xref: /linux/include/net/xfrm.h (revision 4413e16d9d21673bb5048a2e542f1aaa00015c2e)
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 extern struct mutex xfrm_cfg_mutex;
57 
58 /* Organization of SPD aka "XFRM rules"
59    ------------------------------------
60 
61    Basic objects:
62    - policy rule, struct xfrm_policy (=SPD entry)
63    - bundle of transformations, struct dst_entry == struct xfrm_dst (=SA bundle)
64    - instance of a transformer, struct xfrm_state (=SA)
65    - template to clone xfrm_state, struct xfrm_tmpl
66 
67    SPD is plain linear list of xfrm_policy rules, ordered by priority.
68    (To be compatible with existing pfkeyv2 implementations,
69    many rules with priority of 0x7fffffff are allowed to exist and
70    such rules are ordered in an unpredictable way, thanks to bsd folks.)
71 
72    Lookup is plain linear search until the first match with selector.
73 
74    If "action" is "block", then we prohibit the flow, otherwise:
75    if "xfrms_nr" is zero, the flow passes untransformed. Otherwise,
76    policy entry has list of up to XFRM_MAX_DEPTH transformations,
77    described by templates xfrm_tmpl. Each template is resolved
78    to a complete xfrm_state (see below) and we pack bundle of transformations
79    to a dst_entry returned to requestor.
80 
81    dst -. xfrm  .-> xfrm_state #1
82     |---. child .-> dst -. xfrm .-> xfrm_state #2
83                      |---. child .-> dst -. xfrm .-> xfrm_state #3
84                                       |---. child .-> NULL
85 
86    Bundles are cached at xrfm_policy struct (field ->bundles).
87 
88 
89    Resolution of xrfm_tmpl
90    -----------------------
91    Template contains:
92    1. ->mode		Mode: transport or tunnel
93    2. ->id.proto	Protocol: AH/ESP/IPCOMP
94    3. ->id.daddr	Remote tunnel endpoint, ignored for transport mode.
95       Q: allow to resolve security gateway?
96    4. ->id.spi          If not zero, static SPI.
97    5. ->saddr		Local tunnel endpoint, ignored for transport mode.
98    6. ->algos		List of allowed algos. Plain bitmask now.
99       Q: ealgos, aalgos, calgos. What a mess...
100    7. ->share		Sharing mode.
101       Q: how to implement private sharing mode? To add struct sock* to
102       flow id?
103 
104    Having this template we search through SAD searching for entries
105    with appropriate mode/proto/algo, permitted by selector.
106    If no appropriate entry found, it is requested from key manager.
107 
108    PROBLEMS:
109    Q: How to find all the bundles referring to a physical path for
110       PMTU discovery? Seems, dst should contain list of all parents...
111       and enter to infinite locking hierarchy disaster.
112       No! It is easier, we will not search for them, let them find us.
113       We add genid to each dst plus pointer to genid of raw IP route,
114       pmtu disc will update pmtu on raw IP route and increase its genid.
115       dst_check() will see this for top level and trigger resyncing
116       metrics. Plus, it will be made via sk->sk_dst_cache. Solved.
117  */
118 
119 struct xfrm_state_walk {
120 	struct list_head	all;
121 	u8			state;
122 	union {
123 		u8		dying;
124 		u8		proto;
125 	};
126 	u32			seq;
127 };
128 
129 /* Full description of state of transformer. */
130 struct xfrm_state {
131 #ifdef CONFIG_NET_NS
132 	struct net		*xs_net;
133 #endif
134 	union {
135 		struct hlist_node	gclist;
136 		struct hlist_node	bydst;
137 	};
138 	struct hlist_node	bysrc;
139 	struct hlist_node	byspi;
140 
141 	atomic_t		refcnt;
142 	spinlock_t		lock;
143 
144 	struct xfrm_id		id;
145 	struct xfrm_selector	sel;
146 	struct xfrm_mark	mark;
147 	u32			tfcpad;
148 
149 	u32			genid;
150 
151 	/* Key manager bits */
152 	struct xfrm_state_walk	km;
153 
154 	/* Parameters of this state. */
155 	struct {
156 		u32		reqid;
157 		u8		mode;
158 		u8		replay_window;
159 		u8		aalgo, ealgo, calgo;
160 		u8		flags;
161 		u16		family;
162 		xfrm_address_t	saddr;
163 		int		header_len;
164 		int		trailer_len;
165 	} props;
166 
167 	struct xfrm_lifetime_cfg lft;
168 
169 	/* Data for transformer */
170 	struct xfrm_algo_auth	*aalg;
171 	struct xfrm_algo	*ealg;
172 	struct xfrm_algo	*calg;
173 	struct xfrm_algo_aead	*aead;
174 
175 	/* Data for encapsulator */
176 	struct xfrm_encap_tmpl	*encap;
177 
178 	/* Data for care-of address */
179 	xfrm_address_t	*coaddr;
180 
181 	/* IPComp needs an IPIP tunnel for handling uncompressed packets */
182 	struct xfrm_state	*tunnel;
183 
184 	/* If a tunnel, number of users + 1 */
185 	atomic_t		tunnel_users;
186 
187 	/* State for replay detection */
188 	struct xfrm_replay_state replay;
189 	struct xfrm_replay_state_esn *replay_esn;
190 
191 	/* Replay detection state at the time we sent the last notification */
192 	struct xfrm_replay_state preplay;
193 	struct xfrm_replay_state_esn *preplay_esn;
194 
195 	/* The functions for replay detection. */
196 	struct xfrm_replay	*repl;
197 
198 	/* internal flag that only holds state for delayed aevent at the
199 	 * moment
200 	*/
201 	u32			xflags;
202 
203 	/* Replay detection notification settings */
204 	u32			replay_maxage;
205 	u32			replay_maxdiff;
206 
207 	/* Replay detection notification timer */
208 	struct timer_list	rtimer;
209 
210 	/* Statistics */
211 	struct xfrm_stats	stats;
212 
213 	struct xfrm_lifetime_cur curlft;
214 	struct tasklet_hrtimer	mtimer;
215 
216 	/* used to fix curlft->add_time when changing date */
217 	long		saved_tmo;
218 
219 	/* Last used time */
220 	unsigned long		lastused;
221 
222 	/* Reference to data common to all the instances of this
223 	 * transformer. */
224 	const struct xfrm_type	*type;
225 	struct xfrm_mode	*inner_mode;
226 	struct xfrm_mode	*inner_mode_iaf;
227 	struct xfrm_mode	*outer_mode;
228 
229 	/* Security context */
230 	struct xfrm_sec_ctx	*security;
231 
232 	/* Private data of this transformer, format is opaque,
233 	 * interpreted by xfrm_type methods. */
234 	void			*data;
235 };
236 
237 static inline struct net *xs_net(struct xfrm_state *x)
238 {
239 	return read_pnet(&x->xs_net);
240 }
241 
242 /* xflags - make enum if more show up */
243 #define XFRM_TIME_DEFER	1
244 #define XFRM_SOFT_EXPIRE 2
245 
246 enum {
247 	XFRM_STATE_VOID,
248 	XFRM_STATE_ACQ,
249 	XFRM_STATE_VALID,
250 	XFRM_STATE_ERROR,
251 	XFRM_STATE_EXPIRED,
252 	XFRM_STATE_DEAD
253 };
254 
255 /* callback structure passed from either netlink or pfkey */
256 struct km_event {
257 	union {
258 		u32 hard;
259 		u32 proto;
260 		u32 byid;
261 		u32 aevent;
262 		u32 type;
263 	} data;
264 
265 	u32	seq;
266 	u32	pid;
267 	u32	event;
268 	struct net *net;
269 };
270 
271 struct xfrm_replay {
272 	void	(*advance)(struct xfrm_state *x, __be32 net_seq);
273 	int	(*check)(struct xfrm_state *x,
274 			 struct sk_buff *skb,
275 			 __be32 net_seq);
276 	int	(*recheck)(struct xfrm_state *x,
277 			   struct sk_buff *skb,
278 			   __be32 net_seq);
