xref: /openbmc/linux/include/net/xfrm.h (revision 17c2a42a24e1e8dd6aa7cea4f84e034ab1bfff31)
1 #ifndef _NET_XFRM_H
2 #define _NET_XFRM_H
3 
4 #include <linux/compiler.h>
5 #include <linux/xfrm.h>
6 #include <linux/spinlock.h>
7 #include <linux/list.h>
8 #include <linux/skbuff.h>
9 #include <linux/socket.h>
10 #include <linux/pfkeyv2.h>
11 #include <linux/ipsec.h>
12 #include <linux/in6.h>
13 #include <linux/mutex.h>
14 #include <linux/audit.h>
15 
16 #include <net/sock.h>
17 #include <net/dst.h>
18 #include <net/ip.h>
19 #include <net/route.h>
20 #include <net/ipv6.h>
21 #include <net/ip6_fib.h>
22 
23 #define XFRM_PROTO_ESP		50
24 #define XFRM_PROTO_AH		51
25 #define XFRM_PROTO_COMP		108
26 #define XFRM_PROTO_IPIP		4
27 #define XFRM_PROTO_IPV6		41
28 #define XFRM_PROTO_ROUTING	IPPROTO_ROUTING
29 #define XFRM_PROTO_DSTOPTS	IPPROTO_DSTOPTS
30 
31 #define XFRM_ALIGN8(len)	(((len) + 7) & ~7)
32 #define MODULE_ALIAS_XFRM_MODE(family, encap) \
33 	MODULE_ALIAS("xfrm-mode-" __stringify(family) "-" __stringify(encap))
34 #define MODULE_ALIAS_XFRM_TYPE(family, proto) \
35 	MODULE_ALIAS("xfrm-type-" __stringify(family) "-" __stringify(proto))
36 
37 extern struct sock *xfrm_nl;
38 extern u32 sysctl_xfrm_aevent_etime;
39 extern u32 sysctl_xfrm_aevent_rseqth;
40 
41 extern struct mutex xfrm_cfg_mutex;
42 
43 /* Organization of SPD aka "XFRM rules"
44    ------------------------------------
45 
46    Basic objects:
47    - policy rule, struct xfrm_policy (=SPD entry)
48    - bundle of transformations, struct dst_entry == struct xfrm_dst (=SA bundle)
49    - instance of a transformer, struct xfrm_state (=SA)
50    - template to clone xfrm_state, struct xfrm_tmpl
51 
52    SPD is plain linear list of xfrm_policy rules, ordered by priority.
53    (To be compatible with existing pfkeyv2 implementations,
54    many rules with priority of 0x7fffffff are allowed to exist and
55    such rules are ordered in an unpredictable way, thanks to bsd folks.)
56 
57    Lookup is plain linear search until the first match with selector.
58 
59    If "action" is "block", then we prohibit the flow, otherwise:
60    if "xfrms_nr" is zero, the flow passes untransformed. Otherwise,
61    policy entry has list of up to XFRM_MAX_DEPTH transformations,
62    described by templates xfrm_tmpl. Each template is resolved
63    to a complete xfrm_state (see below) and we pack bundle of transformations
64    to a dst_entry returned to requestor.
65 
66    dst -. xfrm  .-> xfrm_state #1
67     |---. child .-> dst -. xfrm .-> xfrm_state #2
68                      |---. child .-> dst -. xfrm .-> xfrm_state #3
69                                       |---. child .-> NULL
70 
71    Bundles are cached at xrfm_policy struct (field ->bundles).
72 
73 
74    Resolution of xrfm_tmpl
75    -----------------------
76    Template contains:
77    1. ->mode		Mode: transport or tunnel
78    2. ->id.proto	Protocol: AH/ESP/IPCOMP
79    3. ->id.daddr	Remote tunnel endpoint, ignored for transport mode.
80       Q: allow to resolve security gateway?
81    4. ->id.spi          If not zero, static SPI.
82    5. ->saddr		Local tunnel endpoint, ignored for transport mode.
83    6. ->algos		List of allowed algos. Plain bitmask now.
84       Q: ealgos, aalgos, calgos. What a mess...
85    7. ->share		Sharing mode.
86       Q: how to implement private sharing mode? To add struct sock* to
87       flow id?
88 
89    Having this template we search through SAD searching for entries
90    with appropriate mode/proto/algo, permitted by selector.
91    If no appropriate entry found, it is requested from key manager.
92 
93    PROBLEMS:
94    Q: How to find all the bundles referring to a physical path for
95       PMTU discovery? Seems, dst should contain list of all parents...
96       and enter to infinite locking hierarchy disaster.
97       No! It is easier, we will not search for them, let them find us.
98       We add genid to each dst plus pointer to genid of raw IP route,
99       pmtu disc will update pmtu on raw IP route and increase its genid.
100       dst_check() will see this for top level and trigger resyncing
101       metrics. Plus, it will be made via sk->sk_dst_cache. Solved.
