include/net/xfrm.h

   1 #ifndef _NET_XFRM_H
   2 #define _NET_XFRM_H
   3
   4 #include <linux/compiler.h>
   5 #include <linux/in.h>
   6 #include <linux/xfrm.h>
   7 #include <linux/spinlock.h>
   8 #include <linux/list.h>
   9 #include <linux/skbuff.h>
  10 #include <linux/socket.h>
  11 #include <linux/pfkeyv2.h>
  12 #include <linux/ipsec.h>
  13 #include <linux/in6.h>
  14 #include <linux/mutex.h>
  15
  16 #include <net/sock.h>
  17 #include <net/dst.h>
  18 #include <net/route.h>
  19 #include <net/ipv6.h>
  20 #include <net/ip6_fib.h>
  21
  22 #define XFRM_ALIGN8(len)        (((len) + 7) & ~7)
  23 #define MODULE_ALIAS_XFRM_MODE(family, encap) \
  24         MODULE_ALIAS("xfrm-mode-" __stringify(family) "-" __stringify(encap))
  25
  26 extern struct sock *xfrm_nl;
  27 extern u32 sysctl_xfrm_aevent_etime;
  28 extern u32 sysctl_xfrm_aevent_rseqth;
  29
  30 extern struct mutex xfrm_cfg_mutex;
  31
  32 /* Organization of SPD aka "XFRM rules"
  33    ------------------------------------
  34
  35    Basic objects:
  36    - policy rule, struct xfrm_policy (=SPD entry)
  37    - bundle of transformations, struct dst_entry == struct xfrm_dst (=SA bundle)
  38    - instance of a transformer, struct xfrm_state (=SA)
  39    - template to clone xfrm_state, struct xfrm_tmpl
  40
  41    SPD is plain linear list of xfrm_policy rules, ordered by priority.
  42    (To be compatible with existing pfkeyv2 implementations,
  43    many rules with priority of 0x7fffffff are allowed to exist and
  44    such rules are ordered in an unpredictable way, thanks to bsd folks.)
  45
  46    Lookup is plain linear search until the first match with selector.
  47
  48    If "action" is "block", then we prohibit the flow, otherwise:
  49    if "xfrms_nr" is zero, the flow passes untransformed. Otherwise,
  50    policy entry has list of up to XFRM_MAX_DEPTH transformations,
  51    described by templates xfrm_tmpl. Each template is resolved
  52    to a complete xfrm_state (see below) and we pack bundle of transformations
  53    to a dst_entry returned to requestor.
  54
  55    dst -. xfrm  .-> xfrm_state #1
  56     |---. child .-> dst -. xfrm .-> xfrm_state #2
  57                      |---. child .-> dst -. xfrm .-> xfrm_state #3
  58                                       |---. child .-> NULL
  59
  60    Bundles are cached at xrfm_policy struct (field ->bundles).
  61
  62
  63    Resolution of xrfm_tmpl
  64    -----------------------
  65    Template contains:
  66    1. ->mode            Mode: transport or tunnel
  67    2. ->id.proto        Protocol: AH/ESP/IPCOMP
  68    3. ->id.daddr        Remote tunnel endpoint, ignored for transport mode.
  69       Q: allow to resolve security gateway?
  70    4. ->id.spi          If not zero, static SPI.
  71    5. ->saddr           Local tunnel endpoint, ignored for transport mode.
  72    6. ->algos           List of allowed algos. Plain bitmask now.
  73       Q: ealgos, aalgos, calgos. What a mess...
  74    7. ->share           Sharing mode.
  75       Q: how to implement private sharing mode? To add struct sock* to
  76       flow id?
  77
  78    Having this template we search through SAD searching for entries
  79    with appropriate mode/proto/algo, permitted by selector.
  80    If no appropriate entry found, it is requested from key manager.
  81
  82    PROBLEMS:
  83    Q: How to find all the bundles referring to a physical path for
  84       PMTU discovery? Seems, dst should contain list of all parents...
  85       and enter to infinite locking hierarchy disaster.
  86       No! It is easier, we will not search for them, let them find us.
  87       We add genid to each dst plus pointer to genid of raw IP route,
  88       pmtu disc will update pmtu on raw IP route and increase its genid.
  89       dst_check() will see this for top level and trigger resyncing
  90       metrics. Plus, it will be made via sk->sk_dst_cache. Solved.
