include/net/ipv6.h

   1 /*
   2  *      Linux INET6 implementation
   3  *
   4  *      Authors:
   5  *      Pedro Roque             <roque@di.fc.ul.pt>
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  */
  12
  13 #ifndef _NET_IPV6_H
  14 #define _NET_IPV6_H
  15
  16 #include <linux/ipv6.h>
  17 #include <linux/hardirq.h>
  18 #include <linux/jhash.h>
  19 #include <linux/refcount.h>
  20 #include <net/if_inet6.h>
  21 #include <net/ndisc.h>
  22 #include <net/flow.h>
  23 #include <net/flow_dissector.h>
  24 #include <net/snmp.h>
  25 #include <net/netns/hash.h>
  26
  27 #define SIN6_LEN_RFC2133        24
  28
  29 #define IPV6_MAXPLEN            65535
  30
  31 /*
  32  *      NextHeader field of IPv6 header
  33  */
  34
  35 #define NEXTHDR_HOP             0       /* Hop-by-hop option header. */
  36 #define NEXTHDR_TCP             6       /* TCP segment. */
  37 #define NEXTHDR_UDP             17      /* UDP message. */
  38 #define NEXTHDR_IPV6            41      /* IPv6 in IPv6 */
  39 #define NEXTHDR_ROUTING         43      /* Routing header. */
  40 #define NEXTHDR_FRAGMENT        44      /* Fragmentation/reassembly header. */
  41 #define NEXTHDR_GRE             47      /* GRE header. */
  42 #define NEXTHDR_ESP             50      /* Encapsulating security payload. */
  43 #define NEXTHDR_AUTH            51      /* Authentication header. */
  44 #define NEXTHDR_ICMP            58      /* ICMP for IPv6. */
  45 #define NEXTHDR_NONE            59      /* No next header */
  46 #define NEXTHDR_DEST            60      /* Destination options header. */
  47 #define NEXTHDR_SCTP            132     /* SCTP message. */
  48 #define NEXTHDR_MOBILITY        135     /* Mobility header. */
  49
  50 #define NEXTHDR_MAX             255
  51
  52 #define IPV6_DEFAULT_HOPLIMIT   64
  53 #define IPV6_DEFAULT_MCASTHOPS  1
  54
  55 /* Limits on Hop-by-Hop and Destination options.
  56  *
  57  * Per RFC8200 there is no limit on the maximum number or lengths of options in
  58  * Hop-by-Hop or Destination options other then the packet must fit in an MTU.
  59  * We allow configurable limits in order to mitigate potential denial of
  60  * service attacks.
  61  *
  62  * There are three limits that may be set:
  63  *   - Limit the number of options in a Hop-by-Hop or Destination options
  64  *     extension header
  65  *   - Limit the byte length of a Hop-by-Hop or Destination options extension
  66  *     header
  67  *   - Disallow unknown options
  68  *
  69  * The limits are expressed in corresponding sysctls:
  70  *
  71  * ipv6.sysctl.max_dst_opts_cnt
  72  * ipv6.sysctl.max_hbh_opts_cnt
  73  * ipv6.sysctl.max_dst_opts_len
  74  * ipv6.sysctl.max_hbh_opts_len
  75  *
  76  * max_*_opts_cnt is the number of TLVs that are allowed for Destination
  77  * options or Hop-by-Hop options. If the number is less than zero then unknown
  78  * TLVs are disallowed and the number of known options that are allowed is the
  79  * absolute value. Setting the value to INT_MAX indicates no limit.
  80  *
  81  * max_*_opts_len is the length limit in bytes of a Destination or
  82  * Hop-by-Hop options extension header. Setting the value to INT_MAX
  83  * indicates no length limit.
  84  *
  85  * If a limit is exceeded when processing an extension header the packet is
  86  * silently discarded.
