net/ipv6/addrlabel.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * IPv6 Address Label subsystem
   4  * for the IPv6 "Default" Source Address Selection
   5  *
   6  * Copyright (C)2007 USAGI/WIDE Project
   7  */
   8 /*
   9  * Author:
  10  *      YOSHIFUJI Hideaki @ USAGI/WIDE Project <yoshfuji@linux-ipv6.org>
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/list.h>
  15 #include <linux/rcupdate.h>
  16 #include <linux/in6.h>
  17 #include <linux/slab.h>
  18 #include <net/addrconf.h>
  19 #include <linux/if_addrlabel.h>
  20 #include <linux/netlink.h>
  21 #include <linux/rtnetlink.h>
  22
  23 #if 0
  24 #define ADDRLABEL(x...) printk(x)
  25 #else
  26 #define ADDRLABEL(x...) do { ; } while (0)
  27 #endif
  28
  29 /*
  30  * Policy Table
  31  */
  32 struct ip6addrlbl_entry {
  33         struct in6_addr prefix;
  34         int prefixlen;
  35         int ifindex;
  36         int addrtype;
  37         u32 label;
  38         struct hlist_node list;
  39         struct rcu_head rcu;
  40 };
  41
  42 /*
  43  * Default policy table (RFC6724 + extensions)
  44  *
  45  * prefix               addr_type       label
  46  * -------------------------------------------------------------------------
  47  * ::1/128              LOOPBACK        0
  48  * ::/0                 N/A             1
  49  * 2002::/16            N/A             2
  50  * ::/96                COMPATv4        3
  51  * ::ffff:0:0/96        V4MAPPED        4
  52  * fc00::/7             N/A             5               ULA (RFC 4193)
  53  * 2001::/32            N/A             6               Teredo (RFC 4380)
  54  * 2001:10::/28         N/A             7               ORCHID (RFC 4843)
  55  * fec0::/10            N/A             11              Site-local
  56  *                                                      (deprecated by RFC3879)
  57  * 3ffe::/16            N/A             12              6bone
  58  *
  59  * Note: 0xffffffff is used if we do not have any policies.
  60  * Note: Labels for ULA and 6to4 are different from labels listed in RFC6724.
  61  */
  62
  63 #define IPV6_ADDR_LABEL_DEFAULT 0xffffffffUL
  64
  65 static const __net_initconst struct ip6addrlbl_init_table
  66 {
  67         const struct in6_addr *prefix;
  68         int prefixlen;
  69         u32 label;
  70 } ip6addrlbl_init_table[] = {
  71         {       /* ::/0 */
  72                 .prefix = &in6addr_any,
  73                 .label = 1,
  74         }, {    /* fc00::/7 */
  75                 .prefix = &(struct in6_addr){ { { 0xfc } } } ,
  76                 .prefixlen = 7,
  77                 .label = 5,
  78         }, {    /* fec0::/10 */
  79                 .prefix = &(struct in6_addr){ { { 0xfe, 0xc0 } } },
  80                 .prefixlen = 10,
  81                 .label = 11,
  82         }, {    /* 2002::/16 */
  83                 .prefix = &(struct in6_addr){ { { 0x20, 0x02 } } },
  84                 .prefixlen = 16,
  85                 .label = 2,
  86         }, {    /* 3ffe::/16 */
  87                 .prefix = &(struct in6_addr){ { { 0x3f, 0xfe } } },
  88                 .prefixlen = 16,
  89                 .label = 12,
  90         }, {    /* 2001::/32 */
  91                 .prefix = &(struct in6_addr){ { { 0x20, 0x01 } } },
  92                 .prefixlen = 32,
  93                 .label = 6,
  94         }, {    /* 2001:10::/28 */
  95                 .prefix = &(struct in6_addr){ { { 0x20, 0x01, 0x00, 0x10 } } },
  96                 .prefixlen = 28,
  97                 .label = 7,
  98         }, {    /* ::ffff:0:0 */
  99                 .prefix = &(struct in6_addr){ { { [10] = 0xff, [11] = 0xff } } },
 100                 .prefixlen = 96,
 101                 .label = 4,
 102         }, {    /* ::/96 */
 103                 .prefix = &in6addr_any,
 104                 .prefixlen = 96,
 105                 .label = 3,
 106         }, {    /* ::1/128 */
 107                 .prefix = &in6addr_loopback,
 108                 .prefixlen = 128,
 109                 .label = 0,
 110         }
 111 };
 112
 113 /* Find label */