  91  */
  92
  93 /* Full description of state of transformer. */
  94 struct xfrm_state
  95 {
  96         /* Note: bydst is re-used during gc */
  97         struct list_head        bydst;
  98         struct list_head        bysrc;
  99         struct list_head        byspi;
 100
 101         atomic_t                refcnt;
 102         spinlock_t              lock;
 103
 104         struct xfrm_id          id;
 105         struct xfrm_selector    sel;
 106
 107         /* Key manger bits */
 108         struct {
 109                 u8              state;
 110                 u8              dying;
 111                 u32             seq;
 112         } km;
 113
 114         /* Parameters of this state. */
 115         struct {
 116                 u32             reqid;
 117                 u8              mode;
 118                 u8              replay_window;
 119                 u8              aalgo, ealgo, calgo;
 120                 u8              flags;
 121                 u16             family;
 122                 xfrm_address_t  saddr;
 123                 int             header_len;
 124                 int             trailer_len;
 125         } props;
 126
 127         struct xfrm_lifetime_cfg lft;
 128
 129         /* Data for transformer */
 130         struct xfrm_algo        *aalg;
 131         struct xfrm_algo        *ealg;
 132         struct xfrm_algo        *calg;
 133
 134         /* Data for encapsulator */
 135         struct xfrm_encap_tmpl  *encap;
 136
 137         /* Data for care-of address */
 138         xfrm_address_t  *coaddr;
 139
 140         /* IPComp needs an IPIP tunnel for handling uncompressed packets */
 141         struct xfrm_state       *tunnel;
 142
 143         /* If a tunnel, number of users + 1 */
 144         atomic_t                tunnel_users;
 145
 146         /* State for replay detection */
 147         struct xfrm_replay_state replay;
 148
 149         /* Replay detection state at the time we sent the last notification */
 150         struct xfrm_replay_state preplay;
 151
 152         /* internal flag that only holds state for delayed aevent at the
 153          * moment
 154         */
 155         u32                     xflags;
 156
 157         /* Replay detection notification settings */
 158         u32                     replay_maxage;
 159         u32                     replay_maxdiff;
 160
 161         /* Replay detection notification timer */
 162         struct timer_list       rtimer;
 163
 164         /* Statistics */
 165         struct xfrm_stats       stats;
 166
 167         struct xfrm_lifetime_cur curlft;
 168         struct timer_list       timer;
 169
 170         /* Last used time */
 171         u64                     lastused;
 172
 173         /* Reference to data common to all the instances of this
 174          * transformer. */
 175         struct xfrm_type        *type;
 176         struct xfrm_mode        *mode;
 177
 178         /* Security context */
 179         struct xfrm_sec_ctx     *security;
 180
 181         /* Private data of this transformer, format is opaque,
 182          * interpreted by xfrm_type methods. */
 183         void                    *data;
 184 };
 185
 186 /* xflags - make enum if more show up */
 187 #define XFRM_TIME_DEFER 1
 188
 189 enum {
 190         XFRM_STATE_VOID,
 191         XFRM_STATE_ACQ,
 192         XFRM_STATE_VALID,
 193         XFRM_STATE_ERROR,
 194         XFRM_STATE_EXPIRED,
 195         XFRM_STATE_DEAD
 196 };
 197
 198 /* callback structure passed from either netlink or pfkey */
 199 struct km_event
 200 {
 201         union {
 202                 u32 hard;
 203                 u32 proto;
 204                 u32 byid;
 205                 u32 aevent;
 206         } data;
 207
 208         u32     seq;
 209         u32     pid;
 210         u32     event;
 211 };
 212
 213 struct xfrm_type;
 214 struct xfrm_dst;
 215 struct xfrm_policy_afinfo {
 216         unsigned short          family;
 217         struct xfrm_type        *type_map[IPPROTO_MAX];
 218         struct xfrm_mode        *mode_map[XFRM_MODE_MAX];
 219         struct dst_ops          *dst_ops;
 220         void                    (*garbage_collect)(void);
 221         int                     (*dst_lookup)(struct xfrm_dst **dst, struct flowi *fl);
 222         struct dst_entry        *(*find_bundle)(struct flowi *fl, struct xfrm_policy *policy);
 223         int                     (*bundle_create)(struct xfrm_policy *policy,
 224                                                  struct xfrm_state **xfrm,
 225                                                  int nx,
 226                                                  struct flowi *fl,
 227                                                  struct dst_entry **dst_p);
 228         void                    (*decode_session)(struct sk_buff *skb,
 229                                                   struct flowi *fl);
 230 };
 231
 232 extern int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo);
 233 extern int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo);
 234 extern void km_policy_notify(struct xfrm_policy *xp, int dir, struct km_event *c);
 235 extern void km_state_notify(struct xfrm_state *x, struct km_event *c);
