xref: /linux/include/net/xfrm.h (revision 5e8c0fb6a95728b852d56c0a9244425d474670c0)
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 #ifdef CONFIG_NET_NS
130 	struct net		*xs_net;
131 #endif
132 	union {
133 		struct hlist_node	gclist;
134 		struct hlist_node	bydst;
135 	};
136 	struct hlist_node	bysrc;
137 	struct hlist_node	byspi;
138 
139 	atomic_t		refcnt;
140 	spinlock_t		lock;
141 
142 	struct xfrm_id		id;
143 	struct xfrm_selector	sel;
144 	struct xfrm_mark	mark;
145 	u32			tfcpad;
146 
147 	u32			genid;
148 
149 	/* Key manager bits */
150 	struct xfrm_state_walk	km;
151 
152 	/* Parameters of this state. */
153 	struct {
154 		u32		reqid;
155 		u8		mode;
156 		u8		replay_window;
157 		u8		aalgo, ealgo, calgo;
158 		u8		flags;
159 		u16		family;
160 		xfrm_address_t	saddr;
161 		int		header_len;
162 		int		trailer_len;
163 		u32		extra_flags;
164 	} props;
165 
166 	struct xfrm_lifetime_cfg lft;
167 
168 	/* Data for transformer */
169 	struct xfrm_algo_auth	*aalg;
170 	struct xfrm_algo	*ealg;
171 	struct xfrm_algo	*calg;
172 	struct xfrm_algo_aead	*aead;
173 
174 	/* Data for encapsulator */
175 	struct xfrm_encap_tmpl	*encap;
176 
177 	/* Data for care-of address */
178 	xfrm_address_t	*coaddr;
179 
180 	/* IPComp needs an IPIP tunnel for handling uncompressed packets */
181 	struct xfrm_state	*tunnel;
182 
183 	/* If a tunnel, number of users + 1 */
184 	atomic_t		tunnel_users;
185 
186 	/* State for replay detection */
187 	struct xfrm_replay_state replay;
188 	struct xfrm_replay_state_esn *replay_esn;
189 
190 	/* Replay detection state at the time we sent the last notification */
191 	struct xfrm_replay_state preplay;
192 	struct xfrm_replay_state_esn *preplay_esn;
193 
194 	/* The functions for replay detection. */
195 	struct xfrm_replay	*repl;
196 
197 	/* internal flag that only holds state for delayed aevent at the
198 	 * moment
199 	*/
200 	u32			xflags;
201 
202 	/* Replay detection notification settings */
203 	u32			replay_maxage;
204 	u32			replay_maxdiff;
205 
206 	/* Replay detection notification timer */
207 	struct timer_list	rtimer;
208 
209 	/* Statistics */
210 	struct xfrm_stats	stats;
211 
212 	struct xfrm_lifetime_cur curlft;
213 	struct tasklet_hrtimer	mtimer;
214 
215 	/* used to fix curlft->add_time when changing date */
216 	long		saved_tmo;
217 
218 	/* Last used time */
219 	unsigned long		lastused;
220 
221 	/* Reference to data common to all the instances of this
222 	 * transformer. */
223 	const struct xfrm_type	*type;
224 	struct xfrm_mode	*inner_mode;
225 	struct xfrm_mode	*inner_mode_iaf;
226 	struct xfrm_mode	*outer_mode;
227 
228 	/* Security context */
229 	struct xfrm_sec_ctx	*security;
230 
231 	/* Private data of this transformer, format is opaque,
232 	 * interpreted by xfrm_type methods. */
233 	void			*data;
234 };
235 
236 static inline struct net *xs_net(struct xfrm_state *x)
237 {
238 	return read_pnet(&x->xs_net);
239 }
240 
241 /* xflags - make enum if more show up */
242 #define XFRM_TIME_DEFER	1
243 #define XFRM_SOFT_EXPIRE 2
244 
245 enum {
246 	XFRM_STATE_VOID,
247 	XFRM_STATE_ACQ,
248 	XFRM_STATE_VALID,
249 	XFRM_STATE_ERROR,
250 	XFRM_STATE_EXPIRED,
251 	XFRM_STATE_DEAD
252 };
253 
254 /* callback structure passed from either netlink or pfkey */
255 struct km_event {
256 	union {
257 		u32 hard;
258 		u32 proto;
259 		u32 byid;
260 		u32 aevent;
261 		u32 type;
262 	} data;
263 
264 	u32	seq;
265 	u32	portid;
266 	u32	event;
267 	struct net *net;
268 };
269 
270 struct xfrm_replay {
271 	void	(*advance)(struct xfrm_state *x, __be32 net_seq);
272 	int	(*check)(struct xfrm_state *x,
273 			 struct sk_buff *skb,
274 			 __be32 net_seq);
275 	int	(*recheck)(struct xfrm_state *x,
