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                     (grt->rt6i_flags & flags || dev != grt->dst.dev)) {
2749                         NL_SET_ERR_MSG(extack,
2750                                        "Nexthop has invalid gateway or device mismatch");
2751                         err = -EINVAL;
2752                 }
2753
2754                 ip6_rt_put(grt);
2755         }
2756
2757         return err;
2758 }
2759
2760 static int ip6_route_check_nh(struct net *net,
2761                               struct fib6_config *cfg,
2762                               struct net_device **_dev,
2763                               struct inet6_dev **idev)
2764 {
2765         const struct in6_addr *gw_addr = &cfg->fc_gateway;
2766         struct net_device *dev = _dev ? *_dev : NULL;
2767         struct rt6_info *grt = NULL;
2768         int err = -EHOSTUNREACH;
2769
2770         if (cfg->fc_table) {
2771                 int flags = RT6_LOOKUP_F_IFACE;
2772
2773                 grt = ip6_nh_lookup_table(net, cfg, gw_addr,
2774                                           cfg->fc_table, flags);
2775                 if (grt) {
2776                         if (grt->rt6i_flags & RTF_GATEWAY ||
2777                             (dev && dev != grt->dst.dev)) {
2778                                 ip6_rt_put(grt);
2779                                 grt = NULL;
2780                         }
2781                 }
2782         }
2783
2784         if (!grt)
2785                 grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, NULL, 1);
2786
2787         if (!grt)
2788                 goto out;
2789
2790         if (dev) {
2791                 if (dev != grt->dst.dev) {
2792                         ip6_rt_put(grt);
2793                         goto out;
2794                 }
2795         } else {
2796                 *_dev = dev = grt->dst.dev;
2797                 *idev = grt->rt6i_idev;
2798                 dev_hold(dev);
2799                 in6_dev_hold(grt->rt6i_idev);
2800         }
2801
2802         if (!(grt->rt6i_flags & RTF_GATEWAY))
2803                 err = 0;
2804
2805         ip6_rt_put(grt);
2806
2807 out:
2808         return err;
2809 }
2810
2811 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
2812                            struct net_device **_dev, struct inet6_dev **idev,
2813                            struct netlink_ext_ack *extack)
2814 {
2815         const struct in6_addr *gw_addr = &cfg->fc_gateway;
2816         int gwa_type = ipv6_addr_type(gw_addr);
2817         bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
2818         const struct net_device *dev = *_dev;
2819         bool need_addr_check = !dev;
2820         int err = -EINVAL;
2821
2822         /* if gw_addr is local we will fail to detect this in case
2823          * address is still TENTATIVE (DAD in progress). rt6_lookup()
2824          * will return already-added prefix route via interface that
2825          * prefix route was assigned to, which might be non-loopback.
2826          */
2827         if (dev &&
2828             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
2829                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
2830                 goto out;
2831         }
2832
2833         if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
2834                 /* IPv6 strictly inhibits using not link-local
2835                  * addresses as nexthop address.
2836                  * Otherwise, router will not able to send redirects.
2837                  * It is very good, but in some (rare!) circumstances
2838                  * (SIT, PtP, NBMA NOARP links) it is handy to allow
2839                  * some exceptions. --ANK
2840                  * We allow IPv4-mapped nexthops to support RFC4798-type
2841                  * addressing
2842                  */
2843                 if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
2844                         NL_SET_ERR_MSG(extack, "Invalid gateway address");
2845                         goto out;
2846                 }
2847
2848                 if (cfg->fc_flags & RTNH_F_ONLINK)
2849                         err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
2850                 else
2851                         err = ip6_route_check_nh(net, cfg, _dev, idev);
2852
2853                 if (err)
2854                         goto out;
2855         }
2856
2857         /* reload in case device was changed */
2858         dev = *_dev;
2859
2860         err = -EINVAL;
2861         if (!dev) {
2862                 NL_SET_ERR_MSG(extack, "Egress device not specified");
2863                 goto out;
2864         } else if (dev->flags & IFF_LOOPBACK) {
2865                 NL_SET_ERR_MSG(extack,
2866                                "Egress device can not be loopback device for this route");
2867                 goto out;
2868         }
2869
2870         /* if we did not check gw_addr above, do so now that the
2871          * egress device has been resolved.
2872          */
2873         if (need_addr_check &&
2874             ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
2875                 NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
2876                 goto out;
2877         }
2878
2879         err = 0;
2880 out:
2881         return err;
2882 }
2883
2884 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
2885                                               gfp_t gfp_flags,
2886                                               struct netlink_ext_ack *extack)
2887 {
2888         struct net *net = cfg->fc_nlinfo.nl_net;
2889         struct fib6_info *rt = NULL;
2890         struct net_device *dev = NULL;
2891         struct inet6_dev *idev = NULL;
2892         struct fib6_table *table;
2893         int addr_type;
2894         int err = -EINVAL;
2895
2896         /* RTF_PCPU is an internal flag; can not be set by userspace */
2897         if (cfg->fc_flags & RTF_PCPU) {
2898                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
2899                 goto out;
2900         }
2901
2902         /* RTF_CACHE is an internal flag; can not be set by userspace */
2903         if (cfg->fc_flags & RTF_CACHE) {
2904                 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
2905                 goto out;
2906         }
2907
2908         if (cfg->fc_type > RTN_MAX) {
2909                 NL_SET_ERR_MSG(extack, "Invalid route type");
2910                 goto out;
2911         }
2912
2913         if (cfg->fc_dst_len > 128) {
2914                 NL_SET_ERR_MSG(extack, "Invalid prefix length");
2915                 goto out;
2916         }
2917         if (cfg->fc_src_len > 128) {
2918                 NL_SET_ERR_MSG(extack, "Invalid source address length");
2919                 goto out;
2920         }
2921 #ifndef CONFIG_IPV6_SUBTREES
2922         if (cfg->fc_src_len) {
2923                 NL_SET_ERR_MSG(extack,
2924                                "Specifying source address requires IPV6_SUBTREES to be enabled");
2925                 goto out;
2926         }
2927 #endif
2928         if (cfg->fc_ifindex) {
2929                 err = -ENODEV;
2930                 dev = dev_get_by_index(net, cfg->fc_ifindex);
2931                 if (!dev)
2932                         goto out;
2933                 idev = in6_dev_get(dev);
2934                 if (!idev)
2935                         goto out;
2936         }
2937
2938         if (cfg->fc_metric == 0)
2939                 cfg->fc_metric = IP6_RT_PRIO_USER;
2940
2941         if (cfg->fc_flags & RTNH_F_ONLINK) {
2942                 if (!dev) {
2943                         NL_SET_ERR_MSG(extack,
2944                                        "Nexthop device required for onlink");
2945                         err = -ENODEV;
2946                         goto out;
2947                 }
2948
2949                 if (!(dev->flags & IFF_UP)) {
2950                         NL_SET_ERR_MSG(extack, "Nexthop device is not up");
2951                         err = -ENETDOWN;
2952                         goto out;
2953                 }
2954         }
2955
2956         err = -ENOBUFS;
2957         if (cfg->fc_nlinfo.nlh &&
2958             !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
2959                 table = fib6_get_table(net, cfg->fc_table);
2960                 if (!table) {
2961                         pr_warn("NLM_F_CREATE should be specified when creating new route\n");
2962                         table = fib6_new_table(net, cfg->fc_table);
2963                 }
2964         } else {
2965                 table = fib6_new_table(net, cfg->fc_table);
2966         }
2967
2968         if (!table)
2969                 goto out;
2970
2971         err = -ENOMEM;
2972         rt = fib6_info_alloc(gfp_flags);
2973         if (!rt)
2974                 goto out;
2975
2976         rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len);
2977         if (IS_ERR(rt->fib6_metrics)) {
2978                 err = PTR_ERR(rt->fib6_metrics);
2979                 /* Do not leave garbage there. */
2980                 rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
2981                 goto out;
2982         }
2983
2984         if (cfg->fc_flags & RTF_ADDRCONF)
2985                 rt->dst_nocount = true;
2986
2987         if (cfg->fc_flags & RTF_EXPIRES)
2988                 fib6_set_expires(rt, jiffies +
2989                                 clock_t_to_jiffies(cfg->fc_expires));
2990         else
2991                 fib6_clean_expires(rt);
2992
2993         if (cfg->fc_protocol == RTPROT_UNSPEC)
2994                 cfg->fc_protocol = RTPROT_BOOT;
2995         rt->fib6_protocol = cfg->fc_protocol;
2996
2997         addr_type = ipv6_addr_type(&cfg->fc_dst);
2998
2999         if (cfg->fc_encap) {
3000                 struct lwtunnel_state *lwtstate;
3001
3002                 err = lwtunnel_build_state(cfg->fc_encap_type,
3003                                            cfg->fc_encap, AF_INET6, cfg,
3004                                            &lwtstate, extack);
3005                 if (err)
3006                         goto out;
3007                 rt->fib6_nh.nh_lwtstate = lwtstate_get(lwtstate);
3008         }
3009
3010         ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
3011         rt->fib6_dst.plen = cfg->fc_dst_len;
3012         if (rt->fib6_dst.plen == 128)
3013                 rt->dst_host = true;
3014
3015 #ifdef CONFIG_IPV6_SUBTREES
3016         ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
3017         rt->fib6_src.plen = cfg->fc_src_len;
3018 #endif
3019
3020         rt->fib6_metric = cfg->fc_metric;
3021         rt->fib6_nh.nh_weight = 1;
3022
3023         rt->fib6_type = cfg->fc_type;
3024
3025         /* We cannot add true routes via loopback here,
3026            they would result in kernel looping; promote them to reject routes
3027          */
3028         if ((cfg->fc_flags & RTF_REJECT) ||
3029             (dev && (dev->flags & IFF_LOOPBACK) &&
3030              !(addr_type & IPV6_ADDR_LOOPBACK) &&
3031              !(cfg->fc_flags & RTF_LOCAL))) {
3032                 /* hold loopback dev/idev if we haven't done so. */
3033                 if (dev != net->loopback_dev) {
3034                         if (dev) {
3035                                 dev_put(dev);
3036                                 in6_dev_put(idev);
3037                         }
3038                         dev = net->loopback_dev;
3039                         dev_hold(dev);
3040                         idev = in6_dev_get(dev);
3041                         if (!idev) {
3042                                 err = -ENODEV;
3043                                 goto out;
3044                         }
3045                 }
3046                 rt->fib6_flags = RTF_REJECT|RTF_NONEXTHOP;
3047                 goto install_route;
3048         }
3049
3050         if (cfg->fc_flags & RTF_GATEWAY) {
3051                 err = ip6_validate_gw(net, cfg, &dev, &idev, extack);
3052                 if (err)
3053                         goto out;
3054
3055                 rt->fib6_nh.nh_gw = cfg->fc_gateway;
