xref: /openbmc/linux/include/net/ipv6.h (revision 089a49b6)
1 /*
2  *	Linux INET6 implementation
3  *
4  *	Authors:
5  *	Pedro Roque		<roque@di.fc.ul.pt>
6  *
7  *	This program is free software; you can redistribute it and/or
8  *      modify it under the terms of the GNU General Public License
9  *      as published by the Free Software Foundation; either version
10  *      2 of the License, or (at your option) any later version.
11  */
12 
13 #ifndef _NET_IPV6_H
14 #define _NET_IPV6_H
15 
16 #include <linux/ipv6.h>
17 #include <linux/hardirq.h>
18 #include <linux/jhash.h>
19 #include <net/if_inet6.h>
20 #include <net/ndisc.h>
21 #include <net/flow.h>
22 #include <net/snmp.h>
23 
24 #define SIN6_LEN_RFC2133	24
25 
26 #define IPV6_MAXPLEN		65535
27 
28 /*
29  *	NextHeader field of IPv6 header
30  */
31 
32 #define NEXTHDR_HOP		0	/* Hop-by-hop option header. */
33 #define NEXTHDR_TCP		6	/* TCP segment. */
34 #define NEXTHDR_UDP		17	/* UDP message. */
35 #define NEXTHDR_IPV6		41	/* IPv6 in IPv6 */
36 #define NEXTHDR_ROUTING		43	/* Routing header. */
37 #define NEXTHDR_FRAGMENT	44	/* Fragmentation/reassembly header. */
38 #define NEXTHDR_GRE		47	/* GRE header. */
39 #define NEXTHDR_ESP		50	/* Encapsulating security payload. */
40 #define NEXTHDR_AUTH		51	/* Authentication header. */
41 #define NEXTHDR_ICMP		58	/* ICMP for IPv6. */
42 #define NEXTHDR_NONE		59	/* No next header */
43 #define NEXTHDR_DEST		60	/* Destination options header. */
44 #define NEXTHDR_SCTP		132	/* SCTP message. */
45 #define NEXTHDR_MOBILITY	135	/* Mobility header. */
46 
47 #define NEXTHDR_MAX		255
48 
49 
50 
51 #define IPV6_DEFAULT_HOPLIMIT   64
52 #define IPV6_DEFAULT_MCASTHOPS	1
53 
54 /*
55  *	Addr type
56  *
57  *	type	-	unicast | multicast
58  *	scope	-	local	| site	    | global
59  *	v4	-	compat
60  *	v4mapped
61  *	any
62  *	loopback
63  */
64 
65 #define IPV6_ADDR_ANY		0x0000U
66 
67 #define IPV6_ADDR_UNICAST      	0x0001U
68 #define IPV6_ADDR_MULTICAST    	0x0002U
69 
70 #define IPV6_ADDR_LOOPBACK	0x0010U
71 #define IPV6_ADDR_LINKLOCAL	0x0020U
72 #define IPV6_ADDR_SITELOCAL	0x0040U
73 
74 #define IPV6_ADDR_COMPATv4	0x0080U
75 
76 #define IPV6_ADDR_SCOPE_MASK	0x00f0U
77 
78 #define IPV6_ADDR_MAPPED	0x1000U
79 
80 /*
81  *	Addr scopes
82  */
83 #define IPV6_ADDR_MC_SCOPE(a)	\
84 	((a)->s6_addr[1] & 0x0f)	/* nonstandard */
85 #define __IPV6_ADDR_SCOPE_INVALID	-1
86 #define IPV6_ADDR_SCOPE_NODELOCAL	0x01
87 #define IPV6_ADDR_SCOPE_LINKLOCAL	0x02
88 #define IPV6_ADDR_SCOPE_SITELOCAL	0x05
89 #define IPV6_ADDR_SCOPE_ORGLOCAL	0x08
90 #define IPV6_ADDR_SCOPE_GLOBAL		0x0e
91 
92 /*
93  *	Addr flags
94  */
95 #define IPV6_ADDR_MC_FLAG_TRANSIENT(a)	\
96 	((a)->s6_addr[1] & 0x10)
97 #define IPV6_ADDR_MC_FLAG_PREFIX(a)	\
98 	((a)->s6_addr[1] & 0x20)
99 #define IPV6_ADDR_MC_FLAG_RENDEZVOUS(a)	\
100 	((a)->s6_addr[1] & 0x40)
101 
102 /*
103  *	fragmentation header
104  */
105 
106 struct frag_hdr {
107 	__u8	nexthdr;
108 	__u8	reserved;
109 	__be16	frag_off;
110 	__be32	identification;
111 };
112 
113 #define	IP6_MF	0x0001
114 
115 #include <net/sock.h>
116 
117 /* sysctls */
118 extern int sysctl_mld_max_msf;
119 
