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_dissector.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_FLOWLABEL_STATELESS_FLAG   cpu_to_be32(0x00080000)
 245
 246#define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
 247#define IPV6_TCLASS_SHIFT       20
 248
 249struct ipv6_fl_socklist {
 250        struct ipv6_fl_socklist __rcu   *next;
 251        struct ip6_flowlabel            *fl;
 252        struct rcu_head                 rcu;
 253};
 254
 255struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label);
 256struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 257                                         struct ip6_flowlabel *fl,
 258                                         struct ipv6_txoptions *fopt);
 259void fl6_free_socklist(struct sock *sk);
 260int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
 261int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
 262                           int flags);
 263int ip6_flowlabel_init(void);
 264void ip6_flowlabel_cleanup(void);
 265
 266static inline void fl6_sock_release(struct ip6_flowlabel *fl)
 267{
 268        if (fl)
 269                atomic_dec(&fl->users);
 270}
 271
 272void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
 273
 274int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 275                               struct icmp6hdr *thdr, int len);
 276
 277int ip6_ra_control(struct sock *sk, int sel);
 278
 279int ipv6_parse_hopopts(struct sk_buff *skb);
 280
 281struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
 282                                        struct ipv6_txoptions *opt);
 283struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
 284                                          struct ipv6_txoptions *opt,
 285                                          int newtype,
 286                                          struct ipv6_opt_hdr __user *newopt,
 287                                          int newoptlen);
 288struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
 289                                          struct ipv6_txoptions *opt);
 290
 291bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
 292                       const struct inet6_skb_parm *opt);
 293
 294static inline bool ipv6_accept_ra(struct inet6_dev *idev)
 295{
 296        /* If forwarding is enabled, RA are not accepted unless the special
 297         * hybrid mode (accept_ra=2) is enabled.
 298         */
 299        return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
 300            idev->cnf.accept_ra;
 301}
 302
 303#if IS_ENABLED(CONFIG_IPV6)
 304static inline int ip6_frag_mem(struct net *net)
 305{
 306        return sum_frag_mem_limit(&net->ipv6.frags);
 307}
 308#endif
 309
 310#define IPV6_FRAG_HIGH_THRESH   (4 * 1024*1024) /* 4194304 */
 311#define IPV6_FRAG_LOW_THRESH    (3 * 1024*1024) /* 3145728 */
 312#define IPV6_FRAG_TIMEOUT       (60 * HZ)       /* 60 seconds */
 313
 314int __ipv6_addr_type(const struct in6_addr *addr);
 315static inline int ipv6_addr_type(const struct in6_addr *addr)
 316{
 317        return __ipv6_addr_type(addr) & 0xffff;
 318}
 319
 320static inline int ipv6_addr_scope(const struct in6_addr *addr)
 321{
 322        return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
 323}
 324
 325static inline int __ipv6_addr_src_scope(int type)
 326{
 327        return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
 328}
 329
 330static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
 331{
 332        return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
 333}
 334
 335static inline bool __ipv6_addr_needs_scope_id(int type)
 336{
 337        return type & IPV6_ADDR_LINKLOCAL ||
 338               (type & IPV6_ADDR_MULTICAST &&
 339                (type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
 340}
 341
 342static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
 343{
 344        return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
 345}
 346
 347static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
 348{
 349        return memcmp(a1, a2, sizeof(struct in6_addr));
 350}
 351
 352static inline bool
 353ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
 354                     const struct in6_addr *a2)
 355{
 356#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 357        const unsigned long *ul1 = (const unsigned long *)a1;
 358        const unsigned long *ulm = (const unsigned long *)m;
 359        const unsigned long *ul2 = (const unsigned long *)a2;
 360
 361        return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
 362                  ((ul1[1] ^ ul2[1]) & ulm[1]));
 363#else
 364        return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
 365                  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
 366                  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
 367                  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
 368#endif
 369}
 370
 371static inline void ipv6_addr_prefix(struct in6_addr *pfx, 
 372                                    const struct in6_addr *addr,
 373                                    int plen)
 374{
 375        /* caller must guarantee 0 <= plen <= 128 */
 376        int o = plen >> 3,
 377            b = plen & 0x7;
 378
 379        memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
 380        memcpy(pfx->s6_addr, addr, o);
 381        if (b != 0)
 382                pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
 383}
 384
 385static inline void __ipv6_addr_set_half(__be32 *addr,
 386                                        __be32 wh, __be32 wl)
 387{
 388#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 389#if defined(__BIG_ENDIAN)
 390        if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
 391                *(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
 392                return;
 393        }
 394#elif defined(__LITTLE_ENDIAN)
 395        if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
 396                *(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
 397                return;
 398        }
