net/ipv4/nexthop.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Generic nexthop implementation
   3  *
   4  * Copyright (c) 2017-19 Cumulus Networks
   5  * Copyright (c) 2017-19 David Ahern <dsa@cumulusnetworks.com>
   6  */
   7
   8 #include <linux/nexthop.h>
   9 #include <linux/rtnetlink.h>
  10 #include <linux/slab.h>
  11 #include <net/arp.h>
  12 #include <net/ipv6_stubs.h>
  13 #include <net/lwtunnel.h>
  14 #include <net/ndisc.h>
  15 #include <net/nexthop.h>
  16 #include <net/route.h>
  17 #include <net/sock.h>
  18
  19 static void remove_nexthop(struct net *net, struct nexthop *nh,
  20                            struct nl_info *nlinfo);
  21
  22 #define NH_DEV_HASHBITS  8
  23 #define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS)
  24
  25 static const struct nla_policy rtm_nh_policy[NHA_MAX + 1] = {
  26         [NHA_ID]                = { .type = NLA_U32 },
  27         [NHA_GROUP]             = { .type = NLA_BINARY },
  28         [NHA_GROUP_TYPE]        = { .type = NLA_U16 },
  29         [NHA_BLACKHOLE]         = { .type = NLA_FLAG },
  30         [NHA_OIF]               = { .type = NLA_U32 },
  31         [NHA_GATEWAY]           = { .type = NLA_BINARY },
  32         [NHA_ENCAP_TYPE]        = { .type = NLA_U16 },
  33         [NHA_ENCAP]             = { .type = NLA_NESTED },
  34         [NHA_GROUPS]            = { .type = NLA_FLAG },
  35         [NHA_MASTER]            = { .type = NLA_U32 },
  36         [NHA_FDB]               = { .type = NLA_FLAG },
  37 };
  38
  39 static int call_nexthop_notifiers(struct net *net,
  40                                   enum nexthop_event_type event_type,
  41                                   struct nexthop *nh)
  42 {
  43         int err;
  44
  45         err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
  46                                            event_type, nh);
  47         return notifier_to_errno(err);
  48 }
  49
  50 static unsigned int nh_dev_hashfn(unsigned int val)
  51 {
  52         unsigned int mask = NH_DEV_HASHSIZE - 1;
  53
  54         return (val ^
  55                 (val >> NH_DEV_HASHBITS) ^
  56                 (val >> (NH_DEV_HASHBITS * 2))) & mask;
  57 }
  58
  59 static void nexthop_devhash_add(struct net *net, struct nh_info *nhi)
  60 {
  61         struct net_device *dev = nhi->fib_nhc.nhc_dev;
  62         struct hlist_head *head;
  63         unsigned int hash;
  64
  65         WARN_ON(!dev);
  66
  67         hash = nh_dev_hashfn(dev->ifindex);
  68         head = &net->nexthop.devhash[hash];
  69         hlist_add_head(&nhi->dev_hash, head);
  70 }
  71
  72 static void nexthop_free_mpath(struct nexthop *nh)
  73 {
  74         struct nh_group *nhg;
  75         int i;
  76
  77         nhg = rcu_dereference_raw(nh->nh_grp);
  78         for (i = 0; i < nhg->num_nh; ++i) {
  79                 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
  80
  81                 WARN_ON(!list_empty(&nhge->nh_list));
  82                 nexthop_put(nhge->nh);
  83         }
  84
  85         WARN_ON(nhg->spare == nhg);
  86
  87         kfree(nhg->spare);
  88         kfree(nhg);
  89 }
  90
  91 static void nexthop_free_single(struct nexthop *nh)
  92 {
  93         struct nh_info *nhi;
  94
  95         nhi = rcu_dereference_raw(nh->nh_info);
  96         switch (nhi->family) {
  97         case AF_INET:
  98                 fib_nh_release(nh->net, &nhi->fib_nh);
  99                 break;
 100         case AF_INET6:
 101                 ipv6_stub->fib6_nh_release(&nhi->fib6_nh);
 102                 break;
 103         }
 104         kfree(nhi);
 105 }
 106
 107 void nexthop_free_rcu(struct rcu_head *head)
 108 {
 109         struct nexthop *nh = container_of(head, struct nexthop, rcu);
 110
 111         if (nh->is_group)
 112                 nexthop_free_mpath(nh);
 113         else
 114                 nexthop_free_single(nh);
 115
 116         kfree(nh);
 117 }
 118 EXPORT_SYMBOL_GPL(nexthop_free_rcu);
 119
 120 static struct nexthop *nexthop_alloc(void)
 121 {
 122         struct nexthop *nh;
 123
 124         nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL);
 125         if (nh) {
 126                 INIT_LIST_HEAD(&nh->fi_list);
 127                 INIT_LIST_HEAD(&nh->f6i_list);
 128                 INIT_LIST_HEAD(&nh->grp_list);
 129                 INIT_LIST_HEAD(&nh->fdb_list);
 130         }
 131         return nh;
 132 }
 133
 134 static struct nh_group *nexthop_grp_alloc(u16 num_nh)
 135 {
 136         struct nh_group *nhg;
 137
 138         nhg = kzalloc(struct_size(nhg, nh_entries, num_nh), GFP_KERNEL);
 139         if (nhg)
 140                 nhg->num_nh = num_nh;
 141
 142         return nhg;
 143 }
 144
 145 static void nh_base_seq_inc(struct net *net)
 146 {
 147         while (++net->nexthop.seq == 0)
 148                 ;
 149 }
 150
 151 /* no reference taken; rcu lock or rtnl must be held */
 152 struct nexthop *nexthop_find_by_id(struct net *net, u32 id)
 153 {
 154         struct rb_node **pp, *parent = NULL, *next;
 155
 156         pp = &net->nexthop.rb_root.rb_node;
 157         while (1) {
 158                 struct nexthop *nh;
 159
 160                 next = rcu_dereference_raw(*pp);
 161                 if (!next)
 162                         break;
 163                 parent = next;
 164
 165                 nh = rb_entry(parent, struct nexthop, rb_node);
 166                 if (id < nh->id)
 167                         pp = &next->rb_left;
 168                 else if (id > nh->id)
 169                         pp = &next->rb_right;
 170                 else
 171                         return nh;
 172         }
 173         return NULL;
 174 }
 175 EXPORT_SYMBOL_GPL(nexthop_find_by_id);
 176
 177 /* used for auto id allocation; called with rtnl held */
 178 static u32 nh_find_unused_id(struct net *net)
 179 {
 180         u32 id_start = net->nexthop.last_id_allocated;
 181
 182         while (1) {
 183                 net->nexthop.last_id_allocated++;
 184                 if (net->nexthop.last_id_allocated == id_start)
 185                         break;
 186
 187                 if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated))
 188                         return net->nexthop.last_id_allocated;
 189         }
 190         return 0;
 191 }
 192
 193 static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg)
 194 {
 195         struct nexthop_grp *p;
 196         size_t len = nhg->num_nh * sizeof(*p);
 197         struct nlattr *nla;
 198         u16 group_type = 0;
 199         int i;
 200
 201         if (nhg->mpath)
 202                 group_type = NEXTHOP_GRP_TYPE_MPATH;
 203
 204         if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type))
 205                 goto nla_put_failure;
 206
 207         nla = nla_reserve(skb, NHA_GROUP, len);
 208         if (!nla)
 209                 goto nla_put_failure;
 210
 211         p = nla_data(nla);
 212         for (i = 0; i < nhg->num_nh; ++i) {
 213                 p->id = nhg->nh_entries[i].nh->id;
 214                 p->weight = nhg->nh_entries[i].weight - 1;
 215                 p += 1;
 216         }
 217
 218         return 0;
 219
 220 nla_put_failure:
 221         return -EMSGSIZE;
 222 }
 223
 224 static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh,
 225                         int event, u32 portid, u32 seq, unsigned int nlflags)
 226 {
 227         struct fib6_nh *fib6_nh;
 228         struct fib_nh *fib_nh;
 229         struct nlmsghdr *nlh;
 230         struct nh_info *nhi;
 231         struct nhmsg *nhm;
 232
 233         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
 234         if (!nlh)
 235                 return -EMSGSIZE;
 236
 237         nhm = nlmsg_data(nlh);
 238         nhm->nh_family = AF_UNSPEC;
 239         nhm->nh_flags = nh->nh_flags;
 240         nhm->nh_protocol = nh->protocol;
 241         nhm->nh_scope = 0;
 242         nhm->resvd = 0;
 243
 244         if (nla_put_u32(skb, NHA_ID, nh->id))
 245                 goto nla_put_failure;
 246
 247         if (nh->is_group) {
 248                 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
 249
 250                 if (nhg->fdb_nh && nla_put_flag(skb, NHA_FDB))