 114 static bool __ip6addrlbl_match(const struct ip6addrlbl_entry *p,
 115                                const struct in6_addr *addr,
 116                                int addrtype, int ifindex)
 117 {
 118         if (p->ifindex && p->ifindex != ifindex)
 119                 return false;
 120         if (p->addrtype && p->addrtype != addrtype)
 121                 return false;
 122         if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
 123                 return false;
 124         return true;
 125 }
 126
 127 static struct ip6addrlbl_entry *__ipv6_addr_label(struct net *net,
 128                                                   const struct in6_addr *addr,
 129                                                   int type, int ifindex)
 130 {
 131         struct ip6addrlbl_entry *p;
 132
 133         hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) {
 134                 if (__ip6addrlbl_match(p, addr, type, ifindex))
 135                         return p;
 136         }
 137         return NULL;
 138 }
 139
 140 u32 ipv6_addr_label(struct net *net,
 141                     const struct in6_addr *addr, int type, int ifindex)
 142 {
 143         u32 label;
 144         struct ip6addrlbl_entry *p;
 145
 146         type &= IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK;
 147
 148         rcu_read_lock();
 149         p = __ipv6_addr_label(net, addr, type, ifindex);
 150         label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
 151         rcu_read_unlock();
 152
 153         ADDRLABEL(KERN_DEBUG "%s(addr=%pI6, type=%d, ifindex=%d) => %08x\n",
 154                   __func__, addr, type, ifindex, label);
 155
 156         return label;
 157 }
 158
 159 /* allocate one entry */
 160 static struct ip6addrlbl_entry *ip6addrlbl_alloc(const struct in6_addr *prefix,
 161                                                  int prefixlen, int ifindex,
 162                                                  u32 label)
 163 {
 164         struct ip6addrlbl_entry *newp;
 165         int addrtype;
 166
 167         ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u)\n",
 168                   __func__, prefix, prefixlen, ifindex, (unsigned int)label);
 169
 170         addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK);
 171
 172         switch (addrtype) {
 173         case IPV6_ADDR_MAPPED:
 174                 if (prefixlen > 96)
 175                         return ERR_PTR(-EINVAL);
 176                 if (prefixlen < 96)
 177                         addrtype = 0;
 178                 break;
 179         case IPV6_ADDR_COMPATv4:
 180                 if (prefixlen != 96)
 181                         addrtype = 0;
 182                 break;
 183         case IPV6_ADDR_LOOPBACK:
 184                 if (prefixlen != 128)
 185                         addrtype = 0;
 186                 break;
 187         }
 188
 189         newp = kmalloc(sizeof(*newp), GFP_KERNEL);
 190         if (!newp)
 191                 return ERR_PTR(-ENOMEM);
 192
 193         ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
 194         newp->prefixlen = prefixlen;
 195         newp->ifindex = ifindex;
 196         newp->addrtype = addrtype;
 197         newp->label = label;
 198         INIT_HLIST_NODE(&newp->list);
 199         return newp;
 200 }
 201
 202 /* add a label */
 203 static int __ip6addrlbl_add(struct net *net, struct ip6addrlbl_entry *newp,
 204                             int replace)
 205 {
 206         struct ip6addrlbl_entry *last = NULL, *p = NULL;
 207         struct hlist_node *n;
 208         int ret = 0;
 209
 210         ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n", __func__, newp,
 211                   replace);
 212
 213         hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
 214                 if (p->prefixlen == newp->prefixlen &&
 215                     p->ifindex == newp->ifindex &&
 216                     ipv6_addr_equal(&p->prefix, &newp->prefix)) {
 217                         if (!replace) {
 218                                 ret = -EEXIST;
 219                                 goto out;