276 			   struct sk_buff *skb,
277 			   __be32 net_seq);
278 	void	(*notify)(struct xfrm_state *x, int event);
279 	int	(*overflow)(struct xfrm_state *x, struct sk_buff *skb);
280 };
281 
282 struct net_device;
283 struct xfrm_type;
284 struct xfrm_dst;
285 struct xfrm_policy_afinfo {
286 	unsigned short		family;
287 	struct dst_ops		*dst_ops;
288 	void			(*garbage_collect)(struct net *net);
289 	struct dst_entry	*(*dst_lookup)(struct net *net, int tos,
290 					       const xfrm_address_t *saddr,
291 					       const xfrm_address_t *daddr);
292 	int			(*get_saddr)(struct net *net, xfrm_address_t *saddr, xfrm_address_t *daddr);
293 	void			(*decode_session)(struct sk_buff *skb,
294 						  struct flowi *fl,
295 						  int reverse);
296 	int			(*get_tos)(const struct flowi *fl);
297 	void			(*init_dst)(struct net *net,
298 					    struct xfrm_dst *dst);
299 	int			(*init_path)(struct xfrm_dst *path,
300 					     struct dst_entry *dst,
301 					     int nfheader_len);
302 	int			(*fill_dst)(struct xfrm_dst *xdst,
303 					    struct net_device *dev,
304 					    const struct flowi *fl);
305 	struct dst_entry	*(*blackhole_route)(struct net *net, struct dst_entry *orig);
306 };
307 
308 int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo);
309 int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo);
310 void km_policy_notify(struct xfrm_policy *xp, int dir,
311 		      const struct km_event *c);
312 void km_state_notify(struct xfrm_state *x, const struct km_event *c);
313 
314 struct xfrm_tmpl;
315 int km_query(struct xfrm_state *x, struct xfrm_tmpl *t,
316 	     struct xfrm_policy *pol);
317 void km_state_expired(struct xfrm_state *x, int hard, u32 portid);
318 int __xfrm_state_delete(struct xfrm_state *x);
319 
320 struct xfrm_state_afinfo {
321 	unsigned int		family;
322 	unsigned int		proto;
323 	__be16			eth_proto;
324 	struct module		*owner;
325 	const struct xfrm_type	*type_map[IPPROTO_MAX];
326 	struct xfrm_mode	*mode_map[XFRM_MODE_MAX];
327 	int			(*init_flags)(struct xfrm_state *x);
328 	void			(*init_tempsel)(struct xfrm_selector *sel,
329 						const struct flowi *fl);
330 	void			(*init_temprop)(struct xfrm_state *x,
331 						const struct xfrm_tmpl *tmpl,
332 						const xfrm_address_t *daddr,
333 						const xfrm_address_t *saddr);
334 	int			(*tmpl_sort)(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n);
335 	int			(*state_sort)(struct xfrm_state **dst, struct xfrm_state **src, int n);
336 	int			(*output)(struct sock *sk, struct sk_buff *skb);
337 	int			(*output_finish)(struct sk_buff *skb);
338 	int			(*extract_input)(struct xfrm_state *x,
339 						 struct sk_buff *skb);
340 	int			(*extract_output)(struct xfrm_state *x,
341 						  struct sk_buff *skb);
342 	int			(*transport_finish)(struct sk_buff *skb,
343 						    int async);
344 	void			(*local_error)(struct sk_buff *skb, u32 mtu);
345 };
346 
347 int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo);
348 int xfrm_state_unregister_afinfo(struct xfrm_state_afinfo *afinfo);
349 struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned int family);
350 void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo);
351 
352 struct xfrm_input_afinfo {
353 	unsigned int		family;
354 	struct module		*owner;
355 	int			(*callback)(struct sk_buff *skb, u8 protocol,
356 					    int err);
357 };
358 
359 int xfrm_input_register_afinfo(struct xfrm_input_afinfo *afinfo);
360 int xfrm_input_unregister_afinfo(struct xfrm_input_afinfo *afinfo);
361 
362 void xfrm_state_delete_tunnel(struct xfrm_state *x);
363 
364 struct xfrm_type {
365 	char			*description;
366 	struct module		*owner;
367 	u8			proto;
368 	u8			flags;
369 #define XFRM_TYPE_NON_FRAGMENT	1
370 #define XFRM_TYPE_REPLAY_PROT	2
