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 <linux/refcount.h>
  20 #include <net/if_inet6.h>
  21 #include <net/ndisc.h>
  22 #include <net/flow.h>
  23 #include <net/flow_dissector.h>
  24 #include <net/snmp.h>
  25
  26 #define SIN6_LEN_RFC2133        24
  27
  28 #define IPV6_MAXPLEN            65535
  29
  30 /*
  31  *      NextHeader field of IPv6 header
  32  */
  33
  34 #define NEXTHDR_HOP             0       /* Hop-by-hop option header. */
  35 #define NEXTHDR_TCP             6       /* TCP segment. */
  36 #define NEXTHDR_UDP             17      /* UDP message. */
  37 #define NEXTHDR_IPV6            41      /* IPv6 in IPv6 */
  38 #define NEXTHDR_ROUTING         43      /* Routing header. */
  39 #define NEXTHDR_FRAGMENT        44      /* Fragmentation/reassembly header. */
  40 #define NEXTHDR_GRE             47      /* GRE header. */
  41 #define NEXTHDR_ESP             50      /* Encapsulating security payload. */
  42 #define NEXTHDR_AUTH            51      /* Authentication header. */
  43 #define NEXTHDR_ICMP            58      /* ICMP for IPv6. */
  44 #define NEXTHDR_NONE            59      /* No next header */
  45 #define NEXTHDR_DEST            60      /* Destination options header. */
  46 #define NEXTHDR_SCTP            132     /* SCTP message. */
  47 #define NEXTHDR_MOBILITY        135     /* Mobility header. */
  48
  49 #define NEXTHDR_MAX             255
  50
  51 #define IPV6_DEFAULT_HOPLIMIT   64
  52 #define IPV6_DEFAULT_MCASTHOPS  1
  53
  54 /* Limits on Hop-by-Hop and Destination options.
  55  *
  56  * Per RFC8200 there is no limit on the maximum number or lengths of options in
  57  * Hop-by-Hop or Destination options other then the packet must fit in an MTU.
  58  * We allow configurable limits in order to mitigate potential denial of
  59  * service attacks.
  60  *
  61  * There are three limits that may be set:
  62  *   - Limit the number of options in a Hop-by-Hop or Destination options
  63  *     extension header
  64  *   - Limit the byte length of a Hop-by-Hop or Destination options extension
  65  *     header
  66  *   - Disallow unknown options
  67  *
  68  * The limits are expressed in corresponding sysctls:
  69  *
  70  * ipv6.sysctl.max_dst_opts_cnt
  71  * ipv6.sysctl.max_hbh_opts_cnt
  72  * ipv6.sysctl.max_dst_opts_len
  73  * ipv6.sysctl.max_hbh_opts_len
  74  *
  75  * max_*_opts_cnt is the number of TLVs that are allowed for Destination
  76  * options or Hop-by-Hop options. If the number is less than zero then unknown
  77  * TLVs are disallowed and the number of known options that are allowed is the
  78  * absolute value. Setting the value to INT_MAX indicates no limit.
  79  *
  80  * max_*_opts_len is the length limit in bytes of a Destination or
  81  * Hop-by-Hop options extension header. Setting the value to INT_MAX
  82  * indicates no length limit.
  83  *
  84  * If a limit is exceeded when processing an extension header the packet is
  85  * silently discarded.