120 #define _DEVINC(net, statname, modifier, idev, field)			\
121 ({									\
122 	struct inet6_dev *_idev = (idev);				\
123 	if (likely(_idev != NULL))					\
124 		SNMP_INC_STATS##modifier((_idev)->stats.statname, (field)); \
125 	SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
126 })
127 
128 /* per device counters are atomic_long_t */
129 #define _DEVINCATOMIC(net, statname, modifier, idev, field)		\
130 ({									\
131 	struct inet6_dev *_idev = (idev);				\
132 	if (likely(_idev != NULL))					\
133 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
134 	SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
135 })
136 
137 /* per device and per net counters are atomic_long_t */
138 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)		\
139 ({									\
140 	struct inet6_dev *_idev = (idev);				\
141 	if (likely(_idev != NULL))					\
142 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
143 	SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
144 })
145 
146 #define _DEVADD(net, statname, modifier, idev, field, val)		\
147 ({									\
148 	struct inet6_dev *_idev = (idev);				\
149 	if (likely(_idev != NULL))					\
150 		SNMP_ADD_STATS##modifier((_idev)->stats.statname, (field), (val)); \
151 	SNMP_ADD_STATS##modifier((net)->mib.statname##_statistics, (field), (val));\
152 })
153 
154 #define _DEVUPD(net, statname, modifier, idev, field, val)		\
155 ({									\
156 	struct inet6_dev *_idev = (idev);				\
157 	if (likely(_idev != NULL))					\
158 		SNMP_UPD_PO_STATS##modifier((_idev)->stats.statname, field, (val)); \
159 	SNMP_UPD_PO_STATS##modifier((net)->mib.statname##_statistics, field, (val));\
160 })
161 
162 /* MIBs */
163 
164 #define IP6_INC_STATS(net, idev,field)		\
165 		_DEVINC(net, ipv6, 64, idev, field)
166 #define IP6_INC_STATS_BH(net, idev,field)	\
167 		_DEVINC(net, ipv6, 64_BH, idev, field)
168 #define IP6_ADD_STATS(net, idev,field,val)	\
169 		_DEVADD(net, ipv6, 64, idev, field, val)
170 #define IP6_ADD_STATS_BH(net, idev,field,val)	\
171 		_DEVADD(net, ipv6, 64_BH, idev, field, val)
172 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
173 		_DEVUPD(net, ipv6, 64, idev, field, val)
174 #define IP6_UPD_PO_STATS_BH(net, idev,field,val)   \
175 		_DEVUPD(net, ipv6, 64_BH, idev, field, val)
176 #define ICMP6_INC_STATS(net, idev, field)	\
177 		_DEVINCATOMIC(net, icmpv6, , idev, field)
178 #define ICMP6_INC_STATS_BH(net, idev, field)	\
179 		_DEVINCATOMIC(net, icmpv6, _BH, idev, field)
180 
181 #define ICMP6MSGOUT_INC_STATS(net, idev, field)		\
182 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
183 #define ICMP6MSGOUT_INC_STATS_BH(net, idev, field)	\
184 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
185 #define ICMP6MSGIN_INC_STATS_BH(net, idev, field)	\
186 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
187 
188 struct ip6_ra_chain {
189 	struct ip6_ra_chain	*next;
190 	struct sock		*sk;
191 	int			sel;
192 	void			(*destructor)(struct sock *);
193 };
194 
195 extern struct ip6_ra_chain	*ip6_ra_chain;
196 extern rwlock_t ip6_ra_lock;
197 
198 /*
199    This structure is prepared by protocol, when parsing
200    ancillary data and passed to IPv6.