 220                         }
 221                         hlist_replace_rcu(&p->list, &newp->list);
 222                         kfree_rcu(p, rcu);
 223                         goto out;
 224                 } else if ((p->prefixlen == newp->prefixlen && !p->ifindex) ||
 225                            (p->prefixlen < newp->prefixlen)) {
 226                         hlist_add_before_rcu(&newp->list, &p->list);
 227                         goto out;
 228                 }
 229                 last = p;
 230         }
 231         if (last)
 232                 hlist_add_behind_rcu(&newp->list, &last->list);
 233         else
 234                 hlist_add_head_rcu(&newp->list, &net->ipv6.ip6addrlbl_table.head);
 235 out:
 236         if (!ret)
 237                 WRITE_ONCE(net->ipv6.ip6addrlbl_table.seq,
 238                            net->ipv6.ip6addrlbl_table.seq + 1);
 239         return ret;
 240 }
 241
 242 /* add a label */
 243 static int ip6addrlbl_add(struct net *net,
 244                           const struct in6_addr *prefix, int prefixlen,
 245                           int ifindex, u32 label, int replace)
 246 {
 247         struct ip6addrlbl_entry *newp;
 248         int ret = 0;
 249
 250         ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
 251                   __func__, prefix, prefixlen, ifindex, (unsigned int)label,
 252                   replace);
 253
 254         newp = ip6addrlbl_alloc(prefix, prefixlen, ifindex, label);
 255         if (IS_ERR(newp))
 256                 return PTR_ERR(newp);
 257         spin_lock(&net->ipv6.ip6addrlbl_table.lock);
 258         ret = __ip6addrlbl_add(net, newp, replace);
 259         spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
 260         if (ret)
 261                 kfree(newp);
 262         return ret;
 263 }
 264
 265 /* remove a label */
 266 static int __ip6addrlbl_del(struct net *net,
 267                             const struct in6_addr *prefix, int prefixlen,
 268                             int ifindex)
 269 {
 270         struct ip6addrlbl_entry *p = NULL;
 271         struct hlist_node *n;
 272         int ret = -ESRCH;
 273
 274         ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n",
 275                   __func__, prefix, prefixlen, ifindex);
 276
 277         hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
 278                 if (p->prefixlen == prefixlen &&
 279                     p->ifindex == ifindex &&
 280                     ipv6_addr_equal(&p->prefix, prefix)) {
 281                         hlist_del_rcu(&p->list);
 282                         kfree_rcu(p, rcu);
 283                         ret = 0;
 284                         break;
 285                 }
 286         }
 287         return ret;
 288 }
 289
 290 static int ip6addrlbl_del(struct net *net,
 291                           const struct in6_addr *prefix, int prefixlen,
 292                           int ifindex)
 293 {
 294         struct in6_addr prefix_buf;
 295         int ret;
 296
 297         ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n",
 298                   __func__, prefix, prefixlen, ifindex);
 299
 300         ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
 301         spin_lock(&net->ipv6.ip6addrlbl_table.lock);
 302         ret = __ip6addrlbl_del(net, &prefix_buf, prefixlen, ifindex);
 303         spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
 304         return ret;
 305 }
 306
 307 /* add default label */
 308 static int __net_init ip6addrlbl_net_init(struct net *net)
 309 {
 310         struct ip6addrlbl_entry *p = NULL;
 311         struct hlist_node *n;
 312         int err;
 313         int i;
 314
 315         ADDRLABEL(KERN_DEBUG "%s\n", __func__);
 316
 317         spin_lock_init(&net->ipv6.ip6addrlbl_table.lock);
 318         INIT_HLIST_HEAD(&net->ipv6.ip6addrlbl_table.head);
 319
 320         for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
 321                 err = ip6addrlbl_add(net,
 322                                      ip6addrlbl_init_table[i].prefix,
 323                                      ip6addrlbl_init_table[i].prefixlen,