  86  */
  87
  88 /* Default limits for Hop-by-Hop and Destination options */
  89 #define IP6_DEFAULT_MAX_DST_OPTS_CNT     8
  90 #define IP6_DEFAULT_MAX_HBH_OPTS_CNT     8
  91 #define IP6_DEFAULT_MAX_DST_OPTS_LEN     INT_MAX /* No limit */
  92 #define IP6_DEFAULT_MAX_HBH_OPTS_LEN     INT_MAX /* No limit */
  93
  94 /*
  95  *      Addr type
  96  *
  97  *      type    -       unicast | multicast
  98  *      scope   -       local   | site      | global
  99  *      v4      -       compat
 100  *      v4mapped
 101  *      any
 102  *      loopback
 103  */
 104
 105 #define IPV6_ADDR_ANY           0x0000U
 106
 107 #define IPV6_ADDR_UNICAST       0x0001U
 108 #define IPV6_ADDR_MULTICAST     0x0002U
 109
 110 #define IPV6_ADDR_LOOPBACK      0x0010U
 111 #define IPV6_ADDR_LINKLOCAL     0x0020U
 112 #define IPV6_ADDR_SITELOCAL     0x0040U
 113
 114 #define IPV6_ADDR_COMPATv4      0x0080U
 115
 116 #define IPV6_ADDR_SCOPE_MASK    0x00f0U
 117
 118 #define IPV6_ADDR_MAPPED        0x1000U
 119
 120 /*
 121  *      Addr scopes
 122  */
 123 #define IPV6_ADDR_MC_SCOPE(a)   \
 124         ((a)->s6_addr[1] & 0x0f)        /* nonstandard */
 125 #define __IPV6_ADDR_SCOPE_INVALID       -1
 126 #define IPV6_ADDR_SCOPE_NODELOCAL       0x01
 127 #define IPV6_ADDR_SCOPE_LINKLOCAL       0x02
 128 #define IPV6_ADDR_SCOPE_SITELOCAL       0x05
 129 #define IPV6_ADDR_SCOPE_ORGLOCAL        0x08
 130 #define IPV6_ADDR_SCOPE_GLOBAL          0x0e
 131
 132 /*
 133  *      Addr flags
 134  */
 135 #define IPV6_ADDR_MC_FLAG_TRANSIENT(a)  \
 136         ((a)->s6_addr[1] & 0x10)
 137 #define IPV6_ADDR_MC_FLAG_PREFIX(a)     \
 138         ((a)->s6_addr[1] & 0x20)
 139 #define IPV6_ADDR_MC_FLAG_RENDEZVOUS(a) \
 140         ((a)->s6_addr[1] & 0x40)
 141
 142 /*
 143  *      fragmentation header
 144  */
 145
 146 struct frag_hdr {
 147         __u8    nexthdr;
 148         __u8    reserved;
 149         __be16  frag_off;
 150         __be32  identification;
 151 };
 152
 153 #define IP6_MF          0x0001
 154 #define IP6_OFFSET      0xFFF8
 155
 156 #define IP6_REPLY_MARK(net, mark) \
 157         ((net)->ipv6.sysctl.fwmark_reflect ? (mark) : 0)
 158
 159 #include <net/sock.h>
 160
 161 /* sysctls */
 162 extern int sysctl_mld_max_msf;
 163 extern int sysctl_mld_qrv;
 164
 165 #define _DEVINC(net, statname, mod, idev, field)                        \
 166 ({                                                                      \
 167         struct inet6_dev *_idev = (idev);                               \
 168         if (likely(_idev != NULL))                                      \
 169                 mod##SNMP_INC_STATS64((_idev)->stats.statname, (field));\
 170         mod##SNMP_INC_STATS64((net)->mib.statname##_statistics, (field));\
 171 })
 172
 173 /* per device counters are atomic_long_t */
 174 #define _DEVINCATOMIC(net, statname, mod, idev, field)                  \
 175 ({                                                                      \
 176         struct inet6_dev *_idev = (idev);                               \
 177         if (likely(_idev != NULL))                                      \
 178                 SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
 179         mod##SNMP_INC_STATS((net)->mib.statname##_statistics, (field));\
 180 })
 181
 182 /* per device and per net counters are atomic_long_t */
 183 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)               \
 184 ({                                                                      \
 185         struct inet6_dev *_idev = (idev);                               \
 186         if (likely(_idev != NULL))                                      \
 187                 SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
 188         SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
 189 })
 190
 191 #define _DEVADD(net, statname, mod, idev, field, val)                   \
 192 ({                                                                      \
 193         struct inet6_dev *_idev = (idev);                               \
 194         if (likely(_idev != NULL))                                      \
 195                 mod##SNMP_ADD_STATS((_idev)->stats.statname, (field), (val)); \
 196         mod##SNMP_ADD_STATS((net)->mib.statname##_statistics, (field), (val));\
 197 })
 198
 199 #define _DEVUPD(net, statname, mod, idev, field, val)                   \
 200 ({                                                                      \
 201         struct inet6_dev *_idev = (idev);                               \
 202         if (likely(_idev != NULL))                                      \
 203                 mod##SNMP_UPD_PO_STATS((_idev)->stats.statname, field, (val)); \
 204         mod##SNMP_UPD_PO_STATS((net)->mib.statname##_statistics, field, (val));\
 205 })
 206
 207 /* MIBs */
 208
 209 #define IP6_INC_STATS(net, idev,field)          \
 210                 _DEVINC(net, ipv6, , idev, field)
 211 #define __IP6_INC_STATS(net, idev,field)        \
 212                 _DEVINC(net, ipv6, __, idev, field)
 213 #define IP6_ADD_STATS(net, idev,field,val)      \
 214                 _DEVADD(net, ipv6, , idev, field, val)
 215 #define __IP6_ADD_STATS(net, idev,field,val)    \
 216                 _DEVADD(net, ipv6, __, idev, field, val)
 217 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
 218                 _DEVUPD(net, ipv6, , idev, field, val)
 219 #define __IP6_UPD_PO_STATS(net, idev,field,val)   \
 220                 _DEVUPD(net, ipv6, __, idev, field, val)
 221 #define ICMP6_INC_STATS(net, idev, field)       \
 222                 _DEVINCATOMIC(net, icmpv6, , idev, field)
 223 #define __ICMP6_INC_STATS(net, idev, field)     \
 224                 _DEVINCATOMIC(net, icmpv6, __, idev, field)
 225
 226 #define ICMP6MSGOUT_INC_STATS(net, idev, field)         \
 227         _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
 228 #define ICMP6MSGIN_INC_STATS(net, idev, field)  \
 229         _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
 230
 231 struct ip6_ra_chain {
 232         struct ip6_ra_chain     *next;
 233         struct sock             *sk;
 234         int                     sel;
 235         void                    (*destructor)(struct sock *);
 236 };
 237
 238 extern struct ip6_ra_chain      *ip6_ra_chain;
 239 extern rwlock_t ip6_ra_lock;
 240
 241 /*
 242    This structure is prepared by protocol, when parsing
 243    ancillary data and passed to IPv6.