 251                         goto nla_put_failure;
 252                 if (nla_put_nh_group(skb, nhg))
 253                         goto nla_put_failure;
 254                 goto out;
 255         }
 256
 257         nhi = rtnl_dereference(nh->nh_info);
 258         nhm->nh_family = nhi->family;
 259         if (nhi->reject_nh) {
 260                 if (nla_put_flag(skb, NHA_BLACKHOLE))
 261                         goto nla_put_failure;
 262                 goto out;
 263         } else if (nhi->fdb_nh) {
 264                 if (nla_put_flag(skb, NHA_FDB))
 265                         goto nla_put_failure;
 266         } else {
 267                 const struct net_device *dev;
 268
 269                 dev = nhi->fib_nhc.nhc_dev;
 270                 if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex))
 271                         goto nla_put_failure;
 272         }
 273
 274         nhm->nh_scope = nhi->fib_nhc.nhc_scope;
 275         switch (nhi->family) {
 276         case AF_INET:
 277                 fib_nh = &nhi->fib_nh;
 278                 if (fib_nh->fib_nh_gw_family &&
 279                     nla_put_be32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4))
 280                         goto nla_put_failure;
 281                 break;
 282
 283         case AF_INET6:
 284                 fib6_nh = &nhi->fib6_nh;
 285                 if (fib6_nh->fib_nh_gw_family &&
 286                     nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6))
 287                         goto nla_put_failure;
 288                 break;
 289         }
 290
 291         if (nhi->fib_nhc.nhc_lwtstate &&
 292             lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate,
 293                                 NHA_ENCAP, NHA_ENCAP_TYPE) < 0)
 294                 goto nla_put_failure;
 295
 296 out:
 297         nlmsg_end(skb, nlh);
 298         return 0;
 299
 300 nla_put_failure:
 301         nlmsg_cancel(skb, nlh);
 302         return -EMSGSIZE;
 303 }
 304
 305 static size_t nh_nlmsg_size_grp(struct nexthop *nh)
 306 {
 307         struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
 308         size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh;
 309
 310         return nla_total_size(sz) +
 311                nla_total_size(2);  /* NHA_GROUP_TYPE */
 312 }
 313
 314 static size_t nh_nlmsg_size_single(struct nexthop *nh)
 315 {
 316         struct nh_info *nhi = rtnl_dereference(nh->nh_info);
 317         size_t sz;
 318
 319         /* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE
 320          * are mutually exclusive
 321          */
 322         sz = nla_total_size(4);  /* NHA_OIF */
 323
 324         switch (nhi->family) {
 325         case AF_INET:
 326                 if (nhi->fib_nh.fib_nh_gw_family)
 327                         sz += nla_total_size(4);  /* NHA_GATEWAY */
 328                 break;
 329
 330         case AF_INET6:
 331                 /* NHA_GATEWAY */
 332                 if (nhi->fib6_nh.fib_nh_gw_family)
 333                         sz += nla_total_size(sizeof(const struct in6_addr));
 334                 break;
 335         }
 336
 337         if (nhi->fib_nhc.nhc_lwtstate) {
 338                 sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate);
 339                 sz += nla_total_size(2);  /* NHA_ENCAP_TYPE */
 340         }
 341
 342         return sz;
 343 }
 344
 345 static size_t nh_nlmsg_size(struct nexthop *nh)
 346 {
 347         size_t sz = NLMSG_ALIGN(sizeof(struct nhmsg));
 348
 349         sz += nla_total_size(4); /* NHA_ID */
 350
 351         if (nh->is_group)
 352                 sz += nh_nlmsg_size_grp(nh);
 353         else
 354                 sz += nh_nlmsg_size_single(nh);
 355
 356         return sz;
 357 }
 358
 359 static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info)
 360 {
 361         unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0;
 362         u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
 363         struct sk_buff *skb;
 364         int err = -ENOBUFS;
 365
 366         skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any());
 367         if (!skb)
 368                 goto errout;
 369
 370         err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags);
 371         if (err < 0) {
 372                 /* -EMSGSIZE implies BUG in nh_nlmsg_size() */
 373                 WARN_ON(err == -EMSGSIZE);
 374                 kfree_skb(skb);
 375                 goto errout;
 376         }
 377
 378         rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP,
 379                     info->nlh, gfp_any());
 380         return;
 381 errout:
 382         if (err < 0)
 383                 rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err);
 384 }
 385
 386 static bool valid_group_nh(struct nexthop *nh, unsigned int npaths,
 387                            bool *is_fdb, struct netlink_ext_ack *extack)
 388 {
 389         if (nh->is_group) {
 390                 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
 391
 392                 /* nested multipath (group within a group) is not
 393                  * supported
 394                  */
 395                 if (nhg->mpath) {
 396                         NL_SET_ERR_MSG(extack,
 397                                        "Multipath group can not be a nexthop within a group");
 398                         return false;
 399                 }
 400                 *is_fdb = nhg->fdb_nh;
 401         } else {
 402                 struct nh_info *nhi = rtnl_dereference(nh->nh_info);
 403
 404                 if (nhi->reject_nh && npaths > 1) {
 405                         NL_SET_ERR_MSG(extack,
 406                                        "Blackhole nexthop can not be used in a group with more than 1 path");
 407                         return false;
 408                 }
 409                 *is_fdb = nhi->fdb_nh;
 410         }
 411
 412         return true;
 413 }
 414
 415 static int nh_check_attr_fdb_group(struct nexthop *nh, u8 *nh_family,
 416                                    struct netlink_ext_ack *extack)
 417 {
 418         struct nh_info *nhi;
 419
 420         nhi = rtnl_dereference(nh->nh_info);
 421
 422         if (!nhi->fdb_nh) {
 423                 NL_SET_ERR_MSG(extack, "FDB nexthop group can only have fdb nexthops");
 424                 return -EINVAL;
 425         }
 426
 427         if (*nh_family == AF_UNSPEC) {
 428                 *nh_family = nhi->family;
 429         } else if (*nh_family != nhi->family) {
 430                 NL_SET_ERR_MSG(extack, "FDB nexthop group cannot have mixed family nexthops");
 431                 return -EINVAL;
 432         }
 433
 434         return 0;
 435 }
 436
 437 static int nh_check_attr_group(struct net *net, struct nlattr *tb[],
 438                                struct netlink_ext_ack *extack)
 439 {
 440         unsigned int len = nla_len(tb[NHA_GROUP]);
 441         u8 nh_family = AF_UNSPEC;
 442         struct nexthop_grp *nhg;
 443         unsigned int i, j;
 444         u8 nhg_fdb = 0;
 445
 446         if (!len || len & (sizeof(struct nexthop_grp) - 1)) {
 447                 NL_SET_ERR_MSG(extack,
 448                                "Invalid length for nexthop group attribute");
 449                 return -EINVAL;
 450         }
 451
 452         /* convert len to number of nexthop ids */
 453         len /= sizeof(*nhg);
 454
 455         nhg = nla_data(tb[NHA_GROUP]);
 456         for (i = 0; i < len; ++i) {
 457                 if (nhg[i].resvd1 || nhg[i].resvd2) {
 458                         NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0");
 459                         return -EINVAL;
 460                 }
 461                 if (nhg[i].weight > 254) {
 462                         NL_SET_ERR_MSG(extack, "Invalid value for weight");
 463                         return -EINVAL;
 464                 }
 465                 for (j = i + 1; j < len; ++j) {
 466                         if (nhg[i].id == nhg[j].id) {
 467                                 NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group");
 468                                 return -EINVAL;
 469                         }
 470                 }
 471         }
 472
