 return NULL;
2158
2159         if (rt6_check_expired(rt))
2160                 return NULL;
2161
2162         return &rt->dst;
2163 }
2164
2165 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
2166                                             struct fib6_info *from,
2167                                             u32 cookie)
2168 {
2169         if (!__rt6_check_expired(rt) &&
2170             rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
2171             fib6_check(from, cookie))
2172                 return &rt->dst;
2173         else
2174                 return NULL;
2175 }
2176
2177 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
2178 {
2179         struct dst_entry *dst_ret;
2180         struct fib6_info *from;
2181         struct rt6_info *rt;
2182
2183         rt = container_of(dst, struct rt6_info, dst);
2184
2185         rcu_read_lock();
2186
2187         /* All IPV6 dsts are created with ->obsolete set to the value
2188          * DST_OBSOLETE_FORCE_CHK which forces validation calls down
2189          * into this function always.
2190          */
2191
2192         from = rcu_dereference(rt->from);
2193
2194         if (from && (rt->rt6i_flags & RTF_PCPU ||
2195             unlikely(!list_empty(&rt->rt6i_uncached))))
2196                 dst_ret = rt6_dst_from_check(rt, from, cookie);
2197         else
2198                 dst_ret = rt6_check(rt, from, cookie);
2199
2200         rcu_read_unlock();
2201
2202         return dst_ret;
2203 }
2204
2205 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
2206 {
2207         struct rt6_info *rt = (struct rt6_info *) dst;
2208
2209         if (rt) {
2210                 if (rt->rt6i_flags & RTF_CACHE) {
2211                         rcu_read_lock();
2212                         if (rt6_check_expired(rt)) {
2213                                 rt6_remove_exception_rt(rt);
2214                                 dst = NULL;
2215                         }
2216                         rcu_read_unlock();
2217                 } else {
2218                         dst_release(dst);
2219                         dst = NULL;
2220                 }
2221         }
2222         return dst;
2223 }
2224
2225 static void ip6_link_failure(struct sk_buff *skb)
2226 {
2227         struct rt6_info *rt;
2228
2229         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
2230
2231         rt = (struct rt6_info *) skb_dst(skb);
2232         if (rt) {
2233                 rcu_read_lock();
2234                 if (rt->rt6i_flags & RTF_CACHE) {
2235                         if (dst_hold_safe(&rt->dst))
2236                                 rt6_remove_exception_rt(rt);
2237                 } else {
2238                         struct fib6_info *from;
2239                         struct fib6_node *fn;
2240
2241                         from = rcu_dereference(rt->from);
2242                         if (from) {
2243                                 fn = rcu_dereference(from->fib6_node);
2244                                 if (fn && (rt->rt6i_flags & RTF_DEFAULT))
2245                                         fn->fn_sernum = -1;
2246                         }
2247                 }
2248                 rcu_read_unlock();
2249         }
2250 }
2251
2252 static void rt6_update_expires(struct rt6_info *rt0, int timeout)
2253 {
2254         if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
2255                 struct fib6_info *from;
2256
2257                 rcu_read_lock();
2258                 from = rcu_dereference(rt0->from);
2259                 if (from)
2260                         rt0->dst.expires = from->expires;
2261                 rcu_read_unlock();
2262         }
2263
2264         dst_set_expires(&rt0->dst, timeout);
2265         rt0->rt6i_flags |= RTF_EXPIRES;
2266 }
2267
2268 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
2269 {
2270         struct net *net = dev_net(rt->dst.dev);
2271
2272         dst_metric_set(&rt->dst, RTAX_MTU, mtu);
2273         rt->rt6i_flags |= RTF_MODIFIED;
2274         rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
2275 }
2276
2277 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
2278 {
2279         bool from_set;
2280
2281         rcu_read_lock();
2282         from_set = !!rcu_dereference(rt->from);
2283         rcu_read_unlock();
2284
2285         return !(rt->rt6i_flags & RTF_CACHE) &&
2286                 (rt->rt6i_flags & RTF_PCPU || from_set);
2287 }
2288
2289 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
2290                                  const struct ipv6hdr *iph, u32 mtu)
2291 {
2292         const struct in6_addr *daddr, *saddr;
2293         struct rt6_info *rt6 = (struct rt6_info *)dst;
2294
2295         if (dst_metric_locked(dst, RTAX_MTU))
2296                 return;
2297
2298         if (iph) {
2299                 daddr = &iph->daddr;
2300                 saddr = &iph->saddr;
2301         } else if (sk) {
2302                 daddr = &sk->sk_v6_daddr;
2303                 saddr = &inet6_sk(sk)->saddr;
2304         } else {
2305                 daddr = NULL;
2306                 saddr = NULL;
2307         }
2308         dst_confirm_neigh(dst, daddr);
2309         mtu = max_t(u32, mtu, IPV6_MIN_MTU);
2310         if (mtu >= dst_mtu(dst))
2311                 return;
2312
2313         if (!rt6_cache_allowed_for_pmtu(rt6)) {
2314                 rt6_do_update_pmtu(rt6, mtu);
2315                 /* update rt6_ex->stamp for cache */
2316                 if (rt6->rt6i_flags & RTF_CACHE)
2317                         rt6_update_exception_stamp_rt(rt6);
2318         } else if (daddr) {
2319                 struct fib6_info *from;
2320                 struct rt6_info *nrt6;
2321
2322                 rcu_read_lock();
2323                 from = rcu_dereference(rt6->from);
2324                 nrt6 = ip6_rt_cache_alloc(from, daddr, saddr);
2325                 if (nrt6) {
2326                         rt6_do_update_pmtu(nrt6, mtu);
2327                         if (rt6_insert_exception(nrt6, from))
2328                                 dst_release_immediate(&nrt6->dst);
2329                 }
2330                 rcu_read_unlock();
2331         }
2332 }
2333
2334 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
2335                                struct sk_buff *skb, u32 mtu)
2336 {
2337         __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu);
2338 }
2339
2340 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
2341                      int oif, u32 mark, kuid_t uid)
2342 {
2343         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2344         struct dst_entry *dst;
2345         struct flowi6 fl6 = {
2346                 .flowi6_oif = oif,
2347                 .flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
2348                 .daddr = iph->daddr,
2349                 .saddr = iph->saddr,
2350                 .flowlabel = ip6_flowinfo(iph),
2351                 .flowi6_uid = uid,
2352         };
2353
2354         dst = ip6_route_output(net, NULL, &fl6);
2355         if (!dst->error)
2356                 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu));
2357         dst_release(dst);
2358 }
2359 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
2360
2361 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
2362 {
2363         struct dst_entry *dst;
2364
2365         ip6_update_pmtu(skb, sock_net(sk), mtu,
2366                         sk->sk_bound_dev_if, sk->sk_mark, sk->sk_uid);
2367
2368         dst = __sk_dst_get(sk);
2369         if (!dst || !dst->obsolete ||
2370             dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
2371                 return;
2372
2373         bh_lock_sock(sk);
2374         if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
2375                 ip6_datagram_dst_update(sk, false);
2376         bh_unlock_sock(sk);
2377 }
2378 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
2379
2380 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
2381                            const struct flowi6 *fl6)
2382 {
2383 #ifdef CONFIG_IPV6_SUBTREES
2384         struct ipv6_pinfo *np = inet6_sk(sk);
2385 #endif
2386
2387         ip6_dst_store(sk, dst,
2388                       ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
2389                       &sk->sk_v6_daddr : NULL,
2390 #ifdef CONFIG_IPV6_SUBTREES
2391                       ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
2392                       &np->saddr :
2393 #endif
2394                       NULL);
2395 }
2396
2397 /* Handle redirects */
2398 struct ip6rd_flowi {
2399         struct flowi6 fl6;
2400         struct in6_addr gateway;
2401 };
2402
2403 static struct rt6_info *__ip6_route_redirect(struct net *net,
2404                                              struct fib6_table *table,
2405                                              struct flowi6 *fl6,
2406                                              const struct sk_buff *skb,
2407                                              int flags)
2408 {
2409         struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
2410         struct rt6_info *ret = NULL, *rt_cache;
2411         struct fib6_info *rt;
2412         struct fib6_node *fn;
2413
2414         /* Get the "current" route for this destination and
2415          * check if the redirect has come from appropriate router.
2416          *
2417          * RFC 4861 specifies that redirects should only be
2418          * accepted if they come from the nexthop to the target.
2419          * Due to the way the routes are chosen, this notion
2420          * is a bit fuzzy and one might need to check all possible
2421          * routes.
2422          */
2423
2424         rcu_read_lock();
2425         fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
2426 restart:
2427         for_each_fib6_node_rt_rcu(fn) {
2428                 if (rt->fib6_nh.nh_flags & RTNH_F_DEAD)
2429                         continue;
2430                 if (fib6_check_expired(rt))
2431                         continue;
2432                 if (rt->fib6_flags & RTF_REJECT)
2433                         break;
2434                 if (!(rt->fib6_flags & RTF_GATEWAY))
2435                         continue;
2436                 if (fl6->flowi6_oif != rt->fib6_nh.nh_dev->ifindex)
2437                         continue;
2438                 /* rt_cache's gateway might be different from its 'parent'
2439                  * in the case of an ip redirect.
2440                  * So we keep searching in the exception table if the gateway
2441                  * is different.
2442                  */
2443                 if (!ipv6_addr_equal(&rdfl->gateway, &rt->fib6_nh.nh_gw)) {
2444                         rt_cache = rt6_find_cached_rt(rt,
2445                                                       &fl6->daddr,
2446                                                       &fl6->saddr);
2447                         if (rt_cache &&
2448                             ipv6_addr_equal(&rdfl->gateway,
2449                                             &rt_cache->rt6i_gateway)) {
2450                                 ret = rt_cache;
2451                                 break;
2452                         }
2453                         continue;
2454                 }
2455                 break;
2456         }
2457
2458         if (!rt)
2459                 rt = net->ipv6.fib6_null_entry;
2460         else if (rt->fib6_flags & RTF_REJECT) {
2461                 ret = net->ipv6.ip6_null_entry;
2462                 goto out;
2463         }
2464
2465         if (rt == net->ipv6.fib6_null_entry) {
2466                 fn = fib6_backtrack(fn, &fl6->saddr);
2467                 if (fn)
2468                         goto restart;
2469         }
2470
2471 out:
2472         if (ret)
2473                 ip6_hold_safe(net, &ret, true);
2474         else
2475                 ret = ip6_create_rt_rcu(rt);
2476
2477         rcu_read_unlock();
2478
2479         trace_fib6_table_lookup(net, rt, table, fl6);
2480         return ret;
2481 };
2482
2483 static struct dst_entry *ip6_route_redirect(struct net *net,
2484                                             const struct flowi6 *fl6,
2485                                             const struct sk_buff *skb,
2486                                             const struct in6_addr *gateway)
2487 {
2488         int flags = RT6_LOOKUP_F_HAS_SADDR;
2489         struct ip6rd_flowi rdfl;
2490
2491         rdfl.fl6 = *fl6;
2492         rdfl.gateway = *gateway;
2493
2494         return fib6_rule_lookup(net, &rdfl.fl6, skb,
2495                                 flags, __ip6_route_redirect);
2496 }
2497
2498 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
2499                   kuid_t uid)
2500 {
2501         const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2502         struct dst_entry *dst;
2503         struct flowi6 fl6 = {
2504                 .flowi6_iif = LOOPBACK_IFINDEX,
2505                 .flowi6_oif = oif,
2506                 .flowi6_mark = mark,
2507                 .daddr = iph->daddr,
2508                 .saddr = iph->saddr,
2509                 .flowlabel = ip6_flowinfo(iph),
2510                 .flowi6_uid = uid,
2511         };
2512
2513         dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
2514         rt6_do_redirect(dst, NULL, skb);
2515         dst_release(dst);
2516 }
2517 EXPORT_SYMBOL_GPL(ip6_redirect);
2518
2519 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
2520 {
2521         const struct ipv6hdr *iph = ipv6_hdr(skb);