 244  */
 245
 246 struct ipv6_txoptions {
 247         refcount_t              refcnt;
 248         /* Length of this structure */
 249         int                     tot_len;
 250
 251         /* length of extension headers   */
 252
 253         __u16                   opt_flen;       /* after fragment hdr */
 254         __u16                   opt_nflen;      /* before fragment hdr */
 255
 256         struct ipv6_opt_hdr     *hopopt;
 257         struct ipv6_opt_hdr     *dst0opt;
 258         struct ipv6_rt_hdr      *srcrt; /* Routing Header */
 259         struct ipv6_opt_hdr     *dst1opt;
 260         struct rcu_head         rcu;
 261         /* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
 262 };
 263
 264 struct ip6_flowlabel {
 265         struct ip6_flowlabel __rcu *next;
 266         __be32                  label;
 267         atomic_t                users;
 268         struct in6_addr         dst;
 269         struct ipv6_txoptions   *opt;
 270         unsigned long           linger;
 271         struct rcu_head         rcu;
 272         u8                      share;
 273         union {
 274                 struct pid *pid;
 275                 kuid_t uid;
 276         } owner;
 277         unsigned long           lastuse;
 278         unsigned long           expires;
 279         struct net              *fl_net;
 280 };
 281
 282 #define IPV6_FLOWINFO_MASK              cpu_to_be32(0x0FFFFFFF)
 283 #define IPV6_FLOWLABEL_MASK             cpu_to_be32(0x000FFFFF)
 284 #define IPV6_FLOWLABEL_STATELESS_FLAG   cpu_to_be32(0x00080000)
 285
 286 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
 287 #define IPV6_TCLASS_SHIFT       20
 288
 289 struct ipv6_fl_socklist {
 290         struct ipv6_fl_socklist __rcu   *next;
 291         struct ip6_flowlabel            *fl;
 292         struct rcu_head                 rcu;
 293 };
 294
 295 struct ipcm6_cookie {
 296         __s16 hlimit;
 297         __s16 tclass;
 298         __s8  dontfrag;
 299         struct ipv6_txoptions *opt;
 300 };
 301
 302 static inline struct ipv6_txoptions *txopt_get(const struct ipv6_pinfo *np)
 303 {
 304         struct ipv6_txoptions *opt;
 305
 306         rcu_read_lock();
 307         opt = rcu_dereference(np->opt);
 308         if (opt) {
 309                 if (!refcount_inc_not_zero(&opt->refcnt))
 310                         opt = NULL;
 311                 else
 312                         opt = rcu_pointer_handoff(opt);
 313         }
 314         rcu_read_unlock();
 315         return opt;
 316 }
 317
 318 static inline void txopt_put(struct ipv6_txoptions *opt)
 319 {
 320         if (opt && refcount_dec_and_test(&opt->refcnt))
 321                 kfree_rcu(opt, rcu);
 322 }
 323
 324 struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label);
 325 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 326                                          struct ip6_flowlabel *fl,
 327                                          struct ipv6_txoptions *fopt);
 328 void fl6_free_socklist(struct sock *sk);
 329 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
 330 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
 331                            int flags);
 332 int ip6_flowlabel_init(void);
 333 void ip6_flowlabel_cleanup(void);
 334 bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np);
 335
 336 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
 337 {
 338         if (fl)
 339                 atomic_dec(&fl->users);
 340 }
 341
 342 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
 343
 344 void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 345                                 struct icmp6hdr *thdr, int len);
 346
 347 int ip6_ra_control(struct sock *sk, int sel);
 348
 349 int ipv6_parse_hopopts(struct sk_buff *skb);
 350
 351 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
 352                                         struct ipv6_txoptions *opt);
 353 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
 354                                           struct ipv6_txoptions *opt,
 355                                           int newtype,
 356                                           struct ipv6_opt_hdr __user *newopt,
 357                                           int newoptlen);
 358 struct ipv6_txoptions *
 359 ipv6_renew_options_kern(struct sock *sk,
 360                         struct ipv6_txoptions *opt,
 361                         int newtype,
 362                         struct ipv6_opt_hdr *newopt,
 363                         int newoptlen);
 364 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
 365                                           struct ipv6_txoptions *opt);
 366
 367 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
 368                        const struct inet6_skb_parm *opt);
 369 struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
 370                                            struct ipv6_txoptions *opt);
 371
 372 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
 373 {
 374         /* If forwarding is enabled, RA are not accepted unless the special
 375          * hybrid mode (accept_ra=2) is enabled.
