include/net/xfrm.h

   1 #ifndef _NET_XFRM_H
   2 #define _NET_XFRM_H
   3
   4 #include <linux/xfrm.h>
   5 #include <linux/spinlock.h>
   6 #include <linux/list.h>
   7 #include <linux/skbuff.h>
   8 #include <linux/netdevice.h>
   9 #include <linux/crypto.h>
  10 #include <linux/pfkeyv2.h>
  11 #include <linux/in6.h>
  12
  13 #include <net/sock.h>
  14 #include <net/dst.h>
  15 #include <net/route.h>
  16 #include <net/ipv6.h>
  17 #include <net/ip6_fib.h>
  18
  19 #define XFRM_ALIGN8(len)        (((len) + 7) & ~7)
  20
  21 extern struct semaphore xfrm_cfg_sem;
  22
  23 /* Organization of SPD aka "XFRM rules"
  24    ------------------------------------
  25
  26    Basic objects:
  27    - policy rule, struct xfrm_policy (=SPD entry)
  28    - bundle of transformations, struct dst_entry == struct xfrm_dst (=SA bundle)
  29    - instance of a transformer, struct xfrm_state (=SA)
  30    - template to clone xfrm_state, struct xfrm_tmpl
  31
  32    SPD is plain linear list of xfrm_policy rules, ordered by priority.
  33    (To be compatible with existing pfkeyv2 implementations,
  34    many rules with priority of 0x7fffffff are allowed to exist and
  35    such rules are ordered in an unpredictable way, thanks to bsd folks.)
  36
  37    Lookup is plain linear search until the first match with selector.
  38
  39    If "action" is "block", then we prohibit the flow, otherwise:
  40    if "xfrms_nr" is zero, the flow passes untransformed. Otherwise,
  41    policy entry has list of up to XFRM_MAX_DEPTH transformations,
  42    described by templates xfrm_tmpl. Each template is resolved
  43    to a complete xfrm_state (see below) and we pack bundle of transformations
  44    to a dst_entry returned to requestor.
  45
  46    dst -. xfrm  .-> xfrm_state #1
  47     |---. child .-> dst -. xfrm .-> xfrm_state #2
  48                      |---. child .-> dst -. xfrm .-> xfrm_state #3
  49                                       |---. child .-> NULL
  50
  51    Bundles are cached at xrfm_policy struct (field ->bundles).
  52
  53
  54    Resolution of xrfm_tmpl
  55    -----------------------
  56    Template contains:
  57    1. ->mode            Mode: transport or tunnel
  58    2. ->id.proto        Protocol: AH/ESP/IPCOMP
  59    3. ->id.daddr        Remote tunnel endpoint, ignored for transport mode.
  60       Q: allow to resolve security gateway?
  61    4. ->id.spi          If not zero, static SPI.
  62    5. ->saddr           Local tunnel endpoint, ignored for transport mode.
  63    6. ->algos           List of allowed algos. Plain bitmask now.
  64       Q: ealgos, aalgos, calgos. What a mess...
  65    7. ->share           Sharing mode.
  66       Q: how to implement private sharing mode? To add struct sock* to
  67       flow id?
  68
  69    Having this template we search through SAD searching for entries
  70    with appropriate mode/proto/algo, permitted by selector.
  71    If no appropriate entry found, it is requested from key manager.
  72
  73    PROBLEMS:
  74    Q: How to find all the bundles referring to a physical path for
  75       PMTU discovery? Seems, dst should contain list of all parents...
  76       and enter to infinite locking hierarchy disaster.
  77       No! It is easier, we will not search for them, let them find us.
  78       We add genid to each dst plus pointer to genid of raw IP route,
  79       pmtu disc will update pmtu on raw IP route and increase its genid.
  80       dst_check() will see this for top level and trigger resyncing
  81       metrics. Plus, it will be made via sk->sk_dst_cache. Solved.
