include/net/ipv6.h

   1 /*
   2  *      Linux INET6 implementation
   3  *
   4  *      Authors:
   5  *      Pedro Roque             <roque@di.fc.ul.pt>
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  */
  12
  13 #ifndef _NET_IPV6_H
  14 #define _NET_IPV6_H
  15
  16 #include <linux/ipv6.h>
  17 #include <linux/hardirq.h>
  18 #include <linux/jhash.h>
  19 #include <net/if_inet6.h>
  20 #include <net/ndisc.h>
  21 #include <net/flow.h>
  22 #include <net/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
  51
  52 #define IPV6_DEFAULT_HOPLIMIT   64
  53 #define IPV6_DEFAULT_MCASTHOPS  1
  54
  55 /*
  56  *      Addr type
  57  *
  58  *      type    -       unicast | multicast
  59  *      scope   -       local   | site      | global
  60  *      v4      -       compat
  61  *      v4mapped
  62  *      any
  63  *      loopback
  64  */
  65
  66 #define IPV6_ADDR_ANY           0x0000U
  67
  68 #define IPV6_ADDR_UNICAST       0x0001U
  69 #define IPV6_ADDR_MULTICAST     0x0002U
  70
  71 #define IPV6_ADDR_LOOPBACK      0x0010U
  72 #define IPV6_ADDR_LINKLOCAL     0x0020U
  73 #define IPV6_ADDR_SITELOCAL     0x0040U
  74
  75 #define IPV6_ADDR_COMPATv4      0x0080U
  76
  77 #define IPV6_ADDR_SCOPE_MASK    0x00f0U
  78
  79 #define IPV6_ADDR_MAPPED        0x1000U
  80
  81 /*
  82  *      Addr scopes
  83  */
  84 #define IPV6_ADDR_MC_SCOPE(a)   \
  85         ((a)->s6_addr[1] & 0x0f)        /* nonstandard */
  86 #define __IPV6_ADDR_SCOPE_INVALID       -1
  87 #define IPV6_ADDR_SCOPE_NODELOCAL       0x01
  88 #define IPV6_ADDR_SCOPE_LINKLOCAL       0x02
  89 #define IPV6_ADDR_SCOPE_SITELOCAL       0x05
  90 #define IPV6_ADDR_SCOPE_ORGLOCAL        0x08
  91 #define IPV6_ADDR_SCOPE_GLOBAL          0x0e
  92
  93 /*
  94  *      Addr flags
  95  */
  96 #define IPV6_ADDR_MC_FLAG_TRANSIENT(a)  \
  97         ((a)->s6_addr[1] & 0x10)
  98 #define IPV6_ADDR_MC_FLAG_PREFIX(a)     \
  99         ((a)->s6_addr[1] & 0x20)
 100 #define IPV6_ADDR_MC_FLAG_RENDEZVOUS(a) \
 101         ((a)->s6_addr[1] & 0x40)
 102
 103 /*
 104  *      fragmentation header
 105  */
 106
 107 struct frag_hdr {
 108         __u8    nexthdr;
 109         __u8    reserved;
 110         __be16  frag_off;
 111         __be32  identification;
 112 };
 113
 114 #define IP6_MF          0x0001
 115 #define IP6_OFFSET      0xFFF8
 116
 117 #define IP6_REPLY_MARK(net, mark) \
 118         ((net)->ipv6.sysctl.fwmark_reflect ? (mark) : 0)
 119
 120 #include <net/sock.h>
 121
 122 /* sysctls */
 123 extern int sysctl_mld_max_msf;
 124 extern int sysctl_mld_qrv;
 125
 126 #define _DEVINC(net, statname, modifier, idev, field)                   \
 127 ({                                                                      \
 128         struct inet6_dev *_idev = (idev);                               \
 129         if (likely(_idev != NULL))                                      \
 130                 SNMP_INC_STATS##modifier((_idev)->stats.statname, (field)); \
 131         SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
 132 })
 133
 134 /* per device counters are atomic_long_t */
 135 #define _DEVINCATOMIC(net, statname, modifier, idev, field)             \
 136 ({                                                                      \
 137         struct inet6_dev *_idev = (idev);                               \
 138         if (likely(_idev != NULL))                                      \
 139                 SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