2522         const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
2523         struct dst_entry *dst;
2524         struct flowi6 fl6 = {
2525                 .flowi6_iif = LOOPBACK_IFINDEX,
2526                 .flowi6_oif = oif,
2527                 .daddr = msg->dest,
2528                 .saddr = iph->daddr,
2529                 .flowi6_uid = sock_net_uid(net, NULL),
2530         };
2531
2532         dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
2533         rt6_do_redirect(dst, NULL, skb);
2534         dst_release(dst);
2535 }
2536
2537 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
2538 {
2539         ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark,
2540                      sk->sk_uid);
2541 }
2542 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
2543
2544 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
2545 {
2546         struct net_device *dev = dst->dev;
2547         unsigned int mtu = dst_mtu(dst);
2548         struct net *net = dev_net(dev);
2549
2550         mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
2551
2552         if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
2553                 mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
2554
2555         /*
2556          * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
2557          * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
2558          * IPV6_MAXPLEN is also valid and means: "any MSS,
2559          * rely only on pmtu discovery"
2560          */
2561         if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
2562                 mtu = IPV6_MAXPLEN;
2563         return mtu;
2564 }
2565
2566 static unsigned int ip6_mtu(const struct dst_entry *dst)
2567 {
2568         struct inet6_dev *idev;
2569         unsigned int mtu;
2570
2571         mtu = dst_metric_raw(dst, RTAX_MTU);
2572         if (mtu)
2573                 goto out;
2574
2575         mtu = IPV6_MIN_MTU;
2576
2577         rcu_read_lock();
2578         idev = __in6_dev_get(dst->dev);
2579         if (idev)
2580                 mtu = idev->cnf.mtu6;
2581         rcu_read_unlock();
2582
2583 out:
2584         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
2585
2586         return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
2587 }
2588
2589 /* MTU selection:
2590  * 1. mtu on route is locked - use it
2591  * 2. mtu from nexthop exception
2592  * 3. mtu from egress device
2593  *
2594  * based on ip6_dst_mtu_forward and exception logic of
2595  * rt6_find_cached_rt; called with rcu_read_lock
2596  */
2597 u32 ip6_mtu_from_fib6(struct fib6_info *f6i, struct in6_addr *daddr,
2598                       struct in6_addr *saddr)
2599 {
2600         struct rt6_exception_bucket *bucket;
2601         struct rt6_exception *rt6_ex;
2602         struct in6_addr *src_key;
2603         struct inet6_dev *idev;
2604         u32 mtu = 0;
2605
2606         if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
2607                 mtu = f6i->fib6_pmtu;
2608                 if (mtu)
2609                         goto out;
2610         }
2611
2612         src_key = NULL;
2613 #ifdef CONFIG_IPV6_SUBTREES
2614         if (f6i->fib6_src.plen)
2615                 src_key = saddr;
2616 #endif
2617
2618         bucket = rcu_dereference(f6i->rt6i_exception_bucket);
2619         rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
2620         if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
2621                 mtu = dst_metric_raw(&rt6_ex->rt6i->dst, RTAX_MTU);
2622
2623         if (likely(!mtu)) {
2624                 struct net_device *dev = fib6_info_nh_dev(f6i);
2625
2626                 mtu = IPV6_MIN_MTU;
2627                 idev = __in6_dev_get(dev);
2628                 if (idev && idev->cnf.mtu6 > mtu)
2629                         mtu = idev->cnf.mtu6;
2630         }
2631
2632         mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
2633 out:
2634         return mtu - lwtunnel_headroom(fib6_info_nh_lwt(f6i), mtu);
2635 }
2636
2637 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
2638                                   struct flowi6 *fl6)
2639 {
2640         struct dst_entry *dst;
2641         struct rt6_info *rt;
2642         struct inet6_dev *idev = in6_dev_get(dev);
2643         struct net *net = dev_net(dev);
2644
2645         if (unlikely(!idev))
2646                 return ERR_PTR(-ENODEV);
2647
2648         rt = ip6_dst_alloc(net, dev, 0);
2649         if (unlikely(!rt)) {
2650                 in6_dev_put(idev);
2651                 dst = ERR_PTR(-ENOMEM);
2652                 goto out;
2653         }
2654
2655         rt->dst.flags |= DST_HOST;
2656         rt->dst.input = ip6_input;
2657         rt->dst.output  = ip6_output;
2658         rt->rt6i_gateway  = fl6->daddr;
2659         rt->rt6i_dst.addr = fl6->daddr;
2660         rt->rt6i_dst.plen = 128;
2661         rt->rt6i_idev     = idev;
2662         dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
2663
2664         /* Add this dst into uncached_list so that rt6_disable_ip() can
2665          * do proper release of the net_device
2666          */
2667         rt6_uncached_list_add(rt);
2668         atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
2669
2670         dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
2671
2672 out:
2673         return dst;
2674 }
2675
2676 static int ip6_dst_gc(struct dst_ops *ops)
2677 {
2678         struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
2679         int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
2680         int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
2681         int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
2682         int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
2683         unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
2684         int entries;
2685
2686         entries = dst_entries_get_fast(ops);
2687         if (time_after(rt_last_gc + rt_min_interval, jiffies) &&
2688             entries <= rt_max_size)
2689                 goto out;
2690
2691         net->ipv6.ip6_rt_gc_expire++;
2692         fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net, true);
2693         entries = dst_entries_get_slow(ops);
2694         if (entries < ops->gc_thresh)
2695                 net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;
2696 out:
2697         net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity;
2698         return entries > rt_max_size;
2699 }
2700
2701 static struct rt6_info *ip6_nh_lookup_table(struct net *net,
2702                                             struct fib6_config *cfg,
2703                                             const struct in6_addr *gw_addr,
2704                                             u32 tbid, int flags)
2705 {
2706         struct flowi6 fl6 = {
2707                 .flowi6_oif = cfg->fc_ifindex,
2708                 .daddr = *gw_addr,
2709                 .saddr = cfg->fc_prefsrc,
2710         };
2711         struct fib6_table *table;
2712         struct rt6_info *rt;
2713
2714         table = fib6_get_table(net, tbid);
2715         if (!table)
2716                 return NULL;
2717
2718         if (!ipv6_addr_any(&cfg->fc_prefsrc))
2719                 flags |= RT6_LOOKUP_F_HAS_SADDR;
2720
2721         flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
2722         rt = ip6_pol_route(net, table, cfg->fc_ifindex, &fl6, NULL, flags);
2723
2724         /* if table lookup failed, fall back to full lookup */
2725         if (rt == net->ipv6.ip6_null_entry) {
2726                 ip6_rt_put(rt);
2727                 rt = NULL;
2728         }
2729
2730         return rt;
2731 }
2732
2733 static int ip6_route_check_nh_onlink(struct net *net,
2734                                      struct fib6_config *cfg,
2735                                      const struct net_device *dev,
2736                                      struct netlink_ext_ack *extack)
2737 {
2738         u32 tbid = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN;
2739         const struct in6_addr *gw_addr = &cfg->fc_gateway;
2740         u32 flags = RTF_LOCAL | RTF_ANYCAST | RTF_REJECT;
2741         struct rt6_info *grt;
2742         int err;
2743
2744         err = 0;
2745         grt = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0);
2746         if (grt) {
2747                 if (!grt->dst.error &&
2748                     /* ignore match if it is the default route */
2749                     grt->from && !ipv6_addr_any(&grt->from->fib6_dst.addr) &&
2750                     (grt->rt6i_flags & flags || dev != grt->dst.dev)) {
2751                         NL_SET_ERR_MSG(extack,
2752                                        "Nexthop has invalid gateway or device mismatch");
2753                         err = -EINVAL;
2754                 }
2755
2756                 ip6_rt_put(grt);
2757         }
2758
2759         return err;
2760 }
2761
2762 static int ip6_route_check_nh(struct net *net,
2763                               struct fib6_config *cfg,
2764                               struct net_device **_dev,
2765                               struct inet6_dev **idev)
2766 {
2767         const struct in6_addr *gw_addr = &cfg->fc_gateway;
2768         struct net_device *dev = _dev ? *_dev : NULL;
2769         struct rt6_info *grt = NULL;
2770         int err = -EHOSTUNREACH;
2771
2772         if (cfg->fc_table) {
2773                 int flags = RT6_LOOKUP_F_IFACE;
2774
2775                 grt = ip6_nh_lookup_table(net, cfg, gw_addr,
2776                                           cfg->fc_table, flags);
2777                 if (grt) {
2778                         if (grt->rt6i_flags & RTF_GATEWAY ||
2779                             (dev && dev != grt->dst.dev)) {
2780                                 ip6_rt_put(grt);
2781                                 grt = NULL;
2782                         }
2783                 }
2784         }
2785
2786         if (!grt)
2787                 grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, NULL, 1);
2788
2789         if (!grt)
2790                 goto out;
2791
2792         if (dev) {
2793                 if (dev != grt->dst.dev) {
2794                         ip6_rt_put(grt);
2795                         goto out;
2796                 }
2797         } else {
2798                 *_dev = dev = grt->dst.dev;
2799                 *idev = grt->rt6i_idev;
2800                 dev_hold(dev);
2801                 in6_dev_hold(grt->rt6i_idev);
2802         }
2803
2804         if (!(grt->rt6i_flags & RTF_GATEWAY))
2805                 err = 0;
2806
2807         ip6_rt_put(grt);
2808
2809 out:
2810         return err;
2811 }
2812
2813 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
2814                            struct net_device **_dev, struct inet6_dev **idev,
2815                            struct netlink_ext_ack *extack)
2816 {
2817         const struct in6_addr *gw_addr = &cfg->fc_gateway;
2818         int gwa_type = ipv6_addr_type(gw_addr);
2819         bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
2820         const struct net_device *dev = *_dev;
2821         bool need_addr_check = !dev;
2822         int err = -EINVAL;
2823
2824         /* if gw_addr is local we will fail to detect this in case
2825          * address is still TENTATIVE (DAD in progress). rt6_lookup()
2826          * will return already-added prefix route via interface that
2827          * prefix route was assigned to, which might be non-loopback.
2828          */
2829         if (dev &&
2830             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
2831                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
2832                 goto out;
2833         }
2834
2835         if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
2836                 /* IPv6 strictly inhibits using not link-local
2837                  * addresses as nexthop address.
2838                  * Otherwise, router will not able to send redirects.
2839                  * It is very good, but in some (rare!) circumstances
2840                  * (SIT, PtP, NBMA NOARP links) it is handy to allow
2841                  * some exceptions. --ANK
2842                  * We allow IPv4-mapped nexthops to support RFC4798-type
2843                  * addressing
2844                  */
2845                 if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
2846                         NL_SET_ERR_MSG(extack, "Invalid gateway address");
2847                         goto out;
2848                 }
2849
2850                 if (cfg->fc_flags & RTNH_F_ONLINK)
2851                         err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
2852                 else
2853                         err = ip6_route_check_nh(net, cfg, _dev, idev);
2854
2855                 if (err)
2856                         goto out;
2857         }
2858
2859         /* reload in case device was changed */
2860         dev = *_dev;
2861
2862         err = -EINVAL;
2863         if (!dev) {
2864                 NL_SET_ERR_MSG(extack, "Egress device not specified");
2865                 goto out;
2866         } else if (dev->flags & IFF_LOOPBACK) {
2867                 NL_SET_ERR_MSG(extack,
2868                                "Egress device can not be loopback device for this route");
2869                 goto out;
2870         }
2871
2872         /* if we did not check gw_addr above, do so now that the
2873          * egress device has been resolved.
