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 <net/if_inet6.h>
  20 #include <net/ndisc.h>
  21 #include <net/flow.h>
  22 #include <net/snmp.h>
  23
  24 #define SIN6_LEN_RFC2133        24
  25
  26 #define IPV6_MAXPLEN            65535
  27
  28 /*
  29  *      NextHeader field of IPv6 header
  30  */
  31
  32 #define NEXTHDR_HOP             0       /* Hop-by-hop option header. */
  33 #define NEXTHDR_TCP             6       /* TCP segment. */
  34 #define NEXTHDR_UDP             17      /* UDP message. */
  35 #define NEXTHDR_IPV6            41      /* IPv6 in IPv6 */
  36 #define NEXTHDR_ROUTING         43      /* Routing header. */
  37 #define NEXTHDR_FRAGMENT        44      /* Fragmentation/reassembly header. */
  38 #define NEXTHDR_GRE             47      /* GRE header. */
  39 #define NEXTHDR_ESP             50      /* Encapsulating security payload. */
  40 #define NEXTHDR_AUTH            51      /* Authentication header. */
  41 #define NEXTHDR_ICMP            58      /* ICMP for IPv6. */
  42 #define NEXTHDR_NONE            59      /* No next header */
  43 #define NEXTHDR_DEST            60      /* Destination options header. */
  44 #define NEXTHDR_MOBILITY        135     /* Mobility header. */
  45
  46 #define NEXTHDR_MAX             255
  47
  48
  49
  50 #define IPV6_DEFAULT_HOPLIMIT   64
  51 #define IPV6_DEFAULT_MCASTHOPS  1
  52
  53 /*
  54  *      Addr type
  55  *
  56  *      type    -       unicast | multicast
  57  *      scope   -       local   | site      | global
  58  *      v4      -       compat
  59  *      v4mapped
  60  *      any
  61  *      loopback
  62  */
  63
  64 #define IPV6_ADDR_ANY           0x0000U
  65
  66 #define IPV6_ADDR_UNICAST       0x0001U
  67 #define IPV6_ADDR_MULTICAST     0x0002U
  68
  69 #define IPV6_ADDR_LOOPBACK      0x0010U
  70 #define IPV6_ADDR_LINKLOCAL     0x0020U
  71 #define IPV6_ADDR_SITELOCAL     0x0040U
  72
  73 #define IPV6_ADDR_COMPATv4      0x0080U
  74
  75 #define IPV6_ADDR_SCOPE_MASK    0x00f0U
  76
  77 #define IPV6_ADDR_MAPPED        0x1000U
  78
  79 /*
  80  *      Addr scopes
  81  */
  82 #define IPV6_ADDR_MC_SCOPE(a)   \
  83         ((a)->s6_addr[1] & 0x0f)        /* nonstandard */
  84 #define __IPV6_ADDR_SCOPE_INVALID       -1
  85 #define IPV6_ADDR_SCOPE_NODELOCAL       0x01
  86 #define IPV6_ADDR_SCOPE_LINKLOCAL       0x02
  87 #define IPV6_ADDR_SCOPE_SITELOCAL       0x05
  88 #define IPV6_ADDR_SCOPE_ORGLOCAL        0x08
  89 #define IPV6_ADDR_SCOPE_GLOBAL          0x0e
  90
  91 /*
  92  *      Addr flags
  93  */
  94 #define IPV6_ADDR_MC_FLAG_TRANSIENT(a)  \
  95         ((a)->s6_addr[1] & 0x10)
  96 #define IPV6_ADDR_MC_FLAG_PREFIX(a)     \
  97         ((a)->s6_addr[1] & 0x20)
  98 #define IPV6_ADDR_MC_FLAG_RENDEZVOUS(a) \
  99         ((a)->s6_addr[1] & 0x40)
 100
 101 /*
 102  *      fragmentation header
 103  */
 104
 105 struct frag_hdr {
 106         __u8    nexthdr;
 107         __u8    reserved;
 108         __be16  frag_off;
 109         __be32  identification;
 110 };
 111
 112 #define IP6_MF  0x0001
 113
 114 #include <net/sock.h>
 115
 116 /* sysctls */
 117 extern int sysctl_mld_max_msf;
 118
 119 #define _DEVINC(net, statname, modifier, idev, field)                   \
 120 ({                                                                      \
 121         struct inet6_dev *_idev = (idev);                               \
 122         if (likely(_idev != NULL))                                      \
 123                 SNMP_INC_STATS##modifier((_idev)->stats.statname, (field)); \
 124         SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
 125 })
 126
 127 /* per device counters are atomic_long_t */
 128 #define _DEVINCATOMIC(net, statname, modifier, idev, field)             \