201  */
202 
203 struct ipv6_txoptions {
204 	/* Length of this structure */
205 	int			tot_len;
206 
207 	/* length of extension headers   */
208 
209 	__u16			opt_flen;	/* after fragment hdr */
210 	__u16			opt_nflen;	/* before fragment hdr */
211 
212 	struct ipv6_opt_hdr	*hopopt;
213 	struct ipv6_opt_hdr	*dst0opt;
214 	struct ipv6_rt_hdr	*srcrt;	/* Routing Header */
215 	struct ipv6_opt_hdr	*dst1opt;
216 
217 	/* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
218 };
219 
220 struct ip6_flowlabel {
221 	struct ip6_flowlabel __rcu *next;
222 	__be32			label;
223 	atomic_t		users;
224 	struct in6_addr		dst;
225 	struct ipv6_txoptions	*opt;
226 	unsigned long		linger;
227 	struct rcu_head		rcu;
228 	u8			share;
229 	union {
230 		struct pid *pid;
231 		kuid_t uid;
232 	} owner;
233 	unsigned long		lastuse;
234 	unsigned long		expires;
235 	struct net		*fl_net;
236 };
237 
238 #define IPV6_FLOWINFO_MASK	cpu_to_be32(0x0FFFFFFF)
239 #define IPV6_FLOWLABEL_MASK	cpu_to_be32(0x000FFFFF)
240 
241 struct ipv6_fl_socklist {
242 	struct ipv6_fl_socklist	__rcu	*next;
243 	struct ip6_flowlabel		*fl;
244 	struct rcu_head			rcu;
245 };
246 
247 extern struct ip6_flowlabel	*fl6_sock_lookup(struct sock *sk, __be32 label);
248 extern struct ipv6_txoptions	*fl6_merge_options(struct ipv6_txoptions * opt_space,
249 						   struct ip6_flowlabel * fl,
250 						   struct ipv6_txoptions * fopt);
251 extern void			fl6_free_socklist(struct sock *sk);
252 extern int			ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
253 extern int			ip6_flowlabel_init(void);
254 extern void			ip6_flowlabel_cleanup(void);
255 
256 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
257 {
258 	if (fl)
259 		atomic_dec(&fl->users);
260 }
261 
262 extern void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
263 
264 int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
265 			       struct icmp6hdr *thdr, int len);
266 
267 struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb,
268 				      struct sock *sk, struct flowi6 *fl6);
269 
270 extern int 			ip6_ra_control(struct sock *sk, int sel);
271 
272 extern int			ipv6_parse_hopopts(struct sk_buff *skb);
273 
274 extern struct ipv6_txoptions *  ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt);
275 extern struct ipv6_txoptions *	ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
276 						   int newtype,
277 						   struct ipv6_opt_hdr __user *newopt,
278 						   int newoptlen);
279 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
280 					  struct ipv6_txoptions *opt);
281 
282 extern bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb);
283 
284 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
285 {
286 	/* If forwarding is enabled, RA are not accepted unless the special
287 	 * hybrid mode (accept_ra=2) is enabled.