  87  */
  88
  89 /* Default limits for Hop-by-Hop and Destination options */
  90 #define IP6_DEFAULT_MAX_DST_OPTS_CNT     8
  91 #define IP6_DEFAULT_MAX_HBH_OPTS_CNT     8
  92 #define IP6_DEFAULT_MAX_DST_OPTS_LEN     INT_MAX /* No limit */
  93 #define IP6_DEFAULT_MAX_HBH_OPTS_LEN     INT_MAX /* No limit */
  94
  95 /*
  96  *      Addr type
  97  *
  98  *      type    -       unicast | multicast
  99  *      scope   -       local   | site      | global
 100  *      v4      -       compat
 101  *      v4mapped
 102  *      any
 103  *      loopback
 104  */
 105
 106 #define IPV6_ADDR_ANY           0x0000U
 107
 108 #define IPV6_ADDR_UNICAST       0x0001U
 109 #define IPV6_ADDR_MULTICAST     0x0002U
 110
 111 #define IPV6_ADDR_LOOPBACK      0x0010U
 112 #define IPV6_ADDR_LINKLOCAL     0x0020U
 113 #define IPV6_ADDR_SITELOCAL     0x0040U
 114
 115 #define IPV6_ADDR_COMPATv4      0x0080U
 116
 117 #define IPV6_ADDR_SCOPE_MASK    0x00f0U
 118
 119 #define IPV6_ADDR_MAPPED        0x1000U
 120
 121 /*
 122  *      Addr scopes
 123  */
 124 #define IPV6_ADDR_MC_SCOPE(a)   \
 125         ((a)->s6_addr[1] & 0x0f)        /* nonstandard */
 126 #define __IPV6_ADDR_SCOPE_INVALID       -1
 127 #define IPV6_ADDR_SCOPE_NODELOCAL       0x01
 128 #define IPV6_ADDR_SCOPE_LINKLOCAL       0x02
 129 #define IPV6_ADDR_SCOPE_SITELOCAL       0x05
 130 #define IPV6_ADDR_SCOPE_ORGLOCAL        0x08
 131 #define IPV6_ADDR_SCOPE_GLOBAL          0x0e
 132
 133 /*
 134  *      Addr flags
 135  */
 136 #define IPV6_ADDR_MC_FLAG_TRANSIENT(a)  \
 137         ((a)->s6_addr[1] & 0x10)
 138 #define IPV6_ADDR_MC_FLAG_PREFIX(a)     \
 139         ((a)->s6_addr[1] & 0x20)
 140 #define IPV6_ADDR_MC_FLAG_RENDEZVOUS(a) \
 141         ((a)->s6_addr[1] & 0x40)
 142
 143 /*
 144  *      fragmentation header
 145  */
 146
 147 struct frag_hdr {
 148         __u8    nexthdr;
 149         __u8    reserved;
 150         __be16  frag_off;
 151         __be32  identification;
 152 };
 153
 154 #define IP6_MF          0x0001
 155 #define IP6_OFFSET      0xFFF8
 156
 157 #define IP6_REPLY_MARK(net, mark) \
 158         ((net)->ipv6.sysctl.fwmark_reflect ? (mark) : 0)
 159
 160 #include <net/sock.h>
 161
 162 /* sysctls */
 163 extern int sysctl_mld_max_msf;
 164 extern int sysctl_mld_qrv;
 165
 166 #define _DEVINC(net, statname, mod, idev, field)                        \
 167 ({                                                                      \
 168         struct inet6_dev *_idev = (idev);                               \
 169         if (likely(_idev != NULL))                                      \
 170                 mod##SNMP_INC_STATS64((_idev)->stats.statname, (field));\
 171         mod##SNMP_INC_STATS64((net)->mib.statname##_statistics, (field));\
 172 })
 173
 174 /* per device counters are atomic_long_t */
 175 #define _DEVINCATOMIC(net, statname, mod, idev, field)                  \
 176 ({                                                                      \
 177         struct inet6_dev *_idev = (idev);                               \
 178         if (likely(_idev != NULL))                                      \
 179                 SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
 180         mod##SNMP_INC_STATS((net)->mib.statname##_statistics, (field));\
 181 })
 182
 183 /* per device and per net counters are atomic_long_t */
 184 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)               \
 185 ({                                                                      \
 186         struct inet6_dev *_idev = (idev);                               \
 187         if (likely(_idev != NULL))                                      \
 188                 SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
 189         SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
 190 })
 191
 192 #define _DEVADD(net, statname, mod, idev, field, val)                   \
 193 ({                                                                      \
 194         struct inet6_dev *_idev = (idev);                               \
 195         if (likely(_idev != NULL))                                      \
 196                 mod##SNMP_ADD_STATS((_idev)->stats.statname, (field), (val)); \
 197         mod##SNMP_ADD_STATS((net)->mib.statname##_statistics, (field), (val));\
 198 })
 199
 200 #define _DEVUPD(net, statname, mod, idev, field, val)                   \
 201 ({                                                                      \
 202         struct inet6_dev *_idev = (idev);                               \
 203         if (likely(_idev != NULL))                                      \
 204                 mod##SNMP_UPD_PO_STATS((_idev)->stats.statname, field, (val)); \
 205         mod##SNMP_UPD_PO_STATS((net)->mib.statname##_statistics, field, (val));\
 206 })
 207
 208 /* MIBs */
 209
 210 #define IP6_INC_STATS(net, idev,field)          \
 211                 _DEVINC(net, ipv6, , idev, field)
 212 #define __IP6_INC_STATS(net, idev,field)        \
 213                 _DEVINC(net, ipv6, __, idev, field)
 214 #define IP6_ADD_STATS(net, idev,field,val)      \
 215                 _DEVADD(net, ipv6, , idev, field, val)
 216 #define __IP6_ADD_STATS(net, idev,field,val)    \
