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/flow_keys.h>
  23#include <net/snmp.h>
  24
  25#define SIN6_LEN_RFC2133        24
  26
  27#define IPV6_MAXPLEN            65535
  28
  29/*
  30 *      NextHeader field of IPv6 header
  31 */
  32
  33#define NEXTHDR_HOP             0       /* Hop-by-hop option header. */
  34#define NEXTHDR_TCP             6       /* TCP segment. */
  35#define NEXTHDR_UDP             17      /* UDP message. */
  36#define NEXTHDR_IPV6            41      /* IPv6 in IPv6 */
  37#define NEXTHDR_ROUTING         43      /* Routing header. */
  38#define NEXTHDR_FRAGMENT        44      /* Fragmentation/reassembly header. */
  39#define NEXTHDR_GRE             47      /* GRE header. */
  40#define NEXTHDR_ESP             50      /* Encapsulating security payload. */
  41#define NEXTHDR_AUTH            51      /* Authentication header. */
  42#define NEXTHDR_ICMP            58      /* ICMP for IPv6. */
  43#define NEXTHDR_NONE            59      /* No next header */
  44#define NEXTHDR_DEST            60      /* Destination options header. */
  45#define NEXTHDR_SCTP            132     /* SCTP message. */
  46#define NEXTHDR_MOBILITY        135     /* Mobility header. */
  47
  48#define NEXTHDR_MAX             255
  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#define IP6_OFFSET      0xFFF8
 114
 115#define IP6_REPLY_MARK(net, mark) \
 116        ((net)->ipv6.sysctl.fwmark_reflect ? (mark) : 0)
 117
 118#include <net/sock.h>
 119
 120/* sysctls */
 121extern int sysctl_mld_max_msf;
 122extern int sysctl_mld_qrv;
 123
 124#define _DEVINC(net, statname, modifier, idev, field)                   \
 125({                                                                      \
 126        struct inet6_dev *_idev = (idev);                               \
 127        if (likely(_idev != NULL))                                      \
 128                SNMP_INC_STATS##modifier((_idev)->stats.statname, (field)); \
 129        SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
 130})
 131
 132/* per device counters are atomic_long_t */
 133#define _DEVINCATOMIC(net, statname, modifier, idev, field)             \
 134({                                                                      \
 135        struct inet6_dev *_idev = (idev);                               \
 136        if (likely(_idev != NULL))                                      \
 137                SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
 138        SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
 139})
 140
 141/* per device and per net counters are atomic_long_t */
 142#define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)               \
 143({                                                                      \
 144        struct inet6_dev *_idev = (idev);                               \
 145        if (likely(_idev != NULL))                                      \
 146                SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
 147        SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
 148})
 149
 150#define _DEVADD(net, statname, modifier, idev, field, val)              \
 151({                                                                      \
 152        struct inet6_dev *_idev = (idev);                               \
 153        if (likely(_idev != NULL))                                      \
 154                SNMP_ADD_STATS##modifier((_idev)->stats.statname, (field), (val)); \
 155        SNMP_ADD_STATS##modifier((net)->mib.statname##_statistics, (field), (val));\
 156})
 157
 158#define _DEVUPD(net, statname, modifier, idev, field, val)              \
 159({                                                                      \
 160        struct inet6_dev *_idev = (idev);                               \
 161        if (likely(_idev != NULL))                                      \
 162                SNMP_UPD_PO_STATS##modifier((_idev)->stats.statname, field, (val)); \
 163        SNMP_UPD_PO_STATS##modifier((net)->mib.statname##_statistics, field, (val));\
 164})
 165
 166/* MIBs */
 167
 168#define IP6_INC_STATS(net, idev,field)          \
 169                _DEVINC(net, ipv6, 64, idev, field)
 170#define IP6_INC_STATS_BH(net, idev,field)       \
 171                _DEVINC(net, ipv6, 64_BH, idev, field)
 172#define IP6_ADD_STATS(net, idev,field,val)      \
 173                _DEVADD(net, ipv6, 64, idev, field, val)
 174#define IP6_ADD_STATS_BH(net, idev,field,val)   \
 175                _DEVADD(net, ipv6, 64_BH, idev, field, val)
 176#define IP6_UPD_PO_STATS(net, idev,field,val)   \
 177                _DEVUPD(net, ipv6, 64, idev, field, val)
 178#define IP6_UPD_PO_STATS_BH(net, idev,field,val)   \