279 	void	(*notify)(struct xfrm_state *x, int event);
280 	int	(*overflow)(struct xfrm_state *x, struct sk_buff *skb);
281 };
282 
283 struct net_device;
284 struct xfrm_type;
285 struct xfrm_dst;
286 struct xfrm_policy_afinfo {
287 	unsigned short		family;
288 	struct dst_ops		*dst_ops;
289 	void			(*garbage_collect)(struct net *net);
290 	struct dst_entry	*(*dst_lookup)(struct net *net, int tos,
291 					       const xfrm_address_t *saddr,
292 					       const xfrm_address_t *daddr);
293 	int			(*get_saddr)(struct net *net, xfrm_address_t *saddr, xfrm_address_t *daddr);
294 	void			(*decode_session)(struct sk_buff *skb,
295 						  struct flowi *fl,
296 						  int reverse);
297 	int			(*get_tos)(const struct flowi *fl);
298 	void			(*init_dst)(struct net *net,
299 					    struct xfrm_dst *dst);
300 	int			(*init_path)(struct xfrm_dst *path,
301 					     struct dst_entry *dst,
302 					     int nfheader_len);
303 	int			(*fill_dst)(struct xfrm_dst *xdst,
304 					    struct net_device *dev,
305 					    const struct flowi *fl);
306 	struct dst_entry	*(*blackhole_route)(struct net *net, struct dst_entry *orig);
307 };
308 
309 extern int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo);
310 extern int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo);
311 extern void km_policy_notify(struct xfrm_policy *xp, int dir, const struct km_event *c);
312 extern void km_state_notify(struct xfrm_state *x, const struct km_event *c);
313 
314 struct xfrm_tmpl;
315 extern int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol);
316 extern void km_state_expired(struct xfrm_state *x, int hard, u32 pid);
317 extern int __xfrm_state_delete(struct xfrm_state *x);
318 
319 struct xfrm_state_afinfo {
320 	unsigned int		family;
321 	unsigned int		proto;
322 	__be16			eth_proto;
323 	struct module		*owner;
324 	const struct xfrm_type	*type_map[IPPROTO_MAX];
325 	struct xfrm_mode	*mode_map[XFRM_MODE_MAX];
326 	int			(*init_flags)(struct xfrm_state *x);
327 	void			(*init_tempsel)(struct xfrm_selector *sel,
328 						const struct flowi *fl);
329 	void			(*init_temprop)(struct xfrm_state *x,
330 						const struct xfrm_tmpl *tmpl,
331 						const xfrm_address_t *daddr,
332 						const xfrm_address_t *saddr);
333 	int			(*tmpl_sort)(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n);
334 	int			(*state_sort)(struct xfrm_state **dst, struct xfrm_state **src, int n);
335 	int			(*output)(struct sk_buff *skb);
336 	int			(*output_finish)(struct sk_buff *skb);
337 	int			(*extract_input)(struct xfrm_state *x,
338 						 struct sk_buff *skb);
339 	int			(*extract_output)(struct xfrm_state *x,
340 						  struct sk_buff *skb);
341 	int			(*transport_finish)(struct sk_buff *skb,
342 						    int async);
343 };
344 
345 extern int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo);
346 extern int xfrm_state_unregister_afinfo(struct xfrm_state_afinfo *afinfo);
347 
348 extern void xfrm_state_delete_tunnel(struct xfrm_state *x);
349 
350 struct xfrm_type {
351 	char			*description;
352 	struct module		*owner;
353 	u8			proto;
354 	u8			flags;
355 #define XFRM_TYPE_NON_FRAGMENT	1
356 #define XFRM_TYPE_REPLAY_PROT	2
357 #define XFRM_TYPE_LOCAL_COADDR	4
358 #define XFRM_TYPE_REMOTE_COADDR	8
359 
360 	int			(*init_state)(struct xfrm_state *x);
361 	void			(*destructor)(struct xfrm_state *);
362 	int			(*input)(struct xfrm_state *, struct sk_buff *skb);
363 	int			(*output)(struct xfrm_state *, struct sk_buff *pskb);
364 	int			(*reject)(struct xfrm_state *, struct sk_buff *,
365 					  const struct flowi *);
366 	int			(*hdr_offset)(struct xfrm_state *, struct sk_buff *, u8 **);
367 	/* Estimate maximal size of result of transformation of a dgram */
368 	u32			(*get_mtu)(struct xfrm_state *, int size);
369 };
370 
371 extern int xfrm_register_type(const struct xfrm_type *type, unsigned short family);
372 extern int xfrm_unregister_type(const struct xfrm_type *type, unsigned short family);
373 
374 struct xfrm_mode {
375 	/*
376 	 * Remove encapsulation header.
377 	 *
378 	 * The IP header will be moved over the top of the encapsulation
379 	 * header.
380 	 *
381 	 * On entry, the transport header shall point to where the IP header
382 	 * should be and the network header shall be set to where the IP
383 	 * header currently is.  skb->data shall point to the start of the
384 	 * payload.
385 	 */
386 	int (*input2)(struct xfrm_state *x, struct sk_buff *skb);
387 
388 	/*
389 	 * This is the actual input entry point.
390 	 *
391 	 * For transport mode and equivalent this would be identical to
392 	 * input2 (which does not need to be set).  While tunnel mode
393 	 * and equivalent would set this to the tunnel encapsulation function
394 	 * xfrm4_prepare_input that would in turn call input2.
395 	 */
396 	int (*input)(struct xfrm_state *x, struct sk_buff *skb);
397 
398 	/*
399 	 * Add encapsulation header.
400 	 *
401 	 * On exit, the transport header will be set to the start of the
402 	 * encapsulation header to be filled in by x->type->output and
403 	 * the mac header will be set to the nextheader (protocol for
404 	 * IPv4) field of the extension header directly preceding the
405 	 * encapsulation header, or in its absence, that of the top IP
406 	 * header.  The value of the network header will always point
407 	 * to the top IP header while skb->data will point to the payload.
408 	 */
409 	int (*output2)(struct xfrm_state *x,struct sk_buff *skb);
410 
411 	/*
412 	 * This is the actual output entry point.
413 	 *
414 	 * For transport mode and equivalent this would be identical to
415 	 * output2 (which does not need to be set).  While tunnel mode
416 	 * and equivalent would set this to a tunnel encapsulation function
417 	 * (xfrm4_prepare_output or xfrm6_prepare_output) that would in turn
418 	 * call output2.
419 	 */
420 	int (*output)(struct xfrm_state *x, struct sk_buff *skb);
421 
422 	struct xfrm_state_afinfo *afinfo;
423 	struct module *owner;
424 	unsigned int encap;
425 	int flags;
426 };
427 
428 /* Flags for xfrm_mode. */
429 enum {
430 	XFRM_MODE_FLAG_TUNNEL = 1,
431 };
432 
433 extern int xfrm_register_mode(struct xfrm_mode *mode, int family);
434 extern int xfrm_unregister_mode(struct xfrm_mode *mode, int family);
435 
436 static inline int xfrm_af2proto(unsigned int family)
437 {
438 	switch(family) {
439 	case AF_INET:
440 		return IPPROTO_IPIP;
441 	case AF_INET6:
442 		return IPPROTO_IPV6;
443 	default:
444 		return 0;
445 	}
446 }
447 
448 static inline struct xfrm_mode *xfrm_ip2inner_mode(struct xfrm_state *x, int ipproto)
449 {
450 	if ((ipproto == IPPROTO_IPIP && x->props.family == AF_INET) ||
451 	    (ipproto == IPPROTO_IPV6 && x->props.family == AF_INET6))
452 		return x->inner_mode;
453 	else
454 		return x->inner_mode_iaf;
455 }
456 
457 struct xfrm_tmpl {
458 /* id in template is interpreted as:
459  * daddr - destination of tunnel, may be zero for transport mode.