 399#endif
 400#endif
 401        addr[0] = wh;
 402        addr[1] = wl;
 403}
 404
 405static inline void ipv6_addr_set(struct in6_addr *addr, 
 406                                     __be32 w1, __be32 w2,
 407                                     __be32 w3, __be32 w4)
 408{
 409        __ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
 410        __ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
 411}
 412
 413static inline bool ipv6_addr_equal(const struct in6_addr *a1,
 414                                   const struct in6_addr *a2)
 415{
 416#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 417        const unsigned long *ul1 = (const unsigned long *)a1;
 418        const unsigned long *ul2 = (const unsigned long *)a2;
 419
 420        return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
 421#else
 422        return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
 423                (a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
 424                (a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
 425                (a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
 426#endif
 427}
 428
 429#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 430static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
 431                                              const __be64 *a2,
 432                                              unsigned int len)
 433{
 434        if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
 435                return false;
 436        return true;
 437}
 438
 439static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 440                                     const struct in6_addr *addr2,
 441                                     unsigned int prefixlen)
 442{
 443        const __be64 *a1 = (const __be64 *)addr1;
 444        const __be64 *a2 = (const __be64 *)addr2;
 445
 446        if (prefixlen >= 64) {
 447                if (a1[0] ^ a2[0])
 448                        return false;
 449                return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
 450        }
 451        return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
 452}
 453#else
 454static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 455                                     const struct in6_addr *addr2,
 456                                     unsigned int prefixlen)
 457{
 458        const __be32 *a1 = addr1->s6_addr32;
 459        const __be32 *a2 = addr2->s6_addr32;
 460        unsigned int pdw, pbi;
 461
 462        /* check complete u32 in prefix */
 463        pdw = prefixlen >> 5;
 464        if (pdw && memcmp(a1, a2, pdw << 2))
 465                return false;
 466
 467        /* check incomplete u32 in prefix */
 468        pbi = prefixlen & 0x1f;
 469        if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
 470                return false;
 471
 472        return true;
 473}
 474#endif
 475
 476struct inet_frag_queue;
 477
 478enum ip6_defrag_users {
 479        IP6_DEFRAG_LOCAL_DELIVER,
 480        IP6_DEFRAG_CONNTRACK_IN,
 481        __IP6_DEFRAG_CONNTRACK_IN       = IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 482        IP6_DEFRAG_CONNTRACK_OUT,
 483        __IP6_DEFRAG_CONNTRACK_OUT      = IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 484        IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
 485        __IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 486};
 487
 488struct ip6_create_arg {
 489        __be32 id;
 490        u32 user;
 491        const struct in6_addr *src;
 492        const struct in6_addr *dst;
 493        u8 ecn;
 494};
 495
 496void ip6_frag_init(struct inet_frag_queue *q, const void *a);
 497bool ip6_frag_match(const struct inet_frag_queue *q, const void *a);
 498
 499/*
 500 *      Equivalent of ipv4 struct ip
 501 */
 502struct frag_queue {
 503        struct inet_frag_queue  q;
 504
 505        __be32                  id;             /* fragment id          */
 506        u32                     user;
 507        struct in6_addr         saddr;
 508        struct in6_addr         daddr;
 509
 510        int                     iif;
 511        unsigned int            csum;
 512        __u16                   nhoffset;
 513        u8                      ecn;
 514};
 515
 516void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
 517                           struct inet_frags *frags);
 518
 519static inline bool ipv6_addr_any(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
 524        return (ul[0] | ul[1]) == 0UL;
 525#else
 526        return (a->s6_addr32[0] | a->s6_addr32[1] |
 527                a->s6_addr32[2] | a->s6_addr32[3]) == 0;
 528#endif
 529}
 530
 531static inline u32 ipv6_addr_hash(const struct in6_addr *a)
 532{
 533#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 534        const unsigned long *ul = (const unsigned long *)a;
 535        unsigned long x = ul[0] ^ ul[1];
 536
 537        return (u32)(x ^ (x >> 32));
 538#else
 539        return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
 540                             a->s6_addr32[2] ^ a->s6_addr32[3]);
 541#endif
 542}
 543
 544/* more secured version of ipv6_addr_hash() */
 545static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
 546{
 547        u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
 548
 549        return jhash_3words(v,
 550                            (__force u32)a->s6_addr32[2],
 551                            (__force u32)a->s6_addr32[3],
 552                            initval);
 553}
 554
 555static inline bool ipv6_addr_loopback(const struct in6_addr *a)
 556{
 557#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 558        const __be64 *be = (const __be64 *)a;
 559
 560        return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
 561#else
 562        return (a->s6_addr32[0] | a->s6_addr32[1] |
 563                a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
 564#endif
 565}
 566
 567/*
 568 * Note that we must __force cast these to unsigned long to make sparse happy,
 569 * since all of the endian-annotated types are fixed size regardless of arch.