371 #define XFRM_TYPE_LOCAL_COADDR	4
372 #define XFRM_TYPE_REMOTE_COADDR	8
373 
374 	int			(*init_state)(struct xfrm_state *x);
375 	void			(*destructor)(struct xfrm_state *);
376 	int			(*input)(struct xfrm_state *, struct sk_buff *skb);
377 	int			(*output)(struct xfrm_state *, struct sk_buff *pskb);
378 	int			(*reject)(struct xfrm_state *, struct sk_buff *,
379 					  const struct flowi *);
380 	int			(*hdr_offset)(struct xfrm_state *, struct sk_buff *, u8 **);
381 	/* Estimate maximal size of result of transformation of a dgram */
382 	u32			(*get_mtu)(struct xfrm_state *, int size);
383 };
384 
385 int xfrm_register_type(const struct xfrm_type *type, unsigned short family);
386 int xfrm_unregister_type(const struct xfrm_type *type, unsigned short family);
387 
388 struct xfrm_mode {
389 	/*
390 	 * Remove encapsulation header.
391 	 *
392 	 * The IP header will be moved over the top of the encapsulation
393 	 * header.
394 	 *
395 	 * On entry, the transport header shall point to where the IP header
396 	 * should be and the network header shall be set to where the IP
397 	 * header currently is.  skb->data shall point to the start of the
398 	 * payload.
399 	 */
400 	int (*input2)(struct xfrm_state *x, struct sk_buff *skb);
401 
402 	/*
403 	 * This is the actual input entry point.
404 	 *
405 	 * For transport mode and equivalent this would be identical to
406 	 * input2 (which does not need to be set).  While tunnel mode
407 	 * and equivalent would set this to the tunnel encapsulation function
408 	 * xfrm4_prepare_input that would in turn call input2.
409 	 */
410 	int (*input)(struct xfrm_state *x, struct sk_buff *skb);
411 
412 	/*
413 	 * Add encapsulation header.
414 	 *
415 	 * On exit, the transport header will be set to the start of the
416 	 * encapsulation header to be filled in by x->type->output and
417 	 * the mac header will be set to the nextheader (protocol for
418 	 * IPv4) field of the extension header directly preceding the
419 	 * encapsulation header, or in its absence, that of the top IP
420 	 * header.  The value of the network header will always point
421 	 * to the top IP header while skb->data will point to the payload.
422 	 */
423 	int (*output2)(struct xfrm_state *x,struct sk_buff *skb);
424 
425 	/*
426 	 * This is the actual output entry point.
427 	 *
428 	 * For transport mode and equivalent this would be identical to
429 	 * output2 (which does not need to be set).  While tunnel mode
430 	 * and equivalent would set this to a tunnel encapsulation function
431 	 * (xfrm4_prepare_output or xfrm6_prepare_output) that would in turn
432 	 * call output2.
433 	 */
434 	int (*output)(struct xfrm_state *x, struct sk_buff *skb);
435 
436 	struct xfrm_state_afinfo *afinfo;
437 	struct module *owner;
438 	unsigned int encap;
439 	int flags;
440 };
441 
442 /* Flags for xfrm_mode. */
443 enum {
444 	XFRM_MODE_FLAG_TUNNEL = 1,
445 };
446 
447 int xfrm_register_mode(struct xfrm_mode *mode, int family);
448 int xfrm_unregister_mode(struct xfrm_mode *mode, int family);
449 
450 static inline int xfrm_af2proto(unsigned int family)
451 {
452 	switch(family) {
453 	case AF_INET:
454 		return IPPROTO_IPIP;
455 	case AF_INET6:
456 		return IPPROTO_IPV6;
457 	default:
458 		return 0;
459 	}
460 }
461 
462 static inline struct xfrm_mode *xfrm_ip2inner_mode(struct xfrm_state *x, int ipproto)
463 {
464 	if ((ipproto == IPPROTO_IPIP && x->props.family == AF_INET) ||
465 	    (ipproto == IPPROTO_IPV6 && x->props.family == AF_INET6))
466 		return x->inner_mode;
467 	else
468 		return x->inner_mode_iaf;
469 }
470 
471 struct xfrm_tmpl {
472 /* id in template is interpreted as:
473  * daddr - destination of tunnel, may be zero for transport mode.