 140         SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
 141 })
 142
 143 /* per device and per net counters are atomic_long_t */
 144 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)               \
 145 ({                                                                      \
 146         struct inet6_dev *_idev = (idev);                               \
 147         if (likely(_idev != NULL))                                      \
 148                 SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
 149         SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
 150 })
 151
 152 #define _DEVADD(net, statname, modifier, idev, field, val)              \
 153 ({                                                                      \
 154         struct inet6_dev *_idev = (idev);                               \
 155         if (likely(_idev != NULL))                                      \
 156                 SNMP_ADD_STATS##modifier((_idev)->stats.statname, (field), (val)); \
 157         SNMP_ADD_STATS##modifier((net)->mib.statname##_statistics, (field), (val));\
 158 })
 159
 160 #define _DEVUPD(net, statname, modifier, idev, field, val)              \
 161 ({                                                                      \
 162         struct inet6_dev *_idev = (idev);                               \
 163         if (likely(_idev != NULL))                                      \
 164                 SNMP_UPD_PO_STATS##modifier((_idev)->stats.statname, field, (val)); \
 165         SNMP_UPD_PO_STATS##modifier((net)->mib.statname##_statistics, field, (val));\
 166 })
 167
 168 /* MIBs */
 169
 170 #define IP6_INC_STATS(net, idev,field)          \
 171                 _DEVINC(net, ipv6, 64, idev, field)
 172 #define IP6_INC_STATS_BH(net, idev,field)       \
 173                 _DEVINC(net, ipv6, 64_BH, idev, field)
 174 #define IP6_ADD_STATS(net, idev,field,val)      \
 175                 _DEVADD(net, ipv6, 64, idev, field, val)
 176 #define IP6_ADD_STATS_BH(net, idev,field,val)   \
 177                 _DEVADD(net, ipv6, 64_BH, idev, field, val)
 178 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
 179                 _DEVUPD(net, ipv6, 64, idev, field, val)
 180 #define IP6_UPD_PO_STATS_BH(net, idev,field,val)   \
 181                 _DEVUPD(net, ipv6, 64_BH, idev, field, val)
 182 #define ICMP6_INC_STATS(net, idev, field)       \
 183                 _DEVINCATOMIC(net, icmpv6, , idev, field)
 184 #define ICMP6_INC_STATS_BH(net, idev, field)    \
 185                 _DEVINCATOMIC(net, icmpv6, _BH, idev, field)
 186
 187 #define ICMP6MSGOUT_INC_STATS(net, idev, field)         \
 188         _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
 189 #define ICMP6MSGOUT_INC_STATS_BH(net, idev, field)      \
 190         _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
 191 #define ICMP6MSGIN_INC_STATS_BH(net, idev, field)       \
 192         _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
 193
 194 struct ip6_ra_chain {
 195         struct ip6_ra_chain     *next;
 196         struct sock             *sk;
 197         int                     sel;
 198         void                    (*destructor)(struct sock *);
 199 };
 200
 201 extern struct ip6_ra_chain      *ip6_ra_chain;
 202 extern rwlock_t ip6_ra_lock;
 203
 204 /*
 205    This structure is prepared by protocol, when parsing
 206    ancillary data and passed to IPv6.
