xref: /linux/include/net/xfrm.h (revision 2a2c74b2efcb1a0ca3fdcb5fbb96ad8de6a29177)
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 /* Audit Information */
695 struct xfrm_audit {
696 	u32	secid;
697 	kuid_t	loginuid;
698 	unsigned int sessionid;
699 };
700 
701 #ifdef CONFIG_AUDITSYSCALL
702 static inline struct audit_buffer *xfrm_audit_start(const char *op)
703 {
704 	struct audit_buffer *audit_buf = NULL;
705 
706 	if (audit_enabled == 0)
707 		return NULL;
708 	audit_buf = audit_log_start(current->audit_context, GFP_ATOMIC,
709 				    AUDIT_MAC_IPSEC_EVENT);
710 	if (audit_buf == NULL)
711 		return NULL;
712 	audit_log_format(audit_buf, "op=%s", op);
713 	return audit_buf;
714 }
715 
716 static inline void xfrm_audit_helper_usrinfo(kuid_t auid, unsigned int ses, u32 secid,
717 					     struct audit_buffer *audit_buf)
718 {
719 	char *secctx;
720 	u32 secctx_len;
721 
722 	audit_log_format(audit_buf, " auid=%u ses=%u",
723 			 from_kuid(&init_user_ns, auid), ses);
724 	if (secid != 0 &&
725 	    security_secid_to_secctx(secid, &secctx, &secctx_len) == 0) {
726 		audit_log_format(audit_buf, " subj=%s", secctx);
727 		security_release_secctx(secctx, secctx_len);
728 	} else
729 		audit_log_task_context(audit_buf);
730 }
731 
732 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, kuid_t auid,
733 			   unsigned int ses, u32 secid);
734 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result, kuid_t auid,
735 			      unsigned int ses, u32 secid);
736 void xfrm_audit_state_add(struct xfrm_state *x, int result, kuid_t auid,
737 			  unsigned int ses, u32 secid);
738 void xfrm_audit_state_delete(struct xfrm_state *x, int result, kuid_t auid,
739 			     unsigned int ses, u32 secid);
740 void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
741 				      struct sk_buff *skb);
742 void xfrm_audit_state_replay(struct xfrm_state *x, struct sk_buff *skb,
743 			     __be32 net_seq);
744 void xfrm_audit_state_notfound_simple(struct sk_buff *skb, u16 family);
745 void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family, __be32 net_spi,
746 			       __be32 net_seq);
747 void xfrm_audit_state_icvfail(struct xfrm_state *x, struct sk_buff *skb,
748 			      u8 proto);
749 #else
750 
751 static inline void xfrm_audit_policy_add(struct xfrm_policy *xp, int result,
752 				  kuid_t auid, unsigned int ses, u32 secid)
753 {
754 }
755 
756 static inline void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
757 				  kuid_t auid, unsigned int ses, u32 secid)
758 {
759 }
760 
761 static inline void xfrm_audit_state_add(struct xfrm_state *x, int result,
762 				 kuid_t auid, unsigned int ses, u32 secid)
763 {
764 }
765 
766 static inline void xfrm_audit_state_delete(struct xfrm_state *x, int result,
767 				    kuid_t auid, unsigned int ses, u32 secid)
768 {
769 }
770 
771 static inline void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
772 					     struct sk_buff *skb)
773 {
774 }
775 
776 static inline void xfrm_audit_state_replay(struct xfrm_state *x,
777 					   struct sk_buff *skb, __be32 net_seq)
778 {
779 }
780 
781 static inline void xfrm_audit_state_notfound_simple(struct sk_buff *skb,
782 				      u16 family)
783 {
784 }
785 
786 static inline void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family,
787 				      __be32 net_spi, __be32 net_seq)
788 {
789 }
790 
791 static inline void xfrm_audit_state_icvfail(struct xfrm_state *x,
792 				     struct sk_buff *skb, u8 proto)
793 {
794 }
795 #endif /* CONFIG_AUDITSYSCALL */
796 
797 static inline void xfrm_pol_hold(struct xfrm_policy *policy)
798 {
799 	if (likely(policy != NULL))
800 		atomic_inc(&policy->refcnt);
801 }
802 
803 void xfrm_policy_destroy(struct xfrm_policy *policy);
804 
805 static inline void xfrm_pol_put(struct xfrm_policy *policy)
806 {
807 	if (atomic_dec_and_test(&policy->refcnt))
808 		xfrm_policy_destroy(policy);