102  */
103 
104 /* Full description of state of transformer. */
105 struct xfrm_state
106 {
107 	/* Note: bydst is re-used during gc */
108 	struct hlist_node	bydst;
109 	struct hlist_node	bysrc;
110 	struct hlist_node	byspi;
111 
112 	atomic_t		refcnt;
113 	spinlock_t		lock;
114 
115 	struct xfrm_id		id;
116 	struct xfrm_selector	sel;
117 
118 	u32			genid;
119 
120 	/* Key manger bits */
121 	struct {
122 		u8		state;
123 		u8		dying;
124 		u32		seq;
125 	} km;
126 
127 	/* Parameters of this state. */
128 	struct {
129 		u32		reqid;
130 		u8		mode;
131 		u8		replay_window;
132 		u8		aalgo, ealgo, calgo;
133 		u8		flags;
134 		u16		family;
135 		xfrm_address_t	saddr;
136 		int		header_len;
137 		int		trailer_len;
138 	} props;
139 
140 	struct xfrm_lifetime_cfg lft;
141 
142 	/* Data for transformer */
143 	struct xfrm_algo	*aalg;
144 	struct xfrm_algo	*ealg;
145 	struct xfrm_algo	*calg;
146 
147 	/* Data for encapsulator */
148 	struct xfrm_encap_tmpl	*encap;
149 
150 	/* Data for care-of address */
151 	xfrm_address_t	*coaddr;
152 
153 	/* IPComp needs an IPIP tunnel for handling uncompressed packets */
154 	struct xfrm_state	*tunnel;
155 
156 	/* If a tunnel, number of users + 1 */
157 	atomic_t		tunnel_users;
158 
159 	/* State for replay detection */
160 	struct xfrm_replay_state replay;
161 
162 	/* Replay detection state at the time we sent the last notification */
163 	struct xfrm_replay_state preplay;
164 
165 	/* internal flag that only holds state for delayed aevent at the
166 	 * moment
167 	*/
168 	u32			xflags;
169 
170 	/* Replay detection notification settings */
171 	u32			replay_maxage;
172 	u32			replay_maxdiff;
173 
174 	/* Replay detection notification timer */
175 	struct timer_list	rtimer;
176 
177 	/* Statistics */
178 	struct xfrm_stats	stats;
179 
180 	struct xfrm_lifetime_cur curlft;
181 	struct timer_list	timer;
182 
183 	/* Last used time */
184 	u64			lastused;
185 
186 	/* Reference to data common to all the instances of this
187 	 * transformer. */
188 	struct xfrm_type	*type;
189 	struct xfrm_mode	*mode;
190 
191 	/* Security context */
192 	struct xfrm_sec_ctx	*security;
193 
194 	/* Private data of this transformer, format is opaque,
195 	 * interpreted by xfrm_type methods. */
196 	void			*data;
197 };
198 
199 /* xflags - make enum if more show up */
200 #define XFRM_TIME_DEFER	1
201 
202 enum {
203 	XFRM_STATE_VOID,
204 	XFRM_STATE_ACQ,
205 	XFRM_STATE_VALID,
206 	XFRM_STATE_ERROR,
207 	XFRM_STATE_EXPIRED,
208 	XFRM_STATE_DEAD
209 };
210 
211 /* callback structure passed from either netlink or pfkey */
212 struct km_event
213 {
214 	union {
215 		u32 hard;
216 		u32 proto;
217 		u32 byid;
218 		u32 aevent;
219 		u32 type;
220 	} data;
221 
222 	u32	seq;
223 	u32	pid;
224 	u32	event;
225 };
226 
227 struct xfrm_type;
228 struct xfrm_dst;
229 struct xfrm_policy_afinfo {
230 	unsigned short		family;
231 	struct dst_ops		*dst_ops;
232 	void			(*garbage_collect)(void);
233 	int			(*dst_lookup)(struct xfrm_dst **dst, struct flowi *fl);
234 	int			(*get_saddr)(xfrm_address_t *saddr, xfrm_address_t *daddr);
235 	struct dst_entry	*(*find_bundle)(struct flowi *fl, struct xfrm_policy *policy);
236 	int			(*bundle_create)(struct xfrm_policy *policy,
237 						 struct xfrm_state **xfrm,
238 						 int nx,
239 						 struct flowi *fl,
240 						 struct dst_entry **dst_p);
241 	void			(*decode_session)(struct sk_buff *skb,
242 						  struct flowi *fl);
243 };
244 
245 extern int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo);
246 extern int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo);
247 extern void km_policy_notify(struct xfrm_policy *xp, int dir, struct km_event *c);
248 extern void km_state_notify(struct xfrm_state *x, struct km_event *c);
249 
250 struct xfrm_tmpl;
251 extern int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol);
252 extern void km_state_expired(struct xfrm_state *x, int hard, u32 pid);
253 extern int __xfrm_state_delete(struct xfrm_state *x);
254 
255 struct xfrm_state_afinfo {
256 	unsigned int		family;
257 	struct module		*owner;
258 	struct xfrm_type	*type_map[IPPROTO_MAX];
259 	struct xfrm_mode	*mode_map[XFRM_MODE_MAX];
260 	int			(*init_flags)(struct xfrm_state *x);
261 	void			(*init_tempsel)(struct xfrm_state *x, struct flowi *fl,
262 						struct xfrm_tmpl *tmpl,
263 						xfrm_address_t *daddr, xfrm_address_t *saddr);
264 	int			(*tmpl_sort)(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n);
265 	int			(*state_sort)(struct xfrm_state **dst, struct xfrm_state **src, int n);
266 	int			(*output)(struct sk_buff *skb);
267 };
268 
269 extern int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo);
270 extern int xfrm_state_unregister_afinfo(struct xfrm_state_afinfo *afinfo);
271 
272 extern void xfrm_state_delete_tunnel(struct xfrm_state *x);
273 
274 struct xfrm_type
275 {
276 	char			*description;
277 	struct module		*owner;
278 	__u8			proto;
279 	__u8			flags;
280 #define XFRM_TYPE_NON_FRAGMENT	1
281 #define XFRM_TYPE_REPLAY_PROT	2
282 
283 	int			(*init_state)(struct xfrm_state *x);
284 	void			(*destructor)(struct xfrm_state *);
285 	int			(*input)(struct xfrm_state *, struct sk_buff *skb);
286 	int			(*output)(struct xfrm_state *, struct sk_buff *pskb);
287 	int			(*reject)(struct xfrm_state *, struct sk_buff *, struct flowi *);
288 	int			(*hdr_offset)(struct xfrm_state *, struct sk_buff *, u8 **);
289 	xfrm_address_t		*(*local_addr)(struct xfrm_state *, xfrm_address_t *);
290 	xfrm_address_t		*(*remote_addr)(struct xfrm_state *, xfrm_address_t *);
291 	/* Estimate maximal size of result of transformation of a dgram */
292 	u32			(*get_mtu)(struct xfrm_state *, int size);
293 };
294 
295 extern int xfrm_register_type(struct xfrm_type *type, unsigned short family);
296 extern int xfrm_unregister_type(struct xfrm_type *type, unsigned short family);
297 
298 struct xfrm_mode {
299 	int (*input)(struct xfrm_state *x, struct sk_buff *skb);
300 
301 	/*
302 	 * Add encapsulation header.