 376          */
 377         return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
 378             idev->cnf.accept_ra;
 379 }
 380
 381 #if IS_ENABLED(CONFIG_IPV6)
 382 static inline int ip6_frag_mem(struct net *net)
 383 {
 384         return sum_frag_mem_limit(&net->ipv6.frags);
 385 }
 386 #endif
 387
 388 #define IPV6_FRAG_HIGH_THRESH   (4 * 1024*1024) /* 4194304 */
 389 #define IPV6_FRAG_LOW_THRESH    (3 * 1024*1024) /* 3145728 */
 390 #define IPV6_FRAG_TIMEOUT       (60 * HZ)       /* 60 seconds */
 391
 392 int __ipv6_addr_type(const struct in6_addr *addr);
 393 static inline int ipv6_addr_type(const struct in6_addr *addr)
 394 {
 395         return __ipv6_addr_type(addr) & 0xffff;
 396 }
 397
 398 static inline int ipv6_addr_scope(const struct in6_addr *addr)
 399 {
 400         return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
 401 }
 402
 403 static inline int __ipv6_addr_src_scope(int type)
 404 {
 405         return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
 406 }
 407
 408 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
 409 {
 410         return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
 411 }
 412
 413 static inline bool __ipv6_addr_needs_scope_id(int type)
 414 {
 415         return type & IPV6_ADDR_LINKLOCAL ||
 416                (type & IPV6_ADDR_MULTICAST &&
 417                 (type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
 418 }
 419
 420 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
 421 {
 422         return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
 423 }
 424
 425 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
 426 {
 427         return memcmp(a1, a2, sizeof(struct in6_addr));
 428 }
 429
 430 static inline bool
 431 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
 432                      const struct in6_addr *a2)
 433 {
 434 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 435         const unsigned long *ul1 = (const unsigned long *)a1;
 436         const unsigned long *ulm = (const unsigned long *)m;
 437         const unsigned long *ul2 = (const unsigned long *)a2;
 438
 439         return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
 440                   ((ul1[1] ^ ul2[1]) & ulm[1]));
 441 #else
 442         return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
 443                   ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
 444                   ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
 445                   ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
 446 #endif
 447 }
 448
 449 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
 450                                     const struct in6_addr *addr,
 451                                     int plen)
 452 {
 453         /* caller must guarantee 0 <= plen <= 128 */
 454         int o = plen >> 3,
 455             b = plen & 0x7;
 456
 457         memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
 458         memcpy(pfx->s6_addr, addr, o);
 459         if (b != 0)
 460                 pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
 461 }
 462
 463 static inline void ipv6_addr_prefix_copy(struct in6_addr *addr,
 464                                          const struct in6_addr *pfx,
 465                                          int plen)
 466 {
 467         /* caller must guarantee 0 <= plen <= 128 */
 468         int o = plen >> 3,
 469             b = plen & 0x7;
 470
 471         memcpy(addr->s6_addr, pfx, o);
 472         if (b != 0) {
 473                 addr->s6_addr[o] &= ~(0xff00 >> b);
 474                 addr->s6_addr[o] |= (pfx->s6_addr[o] & (0xff00 >> b));
 475         }
 476 }
 477
 478 static inline void __ipv6_addr_set_half(__be32 *addr,
 479                                         __be32 wh, __be32 wl)
 480 {
 481 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 482 #if defined(__BIG_ENDIAN)
 483         if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
 484                 *(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
 485                 return;
 486         }
 487 #elif defined(__LITTLE_ENDIAN)
 488         if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
 489                 *(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
 490                 return;
 491         }
 492 #endif
 493 #endif
 494         addr[0] = wh;
 495         addr[1] = wl;
 496 }
 497
 498 static inline void ipv6_addr_set(struct in6_addr *addr,
 499                                      __be32 w1, __be32 w2,
 500                                      __be32 w3, __be32 w4)
 501 {
 502         __ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
 503         __ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
 504 }
 505
 506 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
 507                                    const struct in6_addr *a2)
 508 {
 509 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 510         const unsigned long *ul1 = (const unsigned long *)a1;
 511         const unsigned long *ul2 = (const unsigned long *)a2;
 512
 513         return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
 514 #else
 515         return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
 516                 (a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