 217                 _DEVADD(net, ipv6, __, idev, field, val)
 218 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
 219                 _DEVUPD(net, ipv6, , idev, field, val)
 220 #define __IP6_UPD_PO_STATS(net, idev,field,val)   \
 221                 _DEVUPD(net, ipv6, __, idev, field, val)
 222 #define ICMP6_INC_STATS(net, idev, field)       \
 223                 _DEVINCATOMIC(net, icmpv6, , idev, field)
 224 #define __ICMP6_INC_STATS(net, idev, field)     \
 225                 _DEVINCATOMIC(net, icmpv6, __, idev, field)
 226
 227 #define ICMP6MSGOUT_INC_STATS(net, idev, field)         \
 228         _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
 229 #define ICMP6MSGIN_INC_STATS(net, idev, field)  \
 230         _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
 231
 232 struct ip6_ra_chain {
 233         struct ip6_ra_chain     *next;
 234         struct sock             *sk;
 235         int                     sel;
 236         void                    (*destructor)(struct sock *);
 237 };
 238
 239 extern struct ip6_ra_chain      *ip6_ra_chain;
 240 extern rwlock_t ip6_ra_lock;
 241
 242 /*
 243    This structure is prepared by protocol, when parsing
 244    ancillary data and passed to IPv6.
 245  */
 246
 247 struct ipv6_txoptions {
 248         refcount_t              refcnt;
 249         /* Length of this structure */
 250         int                     tot_len;
 251
 252         /* length of extension headers   */
 253
 254         __u16                   opt_flen;       /* after fragment hdr */
 255         __u16                   opt_nflen;      /* before fragment hdr */
 256
 257         struct ipv6_opt_hdr     *hopopt;
 258         struct ipv6_opt_hdr     *dst0opt;
 259         struct ipv6_rt_hdr      *srcrt; /* Routing Header */
 260         struct ipv6_opt_hdr     *dst1opt;
 261         struct rcu_head         rcu;
 262         /* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
 263 };
 264
 265 struct ip6_flowlabel {
 266         struct ip6_flowlabel __rcu *next;
 267         __be32                  label;
 268         atomic_t                users;
 269         struct in6_addr         dst;
 270         struct ipv6_txoptions   *opt;
 271         unsigned long           linger;
 272         struct rcu_head         rcu;
 273         u8                      share;
 274         union {
 275                 struct pid *pid;
 276                 kuid_t uid;
 277         } owner;
 278         unsigned long           lastuse;
 279         unsigned long           expires;
 280         struct net              *fl_net;
 281 };
 282
 283 #define IPV6_FLOWINFO_MASK              cpu_to_be32(0x0FFFFFFF)
 284 #define IPV6_FLOWLABEL_MASK             cpu_to_be32(0x000FFFFF)
 285 #define IPV6_FLOWLABEL_STATELESS_FLAG   cpu_to_be32(0x00080000)
 286
 287 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
 288 #define IPV6_TCLASS_SHIFT       20
 289
 290 struct ipv6_fl_socklist {
 291         struct ipv6_fl_socklist __rcu   *next;
 292         struct ip6_flowlabel            *fl;
 293         struct rcu_head                 rcu;
 294 };
 295
 296 struct ipcm6_cookie {
 297         struct sockcm_cookie sockc;
 298         __s16 hlimit;
 299         __s16 tclass;
 300         __s8  dontfrag;
 301         struct ipv6_txoptions *opt;
 302         __u16 gso_size;
 303 };
 304
 305 static inline void ipcm6_init(struct ipcm6_cookie *ipc6)
 306 {
 307         *ipc6 = (struct ipcm6_cookie) {
 308                 .hlimit = -1,
 309                 .tclass = -1,
 310                 .dontfrag = -1,
 311         };
 312 }
 313
 314 static inline void ipcm6_init_sk(struct ipcm6_cookie *ipc6,
 315                                  const struct ipv6_pinfo *np)
 316 {
 317         *ipc6 = (struct ipcm6_cookie) {
 318                 .hlimit = -1,
 319                 .tclass = np->tclass,
 320                 .dontfrag = np->dontfrag,
 321         };
 322 }
 323
 324 static inline struct ipv6_txoptions *txopt_get(const struct ipv6_pinfo *np)
 325 {
 326         struct ipv6_txoptions *opt;
 327
 328         rcu_read_lock();
 329         opt = rcu_dereference(np->opt);
 330         if (opt) {
 331                 if (!refcount_inc_not_zero(&opt->refcnt))
 332                         opt = NULL;
 333                 else
 334                         opt = rcu_pointer_handoff(opt);
 335         }
 336         rcu_read_unlock();
 337         return opt;
 338 }
 339
 340 static inline void txopt_put(struct ipv6_txoptions *opt)
 341 {
 342         if (opt && refcount_dec_and_test(&opt->refcnt))
 343                 kfree_rcu(opt, rcu);
 344 }
 345
 346 struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label);
 347 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 348                                          struct ip6_flowlabel *fl,
 349                                          struct ipv6_txoptions *fopt);
 350 void fl6_free_socklist(struct sock *sk);
 351 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
 352 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
 353                            int flags);
 354 int ip6_flowlabel_init(void);
 355 void ip6_flowlabel_cleanup(void);
 356 bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np);