303 	 *
304 	 * On exit, the transport header will be set to the start of the
305 	 * encapsulation header to be filled in by x->type->output and
306 	 * the mac header will be set to the nextheader (protocol for
307 	 * IPv4) field of the extension header directly preceding the
308 	 * encapsulation header, or in its absence, that of the top IP
309 	 * header.  The value of the network header will always point
310 	 * to the top IP header while skb->data will point to the payload.
311 	 */
312 	int (*output)(struct xfrm_state *x,struct sk_buff *skb);
313 
314 	struct xfrm_state_afinfo *afinfo;
315 	struct module *owner;
316 	unsigned int encap;
317 	int flags;
318 };
319 
320 /* Flags for xfrm_mode. */
321 enum {
322 	XFRM_MODE_FLAG_TUNNEL = 1,
323 };
324 
325 extern int xfrm_register_mode(struct xfrm_mode *mode, int family);
326 extern int xfrm_unregister_mode(struct xfrm_mode *mode, int family);
327 
328 struct xfrm_tmpl
329 {
330 /* id in template is interpreted as:
331  * daddr - destination of tunnel, may be zero for transport mode.
332  * spi   - zero to acquire spi. Not zero if spi is static, then
333  *	   daddr must be fixed too.
334  * proto - AH/ESP/IPCOMP
335  */
336 	struct xfrm_id		id;
337 
338 /* Source address of tunnel. Ignored, if it is not a tunnel. */
339 	xfrm_address_t		saddr;
340 
341 	unsigned short		encap_family;
342 
343 	__u32			reqid;
344 
345 /* Mode: transport, tunnel etc. */
346 	__u8			mode;
347 
348 /* Sharing mode: unique, this session only, this user only etc. */
349 	__u8			share;
350 
351 /* May skip this transfomration if no SA is found */
352 	__u8			optional;
353 
354 /* Bit mask of algos allowed for acquisition */
355 	__u32			aalgos;
356 	__u32			ealgos;
357 	__u32			calgos;
358 };
359 
360 #define XFRM_MAX_DEPTH		6
361 
362 struct xfrm_policy
363 {
364 	struct xfrm_policy	*next;
365 	struct hlist_node	bydst;
366 	struct hlist_node	byidx;
367 
368 	/* This lock only affects elements except for entry. */
369 	rwlock_t		lock;
370 	atomic_t		refcnt;
371 	struct timer_list	timer;
372 
373 	u32			priority;
374 	u32			index;
375 	struct xfrm_selector	selector;
376 	struct xfrm_lifetime_cfg lft;
377 	struct xfrm_lifetime_cur curlft;
378 	struct dst_entry       *bundles;
379 	u16			family;
380 	u8			type;
381 	u8			action;
382 	u8			flags;
383 	u8			dead;
384 	u8			xfrm_nr;
385 	/* XXX 1 byte hole, try to pack */
386 	struct xfrm_sec_ctx	*security;
387 	struct xfrm_tmpl       	xfrm_vec[XFRM_MAX_DEPTH];
388 };
389 
390 struct xfrm_migrate {
391 	xfrm_address_t		old_daddr;
392 	xfrm_address_t		old_saddr;
393 	xfrm_address_t		new_daddr;
394 	xfrm_address_t		new_saddr;
395 	u8			proto;
396 	u8			mode;
397 	u16			reserved;
398 	u32			reqid;
399 	u16			old_family;
400 	u16			new_family;
401 };
402 
403 #define XFRM_KM_TIMEOUT                30
404 /* which seqno */
405 #define XFRM_REPLAY_SEQ		1
406 #define XFRM_REPLAY_OSEQ	2
407 #define XFRM_REPLAY_SEQ_MASK	3
408 /* what happened */
409 #define XFRM_REPLAY_UPDATE	XFRM_AE_CR
410 #define XFRM_REPLAY_TIMEOUT	XFRM_AE_CE
411 
412 /* default aevent timeout in units of 100ms */
413 #define XFRM_AE_ETIME			10
414 /* Async Event timer multiplier */
415 #define XFRM_AE_ETH_M			10
416 /* default seq threshold size */
417 #define XFRM_AE_SEQT_SIZE		2
418 
419 struct xfrm_mgr
420 {
421 	struct list_head	list;
422 	char			*id;
423 	int			(*notify)(struct xfrm_state *x, struct km_event *c);
424 	int			(*acquire)(struct xfrm_state *x, struct xfrm_tmpl *, struct xfrm_policy *xp, int dir);
425 	struct xfrm_policy	*(*compile_policy)(struct sock *sk, int opt, u8 *data, int len, int *dir);
426 	int			(*new_mapping)(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport);
427 	int			(*notify_policy)(struct xfrm_policy *x, int dir, struct km_event *c);
428 	int			(*report)(u8 proto, struct xfrm_selector *sel, xfrm_address_t *addr);
429 	int			(*migrate)(struct xfrm_selector *sel, u8 dir, u8 type, struct xfrm_migrate *m, int num_bundles);
430 };
431 
432 extern int xfrm_register_km(struct xfrm_mgr *km);
433 extern int xfrm_unregister_km(struct xfrm_mgr *km);
434 
435 extern unsigned int xfrm_policy_count[XFRM_POLICY_MAX*2];
436 
437 /*
438  * This structure is used for the duration where packets are being
439  * transformed by IPsec.  As soon as the packet leaves IPsec the
440  * area beyond the generic IP part may be overwritten.