 207  */
 208
 209 struct ipv6_txoptions {
 210         /* Length of this structure */
 211         int                     tot_len;
 212
 213         /* length of extension headers   */
 214
 215         __u16                   opt_flen;       /* after fragment hdr */
 216         __u16                   opt_nflen;      /* before fragment hdr */
 217
 218         struct ipv6_opt_hdr     *hopopt;
 219         struct ipv6_opt_hdr     *dst0opt;
 220         struct ipv6_rt_hdr      *srcrt; /* Routing Header */
 221         struct ipv6_opt_hdr     *dst1opt;
 222
 223         /* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
 224 };
 225
 226 struct ip6_flowlabel {
 227         struct ip6_flowlabel __rcu *next;
 228         __be32                  label;
 229         atomic_t                users;
 230         struct in6_addr         dst;
 231         struct ipv6_txoptions   *opt;
 232         unsigned long           linger;
 233         struct rcu_head         rcu;
 234         u8                      share;
 235         union {
 236                 struct pid *pid;
 237                 kuid_t uid;
 238         } owner;
 239         unsigned long           lastuse;
 240         unsigned long           expires;
 241         struct net              *fl_net;
 242 };
 243
 244 #define IPV6_FLOWINFO_MASK      cpu_to_be32(0x0FFFFFFF)
 245 #define IPV6_FLOWLABEL_MASK     cpu_to_be32(0x000FFFFF)
 246 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
 247 #define IPV6_TCLASS_SHIFT       20
 248
 249 struct ipv6_fl_socklist {
 250         struct ipv6_fl_socklist __rcu   *next;
 251         struct ip6_flowlabel            *fl;
 252         struct rcu_head                 rcu;
 253 };
 254
 255 struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label);
 256 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 257                                          struct ip6_flowlabel *fl,
 258                                          struct ipv6_txoptions *fopt);
 259 void fl6_free_socklist(struct sock *sk);
 260 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
 261 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
 262                            int flags);
 263 int ip6_flowlabel_init(void);
 264 void ip6_flowlabel_cleanup(void);
 265
 266 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
 267 {
 268         if (fl)
 269                 atomic_dec(&fl->users);
 270 }
 271
 272 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
 273
 274 int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 275                                struct icmp6hdr *thdr, int len);
 276
 277 int ip6_ra_control(struct sock *sk, int sel);
 278
 279 int ipv6_parse_hopopts(struct sk_buff *skb);
 280
 281 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
 282                                         struct ipv6_txoptions *opt);
 283 struct 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);
 288 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
 289                                           struct ipv6_txoptions *opt);
 290
 291 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
 292                        const struct inet6_skb_parm *opt);
 293
 294 static 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)
 304 static 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
 314 int __ipv6_addr_type(const struct in6_addr *addr);
 315 static inline int ipv6_addr_type(const struct in6_addr *addr)
 316 {
 317         return __ipv6_addr_type(addr) & 0xffff;
 318 }
 319
 320 static inline int ipv6_addr_scope(const struct in6_addr *addr)
 321 {
 322         return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
 323 }
 324
 325 static inline int __ipv6_addr_src_scope(int type)
 326 {
 327         return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
 328 }
 329
 330 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
 331 {
 332         return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
 333 }
 334
 335 static 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
 342 static 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
 347 static 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
 352 static inline bool
 353 ipv6_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
 371 static 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
 385 static 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
 405 static 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
 413 static 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
 430 static 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
 439 static 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
 454 static 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
 476 struct inet_frag_queue;
 477
 478 enum 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
 488 struct 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
 496 void ip6_frag_init(struct inet_frag_queue *q, const void *a);
 497 bool ip6_frag_match(const struct inet_frag_queue *q, const void *a);
 498
 499 /*
 500  *      Equivalent of ipv4 struct ip
 501  */