  82  */
  83
  84 /* Full description of state of transformer. */
  85 struct xfrm_state
  86 {
  87         /* Note: bydst is re-used during gc */
  88         struct list_head        bydst;
  89         struct list_head        byspi;
  90
  91         atomic_t                refcnt;
  92         spinlock_t              lock;
  93
  94         struct xfrm_id          id;
  95         struct xfrm_selector    sel;
  96
  97         /* Key manger bits */
  98         struct {
  99                 u8              state;
 100                 u8              dying;
 101                 u32             seq;
 102         } km;
 103
 104         /* Parameters of this state. */
 105         struct {
 106                 u32             reqid;
 107                 u8              mode;
 108                 u8              replay_window;
 109                 u8              aalgo, ealgo, calgo;
 110                 u8              flags;
 111                 u16             family;
 112                 xfrm_address_t  saddr;
 113                 int             header_len;
 114                 int             trailer_len;
 115         } props;
 116
 117         struct xfrm_lifetime_cfg lft;
 118
 119         /* Data for transformer */
 120         struct xfrm_algo        *aalg;
 121         struct xfrm_algo        *ealg;
 122         struct xfrm_algo        *calg;
 123
 124         /* Data for encapsulator */
 125         struct xfrm_encap_tmpl  *encap;
 126
 127         /* IPComp needs an IPIP tunnel for handling uncompressed packets */
 128         struct xfrm_state       *tunnel;
 129
 130         /* If a tunnel, number of users + 1 */
 131         atomic_t                tunnel_users;
 132
 133         /* State for replay detection */
 134         struct xfrm_replay_state replay;
 135
 136         /* Statistics */
 137         struct xfrm_stats       stats;
 138
 139         struct xfrm_lifetime_cur curlft;
 140         struct timer_list       timer;
 141
 142         /* Reference to data common to all the instances of this
 143          * transformer. */
 144         struct xfrm_type        *type;
 145
 146         /* Private data of this transformer, format is opaque,
 147          * interpreted by xfrm_type methods. */
 148         void                    *data;
 149 };
 150
 151 enum {
 152         XFRM_STATE_VOID,
 153         XFRM_STATE_ACQ,
 154         XFRM_STATE_VALID,
 155         XFRM_STATE_ERROR,
 156         XFRM_STATE_EXPIRED,
 157         XFRM_STATE_DEAD
 158 };
 159
 160 struct xfrm_type;
 161 struct xfrm_dst;
 162 struct xfrm_policy_afinfo {
 163         unsigned short          family;
 164         rwlock_t                lock;
 165         struct xfrm_type_map    *type_map;
 166         struct dst_ops          *dst_ops;
 167         void                    (*garbage_collect)(void);
 168         int                     (*dst_lookup)(struct xfrm_dst **dst, struct flowi *fl);
 169         struct dst_entry        *(*find_bundle)(struct flowi *fl, struct xfrm_policy *policy);
 170         int                     (*bundle_create)(struct xfrm_policy *policy,
 171                                                  struct xfrm_state **xfrm,
 172                                                  int nx,
 173                                                  struct flowi *fl,
 174                                                  struct dst_entry **dst_p);
 175         void                    (*decode_session)(struct sk_buff *skb,
 176                                                   struct flowi *fl);
 177 };
 178
 179 extern int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo);
 180 extern int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo);
 181 extern struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);
 182 extern void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);
 183
 184 #define XFRM_ACQ_EXPIRES        30
 185
 186 struct xfrm_tmpl;
 187 struct xfrm_state_afinfo {
 188         unsigned short          family;
 189         rwlock_t                lock;
 190         struct list_head        *state_bydst;
 191         struct list_head        *state_byspi;
 192         void                    (*init_tempsel)(struct xfrm_state *x, struct flowi *fl,
 193                                                 struct xfrm_tmpl *tmpl,
 194                                                 xfrm_address_t *daddr, xfrm_address_t *saddr);
 195         struct xfrm_state       *(*state_lookup)(xfrm_address_t *daddr, u32 spi, u8 proto);
 196         struct xfrm_state       *(*find_acq)(u8 mode, u32 reqid, u8 proto,
 197                                              xfrm_address_t *daddr, xfrm_address_t *saddr,
 198                                              int create);
 199 };
 200
 201 extern int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo);
 202 extern int xfrm_state_unregister_afinfo(struct xfrm_state_afinfo *afinfo);
 203 extern struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned short family);
 204 extern void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo);
 205
 206 extern void xfrm_state_delete_tunnel(struct xfrm_state *x);
 207
 208 struct xfrm_decap_state;
 209 struct xfrm_type
 210 {
 211         char                    *description;
 212         struct module           *owner;
 213         __u8                    proto;
 214
 215         int                     (*init_state)(struct xfrm_state *x, void *args);
 216         void                    (*destructor)(struct xfrm_state *);
 217         int                     (*input)(struct xfrm_state *, struct xfrm_decap_state *, struct sk_buff *skb);
 218         int                     (*post_input)(struct xfrm_state *, struct xfrm_decap_state *, struct sk_buff *skb);
 219         int                     (*output)(struct sk_buff *pskb);
 220         /* Estimate maximal size of result of transformation of a dgram */
 221         u32                     (*get_max_size)(struct xfrm_state *, int size);
 222 };
 223
 224 struct xfrm_type_map {
 225         rwlock_t                lock;
 226         struct xfrm_type        *map[256];
 227 };
 228
 229 extern int xfrm_register_type(struct xfrm_type *type, unsigned short family);
 230 extern int xfrm_unregister_type(struct xfrm_type *type, unsigned short family);
 231 extern struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family);
 232 extern void xfrm_put_type(struct xfrm_type *type);
 233
 234 struct xfrm_tmpl
 235 {
 236 /* id in template is interpreted as:
 237  * daddr - destination of tunnel, may be zero for transport mode.