 324                                      0,
 325                                      ip6addrlbl_init_table[i].label, 0);
 326                 if (err)
 327                         goto err_ip6addrlbl_add;
 328         }
 329         return 0;
 330
 331 err_ip6addrlbl_add:
 332         hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
 333                 hlist_del_rcu(&p->list);
 334                 kfree_rcu(p, rcu);
 335         }
 336         return err;
 337 }
 338
 339 static void __net_exit ip6addrlbl_net_exit(struct net *net)
 340 {
 341         struct ip6addrlbl_entry *p = NULL;
 342         struct hlist_node *n;
 343
 344         /* Remove all labels belonging to the exiting net */
 345         spin_lock(&net->ipv6.ip6addrlbl_table.lock);
 346         hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
 347                 hlist_del_rcu(&p->list);
 348                 kfree_rcu(p, rcu);
 349         }
 350         spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
 351 }
 352
 353 static struct pernet_operations ipv6_addr_label_ops = {
 354         .init = ip6addrlbl_net_init,
 355         .exit = ip6addrlbl_net_exit,
 356 };
 357
 358 int __init ipv6_addr_label_init(void)
 359 {
 360         return register_pernet_subsys(&ipv6_addr_label_ops);
 361 }
 362
 363 void ipv6_addr_label_cleanup(void)
 364 {
 365         unregister_pernet_subsys(&ipv6_addr_label_ops);
 366 }
 367
 368 static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
 369         [IFAL_ADDRESS]          = { .len = sizeof(struct in6_addr), },
 370         [IFAL_LABEL]            = { .len = sizeof(u32), },
 371 };
 372
 373 static bool addrlbl_ifindex_exists(struct net *net, int ifindex)
 374 {
 375
 376         struct net_device *dev;
 377
 378         rcu_read_lock();
 379         dev = dev_get_by_index_rcu(net, ifindex);
 380         rcu_read_unlock();
 381
 382         return dev != NULL;
 383 }
 384
 385 static int ip6addrlbl_newdel(struct sk_buff *skb, struct nlmsghdr *nlh,
 386                              struct netlink_ext_ack *extack)
 387 {
 388         struct net *net = sock_net(skb->sk);
 389         struct ifaddrlblmsg *ifal;
 390         struct nlattr *tb[IFAL_MAX+1];
 391         struct in6_addr *pfx;
 392         u32 label;
 393         int err = 0;
 394
 395         err = nlmsg_parse_deprecated(nlh, sizeof(*ifal), tb, IFAL_MAX,
 396                                      ifal_policy, extack);
 397         if (err < 0)
 398                 return err;
 399
 400         ifal = nlmsg_data(nlh);
 401
 402         if (ifal->ifal_family != AF_INET6 ||
 403             ifal->ifal_prefixlen > 128)
 404                 return -EINVAL;
 405
 406         if (!tb[IFAL_ADDRESS])
 407                 return -EINVAL;
 408         pfx = nla_data(tb[IFAL_ADDRESS]);
 409
 410         if (!tb[IFAL_LABEL])
 411                 return -EINVAL;
 412         label = nla_get_u32(tb[IFAL_LABEL]);
 413         if (label == IPV6_ADDR_LABEL_DEFAULT)
 414                 return -EINVAL;
 415
 416         switch (nlh->nlmsg_type) {
 417         case RTM_NEWADDRLABEL:
 418                 if (ifal->ifal_index &&
 419                     !addrlbl_ifindex_exists(net, ifal->ifal_index))
 420                         return -EINVAL;
 421
 422                 err = ip6addrlbl_add(net, pfx, ifal->ifal_prefixlen,
 423                                      ifal->ifal_index, label,
 424                                      nlh->nlmsg_flags & NLM_F_REPLACE);
 425                 break;
 426         case RTM_DELADDRLABEL:
 427                 err = ip6addrlbl_del(net, pfx, ifal->ifal_prefixlen,
 428                                      ifal->ifal_index);
 429                 break;
 430         default:
 431                 err = -EOPNOTSUPP;
 432         }
 433         return err;
 434 }
 435
 436 static void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
 437                               int prefixlen, int ifindex, u32 lseq)
 438 {
 439         struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
 440         ifal->ifal_family = AF_INET6;