474  * spi   - zero to acquire spi. Not zero if spi is static, then
475  *	   daddr must be fixed too.
476  * proto - AH/ESP/IPCOMP
477  */
478 	struct xfrm_id		id;
479 
480 /* Source address of tunnel. Ignored, if it is not a tunnel. */
481 	xfrm_address_t		saddr;
482 
483 	unsigned short		encap_family;
484 
485 	u32			reqid;
486 
487 /* Mode: transport, tunnel etc. */
488 	u8			mode;
489 
490 /* Sharing mode: unique, this session only, this user only etc. */
491 	u8			share;
492 
493 /* May skip this transfomration if no SA is found */
494 	u8			optional;
495 
496 /* Skip aalgos/ealgos/calgos checks. */
497 	u8			allalgs;
498 
499 /* Bit mask of algos allowed for acquisition */
500 	u32			aalgos;
501 	u32			ealgos;
502 	u32			calgos;
503 };
504 
505 #define XFRM_MAX_DEPTH		6
506 
507 struct xfrm_policy_walk_entry {
508 	struct list_head	all;
509 	u8			dead;
510 };
511 
512 struct xfrm_policy_walk {
513 	struct xfrm_policy_walk_entry walk;
514 	u8 type;
515 	u32 seq;
516 };
517 
518 struct xfrm_policy_queue {
519 	struct sk_buff_head	hold_queue;
520 	struct timer_list	hold_timer;
521 	unsigned long		timeout;
522 };
523 
524 struct xfrm_policy {
525 #ifdef CONFIG_NET_NS
526 	struct net		*xp_net;
527 #endif
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((struct in6_addr *)&addr->a6);
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 		*(struct in6_addr *)saddr->a6 = fl->u.ip6.saddr;
1246 		*(struct in6_addr *)daddr->a6 = 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 	u16 icv_truncbits;
1322 };
1323 
1324 struct xfrm_algo_auth_info {
1325 	u16 icv_truncbits;
1326 	u16 icv_fullbits;
1327 };
1328 
1329 struct xfrm_algo_encr_info {
1330 	u16 blockbits;
1331 	u16 defkeybits;
1332 };
1333 
1334 struct xfrm_algo_comp_info {
1335 	u16 threshold;
1336 };
1337 
1338 struct xfrm_algo_desc {
1339 	char *name;
1340 	char *compat;
1341 	u8 available:1;
1342 	u8 pfkey_supported:1;
1343 	union {
1344 		struct xfrm_algo_aead_info aead;
1345 		struct xfrm_algo_auth_info auth;
1346 		struct xfrm_algo_encr_info encr;
1347 		struct xfrm_algo_comp_info comp;
1348 	} uinfo;
1349 	struct sadb_alg desc;
1350 };
1351 
1352 /* XFRM protocol handlers.  */
1353 struct xfrm4_protocol {
1354 	int (*handler)(struct sk_buff *skb);
1355 	int (*input_handler)(struct sk_buff *skb, int nexthdr, __be32 spi,
1356 			     int encap_type);
1357 	int (*cb_handler)(struct sk_buff *skb, int err);
1358 	int (*err_handler)(struct sk_buff *skb, u32 info);
1359 
1360 	struct xfrm4_protocol __rcu *next;
1361 	int priority;
1362 };
1363 
1364 struct xfrm6_protocol {
1365 	int (*handler)(struct sk_buff *skb);
1366 	int (*cb_handler)(struct sk_buff *skb, int err);
1367 	int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
1368 			   u8 type, u8 code, int offset, __be32 info);
1369 
1370 	struct xfrm6_protocol __rcu *next;
1371 	int priority;
1372 };
1373 
1374 /* XFRM tunnel handlers.  */
1375 struct xfrm_tunnel {
1376 	int (*handler)(struct sk_buff *skb);
1377 	int (*err_handler)(struct sk_buff *skb, u32 info);
1378 
1379 	struct xfrm_tunnel __rcu *next;
1380 	int priority;
1381 };
1382 
1383 struct xfrm6_tunnel {
1384 	int (*handler)(struct sk_buff *skb);
1385 	int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
1386 			   u8 type, u8 code, int offset, __be32 info);
1387 	struct xfrm6_tunnel __rcu *next;
1388 	int priority;
1389 };
1390 
1391 void xfrm_init(void);
1392 void xfrm4_init(void);
1393 int xfrm_state_init(struct net *net);
1394 void xfrm_state_fini(struct net *net);
1395 void xfrm4_state_init(void);
1396 void xfrm4_protocol_init(void);
1397 #ifdef CONFIG_XFRM
1398 int xfrm6_init(void);
1399 void xfrm6_fini(void);
1400 int xfrm6_state_init(void);
1401 void xfrm6_state_fini(void);
1402 int xfrm6_protocol_init(void);
1403 void xfrm6_protocol_fini(void);
