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_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
 105 struct frag_hdr {
 106         __u8    nexthdr;
 107         __u8    reserved;
 108         __be16  frag_off;
 109         __be32  identification;
 110 };
 111
 112 #define IP6_MF          0x0001
 113 #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 */
 121 extern int sysctl_mld_max_msf;
 122 extern 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
 192 struct ip6_ra_chain {
 193         struct ip6_ra_chain     *next;
 194         struct sock             *sk;
 195         int                     sel;
 196         void                    (*destructor)(struct sock *);
 197 };
 198
 199 extern struct ip6_ra_chain      *ip6_ra_chain;
 200 extern 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
 207 struct ipv6_txoptions {
 208         atomic_t                refcnt;
 209         /* Length of this structure */
 210         int                     tot_len;
 211
 212         /* length of extension headers   */
 213
 214         __u16                   opt_flen;       /* after fragment hdr */
 215         __u16                   opt_nflen;      /* before fragment hdr */
 216
 217         struct ipv6_opt_hdr     *hopopt;
 218         struct ipv6_opt_hdr     *dst0opt;
 219         struct ipv6_rt_hdr      *srcrt; /* Routing Header */
 220         struct ipv6_opt_hdr     *dst1opt;
 221         struct rcu_head         rcu;
 222         /* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
 223 };
 224
 225 struct ip6_flowlabel {
 226         struct ip6_flowlabel __rcu *next;
 227         __be32                  label;
 228         atomic_t                users;
 229         struct in6_addr         dst;
 230         struct ipv6_txoptions   *opt;
 231         unsigned long           linger;
 232         struct rcu_head         rcu;
 233         u8                      share;
 234         union {
 235                 struct pid *pid;
 236                 kuid_t uid;
 237         } owner;
 238         unsigned long           lastuse;
 239         unsigned long           expires;
 240         struct net              *fl_net;
 241 };
 242
 243 #define IPV6_FLOWINFO_MASK              cpu_to_be32(0x0FFFFFFF)
 244 #define IPV6_FLOWLABEL_MASK             cpu_to_be32(0x000FFFFF)
 245 #define IPV6_FLOWLABEL_STATELESS_FLAG   cpu_to_be32(0x00080000)
 246
 247 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
 248 #define IPV6_TCLASS_SHIFT       20
 249
 250 struct ipv6_fl_socklist {
 251         struct ipv6_fl_socklist __rcu   *next;
 252         struct ip6_flowlabel            *fl;
 253         struct rcu_head                 rcu;
 254 };
 255
 256 static inline struct ipv6_txoptions *txopt_get(const struct ipv6_pinfo *np)
 257 {
 258         struct ipv6_txoptions *opt;
 259
 260         rcu_read_lock();
 261         opt = rcu_dereference(np->opt);
 262         if (opt) {
 263                 if (!atomic_inc_not_zero(&opt->refcnt))
 264                         opt = NULL;
 265                 else
 266                         opt = rcu_pointer_handoff(opt);
 267         }
 268         rcu_read_unlock();
 269         return opt;
 270 }
 271
 272 static inline void txopt_put(struct ipv6_txoptions *opt)
 273 {
 274         if (opt && atomic_dec_and_test(&opt->refcnt))
 275                 kfree_rcu(opt, rcu);
 276 }
 277
 278 struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label);
 279 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 280                                          struct ip6_flowlabel *fl,
 281                                          struct ipv6_txoptions *fopt);
 282 void fl6_free_socklist(struct sock *sk);
 283 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
 284 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
 285                            int flags);
 286 int ip6_flowlabel_init(void);
 287 void ip6_flowlabel_cleanup(void);
 288
 289 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
 290 {
 291         if (fl)
 292                 atomic_dec(&fl->users);
 293 }
 294
 295 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
 296
 297 int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 298                                struct icmp6hdr *thdr, int len);
 299
 300 int ip6_ra_control(struct sock *sk, int sel);
 301
 302 int ipv6_parse_hopopts(struct sk_buff *skb);
 303
 304 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
 305                                         struct ipv6_txoptions *opt);
 306 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
 307                                           struct ipv6_txoptions *opt,
 308                                           int newtype,
 309                                           struct ipv6_opt_hdr __user *newopt,
 310                                           int newoptlen);
 311 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
 312                                           struct ipv6_txoptions *opt);
 313
 314 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
 315                        const struct inet6_skb_parm *opt);
 316
 317 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
 318 {
 319         /* If forwarding is enabled, RA are not accepted unless the special
 320          * hybrid mode (accept_ra=2) is enabled.
