xref: /linux/include/net/xfrm.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 #include <linux/slab.h>
16 
17 #include <net/sock.h>
18 #include <net/dst.h>
19 #include <net/ip.h>
20 #include <net/route.h>
21 #include <net/ipv6.h>
22 #include <net/ip6_fib.h>
23 #include <net/flow.h>
24 
25 #include <linux/interrupt.h>
26 
27 #ifdef CONFIG_XFRM_STATISTICS
28 #include <net/snmp.h>
29 #endif
30 
31 #define XFRM_PROTO_ESP		50
32 #define XFRM_PROTO_AH		51
33 #define XFRM_PROTO_COMP		108
34 #define XFRM_PROTO_IPIP		4
35 #define XFRM_PROTO_IPV6		41
36 #define XFRM_PROTO_ROUTING	IPPROTO_ROUTING
37 #define XFRM_PROTO_DSTOPTS	IPPROTO_DSTOPTS
38 
39 #define XFRM_ALIGN4(len)	(((len) + 3) & ~3)
40 #define XFRM_ALIGN8(len)	(((len) + 7) & ~7)
41 #define MODULE_ALIAS_XFRM_MODE(family, encap) \
42 	MODULE_ALIAS("xfrm-mode-" __stringify(family) "-" __stringify(encap))
43 #define MODULE_ALIAS_XFRM_TYPE(family, proto) \
44 	MODULE_ALIAS("xfrm-type-" __stringify(family) "-" __stringify(proto))
45 
46 #ifdef CONFIG_XFRM_STATISTICS
47 #define XFRM_INC_STATS(net, field)	SNMP_INC_STATS((net)->mib.xfrm_statistics, field)
48 #define XFRM_INC_STATS_BH(net, field)	SNMP_INC_STATS_BH((net)->mib.xfrm_statistics, field)
49 #define XFRM_INC_STATS_USER(net, field)	SNMP_INC_STATS_USER((net)-mib.xfrm_statistics, field)
50 #else
51 #define XFRM_INC_STATS(net, field)	((void)(net))
52 #define XFRM_INC_STATS_BH(net, field)	((void)(net))
53 #define XFRM_INC_STATS_USER(net, field)	((void)(net))
54 #endif
55 
56 
57 /* Organization of SPD aka "XFRM rules"
58    ------------------------------------
59 
60    Basic objects:
61    - policy rule, struct xfrm_policy (=SPD entry)
62    - bundle of transformations, struct dst_entry == struct xfrm_dst (=SA bundle)
63    - instance of a transformer, struct xfrm_state (=SA)
64    - template to clone xfrm_state, struct xfrm_tmpl
65 
66    SPD is plain linear list of xfrm_policy rules, ordered by priority.
67    (To be compatible with existing pfkeyv2 implementations,
68    many rules with priority of 0x7fffffff are allowed to exist and
69    such rules are ordered in an unpredictable way, thanks to bsd folks.)
70 
71    Lookup is plain linear search until the first match with selector.
72 
73    If "action" is "block", then we prohibit the flow, otherwise:
74    if "xfrms_nr" is zero, the flow passes untransformed. Otherwise,
75    policy entry has list of up to XFRM_MAX_DEPTH transformations,
76    described by templates xfrm_tmpl. Each template is resolved
77    to a complete xfrm_state (see below) and we pack bundle of transformations
78    to a dst_entry returned to requestor.
79 
80    dst -. xfrm  .-> xfrm_state #1
81     |---. child .-> dst -. xfrm .-> xfrm_state #2
82                      |---. child .-> dst -. xfrm .-> xfrm_state #3
83                                       |---. child .-> NULL
84 
85    Bundles are cached at xrfm_policy struct (field ->bundles).
86 
87 
88    Resolution of xrfm_tmpl
89    -----------------------
90    Template contains:
91    1. ->mode		Mode: transport or tunnel
92    2. ->id.proto	Protocol: AH/ESP/IPCOMP
93    3. ->id.daddr	Remote tunnel endpoint, ignored for transport mode.
94       Q: allow to resolve security gateway?
95    4. ->id.spi          If not zero, static SPI.
96    5. ->saddr		Local tunnel endpoint, ignored for transport mode.
97    6. ->algos		List of allowed algos. Plain bitmask now.
98       Q: ealgos, aalgos, calgos. What a mess...
99    7. ->share		Sharing mode.
100       Q: how to implement private sharing mode? To add struct sock* to
101       flow id?
102 
103    Having this template we search through SAD searching for entries
104    with appropriate mode/proto/algo, permitted by selector.
105    If no appropriate entry found, it is requested from key manager.
106 
107    PROBLEMS:
108    Q: How to find all the bundles referring to a physical path for
109       PMTU discovery? Seems, dst should contain list of all parents...
110       and enter to infinite locking hierarchy disaster.
111       No! It is easier, we will not search for them, let them find us.
112       We add genid to each dst plus pointer to genid of raw IP route,
113       pmtu disc will update pmtu on raw IP route and increase its genid.
114       dst_check() will see this for top level and trigger resyncing
115       metrics. Plus, it will be made via sk->sk_dst_cache. Solved.
116  */
117 
118 struct xfrm_state_walk {
119 	struct list_head	all;
120 	u8			state;
121 	u8			dying;
122 	u8			proto;
123 	u32			seq;
124 	struct xfrm_address_filter *filter;
125 };
126 
127 /* Full description of state of transformer. */
128 struct xfrm_state {
129 	possible_net_t		xs_net;
130 	union {
131 		struct hlist_node	gclist;
132 		struct hlist_node	bydst;
133 	};
134 	struct hlist_node	bysrc;
135 	struct hlist_node	byspi;
136 
137 	atomic_t		refcnt;
138 	spinlock_t		lock;
139 
140 	struct xfrm_id		id;
141 	struct xfrm_selector	sel;
142 	struct xfrm_mark	mark;
143 	u32			tfcpad;
144 
145 	u32			genid;
146 
147 	/* Key manager bits */
148 	struct xfrm_state_walk	km;
149 
150 	/* Parameters of this state. */
151 	struct {
152 		u32		reqid;
153 		u8		mode;
154 		u8		replay_window;
155 		u8		aalgo, ealgo, calgo;
156 		u8		flags;
157 		u16		family;
158 		xfrm_address_t	saddr;
159 		int		header_len;
160 		int		trailer_len;
161 		u32		extra_flags;
162 	} props;
163 
164 	struct xfrm_lifetime_cfg lft;
165 
166 	/* Data for transformer */
167 	struct xfrm_algo_auth	*aalg;
168 	struct xfrm_algo	*ealg;
169 	struct xfrm_algo	*calg;
170 	struct xfrm_algo_aead	*aead;
171 	const char		*geniv;
172 
173 	/* Data for encapsulator */
174 	struct xfrm_encap_tmpl	*encap;
175 
176 	/* Data for care-of address */
177 	xfrm_address_t	*coaddr;
178 
179 	/* IPComp needs an IPIP tunnel for handling uncompressed packets */
180 	struct xfrm_state	*tunnel;
181 
182 	/* If a tunnel, number of users + 1 */
183 	atomic_t		tunnel_users;
184 
185 	/* State for replay detection */
186 	struct xfrm_replay_state replay;
187 	struct xfrm_replay_state_esn *replay_esn;
188 
189 	/* Replay detection state at the time we sent the last notification */
190 	struct xfrm_replay_state preplay;
191 	struct xfrm_replay_state_esn *preplay_esn;
192 
193 	/* The functions for replay detection. */
194 	struct xfrm_replay	*repl;
195 
196 	/* internal flag that only holds state for delayed aevent at the
197 	 * moment
198 	*/
199 	u32			xflags;
200 
201 	/* Replay detection notification settings */
202 	u32			replay_maxage;
203 	u32			replay_maxdiff;
204 
205 	/* Replay detection notification timer */
206 	struct timer_list	rtimer;
207 
208 	/* Statistics */
209 	struct xfrm_stats	stats;
210 
211 	struct xfrm_lifetime_cur curlft;
212 	struct tasklet_hrtimer	mtimer;
213 
214 	/* used to fix curlft->add_time when changing date */
215 	long		saved_tmo;
216 
217 	/* Last used time */
218 	unsigned long		lastused;
219 
220 	/* Reference to data common to all the instances of this
221 	 * transformer. */
222 	const struct xfrm_type	*type;
223 	struct xfrm_mode	*inner_mode;
224 	struct xfrm_mode	*inner_mode_iaf;
225 	struct xfrm_mode	*outer_mode;
226 
227 	/* Security context */
228 	struct xfrm_sec_ctx	*security;
229 
230 	/* Private data of this transformer, format is opaque,
231 	 * interpreted by xfrm_type methods. */
232 	void			*data;
233 };