3056         }
3057
3058         err = -ENODEV;
3059         if (!dev)
3060                 goto out;
3061
3062         if (idev->cnf.disable_ipv6) {
3063                 NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
3064                 err = -EACCES;
3065                 goto out;
3066         }
3067
3068         if (!(dev->flags & IFF_UP)) {
3069                 NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3070                 err = -ENETDOWN;
3071                 goto out;
3072         }
3073
3074         if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
3075                 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
3076                         NL_SET_ERR_MSG(extack, "Invalid source address");
3077                         err = -EINVAL;
3078                         goto out;
3079                 }
3080                 rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
3081                 rt->fib6_prefsrc.plen = 128;
3082         } else
3083                 rt->fib6_prefsrc.plen = 0;
3084
3085         rt->fib6_flags = cfg->fc_flags;
3086
3087 install_route:
3088         if (!(rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
3089             !netif_carrier_ok(dev))
3090                 rt->fib6_nh.nh_flags |= RTNH_F_LINKDOWN;
3091         rt->fib6_nh.nh_flags |= (cfg->fc_flags & RTNH_F_ONLINK);
3092         rt->fib6_nh.nh_dev = dev;
3093         rt->fib6_table = table;
3094
3095         if (idev)
3096                 in6_dev_put(idev);
3097
3098         return rt;
3099 out:
3100         if (dev)
3101                 dev_put(dev);
3102         if (idev)
3103                 in6_dev_put(idev);
3104
3105         fib6_info_release(rt);
3106         return ERR_PTR(err);
3107 }
3108
3109 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
3110                   struct netlink_ext_ack *extack)
3111 {
3112         struct fib6_info *rt;
3113         int err;
3114
3115         rt = ip6_route_info_create(cfg, gfp_flags, extack);
3116         if (IS_ERR(rt))
3117                 return PTR_ERR(rt);
3118
3119         err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
3120         fib6_info_release(rt);
3121
3122         return err;
3123 }
3124
3125 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
3126 {
3127         struct net *net = info->nl_net;
3128         struct fib6_table *table;
3129         int err;
3130
3131         if (rt == net->ipv6.fib6_null_entry) {
3132                 err = -ENOENT;
3133                 goto out;
3134         }
3135
3136         table = rt->fib6_table;
3137         spin_lock_bh(&table->tb6_lock);
3138         err = fib6_del(rt, info);
3139         spin_unlock_bh(&table->tb6_lock);
3140
3141 out:
3142         fib6_info_release(rt);
3143         return err;
3144 }
3145
3146 int ip6_del_rt(struct net *net, struct fib6_info *rt)
3147 {
3148         struct nl_info info = { .nl_net = net };
3149
3150         return __ip6_del_rt(rt, &info);
3151 }
3152
3153 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
3154 {
3155         struct nl_info *info = &cfg->fc_nlinfo;
3156         struct net *net = info->nl_net;
3157         struct sk_buff *skb = NULL;
3158         struct fib6_table *table;
3159         int err = -ENOENT;
3160
3161         if (rt == net->ipv6.fib6_null_entry)
3162                 goto out_put;
3163         table = rt->fib6_table;
3164         spin_lock_bh(&table->tb6_lock);
3165
3166         if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
3167                 struct fib6_info *sibling, *next_sibling;
3168
3169                 /* prefer to send a single notification with all hops */
3170                 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3171                 if (skb) {
3172                         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3173
3174                         if (rt6_fill_node(net, skb, rt, NULL,
3175                                           NULL, NULL, 0, RTM_DELROUTE,
3176                                           info->portid, seq, 0) < 0) {
3177                                 kfree_skb(skb);
3178                                 skb = NULL;
3179                         } else
3180                                 info->skip_notify = 1;
3181                 }
3182
3183                 list_for_each_entry_safe(sibling, next_sibling,
3184                                          &rt->fib6_siblings,
3185                                          fib6_siblings) {
3186                         err = fib6_del(sibling, info);
3187                         if (err)
3188                                 goto out_unlock;
3189                 }
3190         }
3191
3192         err = fib6_del(rt, info);
3193 out_unlock:
3194         spin_unlock_bh(&table->tb6_lock);
3195 out_put:
3196         fib6_info_release(rt);
3197
3198         if (skb) {
3199                 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3200                             info->nlh, gfp_any());
3201         }
3202         return err;
3203 }
3204
3205 static int ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
3206 {
3207         int rc = -ESRCH;
3208
3209         if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
3210                 goto out;
3211
3212         if (cfg->fc_flags & RTF_GATEWAY &&
3213             !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
3214                 goto out;
3215         if (dst_hold_safe(&rt->dst))
3216                 rc = rt6_remove_exception_rt(rt);
3217 out:
3218         return rc;
3219 }
3220
3221 static int ip6_route_del(struct fib6_config *cfg,
3222                          struct netlink_ext_ack *extack)
3223 {
3224         struct rt6_info *rt_cache;
3225         struct fib6_table *table;
3226         struct fib6_info *rt;
3227         struct fib6_node *fn;
3228         int err = -ESRCH;
3229
3230         table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
3231         if (!table) {
3232                 NL_SET_ERR_MSG(extack, "FIB table does not exist");
3233                 return err;
3234         }
3235
3236         rcu_read_lock();
3237
3238         fn = fib6_locate(&table->tb6_root,
3239                          &cfg->fc_dst, cfg->fc_dst_len,
3240                          &cfg->fc_src, cfg->fc_src_len,
3241                          !(cfg->fc_flags & RTF_CACHE));
3242
3243         if (fn) {
3244                 for_each_fib6_node_rt_rcu(fn) {
3245                         if (cfg->fc_flags & RTF_CACHE) {
3246                                 int rc;
3247
3248                                 rt_cache = rt6_find_cached_rt(rt, &cfg->fc_dst,
3249                                                               &cfg->fc_src);
3250                                 if (rt_cache) {
3251                                         rc = ip6_del_cached_rt(rt_cache, cfg);
3252                                         if (rc != -ESRCH) {
3253                                                 rcu_read_unlock();
3254                                                 return rc;
3255                                         }
3256                                 }
3257                                 continue;
3258                         }
3259                         if (cfg->fc_ifindex &&
3260                             (!rt->fib6_nh.nh_dev ||
3261                              rt->fib6_nh.nh_dev->ifindex != cfg->fc_ifindex))
3262                                 continue;
3263                         if (cfg->fc_flags & RTF_GATEWAY &&
3264                             !ipv6_addr_equal(&cfg->fc_gateway, &rt->fib6_nh.nh_gw))
3265                                 continue;
3266                         if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
3267                                 continue;
3268                         if (cfg->fc_protocol && cfg->fc_protocol != rt->fib6_protocol)
3269                                 continue;
3270                         if (!fib6_info_hold_safe(rt))
3271                                 continue;
3272                         rcu_read_unlock();
3273
3274                         /* if gateway was specified only delete the one hop */
3275                         if (cfg->fc_flags & RTF_GATEWAY)
3276                                 return __ip6_del_rt(rt, &cfg->fc_nlinfo);
3277
3278                         return __ip6_del_rt_siblings(rt, cfg);
3279                 }
3280         }
3281         rcu_read_unlock();
3282
3283         return err;
3284 }
3285
3286 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
3287 {
3288         struct netevent_redirect netevent;
3289         struct rt6_info *rt, *nrt = NULL;
3290         struct ndisc_options ndopts;
3291         struct inet6_dev *in6_dev;
3292         struct neighbour *neigh;
3293         struct fib6_info *from;
3294         struct rd_msg *msg;
3295         int optlen, on_link;
3296         u8 *lladdr;
3297
3298         optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
3299         optlen -= sizeof(*msg);
3300
3301         if (optlen < 0) {
3302                 net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
3303                 return;
3304         }
3305
3306         msg = (struct rd_msg *)icmp6_hdr(skb);
3307
3308         if (ipv6_addr_is_multicast(&msg->dest)) {
3309                 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
3310                 return;
3311         }
3312
3313         on_link = 0;
3314         if (ipv6_addr_equal(&msg->dest, &msg->target)) {
3315                 on_link = 1;
3316         } else if (ipv6_addr_type(&msg->target) !=
3317                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
3318                 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
3319                 return;
3320         }
3321
3322         in6_dev = __in6_dev_get(skb->dev);
3323         if (!in6_dev)
3324                 return;
3325         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
3326                 return;
3327
3328         /* RFC2461 8.1:
3329          *      The IP source address of the Redirect MUST be the same as the current
3330          *      first-hop router for the specified ICMP Destination Address.
3331          */
3332
3333         if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
3334                 net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
3335                 return;
3336         }
3337
3338         lladdr = NULL;
3339         if (ndopts.nd_opts_tgt_lladdr) {
3340                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
3341                                              skb->dev);
3342                 if (!lladdr) {
3343                         net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
3344                         return;
3345                 }
3346         }
3347
3348         rt = (struct rt6_info *) dst;
3349         if (rt->rt6i_flags & RTF_REJECT) {
3350                 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
3351                 return;
3352         }
3353
3354         /* Redirect received -> path was valid.
3355          * Look, redirects are sent only in response to data packets,
3356          * so that this nexthop apparently is reachable. --ANK
3357          */
3358         dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
3359
3360         neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
3361         if (!neigh)
3362                 return;
3363
3364         /*
3365          *      We have finally decided to accept it.
3366          */
3367
3368         ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
3369                      NEIGH_UPDATE_F_WEAK_OVERRIDE|
3370                      NEIGH_UPDATE_F_OVERRIDE|
3371                      (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
3372                                      NEIGH_UPDATE_F_ISROUTER)),
3373                      NDISC_REDIRECT, &ndopts);
3374
3375         rcu_read_lock();
3376         from = rcu_dereference(rt->from);
3377         /* This fib6_info_hold() is safe here because we hold reference to rt
3378          * and rt already holds reference to fib6_info.