441  */
442 struct xfrm_skb_cb {
443 	union {
444 		struct inet_skb_parm h4;
445 		struct inet6_skb_parm h6;
446         } header;
447 
448         /* Sequence number for replay protection. */
449         u64 seq;
450 };
451 
452 #define XFRM_SKB_CB(__skb) ((struct xfrm_skb_cb *)&((__skb)->cb[0]))
453 
454 /* Audit Information */
455 struct xfrm_audit
456 {
457 	u32	loginuid;
458 	u32	secid;
459 };
460 
461 #ifdef CONFIG_AUDITSYSCALL
462 static inline struct audit_buffer *xfrm_audit_start(u32 auid, u32 sid)
463 {
464 	struct audit_buffer *audit_buf = NULL;
465 	char *secctx;
466 	u32 secctx_len;
467 
468 	audit_buf = audit_log_start(current->audit_context, GFP_ATOMIC,
469 			      AUDIT_MAC_IPSEC_EVENT);
470 	if (audit_buf == NULL)
471 		return NULL;
472 
473 	audit_log_format(audit_buf, "auid=%u", auid);
474 
475 	if (sid != 0 &&
476 	    security_secid_to_secctx(sid, &secctx, &secctx_len) == 0) {
477 		audit_log_format(audit_buf, " subj=%s", secctx);
478 		security_release_secctx(secctx, secctx_len);
479 	} else
480 		audit_log_task_context(audit_buf);
481 	return audit_buf;
482 }
483 
484 extern void xfrm_audit_policy_add(struct xfrm_policy *xp, int result,
485 				  u32 auid, u32 sid);
486 extern void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
487 				  u32 auid, u32 sid);
488 extern void xfrm_audit_state_add(struct xfrm_state *x, int result,
489 				 u32 auid, u32 sid);
490 extern void xfrm_audit_state_delete(struct xfrm_state *x, int result,
491 				    u32 auid, u32 sid);
492 #else
493 #define xfrm_audit_policy_add(x, r, a, s)	do { ; } while (0)
494 #define xfrm_audit_policy_delete(x, r, a, s)	do { ; } while (0)
495 #define xfrm_audit_state_add(x, r, a, s)	do { ; } while (0)
496 #define xfrm_audit_state_delete(x, r, a, s)	do { ; } while (0)
497 #endif /* CONFIG_AUDITSYSCALL */
498 
499 static inline void xfrm_pol_hold(struct xfrm_policy *policy)
500 {
501 	if (likely(policy != NULL))
502 		atomic_inc(&policy->refcnt);
503 }
504 
505 extern void __xfrm_policy_destroy(struct xfrm_policy *policy);
506 
507 static inline void xfrm_pol_put(struct xfrm_policy *policy)
508 {
509 	if (atomic_dec_and_test(&policy->refcnt))
510 		__xfrm_policy_destroy(policy);
511 }
512 
513 #ifdef CONFIG_XFRM_SUB_POLICY
514 static inline void xfrm_pols_put(struct xfrm_policy **pols, int npols)
515 {
516 	int i;
517 	for (i = npols - 1; i >= 0; --i)
518 		xfrm_pol_put(pols[i]);
519 }
520 #else
521 static inline void xfrm_pols_put(struct xfrm_policy **pols, int npols)
522 {
523 	xfrm_pol_put(pols[0]);
524 }
525 #endif
526 
527 extern void __xfrm_state_destroy(struct xfrm_state *);
528 
529 static inline void __xfrm_state_put(struct xfrm_state *x)
530 {
531 	atomic_dec(&x->refcnt);
532 }
533 
534 static inline void xfrm_state_put(struct xfrm_state *x)
535 {
536 	if (atomic_dec_and_test(&x->refcnt))
537 		__xfrm_state_destroy(x);
538 }
539 
540 static inline void xfrm_state_hold(struct xfrm_state *x)
541 {
542 	atomic_inc(&x->refcnt);
543 }
544 
545 static __inline__ int addr_match(void *token1, void *token2, int prefixlen)
546 {
547 	__be32 *a1 = token1;
548 	__be32 *a2 = token2;
549 	int pdw;
550 	int pbi;
551 
552 	pdw = prefixlen >> 5;	  /* num of whole __u32 in prefix */
553 	pbi = prefixlen &  0x1f;  /* num of bits in incomplete u32 in prefix */
554 
555 	if (pdw)
556 		if (memcmp(a1, a2, pdw << 2))
557 			return 0;
558 
559 	if (pbi) {
560 		__be32 mask;
561 
562 		mask = htonl((0xffffffff) << (32 - pbi));
563 
564 		if ((a1[pdw] ^ a2[pdw]) & mask)
565 			return 0;
566 	}
567 
568 	return 1;
569 }
570 
571 static __inline__
572 __be16 xfrm_flowi_sport(struct flowi *fl)
573 {
574 	__be16 port;
575 	switch(fl->proto) {
576 	case IPPROTO_TCP:
577 	case IPPROTO_UDP:
578 	case IPPROTO_UDPLITE:
579 	case IPPROTO_SCTP:
580 		port = fl->fl_ip_sport;
581 		break;
582 	case IPPROTO_ICMP:
583 	case IPPROTO_ICMPV6:
584 		port = htons(fl->fl_icmp_type);
585 		break;
586 	case IPPROTO_MH:
587 		port = htons(fl->fl_mh_type);
588 		break;
589 	default:
590 		port = 0;	/*XXX*/
591 	}
592 	return port;
593 }
594 
595 static __inline__
596 __be16 xfrm_flowi_dport(struct flowi *fl)
597 {
598 	__be16 port;
599 	switch(fl->proto) {
600 	case IPPROTO_TCP:
601 	case IPPROTO_UDP:
602 	case IPPROTO_UDPLITE:
603 	case IPPROTO_SCTP:
604 		port = fl->fl_ip_dport;
605 		break;
606 	case IPPROTO_ICMP:
607 	case IPPROTO_ICMPV6:
608 		port = htons(fl->fl_icmp_code);
609 		break;
610 	default:
611 		port = 0;	/*XXX*/
612 	}
613 	return port;
614 }
615 
616 extern int xfrm_selector_match(struct xfrm_selector *sel, struct flowi *fl,
617 			       unsigned short family);
618 
619 #ifdef CONFIG_SECURITY_NETWORK_XFRM
620 /*	If neither has a context --> match
621  * 	Otherwise, both must have a context and the sids, doi, alg must match
622  */
623 static inline int xfrm_sec_ctx_match(struct xfrm_sec_ctx *s1, struct xfrm_sec_ctx *s2)
624 {
625 	return ((!s1 && !s2) ||
626 		(s1 && s2 &&
627 		 (s1->ctx_sid == s2->ctx_sid) &&
628 		 (s1->ctx_doi == s2->ctx_doi) &&
629 		 (s1->ctx_alg == s2->ctx_alg)));
630 }
631 #else
632 static inline int xfrm_sec_ctx_match(struct xfrm_sec_ctx *s1, struct xfrm_sec_ctx *s2)
633 {
634 	return 1;
635 }
636 #endif
637 
638 /* A struct encoding bundle of transformations to apply to some set of flow.