 179                _DEVUPD(net, ipv6, 64_BH, idev, field, val)
 180#define ICMP6_INC_STATS(net, idev, field)       \
 181                _DEVINCATOMIC(net, icmpv6, , idev, field)
 182#define ICMP6_INC_STATS_BH(net, idev, field)    \
 183                _DEVINCATOMIC(net, icmpv6, _BH, idev, field)
 184
 185#define ICMP6MSGOUT_INC_STATS(net, idev, field)         \
 186        _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
 187#define ICMP6MSGOUT_INC_STATS_BH(net, idev, field)      \
 188        _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
 189#define ICMP6MSGIN_INC_STATS_BH(net, idev, field)       \
 190        _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
 191
 192struct ip6_ra_chain {
 193        struct ip6_ra_chain     *next;
 194        struct sock             *sk;
 195        int                     sel;
 196        void                    (*destructor)(struct sock *);
 197};
 198
 199extern struct ip6_ra_chain      *ip6_ra_chain;
 200extern rwlock_t ip6_ra_lock;
 201
 202/*
 203   This structure is prepared by protocol, when parsing
 204   ancillary data and passed to IPv6.
 205 */
 206
 207struct ipv6_txoptions {
 208        /* Length of this structure */
 209        int                     tot_len;
 210
 211        /* length of extension headers   */
 212
 213        __u16                   opt_flen;       /* after fragment hdr */
 214        __u16                   opt_nflen;      /* before fragment hdr */
 215
 216        struct ipv6_opt_hdr     *hopopt;
 217        struct ipv6_opt_hdr     *dst0opt;
 218        struct ipv6_rt_hdr      *srcrt; /* Routing Header */
 219        struct ipv6_opt_hdr     *dst1opt;
 220
 221        /* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
 222};
 223
 224struct ip6_flowlabel {
 225        struct ip6_flowlabel __rcu *next;
 226        __be32                  label;
 227        atomic_t                users;
 228        struct in6_addr         dst;
 229        struct ipv6_txoptions   *opt;
 230        unsigned long           linger;
 231        struct rcu_head         rcu;
 232        u8                      share;
 233        union {
 234                struct pid *pid;
 235                kuid_t uid;
 236        } owner;
 237        unsigned long           lastuse;
 238        unsigned long           expires;
 239        struct net              *fl_net;
 240};
 241
 242#define IPV6_FLOWINFO_MASK      cpu_to_be32(0x0FFFFFFF)
 243#define IPV6_FLOWLABEL_MASK     cpu_to_be32(0x000FFFFF)
 244#define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
 245#define IPV6_TCLASS_SHIFT       20
 246
 247struct ipv6_fl_socklist {
 248        struct ipv6_fl_socklist __rcu   *next;
 249        struct ip6_flowlabel            *fl;
 250        struct rcu_head                 rcu;
 251};
 252
 253struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label);
 254struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 255                                         struct ip6_flowlabel *fl,
 256                                         struct ipv6_txoptions *fopt);
 257void fl6_free_socklist(struct sock *sk);
 258int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
 259int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
 260                           int flags);
 261int ip6_flowlabel_init(void);
 262void ip6_flowlabel_cleanup(void);
 263
 264static inline void fl6_sock_release(struct ip6_flowlabel *fl)
 265{
 266        if (fl)
 267                atomic_dec(&fl->users);
 268}
 269
 270void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
 271
 272int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 273                               struct icmp6hdr *thdr, int len);
 274
 275int ip6_ra_control(struct sock *sk, int sel);
 276
 277int ipv6_parse_hopopts(struct sk_buff *skb);
 278
 279struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
 280                                        struct ipv6_txoptions *opt);
 281struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
 282                                          struct ipv6_txoptions *opt,
 283                                          int newtype,
 284                                          struct ipv6_opt_hdr __user *newopt,
 285                                          int newoptlen);
 286struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
 287                                          struct ipv6_txoptions *opt);
 288
 289bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
 290                       const struct inet6_skb_parm *opt);
 291
 292static inline bool ipv6_accept_ra(struct inet6_dev *idev)
 293{
 294        /* If forwarding is enabled, RA are not accepted unless the special
 295         * hybrid mode (accept_ra=2) is enabled.