 129 ({                                                                      \
 130         struct inet6_dev *_idev = (idev);                               \
 131         if (likely(_idev != NULL))                                      \
 132                 SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
 133         SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
 134 })
 135
 136 /* per device and per net counters are atomic_long_t */
 137 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)               \
 138 ({                                                                      \
 139         struct inet6_dev *_idev = (idev);                               \
 140         if (likely(_idev != NULL))                                      \
 141                 SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
 142         SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
 143 })
 144
 145 #define _DEVADD(net, statname, modifier, idev, field, val)              \
 146 ({                                                                      \
 147         struct inet6_dev *_idev = (idev);                               \
 148         if (likely(_idev != NULL))                                      \
 149                 SNMP_ADD_STATS##modifier((_idev)->stats.statname, (field), (val)); \
 150         SNMP_ADD_STATS##modifier((net)->mib.statname##_statistics, (field), (val));\
 151 })
 152
 153 #define _DEVUPD(net, statname, modifier, idev, field, val)              \
 154 ({                                                                      \
 155         struct inet6_dev *_idev = (idev);                               \
 156         if (likely(_idev != NULL))                                      \
 157                 SNMP_UPD_PO_STATS##modifier((_idev)->stats.statname, field, (val)); \
 158         SNMP_UPD_PO_STATS##modifier((net)->mib.statname##_statistics, field, (val));\
 159 })
 160
 161 /* MIBs */
 162
 163 #define IP6_INC_STATS(net, idev,field)          \
 164                 _DEVINC(net, ipv6, 64, idev, field)
 165 #define IP6_INC_STATS_BH(net, idev,field)       \
 166                 _DEVINC(net, ipv6, 64_BH, idev, field)
 167 #define IP6_ADD_STATS(net, idev,field,val)      \
 168                 _DEVADD(net, ipv6, 64, idev, field, val)
 169 #define IP6_ADD_STATS_BH(net, idev,field,val)   \
 170                 _DEVADD(net, ipv6, 64_BH, idev, field, val)
 171 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
 172                 _DEVUPD(net, ipv6, 64, idev, field, val)
 173 #define IP6_UPD_PO_STATS_BH(net, idev,field,val)   \
 174                 _DEVUPD(net, ipv6, 64_BH, idev, field, val)
 175 #define ICMP6_INC_STATS(net, idev, field)       \
 176                 _DEVINCATOMIC(net, icmpv6, , idev, field)
 177 #define ICMP6_INC_STATS_BH(net, idev, field)    \
 178                 _DEVINCATOMIC(net, icmpv6, _BH, idev, field)
 179
 180 #define ICMP6MSGOUT_INC_STATS(net, idev, field)         \
 181         _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
 182 #define ICMP6MSGOUT_INC_STATS_BH(net, idev, field)      \
 183         _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
 184 #define ICMP6MSGIN_INC_STATS_BH(net, idev, field)       \
 185         _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
 186
 187 struct ip6_ra_chain {
 188         struct ip6_ra_chain     *next;
 189         struct sock             *sk;
 190         int                     sel;
 191         void                    (*destructor)(struct sock *);
 192 };
 193
 194 extern struct ip6_ra_chain      *ip6_ra_chain;
 195 extern rwlock_t ip6_ra_lock;
 196
 197 /*
 198    This structure is prepared by protocol, when parsing
 199    ancillary data and passed to IPv6.