639  *
640  * dst->child points to the next element of bundle.
641  * dst->xfrm  points to an instanse of transformer.
642  *
643  * Due to unfortunate limitations of current routing cache, which we
644  * have no time to fix, it mirrors struct rtable and bound to the same
645  * routing key, including saddr,daddr. However, we can have many of
646  * bundles differing by session id. All the bundles grow from a parent
647  * policy rule.
648  */
649 struct xfrm_dst
650 {
651 	union {
652 		struct dst_entry	dst;
653 		struct rtable		rt;
654 		struct rt6_info		rt6;
655 	} u;
656 	struct dst_entry *route;
657 #ifdef CONFIG_XFRM_SUB_POLICY
658 	struct flowi *origin;
659 	struct xfrm_selector *partner;
660 #endif
661 	u32 genid;
662 	u32 route_mtu_cached;
663 	u32 child_mtu_cached;
664 	u32 route_cookie;
665 	u32 path_cookie;
666 };
667 
668 static inline void xfrm_dst_destroy(struct xfrm_dst *xdst)
669 {
670 	dst_release(xdst->route);
671 	if (likely(xdst->u.dst.xfrm))
672 		xfrm_state_put(xdst->u.dst.xfrm);
673 #ifdef CONFIG_XFRM_SUB_POLICY
674 	kfree(xdst->origin);
675 	xdst->origin = NULL;
676 	kfree(xdst->partner);
677 	xdst->partner = NULL;
678 #endif
679 }
680 
681 extern void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev);
682 
683 struct sec_path
684 {
685 	atomic_t		refcnt;
686 	int			len;
687 	struct xfrm_state	*xvec[XFRM_MAX_DEPTH];
688 };
689 
690 static inline struct sec_path *
691 secpath_get(struct sec_path *sp)
692 {
693 	if (sp)
694 		atomic_inc(&sp->refcnt);
695 	return sp;
696 }
697 
698 extern void __secpath_destroy(struct sec_path *sp);
699 
700 static inline void
701 secpath_put(struct sec_path *sp)
702 {
703 	if (sp && atomic_dec_and_test(&sp->refcnt))
704 		__secpath_destroy(sp);
705 }
706 
707 extern struct sec_path *secpath_dup(struct sec_path *src);
708 
709 static inline void
710 secpath_reset(struct sk_buff *skb)
711 {
712 #ifdef CONFIG_XFRM
713 	secpath_put(skb->sp);
714 	skb->sp = NULL;
715 #endif
716 }
717 
718 static inline int
719 xfrm_addr_any(xfrm_address_t *addr, unsigned short family)
720 {
721 	switch (family) {
722 	case AF_INET:
723 		return addr->a4 == 0;
724 	case AF_INET6:
725 		return ipv6_addr_any((struct in6_addr *)&addr->a6);
726 	}
727 	return 0;
728 }
729 
730 static inline int
731 __xfrm4_state_addr_cmp(struct xfrm_tmpl *tmpl, struct xfrm_state *x)
732 {
733 	return	(tmpl->saddr.a4 &&
734 		 tmpl->saddr.a4 != x->props.saddr.a4);
735 }
736 
737 static inline int
738 __xfrm6_state_addr_cmp(struct xfrm_tmpl *tmpl, struct xfrm_state *x)
739 {
740 	return	(!ipv6_addr_any((struct in6_addr*)&tmpl->saddr) &&
741 		 ipv6_addr_cmp((struct in6_addr *)&tmpl->saddr, (struct in6_addr*)&x->props.saddr));
742 }
743 
744 static inline int
745 xfrm_state_addr_cmp(struct xfrm_tmpl *tmpl, struct xfrm_state *x, unsigned short family)
746 {
747 	switch (family) {
748 	case AF_INET:
749 		return __xfrm4_state_addr_cmp(tmpl, x);
750 	case AF_INET6:
751 		return __xfrm6_state_addr_cmp(tmpl, x);
752 	}
753 	return !0;
754 }
755 
756 #ifdef CONFIG_XFRM
757 
758 extern int __xfrm_policy_check(struct sock *, int dir, struct sk_buff *skb, unsigned short family);
759 
760 static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family)
761 {
762 	if (sk && sk->sk_policy[XFRM_POLICY_IN])
763 		return __xfrm_policy_check(sk, dir, skb, family);
764 
765 	return	(!xfrm_policy_count[dir] && !skb->sp) ||
766 		(skb->dst->flags & DST_NOPOLICY) ||
767 		__xfrm_policy_check(sk, dir, skb, family);
768 }
769 
770 static inline int xfrm4_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
771 {
772 	return xfrm_policy_check(sk, dir, skb, AF_INET);
773 }
774 
775 static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
776 {
777 	return xfrm_policy_check(sk, dir, skb, AF_INET6);
778 }
779 
780 extern int xfrm_decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family);
781 extern int __xfrm_route_forward(struct sk_buff *skb, unsigned short family);
782 
783 static inline int xfrm_route_forward(struct sk_buff *skb, unsigned short family)
784 {
785 	return	!xfrm_policy_count[XFRM_POLICY_OUT] ||
786 		(skb->dst->flags & DST_NOXFRM) ||
787 		__xfrm_route_forward(skb, family);
788 }
789 
790 static inline int xfrm4_route_forward(struct sk_buff *skb)
791 {
792 	return xfrm_route_forward(skb, AF_INET);
793 }
794 
795 static inline int xfrm6_route_forward(struct sk_buff *skb)
796 {
797 	return xfrm_route_forward(skb, AF_INET6);
798 }
799 
800 extern int __xfrm_sk_clone_policy(struct sock *sk);
801 
802 static inline int xfrm_sk_clone_policy(struct sock *sk)
803 {
804 	if (unlikely(sk->sk_policy[0] || sk->sk_policy[1]))
805 		return __xfrm_sk_clone_policy(sk);
806 	return 0;
807 }
808 
809 extern int xfrm_policy_delete(struct xfrm_policy *pol, int dir);