3379          */
3380         fib6_info_hold(from);
3381         rcu_read_unlock();
3382
3383         nrt = ip6_rt_cache_alloc(from, &msg->dest, NULL);
3384         if (!nrt)
3385                 goto out;
3386
3387         nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
3388         if (on_link)
3389                 nrt->rt6i_flags &= ~RTF_GATEWAY;
3390
3391         nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
3392
3393         /* No need to remove rt from the exception table if rt is
3394          * a cached route because rt6_insert_exception() will
3395          * takes care of it
3396          */
3397         if (rt6_insert_exception(nrt, from)) {
3398                 dst_release_immediate(&nrt->dst);
3399                 goto out;
3400         }
3401
3402         netevent.old = &rt->dst;
3403         netevent.new = &nrt->dst;
3404         netevent.daddr = &msg->dest;
3405         netevent.neigh = neigh;
3406         call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
3407
3408 out:
3409         fib6_info_release(from);
3410         neigh_release(neigh);
3411 }
3412
3413 #ifdef CONFIG_IPV6_ROUTE_INFO
3414 static struct fib6_info *rt6_get_route_info(struct net *net,
3415                                            const struct in6_addr *prefix, int prefixlen,
3416                                            const struct in6_addr *gwaddr,
3417                                            struct net_device *dev)
3418 {
3419         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
3420         int ifindex = dev->ifindex;
3421         struct fib6_node *fn;
3422         struct fib6_info *rt = NULL;
3423         struct fib6_table *table;
3424
3425         table = fib6_get_table(net, tb_id);
3426         if (!table)
3427                 return NULL;
3428
3429         rcu_read_lock();
3430         fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
3431         if (!fn)
3432                 goto out;
3433
3434         for_each_fib6_node_rt_rcu(fn) {
3435                 if (rt->fib6_nh.nh_dev->ifindex != ifindex)
3436                         continue;
3437                 if ((rt->fib6_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY))
3438                         continue;
3439                 if (!ipv6_addr_equal(&rt->fib6_nh.nh_gw, gwaddr))
3440                         continue;
3441                 if (!fib6_info_hold_safe(rt))
3442                         continue;
3443                 break;
3444         }
3445 out:
3446         rcu_read_unlock();
3447         return rt;
3448 }
3449
3450 static struct fib6_info *rt6_add_route_info(struct net *net,
3451                                            const struct in6_addr *prefix, int prefixlen,
3452                                            const struct in6_addr *gwaddr,
3453                                            struct net_device *dev,
3454                                            unsigned int pref)
3455 {
3456         struct fib6_config cfg = {
3457                 .fc_metric      = IP6_RT_PRIO_USER,
3458                 .fc_ifindex     = dev->ifindex,
3459                 .fc_dst_len     = prefixlen,
3460                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
3461                                   RTF_UP | RTF_PREF(pref),
3462                 .fc_protocol = RTPROT_RA,
3463                 .fc_type = RTN_UNICAST,
3464                 .fc_nlinfo.portid = 0,
3465                 .fc_nlinfo.nlh = NULL,
3466                 .fc_nlinfo.nl_net = net,
3467         };
3468
3469         cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO,
3470         cfg.fc_dst = *prefix;
3471         cfg.fc_gateway = *gwaddr;
3472
3473         /* We should treat it as a default route if prefix length is 0. */
3474         if (!prefixlen)
3475                 cfg.fc_flags |= RTF_DEFAULT;
3476
3477         ip6_route_add(&cfg, GFP_ATOMIC, NULL);
3478
3479         return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
3480 }
3481 #endif
3482
3483 struct fib6_info *rt6_get_dflt_router(struct net *net,
3484                                      const struct in6_addr *addr,
3485                                      struct net_device *dev)
3486 {
3487         u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
3488         struct fib6_info *rt;
3489         struct fib6_table *table;
3490
3491         table = fib6_get_table(net, tb_id);
3492         if (!table)
3493                 return NULL;
3494
3495         rcu_read_lock();
3496         for_each_fib6_node_rt_rcu(&table->tb6_root) {
3497                 if (dev == rt->fib6_nh.nh_dev &&
3498                     ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
3499                     ipv6_addr_equal(&rt->fib6_nh.nh_gw, addr))
3500                         break;
3501         }
3502         if (rt && !fib6_info_hold_safe(rt))
3503                 rt = NULL;
3504         rcu_read_unlock();
3505         return rt;
3506 }
3507
3508 struct fib6_info *rt6_add_dflt_router(struct net *net,
3509                                      const struct in6_addr *gwaddr,
3510                                      struct net_device *dev,
3511                                      unsigned int pref)
3512 {
3513         struct fib6_config cfg = {
3514                 .fc_table       = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
3515                 .fc_metric      = IP6_RT_PRIO_USER,
3516                 .fc_ifindex     = dev->ifindex,
3517                 .fc_flags       = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
3518                                   RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
3519                 .fc_protocol = RTPROT_RA,
3520                 .fc_type = RTN_UNICAST,
3521                 .fc_nlinfo.portid = 0,
3522                 .fc_nlinfo.nlh = NULL,
3523                 .fc_nlinfo.nl_net = net,
3524         };
3525
3526         cfg.fc_gateway = *gwaddr;
3527
3528         if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
3529                 struct fib6_table *table;
3530
3531                 table = fib6_get_table(dev_net(dev), cfg.fc_table);
3532                 if (table)
3533                         table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
3534         }
3535
3536         return rt6_get_dflt_router(net, gwaddr, dev);
3537 }
3538
3539 static void __rt6_purge_dflt_routers(struct net *net,
3540                                      struct fib6_table *table)
3541 {
3542         struct fib6_info *rt;
3543
3544 restart:
3545         rcu_read_lock();
3546         for_each_fib6_node_rt_rcu(&table->tb6_root) {
3547                 struct net_device *dev = fib6_info_nh_dev(rt);
3548                 struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
3549
3550                 if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
3551                     (!idev || idev->cnf.accept_ra != 2) &&
3552                     fib6_info_hold_safe(rt)) {
3553                         rcu_read_unlock();
3554                         ip6_del_rt(net, rt);
3555                         goto restart;
3556                 }
3557         }
3558         rcu_read_unlock();
3559
3560         table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
3561 }
3562
3563 void rt6_purge_dflt_routers(struct net *net)
3564 {
3565         struct fib6_table *table;
3566         struct hlist_head *head;
3567         unsigned int h;
3568
3569         rcu_read_lock();
3570
3571         for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
3572                 head = &net->ipv6.fib_table_hash[h];
3573                 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
3574                         if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
3575                                 __rt6_purge_dflt_routers(net, table);
3576                 }
3577         }
3578
3579         rcu_read_unlock();
3580 }
3581
3582 static void rtmsg_to_fib6_config(struct net *net,
3583                                  struct in6_rtmsg *rtmsg,
3584                                  struct fib6_config *cfg)
3585 {
3586         *cfg = (struct fib6_config){
3587                 .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
3588                          : RT6_TABLE_MAIN,
3589                 .fc_ifindex = rtmsg->rtmsg_ifindex,
3590                 .fc_metric = rtmsg->rtmsg_metric,
3591                 .fc_expires = rtmsg->rtmsg_info,
3592                 .fc_dst_len = rtmsg->rtmsg_dst_len,
3593                 .fc_src_len = rtmsg->rtmsg_src_len,
3594                 .fc_flags = rtmsg->rtmsg_flags,
3595                 .fc_type = rtmsg->rtmsg_type,
3596
3597                 .fc_nlinfo.nl_net = net,
3598
3599                 .fc_dst = rtmsg->rtmsg_dst,
3600                 .fc_src = rtmsg->rtmsg_src,
3601                 .fc_gateway = rtmsg->rtmsg_gateway,
3602         };
3603 }
3604
3605 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg)
3606 {
3607         struct fib6_config cfg;
3608         struct in6_rtmsg rtmsg;
3609         int err;
3610
3611         switch (cmd) {
3612         case SIOCADDRT:         /* Add a route */
3613         case SIOCDELRT:         /* Delete a route */
3614                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
3615                         return -EPERM;
3616                 err = copy_from_user(&rtmsg, arg,
3617                                      sizeof(struct in6_rtmsg));
3618                 if (err)
3619                         return -EFAULT;
3620
3621                 rtmsg_to_fib6_config(net, &rtmsg, &cfg);
3622
3623                 rtnl_lock();
3624                 switch (cmd) {
3625                 case SIOCADDRT:
3626                         err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
3627                         break;
3628                 case SIOCDELRT:
3629                         err = ip6_route_del(&cfg, NULL);
3630                         break;
3631                 default:
3632                         err = -EINVAL;
3633                 }
3634                 rtnl_unlock();
3635
3636                 return err;
3637         }
3638
3639         return -EINVAL;
3640 }
3641
3642 /*
3643  *      Drop the packet on the floor
3644  */
3645
3646 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
3647 {
3648         int type;
3649         struct dst_entry *dst = skb_dst(skb);
3650         switch (ipstats_mib_noroutes) {
3651         case IPSTATS_MIB_INNOROUTES:
3652                 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
3653                 if (type == IPV6_ADDR_ANY) {
3654                         IP6_INC_STATS(dev_net(dst->dev),
3655                                       __in6_dev_get_safely(skb->dev),
3656                                       IPSTATS_MIB_INADDRERRORS);
3657                         break;
3658                 }
3659                 /* FALLTHROUGH */
3660         case IPSTATS_MIB_OUTNOROUTES:
3661                 IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
3662                               ipstats_mib_noroutes);
3663                 break;
3664         }
3665         icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
3666         kfree_skb(skb);
3667         return 0;
3668 }
3669
3670 static int ip6_pkt_discard(struct sk_buff *skb)
3671 {
3672         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
3673 }
3674
3675 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
3676 {
3677         skb->dev = skb_dst(skb)->dev;
3678         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
3679 }
3680
3681 static int ip6_pkt_prohibit(struct sk_buff *skb)
3682 {
3683         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
3684 }
3685
3686 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
3687 {
3688         skb->dev = skb_dst(skb)->dev;
3689         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
3690 }
3691
3692 /*
3693  *      Allocate a dst for local (unicast / anycast) address.
3694  */
3695
3696 struct fib6_info *addrconf_f6i_alloc(struct net *net,
3697                                      struct inet6_dev *idev,
3698                                      const struct in6_addr *addr,
3699                                      bool anycast, gfp_t gfp_flags)
3700 {
3701         u32 tb_id;
3702         struct net_device *dev = idev->dev;
3703         struct fib6_info *f6i;
3704
3705         f6i = fib6_info_alloc(gfp_flags);
3706         if (!f6i)
3707                 return ERR_PTR(-ENOMEM);
3708
3709         f6i->fib6_metrics = ip_fib_metrics_init(net, NULL, 0);
3710         f6i->dst_nocount = true;
3711         f6i->dst_host = true;
3712         f6i->fib6_protocol = RTPROT_KERNEL;
3713         f6i->fib6_flags = RTF_UP | RTF_NONEXTHOP;
3714         if (anycast) {
3715                 f6i->fib6_type = RTN_ANYCAST;
3716                 f6i->fib6_flags |= RTF_ANYCAST;
3717         } else {
3718                 f6i->fib6_type = RTN_LOCAL;
3719                 f6i->fib6_flags |= RTF_LOCAL;
3720         }
3721
3722         f6i->fib6_nh.nh_gw = *addr;
3723         dev_hold(dev);
3724         f6i->fib6_nh.nh_dev = dev;
3725         f6i->fib6_dst.addr = *addr;
3726         f6i->fib6_dst.plen = 128;
3727         tb_id = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL;
3728         f6i->fib6_table = fib6_get_table(net, tb_id);
3729
3730         return f6i;
3731 }
3732
3733 /* remove deleted ip from prefsrc entries */
3734 struct arg_dev_net_ip {
3735         struct net_device *dev;
3736         struct net *net;
3737         struct in6_addr *addr;
3738 };
3739
3740 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
3741 {
3742         struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev;
3743         struct net *net = ((struct arg_dev_net_ip *)arg)->net;
3744         struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
3745
3746         if (((void *)rt->fib6_nh.nh_dev == dev || !dev) &&
3747             rt != net->ipv6.fib6_null_entry &&
3748             ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr)) {
3749                 spin_lock_bh(&rt6_exception_lock);
3750                 /* remove prefsrc entry */
3751                 rt->fib6_prefsrc.plen = 0;
3752                 spin_unlock_bh(&rt6_exception_lock);
3753         }
3754         return 0;
3755 }
3756
3757 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
3758 {
3759         struct net *net = dev_net(ifp->idev->dev);
3760         struct arg_dev_net_ip adni = {
3761                 .dev = ifp->idev->dev,
3762                 .net = net,
3763                 .addr = &ifp->addr,
3764         };
3765         fib6_clean_all(net, fib6_remove_prefsrc, &adni);
3766 }
3767
3768 #define RTF_RA_ROUTER           (RTF_ADDRCONF | RTF_DEFAULT | RTF_GATEWAY)
3769
3770 /* Remove routers and update dst entries when gateway turn into host. */
3771 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
3772 {
3773         struct in6_addr *gateway = (struct in6_addr *)arg;
3774
3775         if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
3776             ipv6_addr_equal(gateway, &rt->fib6_nh.nh_gw)) {
3777                 return -1;
3778         }
3779
3780         /* Further clean up cached routes in exception table.