2874          */
2875         if (need_addr_check &&
2876             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
2877                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
2878                 goto out;
2879         }
2880
2881         err = 0;
2882 out:
2883         return err;
2884 }
2885
2886 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
2887                                               gfp_t gfp_flags,
2888                                               struct netlink_ext_ack *extack)
2889 {
2890         struct net *net = cfg->fc_nlinfo.nl_net;
2891         struct fib6_info *rt = NULL;
2892         struct net_device *dev = NULL;
2893         struct inet6_dev *idev = NULL;
2894         struct fib6_table *table;
2895         int addr_type;
2896         int err = -EINVAL;
2897
2898         /* RTF_PCPU is an internal flag; can not be set by userspace */
2899         if (cfg->fc_flags & RTF_PCPU) {
2900                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
2901                 goto out;
2902         }
2903
2904         /* RTF_CACHE is an internal flag; can not be set by userspace */
2905         if (cfg->fc_flags & RTF_CACHE) {
2906                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
2907                 goto out;
2908         }
2909
2910         if (cfg->fc_type > RTN_MAX) {
2911                 NL_SET_ERR_MSG(extack, "Invalid route type");
2912                 goto out;
2913         }
2914
2915         if (cfg->fc_dst_len > 128) {
2916                 NL_SET_ERR_MSG(extack, "Invalid prefix length");
2917                 goto out;
2918         }
2919         if (cfg->fc_src_len > 128) {
2920                 NL_SET_ERR_MSG(extack, "Invalid source address length");
2921                 goto out;
2922         }
2923 #ifndef CONFIG_IPV6_SUBTREES
2924         if (cfg->fc_src_len) {
2925                 NL_SET_ERR_MSG(extack,
2926                                "Specifying source address requires IPV6_SUBTREES to be enabled");
2927                 goto out;
2928         }
2929 #endif
2930         if (cfg->fc_ifindex) {
2931                 err = -ENODEV;
2932                 dev = dev_get_by_index(net, cfg->fc_ifindex);
2933                 if (!dev)
2934                         goto out;
2935                 idev = in6_dev_get(dev);
2936                 if (!idev)
2937                         goto out;
2938         }
2939
2940         if (cfg->fc_metric == 0)
2941                 cfg->fc_metric = IP6_RT_PRIO_USER;
2942
2943         if (cfg->fc_flags & RTNH_F_ONLINK) {
2944                 if (!dev) {
2945                         NL_SET_ERR_MSG(extack,
2946                                        "Nexthop device required for onlink");
2947                         err = -ENODEV;
2948                         goto out;
2949                 }
2950
2951                 if (!(dev->flags & IFF_UP)) {
2952                         NL_SET_ERR_MSG(extack, "Nexthop device is not up");
2953                         err = -ENETDOWN;
2954                         goto out;
2955                 }
2956         }
2957
2958         err = -ENOBUFS;
2959         if (cfg->fc_nlinfo.nlh &&
2960             !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
2961                 table = fib6_get_table(net, cfg->fc_table);
2962                 if (!table) {
2963                         pr_warn("NLM_F_CREATE should be specified when creating new route\n");
2964                         table = fib6_new_table(net, cfg->fc_table);
2965                 }
2966         } else {
2967                 table = fib6_new_table(net, cfg->fc_table);
2968         }
2969
2970         if (!table)
2971                 goto out;
2972
2973         err = -ENOMEM;
2974         rt = fib6_info_alloc(gfp_flags);
2975         if (!rt)
2976                 goto out;
2977
2978         rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len);
2979         if (IS_ERR(rt->fib6_metrics)) {
2980                 err = PTR_ERR(rt->fib6_metrics);
2981                 /* Do not leave garbage there. */
2982                 rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
2983                 goto out;
2984         }
2985
2986         if (cfg->fc_flags & RTF_ADDRCONF)
2987                 rt->dst_nocount = true;
2988
2989         if (cfg->fc_flags & RTF_EXPIRES)
2990                 fib6_set_expires(rt, jiffies +
2991                                 clock_t_to_jiffies(cfg->fc_expires));
2992         else
2993                 fib6_clean_expires(rt);
2994
2995         if (cfg->fc_protocol == RTPROT_UNSPEC)
2996                 cfg->fc_protocol = RTPROT_BOOT;
2997         rt->fib6_protocol = cfg->fc_protocol;
2998
2999         addr_type = ipv6_addr_type(&cfg->fc_dst);
3000
3001         if (cfg->fc_encap) {
3002                 struct lwtunnel_state *lwtstate;
3003
3004                 err = lwtunnel_build_state(cfg->fc_encap_type,
3005                                            cfg->fc_encap, AF_INET6, cfg,
3006                                            &lwtstate, extack);
3007                 if (err)
3008                         goto out;
3009                 rt->fib6_nh.nh_lwtstate = lwtstate_get(lwtstate);
3010         }
3011
3012         ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
3013         rt->fib6_dst.plen = cfg->fc_dst_len;
3014         if (rt->fib6_dst.plen == 128)
3015                 rt->dst_host = true;
3016
3017 #ifdef CONFIG_IPV6_SUBTREES
3018         ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
3019         rt->fib6_src.plen = cfg->fc_src_len;
3020 #endif
3021
3022         rt->fib6_metric = cfg->fc_metric;
3023         rt->fib6_nh.nh_weight = 1;
3024
3025         rt->fib6_type = cfg->fc_type;
3026
3027         /* We cannot add true routes via loopback here,
3028            they would result in kernel looping; promote them to reject routes
3029          */
3030         if ((cfg->fc_flags & RTF_REJECT) ||
3031             (dev && (dev->flags & IFF_LOOPBACK) &&
3032              !(addr_type & IPV6_ADDR_LOOPBACK) &&
3033              !(cfg->fc_flags & RTF_LOCAL))) {
3034                 /* hold loopback dev/idev if we haven't done so. */
3035                 if (dev != net->loopback_dev) {
3036                         if (dev) {
3037                                 dev_put(dev);
3038                                 in6_dev_put(idev);
3039                         }
3040                         dev = net->loopback_dev;
3041                         dev_hold(dev);
3042                         idev = in6_dev_get(dev);
3043                         if (!idev) {
3044                                 err = -ENODEV;
3045                                 goto out;
3046                         }
3047                 }
3048                 rt->fib6_flags = RTF_REJECT|RTF_NONEXTHOP;
3049                 goto install_route;
3050         }
3051
3052         if (cfg->fc_flags & RTF_GATEWAY) {
3053                 err = ip6_validate_gw(net, cfg, &dev, &idev, extack);
3054                 if (err)
3055                         goto out;
3056
3057                 rt->fib6_nh.nh_gw = cfg->fc_gateway;
3058         }
3059
3060         err = -ENODEV;
3061         if (!dev)
3062                 goto out;
3063
3064         if (idev->cnf.disable_ipv6) {
3065                 NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
3066                 err = -EACCES;
3067                 goto out;
3068         }
3069
3070         if (!(dev->flags & IFF_UP)) {
3071                 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3072                 err = -ENETDOWN;
3073                 goto out;
3074         }
3075
3076         if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
3077                 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
3078                         NL_SET_ERR_MSG(extack, "Invalid source address");
3079                         err = -EINVAL;
3080                         goto out;
3081                 }
3082                 rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
3083                 rt->fib6_prefsrc.plen = 128;
3084         } else
3085                 rt->fib6_prefsrc.plen = 0;
3086
3087         rt->fib6_flags = cfg->fc_flags;
3088
3089 install_route:
3090         if (!(rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
3091             !netif_carrier_ok(dev))
3092                 rt->fib6_nh.nh_flags |= RTNH_F_LINKDOWN;
3093         rt->fib6_nh.nh_flags |= (cfg->fc_flags & RTNH_F_ONLINK);
3094         rt->fib6_nh.nh_dev = dev;
3095         rt->fib6_table = table;
3096
3097         if (idev)
3098                 in6_dev_put(idev);
3099
3100         return rt;
3101 out:
3102         if (dev)
3103                 dev_put(dev);
3104         if (idev)
3105                 in6_dev_put(idev);
3106
3107         fib6_info_release(rt);
3108         return ERR_PTR(err);
3109 }
3110
3111 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
3112                   struct netlink_ext_ack *extack)
3113 {
3114         struct fib6_info *rt;
3115         int err;
3116
3117         rt = ip6_route_info_create(cfg, gfp_flags, extack);
3118         if (IS_ERR(rt))
3119                 return PTR_ERR(rt);
3120
3121         err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
3122         fib6_info_release(rt);
3123
3124         return err;
3125 }
3126
3127 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
3128 {
3129         struct net *net = info->nl_net;
3130         struct fib6_table *table;
3131         int err;
3132
3133         if (rt == net->ipv6.fib6_null_entry) {
3134                 err = -ENOENT;
3135                 goto out;
3136         }
3137
3138         table = rt->fib6_table;
3139         spin_lock_bh(&table->tb6_lock);
3140         err = fib6_del(rt, info);
3141         spin_unlock_bh(&table->tb6_lock);
3142
3143 out:
3144         fib6_info_release(rt);
3145         return err;
3146 }
3147
3148 int ip6_del_rt(struct net *net, struct fib6_info *rt)
3149 {
3150         struct nl_info info = { .nl_net = net };
3151
3152         return __ip6_del_rt(rt, &info);
3153 }
3154
3155 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
3156 {
3157         struct nl_info *info = &cfg->fc_nlinfo;
3158         struct net *net = info->nl_net;
3159         struct sk_buff *skb = NULL;
3160         struct fib6_table *table;
3161         int err = -ENOENT;
3162
3163         if (rt == net->ipv6.fib6_null_entry)
3164                 goto out_put;
3165         table = rt->fib6_table;
3166         spin_lock_bh(&table->tb6_lock);
3167
3168         if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
3169                 struct fib6_info *sibling, *next_sibling;
3170
3171                 /* prefer to send a single notification with all hops */
3172                 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3173                 if (skb) {
3174                         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3175
3176                         if (rt6_fill_node(net, skb, rt, NULL,
3177                                           NULL, NULL, 0, RTM_DELROUTE,
3178                                           info->portid, seq, 0) < 0) {
3179                                 kfree_skb(skb);
3180                                 skb = NULL;
3181                         } else
3182                                 info->skip_notify = 1;
3183                 }
3184
3185                 list_for_each_entry_safe(sibling, next_sibling,
3186                                          &rt->fib6_siblings,
3187                                          fib6_siblings) {
3188                         err = fib6_del(sibling, info);
3189                         if (err)
3190                                 goto out_unlock;
3191                 }
3192         }
3193
3194         err = fib6_del(rt, info);
3195 out_unlock:
3196         spin_unlock_bh(&table->tb6_lock);
3197 out_put:
3198         fib6_info_release(rt);
3199
3200         if (skb) {
3201                 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3202                             info->nlh, gfp_any());
3203         }
3204         return err;
3205 }
3206
3207 static int ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
3208 {
3209         int rc = -ESRCH;
3210
3211         if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
3212                 goto out;
3213
3214         if (cfg->fc_flags & RTF_GATEWAY &&
3215             !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
3216                 goto out;
3217         if (dst_hold_safe(&rt->dst))
3218                 rc = rt6_remove_exception_rt(rt);
3219 out:
3220         return rc;
3221 }
3222
3223 static int ip6_route_del(struct fib6_config *cfg,
3224                          struct netlink_ext_ack *extack)
3225 {
3226         struct rt6_info *rt_cache;
3227         struct fib6_table *table;
3228         struct fib6_info *rt;
3229         struct fib6_node *fn;
3230         int err = -ESRCH;
3231
3232         table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
3233         if (!table) {
3234                 NL_SET_ERR_MSG(extack, "FIB table does not exist");
3235                 return err;
3236         }
3237
3238         rcu_read_lock();
3239
3240         fn = fib6_locate(&table->tb6_root,
3241                          &cfg->fc_dst, cfg->fc_dst_len,
3242                          &cfg->fc_src, cfg->fc_src_len,
3243                          !(cfg->fc_flags & RTF_CACHE));
3244
3245         if (fn) {
3246                 for_each_fib6_node_rt_rcu(fn) {
3247                         if (cfg->fc_flags & RTF_CACHE) {
3248                                 int rc;
3249
3250                                 rt_cache = rt6_find_cached_rt(rt, &cfg->fc_dst,
3251                                                               &cfg->fc_src);
3252                                 if (rt_cache) {
3253                                         rc = ip6_del_cached_rt(rt_cache, cfg);
3254                                         if (rc != -ESRCH) {
3255                                                 rcu_read_unlock();
3256                                                 return rc;
3257                                         }
3258                                 }
3259                                 continue;
3260                         }
3261                         if (cfg->fc_ifindex &&
3262                             (!rt->fib6_nh.nh_dev ||
3263                              rt->fib6_nh.nh_dev->ifindex != cfg->fc_ifindex))
3264                                 continue;
3265                         if (cfg->fc_flags & RTF_GATEWAY &&
3266                             !ipv6_addr_equal(&cfg->fc_gateway, &rt->fib6_nh.nh_gw))
3267                                 continue;
3268                         if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
3269                                 continue;
3270                         if (cfg->fc_protocol && cfg->fc_protocol != rt->fib6_protocol)
3271                                 continue;
3272                         if (!fib6_info_hold_safe(rt))
3273                                 continue;
3274                         rcu_read_unlock();
3275
3276                         /* if gateway was specified only delete the one hop */
3277                         if (cfg->fc_flags & RTF_GATEWAY)
3278                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
3279
3280                         return __ip6_del_rt_siblings(rt, cfg);
3281                 }
3282         }
3283         rcu_read_unlock();
3284
3285         return err;
3286 }
3287
3288 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
3289 {
3290         struct netevent_redirect netevent;
3291         struct rt6_info *rt, *nrt = NULL;
3292         struct ndisc_options ndopts;
3293         struct inet6_dev *in6_dev;
3294         struct neighbour *neigh;
3295         struct fib6_info *from;
3296         struct rd_msg *msg;
3297         int optlen, on_link;
3298         u8 *lladdr;
3299
3300         optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
3301         optlen -= sizeof(*msg);
3302
3303         if (optlen < 0) {
3304                 net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
3305                 return;
3306         }
3307
3308         msg = (struct rd_msg *)icmp6_hdr(skb);
3309
3310         if (ipv6_addr_is_multicast(&msg->dest)) {
3311                 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
3312                 return;
3313         }
3314
3315         on_link = 0;
3316         if (ipv6_addr_equal(&msg->dest, &msg->target)) {
3317                 on_link = 1;
3318         } else if (ipv6_addr_type(&msg->target) !=
3319                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
3320                 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
3321                 return;
3322         }
3323
3324         in6_dev = __in6_dev_get(skb->dev);
3325         if (!in6_dev)
3326                 return;
3327         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
3328                 return;
3329
3330         /* RFC2461 8.1:
3331          *      The IP source address of the Redirect MUST be the same as the current
3332          *      first-hop router for the specified ICMP Destination Address.
3333          */
3334
3335         if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
3336                 net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
3337                 return;
3338         }
3339
3340         lladdr = NULL;
3341         if (ndopts.nd_opts_tgt_lladdr) {
3342                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
3343                                              skb->dev);
3344                 if (!lladdr) {
3345                         net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
3346                         return;
3347                 }
3348         }
3349
3350         rt = (struct rt6_info *) dst;
3351         if (rt->rt6i_flags & RTF_REJECT) {
3352                 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
3353                 return;
3354         }
3355
3356         /* Redirect received -> path was valid.
3357          * Look, redirects are sent only in response to data packets,
3358          * so that this nexthop apparently is reachable. --ANK
3359          */
3360         dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
3361
3362         neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
3363         if (!neigh)
3364                 return;
3365
3366         /*
3367          *      We have finally decided to accept it.
3368          */
3369
3370         ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
3371                      NEIGH_UPDATE_F_WEAK_OVERRIDE|
3372                      NEIGH_UPDATE_F_OVERRIDE|
3373                      (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
3374                                      NEIGH_UPDATE_F_ISROUTER)),
3375                      NDISC_REDIRECT, &ndopts);
3376
3377         rcu_read_lock();
3378         from = rcu_dereference(rt->from);
3379         /* This fib6_info_hold() is safe here because we hold reference to rt
3380          * and rt already holds reference to fib6_info.