 236 #define XFRM_ACQ_EXPIRES        30
 237
 238 struct xfrm_tmpl;
 239 extern int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol);
 240 extern void km_state_expired(struct xfrm_state *x, int hard, u32 pid);
 241 extern int __xfrm_state_delete(struct xfrm_state *x);
 242
 243 struct xfrm_state_afinfo {
 244         unsigned short          family;
 245         struct list_head        *state_bydst;
 246         struct list_head        *state_bysrc;
 247         struct list_head        *state_byspi;
 248         int                     (*init_flags)(struct xfrm_state *x);
 249         void                    (*init_tempsel)(struct xfrm_state *x, struct flowi *fl,
 250                                                 struct xfrm_tmpl *tmpl,
 251                                                 xfrm_address_t *daddr, xfrm_address_t *saddr);
 252         struct xfrm_state       *(*state_lookup)(xfrm_address_t *daddr, u32 spi, u8 proto);
 253         struct xfrm_state       *(*state_lookup_byaddr)(xfrm_address_t *daddr, xfrm_address_t *saddr, u8 proto);
 254         struct xfrm_state       *(*find_acq)(u8 mode, u32 reqid, u8 proto,
 255                                              xfrm_address_t *daddr, xfrm_address_t *saddr,
 256                                              int create);
 257 };
 258
 259 extern int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo);
 260 extern int xfrm_state_unregister_afinfo(struct xfrm_state_afinfo *afinfo);
 261
 262 extern void xfrm_state_delete_tunnel(struct xfrm_state *x);
 263
 264 struct xfrm_type
 265 {
 266         char                    *description;
 267         struct module           *owner;
 268         __u8                    proto;
 269         __u8                    flags;
 270 #define XFRM_TYPE_NON_FRAGMENT  1
 271
 272         int                     (*init_state)(struct xfrm_state *x);
 273         void                    (*destructor)(struct xfrm_state *);
 274         int                     (*input)(struct xfrm_state *, struct sk_buff *skb);
 275         int                     (*output)(struct xfrm_state *, struct sk_buff *pskb);
 276         int                     (*hdr_offset)(struct xfrm_state *, struct sk_buff *, u8 **);
 277         xfrm_address_t          *(*local_addr)(struct xfrm_state *, xfrm_address_t *);
 278         xfrm_address_t          *(*remote_addr)(struct xfrm_state *, xfrm_address_t *);
 279         /* Estimate maximal size of result of transformation of a dgram */
 280         u32                     (*get_max_size)(struct xfrm_state *, int size);
 281 };
 282
 283 extern int xfrm_register_type(struct xfrm_type *type, unsigned short family);
 284 extern int xfrm_unregister_type(struct xfrm_type *type, unsigned short family);
 285 extern struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family);
 286 extern void xfrm_put_type(struct xfrm_type *type);
 287
 288 struct xfrm_mode {
 289         int (*input)(struct xfrm_state *x, struct sk_buff *skb);
 290         int (*output)(struct sk_buff *skb);
 291
 292         struct module *owner;
 293         unsigned int encap;
 294 };
 295
 296 extern int xfrm_register_mode(struct xfrm_mode *mode, int family);
 297 extern int xfrm_unregister_mode(struct xfrm_mode *mode, int family);
 298 extern struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family);
 299 extern void xfrm_put_mode(struct xfrm_mode *mode);
 300
 301 struct xfrm_tmpl
 302 {
 303 /* id in template is interpreted as:
 304  * daddr - destination of tunnel, may be zero for transport mode.
 305  * spi   - zero to acquire spi. Not zero if spi is static, then
 306  *         daddr must be fixed too.
 307  * proto - AH/ESP/IPCOMP
 308  */
 309         struct xfrm_id          id;
 310
 311 /* Source address of tunnel. Ignored, if it is not a tunnel. */
 312         xfrm_address_t          saddr;
 313
 314         __u32                   reqid;
 315
 316 /* Mode: transport, tunnel etc. */
 317         __u8                    mode;
 318
 319 /* Sharing mode: unique, this session only, this user only etc. */
 320         __u8                    share;
 321
 322 /* May skip this transfomration if no SA is found */
 323         __u8                    optional;
 324
 325 /* Bit mask of algos allowed for acquisition */
 326         __u32                   aalgos;
 327         __u32                   ealgos;
 328         __u32                   calgos;
 329 };
 330
 331 #define XFRM_MAX_DEPTH          6
 332
 333 struct xfrm_policy
 334 {
 335         struct xfrm_policy      *next;
 336         struct list_head        list;
 337
 338         /* This lock only affects elements except for entry. */
 339         rwlock_t                lock;
 340         atomic_t                refcnt;
 341         struct timer_list       timer;
 342
 343         u32                     priority;
 344         u32                     index;
 345         struct xfrm_selector    selector;
 346         struct xfrm_lifetime_cfg lft;
 347         struct xfrm_lifetime_cur curlft;
 348         struct dst_entry       *bundles;
 349         __u16                   family;
 350         __u8                    action;
 351         __u8                    flags;
 352         __u8                    dead;
