linux/include/net/ipv6.h
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   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
 105struct 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 */
 117extern 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
 187struct ip6_ra_chain {
 188        struct ip6_ra_chain     *next;
 189        struct sock             *sk;
 190        int                     sel;
 191        void                    (*destructor)(struct sock *);
 192};
 193
 194extern struct ip6_ra_chain      *ip6_ra_chain;
 195extern 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
 202struct 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
 219struct 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
 240struct ipv6_fl_socklist {
 241        struct ipv6_fl_socklist __rcu   *next;
 242        struct ip6_flowlabel            *fl;
 243        struct rcu_head                 rcu;
 244};
 245
 246extern struct ip6_flowlabel     *fl6_sock_lookup(struct sock *sk, __be32 label);
 247extern struct ipv6_txoptions    *fl6_merge_options(struct ipv6_txoptions * opt_space,
 248                                                   struct ip6_flowlabel * fl,
 249                                                   struct ipv6_txoptions * fopt);
 250extern void                     fl6_free_socklist(struct sock *sk);
 251extern int                      ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
 252extern int                      ip6_flowlabel_init(void);
 253extern void                     ip6_flowlabel_cleanup(void);
 254
 255static inline void fl6_sock_release(struct ip6_flowlabel *fl)
 256{
 257        if (fl)
 258                atomic_dec(&fl->users);
 259}
 260
 261extern void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
 262
 263extern int                      ip6_ra_control(struct sock *sk, int sel);
 264
 265extern int                      ipv6_parse_hopopts(struct sk_buff *skb);
 266
 267extern struct ipv6_txoptions *  ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt);
 268extern struct ipv6_txoptions *  ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
 269                                                   int newtype,
 270                                                   struct ipv6_opt_hdr __user *newopt,
 271                                                   int newoptlen);
 272struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
 273                                          struct ipv6_txoptions *opt);
 274
 275extern bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb);
 276
 277static inline bool ipv6_accept_ra(struct inet6_dev *idev)
 278{
 279        /* If forwarding is enabled, RA are not accepted unless the special
 280         * hybrid mode (accept_ra=2) is enabled.
 281         */
 282        return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
 283            idev->cnf.accept_ra;
 284}
 285
 286#if IS_ENABLED(CONFIG_IPV6)
 287static inline int ip6_frag_nqueues(struct net *net)
 288{
 289        return net->ipv6.frags.nqueues;
 290}
 291
 292static inline int ip6_frag_mem(struct net *net)
 293{
 294        return sum_frag_mem_limit(&net->ipv6.frags);
 295}
 296#endif
 297
 298#define IPV6_FRAG_HIGH_THRESH   (4 * 1024*1024) /* 4194304 */
 299#define IPV6_FRAG_LOW_THRESH    (3 * 1024*1024) /* 3145728 */
 300#define IPV6_FRAG_TIMEOUT       (60 * HZ)       /* 60 seconds */
 301
 302extern int __ipv6_addr_type(const struct in6_addr *addr);
 303static inline int ipv6_addr_type(const struct in6_addr *addr)
 304{
 305        return __ipv6_addr_type(addr) & 0xffff;
 306}
 307
 308static inline int ipv6_addr_scope(const struct in6_addr *addr)
 309{
 310        return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
 311}
 312
 313static inline int __ipv6_addr_src_scope(int type)
 314{
 315        return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
 316}
 317
 318static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
 319{
 320        return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
 321}
 322
 323static inline bool __ipv6_addr_needs_scope_id(int type)
 324{
 325        return type & IPV6_ADDR_LINKLOCAL ||
 326               (type & IPV6_ADDR_MULTICAST &&
 327                (type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
 328}
 329
 330static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
 331{
 332        return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
 333}
 334
 335static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
 336{
 337        return memcmp(a1, a2, sizeof(struct in6_addr));
 338}
 339
 340static inline bool
 341ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
 342                     const struct in6_addr *a2)
 343{
 344#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 345        const unsigned long *ul1 = (const unsigned long *)a1;
 346        const unsigned long *ulm = (const unsigned long *)m;