3381          */
3382         fib6_info_hold(from);
3383         rcu_read_unlock();
3384
3385         nrt = ip6_rt_cache_alloc(from, &msg->dest, NULL);
3386         if (!nrt)
3387                 goto out;
3388
3389         nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
3390         if (on_link)
3391                 nrt->rt6i_flags &= ~RTF_GATEWAY;
3392
3393         nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
3394
3395         /* No need to remove rt from the exception table if rt is
3396          * a cached route because rt6_insert_exception() will
3397          * takes care of it
3398          */
3399         if (rt6_insert_exception(nrt, from)) {
3400                 dst_release_immediate(&nrt->dst);
3401                 goto out;
3402         }
3403
3404         netevent.old = &rt->dst;
3405         netevent.new = &nrt->dst;
3406         netevent.daddr = &msg->dest;
3407         netevent.neigh = neigh;
3408         call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
3409
3410 out:
3411         fib6_info_release(from);
3412         neigh_release(neigh);
3413 }
3414
3415 #ifdef CONFIG_IPV6_ROUTE_INFO
3416 static struct fib6_info *rt6_get_route_info(struct net *net,
3417                                            const struct in6_addr *prefix, int prefixlen,
3418                                            const struct in6_addr *gwaddr,
3419                                            struct net_device *dev)
3420 {
3421         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
3422         int ifindex = dev->ifindex;
3423         struct fib6_node *fn;
3424         struct fib6_info *rt = NULL;
3425         struct fib6_table *table;
3426
3427         table = fib6_get_table(net, tb_id);
3428         if (!table)
3429                 return NULL;
3430
3431         rcu_read_lock();
3432         fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
3433         if (!fn)
3434                 goto out;
3435
3436         for_each_fib6_node_rt_rcu(fn) {
3437                 if (rt->fib6_nh.nh_dev->ifindex != ifindex)
3438                         continue;
3439                 if ((rt->fib6_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY))
3440                         continue;
3441                 if (!ipv6_addr_equal(&rt->fib6_nh.nh_gw, gwaddr))
3442                         continue;
3443                 if (!fib6_info_hold_safe(rt))
3444                         continue;
3445                 break;
3446         }
3447 out:
3448         rcu_read_unlock();
3449         return rt;
3450 }
3451
3452 static struct fib6_info *rt6_add_route_info(struct net *net,
3453                                            const struct in6_addr *prefix, int prefixlen,
3454                                            const struct in6_addr *gwaddr,
3455                                            struct net_device *dev,
3456                                            unsigned int pref)
3457 {
3458         struct fib6_config cfg = {
3459                 .fc_metric      = IP6_RT_PRIO_USER,
3460                 .fc_ifindex     = dev->ifindex,
3461                 .fc_dst_len     = prefixlen,
3462                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
3463                                   RTF_UP | RTF_PREF(pref),
3464                 .fc_protocol = RTPROT_RA,
3465                 .fc_type = RTN_UNICAST,
3466                 .fc_nlinfo.portid = 0,
3467                 .fc_nlinfo.nlh = NULL,
3468                 .fc_nlinfo.nl_net = net,
3469         };
3470
3471         cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO,
3472         cfg.fc_dst = *prefix;
3473         cfg.fc_gateway = *gwaddr;
3474
3475         /* We should treat it as a default route if prefix length is 0. */
3476         if (!prefixlen)
3477                 cfg.fc_flags |= RTF_DEFAULT;
3478
3479         ip6_route_add(&cfg, GFP_ATOMIC, NULL);
3480
3481         return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
3482 }
3483 #endif
3484
3485 struct fib6_info *rt6_get_dflt_router(struct net *net,
3486                                      const struct in6_addr *addr,
3487                                      struct net_device *dev)
3488 {
3489         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
3490         struct fib6_info *rt;
3491         struct fib6_table *table;
3492
3493         table = fib6_get_table(net, tb_id);
3494         if (!table)
3495                 return NULL;
3496
3497         rcu_read_lock();
3498         for_each_fib6_node_rt_rcu(&table->tb6_root) {
3499                 if (dev == rt->fib6_nh.nh_dev &&
3500                     ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
3501                     ipv6_addr_equal(&rt->fib6_nh.nh_gw, addr))
3502                         break;
3503         }
3504         if (rt && !fib6_info_hold_safe(rt))
3505                 rt = NULL;
3506         rcu_read_unlock();
3507         return rt;
3508 }
3509
3510 struct fib6_info *rt6_add_dflt_router(struct net *net,
3511                                      const struct in6_addr *gwaddr,
3512                                      struct net_device *dev,
3513                                      unsigned int pref)
3514 {
3515         struct fib6_config cfg = {
3516                 .fc_table       = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
3517                 .fc_metric      = IP6_RT_PRIO_USER,
3518                 .fc_ifindex     = dev->ifindex,
3519                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
3520                                   RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
3521                 .fc_protocol = RTPROT_RA,
3522                 .fc_type = RTN_UNICAST,
3523                 .fc_nlinfo.portid = 0,
3524                 .fc_nlinfo.nlh = NULL,
3525                 .fc_nlinfo.nl_net = net,
3526         };
3527
3528         cfg.fc_gateway = *gwaddr;
3529
3530         if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
3531                 struct fib6_table *table;
3532
3533                 table = fib6_get_table(dev_net(dev), cfg.fc_table);
3534                 if (table)
3535                         table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
3536         }
3537
3538         return rt6_get_dflt_router(net, gwaddr, dev);
3539 }
3540
3541 static void __rt6_purge_dflt_routers(struct net *net,
3542                                      struct fib6_table *table)
3543 {
3544         struct fib6_info *rt;
3545
3546 restart:
3547         rcu_read_lock();
3548         for_each_fib6_node_rt_rcu(&table->tb6_root) {
3549                 struct net_device *dev = fib6_info_nh_dev(rt);
3550                 struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
3551
3552                 if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
3553                     (!idev || idev->cnf.accept_ra != 2) &&
3554                     fib6_info_hold_safe(rt)) {
3555                         rcu_read_unlock();
3556                         ip6_del_rt(net, rt);
3557                         goto restart;
3558                 }
3559         }
3560         rcu_read_unlock();
3561
3562         table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
3563 }
3564
3565 void rt6_purge_dflt_routers(struct net *net)
3566 {
3567         struct fib6_table *table;
3568         struct hlist_head *head;
3569         unsigned int h;
3570
3571         rcu_read_lock();
3572
3573         for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
3574                 head = &net->ipv6.fib_table_hash[h];
3575                 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
3576                         if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
3577                                 __rt6_purge_dflt_routers(net, table);
3578                 }
3579         }
3580
3581         rcu_read_unlock();
3582 }
3583
3584 static void rtmsg_to_fib6_config(struct net *net,
3585                                  struct in6_rtmsg *rtmsg,
3586                                  struct fib6_config *cfg)
3587 {
3588         *cfg = (struct fib6_config){
3589                 .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
3590                          : RT6_TABLE_MAIN,
3591                 .fc_ifindex = rtmsg->rtmsg_ifindex,
3592                 .fc_metric = rtmsg->rtmsg_metric,
3593                 .fc_expires = rtmsg->rtmsg_info,
3594                 .fc_dst_len = rtmsg->rtmsg_dst_len,
3595                 .fc_src_len = rtmsg->rtmsg_src_len,
3596                 .fc_flags = rtmsg->rtmsg_flags,
3597                 .fc_type = rtmsg->rtmsg_type,
3598
3599                 .fc_nlinfo.nl_net = net,
3600
3601                 .fc_dst = rtmsg->rtmsg_dst,
3602                 .fc_src = rtmsg->rtmsg_src,
3603                 .fc_gateway = rtmsg->rtmsg_gateway,
3604         };
3605 }
3606
3607 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg)
3608 {
3609         struct fib6_config cfg;
3610         struct in6_rtmsg rtmsg;
3611         int err;
3612
3613         switch (cmd) {
3614         case SIOCADDRT:         /* Add a route */
3615         case SIOCDELRT:         /* Delete a route */
3616                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
3617                         return -EPERM;
3618                 err = copy_from_user(&rtmsg, arg,
3619                                      sizeof(struct in6_rtmsg));
3620                 if (err)
3621                         return -EFAULT;
3622
3623                 rtmsg_to_fib6_config(net, &rtmsg, &cfg);
3624
3625                 rtnl_lock();
3626                 switch (cmd) {
3627                 case SIOCADDRT:
3628                         err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
3629                         break;
3630                 case SIOCDELRT:
3631                         err = ip6_route_del(&cfg, NULL);
3632                         break;
3633                 default:
3634                         err = -EINVAL;
3635                 }
3636                 rtnl_unlock();
3637
3638                 return err;
3639         }
3640
3641         return -EINVAL;
3642 }
3643
3644 /*
3645  *      Drop the packet on the floor
3646  */
3647
3648 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
3649 {
3650         int type;
3651         struct dst_entry *dst = skb_dst(skb);
3652         switch (ipstats_mib_noroutes) {
3653         case IPSTATS_MIB_INNOROUTES:
3654                 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
3655                 if (type == IPV6_ADDR_ANY) {
3656                         IP6_INC_STATS(dev_net(dst->dev),
3657                                       __in6_dev_get_safely(skb->dev),
3658                                       IPSTATS_MIB_INADDRERRORS);
3659                         break;
3660                 }
3661                 /* FALLTHROUGH */
3662         case IPSTATS_MIB_OUTNOROUTES:
3663                 IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
3664                               ipstats_mib_noroutes);
3665                 break;
3666         }
3667         icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
3668         kfree_skb(skb);
3669         return 0;
3670 }
3671
3672 static int ip6_pkt_discard(struct sk_buff *skb)
3673 {
3674         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
3675 }
3676
3677 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
3678 {
3679         skb->dev = skb_dst(skb)->dev;
3680         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
3681 }
3682
3683 static int ip6_pkt_prohibit(struct sk_buff *skb)
3684 {
3685         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
3686 }
3687
3688 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
3689 {
3690         skb->dev = skb_dst(skb)->dev;
3691         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
3692 }
3693
3694 /*
3695  *      Allocate a dst for local (unicast / anycast) address.
3696  */
3697
3698 struct fib6_info *addrconf_f6i_alloc(struct net *net,
3699                                      struct inet6_dev *idev,
3700                                      const struct in6_addr *addr,
3701                                      bool anycast, gfp_t gfp_flags)
3702 {
3703         u32 tb_id;
3704         struct net_device *dev = idev->dev;
3705         struct fib6_info *f6i;
3706
3707         f6i = fib6_info_alloc(gfp_flags);
3708         if (!f6i)
3709                 return ERR_PTR(-ENOMEM);
3710
3711         f6i->fib6_metrics = ip_fib_metrics_init(net, NULL, 0);
3712         f6i->dst_nocount = true;
3713         f6i->dst_host = true;
3714         f6i->fib6_protocol = RTPROT_KERNEL;
3715         f6i->fib6_flags = RTF_UP | RTF_NONEXTHOP;
3716         if (anycast) {
3717                 f6i->fib6_type = RTN_ANYCAST;
3718                 f6i->fib6_flags |= RTF_ANYCAST;
3719         } else {
3720                 f6i->fib6_type = RTN_LOCAL;
3721                 f6i->fib6_flags |= RTF_LOCAL;
3722         }
3723
3724         f6i->fib6_nh.nh_gw = *addr;
3725         dev_hold(dev);
3726         f6i->fib6_nh.nh_dev = dev;
3727         f6i->fib6_dst.addr = *addr;
3728         f6i->fib6_dst.plen = 128;
3729         tb_id = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL;
3730         f6i->fib6_table = fib6_get_table(net, tb_id);
3731
3732         return f6i;
3733 }
3734
3735 /* remove deleted ip from prefsrc entries */
3736 struct arg_dev_net_ip {
3737         struct net_device *dev;
3738         struct net *net;
3739         struct in6_addr *addr;
3740 };
3741
3742 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
3743 {
3744         struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev;
3745         struct net *net = ((struct arg_dev_net_ip *)arg)->net;
3746         struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
3747
3748         if (((void *)rt->fib6_nh.nh_dev == dev || !dev) &&
3749             rt != net->ipv6.fib6_null_entry &&
3750             ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr)) {
3751                 spin_lock_bh(&rt6_exception_lock);
3752                 /* remove prefsrc entry */
3753                 rt->fib6_prefsrc.plen = 0;
3754                 spin_unlock_bh(&rt6_exception_lock);
3755         }
3756         return 0;
3757 }
3758
3759 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
3760 {
3761         struct net *net = dev_net(ifp->idev->dev);
3762         struct arg_dev_net_ip adni = {
3763                 .dev = ifp->idev->dev,
3764                 .net = net,
3765                 .addr = &ifp->addr,
3766         };
3767         fib6_clean_all(net, fib6_remove_prefsrc, &adni);
3768 }
3769
3770 #define RTF_RA_ROUTER           (RTF_ADDRCONF | RTF_DEFAULT | RTF_GATEWAY)
3771
3772 /* Remove routers and update dst entries when gateway turn into host. */
3773 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
3774 {
3775         struct in6_addr *gateway = (struct in6_addr *)arg;
3776
3777         if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
3778             ipv6_addr_equal(gateway, &rt->fib6_nh.nh_gw)) {
3779                 return -1;
3780         }
3781
3782         /* Further clean up cached routes in exception table.
3783          * This is needed because cached route may have a different
3784          * gateway than its 'parent' in the case of an ip redirect.