3781          * This is needed because cached route may have a different
3782          * gateway than its 'parent' in the case of an ip redirect.
3783          */
3784         rt6_exceptions_clean_tohost(rt, gateway);
3785
3786         return 0;
3787 }
3788
3789 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
3790 {
3791         fib6_clean_all(net, fib6_clean_tohost, gateway);
3792 }
3793
3794 struct arg_netdev_event {
3795         const struct net_device *dev;
3796         union {
3797                 unsigned int nh_flags;
3798                 unsigned long event;
3799         };
3800 };
3801
3802 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
3803 {
3804         struct fib6_info *iter;
3805         struct fib6_node *fn;
3806
3807         fn = rcu_dereference_protected(rt->fib6_node,
3808                         lockdep_is_held(&rt->fib6_table->tb6_lock));
3809         iter = rcu_dereference_protected(fn->leaf,
3810                         lockdep_is_held(&rt->fib6_table->tb6_lock));
3811         while (iter) {
3812                 if (iter->fib6_metric == rt->fib6_metric &&
3813                     rt6_qualify_for_ecmp(iter))
3814                         return iter;
3815                 iter = rcu_dereference_protected(iter->fib6_next,
3816                                 lockdep_is_held(&rt->fib6_table->tb6_lock));
3817         }
3818
3819         return NULL;
3820 }
3821
3822 static bool rt6_is_dead(const struct fib6_info *rt)
3823 {
3824         if (rt->fib6_nh.nh_flags & RTNH_F_DEAD ||
3825             (rt->fib6_nh.nh_flags & RTNH_F_LINKDOWN &&
3826              fib6_ignore_linkdown(rt)))
3827                 return true;
3828
3829         return false;
3830 }
3831
3832 static int rt6_multipath_total_weight(const struct fib6_info *rt)
3833 {
3834         struct fib6_info *iter;
3835         int total = 0;
3836
3837         if (!rt6_is_dead(rt))
3838                 total += rt->fib6_nh.nh_weight;
3839
3840         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
3841                 if (!rt6_is_dead(iter))
3842                         total += iter->fib6_nh.nh_weight;
3843         }
3844
3845         return total;
3846 }
3847
3848 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
3849 {
3850         int upper_bound = -1;
3851
3852         if (!rt6_is_dead(rt)) {
3853                 *weight += rt->fib6_nh.nh_weight;
3854                 upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
3855                                                     total) - 1;
3856         }
3857         atomic_set(&rt->fib6_nh.nh_upper_bound, upper_bound);
3858 }
3859
3860 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
3861 {
3862         struct fib6_info *iter;
3863         int weight = 0;
3864
3865         rt6_upper_bound_set(rt, &weight, total);
3866
3867         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
3868                 rt6_upper_bound_set(iter, &weight, total);
3869 }
3870
3871 void rt6_multipath_rebalance(struct fib6_info *rt)
3872 {
3873         struct fib6_info *first;
3874         int total;
3875
3876         /* In case the entire multipath route was marked for flushing,
3877          * then there is no need to rebalance upon the removal of every
3878          * sibling route.
3879          */
3880         if (!rt->fib6_nsiblings || rt->should_flush)
3881                 return;
3882
3883         /* During lookup routes are evaluated in order, so we need to
3884          * make sure upper bounds are assigned from the first sibling
3885          * onwards.
3886          */
3887         first = rt6_multipath_first_sibling(rt);
3888         if (WARN_ON_ONCE(!first))
3889                 return;
3890
3891         total = rt6_multipath_total_weight(first);
3892         rt6_multipath_upper_bound_set(first, total);
3893 }
3894
3895 static int fib6_ifup(struct fib6_info *rt, void *p_arg)
3896 {
3897         const struct arg_netdev_event *arg = p_arg;
3898         struct net *net = dev_net(arg->dev);
3899
3900         if (rt != net->ipv6.fib6_null_entry && rt->fib6_nh.nh_dev == arg->dev) {
3901                 rt->fib6_nh.nh_flags &= ~arg->nh_flags;
3902                 fib6_update_sernum_upto_root(net, rt);
3903                 rt6_multipath_rebalance(rt);
3904         }
3905
3906         return 0;
3907 }
3908
3909 void rt6_sync_up(struct net_device *dev, unsigned int nh_flags)
3910 {
3911         struct arg_netdev_event arg = {
3912                 .dev = dev,
3913                 {
3914                         .nh_flags = nh_flags,
3915                 },
3916         };
3917
3918         if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
3919                 arg.nh_flags |= RTNH_F_LINKDOWN;
3920
3921         fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
3922 }
3923
3924 static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
3925                                    const struct net_device *dev)
3926 {
3927         struct fib6_info *iter;
3928
3929         if (rt->fib6_nh.nh_dev == dev)
3930                 return true;
3931         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
3932                 if (iter->fib6_nh.nh_dev == dev)
3933                         return true;
3934
3935         return false;
3936 }
3937
3938 static void rt6_multipath_flush(struct fib6_info *rt)
3939 {
3940         struct fib6_info *iter;
3941
3942         rt->should_flush = 1;
3943         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
3944                 iter->should_flush = 1;
3945 }
3946
3947 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
3948                                              const struct net_device *down_dev)
3949 {
3950         struct fib6_info *iter;
3951         unsigned int dead = 0;
3952
3953         if (rt->fib6_nh.nh_dev == down_dev ||
3954             rt->fib6_nh.nh_flags & RTNH_F_DEAD)
3955                 dead++;
3956         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
3957                 if (iter->fib6_nh.nh_dev == down_dev ||
3958                     iter->fib6_nh.nh_flags & RTNH_F_DEAD)
3959                         dead++;
3960
3961         return dead;
3962 }
3963
3964 static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
3965                                        const struct net_device *dev,
3966                                        unsigned int nh_flags)
3967 {
3968         struct fib6_info *iter;
3969
3970         if (rt->fib6_nh.nh_dev == dev)
3971                 rt->fib6_nh.nh_flags |= nh_flags;
3972         list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
3973                 if (iter->fib6_nh.nh_dev == dev)
3974                         iter->fib6_nh.nh_flags |= nh_flags;
3975 }
3976
3977 /* called with write lock held for table with rt */
3978 static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
3979 {
3980         const struct arg_netdev_event *arg = p_arg;
3981         const struct net_device *dev = arg->dev;
3982         struct net *net = dev_net(dev);
3983
3984         if (rt == net->ipv6.fib6_null_entry)
3985                 return 0;
3986
3987         switch (arg->event) {
3988         case NETDEV_UNREGISTER:
3989                 return rt->fib6_nh.nh_dev == dev ? -1 : 0;
3990         case NETDEV_DOWN:
3991                 if (rt->should_flush)
3992                         return -1;
3993                 if (!rt->fib6_nsiblings)
3994                         return rt->fib6_nh.nh_dev == dev ? -1 : 0;
3995                 if (rt6_multipath_uses_dev(rt, dev)) {
3996                         unsigned int count;
3997
3998                         count = rt6_multipath_dead_count(rt, dev);
3999                         if (rt->fib6_nsiblings + 1 == count) {
4000                                 rt6_multipath_flush(rt);
4001                                 return -1;
4002                         }
4003                         rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
4004                                                    RTNH_F_LINKDOWN);
4005                         fib6_update_sernum(net, rt);
4006                         rt6_multipath_rebalance(rt);
4007                 }
4008                 return -2;
4009         case NETDEV_CHANGE:
4010                 if (rt->fib6_nh.nh_dev != dev ||
4011                     rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
4012                         break;
4013                 rt->fib6_nh.nh_flags |= RTNH_F_LINKDOWN;
4014                 rt6_multipath_rebalance(rt);
4015                 break;
4016         }
4017
4018         return 0;
4019 }
4020
4021 void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
4022 {
4023         struct arg_netdev_event arg = {
4024                 .dev = dev,
4025                 {
4026                         .event = event,
4027                 },
4028         };
4029         struct net *net = dev_net(dev);
4030
4031         if (net->ipv6.sysctl.skip_notify_on_dev_down)
4032                 fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
4033         else
4034                 fib6_clean_all(net, fib6_ifdown, &arg);
4035 }
4036
4037 void rt6_disable_ip(struct net_device *dev, unsigned long event)
4038 {
4039         rt6_sync_down_dev(dev, event);
4040         rt6_uncached_list_flush_dev(dev_net(dev), dev);
4041         neigh_ifdown(&nd_tbl, dev);
4042 }
4043
4044 struct rt6_mtu_change_arg {
4045         struct net_device *dev;
4046         unsigned int mtu;
4047 };
4048
4049 static int rt6_mtu_change_route(struct fib6_info *rt, void *p_arg)
4050 {
4051         struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
4052         struct inet6_dev *idev;
4053
4054         /* In IPv6 pmtu discovery is not optional,
4055            so that RTAX_MTU lock cannot disable it.
4056            We still use this lock to block changes
4057            caused by addrconf/ndisc.
4058         */
4059
4060         idev = __in6_dev_get(arg->dev);
4061         if (!idev)
4062                 return 0;