 570 */
 571static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
 572{
 573        return (
 574#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 575                *(unsigned long *)a |
 576#else
 577                (__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
 578#endif
 579                (__force unsigned long)(a->s6_addr32[2] ^
 580                                        cpu_to_be32(0x0000ffff))) == 0UL;
 581}
 582
 583/*
 584 * Check for a RFC 4843 ORCHID address
 585 * (Overlay Routable Cryptographic Hash Identifiers)
 586 */
 587static inline bool ipv6_addr_orchid(const struct in6_addr *a)
 588{
 589        return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
 590}
 591
 592static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
 593{
 594        return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
 595}
 596
 597static inline void ipv6_addr_set_v4mapped(const __be32 addr,
 598                                          struct in6_addr *v4mapped)
 599{
 600        ipv6_addr_set(v4mapped,
 601                        0, 0,
 602                        htonl(0x0000FFFF),
 603                        addr);
 604}
 605
 606/*
 607 * find the first different bit between two addresses
 608 * length of address must be a multiple of 32bits
 609 */
 610static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
 611{
 612        const __be32 *a1 = token1, *a2 = token2;
 613        int i;
 614
 615        addrlen >>= 2;
 616
 617        for (i = 0; i < addrlen; i++) {
 618                __be32 xb = a1[i] ^ a2[i];
 619                if (xb)
 620                        return i * 32 + 31 - __fls(ntohl(xb));
 621        }
 622
 623        /*
 624         *      we should *never* get to this point since that 
 625         *      would mean the addrs are equal
 626         *
 627         *      However, we do get to it 8) And exacly, when
 628         *      addresses are equal 8)
 629         *
 630         *      ip route add 1111::/128 via ...
 631         *      ip route add 1111::/64 via ...
 632         *      and we are here.
 633         *
 634         *      Ideally, this function should stop comparison
 635         *      at prefix length. It does not, but it is still OK,
 636         *      if returned value is greater than prefix length.
 637         *                                      --ANK (980803)
 638         */
 639        return addrlen << 5;
 640}
 641
 642#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 643static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
 644{
 645        const __be64 *a1 = token1, *a2 = token2;
 646        int i;
 647
 648        addrlen >>= 3;
 649
 650        for (i = 0; i < addrlen; i++) {
 651                __be64 xb = a1[i] ^ a2[i];
 652                if (xb)
 653                        return i * 64 + 63 - __fls(be64_to_cpu(xb));
 654        }
 655
 656        return addrlen << 6;
 657}
 658#endif
 659
 660static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
 661{
 662#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 663        if (__builtin_constant_p(addrlen) && !(addrlen & 7))
 664                return __ipv6_addr_diff64(token1, token2, addrlen);
 665#endif
 666        return __ipv6_addr_diff32(token1, token2, addrlen);
 667}
 668
 669static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
 670{
 671        return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
 672}
 673
 674__be32 ipv6_select_ident(struct net *net,
 675                         const struct in6_addr *daddr,
 676                         const struct in6_addr *saddr);
 677void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
 678
 679int ip6_dst_hoplimit(struct dst_entry *dst);
 680
 681static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
 682                                      struct dst_entry *dst)
 683{
 684        int hlimit;
 685
 686        if (ipv6_addr_is_multicast(&fl6->daddr))
 687                hlimit = np->mcast_hops;
 688        else
 689                hlimit = np->hop_limit;
 690        if (hlimit < 0)
 691                hlimit = ip6_dst_hoplimit(dst);
 692        return hlimit;
 693}
 694
 695/* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
 696 * Equivalent to :      flow->v6addrs.src = iph->saddr;
 697 *                      flow->v6addrs.dst = iph->daddr;
 698 */
 699static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
 700                                            const struct ipv6hdr *iph)
 701{
 702        BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
 703                     offsetof(typeof(flow->addrs), v6addrs.src) +
 704                     sizeof(flow->addrs.v6addrs.src));
 705        memcpy(&flow->addrs.v6addrs, &iph->saddr, sizeof(flow->addrs.v6addrs));
 706        flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 707}
 708
 709#if IS_ENABLED(CONFIG_IPV6)
 710
 711/* Sysctl settings for net ipv6.auto_flowlabels */
 712#define IP6_AUTO_FLOW_LABEL_OFF         0
 713#define IP6_AUTO_FLOW_LABEL_OPTOUT      1
 714#define IP6_AUTO_FLOW_LABEL_OPTIN       2
 715#define IP6_AUTO_FLOW_LABEL_FORCED      3
 716
 717#define IP6_AUTO_FLOW_LABEL_MAX         IP6_AUTO_FLOW_LABEL_FORCED
 718
 719#define IP6_DEFAULT_AUTO_FLOW_LABELS    IP6_AUTO_FLOW_LABEL_OPTOUT
 720
 721static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 722                                        __be32 flowlabel, bool autolabel,
 723                                        struct flowi6 *fl6)
 724{
 725        u32 hash;
 726
 727        if (flowlabel ||
 728            net->ipv6.sysctl.auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF ||
 729            (!autolabel &&
 730             net->ipv6.sysctl.auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED))
 731                return flowlabel;
 732
 733        hash = skb_get_hash_flowi6(skb, fl6);
 734
 735        /* Since this is being sent on the wire obfuscate hash a bit
 736         * to minimize possbility that any useful information to an
 737         * attacker is leaked. Only lower 20 bits are relevant.