460  * spi   - zero to acquire spi. Not zero if spi is static, then
461  *	   daddr must be fixed too.
462  * proto - AH/ESP/IPCOMP
463  */
464 	struct xfrm_id		id;
465 
466 /* Source address of tunnel. Ignored, if it is not a tunnel. */
467 	xfrm_address_t		saddr;
468 
469 	unsigned short		encap_family;
470 
471 	u32			reqid;
472 
473 /* Mode: transport, tunnel etc. */
474 	u8			mode;
475 
476 /* Sharing mode: unique, this session only, this user only etc. */
477 	u8			share;
478 
479 /* May skip this transfomration if no SA is found */
480 	u8			optional;
481 
482 /* Skip aalgos/ealgos/calgos checks. */
483 	u8			allalgs;
484 
485 /* Bit mask of algos allowed for acquisition */
486 	u32			aalgos;
487 	u32			ealgos;
488 	u32			calgos;
489 };
490 
491 #define XFRM_MAX_DEPTH		6
492 
493 struct xfrm_policy_walk_entry {
494 	struct list_head	all;
495 	u8			dead;
496 };
497 
498 struct xfrm_policy_walk {
499 	struct xfrm_policy_walk_entry walk;
500 	u8 type;
501 	u32 seq;
502 };
503 
504 struct xfrm_policy {
505 #ifdef CONFIG_NET_NS
506 	struct net		*xp_net;
507 #endif
508 	struct hlist_node	bydst;
509 	struct hlist_node	byidx;
510 
511 	/* This lock only affects elements except for entry. */
512 	rwlock_t		lock;
513 	atomic_t		refcnt;
514 	struct timer_list	timer;
515 
516 	struct flow_cache_object flo;
517 	atomic_t		genid;
518 	u32			priority;
519 	u32			index;
520 	struct xfrm_mark	mark;
521 	struct xfrm_selector	selector;
522 	struct xfrm_lifetime_cfg lft;
523 	struct xfrm_lifetime_cur curlft;
524 	struct xfrm_policy_walk_entry walk;
525 	u8			type;
526 	u8			action;
527 	u8			flags;
528 	u8			xfrm_nr;
529 	u16			family;
530 	struct xfrm_sec_ctx	*security;
531 	struct xfrm_tmpl       	xfrm_vec[XFRM_MAX_DEPTH];
532 };
533 
534 static inline struct net *xp_net(const struct xfrm_policy *xp)
535 {
536 	return read_pnet(&xp->xp_net);
537 }
538 
539 struct xfrm_kmaddress {
540 	xfrm_address_t          local;
541 	xfrm_address_t          remote;
542 	u32			reserved;
543 	u16			family;
544 };
545 
546 struct xfrm_migrate {
547 	xfrm_address_t		old_daddr;
548 	xfrm_address_t		old_saddr;
549 	xfrm_address_t		new_daddr;
550 	xfrm_address_t		new_saddr;
551 	u8			proto;
552 	u8			mode;
553 	u16			reserved;
554 	u32			reqid;
555 	u16			old_family;
556 	u16			new_family;
557 };
558 
559 #define XFRM_KM_TIMEOUT                30
560 /* which seqno */
561 #define XFRM_REPLAY_SEQ		1
562 #define XFRM_REPLAY_OSEQ	2
563 #define XFRM_REPLAY_SEQ_MASK	3
564 /* what happened */
565 #define XFRM_REPLAY_UPDATE	XFRM_AE_CR
566 #define XFRM_REPLAY_TIMEOUT	XFRM_AE_CE
567 
568 /* default aevent timeout in units of 100ms */
569 #define XFRM_AE_ETIME			10
570 /* Async Event timer multiplier */
571 #define XFRM_AE_ETH_M			10
572 /* default seq threshold size */
573 #define XFRM_AE_SEQT_SIZE		2
574 
575 struct xfrm_mgr {
576 	struct list_head	list;
577 	char			*id;
578 	int			(*notify)(struct xfrm_state *x, const struct km_event *c);
579 	int			(*acquire)(struct xfrm_state *x, struct xfrm_tmpl *, struct xfrm_policy *xp, int dir);
580 	struct xfrm_policy	*(*compile_policy)(struct sock *sk, int opt, u8 *data, int len, int *dir);
581 	int			(*new_mapping)(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport);
582 	int			(*notify_policy)(struct xfrm_policy *x, int dir, const struct km_event *c);
583 	int			(*report)(struct net *net, u8 proto, struct xfrm_selector *sel, xfrm_address_t *addr);
584 	int			(*migrate)(const struct xfrm_selector *sel,
585 					   u8 dir, u8 type,
586 					   const struct xfrm_migrate *m,
587 					   int num_bundles,
588 					   const struct xfrm_kmaddress *k);
589 };
590 
591 extern int xfrm_register_km(struct xfrm_mgr *km);
592 extern int xfrm_unregister_km(struct xfrm_mgr *km);
593 
594 /*
595  * This structure is used for the duration where packets are being
596  * transformed by IPsec.  As soon as the packet leaves IPsec the
597  * area beyond the generic IP part may be overwritten.
598  */
599 struct xfrm_skb_cb {
600 	union {
601 		struct inet_skb_parm h4;
602 		struct inet6_skb_parm h6;
603         } header;
604 
605         /* Sequence number for replay protection. */
606 	union {
607 		struct {
608 			__u32 low;
609 			__u32 hi;
610 		} output;
611 		struct {
612 			__be32 low;
613 			__be32 hi;
614 		} input;
615 	} seq;
616 };
617 
618 #define XFRM_SKB_CB(__skb) ((struct xfrm_skb_cb *)&((__skb)->cb[0]))
619 
620 /*
621  * This structure is used by the afinfo prepare_input/prepare_output functions
622  * to transmit header information to the mode input/output functions.
623  */
624 struct xfrm_mode_skb_cb {
625 	union {
626 		struct inet_skb_parm h4;
627 		struct inet6_skb_parm h6;
628 	} header;
629 
630 	/* Copied from header for IPv4, always set to zero and DF for IPv6. */
631 	__be16 id;
632 	__be16 frag_off;
633 
634 	/* IP header length (excluding options or extension headers). */
635 	u8 ihl;
636 
637 	/* TOS for IPv4, class for IPv6. */
638 	u8 tos;
639 
640 	/* TTL for IPv4, hop limitfor IPv6. */
641 	u8 ttl;
642 
643 	/* Protocol for IPv4, NH for IPv6. */
644 	u8 protocol;
645 
646 	/* Option length for IPv4, zero for IPv6. */
647 	u8 optlen;
648 
649 	/* Used by IPv6 only, zero for IPv4. */
650 	u8 flow_lbl[3];
651 };
652 
653 #define XFRM_MODE_SKB_CB(__skb) ((struct xfrm_mode_skb_cb *)&((__skb)->cb[0]))
654 
655 /*
656  * This structure is used by the input processing to locate the SPI and
657  * related information.