 353         __u8                    xfrm_nr;
 354         struct xfrm_sec_ctx     *security;
 355         struct xfrm_tmpl        xfrm_vec[XFRM_MAX_DEPTH];
 356 };
 357
 358 #define XFRM_KM_TIMEOUT                30
 359 /* which seqno */
 360 #define XFRM_REPLAY_SEQ         1
 361 #define XFRM_REPLAY_OSEQ        2
 362 #define XFRM_REPLAY_SEQ_MASK    3
 363 /* what happened */
 364 #define XFRM_REPLAY_UPDATE      XFRM_AE_CR
 365 #define XFRM_REPLAY_TIMEOUT     XFRM_AE_CE
 366
 367 /* default aevent timeout in units of 100ms */
 368 #define XFRM_AE_ETIME                   10
 369 /* Async Event timer multiplier */
 370 #define XFRM_AE_ETH_M                   10
 371 /* default seq threshold size */
 372 #define XFRM_AE_SEQT_SIZE               2
 373
 374 struct xfrm_mgr
 375 {
 376         struct list_head        list;
 377         char                    *id;
 378         int                     (*notify)(struct xfrm_state *x, struct km_event *c);
 379         int                     (*acquire)(struct xfrm_state *x, struct xfrm_tmpl *, struct xfrm_policy *xp, int dir);
 380         struct xfrm_policy      *(*compile_policy)(struct sock *sk, int opt, u8 *data, int len, int *dir);
 381         int                     (*new_mapping)(struct xfrm_state *x, xfrm_address_t *ipaddr, u16 sport);
 382         int                     (*notify_policy)(struct xfrm_policy *x, int dir, struct km_event *c);
 383 };
 384
 385 extern int xfrm_register_km(struct xfrm_mgr *km);
 386 extern int xfrm_unregister_km(struct xfrm_mgr *km);
 387
 388
 389 extern struct xfrm_policy *xfrm_policy_list[XFRM_POLICY_MAX*2];
 390
 391 static inline void xfrm_pol_hold(struct xfrm_policy *policy)
 392 {
 393         if (likely(policy != NULL))
 394                 atomic_inc(&policy->refcnt);
 395 }
 396
 397 extern void __xfrm_policy_destroy(struct xfrm_policy *policy);
 398
 399 static inline void xfrm_pol_put(struct xfrm_policy *policy)
 400 {
 401         if (atomic_dec_and_test(&policy->refcnt))
 402                 __xfrm_policy_destroy(policy);
 403 }
 404
 405 #define XFRM_DST_HSIZE          1024
 406
 407 static __inline__
 408 unsigned __xfrm4_dst_hash(xfrm_address_t *addr)
 409 {
 410         unsigned h;
 411         h = ntohl(addr->a4);
 412         h = (h ^ (h>>16)) % XFRM_DST_HSIZE;
 413         return h;
 414 }
 415
 416 static __inline__
 417 unsigned __xfrm6_dst_hash(xfrm_address_t *addr)
 418 {
 419         unsigned h;
 420         h = ntohl(addr->a6[2]^addr->a6[3]);
 421         h = (h ^ (h>>16)) % XFRM_DST_HSIZE;
 422         return h;
 423 }
 424
 425 static __inline__
 426 unsigned xfrm_dst_hash(xfrm_address_t *addr, unsigned short family)
 427 {
 428         switch (family) {
 429         case AF_INET:
 430                 return __xfrm4_dst_hash(addr);
 431         case AF_INET6:
 432                 return __xfrm6_dst_hash(addr);
 433         }
 434         return 0;
 435 }
 436
 437 static __inline__
 438 unsigned __xfrm4_src_hash(xfrm_address_t *addr)
 439 {
 440         return __xfrm4_dst_hash(addr);
 441 }
 442
 443 static __inline__
 444 unsigned __xfrm6_src_hash(xfrm_address_t *addr)
 445 {
 446         return __xfrm6_dst_hash(addr);
 447 }
 448
 449 static __inline__
 450 unsigned xfrm_src_hash(xfrm_address_t *addr, unsigned short family)
 451 {
 452         switch (family) {
 453         case AF_INET:
 454                 return __xfrm4_src_hash(addr);
 455         case AF_INET6:
 456                 return __xfrm6_src_hash(addr);
 457         }
 458         return 0;
 459 }
 460
 461 static __inline__
 462 unsigned __xfrm4_spi_hash(xfrm_address_t *addr, u32 spi, u8 proto)
 463 {
 464         unsigned h;
 465         h = ntohl(addr->a4^spi^proto);
 466         h = (h ^ (h>>10) ^ (h>>20)) % XFRM_DST_HSIZE;
 467         return h;
 468 }
 469
 470 static __inline__
 471 unsigned __xfrm6_spi_hash(xfrm_address_t *addr, u32 spi, u8 proto)
 472 {
 473         unsigned h;
 474         h = ntohl(addr->a6[2]^addr->a6[3]^spi^proto);
 475         h = (h ^ (h>>10) ^ (h>>20)) % XFRM_DST_HSIZE;
 476         return h;
 477 }
 478
 479 static __inline__
 480 unsigned xfrm_spi_hash(xfrm_address_t *addr, u32 spi, u8 proto, unsigned short family)
 481 {
 482         switch (family) {
 483         case AF_INET:
 484                 return __xfrm4_spi_hash(addr, spi, proto);
 485         case AF_INET6:
 486                 return __xfrm6_spi_hash(addr, spi, proto);
 487         }
 488         return 0;       /*XXX*/
 489 }
 490
 491 extern void __xfrm_state_destroy(struct xfrm_state *);
 492
 493 static inline void __xfrm_state_put(struct xfrm_state *x)
 494 {
 495         atomic_dec(&x->refcnt);
 496 }
 497
 498 static inline void xfrm_state_put(struct xfrm_state *x)
 499 {
 500         if (atomic_dec_and_test(&x->refcnt))
 501                 __xfrm_state_destroy(x);
 502 }
 503
 504 static inline void xfrm_state_hold(struct xfrm_state *x)
 505 {
 506         atomic_inc(&x->refcnt);
 507 }
 508
 509 static __inline__ int addr_match(void *token1, void *token2, int prefixlen)
 510 {
 511         __u32 *a1 = token1;
 512         __u32 *a2 = token2;
 513         int pdw;
 514         int pbi;
 515
 516         pdw = prefixlen >> 5;     /* num of whole __u32 in prefix */
 517         pbi = prefixlen &  0x1f;  /* num of bits in incomplete u32 in prefix */