288 	 */
289 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
290 	    idev->cnf.accept_ra;
291 }
292 
293 #if IS_ENABLED(CONFIG_IPV6)
294 static inline int ip6_frag_nqueues(struct net *net)
295 {
296 	return net->ipv6.frags.nqueues;
297 }
298 
299 static inline int ip6_frag_mem(struct net *net)
300 {
301 	return sum_frag_mem_limit(&net->ipv6.frags);
302 }
303 #endif
304 
305 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
306 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
307 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
308 
309 extern int __ipv6_addr_type(const struct in6_addr *addr);
310 static inline int ipv6_addr_type(const struct in6_addr *addr)
311 {
312 	return __ipv6_addr_type(addr) & 0xffff;
313 }
314 
315 static inline int ipv6_addr_scope(const struct in6_addr *addr)
316 {
317 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
318 }
319 
320 static inline int __ipv6_addr_src_scope(int type)
321 {
322 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
323 }
324 
325 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
326 {
327 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
328 }
329 
330 static inline bool __ipv6_addr_needs_scope_id(int type)
331 {
332 	return type & IPV6_ADDR_LINKLOCAL ||
333 	       (type & IPV6_ADDR_MULTICAST &&
334 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
335 }
336 
337 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
338 {
339 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
340 }
341 
342 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
343 {
344 	return memcmp(a1, a2, sizeof(struct in6_addr));
345 }
346 
347 static inline bool
348 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
349 		     const struct in6_addr *a2)
350 {
351 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
352 	const unsigned long *ul1 = (const unsigned long *)a1;
353 	const unsigned long *ulm = (const unsigned long *)m;
354 	const unsigned long *ul2 = (const unsigned long *)a2;
355 
356 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
357 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
358 #else
359 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
360 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
361 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
362 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
363 #endif
364 }
365 
366 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
367 				    const struct in6_addr *addr,
368 				    int plen)
369 {
370 	/* caller must guarantee 0 <= plen <= 128 */
371 	int o = plen >> 3,
372 	    b = plen & 0x7;
373 
374 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
375 	memcpy(pfx->s6_addr, addr, o);
376 	if (b != 0)
377 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
378 }
379 
380 static inline void __ipv6_addr_set_half(__be32 *addr,
381 					__be32 wh, __be32 wl)
382 {
383 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
384 #if defined(__BIG_ENDIAN)
385 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
386 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
387 		return;
388 	}
389 #elif defined(__LITTLE_ENDIAN)
390 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
391 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
392 		return;
393 	}
394 #endif
395 #endif
396 	addr[0] = wh;
397 	addr[1] = wl;
398 }
399 
400 static inline void ipv6_addr_set(struct in6_addr *addr,
401 				     __be32 w1, __be32 w2,
402 				     __be32 w3, __be32 w4)
403 {
404 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
405 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
406 }
407 
408 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
409 				   const struct in6_addr *a2)
410 {
411 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
412 	const unsigned long *ul1 = (const unsigned long *)a1;
413 	const unsigned long *ul2 = (const unsigned long *)a2;
414 
415 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
416 #else
417 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
418 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
419 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
420 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
421 #endif
422 }
423 
424 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
425 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
426 					      const __be64 *a2,
427 					      unsigned int len)
428 {
429 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
430 		return false;
431 	return true;
432 }
433 
434 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
435 				     const struct in6_addr *addr2,
436 				     unsigned int prefixlen)
437 {
438 	const __be64 *a1 = (const __be64 *)addr1;
439 	const __be64 *a2 = (const __be64 *)addr2;
440 
441 	if (prefixlen >= 64) {
442 		if (a1[0] ^ a2[0])