658  */
659 struct xfrm_spi_skb_cb {
660 	union {
661 		struct inet_skb_parm h4;
662 		struct inet6_skb_parm h6;
663 	} header;
664 
665 	unsigned int daddroff;
666 	unsigned int family;
667 };
668 
669 #define XFRM_SPI_SKB_CB(__skb) ((struct xfrm_spi_skb_cb *)&((__skb)->cb[0]))
670 
671 /* Audit Information */
672 struct xfrm_audit {
673 	u32	secid;
674 	uid_t	loginuid;
675 	u32	sessionid;
676 };
677 
678 #ifdef CONFIG_AUDITSYSCALL
679 static inline struct audit_buffer *xfrm_audit_start(const char *op)
680 {
681 	struct audit_buffer *audit_buf = NULL;
682 
683 	if (audit_enabled == 0)
684 		return NULL;
685 	audit_buf = audit_log_start(current->audit_context, GFP_ATOMIC,
686 				    AUDIT_MAC_IPSEC_EVENT);
687 	if (audit_buf == NULL)
688 		return NULL;
689 	audit_log_format(audit_buf, "op=%s", op);
690 	return audit_buf;
691 }
692 
693 static inline void xfrm_audit_helper_usrinfo(uid_t auid, u32 ses, u32 secid,
694 					     struct audit_buffer *audit_buf)
695 {
696 	char *secctx;
697 	u32 secctx_len;
698 
699 	audit_log_format(audit_buf, " auid=%u ses=%u", auid, ses);
700 	if (secid != 0 &&
701 	    security_secid_to_secctx(secid, &secctx, &secctx_len) == 0) {
702 		audit_log_format(audit_buf, " subj=%s", secctx);
703 		security_release_secctx(secctx, secctx_len);
704 	} else
705 		audit_log_task_context(audit_buf);
706 }
707 
708 extern void xfrm_audit_policy_add(struct xfrm_policy *xp, int result,
709 				  u32 auid, u32 ses, u32 secid);
710 extern void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
711 				  u32 auid, u32 ses, u32 secid);
712 extern void xfrm_audit_state_add(struct xfrm_state *x, int result,
713 				 u32 auid, u32 ses, u32 secid);
714 extern void xfrm_audit_state_delete(struct xfrm_state *x, int result,
715 				    u32 auid, u32 ses, u32 secid);
716 extern void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
717 					     struct sk_buff *skb);
718 extern void xfrm_audit_state_replay(struct xfrm_state *x,
719 				    struct sk_buff *skb, __be32 net_seq);
720 extern void xfrm_audit_state_notfound_simple(struct sk_buff *skb, u16 family);
721 extern void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family,
722 				      __be32 net_spi, __be32 net_seq);
723 extern void xfrm_audit_state_icvfail(struct xfrm_state *x,
724 				     struct sk_buff *skb, u8 proto);
725 #else
726 
727 static inline void xfrm_audit_policy_add(struct xfrm_policy *xp, int result,
728 				  u32 auid, u32 ses, u32 secid)
729 {
730 }
731 
732 static inline void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
733 				  u32 auid, u32 ses, u32 secid)
734 {
735 }
736 
737 static inline void xfrm_audit_state_add(struct xfrm_state *x, int result,
738 				 u32 auid, u32 ses, u32 secid)
739 {
740 }
741 
742 static inline void xfrm_audit_state_delete(struct xfrm_state *x, int result,
743 				    u32 auid, u32 ses, u32 secid)
744 {
745 }
746 
747 static inline void xfrm_audit_state_replay_overflow(struct xfrm_state *x,
748 					     struct sk_buff *skb)
749 {
750 }
751 
752 static inline void xfrm_audit_state_replay(struct xfrm_state *x,
753 					   struct sk_buff *skb, __be32 net_seq)
754 {
755 }
756 
757 static inline void xfrm_audit_state_notfound_simple(struct sk_buff *skb,
758 				      u16 family)
759 {
760 }
761 
762 static inline void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family,
763 				      __be32 net_spi, __be32 net_seq)
764 {
765 }
766 
767 static inline void xfrm_audit_state_icvfail(struct xfrm_state *x,
768 				     struct sk_buff *skb, u8 proto)
769 {
770 }
771 #endif /* CONFIG_AUDITSYSCALL */
772 
773 static inline void xfrm_pol_hold(struct xfrm_policy *policy)
774 {
775 	if (likely(policy != NULL))
776 		atomic_inc(&policy->refcnt);
777 }
778 
779 extern void xfrm_policy_destroy(struct xfrm_policy *policy);
780 
781 static inline void xfrm_pol_put(struct xfrm_policy *policy)
782 {
783 	if (atomic_dec_and_test(&policy->refcnt))
784 		xfrm_policy_destroy(policy);
785 }
786 
787 static inline void xfrm_pols_put(struct xfrm_policy **pols, int npols)
788 {
789 	int i;
790 	for (i = npols - 1; i >= 0; --i)
791 		xfrm_pol_put(pols[i]);
792 }
793 
794 extern void __xfrm_state_destroy(struct xfrm_state *);
795 
796 static inline void __xfrm_state_put(struct xfrm_state *x)
797 {
798 	atomic_dec(&x->refcnt);
799 }
800 
801 static inline void xfrm_state_put(struct xfrm_state *x)
802 {
803 	if (atomic_dec_and_test(&x->refcnt))
804 		__xfrm_state_destroy(x);
805 }
806 
807 static inline void xfrm_state_hold(struct xfrm_state *x)
808 {
809 	atomic_inc(&x->refcnt);
810 }
811 
812 static inline bool addr_match(const void *token1, const void *token2,
813 			      int prefixlen)
814 {
815 	const __be32 *a1 = token1;
816 	const __be32 *a2 = token2;
817 	int pdw;
818 	int pbi;
819 
820 	pdw = prefixlen >> 5;	  /* num of whole u32 in prefix */
821 	pbi = prefixlen &  0x1f;  /* num of bits in incomplete u32 in prefix */
822 
823 	if (pdw)
824 		if (memcmp(a1, a2, pdw << 2))
825 			return false;
826 
827 	if (pbi) {
828 		__be32 mask;
829 
830 		mask = htonl((0xffffffff) << (32 - pbi));
831 
832 		if ((a1[pdw] ^ a2[pdw]) & mask)
833 			return false;
834 	}
835 
836 	return true;
837 }
838 
839 static inline bool addr4_match(__be32 a1, __be32 a2, u8 prefixlen)
840 {
841 	/* C99 6.5.7 (3): u32 << 32 is undefined behaviour */
842 	if (prefixlen == 0)
843 		return true;
844 	return !((a1 ^ a2) & htonl(0xFFFFFFFFu << (32 - prefixlen)));
845 }
846 
847 static __inline__
848 __be16 xfrm_flowi_sport(const struct flowi *fl, const union flowi_uli *uli)
849 {
850 	__be16 port;
851 	switch(fl->flowi_proto) {
852 	case IPPROTO_TCP:
853 	case IPPROTO_UDP:
854 	case IPPROTO_UDPLITE:
855 	case IPPROTO_SCTP:
856 		port = uli->ports.sport;
857 		break;
858 	case IPPROTO_ICMP:
859 	case IPPROTO_ICMPV6:
860 		port = htons(uli->icmpt.type);
861 		break;
862 	case IPPROTO_MH:
863 		port = htons(uli->mht.type);
864 		break;
865 	case IPPROTO_GRE:
866 		port = htons(ntohl(uli->gre_key) >> 16);
867 		break;
868 	default:
869 		port = 0;	/*XXX*/
870 	}
871 	return port;
872 }
873 
874 static __inline__
875 __be16 xfrm_flowi_dport(const struct flowi *fl, const union flowi_uli *uli)
876 {
877 	__be16 port;
878 	switch(fl->flowi_proto) {
879 	case IPPROTO_TCP:
880 	case IPPROTO_UDP:
881 	case IPPROTO_UDPLITE:
882 	case IPPROTO_SCTP:
883 		port = uli->ports.dport;
884 		break;
885 	case IPPROTO_ICMP:
886 	case IPPROTO_ICMPV6:
887 		port = htons(uli->icmpt.code);
888 		break;
889 	case IPPROTO_GRE:
890 		port = htons(ntohl(uli->gre_key) & 0xffff);
891 		break;
892 	default:
893 		port = 0;	/*XXX*/
894 	}
895 	return port;
896 }
897 
898 extern bool xfrm_selector_match(const struct xfrm_selector *sel,
899 				const struct flowi *fl,
900 				unsigned short family);
901 
902 #ifdef CONFIG_SECURITY_NETWORK_XFRM
903 /*	If neither has a context --> match
904  * 	Otherwise, both must have a context and the sids, doi, alg must match
905  */
906 static inline bool xfrm_sec_ctx_match(struct xfrm_sec_ctx *s1, struct xfrm_sec_ctx *s2)
907 {
908 	return ((!s1 && !s2) ||
909 		(s1 && s2 &&
910 		 (s1->ctx_sid == s2->ctx_sid) &&
911 		 (s1->ctx_doi == s2->ctx_doi) &&
912 		 (s1->ctx_alg == s2->ctx_alg)));
913 }
914 #else
915 static inline bool xfrm_sec_ctx_match(struct xfrm_sec_ctx *s1, struct xfrm_sec_ctx *s2)
916 {
917 	return true;
918 }
919 #endif
920 
921 /* A struct encoding bundle of transformations to apply to some set of flow.