 502 struct 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
 516 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
 517                            struct inet_frags *frags);
 518
 519 static 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
 531 static 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() */
 545 static 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
 555 static 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  */
 571 static 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  */
 587 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
 588 {
 589         return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
 590 }
 591
 592 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
 593 {
 594         return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
 595 }
 596
 597 static 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  */
 610 static 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
 643 static 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
 660 static 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
 669 static 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 int ip6_dst_hoplimit(struct dst_entry *dst);
 675
 676 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
 677                                       struct dst_entry *dst)
 678 {
 679         int hlimit;
 680
 681         if (ipv6_addr_is_multicast(&fl6->daddr))
 682                 hlimit = np->mcast_hops;
 683         else
 684                 hlimit = np->hop_limit;
 685         if (hlimit < 0)
 686                 hlimit = ip6_dst_hoplimit(dst);
 687         return hlimit;
 688 }
 689
 690 #if IS_ENABLED(CONFIG_IPV6)
 691 static inline void ip6_set_txhash(struct sock *sk)
 692 {
 693         struct inet_sock *inet = inet_sk(sk);
 694         struct ipv6_pinfo *np = inet6_sk(sk);
 695         struct flow_keys keys;
 696
 697         keys.src = (__force __be32)ipv6_addr_hash(&np->saddr);
 698         keys.dst = (__force __be32)ipv6_addr_hash(&sk->sk_v6_daddr);
 699         keys.port16[0] = inet->inet_sport;
 700         keys.port16[1] = inet->inet_dport;
 701
 702         sk->sk_txhash = flow_hash_from_keys(&keys);
 703 }
 704
 705 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 706                                         __be32 flowlabel, bool autolabel)
 707 {
 708         if (!flowlabel && (autolabel || net->ipv6.sysctl.auto_flowlabels)) {
 709                 __be32 hash;
 710
 711                 hash = skb_get_hash(skb);
 712
 713                 /* Since this is being sent on the wire obfuscate hash a bit
 714                  * to minimize possbility that any useful information to an
 715                  * attacker is leaked. Only lower 20 bits are relevant.
 716                  */
 717                 hash ^= hash >> 12;
 718
 719                 flowlabel = hash & IPV6_FLOWLABEL_MASK;
 720         }
 721
 722         return flowlabel;
 723 }
 724 #else
 725 static inline void ip6_set_txhash(struct sock *sk) { }
 726 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 727                                         __be32 flowlabel, bool autolabel)
 728 {
 729         return flowlabel;
 730 }
 731 #endif
 732
 733
 734 /*
 735  *      Header manipulation
 736  */
 737 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
 738                                 __be32 flowlabel)
 739 {
 740         *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
 741 }
 742
 743 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
 744 {
 745         return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
 746 }
 747
 748 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
 749 {
 750         return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
 751 }
 752
 753 static inline u8 ip6_tclass(__be32 flowinfo)
 754 {
 755         return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
 756 }
 757 /*
 758  *      Prototypes exported by ipv6
 759  */
 760
 761 /*
 762  *      rcv function (called from netdevice level)
 763  */
 764
 765 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
 766              struct packet_type *pt, struct net_device *orig_dev);
 767
 768 int ip6_rcv_finish(struct sk_buff *skb);
 769
 770 /*
 771  *      upper-layer output functions
 772  */
 773 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 774              struct ipv6_txoptions *opt, int tclass);
 775
 776 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
 777
 778 int ip6_append_data(struct sock *sk,
 779                     int getfrag(void *from, char *to, int offset, int len,
 780                                 int odd, struct sk_buff *skb),
 781                     void *from, int length, int transhdrlen, int hlimit,
 782                     int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
 783                     struct rt6_info *rt, unsigned int flags, int dontfrag);
 784
 785 int ip6_push_pending_frames(struct sock *sk);
 786
 787 void ip6_flush_pending_frames(struct sock *sk);
 788
 789 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6);