809 }
810 
811 static inline void xfrm_pols_put(struct xfrm_policy **pols, int npols)
812 {
813 	int i;
814 	for (i = npols - 1; i >= 0; --i)
815 		xfrm_pol_put(pols[i]);
816 }
817 
818 void __xfrm_state_destroy(struct xfrm_state *);
819 
820 static inline void __xfrm_state_put(struct xfrm_state *x)
821 {
822 	atomic_dec(&x->refcnt);
823 }
824 
825 static inline void xfrm_state_put(struct xfrm_state *x)
826 {
827 	if (atomic_dec_and_test(&x->refcnt))
828 		__xfrm_state_destroy(x);
829 }
830 
831 static inline void xfrm_state_hold(struct xfrm_state *x)
832 {
833 	atomic_inc(&x->refcnt);
834 }
835 
836 static inline bool addr_match(const void *token1, const void *token2,
837 			      int prefixlen)
838 {
839 	const __be32 *a1 = token1;
840 	const __be32 *a2 = token2;
841 	int pdw;
842 	int pbi;
843 
844 	pdw = prefixlen >> 5;	  /* num of whole u32 in prefix */
845 	pbi = prefixlen &  0x1f;  /* num of bits in incomplete u32 in prefix */
846 
847 	if (pdw)
848 		if (memcmp(a1, a2, pdw << 2))
849 			return false;
850 
851 	if (pbi) {
852 		__be32 mask;
853 
854 		mask = htonl((0xffffffff) << (32 - pbi));
855 
856 		if ((a1[pdw] ^ a2[pdw]) & mask)
857 			return false;
858 	}
859 
860 	return true;
861 }
862 
863 static inline bool addr4_match(__be32 a1, __be32 a2, u8 prefixlen)
864 {
865 	/* C99 6.5.7 (3): u32 << 32 is undefined behaviour */
866 	if (prefixlen == 0)
867 		return true;
868 	return !((a1 ^ a2) & htonl(0xFFFFFFFFu << (32 - prefixlen)));
869 }
870 
871 static __inline__
872 __be16 xfrm_flowi_sport(const struct flowi *fl, const union flowi_uli *uli)
873 {
874 	__be16 port;
875 	switch(fl->flowi_proto) {
876 	case IPPROTO_TCP:
877 	case IPPROTO_UDP:
878 	case IPPROTO_UDPLITE:
879 	case IPPROTO_SCTP:
880 		port = uli->ports.sport;
881 		break;
882 	case IPPROTO_ICMP:
883 	case IPPROTO_ICMPV6:
884 		port = htons(uli->icmpt.type);
885 		break;
886 	case IPPROTO_MH:
887 		port = htons(uli->mht.type);
888 		break;
889 	case IPPROTO_GRE:
890 		port = htons(ntohl(uli->gre_key) >> 16);
891 		break;
892 	default:
893 		port = 0;	/*XXX*/
894 	}
895 	return port;
896 }
897 
898 static __inline__
899 __be16 xfrm_flowi_dport(const struct flowi *fl, const union flowi_uli *uli)
900 {
901 	__be16 port;
902 	switch(fl->flowi_proto) {
903 	case IPPROTO_TCP:
904 	case IPPROTO_UDP:
905 	case IPPROTO_UDPLITE:
906 	case IPPROTO_SCTP:
907 		port = uli->ports.dport;
908 		break;
909 	case IPPROTO_ICMP:
910 	case IPPROTO_ICMPV6:
911 		port = htons(uli->icmpt.code);
912 		break;
913 	case IPPROTO_GRE:
914 		port = htons(ntohl(uli->gre_key) & 0xffff);
915 		break;
916 	default:
917 		port = 0;	/*XXX*/
918 	}
919 	return port;
920 }
921 
922 bool xfrm_selector_match(const struct xfrm_selector *sel,
923 			 const struct flowi *fl, unsigned short family);
924 
925 #ifdef CONFIG_SECURITY_NETWORK_XFRM
926 /*	If neither has a context --> match
927  * 	Otherwise, both must have a context and the sids, doi, alg must match
928  */
929 static inline bool xfrm_sec_ctx_match(struct xfrm_sec_ctx *s1, struct xfrm_sec_ctx *s2)
930 {
931 	return ((!s1 && !s2) ||
932 		(s1 && s2 &&
933 		 (s1->ctx_sid == s2->ctx_sid) &&
934 		 (s1->ctx_doi == s2->ctx_doi) &&
935 		 (s1->ctx_alg == s2->ctx_alg)));
936 }
937 #else
938 static inline bool xfrm_sec_ctx_match(struct xfrm_sec_ctx *s1, struct xfrm_sec_ctx *s2)
939 {
940 	return true;
941 }
942 #endif
943 
944 /* A struct encoding bundle of transformations to apply to some set of flow.
945  *
946  * dst->child points to the next element of bundle.
947  * dst->xfrm  points to an instanse of transformer.
948  *
949  * Due to unfortunate limitations of current routing cache, which we
950  * have no time to fix, it mirrors struct rtable and bound to the same
951  * routing key, including saddr,daddr. However, we can have many of
952  * bundles differing by session id. All the bundles grow from a parent
953  * policy rule.