 357
 358 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
 359 {
 360         if (fl)
 361                 atomic_dec(&fl->users);
 362 }
 363
 364 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
 365
 366 void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 367                                 struct icmp6hdr *thdr, int len);
 368
 369 int ip6_ra_control(struct sock *sk, int sel);
 370
 371 int ipv6_parse_hopopts(struct sk_buff *skb);
 372
 373 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
 374                                         struct ipv6_txoptions *opt);
 375 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
 376                                           struct ipv6_txoptions *opt,
 377                                           int newtype,
 378                                           struct ipv6_opt_hdr *newopt);
 379 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
 380                                           struct ipv6_txoptions *opt);
 381
 382 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
 383                        const struct inet6_skb_parm *opt);
 384 struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
 385                                            struct ipv6_txoptions *opt);
 386
 387 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
 388 {
 389         /* If forwarding is enabled, RA are not accepted unless the special
 390          * hybrid mode (accept_ra=2) is enabled.
 391          */
 392         return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
 393             idev->cnf.accept_ra;
 394 }
 395
 396 #define IPV6_FRAG_HIGH_THRESH   (4 * 1024*1024) /* 4194304 */
 397 #define IPV6_FRAG_LOW_THRESH    (3 * 1024*1024) /* 3145728 */
 398 #define IPV6_FRAG_TIMEOUT       (60 * HZ)       /* 60 seconds */
 399
 400 int __ipv6_addr_type(const struct in6_addr *addr);
 401 static inline int ipv6_addr_type(const struct in6_addr *addr)
 402 {
 403         return __ipv6_addr_type(addr) & 0xffff;
 404 }
 405
 406 static inline int ipv6_addr_scope(const struct in6_addr *addr)
 407 {
 408         return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
 409 }
 410
 411 static inline int __ipv6_addr_src_scope(int type)
 412 {
 413         return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
 414 }
 415
 416 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
 417 {
 418         return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
 419 }
 420
 421 static inline bool __ipv6_addr_needs_scope_id(int type)
 422 {
 423         return type & IPV6_ADDR_LINKLOCAL ||
 424                (type & IPV6_ADDR_MULTICAST &&
 425                 (type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
 426 }
 427
 428 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
 429 {
 430         return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
 431 }
 432
 433 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
 434 {
 435         return memcmp(a1, a2, sizeof(struct in6_addr));
 436 }
 437
 438 static inline bool
 439 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
 440                      const struct in6_addr *a2)
 441 {
 442 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 443         const unsigned long *ul1 = (const unsigned long *)a1;
 444         const unsigned long *ulm = (const unsigned long *)m;
 445         const unsigned long *ul2 = (const unsigned long *)a2;
 446
 447         return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
 448                   ((ul1[1] ^ ul2[1]) & ulm[1]));
 449 #else
 450         return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
 451                   ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
 452                   ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
 453                   ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
 454 #endif
 455 }
 456
 457 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
 458                                     const struct in6_addr *addr,
 459                                     int plen)
 460 {
 461         /* caller must guarantee 0 <= plen <= 128 */
 462         int o = plen >> 3,
 463             b = plen & 0x7;
 464
 465         memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
 466         memcpy(pfx->s6_addr, addr, o);
 467         if (b != 0)
 468                 pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
 469 }
 470
 471 static inline void ipv6_addr_prefix_copy(struct in6_addr *addr,
 472                                          const struct in6_addr *pfx,
 473                                          int plen)
 474 {
 475         /* caller must guarantee 0 <= plen <= 128 */
 476         int o = plen >> 3,
 477             b = plen & 0x7;
 478
 479         memcpy(addr->s6_addr, pfx, o);
 480         if (b != 0) {
 481                 addr->s6_addr[o] &= ~(0xff00 >> b);
 482                 addr->s6_addr[o] |= (pfx->s6_addr[o] & (0xff00 >> b));
 483         }
 484 }
 485
 486 static inline void __ipv6_addr_set_half(__be32 *addr,
 487                                         __be32 wh, __be32 wl)
 488 {
 489 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 490 #if defined(__BIG_ENDIAN)