234 
235 static inline struct net *xs_net(struct xfrm_state *x)
236 {
237 	return read_pnet(&x->xs_net);
238 }
239 
240 /* xflags - make enum if more show up */
241 #define XFRM_TIME_DEFER	1
242 #define XFRM_SOFT_EXPIRE 2
243 
244 enum {
245 	XFRM_STATE_VOID,
246 	XFRM_STATE_ACQ,
247 	XFRM_STATE_VALID,
248 	XFRM_STATE_ERROR,
249 	XFRM_STATE_EXPIRED,
250 	XFRM_STATE_DEAD
251 };
252 
253 /* callback structure passed from either netlink or pfkey */
254 struct km_event {
255 	union {
256 		u32 hard;
257 		u32 proto;
258 		u32 byid;
259 		u32 aevent;
260 		u32 type;
261 	} data;
262 
263 	u32	seq;
264 	u32	portid;
265 	u32	event;
266 	struct net *net;
267 };
268 
269 struct xfrm_replay {
270 	void	(*advance)(struct xfrm_state *x, __be32 net_seq);
271 	int	(*check)(struct xfrm_state *x,
272 			 struct sk_buff *skb,
273 			 __be32 net_seq);
274 	int	(*recheck)(struct xfrm_state *x,
275 			   struct sk_buff *skb,
276 			   __be32 net_seq);
277 	void	(*notify)(struct xfrm_state *x, int event);
278 	int	(*overflow)(struct xfrm_state *x, struct sk_buff *skb);
279 };
280 
281 struct net_device;
282 struct xfrm_type;
283 struct xfrm_dst;
284 struct xfrm_policy_afinfo {
285 	unsigned short		family;
286 	struct dst_ops		*dst_ops;
287 	void			(*garbage_collect)(struct net *net);
288 	struct dst_entry	*(*dst_lookup)(struct net *net,
289 					       int tos, int oif,
290 					       const xfrm_address_t *saddr,
291 					       const xfrm_address_t *daddr);
292 	int			(*get_saddr)(struct net *net, int oif,
293 					     xfrm_address_t *saddr,
294 					     xfrm_address_t *daddr);
295 	void			(*decode_session)(struct sk_buff *skb,
296 						  struct flowi *fl,
297 						  int reverse);
298 	int			(*get_tos)(const struct flowi *fl);
299 	void			(*init_dst)(struct net *net,
300 					    struct xfrm_dst *dst);
301 	int			(*init_path)(struct xfrm_dst *path,
302 					     struct dst_entry *dst,
303 					     int nfheader_len);
304 	int			(*fill_dst)(struct xfrm_dst *xdst,
305 					    struct net_device *dev,
306 					    const struct flowi *fl);
307 	struct dst_entry	*(*blackhole_route)(struct net *net, struct dst_entry *orig);
308 };
309 
310 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo);
311 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo);
312 void km_policy_notify(struct xfrm_policy *xp, int dir,
313 		      const struct km_event *c);
314 void km_state_notify(struct xfrm_state *x, const struct km_event *c);
315 
316 struct xfrm_tmpl;
317 int km_query(struct xfrm_state *x, struct xfrm_tmpl *t,
318 	     struct xfrm_policy *pol);
319 void km_state_expired(struct xfrm_state *x, int hard, u32 portid);
320 int __xfrm_state_delete(struct xfrm_state *x);
321 
322 struct xfrm_state_afinfo {
323 	unsigned int		family;
324 	unsigned int		proto;
325 	__be16			eth_proto;
326 	struct module		*owner;
327 	const struct xfrm_type	*type_map[IPPROTO_MAX];
328 	struct xfrm_mode	*mode_map[XFRM_MODE_MAX];
329 	int			(*init_flags)(struct xfrm_state *x);
330 	void			(*init_tempsel)(struct xfrm_selector *sel,
331 						const struct flowi *fl);
332 	void			(*init_temprop)(struct xfrm_state *x,
333 						const struct xfrm_tmpl *tmpl,
334 						const xfrm_address_t *daddr,
335 						const xfrm_address_t *saddr);
336 	int			(*tmpl_sort)(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n);
337 	int			(*state_sort)(struct xfrm_state **dst, struct xfrm_state **src, int n);
338 	int			(*output)(struct sock *sk, struct sk_buff *skb);
339 	int			(*output_finish)(struct sock *sk, struct sk_buff *skb);
340 	int			(*extract_input)(struct xfrm_state *x,
341 						 struct sk_buff *skb);
342 	int			(*extract_output)(struct xfrm_state *x,
343 						  struct sk_buff *skb);
344 	int			(*transport_finish)(struct sk_buff *skb,
345 						    int async);
346 	void			(*local_error)(struct sk_buff *skb, u32 mtu);
347 };
348 
349 int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo);
350 int xfrm_state_unregister_afinfo(struct xfrm_state_afinfo *afinfo);
351 struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned int family);
352 void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo);
353 
354 struct xfrm_input_afinfo {
355 	unsigned int		family;
356 	struct module		*owner;
357 	int			(*callback)(struct sk_buff *skb, u8 protocol,
358 					    int err);
359 };
360 
361 int xfrm_input_register_afinfo(struct xfrm_input_afinfo *afinfo);
362 int xfrm_input_unregister_afinfo(struct xfrm_input_afinfo *afinfo);
363 
364 void xfrm_state_delete_tunnel(struct xfrm_state *x);
365 
366 struct xfrm_type {
367 	char			*description;
368 	struct module		*owner;
369 	u8			proto;
370 	u8			flags;
371 #define XFRM_TYPE_NON_FRAGMENT	1
372 #define XFRM_TYPE_REPLAY_PROT	2
373 #define XFRM_TYPE_LOCAL_COADDR	4
374 #define XFRM_TYPE_REMOTE_COADDR	8
375 
376 	int			(*init_state)(struct xfrm_state *x);
377 	void			(*destructor)(struct xfrm_state *);
378 	int			(*input)(struct xfrm_state *, struct sk_buff *skb);
379 	int			(*output)(struct xfrm_state *, struct sk_buff *pskb);
380 	int			(*reject)(struct xfrm_state *, struct sk_buff *,
381 					  const struct flowi *);
382 	int			(*hdr_offset)(struct xfrm_state *, struct sk_buff *, u8 **);
383 	/* Estimate maximal size of result of transformation of a dgram */
384 	u32			(*get_mtu)(struct xfrm_state *, int size);
385 };
386 
387 int xfrm_register_type(const struct xfrm_type *type, unsigned short family);
388 int xfrm_unregister_type(const struct xfrm_type *type, unsigned short family);
389 
390 struct xfrm_mode {
391 	/*
392 	 * Remove encapsulation header.
393 	 *
394 	 * The IP header will be moved over the top of the encapsulation
395 	 * header.
396 	 *
397 	 * On entry, the transport header shall point to where the IP header
398 	 * should be and the network header shall be set to where the IP
399 	 * header currently is.  skb->data shall point to the start of the
400 	 * payload.
401 	 */
402 	int (*input2)(struct xfrm_state *x, struct sk_buff *skb);
403 
404 	/*
405 	 * This is the actual input entry point.
406 	 *
407 	 * For transport mode and equivalent this would be identical to
408 	 * input2 (which does not need to be set).  While tunnel mode
409 	 * and equivalent would set this to the tunnel encapsulation function
410 	 * xfrm4_prepare_input that would in turn call input2.
411 	 */
412 	int (*input)(struct xfrm_state *x, struct sk_buff *skb);
413 
414 	/*
415 	 * Add encapsulation header.
416 	 *
417 	 * On exit, the transport header will be set to the start of the
418 	 * encapsulation header to be filled in by x->type->output and
419 	 * the mac header will be set to the nextheader (protocol for
420 	 * IPv4) field of the extension header directly preceding the
421 	 * encapsulation header, or in its absence, that of the top IP
422 	 * header.  The value of the network header will always point
423 	 * to the top IP header while skb->data will point to the payload.
424 	 */
425 	int (*output2)(struct xfrm_state *x,struct sk_buff *skb);
426 
427 	/*
428 	 * This is the actual output entry point.
429 	 *
430 	 * For transport mode and equivalent this would be identical to
431 	 * output2 (which does not need to be set).  While tunnel mode
432 	 * and equivalent would set this to a tunnel encapsulation function
433 	 * (xfrm4_prepare_output or xfrm6_prepare_output) that would in turn
434 	 * call output2.