 200  */
 201
 202 struct ipv6_txoptions {
 203         /* Length of this structure */
 204         int                     tot_len;
 205
 206         /* length of extension headers   */
 207
 208         __u16                   opt_flen;       /* after fragment hdr */
 209         __u16                   opt_nflen;      /* before fragment hdr */
 210
 211         struct ipv6_opt_hdr     *hopopt;
 212         struct ipv6_opt_hdr     *dst0opt;
 213         struct ipv6_rt_hdr      *srcrt; /* Routing Header */
 214         struct ipv6_opt_hdr     *dst1opt;
 215
 216         /* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
 217 };
 218
 219 struct ip6_flowlabel {
 220         struct ip6_flowlabel __rcu *next;
 221         __be32                  label;
 222         atomic_t                users;
 223         struct in6_addr         dst;
 224         struct ipv6_txoptions   *opt;
 225         unsigned long           linger;
 226         struct rcu_head         rcu;
 227         u8                      share;
 228         union {
 229                 struct pid *pid;
 230                 kuid_t uid;
 231         } owner;
 232         unsigned long           lastuse;
 233         unsigned long           expires;
 234         struct net              *fl_net;
 235 };
 236
 237 #define IPV6_FLOWINFO_MASK      cpu_to_be32(0x0FFFFFFF)
 238 #define IPV6_FLOWLABEL_MASK     cpu_to_be32(0x000FFFFF)
 239
 240 struct ipv6_fl_socklist {
 241         struct ipv6_fl_socklist __rcu   *next;
 242         struct ip6_flowlabel            *fl;
 243         struct rcu_head                 rcu;
 244 };
 245
 246 extern struct ip6_flowlabel     *fl6_sock_lookup(struct sock *sk, __be32 label);
 247 extern struct ipv6_txoptions    *fl6_merge_options(struct ipv6_txoptions * opt_space,
 248                                                    struct ip6_flowlabel * fl,
 249                                                    struct ipv6_txoptions * fopt);
 250 extern void                     fl6_free_socklist(struct sock *sk);
 251 extern int                      ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
 252 extern int                      ip6_flowlabel_init(void);
 253 extern void                     ip6_flowlabel_cleanup(void);
 254
 255 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
 256 {
 257         if (fl)
 258                 atomic_dec(&fl->users);
 259 }
 260
 261 extern void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
 262
 263 int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 264                                struct icmp6hdr *thdr, int len);
 265
 266 struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb,
 267                                       struct sock *sk, struct flowi6 *fl6);
 268
 269 extern int                      ip6_ra_control(struct sock *sk, int sel);
 270
 271 extern int                      ipv6_parse_hopopts(struct sk_buff *skb);
 272
 273 extern struct ipv6_txoptions *  ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt);
 274 extern struct ipv6_txoptions *  ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
 275                                                    int newtype,
 276                                                    struct ipv6_opt_hdr __user *newopt,
 277                                                    int newoptlen);
 278 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
 279                                           struct ipv6_txoptions *opt);
 280
 281 extern bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb);
 282
 283 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
 284 {
 285         /* If forwarding is enabled, RA are not accepted unless the special
 286          * hybrid mode (accept_ra=2) is enabled.
 287          */
 288         return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
 289             idev->cnf.accept_ra;
 290 }
 291
 292 #if IS_ENABLED(CONFIG_IPV6)
 293 static inline int ip6_frag_nqueues(struct net *net)
 294 {
 295         return net->ipv6.frags.nqueues;
 296 }
 297
 298 static inline int ip6_frag_mem(struct net *net)
 299 {
 300         return sum_frag_mem_limit(&net->ipv6.frags);
 301 }
 302 #endif
 303
 304 #define IPV6_FRAG_HIGH_THRESH   (4 * 1024*1024) /* 4194304 */
 305 #define IPV6_FRAG_LOW_THRESH    (3 * 1024*1024) /* 3145728 */
 306 #define IPV6_FRAG_TIMEOUT       (60 * HZ)       /* 60 seconds */
 307
 308 extern int __ipv6_addr_type(const struct in6_addr *addr);
 309 static inline int ipv6_addr_type(const struct in6_addr *addr)
 310 {
 311         return __ipv6_addr_type(addr) & 0xffff;
 312 }
 313
 314 static inline int ipv6_addr_scope(const struct in6_addr *addr)
 315 {
 316         return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
 317 }
 318
 319 static inline int __ipv6_addr_src_scope(int type)
 320 {
 321         return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
 322 }
 323
 324 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
 325 {
 326         return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
 327 }
 328
 329 static inline bool __ipv6_addr_needs_scope_id(int type)
 330 {
 331         return type & IPV6_ADDR_LINKLOCAL ||
 332                (type & IPV6_ADDR_MULTICAST &&
 333                 (type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