 473         if (tb[NHA_FDB])
 474                 nhg_fdb = 1;
 475         nhg = nla_data(tb[NHA_GROUP]);
 476         for (i = 0; i < len; ++i) {
 477                 struct nexthop *nh;
 478                 bool is_fdb_nh;
 479
 480                 nh = nexthop_find_by_id(net, nhg[i].id);
 481                 if (!nh) {
 482                         NL_SET_ERR_MSG(extack, "Invalid nexthop id");
 483                         return -EINVAL;
 484                 }
 485                 if (!valid_group_nh(nh, len, &is_fdb_nh, extack))
 486                         return -EINVAL;
 487
 488                 if (nhg_fdb && nh_check_attr_fdb_group(nh, &nh_family, extack))
 489                         return -EINVAL;
 490
 491                 if (!nhg_fdb && is_fdb_nh) {
 492                         NL_SET_ERR_MSG(extack, "Non FDB nexthop group cannot have fdb nexthops");
 493                         return -EINVAL;
 494                 }
 495         }
 496         for (i = NHA_GROUP_TYPE + 1; i < __NHA_MAX; ++i) {
 497                 if (!tb[i])
 498                         continue;
 499                 if (tb[NHA_FDB])
 500                         continue;
 501                 NL_SET_ERR_MSG(extack,
 502                                "No other attributes can be set in nexthop groups");
 503                 return -EINVAL;
 504         }
 505
 506         return 0;
 507 }
 508
 509 static bool ipv6_good_nh(const struct fib6_nh *nh)
 510 {
 511         int state = NUD_REACHABLE;
 512         struct neighbour *n;
 513
 514         rcu_read_lock_bh();
 515
 516         n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6);
 517         if (n)
 518                 state = n->nud_state;
 519
 520         rcu_read_unlock_bh();
 521
 522         return !!(state & NUD_VALID);
 523 }
 524
 525 static bool ipv4_good_nh(const struct fib_nh *nh)
 526 {
 527         int state = NUD_REACHABLE;
 528         struct neighbour *n;
 529
 530         rcu_read_lock_bh();
 531
 532         n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
 533                                       (__force u32)nh->fib_nh_gw4);
 534         if (n)
 535                 state = n->nud_state;
 536
 537         rcu_read_unlock_bh();
 538
 539         return !!(state & NUD_VALID);
 540 }
 541
 542 struct nexthop *nexthop_select_path(struct nexthop *nh, int hash)
 543 {
 544         struct nexthop *rc = NULL;
 545         struct nh_group *nhg;
 546         int i;
 547
 548         if (!nh->is_group)
 549                 return nh;
 550
 551         nhg = rcu_dereference(nh->nh_grp);
 552         for (i = 0; i < nhg->num_nh; ++i) {
 553                 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
 554                 struct nh_info *nhi;
 555
 556                 if (hash > atomic_read(&nhge->upper_bound))
 557                         continue;
 558
 559                 nhi = rcu_dereference(nhge->nh->nh_info);
 560                 if (nhi->fdb_nh)
 561                         return nhge->nh;
 562
 563                 /* nexthops always check if it is good and does
 564                  * not rely on a sysctl for this behavior
 565                  */
 566                 switch (nhi->family) {
 567                 case AF_INET:
 568                         if (ipv4_good_nh(&nhi->fib_nh))
 569                                 return nhge->nh;
 570                         break;
 571                 case AF_INET6:
 572                         if (ipv6_good_nh(&nhi->fib6_nh))
 573                                 return nhge->nh;
 574                         break;
 575                 }
 576
 577                 if (!rc)
 578                         rc = nhge->nh;
 579         }
 580
 581         return rc;
 582 }
 583 EXPORT_SYMBOL_GPL(nexthop_select_path);
 584
 585 int nexthop_for_each_fib6_nh(struct nexthop *nh,
 586                              int (*cb)(struct fib6_nh *nh, void *arg),
 587                              void *arg)
 588 {
 589         struct nh_info *nhi;
 590         int err;
 591
 592         if (nh->is_group) {
 593                 struct nh_group *nhg;
 594                 int i;
 595
 596                 nhg = rcu_dereference_rtnl(nh->nh_grp);
 597                 for (i = 0; i < nhg->num_nh; i++) {
 598                         struct nh_grp_entry *nhge = &nhg->nh_entries[i];
 599
 600                         nhi = rcu_dereference_rtnl(nhge->nh->nh_info);
 601                         err = cb(&nhi->fib6_nh, arg);
 602                         if (err)
 603                                 return err;
 604                 }
 605         } else {
 606                 nhi = rcu_dereference_rtnl(nh->nh_info);
 607                 err = cb(&nhi->fib6_nh, arg);
 608                 if (err)
 609                         return err;
 610         }
 611
 612         return 0;
 613 }
 614 EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh);
 615
 616 static int check_src_addr(const struct in6_addr *saddr,
 617                           struct netlink_ext_ack *extack)
 618 {
 619         if (!ipv6_addr_any(saddr)) {
 620                 NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects");
 621                 return -EINVAL;
 622         }
 623         return 0;
 624 }
 625
 626 int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
 627                        struct netlink_ext_ack *extack)
 628 {
 629         struct nh_info *nhi;
 630         bool is_fdb_nh;
 631
 632         /* fib6_src is unique to a fib6_info and limits the ability to cache
 633          * routes in fib6_nh within a nexthop that is potentially shared
 634          * across multiple fib entries. If the config wants to use source
 635          * routing it can not use nexthop objects. mlxsw also does not allow
 636          * fib6_src on routes.
 637          */
 638         if (cfg && check_src_addr(&cfg->fc_src, extack) < 0)
 639                 return -EINVAL;
 640
 641         if (nh->is_group) {
 642                 struct nh_group *nhg;
 643
 644                 nhg = rtnl_dereference(nh->nh_grp);
 645                 if (nhg->has_v4)
 646                         goto no_v4_nh;
 647                 is_fdb_nh = nhg->fdb_nh;
 648         } else {
 649                 nhi = rtnl_dereference(nh->nh_info);
 650                 if (nhi->family == AF_INET)
 651                         goto no_v4_nh;
 652                 is_fdb_nh = nhi->fdb_nh;
 653         }
 654
 655         if (is_fdb_nh) {
 656                 NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
 657                 return -EINVAL;
 658         }
 659
 660         return 0;
 661 no_v4_nh:
 662         NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop");
 663         return -EINVAL;
 664 }
 665 EXPORT_SYMBOL_GPL(fib6_check_nexthop);
 666
 667 /* if existing nexthop has ipv6 routes linked to it, need
 668  * to verify this new spec works with ipv6
 669  */
 670 static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new,
 671                               struct netlink_ext_ack *extack)
 672 {
 673         struct fib6_info *f6i;
 674
 675         if (list_empty(&old->f6i_list))
 676                 return 0;
 677
 678         list_for_each_entry(f6i, &old->f6i_list, nh_list) {
 679                 if (check_src_addr(&f6i->fib6_src.addr, extack) < 0)
 680                         return -EINVAL;
 681         }
 682
 683         return fib6_check_nexthop(new, NULL, extack);
 684 }
 685
 686 static int nexthop_check_scope(struct nh_info *nhi, u8 scope,
 687                                struct netlink_ext_ack *extack)
 688 {
 689         if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) {
 690                 NL_SET_ERR_MSG(extack,
 691                                "Route with host scope can not have a gateway");
 692                 return -EINVAL;
 693         }
 694
 695         if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) {
 696                 NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop");
 697                 return -EINVAL;
 698         }
 699
 700         return 0;
 701 }
 702
 703 /* Invoked by fib add code to verify nexthop by id is ok with
 704  * config for prefix; parts of fib_check_nh not done when nexthop
 705  * object is used.