 238  * spi   - zero to acquire spi. Not zero if spi is static, then
 239  *         daddr must be fixed too.
 240  * proto - AH/ESP/IPCOMP
 241  */
 242         struct xfrm_id          id;
 243
 244 /* Source address of tunnel. Ignored, if it is not a tunnel. */
 245         xfrm_address_t          saddr;
 246
 247         __u32                   reqid;
 248
 249 /* Mode: transport/tunnel */
 250         __u8                    mode;
 251
 252 /* Sharing mode: unique, this session only, this user only etc. */
 253         __u8                    share;
 254
 255 /* May skip this transfomration if no SA is found */
 256         __u8                    optional;
 257
 258 /* Bit mask of algos allowed for acquisition */
 259         __u32                   aalgos;
 260         __u32                   ealgos;
 261         __u32                   calgos;
 262 };
 263
 264 #define XFRM_MAX_DEPTH          4
 265
 266 struct xfrm_policy
 267 {
 268         struct xfrm_policy      *next;
 269         struct list_head        list;
 270
 271         /* This lock only affects elements except for entry. */
 272         rwlock_t                lock;
 273         atomic_t                refcnt;
 274         struct timer_list       timer;
 275
 276         u32                     priority;
 277         u32                     index;
 278         struct xfrm_selector    selector;
 279         struct xfrm_lifetime_cfg lft;
 280         struct xfrm_lifetime_cur curlft;
 281         struct dst_entry       *bundles;
 282         __u16                   family;
 283         __u8                    action;
 284         __u8                    flags;
 285         __u8                    dead;
 286         __u8                    xfrm_nr;
 287         struct xfrm_tmpl        xfrm_vec[XFRM_MAX_DEPTH];
 288 };
 289
 290 #define XFRM_KM_TIMEOUT         30
 291
 292 struct xfrm_mgr
 293 {
 294         struct list_head        list;
 295         char                    *id;
 296         int                     (*notify)(struct xfrm_state *x, int event);
 297         int                     (*acquire)(struct xfrm_state *x, struct xfrm_tmpl *, struct xfrm_policy *xp, int dir);
 298         struct xfrm_policy      *(*compile_policy)(u16 family, int opt, u8 *data, int len, int *dir);
 299         int                     (*new_mapping)(struct xfrm_state *x, xfrm_address_t *ipaddr, u16 sport);
 300         int                     (*notify_policy)(struct xfrm_policy *x, int dir, int event);
 301 };
 302
 303 extern int xfrm_register_km(struct xfrm_mgr *km);
 304 extern int xfrm_unregister_km(struct xfrm_mgr *km);
 305
 306
 307 extern struct xfrm_policy *xfrm_policy_list[XFRM_POLICY_MAX*2];
 308
 309 static inline void xfrm_pol_hold(struct xfrm_policy *policy)
 310 {
 311         if (likely(policy != NULL))
 312                 atomic_inc(&policy->refcnt);
 313 }
 314
 315 extern void __xfrm_policy_destroy(struct xfrm_policy *policy);
 316
 317 static inline void xfrm_pol_put(struct xfrm_policy *policy)
 318 {
 319         if (atomic_dec_and_test(&policy->refcnt))
 320                 __xfrm_policy_destroy(policy);
 321 }
 322
 323 #define XFRM_DST_HSIZE          1024
 324
 325 static __inline__
 326 unsigned __xfrm4_dst_hash(xfrm_address_t *addr)
 327 {
 328         unsigned h;
 329         h = ntohl(addr->a4);
 330         h = (h ^ (h>>16)) % XFRM_DST_HSIZE;
 331         return h;
 332 }
 333
 334 static __inline__
 335 unsigned __xfrm6_dst_hash(xfrm_address_t *addr)
 336 {
 337         unsigned h;
 338         h = ntohl(addr->a6[2]^addr->a6[3]);
 339         h = (h ^ (h>>16)) % XFRM_DST_HSIZE;
 340         return h;
 341 }
 342
 343 static __inline__
 344 unsigned xfrm_dst_hash(xfrm_address_t *addr, unsigned short family)
 345 {
 346         switch (family) {
 347         case AF_INET:
 348                 return __xfrm4_dst_hash(addr);
 349         case AF_INET6:
 350                 return __xfrm6_dst_hash(addr);
 351         }
 352         return 0;
 353 }
 354
 355 static __inline__
 356 unsigned __xfrm4_spi_hash(xfrm_address_t *addr, u32 spi, u8 proto)
 357 {
 358         unsigned h;
 359         h = ntohl(addr->a4^spi^proto);
 360         h = (h ^ (h>>10) ^ (h>>20)) % XFRM_DST_HSIZE;
 361         return h;
 362 }
 363
 364 static __inline__
 365 unsigned __xfrm6_spi_hash(xfrm_address_t *addr, u32 spi, u8 proto)
 366 {
 367         unsigned h;