810 
811 static inline void xfrm_sk_free_policy(struct sock *sk)
812 {
813 	if (unlikely(sk->sk_policy[0] != NULL)) {
814 		xfrm_policy_delete(sk->sk_policy[0], XFRM_POLICY_MAX);
815 		sk->sk_policy[0] = NULL;
816 	}
817 	if (unlikely(sk->sk_policy[1] != NULL)) {
818 		xfrm_policy_delete(sk->sk_policy[1], XFRM_POLICY_MAX+1);
819 		sk->sk_policy[1] = NULL;
820 	}
821 }
822 
823 #else
824 
825 static inline void xfrm_sk_free_policy(struct sock *sk) {}
826 static inline int xfrm_sk_clone_policy(struct sock *sk) { return 0; }
827 static inline int xfrm6_route_forward(struct sk_buff *skb) { return 1; }
828 static inline int xfrm4_route_forward(struct sk_buff *skb) { return 1; }
829 static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
830 {
831 	return 1;
832 }
833 static inline int xfrm4_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
834 {
835 	return 1;
836 }
837 static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family)
838 {
839 	return 1;
840 }
841 #endif
842 
843 static __inline__
844 xfrm_address_t *xfrm_flowi_daddr(struct flowi *fl, unsigned short family)
845 {
846 	switch (family){
847 	case AF_INET:
848 		return (xfrm_address_t *)&fl->fl4_dst;
849 	case AF_INET6:
850 		return (xfrm_address_t *)&fl->fl6_dst;
851 	}
852 	return NULL;
853 }
854 
855 static __inline__
856 xfrm_address_t *xfrm_flowi_saddr(struct flowi *fl, unsigned short family)
857 {
858 	switch (family){
859 	case AF_INET:
860 		return (xfrm_address_t *)&fl->fl4_src;
861 	case AF_INET6:
862 		return (xfrm_address_t *)&fl->fl6_src;
863 	}
864 	return NULL;
865 }
866 
867 static __inline__ int
868 __xfrm4_state_addr_check(struct xfrm_state *x,
869 			 xfrm_address_t *daddr, xfrm_address_t *saddr)
870 {
871 	if (daddr->a4 == x->id.daddr.a4 &&
872 	    (saddr->a4 == x->props.saddr.a4 || !saddr->a4 || !x->props.saddr.a4))
873 		return 1;
874 	return 0;
875 }
876 
877 static __inline__ int
878 __xfrm6_state_addr_check(struct xfrm_state *x,
879 			 xfrm_address_t *daddr, xfrm_address_t *saddr)
880 {
881 	if (!ipv6_addr_cmp((struct in6_addr *)daddr, (struct in6_addr *)&x->id.daddr) &&
882 	    (!ipv6_addr_cmp((struct in6_addr *)saddr, (struct in6_addr *)&x->props.saddr)||
883 	     ipv6_addr_any((struct in6_addr *)saddr) ||
884 	     ipv6_addr_any((struct in6_addr *)&x->props.saddr)))
885 		return 1;
886 	return 0;
887 }
888 
889 static __inline__ int
890 xfrm_state_addr_check(struct xfrm_state *x,
891 		      xfrm_address_t *daddr, xfrm_address_t *saddr,
892 		      unsigned short family)
893 {
894 	switch (family) {
895 	case AF_INET:
896 		return __xfrm4_state_addr_check(x, daddr, saddr);
897 	case AF_INET6:
898 		return __xfrm6_state_addr_check(x, daddr, saddr);
899 	}
900 	return 0;
901 }
902 
903 static __inline__ int
904 xfrm_state_addr_flow_check(struct xfrm_state *x, struct flowi *fl,
905 			   unsigned short family)
906 {
907 	switch (family) {
908 	case AF_INET:
909 		return __xfrm4_state_addr_check(x,
910 						(xfrm_address_t *)&fl->fl4_dst,
911 						(xfrm_address_t *)&fl->fl4_src);
912 	case AF_INET6:
913 		return __xfrm6_state_addr_check(x,
914 						(xfrm_address_t *)&fl->fl6_dst,
915 						(xfrm_address_t *)&fl->fl6_src);
916 	}
917 	return 0;
918 }
919 
920 static inline int xfrm_state_kern(struct xfrm_state *x)
921 {
922 	return atomic_read(&x->tunnel_users);
923 }
924 
925 static inline int xfrm_id_proto_match(u8 proto, u8 userproto)
926 {
927 	return (!userproto || proto == userproto ||
928 		(userproto == IPSEC_PROTO_ANY && (proto == IPPROTO_AH ||
929 						  proto == IPPROTO_ESP ||
930 						  proto == IPPROTO_COMP)));
931 }
932 
933 /*
934  * xfrm algorithm information
935  */
936 struct xfrm_algo_auth_info {
937 	u16 icv_truncbits;
938 	u16 icv_fullbits;
939 };
940 
941 struct xfrm_algo_encr_info {
942 	u16 blockbits;
943 	u16 defkeybits;
944 };
945 
946 struct xfrm_algo_comp_info {
947 	u16 threshold;
948 };
949 
950 struct xfrm_algo_desc {
951 	char *name;
952 	char *compat;
953 	u8 available:1;
954 	union {
955 		struct xfrm_algo_auth_info auth;
956 		struct xfrm_algo_encr_info encr;
957 		struct xfrm_algo_comp_info comp;
958 	} uinfo;
959 	struct sadb_alg desc;
960 };
961 
962 /* XFRM tunnel handlers.  */
963 struct xfrm_tunnel {
964 	int (*handler)(struct sk_buff *skb);
965 	int (*err_handler)(struct sk_buff *skb, __u32 info);
966 
967 	struct xfrm_tunnel *next;
968 	int priority;
969 };
970 
971 struct xfrm6_tunnel {
972 	int (*handler)(struct sk_buff *skb);
973 	int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
974 			   int type, int code, int offset, __be32 info);
975 	struct xfrm6_tunnel *next;
976 	int priority;
977 };
978 
979 extern void xfrm_init(void);
980 extern void xfrm4_init(void);