954  */
955 struct xfrm_dst {
956 	union {
957 		struct dst_entry	dst;
958 		struct rtable		rt;
959 		struct rt6_info		rt6;
960 	} u;
961 	struct dst_entry *route;
962 	struct flow_cache_object flo;
963 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
964 	int num_pols, num_xfrms;
965 #ifdef CONFIG_XFRM_SUB_POLICY
966 	struct flowi *origin;
967 	struct xfrm_selector *partner;
968 #endif
969 	u32 xfrm_genid;
970 	u32 policy_genid;
971 	u32 route_mtu_cached;
972 	u32 child_mtu_cached;
973 	u32 route_cookie;
974 	u32 path_cookie;
975 };
976 
977 #ifdef CONFIG_XFRM
978 static inline void xfrm_dst_destroy(struct xfrm_dst *xdst)
979 {
980 	xfrm_pols_put(xdst->pols, xdst->num_pols);
981 	dst_release(xdst->route);
982 	if (likely(xdst->u.dst.xfrm))
983 		xfrm_state_put(xdst->u.dst.xfrm);
984 #ifdef CONFIG_XFRM_SUB_POLICY
985 	kfree(xdst->origin);
986 	xdst->origin = NULL;
987 	kfree(xdst->partner);
988 	xdst->partner = NULL;
989 #endif
990 }
991 #endif
992 
993 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev);
994 
995 struct sec_path {
996 	atomic_t		refcnt;
997 	int			len;
998 	struct xfrm_state	*xvec[XFRM_MAX_DEPTH];
999 };
1000 
1001 static inline int secpath_exists(struct sk_buff *skb)
1002 {
1003 #ifdef CONFIG_XFRM
1004 	return skb->sp != NULL;
1005 #else
1006 	return 0;
1007 #endif
1008 }
1009 
1010 static inline struct sec_path *
1011 secpath_get(struct sec_path *sp)
1012 {
1013 	if (sp)
1014 		atomic_inc(&sp->refcnt);
1015 	return sp;
1016 }
1017 
1018 void __secpath_destroy(struct sec_path *sp);
1019 
1020 static inline void
1021 secpath_put(struct sec_path *sp)
1022 {
1023 	if (sp && atomic_dec_and_test(&sp->refcnt))
1024 		__secpath_destroy(sp);
1025 }
1026 
1027 struct sec_path *secpath_dup(struct sec_path *src);
1028 
1029 static inline void
1030 secpath_reset(struct sk_buff *skb)
1031 {
1032 #ifdef CONFIG_XFRM
1033 	secpath_put(skb->sp);
1034 	skb->sp = NULL;
1035 #endif
1036 }
1037 
1038 static inline int
1039 xfrm_addr_any(const xfrm_address_t *addr, unsigned short family)
1040 {
1041 	switch (family) {
1042 	case AF_INET:
1043 		return addr->a4 == 0;
1044 	case AF_INET6:
1045 		return ipv6_addr_any((struct in6_addr *)&addr->a6);
1046 	}
1047 	return 0;
1048 }
1049 
1050 static inline int
1051 __xfrm4_state_addr_cmp(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x)
1052 {
1053 	return	(tmpl->saddr.a4 &&
1054 		 tmpl->saddr.a4 != x->props.saddr.a4);
1055 }
1056 
1057 static inline int
1058 __xfrm6_state_addr_cmp(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x)
1059 {
1060 	return	(!ipv6_addr_any((struct in6_addr*)&tmpl->saddr) &&
1061 		 !ipv6_addr_equal((struct in6_addr *)&tmpl->saddr, (struct in6_addr*)&x->props.saddr));
1062 }
1063 
1064 static inline int
1065 xfrm_state_addr_cmp(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x, unsigned short family)
1066 {
1067 	switch (family) {
1068 	case AF_INET:
1069 		return __xfrm4_state_addr_cmp(tmpl, x);
1070 	case AF_INET6:
1071 		return __xfrm6_state_addr_cmp(tmpl, x);
1072 	}
1073 	return !0;
1074 }
1075 
1076 #ifdef CONFIG_XFRM
1077 int __xfrm_policy_check(struct sock *, int dir, struct sk_buff *skb,
1078 			unsigned short family);
1079 
1080 static inline int __xfrm_policy_check2(struct sock *sk, int dir,
1081 				       struct sk_buff *skb,
1082 				       unsigned int family, int reverse)
1083 {
1084 	struct net *net = dev_net(skb->dev);
1085 	int ndir = dir | (reverse ? XFRM_POLICY_MASK + 1 : 0);
1086 
1087 	if (sk && sk->sk_policy[XFRM_POLICY_IN])
1088 		return __xfrm_policy_check(sk, ndir, skb, family);
1089 
1090 	return	(!net->xfrm.policy_count[dir] && !skb->sp) ||
1091 		(skb_dst(skb)->flags & DST_NOPOLICY) ||
1092 		__xfrm_policy_check(sk, ndir, skb, family);
1093 }
1094 
1095 static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family)
1096 {
1097 	return __xfrm_policy_check2(sk, dir, skb, family, 0);
1098 }
1099 
1100 static inline int xfrm4_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
1101 {
1102 	return xfrm_policy_check(sk, dir, skb, AF_INET);
1103 }
1104 
1105 static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
1106 {
1107 	return xfrm_policy_check(sk, dir, skb, AF_INET6);
1108 }
1109 
1110 static inline int xfrm4_policy_check_reverse(struct sock *sk, int dir,
1111 					     struct sk_buff *skb)
1112 {
1113 	return __xfrm_policy_check2(sk, dir, skb, AF_INET, 1);
1114 }
1115 
1116 static inline int xfrm6_policy_check_reverse(struct sock *sk, int dir,
1117 					     struct sk_buff *skb)
1118 {
1119 	return __xfrm_policy_check2(sk, dir, skb, AF_INET6, 1);
1120 }
1121 
1122 int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
1123 			  unsigned int family, int reverse);
1124 
1125 static inline int xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