 491         if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
 492                 *(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
 493                 return;
 494         }
 495 #elif defined(__LITTLE_ENDIAN)
 496         if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
 497                 *(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
 498                 return;
 499         }
 500 #endif
 501 #endif
 502         addr[0] = wh;
 503         addr[1] = wl;
 504 }
 505
 506 static inline void ipv6_addr_set(struct in6_addr *addr,
 507                                      __be32 w1, __be32 w2,
 508                                      __be32 w3, __be32 w4)
 509 {
 510         __ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
 511         __ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
 512 }
 513
 514 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
 515                                    const struct in6_addr *a2)
 516 {
 517 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 518         const unsigned long *ul1 = (const unsigned long *)a1;
 519         const unsigned long *ul2 = (const unsigned long *)a2;
 520
 521         return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
 522 #else
 523         return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
 524                 (a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
 525                 (a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
 526                 (a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
 527 #endif
 528 }
 529
 530 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 531 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
 532                                               const __be64 *a2,
 533                                               unsigned int len)
 534 {
 535         if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
 536                 return false;
 537         return true;
 538 }
 539
 540 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 541                                      const struct in6_addr *addr2,
 542                                      unsigned int prefixlen)
 543 {
 544         const __be64 *a1 = (const __be64 *)addr1;
 545         const __be64 *a2 = (const __be64 *)addr2;
 546
 547         if (prefixlen >= 64) {
 548                 if (a1[0] ^ a2[0])
 549                         return false;
 550                 return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
 551         }
 552         return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
 553 }
 554 #else
 555 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 556                                      const struct in6_addr *addr2,
 557                                      unsigned int prefixlen)
 558 {
 559         const __be32 *a1 = addr1->s6_addr32;
 560         const __be32 *a2 = addr2->s6_addr32;
 561         unsigned int pdw, pbi;
 562
 563         /* check complete u32 in prefix */
 564         pdw = prefixlen >> 5;
 565         if (pdw && memcmp(a1, a2, pdw << 2))
 566                 return false;
 567
 568         /* check incomplete u32 in prefix */
 569         pbi = prefixlen & 0x1f;
 570         if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
 571                 return false;
 572
 573         return true;
 574 }
 575 #endif
 576
 577 static inline bool ipv6_addr_any(const struct in6_addr *a)
 578 {
 579 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 580         const unsigned long *ul = (const unsigned long *)a;
 581
 582         return (ul[0] | ul[1]) == 0UL;
 583 #else
 584         return (a->s6_addr32[0] | a->s6_addr32[1] |
 585                 a->s6_addr32[2] | a->s6_addr32[3]) == 0;
 586 #endif
 587 }
 588
 589 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
 590 {
 591 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 592         const unsigned long *ul = (const unsigned long *)a;
 593         unsigned long x = ul[0] ^ ul[1];
 594
 595         return (u32)(x ^ (x >> 32));
 596 #else
 597         return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
 598                              a->s6_addr32[2] ^ a->s6_addr32[3]);
 599 #endif
 600 }
 601
 602 /* more secured version of ipv6_addr_hash() */
 603 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
 604 {
 605         u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
 606
 607         return jhash_3words(v,
 608                             (__force u32)a->s6_addr32[2],
 609                             (__force u32)a->s6_addr32[3],
 610                             initval);
 611 }
 612
 613 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
 614 {
 615 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 616         const __be64 *be = (const __be64 *)a;
 617
 618         return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
 619 #else
 620         return (a->s6_addr32[0] | a->s6_addr32[1] |
 621                 a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
 622 #endif
 623 }
 624
 625 /*
 626  * Note that we must __force cast these to unsigned long to make sparse happy,
 627  * since all of the endian-annotated types are fixed size regardless of arch.