981 extern void xfrm6_init(void);
982 extern void xfrm6_fini(void);
983 extern void xfrm_state_init(void);
984 extern void xfrm4_state_init(void);
985 extern void xfrm6_state_init(void);
986 extern void xfrm6_state_fini(void);
987 
988 extern int xfrm_state_walk(u8 proto, int (*func)(struct xfrm_state *, int, void*), void *);
989 extern struct xfrm_state *xfrm_state_alloc(void);
990 extern struct xfrm_state *xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr,
991 					  struct flowi *fl, struct xfrm_tmpl *tmpl,
992 					  struct xfrm_policy *pol, int *err,
993 					  unsigned short family);
994 extern struct xfrm_state * xfrm_stateonly_find(xfrm_address_t *daddr,
995 					       xfrm_address_t *saddr,
996 					       unsigned short family,
997 					       u8 mode, u8 proto, u32 reqid);
998 extern int xfrm_state_check_expire(struct xfrm_state *x);
999 extern void xfrm_state_insert(struct xfrm_state *x);
1000 extern int xfrm_state_add(struct xfrm_state *x);
1001 extern int xfrm_state_update(struct xfrm_state *x);
1002 extern struct xfrm_state *xfrm_state_lookup(xfrm_address_t *daddr, __be32 spi, u8 proto, unsigned short family);
1003 extern struct xfrm_state *xfrm_state_lookup_byaddr(xfrm_address_t *daddr, xfrm_address_t *saddr, u8 proto, unsigned short family);
1004 #ifdef CONFIG_XFRM_SUB_POLICY
1005 extern int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src,
1006 			  int n, unsigned short family);
1007 extern int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src,
1008 			   int n, unsigned short family);
1009 #else
1010 static inline int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src,
1011 				 int n, unsigned short family)
1012 {
1013 	return -ENOSYS;
1014 }
1015 
1016 static inline int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src,
1017 				  int n, unsigned short family)
1018 {
1019 	return -ENOSYS;
1020 }
1021 #endif
1022 
1023 struct xfrmk_sadinfo {
1024 	u32 sadhcnt; /* current hash bkts */
1025 	u32 sadhmcnt; /* max allowed hash bkts */
1026 	u32 sadcnt; /* current running count */
1027 };
1028 
1029 struct xfrmk_spdinfo {
1030 	u32 incnt;
1031 	u32 outcnt;
1032 	u32 fwdcnt;
1033 	u32 inscnt;
1034 	u32 outscnt;
1035 	u32 fwdscnt;
1036 	u32 spdhcnt;
1037 	u32 spdhmcnt;
1038 };
1039 
1040 extern struct xfrm_state *xfrm_find_acq_byseq(u32 seq);
1041 extern int xfrm_state_delete(struct xfrm_state *x);
1042 extern int xfrm_state_flush(u8 proto, struct xfrm_audit *audit_info);
1043 extern void xfrm_sad_getinfo(struct xfrmk_sadinfo *si);
1044 extern void xfrm_spd_getinfo(struct xfrmk_spdinfo *si);
1045 extern int xfrm_replay_check(struct xfrm_state *x, __be32 seq);
1046 extern void xfrm_replay_advance(struct xfrm_state *x, __be32 seq);
1047 extern void xfrm_replay_notify(struct xfrm_state *x, int event);
1048 extern int xfrm_state_mtu(struct xfrm_state *x, int mtu);
1049 extern int xfrm_init_state(struct xfrm_state *x);
1050 extern int xfrm_output(struct sk_buff *skb);
1051 extern int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
1052 			   int encap_type);
1053 extern int xfrm4_rcv(struct sk_buff *skb);
1054 
1055 static inline int xfrm4_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
1056 {
1057 	return xfrm4_rcv_encap(skb, nexthdr, spi, 0);
1058 }
1059 
1060 extern int xfrm4_output(struct sk_buff *skb);
1061 extern int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family);
1062 extern int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family);
1063 extern int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi);
1064 extern int xfrm6_rcv(struct sk_buff *skb);
1065 extern int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
1066 			    xfrm_address_t *saddr, u8 proto);
1067 extern int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family);
1068 extern int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family);
1069 extern __be32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr);
1070 extern void xfrm6_tunnel_free_spi(xfrm_address_t *saddr);
1071 extern __be32 xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr);
1072 extern int xfrm6_output(struct sk_buff *skb);
1073 extern int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
1074 				 u8 **prevhdr);
1075 
1076 #ifdef CONFIG_XFRM
1077 extern int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb);
1078 extern int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen);
1079 extern int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl, unsigned short family);
1080 #else
1081 static inline int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen)
1082 {
1083  	return -ENOPROTOOPT;
1084 }
1085 
1086 static inline int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
1087 {
1088  	/* should not happen */