3785          */
3786         rt6_exceptions_clean_tohost(rt, gateway);
3787
3788         return 0;
3789 }
3790
3791 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
3792 {
3793         fib6_clean_all(net, fib6_clean_tohost, gateway);
3794 }
3795
3796 struct arg_netdev_event {
3797         const struct net_device *dev;
3798         union {
3799                 unsigned int nh_flags;
3800                 unsigned long event;
3801         };
3802 };
3803
3804 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
3805 {
3806         struct fib6_info *iter;
3807         struct fib6_node *fn;
3808
3809         fn = rcu_dereference_protected(rt->fib6_node,
3810                         lockdep_is_held(&rt->fib6_table->tb6_lock));
3811         iter = rcu_dereference_protected(fn->leaf,
3812                         lockdep_is_held(&rt->fib6_table->tb6_lock));
3813         while (iter) {
3814                 if (iter->fib6_metric == rt->fib6_metric &&
3815                     rt6_qualify_for_ecmp(iter))
3816                         return iter;
3817                 iter = rcu_dereference_protected(iter->fib6_next,
3818                                 lockdep_is_held(&rt->fib6_table->tb6_lock));
3819         }
3820
3821         return NULL;
3822 }
3823
3824 static bool rt6_is_dead(const struct fib6_info *rt)
3825 {
3826         if (rt->fib6_nh.nh_flags & RTNH_F_DEAD ||
3827             (rt->fib6_nh.nh_flags & RTNH_F_LINKDOWN &&
3828              fib6_ignore_linkdown(rt)))
3829                 return true;
3830
3831         return false;
3832 }
3833
3834 static int rt6_multipath_total_weight(const struct fib6_info *rt)
3835 {
3836         struct fib6_info *iter;
3837         int total = 0;
3838
3839         if (!rt6_is_dead(rt))
3840                 total += rt->fib6_nh.nh_weight;
3841
3842         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
3843                 if (!rt6_is_dead(iter))
3844                         total += iter->fib6_nh.nh_weight;
3845         }
3846
3847         return total;
3848 }
3849
3850 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
3851 {
3852         int upper_bound = -1;
3853
3854         if (!rt6_is_dead(rt)) {
3855                 *weight += rt->fib6_nh.nh_weight;
3856                 upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
3857                                                     total) - 1;
3858         }
3859         atomic_set(&rt->fib6_nh.nh_upper_bound, upper_bound);
3860 }
3861
3862 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
3863 {
3864         struct fib6_info *iter;
3865         int weight = 0;
3866
3867         rt6_upper_bound_set(rt, &weight, total);
3868
3869         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
3870                 rt6_upper_bound_set(iter, &weight, total);
3871 }
3872
3873 void rt6_multipath_rebalance(struct fib6_info *rt)
3874 {
3875         struct fib6_info *first;
3876         int total;
3877
3878         /* In case the entire multipath route was marked for flushing,
3879          * then there is no need to rebalance upon the removal of every
3880          * sibling route.
3881          */
3882         if (!rt->fib6_nsiblings || rt->should_flush)
3883                 return;
3884
3885         /* During lookup routes are evaluated in order, so we need to
3886          * make sure upper bounds are assigned from the first sibling
3887          * onwards.
3888          */
3889         first = rt6_multipath_first_sibling(rt);
3890         if (WARN_ON_ONCE(!first))
3891                 return;
3892
3893         total = rt6_multipath_total_weight(first);
3894         rt6_multipath_upper_bound_set(first, total);
3895 }
3896
3897 static int fib6_ifup(struct fib6_info *rt, void *p_arg)
3898 {
3899         const struct arg_netdev_event *arg = p_arg;
3900         struct net *net = dev_net(arg->dev);
3901
3902         if (rt != net->ipv6.fib6_null_entry && rt->fib6_nh.nh_dev == arg->dev) {
3903                 rt->fib6_nh.nh_flags &= ~arg->nh_flags;
3904                 fib6_update_sernum_upto_root(net, rt);
3905                 rt6_multipath_rebalance(rt);
3906         }
3907
3908         return 0;
3909 }
3910
3911 void rt6_sync_up(struct net_device *dev, unsigned int nh_flags)
3912 {
3913         struct arg_netdev_event arg = {
3914                 .dev = dev,
3915                 {
3916                         .nh_flags = nh_flags,
3917                 },
3918         };
3919
3920         if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
3921                 arg.nh_flags |= RTNH_F_LINKDOWN;
3922
3923         fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
3924 }
3925
3926 static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
3927                                    const struct net_device *dev)
3928 {
3929         struct fib6_info *iter;
3930
3931         if (rt->fib6_nh.nh_dev == dev)
3932                 return true;
3933         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
3934                 if (iter->fib6_nh.nh_dev == dev)
3935                         return true;
3936
3937         return false;
3938 }
3939
3940 static void rt6_multipath_flush(struct fib6_info *rt)
3941 {
3942         struct fib6_info *iter;
3943
3944         rt->should_flush = 1;
3945         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
3946                 iter->should_flush = 1;
3947 }
3948
3949 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
3950                                              const struct net_device *down_dev)
3951 {
3952         struct fib6_info *iter;
3953         unsigned int dead = 0;
3954
3955         if (rt->fib6_nh.nh_dev == down_dev ||
3956             rt->fib6_nh.nh_flags & RTNH_F_DEAD)
3957                 dead++;
3958         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
3959                 if (iter->fib6_nh.nh_dev == down_dev ||
3960                     iter->fib6_nh.nh_flags & RTNH_F_DEAD)
3961                         dead++;
3962
3963         return dead;
3964 }
3965
3966 static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
3967                                        const struct net_device *dev,
3968                                        unsigned int nh_flags)
3969 {
3970         struct fib6_info *iter;
3971
3972         if (rt->fib6_nh.nh_dev == dev)
3973                 rt->fib6_nh.nh_flags |= nh_flags;
3974         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
3975                 if (iter->fib6_nh.nh_dev == dev)
3976                         iter->fib6_nh.nh_flags |= nh_flags;
3977 }
3978
3979 /* called with write lock held for table with rt */
3980 static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
3981 {
3982         const struct arg_netdev_event *arg = p_arg;
3983         const struct net_device *dev = arg->dev;
3984         struct net *net = dev_net(dev);
3985
3986         if (rt == net->ipv6.fib6_null_entry)
3987                 return 0;
3988
3989         switch (arg->event) {
3990         case NETDEV_UNREGISTER:
3991                 return rt->fib6_nh.nh_dev == dev ? -1 : 0;
3992         case NETDEV_DOWN:
3993                 if (rt->should_flush)
3994                         return -1;
3995                 if (!rt->fib6_nsiblings)
3996                         return rt->fib6_nh.nh_dev == dev ? -1 : 0;
3997                 if (rt6_multipath_uses_dev(rt, dev)) {
3998                         unsigned int count;
3999
4000                         count = rt6_multipath_dead_count(rt, dev);
4001                         if (rt->fib6_nsiblings + 1 == count) {
4002                                 rt6_multipath_flush(rt);
4003                                 return -1;
4004                         }
4005                         rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
4006                                                    RTNH_F_LINKDOWN);
4007                         fib6_update_sernum(net, rt);
4008                         rt6_multipath_rebalance(rt);
4009                 }
4010                 return -2;
4011         case NETDEV_CHANGE:
4012                 if (rt->fib6_nh.nh_dev != dev ||
4013                     rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
4014                         break;
4015                 rt->fib6_nh.nh_flags |= RTNH_F_LINKDOWN;
4016                 rt6_multipath_rebalance(rt);
4017                 break;
4018         }
4019
4020         return 0;
4021 }
4022
4023 void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
4024 {
4025         struct arg_netdev_event arg = {
4026                 .dev = dev,
4027                 {
4028                         .event = event,
4029                 },
4030         };
4031         struct net *net = dev_net(dev);
4032
4033         if (net->ipv6.sysctl.skip_notify_on_dev_down)
4034                 fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
4035         else
4036                 fib6_clean_all(net, fib6_ifdown, &arg);
4037 }
4038
4039 void rt6_disable_ip(struct net_device *dev, unsigned long event)
4040 {
4041         rt6_sync_down_dev(dev, event);
4042         rt6_uncached_list_flush_dev(dev_net(dev), dev);
4043         neigh_ifdown(&nd_tbl, dev);
4044 }
4045
4046 struct rt6_mtu_change_arg {
4047         struct net_device *dev;
4048         unsigned int mtu;
4049 };
4050
4051 static int rt6_mtu_change_route(struct fib6_info *rt, void *p_arg)
4052 {
4053         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
4054         struct inet6_dev *idev;
4055
4056         /* In IPv6 pmtu discovery is not optional,
4057            so that RTAX_MTU lock cannot disable it.
4058            We still use this lock to block changes
4059            caused by addrconf/ndisc.
4060         */
4061
4062         idev = __in6_dev_get(arg->dev);
4063         if (!idev)
4064                 return 0;
4065
4066         /* For administrative MTU increase, there is no way to discover
4067            IPv6 PMTU increase, so PMTU increase should be updated here.
4068            Since RFC 1981 doesn't include administrative MTU increase
4069            update PMTU increase is a MUST. (i.e. jumbo frame)
4070          */
4071         if (rt->fib6_nh.nh_dev == arg->dev &&
4072             !fib6_metric_locked(rt, RTAX_MTU)) {
4073                 u32 mtu = rt->fib6_pmtu;
4074
4075                 if (mtu >= arg->mtu ||
4076                     (mtu < arg->mtu && mtu == idev->cnf.mtu6))
4077                         fib6_metric_set(rt, RTAX_MTU, arg->mtu);
4078
4079                 spin_lock_bh(&rt6_exception_lock);
4080                 rt6_exceptions_update_pmtu(idev, rt, arg->mtu);
4081                 spin_unlock_bh(&rt6_exception_lock);
4082         }
4083         return 0;
4084 }
4085
4086 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
4087 {
4088         struct rt6_mtu_change_arg arg = {
4089                 .dev = dev,
4090                 .mtu = mtu,
4091         };
4092
4093         fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
4094 }
4095
4096 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
4097         [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
4098         [RTA_PREFSRC]           = { .len = sizeof(struct in6_addr) },
4099         [RTA_OIF]               = { .type = NLA_U32 },
4100         [RTA_IIF]               = { .type = NLA_U32 },
4101         [RTA_PRIORITY]          = { .type = NLA_U32 },
4102         [RTA_METRICS]           = { .type = NLA_NESTED },
4103         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
4104         [RTA_PREF]              = { .type = NLA_U8 },
4105         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
4106         [RTA_ENCAP]             = { .type = NLA_NESTED },
4107         [RTA_EXPIRES]           = { .type = NLA_U32 },
4108         [RTA_UID]               = { .type = NLA_U32 },
4109         [RTA_MARK]              = { .type = NLA_U32 },
4110         [RTA_TABLE]             = { .type = NLA_U32 },
4111         [RTA_IP_PROTO]          = { .type = NLA_U8 },
4112         [RTA_SPORT]             = { .type = NLA_U16 },
4113         [RTA_DPORT]             = { .type = NLA_U16 },
4114 };
4115
4116 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
4117                               struct fib6_config *cfg,
4118                               struct netlink_ext_ack *extack)
4119 {
4120         struct rtmsg *rtm;
4121         struct nlattr *tb[RTA_MAX+1];
4122         unsigned int pref;
4123         int err;
4124
4125         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy,
4126                           extack);
4127         if (err < 0)
4128                 goto errout;
4129
4130         err = -EINVAL;
4131         rtm = nlmsg_data(nlh);
4132
4133         *cfg = (struct fib6_config){
4134                 .fc_table = rtm->rtm_table,
4135                 .fc_dst_len = rtm->rtm_dst_len,
4136                 .fc_src_len = rtm->rtm_src_len,
4137                 .fc_flags = RTF_UP,
4138                 .fc_protocol = rtm->rtm_protocol,
4139                 .fc_type = rtm->rtm_type,
4140
4141                 .fc_nlinfo.portid = NETLINK_CB(skb).portid,
4142                 .fc_nlinfo.nlh = nlh,
4143                 .fc_nlinfo.nl_net = sock_net(skb->sk),
4144         };
4145
4146         if (rtm->rtm_type == RTN_UNREACHABLE ||
4147             rtm->rtm_type == RTN_BLACKHOLE ||
4148             rtm->rtm_type == RTN_PROHIBIT ||
4149             rtm->rtm_type == RTN_THROW)
4150                 cfg->fc_flags |= RTF_REJECT;
4151
4152         if (rtm->rtm_type == RTN_LOCAL)
4153                 cfg->fc_flags |= RTF_LOCAL;
4154
4155         if (rtm->rtm_flags & RTM_F_CLONED)
4156                 cfg->fc_flags |= RTF_CACHE;
4157
4158         cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
4159
4160         if (tb[RTA_GATEWAY]) {
4161                 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
4162                 cfg->fc_flags |= RTF_GATEWAY;
4163         }
4164
4165         if (tb[RTA_DST]) {
4166                 int plen = (rtm->rtm_dst_len + 7) >> 3;
4167
4168                 if (nla_len(tb[RTA_DST]) < plen)
4169                         goto errout;
4170
4171                 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
4172         }
4173
4174         if (tb[RTA_SRC]) {
4175                 int plen = (rtm->rtm_src_len + 7) >> 3;
4176
4177                 if (nla_len(tb[RTA_SRC]) < plen)
4178                         goto errout;
4179
4180                 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
4181         }
4182
4183         if (tb[RTA_PREFSRC])
4184                 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
4185
4186         if (tb[RTA_OIF])
4187                 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
4188
4189         if (tb[RTA_PRIORITY])
4190                 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
4191
4192         if (tb[RTA_METRICS]) {
4193                 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
4194                 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
4195         }
4196
4197         if (tb[RTA_TABLE])
4198                 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
4199
4200         if (tb[RTA_MULTIPATH]) {
4201                 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
4202                 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
4203
4204                 err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
4205                                                      cfg->fc_mp_len, extack);
4206                 if (err < 0)
4207                         goto errout;
4208         }
4209
4210         if (tb[RTA_PREF]) {
4211                 pref = nla_get_u8(tb[RTA_PREF]);
4212                 if (pref != ICMPV6_ROUTER_PREF_LOW &&
4213                     pref != ICMPV6_ROUTER_PREF_HIGH)
4214                         pref = ICMPV6_ROUTER_PREF_MEDIUM;
4215                 cfg->fc_flags |= RTF_PREF(pref);
4216         }
4217
4218         if (tb[RTA_ENCAP])
4219                 cfg->fc_encap = tb[RTA_ENCAP];
4220
4221         if (tb[RTA_ENCAP_TYPE]) {
4222                 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
4223
4224                 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
4225                 if (err < 0)
4226                         goto errout;
4227         }
4228
4229         if (tb[RTA_EXPIRES]) {
4230                 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
4231
4232                 if (addrconf_finite_timeout(timeout)) {
4233                         cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
4234                         cfg->fc_flags |= RTF_EXPIRES;
4235                 }
4236         }
4237
4238         err = 0;
4239 errout:
4240         return err;
4241 }
4242
4243 struct rt6_nh {
4244         struct fib6_info *fib6_info;
4245         struct fib6_config r_cfg;
4246         struct list_head next;
4247 };
4248
4249 static void ip6_print_replace_route_err(struct list_head *rt6_nh_list)
4250 {
4251         struct rt6_nh *nh;
4252
4253         list_for_each_entry(nh, rt6_nh_list, next) {
4254                 pr_warn("IPV6: multipath route replace failed (check consistency of installed routes): %pI6c nexthop %pI6c ifi %d\n",
4255                         &nh->r_cfg.fc_dst, &nh->r_cfg.fc_gateway,
4256                         nh->r_cfg.fc_ifindex);
4257         }
4258 }
4259
4260 static int ip6_route_info_append(struct net *net,
4261                                  struct list_head *rt6_nh_list,
4262                                  struct fib6_info *rt,
4263                                  struct fib6_config *r_cfg)
4264 {
4265         struct rt6_nh *nh;
4266         int err = -EEXIST;
4267
4268         list_for_each_entry(nh, rt6_nh_list, next) {
4269                 /* check if fib6_info already exists */
4270                 if (rt6_duplicate_nexthop(nh->fib6_info, rt))
4271                         return err;
4272         }
4273
4274         nh = kzalloc(sizeof(*nh), GFP_KERNEL);
4275         if (!nh)