4063
4064         /* For administrative MTU increase, there is no way to discover
4065            IPv6 PMTU increase, so PMTU increase should be updated here.
4066            Since RFC 1981 doesn't include administrative MTU increase
4067            update PMTU increase is a MUST. (i.e. jumbo frame)
4068          */
4069         if (rt->fib6_nh.nh_dev == arg->dev &&
4070             !fib6_metric_locked(rt, RTAX_MTU)) {
4071                 u32 mtu = rt->fib6_pmtu;
4072
4073                 if (mtu >= arg->mtu ||
4074                     (mtu < arg->mtu && mtu == idev->cnf.mtu6))
4075                         fib6_metric_set(rt, RTAX_MTU, arg->mtu);
4076
4077                 spin_lock_bh(&rt6_exception_lock);
4078                 rt6_exceptions_update_pmtu(idev, rt, arg->mtu);
4079                 spin_unlock_bh(&rt6_exception_lock);
4080         }
4081         return 0;
4082 }
4083
4084 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
4085 {
4086         struct rt6_mtu_change_arg arg = {
4087                 .dev = dev,
4088                 .mtu = mtu,
4089         };
4090
4091         fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
4092 }
4093
4094 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
4095         [RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
4096         [RTA_PREFSRC]           = { .len = sizeof(struct in6_addr) },
4097         [RTA_OIF]               = { .type = NLA_U32 },
4098         [RTA_IIF]               = { .type = NLA_U32 },
4099         [RTA_PRIORITY]          = { .type = NLA_U32 },
4100         [RTA_METRICS]           = { .type = NLA_NESTED },
4101         [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
4102         [RTA_PREF]              = { .type = NLA_U8 },
4103         [RTA_ENCAP_TYPE]        = { .type = NLA_U16 },
4104         [RTA_ENCAP]             = { .type = NLA_NESTED },
4105         [RTA_EXPIRES]           = { .type = NLA_U32 },
4106         [RTA_UID]               = { .type = NLA_U32 },
4107         [RTA_MARK]              = { .type = NLA_U32 },
4108         [RTA_TABLE]             = { .type = NLA_U32 },
4109         [RTA_IP_PROTO]          = { .type = NLA_U8 },
4110         [RTA_SPORT]             = { .type = NLA_U16 },
4111         [RTA_DPORT]             = { .type = NLA_U16 },
4112 };
4113
4114 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
4115                               struct fib6_config *cfg,
4116                               struct netlink_ext_ack *extack)
4117 {
4118         struct rtmsg *rtm;
4119         struct nlattr *tb[RTA_MAX+1];
4120         unsigned int pref;
4121         int err;
4122
4123         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy,
4124                           extack);
4125         if (err < 0)
4126                 goto errout;
4127
4128         err = -EINVAL;
4129         rtm = nlmsg_data(nlh);
4130
4131         *cfg = (struct fib6_config){
4132                 .fc_table = rtm->rtm_table,
4133                 .fc_dst_len = rtm->rtm_dst_len,
4134                 .fc_src_len = rtm->rtm_src_len,
4135                 .fc_flags = RTF_UP,
4136                 .fc_protocol = rtm->rtm_protocol,
4137                 .fc_type = rtm->rtm_type,
4138
4139                 .fc_nlinfo.portid = NETLINK_CB(skb).portid,
4140                 .fc_nlinfo.nlh = nlh,
4141                 .fc_nlinfo.nl_net = sock_net(skb->sk),
4142         };
4143
4144         if (rtm->rtm_type == RTN_UNREACHABLE ||
4145             rtm->rtm_type == RTN_BLACKHOLE ||
4146             rtm->rtm_type == RTN_PROHIBIT ||
4147             rtm->rtm_type == RTN_THROW)
4148                 cfg->fc_flags |= RTF_REJECT;
4149
4150         if (rtm->rtm_type == RTN_LOCAL)
4151                 cfg->fc_flags |= RTF_LOCAL;
4152
4153         if (rtm->rtm_flags & RTM_F_CLONED)
4154                 cfg->fc_flags |= RTF_CACHE;
4155
4156         cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
4157
4158         if (tb[RTA_GATEWAY]) {
4159                 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
4160                 cfg->fc_flags |= RTF_GATEWAY;
4161         }
4162
4163         if (tb[RTA_DST]) {
4164                 int plen = (rtm->rtm_dst_len + 7) >> 3;
4165
4166                 if (nla_len(tb[RTA_DST]) < plen)
4167                         goto errout;
4168
4169                 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
4170         }
4171
4172         if (tb[RTA_SRC]) {
4173                 int plen = (rtm->rtm_src_len + 7) >> 3;
4174
4175                 if (nla_len(tb[RTA_SRC]) < plen)
4176                         goto errout;
4177
4178                 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
4179         }
4180
4181         if (tb[RTA_PREFSRC])
4182                 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
4183
4184         if (tb[RTA_OIF])
4185                 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
4186
4187         if (tb[RTA_PRIORITY])
4188                 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
4189
4190         if (tb[RTA_METRICS]) {
4191                 cfg->fc_mx = nla_data(tb[RTA_METRICS]);
4192                 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
4193         }
4194
4195         if (tb[RTA_TABLE])
4196                 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
4197
4198         if (tb[RTA_MULTIPATH]) {
4199                 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
4200                 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
4201
4202                 err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
4203                                                      cfg->fc_mp_len, extack);
4204                 if (err < 0)
4205                         goto errout;
4206         }
4207
4208         if (tb[RTA_PREF]) {
4209                 pref = nla_get_u8(tb[RTA_PREF]);
4210                 if (pref != ICMPV6_ROUTER_PREF_LOW &&
4211                     pref != ICMPV6_ROUTER_PREF_HIGH)
4212                         pref = ICMPV6_ROUTER_PREF_MEDIUM;
4213                 cfg->fc_flags |= RTF_PREF(pref);
4214         }
4215
4216         if (tb[RTA_ENCAP])
4217                 cfg->fc_encap = tb[RTA_ENCAP];
4218
4219         if (tb[RTA_ENCAP_TYPE]) {
4220                 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
4221
4222                 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
4223                 if (err < 0)
4224                         goto errout;
4225         }
4226
4227         if (tb[RTA_EXPIRES]) {
4228                 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
4229
4230                 if (addrconf_finite_timeout(timeout)) {
4231                         cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
4232                         cfg->fc_flags |= RTF_EXPIRES;
4233                 }
4234         }
4235
4236         err = 0;
4237 errout:
4238         return err;
4239 }
4240
4241 struct rt6_nh {
4242         struct fib6_info *fib6_info;
4243         struct fib6_config r_cfg;
4244         struct list_head next;
4245 };
4246
4247 static void ip6_print_replace_route_err(struct list_head *rt6_nh_list)
4248 {
4249         struct rt6_nh *nh;
4250
4251         list_for_each_entry(nh, rt6_nh_list, next) {
4252                 pr_warn("IPV6: multipath route replace failed (check consistency of installed routes): %pI6c nexthop %pI6c ifi %d\n",
4253                         &nh->r_cfg.fc_dst, &nh->r_cfg.fc_gateway,
4254                         nh->r_cfg.fc_ifindex);
4255         }
4256 }
4257
4258 static int ip6_route_info_append(struct net *net,
4259                                  struct list_head *rt6_nh_list,
4260                                  struct fib6_info *rt,
4261                                  struct fib6_config *r_cfg)
4262 {
4263         struct rt6_nh *nh;
4264         int err = -EEXIST;
4265
4266         list_for_each_entry(nh, rt6_nh_list, next) {
4267                 /* check if fib6_info already exists */
4268                 if (rt6_duplicate_nexthop(nh->fib6_info, rt))
4269                         return err;
4270         }
4271
4272         nh = kzalloc(sizeof(*nh), GFP_KERNEL);
4273         if (!nh)
4274                 return -ENOMEM;
4275         nh->fib6_info = rt;
4276         memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
4277         list_add_tail(&nh->next, rt6_nh_list);
4278
4279         return 0;
4280 }
4281
4282 static void ip6_route_mpath_notify(struct fib6_info *rt,
4283                                    struct fib6_info *rt_last,
4284                                    struct nl_info *info,
4285                                    __u16 nlflags)
4286 {
4287         /* if this is an APPEND route, then rt points to the first route
4288          * inserted and rt_last points to last route inserted. Userspace
4289          * wants a consistent dump of the route which starts at the first
4290          * nexthop. Since sibling routes are always added at the end of
4291          * the list, find the first sibling of the last route appended
4292          */
4293         if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
4294                 rt = list_first_entry(&rt_last->fib6_siblings,
4295                                       struct fib6_info,
4296                                       fib6_siblings);
4297         }
4298
4299         if (rt)
4300                 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
4301 }
4302
4303 static int ip6_route_multipath_add(struct fib6_config *cfg,
4304                                    struct netlink_ext_ack *extack)
4305 {
4306         struct fib6_info *rt_notif = NULL, *rt_last = NULL;
4307         struct nl_info *info = &cfg->fc_nlinfo;
4308         struct fib6_config r_cfg;
4309         struct rtnexthop *rtnh;
4310         struct fib6_info *rt;
4311         struct rt6_nh *err_nh;
4312         struct rt6_nh *nh, *nh_safe;
4313         __u16 nlflags;
4314         int remaining;
4315         int attrlen;
4316         int err = 1;
4317         int nhn = 0;
4318         int replace = (cfg->fc_nlinfo.nlh &&
4319                        (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
4320         LIST_HEAD(rt6_nh_list);
4321
4322         nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
4323         if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
4324                 nlflags |= NLM_F_APPEND;
4325
4326         remaining = cfg->fc_mp_len;
4327         rtnh = (struct rtnexthop *)cfg->fc_mp;
4328
4329         /* Parse a Multipath Entry and build a list (rt6_nh_list) of
4330          * fib6_info structs per nexthop
4331          */
4332         while (rtnh_ok(rtnh, remaining)) {
4333                 memcpy(&r_cfg, cfg, sizeof(*cfg));
4334                 if (rtnh->rtnh_ifindex)
4335                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
4336
4337                 attrlen = rtnh_attrlen(rtnh);
4338                 if (attrlen > 0) {
4339                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
4340
4341                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
4342                         if (nla) {
4343                                 r_cfg.fc_gateway = nla_get_in6_addr(nla);
4344                                 r_cfg.fc_flags |= RTF_GATEWAY;
4345                         }
4346                         r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
4347                         nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
4348                         if (nla)
4349                                 r_cfg.fc_encap_type = nla_get_u16(nla);
4350                 }
4351
4352                 r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
4353                 rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
4354                 if (IS_ERR(rt)) {
4355                         err = PTR_ERR(rt);
4356                         rt = NULL;
4357                         goto cleanup;
4358                 }
4359                 if (!rt6_qualify_for_ecmp(rt)) {
4360                         err = -EINVAL;
4361                         NL_SET_ERR_MSG(extack,
4362                                        "Device only routes can not be added for IPv6 using the multipath API.");
4363                         fib6_info_release(rt);
4364                         goto cleanup;
4365                 }
4366
4367                 rt->fib6_nh.nh_weight = rtnh->rtnh_hops + 1;
4368
4369                 err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
4370                                             rt, &r_cfg);
4371                 if (err) {
4372                         fib6_info_release(rt);
4373                         goto cleanup;
4374                 }
4375
4376                 rtnh = rtnh_next(rtnh, &remaining);
4377         }
4378
4379         /* for add and replace send one notification with all nexthops.
4380          * Skip the notification in fib6_add_rt2node and send one with
4381          * the full route when done
4382          */
4383         info->skip_notify = 1;
4384
4385         err_nh = NULL;
4386         list_for_each_entry(nh, &rt6_nh_list, next) {
4387                 err = __ip6_ins_rt(nh->fib6_info, info, extack);
4388                 fib6_info_release(nh->fib6_info);
4389
4390                 if (!err) {
4391                         /* save reference to last route successfully inserted */
4392                         rt_last = nh->fib6_info;
4393
4394                         /* save reference to first route for notification */
4395                         if (!rt_notif)
4396                                 rt_notif = nh->fib6_info;
4397                 }
4398
4399                 /* nh->fib6_info is used or freed at this point, reset to NULL*/
4400                 nh->fib6_info = NULL;
4401                 if (err) {
4402                         if (replace && nhn)
4403                                 ip6_print_replace_route_err(&rt6_nh_list);
4404                         err_nh = nh;
4405                         goto add_errout;
4406                 }
4407
4408                 /* Because each route is added like a single route we remove
4409                  * these flags after the first nexthop: if there is a collision,
4410                  * we have already failed to add the first nexthop:
4411                  * fib6_add_rt2node() has rejected it; when replacing, old
4412                  * nexthops have been replaced by first new, the rest should
4413                  * be added to it.