443 			return false;
444 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
445 	}
446 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
447 }
448 #else
449 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
450 				     const struct in6_addr *addr2,
451 				     unsigned int prefixlen)
452 {
453 	const __be32 *a1 = addr1->s6_addr32;
454 	const __be32 *a2 = addr2->s6_addr32;
455 	unsigned int pdw, pbi;
456 
457 	/* check complete u32 in prefix */
458 	pdw = prefixlen >> 5;
459 	if (pdw && memcmp(a1, a2, pdw << 2))
460 		return false;
461 
462 	/* check incomplete u32 in prefix */
463 	pbi = prefixlen & 0x1f;
464 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
465 		return false;
466 
467 	return true;
468 }
469 #endif
470 
471 struct inet_frag_queue;
472 
473 enum ip6_defrag_users {
474 	IP6_DEFRAG_LOCAL_DELIVER,
475 	IP6_DEFRAG_CONNTRACK_IN,
476 	__IP6_DEFRAG_CONNTRACK_IN	= IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
477 	IP6_DEFRAG_CONNTRACK_OUT,
478 	__IP6_DEFRAG_CONNTRACK_OUT	= IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
479 	IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
480 	__IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
481 };
482 
483 struct ip6_create_arg {
484 	__be32 id;
485 	u32 user;
486 	const struct in6_addr *src;
487 	const struct in6_addr *dst;
488 	u8 ecn;
489 };
490 
491 void ip6_frag_init(struct inet_frag_queue *q, void *a);
492 bool ip6_frag_match(struct inet_frag_queue *q, void *a);
493 
494 /*
495  *	Equivalent of ipv4 struct ip
496  */
497 struct frag_queue {
498 	struct inet_frag_queue	q;
499 
500 	__be32			id;		/* fragment id		*/
501 	u32			user;
502 	struct in6_addr		saddr;
503 	struct in6_addr		daddr;
504 
505 	int			iif;
506 	unsigned int		csum;
507 	__u16			nhoffset;
508 	u8			ecn;
509 };
510 
511 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
512 			   struct inet_frags *frags);
513 
514 static inline bool ipv6_addr_any(const struct in6_addr *a)
515 {
516 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
517 	const unsigned long *ul = (const unsigned long *)a;
518 
519 	return (ul[0] | ul[1]) == 0UL;
520 #else
521 	return (a->s6_addr32[0] | a->s6_addr32[1] |
522 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
523 #endif
524 }
525 
526 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
527 {
528 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
529 	const unsigned long *ul = (const unsigned long *)a;
530 	unsigned long x = ul[0] ^ ul[1];
531 
532 	return (u32)(x ^ (x >> 32));
533 #else
534 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
535 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
536 #endif
537 }
538 
539 /* more secured version of ipv6_addr_hash() */
540 static inline u32 ipv6_addr_jhash(const struct in6_addr *a)
541 {
542 	u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
543 
544 	return jhash_3words(v,
545 			    (__force u32)a->s6_addr32[2],
546 			    (__force u32)a->s6_addr32[3],
547 			    ipv6_hash_secret);
548 }
549 
550 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
551 {
552 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
553 	const unsigned long *ul = (const unsigned long *)a;
554 
555 	return (ul[0] | (ul[1] ^ cpu_to_be64(1))) == 0UL;
556 #else
557 	return (a->s6_addr32[0] | a->s6_addr32[1] |
558 		a->s6_addr32[2] | (a->s6_addr32[3] ^ htonl(1))) == 0;
559 #endif
560 }
561 
562 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
563 {
564 	return (
565 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
566 		*(__be64 *)a |
567 #else
568 		(a->s6_addr32[0] | a->s6_addr32[1]) |
569 #endif
570 		(a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0UL;
571 }
572 
573 /*
574  * Check for a RFC 4843 ORCHID address
575  * (Overlay Routable Cryptographic Hash Identifiers)
576  */
577 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
578 {
579 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
580 }
581 
582 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
583 					  struct in6_addr *v4mapped)
584 {
585 	ipv6_addr_set(v4mapped,
586 			0, 0,
587 			htonl(0x0000FFFF),
588 			addr);
589 }
590 
591 /*
592  * find the first different bit between two addresses
593  * length of address must be a multiple of 32bits
594  */
595 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
596 {
597 	const __be32 *a1 = token1, *a2 = token2;
598 	int i;
599 
600 	addrlen >>= 2;
601 
602 	for (i = 0; i < addrlen; i++) {
603 		__be32 xb = a1[i] ^ a2[i];
604 		if (xb)
605 			return i * 32 + 31 - __fls(ntohl(xb));
606 	}
607 
608 	/*
609 	 *	we should *never* get to this point since that
610 	 *	would mean the addrs are equal
611 	 *
612 	 *	However, we do get to it 8) And exacly, when
613 	 *	addresses are equal 8)
614 	 *
615 	 *	ip route add 1111::/128 via ...