922  *
923  * dst->child points to the next element of bundle.
924  * dst->xfrm  points to an instanse of transformer.
925  *
926  * Due to unfortunate limitations of current routing cache, which we
927  * have no time to fix, it mirrors struct rtable and bound to the same
928  * routing key, including saddr,daddr. However, we can have many of
929  * bundles differing by session id. All the bundles grow from a parent
930  * policy rule.
931  */
932 struct xfrm_dst {
933 	union {
934 		struct dst_entry	dst;
935 		struct rtable		rt;
936 		struct rt6_info		rt6;
937 	} u;
938 	struct dst_entry *route;
939 	struct flow_cache_object flo;
940 	struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
941 	int num_pols, num_xfrms;
942 #ifdef CONFIG_XFRM_SUB_POLICY
943 	struct flowi *origin;
944 	struct xfrm_selector *partner;
945 #endif
946 	u32 xfrm_genid;
947 	u32 policy_genid;
948 	u32 route_mtu_cached;
949 	u32 child_mtu_cached;
950 	u32 route_cookie;
951 	u32 path_cookie;
952 };
953 
954 #ifdef CONFIG_XFRM
955 static inline void xfrm_dst_destroy(struct xfrm_dst *xdst)
956 {
957 	xfrm_pols_put(xdst->pols, xdst->num_pols);
958 	dst_release(xdst->route);
959 	if (likely(xdst->u.dst.xfrm))
960 		xfrm_state_put(xdst->u.dst.xfrm);
961 #ifdef CONFIG_XFRM_SUB_POLICY
962 	kfree(xdst->origin);
963 	xdst->origin = NULL;
964 	kfree(xdst->partner);
965 	xdst->partner = NULL;
966 #endif
967 }
968 #endif
969 
970 extern void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev);
971 
972 struct sec_path {
973 	atomic_t		refcnt;
974 	int			len;
975 	struct xfrm_state	*xvec[XFRM_MAX_DEPTH];
976 };
977 
978 static inline int secpath_exists(struct sk_buff *skb)
979 {
980 #ifdef CONFIG_XFRM
981 	return skb->sp != NULL;
982 #else
983 	return 0;
984 #endif
985 }
986 
987 static inline struct sec_path *
988 secpath_get(struct sec_path *sp)
989 {
990 	if (sp)
991 		atomic_inc(&sp->refcnt);
992 	return sp;
993 }
994 
995 extern void __secpath_destroy(struct sec_path *sp);
996 
997 static inline void
998 secpath_put(struct sec_path *sp)
999 {
1000 	if (sp && atomic_dec_and_test(&sp->refcnt))
1001 		__secpath_destroy(sp);
1002 }
1003 
1004 extern struct sec_path *secpath_dup(struct sec_path *src);
1005 
1006 static inline void
1007 secpath_reset(struct sk_buff *skb)
1008 {
1009 #ifdef CONFIG_XFRM
1010 	secpath_put(skb->sp);
1011 	skb->sp = NULL;
1012 #endif
1013 }
1014 
1015 static inline int
1016 xfrm_addr_any(const xfrm_address_t *addr, unsigned short family)
1017 {
1018 	switch (family) {
1019 	case AF_INET:
1020 		return addr->a4 == 0;
1021 	case AF_INET6:
1022 		return ipv6_addr_any((struct in6_addr *)&addr->a6);
1023 	}
1024 	return 0;
1025 }
1026 
1027 static inline int
1028 __xfrm4_state_addr_cmp(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x)
1029 {
1030 	return	(tmpl->saddr.a4 &&
1031 		 tmpl->saddr.a4 != x->props.saddr.a4);
1032 }
1033 
1034 static inline int
1035 __xfrm6_state_addr_cmp(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x)
1036 {
1037 	return	(!ipv6_addr_any((struct in6_addr*)&tmpl->saddr) &&
1038 		 ipv6_addr_cmp((struct in6_addr *)&tmpl->saddr, (struct in6_addr*)&x->props.saddr));
1039 }
1040 
1041 static inline int
1042 xfrm_state_addr_cmp(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x, unsigned short family)
1043 {
1044 	switch (family) {
1045 	case AF_INET:
1046 		return __xfrm4_state_addr_cmp(tmpl, x);
1047 	case AF_INET6:
1048 		return __xfrm6_state_addr_cmp(tmpl, x);
1049 	}
1050 	return !0;
1051 }
1052 
1053 #ifdef CONFIG_XFRM
1054 extern int __xfrm_policy_check(struct sock *, int dir, struct sk_buff *skb, unsigned short family);
1055 
1056 static inline int __xfrm_policy_check2(struct sock *sk, int dir,
1057 				       struct sk_buff *skb,
1058 				       unsigned int family, int reverse)
1059 {
1060 	struct net *net = dev_net(skb->dev);
1061 	int ndir = dir | (reverse ? XFRM_POLICY_MASK + 1 : 0);
1062 
1063 	if (sk && sk->sk_policy[XFRM_POLICY_IN])
1064 		return __xfrm_policy_check(sk, ndir, skb, family);
1065 
1066 	return	(!net->xfrm.policy_count[dir] && !skb->sp) ||
1067 		(skb_dst(skb)->flags & DST_NOPOLICY) ||
1068 		__xfrm_policy_check(sk, ndir, skb, family);
1069 }
1070 
1071 static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family)
1072 {
1073 	return __xfrm_policy_check2(sk, dir, skb, family, 0);
1074 }
1075 
1076 static inline int xfrm4_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
1077 {
1078 	return xfrm_policy_check(sk, dir, skb, AF_INET);
1079 }
1080 
1081 static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
1082 {
1083 	return xfrm_policy_check(sk, dir, skb, AF_INET6);
1084 }
1085 
1086 static inline int xfrm4_policy_check_reverse(struct sock *sk, int dir,
1087 					     struct sk_buff *skb)
1088 {
1089 	return __xfrm_policy_check2(sk, dir, skb, AF_INET, 1);
1090 }
1091 
1092 static inline int xfrm6_policy_check_reverse(struct sock *sk, int dir,
1093 					     struct sk_buff *skb)
1094 {
1095 	return __xfrm_policy_check2(sk, dir, skb, AF_INET6, 1);
1096 }
1097 
1098 extern int __xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
1099 				 unsigned int family, int reverse);
1100 
1101 static inline int xfrm_decode_session(struct sk_buff *skb, struct flowi *fl,
1102 				      unsigned int family)
1103 {
1104 	return __xfrm_decode_session(skb, fl, family, 0);
1105 }
1106 
1107 static inline int xfrm_decode_session_reverse(struct sk_buff *skb,
1108 					      struct flowi *fl,
1109 					      unsigned int family)
1110 {
1111 	return __xfrm_decode_session(skb, fl, family, 1);
1112 }
1113 
1114 extern int __xfrm_route_forward(struct sk_buff *skb, unsigned short family);
1115 
1116 static inline int xfrm_route_forward(struct sk_buff *skb, unsigned short family)
1117 {
1118 	struct net *net = dev_net(skb->dev);
1119 
1120 	return	!net->xfrm.policy_count[XFRM_POLICY_OUT] ||
1121 		(skb_dst(skb)->flags & DST_NOXFRM) ||
1122 		__xfrm_route_forward(skb, family);
1123 }
1124 
1125 static inline int xfrm4_route_forward(struct sk_buff *skb)
1126 {
1127 	return xfrm_route_forward(skb, AF_INET);
1128 }
1129 
1130 static inline int xfrm6_route_forward(struct sk_buff *skb)
1131 {
1132 	return xfrm_route_forward(skb, AF_INET6);
1133 }
1134 
1135 extern int __xfrm_sk_clone_policy(struct sock *sk);
1136 
1137 static inline int xfrm_sk_clone_policy(struct sock *sk)
1138 {
1139 	if (unlikely(sk->sk_policy[0] || sk->sk_policy[1]))
1140 		return __xfrm_sk_clone_policy(sk);
1141 	return 0;
1142 }
1143 
1144 extern int xfrm_policy_delete(struct xfrm_policy *pol, int dir);
1145 
1146 static inline void xfrm_sk_free_policy(struct sock *sk)