4414                  */
4415                 cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
4416                                                      NLM_F_REPLACE);
4417                 nhn++;
4418         }
4419
4420         /* success ... tell user about new route */
4421         ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
4422         goto cleanup;
4423
4424 add_errout:
4425         /* send notification for routes that were added so that
4426          * the delete notifications sent by ip6_route_del are
4427          * coherent
4428          */
4429         if (rt_notif)
4430                 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
4431
4432         /* Delete routes that were already added */
4433         list_for_each_entry(nh, &rt6_nh_list, next) {
4434                 if (err_nh == nh)
4435                         break;
4436                 ip6_route_del(&nh->r_cfg, extack);
4437         }
4438
4439 cleanup:
4440         list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
4441                 if (nh->fib6_info)
4442                         fib6_info_release(nh->fib6_info);
4443                 list_del(&nh->next);
4444                 kfree(nh);
4445         }
4446
4447         return err;
4448 }
4449
4450 static int ip6_route_multipath_del(struct fib6_config *cfg,
4451                                    struct netlink_ext_ack *extack)
4452 {
4453         struct fib6_config r_cfg;
4454         struct rtnexthop *rtnh;
4455         int remaining;
4456         int attrlen;
4457         int err = 1, last_err = 0;
4458
4459         remaining = cfg->fc_mp_len;
4460         rtnh = (struct rtnexthop *)cfg->fc_mp;
4461
4462         /* Parse a Multipath Entry */
4463         while (rtnh_ok(rtnh, remaining)) {
4464                 memcpy(&r_cfg, cfg, sizeof(*cfg));
4465                 if (rtnh->rtnh_ifindex)
4466                         r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
4467
4468                 attrlen = rtnh_attrlen(rtnh);
4469                 if (attrlen > 0) {
4470                         struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
4471
4472                         nla = nla_find(attrs, attrlen, RTA_GATEWAY);
4473                         if (nla) {
4474                                 nla_memcpy(&r_cfg.fc_gateway, nla, 16);
4475                                 r_cfg.fc_flags |= RTF_GATEWAY;
4476                         }
4477                 }
4478                 err = ip6_route_del(&r_cfg, extack);
4479                 if (err)
4480                         last_err = err;
4481
4482                 rtnh = rtnh_next(rtnh, &remaining);
4483         }
4484
4485         return last_err;
4486 }
4487
4488 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
4489                               struct netlink_ext_ack *extack)
4490 {
4491         struct fib6_config cfg;
4492         int err;
4493
4494         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
4495         if (err < 0)
4496                 return err;
4497
4498         if (cfg.fc_mp)
4499                 return ip6_route_multipath_del(&cfg, extack);
4500         else {
4501                 cfg.fc_delete_all_nh = 1;
4502                 return ip6_route_del(&cfg, extack);
4503         }
4504 }
4505
4506 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
4507                               struct netlink_ext_ack *extack)
4508 {
4509         struct fib6_config cfg;
4510         int err;
4511
4512         err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
4513         if (err < 0)
4514                 return err;
4515
4516         if (cfg.fc_mp)
4517                 return ip6_route_multipath_add(&cfg, extack);
4518         else
4519                 return ip6_route_add(&cfg, GFP_KERNEL, extack);
4520 }
4521
4522 static size_t rt6_nlmsg_size(struct fib6_info *rt)
4523 {
4524         int nexthop_len = 0;
4525
4526         if (rt->fib6_nsiblings) {
4527                 nexthop_len = nla_total_size(0)  /* RTA_MULTIPATH */
4528                             + NLA_ALIGN(sizeof(struct rtnexthop))
4529                             + nla_total_size(16) /* RTA_GATEWAY */
4530                             + lwtunnel_get_encap_size(rt->fib6_nh.nh_lwtstate);
4531
4532                 nexthop_len *= rt->fib6_nsiblings;
4533         }
4534
4535         return NLMSG_ALIGN(sizeof(struct rtmsg))
4536                + nla_total_size(16) /* RTA_SRC */
4537                + nla_total_size(16) /* RTA_DST */
4538                + nla_total_size(16) /* RTA_GATEWAY */
4539                + nla_total_size(16) /* RTA_PREFSRC */
4540                + nla_total_size(4) /* RTA_TABLE */
4541                + nla_total_size(4) /* RTA_IIF */
4542                + nla_total_size(4) /* RTA_OIF */
4543                + nla_total_size(4) /* RTA_PRIORITY */
4544                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
4545                + nla_total_size(sizeof(struct rta_cacheinfo))
4546                + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
4547                + nla_total_size(1) /* RTA_PREF */
4548                + lwtunnel_get_encap_size(rt->fib6_nh.nh_lwtstate)
4549                + nexthop_len;
4550 }
4551
4552 static int rt6_nexthop_info(struct sk_buff *skb, struct fib6_info *rt,
4553                             unsigned int *flags, bool skip_oif)
4554 {
4555         if (rt->fib6_nh.nh_flags & RTNH_F_DEAD)
4556                 *flags |= RTNH_F_DEAD;
4557
4558         if (rt->fib6_nh.nh_flags & RTNH_F_LINKDOWN) {
4559                 *flags |= RTNH_F_LINKDOWN;
4560
4561                 rcu_read_lock();
4562                 if (fib6_ignore_linkdown(rt))
4563                         *flags |= RTNH_F_DEAD;
4564                 rcu_read_unlock();
4565         }
4566
4567         if (rt->fib6_flags & RTF_GATEWAY) {
4568                 if (nla_put_in6_addr(skb, RTA_GATEWAY, &rt->fib6_nh.nh_gw) < 0)
4569                         goto nla_put_failure;
4570         }
4571
4572         *flags |= (rt->fib6_nh.nh_flags & RTNH_F_ONLINK);
4573         if (rt->fib6_nh.nh_flags & RTNH_F_OFFLOAD)
4574                 *flags |= RTNH_F_OFFLOAD;
4575
4576         /* not needed for multipath encoding b/c it has a rtnexthop struct */
4577         if (!skip_oif && rt->fib6_nh.nh_dev &&
4578             nla_put_u32(skb, RTA_OIF, rt->fib6_nh.nh_dev->ifindex))
4579                 goto nla_put_failure;
4580
4581         if (rt->fib6_nh.nh_lwtstate &&
4582             lwtunnel_fill_encap(skb, rt->fib6_nh.nh_lwtstate) < 0)
4583                 goto nla_put_failure;
4584
4585         return 0;
4586
4587 nla_put_failure:
4588         return -EMSGSIZE;
4589 }
4590
4591 /* add multipath next hop */
4592 static int rt6_add_nexthop(struct sk_buff *skb, struct fib6_info *rt)
4593 {
4594         const struct net_device *dev = rt->fib6_nh.nh_dev;
4595         struct rtnexthop *rtnh;
4596         unsigned int flags = 0;
4597
4598         rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
4599         if (!rtnh)
4600                 goto nla_put_failure;
4601
4602         rtnh->rtnh_hops = rt->fib6_nh.nh_weight - 1;
4603         rtnh->rtnh_ifindex = dev ? dev->ifindex : 0;
4604
4605         if (rt6_nexthop_info(skb, rt, &flags, true) < 0)
4606                 goto nla_put_failure;
4607
4608         rtnh->rtnh_flags = flags;
4609
4610         /* length of rtnetlink header + attributes */
4611         rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
4612
4613         return 0;
4614
4615 nla_put_failure:
4616         return -EMSGSIZE;
4617 }
4618
4619 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
4620                          struct fib6_info *rt, struct dst_entry *dst,
4621                          struct in6_addr *dest, struct in6_addr *src,
4622                          int iif, int type, u32 portid, u32 seq,
4623                          unsigned int flags)
4624 {
4625         struct rt6_info *rt6 = (struct rt6_info *)dst;
4626         struct rt6key *rt6_dst, *rt6_src;
4627         u32 *pmetrics, table, rt6_flags;
4628         struct nlmsghdr *nlh;
4629         struct rtmsg *rtm;
4630         long expires = 0;
4631
4632         nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
4633         if (!nlh)
4634                 return -EMSGSIZE;
4635
4636         if (rt6) {
4637                 rt6_dst = &rt6->rt6i_dst;
4638                 rt6_src = &rt6->rt6i_src;
4639                 rt6_flags = rt6->rt6i_flags;
4640         } else {
4641                 rt6_dst = &rt->fib6_dst;
4642                 rt6_src = &rt->fib6_src;
4643                 rt6_flags = rt->fib6_flags;
4644         }
4645
4646         rtm = nlmsg_data(nlh);
4647         rtm->rtm_family = AF_INET6;
4648         rtm->rtm_dst_len = rt6_dst->plen;
4649         rtm->rtm_src_len = rt6_src->plen;
4650         rtm->rtm_tos = 0;
4651         if (rt->fib6_table)
4652                 table = rt->fib6_table->tb6_id;
4653         else
4654                 table = RT6_TABLE_UNSPEC;
4655         rtm->rtm_table = table;
4656         if (nla_put_u32(skb, RTA_TABLE, table))
4657                 goto nla_put_failure;
4658
4659         rtm->rtm_type = rt->fib6_type;
4660         rtm->rtm_flags = 0;
4661         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
4662         rtm->rtm_protocol = rt->fib6_protocol;
4663
4664         if (rt6_flags & RTF_CACHE)
4665                 rtm->rtm_flags |= RTM_F_CLONED;
4666
4667         if (dest) {
4668                 if (nla_put_in6_addr(skb, RTA_DST, dest))
4669                         goto nla_put_failure;
4670                 rtm->rtm_dst_len = 128;
4671         } else if (rtm->rtm_dst_len)
4672                 if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
4673                         goto nla_put_failure;
4674 #ifdef CONFIG_IPV6_SUBTREES
4675         if (src) {
4676                 if (nla_put_in6_addr(skb, RTA_SRC, src))
4677                         goto nla_put_failure;
4678                 rtm->rtm_src_len = 128;
4679         } else if (rtm->rtm_src_len &&
4680                    nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
4681                 goto nla_put_failure;
4682 #endif
4683         if (iif) {
4684 #ifdef CONFIG_IPV6_MROUTE
4685                 if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
4686                         int err = ip6mr_get_route(net, skb, rtm, portid);
4687
4688                         if (err == 0)
4689                                 return 0;
4690                         if (err < 0)
4691                                 goto nla_put_failure;
4692                 } else
4693 #endif
4694                         if (nla_put_u32(skb, RTA_IIF, iif))
4695                                 goto nla_put_failure;
4696         } else if (dest) {
4697                 struct in6_addr saddr_buf;
4698                 if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 &&
4699                     nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
4700                         goto nla_put_failure;
4701         }
4702
4703         if (rt->fib6_prefsrc.plen) {
4704                 struct in6_addr saddr_buf;
4705                 saddr_buf = rt->fib6_prefsrc.addr;
4706                 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
4707                         goto nla_put_failure;
4708         }
4709
4710         pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
4711         if (rtnetlink_put_metrics(skb, pmetrics) < 0)
4712                 goto nla_put_failure;
4713
4714         if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
4715                 goto nla_put_failure;
4716
4717         /* For multipath routes, walk the siblings list and add
4718          * each as a nexthop within RTA_MULTIPATH.