1404 #else
1405 static inline int xfrm6_init(void)
1406 {
1407 	return 0;
1408 }
1409 static inline void xfrm6_fini(void)
1410 {
1411 	;
1412 }
1413 #endif
1414 
1415 #ifdef CONFIG_XFRM_STATISTICS
1416 int xfrm_proc_init(struct net *net);
1417 void xfrm_proc_fini(struct net *net);
1418 #endif
1419 
1420 int xfrm_sysctl_init(struct net *net);
1421 #ifdef CONFIG_SYSCTL
1422 void xfrm_sysctl_fini(struct net *net);
1423 #else
1424 static inline void xfrm_sysctl_fini(struct net *net)
1425 {
1426 }
1427 #endif
1428 
1429 void xfrm_state_walk_init(struct xfrm_state_walk *walk, u8 proto,
1430 			  struct xfrm_address_filter *filter);
1431 int xfrm_state_walk(struct net *net, struct xfrm_state_walk *walk,
1432 		    int (*func)(struct xfrm_state *, int, void*), void *);
1433 void xfrm_state_walk_done(struct xfrm_state_walk *walk, struct net *net);
1434 struct xfrm_state *xfrm_state_alloc(struct net *net);
1435 struct xfrm_state *xfrm_state_find(const xfrm_address_t *daddr,
1436 				   const xfrm_address_t *saddr,
1437 				   const struct flowi *fl,
1438 				   struct xfrm_tmpl *tmpl,
1439 				   struct xfrm_policy *pol, int *err,
1440 				   unsigned short family);
1441 struct xfrm_state *xfrm_stateonly_find(struct net *net, u32 mark,
1442 				       xfrm_address_t *daddr,
1443 				       xfrm_address_t *saddr,
1444 				       unsigned short family,
1445 				       u8 mode, u8 proto, u32 reqid);
1446 struct xfrm_state *xfrm_state_lookup_byspi(struct net *net, __be32 spi,
1447 					      unsigned short family);
1448 int xfrm_state_check_expire(struct xfrm_state *x);
1449 void xfrm_state_insert(struct xfrm_state *x);
1450 int xfrm_state_add(struct xfrm_state *x);
1451 int xfrm_state_update(struct xfrm_state *x);
1452 struct xfrm_state *xfrm_state_lookup(struct net *net, u32 mark,
1453 				     const xfrm_address_t *daddr, __be32 spi,
1454 				     u8 proto, unsigned short family);
1455 struct xfrm_state *xfrm_state_lookup_byaddr(struct net *net, u32 mark,
1456 					    const xfrm_address_t *daddr,
1457 					    const xfrm_address_t *saddr,
1458 					    u8 proto,
1459 					    unsigned short family);
1460 #ifdef CONFIG_XFRM_SUB_POLICY
1461 int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n,
1462 		   unsigned short family, struct net *net);
1463 int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n,
1464 		    unsigned short family);
1465 #else
1466 static inline int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src,
1467 				 int n, unsigned short family, struct net *net)
1468 {
1469 	return -ENOSYS;
1470 }
1471 
1472 static inline int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src,
1473 				  int n, unsigned short family)
1474 {
1475 	return -ENOSYS;
1476 }
1477 #endif
1478 
1479 struct xfrmk_sadinfo {
1480 	u32 sadhcnt; /* current hash bkts */
1481 	u32 sadhmcnt; /* max allowed hash bkts */
1482 	u32 sadcnt; /* current running count */
1483 };
1484 
1485 struct xfrmk_spdinfo {
1486 	u32 incnt;
1487 	u32 outcnt;
1488 	u32 fwdcnt;
1489 	u32 inscnt;
1490 	u32 outscnt;
1491 	u32 fwdscnt;
1492 	u32 spdhcnt;
1493 	u32 spdhmcnt;
1494 };
1495 
1496 struct xfrm_state *xfrm_find_acq_byseq(struct net *net, u32 mark, u32 seq);
1497 int xfrm_state_delete(struct xfrm_state *x);
1498 int xfrm_state_flush(struct net *net, u8 proto, bool task_valid);
1499 void xfrm_sad_getinfo(struct net *net, struct xfrmk_sadinfo *si);
1500 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si);
1501 u32 xfrm_replay_seqhi(struct xfrm_state *x, __be32 net_seq);
1502 int xfrm_init_replay(struct xfrm_state *x);
1503 int xfrm_state_mtu(struct xfrm_state *x, int mtu);
1504 int __xfrm_init_state(struct xfrm_state *x, bool init_replay);
1505 int xfrm_init_state(struct xfrm_state *x);
1506 int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb);