435 	 */
436 	int (*output)(struct xfrm_state *x, struct sk_buff *skb);
437 
438 	struct xfrm_state_afinfo *afinfo;
439 	struct module *owner;
440 	unsigned int encap;
441 	int flags;
442 };
443 
444 /* Flags for xfrm_mode. */
445 enum {
446 	XFRM_MODE_FLAG_TUNNEL = 1,
447 };
448 
449 int xfrm_register_mode(struct xfrm_mode *mode, int family);
450 int xfrm_unregister_mode(struct xfrm_mode *mode, int family);
451 
452 static inline int xfrm_af2proto(unsigned int family)
453 {
454 	switch(family) {
455 	case AF_INET:
456 		return IPPROTO_IPIP;
457 	case AF_INET6:
458 		return IPPROTO_IPV6;
459 	default:
460 		return 0;
461 	}
462 }
463 
464 static inline struct xfrm_mode *xfrm_ip2inner_mode(struct xfrm_state *x, int ipproto)
465 {
466 	if ((ipproto == IPPROTO_IPIP && x->props.family == AF_INET) ||
467 	    (ipproto == IPPROTO_IPV6 && x->props.family == AF_INET6))
468 		return x->inner_mode;
469 	else
470 		return x->inner_mode_iaf;
471 }
472 
473 struct xfrm_tmpl {
474 /* id in template is interpreted as:
475  * daddr - destination of tunnel, may be zero for transport mode.
476  * spi   - zero to acquire spi. Not zero if spi is static, then
477  *	   daddr must be fixed too.
478  * proto - AH/ESP/IPCOMP
479  */
480 	struct xfrm_id		id;
481 
482 /* Source address of tunnel. Ignored, if it is not a tunnel. */
483 	xfrm_address_t		saddr;
484 
485 	unsigned short		encap_family;
486 
487 	u32			reqid;
488 
489 /* Mode: transport, tunnel etc. */
490 	u8			mode;
491 
492 /* Sharing mode: unique, this session only, this user only etc. */
493 	u8			share;
494 
495 /* May skip this transfomration if no SA is found */
496 	u8			optional;
497 
498 /* Skip aalgos/ealgos/calgos checks. */
499 	u8			allalgs;
500 
501 /* Bit mask of algos allowed for acquisition */
502 	u32			aalgos;
503 	u32			ealgos;
504 	u32			calgos;
505 };
506 
507 #define XFRM_MAX_DEPTH		6
508 
509 struct xfrm_policy_walk_entry {
510 	struct list_head	all;
511 	u8			dead;
512 };
513 
514 struct xfrm_policy_walk {
515 	struct xfrm_policy_walk_entry walk;
516 	u8 type;
517 	u32 seq;
518 };
519 
520 struct xfrm_policy_queue {
521 	struct sk_buff_head	hold_queue;
522 	struct timer_list	hold_timer;
523 	unsigned long		timeout;
524 };
525 
526 struct xfrm_policy {
527 	possible_net_t		xp_net;
528 	struct hlist_node	bydst;
529 	struct hlist_node	byidx;
530 
531 	/* This lock only affects elements except for entry. */
532 	rwlock_t		lock;
533 	atomic_t		refcnt;
534 	struct timer_list	timer;
535 
536 	struct flow_cache_object flo;
537 	atomic_t		genid;
538 	u32			priority;
539 	u32			index;
540 	struct xfrm_mark	mark;
541 	struct xfrm_selector	selector;
542 	struct xfrm_lifetime_cfg lft;
543 	struct xfrm_lifetime_cur curlft;
544 	struct xfrm_policy_walk_entry walk;
545 	struct xfrm_policy_queue polq;
546 	u8			type;
547 	u8			action;
548 	u8			flags;
549 	u8			xfrm_nr;
550 	u16			family;
551 	struct xfrm_sec_ctx	*security;
552 	struct xfrm_tmpl       	xfrm_vec[XFRM_MAX_DEPTH];
553 };
554 
555 static inline struct net *xp_net(const struct xfrm_policy *xp)
556 {
557 	return read_pnet(&xp->xp_net);
558 }
559 
560 struct xfrm_kmaddress {
561 	xfrm_address_t          local;
562 	xfrm_address_t          remote;
563 	u32			reserved;
564 	u16			family;
565 };
566 
567 struct xfrm_migrate {
568 	xfrm_address_t		old_daddr;
569 	xfrm_address_t		old_saddr;
570 	xfrm_address_t		new_daddr;
571 	xfrm_address_t		new_saddr;
572 	u8			proto;
573 	u8			mode;
574 	u16			reserved;
575 	u32			reqid;
576 	u16			old_family;
577 	u16			new_family;
578 };
579 
580 #define XFRM_KM_TIMEOUT                30
581 /* what happened */
582 #define XFRM_REPLAY_UPDATE	XFRM_AE_CR
583 #define XFRM_REPLAY_TIMEOUT	XFRM_AE_CE
584 
585 /* default aevent timeout in units of 100ms */
586 #define XFRM_AE_ETIME			10
587 /* Async Event timer multiplier */
588 #define XFRM_AE_ETH_M			10
589 /* default seq threshold size */
590 #define XFRM_AE_SEQT_SIZE		2
591 
592 struct xfrm_mgr {
593 	struct list_head	list;
594 	char			*id;
595 	int			(*notify)(struct xfrm_state *x, const struct km_event *c);
596 	int			(*acquire)(struct xfrm_state *x, struct xfrm_tmpl *, struct xfrm_policy *xp);
597 	struct xfrm_policy	*(*compile_policy)(struct sock *sk, int opt, u8 *data, int len, int *dir);
598 	int			(*new_mapping)(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport);
599 	int			(*notify_policy)(struct xfrm_policy *x, int dir, const struct km_event *c);
600 	int			(*report)(struct net *net, u8 proto, struct xfrm_selector *sel, xfrm_address_t *addr);
601 	int			(*migrate)(const struct xfrm_selector *sel,
602 					   u8 dir, u8 type,
603 					   const struct xfrm_migrate *m,
604 					   int num_bundles,
605 					   const struct xfrm_kmaddress *k);
606 	bool			(*is_alive)(const struct km_event *c);
607 };
608 
609 int xfrm_register_km(struct xfrm_mgr *km);
610 int xfrm_unregister_km(struct xfrm_mgr *km);
611 
612 struct xfrm_tunnel_skb_cb {
613 	union {
614 		struct inet_skb_parm h4;
615 		struct inet6_skb_parm h6;
616 	} header;
617 
618 	union {
619 		struct ip_tunnel *ip4;
620 		struct ip6_tnl *ip6;
621 	} tunnel;
622 };
623 
624 #define XFRM_TUNNEL_SKB_CB(__skb) ((struct xfrm_tunnel_skb_cb *)&((__skb)->cb[0]))
625 
626 /*
627  * This structure is used for the duration where packets are being
628  * transformed by IPsec.  As soon as the packet leaves IPsec the
629  * area beyond the generic IP part may be overwritten.
630  */
631 struct xfrm_skb_cb {
632 	struct xfrm_tunnel_skb_cb header;
633 
634         /* Sequence number for replay protection. */
635 	union {
636 		struct {
637 			__u32 low;
638 			__u32 hi;
639 		} output;
640 		struct {
641 			__be32 low;
642 			__be32 hi;
643 		} input;
644 	} seq;
645 };
646 
647 #define XFRM_SKB_CB(__skb) ((struct xfrm_skb_cb *)&((__skb)->cb[0]))
648 
649 /*
650  * This structure is used by the afinfo prepare_input/prepare_output functions
651  * to transmit header information to the mode input/output functions.
652  */
653 struct xfrm_mode_skb_cb {
654 	struct xfrm_tunnel_skb_cb header;
655 
656 	/* Copied from header for IPv4, always set to zero and DF for IPv6. */
657 	__be16 id;
658 	__be16 frag_off;
659 
660 	/* IP header length (excluding options or extension headers). */
661 	u8 ihl;
662 
663 	/* TOS for IPv4, class for IPv6. */
664 	u8 tos;
665 
666 	/* TTL for IPv4, hop limitfor IPv6. */
667 	u8 ttl;
668 
669 	/* Protocol for IPv4, NH for IPv6. */
670 	u8 protocol;
671 
672 	/* Option length for IPv4, zero for IPv6. */
673 	u8 optlen;
674 
675 	/* Used by IPv6 only, zero for IPv4. */
676 	u8 flow_lbl[3];
677 };
678 
679 #define XFRM_MODE_SKB_CB(__skb) ((struct xfrm_mode_skb_cb *)&((__skb)->cb[0]))
680 
681 /*
682  * This structure is used by the input processing to locate the SPI and
683  * related information.