 628  */
 629 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
 630 {
 631         return (
 632 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 633                 *(unsigned long *)a |
 634 #else
 635                 (__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
 636 #endif
 637                 (__force unsigned long)(a->s6_addr32[2] ^
 638                                         cpu_to_be32(0x0000ffff))) == 0UL;
 639 }
 640
 641 static inline u32 ipv6_portaddr_hash(const struct net *net,
 642                                      const struct in6_addr *addr6,
 643                                      unsigned int port)
 644 {
 645         unsigned int hash, mix = net_hash_mix(net);
 646
 647         if (ipv6_addr_any(addr6))
 648                 hash = jhash_1word(0, mix);
 649         else if (ipv6_addr_v4mapped(addr6))
 650                 hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
 651         else
 652                 hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
 653
 654         return hash ^ port;
 655 }
 656
 657 /*
 658  * Check for a RFC 4843 ORCHID address
 659  * (Overlay Routable Cryptographic Hash Identifiers)
 660  */
 661 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
 662 {
 663         return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
 664 }
 665
 666 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
 667 {
 668         return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
 669 }
 670
 671 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
 672                                           struct in6_addr *v4mapped)
 673 {
 674         ipv6_addr_set(v4mapped,
 675                         0, 0,
 676                         htonl(0x0000FFFF),
 677                         addr);
 678 }
 679
 680 /*
 681  * find the first different bit between two addresses
 682  * length of address must be a multiple of 32bits
 683  */
 684 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
 685 {
 686         const __be32 *a1 = token1, *a2 = token2;
 687         int i;
 688
 689         addrlen >>= 2;
 690
 691         for (i = 0; i < addrlen; i++) {
 692                 __be32 xb = a1[i] ^ a2[i];
 693                 if (xb)
 694                         return i * 32 + 31 - __fls(ntohl(xb));
 695         }
 696
 697         /*
 698          *      we should *never* get to this point since that
 699          *      would mean the addrs are equal
 700          *
 701          *      However, we do get to it 8) And exacly, when
 702          *      addresses are equal 8)
 703          *
 704          *      ip route add 1111::/128 via ...
 705          *      ip route add 1111::/64 via ...
 706          *      and we are here.
 707          *
 708          *      Ideally, this function should stop comparison
 709          *      at prefix length. It does not, but it is still OK,
 710          *      if returned value is greater than prefix length.
 711          *                                      --ANK (980803)
 712          */
 713         return addrlen << 5;
 714 }
 715
 716 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 717 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
 718 {
 719         const __be64 *a1 = token1, *a2 = token2;
 720         int i;
 721
 722         addrlen >>= 3;
 723
 724         for (i = 0; i < addrlen; i++) {
 725                 __be64 xb = a1[i] ^ a2[i];
 726                 if (xb)
 727                         return i * 64 + 63 - __fls(be64_to_cpu(xb));
 728         }
 729
 730         return addrlen << 6;
 731 }
 732 #endif
 733
 734 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
 735 {
 736 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 737         if (__builtin_constant_p(addrlen) && !(addrlen & 7))
 738                 return __ipv6_addr_diff64(token1, token2, addrlen);
 739 #endif
 740         return __ipv6_addr_diff32(token1, token2, addrlen);
 741 }
 742
 743 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
 744 {
 745         return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
 746 }
 747
 748 __be32 ipv6_select_ident(struct net *net,
 749                          const struct in6_addr *daddr,
 750                          const struct in6_addr *saddr);
 751 __be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
 752
 753 int ip6_dst_hoplimit(struct dst_entry *dst);
 754
 755 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
 756                                       struct dst_entry *dst)
 757 {
 758         int hlimit;
 759
 760         if (ipv6_addr_is_multicast(&fl6->daddr))
 761                 hlimit = np->mcast_hops;
 762         else
 763                 hlimit = np->hop_limit;
 764         if (hlimit < 0)
 765                 hlimit = ip6_dst_hoplimit(dst);
 766         return hlimit;
 767 }
 768
 769 /* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
 770  * Equivalent to :      flow->v6addrs.src = iph->saddr;
 771  *                      flow->v6addrs.dst = iph->daddr;
 772  */
 773 static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
 774                                             const struct ipv6hdr *iph)
 775 {
 776         BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
 777                      offsetof(typeof(flow->addrs), v6addrs.src) +
 778                      sizeof(flow->addrs.v6addrs.src));
 779         memcpy(&flow->addrs.v6addrs, &iph->saddr, sizeof(flow->addrs.v6addrs));
 780         flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 781 }
 782
 783 #if IS_ENABLED(CONFIG_IPV6)
 784
 785 static inline bool ipv6_can_nonlocal_bind(struct net *net,
 786                                           struct inet_sock *inet)
 787 {
 788         return net->ipv6.sysctl.ip_nonlocal_bind ||
 789                 inet->freebind || inet->transparent;
 790 }
 791
 792 /* Sysctl settings for net ipv6.auto_flowlabels */
 793 #define IP6_AUTO_FLOW_LABEL_OFF         0
 794 #define IP6_AUTO_FLOW_LABEL_OPTOUT      1
 795 #define IP6_AUTO_FLOW_LABEL_OPTIN       2
 796 #define IP6_AUTO_FLOW_LABEL_FORCED      3
 797
 798 #define IP6_AUTO_FLOW_LABEL_MAX         IP6_AUTO_FLOW_LABEL_FORCED
 799
 800 #define IP6_DEFAULT_AUTO_FLOW_LABELS    IP6_AUTO_FLOW_LABEL_OPTOUT
 801
 802 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 803                                         __be32 flowlabel, bool autolabel,
 804                                         struct flowi6 *fl6)
 805 {
 806         u32 hash;
 807
 808         /* @flowlabel may include more than a flow label, eg, the traffic class.