 347        const unsigned long *ul2 = (const unsigned long *)a2;
 348
 349        return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
 350                  ((ul1[1] ^ ul2[1]) & ulm[1]));
 351#else
 352        return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
 353                  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
 354                  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
 355                  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
 356#endif
 357}
 358
 359static inline void ipv6_addr_prefix(struct in6_addr *pfx, 
 360                                    const struct in6_addr *addr,
 361                                    int plen)
 362{
 363        /* caller must guarantee 0 <= plen <= 128 */
 364        int o = plen >> 3,
 365            b = plen & 0x7;
 366
 367        memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
 368        memcpy(pfx->s6_addr, addr, o);
 369        if (b != 0)
 370                pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
 371}
 372
 373static inline void __ipv6_addr_set_half(__be32 *addr,
 374                                        __be32 wh, __be32 wl)
 375{
 376#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 377#if defined(__BIG_ENDIAN)
 378        if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
 379                *(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
 380                return;
 381        }
 382#elif defined(__LITTLE_ENDIAN)
 383        if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
 384                *(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
 385                return;
 386        }
 387#endif
 388#endif
 389        addr[0] = wh;
 390        addr[1] = wl;
 391}
 392
 393static inline void ipv6_addr_set(struct in6_addr *addr, 
 394                                     __be32 w1, __be32 w2,
 395                                     __be32 w3, __be32 w4)
 396{
 397        __ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
 398        __ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
 399}
 400
 401static inline bool ipv6_addr_equal(const struct in6_addr *a1,
 402                                   const struct in6_addr *a2)
 403{
 404#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 405        const unsigned long *ul1 = (const unsigned long *)a1;
 406        const unsigned long *ul2 = (const unsigned long *)a2;
 407
 408        return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
 409#else
 410        return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
 411                (a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
 412                (a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
 413                (a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
 414#endif
 415}
 416
 417#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 418static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
 419                                              const __be64 *a2,
 420                                              unsigned int len)
 421{
 422        if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
 423                return false;
 424        return true;
 425}
 426
 427static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 428                                     const struct in6_addr *addr2,
 429                                     unsigned int prefixlen)
 430{
 431        const __be64 *a1 = (const __be64 *)addr1;
 432        const __be64 *a2 = (const __be64 *)addr2;
 433
 434        if (prefixlen >= 64) {
 435                if (a1[0] ^ a2[0])
 436                        return false;
 437                return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
 438        }
 439        return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
 440}
 441#else
 442static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 443                                     const struct in6_addr *addr2,
 444                                     unsigned int prefixlen)
 445{
 446        const __be32 *a1 = addr1->s6_addr32;
 447        const __be32 *a2 = addr2->s6_addr32;
 448        unsigned int pdw, pbi;
 449
 450        /* check complete u32 in prefix */
 451        pdw = prefixlen >> 5;
 452        if (pdw && memcmp(a1, a2, pdw << 2))
 453                return false;
 454
 455        /* check incomplete u32 in prefix */
 456        pbi = prefixlen & 0x1f;
 457        if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
 458                return false;
 459
 460        return true;
 461}
 462#endif
 463
 464struct inet_frag_queue;
 465
 466enum ip6_defrag_users {
 467        IP6_DEFRAG_LOCAL_DELIVER,
 468        IP6_DEFRAG_CONNTRACK_IN,
 469        __IP6_DEFRAG_CONNTRACK_IN       = IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 470        IP6_DEFRAG_CONNTRACK_OUT,