 706  */
 707 int fib_check_nexthop(struct nexthop *nh, u8 scope,
 708                       struct netlink_ext_ack *extack)
 709 {
 710         struct nh_info *nhi;
 711         int err = 0;
 712
 713         if (nh->is_group) {
 714                 struct nh_group *nhg;
 715
 716                 nhg = rtnl_dereference(nh->nh_grp);
 717                 if (nhg->fdb_nh) {
 718                         NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
 719                         err = -EINVAL;
 720                         goto out;
 721                 }
 722
 723                 if (scope == RT_SCOPE_HOST) {
 724                         NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops");
 725                         err = -EINVAL;
 726                         goto out;
 727                 }
 728
 729                 /* all nexthops in a group have the same scope */
 730                 nhi = rtnl_dereference(nhg->nh_entries[0].nh->nh_info);
 731                 err = nexthop_check_scope(nhi, scope, extack);
 732         } else {
 733                 nhi = rtnl_dereference(nh->nh_info);
 734                 if (nhi->fdb_nh) {
 735                         NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
 736                         err = -EINVAL;
 737                         goto out;
 738                 }
 739                 err = nexthop_check_scope(nhi, scope, extack);
 740         }
 741
 742 out:
 743         return err;
 744 }
 745
 746 static int fib_check_nh_list(struct nexthop *old, struct nexthop *new,
 747                              struct netlink_ext_ack *extack)
 748 {
 749         struct fib_info *fi;
 750
 751         list_for_each_entry(fi, &old->fi_list, nh_list) {
 752                 int err;
 753
 754                 err = fib_check_nexthop(new, fi->fib_scope, extack);
 755                 if (err)
 756                         return err;
 757         }
 758         return 0;
 759 }
 760
 761 static void nh_group_rebalance(struct nh_group *nhg)
 762 {
 763         int total = 0;
 764         int w = 0;
 765         int i;
 766
 767         for (i = 0; i < nhg->num_nh; ++i)
 768                 total += nhg->nh_entries[i].weight;
 769
 770         for (i = 0; i < nhg->num_nh; ++i) {
 771                 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
 772                 int upper_bound;
 773
 774                 w += nhge->weight;
 775                 upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1;
 776                 atomic_set(&nhge->upper_bound, upper_bound);
 777         }
 778 }
 779
 780 static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge,
 781                                 struct nl_info *nlinfo)
 782 {
 783         struct nh_grp_entry *nhges, *new_nhges;
 784         struct nexthop *nhp = nhge->nh_parent;
 785         struct nexthop *nh = nhge->nh;
 786         struct nh_group *nhg, *newg;
 787         int i, j;
 788
 789         WARN_ON(!nh);
 790
 791         nhg = rtnl_dereference(nhp->nh_grp);
 792         newg = nhg->spare;
 793
 794         /* last entry, keep it visible and remove the parent */
 795         if (nhg->num_nh == 1) {
 796                 remove_nexthop(net, nhp, nlinfo);
 797                 return;
 798         }
 799
 800         newg->has_v4 = false;
 801         newg->mpath = nhg->mpath;
 802         newg->fdb_nh = nhg->fdb_nh;
 803         newg->num_nh = nhg->num_nh;
 804
 805         /* copy old entries to new except the one getting removed */
 806         nhges = nhg->nh_entries;
 807         new_nhges = newg->nh_entries;
 808         for (i = 0, j = 0; i < nhg->num_nh; ++i) {
 809                 struct nh_info *nhi;
 810
 811                 /* current nexthop getting removed */
 812                 if (nhg->nh_entries[i].nh == nh) {
 813                         newg->num_nh--;
 814                         continue;
 815                 }
 816
 817                 nhi = rtnl_dereference(nhges[i].nh->nh_info);
 818                 if (nhi->family == AF_INET)
 819                         newg->has_v4 = true;
 820
 821                 list_del(&nhges[i].nh_list);
 822                 new_nhges[j].nh_parent = nhges[i].nh_parent;
 823                 new_nhges[j].nh = nhges[i].nh;
 824                 new_nhges[j].weight = nhges[i].weight;
 825                 list_add(&new_nhges[j].nh_list, &new_nhges[j].nh->grp_list);
 826                 j++;
 827         }
 828
 829         nh_group_rebalance(newg);
 830         rcu_assign_pointer(nhp->nh_grp, newg);
 831
 832         list_del(&nhge->nh_list);
 833         nexthop_put(nhge->nh);
 834
 835         if (nlinfo)
 836                 nexthop_notify(RTM_NEWNEXTHOP, nhp, nlinfo);
 837 }
 838
 839 static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh,
 840                                        struct nl_info *nlinfo)
 841 {
 842         struct nh_grp_entry *nhge, *tmp;
 843
 844         list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list)
 845                 remove_nh_grp_entry(net, nhge, nlinfo);
 846
 847         /* make sure all see the newly published array before releasing rtnl */
 848         synchronize_net();
 849 }
 850
 851 static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo)
 852 {
 853         struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp);
 854         int i, num_nh = nhg->num_nh;
 855
 856         for (i = 0; i < num_nh; ++i) {
 857                 struct nh_grp_entry *nhge = &nhg->nh_entries[i];
 858
 859                 if (WARN_ON(!nhge->nh))
 860                         continue;
 861
 862                 list_del_init(&nhge->nh_list);
 863         }
 864 }
 865
 866 /* not called for nexthop replace */
 867 static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
 868 {
 869         struct fib6_info *f6i, *tmp;
 870         bool do_flush = false;
 871         struct fib_info *fi;
 872
 873         list_for_each_entry(fi, &nh->fi_list, nh_list) {
 874                 fi->fib_flags |= RTNH_F_DEAD;
 875                 do_flush = true;
 876         }
 877         if (do_flush)
 878                 fib_flush(net);
 879
 880         /* ip6_del_rt removes the entry from this list hence the _safe */
 881         list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) {
 882                 /* __ip6_del_rt does a release, so do a hold here */
 883                 fib6_info_hold(f6i);
 884                 ipv6_stub->ip6_del_rt(net, f6i,
 885                                       !net->ipv4.sysctl_nexthop_compat_mode);
 886         }
 887 }
 888
 889 static void __remove_nexthop(struct net *net, struct nexthop *nh,
 890                              struct nl_info *nlinfo)
 891 {
 892         __remove_nexthop_fib(net, nh);
 893
 894         if (nh->is_group) {
 895                 remove_nexthop_group(nh, nlinfo);
 896         } else {
 897                 struct nh_info *nhi;
 898
 899                 nhi = rtnl_dereference(nh->nh_info);
 900                 if (nhi->fib_nhc.nhc_dev)
 901                         hlist_del(&nhi->dev_hash);
 902
 903                 remove_nexthop_from_groups(net, nh, nlinfo);
 904         }
 905 }
 906
 907 static void remove_nexthop(struct net *net, struct nexthop *nh,
 908                            struct nl_info *nlinfo)
 909 {
 910         call_nexthop_notifiers(net, NEXTHOP_EVENT_DEL, nh);
 911
 912         /* remove from the tree */
 913         rb_erase(&nh->rb_node, &net->nexthop.rb_root);
 914
 915         if (nlinfo)
 916                 nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo);
 917
 918         __remove_nexthop(net, nh, nlinfo);
 919         nh_base_seq_inc(net);
 920
 921         nexthop_put(nh);
 922 }
 923
 924 /* if any FIB entries reference this nexthop, any dst entries
 925  * need to be regenerated
 926  */
 927 static void nh_rt_cache_flush(struct net *net, struct nexthop *nh)
 928 {
 929         struct fib6_info *f6i;
 930
 931         if (!list_empty(&nh->fi_list))
 932                 rt_cache_flush(net);
 933
 934         list_for_each_entry(f6i, &nh->f6i_list, nh_list)
 935                 ipv6_stub->fib6_update_sernum(net, f6i);
 936 }
 937
 938 static int replace_nexthop_grp(struct net *net, struct nexthop *old,
 939                                struct nexthop *new,
 940                                struct netlink_ext_ack *extack)
 941 {
 942         struct nh_group *oldg, *newg;
 943         int i;
 944
 945         if (!new->is_group) {
 946                 NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop.");
 947                 return -EINVAL;
 948         }
 949
 950         oldg = rtnl_dereference(old->nh_grp);
 951         newg = rtnl_dereference(new->nh_grp);
 952
 953         /* update parents - used by nexthop code for cleanup */
 954         for (i = 0; i < newg->num_nh; i++)
 955                 newg->nh_entries[i].nh_parent = old;
 956
 957         rcu_assign_pointer(old->nh_grp, newg);
 958
 959         for (i = 0; i < oldg->num_nh; i++)
 960                 oldg->nh_entries[i].nh_parent = new;
 961
 962         rcu_assign_pointer(new->nh_grp, oldg);
 963
 964         return 0;
 965 }
 966
 967 static void nh_group_v4_update(struct nh_group *nhg)
 968 {
 969         struct nh_grp_entry *nhges;
 970         bool has_v4 = false;
 971         int i;
 972
 973         nhges = nhg->nh_entries;
 974         for (i = 0; i < nhg->num_nh; i++) {
 975                 struct nh_info *nhi;
 976
 977                 nhi = rtnl_dereference(nhges[i].nh->nh_info);
 978                 if (nhi->family == AF_INET)
 979                         has_v4 = true;
 980         }
 981         nhg->has_v4 = has_v4;
 982 }
 983
 984 static int replace_nexthop_single(struct net *net, struct nexthop *old,
 985                                   struct nexthop *new,
 986                                   struct netlink_ext_ack *extack)
 987 {
 988         struct nh_info *oldi, *newi;
 989
 990         if (new->is_group) {
 991                 NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group.");
 992                 return -EINVAL;
 993         }
 994
 995         oldi = rtnl_dereference(old->nh_info);
 996         newi = rtnl_dereference(new->nh_info);
 997
 998         newi->nh_parent = old;
 999         oldi->nh_parent = new;
1000
1001         old->protocol = new->protocol;
1002         old->nh_flags = new->nh_flags;
1003
1004         rcu_assign_pointer(old->nh_info, newi);
1005         rcu_assign_pointer(new->nh_info, oldi);
1006
1007         /* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially
1008          * update IPv4 indication in all the groups using the nexthop.