 321          */
 322         return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
 323             idev->cnf.accept_ra;
 324 }
 325
 326 #if IS_ENABLED(CONFIG_IPV6)
 327 static inline int ip6_frag_mem(struct net *net)
 328 {
 329         return sum_frag_mem_limit(&net->ipv6.frags);
 330 }
 331 #endif
 332
 333 #define IPV6_FRAG_HIGH_THRESH   (4 * 1024*1024) /* 4194304 */
 334 #define IPV6_FRAG_LOW_THRESH    (3 * 1024*1024) /* 3145728 */
 335 #define IPV6_FRAG_TIMEOUT       (60 * HZ)       /* 60 seconds */
 336
 337 int __ipv6_addr_type(const struct in6_addr *addr);
 338 static inline int ipv6_addr_type(const struct in6_addr *addr)
 339 {
 340         return __ipv6_addr_type(addr) & 0xffff;
 341 }
 342
 343 static inline int ipv6_addr_scope(const struct in6_addr *addr)
 344 {
 345         return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
 346 }
 347
 348 static inline int __ipv6_addr_src_scope(int type)
 349 {
 350         return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
 351 }
 352
 353 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
 354 {
 355         return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
 356 }
 357
 358 static inline bool __ipv6_addr_needs_scope_id(int type)
 359 {
 360         return type & IPV6_ADDR_LINKLOCAL ||
 361                (type & IPV6_ADDR_MULTICAST &&
 362                 (type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
 363 }
 364
 365 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
 366 {
 367         return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
 368 }
 369
 370 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
 371 {
 372         return memcmp(a1, a2, sizeof(struct in6_addr));
 373 }
 374
 375 static inline bool
 376 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
 377                      const struct in6_addr *a2)
 378 {
 379 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 380         const unsigned long *ul1 = (const unsigned long *)a1;
 381         const unsigned long *ulm = (const unsigned long *)m;
 382         const unsigned long *ul2 = (const unsigned long *)a2;
 383
 384         return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
 385                   ((ul1[1] ^ ul2[1]) & ulm[1]));
 386 #else
 387         return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
 388                   ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
 389                   ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
 390                   ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
 391 #endif
 392 }
 393
 394 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
 395                                     const struct in6_addr *addr,
 396                                     int plen)
 397 {
 398         /* caller must guarantee 0 <= plen <= 128 */
 399         int o = plen >> 3,
 400             b = plen & 0x7;
 401
 402         memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
 403         memcpy(pfx->s6_addr, addr, o);
 404         if (b != 0)
 405                 pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
 406 }
 407
 408 static inline void ipv6_addr_prefix_copy(struct in6_addr *addr,
 409                                          const struct in6_addr *pfx,
 410                                          int plen)
 411 {
 412         /* caller must guarantee 0 <= plen <= 128 */
 413         int o = plen >> 3,
 414             b = plen & 0x7;
 415
 416         memcpy(addr->s6_addr, pfx, o);
 417         if (b != 0) {
 418                 addr->s6_addr[o] &= ~(0xff00 >> b);
 419                 addr->s6_addr[o] |= (pfx->s6_addr[o] & (0xff00 >> b));
 420         }
 421 }
 422
 423 static inline void __ipv6_addr_set_half(__be32 *addr,
 424                                         __be32 wh, __be32 wl)
 425 {
 426 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 427 #if defined(__BIG_ENDIAN)
 428         if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
 429                 *(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
 430                 return;
 431         }
 432 #elif defined(__LITTLE_ENDIAN)
 433         if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
 434                 *(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
 435                 return;
 436         }
 437 #endif
 438 #endif
 439         addr[0] = wh;
 440         addr[1] = wl;
 441 }
 442
 443 static inline void ipv6_addr_set(struct in6_addr *addr,
 444                                      __be32 w1, __be32 w2,
 445                                      __be32 w3, __be32 w4)
 446 {
 447         __ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
 448         __ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
 449 }
 450
 451 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
 452                                    const struct in6_addr *a2)
 453 {
 454 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 455         const unsigned long *ul1 = (const unsigned long *)a1;
 456         const unsigned long *ul2 = (const unsigned long *)a2;
 457
 458         return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
 459 #else
 460         return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
 461                 (a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