 471        __IP6_DEFRAG_CONNTRACK_OUT      = IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 472        IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
 473        __IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 474};
 475
 476struct ip6_create_arg {
 477        __be32 id;
 478        u32 user;
 479        const struct in6_addr *src;
 480        const struct in6_addr *dst;
 481        u8 ecn;
 482};
 483
 484void ip6_frag_init(struct inet_frag_queue *q, void *a);
 485bool ip6_frag_match(struct inet_frag_queue *q, void *a);
 486
 487/*
 488 *      Equivalent of ipv4 struct ip
 489 */
 490struct frag_queue {
 491        struct inet_frag_queue  q;
 492
 493        __be32                  id;             /* fragment id          */
 494        u32                     user;
 495        struct in6_addr         saddr;
 496        struct in6_addr         daddr;
 497
 498        int                     iif;
 499        unsigned int            csum;
 500        __u16                   nhoffset;
 501        u8                      ecn;
 502};
 503
 504void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
 505                           struct inet_frags *frags);
 506
 507static inline bool ipv6_addr_any(const struct in6_addr *a)
 508{
 509#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 510        const unsigned long *ul = (const unsigned long *)a;
 511
 512        return (ul[0] | ul[1]) == 0UL;
 513#else
 514        return (a->s6_addr32[0] | a->s6_addr32[1] |
 515                a->s6_addr32[2] | a->s6_addr32[3]) == 0;
 516#endif
 517}
 518
 519static inline u32 ipv6_addr_hash(const struct in6_addr *a)
 520{
 521#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 522        const unsigned long *ul = (const unsigned long *)a;
 523        unsigned long x = ul[0] ^ ul[1];
 524
 525        return (u32)(x ^ (x >> 32));
 526#else
 527        return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
 528                             a->s6_addr32[2] ^ a->s6_addr32[3]);
 529#endif
 530}
 531
 532/* more secured version of ipv6_addr_hash() */
 533static inline u32 ipv6_addr_jhash(const struct in6_addr *a)
 534{
 535        u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
 536
 537        return jhash_3words(v,
 538                            (__force u32)a->s6_addr32[2],
 539                            (__force u32)a->s6_addr32[3],
 540                            ipv6_hash_secret);
 541}
 542
 543static inline bool ipv6_addr_loopback(const struct in6_addr *a)
 544{
 545#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 546        const unsigned long *ul = (const unsigned long *)a;
 547
 548        return (ul[0] | (ul[1] ^ cpu_to_be64(1))) == 0UL;
 549#else
 550        return (a->s6_addr32[0] | a->s6_addr32[1] |
 551                a->s6_addr32[2] | (a->s6_addr32[3] ^ htonl(1))) == 0;
 552#endif
 553}
 554
 555static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
 556{
 557        return (
 558#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 559                *(__be64 *)a |
 560#else
 561                (a->s6_addr32[0] | a->s6_addr32[1]) |
 562#endif
 563                (a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0UL;
 564}
 565
 566/*
 567 * Check for a RFC 4843 ORCHID address
 568 * (Overlay Routable Cryptographic Hash Identifiers)
 569 */
 570static inline bool ipv6_addr_orchid(const struct in6_addr *a)
 571{
 572        return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
 573}
 574
 575static inline void ipv6_addr_set_v4mapped(const __be32 addr,
 576                                          struct in6_addr *v4mapped)
 577{
 578        ipv6_addr_set(v4mapped,
 579                        0, 0,
 580                        htonl(0x0000FFFF),
 581                        addr);
 582}
 583
 584/*
 585 * find the first different bit between two addresses
 586 * length of address must be a multiple of 32bits
 587 */
 588static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
 589{
 590        const __be32 *a1 = token1, *a2 = token2;
 591        int i;
 592
 593        addrlen >>= 2;
 594
 595        for (i = 0; i < addrlen; i++) {
 596                __be32 xb = a1[i] ^ a2[i];
 597                if (xb)
 598                        return i * 32 + 31 - __fls(ntohl(xb));
 599        }
 600
 601        /*
 602         *      we should *never* get to this point since that 
 603         *      would mean the addrs are equal
 604         *
 605         *      However, we do get to it 8) And exacly, when
 606         *      addresses are equal 8)
 607         *
 608         *      ip route add 1111::/128 via ...
 609         *      ip route add 1111::/64 via ...
 610         *      and we are here.
 611         *
 612         *      Ideally, this function should stop comparison
 613         *      at prefix length. It does not, but it is still OK,
 614         *      if returned value is greater than prefix length.