1009          */
1010         if (oldi->family == AF_INET && newi->family == AF_INET6) {
1011                 struct nh_grp_entry *nhge;
1012
1013                 list_for_each_entry(nhge, &old->grp_list, nh_list) {
1014                         struct nexthop *nhp = nhge->nh_parent;
1015                         struct nh_group *nhg;
1016
1017                         nhg = rtnl_dereference(nhp->nh_grp);
1018                         nh_group_v4_update(nhg);
1019                 }
1020         }
1021
1022         return 0;
1023 }
1024
1025 static void __nexthop_replace_notify(struct net *net, struct nexthop *nh,
1026                                      struct nl_info *info)
1027 {
1028         struct fib6_info *f6i;
1029
1030         if (!list_empty(&nh->fi_list)) {
1031                 struct fib_info *fi;
1032
1033                 /* expectation is a few fib_info per nexthop and then
1034                  * a lot of routes per fib_info. So mark the fib_info
1035                  * and then walk the fib tables once
1036                  */
1037                 list_for_each_entry(fi, &nh->fi_list, nh_list)
1038                         fi->nh_updated = true;
1039
1040                 fib_info_notify_update(net, info);
1041
1042                 list_for_each_entry(fi, &nh->fi_list, nh_list)
1043                         fi->nh_updated = false;
1044         }
1045
1046         list_for_each_entry(f6i, &nh->f6i_list, nh_list)
1047                 ipv6_stub->fib6_rt_update(net, f6i, info);
1048 }
1049
1050 /* send RTM_NEWROUTE with REPLACE flag set for all FIB entries
1051  * linked to this nexthop and for all groups that the nexthop
1052  * is a member of
1053  */
1054 static void nexthop_replace_notify(struct net *net, struct nexthop *nh,
1055                                    struct nl_info *info)
1056 {
1057         struct nh_grp_entry *nhge;
1058
1059         __nexthop_replace_notify(net, nh, info);
1060
1061         list_for_each_entry(nhge, &nh->grp_list, nh_list)
1062                 __nexthop_replace_notify(net, nhge->nh_parent, info);
1063 }
1064
1065 static int replace_nexthop(struct net *net, struct nexthop *old,
1066                            struct nexthop *new, struct netlink_ext_ack *extack)
1067 {
1068         bool new_is_reject = false;
1069         struct nh_grp_entry *nhge;
1070         int err;
1071
1072         /* check that existing FIB entries are ok with the
1073          * new nexthop definition
1074          */
1075         err = fib_check_nh_list(old, new, extack);
1076         if (err)
1077                 return err;
1078
1079         err = fib6_check_nh_list(old, new, extack);
1080         if (err)
1081                 return err;
1082
1083         if (!new->is_group) {
1084                 struct nh_info *nhi = rtnl_dereference(new->nh_info);
1085
1086                 new_is_reject = nhi->reject_nh;
1087         }
1088
1089         list_for_each_entry(nhge, &old->grp_list, nh_list) {
1090                 /* if new nexthop is a blackhole, any groups using this
1091                  * nexthop cannot have more than 1 path
1092                  */
1093                 if (new_is_reject &&
1094                     nexthop_num_path(nhge->nh_parent) > 1) {
1095                         NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path");
1096                         return -EINVAL;
1097                 }
1098
1099                 err = fib_check_nh_list(nhge->nh_parent, new, extack);
1100                 if (err)
1101                         return err;
1102
1103                 err = fib6_check_nh_list(nhge->nh_parent, new, extack);
1104                 if (err)
1105                         return err;
1106         }
1107
1108         if (old->is_group)
1109                 err = replace_nexthop_grp(net, old, new, extack);
1110         else
1111                 err = replace_nexthop_single(net, old, new, extack);
1112
1113         if (!err) {
1114                 nh_rt_cache_flush(net, old);
1115
1116                 __remove_nexthop(net, new, NULL);
1117                 nexthop_put(new);
1118         }
1119
1120         return err;
1121 }
1122
1123 /* called with rtnl_lock held */
1124 static int insert_nexthop(struct net *net, struct nexthop *new_nh,
1125                           struct nh_config *cfg, struct netlink_ext_ack *extack)
1126 {
1127         struct rb_node **pp, *parent = NULL, *next;
1128         struct rb_root *root = &net->nexthop.rb_root;
1129         bool replace = !!(cfg->nlflags & NLM_F_REPLACE);
1130         bool create = !!(cfg->nlflags & NLM_F_CREATE);
1131         u32 new_id = new_nh->id;
1132         int replace_notify = 0;
1133         int rc = -EEXIST;
1134
1135         pp = &root->rb_node;
1136         while (1) {
1137                 struct nexthop *nh;
1138
1139                 next = *pp;
1140                 if (!next)
1141                         break;
1142
1143                 parent = next;
1144
1145                 nh = rb_entry(parent, struct nexthop, rb_node);
1146                 if (new_id < nh->id) {
1147                         pp = &next->rb_left;
1148                 } else if (new_id > nh->id) {
1149                         pp = &next->rb_right;
1150                 } else if (replace) {
1151                         rc = replace_nexthop(net, nh, new_nh, extack);
1152                         if (!rc) {
1153                                 new_nh = nh; /* send notification with old nh */
1154                                 replace_notify = 1;
1155                         }
1156                         goto out;
1157                 } else {
1158                         /* id already exists and not a replace */
1159                         goto out;
1160                 }
1161         }
1162
1163         if (replace && !create) {
1164                 NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists");
1165                 rc = -ENOENT;
1166                 goto out;
1167         }
1168
1169         rb_link_node_rcu(&new_nh->rb_node, parent, pp);
1170         rb_insert_color(&new_nh->rb_node, root);
1171         rc = 0;
1172 out:
1173         if (!rc) {
1174                 nh_base_seq_inc(net);
1175                 nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
1176                 if (replace_notify && net->ipv4.sysctl_nexthop_compat_mode)
1177                         nexthop_replace_notify(net, new_nh, &cfg->nlinfo);
1178         }
1179
1180         return rc;
1181 }
1182
1183 /* rtnl */
1184 /* remove all nexthops tied to a device being deleted */
1185 static void nexthop_flush_dev(struct net_device *dev)
1186 {
1187         unsigned int hash = nh_dev_hashfn(dev->ifindex);
1188         struct net *net = dev_net(dev);
1189         struct hlist_head *head = &net->nexthop.devhash[hash];
1190         struct hlist_node *n;
1191         struct nh_info *nhi;
1192
1193         hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
1194                 if (nhi->fib_nhc.nhc_dev != dev)
1195                         continue;
1196
1197                 remove_nexthop(net, nhi->nh_parent, NULL);
1198         }
1199 }
1200
1201 /* rtnl; called when net namespace is deleted */
1202 static void flush_all_nexthops(struct net *net)
1203 {
1204         struct rb_root *root = &net->nexthop.rb_root;
1205         struct rb_node *node;
1206         struct nexthop *nh;
1207
1208         while ((node = rb_first(root))) {
1209                 nh = rb_entry(node, struct nexthop, rb_node);
1210                 remove_nexthop(net, nh, NULL);
1211                 cond_resched();
1212         }
1213 }
1214
1215 static struct nexthop *nexthop_create_group(struct net *net,
1216                                             struct nh_config *cfg)
1217 {
1218         struct nlattr *grps_attr = cfg->nh_grp;
1219         struct nexthop_grp *entry = nla_data(grps_attr);
1220         u16 num_nh = nla_len(grps_attr) / sizeof(*entry);
1221         struct nh_group *nhg;
1222         struct nexthop *nh;
1223         int i;
1224
1225         if (WARN_ON(!num_nh))
1226                 return ERR_PTR(-EINVAL);
1227
1228         nh = nexthop_alloc();
1229         if (!nh)
1230                 return ERR_PTR(-ENOMEM);
1231
1232         nh->is_group = 1;
1233
1234         nhg = nexthop_grp_alloc(num_nh);
1235         if (!nhg) {
1236                 kfree(nh);
1237                 return ERR_PTR(-ENOMEM);
1238         }
1239
1240         /* spare group used for removals */
1241         nhg->spare = nexthop_grp_alloc(num_nh);
1242         if (!nhg->spare) {
1243                 kfree(nhg);
1244                 kfree(nh);
1245                 return ERR_PTR(-ENOMEM);
1246         }
1247         nhg->spare->spare = nhg;
1248
1249         for (i = 0; i < nhg->num_nh; ++i) {
1250                 struct nexthop *nhe;
1251                 struct nh_info *nhi;
1252
1253                 nhe = nexthop_find_by_id(net, entry[i].id);
1254                 if (!nexthop_get(nhe))
1255                         goto out_no_nh;
1256
1257                 nhi = rtnl_dereference(nhe->nh_info);
1258                 if (nhi->family == AF_INET)