4276                 return -ENOMEM;
4277         nh->fib6_info = rt;
4278         memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
4279         list_add_tail(&nh->next, rt6_nh_list);
4280
4281         return 0;
4282 }
4283
4284 static void ip6_route_mpath_notify(struct fib6_info *rt,
4285                                    struct fib6_info *rt_last,
4286                                    struct nl_info *info,
4287                                    __u16 nlflags)
4288 {
4289         /* if this is an APPEND route, then rt points to the first route
4290          * inserted and rt_last points to last route inserted. Userspace
4291          * wants a consistent dump of the route which starts at the first
4292          * nexthop. Since sibling routes are always added at the end of
4293          * the list, find the first sibling of the last route appended
4294          */
4295         if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
4296                 rt = list_first_entry(&rt_last->fib6_siblings,
4297                                       struct fib6_info,
4298                                       fib6_siblings);
4299         }
4300
4301         if (rt)
4302                 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
4303 }
4304
4305 static int ip6_route_multipath_add(struct fib6_config *cfg,
4306                                    struct netlink_ext_ack *extack)
4307 {
4308         struct fib6_info *rt_notif = NULL, *rt_last = NULL;
4309         struct nl_info *info = &cfg->fc_nlinfo;
4310         struct fib6_config r_cfg;
4311         struct rtnexthop *rtnh;
4312         struct fib6_info *rt;
4313         struct rt6_nh *err_nh;
4314         struct rt6_nh *nh, *nh_safe;
4315         __u16 nlflags;
4316         int remaining;
4317         int attrlen;
4318         int err = 1;
4319         int nhn = 0;
4320         int replace = (cfg->fc_nlinfo.nlh &&
4321                        (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
4322         LIST_HEAD(rt6_nh_list);
4323
4324         nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
4325         if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
4326                 nlflags |= NLM_F_APPEND;
4327
4328         remaining = cfg->fc_mp_len;
4329         rtnh = (struct rtnexthop *)cfg->fc_mp;
4330
4331         /* Parse a Multipath Entry and build a list (rt6_nh_list) of
4332          * fib6_info structs per nexthop
4333          */
4334         while (rtnh_ok(rtnh, remaining)) {
4335                 memcpy(&r_cfg, cfg, sizeof(*cfg));
4336                 if (rtnh->rtnh_ifindex)
4337                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
4338
4339                 attrlen = rtnh_attrlen(rtnh);
4340                 if (attrlen > 0) {
4341                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
4342
4343                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
4344                         if (nla) {
4345                                 r_cfg.fc_gateway = nla_get_in6_addr(nla);
4346                                 r_cfg.fc_flags |= RTF_GATEWAY;
4347                         }
4348                         r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
4349                         nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
4350                         if (nla)
4351                                 r_cfg.fc_encap_type = nla_get_u16(nla);
4352                 }
4353
4354                 r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
4355                 rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
4356                 if (IS_ERR(rt)) {
4357                         err = PTR_ERR(rt);
4358                         rt = NULL;
4359                         goto cleanup;
4360                 }
4361                 if (!rt6_qualify_for_ecmp(rt)) {
4362                         err = -EINVAL;
4363                         NL_SET_ERR_MSG(extack,
4364                                        "Device only routes can not be added for IPv6 using the multipath API.");
4365                         fib6_info_release(rt);
4366                         goto cleanup;
4367                 }
4368
4369                 rt->fib6_nh.nh_weight = rtnh->rtnh_hops + 1;
4370
4371                 err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
4372                                             rt, &r_cfg);
4373                 if (err) {
4374                         fib6_info_release(rt);
4375                         goto cleanup;
4376                 }
4377
4378                 rtnh = rtnh_next(rtnh, &remaining);
4379         }
4380
4381         /* for add and replace send one notification with all nexthops.
4382          * Skip the notification in fib6_add_rt2node and send one with
4383          * the full route when done
4384          */
4385         info->skip_notify = 1;
4386
4387         err_nh = NULL;
4388         list_for_each_entry(nh, &rt6_nh_list, next) {
4389                 err = __ip6_ins_rt(nh->fib6_info, info, extack);
4390                 fib6_info_release(nh->fib6_info);
4391
4392                 if (!err) {
4393                         /* save reference to last route successfully inserted */
4394                         rt_last = nh->fib6_info;
4395
4396                         /* save reference to first route for notification */
4397                         if (!rt_notif)
4398                                 rt_notif = nh->fib6_info;
4399                 }
4400
4401                 /* nh->fib6_info is used or freed at this point, reset to NULL*/
4402                 nh->fib6_info = NULL;
4403                 if (err) {
4404                         if (replace && nhn)
4405                                 ip6_print_replace_route_err(&rt6_nh_list);
4406                         err_nh = nh;
4407                         goto add_errout;
4408                 }
4409
4410                 /* Because each route is added like a single route we remove
4411                  * these flags after the first nexthop: if there is a collision,
4412                  * we have already failed to add the first nexthop:
4413                  * fib6_add_rt2node() has rejected it; when replacing, old
4414                  * nexthops have been replaced by first new, the rest should
4415                  * be added to it.
4416                  */
4417                 cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
4418                                                      NLM_F_REPLACE);
4419                 nhn++;
4420         }
4421
4422         /* success ... tell user about new route */
4423         ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
4424         goto cleanup;
4425
4426 add_errout:
4427         /* send notification for routes that were added so that
4428          * the delete notifications sent by ip6_route_del are
4429          * coherent
4430          */
4431         if (rt_notif)
4432                 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
4433
4434         /* Delete routes that were already added */
4435         list_for_each_entry(nh, &rt6_nh_list, next) {
4436                 if (err_nh == nh)
4437                         break;
4438                 ip6_route_del(&nh->r_cfg, extack);
4439         }
4440
4441 cleanup:
4442         list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
4443                 if (nh->fib6_info)
4444                         fib6_info_release(nh->fib6_info);
4445                 list_del(&nh->next);
4446                 kfree(nh);
4447         }
4448
4449         return err;
4450 }
4451
4452 static int ip6_route_multipath_del(struct fib6_config *cfg,
4453                                    struct netlink_ext_ack *extack)
4454 {
4455         struct fib6_config r_cfg;
4456         struct rtnexthop *rtnh;
4457         int remaining;
4458         int attrlen;
4459         int err = 1, last_err = 0;
4460
4461         remaining = cfg->fc_mp_len;
4462         rtnh = (struct rtnexthop *)cfg->fc_mp;
4463
4464         /* Parse a Multipath Entry */
4465         while (rtnh_ok(rtnh, remaining)) {
4466                 memcpy(&r_cfg, cfg, sizeof(*cfg));
4467                 if (rtnh->rtnh_ifindex)
4468                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
4469
4470                 attrlen = rtnh_attrlen(rtnh);
4471                 if (attrlen > 0) {
4472                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
4473
4474                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
4475                         if (nla) {
4476                                 nla_memcpy(&r_cfg.fc_gateway, nla, 16);
4477                                 r_cfg.fc_flags |= RTF_GATEWAY;
4478                         }
4479                 }
4480                 err = ip6_route_del(&r_cfg, extack);
4481                 if (err)
4482                         last_err = err;
4483
4484                 rtnh = rtnh_next(rtnh, &remaining);
4485         }
4486
4487         return last_err;
4488 }
4489
4490 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
4491                               struct netlink_ext_ack *extack)
4492 {
4493         struct fib6_config cfg;
4494         int err;
4495
4496         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
4497         if (err < 0)
4498                 return err;
4499
4500         if (cfg.fc_mp)
4501                 return ip6_route_multipath_del(&cfg, extack);
4502         else {
4503                 cfg.fc_delete_all_nh = 1;
4504                 return ip6_route_del(&cfg, extack);
4505         }
4506 }
4507
4508 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
4509                               struct netlink_ext_ack *extack)
4510 {
4511         struct fib6_config cfg;
4512         int err;
4513
4514         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
4515         if (err < 0)
4516                 return err;
4517
4518         if (cfg.fc_mp)
4519                 return ip6_route_multipath_add(&cfg, extack);
4520         else
4521                 return ip6_route_add(&cfg, GFP_KERNEL, extack);
4522 }
4523
4524 static size_t rt6_nlmsg_size(struct fib6_info *rt)
4525 {
4526         int nexthop_len = 0;
4527
4528         if (rt->fib6_nsiblings) {
4529                 nexthop_len = nla_total_size(0)  /* RTA_MULTIPATH */
4530                             + NLA_ALIGN(sizeof(struct rtnexthop))
4531                             + nla_total_size(16) /* RTA_GATEWAY */
4532                             + lwtunnel_get_encap_size(rt->fib6_nh.nh_lwtstate);
4533
4534                 nexthop_len *= rt->fib6_nsiblings;
4535         }
4536
4537         return NLMSG_ALIGN(sizeof(struct rtmsg))
4538                + nla_total_size(16) /* RTA_SRC */
4539                + nla_total_size(16) /* RTA_DST */
4540                + nla_total_size(16) /* RTA_GATEWAY */
4541                + nla_total_size(16) /* RTA_PREFSRC */
4542                + nla_total_size(4) /* RTA_TABLE */
4543                + nla_total_size(4) /* RTA_IIF */
4544                + nla_total_size(4) /* RTA_OIF */
4545                + nla_total_size(4) /* RTA_PRIORITY */
4546                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
4547                + nla_total_size(sizeof(struct rta_cacheinfo))
4548                + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
4549                + nla_total_size(1) /* RTA_PREF */
4550                + lwtunnel_get_encap_size(rt->fib6_nh.nh_lwtstate)
4551                + nexthop_len;
4552 }
4553
4554 static int rt6_nexthop_info(struct sk_buff *skb, struct fib6_info *rt,
4555                             unsigned int *flags, bool skip_oif)
4556 {
4557         if (rt->fib6_nh.nh_flags & RTNH_F_DEAD)
4558                 *flags |= RTNH_F_DEAD;
4559
4560         if (rt->fib6_nh.nh_flags & RTNH_F_LINKDOWN) {
4561                 *flags |= RTNH_F_LINKDOWN;
4562
4563                 rcu_read_lock();
4564                 if (fib6_ignore_linkdown(rt))
4565                         *flags |= RTNH_F_DEAD;
4566                 rcu_read_unlock();
4567         }
4568
4569         if (rt->fib6_flags & RTF_GATEWAY) {
4570                 if (nla_put_in6_addr(skb, RTA_GATEWAY, &rt->fib6_nh.nh_gw) < 0)
4571                         goto nla_put_failure;
4572         }
4573
4574         *flags |= (rt->fib6_nh.nh_flags & RTNH_F_ONLINK);
4575         if (rt->fib6_nh.nh_flags & RTNH_F_OFFLOAD)
4576                 *flags |= RTNH_F_OFFLOAD;
4577
4578         /* not needed for multipath encoding b/c it has a rtnexthop struct */
4579         if (!skip_oif && rt->fib6_nh.nh_dev &&
4580             nla_put_u32(skb, RTA_OIF, rt->fib6_nh.nh_dev->ifindex))
4581                 goto nla_put_failure;
4582
4583         if (rt->fib6_nh.nh_lwtstate &&
4584             lwtunnel_fill_encap(skb, rt->fib6_nh.nh_lwtstate) < 0)
4585                 goto nla_put_failure;
4586
4587         return 0;
4588
4589 nla_put_failure:
4590         return -EMSGSIZE;
4591 }
4592
4593 /* add multipath next hop */
4594 static int rt6_add_nexthop(struct sk_buff *skb, struct fib6_info *rt)
4595 {
4596         const struct net_device *dev = rt->fib6_nh.nh_dev;
4597         struct rtnexthop *rtnh;
4598         unsigned int flags = 0;
4599
4600         rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
4601         if (!rtnh)
4602                 goto nla_put_failure;
4603
4604         rtnh->rtnh_hops = rt->fib6_nh.nh_weight - 1;
4605         rtnh->rtnh_ifindex = dev ? dev->ifindex : 0;
4606
4607         if (rt6_nexthop_info(skb, rt, &flags, true) < 0)
4608                 goto nla_put_failure;
4609
4610         rtnh->rtnh_flags = flags;
4611
4612         /* length of rtnetlink header + attributes */
4613         rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
4614
4615         return 0;
4616
4617 nla_put_failure:
4618         return -EMSGSIZE;
4619 }
4620
4621 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
4622                          struct fib6_info *rt, struct dst_entry *dst,
4623                          struct in6_addr *dest, struct in6_addr *src,
4624                          int iif, int type, u32 portid, u32 seq,
4625                          unsigned int flags)
4626 {
4627         struct rt6_info *rt6 = (struct rt6_info *)dst;
4628         struct rt6key *rt6_dst, *rt6_src;
4629         u32 *pmetrics, table, rt6_flags;
4630         struct nlmsghdr *nlh;
4631         struct rtmsg *rtm;
4632         long expires = 0;
4633
4634         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
4635         if (!nlh)
4636                 return -EMSGSIZE;
4637
4638         if (rt6) {
4639                 rt6_dst = &rt6->rt6i_dst;
4640                 rt6_src = &rt6->rt6i_src;
4641                 rt6_flags = rt6->rt6i_flags;
4642         } else {
4643                 rt6_dst = &rt->fib6_dst;
4644                 rt6_src = &rt->fib6_src;
4645                 rt6_flags = rt->fib6_flags;
4646         }
4647
4648         rtm = nlmsg_data(nlh);
4649         rtm->rtm_family = AF_INET6;
4650         rtm->rtm_dst_len = rt6_dst->plen;
4651         rtm->rtm_src_len = rt6_src->plen;
4652         rtm->rtm_tos = 0;
4653         if (rt->fib6_table)
4654                 table = rt->fib6_table->tb6_id;
4655         else
4656                 table = RT6_TABLE_UNSPEC;
4657         rtm->rtm_table = table;
4658         if (nla_put_u32(skb, RTA_TABLE, table))
4659                 goto nla_put_failure;
4660
4661         rtm->rtm_type = rt->fib6_type;
4662         rtm->rtm_flags = 0;
4663         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
4664         rtm->rtm_protocol = rt->fib6_protocol;
4665
4666         if (rt6_flags & RTF_CACHE)
4667                 rtm->rtm_flags |= RTM_F_CLONED;
4668
4669         if (dest) {
4670                 if (nla_put_in6_addr(skb, RTA_DST, dest))
4671                         goto nla_put_failure;
4672                 rtm->rtm_dst_len = 128;
4673         } else if (rtm->rtm_dst_len)
4674                 if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
4675                         goto nla_put_failure;
4676 #ifdef CONFIG_IPV6_SUBTREES
4677         if (src) {
4678                 if (nla_put_in6_addr(skb, RTA_SRC, src))
4679                         goto nla_put_failure;
4680                 rtm->rtm_src_len = 128;
4681         } else if (rtm->rtm_src_len &&
4682                    nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
4683                 goto nla_put_failure;
4684 #endif
4685         if (iif) {
4686 #ifdef CONFIG_IPV6_MROUTE
4687                 if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
4688                         int err = ip6mr_get_route(net, skb, rtm, portid);
4689
4690                         if (err == 0)
4691                                 return 0;
4692                         if (err < 0)
4693                                 goto nla_put_failure;
4694                 } else
4695 #endif
4696                         if (nla_put_u32(skb, RTA_IIF, iif))
4697                                 goto nla_put_failure;
4698         } else if (dest) {
4699                 struct in6_addr saddr_buf;
4700                 if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 &&
4701                     nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
4702                         goto nla_put_failure;
4703         }
4704
4705         if (rt->fib6_prefsrc.plen) {
4706                 struct in6_addr saddr_buf;
4707                 saddr_buf = rt->fib6_prefsrc.addr;
4708                 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
4709                         goto nla_put_failure;
4710         }
4711
4712         pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
4713         if (rtnetlink_put_metrics(skb, pmetrics) < 0)
4714                 goto nla_put_failure;
4715
4716         if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
4717                 goto nla_put_failure;
4718
4719         /* For multipath routes, walk the siblings list and add
4720          * each as a nexthop within RTA_MULTIPATH.