1126 				      unsigned int family)
1127 {
1128 	return __xfrm_decode_session(skb, fl, family, 0);
1129 }
1130 
1131 static inline int xfrm_decode_session_reverse(struct sk_buff *skb,
1132 					      struct flowi *fl,
1133 					      unsigned int family)
1134 {
1135 	return __xfrm_decode_session(skb, fl, family, 1);
1136 }
1137 
1138 int __xfrm_route_forward(struct sk_buff *skb, unsigned short family);
1139 
1140 static inline int xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1141 {
1142 	struct net *net = dev_net(skb->dev);
1143 
1144 	return	!net->xfrm.policy_count[XFRM_POLICY_OUT] ||
1145 		(skb_dst(skb)->flags & DST_NOXFRM) ||
1146 		__xfrm_route_forward(skb, family);
1147 }
1148 
1149 static inline int xfrm4_route_forward(struct sk_buff *skb)
1150 {
1151 	return xfrm_route_forward(skb, AF_INET);
1152 }
1153 
1154 static inline int xfrm6_route_forward(struct sk_buff *skb)
1155 {
1156 	return xfrm_route_forward(skb, AF_INET6);
1157 }
1158 
1159 int __xfrm_sk_clone_policy(struct sock *sk);
1160 
1161 static inline int xfrm_sk_clone_policy(struct sock *sk)
1162 {
1163 	if (unlikely(sk->sk_policy[0] || sk->sk_policy[1]))
1164 		return __xfrm_sk_clone_policy(sk);
1165 	return 0;
1166 }
1167 
1168 int xfrm_policy_delete(struct xfrm_policy *pol, int dir);
1169 
1170 static inline void xfrm_sk_free_policy(struct sock *sk)
1171 {
1172 	if (unlikely(sk->sk_policy[0] != NULL)) {
1173 		xfrm_policy_delete(sk->sk_policy[0], XFRM_POLICY_MAX);
1174 		sk->sk_policy[0] = NULL;
1175 	}
1176 	if (unlikely(sk->sk_policy[1] != NULL)) {
1177 		xfrm_policy_delete(sk->sk_policy[1], XFRM_POLICY_MAX+1);
1178 		sk->sk_policy[1] = NULL;
1179 	}
1180 }
1181 
1182 void xfrm_garbage_collect(struct net *net);
1183 
1184 #else
1185 
1186 static inline void xfrm_sk_free_policy(struct sock *sk) {}
1187 static inline int xfrm_sk_clone_policy(struct sock *sk) { return 0; }
1188 static inline int xfrm6_route_forward(struct sk_buff *skb) { return 1; }
1189 static inline int xfrm4_route_forward(struct sk_buff *skb) { return 1; }
1190 static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
1191 {
1192 	return 1;
1193 }
1194 static inline int xfrm4_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
1195 {
1196 	return 1;
1197 }
1198 static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family)
1199 {
1200 	return 1;
1201 }
1202 static inline int xfrm_decode_session_reverse(struct sk_buff *skb,
1203 					      struct flowi *fl,
1204 					      unsigned int family)
1205 {
1206 	return -ENOSYS;
1207 }
1208 static inline int xfrm4_policy_check_reverse(struct sock *sk, int dir,
1209 					     struct sk_buff *skb)
1210 {
1211 	return 1;
1212 }
1213 static inline int xfrm6_policy_check_reverse(struct sock *sk, int dir,
1214 					     struct sk_buff *skb)
1215 {
1216 	return 1;
1217 }
1218 static inline void xfrm_garbage_collect(struct net *net)
1219 {
1220 }
1221 #endif
1222 
1223 static __inline__
1224 xfrm_address_t *xfrm_flowi_daddr(const struct flowi *fl, unsigned short family)
1225 {
1226 	switch (family){
1227 	case AF_INET:
1228 		return (xfrm_address_t *)&fl->u.ip4.daddr;
1229 	case AF_INET6:
1230 		return (xfrm_address_t *)&fl->u.ip6.daddr;
1231 	}
1232 	return NULL;
1233 }
1234 
1235 static __inline__
1236 xfrm_address_t *xfrm_flowi_saddr(const struct flowi *fl, unsigned short family)
1237 {
1238 	switch (family){
1239 	case AF_INET:
1240 		return (xfrm_address_t *)&fl->u.ip4.saddr;
1241 	case AF_INET6:
1242 		return (xfrm_address_t *)&fl->u.ip6.saddr;
1243 	}
1244 	return NULL;
1245 }
1246 
1247 static __inline__
1248 void xfrm_flowi_addr_get(const struct flowi *fl,
1249 			 xfrm_address_t *saddr, xfrm_address_t *daddr,
1250 			 unsigned short family)
1251 {
1252 	switch(family) {
1253 	case AF_INET:
1254 		memcpy(&saddr->a4, &fl->u.ip4.saddr, sizeof(saddr->a4));
1255 		memcpy(&daddr->a4, &fl->u.ip4.daddr, sizeof(daddr->a4));
1256 		break;
1257 	case AF_INET6:
1258 		*(struct in6_addr *)saddr->a6 = fl->u.ip6.saddr;
1259 		*(struct in6_addr *)daddr->a6 = fl->u.ip6.daddr;
1260 		break;
1261 	}
1262 }
1263 
1264 static __inline__ int
1265 __xfrm4_state_addr_check(const struct xfrm_state *x,
1266 			 const xfrm_address_t *daddr, const xfrm_address_t *saddr)
1267 {
1268 	if (daddr->a4 == x->id.daddr.a4 &&
1269 	    (saddr->a4 == x->props.saddr.a4 || !saddr->a4 || !x->props.saddr.a4))
1270 		return 1;
1271 	return 0;
1272 }
1273 
1274 static __inline__ int
1275 __xfrm6_state_addr_check(const struct xfrm_state *x,
1276 			 const xfrm_address_t *daddr, const xfrm_address_t *saddr)
1277 {
1278 	if (ipv6_addr_equal((struct in6_addr *)daddr, (struct in6_addr *)&x->id.daddr) &&
1279 	    (ipv6_addr_equal((struct in6_addr *)saddr, (struct in6_addr *)&x->props.saddr) ||