 462                 (a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
 463                 (a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
 464 #endif
 465 }
 466
 467 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 468 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
 469                                               const __be64 *a2,
 470                                               unsigned int len)
 471 {
 472         if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
 473                 return false;
 474         return true;
 475 }
 476
 477 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 478                                      const struct in6_addr *addr2,
 479                                      unsigned int prefixlen)
 480 {
 481         const __be64 *a1 = (const __be64 *)addr1;
 482         const __be64 *a2 = (const __be64 *)addr2;
 483
 484         if (prefixlen >= 64) {
 485                 if (a1[0] ^ a2[0])
 486                         return false;
 487                 return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
 488         }
 489         return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
 490 }
 491 #else
 492 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 493                                      const struct in6_addr *addr2,
 494                                      unsigned int prefixlen)
 495 {
 496         const __be32 *a1 = addr1->s6_addr32;
 497         const __be32 *a2 = addr2->s6_addr32;
 498         unsigned int pdw, pbi;
 499
 500         /* check complete u32 in prefix */
 501         pdw = prefixlen >> 5;
 502         if (pdw && memcmp(a1, a2, pdw << 2))
 503                 return false;
 504
 505         /* check incomplete u32 in prefix */
 506         pbi = prefixlen & 0x1f;
 507         if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
 508                 return false;
 509
 510         return true;
 511 }
 512 #endif
 513
 514 struct inet_frag_queue;
 515
 516 enum ip6_defrag_users {
 517         IP6_DEFRAG_LOCAL_DELIVER,
 518         IP6_DEFRAG_CONNTRACK_IN,
 519         __IP6_DEFRAG_CONNTRACK_IN       = IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 520         IP6_DEFRAG_CONNTRACK_OUT,
 521         __IP6_DEFRAG_CONNTRACK_OUT      = IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 522         IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
 523         __IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 524 };
 525
 526 struct ip6_create_arg {
 527         __be32 id;
 528         u32 user;
 529         const struct in6_addr *src;
 530         const struct in6_addr *dst;
 531         int iif;
 532         u8 ecn;
 533 };
 534
 535 void ip6_frag_init(struct inet_frag_queue *q, const void *a);
 536 bool ip6_frag_match(const struct inet_frag_queue *q, const void *a);
 537
 538 /*
 539  *      Equivalent of ipv4 struct ip
 540  */
 541 struct frag_queue {
 542         struct inet_frag_queue  q;
 543
 544         __be32                  id;             /* fragment id          */
 545         u32                     user;
 546         struct in6_addr         saddr;
 547         struct in6_addr         daddr;
 548
 549         int                     iif;
 550         unsigned int            csum;
 551         __u16                   nhoffset;
 552         u8                      ecn;
 553 };
 554
 555 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
 556                            struct inet_frags *frags);
 557
 558 static inline bool ipv6_addr_any(const struct in6_addr *a)
 559 {
 560 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 561         const unsigned long *ul = (const unsigned long *)a;
 562
 563         return (ul[0] | ul[1]) == 0UL;
 564 #else
 565         return (a->s6_addr32[0] | a->s6_addr32[1] |
 566                 a->s6_addr32[2] | a->s6_addr32[3]) == 0;
 567 #endif
 568 }
 569
 570 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
 571 {
 572 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 573         const unsigned long *ul = (const unsigned long *)a;
 574         unsigned long x = ul[0] ^ ul[1];
 575
 576         return (u32)(x ^ (x >> 32));
 577 #else
 578         return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
 579                              a->s6_addr32[2] ^ a->s6_addr32[3]);
 580 #endif
 581 }
 582
 583 /* more secured version of ipv6_addr_hash() */
 584 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
 585 {
 586         u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
 587
 588         return jhash_3words(v,
 589                             (__force u32)a->s6_addr32[2],
 590                             (__force u32)a->s6_addr32[3],
 591                             initval);
 592 }
 593
 594 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
 595 {
 596 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 597         const __be64 *be = (const __be64 *)a;
 598
 599         return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
 600 #else
 601         return (a->s6_addr32[0] | a->s6_addr32[1] |
 602                 a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
 603 #endif
 604 }
 605
 606 /*
 607  * Note that we must __force cast these to unsigned long to make sparse happy,
 608  * since all of the endian-annotated types are fixed size regardless of arch.