 615         *                                      --ANK (980803)
 616         */
 617        return addrlen << 5;
 618}
 619
 620#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 621static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
 622{
 623        const __be64 *a1 = token1, *a2 = token2;
 624        int i;
 625
 626        addrlen >>= 3;
 627
 628        for (i = 0; i < addrlen; i++) {
 629                __be64 xb = a1[i] ^ a2[i];
 630                if (xb)
 631                        return i * 64 + 63 - __fls(be64_to_cpu(xb));
 632        }
 633
 634        return addrlen << 6;
 635}
 636#endif
 637
 638static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
 639{
 640#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 641        if (__builtin_constant_p(addrlen) && !(addrlen & 7))
 642                return __ipv6_addr_diff64(token1, token2, addrlen);
 643#endif
 644        return __ipv6_addr_diff32(token1, token2, addrlen);
 645}
 646
 647static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
 648{
 649        return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
 650}
 651
 652extern void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt);
 653
 654/*
 655 *      Header manipulation
 656 */
 657static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
 658                                __be32 flowlabel)
 659{
 660        *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
 661}
 662
 663static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
 664{
 665        return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
 666}
 667
 668/*
 669 *      Prototypes exported by ipv6
 670 */
 671
 672/*
 673 *      rcv function (called from netdevice level)
 674 */
 675
 676extern int                      ipv6_rcv(struct sk_buff *skb, 
 677                                         struct net_device *dev, 
 678                                         struct packet_type *pt,
 679                                         struct net_device *orig_dev);
 680
 681extern int                      ip6_rcv_finish(struct sk_buff *skb);
 682
 683/*
 684 *      upper-layer output functions
 685 */
 686extern int                      ip6_xmit(struct sock *sk,
 687                                         struct sk_buff *skb,
 688                                         struct flowi6 *fl6,
 689                                         struct ipv6_txoptions *opt,
 690                                         int tclass);
 691
 692extern int                      ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
 693
 694extern int                      ip6_append_data(struct sock *sk,
 695                                                int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb),
 696                                                void *from,
 697                                                int length,
 698                                                int transhdrlen,
 699                                                int hlimit,
 700                                                int tclass,
 701                                                struct ipv6_txoptions *opt,
 702                                                struct flowi6 *fl6,
 703                                                struct rt6_info *rt,
 704                                                unsigned int flags,
 705                                                int dontfrag);
 706
 707extern int                      ip6_push_pending_frames(struct sock *sk);
 708
 709extern void                     ip6_flush_pending_frames(struct sock *sk);
 710
 711extern int                      ip6_dst_lookup(struct sock *sk,
 712                                               struct dst_entry **dst,
 713                                               struct flowi6 *fl6);
 714extern struct dst_entry *       ip6_dst_lookup_flow(struct sock *sk,
 715                                                    struct flowi6 *fl6,
 716                                                    const struct in6_addr *final_dst,
 717                                                    bool can_sleep);
 718extern struct dst_entry *       ip6_sk_dst_lookup_flow(struct sock *sk,
 719                                                       struct flowi6 *fl6,
 720                                                       const struct in6_addr *final_dst,
 721                                                       bool can_sleep);
 722extern struct dst_entry *       ip6_blackhole_route(struct net *net,
 723                                                    struct dst_entry *orig_dst);
 724
 725/*
 726 *      skb processing functions
 727 */
 728
 729extern int                      ip6_output(struct sk_buff *skb);
 730extern int                      ip6_forward(struct sk_buff *skb);
 731extern int                      ip6_input(struct sk_buff *skb);
 732extern int                      ip6_mc_input(struct sk_buff *skb);
 733
 734extern int                      __ip6_local_out(struct sk_buff *skb);
 735extern int                      ip6_local_out(struct sk_buff *skb);
 736
 737/*
 738 *      Extension header (options) processing
 739 */
 740
 741extern void                     ipv6_push_nfrag_opts(struct sk_buff *skb,
 742                                                     struct ipv6_txoptions *opt,
 743                                                     u8 *proto,
 744                                                     struct in6_addr **daddr_p);
 745extern void                     ipv6_push_frag_opts(struct sk_buff *skb,
 746                                                    struct ipv6_txoptions *opt,