1147 {
1148 	if (unlikely(sk->sk_policy[0] != NULL)) {
1149 		xfrm_policy_delete(sk->sk_policy[0], XFRM_POLICY_MAX);
1150 		sk->sk_policy[0] = NULL;
1151 	}
1152 	if (unlikely(sk->sk_policy[1] != NULL)) {
1153 		xfrm_policy_delete(sk->sk_policy[1], XFRM_POLICY_MAX+1);
1154 		sk->sk_policy[1] = NULL;
1155 	}
1156 }
1157 
1158 #else
1159 
1160 static inline void xfrm_sk_free_policy(struct sock *sk) {}
1161 static inline int xfrm_sk_clone_policy(struct sock *sk) { return 0; }
1162 static inline int xfrm6_route_forward(struct sk_buff *skb) { return 1; }
1163 static inline int xfrm4_route_forward(struct sk_buff *skb) { return 1; }
1164 static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
1165 {
1166 	return 1;
1167 }
1168 static inline int xfrm4_policy_check(struct sock *sk, int dir, struct sk_buff *skb)
1169 {
1170 	return 1;
1171 }
1172 static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family)
1173 {
1174 	return 1;
1175 }
1176 static inline int xfrm_decode_session_reverse(struct sk_buff *skb,
1177 					      struct flowi *fl,
1178 					      unsigned int family)
1179 {
1180 	return -ENOSYS;
1181 }
1182 static inline int xfrm4_policy_check_reverse(struct sock *sk, int dir,
1183 					     struct sk_buff *skb)
1184 {
1185 	return 1;
1186 }
1187 static inline int xfrm6_policy_check_reverse(struct sock *sk, int dir,
1188 					     struct sk_buff *skb)
1189 {
1190 	return 1;
1191 }
1192 #endif
1193 
1194 static __inline__
1195 xfrm_address_t *xfrm_flowi_daddr(const struct flowi *fl, unsigned short family)
1196 {
1197 	switch (family){
1198 	case AF_INET:
1199 		return (xfrm_address_t *)&fl->u.ip4.daddr;
1200 	case AF_INET6:
1201 		return (xfrm_address_t *)&fl->u.ip6.daddr;
1202 	}
1203 	return NULL;
1204 }
1205 
1206 static __inline__
1207 xfrm_address_t *xfrm_flowi_saddr(const struct flowi *fl, unsigned short family)
1208 {
1209 	switch (family){
1210 	case AF_INET:
1211 		return (xfrm_address_t *)&fl->u.ip4.saddr;
1212 	case AF_INET6:
1213 		return (xfrm_address_t *)&fl->u.ip6.saddr;
1214 	}
1215 	return NULL;
1216 }
1217 
1218 static __inline__
1219 void xfrm_flowi_addr_get(const struct flowi *fl,
1220 			 xfrm_address_t *saddr, xfrm_address_t *daddr,
1221 			 unsigned short family)
1222 {
1223 	switch(family) {
1224 	case AF_INET:
1225 		memcpy(&saddr->a4, &fl->u.ip4.saddr, sizeof(saddr->a4));
1226 		memcpy(&daddr->a4, &fl->u.ip4.daddr, sizeof(daddr->a4));
1227 		break;
1228 	case AF_INET6:
1229 		*(struct in6_addr *)saddr->a6 = fl->u.ip6.saddr;
1230 		*(struct in6_addr *)daddr->a6 = fl->u.ip6.daddr;
1231 		break;
1232 	}
1233 }
1234 
1235 static __inline__ int
1236 __xfrm4_state_addr_check(const struct xfrm_state *x,
1237 			 const xfrm_address_t *daddr, const xfrm_address_t *saddr)
1238 {
1239 	if (daddr->a4 == x->id.daddr.a4 &&
1240 	    (saddr->a4 == x->props.saddr.a4 || !saddr->a4 || !x->props.saddr.a4))
1241 		return 1;
1242 	return 0;
1243 }
1244 
1245 static __inline__ int
1246 __xfrm6_state_addr_check(const struct xfrm_state *x,
1247 			 const xfrm_address_t *daddr, const xfrm_address_t *saddr)
1248 {
1249 	if (!ipv6_addr_cmp((struct in6_addr *)daddr, (struct in6_addr *)&x->id.daddr) &&
1250 	    (!ipv6_addr_cmp((struct in6_addr *)saddr, (struct in6_addr *)&x->props.saddr)||
1251 	     ipv6_addr_any((struct in6_addr *)saddr) ||
1252 	     ipv6_addr_any((struct in6_addr *)&x->props.saddr)))
1253 		return 1;
1254 	return 0;
1255 }
1256 
1257 static __inline__ int
1258 xfrm_state_addr_check(const struct xfrm_state *x,
1259 		      const xfrm_address_t *daddr, const xfrm_address_t *saddr,
1260 		      unsigned short family)
1261 {
1262 	switch (family) {
1263 	case AF_INET:
1264 		return __xfrm4_state_addr_check(x, daddr, saddr);
1265 	case AF_INET6:
1266 		return __xfrm6_state_addr_check(x, daddr, saddr);
1267 	}
1268 	return 0;
1269 }
1270 
1271 static __inline__ int
1272 xfrm_state_addr_flow_check(const struct xfrm_state *x, const struct flowi *fl,
1273 			   unsigned short family)
1274 {
1275 	switch (family) {
1276 	case AF_INET:
1277 		return __xfrm4_state_addr_check(x,
1278 						(const xfrm_address_t *)&fl->u.ip4.daddr,
1279 						(const xfrm_address_t *)&fl->u.ip4.saddr);
1280 	case AF_INET6:
1281 		return __xfrm6_state_addr_check(x,
1282 						(const xfrm_address_t *)&fl->u.ip6.daddr,
1283 						(const xfrm_address_t *)&fl->u.ip6.saddr);
1284 	}
1285 	return 0;
1286 }
1287 
1288 static inline int xfrm_state_kern(const struct xfrm_state *x)
1289 {
1290 	return atomic_read(&x->tunnel_users);
1291 }
1292 
1293 static inline int xfrm_id_proto_match(u8 proto, u8 userproto)
1294 {
1295 	return (!userproto || proto == userproto ||
1296 		(userproto == IPSEC_PROTO_ANY && (proto == IPPROTO_AH ||
1297 						  proto == IPPROTO_ESP ||
1298 						  proto == IPPROTO_COMP)));
1299 }
1300 
1301 /*
1302  * xfrm algorithm information
1303  */
1304 struct xfrm_algo_aead_info {
1305 	u16 icv_truncbits;
1306 };
1307 
1308 struct xfrm_algo_auth_info {
1309 	u16 icv_truncbits;
1310 	u16 icv_fullbits;
1311 };
1312 
1313 struct xfrm_algo_encr_info {
1314 	u16 blockbits;
1315 	u16 defkeybits;
1316 };
1317 
1318 struct xfrm_algo_comp_info {
1319 	u16 threshold;
1320 };
1321 
1322 struct xfrm_algo_desc {
1323 	char *name;
1324 	char *compat;
1325 	u8 available:1;
1326 	union {
1327 		struct xfrm_algo_aead_info aead;
1328 		struct xfrm_algo_auth_info auth;
1329 		struct xfrm_algo_encr_info encr;
1330 		struct xfrm_algo_comp_info comp;
1331 	} uinfo;
1332 	struct sadb_alg desc;
1333 };
1334 
1335 /* XFRM tunnel handlers.  */
1336 struct xfrm_tunnel {
1337 	int (*handler)(struct sk_buff *skb);
1338 	int (*err_handler)(struct sk_buff *skb, u32 info);
1339 
1340 	struct xfrm_tunnel __rcu *next;
1341 	int priority;
1342 };
1343 
1344 struct xfrm6_tunnel {
1345 	int (*handler)(struct sk_buff *skb);
1346 	int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
1347 			   u8 type, u8 code, int offset, __be32 info);
1348 	struct xfrm6_tunnel __rcu *next;
1349 	int priority;
1350 };
1351 
1352 extern void xfrm_init(void);
1353 extern void xfrm4_init(int rt_hash_size);
1354 extern int xfrm_state_init(struct net *net);
1355 extern void xfrm_state_fini(struct net *net);
1356 extern void xfrm4_state_init(void);
1357 #ifdef CONFIG_XFRM
1358 extern int xfrm6_init(void);
1359 extern void xfrm6_fini(void);
1360 extern int xfrm6_state_init(void);
1361 extern void xfrm6_state_fini(void);
1362 #else
1363 static inline int xfrm6_init(void)
1364 {
1365 	return 0;
1366 }
1367 static inline void xfrm6_fini(void)
1368 {
1369 	;
1370 }
1371 #endif
1372 