 609  */
 610 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
 611 {
 612         return (
 613 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 614                 *(unsigned long *)a |
 615 #else
 616                 (__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
 617 #endif
 618                 (__force unsigned long)(a->s6_addr32[2] ^
 619                                         cpu_to_be32(0x0000ffff))) == 0UL;
 620 }
 621
 622 /*
 623  * Check for a RFC 4843 ORCHID address
 624  * (Overlay Routable Cryptographic Hash Identifiers)
 625  */
 626 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
 627 {
 628         return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
 629 }
 630
 631 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
 632 {
 633         return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
 634 }
 635
 636 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
 637                                           struct in6_addr *v4mapped)
 638 {
 639         ipv6_addr_set(v4mapped,
 640                         0, 0,
 641                         htonl(0x0000FFFF),
 642                         addr);
 643 }
 644
 645 /*
 646  * find the first different bit between two addresses
 647  * length of address must be a multiple of 32bits
 648  */
 649 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
 650 {
 651         const __be32 *a1 = token1, *a2 = token2;
 652         int i;
 653
 654         addrlen >>= 2;
 655
 656         for (i = 0; i < addrlen; i++) {
 657                 __be32 xb = a1[i] ^ a2[i];
 658                 if (xb)
 659                         return i * 32 + 31 - __fls(ntohl(xb));
 660         }
 661
 662         /*
 663          *      we should *never* get to this point since that
 664          *      would mean the addrs are equal
 665          *
 666          *      However, we do get to it 8) And exacly, when
 667          *      addresses are equal 8)
 668          *
 669          *      ip route add 1111::/128 via ...
 670          *      ip route add 1111::/64 via ...
 671          *      and we are here.
 672          *
 673          *      Ideally, this function should stop comparison
 674          *      at prefix length. It does not, but it is still OK,
 675          *      if returned value is greater than prefix length.
 676          *                                      --ANK (980803)
 677          */
 678         return addrlen << 5;
 679 }
 680
 681 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 682 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
 683 {
 684         const __be64 *a1 = token1, *a2 = token2;
 685         int i;
 686
 687         addrlen >>= 3;
 688
 689         for (i = 0; i < addrlen; i++) {
 690                 __be64 xb = a1[i] ^ a2[i];
 691                 if (xb)
 692                         return i * 64 + 63 - __fls(be64_to_cpu(xb));
 693         }
 694
 695         return addrlen << 6;
 696 }
 697 #endif
 698
 699 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
 700 {
 701 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 702         if (__builtin_constant_p(addrlen) && !(addrlen & 7))
 703                 return __ipv6_addr_diff64(token1, token2, addrlen);
 704 #endif
 705         return __ipv6_addr_diff32(token1, token2, addrlen);
 706 }
 707
 708 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
 709 {
 710         return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
 711 }
 712
 713 __be32 ipv6_select_ident(struct net *net,
 714                          const struct in6_addr *daddr,
 715                          const struct in6_addr *saddr);
 716 void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
 717
 718 int ip6_dst_hoplimit(struct dst_entry *dst);
 719
 720 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
 721                                       struct dst_entry *dst)
 722 {
 723         int hlimit;
 724
 725         if (ipv6_addr_is_multicast(&fl6->daddr))
 726                 hlimit = np->mcast_hops;
 727         else
 728                 hlimit = np->hop_limit;
 729         if (hlimit < 0)
 730                 hlimit = ip6_dst_hoplimit(dst);
 731         return hlimit;
 732 }
 733
 734 /* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
 735  * Equivalent to :      flow->v6addrs.src = iph->saddr;
 736  *                      flow->v6addrs.dst = iph->daddr;
 737  */
 738 static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
 739                                             const struct ipv6hdr *iph)
 740 {
 741         BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
 742                      offsetof(typeof(flow->addrs), v6addrs.src) +
 743                      sizeof(flow->addrs.v6addrs.src));
 744         memcpy(&flow->addrs.v6addrs, &iph->saddr, sizeof(flow->addrs.v6addrs));
 745         flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 746 }
 747
 748 #if IS_ENABLED(CONFIG_IPV6)
 749
 750 /* Sysctl settings for net ipv6.auto_flowlabels */
 751 #define IP6_AUTO_FLOW_LABEL_OFF         0
 752 #define IP6_AUTO_FLOW_LABEL_OPTOUT      1
 753 #define IP6_AUTO_FLOW_LABEL_OPTIN       2
 754 #define IP6_AUTO_FLOW_LABEL_FORCED      3
 755
 756 #define IP6_AUTO_FLOW_LABEL_MAX         IP6_AUTO_FLOW_LABEL_FORCED
 757
 758 #define IP6_DEFAULT_AUTO_FLOW_LABELS    IP6_AUTO_FLOW_LABEL_OPTOUT
 759
 760 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 761                                         __be32 flowlabel, bool autolabel,
 762                                         struct flowi6 *fl6)
 763 {
 764         u32 hash;
 765
 766         if (flowlabel ||
 767             net->ipv6.sysctl.auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF ||
 768             (!autolabel &&
 769              net->ipv6.sysctl.auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED))
 770                 return flowlabel;
 771
 772         hash = skb_get_hash_flowi6(skb, fl6);
 773
 774         /* Since this is being sent on the wire obfuscate hash a bit
 775          * to minimize possbility that any useful information to an
 776          * attacker is leaked. Only lower 20 bits are relevant.