 518
 519         if (pdw)
 520                 if (memcmp(a1, a2, pdw << 2))
 521                         return 0;
 522
 523         if (pbi) {
 524                 __u32 mask;
 525
 526                 mask = htonl((0xffffffff) << (32 - pbi));
 527
 528                 if ((a1[pdw] ^ a2[pdw]) & mask)
 529                         return 0;
 530         }
 531
 532         return 1;
 533 }
 534
 535 static __inline__
 536 u16 xfrm_flowi_sport(struct flowi *fl)
 537 {
 538         u16 port;
 539         switch(fl->proto) {
 540         case IPPROTO_TCP:
 541         case IPPROTO_UDP:
 542         case IPPROTO_SCTP:
 543                 port = fl->fl_ip_sport;
 544                 break;
 545         case IPPROTO_ICMP:
 546         case IPPROTO_ICMPV6:
 547                 port = htons(fl->fl_icmp_type);
 548                 break;
 549         default:
 550                 port = 0;       /*XXX*/
 551         }
 552         return port;
 553 }
 554
 555 static __inline__
 556 u16 xfrm_flowi_dport(struct flowi *fl)
 557 {
 558         u16 port;
 559         switch(fl->proto) {
 560         case IPPROTO_TCP:
 561         case IPPROTO_UDP:
 562         case IPPROTO_SCTP:
 563                 port = fl->fl_ip_dport;
 564                 break;
 565         case IPPROTO_ICMP:
 566         case IPPROTO_ICMPV6:
 567                 port = htons(fl->fl_icmp_code);
 568                 break;
 569         default:
 570                 port = 0;       /*XXX*/
 571         }
 572         return port;
 573 }
 574
 575 static inline int
 576 __xfrm4_selector_match(struct xfrm_selector *sel, struct flowi *fl)
 577 {
 578         return  addr_match(&fl->fl4_dst, &sel->daddr, sel->prefixlen_d) &&
 579                 addr_match(&fl->fl4_src, &sel->saddr, sel->prefixlen_s) &&
 580                 !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
 581                 !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
 582                 (fl->proto == sel->proto || !sel->proto) &&
 583                 (fl->oif == sel->ifindex || !sel->ifindex);
 584 }
 585
 586 static inline int
 587 __xfrm6_selector_match(struct xfrm_selector *sel, struct flowi *fl)
 588 {
 589         return  addr_match(&fl->fl6_dst, &sel->daddr, sel->prefixlen_d) &&
 590                 addr_match(&fl->fl6_src, &sel->saddr, sel->prefixlen_s) &&
 591                 !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
 592                 !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
 593                 (fl->proto == sel->proto || !sel->proto) &&
 594                 (fl->oif == sel->ifindex || !sel->ifindex);
 595 }
 596
 597 static inline int
 598 xfrm_selector_match(struct xfrm_selector *sel, struct flowi *fl,
 599                     unsigned short family)
 600 {
 601         switch (family) {
 602         case AF_INET:
 603                 return __xfrm4_selector_match(sel, fl);
 604         case AF_INET6:
 605                 return __xfrm6_selector_match(sel, fl);
 606         }
 607         return 0;
 608 }
 609
 610 #ifdef CONFIG_SECURITY_NETWORK_XFRM
 611 /*      If neither has a context --> match
 612  *      Otherwise, both must have a context and the sids, doi, alg must match
 613  */
 614 static inline int xfrm_sec_ctx_match(struct xfrm_sec_ctx *s1, struct xfrm_sec_ctx *s2)
 615 {
 616         return ((!s1 && !s2) ||
 617                 (s1 && s2 &&
 618                  (s1->ctx_sid == s2->ctx_sid) &&
 619                  (s1->ctx_doi == s2->ctx_doi) &&
 620                  (s1->ctx_alg == s2->ctx_alg)));
 621 }
 622 #else
 623 static inline int xfrm_sec_ctx_match(struct xfrm_sec_ctx *s1, struct xfrm_sec_ctx *s2)
 624 {
 625         return 1;
 626 }
 627 #endif
 628
 629 /* A struct encoding bundle of transformations to apply to some set of flow.
 630  *
 631  * dst->child points to the next element of bundle.
 632  * dst->xfrm  points to an instanse of transformer.
 633  *
 634  * Due to unfortunate limitations of current routing cache, which we
 635  * have no time to fix, it mirrors struct rtable and bound to the same
 636  * routing key, including saddr,daddr. However, we can have many of
 637  * bundles differing by session id. All the bundles grow from a parent
 638  * policy rule.
 639  */
 640 struct xfrm_dst
 641 {
 642         union {
 643                 struct xfrm_dst         *next;
 644                 struct dst_entry        dst;
 645                 struct rtable           rt;
 646                 struct rt6_info         rt6;
 647         } u;
 648         struct dst_entry *route;
 649         u32 route_mtu_cached;
 650         u32 child_mtu_cached;
 651         u32 route_cookie;
 652         u32 path_cookie;
 653 };
 654
 655 static inline void xfrm_dst_destroy(struct xfrm_dst *xdst)
 656 {
 657         dst_release(xdst->route);
 658         if (likely(xdst->u.dst.xfrm))
 659                 xfrm_state_put(xdst->u.dst.xfrm);
 660 }
 661
 662 extern void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev);
 663
 664 struct sec_path
 665 {
 666         atomic_t                refcnt;
 667         int                     len;
 668         struct xfrm_state       *xvec[XFRM_MAX_DEPTH];
 669 };
 670
 671 static inline struct sec_path *