 296         */
 297        return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
 298            idev->cnf.accept_ra;
 299}
 300
 301#if IS_ENABLED(CONFIG_IPV6)
 302static inline int ip6_frag_mem(struct net *net)
 303{
 304        return sum_frag_mem_limit(&net->ipv6.frags);
 305}
 306#endif
 307
 308#define IPV6_FRAG_HIGH_THRESH   (4 * 1024*1024) /* 4194304 */
 309#define IPV6_FRAG_LOW_THRESH    (3 * 1024*1024) /* 3145728 */
 310#define IPV6_FRAG_TIMEOUT       (60 * HZ)       /* 60 seconds */
 311
 312int __ipv6_addr_type(const struct in6_addr *addr);
 313static inline int ipv6_addr_type(const struct in6_addr *addr)
 314{
 315        return __ipv6_addr_type(addr) & 0xffff;
 316}
 317
 318static inline int ipv6_addr_scope(const struct in6_addr *addr)
 319{
 320        return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
 321}
 322
 323static inline int __ipv6_addr_src_scope(int type)
 324{
 325        return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
 326}
 327
 328static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
 329{
 330        return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
 331}
 332
 333static inline bool __ipv6_addr_needs_scope_id(int type)
 334{
 335        return type & IPV6_ADDR_LINKLOCAL ||
 336               (type & IPV6_ADDR_MULTICAST &&
 337                (type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
 338}
 339
 340static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
 341{
 342        return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
 343}
 344
 345static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
 346{
 347        return memcmp(a1, a2, sizeof(struct in6_addr));
 348}
 349
 350static inline bool
 351ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
 352                     const struct in6_addr *a2)
 353{
 354#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 355        const unsigned long *ul1 = (const unsigned long *)a1;
 356        const unsigned long *ulm = (const unsigned long *)m;
 357        const unsigned long *ul2 = (const unsigned long *)a2;
 358
 359        return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
 360                  ((ul1[1] ^ ul2[1]) & ulm[1]));
 361#else
 362        return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
 363                  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
 364                  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
 365                  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
 366#endif
 367}
 368
 369static inline void ipv6_addr_prefix(struct in6_addr *pfx, 
 370                                    const struct in6_addr *addr,
 371                                    int plen)
 372{
 373        /* caller must guarantee 0 <= plen <= 128 */
 374        int o = plen >> 3,
 375            b = plen & 0x7;
 376
 377        memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
 378        memcpy(pfx->s6_addr, addr, o);
 379        if (b != 0)
 380                pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
 381}
 382
 383static inline void __ipv6_addr_set_half(__be32 *addr,
 384                                        __be32 wh, __be32 wl)
 385{
 386#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 387#if defined(__BIG_ENDIAN)
 388        if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
 389                *(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
 390                return;
 391        }
 392#elif defined(__LITTLE_ENDIAN)
 393        if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
 394                *(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
 395                return;
 396        }
 397#endif
 398#endif
 399        addr[0] = wh;
 400        addr[1] = wl;
 401}
 402
 403static inline void ipv6_addr_set(struct in6_addr *addr, 
 404                                     __be32 w1, __be32 w2,
 405                                     __be32 w3, __be32 w4)
 406{
 407        __ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
 408        __ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
 409}
 410
 411static inline bool ipv6_addr_equal(const struct in6_addr *a1,
 412                                   const struct in6_addr *a2)
 413{
 414#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 415        const unsigned long *ul1 = (const unsigned long *)a1;
 416        const unsigned long *ul2 = (const unsigned long *)a2;
 417
 418        return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
 419#else
 420        return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
 421                (a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
 422                (a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
 423                (a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
 424#endif
 425}
 426
 427#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 428static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