 809          * Here we want only the flow label value.
 810          */
 811         flowlabel &= IPV6_FLOWLABEL_MASK;
 812
 813         if (flowlabel ||
 814             net->ipv6.sysctl.auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF ||
 815             (!autolabel &&
 816              net->ipv6.sysctl.auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED))
 817                 return flowlabel;
 818
 819         hash = skb_get_hash_flowi6(skb, fl6);
 820
 821         /* Since this is being sent on the wire obfuscate hash a bit
 822          * to minimize possbility that any useful information to an
 823          * attacker is leaked. Only lower 20 bits are relevant.
 824          */
 825         hash = rol32(hash, 16);
 826
 827         flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
 828
 829         if (net->ipv6.sysctl.flowlabel_state_ranges)
 830                 flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
 831
 832         return flowlabel;
 833 }
 834
 835 static inline int ip6_default_np_autolabel(struct net *net)
 836 {
 837         switch (net->ipv6.sysctl.auto_flowlabels) {
 838         case IP6_AUTO_FLOW_LABEL_OFF:
 839         case IP6_AUTO_FLOW_LABEL_OPTIN:
 840         default:
 841                 return 0;
 842         case IP6_AUTO_FLOW_LABEL_OPTOUT:
 843         case IP6_AUTO_FLOW_LABEL_FORCED:
 844                 return 1;
 845         }
 846 }
 847 #else
 848 static inline void ip6_set_txhash(struct sock *sk) { }
 849 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 850                                         __be32 flowlabel, bool autolabel,
 851                                         struct flowi6 *fl6)
 852 {
 853         return flowlabel;
 854 }
 855 static inline int ip6_default_np_autolabel(struct net *net)
 856 {
 857         return 0;
 858 }
 859 #endif
 860
 861 #if IS_ENABLED(CONFIG_IPV6)
 862 static inline int ip6_multipath_hash_policy(const struct net *net)
 863 {
 864         return net->ipv6.sysctl.multipath_hash_policy;
 865 }
 866 #else
 867 static inline int ip6_multipath_hash_policy(const struct net *net)
 868 {
 869         return 0;
 870 }
 871 #endif
 872
 873 /*
 874  *      Header manipulation
 875  */
 876 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
 877                                 __be32 flowlabel)
 878 {
 879         *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
 880 }
 881
 882 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
 883 {
 884         return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
 885 }
 886
 887 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
 888 {
 889         return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
 890 }
 891
 892 static inline u8 ip6_tclass(__be32 flowinfo)
 893 {
 894         return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
 895 }
 896
 897 static inline __be32 ip6_make_flowinfo(unsigned int tclass, __be32 flowlabel)
 898 {
 899         return htonl(tclass << IPV6_TCLASS_SHIFT) | flowlabel;
 900 }
 901
 902 static inline __be32 flowi6_get_flowlabel(const struct flowi6 *fl6)
 903 {
 904         return fl6->flowlabel & IPV6_FLOWLABEL_MASK;
 905 }
 906
 907 /*
 908  *      Prototypes exported by ipv6
 909  */
 910
 911 /*
 912  *      rcv function (called from netdevice level)
 913  */
 914
 915 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
 916              struct packet_type *pt, struct net_device *orig_dev);
 917 void ipv6_list_rcv(struct list_head *head, struct packet_type *pt,
 918                    struct net_device *orig_dev);
 919
 920 int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
 921
 922 /*
 923  *      upper-layer output functions
 924  */
 925 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 926              __u32 mark, struct ipv6_txoptions *opt, int tclass);
 927
 928 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
 929
 930 int ip6_append_data(struct sock *sk,
 931                     int getfrag(void *from, char *to, int offset, int len,
 932                                 int odd, struct sk_buff *skb),
 933                     void *from, int length, int transhdrlen,
 934                     struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
 935                     struct rt6_info *rt, unsigned int flags);
 936
 937 int ip6_push_pending_frames(struct sock *sk);
 938
 939 void ip6_flush_pending_frames(struct sock *sk);
 940
 941 int ip6_send_skb(struct sk_buff *skb);
 942
 943 struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
 944                                struct inet_cork_full *cork,
 945                                struct inet6_cork *v6_cork);
 946 struct sk_buff *ip6_make_skb(struct sock *sk,
 947                              int getfrag(void *from, char *to, int offset,
 948                                          int len, int odd, struct sk_buff *skb),
 949                              void *from, int length, int transhdrlen,
 950                              struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
 951                              struct rt6_info *rt, unsigned int flags,
 952                              struct inet_cork_full *cork);
 953
 954 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
 955 {
 956         return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
 957                               &inet6_sk(sk)->cork);
 958 }
 959
 960 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
 961                    struct flowi6 *fl6);
 962 struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
 963                                       const struct in6_addr *final_dst);
 964 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 965                                          const struct in6_addr *final_dst,