 672 secpath_get(struct sec_path *sp)
 673 {
 674         if (sp)
 675                 atomic_inc(&sp->refcnt);
 676         return sp;
 677 }
 678
 679 extern void __secpath_destroy(struct sec_path *sp);
 680
 681 static inline void
 682 secpath_put(struct sec_path *sp)
 683 {
 684         if (sp && atomic_dec_and_test(&sp->refcnt))
 685                 __secpath_destroy(sp);
 686 }
 687
 688 extern struct sec_path *secpath_dup(struct sec_path *src);
 689
 690 static inline void
 691 secpath_reset(struct sk_buff *skb)
 692 {
 693 #ifdef CONFIG_XFRM
 694         secpath_put(skb->sp);
 695         skb->sp = NULL;
 696 #endif
 697 }
 698
 699 static inline int
 700 __xfrm4_state_addr_cmp(struct xfrm_tmpl *tmpl, struct xfrm_state *x)
 701 {
 702         return  (tmpl->saddr.a4 &&
 703                  tmpl->saddr.a4 != x->props.saddr.a4);
 704 }
 705
 706 static inline int
 707 __xfrm6_state_addr_cmp(struct xfrm_tmpl *tmpl, struct xfrm_state *x)
 708 {
 709         return  (!ipv6_addr_any((struct in6_addr*)&tmpl->saddr) &&
 710                  ipv6_addr_cmp((struct in6_addr *)&tmpl->saddr, (struct in6_addr*)&x->props.saddr));
 711 }
 712
 713 static inline int
 714 xfrm_state_addr_cmp(struct xfrm_tmpl *tmpl, struct xfrm_state *x, unsigned short family)
 715 {
 716         switch (family) {
 717         case AF_INET:
 718                 return __xfrm4_state_addr_cmp(tmpl, x);
 719         case AF_INET6:
 720                 return __xfrm6_state_addr_cmp(tmpl, x);
 721         }
 722         return !0;
 723 }
 724
 725 #ifdef CONFIG_XFRM
 726
 727 extern int __xfrm_policy_check(struct sock *, int dir, struct sk_buff *skb, unsigned short family);
 728
 729 static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family)
 730 {
 731         if (sk && sk->sk_policy[XFRM_POLICY_IN])
 732                 return __xfrm_policy_check(sk, dir, skb, family);
 733
 734         return  (!xfrm_policy_list[dir] && !skb->sp) ||
 735                 (skb->dst->flags & DST_NOPOLICY) ||
 736                 __xfrm_policy_check(sk, dir, skb, family);
 737 }
 738
 739 static inline int xfrm4_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
 740 {
 741         return xfrm_policy_check(sk, dir, skb, AF_INET);
 742 }
 743
 744 static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
 745 {
 746         return xfrm_policy_check(sk, dir, skb, AF_INET6);
 747 }
 748
 749 extern int xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family);
 750 extern int __xfrm_route_forward(struct sk_buff *skb, unsigned short family);
 751
 752 static inline int xfrm_route_forward(struct sk_buff *skb, unsigned short family)
 753 {
 754         return  !xfrm_policy_list[XFRM_POLICY_OUT] ||
 755                 (skb->dst->flags & DST_NOXFRM) ||
 756                 __xfrm_route_forward(skb, family);
 757 }
 758
 759 static inline int xfrm4_route_forward(struct sk_buff *skb)
 760 {
 761         return xfrm_route_forward(skb, AF_INET);
 762 }
 763
 764 static inline int xfrm6_route_forward(struct sk_buff *skb)
 765 {
 766         return xfrm_route_forward(skb, AF_INET6);
 767 }
 768
 769 extern int __xfrm_sk_clone_policy(struct sock *sk);
 770
 771 static inline int xfrm_sk_clone_policy(struct sock *sk)
 772 {
 773         if (unlikely(sk->sk_policy[0] || sk->sk_policy[1]))
 774                 return __xfrm_sk_clone_policy(sk);
 775         return 0;
 776 }
 777
 778 extern int xfrm_policy_delete(struct xfrm_policy *pol, int dir);
 779
 780 static inline void xfrm_sk_free_policy(struct sock *sk)
 781 {
 782         if (unlikely(sk->sk_policy[0] != NULL)) {
 783                 xfrm_policy_delete(sk->sk_policy[0], XFRM_POLICY_MAX);
 784                 sk->sk_policy[0] = NULL;
 785         }
 786         if (unlikely(sk->sk_policy[1] != NULL)) {
 787                 xfrm_policy_delete(sk->sk_policy[1], XFRM_POLICY_MAX+1);
 788                 sk->sk_policy[1] = NULL;
 789         }
 790 }
 791
 792 #else
 793
 794 static inline void xfrm_sk_free_policy(struct sock *sk) {}
 795 static inline int xfrm_sk_clone_policy(struct sock *sk) { return 0; }
 796 static inline int xfrm6_route_forward(struct sk_buff *skb) { return 1; }
 797 static inline int xfrm4_route_forward(struct sk_buff *skb) { return 1; }
 798 static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
 799 {
 800         return 1;
 801 }
 802 static inline int xfrm4_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
 803 {
 804         return 1;
 805 }
 806 static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family)
 807 {
 808         return 1;
 809 }
 810 #endif
 811
 812 static __inline__
 813 xfrm_address_t *xfrm_flowi_daddr(struct flowi *fl, unsigned short family)
 814 {
 815         switch (family){
 816         case AF_INET:
 817                 return (xfrm_address_t *)&fl->fl4_dst;
 818         case AF_INET6:
 819                 return (xfrm_address_t *)&fl->fl6_dst;
 820         }
 821         return NULL;
 822 }
 823
 824 static __inline__
 825 xfrm_address_t *xfrm_flowi_saddr(struct flowi *fl, unsigned short family)
 826 {
 827         switch (family){
 828         case AF_INET:
 829                 return (xfrm_address_t *)&fl->fl4_src;
 830         case AF_INET6:
 831                 return (xfrm_address_t *)&fl->fl6_src;
 832         }