1373 #ifdef CONFIG_XFRM_STATISTICS
1374 extern int xfrm_proc_init(struct net *net);
1375 extern void xfrm_proc_fini(struct net *net);
1376 #endif
1377 
1378 extern int xfrm_sysctl_init(struct net *net);
1379 #ifdef CONFIG_SYSCTL
1380 extern void xfrm_sysctl_fini(struct net *net);
1381 #else
1382 static inline void xfrm_sysctl_fini(struct net *net)
1383 {
1384 }
1385 #endif
1386 
1387 extern void xfrm_state_walk_init(struct xfrm_state_walk *walk, u8 proto);
1388 extern int xfrm_state_walk(struct net *net, struct xfrm_state_walk *walk,
1389 			   int (*func)(struct xfrm_state *, int, void*), void *);
1390 extern void xfrm_state_walk_done(struct xfrm_state_walk *walk);
1391 extern struct xfrm_state *xfrm_state_alloc(struct net *net);
1392 extern struct xfrm_state *xfrm_state_find(const xfrm_address_t *daddr,
1393 					  const xfrm_address_t *saddr,
1394 					  const struct flowi *fl,
1395 					  struct xfrm_tmpl *tmpl,
1396 					  struct xfrm_policy *pol, int *err,
1397 					  unsigned short family);
1398 extern struct xfrm_state *xfrm_stateonly_find(struct net *net, u32 mark,
1399 					       xfrm_address_t *daddr,
1400 					       xfrm_address_t *saddr,
1401 					       unsigned short family,
1402 					       u8 mode, u8 proto, u32 reqid);
1403 extern int xfrm_state_check_expire(struct xfrm_state *x);
1404 extern void xfrm_state_insert(struct xfrm_state *x);
1405 extern int xfrm_state_add(struct xfrm_state *x);
1406 extern int xfrm_state_update(struct xfrm_state *x);
1407 extern struct xfrm_state *xfrm_state_lookup(struct net *net, u32 mark,
1408 					    const xfrm_address_t *daddr, __be32 spi,
1409 					    u8 proto, unsigned short family);
1410 extern struct xfrm_state *xfrm_state_lookup_byaddr(struct net *net, u32 mark,
1411 						   const xfrm_address_t *daddr,
1412 						   const xfrm_address_t *saddr,
1413 						   u8 proto,
1414 						   unsigned short family);
1415 #ifdef CONFIG_XFRM_SUB_POLICY
1416 extern int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src,
1417 			  int n, unsigned short family);
1418 extern int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src,
1419 			   int n, unsigned short family);
1420 #else
1421 static inline int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src,
1422 				 int n, unsigned short family)
1423 {
1424 	return -ENOSYS;
1425 }
1426 
1427 static inline int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src,
1428 				  int n, unsigned short family)
1429 {
1430 	return -ENOSYS;
1431 }
1432 #endif
1433 
1434 struct xfrmk_sadinfo {
1435 	u32 sadhcnt; /* current hash bkts */
1436 	u32 sadhmcnt; /* max allowed hash bkts */
1437 	u32 sadcnt; /* current running count */
1438 };
1439 
1440 struct xfrmk_spdinfo {
1441 	u32 incnt;
1442 	u32 outcnt;
1443 	u32 fwdcnt;
1444 	u32 inscnt;
1445 	u32 outscnt;
1446 	u32 fwdscnt;
1447 	u32 spdhcnt;
1448 	u32 spdhmcnt;
1449 };
1450 
1451 extern struct xfrm_state *xfrm_find_acq_byseq(struct net *net, u32 mark,
1452 					      u32 seq);
1453 extern int xfrm_state_delete(struct xfrm_state *x);
1454 extern int xfrm_state_flush(struct net *net, u8 proto, struct xfrm_audit *audit_info);
1455 extern void xfrm_sad_getinfo(struct net *net, struct xfrmk_sadinfo *si);
1456 extern void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si);
1457 extern u32 xfrm_replay_seqhi(struct xfrm_state *x, __be32 net_seq);
1458 extern int xfrm_init_replay(struct xfrm_state *x);
1459 extern int xfrm_state_mtu(struct xfrm_state *x, int mtu);
1460 extern int __xfrm_init_state(struct xfrm_state *x, bool init_replay);
1461 extern int xfrm_init_state(struct xfrm_state *x);
1462 extern int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb);
1463 extern int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi,
1464 		      int encap_type);
1465 extern int xfrm_input_resume(struct sk_buff *skb, int nexthdr);
1466 extern int xfrm_output_resume(struct sk_buff *skb, int err);
1467 extern int xfrm_output(struct sk_buff *skb);
1468 extern int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb);
1469 extern int xfrm4_extract_header(struct sk_buff *skb);
1470 extern int xfrm4_extract_input(struct xfrm_state *x, struct sk_buff *skb);
1471 extern int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
1472 			   int encap_type);
1473 extern int xfrm4_transport_finish(struct sk_buff *skb, int async);
1474 extern int xfrm4_rcv(struct sk_buff *skb);
1475 
1476 static inline int xfrm4_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
1477 {
1478 	return xfrm4_rcv_encap(skb, nexthdr, spi, 0);
1479 }
1480 
1481 extern int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb);
1482 extern int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb);
1483 extern int xfrm4_output(struct sk_buff *skb);
1484 extern int xfrm4_output_finish(struct sk_buff *skb);
1485 extern int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family);
1486 extern int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family);
1487 extern int xfrm4_mode_tunnel_input_register(struct xfrm_tunnel *handler);
1488 extern int xfrm4_mode_tunnel_input_deregister(struct xfrm_tunnel *handler);
1489 extern int xfrm6_extract_header(struct sk_buff *skb);
1490 extern int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb);
1491 extern int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi);
1492 extern int xfrm6_transport_finish(struct sk_buff *skb, int async);
1493 extern int xfrm6_rcv(struct sk_buff *skb);
1494 extern int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
1495 			    xfrm_address_t *saddr, u8 proto);
1496 extern int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family);
1497 extern int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family);
1498 extern __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr);
1499 extern __be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr);
1500 extern int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb);
1501 extern int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb);
1502 extern int xfrm6_output(struct sk_buff *skb);
1503 extern int xfrm6_output_finish(struct sk_buff *skb);
1504 extern int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
1505 				 u8 **prevhdr);
1506 
1507 #ifdef CONFIG_XFRM
1508 extern int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb);
1509 extern int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen);
1510 #else
1511 static inline int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen)
1512 {
1513  	return -ENOPROTOOPT;
1514 }
1515 
1516 static inline int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
1517 {