1507 int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type);
1508 int xfrm_input_resume(struct sk_buff *skb, int nexthdr);
1509 int xfrm_output_resume(struct sk_buff *skb, int err);
1510 int xfrm_output(struct sk_buff *skb);
1511 int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb);
1512 void xfrm_local_error(struct sk_buff *skb, int mtu);
1513 int xfrm4_extract_header(struct sk_buff *skb);
1514 int xfrm4_extract_input(struct xfrm_state *x, struct sk_buff *skb);
1515 int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
1516 		    int encap_type);
1517 int xfrm4_transport_finish(struct sk_buff *skb, int async);
1518 int xfrm4_rcv(struct sk_buff *skb);
1519 
1520 static inline int xfrm4_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
1521 {
1522 	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
1523 	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
1524 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
1525 	return xfrm_input(skb, nexthdr, spi, 0);
1526 }
1527 
1528 int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb);
1529 int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb);
1530 int xfrm4_output(struct sock *sk, struct sk_buff *skb);
1531 int xfrm4_output_finish(struct sk_buff *skb);
1532 int xfrm4_rcv_cb(struct sk_buff *skb, u8 protocol, int err);
1533 int xfrm4_protocol_register(struct xfrm4_protocol *handler, unsigned char protocol);
1534 int xfrm4_protocol_deregister(struct xfrm4_protocol *handler, unsigned char protocol);
1535 int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family);
1536 int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family);
1537 void xfrm4_local_error(struct sk_buff *skb, u32 mtu);
1538 int xfrm6_extract_header(struct sk_buff *skb);
1539 int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb);
1540 int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi);
1541 int xfrm6_transport_finish(struct sk_buff *skb, int async);
1542 int xfrm6_rcv(struct sk_buff *skb);
1543 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
1544 		     xfrm_address_t *saddr, u8 proto);
1545 void xfrm6_local_error(struct sk_buff *skb, u32 mtu);
1546 int xfrm6_rcv_cb(struct sk_buff *skb, u8 protocol, int err);
1547 int xfrm6_protocol_register(struct xfrm6_protocol *handler, unsigned char protocol);
1548 int xfrm6_protocol_deregister(struct xfrm6_protocol *handler, unsigned char protocol);
1549 int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family);
1550 int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family);
1551 __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr);
1552 __be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr);
1553 int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb);
1554 int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb);
1555 int xfrm6_output(struct sock *sk, struct sk_buff *skb);
1556 int xfrm6_output_finish(struct sk_buff *skb);
1557 int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
1558 			  u8 **prevhdr);
1559 
1560 #ifdef CONFIG_XFRM
1561 int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb);
1562 int xfrm_user_policy(struct sock *sk, int optname,
1563 		     u8 __user *optval, int optlen);
1564 #else
1565 static inline int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen)
1566 {
1567  	return -ENOPROTOOPT;
1568 }
1569 
1570 static inline int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
1571 {
1572  	/* should not happen */
1573  	kfree_skb(skb);
1574 	return 0;
1575 }
1576 #endif
1577 
1578 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp);
1579 
1580 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type);
1581 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
1582 		     int (*func)(struct xfrm_policy *, int, int, void*),
1583 		     void *);