1280 	     ipv6_addr_any((struct in6_addr *)saddr) ||
1281 	     ipv6_addr_any((struct in6_addr *)&x->props.saddr)))
1282 		return 1;
1283 	return 0;
1284 }
1285 
1286 static __inline__ int
1287 xfrm_state_addr_check(const struct xfrm_state *x,
1288 		      const xfrm_address_t *daddr, const xfrm_address_t *saddr,
1289 		      unsigned short family)
1290 {
1291 	switch (family) {
1292 	case AF_INET:
1293 		return __xfrm4_state_addr_check(x, daddr, saddr);
1294 	case AF_INET6:
1295 		return __xfrm6_state_addr_check(x, daddr, saddr);
1296 	}
1297 	return 0;
1298 }
1299 
1300 static __inline__ int
1301 xfrm_state_addr_flow_check(const struct xfrm_state *x, const struct flowi *fl,
1302 			   unsigned short family)
1303 {
1304 	switch (family) {
1305 	case AF_INET:
1306 		return __xfrm4_state_addr_check(x,
1307 						(const xfrm_address_t *)&fl->u.ip4.daddr,
1308 						(const xfrm_address_t *)&fl->u.ip4.saddr);
1309 	case AF_INET6:
1310 		return __xfrm6_state_addr_check(x,
1311 						(const xfrm_address_t *)&fl->u.ip6.daddr,
1312 						(const xfrm_address_t *)&fl->u.ip6.saddr);
1313 	}
1314 	return 0;
1315 }
1316 
1317 static inline int xfrm_state_kern(const struct xfrm_state *x)
1318 {
1319 	return atomic_read(&x->tunnel_users);
1320 }
1321 
1322 static inline int xfrm_id_proto_match(u8 proto, u8 userproto)
1323 {
1324 	return (!userproto || proto == userproto ||
1325 		(userproto == IPSEC_PROTO_ANY && (proto == IPPROTO_AH ||
1326 						  proto == IPPROTO_ESP ||
1327 						  proto == IPPROTO_COMP)));
1328 }
1329 
1330 /*
1331  * xfrm algorithm information
1332  */
1333 struct xfrm_algo_aead_info {
1334 	u16 icv_truncbits;
1335 };
1336 
1337 struct xfrm_algo_auth_info {
1338 	u16 icv_truncbits;
1339 	u16 icv_fullbits;
1340 };
1341 
1342 struct xfrm_algo_encr_info {
1343 	u16 blockbits;
1344 	u16 defkeybits;
1345 };
1346 
1347 struct xfrm_algo_comp_info {
1348 	u16 threshold;
1349 };
1350 
1351 struct xfrm_algo_desc {
1352 	char *name;
1353 	char *compat;
1354 	u8 available:1;
1355 	u8 pfkey_supported:1;
1356 	union {
1357 		struct xfrm_algo_aead_info aead;
1358 		struct xfrm_algo_auth_info auth;
1359 		struct xfrm_algo_encr_info encr;
1360 		struct xfrm_algo_comp_info comp;
1361 	} uinfo;
1362 	struct sadb_alg desc;
1363 };
1364 
1365 /* XFRM protocol handlers.  */
1366 struct xfrm4_protocol {
1367 	int (*handler)(struct sk_buff *skb);
1368 	int (*input_handler)(struct sk_buff *skb, int nexthdr, __be32 spi,
1369 			     int encap_type);
1370 	int (*cb_handler)(struct sk_buff *skb, int err);
1371 	int (*err_handler)(struct sk_buff *skb, u32 info);
1372 
1373 	struct xfrm4_protocol __rcu *next;
1374 	int priority;
1375 };
1376 
1377 struct xfrm6_protocol {
1378 	int (*handler)(struct sk_buff *skb);
1379 	int (*cb_handler)(struct sk_buff *skb, int err);
1380 	int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
1381 			   u8 type, u8 code, int offset, __be32 info);
1382 
1383 	struct xfrm6_protocol __rcu *next;
1384 	int priority;
1385 };
1386 
1387 /* XFRM tunnel handlers.  */
1388 struct xfrm_tunnel {
1389 	int (*handler)(struct sk_buff *skb);
1390 	int (*err_handler)(struct sk_buff *skb, u32 info);
1391 
1392 	struct xfrm_tunnel __rcu *next;
1393 	int priority;
1394 };
1395 
1396 struct xfrm6_tunnel {
1397 	int (*handler)(struct sk_buff *skb);
1398 	int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
1399 			   u8 type, u8 code, int offset, __be32 info);
1400 	struct xfrm6_tunnel __rcu *next;
1401 	int priority;
1402 };
1403 
1404 void xfrm_init(void);
1405 void xfrm4_init(void);
1406 int xfrm_state_init(struct net *net);
1407 void xfrm_state_fini(struct net *net);
1408 void xfrm4_state_init(void);
1409 void xfrm4_protocol_init(void);
1410 #ifdef CONFIG_XFRM
1411 int xfrm6_init(void);
1412 void xfrm6_fini(void);
1413 int xfrm6_state_init(void);
1414 void xfrm6_state_fini(void);
1415 int xfrm6_protocol_init(void);
1416 void xfrm6_protocol_fini(void);
1417 #else
1418 static inline int xfrm6_init(void)
1419 {
1420 	return 0;
1421 }
1422 static inline void xfrm6_fini(void)
1423 {
1424 	;
1425 }
1426 #endif
1427 
1428 #ifdef CONFIG_XFRM_STATISTICS
1429 int xfrm_proc_init(struct net *net);
1430 void xfrm_proc_fini(struct net *net);
1431 #endif
1432 
1433 int xfrm_sysctl_init(struct net *net);
1434 #ifdef CONFIG_SYSCTL
1435 void xfrm_sysctl_fini(struct net *net);
1436 #else
1437 static inline void xfrm_sysctl_fini(struct net *net)
1438 {
1439 }
1440 #endif
1441 
1442 void xfrm_state_walk_init(struct xfrm_state_walk *walk, u8 proto,
1443 			  struct xfrm_address_filter *filter);
1444 int xfrm_state_walk(struct net *net, struct xfrm_state_walk *walk,
1445 		    int (*func)(struct xfrm_state *, int, void*), void *);
1446 void xfrm_state_walk_done(struct xfrm_state_walk *walk, struct net *net);