 368         h = ntohl(addr->a6[2]^addr->a6[3]^spi^proto);
 369         h = (h ^ (h>>10) ^ (h>>20)) % XFRM_DST_HSIZE;
 370         return h;
 371 }
 372
 373 static __inline__
 374 unsigned xfrm_spi_hash(xfrm_address_t *addr, u32 spi, u8 proto, unsigned short family)
 375 {
 376         switch (family) {
 377         case AF_INET:
 378                 return __xfrm4_spi_hash(addr, spi, proto);
 379         case AF_INET6:
 380                 return __xfrm6_spi_hash(addr, spi, proto);
 381         }
 382         return 0;       /*XXX*/
 383 }
 384
 385 extern void __xfrm_state_destroy(struct xfrm_state *);
 386
 387 static inline void xfrm_state_put(struct xfrm_state *x)
 388 {
 389         if (atomic_dec_and_test(&x->refcnt))
 390                 __xfrm_state_destroy(x);
 391 }
 392
 393 static inline void xfrm_state_hold(struct xfrm_state *x)
 394 {
 395         atomic_inc(&x->refcnt);
 396 }
 397
 398 static __inline__ int addr_match(void *token1, void *token2, int prefixlen)
 399 {
 400         __u32 *a1 = token1;
 401         __u32 *a2 = token2;
 402         int pdw;
 403         int pbi;
 404
 405         pdw = prefixlen >> 5;     /* num of whole __u32 in prefix */
 406         pbi = prefixlen &  0x1f;  /* num of bits in incomplete u32 in prefix */
 407
 408         if (pdw)
 409                 if (memcmp(a1, a2, pdw << 2))
 410                         return 0;
 411
 412         if (pbi) {
 413                 __u32 mask;
 414
 415                 mask = htonl((0xffffffff) << (32 - pbi));
 416
 417                 if ((a1[pdw] ^ a2[pdw]) & mask)
 418                         return 0;
 419         }
 420
 421         return 1;
 422 }
 423
 424 static __inline__
 425 u16 xfrm_flowi_sport(struct flowi *fl)
 426 {
 427         u16 port;
 428         switch(fl->proto) {
 429         case IPPROTO_TCP:
 430         case IPPROTO_UDP:
 431         case IPPROTO_SCTP:
 432                 port = fl->fl_ip_sport;
 433                 break;
 434         case IPPROTO_ICMP:
 435         case IPPROTO_ICMPV6:
 436                 port = htons(fl->fl_icmp_type);
 437                 break;
 438         default:
 439                 port = 0;       /*XXX*/
 440         }
 441         return port;
 442 }
 443
 444 static __inline__
 445 u16 xfrm_flowi_dport(struct flowi *fl)
 446 {
 447         u16 port;
 448         switch(fl->proto) {
 449         case IPPROTO_TCP:
 450         case IPPROTO_UDP:
 451         case IPPROTO_SCTP:
 452                 port = fl->fl_ip_dport;
 453                 break;
 454         case IPPROTO_ICMP:
 455         case IPPROTO_ICMPV6:
 456                 port = htons(fl->fl_icmp_code);
 457                 break;
 458         default:
 459                 port = 0;       /*XXX*/
 460         }
 461         return port;
 462 }
 463
 464 static inline int
 465 __xfrm4_selector_match(struct xfrm_selector *sel, struct flowi *fl)
 466 {
 467         return  addr_match(&fl->fl4_dst, &sel->daddr, sel->prefixlen_d) &&
 468                 addr_match(&fl->fl4_src, &sel->saddr, sel->prefixlen_s) &&
 469                 !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
 470                 !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
 471                 (fl->proto == sel->proto || !sel->proto) &&
 472                 (fl->oif == sel->ifindex || !sel->ifindex);
 473 }
 474
 475 static inline int
 476 __xfrm6_selector_match(struct xfrm_selector *sel, struct flowi *fl)
 477 {
 478         return  addr_match(&fl->fl6_dst, &sel->daddr, sel->prefixlen_d) &&
 479                 addr_match(&fl->fl6_src, &sel->saddr, sel->prefixlen_s) &&
 480                 !((xfrm_flowi_dport(fl) ^ sel->dport) & sel->dport_mask) &&
 481                 !((xfrm_flowi_sport(fl) ^ sel->sport) & sel->sport_mask) &&
 482                 (fl->proto == sel->proto || !sel->proto) &&
 483                 (fl->oif == sel->ifindex || !sel->ifindex);
 484 }
 485
 486 static inline int
 487 xfrm_selector_match(struct xfrm_selector *sel, struct flowi *fl,
 488                     unsigned short family)
 489 {
 490         switch (family) {
 491         case AF_INET:
 492                 return __xfrm4_selector_match(sel, fl);
 493         case AF_INET6:
 494                 return __xfrm6_selector_match(sel, fl);
 495         }
 496         return 0;
 497 }
 498
 499 /* A struct encoding bundle of transformations to apply to some set of flow.