684  */
685 struct xfrm_spi_skb_cb {
686 	struct xfrm_tunnel_skb_cb header;
687 
688 	unsigned int daddroff;
689 	unsigned int family;
690 };
691 
692 #define XFRM_SPI_SKB_CB(__skb) ((struct xfrm_spi_skb_cb *)&((__skb)->cb[0]))
693 
694 #ifdef CONFIG_AUDITSYSCALL
695 static inline struct audit_buffer *xfrm_audit_start(const char *op)
696 {
697 	struct audit_buffer *audit_buf = NULL;
698 
699 	if (audit_enabled == 0)
700 		return NULL;
701 	audit_buf = audit_log_start(current->audit_context, GFP_ATOMIC,
702 				    AUDIT_MAC_IPSEC_EVENT);
703 	if (audit_buf == NULL)
704 		return NULL;
705 	audit_log_format(audit_buf, "op=%s", op);
706 	return audit_buf;
707 }
708 
709 static inline void xfrm_audit_helper_usrinfo(bool task_valid,
710 					     struct audit_buffer *audit_buf)
711 {
712 	const unsigned int auid = from_kuid(&init_user_ns, task_valid ?
713 					    audit_get_loginuid(current) :
714 					    INVALID_UID);
715 	const unsigned int ses = task_valid ? audit_get_sessionid(current) :
716 		(unsigned int) -1;
717 
718 	audit_log_format(audit_buf, " auid=%u ses=%u", auid, ses);
719 	audit_log_task_context(audit_buf);
720 }
721 
722 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid);
723 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
724 			      bool task_valid);
725 void xfrm_audit_state_add(struct xfrm_state *x, int result, bool task_valid);
726 void xfrm_audit_state_delete(struct xfrm_state *x, int result, bool task_valid);
727 void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
728 				      struct sk_buff *skb);
729 void xfrm_audit_state_replay(struct xfrm_state *x, struct sk_buff *skb,
730 			     __be32 net_seq);
731 void xfrm_audit_state_notfound_simple(struct sk_buff *skb, u16 family);
732 void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family, __be32 net_spi,
733 			       __be32 net_seq);
734 void xfrm_audit_state_icvfail(struct xfrm_state *x, struct sk_buff *skb,
735 			      u8 proto);
736 #else
737 
738 static inline void xfrm_audit_policy_add(struct xfrm_policy *xp, int result,
739 					 bool task_valid)
740 {
741 }
742 
743 static inline void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
744 					    bool task_valid)
745 {
746 }
747 
748 static inline void xfrm_audit_state_add(struct xfrm_state *x, int result,
749 					bool task_valid)
750 {
751 }
752 
753 static inline void xfrm_audit_state_delete(struct xfrm_state *x, int result,
754 					   bool task_valid)
755 {
756 }
757 
758 static inline void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
759 					     struct sk_buff *skb)
760 {
761 }
762 
763 static inline void xfrm_audit_state_replay(struct xfrm_state *x,
764 					   struct sk_buff *skb, __be32 net_seq)
765 {
766 }
767 
768 static inline void xfrm_audit_state_notfound_simple(struct sk_buff *skb,
769 				      u16 family)
770 {
771 }
772 
773 static inline void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family,
774 				      __be32 net_spi, __be32 net_seq)
775 {
776 }
777 
778 static inline void xfrm_audit_state_icvfail(struct xfrm_state *x,
779 				     struct sk_buff *skb, u8 proto)
780 {
781 }
782 #endif /* CONFIG_AUDITSYSCALL */
783 
784 static inline void xfrm_pol_hold(struct xfrm_policy *policy)
785 {
786 	if (likely(policy != NULL))
787 		atomic_inc(&policy->refcnt);
788 }
789 
790 void xfrm_policy_destroy(struct xfrm_policy *policy);
791 
792 static inline void xfrm_pol_put(struct xfrm_policy *policy)
793 {
794 	if (atomic_dec_and_test(&policy->refcnt))
795 		xfrm_policy_destroy(policy);
796 }
797 
798 static inline void xfrm_pols_put(struct xfrm_policy **pols, int npols)
799 {
800 	int i;
801 	for (i = npols - 1; i >= 0; --i)
802 		xfrm_pol_put(pols[i]);
803 }
804 
805 void __xfrm_state_destroy(struct xfrm_state *);
806 
807 static inline void __xfrm_state_put(struct xfrm_state *x)
808 {
809 	atomic_dec(&x->refcnt);
810 }
811 
812 static inline void xfrm_state_put(struct xfrm_state *x)
813 {
814 	if (atomic_dec_and_test(&x->refcnt))
815 		__xfrm_state_destroy(x);
816 }
817 
818 static inline void xfrm_state_hold(struct xfrm_state *x)
819 {
820 	atomic_inc(&x->refcnt);
821 }
822 
823 static inline bool addr_match(const void *token1, const void *token2,
824 			      int prefixlen)
825 {
826 	const __be32 *a1 = token1;
827 	const __be32 *a2 = token2;
828 	int pdw;
829 	int pbi;
830 
831 	pdw = prefixlen >> 5;	  /* num of whole u32 in prefix */
832 	pbi = prefixlen &  0x1f;  /* num of bits in incomplete u32 in prefix */
833 
834 	if (pdw)
835 		if (memcmp(a1, a2, pdw << 2))
836 			return false;
837 
838 	if (pbi) {
839 		__be32 mask;
840 
841 		mask = htonl((0xffffffff) << (32 - pbi));
842 
843 		if ((a1[pdw] ^ a2[pdw]) & mask)
844 			return false;
845 	}
846 
847 	return true;
848 }
849 
850 static inline bool addr4_match(__be32 a1, __be32 a2, u8 prefixlen)
851 {
852 	/* C99 6.5.7 (3): u32 << 32 is undefined behaviour */
853 	if (prefixlen == 0)
854 		return true;
855 	return !((a1 ^ a2) & htonl(0xFFFFFFFFu << (32 - prefixlen)));
856 }
857 
858 static __inline__
859 __be16 xfrm_flowi_sport(const struct flowi *fl, const union flowi_uli *uli)
860 {
861 	__be16 port;
862 	switch(fl->flowi_proto) {
863 	case IPPROTO_TCP:
864 	case IPPROTO_UDP:
865 	case IPPROTO_UDPLITE:
866 	case IPPROTO_SCTP:
867 		port = uli->ports.sport;
868 		break;
869 	case IPPROTO_ICMP:
870 	case IPPROTO_ICMPV6:
871 		port = htons(uli->icmpt.type);
872 		break;
873 	case IPPROTO_MH:
874 		port = htons(uli->mht.type);
875 		break;
876 	case IPPROTO_GRE:
877 		port = htons(ntohl(uli->gre_key) >> 16);
878 		break;
879 	default:
880 		port = 0;	/*XXX*/
881 	}
882 	return port;
883 }
884 
885 static __inline__
886 __be16 xfrm_flowi_dport(const struct flowi *fl, const union flowi_uli *uli)
887 {
888 	__be16 port;
889 	switch(fl->flowi_proto) {
890 	case IPPROTO_TCP:
891 	case IPPROTO_UDP:
892 	case IPPROTO_UDPLITE:
893 	case IPPROTO_SCTP:
894 		port = uli->ports.dport;
895 		break;
896 	case IPPROTO_ICMP:
897 	case IPPROTO_ICMPV6:
898 		port = htons(uli->icmpt.code);
899 		break;
900 	case IPPROTO_GRE:
901 		port = htons(ntohl(uli->gre_key) & 0xffff);
902 		break;
903 	default:
904 		port = 0;	/*XXX*/
905 	}
906 	return port;
907 }
908 
909 bool xfrm_selector_match(const struct xfrm_selector *sel,
910 			 const struct flowi *fl, unsigned short family);
911 
912 #ifdef CONFIG_SECURITY_NETWORK_XFRM
913 /*	If neither has a context --> match
914  * 	Otherwise, both must have a context and the sids, doi, alg must match
915  */
916 static inline bool xfrm_sec_ctx_match(struct xfrm_sec_ctx *s1, struct xfrm_sec_ctx *s2)
917 {
918 	return ((!s1 && !s2) ||
919 		(s1 && s2 &&
920 		 (s1->ctx_sid == s2->ctx_sid) &&
921 		 (s1->ctx_doi == s2->ctx_doi) &&
922 		 (s1->ctx_alg == s2->ctx_alg)));
923 }
924 #else
925 static inline bool xfrm_sec_ctx_match(struct xfrm_sec_ctx *s1, struct xfrm_sec_ctx *s2)
926 {
927 	return true;
928 }
929 #endif
930 
931 /* A struct encoding bundle of transformations to apply to some set of flow.