1447 struct xfrm_state *xfrm_state_alloc(struct net *net);
1448 struct xfrm_state *xfrm_state_find(const xfrm_address_t *daddr,
1449 				   const xfrm_address_t *saddr,
1450 				   const struct flowi *fl,
1451 				   struct xfrm_tmpl *tmpl,
1452 				   struct xfrm_policy *pol, int *err,
1453 				   unsigned short family);
1454 struct xfrm_state *xfrm_stateonly_find(struct net *net, u32 mark,
1455 				       xfrm_address_t *daddr,
1456 				       xfrm_address_t *saddr,
1457 				       unsigned short family,
1458 				       u8 mode, u8 proto, u32 reqid);
1459 struct xfrm_state *xfrm_state_lookup_byspi(struct net *net, __be32 spi,
1460 					      unsigned short family);
1461 int xfrm_state_check_expire(struct xfrm_state *x);
1462 void xfrm_state_insert(struct xfrm_state *x);
1463 int xfrm_state_add(struct xfrm_state *x);
1464 int xfrm_state_update(struct xfrm_state *x);
1465 struct xfrm_state *xfrm_state_lookup(struct net *net, u32 mark,
1466 				     const xfrm_address_t *daddr, __be32 spi,
1467 				     u8 proto, unsigned short family);
1468 struct xfrm_state *xfrm_state_lookup_byaddr(struct net *net, u32 mark,
1469 					    const xfrm_address_t *daddr,
1470 					    const xfrm_address_t *saddr,
1471 					    u8 proto,
1472 					    unsigned short family);
1473 #ifdef CONFIG_XFRM_SUB_POLICY
1474 int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n,
1475 		   unsigned short family, struct net *net);
1476 int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n,
1477 		    unsigned short family);
1478 #else
1479 static inline int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src,
1480 				 int n, unsigned short family, struct net *net)
1481 {
1482 	return -ENOSYS;
1483 }
1484 
1485 static inline int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src,
1486 				  int n, unsigned short family)
1487 {
1488 	return -ENOSYS;
1489 }
1490 #endif
1491 
1492 struct xfrmk_sadinfo {
1493 	u32 sadhcnt; /* current hash bkts */
1494 	u32 sadhmcnt; /* max allowed hash bkts */
1495 	u32 sadcnt; /* current running count */
1496 };
1497 
1498 struct xfrmk_spdinfo {
1499 	u32 incnt;
1500 	u32 outcnt;
1501 	u32 fwdcnt;
1502 	u32 inscnt;
1503 	u32 outscnt;
1504 	u32 fwdscnt;
1505 	u32 spdhcnt;
1506 	u32 spdhmcnt;
1507 };
1508 
1509 struct xfrm_state *xfrm_find_acq_byseq(struct net *net, u32 mark, u32 seq);
1510 int xfrm_state_delete(struct xfrm_state *x);
1511 int xfrm_state_flush(struct net *net, u8 proto, struct xfrm_audit *audit_info);
1512 void xfrm_sad_getinfo(struct net *net, struct xfrmk_sadinfo *si);
1513 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si);
1514 u32 xfrm_replay_seqhi(struct xfrm_state *x, __be32 net_seq);
1515 int xfrm_init_replay(struct xfrm_state *x);
1516 int xfrm_state_mtu(struct xfrm_state *x, int mtu);
1517 int __xfrm_init_state(struct xfrm_state *x, bool init_replay);
1518 int xfrm_init_state(struct xfrm_state *x);
1519 int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb);
1520 int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type);
1521 int xfrm_input_resume(struct sk_buff *skb, int nexthdr);
1522 int xfrm_output_resume(struct sk_buff *skb, int err);
1523 int xfrm_output(struct sk_buff *skb);
1524 int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb);
1525 void xfrm_local_error(struct sk_buff *skb, int mtu);
1526 int xfrm4_extract_header(struct sk_buff *skb);
1527 int xfrm4_extract_input(struct xfrm_state *x, struct sk_buff *skb);
1528 int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
1529 		    int encap_type);
1530 int xfrm4_transport_finish(struct sk_buff *skb, int async);
1531 int xfrm4_rcv(struct sk_buff *skb);
1532 
1533 static inline int xfrm4_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
1534 {
1535 	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
1536 	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
1537 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
1538 	return xfrm_input(skb, nexthdr, spi, 0);
1539 }
1540 
1541 int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb);
1542 int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb);
1543 int xfrm4_output(struct sock *sk, struct sk_buff *skb);
1544 int xfrm4_output_finish(struct sk_buff *skb);
1545 int xfrm4_rcv_cb(struct sk_buff *skb, u8 protocol, int err);
1546 int xfrm4_protocol_register(struct xfrm4_protocol *handler, unsigned char protocol);
1547 int xfrm4_protocol_deregister(struct xfrm4_protocol *handler, unsigned char protocol);
1548 int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family);
1549 int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family);
1550 void xfrm4_local_error(struct sk_buff *skb, u32 mtu);
1551 int xfrm6_extract_header(struct sk_buff *skb);
1552 int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb);