 517                 (a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
 518                 (a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
 519 #endif
 520 }
 521
 522 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 523 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
 524                                               const __be64 *a2,
 525                                               unsigned int len)
 526 {
 527         if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
 528                 return false;
 529         return true;
 530 }
 531
 532 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 533                                      const struct in6_addr *addr2,
 534                                      unsigned int prefixlen)
 535 {
 536         const __be64 *a1 = (const __be64 *)addr1;
 537         const __be64 *a2 = (const __be64 *)addr2;
 538
 539         if (prefixlen >= 64) {
 540                 if (a1[0] ^ a2[0])
 541                         return false;
 542                 return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
 543         }
 544         return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
 545 }
 546 #else
 547 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
 548                                      const struct in6_addr *addr2,
 549                                      unsigned int prefixlen)
 550 {
 551         const __be32 *a1 = addr1->s6_addr32;
 552         const __be32 *a2 = addr2->s6_addr32;
 553         unsigned int pdw, pbi;
 554
 555         /* check complete u32 in prefix */
 556         pdw = prefixlen >> 5;
 557         if (pdw && memcmp(a1, a2, pdw << 2))
 558                 return false;
 559
 560         /* check incomplete u32 in prefix */
 561         pbi = prefixlen & 0x1f;
 562         if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
 563                 return false;
 564
 565         return true;
 566 }
 567 #endif
 568
 569 struct inet_frag_queue;
 570
 571 enum ip6_defrag_users {
 572         IP6_DEFRAG_LOCAL_DELIVER,
 573         IP6_DEFRAG_CONNTRACK_IN,
 574         __IP6_DEFRAG_CONNTRACK_IN       = IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
 575         IP6_DEFRAG_CONNTRACK_OUT,
 576         __IP6_DEFRAG_CONNTRACK_OUT      = IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
 577         IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
 578         __IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
 579 };
 580
 581 struct ip6_create_arg {
 582         __be32 id;
 583         u32 user;
 584         const struct in6_addr *src;
 585         const struct in6_addr *dst;
 586         int iif;
 587         u8 ecn;
 588 };
 589
 590 void ip6_frag_init(struct inet_frag_queue *q, const void *a);
 591 bool ip6_frag_match(const struct inet_frag_queue *q, const void *a);
 592
 593 /*
 594  *      Equivalent of ipv4 struct ip
 595  */
 596 struct frag_queue {
 597         struct inet_frag_queue  q;
 598
 599         __be32                  id;             /* fragment id          */
 600         u32                     user;
 601         struct in6_addr         saddr;
 602         struct in6_addr         daddr;
 603
 604         int                     iif;
 605         unsigned int            csum;
 606         __u16                   nhoffset;
 607         u8                      ecn;
 608 };
 609
 610 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
 611                            struct inet_frags *frags);
 612
 613 static inline bool ipv6_addr_any(const struct in6_addr *a)
 614 {
 615 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 616         const unsigned long *ul = (const unsigned long *)a;
 617
 618         return (ul[0] | ul[1]) == 0UL;
 619 #else
 620         return (a->s6_addr32[0] | a->s6_addr32[1] |
 621                 a->s6_addr32[2] | a->s6_addr32[3]) == 0;
 622 #endif
 623 }
 624
 625 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
 626 {
 627 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 628         const unsigned long *ul = (const unsigned long *)a;
 629         unsigned long x = ul[0] ^ ul[1];
 630
 631         return (u32)(x ^ (x >> 32));
 632 #else
 633         return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
 634                              a->s6_addr32[2] ^ a->s6_addr32[3]);
 635 #endif
 636 }
 637
 638 /* more secured version of ipv6_addr_hash() */
 639 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
 640 {
 641         u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
 642
 643         return jhash_3words(v,
 644                             (__force u32)a->s6_addr32[2],
 645                             (__force u32)a->s6_addr32[3],
 646                             initval);
 647 }
 648
 649 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
 650 {
 651 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 652         const __be64 *be = (const __be64 *)a;
 653
 654         return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
 655 #else
 656         return (a->s6_addr32[0] | a->s6_addr32[1] |
 657                 a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
 658 #endif
 659 }
 660
 661 /*
 662  * Note that we must __force cast these to unsigned long to make sparse happy,
 663  * since all of the endian-annotated types are fixed size regardless of arch.