 738         */
 739        rol32(hash, 16);
 740
 741        flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
 742
 743        if (net->ipv6.sysctl.flowlabel_state_ranges)
 744                flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
 745
 746        return flowlabel;
 747}
 748
 749static inline int ip6_default_np_autolabel(struct net *net)
 750{
 751        switch (net->ipv6.sysctl.auto_flowlabels) {
 752        case IP6_AUTO_FLOW_LABEL_OFF:
 753        case IP6_AUTO_FLOW_LABEL_OPTIN:
 754        default:
 755                return 0;
 756        case IP6_AUTO_FLOW_LABEL_OPTOUT:
 757        case IP6_AUTO_FLOW_LABEL_FORCED:
 758                return 1;
 759        }
 760}
 761#else
 762static inline void ip6_set_txhash(struct sock *sk) { }
 763static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 764                                        __be32 flowlabel, bool autolabel,
 765                                        struct flowi6 *fl6)
 766{
 767        return flowlabel;
 768}
 769static inline int ip6_default_np_autolabel(struct net *net)
 770{
 771        return 0;
 772}
 773#endif
 774
 775
 776/*
 777 *      Header manipulation
 778 */
 779static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
 780                                __be32 flowlabel)
 781{
 782        *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
 783}
 784
 785static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
 786{
 787        return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
 788}
 789
 790static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
 791{
 792        return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
 793}
 794
 795static inline u8 ip6_tclass(__be32 flowinfo)
 796{
 797        return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
 798}
 799/*
 800 *      Prototypes exported by ipv6
 801 */
 802
 803/*
 804 *      rcv function (called from netdevice level)
 805 */
 806
 807int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
 808             struct packet_type *pt, struct net_device *orig_dev);
 809
 810int ip6_rcv_finish(struct sock *sk, struct sk_buff *skb);
 811
 812/*
 813 *      upper-layer output functions
 814 */
 815int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 816             struct ipv6_txoptions *opt, int tclass);
 817
 818int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
 819
 820int ip6_append_data(struct sock *sk,
 821                    int getfrag(void *from, char *to, int offset, int len,
 822                                int odd, struct sk_buff *skb),
 823                    void *from, int length, int transhdrlen, int hlimit,
 824                    int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
 825                    struct rt6_info *rt, unsigned int flags, int dontfrag);
 826
 827int ip6_push_pending_frames(struct sock *sk);
 828
 829void ip6_flush_pending_frames(struct sock *sk);
 830
 831int ip6_send_skb(struct sk_buff *skb);
 832
 833struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
 834                               struct inet_cork_full *cork,
 835                               struct inet6_cork *v6_cork);
 836struct sk_buff *ip6_make_skb(struct sock *sk,
 837                             int getfrag(void *from, char *to, int offset,
 838                                         int len, int odd, struct sk_buff *skb),
 839                             void *from, int length, int transhdrlen,
 840                             int hlimit, int tclass, struct ipv6_txoptions *opt,
 841                             struct flowi6 *fl6, struct rt6_info *rt,
 842                             unsigned int flags, int dontfrag);
 843
 844static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
 845{
 846        return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
 847                              &inet6_sk(sk)->cork);
 848}
 849
 850int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
 851                   struct flowi6 *fl6);
 852struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 853                                      const struct in6_addr *final_dst);
 854struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 855                                         const struct in6_addr *final_dst);
 856struct dst_entry *ip6_blackhole_route(struct net *net,
 857                                      struct dst_entry *orig_dst);
 858
 859/*
 860 *      skb processing functions
 861 */
 862
 863int ip6_output(struct sock *sk, struct sk_buff *skb);
 864int ip6_forward(struct sk_buff *skb);
 865int ip6_input(struct sk_buff *skb);
 866int ip6_mc_input(struct sk_buff *skb);
 867
 868int __ip6_local_out(struct sk_buff *skb);