 500  *
 501  * dst->child points to the next element of bundle.
 502  * dst->xfrm  points to an instanse of transformer.
 503  *
 504  * Due to unfortunate limitations of current routing cache, which we
 505  * have no time to fix, it mirrors struct rtable and bound to the same
 506  * routing key, including saddr,daddr. However, we can have many of
 507  * bundles differing by session id. All the bundles grow from a parent
 508  * policy rule.
 509  */
 510 struct xfrm_dst
 511 {
 512         union {
 513                 struct xfrm_dst         *next;
 514                 struct dst_entry        dst;
 515                 struct rtable           rt;
 516                 struct rt6_info         rt6;
 517         } u;
 518 };
 519
 520 /* Decapsulation state, used by the input to store data during
 521  * decapsulation procedure, to be used later (during the policy
 522  * check
 523  */
 524 struct xfrm_decap_state {
 525         char    decap_data[20];
 526         __u16   decap_type;
 527 };
 528
 529 struct sec_decap_state {
 530         struct xfrm_state       *xvec;
 531         struct xfrm_decap_state decap;
 532 };
 533
 534 struct sec_path
 535 {
 536         atomic_t                refcnt;
 537         int                     len;
 538         struct sec_decap_state  x[XFRM_MAX_DEPTH];
 539 };
 540
 541 static inline struct sec_path *
 542 secpath_get(struct sec_path *sp)
 543 {
 544         if (sp)
 545                 atomic_inc(&sp->refcnt);
 546         return sp;
 547 }
 548
 549 extern void __secpath_destroy(struct sec_path *sp);
 550
 551 static inline void
 552 secpath_put(struct sec_path *sp)
 553 {
 554         if (sp && atomic_dec_and_test(&sp->refcnt))
 555                 __secpath_destroy(sp);
 556 }
 557
 558 extern struct sec_path *secpath_dup(struct sec_path *src);
 559
 560 static inline void
 561 secpath_reset(struct sk_buff *skb)
 562 {
 563 #ifdef CONFIG_XFRM
 564         secpath_put(skb->sp);
 565         skb->sp = NULL;
 566 #endif
 567 }
 568
 569 static inline int
 570 __xfrm4_state_addr_cmp(struct xfrm_tmpl *tmpl, struct xfrm_state *x)
 571 {
 572         return  (tmpl->saddr.a4 &&
 573                  tmpl->saddr.a4 != x->props.saddr.a4);
 574 }
 575
 576 static inline int
 577 __xfrm6_state_addr_cmp(struct xfrm_tmpl *tmpl, struct xfrm_state *x)
 578 {
 579         return  (!ipv6_addr_any((struct in6_addr*)&tmpl->saddr) &&
 580                  ipv6_addr_cmp((struct in6_addr *)&tmpl->saddr, (struct in6_addr*)&x->props.saddr));
 581 }
 582
 583 static inline int
 584 xfrm_state_addr_cmp(struct xfrm_tmpl *tmpl, struct xfrm_state *x, unsigned short family)
 585 {
 586         switch (family) {
 587         case AF_INET:
 588                 return __xfrm4_state_addr_cmp(tmpl, x);
 589         case AF_INET6:
 590                 return __xfrm6_state_addr_cmp(tmpl, x);
 591         }
 592         return !0;
 593 }
 594
 595 #ifdef CONFIG_XFRM
 596
 597 extern int __xfrm_policy_check(struct sock *, int dir, struct sk_buff *skb, unsigned short family);
 598
 599 static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family)
 600 {
 601         if (sk && sk->sk_policy[XFRM_POLICY_IN])
 602                 return __xfrm_policy_check(sk, dir, skb, family);
 603
 604         return  !xfrm_policy_list[dir] ||
 605                 (skb->dst->flags & DST_NOPOLICY) ||
 606                 __xfrm_policy_check(sk, dir, skb, family);
 607 }
 608
 609 static inline int xfrm4_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
 610 {
 611         return xfrm_policy_check(sk, dir, skb, AF_INET);
 612 }
 613
 614 static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
 615 {
 616         return xfrm_policy_check(sk, dir, skb, AF_INET6);
 617 }
 618
 619
 620 extern int __xfrm_route_forward(struct sk_buff *skb, unsigned short family);
 621
 622 static inline int xfrm_route_forward(struct sk_buff *skb, unsigned short family)
 623 {