 747                                                    u8 *proto);
 748
 749extern int                      ipv6_skip_exthdr(const struct sk_buff *, int start,
 750                                                 u8 *nexthdrp, __be16 *frag_offp);
 751
 752extern bool                     ipv6_ext_hdr(u8 nexthdr);
 753
 754enum {
 755        IP6_FH_F_FRAG           = (1 << 0),
 756        IP6_FH_F_AUTH           = (1 << 1),
 757        IP6_FH_F_SKIP_RH        = (1 << 2),
 758};
 759
 760/* find specified header and get offset to it */
 761extern int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
 762                         int target, unsigned short *fragoff, int *fragflg);
 763
 764extern int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
 765
 766extern struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
 767                                       const struct ipv6_txoptions *opt,
 768                                       struct in6_addr *orig);
 769
 770/*
 771 *      socket options (ipv6_sockglue.c)
 772 */
 773
 774extern int                      ipv6_setsockopt(struct sock *sk, int level, 
 775                                                int optname,
 776                                                char __user *optval, 
 777                                                unsigned int optlen);
 778extern int                      ipv6_getsockopt(struct sock *sk, int level, 
 779                                                int optname,
 780                                                char __user *optval, 
 781                                                int __user *optlen);
 782extern int                      compat_ipv6_setsockopt(struct sock *sk,
 783                                                int level,
 784                                                int optname,
 785                                                char __user *optval,
 786                                                unsigned int optlen);
 787extern int                      compat_ipv6_getsockopt(struct sock *sk,
 788                                                int level,
 789                                                int optname,
 790                                                char __user *optval,
 791                                                int __user *optlen);
 792
 793extern int                      ip6_datagram_connect(struct sock *sk, 
 794                                                     struct sockaddr *addr, int addr_len);
 795
 796extern int                      ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len);
 797extern int                      ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len);
 798extern void                     ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 799                                                u32 info, u8 *payload);
 800extern void                     ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
 801extern void                     ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
 802
 803extern int inet6_release(struct socket *sock);
 804extern int inet6_bind(struct socket *sock, struct sockaddr *uaddr, 
 805                      int addr_len);
 806extern int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
 807                         int *uaddr_len, int peer);
 808extern int inet6_ioctl(struct socket *sock, unsigned int cmd, 
 809                       unsigned long arg);
 810
 811extern int inet6_hash_connect(struct inet_timewait_death_row *death_row,
 812                              struct sock *sk);
 813
 814/*
 815 * reassembly.c
 816 */
 817extern const struct proto_ops inet6_stream_ops;
 818extern const struct proto_ops inet6_dgram_ops;
 819
 820struct group_source_req;
 821struct group_filter;
 822
 823extern int ip6_mc_source(int add, int omode, struct sock *sk,
 824                         struct group_source_req *pgsr);
 825extern int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
 826extern int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
 827                         struct group_filter __user *optval,
 828                         int __user *optlen);
 829extern unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
 830                                    const struct in6_addr *daddr, u32 rnd);
 831
 832#ifdef CONFIG_PROC_FS
 833extern int  ac6_proc_init(struct net *net);
 834extern void ac6_proc_exit(struct net *net);
 835extern int  raw6_proc_init(void);
 836extern void raw6_proc_exit(void);
 837extern int  tcp6_proc_init(struct net *net);
 838extern void tcp6_proc_exit(struct net *net);
 839extern int  udp6_proc_init(struct net *net);
 840extern void udp6_proc_exit(struct net *net);
 841extern int  udplite6_proc_init(void);
 842extern void udplite6_proc_exit(void);
 843extern int  ipv6_misc_proc_init(void);
 844extern void ipv6_misc_proc_exit(void);
 845extern int snmp6_register_dev(struct inet6_dev *idev);
 846extern int snmp6_unregister_dev(struct inet6_dev *idev);
 847
 848#else
 849static inline int ac6_proc_init(struct net *net) { return 0; }
 850static inline void ac6_proc_exit(struct net *net) { }
 851static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
 852static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
 853#endif
 854
 855#ifdef CONFIG_SYSCTL
 856extern ctl_table ipv6_route_table_template[];
 857extern ctl_table ipv6_icmp_table_template[];
 858
 859extern struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
 860extern struct ctl_table *ipv6_route_sysctl_init(struct net *net);
 861extern int ipv6_sysctl_register(void);
 862extern void ipv6_sysctl_unregister(void);
 863#endif
 864
 865#endif /* _NET_IPV6_H */
 866