 334 }
 335
 336 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
 337 {
 338         return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
 339 }
 340
 341 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
 342 {
 343         return memcmp(a1, a2, sizeof(struct in6_addr));
 344 }
 345
 346 static inline bool
 347 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
 348                      const struct in6_addr *a2)
 349 {
 350 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 351         const unsigned long *ul1 = (const unsigned long *)a1;
 352         const unsigned long *ulm = (const unsigned long *)m;
 353         const unsigned long *ul2 = (const unsigned long *)a2;
 354
 355         return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
 356                   ((ul1[1] ^ ul2[1]) & ulm[1]));
 357 #else
 358         return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
 359                   ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
 360                   ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
 361                   ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
 362 #endif
 363 }
 364
 365 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
 366                                     const struct in6_addr *addr,
 367                                     int plen)
 368 {
 369         /* caller must guarantee 0 <= plen <= 128 */
 370         int o = plen >> 3,
 371             b = plen & 0x7;
 372
 373         memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
 374         memcpy(pfx->s6_addr, addr, o);
 375         if (b != 0)
 376                 pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
 377 }
 378
 379 static inline void __ipv6_addr_set_half(__be32 *addr,
 380                                         __be32 wh, __be32 wl)
 381 {
 382 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 383 #if defined(__BIG_ENDIAN)
 384         if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
 385                 *(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
 386                 return;
 387         }
 388 #elif defined(__LITTLE_ENDIAN)
 389         if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
 390                 *(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
 391                 return;
 392         }
 393 #endif
 394 #endif
 395         addr[0] = wh;
 396         addr[1] = wl;
 397 }
 398
 399 static inline void ipv6_addr_set(struct in6_addr *addr,
 400                                      __be32 w1, __be32 w2,
 401                                      __be32 w3, __be32 w4)
 402 {
 403         __ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
 404         __ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
 405 }
 406
 407 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
 408                                    const struct in6_addr *a2)
 409 {
 410 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 411         const unsigned long *ul1 = (const unsigned long *)a1;
 412         const unsigned long *ul2 = (const unsigned long *)a2;
 413
 414         return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
 415 #else
 416         return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
 417                 (a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
 418                 (a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
 419                 (a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
 420 #endif
 421 }
 422
 423 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 424 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
 425                                               const __be64 *a2,
 426                                               unsigned int len)
 427 {
 428         if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
 429                 return false;
 430         return true;
 431 }
 432
 433 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 434                                      const struct in6_addr *addr2,
 435                                      unsigned int prefixlen)
 436 {
 437         const __be64 *a1 = (const __be64 *)addr1;
 438         const __be64 *a2 = (const __be64 *)addr2;
 439
 440         if (prefixlen >= 64) {
 441                 if (a1[0] ^ a2[0])
 442                         return false;
 443                 return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
 444         }
 445         return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
 446 }
 447 #else
 448 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 449                                      const struct in6_addr *addr2,
 450                                      unsigned int prefixlen)
 451 {
 452         const __be32 *a1 = addr1->s6_addr32;
 453         const __be32 *a2 = addr2->s6_addr32;
 454         unsigned int pdw, pbi;
 455
 456         /* check complete u32 in prefix */
 457         pdw = prefixlen >> 5;
 458         if (pdw && memcmp(a1, a2, pdw << 2))
 459                 return false;
 460
 461         /* check incomplete u32 in prefix */
 462         pbi = prefixlen & 0x1f;
 463         if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
 464                 return false;
 465
 466         return true;
 467 }
 468 #endif