932  *
933  * dst->child points to the next element of bundle.
934  * dst->xfrm  points to an instanse of transformer.
935  *
936  * Due to unfortunate limitations of current routing cache, which we
937  * have no time to fix, it mirrors struct rtable and bound to the same
938  * routing key, including saddr,daddr. However, we can have many of
939  * bundles differing by session id. All the bundles grow from a parent
940  * policy rule.
941  */
942 struct xfrm_dst {
943 	union {
944 		struct dst_entry	dst;
945 		struct rtable		rt;
946 		struct rt6_info		rt6;
947 	} u;
948 	struct dst_entry *route;
949 	struct flow_cache_object flo;
950 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
951 	int num_pols, num_xfrms;
952 #ifdef CONFIG_XFRM_SUB_POLICY
953 	struct flowi *origin;
954 	struct xfrm_selector *partner;
955 #endif
956 	u32 xfrm_genid;
957 	u32 policy_genid;
958 	u32 route_mtu_cached;
959 	u32 child_mtu_cached;
960 	u32 route_cookie;
961 	u32 path_cookie;
962 };
963 
964 #ifdef CONFIG_XFRM
965 static inline void xfrm_dst_destroy(struct xfrm_dst *xdst)
966 {
967 	xfrm_pols_put(xdst->pols, xdst->num_pols);
968 	dst_release(xdst->route);
969 	if (likely(xdst->u.dst.xfrm))
970 		xfrm_state_put(xdst->u.dst.xfrm);
971 #ifdef CONFIG_XFRM_SUB_POLICY
972 	kfree(xdst->origin);
973 	xdst->origin = NULL;
974 	kfree(xdst->partner);
975 	xdst->partner = NULL;
976 #endif
977 }
978 #endif
979 
980 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev);
981 
982 struct sec_path {
983 	atomic_t		refcnt;
984 	int			len;
985 	struct xfrm_state	*xvec[XFRM_MAX_DEPTH];
986 };
987 
988 static inline int secpath_exists(struct sk_buff *skb)
989 {
990 #ifdef CONFIG_XFRM
991 	return skb->sp != NULL;
992 #else
993 	return 0;
994 #endif
995 }
996 
997 static inline struct sec_path *
998 secpath_get(struct sec_path *sp)
999 {
1000 	if (sp)
1001 		atomic_inc(&sp->refcnt);
1002 	return sp;
1003 }
1004 
1005 void __secpath_destroy(struct sec_path *sp);
1006 
1007 static inline void
1008 secpath_put(struct sec_path *sp)
1009 {
1010 	if (sp && atomic_dec_and_test(&sp->refcnt))
1011 		__secpath_destroy(sp);
1012 }
1013 
1014 struct sec_path *secpath_dup(struct sec_path *src);
1015 
1016 static inline void
1017 secpath_reset(struct sk_buff *skb)
1018 {
1019 #ifdef CONFIG_XFRM
1020 	secpath_put(skb->sp);
1021 	skb->sp = NULL;
1022 #endif
1023 }
1024 
1025 static inline int
1026 xfrm_addr_any(const xfrm_address_t *addr, unsigned short family)
1027 {
1028 	switch (family) {
1029 	case AF_INET:
1030 		return addr->a4 == 0;
1031 	case AF_INET6:
1032 		return ipv6_addr_any(&addr->in6);
1033 	}
1034 	return 0;
1035 }
1036 
1037 static inline int
1038 __xfrm4_state_addr_cmp(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x)
1039 {
1040 	return	(tmpl->saddr.a4 &&
1041 		 tmpl->saddr.a4 != x->props.saddr.a4);
1042 }
1043 
1044 static inline int
1045 __xfrm6_state_addr_cmp(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x)
1046 {
1047 	return	(!ipv6_addr_any((struct in6_addr*)&tmpl->saddr) &&
1048 		 !ipv6_addr_equal((struct in6_addr *)&tmpl->saddr, (struct in6_addr*)&x->props.saddr));
1049 }
1050 
1051 static inline int
1052 xfrm_state_addr_cmp(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x, unsigned short family)
1053 {
1054 	switch (family) {
1055 	case AF_INET:
1056 		return __xfrm4_state_addr_cmp(tmpl, x);
1057 	case AF_INET6:
1058 		return __xfrm6_state_addr_cmp(tmpl, x);
1059 	}
1060 	return !0;
1061 }
1062 
1063 #ifdef CONFIG_XFRM
1064 int __xfrm_policy_check(struct sock *, int dir, struct sk_buff *skb,
1065 			unsigned short family);
1066 
1067 static inline int __xfrm_policy_check2(struct sock *sk, int dir,
1068 				       struct sk_buff *skb,
1069 				       unsigned int family, int reverse)
1070 {
1071 	struct net *net = dev_net(skb->dev);
1072 	int ndir = dir | (reverse ? XFRM_POLICY_MASK + 1 : 0);
1073 
1074 	if (sk && sk->sk_policy[XFRM_POLICY_IN])
1075 		return __xfrm_policy_check(sk, ndir, skb, family);
1076 
1077 	return	(!net->xfrm.policy_count[dir] && !skb->sp) ||
1078 		(skb_dst(skb)->flags & DST_NOPOLICY) ||
1079 		__xfrm_policy_check(sk, ndir, skb, family);
1080 }
1081 
1082 static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family)
1083 {
1084 	return __xfrm_policy_check2(sk, dir, skb, family, 0);
1085 }
1086 
1087 static inline int xfrm4_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
1088 {
1089 	return xfrm_policy_check(sk, dir, skb, AF_INET);
1090 }
1091 
1092 static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
1093 {
1094 	return xfrm_policy_check(sk, dir, skb, AF_INET6);
1095 }
1096 
1097 static inline int xfrm4_policy_check_reverse(struct sock *sk, int dir,
1098 					     struct sk_buff *skb)
1099 {
1100 	return __xfrm_policy_check2(sk, dir, skb, AF_INET, 1);
1101 }
1102 
1103 static inline int xfrm6_policy_check_reverse(struct sock *sk, int dir,
1104 					     struct sk_buff *skb)
1105 {
1106 	return __xfrm_policy_check2(sk, dir, skb, AF_INET6, 1);
1107 }
1108 
1109 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
1110 			  unsigned int family, int reverse);
1111 
1112 static inline int xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
1113 				      unsigned int family)
1114 {
1115 	return __xfrm_decode_session(skb, fl, family, 0);
1116 }
1117 
1118 static inline int xfrm_decode_session_reverse(struct sk_buff *skb,
1119 					      struct flowi *fl,
1120 					      unsigned int family)
1121 {
1122 	return __xfrm_decode_session(skb, fl, family, 1);
1123 }
1124 
1125 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family);
1126 
1127 static inline int xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1128 {
1129 	struct net *net = dev_net(skb->dev);
1130 
1131 	return	!net->xfrm.policy_count[XFRM_POLICY_OUT] ||
1132 		(skb_dst(skb)->flags & DST_NOXFRM) ||
1133 		__xfrm_route_forward(skb, family);
1134 }
1135 
1136 static inline int xfrm4_route_forward(struct sk_buff *skb)
1137 {
1138 	return xfrm_route_forward(skb, AF_INET);
1139 }
1140 
1141 static inline int xfrm6_route_forward(struct sk_buff *skb)
1142 {
1143 	return xfrm_route_forward(skb, AF_INET6);
1144 }
1145 
1146 int __xfrm_sk_clone_policy(struct sock *sk);
1147 
1148 static inline int xfrm_sk_clone_policy(struct sock *sk)
1149 {
1150 	if (unlikely(sk->sk_policy[0] || sk->sk_policy[1]))
1151 		return __xfrm_sk_clone_policy(sk);
1152 	return 0;
1153 }
1154 
1155 int xfrm_policy_delete(struct xfrm_policy *pol, int dir);
1156 
1157 static inline void xfrm_sk_free_policy(struct sock *sk)
1158 {
1159 	if (unlikely(sk->sk_policy[0] != NULL)) {
1160 		xfrm_policy_delete(sk->sk_policy[0], XFRM_POLICY_MAX);
1161 		sk->sk_policy[0] = NULL;
1162 	}
1163 	if (unlikely(sk->sk_policy[1] != NULL)) {
1164 		xfrm_policy_delete(sk->sk_policy[1], XFRM_POLICY_MAX+1);
1165 		sk->sk_policy[1] = NULL;
1166 	}
1167 }
1168 
1169 void xfrm_garbage_collect(struct net *net);
1170 
1171 #else
1172 
1173 static inline void xfrm_sk_free_policy(struct sock *sk) {}
1174 static inline int xfrm_sk_clone_policy(struct sock *sk) { return 0; }
1175 static inline int xfrm6_route_forward(struct sk_buff *skb) { return 1; }
1176 static inline int xfrm4_route_forward(struct sk_buff *skb) { return 1; }
1177 static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