1553 int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi);
1554 int xfrm6_transport_finish(struct sk_buff *skb, int async);
1555 int xfrm6_rcv(struct sk_buff *skb);
1556 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
1557 		     xfrm_address_t *saddr, u8 proto);
1558 void xfrm6_local_error(struct sk_buff *skb, u32 mtu);
1559 int xfrm6_rcv_cb(struct sk_buff *skb, u8 protocol, int err);
1560 int xfrm6_protocol_register(struct xfrm6_protocol *handler, unsigned char protocol);
1561 int xfrm6_protocol_deregister(struct xfrm6_protocol *handler, unsigned char protocol);
1562 int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family);
1563 int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family);
1564 __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr);
1565 __be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr);
1566 int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb);
1567 int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb);
1568 int xfrm6_output(struct sock *sk, struct sk_buff *skb);
1569 int xfrm6_output_finish(struct sk_buff *skb);
1570 int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
1571 			  u8 **prevhdr);
1572 
1573 #ifdef CONFIG_XFRM
1574 int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb);
1575 int xfrm_user_policy(struct sock *sk, int optname,
1576 		     u8 __user *optval, int optlen);
1577 #else
1578 static inline int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen)
1579 {
1580  	return -ENOPROTOOPT;
1581 }
1582 
1583 static inline int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
1584 {
1585  	/* should not happen */
1586  	kfree_skb(skb);
1587 	return 0;
1588 }
1589 #endif
1590 
1591 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp);
1592 
1593 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type);
1594 int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
1595 		     int (*func)(struct xfrm_policy *, int, int, void*),
1596 		     void *);
1597 void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net);
1598 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl);
1599 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark,
1600 					  u8 type, int dir,
1601 					  struct xfrm_selector *sel,
1602 					  struct xfrm_sec_ctx *ctx, int delete,
1603 					  int *err);
1604 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8, int dir,
1605 				     u32 id, int delete, int *err);
1606 int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info);
1607 u32 xfrm_get_acqseq(void);
1608 int verify_spi_info(u8 proto, u32 min, u32 max);
1609 int xfrm_alloc_spi(struct xfrm_state *x, u32 minspi, u32 maxspi);
1610 struct xfrm_state *xfrm_find_acq(struct net *net, const struct xfrm_mark *mark,
1611 				 u8 mode, u32 reqid, u8 proto,
1612 				 const xfrm_address_t *daddr,
1613 				 const xfrm_address_t *saddr, int create,
1614 				 unsigned short family);
1615 int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol);
1616 
1617 #ifdef CONFIG_XFRM_MIGRATE
1618 int km_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
1619 	       const struct xfrm_migrate *m, int num_bundles,
1620 	       const struct xfrm_kmaddress *k);
1621 struct xfrm_state *xfrm_migrate_state_find(struct xfrm_migrate *m, struct net *net);
1622 struct xfrm_state *xfrm_state_migrate(struct xfrm_state *x,
1623 				      struct xfrm_migrate *m);
1624 int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
1625 		 struct xfrm_migrate *m, int num_bundles,
1626 		 struct xfrm_kmaddress *k, struct net *net);
1627 #endif
1628 
1629 int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport);
1630 void km_policy_expired(struct xfrm_policy *pol, int dir, int hard, u32 portid);
1631 int km_report(struct net *net, u8 proto, struct xfrm_selector *sel,
1632 	      xfrm_address_t *addr);
1633 
1634 void xfrm_input_init(void);
1635 int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq);
1636 
1637 void xfrm_probe_algs(void);
1638 int xfrm_count_pfkey_auth_supported(void);
1639 int xfrm_count_pfkey_enc_supported(void);
1640 struct xfrm_algo_desc *xfrm_aalg_get_byidx(unsigned int idx);
1641 struct xfrm_algo_desc *xfrm_ealg_get_byidx(unsigned int idx);
1642 struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id);
1643 struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id);
1644 struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id);
1645 struct xfrm_algo_desc *xfrm_aalg_get_byname(const char *name, int probe);
1646 struct xfrm_algo_desc *xfrm_ealg_get_byname(const char *name, int probe);
1647 struct xfrm_algo_desc *xfrm_calg_get_byname(const char *name, int probe);
1648 struct xfrm_algo_desc *xfrm_aead_get_byname(const char *name, int icv_len,
1649 					    int probe);
1650 