 833         return NULL;
 834 }
 835
 836 static __inline__ int
 837 __xfrm4_state_addr_check(struct xfrm_state *x,
 838                          xfrm_address_t *daddr, xfrm_address_t *saddr)
 839 {
 840         if (daddr->a4 == x->id.daddr.a4 &&
 841             (saddr->a4 == x->props.saddr.a4 || !saddr->a4 || !x->props.saddr.a4))
 842                 return 1;
 843         return 0;
 844 }
 845
 846 static __inline__ int
 847 __xfrm6_state_addr_check(struct xfrm_state *x,
 848                          xfrm_address_t *daddr, xfrm_address_t *saddr)
 849 {
 850         if (!ipv6_addr_cmp((struct in6_addr *)daddr, (struct in6_addr *)&x->id.daddr) &&
 851             (!ipv6_addr_cmp((struct in6_addr *)saddr, (struct in6_addr *)&x->props.saddr)||
 852              ipv6_addr_any((struct in6_addr *)saddr) ||
 853              ipv6_addr_any((struct in6_addr *)&x->props.saddr)))
 854                 return 1;
 855         return 0;
 856 }
 857
 858 static __inline__ int
 859 xfrm_state_addr_check(struct xfrm_state *x,
 860                       xfrm_address_t *daddr, xfrm_address_t *saddr,
 861                       unsigned short family)
 862 {
 863         switch (family) {
 864         case AF_INET:
 865                 return __xfrm4_state_addr_check(x, daddr, saddr);
 866         case AF_INET6:
 867                 return __xfrm6_state_addr_check(x, daddr, saddr);
 868         }
 869         return 0;
 870 }
 871
 872 static inline int xfrm_state_kern(struct xfrm_state *x)
 873 {
 874         return atomic_read(&x->tunnel_users);
 875 }
 876
 877 static inline int xfrm_id_proto_match(u8 proto, u8 userproto)
 878 {
 879         return (!userproto || proto == userproto ||
 880                 (userproto == IPSEC_PROTO_ANY && (proto == IPPROTO_AH ||
 881                                                   proto == IPPROTO_ESP ||
 882                                                   proto == IPPROTO_COMP)));
 883 }
 884
 885 /*
 886  * xfrm algorithm information
 887  */
 888 struct xfrm_algo_auth_info {
 889         u16 icv_truncbits;
 890         u16 icv_fullbits;
 891 };
 892
 893 struct xfrm_algo_encr_info {
 894         u16 blockbits;
 895         u16 defkeybits;
 896 };
 897
 898 struct xfrm_algo_comp_info {
 899         u16 threshold;
 900 };
 901
 902 struct xfrm_algo_desc {
 903         char *name;
 904         char *compat;
 905         u8 available:1;
 906         union {
 907                 struct xfrm_algo_auth_info auth;
 908                 struct xfrm_algo_encr_info encr;
 909                 struct xfrm_algo_comp_info comp;
 910         } uinfo;
 911         struct sadb_alg desc;
 912 };
 913
 914 /* XFRM tunnel handlers.  */
 915 struct xfrm_tunnel {
 916         int (*handler)(struct sk_buff *skb);
 917         int (*err_handler)(struct sk_buff *skb, __u32 info);
 918
 919         struct xfrm_tunnel *next;
 920         int priority;
 921 };
 922
 923 struct xfrm6_tunnel {
 924         int (*handler)(struct sk_buff *skb);
 925         int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
 926                            int type, int code, int offset, __u32 info);
 927
 928         struct xfrm6_tunnel *next;
 929         int priority;
 930 };
 931
 932 extern void xfrm_init(void);
 933 extern void xfrm4_init(void);
 934 extern void xfrm6_init(void);
 935 extern void xfrm6_fini(void);
 936 extern void xfrm_state_init(void);
 937 extern void xfrm4_state_init(void);
 938 extern void xfrm6_state_init(void);
 939 extern void xfrm6_state_fini(void);
 940
 941 extern int xfrm_state_walk(u8 proto, int (*func)(struct xfrm_state *, int, void*), void *);
 942 extern struct xfrm_state *xfrm_state_alloc(void);
 943 extern struct xfrm_state *xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr,
 944                                           struct flowi *fl, struct xfrm_tmpl *tmpl,
 945                                           struct xfrm_policy *pol, int *err,
 946                                           unsigned short family);
 947 extern int xfrm_state_check_expire(struct xfrm_state *x);
 948 extern void xfrm_state_insert(struct xfrm_state *x);
 949 extern int xfrm_state_add(struct xfrm_state *x);
 950 extern int xfrm_state_update(struct xfrm_state *x);
 951 extern struct xfrm_state *xfrm_state_lookup(xfrm_address_t *daddr, u32 spi, u8 proto, unsigned short family);
 952 extern struct xfrm_state *xfrm_state_lookup_byaddr(xfrm_address_t *daddr, xfrm_address_t *saddr, u8 proto, unsigned short family);
 953 extern struct xfrm_state *xfrm_find_acq_byseq(u32 seq);
 954 extern int xfrm_state_delete(struct xfrm_state *x);
 955 extern void xfrm_state_flush(u8 proto);
 956 extern int xfrm_replay_check(struct xfrm_state *x, u32 seq);
 957 extern void xfrm_replay_advance(struct xfrm_state *x, u32 seq);
 958 extern void xfrm_replay_notify(struct xfrm_state *x, int event);
 959 extern int xfrm_state_check(struct xfrm_state *x, struct sk_buff *skb);
 960 extern int xfrm_state_mtu(struct xfrm_state *x, int mtu);
 961 extern int xfrm_init_state(struct xfrm_state *x);
 962 extern int xfrm4_rcv(struct sk_buff *skb);
 963 extern int xfrm4_output(struct sk_buff *skb);
 964 extern int xfrm4_tunnel_register(struct xfrm_tunnel *handler);
 965 extern int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler);