 777          */
 778         rol32(hash, 16);
 779
 780         flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
 781
 782         if (net->ipv6.sysctl.flowlabel_state_ranges)
 783                 flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
 784
 785         return flowlabel;
 786 }
 787
 788 static inline int ip6_default_np_autolabel(struct net *net)
 789 {
 790         switch (net->ipv6.sysctl.auto_flowlabels) {
 791         case IP6_AUTO_FLOW_LABEL_OFF:
 792         case IP6_AUTO_FLOW_LABEL_OPTIN:
 793         default:
 794                 return 0;
 795         case IP6_AUTO_FLOW_LABEL_OPTOUT:
 796         case IP6_AUTO_FLOW_LABEL_FORCED:
 797                 return 1;
 798         }
 799 }
 800 #else
 801 static inline void ip6_set_txhash(struct sock *sk) { }
 802 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 803                                         __be32 flowlabel, bool autolabel,
 804                                         struct flowi6 *fl6)
 805 {
 806         return flowlabel;
 807 }
 808 static inline int ip6_default_np_autolabel(struct net *net)
 809 {
 810         return 0;
 811 }
 812 #endif
 813
 814
 815 /*
 816  *      Header manipulation
 817  */
 818 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
 819                                 __be32 flowlabel)
 820 {
 821         *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
 822 }
 823
 824 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
 825 {
 826         return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
 827 }
 828
 829 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
 830 {
 831         return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
 832 }
 833
 834 static inline u8 ip6_tclass(__be32 flowinfo)
 835 {
 836         return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
 837 }
 838
 839 static inline __be32 ip6_make_flowinfo(unsigned int tclass, __be32 flowlabel)
 840 {
 841         return htonl(tclass << IPV6_TCLASS_SHIFT) | flowlabel;
 842 }
 843
 844 /*
 845  *      Prototypes exported by ipv6
 846  */
 847
 848 /*
 849  *      rcv function (called from netdevice level)
 850  */
 851
 852 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
 853              struct packet_type *pt, struct net_device *orig_dev);
 854
 855 int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
 856
 857 /*
 858  *      upper-layer output functions
 859  */
 860 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 861              struct ipv6_txoptions *opt, int tclass);
 862
 863 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
 864
 865 int ip6_append_data(struct sock *sk,
 866                     int getfrag(void *from, char *to, int offset, int len,
 867                                 int odd, struct sk_buff *skb),
 868                     void *from, int length, int transhdrlen, int hlimit,
 869                     int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
 870                     struct rt6_info *rt, unsigned int flags, int dontfrag);
 871
 872 int ip6_push_pending_frames(struct sock *sk);
 873
 874 void ip6_flush_pending_frames(struct sock *sk);
 875
 876 int ip6_send_skb(struct sk_buff *skb);
 877
 878 struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
 879                                struct inet_cork_full *cork,
 880                                struct inet6_cork *v6_cork);
 881 struct sk_buff *ip6_make_skb(struct sock *sk,
 882                              int getfrag(void *from, char *to, int offset,
 883                                          int len, int odd, struct sk_buff *skb),
 884                              void *from, int length, int transhdrlen,
 885                              int hlimit, int tclass, struct ipv6_txoptions *opt,
 886                              struct flowi6 *fl6, struct rt6_info *rt,
 887                              unsigned int flags, int dontfrag);
 888
 889 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
 890 {
 891         return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
 892                               &inet6_sk(sk)->cork);
 893 }
 894
 895 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
 896                    struct flowi6 *fl6);
 897 struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
 898                                       const struct in6_addr *final_dst);
 899 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 900                                          const struct in6_addr *final_dst);
 901 struct dst_entry *ip6_blackhole_route(struct net *net,
 902                                       struct dst_entry *orig_dst);
 903
 904 /*
 905  *      skb processing functions
 906  */
 907
 908 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 909 int ip6_forward(struct sk_buff *skb);
 910 int ip6_input(struct sk_buff *skb);
 911 int ip6_mc_input(struct sk_buff *skb);