4721          */
4722         if (rt6) {
4723                 if (rt6_flags & RTF_GATEWAY &&
4724                     nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
4725                         goto nla_put_failure;
4726
4727                 if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
4728                         goto nla_put_failure;
4729         } else if (rt->fib6_nsiblings) {
4730                 struct fib6_info *sibling, *next_sibling;
4731                 struct nlattr *mp;
4732
4733                 mp = nla_nest_start(skb, RTA_MULTIPATH);
4734                 if (!mp)
4735                         goto nla_put_failure;
4736
4737                 if (rt6_add_nexthop(skb, rt) < 0)
4738                         goto nla_put_failure;
4739
4740                 list_for_each_entry_safe(sibling, next_sibling,
4741                                          &rt->fib6_siblings, fib6_siblings) {
4742                         if (rt6_add_nexthop(skb, sibling) < 0)
4743                                 goto nla_put_failure;
4744                 }
4745
4746                 nla_nest_end(skb, mp);
4747         } else {
4748                 if (rt6_nexthop_info(skb, rt, &rtm->rtm_flags, false) < 0)
4749                         goto nla_put_failure;
4750         }
4751
4752         if (rt6_flags & RTF_EXPIRES) {
4753                 expires = dst ? dst->expires : rt->expires;
4754                 expires -= jiffies;
4755         }
4756
4757         if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
4758                 goto nla_put_failure;
4759
4760         if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
4761                 goto nla_put_failure;
4762
4763
4764         nlmsg_end(skb, nlh);
4765         return 0;
4766
4767 nla_put_failure:
4768         nlmsg_cancel(skb, nlh);
4769         return -EMSGSIZE;
4770 }
4771
4772 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
4773                                const struct net_device *dev)
4774 {
4775         if (f6i->fib6_nh.nh_dev == dev)
4776                 return true;
4777
4778         if (f6i->fib6_nsiblings) {
4779                 struct fib6_info *sibling, *next_sibling;
4780
4781                 list_for_each_entry_safe(sibling, next_sibling,
4782                                          &f6i->fib6_siblings, fib6_siblings) {
4783                         if (sibling->fib6_nh.nh_dev == dev)
4784                                 return true;
4785                 }
4786         }
4787
4788         return false;
4789 }
4790
4791 int rt6_dump_route(struct fib6_info *rt, void *p_arg)
4792 {
4793         struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
4794         struct fib_dump_filter *filter = &arg->filter;
4795         unsigned int flags = NLM_F_MULTI;
4796         struct net *net = arg->net;
4797
4798         if (rt == net->ipv6.fib6_null_entry)
4799                 return 0;
4800
4801         if ((filter->flags & RTM_F_PREFIX) &&
4802             !(rt->fib6_flags & RTF_PREFIX_RT)) {
4803                 /* success since this is not a prefix route */
4804                 return 1;
4805         }
4806         if (filter->filter_set) {
4807                 if ((filter->rt_type && rt->fib6_type != filter->rt_type) ||
4808                     (filter->dev && !fib6_info_uses_dev(rt, filter->dev)) ||
4809                     (filter->protocol && rt->fib6_protocol != filter->protocol)) {
4810                         return 1;
4811                 }
4812                 flags |= NLM_F_DUMP_FILTERED;
4813         }
4814
4815         return rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL, 0,
4816                              RTM_NEWROUTE, NETLINK_CB(arg->cb->skb).portid,
4817                              arg->cb->nlh->nlmsg_seq, flags);
4818 }
4819
4820 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
4821                               struct netlink_ext_ack *extack)
4822 {
4823         struct net *net = sock_net(in_skb->sk);
4824         struct nlattr *tb[RTA_MAX+1];
4825         int err, iif = 0, oif = 0;
4826         struct fib6_info *from;
4827         struct dst_entry *dst;
4828         struct rt6_info *rt;
4829         struct sk_buff *skb;
4830         struct rtmsg *rtm;
4831         struct flowi6 fl6 = {};
4832         bool fibmatch;
4833
4834         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy,
4835                           extack);
4836         if (err < 0)
4837                 goto errout;
4838
4839         err = -EINVAL;
4840         rtm = nlmsg_data(nlh);
4841         fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
4842         fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
4843
4844         if (tb[RTA_SRC]) {
4845                 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
4846                         goto errout;
4847
4848                 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
4849         }
4850
4851         if (tb[RTA_DST]) {
4852                 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
4853                         goto errout;
4854
4855                 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
4856         }
4857
4858         if (tb[RTA_IIF])
4859                 iif = nla_get_u32(tb[RTA_IIF]);
4860
4861         if (tb[RTA_OIF])
4862                 oif = nla_get_u32(tb[RTA_OIF]);
4863
4864         if (tb[RTA_MARK])
4865                 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
4866
4867         if (tb[RTA_UID])
4868                 fl6.flowi6_uid = make_kuid(current_user_ns(),
4869                                            nla_get_u32(tb[RTA_UID]));
4870         else
4871                 fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
4872
4873         if (tb[RTA_SPORT])
4874                 fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
4875
4876         if (tb[RTA_DPORT])
4877                 fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
4878
4879         if (tb[RTA_IP_PROTO]) {
4880                 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
4881                                                   &fl6.flowi6_proto, extack);
4882                 if (err)
4883                         goto errout;
4884         }
4885
4886         if (iif) {
4887                 struct net_device *dev;
4888                 int flags = 0;
4889
4890                 rcu_read_lock();
4891
4892                 dev = dev_get_by_index_rcu(net, iif);
4893                 if (!dev) {
4894                         rcu_read_unlock();
4895                         err = -ENODEV;
4896                         goto errout;
4897                 }
4898
4899                 fl6.flowi6_iif = iif;
4900
4901                 if (!ipv6_addr_any(&fl6.saddr))
4902                         flags |= RT6_LOOKUP_F_HAS_SADDR;
4903
4904                 dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
4905
4906                 rcu_read_unlock();
4907         } else {
4908                 fl6.flowi6_oif = oif;
4909
4910                 dst = ip6_route_output(net, NULL, &fl6);
4911         }
4912
4913
4914         rt = container_of(dst, struct rt6_info, dst);
4915         if (rt->dst.error) {
4916                 err = rt->dst.error;
4917                 ip6_rt_put(rt);
4918                 goto errout;
4919         }
4920
4921         if (rt == net->ipv6.ip6_null_entry) {
4922                 err = rt->dst.error;
4923                 ip6_rt_put(rt);
4924                 goto errout;
4925         }
4926
4927         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
4928         if (!skb) {
4929                 ip6_rt_put(rt);
4930                 err = -ENOBUFS;
4931                 goto errout;
4932         }
4933
4934         skb_dst_set(skb, &rt->dst);
4935
4936         rcu_read_lock();
4937         from = rcu_dereference(rt->from);
4938
4939         if (fibmatch)
4940                 err = rt6_fill_node(net, skb, from, NULL, NULL, NULL, iif,
4941                                     RTM_NEWROUTE, NETLINK_CB(in_skb).portid,
4942                                     nlh->nlmsg_seq, 0);
4943         else
4944                 err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
4945                                     &fl6.saddr, iif, RTM_NEWROUTE,
4946                                     NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
4947                                     0);
4948         rcu_read_unlock();
4949
4950         if (err < 0) {
4951                 kfree_skb(skb);
4952                 goto errout;
4953         }
4954
4955         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
4956 errout:
4957         return err;
4958 }
4959
4960 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
4961                      unsigned int nlm_flags)
4962 {
4963         struct sk_buff *skb;
4964         struct net *net = info->nl_net;
4965         u32 seq;
4966         int err;
4967
4968         err = -ENOBUFS;
4969         seq = info->nlh ? info->nlh->nlmsg_seq : 0;
4970
4971         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
4972         if (!skb)
4973                 goto errout;
4974
4975         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
4976                             event, info->portid, seq, nlm_flags);
4977         if (err < 0) {
4978                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
4979                 WARN_ON(err == -EMSGSIZE);
4980                 kfree_skb(skb);
4981                 goto errout;
4982         }
4983         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
4984                     info->nlh, gfp_any());
4985         return;
4986 errout:
4987         if (err < 0)
4988                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
4989 }
4990
4991 static int ip6_route_dev_notify(struct notifier_block *this,
4992                                 unsigned long event, void *ptr)
4993 {
4994         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4995         struct net *net = dev_net(dev);
4996
4997         if (!(dev->flags & IFF_LOOPBACK))
4998                 return NOTIFY_OK;
4999
5000         if (event == NETDEV_REGISTER) {
5001                 net->ipv6.fib6_null_entry->fib6_nh.nh_dev = dev;
5002                 net->ipv6.ip6_null_entry->dst.dev = dev;
5003                 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
5004 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
5005                 net->ipv6.ip6_prohibit_entry->dst.dev = dev;
5006                 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
5007                 net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
5008                 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
5009 #endif
5010          } else if (event == NETDEV_UNREGISTER &&
5011                     dev->reg_state != NETREG_UNREGISTERED) {
5012                 /* NETDEV_UNREGISTER could be fired for multiple times by
5013                  * netdev_wait_allrefs(). Make sure we only call this once.