 429                                              const __be64 *a2,
 430                                              unsigned int len)
 431{
 432        if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
 433                return false;
 434        return true;
 435}
 436
 437static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 438                                     const struct in6_addr *addr2,
 439                                     unsigned int prefixlen)
 440{
 441        const __be64 *a1 = (const __be64 *)addr1;
 442        const __be64 *a2 = (const __be64 *)addr2;
 443
 444        if (prefixlen >= 64) {
 445                if (a1[0] ^ a2[0])
 446                        return false;
 447                return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
 448        }
 449        return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
 450}
 451#else
 452static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 453                                     const struct in6_addr *addr2,
 454                                     unsigned int prefixlen)
 455{
 456        const __be32 *a1 = addr1->s6_addr32;
 457        const __be32 *a2 = addr2->s6_addr32;
 458        unsigned int pdw, pbi;
 459
 460        /* check complete u32 in prefix */
 461        pdw = prefixlen >> 5;
 462        if (pdw && memcmp(a1, a2, pdw << 2))
 463                return false;
 464
 465        /* check incomplete u32 in prefix */
 466        pbi = prefixlen & 0x1f;
 467        if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
 468                return false;
 469
 470        return true;
 471}
 472#endif
 473
 474struct inet_frag_queue;
 475
 476enum ip6_defrag_users {
 477        IP6_DEFRAG_LOCAL_DELIVER,
 478        IP6_DEFRAG_CONNTRACK_IN,
 479        __IP6_DEFRAG_CONNTRACK_IN       = IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 480        IP6_DEFRAG_CONNTRACK_OUT,
 481        __IP6_DEFRAG_CONNTRACK_OUT      = IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 482        IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
 483        __IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 484};
 485
 486struct ip6_create_arg {
 487        __be32 id;
 488        u32 user;
 489        const struct in6_addr *src;
 490        const struct in6_addr *dst;
 491        u8 ecn;
 492};
 493
 494void ip6_frag_init(struct inet_frag_queue *q, const void *a);
 495bool ip6_frag_match(const struct inet_frag_queue *q, const void *a);
 496
 497/*
 498 *      Equivalent of ipv4 struct ip
 499 */
 500struct frag_queue {
 501        struct inet_frag_queue  q;
 502
 503        __be32                  id;             /* fragment id          */
 504        u32                     user;
 505        struct in6_addr         saddr;
 506        struct in6_addr         daddr;
 507
 508        int                     iif;
 509        unsigned int            csum;
 510        __u16                   nhoffset;
 511        u8                      ecn;
 512};
 513
 514void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
 515                           struct inet_frags *frags);
 516
 517static inline bool ipv6_addr_any(const struct in6_addr *a)
 518{
 519#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 520        const unsigned long *ul = (const unsigned long *)a;
 521
 522        return (ul[0] | ul[1]) == 0UL;
 523#else
 524        return (a->s6_addr32[0] | a->s6_addr32[1] |
 525                a->s6_addr32[2] | a->s6_addr32[3]) == 0;
 526#endif
 527}
 528
 529static inline u32 ipv6_addr_hash(const struct in6_addr *a)
 530{
 531#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 532        const unsigned long *ul = (const unsigned long *)a;
 533        unsigned long x = ul[0] ^ ul[1];
 534
 535        return (u32)(x ^ (x >> 32));
 536#else
 537        return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
 538                             a->s6_addr32[2] ^ a->s6_addr32[3]);
 539#endif
 540}
 541
 542/* more secured version of ipv6_addr_hash() */
 543static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
 544{
 545        u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
 546
 547        return jhash_3words(v,
 548                            (__force u32)a->s6_addr32[2],
 549                            (__force u32)a->s6_addr32[3],
 550                            initval);
 551}
 552
 553static inline bool ipv6_addr_loopback(const struct in6_addr *a)
 554{
 555#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 556        const __be64 *be = (const __be64 *)a;
 557
 558        return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
 559#else
 560        return (a->s6_addr32[0] | a->s6_addr32[1] |
 561                a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
 562#endif
 563}
 564
 565/*
 566 * Note that we must __force cast these to unsigned long to make sparse happy,
 567 * since all of the endian-annotated types are fixed size regardless of arch.