 966 extern int xfrm6_rcv_spi(struct sk_buff *skb, u32 spi);
 967 extern int xfrm6_rcv(struct sk_buff **pskb);
 968 extern int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
 969                             xfrm_address_t *saddr, u8 proto);
 970 extern int xfrm6_tunnel_register(struct xfrm6_tunnel *handler);
 971 extern int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler);
 972 extern u32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr);
 973 extern void xfrm6_tunnel_free_spi(xfrm_address_t *saddr);
 974 extern u32 xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr);
 975 extern int xfrm6_output(struct sk_buff *skb);
 976 extern int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
 977                                  u8 **prevhdr);
 978
 979 #ifdef CONFIG_XFRM
 980 extern int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type);
 981 extern int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen);
 982 extern int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl, unsigned short family);
 983 #else
 984 static inline int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen)
 985 {
 986         return -ENOPROTOOPT;
 987 }
 988
 989 static inline int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type)
 990 {
 991         /* should not happen */
 992         kfree_skb(skb);
 993         return 0;
 994 }
 995 static inline int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl, unsigned short family)
 996 {
 997         return -EINVAL;
 998 }
 999 #endif
1000
1001 struct xfrm_policy *xfrm_policy_alloc(gfp_t gfp);
1002 extern int xfrm_policy_walk(int (*func)(struct xfrm_policy *, int, int, void*), void *);
1003 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl);
1004 struct xfrm_policy *xfrm_policy_bysel_ctx(int dir, struct xfrm_selector *sel,
1005                                           struct xfrm_sec_ctx *ctx, int delete);
1006 struct xfrm_policy *xfrm_policy_byid(int dir, u32 id, int delete);
1007 void xfrm_policy_flush(void);
1008 u32 xfrm_get_acqseq(void);
1009 void xfrm_alloc_spi(struct xfrm_state *x, u32 minspi, u32 maxspi);
1010 struct xfrm_state * xfrm_find_acq(u8 mode, u32 reqid, u8 proto,
1011                                   xfrm_address_t *daddr, xfrm_address_t *saddr,
1012                                   int create, unsigned short family);
1013 extern void xfrm_policy_flush(void);
1014 extern int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol);
1015 extern int xfrm_flush_bundles(void);
1016 extern void xfrm_flush_all_bundles(void);
1017 extern int xfrm_bundle_ok(struct xfrm_dst *xdst, struct flowi *fl, int family);
1018 extern void xfrm_init_pmtu(struct dst_entry *dst);
1019
1020 extern wait_queue_head_t km_waitq;
1021 extern int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, u16 sport);
1022 extern void km_policy_expired(struct xfrm_policy *pol, int dir, int hard, u32 pid);
1023
1024 extern void xfrm_input_init(void);
1025 extern int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, u32 *spi, u32 *seq);
1026
1027 extern void xfrm_probe_algs(void);
1028 extern int xfrm_count_auth_supported(void);
1029 extern int xfrm_count_enc_supported(void);
1030 extern struct xfrm_algo_desc *xfrm_aalg_get_byidx(unsigned int idx);
1031 extern struct xfrm_algo_desc *xfrm_ealg_get_byidx(unsigned int idx);
1032 extern struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id);
1033 extern struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id);
1034 extern struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id);
1035 extern struct xfrm_algo_desc *xfrm_aalg_get_byname(char *name, int probe);
1036 extern struct xfrm_algo_desc *xfrm_ealg_get_byname(char *name, int probe);
1037 extern struct xfrm_algo_desc *xfrm_calg_get_byname(char *name, int probe);
1038
1039 struct hash_desc;
1040 struct scatterlist;
1041 typedef int (icv_update_fn_t)(struct hash_desc *, struct scatterlist *,
1042                               unsigned int);
1043
1044 extern int skb_icv_walk(const struct sk_buff *skb, struct hash_desc *tfm,
1045                         int offset, int len, icv_update_fn_t icv_update);
1046
1047 static inline int xfrm_addr_cmp(xfrm_address_t *a, xfrm_address_t *b,
1048                                 int family)
1049 {
1050         switch (family) {
1051         default:
1052         case AF_INET:
1053                 return a->a4 - b->a4;
1054         case AF_INET6:
1055                 return ipv6_addr_cmp((struct in6_addr *)a,
1056                                      (struct in6_addr *)b);
1057         }
1058 }
1059
1060 static inline int xfrm_policy_id2dir(u32 index)
1061 {
1062         return index & 7;
1063 }
1064
1065 static inline int xfrm_aevent_is_on(void)
1066 {
1067         struct sock *nlsk;
1068         int ret = 0;
1069
1070         rcu_read_lock();
1071         nlsk = rcu_dereference(xfrm_nl);
1072         if (nlsk)
1073                 ret = netlink_has_listeners(nlsk, XFRMNLGRP_AEVENTS);
1074         rcu_read_unlock();
1075         return ret;
1076 }
1077
1078 static inline void xfrm_aevent_doreplay(struct xfrm_state *x)
1079 {
1080         if (xfrm_aevent_is_on())
1081                 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
1082 }
1083
1084
1085 #endif  /* _NET_XFRM_H */