 664  */
 665 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
 666 {
 667         return (
 668 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 669                 *(unsigned long *)a |
 670 #else
 671                 (__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
 672 #endif
 673                 (__force unsigned long)(a->s6_addr32[2] ^
 674                                         cpu_to_be32(0x0000ffff))) == 0UL;
 675 }
 676
 677 /*
 678  * Check for a RFC 4843 ORCHID address
 679  * (Overlay Routable Cryptographic Hash Identifiers)
 680  */
 681 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
 682 {
 683         return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
 684 }
 685
 686 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
 687 {
 688         return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
 689 }
 690
 691 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
 692                                           struct in6_addr *v4mapped)
 693 {
 694         ipv6_addr_set(v4mapped,
 695                         0, 0,
 696                         htonl(0x0000FFFF),
 697                         addr);
 698 }
 699
 700 /*
 701  * find the first different bit between two addresses
 702  * length of address must be a multiple of 32bits
 703  */
 704 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
 705 {
 706         const __be32 *a1 = token1, *a2 = token2;
 707         int i;
 708
 709         addrlen >>= 2;
 710
 711         for (i = 0; i < addrlen; i++) {
 712                 __be32 xb = a1[i] ^ a2[i];
 713                 if (xb)
 714                         return i * 32 + 31 - __fls(ntohl(xb));
 715         }
 716
 717         /*
 718          *      we should *never* get to this point since that
 719          *      would mean the addrs are equal
 720          *
 721          *      However, we do get to it 8) And exacly, when
 722          *      addresses are equal 8)
 723          *
 724          *      ip route add 1111::/128 via ...
 725          *      ip route add 1111::/64 via ...
 726          *      and we are here.
 727          *
 728          *      Ideally, this function should stop comparison
 729          *      at prefix length. It does not, but it is still OK,
 730          *      if returned value is greater than prefix length.
 731          *                                      --ANK (980803)
 732          */
 733         return addrlen << 5;
 734 }
 735
 736 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 737 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
 738 {
 739         const __be64 *a1 = token1, *a2 = token2;
 740         int i;
 741
 742         addrlen >>= 3;
 743
 744         for (i = 0; i < addrlen; i++) {
 745                 __be64 xb = a1[i] ^ a2[i];
 746                 if (xb)
 747                         return i * 64 + 63 - __fls(be64_to_cpu(xb));
 748         }
 749
 750         return addrlen << 6;
 751 }
 752 #endif
 753
 754 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
 755 {
 756 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 757         if (__builtin_constant_p(addrlen) && !(addrlen & 7))
 758                 return __ipv6_addr_diff64(token1, token2, addrlen);
 759 #endif
 760         return __ipv6_addr_diff32(token1, token2, addrlen);
 761 }
 762
 763 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
 764 {
 765         return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
 766 }
 767
 768 __be32 ipv6_select_ident(struct net *net,
 769                          const struct in6_addr *daddr,
 770                          const struct in6_addr *saddr);
 771 __be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
 772
 773 int ip6_dst_hoplimit(struct dst_entry *dst);
 774
 775 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
 776                                       struct dst_entry *dst)
 777 {
 778         int hlimit;
 779
 780         if (ipv6_addr_is_multicast(&fl6->daddr))
 781                 hlimit = np->mcast_hops;
 782         else
 783                 hlimit = np->hop_limit;
 784         if (hlimit < 0)
 785                 hlimit = ip6_dst_hoplimit(dst);
 786         return hlimit;
 787 }
 788
 789 /* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
 790  * Equivalent to :      flow->v6addrs.src = iph->saddr;
 791  *                      flow->v6addrs.dst = iph->daddr;
 792  */
 793 static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
 794                                             const struct ipv6hdr *iph)
 795 {
 796         BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
 797                      offsetof(typeof(flow->addrs), v6addrs.src) +
 798                      sizeof(flow->addrs.v6addrs.src));
 799         memcpy(&flow->addrs.v6addrs, &iph->saddr, sizeof(flow->addrs.v6addrs));
 800         flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 801 }
 802
 803 #if IS_ENABLED(CONFIG_IPV6)
 804
 805 /* Sysctl settings for net ipv6.auto_flowlabels */
 806 #define IP6_AUTO_FLOW_LABEL_OFF         0
 807 #define IP6_AUTO_FLOW_LABEL_OPTOUT      1
 808 #define IP6_AUTO_FLOW_LABEL_OPTIN       2
 809 #define IP6_AUTO_FLOW_LABEL_FORCED      3
 810
 811 #define IP6_AUTO_FLOW_LABEL_MAX         IP6_AUTO_FLOW_LABEL_FORCED
 812
 813 #define IP6_DEFAULT_AUTO_FLOW_LABELS    IP6_AUTO_FLOW_LABEL_OPTOUT
 814
 815 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 816                                         __be32 flowlabel, bool autolabel,
 817                                         struct flowi6 *fl6)
 818 {
 819         u32 hash;
 820
 821         /* @flowlabel may include more than a flow label, eg, the traffic class.