1651 static inline bool xfrm6_addr_equal(const xfrm_address_t *a,
1652 				    const xfrm_address_t *b)
1653 {
1654 	return ipv6_addr_equal((const struct in6_addr *)a,
1655 			       (const struct in6_addr *)b);
1656 }
1657 
1658 static inline bool xfrm_addr_equal(const xfrm_address_t *a,
1659 				   const xfrm_address_t *b,
1660 				   sa_family_t family)
1661 {
1662 	switch (family) {
1663 	default:
1664 	case AF_INET:
1665 		return ((__force u32)a->a4 ^ (__force u32)b->a4) == 0;
1666 	case AF_INET6:
1667 		return xfrm6_addr_equal(a, b);
1668 	}
1669 }
1670 
1671 static inline int xfrm_policy_id2dir(u32 index)
1672 {
1673 	return index & 7;
1674 }
1675 
1676 #ifdef CONFIG_XFRM
1677 static inline int xfrm_aevent_is_on(struct net *net)
1678 {
1679 	struct sock *nlsk;
1680 	int ret = 0;
1681 
1682 	rcu_read_lock();
1683 	nlsk = rcu_dereference(net->xfrm.nlsk);
1684 	if (nlsk)
1685 		ret = netlink_has_listeners(nlsk, XFRMNLGRP_AEVENTS);
1686 	rcu_read_unlock();
1687 	return ret;
1688 }
1689 
1690 static inline int xfrm_acquire_is_on(struct net *net)
1691 {
1692 	struct sock *nlsk;
1693 	int ret = 0;
1694 
1695 	rcu_read_lock();
1696 	nlsk = rcu_dereference(net->xfrm.nlsk);
1697 	if (nlsk)
1698 		ret = netlink_has_listeners(nlsk, XFRMNLGRP_ACQUIRE);
1699 	rcu_read_unlock();
1700 
1701 	return ret;
1702 }
1703 #endif
1704 
1705 static inline int aead_len(struct xfrm_algo_aead *alg)
1706 {
1707 	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
1708 }
1709 
1710 static inline int xfrm_alg_len(const struct xfrm_algo *alg)
1711 {
1712 	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
1713 }
1714 
1715 static inline int xfrm_alg_auth_len(const struct xfrm_algo_auth *alg)
1716 {
1717 	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
1718 }
1719 
1720 static inline int xfrm_replay_state_esn_len(struct xfrm_replay_state_esn *replay_esn)
1721 {
1722 	return sizeof(*replay_esn) + replay_esn->bmp_len * sizeof(__u32);
1723 }
1724 
1725 #ifdef CONFIG_XFRM_MIGRATE
1726 static inline int xfrm_replay_clone(struct xfrm_state *x,
1727 				     struct xfrm_state *orig)
1728 {
1729 	x->replay_esn = kzalloc(xfrm_replay_state_esn_len(orig->replay_esn),
1730 				GFP_KERNEL);
1731 	if (!x->replay_esn)
1732 		return -ENOMEM;
1733 
1734 	x->replay_esn->bmp_len = orig->replay_esn->bmp_len;
1735 	x->replay_esn->replay_window = orig->replay_esn->replay_window;
1736 
1737 	x->preplay_esn = kmemdup(x->replay_esn,
1738 				 xfrm_replay_state_esn_len(x->replay_esn),
1739 				 GFP_KERNEL);
1740 	if (!x->preplay_esn) {
1741 		kfree(x->replay_esn);
1742 		return -ENOMEM;
1743 	}
1744 
1745 	return 0;
1746 }
1747 
1748 static inline struct xfrm_algo_aead *xfrm_algo_aead_clone(struct xfrm_algo_aead *orig)
1749 {
1750 	return kmemdup(orig, aead_len(orig), GFP_KERNEL);
1751 }
1752 
1753 
1754 static inline struct xfrm_algo *xfrm_algo_clone(struct xfrm_algo *orig)
1755 {
1756 	return kmemdup(orig, xfrm_alg_len(orig), GFP_KERNEL);
1757 }
1758 
1759 static inline struct xfrm_algo_auth *xfrm_algo_auth_clone(struct xfrm_algo_auth *orig)
1760 {
1761 	return kmemdup(orig, xfrm_alg_auth_len(orig), GFP_KERNEL);
1762 }
1763 
1764 static inline void xfrm_states_put(struct xfrm_state **states, int n)
1765 {
1766 	int i;
1767 	for (i = 0; i < n; i++)
1768 		xfrm_state_put(*(states + i));
1769 }
1770 
1771 static inline void xfrm_states_delete(struct xfrm_state **states, int n)
1772 {
1773 	int i;
1774 	for (i = 0; i < n; i++)
1775 		xfrm_state_delete(*(states + i));
1776 }
1777 #endif
1778 
1779 #ifdef CONFIG_XFRM
1780 static inline struct xfrm_state *xfrm_input_state(struct sk_buff *skb)
1781 {
1782 	return skb->sp->xvec[skb->sp->len - 1];
1783 }
1784 #endif
1785 
1786 static inline int xfrm_mark_get(struct nlattr **attrs, struct xfrm_mark *m)
1787 {
1788 	if (attrs[XFRMA_MARK])
1789 		memcpy(m, nla_data(attrs[XFRMA_MARK]), sizeof(struct xfrm_mark));
1790 	else
1791 		m->v = m->m = 0;
1792 
1793 	return m->v & m->m;
1794 }
1795 
1796 static inline int xfrm_mark_put(struct sk_buff *skb, const struct xfrm_mark *m)
1797 {
1798 	int ret = 0;
1799 
1800 	if (m->m | m->v)
1801 		ret = nla_put(skb, XFRMA_MARK, sizeof(struct xfrm_mark), m);
1802 	return ret;
1803 }
1804 
1805 static inline int xfrm_tunnel_check(struct sk_buff *skb, struct xfrm_state *x,
1806 				    unsigned int family)
1807 {
1808 	bool tunnel = false;
1809 
1810 	switch(family) {
1811 	case AF_INET:
1812 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4)
1813 			tunnel = true;
1814 		break;
1815 	case AF_INET6:
1816 		if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6)
1817 			tunnel = true;
1818 		break;
1819 	}
1820 	if (tunnel && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL))
1821 		return -EINVAL;
1822 
1823 	return 0;
1824 }
1825 #endif	/* _NET_XFRM_H */
1826