1259                         nhg->has_v4 = true;
1260
1261                 nhg->nh_entries[i].nh = nhe;
1262                 nhg->nh_entries[i].weight = entry[i].weight + 1;
1263                 list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list);
1264                 nhg->nh_entries[i].nh_parent = nh;
1265         }
1266
1267         if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) {
1268                 nhg->mpath = 1;
1269                 nh_group_rebalance(nhg);
1270         }
1271
1272         if (cfg->nh_fdb)
1273                 nhg->fdb_nh = 1;
1274
1275         rcu_assign_pointer(nh->nh_grp, nhg);
1276
1277         return nh;
1278
1279 out_no_nh:
1280         for (; i >= 0; --i)
1281                 nexthop_put(nhg->nh_entries[i].nh);
1282
1283         kfree(nhg->spare);
1284         kfree(nhg);
1285         kfree(nh);
1286
1287         return ERR_PTR(-ENOENT);
1288 }
1289
1290 static int nh_create_ipv4(struct net *net, struct nexthop *nh,
1291                           struct nh_info *nhi, struct nh_config *cfg,
1292                           struct netlink_ext_ack *extack)
1293 {
1294         struct fib_nh *fib_nh = &nhi->fib_nh;
1295         struct fib_config fib_cfg = {
1296                 .fc_oif   = cfg->nh_ifindex,
1297                 .fc_gw4   = cfg->gw.ipv4,
1298                 .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0,
1299                 .fc_flags = cfg->nh_flags,
1300                 .fc_encap = cfg->nh_encap,
1301                 .fc_encap_type = cfg->nh_encap_type,
1302         };
1303         u32 tb_id = (cfg->dev ? l3mdev_fib_table(cfg->dev) : RT_TABLE_MAIN);
1304         int err;
1305
1306         err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
1307         if (err) {
1308                 fib_nh_release(net, fib_nh);
1309                 goto out;
1310         }
1311
1312         if (nhi->fdb_nh)
1313                 goto out;
1314
1315         /* sets nh_dev if successful */
1316         err = fib_check_nh(net, fib_nh, tb_id, 0, extack);
1317         if (!err) {
1318                 nh->nh_flags = fib_nh->fib_nh_flags;
1319                 fib_info_update_nhc_saddr(net, &fib_nh->nh_common,
1320                                           fib_nh->fib_nh_scope);
1321         } else {
1322                 fib_nh_release(net, fib_nh);
1323         }
1324 out:
1325         return err;
1326 }
1327
1328 static int nh_create_ipv6(struct net *net,  struct nexthop *nh,
1329                           struct nh_info *nhi, struct nh_config *cfg,
1330                           struct netlink_ext_ack *extack)
1331 {
1332         struct fib6_nh *fib6_nh = &nhi->fib6_nh;
1333         struct fib6_config fib6_cfg = {
1334                 .fc_table = l3mdev_fib_table(cfg->dev),
1335                 .fc_ifindex = cfg->nh_ifindex,
1336                 .fc_gateway = cfg->gw.ipv6,
1337                 .fc_flags = cfg->nh_flags,
1338                 .fc_encap = cfg->nh_encap,
1339                 .fc_encap_type = cfg->nh_encap_type,
1340                 .fc_is_fdb = cfg->nh_fdb,
1341         };
1342         int err;
1343
1344         if (!ipv6_addr_any(&cfg->gw.ipv6))
1345                 fib6_cfg.fc_flags |= RTF_GATEWAY;
1346
1347         /* sets nh_dev if successful */
1348         err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL,
1349                                       extack);
1350         if (err)
1351                 ipv6_stub->fib6_nh_release(fib6_nh);
1352         else
1353                 nh->nh_flags = fib6_nh->fib_nh_flags;
1354
1355         return err;
1356 }
1357
1358 static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg,
1359                                       struct netlink_ext_ack *extack)
1360 {
1361         struct nh_info *nhi;
1362         struct nexthop *nh;
1363         int err = 0;
1364
1365         nh = nexthop_alloc();
1366         if (!nh)
1367                 return ERR_PTR(-ENOMEM);
1368
1369         nhi = kzalloc(sizeof(*nhi), GFP_KERNEL);
1370         if (!nhi) {
1371                 kfree(nh);
1372                 return ERR_PTR(-ENOMEM);
1373         }
1374
1375         nh->nh_flags = cfg->nh_flags;
1376         nh->net = net;
1377
1378         nhi->nh_parent = nh;
1379         nhi->family = cfg->nh_family;
1380         nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK;
1381
1382         if (cfg->nh_fdb)
1383                 nhi->fdb_nh = 1;
1384
1385         if (cfg->nh_blackhole) {
1386                 nhi->reject_nh = 1;
1387                 cfg->nh_ifindex = net->loopback_dev->ifindex;
1388         }
1389
1390         switch (cfg->nh_family) {
1391         case AF_INET:
1392                 err = nh_create_ipv4(net, nh, nhi, cfg, extack);
1393                 break;
1394         case AF_INET6:
1395                 err = nh_create_ipv6(net, nh, nhi, cfg, extack);
1396                 break;
1397         }
1398
1399         if (err) {
1400                 kfree(nhi);
1401                 kfree(nh);
1402                 return ERR_PTR(err);
1403         }
1404
1405         /* add the entry to the device based hash */
1406         if (!nhi->fdb_nh)
1407                 nexthop_devhash_add(net, nhi);
1408
1409         rcu_assign_pointer(nh->nh_info, nhi);
1410
1411         return nh;
1412 }
1413
1414 /* called with rtnl lock held */
1415 static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
1416                                    struct netlink_ext_ack *extack)
1417 {
1418         struct nexthop *nh;
1419         int err;
1420
1421         if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
1422                 NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
1423                 return ERR_PTR(-EINVAL);
1424         }
1425
1426         if (!cfg->nh_id) {
1427                 cfg->nh_id = nh_find_unused_id(net);
1428                 if (!cfg->nh_id) {
1429                         NL_SET_ERR_MSG(extack, "No unused id");
1430                         return ERR_PTR(-EINVAL);
1431                 }
1432         }
1433
1434         if (cfg->nh_grp)
1435                 nh = nexthop_create_group(net, cfg);
1436         else
1437                 nh = nexthop_create(net, cfg, extack);
1438
1439         if (IS_ERR(nh))
1440                 return nh;
1441
1442         refcount_set(&nh->refcnt, 1);
1443         nh->id = cfg->nh_id;
1444         nh->protocol = cfg->nh_protocol;
1445         nh->net = net;
1446
1447         err = insert_nexthop(net, nh, cfg, extack);
1448         if (err) {
1449                 __remove_nexthop(net, nh, NULL);
1450                 nexthop_put(nh);
1451                 nh = ERR_PTR(err);
1452         }
1453
1454         return nh;
1455 }
1456
1457 static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
1458                             struct nlmsghdr *nlh, struct nh_config *cfg,
1459                             struct netlink_ext_ack *extack)
1460 {
1461         struct nhmsg *nhm = nlmsg_data(nlh);
1462         struct nlattr *tb[NHA_MAX + 1];
1463         int err;
1464
1465         err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1466                           extack);
1467         if (err < 0)
1468                 return err;
1469
1470         err = -EINVAL;
1471         if (nhm->resvd || nhm->nh_scope) {
1472                 NL_SET_ERR_MSG(extack, "Invalid values in ancillary header");
1473                 goto out;
1474         }
1475         if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) {
1476                 NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header");
1477                 goto out;
1478         }
1479
1480         switch (nhm->nh_family) {
1481         case AF_INET:
1482         case AF_INET6:
1483                 break;
1484         case AF_UNSPEC:
1485                 if (tb[NHA_GROUP])
1486                         break;
1487                 fallthrough;
1488         default:
1489                 NL_SET_ERR_MSG(extack, "Invalid address family");
1490                 goto out;
1491         }
1492
1493         if (tb[NHA_GROUPS] || tb[NHA_MASTER]) {
1494                 NL_SET_ERR_MSG(extack, "Invalid attributes in request");
1495                 goto out;
1496         }
1497
1498         memset(cfg, 0, sizeof(*cfg));
1499         cfg->nlflags = nlh->nlmsg_flags;
1500         cfg->nlinfo.portid = NETLINK_CB(skb).portid;
1501         cfg->nlinfo.nlh = nlh;
1502         cfg->nlinfo.nl_net = net;
1503
1504         cfg->nh_family = nhm->nh_family;
1505         cfg->nh_protocol = nhm->nh_protocol;
1506         cfg->nh_flags = nhm->nh_flags;
1507
1508         if (tb[NHA_ID])
1509                 cfg->nh_id = nla_get_u32(tb[NHA_ID]);
1510
1511         if (tb[NHA_FDB]) {
1512                 if (tb[NHA_OIF] || tb[NHA_BLACKHOLE] ||
1513                     tb[NHA_ENCAP]   || tb[NHA_ENCAP_TYPE]) {
1514                         NL_SET_ERR_MSG(extack, "Fdb attribute can not be used with encap, oif or blackhole");
1515                         goto out;
1516                 }
1517                 if (nhm->nh_flags) {
1518                         NL_SET_ERR_MSG(extack, "Unsupported nexthop flags in ancillary header");