 790 struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 791                                       const struct in6_addr *final_dst);
 792 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 793                                          const struct in6_addr *final_dst);
 794 struct dst_entry *ip6_blackhole_route(struct net *net,
 795                                       struct dst_entry *orig_dst);
 796
 797 /*
 798  *      skb processing functions
 799  */
 800
 801 int ip6_output(struct sock *sk, struct sk_buff *skb);
 802 int ip6_forward(struct sk_buff *skb);
 803 int ip6_input(struct sk_buff *skb);
 804 int ip6_mc_input(struct sk_buff *skb);
 805
 806 int __ip6_local_out(struct sk_buff *skb);
 807 int ip6_local_out(struct sk_buff *skb);
 808
 809 /*
 810  *      Extension header (options) processing
 811  */
 812
 813 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
 814                           u8 *proto, struct in6_addr **daddr_p);
 815 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
 816                          u8 *proto);
 817
 818 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
 819                      __be16 *frag_offp);
 820
 821 bool ipv6_ext_hdr(u8 nexthdr);
 822
 823 enum {
 824         IP6_FH_F_FRAG           = (1 << 0),
 825         IP6_FH_F_AUTH           = (1 << 1),
 826         IP6_FH_F_SKIP_RH        = (1 << 2),
 827 };
 828
 829 /* find specified header and get offset to it */
 830 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
 831                   unsigned short *fragoff, int *fragflg);
 832
 833 int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
 834
 835 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
 836                                 const struct ipv6_txoptions *opt,
 837                                 struct in6_addr *orig);
 838
 839 /*
 840  *      socket options (ipv6_sockglue.c)
 841  */
 842
 843 int ipv6_setsockopt(struct sock *sk, int level, int optname,
 844                     char __user *optval, unsigned int optlen);
 845 int ipv6_getsockopt(struct sock *sk, int level, int optname,
 846                     char __user *optval, int __user *optlen);
 847 int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
 848                            char __user *optval, unsigned int optlen);
 849 int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
 850                            char __user *optval, int __user *optlen);
 851
 852 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
 853 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
 854                                  int addr_len);
 855
 856 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
 857                     int *addr_len);
 858 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 859                      int *addr_len);
 860 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 861                      u32 info, u8 *payload);
 862 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
 863 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
 864
 865 int inet6_release(struct socket *sock);
 866 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
 867 int inet6_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len,
 868                   int peer);
 869 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
 870
 871 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
 872                               struct sock *sk);
 873
 874 /*
 875  * reassembly.c
 876  */
 877 extern const struct proto_ops inet6_stream_ops;
 878 extern const struct proto_ops inet6_dgram_ops;
 879
 880 struct group_source_req;
 881 struct group_filter;
 882
 883 int ip6_mc_source(int add, int omode, struct sock *sk,
 884                   struct group_source_req *pgsr);
 885 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
 886 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
 887                   struct group_filter __user *optval, int __user *optlen);
 888
 889 #ifdef CONFIG_PROC_FS
 890 int ac6_proc_init(struct net *net);
 891 void ac6_proc_exit(struct net *net);
 892 int raw6_proc_init(void);
 893 void raw6_proc_exit(void);
 894 int tcp6_proc_init(struct net *net);
 895 void tcp6_proc_exit(struct net *net);
 896 int udp6_proc_init(struct net *net);
 897 void udp6_proc_exit(struct net *net);
 898 int udplite6_proc_init(void);
 899 void udplite6_proc_exit(void);
 900 int ipv6_misc_proc_init(void);
 901 void ipv6_misc_proc_exit(void);
 902 int snmp6_register_dev(struct inet6_dev *idev);
 903 int snmp6_unregister_dev(struct inet6_dev *idev);
 904
 905 #else
 906 static inline int ac6_proc_init(struct net *net) { return 0; }
 907 static inline void ac6_proc_exit(struct net *net) { }
 908 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
 909 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
 910 #endif
 911
 912 #ifdef CONFIG_SYSCTL
 913 extern struct ctl_table ipv6_route_table_template[];
 914
 915 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
 916 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
 917 int ipv6_sysctl_register(void);
 918 void ipv6_sysctl_unregister(void);
 919 #endif
 920
 921 #endif /* _NET_IPV6_H */