4719          */
4720         if (rt6) {
4721                 if (rt6_flags & RTF_GATEWAY &&
4722                     nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
4723                         goto nla_put_failure;
4724
4725                 if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
4726                         goto nla_put_failure;
4727         } else if (rt->fib6_nsiblings) {
4728                 struct fib6_info *sibling, *next_sibling;
4729                 struct nlattr *mp;
4730
4731                 mp = nla_nest_start(skb, RTA_MULTIPATH);
4732                 if (!mp)
4733                         goto nla_put_failure;
4734
4735                 if (rt6_add_nexthop(skb, rt) < 0)
4736                         goto nla_put_failure;
4737
4738                 list_for_each_entry_safe(sibling, next_sibling,
4739                                          &rt->fib6_siblings, fib6_siblings) {
4740                         if (rt6_add_nexthop(skb, sibling) < 0)
4741                                 goto nla_put_failure;
4742                 }
4743
4744                 nla_nest_end(skb, mp);
4745         } else {
4746                 if (rt6_nexthop_info(skb, rt, &rtm->rtm_flags, false) < 0)
4747                         goto nla_put_failure;
4748         }
4749
4750         if (rt6_flags & RTF_EXPIRES) {
4751                 expires = dst ? dst->expires : rt->expires;
4752                 expires -= jiffies;
4753         }
4754
4755         if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
4756                 goto nla_put_failure;
4757
4758         if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
4759                 goto nla_put_failure;
4760
4761
4762         nlmsg_end(skb, nlh);
4763         return 0;
4764
4765 nla_put_failure:
4766         nlmsg_cancel(skb, nlh);
4767         return -EMSGSIZE;
4768 }
4769
4770 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
4771                                const struct net_device *dev)
4772 {
4773         if (f6i->fib6_nh.nh_dev == dev)
4774                 return true;
4775
4776         if (f6i->fib6_nsiblings) {
4777                 struct fib6_info *sibling, *next_sibling;
4778
4779                 list_for_each_entry_safe(sibling, next_sibling,
4780                                          &f6i->fib6_siblings, fib6_siblings) {
4781                         if (sibling->fib6_nh.nh_dev == dev)
4782                                 return true;
4783                 }
4784         }
4785
4786         return false;
4787 }
4788
4789 int rt6_dump_route(struct fib6_info *rt, void *p_arg)
4790 {
4791         struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
4792         struct fib_dump_filter *filter = &arg->filter;
4793         unsigned int flags = NLM_F_MULTI;
4794         struct net *net = arg->net;
4795
4796         if (rt == net->ipv6.fib6_null_entry)
4797                 return 0;
4798
4799         if ((filter->flags & RTM_F_PREFIX) &&
4800             !(rt->fib6_flags & RTF_PREFIX_RT)) {
4801                 /* success since this is not a prefix route */
4802                 return 1;
4803         }
4804         if (filter->filter_set) {
4805                 if ((filter->rt_type && rt->fib6_type != filter->rt_type) ||
4806                     (filter->dev && !fib6_info_uses_dev(rt, filter->dev)) ||
4807                     (filter->protocol && rt->fib6_protocol != filter->protocol)) {
4808                         return 1;
4809                 }
4810                 flags |= NLM_F_DUMP_FILTERED;
4811         }
4812
4813         return rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL, 0,
4814                              RTM_NEWROUTE, NETLINK_CB(arg->cb->skb).portid,
4815                              arg->cb->nlh->nlmsg_seq, flags);
4816 }
4817
4818 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
4819                               struct netlink_ext_ack *extack)
4820 {
4821         struct net *net = sock_net(in_skb->sk);
4822         struct nlattr *tb[RTA_MAX+1];
4823         int err, iif = 0, oif = 0;
4824         struct fib6_info *from;
4825         struct dst_entry *dst;
4826         struct rt6_info *rt;
4827         struct sk_buff *skb;
4828         struct rtmsg *rtm;
4829         struct flowi6 fl6 = {};
4830         bool fibmatch;
4831
4832         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy,
4833                           extack);
4834         if (err < 0)
4835                 goto errout;
4836
4837         err = -EINVAL;
4838         rtm = nlmsg_data(nlh);
4839         fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
4840         fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
4841
4842         if (tb[RTA_SRC]) {
4843                 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
4844                         goto errout;
4845
4846                 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
4847         }
4848
4849         if (tb[RTA_DST]) {
4850                 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
4851                         goto errout;
4852
4853                 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
4854         }
4855
4856         if (tb[RTA_IIF])
4857                 iif = nla_get_u32(tb[RTA_IIF]);
4858
4859         if (tb[RTA_OIF])
4860                 oif = nla_get_u32(tb[RTA_OIF]);
4861
4862         if (tb[RTA_MARK])
4863                 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
4864
4865         if (tb[RTA_UID])
4866                 fl6.flowi6_uid = make_kuid(current_user_ns(),
4867                                            nla_get_u32(tb[RTA_UID]));
4868         else
4869                 fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
4870
4871         if (tb[RTA_SPORT])
4872                 fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
4873
4874         if (tb[RTA_DPORT])
4875                 fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
4876
4877         if (tb[RTA_IP_PROTO]) {
4878                 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
4879                                                   &fl6.flowi6_proto, extack);
4880                 if (err)
4881                         goto errout;
4882         }
4883
4884         if (iif) {
4885                 struct net_device *dev;
4886                 int flags = 0;
4887
4888                 rcu_read_lock();
4889
4890                 dev = dev_get_by_index_rcu(net, iif);
4891                 if (!dev) {
4892                         rcu_read_unlock();
4893                         err = -ENODEV;
4894                         goto errout;
4895                 }
4896
4897                 fl6.flowi6_iif = iif;
4898
4899                 if (!ipv6_addr_any(&fl6.saddr))
4900                         flags |= RT6_LOOKUP_F_HAS_SADDR;
4901
4902                 dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
4903
4904                 rcu_read_unlock();
4905         } else {
4906                 fl6.flowi6_oif = oif;
4907
4908                 dst = ip6_route_output(net, NULL, &fl6);
4909         }
4910
4911
4912         rt = container_of(dst, struct rt6_info, dst);
4913         if (rt->dst.error) {
4914                 err = rt->dst.error;
4915                 ip6_rt_put(rt);
4916                 goto errout;
4917         }
4918
4919         if (rt == net->ipv6.ip6_null_entry) {
4920                 err = rt->dst.error;
4921                 ip6_rt_put(rt);
4922                 goto errout;
4923         }
4924
4925         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
4926         if (!skb) {
4927                 ip6_rt_put(rt);
4928                 err = -ENOBUFS;
4929                 goto errout;
4930         }
4931
4932         skb_dst_set(skb, &rt->dst);
4933
4934         rcu_read_lock();
4935         from = rcu_dereference(rt->from);
4936
4937         if (fibmatch)
4938                 err = rt6_fill_node(net, skb, from, NULL, NULL, NULL, iif,
4939                                     RTM_NEWROUTE, NETLINK_CB(in_skb).portid,
4940                                     nlh->nlmsg_seq, 0);
4941         else
4942                 err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
4943                                     &fl6.saddr, iif, RTM_NEWROUTE,
4944                                     NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
4945                                     0);
4946         rcu_read_unlock();
4947
4948         if (err < 0) {
4949                 kfree_skb(skb);
4950                 goto errout;
4951         }
4952
4953         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
4954 errout:
4955         return err;
4956 }
4957
4958 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
4959                      unsigned int nlm_flags)
4960 {
4961         struct sk_buff *skb;
4962         struct net *net = info->nl_net;
4963         u32 seq;
4964         int err;
4965
4966         err = -ENOBUFS;
4967         seq = info->nlh ? info->nlh->nlmsg_seq : 0;
4968
4969         skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
4970         if (!skb)
4971                 goto errout;
4972
4973         err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
4974                             event, info->portid, seq, nlm_flags);
4975         if (err < 0) {
4976                 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
4977                 WARN_ON(err == -EMSGSIZE);
4978                 kfree_skb(skb);
4979                 goto errout;
4980         }
4981         rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
4982                     info->nlh, gfp_any());
4983         return;
4984 errout:
4985         if (err < 0)
4986                 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
4987 }
4988
4989 static int ip6_route_dev_notify(struct notifier_block *this,
4990                                 unsigned long event, void *ptr)
4991 {
4992         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
4993         struct net *net = dev_net(dev);
4994
4995         if (!(dev->flags & IFF_LOOPBACK))
4996                 return NOTIFY_OK;
4997
4998         if (event == NETDEV_REGISTER) {
4999                 net->ipv6.fib6_null_entry->fib6_nh.nh_dev = dev;
5000                 net->ipv6.ip6_null_entry->dst.dev = dev;
5001                 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
5002 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
5003                 net->ipv6.ip6_prohibit_entry->dst.dev = dev;
5004                 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
5005                 net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
5006                 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
5007 #endif
5008          } else if (event == NETDEV_UNREGISTER &&
5009                     dev->reg_state != NETREG_UNREGISTERED) {
5010                 /* NETDEV_UNREGISTER could be fired for multiple times by
5011                  * netdev_wait_allrefs(). Make sure we only call this once.