 624         return  !xfrm_policy_list[XFRM_POLICY_OUT] ||
 625                 (skb->dst->flags & DST_NOXFRM) ||
 626                 __xfrm_route_forward(skb, family);
 627 }
 628
 629 static inline int xfrm4_route_forward(struct sk_buff *skb)
 630 {
 631         return xfrm_route_forward(skb, AF_INET);
 632 }
 633
 634 static inline int xfrm6_route_forward(struct sk_buff *skb)
 635 {
 636         return xfrm_route_forward(skb, AF_INET6);
 637 }
 638
 639 extern int __xfrm_sk_clone_policy(struct sock *sk);
 640
 641 static inline int xfrm_sk_clone_policy(struct sock *sk)
 642 {
 643         if (unlikely(sk->sk_policy[0] || sk->sk_policy[1]))
 644                 return __xfrm_sk_clone_policy(sk);
 645         return 0;
 646 }
 647
 648 extern void xfrm_policy_delete(struct xfrm_policy *pol, int dir);
 649
 650 static inline void xfrm_sk_free_policy(struct sock *sk)
 651 {
 652         if (unlikely(sk->sk_policy[0] != NULL)) {
 653                 xfrm_policy_delete(sk->sk_policy[0], XFRM_POLICY_MAX);
 654                 sk->sk_policy[0] = NULL;
 655         }
 656         if (unlikely(sk->sk_policy[1] != NULL)) {
 657                 xfrm_policy_delete(sk->sk_policy[1], XFRM_POLICY_MAX+1);
 658                 sk->sk_policy[1] = NULL;
 659         }
 660 }
 661
 662 #else
 663
 664 static inline void xfrm_sk_free_policy(struct sock *sk) {}
 665 static inline int xfrm_sk_clone_policy(struct sock *sk) { return 0; }
 666 static inline int xfrm6_route_forward(struct sk_buff *skb) { return 1; }
 667 static inline int xfrm4_route_forward(struct sk_buff *skb) { return 1; }
 668 static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
 669 {
 670         return 1;
 671 }
 672 static inline int xfrm4_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
 673 {
 674         return 1;
 675 }
 676 static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family)
 677 {
 678         return 1;
 679 }
 680 #endif
 681
 682 static __inline__
 683 xfrm_address_t *xfrm_flowi_daddr(struct flowi *fl, unsigned short family)
 684 {
 685         switch (family){
 686         case AF_INET:
 687                 return (xfrm_address_t *)&fl->fl4_dst;
 688         case AF_INET6:
 689                 return (xfrm_address_t *)&fl->fl6_dst;
 690         }
 691         return NULL;
 692 }
 693
 694 static __inline__
 695 xfrm_address_t *xfrm_flowi_saddr(struct flowi *fl, unsigned short family)
 696 {
 697         switch (family){
 698         case AF_INET:
 699                 return (xfrm_address_t *)&fl->fl4_src;
 700         case AF_INET6:
 701                 return (xfrm_address_t *)&fl->fl6_src;
 702         }
 703         return NULL;
 704 }
 705
 706 static __inline__ int
 707 __xfrm4_state_addr_check(struct xfrm_state *x,
 708                          xfrm_address_t *daddr, xfrm_address_t *saddr)
 709 {
 710         if (daddr->a4 == x->id.daddr.a4 &&
 711             (saddr->a4 == x->props.saddr.a4 || !saddr->a4 || !x->props.saddr.a4))
 712                 return 1;
 713         return 0;
 714 }
 715
 716 static __inline__ int
 717 __xfrm6_state_addr_check(struct xfrm_state *x,
 718                          xfrm_address_t *daddr, xfrm_address_t *saddr)
 719 {
 720         if (!ipv6_addr_cmp((struct in6_addr *)daddr, (struct in6_addr *)&x->id.daddr) &&
 721             (!ipv6_addr_cmp((struct in6_addr *)saddr, (struct in6_addr *)&x->props.saddr)||
 722              ipv6_addr_any((struct in6_addr *)saddr) ||
 723              ipv6_addr_any((struct in6_addr *)&x->props.saddr)))
 724                 return 1;
 725         return 0;
 726 }
 727
 728 static __inline__ int
 729 xfrm_state_addr_check(struct xfrm_state *x,
 730                       xfrm_address_t *daddr, xfrm_address_t *saddr,
 731                       unsigned short family)
 732 {
 733         switch (family) {
 734         case AF_INET:
 735                 return __xfrm4_state_addr_check(x, daddr, saddr);
 736         case AF_INET6:
 737                 return __xfrm6_state_addr_check(x, daddr, saddr);
 738         }
 739         return 0;
 740 }
 741
 742 static inline int xfrm_state_kern(struct xfrm_state *x)
 743 {
 744         return atomic_read(&x->tunnel_users);
 745 }
 746
 747 /*
 748  * xfrm algorithm information
 749  */
 750 struct xfrm_algo_auth_info {
 751         u16 icv_truncbits;
 752         u16 icv_fullbits;
 753 };
 754
 755 struct xfrm_algo_encr_info {
 756         u16 blockbits;
 757         u16 defkeybits;
 758 };
 759
 760 struct xfrm_algo_comp_info {
 761         u16 threshold;
 762 };
 763
 764 struct xfrm_algo_desc {
 765         char *name;
 766         u8 available:1;
 767         union {
 768                 struct xfrm_algo_auth_info auth;
 769                 struct xfrm_algo_encr_info encr;
 770                 struct xfrm_algo_comp_info comp;
 771         } uinfo;
 772         struct sadb_alg desc;
 773 };
 774
 775 /* XFRM tunnel handlers.  */
 776 struct xfrm_tunnel {
 777         int (*handler)(struct sk_buff *skb);
 778         void (*err_handler)(struct sk_buff *skb, void *info);
 779 };
 780
 781 struct xfrm6_tunnel {
 782         int (*handler)(struct sk_buff **pskb, unsigned int *nhoffp);
 783         void (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
 784                             int type, int code, int offset, __u32 info);
 785 };
 786
 787 extern void xfrm_init(void);
 788 extern void xfrm4_init(void);
 789 extern void xfrm4_fini(void);
 790 extern void xfrm6_init(void);
 791 extern void xfrm6_fini(void);
 792 extern void xfrm_state_init(void);
 793 extern void xfrm4_state_init(void);
 794 extern void xfrm4_state_fini(void);
 795 extern void xfrm6_state_init(void);
 796 extern void xfrm6_state_fini(void);
 797
 798 extern int xfrm_state_walk(u8 proto, int (*func)(struct xfrm_state *, int, void*), void *);
 799 extern struct xfrm_state *xfrm_state_alloc(void);
 800 extern struct xfrm_state *xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr,
 801                                           struct flowi *fl, struct xfrm_tmpl *tmpl,
 802                                           struct xfrm_policy *pol, int *err,
 803                                           unsigned short family);
 804 extern int xfrm_state_check_expire(struct xfrm_state *x);
 805 extern void xfrm_state_insert(struct xfrm_state *x);
 806 extern int xfrm_state_add(struct xfrm_state *x);
 807 extern int xfrm_state_update(struct xfrm_state *x);
 808 extern int xfrm_state_check_space(struct xfrm_state *x, struct sk_buff *skb);
 809 extern struct xfrm_state *xfrm_state_lookup(xfrm_address_t *daddr, u32 spi, u8 proto, unsigned short family);
 810 extern struct xfrm_state *xfrm_find_acq_byseq(u32 seq);
 811 extern void xfrm_state_delete(struct xfrm_state *x);
 812 extern void xfrm_state_flush(u8 proto);
 813 extern int xfrm_replay_check(struct xfrm_state *x, u32 seq);
 814 extern void xfrm_replay_advance(struct xfrm_state *x, u32 seq);
 815 extern int xfrm_check_selectors(struct xfrm_state **x, int n, struct flowi *fl);
 816 extern int xfrm_state_check(struct xfrm_state *x, struct sk_buff *skb);
 817 extern int xfrm4_rcv(struct sk_buff *skb);
 818 extern int xfrm4_output(struct sk_buff **pskb);
 819 extern int xfrm4_tunnel_register(struct xfrm_tunnel *handler);
 820 extern int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler);
 821 extern int xfrm6_rcv_spi(struct sk_buff **pskb, unsigned int *nhoffp, u32 spi);
 822 extern int xfrm6_rcv(struct sk_buff **pskb, unsigned int *nhoffp);
 823 extern int xfrm6_tunnel_register(struct xfrm6_tunnel *handler);
 824 extern int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler);
 825 extern u32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr);
 826 extern void xfrm6_tunnel_free_spi(xfrm_address_t *saddr);
 827 extern u32 xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr);
 828 extern int xfrm6_output(struct sk_buff **pskb);