 441         ifal->__ifal_reserved = 0;
 442         ifal->ifal_prefixlen = prefixlen;
 443         ifal->ifal_flags = 0;
 444         ifal->ifal_index = ifindex;
 445         ifal->ifal_seq = lseq;
 446 };
 447
 448 static int ip6addrlbl_fill(struct sk_buff *skb,
 449                            const struct ip6addrlbl_entry *p,
 450                            u32 lseq,
 451                            u32 portid, u32 seq, int event,
 452                            unsigned int flags)
 453 {
 454         struct nlmsghdr *nlh = nlmsg_put(skb, portid, seq, event,
 455                                          sizeof(struct ifaddrlblmsg), flags);
 456         if (!nlh)
 457                 return -EMSGSIZE;
 458
 459         ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
 460
 461         if (nla_put_in6_addr(skb, IFAL_ADDRESS, &p->prefix) < 0 ||
 462             nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
 463                 nlmsg_cancel(skb, nlh);
 464                 return -EMSGSIZE;
 465         }
 466
 467         nlmsg_end(skb, nlh);
 468         return 0;
 469 }
 470
 471 static int ip6addrlbl_valid_dump_req(const struct nlmsghdr *nlh,
 472                                      struct netlink_ext_ack *extack)
 473 {
 474         struct ifaddrlblmsg *ifal;
 475
 476         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifal))) {
 477                 NL_SET_ERR_MSG_MOD(extack, "Invalid header for address label dump request");
 478                 return -EINVAL;
 479         }
 480
 481         ifal = nlmsg_data(nlh);
 482         if (ifal->__ifal_reserved || ifal->ifal_prefixlen ||
 483             ifal->ifal_flags || ifal->ifal_index || ifal->ifal_seq) {
 484                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for address label dump request");
 485                 return -EINVAL;
 486         }
 487
 488         if (nlmsg_attrlen(nlh, sizeof(*ifal))) {
 489                 NL_SET_ERR_MSG_MOD(extack, "Invalid data after header for address label dump request");
 490                 return -EINVAL;
 491         }
 492
 493         return 0;
 494 }
 495
 496 static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
 497 {
 498         const struct nlmsghdr *nlh = cb->nlh;
 499         struct net *net = sock_net(skb->sk);
 500         struct ip6addrlbl_entry *p;
 501         int idx = 0, s_idx = cb->args[0];
 502         int err = 0;
 503         u32 lseq;
 504
 505         if (cb->strict_check) {
 506                 err = ip6addrlbl_valid_dump_req(nlh, cb->extack);
 507                 if (err < 0)
 508                         return err;
 509         }
 510
 511         rcu_read_lock();
 512         lseq = READ_ONCE(net->ipv6.ip6addrlbl_table.seq);
 513         hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) {
 514                 if (idx >= s_idx) {
 515                         err = ip6addrlbl_fill(skb, p,
 516                                               lseq,
 517                                               NETLINK_CB(cb->skb).portid,
 518                                               nlh->nlmsg_seq,
 519                                               RTM_NEWADDRLABEL,
 520                                               NLM_F_MULTI);
 521                         if (err < 0)
 522                                 break;
 523                 }
 524                 idx++;
 525         }
 526         rcu_read_unlock();
 527         cb->args[0] = idx;
 528         return err;
 529 }
 530
 531 static inline int ip6addrlbl_msgsize(void)
 532 {
 533         return NLMSG_ALIGN(sizeof(struct ifaddrlblmsg))
 534                 + nla_total_size(16)    /* IFAL_ADDRESS */
 535                 + nla_total_size(4);    /* IFAL_LABEL */
 536 }
 537
 538 static int ip6addrlbl_valid_get_req(struct sk_buff *skb,
 539                                     const struct nlmsghdr *nlh,
 540                                     struct nlattr **tb,
 541                                     struct netlink_ext_ack *extack)
 542 {
 543         struct ifaddrlblmsg *ifal;
 544         int i, err;
 545