1519                         goto out;
1520                 }
1521                 cfg->nh_fdb = nla_get_flag(tb[NHA_FDB]);
1522         }
1523
1524         if (tb[NHA_GROUP]) {
1525                 if (nhm->nh_family != AF_UNSPEC) {
1526                         NL_SET_ERR_MSG(extack, "Invalid family for group");
1527                         goto out;
1528                 }
1529                 cfg->nh_grp = tb[NHA_GROUP];
1530
1531                 cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH;
1532                 if (tb[NHA_GROUP_TYPE])
1533                         cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]);
1534
1535                 if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) {
1536                         NL_SET_ERR_MSG(extack, "Invalid group type");
1537                         goto out;
1538                 }
1539                 err = nh_check_attr_group(net, tb, extack);
1540
1541                 /* no other attributes should be set */
1542                 goto out;
1543         }
1544
1545         if (tb[NHA_BLACKHOLE]) {
1546                 if (tb[NHA_GATEWAY] || tb[NHA_OIF] ||
1547                     tb[NHA_ENCAP]   || tb[NHA_ENCAP_TYPE] || tb[NHA_FDB]) {
1548                         NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway, oif, encap or fdb");
1549                         goto out;
1550                 }
1551
1552                 cfg->nh_blackhole = 1;
1553                 err = 0;
1554                 goto out;
1555         }
1556
1557         if (!cfg->nh_fdb && !tb[NHA_OIF]) {
1558                 NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole and non-fdb nexthops");
1559                 goto out;
1560         }
1561
1562         if (!cfg->nh_fdb && tb[NHA_OIF]) {
1563                 cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
1564                 if (cfg->nh_ifindex)
1565                         cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
1566
1567                 if (!cfg->dev) {
1568                         NL_SET_ERR_MSG(extack, "Invalid device index");
1569                         goto out;
1570                 } else if (!(cfg->dev->flags & IFF_UP)) {
1571                         NL_SET_ERR_MSG(extack, "Nexthop device is not up");
1572                         err = -ENETDOWN;
1573                         goto out;
1574                 } else if (!netif_carrier_ok(cfg->dev)) {
1575                         NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
1576                         err = -ENETDOWN;
1577                         goto out;
1578                 }
1579         }
1580
1581         err = -EINVAL;
1582         if (tb[NHA_GATEWAY]) {
1583                 struct nlattr *gwa = tb[NHA_GATEWAY];
1584
1585                 switch (cfg->nh_family) {
1586                 case AF_INET:
1587                         if (nla_len(gwa) != sizeof(u32)) {
1588                                 NL_SET_ERR_MSG(extack, "Invalid gateway");
1589                                 goto out;
1590                         }
1591                         cfg->gw.ipv4 = nla_get_be32(gwa);
1592                         break;
1593                 case AF_INET6:
1594                         if (nla_len(gwa) != sizeof(struct in6_addr)) {
1595                                 NL_SET_ERR_MSG(extack, "Invalid gateway");
1596                                 goto out;
1597                         }
1598                         cfg->gw.ipv6 = nla_get_in6_addr(gwa);
1599                         break;
1600                 default:
1601                         NL_SET_ERR_MSG(extack,
1602                                        "Unknown address family for gateway");
1603                         goto out;
1604                 }
1605         } else {
1606                 /* device only nexthop (no gateway) */
1607                 if (cfg->nh_flags & RTNH_F_ONLINK) {
1608                         NL_SET_ERR_MSG(extack,
1609                                        "ONLINK flag can not be set for nexthop without a gateway");
1610                         goto out;
1611                 }
1612         }
1613
1614         if (tb[NHA_ENCAP]) {
1615                 cfg->nh_encap = tb[NHA_ENCAP];
1616
1617                 if (!tb[NHA_ENCAP_TYPE]) {
1618                         NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing");
1619                         goto out;
1620                 }
1621
1622                 cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);
1623                 err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack);
1624                 if (err < 0)
1625                         goto out;
1626
1627         } else if (tb[NHA_ENCAP_TYPE]) {
1628                 NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing");
1629                 goto out;
1630         }
1631
1632
1633         err = 0;
1634 out:
1635         return err;
1636 }
1637
1638 /* rtnl */
1639 static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
1640                            struct netlink_ext_ack *extack)
1641 {
1642         struct net *net = sock_net(skb->sk);
1643         struct nh_config cfg;
1644         struct nexthop *nh;
1645         int err;
1646
1647         err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
1648         if (!err) {
1649                 nh = nexthop_add(net, &cfg, extack);
1650                 if (IS_ERR(nh))
1651                         err = PTR_ERR(nh);
1652         }
1653
1654         return err;
1655 }
1656
1657 static int nh_valid_get_del_req(struct nlmsghdr *nlh, u32 *id,
1658                                 struct netlink_ext_ack *extack)
1659 {
1660         struct nhmsg *nhm = nlmsg_data(nlh);
1661         struct nlattr *tb[NHA_MAX + 1];
1662         int err, i;
1663
1664         err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1665                           extack);
1666         if (err < 0)
1667                 return err;
1668
1669         err = -EINVAL;
1670         for (i = 0; i < __NHA_MAX; ++i) {
1671                 if (!tb[i])
1672                         continue;
1673
1674                 switch (i) {
1675                 case NHA_ID:
1676                         break;
1677                 default:
1678                         NL_SET_ERR_MSG_ATTR(extack, tb[i],
1679                                             "Unexpected attribute in request");
1680                         goto out;
1681                 }
1682         }
1683         if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
1684                 NL_SET_ERR_MSG(extack, "Invalid values in header");
1685                 goto out;
1686         }
1687
1688         if (!tb[NHA_ID]) {
1689                 NL_SET_ERR_MSG(extack, "Nexthop id is missing");
1690                 goto out;
1691         }
1692
1693         *id = nla_get_u32(tb[NHA_ID]);
1694         if (!(*id))
1695                 NL_SET_ERR_MSG(extack, "Invalid nexthop id");
1696         else
1697                 err = 0;
1698 out:
1699         return err;
1700 }
1701
1702 /* rtnl */
1703 static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
1704                            struct netlink_ext_ack *extack)
1705 {
1706         struct net *net = sock_net(skb->sk);
1707         struct nl_info nlinfo = {
1708                 .nlh = nlh,
1709                 .nl_net = net,
1710                 .portid = NETLINK_CB(skb).portid,
1711         };
1712         struct nexthop *nh;
1713         int err;
1714         u32 id;
1715
1716         err = nh_valid_get_del_req(nlh, &id, extack);
1717         if (err)
1718                 return err;
1719
1720         nh = nexthop_find_by_id(net, id);
1721         if (!nh)
1722                 return -ENOENT;
1723
1724         remove_nexthop(net, nh, &nlinfo);
1725
1726         return 0;
1727 }
1728
1729 /* rtnl */
1730 static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh,
1731                            struct netlink_ext_ack *extack)
1732 {
1733         struct net *net = sock_net(in_skb->sk);
1734         struct sk_buff *skb = NULL;
1735         struct nexthop *nh;
1736         int err;
1737         u32 id;
1738
1739         err = nh_valid_get_del_req(nlh, &id, extack);
1740         if (err)
1741                 return err;
1742
1743         err = -ENOBUFS;
1744         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1745         if (!skb)
1746                 goto out;
1747
1748         err = -ENOENT;
1749         nh = nexthop_find_by_id(net, id);
1750         if (!nh)
1751                 goto errout_free;
1752
1753         err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid,
1754                            nlh->nlmsg_seq, 0);
1755         if (err < 0) {
1756                 WARN_ON(err == -EMSGSIZE);
1757                 goto errout_free;
1758         }
1759
1760         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1761 out:
1762         return err;
1763 errout_free:
1764         kfree_skb(skb);
1765         goto out;
1766 }
1767
1768 static bool nh_dump_filtered(struct nexthop *nh, int dev_idx, int master_idx,
1769                              bool group_filter, u8 family)