 822          * Here we want only the flow label value.
 823          */
 824         flowlabel &= IPV6_FLOWLABEL_MASK;
 825
 826         if (flowlabel ||
 827             net->ipv6.sysctl.auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF ||
 828             (!autolabel &&
 829              net->ipv6.sysctl.auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED))
 830                 return flowlabel;
 831
 832         hash = skb_get_hash_flowi6(skb, fl6);
 833
 834         /* Since this is being sent on the wire obfuscate hash a bit
 835          * to minimize possbility that any useful information to an
 836          * attacker is leaked. Only lower 20 bits are relevant.
 837          */
 838         rol32(hash, 16);
 839
 840         flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
 841
 842         if (net->ipv6.sysctl.flowlabel_state_ranges)
 843                 flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
 844
 845         return flowlabel;
 846 }
 847
 848 static inline int ip6_default_np_autolabel(struct net *net)
 849 {
 850         switch (net->ipv6.sysctl.auto_flowlabels) {
 851         case IP6_AUTO_FLOW_LABEL_OFF:
 852         case IP6_AUTO_FLOW_LABEL_OPTIN:
 853         default:
 854                 return 0;
 855         case IP6_AUTO_FLOW_LABEL_OPTOUT:
 856         case IP6_AUTO_FLOW_LABEL_FORCED:
 857                 return 1;
 858         }
 859 }
 860 #else
 861 static inline void ip6_set_txhash(struct sock *sk) { }
 862 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 863                                         __be32 flowlabel, bool autolabel,
 864                                         struct flowi6 *fl6)
 865 {
 866         return flowlabel;
 867 }
 868 static inline int ip6_default_np_autolabel(struct net *net)
 869 {
 870         return 0;
 871 }
 872 #endif
 873
 874
 875 /*
 876  *      Header manipulation
 877  */
 878 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
 879                                 __be32 flowlabel)
 880 {
 881         *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
 882 }
 883
 884 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
 885 {
 886         return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
 887 }
 888
 889 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
 890 {
 891         return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
 892 }
 893
 894 static inline u8 ip6_tclass(__be32 flowinfo)
 895 {
 896         return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
 897 }
 898
 899 static inline __be32 ip6_make_flowinfo(unsigned int tclass, __be32 flowlabel)
 900 {
 901         return htonl(tclass << IPV6_TCLASS_SHIFT) | flowlabel;
 902 }
 903
 904 /*
 905  *      Prototypes exported by ipv6
 906  */
 907
 908 /*
 909  *      rcv function (called from netdevice level)
 910  */
 911
 912 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
 913              struct packet_type *pt, struct net_device *orig_dev);
 914
 915 int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
 916
 917 /*
 918  *      upper-layer output functions
 919  */
 920 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 921              __u32 mark, struct ipv6_txoptions *opt, int tclass);
 922
 923 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
 924
 925 int ip6_append_data(struct sock *sk,
 926                     int getfrag(void *from, char *to, int offset, int len,
 927                                 int odd, struct sk_buff *skb),
 928                     void *from, int length, int transhdrlen,
 929                     struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
 930                     struct rt6_info *rt, unsigned int flags,
 931                     const struct sockcm_cookie *sockc);
 932
 933 int ip6_push_pending_frames(struct sock *sk);
 934
 935 void ip6_flush_pending_frames(struct sock *sk);
 936
 937 int ip6_send_skb(struct sk_buff *skb);
 938
 939 struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
 940                                struct inet_cork_full *cork,
 941                                struct inet6_cork *v6_cork);
 942 struct sk_buff *ip6_make_skb(struct sock *sk,
 943                              int getfrag(void *from, char *to, int offset,
 944                                          int len, int odd, struct sk_buff *skb),
 945                              void *from, int length, int transhdrlen,
 946                              struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
 947                              struct rt6_info *rt, unsigned int flags,
 948                              const struct sockcm_cookie *sockc);
 949
 950 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
 951 {
 952         return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
 953                               &inet6_sk(sk)->cork);
 954 }
 955
 956 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
 957                    struct flowi6 *fl6);
 958 struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
 959                                       const struct in6_addr *final_dst);
 960 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 961                                          const struct in6_addr *final_dst);
 962 struct dst_entry *ip6_blackhole_route(struct net *net,
 963                                       struct dst_entry *orig_dst);