 568 */
 569static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
 570{
 571        return (
 572#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 573                *(unsigned long *)a |
 574#else
 575                (__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
 576#endif
 577                (__force unsigned long)(a->s6_addr32[2] ^
 578                                        cpu_to_be32(0x0000ffff))) == 0UL;
 579}
 580
 581/*
 582 * Check for a RFC 4843 ORCHID address
 583 * (Overlay Routable Cryptographic Hash Identifiers)
 584 */
 585static inline bool ipv6_addr_orchid(const struct in6_addr *a)
 586{
 587        return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
 588}
 589
 590static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
 591{
 592        return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
 593}
 594
 595static inline void ipv6_addr_set_v4mapped(const __be32 addr,
 596                                          struct in6_addr *v4mapped)
 597{
 598        ipv6_addr_set(v4mapped,
 599                        0, 0,
 600                        htonl(0x0000FFFF),
 601                        addr);
 602}
 603
 604/*
 605 * find the first different bit between two addresses
 606 * length of address must be a multiple of 32bits
 607 */
 608static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
 609{
 610        const __be32 *a1 = token1, *a2 = token2;
 611        int i;
 612
 613        addrlen >>= 2;
 614
 615        for (i = 0; i < addrlen; i++) {
 616                __be32 xb = a1[i] ^ a2[i];
 617                if (xb)
 618                        return i * 32 + 31 - __fls(ntohl(xb));
 619        }
 620
 621        /*
 622         *      we should *never* get to this point since that 
 623         *      would mean the addrs are equal
 624         *
 625         *      However, we do get to it 8) And exacly, when
 626         *      addresses are equal 8)
 627         *
 628         *      ip route add 1111::/128 via ...
 629         *      ip route add 1111::/64 via ...
 630         *      and we are here.
 631         *
 632         *      Ideally, this function should stop comparison
 633         *      at prefix length. It does not, but it is still OK,
 634         *      if returned value is greater than prefix length.
 635         *                                      --ANK (980803)
 636         */
 637        return addrlen << 5;
 638}
 639
 640#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 641static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
 642{
 643        const __be64 *a1 = token1, *a2 = token2;
 644        int i;
 645
 646        addrlen >>= 3;
 647
 648        for (i = 0; i < addrlen; i++) {
 649                __be64 xb = a1[i] ^ a2[i];
 650                if (xb)
 651                        return i * 64 + 63 - __fls(be64_to_cpu(xb));
 652        }
 653
 654        return addrlen << 6;
 655}
 656#endif
 657
 658static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
 659{
 660#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 661        if (__builtin_constant_p(addrlen) && !(addrlen & 7))
 662                return __ipv6_addr_diff64(token1, token2, addrlen);
 663#endif
 664        return __ipv6_addr_diff32(token1, token2, addrlen);
 665}
 666
 667static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
 668{
 669        return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
 670}
 671
 672void ipv6_select_ident(struct net *net, struct frag_hdr *fhdr,
 673                       struct rt6_info *rt);
 674void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
 675
 676int ip6_dst_hoplimit(struct dst_entry *dst);
 677
 678static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
 679                                      struct dst_entry *dst)
 680{
 681        int hlimit;
 682
 683        if (ipv6_addr_is_multicast(&fl6->daddr))
 684                hlimit = np->mcast_hops;
 685        else
 686                hlimit = np->hop_limit;
 687        if (hlimit < 0)
 688                hlimit = ip6_dst_hoplimit(dst);
 689        return hlimit;
 690}
 691
 692#if IS_ENABLED(CONFIG_IPV6)
 693static inline void ip6_set_txhash(struct sock *sk)
 694{
 695        struct inet_sock *inet = inet_sk(sk);
 696        struct ipv6_pinfo *np = inet6_sk(sk);
 697        struct flow_keys keys;
 698
 699        keys.src = (__force __be32)ipv6_addr_hash(&np->saddr);
 700        keys.dst = (__force __be32)ipv6_addr_hash(&sk->sk_v6_daddr);
 701        keys.port16[0] = inet->inet_sport;
 702        keys.port16[1] = inet->inet_dport;
 703
 704        sk->sk_txhash = flow_hash_from_keys(&keys);
 705}
 706
 707static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 708                                        __be32 flowlabel, bool autolabel)
 709{
 710        if (!flowlabel && (autolabel || net->ipv6.sysctl.auto_flowlabels)) {
 711                u32 hash;
 712
 713                hash = skb_get_hash(skb);
 714
 715                /* Since this is being sent on the wire obfuscate hash a bit
 716                 * to minimize possbility that any useful information to an
 717                 * attacker is leaked. Only lower 20 bits are relevant.