1584 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net);
1585 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl);
1586 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark,
1587 					  u8 type, int dir,
1588 					  struct xfrm_selector *sel,
1589 					  struct xfrm_sec_ctx *ctx, int delete,
1590 					  int *err);
1591 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8, int dir,
1592 				     u32 id, int delete, int *err);
1593 int xfrm_policy_flush(struct net *net, u8 type, bool task_valid);
1594 void xfrm_policy_hash_rebuild(struct net *net);
1595 u32 xfrm_get_acqseq(void);
1596 int verify_spi_info(u8 proto, u32 min, u32 max);
1597 int xfrm_alloc_spi(struct xfrm_state *x, u32 minspi, u32 maxspi);
1598 struct xfrm_state *xfrm_find_acq(struct net *net, const struct xfrm_mark *mark,
1599 				 u8 mode, u32 reqid, u8 proto,
1600 				 const xfrm_address_t *daddr,
1601 				 const xfrm_address_t *saddr, int create,
1602 				 unsigned short family);
1603 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol);
1604 
1605 #ifdef CONFIG_XFRM_MIGRATE
1606 int km_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
1607 	       const struct xfrm_migrate *m, int num_bundles,
1608 	       const struct xfrm_kmaddress *k);
1609 struct xfrm_state *xfrm_migrate_state_find(struct xfrm_migrate *m, struct net *net);
1610 struct xfrm_state *xfrm_state_migrate(struct xfrm_state *x,
1611 				      struct xfrm_migrate *m);
1612 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
1613 		 struct xfrm_migrate *m, int num_bundles,
1614 		 struct xfrm_kmaddress *k, struct net *net);
1615 #endif
1616 
1617 int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport);
1618 void km_policy_expired(struct xfrm_policy *pol, int dir, int hard, u32 portid);
1619 int km_report(struct net *net, u8 proto, struct xfrm_selector *sel,
1620 	      xfrm_address_t *addr);
1621 
1622 void xfrm_input_init(void);
1623 int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq);
1624 
1625 void xfrm_probe_algs(void);
1626 int xfrm_count_pfkey_auth_supported(void);
1627 int xfrm_count_pfkey_enc_supported(void);
1628 struct xfrm_algo_desc *xfrm_aalg_get_byidx(unsigned int idx);
1629 struct xfrm_algo_desc *xfrm_ealg_get_byidx(unsigned int idx);
1630 struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id);
1631 struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id);
1632 struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id);
1633 struct xfrm_algo_desc *xfrm_aalg_get_byname(const char *name, int probe);
1634 struct xfrm_algo_desc *xfrm_ealg_get_byname(const char *name, int probe);
1635 struct xfrm_algo_desc *xfrm_calg_get_byname(const char *name, int probe);
1636 struct xfrm_algo_desc *xfrm_aead_get_byname(const char *name, int icv_len,
1637 					    int probe);
1638 
1639 static inline bool xfrm6_addr_equal(const xfrm_address_t *a,
1640 				    const xfrm_address_t *b)
1641 {
1642 	return ipv6_addr_equal((const struct in6_addr *)a,
1643 			       (const struct in6_addr *)b);
1644 }
1645 
1646 static inline bool xfrm_addr_equal(const xfrm_address_t *a,
1647 				   const xfrm_address_t *b,
1648 				   sa_family_t family)
1649 {
1650 	switch (family) {
1651 	default:
1652 	case AF_INET:
1653 		return ((__force u32)a->a4 ^ (__force u32)b->a4) == 0;
1654 	case AF_INET6:
1655 		return xfrm6_addr_equal(a, b);
1656 	}
1657 }
1658 
1659 static inline int xfrm_policy_id2dir(u32 index)
1660 {
1661 	return index & 7;
1662 }
1663 
1664 #ifdef CONFIG_XFRM
1665 static inline int xfrm_aevent_is_on(struct net *net)
1666 {
1667 	struct sock *nlsk;
1668 	int ret = 0;
1669 
1670 	rcu_read_lock();
1671 	nlsk = rcu_dereference(net->xfrm.nlsk);
1672 	if (nlsk)
1673 		ret = netlink_has_listeners(nlsk, XFRMNLGRP_AEVENTS);
1674 	rcu_read_unlock();
1675 	return ret;