 912
 913 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 914 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 915
 916 /*
 917  *      Extension header (options) processing
 918  */
 919
 920 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
 921                           u8 *proto, struct in6_addr **daddr_p);
 922 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
 923                          u8 *proto);
 924
 925 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
 926                      __be16 *frag_offp);
 927
 928 bool ipv6_ext_hdr(u8 nexthdr);
 929
 930 enum {
 931         IP6_FH_F_FRAG           = (1 << 0),
 932         IP6_FH_F_AUTH           = (1 << 1),
 933         IP6_FH_F_SKIP_RH        = (1 << 2),
 934 };
 935
 936 /* find specified header and get offset to it */
 937 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
 938                   unsigned short *fragoff, int *fragflg);
 939
 940 int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
 941
 942 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
 943                                 const struct ipv6_txoptions *opt,
 944                                 struct in6_addr *orig);
 945
 946 /*
 947  *      socket options (ipv6_sockglue.c)
 948  */
 949
 950 int ipv6_setsockopt(struct sock *sk, int level, int optname,
 951                     char __user *optval, unsigned int optlen);
 952 int ipv6_getsockopt(struct sock *sk, int level, int optname,
 953                     char __user *optval, int __user *optlen);
 954 int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
 955                            char __user *optval, unsigned int optlen);
 956 int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
 957                            char __user *optval, int __user *optlen);
 958
 959 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
 960 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
 961                                  int addr_len);
 962 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr);
 963 void ip6_datagram_release_cb(struct sock *sk);
 964
 965 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
 966                     int *addr_len);
 967 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 968                      int *addr_len);
 969 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 970                      u32 info, u8 *payload);
 971 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
 972 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
 973
 974 int inet6_release(struct socket *sock);
 975 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
 976 int inet6_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len,
 977                   int peer);
 978 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
 979
 980 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
 981                               struct sock *sk);
 982
 983 /*
 984  * reassembly.c
 985  */
 986 extern const struct proto_ops inet6_stream_ops;
 987 extern const struct proto_ops inet6_dgram_ops;
 988
 989 struct group_source_req;
 990 struct group_filter;
 991
 992 int ip6_mc_source(int add, int omode, struct sock *sk,
 993                   struct group_source_req *pgsr);
 994 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
 995 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
 996                   struct group_filter __user *optval, int __user *optlen);
 997
 998 #ifdef CONFIG_PROC_FS
 999 int ac6_proc_init(struct net *net);
1000 void ac6_proc_exit(struct net *net);
1001 int raw6_proc_init(void);
1002 void raw6_proc_exit(void);
1003 int tcp6_proc_init(struct net *net);
1004 void tcp6_proc_exit(struct net *net);
1005 int udp6_proc_init(struct net *net);
1006 void udp6_proc_exit(struct net *net);
1007 int udplite6_proc_init(void);
1008 void udplite6_proc_exit(void);
1009 int ipv6_misc_proc_init(void);
1010 void ipv6_misc_proc_exit(void);
1011 int snmp6_register_dev(struct inet6_dev *idev);
1012 int snmp6_unregister_dev(struct inet6_dev *idev);
1013
1014 #else
1015 static inline int ac6_proc_init(struct net *net) { return 0; }
1016 static inline void ac6_proc_exit(struct net *net) { }
1017 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
1018 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
1019 #endif
1020
1021 #ifdef CONFIG_SYSCTL
1022 extern struct ctl_table ipv6_route_table_template[];
1023
1024 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
1025 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
1026 int ipv6_sysctl_register(void);
1027 void ipv6_sysctl_unregister(void);
1028 #endif
1029
1030 int ipv6_sock_mc_join(struct sock *sk, int ifindex,
1031                       const struct in6_addr *addr);
1032 int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
1033                       const struct in6_addr *addr);
1034 #endif /* _NET_IPV6_H */