 869int ip6_local_out_sk(struct sock *sk, struct sk_buff *skb);
 870int ip6_local_out(struct sk_buff *skb);
 871
 872/*
 873 *      Extension header (options) processing
 874 */
 875
 876void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
 877                          u8 *proto, struct in6_addr **daddr_p);
 878void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
 879                         u8 *proto);
 880
 881int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
 882                     __be16 *frag_offp);
 883
 884bool ipv6_ext_hdr(u8 nexthdr);
 885
 886enum {
 887        IP6_FH_F_FRAG           = (1 << 0),
 888        IP6_FH_F_AUTH           = (1 << 1),
 889        IP6_FH_F_SKIP_RH        = (1 << 2),
 890};
 891
 892/* find specified header and get offset to it */
 893int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
 894                  unsigned short *fragoff, int *fragflg);
 895
 896int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
 897
 898struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
 899                                const struct ipv6_txoptions *opt,
 900                                struct in6_addr *orig);
 901
 902/*
 903 *      socket options (ipv6_sockglue.c)
 904 */
 905
 906int ipv6_setsockopt(struct sock *sk, int level, int optname,
 907                    char __user *optval, unsigned int optlen);
 908int ipv6_getsockopt(struct sock *sk, int level, int optname,
 909                    char __user *optval, int __user *optlen);
 910int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
 911                           char __user *optval, unsigned int optlen);
 912int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
 913                           char __user *optval, int __user *optlen);
 914
 915int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
 916int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
 917                                 int addr_len);
 918
 919int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
 920                    int *addr_len);
 921int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 922                     int *addr_len);
 923void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 924                     u32 info, u8 *payload);
 925void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
 926void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
 927
 928int inet6_release(struct socket *sock);
 929int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
 930int inet6_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len,
 931                  int peer);
 932int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
 933
 934int inet6_hash_connect(struct inet_timewait_death_row *death_row,
 935                              struct sock *sk);
 936
 937/*
 938 * reassembly.c
 939 */
 940extern const struct proto_ops inet6_stream_ops;
 941extern const struct proto_ops inet6_dgram_ops;
 942
 943struct group_source_req;
 944struct group_filter;
 945
 946int ip6_mc_source(int add, int omode, struct sock *sk,
 947                  struct group_source_req *pgsr);
 948int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
 949int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
 950                  struct group_filter __user *optval, int __user *optlen);
 951
 952#ifdef CONFIG_PROC_FS
 953int ac6_proc_init(struct net *net);
 954void ac6_proc_exit(struct net *net);
 955int raw6_proc_init(void);
 956void raw6_proc_exit(void);
 957int tcp6_proc_init(struct net *net);
 958void tcp6_proc_exit(struct net *net);
 959int udp6_proc_init(struct net *net);
 960void udp6_proc_exit(struct net *net);
 961int udplite6_proc_init(void);
 962void udplite6_proc_exit(void);
 963int ipv6_misc_proc_init(void);
 964void ipv6_misc_proc_exit(void);
 965int snmp6_register_dev(struct inet6_dev *idev);
 966int snmp6_unregister_dev(struct inet6_dev *idev);
 967
 968#else
 969static inline int ac6_proc_init(struct net *net) { return 0; }
 970static inline void ac6_proc_exit(struct net *net) { }
 971static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
 972static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
 973#endif
 974
 975#ifdef CONFIG_SYSCTL
 976extern struct ctl_table ipv6_route_table_template[];
 977
 978struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
 979struct ctl_table *ipv6_route_sysctl_init(struct net *net);
 980int ipv6_sysctl_register(void);
 981void ipv6_sysctl_unregister(void);
 982#endif
 983
 984int ipv6_sock_mc_join(struct sock *sk, int ifindex,
 985                      const struct in6_addr *addr);
 986int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
 987                      const struct in6_addr *addr);
 988#endif /* _NET_IPV6_H */
 989