1178 {
1179 	return 1;
1180 }
1181 static inline int xfrm4_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
1182 {
1183 	return 1;
1184 }
1185 static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family)
1186 {
1187 	return 1;
1188 }
1189 static inline int xfrm_decode_session_reverse(struct sk_buff *skb,
1190 					      struct flowi *fl,
1191 					      unsigned int family)
1192 {
1193 	return -ENOSYS;
1194 }
1195 static inline int xfrm4_policy_check_reverse(struct sock *sk, int dir,
1196 					     struct sk_buff *skb)
1197 {
1198 	return 1;
1199 }
1200 static inline int xfrm6_policy_check_reverse(struct sock *sk, int dir,
1201 					     struct sk_buff *skb)
1202 {
1203 	return 1;
1204 }
1205 static inline void xfrm_garbage_collect(struct net *net)
1206 {
1207 }
1208 #endif
1209 
1210 static __inline__
1211 xfrm_address_t *xfrm_flowi_daddr(const struct flowi *fl, unsigned short family)
1212 {
1213 	switch (family){
1214 	case AF_INET:
1215 		return (xfrm_address_t *)&fl->u.ip4.daddr;
1216 	case AF_INET6:
1217 		return (xfrm_address_t *)&fl->u.ip6.daddr;
1218 	}
1219 	return NULL;
1220 }
1221 
1222 static __inline__
1223 xfrm_address_t *xfrm_flowi_saddr(const struct flowi *fl, unsigned short family)
1224 {
1225 	switch (family){
1226 	case AF_INET:
1227 		return (xfrm_address_t *)&fl->u.ip4.saddr;
1228 	case AF_INET6:
1229 		return (xfrm_address_t *)&fl->u.ip6.saddr;
1230 	}
1231 	return NULL;
1232 }
1233 
1234 static __inline__
1235 void xfrm_flowi_addr_get(const struct flowi *fl,
1236 			 xfrm_address_t *saddr, xfrm_address_t *daddr,
1237 			 unsigned short family)
1238 {
1239 	switch(family) {
1240 	case AF_INET:
1241 		memcpy(&saddr->a4, &fl->u.ip4.saddr, sizeof(saddr->a4));
1242 		memcpy(&daddr->a4, &fl->u.ip4.daddr, sizeof(daddr->a4));
1243 		break;
1244 	case AF_INET6:
1245 		saddr->in6 = fl->u.ip6.saddr;
1246 		daddr->in6 = fl->u.ip6.daddr;
1247 		break;
1248 	}
1249 }
1250 
1251 static __inline__ int
1252 __xfrm4_state_addr_check(const struct xfrm_state *x,
1253 			 const xfrm_address_t *daddr, const xfrm_address_t *saddr)
1254 {
1255 	if (daddr->a4 == x->id.daddr.a4 &&
1256 	    (saddr->a4 == x->props.saddr.a4 || !saddr->a4 || !x->props.saddr.a4))
1257 		return 1;
1258 	return 0;
1259 }
1260 
1261 static __inline__ int
1262 __xfrm6_state_addr_check(const struct xfrm_state *x,
1263 			 const xfrm_address_t *daddr, const xfrm_address_t *saddr)
1264 {
1265 	if (ipv6_addr_equal((struct in6_addr *)daddr, (struct in6_addr *)&x->id.daddr) &&
1266 	    (ipv6_addr_equal((struct in6_addr *)saddr, (struct in6_addr *)&x->props.saddr) ||
1267 	     ipv6_addr_any((struct in6_addr *)saddr) ||
1268 	     ipv6_addr_any((struct in6_addr *)&x->props.saddr)))
1269 		return 1;
1270 	return 0;
1271 }
1272 
1273 static __inline__ int
1274 xfrm_state_addr_check(const struct xfrm_state *x,
1275 		      const xfrm_address_t *daddr, const xfrm_address_t *saddr,
1276 		      unsigned short family)
1277 {
1278 	switch (family) {
1279 	case AF_INET:
1280 		return __xfrm4_state_addr_check(x, daddr, saddr);
1281 	case AF_INET6:
1282 		return __xfrm6_state_addr_check(x, daddr, saddr);
1283 	}
1284 	return 0;
1285 }
1286 
1287 static __inline__ int
1288 xfrm_state_addr_flow_check(const struct xfrm_state *x, const struct flowi *fl,
1289 			   unsigned short family)
1290 {
1291 	switch (family) {
1292 	case AF_INET:
1293 		return __xfrm4_state_addr_check(x,
1294 						(const xfrm_address_t *)&fl->u.ip4.daddr,
1295 						(const xfrm_address_t *)&fl->u.ip4.saddr);
1296 	case AF_INET6:
1297 		return __xfrm6_state_addr_check(x,
1298 						(const xfrm_address_t *)&fl->u.ip6.daddr,
1299 						(const xfrm_address_t *)&fl->u.ip6.saddr);
1300 	}
1301 	return 0;
1302 }
1303 
1304 static inline int xfrm_state_kern(const struct xfrm_state *x)
1305 {
1306 	return atomic_read(&x->tunnel_users);
1307 }
1308 
1309 static inline int xfrm_id_proto_match(u8 proto, u8 userproto)
1310 {
1311 	return (!userproto || proto == userproto ||
1312 		(userproto == IPSEC_PROTO_ANY && (proto == IPPROTO_AH ||
1313 						  proto == IPPROTO_ESP ||
1314 						  proto == IPPROTO_COMP)));
1315 }
1316 
1317 /*
1318  * xfrm algorithm information
1319  */
1320 struct xfrm_algo_aead_info {
1321 	char *geniv;
1322 	u16 icv_truncbits;
1323 };
1324 
1325 struct xfrm_algo_auth_info {
1326 	u16 icv_truncbits;
1327 	u16 icv_fullbits;
1328 };
1329 
1330 struct xfrm_algo_encr_info {
1331 	char *geniv;
1332 	u16 blockbits;
1333 	u16 defkeybits;
1334 };
1335 
1336 struct xfrm_algo_comp_info {
1337 	u16 threshold;
1338 };
1339 
1340 struct xfrm_algo_desc {
1341 	char *name;
1342 	char *compat;
1343 	u8 available:1;
1344 	u8 pfkey_supported:1;
1345 	union {
1346 		struct xfrm_algo_aead_info aead;
1347 		struct xfrm_algo_auth_info auth;
1348 		struct xfrm_algo_encr_info encr;
1349 		struct xfrm_algo_comp_info comp;
1350 	} uinfo;
1351 	struct sadb_alg desc;
1352 };
1353 
1354 /* XFRM protocol handlers.  */
1355 struct xfrm4_protocol {
1356 	int (*handler)(struct sk_buff *skb);
1357 	int (*input_handler)(struct sk_buff *skb, int nexthdr, __be32 spi,
1358 			     int encap_type);
1359 	int (*cb_handler)(struct sk_buff *skb, int err);
1360 	int (*err_handler)(struct sk_buff *skb, u32 info);
1361 
1362 	struct xfrm4_protocol __rcu *next;
1363 	int priority;
1364 };
1365 
1366 struct xfrm6_protocol {
1367 	int (*handler)(struct sk_buff *skb);
1368 	int (*cb_handler)(struct sk_buff *skb, int err);
1369 	int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
1370 			   u8 type, u8 code, int offset, __be32 info);
1371 
1372 	struct xfrm6_protocol __rcu *next;
1373 	int priority;
1374 };
1375 
1376 /* XFRM tunnel handlers.  */
1377 struct xfrm_tunnel {
1378 	int (*handler)(struct sk_buff *skb);
1379 	int (*err_handler)(struct sk_buff *skb, u32 info);
1380 
1381 	struct xfrm_tunnel __rcu *next;
1382 	int priority;
1383 };
1384 
1385 struct xfrm6_tunnel {
1386 	int (*handler)(struct sk_buff *skb);
1387 	int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
1388 			   u8 type, u8 code, int offset, __be32 info);
1389 	struct xfrm6_tunnel __rcu *next;
1390 	int priority;
1391 };
1392 
1393 void xfrm_init(void);
1394 void xfrm4_init(void);
1395 int xfrm_state_init(struct net *net);
1396 void xfrm_state_fini(struct net *net);
1397 void xfrm4_state_init(void);
1398 void xfrm4_protocol_init(void);
1399 #ifdef CONFIG_XFRM
1400 int xfrm6_init(void);
1401 void xfrm6_fini(void);
1402 int xfrm6_state_init(void);
1403 void xfrm6_state_fini(void);
1404 int xfrm6_protocol_init(void);
1405 void xfrm6_protocol_fini(void);
1406 #else
1407 static inline int xfrm6_init(void)
1408 {
1409 	return 0;
1410 }
1411 static inline void xfrm6_fini(void)
1412 {
1413 	;
1414 }
1415 #endif
1416 
1417 #ifdef CONFIG_XFRM_STATISTICS
1418 int xfrm_proc_init(struct net *net);
1419 void xfrm_proc_fini(struct net *net);
1420 #endif
1421 
1422 int xfrm_sysctl_init(struct net *net);
1423 #ifdef CONFIG_SYSCTL
1424 void xfrm_sysctl_fini(struct net *net);
1425 #else
1426 static inline void xfrm_sysctl_fini(struct net *net)
1427 {
1428 }
1429 #endif
1430 
1431 void xfrm_state_walk_init(struct xfrm_state_walk *walk, u8 proto,
1432 			  struct xfrm_address_filter *filter);
1433 int xfrm_state_walk(struct net *net, struct xfrm_state_walk *walk,