 718                 */
 719                hash ^= hash >> 12;
 720
 721                flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
 722        }
 723
 724        return flowlabel;
 725}
 726#else
 727static inline void ip6_set_txhash(struct sock *sk) { }
 728static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 729                                        __be32 flowlabel, bool autolabel)
 730{
 731        return flowlabel;
 732}
 733#endif
 734
 735
 736/*
 737 *      Header manipulation
 738 */
 739static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
 740                                __be32 flowlabel)
 741{
 742        *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
 743}
 744
 745static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
 746{
 747        return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
 748}
 749
 750static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
 751{
 752        return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
 753}
 754
 755static inline u8 ip6_tclass(__be32 flowinfo)
 756{
 757        return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
 758}
 759/*
 760 *      Prototypes exported by ipv6
 761 */
 762
 763/*
 764 *      rcv function (called from netdevice level)
 765 */
 766
 767int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
 768             struct packet_type *pt, struct net_device *orig_dev);
 769
 770int ip6_rcv_finish(struct sock *sk, struct sk_buff *skb);
 771
 772/*
 773 *      upper-layer output functions
 774 */
 775int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 776             struct ipv6_txoptions *opt, int tclass);
 777
 778int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
 779
 780int ip6_append_data(struct sock *sk,
 781                    int getfrag(void *from, char *to, int offset, int len,
 782                                int odd, struct sk_buff *skb),
 783                    void *from, int length, int transhdrlen, int hlimit,
 784                    int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
 785                    struct rt6_info *rt, unsigned int flags, int dontfrag);
 786
 787int ip6_push_pending_frames(struct sock *sk);
 788
 789void ip6_flush_pending_frames(struct sock *sk);
 790
 791int ip6_send_skb(struct sk_buff *skb);
 792
 793struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
 794                               struct inet_cork_full *cork,
 795                               struct inet6_cork *v6_cork);
 796struct sk_buff *ip6_make_skb(struct sock *sk,
 797                             int getfrag(void *from, char *to, int offset,
 798                                         int len, int odd, struct sk_buff *skb),
 799                             void *from, int length, int transhdrlen,
 800                             int hlimit, int tclass, struct ipv6_txoptions *opt,
 801                             struct flowi6 *fl6, struct rt6_info *rt,
 802                             unsigned int flags, int dontfrag);
 803
 804static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
 805{
 806        return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
 807                              &inet6_sk(sk)->cork);
 808}
 809
 810int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6);
 811struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 812                                      const struct in6_addr *final_dst);
 813struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 814                                         const struct in6_addr *final_dst);
 815struct dst_entry *ip6_blackhole_route(struct net *net,
 816                                      struct dst_entry *orig_dst);
 817
 818/*
 819 *      skb processing functions
 820 */
 821
 822int ip6_output(struct sock *sk, struct sk_buff *skb);
 823int ip6_forward(struct sk_buff *skb);
 824int ip6_input(struct sk_buff *skb);
 825int ip6_mc_input(struct sk_buff *skb);
 826
 827int __ip6_local_out(struct sk_buff *skb);
 828int ip6_local_out_sk(struct sock *sk, struct sk_buff *skb);
 829int ip6_local_out(struct sk_buff *skb);
 830
 831/*
 832 *      Extension header (options) processing
 833 */
 834
 835void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
 836                          u8 *proto, struct in6_addr **daddr_p);
 837void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