5012                  */
5013                 in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
5014 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
5015                 in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
5016                 in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
5017 #endif
5018         }
5019
5020         return NOTIFY_OK;
5021 }
5022
5023 /*
5024  *      /proc
5025  */
5026
5027 #ifdef CONFIG_PROC_FS
5028 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
5029 {
5030         struct net *net = (struct net *)seq->private;
5031         seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
5032                    net->ipv6.rt6_stats->fib_nodes,
5033                    net->ipv6.rt6_stats->fib_route_nodes,
5034                    atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
5035                    net->ipv6.rt6_stats->fib_rt_entries,
5036                    net->ipv6.rt6_stats->fib_rt_cache,
5037                    dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
5038                    net->ipv6.rt6_stats->fib_discarded_routes);
5039
5040         return 0;
5041 }
5042 #endif  /* CONFIG_PROC_FS */
5043
5044 #ifdef CONFIG_SYSCTL
5045
5046 static
5047 int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
5048                               void __user *buffer, size_t *lenp, loff_t *ppos)
5049 {
5050         struct net *net;
5051         int delay;
5052         if (!write)
5053                 return -EINVAL;
5054
5055         net = (struct net *)ctl->extra1;
5056         delay = net->ipv6.sysctl.flush_delay;
5057         proc_dointvec(ctl, write, buffer, lenp, ppos);
5058         fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
5059         return 0;
5060 }
5061
5062 static int zero;
5063 static int one = 1;
5064
5065 static struct ctl_table ipv6_route_table_template[] = {
5066         {
5067                 .procname       =       "flush",
5068                 .data           =       &init_net.ipv6.sysctl.flush_delay,
5069                 .maxlen         =       sizeof(int),
5070                 .mode           =       0200,
5071                 .proc_handler   =       ipv6_sysctl_rtcache_flush
5072         },
5073         {
5074                 .procname       =       "gc_thresh",
5075                 .data           =       &ip6_dst_ops_template.gc_thresh,
5076                 .maxlen         =       sizeof(int),
5077                 .mode           =       0644,
5078                 .proc_handler   =       proc_dointvec,
5079         },
5080         {
5081                 .procname       =       "max_size",
5082                 .data           =       &init_net.ipv6.sysctl.ip6_rt_max_size,
5083                 .maxlen         =       sizeof(int),
5084                 .mode           =       0644,
5085                 .proc_handler   =       proc_dointvec,
5086         },
5087         {
5088                 .procname       =       "gc_min_interval",
5089                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
5090                 .maxlen         =       sizeof(int),
5091                 .mode           =       0644,
5092                 .proc_handler   =       proc_dointvec_jiffies,
5093         },
5094         {
5095                 .procname       =       "gc_timeout",
5096                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
5097                 .maxlen         =       sizeof(int),
5098                 .mode           =       0644,
5099                 .proc_handler   =       proc_dointvec_jiffies,
5100         },
5101         {
5102                 .procname       =       "gc_interval",
5103                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_interval,
5104                 .maxlen         =       sizeof(int),
5105                 .mode           =       0644,
5106                 .proc_handler   =       proc_dointvec_jiffies,
5107         },
5108         {
5109                 .procname       =       "gc_elasticity",
5110                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
5111                 .maxlen         =       sizeof(int),
5112                 .mode           =       0644,
5113                 .proc_handler   =       proc_dointvec,
5114         },
5115         {
5116                 .procname       =       "mtu_expires",
5117                 .data           =       &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
5118                 .maxlen         =       sizeof(int),
5119                 .mode           =       0644,
5120                 .proc_handler   =       proc_dointvec_jiffies,
5121         },
5122         {
5123                 .procname       =       "min_adv_mss",
5124                 .data           =       &init_net.ipv6.sysctl.ip6_rt_min_advmss,
5125                 .maxlen         =       sizeof(int),
5126                 .mode           =       0644,
5127                 .proc_handler   =       proc_dointvec,
5128         },
5129         {
5130                 .procname       =       "gc_min_interval_ms",
5131                 .data           =       &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
5132                 .maxlen         =       sizeof(int),
5133                 .mode           =       0644,
5134                 .proc_handler   =       proc_dointvec_ms_jiffies,
5135         },
5136         {
5137                 .procname       =       "skip_notify_on_dev_down",
5138                 .data           =       &init_net.ipv6.sysctl.skip_notify_on_dev_down,
5139                 .maxlen         =       sizeof(int),
5140                 .mode           =       0644,
5141                 .proc_handler   =       proc_dointvec,
5142                 .extra1         =       &zero,
5143                 .extra2         =       &one,
5144         },
5145         { }
5146 };
5147
5148 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
5149 {
5150         struct ctl_table *table;
5151
5152         table = kmemdup(ipv6_route_table_template,
5153                         sizeof(ipv6_route_table_template),
5154                         GFP_KERNEL);
5155
5156         if (table) {
5157                 table[0].data = &net->ipv6.sysctl.flush_delay;
5158                 table[0].extra1 = net;
5159                 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
5160                 table[2].data = &net->ipv6.sysctl.ip6_rt_max_size;
5161                 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
5162                 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
5163                 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
5164                 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
5165                 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
5166                 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
5167                 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
5168                 table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
5169
5170                 /* Don't export sysctls to unprivileged users */
5171                 if (net->user_ns != &init_user_ns)
5172                         table[0].procname = NULL;
5173         }
5174
5175         return table;
5176 }
5177 #endif
5178
5179 static int __net_init ip6_route_net_init(struct net *net)
5180 {
5181         int ret = -ENOMEM;
5182
5183         memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
5184                sizeof(net->ipv6.ip6_dst_ops));
5185
5186         if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
5187                 goto out_ip6_dst_ops;
5188
5189         net->ipv6.fib6_null_entry = kmemdup(&fib6_null_entry_template,
5190                                             sizeof(*net->ipv6.fib6_null_entry),
5191                                             GFP_KERNEL);
5192         if (!net->ipv6.fib6_null_entry)
5193                 goto out_ip6_dst_entries;
5194
5195         net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
5196                                            sizeof(*net->ipv6.ip6_null_entry),
5197                                            GFP_KERNEL);
5198         if (!net->ipv6.ip6_null_entry)
5199                 goto out_fib6_null_entry;
5200         net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
5201         dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
5202                          ip6_template_metrics, true);
5203
5204 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
5205         net->ipv6.fib6_has_custom_rules = false;
5206         net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
5207                                                sizeof(*net->ipv6.ip6_prohibit_entry),
5208                                                GFP_KERNEL);
5209         if (!net->ipv6.ip6_prohibit_entry)
5210                 goto out_ip6_null_entry;
5211         net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
5212         dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
5213                          ip6_template_metrics, true);
5214
5215         net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
5216                                                sizeof(*net->ipv6.ip6_blk_hole_entry),
5217                                                GFP_KERNEL);
5218         if (!net->ipv6.ip6_blk_hole_entry)
5219                 goto out_ip6_prohibit_entry;
5220         net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
5221         dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
5222                          ip6_template_metrics, true);
5223 #endif
5224
5225         net->ipv6.sysctl.flush_delay = 0;
5226         net->ipv6.sysctl.ip6_rt_max_size = 4096;
5227         net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
5228         net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
5229         net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
5230         net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
5231         net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
5232         net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
5233         net->ipv6.sysctl.skip_notify_on_dev_down = 0;
5234
5235         net->ipv6.ip6_rt_gc_expire = 30*HZ;
5236
5237         ret = 0;
5238 out:
5239         return ret;
5240
5241 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
5242 out_ip6_prohibit_entry:
5243         kfree(net->ipv6.ip6_prohibit_entry);
5244 out_ip6_null_entry:
5245         kfree(net->ipv6.ip6_null_entry);
5246 #endif
5247 out_fib6_null_entry:
5248         kfree(net->ipv6.fib6_null_entry);
5249 out_ip6_dst_entries:
5250         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
5251 out_ip6_dst_ops:
5252         goto out;
5253 }
5254
5255 static void __net_exit ip6_route_net_exit(struct net *net)
5256 {
5257         kfree(net->ipv6.fib6_null_entry);
5258         kfree(net->ipv6.ip6_null_entry);
5259 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
5260         kfree(net->ipv6.ip6_prohibit_entry);
5261         kfree(net->ipv6.ip6_blk_hole_entry);
5262 #endif
5263         dst_entries_destroy(&net->ipv6.ip6_dst_ops);
5264 }
5265
5266 static int __net_init ip6_route_net_init_late(struct net *net)
5267 {
5268 #ifdef CONFIG_PROC_FS
5269         proc_create_net("ipv6_route", 0, net->proc_net, &ipv6_route_seq_ops,
5270                         sizeof(struct ipv6_route_iter));
5271         proc_create_net_single("rt6_stats", 0444, net->proc_net,
5272                         rt6_stats_seq_show, NULL);
5273 #endif
5274         return 0;
5275 }
5276
5277 static void __net_exit ip6_route_net_exit_late(struct net *net)
5278 {
5279 #ifdef CONFIG_PROC_FS
5280         remove_proc_entry("ipv6_route", net->proc_net);
5281         remove_proc_entry("rt6_stats", net->proc_net);
5282 #endif
5283 }
5284
5285 static struct pernet_operations ip6_route_net_ops = {
5286         .init = ip6_route_net_init,
5287         .exit = ip6_route_net_exit,
5288 };
5289
5290 static int __net_init ipv6_inetpeer_init(struct net *net)
5291 {
5292         struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
5293
5294         if (!bp)
5295                 return -ENOMEM;
5296         inet_peer_base_init(bp);
5297         net->ipv6.peers = bp;
5298         return 0;
5299 }
5300
5301 static void __net_exit ipv6_inetpeer_exit(struct net *net)
5302 {
5303         struct inet_peer_base *bp = net->ipv6.peers;
5304
5305         net->ipv6.peers = NULL;
5306         inetpeer_invalidate_tree(bp);
5307         kfree(bp);
5308 }
5309
5310 static struct pernet_operations ipv6_inetpeer_ops = {
5311         .init   =       ipv6_inetpeer_init,
5312         .exit   =       ipv6_inetpeer_exit,
5313 };
5314
5315 static struct pernet_operations ip6_route_net_late_ops = {
5316         .init = ip6_route_net_init_late,
5317         .exit = ip6_route_net_exit_late,
5318 };
5319
5320 static struct notifier_block ip6_route_dev_notifier = {
5321         .notifier_call = ip6_route_dev_notify,
5322         .priority = ADDRCONF_NOTIFY_PRIORITY - 10,
5323 };
5324
5325 void __init ip6_route_init_special_entries(void)
5326 {
5327         /* Registering of the loopback is done before this portion of code,
5328          * the loopback reference in rt6_info will not be taken, do it
5329          * manually for init_net */
5330         init_net.ipv6.fib6_null_entry->fib6_nh.nh_dev = init_net.loopback_dev;
5331         init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
5332         init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
5333   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
5334         init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
5335         init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
5336         init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
5337         init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
5338   #endif
5339 }
5340
5341 int __init ip6_route_init(void)
5342 {
5343         int ret;
5344         int cpu;
5345
5346         ret = -ENOMEM;
5347         ip6_dst_ops_template.kmem_cachep =
5348                 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
5349                                   SLAB_HWCACHE_ALIGN, NULL);
5350         if (!ip6_dst_ops_template.kmem_cachep)
5351                 goto out;
5352
5353         ret = dst_entries_init(&ip6_dst_blackhole_ops);
5354         if (ret)
5355                 goto out_kmem_cache;
5356
5357         ret = register_pernet_subsys(&ipv6_inetpeer_ops);
5358         if (ret)
5359                 goto out_dst_entries;
5360
5361         ret = register_pernet_subsys(&ip6_route_net_ops);
5362         if (ret)
5363                 goto out_register_inetpeer;
5364
5365         ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
5366
5367         ret = fib6_init();
5368         if (ret)
5369                 goto out_register_subsys;
5370
5371         ret = xfrm6_init();
5372         if (ret)
5373                 goto out_fib6_init;
5374
5375         ret = fib6_rules_init();
5376         if (ret)
5377                 goto xfrm6_init;
5378
5379         ret = register_pernet_subsys(&ip6_route_net_late_ops);
5380         if (ret)
5381                 goto fib6_rules_init;
5382
5383         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
5384                                    inet6_rtm_newroute, NULL, 0);
5385         if (ret < 0)
5386                 goto out_register_late_subsys;
5387
5388         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
5389                                    inet6_rtm_delroute, NULL, 0);
5390         if (ret < 0)
5391                 goto out_register_late_subsys;
5392
5393         ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
5394                                    inet6_rtm_getroute, NULL,
5395                                    RTNL_FLAG_DOIT_UNLOCKED);
5396         if (ret < 0)
5397                 goto out_register_late_subsys;
5398
5399         ret = register_netdevice_notifier(&ip6_route_dev_notifier);
5400         if (ret)
5401                 goto out_register_late_subsys;
5402
5403         for_each_possible_cpu(cpu) {
5404                 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
5405
5406                 INIT_LIST_HEAD(&ul->head);
5407                 spin_lock_init(&ul->lock);
5408         }
5409
5410 out:
5411         return ret;
5412
5413 out_register_late_subsys:
5414         rtnl_unregister_all(PF_INET6);
5415         unregister_pernet_subsys(&ip6_route_net_late_ops);
5416 fib6_rules_init:
5417         fib6_rules_cleanup();
5418 xfrm6_init:
5419         xfrm6_fini();
5420 out_fib6_init:
5421         fib6_gc_cleanup();
5422 out_register_subsys:
5423         unregister_pernet_subsys(&ip6_route_net_ops);
5424 out_register_inetpeer:
5425         unregister_pernet_subsys(&ipv6_inetpeer_ops);
5426 out_dst_entries:
5427         dst_entries_destroy(&ip6_dst_blackhole_ops);
5428 out_kmem_cache:
5429         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
5430         goto out;
5431 }
5432
5433 void ip6_route_cleanup(void)
5434 {
5435         unregister_netdevice_notifier(&ip6_route_dev_notifier);
5436         unregister_pernet_subsys(&ip6_route_net_late_ops);
5437         fib6_rules_cleanup();
5438         xfrm6_fini();
5439         fib6_gc_cleanup();
5440         unregister_pernet_subsys(&ipv6_inetpeer_ops);
5441         unregister_pernet_subsys(&ip6_route_net_ops);
5442         dst_entries_destroy(&ip6_dst_blackhole_ops);
5443         kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
5444 }