 469
 470 struct inet_frag_queue;
 471
 472 enum ip6_defrag_users {
 473         IP6_DEFRAG_LOCAL_DELIVER,
 474         IP6_DEFRAG_CONNTRACK_IN,
 475         __IP6_DEFRAG_CONNTRACK_IN       = IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 476         IP6_DEFRAG_CONNTRACK_OUT,
 477         __IP6_DEFRAG_CONNTRACK_OUT      = IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 478         IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
 479         __IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 480 };
 481
 482 struct ip6_create_arg {
 483         __be32 id;
 484         u32 user;
 485         const struct in6_addr *src;
 486         const struct in6_addr *dst;
 487         u8 ecn;
 488 };
 489
 490 void ip6_frag_init(struct inet_frag_queue *q, void *a);
 491 bool ip6_frag_match(struct inet_frag_queue *q, void *a);
 492
 493 /*
 494  *      Equivalent of ipv4 struct ip
 495  */
 496 struct frag_queue {
 497         struct inet_frag_queue  q;
 498
 499         __be32                  id;             /* fragment id          */
 500         u32                     user;
 501         struct in6_addr         saddr;
 502         struct in6_addr         daddr;
 503
 504         int                     iif;
 505         unsigned int            csum;
 506         __u16                   nhoffset;
 507         u8                      ecn;
 508 };
 509
 510 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
 511                            struct inet_frags *frags);
 512
 513 static inline bool ipv6_addr_any(const struct in6_addr *a)
 514 {
 515 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 516         const unsigned long *ul = (const unsigned long *)a;
 517
 518         return (ul[0] | ul[1]) == 0UL;
 519 #else
 520         return (a->s6_addr32[0] | a->s6_addr32[1] |
 521                 a->s6_addr32[2] | a->s6_addr32[3]) == 0;
 522 #endif
 523 }
 524
 525 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
 526 {
 527 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 528         const unsigned long *ul = (const unsigned long *)a;
 529         unsigned long x = ul[0] ^ ul[1];
 530
 531         return (u32)(x ^ (x >> 32));
 532 #else
 533         return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
 534                              a->s6_addr32[2] ^ a->s6_addr32[3]);
 535 #endif
 536 }
 537
 538 /* more secured version of ipv6_addr_hash() */
 539 static inline u32 ipv6_addr_jhash(const struct in6_addr *a)
 540 {
 541         u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
 542
 543         return jhash_3words(v,
 544                             (__force u32)a->s6_addr32[2],
 545                             (__force u32)a->s6_addr32[3],
 546                             ipv6_hash_secret);
 547 }
 548
 549 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
 550 {
 551 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 552         const unsigned long *ul = (const unsigned long *)a;
 553
 554         return (ul[0] | (ul[1] ^ cpu_to_be64(1))) == 0UL;
 555 #else
 556         return (a->s6_addr32[0] | a->s6_addr32[1] |
 557                 a->s6_addr32[2] | (a->s6_addr32[3] ^ htonl(1))) == 0;
 558 #endif
 559 }
 560
 561 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
 562 {
 563         return (
 564 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 565                 *(__be64 *)a |
 566 #else
 567                 (a->s6_addr32[0] | a->s6_addr32[1]) |
 568 #endif
 569                 (a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0UL;
 570 }
 571
 572 /*
 573  * Check for a RFC 4843 ORCHID address
 574  * (Overlay Routable Cryptographic Hash Identifiers)
 575  */
 576 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
 577 {
 578         return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
 579 }
 580
 581 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
 582                                           struct in6_addr *v4mapped)
 583 {
 584         ipv6_addr_set(v4mapped,
 585                         0, 0,
 586                         htonl(0x0000FFFF),
 587                         addr);
 588 }
 589
 590 /*
 591  * find the first different bit between two addresses
 592  * length of address must be a multiple of 32bits
 593  */
 594 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
 595 {
 596         const __be32 *a1 = token1, *a2 = token2;
 597         int i;
 598
 599         addrlen >>= 2;
 600
 601         for (i = 0; i < addrlen; i++) {
 602                 __be32 xb = a1[i] ^ a2[i];
 603                 if (xb)
 604                         return i * 32 + 31 - __fls(ntohl(xb));
 605         }
 606
 607         /*
 608          *      we should *never* get to this point since that
 609          *      would mean the addrs are equal
 610          *
 611          *      However, we do get to it 8) And exacly, when
 612          *      addresses are equal 8)
 613          *
 614          *      ip route add 1111::/128 via ...
 615          *      ip route add 1111::/64 via ...
 616          *      and we are here.
 617          *
 618          *      Ideally, this function should stop comparison
 619          *      at prefix length. It does not, but it is still OK,
 620          *      if returned value is greater than prefix length.