1434 		    int (*func)(struct xfrm_state *, int, void*), void *);
1435 void xfrm_state_walk_done(struct xfrm_state_walk *walk, struct net *net);
1436 struct xfrm_state *xfrm_state_alloc(struct net *net);
1437 struct xfrm_state *xfrm_state_find(const xfrm_address_t *daddr,
1438 				   const xfrm_address_t *saddr,
1439 				   const struct flowi *fl,
1440 				   struct xfrm_tmpl *tmpl,
1441 				   struct xfrm_policy *pol, int *err,
1442 				   unsigned short family);
1443 struct xfrm_state *xfrm_stateonly_find(struct net *net, u32 mark,
1444 				       xfrm_address_t *daddr,
1445 				       xfrm_address_t *saddr,
1446 				       unsigned short family,
1447 				       u8 mode, u8 proto, u32 reqid);
1448 struct xfrm_state *xfrm_state_lookup_byspi(struct net *net, __be32 spi,
1449 					      unsigned short family);
1450 int xfrm_state_check_expire(struct xfrm_state *x);
1451 void xfrm_state_insert(struct xfrm_state *x);
1452 int xfrm_state_add(struct xfrm_state *x);
1453 int xfrm_state_update(struct xfrm_state *x);
1454 struct xfrm_state *xfrm_state_lookup(struct net *net, u32 mark,
1455 				     const xfrm_address_t *daddr, __be32 spi,
1456 				     u8 proto, unsigned short family);
1457 struct xfrm_state *xfrm_state_lookup_byaddr(struct net *net, u32 mark,
1458 					    const xfrm_address_t *daddr,
1459 					    const xfrm_address_t *saddr,
1460 					    u8 proto,
1461 					    unsigned short family);
1462 #ifdef CONFIG_XFRM_SUB_POLICY
1463 int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n,
1464 		   unsigned short family, struct net *net);
1465 int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n,
1466 		    unsigned short family);
1467 #else
1468 static inline int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src,
1469 				 int n, unsigned short family, struct net *net)
1470 {
1471 	return -ENOSYS;
1472 }
1473 
1474 static inline int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src,
1475 				  int n, unsigned short family)
1476 {
1477 	return -ENOSYS;
1478 }
1479 #endif
1480 
1481 struct xfrmk_sadinfo {
1482 	u32 sadhcnt; /* current hash bkts */
1483 	u32 sadhmcnt; /* max allowed hash bkts */
1484 	u32 sadcnt; /* current running count */
1485 };
1486 
1487 struct xfrmk_spdinfo {
1488 	u32 incnt;
1489 	u32 outcnt;
1490 	u32 fwdcnt;
1491 	u32 inscnt;
1492 	u32 outscnt;
1493 	u32 fwdscnt;
1494 	u32 spdhcnt;
1495 	u32 spdhmcnt;
1496 };
1497 
1498 struct xfrm_state *xfrm_find_acq_byseq(struct net *net, u32 mark, u32 seq);
1499 int xfrm_state_delete(struct xfrm_state *x);
1500 int xfrm_state_flush(struct net *net, u8 proto, bool task_valid);
1501 void xfrm_sad_getinfo(struct net *net, struct xfrmk_sadinfo *si);
1502 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si);
1503 u32 xfrm_replay_seqhi(struct xfrm_state *x, __be32 net_seq);
1504 int xfrm_init_replay(struct xfrm_state *x);
1505 int xfrm_state_mtu(struct xfrm_state *x, int mtu);
1506 int __xfrm_init_state(struct xfrm_state *x, bool init_replay);
1507 int xfrm_init_state(struct xfrm_state *x);
1508 int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb);
1509 int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type);
1510 int xfrm_input_resume(struct sk_buff *skb, int nexthdr);
1511 int xfrm_output_resume(struct sk_buff *skb, int err);
1512 int xfrm_output(struct sock *sk, struct sk_buff *skb);
1513 int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb);
1514 void xfrm_local_error(struct sk_buff *skb, int mtu);
1515 int xfrm4_extract_header(struct sk_buff *skb);
1516 int xfrm4_extract_input(struct xfrm_state *x, struct sk_buff *skb);
1517 int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
1518 		    int encap_type);
1519 int xfrm4_transport_finish(struct sk_buff *skb, int async);
1520 int xfrm4_rcv(struct sk_buff *skb);
1521 
1522 static inline int xfrm4_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
1523 {
1524 	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
1525 	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
1526 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
1527 	return xfrm_input(skb, nexthdr, spi, 0);
1528 }
1529 
1530 int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb);
1531 int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb);
1532 int xfrm4_output(struct sock *sk, struct sk_buff *skb);
1533 int xfrm4_output_finish(struct sock *sk, struct sk_buff *skb);
1534 int xfrm4_rcv_cb(struct sk_buff *skb, u8 protocol, int err);
1535 int xfrm4_protocol_register(struct xfrm4_protocol *handler, unsigned char protocol);
1536 int xfrm4_protocol_deregister(struct xfrm4_protocol *handler, unsigned char protocol);
1537 int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family);
1538 int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family);
1539 void xfrm4_local_error(struct sk_buff *skb, u32 mtu);
1540 int xfrm6_extract_header(struct sk_buff *skb);
1541 int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb);
1542 int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi);
1543 int xfrm6_transport_finish(struct sk_buff *skb, int async);
1544 int xfrm6_rcv(struct sk_buff *skb);
1545 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
1546 		     xfrm_address_t *saddr, u8 proto);
1547 void xfrm6_local_error(struct sk_buff *skb, u32 mtu);
1548 int xfrm6_rcv_cb(struct sk_buff *skb, u8 protocol, int err);
1549 int xfrm6_protocol_register(struct xfrm6_protocol *handler, unsigned char protocol);
1550 int xfrm6_protocol_deregister(struct xfrm6_protocol *handler, unsigned char protocol);
1551 int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family);
1552 int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family);
1553 __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr);
1554 __be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr);
1555 int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb);
1556 int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb);
1557 int xfrm6_output(struct sock *sk, struct sk_buff *skb);
1558 int xfrm6_output_finish(struct sock *sk, struct sk_buff *skb);
1559 int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
1560 			  u8 **prevhdr);
1561 
1562 #ifdef CONFIG_XFRM
1563 int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb);
1564 int xfrm_user_policy(struct sock *sk, int optname,
1565 		     u8 __user *optval, int optlen);
1566 #else
1567 static inline int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen)
1568 {
1569  	return -ENOPROTOOPT;
1570 }
1571 
1572 static inline int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
1573 {
1574  	/* should not happen */
1575  	kfree_skb(skb);
1576 	return 0;
1577 }
1578 #endif
1579 
1580 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp);
1581 
1582 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type);
1583 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
1584 		     int (*func)(struct xfrm_policy *, int, int, void*),
1585 		     void *);
1586 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net);
1587 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl);
1588 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark,
1589 					  u8 type, int dir,
1590 					  struct xfrm_selector *sel,
1591 					  struct xfrm_sec_ctx *ctx, int delete,
1592 					  int *err);