1770 {
1771         const struct net_device *dev;
1772         const struct nh_info *nhi;
1773
1774         if (group_filter && !nh->is_group)
1775                 return true;
1776
1777         if (!dev_idx && !master_idx && !family)
1778                 return false;
1779
1780         if (nh->is_group)
1781                 return true;
1782
1783         nhi = rtnl_dereference(nh->nh_info);
1784         if (family && nhi->family != family)
1785                 return true;
1786
1787         dev = nhi->fib_nhc.nhc_dev;
1788         if (dev_idx && (!dev || dev->ifindex != dev_idx))
1789                 return true;
1790
1791         if (master_idx) {
1792                 struct net_device *master;
1793
1794                 if (!dev)
1795                         return true;
1796
1797                 master = netdev_master_upper_dev_get((struct net_device *)dev);
1798                 if (!master || master->ifindex != master_idx)
1799                         return true;
1800         }
1801
1802         return false;
1803 }
1804
1805 static int nh_valid_dump_req(const struct nlmsghdr *nlh, int *dev_idx,
1806                              int *master_idx, bool *group_filter,
1807                              bool *fdb_filter, struct netlink_callback *cb)
1808 {
1809         struct netlink_ext_ack *extack = cb->extack;
1810         struct nlattr *tb[NHA_MAX + 1];
1811         struct nhmsg *nhm;
1812         int err, i;
1813         u32 idx;
1814
1815         err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX, rtm_nh_policy,
1816                           NULL);
1817         if (err < 0)
1818                 return err;
1819
1820         for (i = 0; i <= NHA_MAX; ++i) {
1821                 if (!tb[i])
1822                         continue;
1823
1824                 switch (i) {
1825                 case NHA_OIF:
1826                         idx = nla_get_u32(tb[i]);
1827                         if (idx > INT_MAX) {
1828                                 NL_SET_ERR_MSG(extack, "Invalid device index");
1829                                 return -EINVAL;
1830                         }
1831                         *dev_idx = idx;
1832                         break;
1833                 case NHA_MASTER:
1834                         idx = nla_get_u32(tb[i]);
1835                         if (idx > INT_MAX) {
1836                                 NL_SET_ERR_MSG(extack, "Invalid master device index");
1837                                 return -EINVAL;
1838                         }
1839                         *master_idx = idx;
1840                         break;
1841                 case NHA_GROUPS:
1842                         *group_filter = true;
1843                         break;
1844                 case NHA_FDB:
1845                         *fdb_filter = true;
1846                         break;
1847                 default:
1848                         NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request");
1849                         return -EINVAL;
1850                 }
1851         }
1852
1853         nhm = nlmsg_data(nlh);
1854         if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
1855                 NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request");
1856                 return -EINVAL;
1857         }
1858
1859         return 0;
1860 }
1861
1862 /* rtnl */
1863 static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
1864 {
1865         bool group_filter = false, fdb_filter = false;
1866         struct nhmsg *nhm = nlmsg_data(cb->nlh);
1867         int dev_filter_idx = 0, master_idx = 0;
1868         struct net *net = sock_net(skb->sk);
1869         struct rb_root *root = &net->nexthop.rb_root;
1870         struct rb_node *node;
1871         int idx = 0, s_idx;
1872         int err;
1873
1874         err = nh_valid_dump_req(cb->nlh, &dev_filter_idx, &master_idx,
1875                                 &group_filter, &fdb_filter, cb);
1876         if (err < 0)
1877                 return err;
1878
1879         s_idx = cb->args[0];
1880         for (node = rb_first(root); node; node = rb_next(node)) {
1881                 struct nexthop *nh;
1882
1883                 if (idx < s_idx)
1884                         goto cont;
1885
1886                 nh = rb_entry(node, struct nexthop, rb_node);
1887                 if (nh_dump_filtered(nh, dev_filter_idx, master_idx,
1888                                      group_filter, nhm->nh_family))
1889                         goto cont;
1890
1891                 err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
1892                                    NETLINK_CB(cb->skb).portid,
1893                                    cb->nlh->nlmsg_seq, NLM_F_MULTI);
1894                 if (err < 0) {
1895                         if (likely(skb->len))
1896                                 goto out;
1897
1898                         goto out_err;
1899                 }
1900 cont:
1901                 idx++;
1902         }
1903
1904 out:
1905         err = skb->len;
1906 out_err:
1907         cb->args[0] = idx;
1908         cb->seq = net->nexthop.seq;
1909         nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1910
1911         return err;
1912 }
1913
1914 static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu)
1915 {
1916         unsigned int hash = nh_dev_hashfn(dev->ifindex);
1917         struct net *net = dev_net(dev);
1918         struct hlist_head *head = &net->nexthop.devhash[hash];
1919         struct hlist_node *n;
1920         struct nh_info *nhi;
1921
1922         hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
1923                 if (nhi->fib_nhc.nhc_dev == dev) {
1924                         if (nhi->family == AF_INET)
1925                                 fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu,
1926                                                    orig_mtu);
1927                 }
1928         }
1929 }
1930
1931 /* rtnl */
1932 static int nh_netdev_event(struct notifier_block *this,
1933                            unsigned long event, void *ptr)
1934 {
1935         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1936         struct netdev_notifier_info_ext *info_ext;
1937
1938         switch (event) {
1939         case NETDEV_DOWN:
1940         case NETDEV_UNREGISTER:
1941                 nexthop_flush_dev(dev);
1942                 break;
1943         case NETDEV_CHANGE:
1944                 if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
1945                         nexthop_flush_dev(dev);
1946                 break;
1947         case NETDEV_CHANGEMTU:
1948                 info_ext = ptr;
1949                 nexthop_sync_mtu(dev, info_ext->ext.mtu);
1950                 rt_cache_flush(dev_net(dev));
1951                 break;
1952         }
1953         return NOTIFY_DONE;
1954 }
1955
1956 static struct notifier_block nh_netdev_notifier = {
1957         .notifier_call = nh_netdev_event,
1958 };
1959
1960 int register_nexthop_notifier(struct net *net, struct notifier_block *nb)
1961 {
1962         return blocking_notifier_chain_register(&net->nexthop.notifier_chain,
1963                                                 nb);
1964 }
1965 EXPORT_SYMBOL(register_nexthop_notifier);
1966
1967 int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb)
1968 {
1969         return blocking_notifier_chain_unregister(&net->nexthop.notifier_chain,
1970                                                   nb);
1971 }
1972 EXPORT_SYMBOL(unregister_nexthop_notifier);
1973
1974 static void __net_exit nexthop_net_exit(struct net *net)
1975 {
1976         rtnl_lock();
1977         flush_all_nexthops(net);
1978         rtnl_unlock();
1979         kfree(net->nexthop.devhash);
1980 }
1981
1982 static int __net_init nexthop_net_init(struct net *net)
1983 {
1984         size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE;
1985
1986         net->nexthop.rb_root = RB_ROOT;
1987         net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
1988         if (!net->nexthop.devhash)
1989                 return -ENOMEM;
1990         BLOCKING_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain);
1991
1992         return 0;
1993 }
1994
1995 static struct pernet_operations nexthop_net_ops = {
1996         .init = nexthop_net_init,
1997         .exit = nexthop_net_exit,
1998 };
1999
2000 static int __init nexthop_init(void)
2001 {
2002         register_pernet_subsys(&nexthop_net_ops);
2003
2004         register_netdevice_notifier(&nh_netdev_notifier);
2005
2006         rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
2007         rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0);
2008         rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop,
2009                       rtm_dump_nexthop, 0);
2010
2011         rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
2012         rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
2013
2014         rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
2015         rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
2016
2017         return 0;
2018 }
2019 subsys_initcall(nexthop_init);