 966                                          bool connected);
 967 struct dst_entry *ip6_blackhole_route(struct net *net,
 968                                       struct dst_entry *orig_dst);
 969
 970 /*
 971  *      skb processing functions
 972  */
 973
 974 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 975 int ip6_forward(struct sk_buff *skb);
 976 int ip6_input(struct sk_buff *skb);
 977 int ip6_mc_input(struct sk_buff *skb);
 978
 979 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 980 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 981
 982 /*
 983  *      Extension header (options) processing
 984  */
 985
 986 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
 987                           u8 *proto, struct in6_addr **daddr_p,
 988                           struct in6_addr *saddr);
 989 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
 990                          u8 *proto);
 991
 992 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
 993                      __be16 *frag_offp);
 994
 995 bool ipv6_ext_hdr(u8 nexthdr);
 996
 997 enum {
 998         IP6_FH_F_FRAG           = (1 << 0),
 999         IP6_FH_F_AUTH           = (1 << 1),
1000         IP6_FH_F_SKIP_RH        = (1 << 2),
1001 };
1002
1003 /* find specified header and get offset to it */
1004 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
1005                   unsigned short *fragoff, int *fragflg);
1006
1007 int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type);
1008
1009 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1010                                 const struct ipv6_txoptions *opt,
1011                                 struct in6_addr *orig);
1012
1013 /*
1014  *      socket options (ipv6_sockglue.c)
1015  */
1016
1017 int ipv6_setsockopt(struct sock *sk, int level, int optname,
1018                     char __user *optval, unsigned int optlen);
1019 int ipv6_getsockopt(struct sock *sk, int level, int optname,
1020                     char __user *optval, int __user *optlen);
1021 int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
1022                            char __user *optval, unsigned int optlen);
1023 int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
1024                            char __user *optval, int __user *optlen);
1025
1026 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *addr,
1027                            int addr_len);
1028 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
1029 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
1030                                  int addr_len);
1031 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr);
1032 void ip6_datagram_release_cb(struct sock *sk);
1033
1034 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
1035                     int *addr_len);
1036 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
1037                      int *addr_len);
1038 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
1039                      u32 info, u8 *payload);
1040 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
1041 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
1042
1043 int inet6_release(struct socket *sock);
1044 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
1045 int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
1046                   int peer);
1047 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
1048
1049 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
1050                               struct sock *sk);
1051
1052 /*
1053  * reassembly.c
1054  */
1055 extern const struct proto_ops inet6_stream_ops;
1056 extern const struct proto_ops inet6_dgram_ops;
1057 extern const struct proto_ops inet6_sockraw_ops;
1058
1059 struct group_source_req;
1060 struct group_filter;
1061
1062 int ip6_mc_source(int add, int omode, struct sock *sk,
1063                   struct group_source_req *pgsr);
1064 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
1065 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
1066                   struct group_filter __user *optval, int __user *optlen);
1067
1068 #ifdef CONFIG_PROC_FS
1069 int ac6_proc_init(struct net *net);
1070 void ac6_proc_exit(struct net *net);
1071 int raw6_proc_init(void);
1072 void raw6_proc_exit(void);
1073 int tcp6_proc_init(struct net *net);
1074 void tcp6_proc_exit(struct net *net);
1075 int udp6_proc_init(struct net *net);
1076 void udp6_proc_exit(struct net *net);
1077 int udplite6_proc_init(void);
1078 void udplite6_proc_exit(void);
1079 int ipv6_misc_proc_init(void);
1080 void ipv6_misc_proc_exit(void);
1081 int snmp6_register_dev(struct inet6_dev *idev);
1082 int snmp6_unregister_dev(struct inet6_dev *idev);
1083
1084 #else
1085 static inline int ac6_proc_init(struct net *net) { return 0; }
1086 static inline void ac6_proc_exit(struct net *net) { }
1087 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
1088 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
1089 #endif
1090
1091 #ifdef CONFIG_SYSCTL
1092 extern struct ctl_table ipv6_route_table_template[];
1093
1094 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
1095 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
1096 int ipv6_sysctl_register(void);
1097 void ipv6_sysctl_unregister(void);
1098 #endif
1099
1100 int ipv6_sock_mc_join(struct sock *sk, int ifindex,
1101                       const struct in6_addr *addr);
1102 int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,
1103                           const struct in6_addr *addr, unsigned int mode);
1104 int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
1105                       const struct in6_addr *addr);
1106 #endif /* _NET_IPV6_H */