1676 }
1677 
1678 static inline int xfrm_acquire_is_on(struct net *net)
1679 {
1680 	struct sock *nlsk;
1681 	int ret = 0;
1682 
1683 	rcu_read_lock();
1684 	nlsk = rcu_dereference(net->xfrm.nlsk);
1685 	if (nlsk)
1686 		ret = netlink_has_listeners(nlsk, XFRMNLGRP_ACQUIRE);
1687 	rcu_read_unlock();
1688 
1689 	return ret;
1690 }
1691 #endif
1692 
1693 static inline int aead_len(struct xfrm_algo_aead *alg)
1694 {
1695 	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
1696 }
1697 
1698 static inline int xfrm_alg_len(const struct xfrm_algo *alg)
1699 {
1700 	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
1701 }
1702 
1703 static inline int xfrm_alg_auth_len(const struct xfrm_algo_auth *alg)
1704 {
1705 	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
1706 }
1707 
1708 static inline int xfrm_replay_state_esn_len(struct xfrm_replay_state_esn *replay_esn)
1709 {
1710 	return sizeof(*replay_esn) + replay_esn->bmp_len * sizeof(__u32);
1711 }
1712 
1713 #ifdef CONFIG_XFRM_MIGRATE
1714 static inline int xfrm_replay_clone(struct xfrm_state *x,
1715 				     struct xfrm_state *orig)
1716 {
1717 	x->replay_esn = kzalloc(xfrm_replay_state_esn_len(orig->replay_esn),
1718 				GFP_KERNEL);
1719 	if (!x->replay_esn)
1720 		return -ENOMEM;
1721 
1722 	x->replay_esn->bmp_len = orig->replay_esn->bmp_len;
1723 	x->replay_esn->replay_window = orig->replay_esn->replay_window;
1724 
1725 	x->preplay_esn = kmemdup(x->replay_esn,
1726 				 xfrm_replay_state_esn_len(x->replay_esn),
1727 				 GFP_KERNEL);
1728 	if (!x->preplay_esn) {
1729 		kfree(x->replay_esn);
1730 		return -ENOMEM;
1731 	}
1732 
1733 	return 0;
1734 }
1735 
1736 static inline struct xfrm_algo_aead *xfrm_algo_aead_clone(struct xfrm_algo_aead *orig)
1737 {
1738 	return kmemdup(orig, aead_len(orig), GFP_KERNEL);
1739 }
1740 
1741 
1742 static inline struct xfrm_algo *xfrm_algo_clone(struct xfrm_algo *orig)
1743 {
1744 	return kmemdup(orig, xfrm_alg_len(orig), GFP_KERNEL);
1745 }
1746 
1747 static inline struct xfrm_algo_auth *xfrm_algo_auth_clone(struct xfrm_algo_auth *orig)
1748 {
1749 	return kmemdup(orig, xfrm_alg_auth_len(orig), GFP_KERNEL);
1750 }
1751 
1752 static inline void xfrm_states_put(struct xfrm_state **states, int n)
1753 {
1754 	int i;
1755 	for (i = 0; i < n; i++)
1756 		xfrm_state_put(*(states + i));
1757 }
1758 
1759 static inline void xfrm_states_delete(struct xfrm_state **states, int n)
1760 {
1761 	int i;
1762 	for (i = 0; i < n; i++)
1763 		xfrm_state_delete(*(states + i));
1764 }
1765 #endif
1766 
1767 #ifdef CONFIG_XFRM
1768 static inline struct xfrm_state *xfrm_input_state(struct sk_buff *skb)
1769 {
1770 	return skb->sp->xvec[skb->sp->len - 1];
1771 }
1772 #endif
1773 
1774 static inline int xfrm_mark_get(struct nlattr **attrs, struct xfrm_mark *m)
1775 {
1776 	if (attrs[XFRMA_MARK])
1777 		memcpy(m, nla_data(attrs[XFRMA_MARK]), sizeof(struct xfrm_mark));
1778 	else
1779 		m->v = m->m = 0;
1780 
1781 	return m->v & m->m;
1782 }
1783 
1784 static inline int xfrm_mark_put(struct sk_buff *skb, const struct xfrm_mark *m)
1785 {
1786 	int ret = 0;
1787 
1788 	if (m->m | m->v)
1789 		ret = nla_put(skb, XFRMA_MARK, sizeof(struct xfrm_mark), m);
1790 	return ret;
1791 }
1792 
1793 static inline int xfrm_tunnel_check(struct sk_buff *skb, struct xfrm_state *x,
1794 				    unsigned int family)
1795 {
1796 	bool tunnel = false;
1797 
1798 	switch(family) {
1799 	case AF_INET:
1800 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4)
1801 			tunnel = true;
1802 		break;
1803 	case AF_INET6:
1804 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6)
1805 			tunnel = true;
1806 		break;
1807 	}
1808 	if (tunnel && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL))
1809 		return -EINVAL;
1810 
1811 	return 0;
1812 }
1813 #endif	/* _NET_XFRM_H */
1814