1593 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8, int dir,
1594 				     u32 id, int delete, int *err);
1595 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid);
1596 void xfrm_policy_hash_rebuild(struct net *net);
1597 u32 xfrm_get_acqseq(void);
1598 int verify_spi_info(u8 proto, u32 min, u32 max);
1599 int xfrm_alloc_spi(struct xfrm_state *x, u32 minspi, u32 maxspi);
1600 struct xfrm_state *xfrm_find_acq(struct net *net, const struct xfrm_mark *mark,
1601 				 u8 mode, u32 reqid, u8 proto,
1602 				 const xfrm_address_t *daddr,
1603 				 const xfrm_address_t *saddr, int create,
1604 				 unsigned short family);
1605 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol);
1606 
1607 #ifdef CONFIG_XFRM_MIGRATE
1608 int km_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
1609 	       const struct xfrm_migrate *m, int num_bundles,
1610 	       const struct xfrm_kmaddress *k);
1611 struct xfrm_state *xfrm_migrate_state_find(struct xfrm_migrate *m, struct net *net);
1612 struct xfrm_state *xfrm_state_migrate(struct xfrm_state *x,
1613 				      struct xfrm_migrate *m);
1614 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
1615 		 struct xfrm_migrate *m, int num_bundles,
1616 		 struct xfrm_kmaddress *k, struct net *net);
1617 #endif
1618 
1619 int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport);
1620 void km_policy_expired(struct xfrm_policy *pol, int dir, int hard, u32 portid);
1621 int km_report(struct net *net, u8 proto, struct xfrm_selector *sel,
1622 	      xfrm_address_t *addr);
1623 
1624 void xfrm_input_init(void);
1625 int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq);
1626 
1627 void xfrm_probe_algs(void);
1628 int xfrm_count_pfkey_auth_supported(void);
1629 int xfrm_count_pfkey_enc_supported(void);
1630 struct xfrm_algo_desc *xfrm_aalg_get_byidx(unsigned int idx);
1631 struct xfrm_algo_desc *xfrm_ealg_get_byidx(unsigned int idx);
1632 struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id);
1633 struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id);
1634 struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id);
1635 struct xfrm_algo_desc *xfrm_aalg_get_byname(const char *name, int probe);
1636 struct xfrm_algo_desc *xfrm_ealg_get_byname(const char *name, int probe);
1637 struct xfrm_algo_desc *xfrm_calg_get_byname(const char *name, int probe);
1638 struct xfrm_algo_desc *xfrm_aead_get_byname(const char *name, int icv_len,
1639 					    int probe);
1640 
1641 static inline bool xfrm6_addr_equal(const xfrm_address_t *a,
1642 				    const xfrm_address_t *b)
1643 {
1644 	return ipv6_addr_equal((const struct in6_addr *)a,
1645 			       (const struct in6_addr *)b);
1646 }
1647 
1648 static inline bool xfrm_addr_equal(const xfrm_address_t *a,
1649 				   const xfrm_address_t *b,
1650 				   sa_family_t family)
1651 {
1652 	switch (family) {
1653 	default:
1654 	case AF_INET:
1655 		return ((__force u32)a->a4 ^ (__force u32)b->a4) == 0;
1656 	case AF_INET6:
1657 		return xfrm6_addr_equal(a, b);
1658 	}
1659 }
1660 
1661 static inline int xfrm_policy_id2dir(u32 index)
1662 {
1663 	return index & 7;
1664 }
1665 
1666 #ifdef CONFIG_XFRM
1667 static inline int xfrm_aevent_is_on(struct net *net)
1668 {
1669 	struct sock *nlsk;
1670 	int ret = 0;
1671 
1672 	rcu_read_lock();
1673 	nlsk = rcu_dereference(net->xfrm.nlsk);
1674 	if (nlsk)
1675 		ret = netlink_has_listeners(nlsk, XFRMNLGRP_AEVENTS);
1676 	rcu_read_unlock();
1677 	return ret;
1678 }
1679 
1680 static inline int xfrm_acquire_is_on(struct net *net)
1681 {
1682 	struct sock *nlsk;
1683 	int ret = 0;
1684 
1685 	rcu_read_lock();
1686 	nlsk = rcu_dereference(net->xfrm.nlsk);
1687 	if (nlsk)
1688 		ret = netlink_has_listeners(nlsk, XFRMNLGRP_ACQUIRE);
1689 	rcu_read_unlock();
1690 
1691 	return ret;
1692 }
1693 #endif
1694 
1695 static inline int aead_len(struct xfrm_algo_aead *alg)
1696 {
1697 	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
1698 }
1699 
1700 static inline int xfrm_alg_len(const struct xfrm_algo *alg)
1701 {
1702 	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
1703 }
1704 
1705 static inline int xfrm_alg_auth_len(const struct xfrm_algo_auth *alg)
1706 {
1707 	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
1708 }
1709 
1710 static inline int xfrm_replay_state_esn_len(struct xfrm_replay_state_esn *replay_esn)
1711 {
1712 	return sizeof(*replay_esn) + replay_esn->bmp_len * sizeof(__u32);
1713 }
1714 
1715 #ifdef CONFIG_XFRM_MIGRATE
1716 static inline int xfrm_replay_clone(struct xfrm_state *x,
1717 				     struct xfrm_state *orig)
1718 {
1719 	x->replay_esn = kzalloc(xfrm_replay_state_esn_len(orig->replay_esn),
1720 				GFP_KERNEL);
1721 	if (!x->replay_esn)
1722 		return -ENOMEM;
1723 
1724 	x->replay_esn->bmp_len = orig->replay_esn->bmp_len;
1725 	x->replay_esn->replay_window = orig->replay_esn->replay_window;
1726 
1727 	x->preplay_esn = kmemdup(x->replay_esn,
1728 				 xfrm_replay_state_esn_len(x->replay_esn),
1729 				 GFP_KERNEL);
1730 	if (!x->preplay_esn) {
1731 		kfree(x->replay_esn);
1732 		return -ENOMEM;
1733 	}
1734 
1735 	return 0;
1736 }
1737 
1738 static inline struct xfrm_algo_aead *xfrm_algo_aead_clone(struct xfrm_algo_aead *orig)
1739 {
1740 	return kmemdup(orig, aead_len(orig), GFP_KERNEL);
1741 }
1742 
1743 
1744 static inline struct xfrm_algo *xfrm_algo_clone(struct xfrm_algo *orig)
1745 {
1746 	return kmemdup(orig, xfrm_alg_len(orig), GFP_KERNEL);
1747 }
1748 
1749 static inline struct xfrm_algo_auth *xfrm_algo_auth_clone(struct xfrm_algo_auth *orig)
1750 {
1751 	return kmemdup(orig, xfrm_alg_auth_len(orig), GFP_KERNEL);
1752 }
1753 
1754 static inline void xfrm_states_put(struct xfrm_state **states, int n)
1755 {
1756 	int i;
1757 	for (i = 0; i < n; i++)
1758 		xfrm_state_put(*(states + i));
1759 }
1760 
1761 static inline void xfrm_states_delete(struct xfrm_state **states, int n)
1762 {
1763 	int i;
1764 	for (i = 0; i < n; i++)
1765 		xfrm_state_delete(*(states + i));
1766 }
1767 #endif
1768 
1769 #ifdef CONFIG_XFRM
1770 static inline struct xfrm_state *xfrm_input_state(struct sk_buff *skb)
1771 {
1772 	return skb->sp->xvec[skb->sp->len - 1];
1773 }
1774 #endif
1775 
1776 static inline int xfrm_mark_get(struct nlattr **attrs, struct xfrm_mark *m)
1777 {
1778 	if (attrs[XFRMA_MARK])
1779 		memcpy(m, nla_data(attrs[XFRMA_MARK]), sizeof(struct xfrm_mark));
1780 	else
1781 		m->v = m->m = 0;
1782 
1783 	return m->v & m->m;
1784 }
1785 
1786 static inline int xfrm_mark_put(struct sk_buff *skb, const struct xfrm_mark *m)
1787 {
1788 	int ret = 0;
1789 
1790 	if (m->m | m->v)
1791 		ret = nla_put(skb, XFRMA_MARK, sizeof(struct xfrm_mark), m);
1792 	return ret;
1793 }
1794 
1795 static inline int xfrm_tunnel_check(struct sk_buff *skb, struct xfrm_state *x,
1796 				    unsigned int family)
1797 {
1798 	bool tunnel = false;
1799 
1800 	switch(family) {
1801 	case AF_INET:
1802 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4)
1803 			tunnel = true;
1804 		break;
1805 	case AF_INET6:
1806 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6)
1807 			tunnel = true;
1808 		break;
1809 	}
1810 	if (tunnel && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL))
1811 		return -EINVAL;
1812 
1813 	return 0;
1814 }
1815 #endif	/* _NET_XFRM_H */
1816