 829
 830 #ifdef CONFIG_XFRM
 831 extern int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type);
 832 extern int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen);
 833 extern int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl, unsigned short family);
 834 #else
 835 static inline int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen)
 836 {
 837         return -ENOPROTOOPT;
 838 }
 839
 840 static inline int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type)
 841 {
 842         /* should not happen */
 843         kfree_skb(skb);
 844         return 0;
 845 }
 846 static inline int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl, unsigned short family)
 847 {
 848         return -EINVAL;
 849 }
 850 #endif
 851
 852 void xfrm_policy_init(void);
 853 struct xfrm_policy *xfrm_policy_alloc(int gfp);
 854 extern int xfrm_policy_walk(int (*func)(struct xfrm_policy *, int, int, void*), void *);
 855 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl);
 856 struct xfrm_policy *xfrm_policy_bysel(int dir, struct xfrm_selector *sel,
 857                                       int delete);
 858 struct xfrm_policy *xfrm_policy_byid(int dir, u32 id, int delete);
 859 void xfrm_policy_flush(void);
 860 u32 xfrm_get_acqseq(void);
 861 void xfrm_alloc_spi(struct xfrm_state *x, u32 minspi, u32 maxspi);
 862 struct xfrm_state * xfrm_find_acq(u8 mode, u32 reqid, u8 proto,
 863                                   xfrm_address_t *daddr, xfrm_address_t *saddr,
 864                                   int create, unsigned short family);
 865 extern void xfrm_policy_flush(void);
 866 extern void xfrm_policy_kill(struct xfrm_policy *);
 867 extern int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol);
 868 extern struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl);
 869 extern int xfrm_flush_bundles(void);
 870
 871 extern wait_queue_head_t km_waitq;
 872 extern void km_state_expired(struct xfrm_state *x, int hard);
 873 extern int km_query(struct xfrm_state *x, struct xfrm_tmpl *, struct xfrm_policy *pol);
 874 extern int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, u16 sport);
 875 extern void km_policy_expired(struct xfrm_policy *pol, int dir, int hard);
 876
 877 extern void xfrm_input_init(void);
 878 extern int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, u32 *spi, u32 *seq);
 879
 880 extern void xfrm_probe_algs(void);
 881 extern int xfrm_count_auth_supported(void);
 882 extern int xfrm_count_enc_supported(void);
 883 extern struct xfrm_algo_desc *xfrm_aalg_get_byidx(unsigned int idx);
 884 extern struct xfrm_algo_desc *xfrm_ealg_get_byidx(unsigned int idx);
 885 extern struct xfrm_algo_desc *xfrm_calg_get_byidx(unsigned int idx);
 886 extern struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id);
 887 extern struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id);
 888 extern struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id);
 889 extern struct xfrm_algo_desc *xfrm_aalg_get_byname(char *name);
 890 extern struct xfrm_algo_desc *xfrm_ealg_get_byname(char *name);
 891 extern struct xfrm_algo_desc *xfrm_calg_get_byname(char *name);
 892
 893 struct crypto_tfm;
 894 typedef void (icv_update_fn_t)(struct crypto_tfm *, struct scatterlist *, unsigned int);
 895
 896 extern void skb_icv_walk(const struct sk_buff *skb, struct crypto_tfm *tfm,
 897                          int offset, int len, icv_update_fn_t icv_update);
 898
 899 static inline int xfrm_addr_cmp(xfrm_address_t *a, xfrm_address_t *b,
 900                                 int family)
 901 {
 902         switch (family) {
 903         default:
 904         case AF_INET:
 905                 return a->a4 - b->a4;
 906         case AF_INET6:
 907                 return ipv6_addr_cmp((struct in6_addr *)a,
 908                                      (struct in6_addr *)b);
 909         }
 910 }
 911
 912 #endif  /* _NET_XFRM_H */