5014                  */
5015                 in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
5016 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
5017                 in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
5018                 in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
5019 #endif
5020         }
5021
5022         return NOTIFY_OK;
5023 }
5024
5025 /*
5026  *      /proc
5027  */
5028
5029 #ifdef CONFIG_PROC_FS
5030 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
5031 {
5032         struct net *net = (struct net *)seq->private;
5033         seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
5034                    net->ipv6.rt6_stats->fib_nodes,
5035                    net->ipv6.rt6_stats->fib_route_nodes,
5036                    atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
5037                    net->ipv6.rt6_stats->fib_rt_entries,
5038                    net->ipv6.rt6_stats->fib_rt_cache,
5039                    dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
5040                    net->ipv6.rt6_stats->fib_discarded_routes);
5041
5042         return 0;
5043 }
5044 #endif  /* CONFIG_PROC_FS */
5045
5046 #ifdef CONFIG_SYSCTL
5047
5048 static
5049 int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
5050                               void __user *buffer, size_t *lenp, loff_t *ppos)
5051 {
5052         struct net *net;
5053         int delay;
5054         if (!write)
5055                 return -EINVAL;
5056
5057         net = (struct net *)ctl->extra1;
5058         delay = net->ipv6.sysctl.flush_delay;
5059         proc_dointvec(ctl, write, buffer, lenp, ppos);
5060         fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
5061         return 0;
5062 }
5063
5064 static int zero;
5065 static int one = 1;
5066
5067 static struct ctl_table ipv6_route_table_template[] = {
5068         {
5069                 .procname       =       "flush",
5070                 .data           =       &init_net.ipv6.sysctl.flush_delay,
5071                 .maxlen         =       sizeof(int),
5072                 .mode           =       0200,
5073                 .proc_handler   =       ipv6_sysctl_rtcache_flush
5074         },
5075         {
5076                 .procname       =       "gc_thresh",
5077                 .data           =       &ip6_dst_ops_template.gc_thresh,
5078                 .maxlen         =       sizeof(int),
5079                 .mode           =       0644,
5080                 .proc_handler   =       proc_dointvec,
5081         },
5082         {
5083                 .procname       =       "max_size",
5084                 .data           =       &init_net.ipv6.sysctl.ip6_rt_max_size,
5085                 .maxlen         =       sizeof(int),
5086                 .mode           =       0644,
5087                 .proc_handler   =       proc_dointvec,
5088         },
5089         {
5090                 .procname       =       "gc_min_interval",
5091                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
5092                 .maxlen         =       sizeof(int),
5093                 .mode           =       0644,
5094                 .proc_handler   =       proc_dointvec_jiffies,
5095         },
5096         {
5097                 .procname       =       "gc_timeout",
5098                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
5099                 .maxlen         =       sizeof(int),
5100                 .mode           =       0644,
5101                 .proc_handler   =       proc_dointvec_jiffies,
5102         },
5103         {
5104                 .procname       =       "gc_interval",
5105                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_interval,
5106                 .maxlen         =       sizeof(int),
5107                 .mode           =       0644,
5108                 .proc_handler   =       proc_dointvec_jiffies,
5109         },
5110         {
5111                 .procname       =       "gc_elasticity",
5112                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
5113                 .maxlen         =       sizeof(int),
5114                 .mode           =       0644,
5115                 .proc_handler   =       proc_dointvec,
5116         },
5117         {
5118                 .procname       =       "mtu_expires",
5119                 .data           =       &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
5120                 .maxlen         =       sizeof(int),
5121                 .mode           =       0644,
5122                 .proc_handler   =       proc_dointvec_jiffies,
5123         },
5124         {
5125                 .procname       =       "min_adv_mss",
5126                 .data           =       &init_net.ipv6.sysctl.ip6_rt_min_advmss,
5127                 .maxlen         =       sizeof(int),
5128                 .mode           =       0644,
5129                 .proc_handler   =       proc_dointvec,
5130         },
5131         {
5132                 .procname       =       "gc_min_interval_ms",
5133                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
5134                 .maxlen         =       sizeof(int),
5135                 .mode           =       0644,
5136                 .proc_handler   =       proc_dointvec_ms_jiffies,
5137         },
5138         {
5139                 .procname       =       "skip_notify_on_dev_down",
5140                 .data           =       &init_net.ipv6.sysctl.skip_notify_on_dev_down,
5141                 .maxlen         =       sizeof(int),
5142                 .mode           =       0644,
5143                 .proc_handler   =       proc_dointvec,
5144                 .extra1         =       &zero,
5145                 .extra2         =       &one,
5146         },
5147         { }
5148 };
5149
5150 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
5151 {
5152         struct ctl_table *table;
5153
5154         table = kmemdup(ipv6_route_table_template,
5155                         sizeof(ipv6_route_table_template),
5156                         GFP_KERNEL);
5157
5158         if (table) {
5159                 table[0].data = &net->ipv6.sysctl.flush_delay;
5160                 table[0].extra1 = net;
5161                 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
5162                 table[2].data = &net->ipv6.sysctl.ip6_rt_max_size;
5163                 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
5164                 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
5165                 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
5166                 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
5167                 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
5168                 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
5169                 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
5170                 table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
5171
5172                 /* Don't export sysctls to unprivileged users */
5173                 if (net->user_ns != &init_user_ns)
5174                         table[0].procname = NULL;
5175         }
5176
5177         return table;
5178 }
5179 #endif
5180
5181 static int __net_init ip6_route_net_init(struct net *net)
5182 {
5183         int ret = -ENOMEM;
5184
5185         memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
5186                sizeof(net->ipv6.ip6_dst_ops));
5187
5188         if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
5189                 goto out_ip6_dst_ops;
5190
5191         net->ipv6.fib6_null_entry = kmemdup(&fib6_null_entry_template,
5192                                             sizeof(*net->ipv6.fib6_null_entry),
5193                                             GFP_KERNEL);
5194         if (!net->ipv6.fib6_null_entry)
5195                 goto out_ip6_dst_entries;
5196
5197         net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
5198                                            sizeof(*net->ipv6.ip6_null_entry),
5199                                            GFP_KERNEL);
5200         if (!net->ipv6.ip6_null_entry)
5201                 goto out_fib6_null_entry;
5202         net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
5203         dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
5204                          ip6_template_metrics, true);
5205
5206 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
5207         net->ipv6.fib6_has_custom_rules = false;
5208         net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
5209                                                sizeof(*net->ipv6.ip6_prohibit_entry),
5210                                                GFP_KERNEL);
5211         if (!net->ipv6.ip6_prohibit_entry)
5212                 goto out_ip6_null_entry;
5213         net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
5214         dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
5215                          ip6_template_metrics, true);
5216
5217         net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
5218                                                sizeof(*net->ipv6.ip6_blk_hole_entry),
5219                                                GFP_KERNEL);
5220         if (!net->ipv6.ip6_blk_hole_entry)
5221                 goto out_ip6_prohibit_entry;
5222         net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
5223         dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
5224                          ip6_template_metrics, true);
5225 #endif
5226
5227         net->ipv6.sysctl.flush_delay = 0;
5228         net->ipv6.sysctl.ip6_rt_max_size = 4096;
5229         net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
5230         net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
5231         net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
5232         net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
5233         net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
5234         net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
5235         net->ipv6.sysctl.skip_notify_on_dev_down = 0;
5236
5237         net->ipv6.ip6_rt_gc_expire = 30*HZ;
5238
5239         ret = 0;
5240 out:
5241         return ret;
5242
5243 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
5244 out_ip6_prohibit_entry:
5245         kfree(net->ipv6.ip6_prohibit_entry);
5246 out_ip6_null_entry:
5247         kfree(net->ipv6.ip6_null_entry);
5248 #endif
5249 out_fib6_null_entry:
5250         kfree(net->ipv6.fib6_null_entry);
5251 out_ip6_dst_entries:
5252         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
5253 out_ip6_dst_ops:
5254         goto out;
5255 }
5256
5257 static void __net_exit ip6_route_net_exit(struct net *net)
5258 {
5259         kfree(net->ipv6.fib6_null_entry);
5260         kfree(net->ipv6.ip6_null_entry);
5261 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
5262         kfree(net->ipv6.ip6_prohibit_entry);
5263         kfree(net->ipv6.ip6_blk_hole_entry);
5264 #endif
5265         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
5266 }
5267
5268 static int __net_init ip6_route_net_init_late(struct net *net)
5269 {
5270 #ifdef CONFIG_PROC_FS
5271         proc_create_net("ipv6_route", 0, net->proc_net, &ipv6_route_seq_ops,
5272                         sizeof(struct ipv6_route_iter));
5273         proc_create_net_single("rt6_stats", 0444, net->proc_net,
5274                         rt6_stats_seq_show, NULL);
5275 #endif
5276         return 0;
5277 }
5278
5279 static void __net_exit ip6_route_net_exit_late(struct net *net)
5280 {
5281 #ifdef CONFIG_PROC_FS
5282         remove_proc_entry("ipv6_route", net->proc_net);
5283         remove_proc_entry("rt6_stats", net->proc_net);
5284 #endif
5285 }
5286
5287 static struct pernet_operations ip6_route_net_ops = {
5288         .init = ip6_route_net_init,
5289         .exit = ip6_route_net_exit,
5290 };
5291
5292 static int __net_init ipv6_inetpeer_init(struct net *net)
5293 {
5294         struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
5295
5296         if (!bp)
5297                 return -ENOMEM;
5298         inet_peer_base_init(bp);
5299         net->ipv6.peers = bp;
5300         return 0;
5301 }
5302
5303 static void __net_exit ipv6_inetpeer_exit(struct net *net)
5304 {
5305         struct inet_peer_base *bp = net->ipv6.peers;
5306
5307         net->ipv6.peers = NULL;
5308         inetpeer_invalidate_tree(bp);
5309         kfree(bp);
5310 }
5311
5312 static struct pernet_operations ipv6_inetpeer_ops = {
5313         .init   =       ipv6_inetpeer_init,
5314         .exit   =       ipv6_inetpeer_exit,
5315 };
5316
5317 static struct pernet_operations ip6_route_net_late_ops = {
5318         .init = ip6_route_net_init_late,
5319         .exit = ip6_route_net_exit_late,
5320 };
5321
5322 static struct notifier_block ip6_route_dev_notifier = {
5323         .notifier_call = ip6_route_dev_notify,
5324         .priority = ADDRCONF_NOTIFY_PRIORITY - 10,
5325 };
5326
5327 void __init ip6_route_init_special_entries(void)
5328 {
5329         /* Registering of the loopback is done before this portion of code,
5330          * the loopback reference in rt6_info will not be taken, do it
5331          * manually for init_net */
5332         init_net.ipv6.fib6_null_entry->fib6_nh.nh_dev = init_net.loopback_dev;
5333         init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
5334         init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
5335   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
5336         init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
5337         init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
5338         init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
5339         init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
5340   #endif
5341 }
5342
5343 int __init ip6_route_init(void)
5344 {
5345         int ret;
5346         int cpu;
5347
5348         ret = -ENOMEM;
5349         ip6_dst_ops_template.kmem_cachep =
5350                 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
5351                                   SLAB_HWCACHE_ALIGN, NULL);
5352         if (!ip6_dst_ops_template.kmem_cachep)
5353                 goto out;
5354
5355         ret = dst_entries_init(&ip6_dst_blackhole_ops);
5356         if (ret)
5357                 goto out_kmem_cache;
5358
5359         ret = register_pernet_subsys(&ipv6_inetpeer_ops);
5360         if (ret)
5361                 goto out_dst_entries;
5362
5363         ret = register_pernet_subsys(&ip6_route_net_ops);
5364         if (ret)
5365                 goto out_register_inetpeer;
5366
5367         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
5368
5369         ret = fib6_init();
5370         if (ret)
5371                 goto out_register_subsys;
5372
5373         ret = xfrm6_init();
5374         if (ret)
5375                 goto out_fib6_init;
5376
5377         ret = fib6_rules_init();
5378         if (ret)
5379                 goto xfrm6_init;
5380
5381         ret = register_pernet_subsys(&ip6_route_net_late_ops);
5382         if (ret)
5383                 goto fib6_rules_init;
5384
5385         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
5386                                    inet6_rtm_newroute, NULL, 0);
5387         if (ret < 0)
5388                 goto out_register_late_subsys;
5389
5390         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
5391                                    inet6_rtm_delroute, NULL, 0);
5392         if (ret < 0)
5393                 goto out_register_late_subsys;
5394
5395         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
5396                                    inet6_rtm_getroute, NULL,
5397                                    RTNL_FLAG_DOIT_UNLOCKED);
5398         if (ret < 0)
5399                 goto out_register_late_subsys;
5400
5401         ret = register_netdevice_notifier(&ip6_route_dev_notifier);
5402         if (ret)
5403                 goto out_register_late_subsys;
5404
5405         for_each_possible_cpu(cpu) {
5406                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
5407
5408                 INIT_LIST_HEAD(&ul->head);
5409                 spin_lock_init(&ul->lock);
5410         }
5411
5412 out:
5413         return ret;
5414
5415 out_register_late_subsys:
5416         rtnl_unregister_all(PF_INET6);
5417         unregister_pernet_subsys(&ip6_route_net_late_ops);
5418 fib6_rules_init:
5419         fib6_rules_cleanup();
5420 xfrm6_init:
5421         xfrm6_fini();
5422 out_fib6_init:
5423         fib6_gc_cleanup();
5424 out_register_subsys:
5425         unregister_pernet_subsys(&ip6_route_net_ops);
5426 out_register_inetpeer:
5427         unregister_pernet_subsys(&ipv6_inetpeer_ops);
5428 out_dst_entries:
5429         dst_entries_destroy(&ip6_dst_blackhole_ops);
5430 out_kmem_cache:
5431         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
5432         goto out;
5433 }
5434
5435 void ip6_route_cleanup(void)
5436 {
5437         unregister_netdevice_notifier(&ip6_route_dev_notifier);
5438         unregister_pernet_subsys(&ip6_route_net_late_ops);
5439         fib6_rules_cleanup();
5440         xfrm6_fini();
5441         fib6_gc_cleanup();
5442         unregister_pernet_subsys(&ipv6_inetpeer_ops);
5443         unregister_pernet_subsys(&ip6_route_net_ops);
5444         dst_entries_destroy(&ip6_dst_blackhole_ops);
5445         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
5446 }