 964
 965 /*
 966  *      skb processing functions
 967  */
 968
 969 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 970 int ip6_forward(struct sk_buff *skb);
 971 int ip6_input(struct sk_buff *skb);
 972 int ip6_mc_input(struct sk_buff *skb);
 973
 974 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 975 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 976
 977 /*
 978  *      Extension header (options) processing
 979  */
 980
 981 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
 982                           u8 *proto, struct in6_addr **daddr_p,
 983                           struct in6_addr *saddr);
 984 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
 985                          u8 *proto);
 986
 987 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
 988                      __be16 *frag_offp);
 989
 990 bool ipv6_ext_hdr(u8 nexthdr);
 991
 992 enum {
 993         IP6_FH_F_FRAG           = (1 << 0),
 994         IP6_FH_F_AUTH           = (1 << 1),
 995         IP6_FH_F_SKIP_RH        = (1 << 2),
 996 };
 997
 998 /* find specified header and get offset to it */
 999 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
1000                   unsigned short *fragoff, int *fragflg);
1001
1002 int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type);
1003
1004 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1005                                 const struct ipv6_txoptions *opt,
1006                                 struct in6_addr *orig);
1007
1008 /*
1009  *      socket options (ipv6_sockglue.c)
1010  */
1011
1012 int ipv6_setsockopt(struct sock *sk, int level, int optname,
1013                     char __user *optval, unsigned int optlen);
1014 int ipv6_getsockopt(struct sock *sk, int level, int optname,
1015                     char __user *optval, int __user *optlen);
1016 int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
1017                            char __user *optval, unsigned int optlen);
1018 int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
1019                            char __user *optval, int __user *optlen);
1020
1021 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *addr,
1022                            int addr_len);
1023 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
1024 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
1025                                  int addr_len);
1026 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr);
1027 void ip6_datagram_release_cb(struct sock *sk);
1028
1029 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
1030                     int *addr_len);
1031 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
1032                      int *addr_len);
1033 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
1034                      u32 info, u8 *payload);
1035 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
1036 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
1037
1038 int inet6_release(struct socket *sock);
1039 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
1040 int inet6_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len,
1041                   int peer);
1042 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
1043
1044 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
1045                               struct sock *sk);
1046
1047 /*
1048  * reassembly.c
1049  */
1050 extern const struct proto_ops inet6_stream_ops;
1051 extern const struct proto_ops inet6_dgram_ops;
1052 extern const struct proto_ops inet6_sockraw_ops;
1053
1054 struct group_source_req;
1055 struct group_filter;
1056
1057 int ip6_mc_source(int add, int omode, struct sock *sk,
1058                   struct group_source_req *pgsr);
1059 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
1060 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
1061                   struct group_filter __user *optval, int __user *optlen);
1062
1063 #ifdef CONFIG_PROC_FS
1064 int ac6_proc_init(struct net *net);
1065 void ac6_proc_exit(struct net *net);
1066 int raw6_proc_init(void);
1067 void raw6_proc_exit(void);
1068 int tcp6_proc_init(struct net *net);
1069 void tcp6_proc_exit(struct net *net);
1070 int udp6_proc_init(struct net *net);
1071 void udp6_proc_exit(struct net *net);
1072 int udplite6_proc_init(void);
1073 void udplite6_proc_exit(void);
1074 int ipv6_misc_proc_init(void);
1075 void ipv6_misc_proc_exit(void);
1076 int snmp6_register_dev(struct inet6_dev *idev);
1077 int snmp6_unregister_dev(struct inet6_dev *idev);
1078
1079 #else
1080 static inline int ac6_proc_init(struct net *net) { return 0; }
1081 static inline void ac6_proc_exit(struct net *net) { }
1082 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
1083 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
1084 #endif
1085
1086 #ifdef CONFIG_SYSCTL
1087 extern struct ctl_table ipv6_route_table_template[];
1088
1089 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
1090 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
1091 int ipv6_sysctl_register(void);
1092 void ipv6_sysctl_unregister(void);
1093 #endif
1094
1095 int ipv6_sock_mc_join(struct sock *sk, int ifindex,
1096                       const struct in6_addr *addr);
1097 int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
1098                       const struct in6_addr *addr);
1099 #endif /* _NET_IPV6_H */