 621          *                                      --ANK (980803)
 622          */
 623         return addrlen << 5;
 624 }
 625
 626 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 627 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
 628 {
 629         const __be64 *a1 = token1, *a2 = token2;
 630         int i;
 631
 632         addrlen >>= 3;
 633
 634         for (i = 0; i < addrlen; i++) {
 635                 __be64 xb = a1[i] ^ a2[i];
 636                 if (xb)
 637                         return i * 64 + 63 - __fls(be64_to_cpu(xb));
 638         }
 639
 640         return addrlen << 6;
 641 }
 642 #endif
 643
 644 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
 645 {
 646 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 647         if (__builtin_constant_p(addrlen) && !(addrlen & 7))
 648                 return __ipv6_addr_diff64(token1, token2, addrlen);
 649 #endif
 650         return __ipv6_addr_diff32(token1, token2, addrlen);
 651 }
 652
 653 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
 654 {
 655         return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
 656 }
 657
 658 extern void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt);
 659
 660 /*
 661  *      Header manipulation
 662  */
 663 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
 664                                 __be32 flowlabel)
 665 {
 666         *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
 667 }
 668
 669 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
 670 {
 671         return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
 672 }
 673
 674 /*
 675  *      Prototypes exported by ipv6
 676  */
 677
 678 /*
 679  *      rcv function (called from netdevice level)
 680  */
 681
 682 extern int                      ipv6_rcv(struct sk_buff *skb,
 683                                          struct net_device *dev,
 684                                          struct packet_type *pt,
 685                                          struct net_device *orig_dev);
 686
 687 extern int                      ip6_rcv_finish(struct sk_buff *skb);
 688
 689 /*
 690  *      upper-layer output functions
 691  */
 692 extern int                      ip6_xmit(struct sock *sk,
 693                                          struct sk_buff *skb,
 694                                          struct flowi6 *fl6,
 695                                          struct ipv6_txoptions *opt,
 696                                          int tclass);
 697
 698 extern int                      ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
 699
 700 extern int                      ip6_append_data(struct sock *sk,
 701                                                 int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb),
 702                                                 void *from,
 703                                                 int length,
 704                                                 int transhdrlen,
 705                                                 int hlimit,
 706                                                 int tclass,
 707                                                 struct ipv6_txoptions *opt,
 708                                                 struct flowi6 *fl6,
 709                                                 struct rt6_info *rt,
 710                                                 unsigned int flags,
 711                                                 int dontfrag);
 712
 713 extern int                      ip6_push_pending_frames(struct sock *sk);
 714
 715 extern void                     ip6_flush_pending_frames(struct sock *sk);
 716
 717 extern int                      ip6_dst_lookup(struct sock *sk,
 718                                                struct dst_entry **dst,
 719                                                struct flowi6 *fl6);
 720 extern struct dst_entry *       ip6_dst_lookup_flow(struct sock *sk,
 721                                                     struct flowi6 *fl6,
 722                                                     const struct in6_addr *final_dst,
 723                                                     bool can_sleep);
 724 extern struct dst_entry *       ip6_sk_dst_lookup_flow(struct sock *sk,
 725                                                        struct flowi6 *fl6,
 726                                                        const struct in6_addr *final_dst,
 727                                                        bool can_sleep);
 728 extern struct dst_entry *       ip6_blackhole_route(struct net *net,
 729                                                     struct dst_entry *orig_dst);
 730
 731 /*
 732  *      skb processing functions
 733  */
 734
 735 extern int                      ip6_output(struct sk_buff *skb);
 736 extern int                      ip6_forward(struct sk_buff *skb);
 737 extern int                      ip6_input(struct sk_buff *skb);
 738 extern int                      ip6_mc_input(struct sk_buff *skb);
 739
 740 extern int                      __ip6_local_out(struct sk_buff *skb);
 741 extern int                      ip6_local_out(struct sk_buff *skb);
 742
 743 /*
 744  *      Extension header (options) processing
 745  */
 746
 747 extern void                     ipv6_push_nfrag_opts(struct sk_buff *skb,
 748                                                      struct ipv6_txoptions *opt,
 749                                                      u8 *proto,
 750                                                      struct in6_addr **daddr_p);
 751 extern void                     ipv6_push_frag_opts(struct sk_buff *skb,
 752                                                     struct ipv6_txoptions *opt,