1089  	kfree_skb(skb);
1090 	return 0;
1091 }
1092 
1093 static inline int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl, unsigned short family)
1094 {
1095 	return -EINVAL;
1096 }
1097 #endif
1098 
1099 struct xfrm_policy *xfrm_policy_alloc(gfp_t gfp);
1100 extern int xfrm_policy_walk(u8 type, int (*func)(struct xfrm_policy *, int, int, void*), void *);
1101 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl);
1102 struct xfrm_policy *xfrm_policy_bysel_ctx(u8 type, int dir,
1103 					  struct xfrm_selector *sel,
1104 					  struct xfrm_sec_ctx *ctx, int delete,
1105 					  int *err);
1106 struct xfrm_policy *xfrm_policy_byid(u8, int dir, u32 id, int delete, int *err);
1107 int xfrm_policy_flush(u8 type, struct xfrm_audit *audit_info);
1108 u32 xfrm_get_acqseq(void);
1109 extern int xfrm_alloc_spi(struct xfrm_state *x, u32 minspi, u32 maxspi);
1110 struct xfrm_state * xfrm_find_acq(u8 mode, u32 reqid, u8 proto,
1111 				  xfrm_address_t *daddr, xfrm_address_t *saddr,
1112 				  int create, unsigned short family);
1113 extern int xfrm_policy_flush(u8 type, struct xfrm_audit *audit_info);
1114 extern int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol);
1115 extern int xfrm_bundle_ok(struct xfrm_policy *pol, struct xfrm_dst *xdst,
1116 			  struct flowi *fl, int family, int strict);
1117 extern void xfrm_init_pmtu(struct dst_entry *dst);
1118 
1119 #ifdef CONFIG_XFRM_MIGRATE
1120 extern int km_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
1121 		      struct xfrm_migrate *m, int num_bundles);
1122 extern struct xfrm_state * xfrm_migrate_state_find(struct xfrm_migrate *m);
1123 extern struct xfrm_state * xfrm_state_migrate(struct xfrm_state *x,
1124 					      struct xfrm_migrate *m);
1125 extern int xfrm_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
1126 			struct xfrm_migrate *m, int num_bundles);
1127 #endif
1128 
1129 extern wait_queue_head_t km_waitq;
1130 extern int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport);
1131 extern void km_policy_expired(struct xfrm_policy *pol, int dir, int hard, u32 pid);
1132 extern int km_report(u8 proto, struct xfrm_selector *sel, xfrm_address_t *addr);
1133 
1134 extern void xfrm_input_init(void);
1135 extern int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq);
1136 
1137 extern void xfrm_probe_algs(void);
1138 extern int xfrm_count_auth_supported(void);
1139 extern int xfrm_count_enc_supported(void);
1140 extern struct xfrm_algo_desc *xfrm_aalg_get_byidx(unsigned int idx);
1141 extern struct xfrm_algo_desc *xfrm_ealg_get_byidx(unsigned int idx);
1142 extern struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id);
1143 extern struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id);
1144 extern struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id);
1145 extern struct xfrm_algo_desc *xfrm_aalg_get_byname(char *name, int probe);
1146 extern struct xfrm_algo_desc *xfrm_ealg_get_byname(char *name, int probe);
1147 extern struct xfrm_algo_desc *xfrm_calg_get_byname(char *name, int probe);
1148 
1149 struct hash_desc;
1150 struct scatterlist;
1151 typedef int (icv_update_fn_t)(struct hash_desc *, struct scatterlist *,
1152 			      unsigned int);
1153 
1154 extern int skb_icv_walk(const struct sk_buff *skb, struct hash_desc *tfm,
1155 			int offset, int len, icv_update_fn_t icv_update);
1156 
1157 static inline int xfrm_addr_cmp(xfrm_address_t *a, xfrm_address_t *b,
1158 				int family)
1159 {
1160 	switch (family) {
1161 	default:
1162 	case AF_INET:
1163 		return (__force __u32)a->a4 - (__force __u32)b->a4;
1164 	case AF_INET6:
1165 		return ipv6_addr_cmp((struct in6_addr *)a,
1166 				     (struct in6_addr *)b);
1167 	}
1168 }
1169 
1170 static inline int xfrm_policy_id2dir(u32 index)
1171 {
1172 	return index & 7;
1173 }
1174 
1175 static inline int xfrm_aevent_is_on(void)
1176 {
1177 	struct sock *nlsk;
1178 	int ret = 0;
1179 
1180 	rcu_read_lock();
1181 	nlsk = rcu_dereference(xfrm_nl);
1182 	if (nlsk)
1183 		ret = netlink_has_listeners(nlsk, XFRMNLGRP_AEVENTS);
1184 	rcu_read_unlock();
1185 	return ret;
1186 }
1187 
1188 #ifdef CONFIG_XFRM_MIGRATE
1189 static inline struct xfrm_algo *xfrm_algo_clone(struct xfrm_algo *orig)
1190 {
1191 	return (struct xfrm_algo *)kmemdup(orig, sizeof(*orig) + orig->alg_key_len, GFP_KERNEL);
1192 }
1193 
1194 static inline void xfrm_states_put(struct xfrm_state **states, int n)
1195 {
1196 	int i;
1197 	for (i = 0; i < n; i++)
1198 		xfrm_state_put(*(states + i));
1199 }
1200 
1201 static inline void xfrm_states_delete(struct xfrm_state **states, int n)
1202 {
1203 	int i;
1204 	for (i = 0; i < n; i++)
1205 		xfrm_state_delete(*(states + i));
1206 }
1207 #endif
1208 
1209 #endif	/* _NET_XFRM_H */
1210