 546         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifal))) {
 547                 NL_SET_ERR_MSG_MOD(extack, "Invalid header for addrlabel get request");
 548                 return -EINVAL;
 549         }
 550
 551         if (!netlink_strict_get_check(skb))
 552                 return nlmsg_parse_deprecated(nlh, sizeof(*ifal), tb,
 553                                               IFAL_MAX, ifal_policy, extack);
 554
 555         ifal = nlmsg_data(nlh);
 556         if (ifal->__ifal_reserved || ifal->ifal_flags || ifal->ifal_seq) {
 557                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for addrlabel get request");
 558                 return -EINVAL;
 559         }
 560
 561         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*ifal), tb, IFAL_MAX,
 562                                             ifal_policy, extack);
 563         if (err)
 564                 return err;
 565
 566         for (i = 0; i <= IFAL_MAX; i++) {
 567                 if (!tb[i])
 568                         continue;
 569
 570                 switch (i) {
 571                 case IFAL_ADDRESS:
 572                         break;
 573                 default:
 574                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in addrlabel get request");
 575                         return -EINVAL;
 576                 }
 577         }
 578
 579         return 0;
 580 }
 581
 582 static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 583                           struct netlink_ext_ack *extack)
 584 {
 585         struct net *net = sock_net(in_skb->sk);
 586         struct ifaddrlblmsg *ifal;
 587         struct nlattr *tb[IFAL_MAX+1];
 588         struct in6_addr *addr;
 589         u32 lseq;
 590         int err = 0;
 591         struct ip6addrlbl_entry *p;
 592         struct sk_buff *skb;
 593
 594         err = ip6addrlbl_valid_get_req(in_skb, nlh, tb, extack);
 595         if (err < 0)
 596                 return err;
 597
 598         ifal = nlmsg_data(nlh);
 599
 600         if (ifal->ifal_family != AF_INET6 ||
 601             ifal->ifal_prefixlen != 128)
 602                 return -EINVAL;
 603
 604         if (ifal->ifal_index &&
 605             !addrlbl_ifindex_exists(net, ifal->ifal_index))
 606                 return -EINVAL;
 607
 608         if (!tb[IFAL_ADDRESS])
 609                 return -EINVAL;
 610         addr = nla_data(tb[IFAL_ADDRESS]);
 611
 612         skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL);
 613         if (!skb)
 614                 return -ENOBUFS;
 615
 616         err = -ESRCH;
 617
 618         rcu_read_lock();
 619         p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);
 620         lseq = READ_ONCE(net->ipv6.ip6addrlbl_table.seq);
 621         if (p)
 622                 err = ip6addrlbl_fill(skb, p, lseq,
 623                                       NETLINK_CB(in_skb).portid,
 624                                       nlh->nlmsg_seq,
 625                                       RTM_NEWADDRLABEL, 0);
 626         rcu_read_unlock();
 627
 628         if (err < 0) {
 629                 WARN_ON(err == -EMSGSIZE);
 630                 kfree_skb(skb);
 631         } else {
 632                 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
 633         }
 634         return err;
 635 }
 636
 637 static const struct rtnl_msg_handler ipv6_adddr_label_rtnl_msg_handlers[] __initconst_or_module = {
 638         {.owner = THIS_MODULE, .protocol = PF_INET6, .msgtype = RTM_NEWADDRLABEL,
 639          .doit = ip6addrlbl_newdel, .flags = RTNL_FLAG_DOIT_UNLOCKED},
 640         {.owner = THIS_MODULE, .protocol = PF_INET6, .msgtype = RTM_DELADDRLABEL,
 641          .doit = ip6addrlbl_newdel, .flags = RTNL_FLAG_DOIT_UNLOCKED},
 642         {.owner = THIS_MODULE, .protocol = PF_INET6, .msgtype = RTM_GETADDRLABEL,
 643          .doit = ip6addrlbl_get, .dumpit = ip6addrlbl_dump,
 644          .flags = RTNL_FLAG_DOIT_UNLOCKED | RTNL_FLAG_DUMP_UNLOCKED},
 645 };
 646
 647 int __init ipv6_addr_label_rtnl_register(void)
 648 {
 649         return rtnl_register_many(ipv6_adddr_label_rtnl_msg_handlers);
 650 }