 753                                                     u8 *proto);
 754
 755 extern int                      ipv6_skip_exthdr(const struct sk_buff *, int start,
 756                                                  u8 *nexthdrp, __be16 *frag_offp);
 757
 758 extern bool                     ipv6_ext_hdr(u8 nexthdr);
 759
 760 enum {
 761         IP6_FH_F_FRAG           = (1 << 0),
 762         IP6_FH_F_AUTH           = (1 << 1),
 763         IP6_FH_F_SKIP_RH        = (1 << 2),
 764 };
 765
 766 /* find specified header and get offset to it */
 767 extern int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 768                          int target, unsigned short *fragoff, int *fragflg);
 769
 770 extern int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
 771
 772 extern struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
 773                                        const struct ipv6_txoptions *opt,
 774                                        struct in6_addr *orig);
 775
 776 /*
 777  *      socket options (ipv6_sockglue.c)
 778  */
 779
 780 extern int                      ipv6_setsockopt(struct sock *sk, int level,
 781                                                 int optname,
 782                                                 char __user *optval,
 783                                                 unsigned int optlen);
 784 extern int                      ipv6_getsockopt(struct sock *sk, int level,
 785                                                 int optname,
 786                                                 char __user *optval,
 787                                                 int __user *optlen);
 788 extern int                      compat_ipv6_setsockopt(struct sock *sk,
 789                                                 int level,
 790                                                 int optname,
 791                                                 char __user *optval,
 792                                                 unsigned int optlen);
 793 extern int                      compat_ipv6_getsockopt(struct sock *sk,
 794                                                 int level,
 795                                                 int optname,
 796                                                 char __user *optval,
 797                                                 int __user *optlen);
 798
 799 extern int                      ip6_datagram_connect(struct sock *sk,
 800                                                      struct sockaddr *addr, int addr_len);
 801
 802 extern int                      ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len);
 803 extern int                      ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len);
 804 extern void                     ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 805                                                 u32 info, u8 *payload);
 806 extern void                     ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
 807 extern void                     ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
 808
 809 extern int inet6_release(struct socket *sock);
 810 extern int inet6_bind(struct socket *sock, struct sockaddr *uaddr,
 811                       int addr_len);
 812 extern int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
 813                          int *uaddr_len, int peer);
 814 extern int inet6_ioctl(struct socket *sock, unsigned int cmd,
 815                        unsigned long arg);
 816
 817 extern int inet6_hash_connect(struct inet_timewait_death_row *death_row,
 818                               struct sock *sk);
 819
 820 /*
 821  * reassembly.c
 822  */
 823 extern const struct proto_ops inet6_stream_ops;
 824 extern const struct proto_ops inet6_dgram_ops;
 825
 826 struct group_source_req;
 827 struct group_filter;
 828
 829 extern int ip6_mc_source(int add, int omode, struct sock *sk,
 830                          struct group_source_req *pgsr);
 831 extern int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
 832 extern int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
 833                          struct group_filter __user *optval,
 834                          int __user *optlen);
 835 extern unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
 836                                     const struct in6_addr *daddr, u32 rnd);
 837
 838 #ifdef CONFIG_PROC_FS
 839 extern int  ac6_proc_init(struct net *net);
 840 extern void ac6_proc_exit(struct net *net);
 841 extern int  raw6_proc_init(void);
 842 extern void raw6_proc_exit(void);
 843 extern int  tcp6_proc_init(struct net *net);
 844 extern void tcp6_proc_exit(struct net *net);
 845 extern int  udp6_proc_init(struct net *net);
 846 extern void udp6_proc_exit(struct net *net);
 847 extern int  udplite6_proc_init(void);
 848 extern void udplite6_proc_exit(void);
 849 extern int  ipv6_misc_proc_init(void);
 850 extern void ipv6_misc_proc_exit(void);
 851 extern int snmp6_register_dev(struct inet6_dev *idev);
 852 extern int snmp6_unregister_dev(struct inet6_dev *idev);
 853
 854 #else
 855 static inline int ac6_proc_init(struct net *net) { return 0; }
 856 static inline void ac6_proc_exit(struct net *net) { }
 857 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
 858 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
 859 #endif
 860
 861 #ifdef CONFIG_SYSCTL
 862 extern struct ctl_table ipv6_route_table_template[];
 863 extern struct ctl_table ipv6_icmp_table_template[];
 864
 865 extern struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
 866 extern struct ctl_table *ipv6_route_sysctl_init(struct net *net);
 867 extern int ipv6_sysctl_register(void);
 868 extern void ipv6_sysctl_unregister(void);
 869 #endif
 870
 871 #endif /* _NET_IPV6_H */