 838                         u8 *proto);
 839
 840int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
 841                     __be16 *frag_offp);
 842
 843bool ipv6_ext_hdr(u8 nexthdr);
 844
 845enum {
 846        IP6_FH_F_FRAG           = (1 << 0),
 847        IP6_FH_F_AUTH           = (1 << 1),
 848        IP6_FH_F_SKIP_RH        = (1 << 2),
 849};
 850
 851/* find specified header and get offset to it */
 852int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
 853                  unsigned short *fragoff, int *fragflg);
 854
 855int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
 856
 857struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
 858                                const struct ipv6_txoptions *opt,
 859                                struct in6_addr *orig);
 860
 861/*
 862 *      socket options (ipv6_sockglue.c)
 863 */
 864
 865int ipv6_setsockopt(struct sock *sk, int level, int optname,
 866                    char __user *optval, unsigned int optlen);
 867int ipv6_getsockopt(struct sock *sk, int level, int optname,
 868                    char __user *optval, int __user *optlen);
 869int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
 870                           char __user *optval, unsigned int optlen);
 871int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
 872                           char __user *optval, int __user *optlen);
 873
 874int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
 875int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
 876                                 int addr_len);
 877
 878int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
 879                    int *addr_len);
 880int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 881                     int *addr_len);
 882void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 883                     u32 info, u8 *payload);
 884void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
 885void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
 886
 887int inet6_release(struct socket *sock);
 888int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
 889int inet6_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len,
 890                  int peer);
 891int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
 892
 893int inet6_hash_connect(struct inet_timewait_death_row *death_row,
 894                              struct sock *sk);
 895
 896/*
 897 * reassembly.c
 898 */
 899extern const struct proto_ops inet6_stream_ops;
 900extern const struct proto_ops inet6_dgram_ops;
 901
 902struct group_source_req;
 903struct group_filter;
 904
 905int ip6_mc_source(int add, int omode, struct sock *sk,
 906                  struct group_source_req *pgsr);
 907int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
 908int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
 909                  struct group_filter __user *optval, int __user *optlen);
 910
 911#ifdef CONFIG_PROC_FS
 912int ac6_proc_init(struct net *net);
 913void ac6_proc_exit(struct net *net);
 914int raw6_proc_init(void);
 915void raw6_proc_exit(void);
 916int tcp6_proc_init(struct net *net);
 917void tcp6_proc_exit(struct net *net);
 918int udp6_proc_init(struct net *net);
 919void udp6_proc_exit(struct net *net);
 920int udplite6_proc_init(void);
 921void udplite6_proc_exit(void);
 922int ipv6_misc_proc_init(void);
 923void ipv6_misc_proc_exit(void);
 924int snmp6_register_dev(struct inet6_dev *idev);
 925int snmp6_unregister_dev(struct inet6_dev *idev);
 926
 927#else
 928static inline int ac6_proc_init(struct net *net) { return 0; }
 929static inline void ac6_proc_exit(struct net *net) { }
 930static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
 931static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
 932#endif
 933
 934#ifdef CONFIG_SYSCTL
 935extern struct ctl_table ipv6_route_table_template[];
 936
 937struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
 938struct ctl_table *ipv6_route_sysctl_init(struct net *net);
 939int ipv6_sysctl_register(void);
 940void ipv6_sysctl_unregister(void);
 941#endif
 942
 943int ipv6_sock_mc_join(struct sock *sk, int ifindex,
 944                      const struct in6_addr *addr);
 945int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
 946                      const struct in6_addr *addr);
 947#endif /* _NET_IPV6_H */
 948