1518  	/* should not happen */
1519  	kfree_skb(skb);
1520 	return 0;
1521 }
1522 #endif
1523 
1524 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp);
1525 
1526 extern void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type);
1527 extern int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
1528 	int (*func)(struct xfrm_policy *, int, int, void*), void *);
1529 extern void xfrm_policy_walk_done(struct xfrm_policy_walk *walk);
1530 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl);
1531 struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark,
1532 					  u8 type, int dir,
1533 					  struct xfrm_selector *sel,
1534 					  struct xfrm_sec_ctx *ctx, int delete,
1535 					  int *err);
1536 struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8, int dir, u32 id, int delete, int *err);
1537 int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info);
1538 u32 xfrm_get_acqseq(void);
1539 extern int xfrm_alloc_spi(struct xfrm_state *x, u32 minspi, u32 maxspi);
1540 struct xfrm_state *xfrm_find_acq(struct net *net, struct xfrm_mark *mark,
1541 				 u8 mode, u32 reqid, u8 proto,
1542 				 const xfrm_address_t *daddr,
1543 				 const xfrm_address_t *saddr, int create,
1544 				 unsigned short family);
1545 extern int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol);
1546 
1547 #ifdef CONFIG_XFRM_MIGRATE
1548 extern int km_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
1549 		      const struct xfrm_migrate *m, int num_bundles,
1550 		      const struct xfrm_kmaddress *k);
1551 extern struct xfrm_state * xfrm_migrate_state_find(struct xfrm_migrate *m);
1552 extern struct xfrm_state * xfrm_state_migrate(struct xfrm_state *x,
1553 					      struct xfrm_migrate *m);
1554 extern int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
1555 			struct xfrm_migrate *m, int num_bundles,
1556 			struct xfrm_kmaddress *k);
1557 #endif
1558 
1559 extern int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport);
1560 extern void km_policy_expired(struct xfrm_policy *pol, int dir, int hard, u32 pid);
1561 extern int km_report(struct net *net, u8 proto, struct xfrm_selector *sel, xfrm_address_t *addr);
1562 
1563 extern void xfrm_input_init(void);
1564 extern int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq);
1565 
1566 extern void xfrm_probe_algs(void);
1567 extern int xfrm_count_auth_supported(void);
1568 extern int xfrm_count_enc_supported(void);
1569 extern struct xfrm_algo_desc *xfrm_aalg_get_byidx(unsigned int idx);
1570 extern struct xfrm_algo_desc *xfrm_ealg_get_byidx(unsigned int idx);
1571 extern struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id);
1572 extern struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id);
1573 extern struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id);
1574 extern struct xfrm_algo_desc *xfrm_aalg_get_byname(const char *name, int probe);
1575 extern struct xfrm_algo_desc *xfrm_ealg_get_byname(const char *name, int probe);
1576 extern struct xfrm_algo_desc *xfrm_calg_get_byname(const char *name, int probe);
1577 extern struct xfrm_algo_desc *xfrm_aead_get_byname(const char *name, int icv_len,
1578 						   int probe);
1579 
1580 static inline int xfrm_addr_cmp(const xfrm_address_t *a,
1581 				const xfrm_address_t *b,
1582 				int family)
1583 {
1584 	switch (family) {
1585 	default:
1586 	case AF_INET:
1587 		return (__force u32)a->a4 - (__force u32)b->a4;
1588 	case AF_INET6:
1589 		return ipv6_addr_cmp((const struct in6_addr *)a,
1590 				     (const struct in6_addr *)b);
1591 	}
1592 }
1593 
1594 static inline int xfrm_policy_id2dir(u32 index)
1595 {
1596 	return index & 7;
1597 }
1598 
1599 #ifdef CONFIG_XFRM
1600 static inline int xfrm_aevent_is_on(struct net *net)
1601 {
1602 	struct sock *nlsk;
1603 	int ret = 0;
1604 
1605 	rcu_read_lock();
1606 	nlsk = rcu_dereference(net->xfrm.nlsk);
1607 	if (nlsk)
1608 		ret = netlink_has_listeners(nlsk, XFRMNLGRP_AEVENTS);
1609 	rcu_read_unlock();
1610 	return ret;
1611 }
1612 #endif
1613 
1614 static inline int xfrm_alg_len(const struct xfrm_algo *alg)
1615 {
1616 	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
1617 }
1618 
1619 static inline int xfrm_alg_auth_len(const struct xfrm_algo_auth *alg)
1620 {
1621 	return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
1622 }
1623 
1624 static inline int xfrm_replay_state_esn_len(struct xfrm_replay_state_esn *replay_esn)
1625 {
1626 	return sizeof(*replay_esn) + replay_esn->bmp_len * sizeof(__u32);
1627 }
1628 
1629 #ifdef CONFIG_XFRM_MIGRATE
1630 static inline int xfrm_replay_clone(struct xfrm_state *x,
1631 				     struct xfrm_state *orig)
1632 {
1633 	x->replay_esn = kzalloc(xfrm_replay_state_esn_len(orig->replay_esn),
1634 				GFP_KERNEL);
1635 	if (!x->replay_esn)
1636 		return -ENOMEM;
1637 
1638 	x->replay_esn->bmp_len = orig->replay_esn->bmp_len;
1639 	x->replay_esn->replay_window = orig->replay_esn->replay_window;
1640 
1641 	x->preplay_esn = kmemdup(x->replay_esn,
1642 				 xfrm_replay_state_esn_len(x->replay_esn),
1643 				 GFP_KERNEL);
1644 	if (!x->preplay_esn) {
1645 		kfree(x->replay_esn);
1646 		return -ENOMEM;
1647 	}
1648 
1649 	return 0;
1650 }
1651 
1652 static inline struct xfrm_algo *xfrm_algo_clone(struct xfrm_algo *orig)
1653 {
1654 	return kmemdup(orig, xfrm_alg_len(orig), GFP_KERNEL);
1655 }
1656 
1657 static inline struct xfrm_algo_auth *xfrm_algo_auth_clone(struct xfrm_algo_auth *orig)
1658 {
1659 	return kmemdup(orig, xfrm_alg_auth_len(orig), GFP_KERNEL);
1660 }
1661 
1662 static inline void xfrm_states_put(struct xfrm_state **states, int n)
1663 {
1664 	int i;
1665 	for (i = 0; i < n; i++)
1666 		xfrm_state_put(*(states + i));
1667 }
1668 
1669 static inline void xfrm_states_delete(struct xfrm_state **states, int n)
1670 {
1671 	int i;
1672 	for (i = 0; i < n; i++)
1673 		xfrm_state_delete(*(states + i));
1674 }
1675 #endif
1676 
1677 #ifdef CONFIG_XFRM
1678 static inline struct xfrm_state *xfrm_input_state(struct sk_buff *skb)
1679 {
1680 	return skb->sp->xvec[skb->sp->len - 1];
1681 }
1682 #endif
1683 
1684 static inline int xfrm_mark_get(struct nlattr **attrs, struct xfrm_mark *m)
1685 {
1686 	if (attrs[XFRMA_MARK])
1687 		memcpy(m, nla_data(attrs[XFRMA_MARK]), sizeof(struct xfrm_mark));
1688 	else
1689 		m->v = m->m = 0;
1690 
1691 	return m->v & m->m;
1692 }
1693 
1694 static inline int xfrm_mark_put(struct sk_buff *skb, const struct xfrm_mark *m)
1695 {
1696 	int ret = 0;
1697 
1698 	if (m->m | m->v)
1699 		ret = nla_put(skb, XFRMA_MARK, sizeof(struct xfrm_mark), m);
1700 	return ret;
1701 }
1702 
1703 #endif	/* _NET_XFRM_H */
1704