616 	 *	ip route add 1111::/64 via ...
617 	 *	and we are here.
618 	 *
619 	 *	Ideally, this function should stop comparison
620 	 *	at prefix length. It does not, but it is still OK,
621 	 *	if returned value is greater than prefix length.
622 	 *					--ANK (980803)
623 	 */
624 	return addrlen << 5;
625 }
626 
627 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
628 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
629 {
630 	const __be64 *a1 = token1, *a2 = token2;
631 	int i;
632 
633 	addrlen >>= 3;
634 
635 	for (i = 0; i < addrlen; i++) {
636 		__be64 xb = a1[i] ^ a2[i];
637 		if (xb)
638 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
639 	}
640 
641 	return addrlen << 6;
642 }
643 #endif
644 
645 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
646 {
647 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
648 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
649 		return __ipv6_addr_diff64(token1, token2, addrlen);
650 #endif
651 	return __ipv6_addr_diff32(token1, token2, addrlen);
652 }
653 
654 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
655 {
656 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
657 }
658 
659 extern void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt);
660 
661 extern int ip6_dst_hoplimit(struct dst_entry *dst);
662 
663 /*
664  *	Header manipulation
665  */
666 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
667 				__be32 flowlabel)
668 {
669 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
670 }
671 
672 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
673 {
674 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
675 }
676 
677 /*
678  *	Prototypes exported by ipv6
679  */
680 
681 /*
682  *	rcv function (called from netdevice level)
683  */
684 
685 extern int			ipv6_rcv(struct sk_buff *skb,
686 					 struct net_device *dev,
687 					 struct packet_type *pt,
688 					 struct net_device *orig_dev);
689 
690 extern int			ip6_rcv_finish(struct sk_buff *skb);
691 
692 /*
693  *	upper-layer output functions
694  */
695 extern int			ip6_xmit(struct sock *sk,
696 					 struct sk_buff *skb,
697 					 struct flowi6 *fl6,
698 					 struct ipv6_txoptions *opt,
699 					 int tclass);
700 
701 extern int			ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
702 
703 extern int			ip6_append_data(struct sock *sk,
704 						int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb),
705 		    				void *from,
706 						int length,
707 						int transhdrlen,
708 		      				int hlimit,
709 		      				int tclass,
710 						struct ipv6_txoptions *opt,
711 						struct flowi6 *fl6,
712 						struct rt6_info *rt,
713 						unsigned int flags,
714 						int dontfrag);
715 
716 extern int			ip6_push_pending_frames(struct sock *sk);
717 
718 extern void			ip6_flush_pending_frames(struct sock *sk);
719 
720 extern int			ip6_dst_lookup(struct sock *sk,
721 					       struct dst_entry **dst,
722 					       struct flowi6 *fl6);
723 extern struct dst_entry *	ip6_dst_lookup_flow(struct sock *sk,
724 						    struct flowi6 *fl6,
725 						    const struct in6_addr *final_dst,
726 						    bool can_sleep);
727 extern struct dst_entry *	ip6_sk_dst_lookup_flow(struct sock *sk,
728 						       struct flowi6 *fl6,
729 						       const struct in6_addr *final_dst,
730 						       bool can_sleep);
731 extern struct dst_entry *	ip6_blackhole_route(struct net *net,
732 						    struct dst_entry *orig_dst);
733 
734 /*
735  *	skb processing functions
736  */
737 
738 extern int			ip6_output(struct sk_buff *skb);
739 extern int			ip6_forward(struct sk_buff *skb);
740 extern int			ip6_input(struct sk_buff *skb);
741 extern int			ip6_mc_input(struct sk_buff *skb);
742 
743 extern int			__ip6_local_out(struct sk_buff *skb);
744 extern int			ip6_local_out(struct sk_buff *skb);
745 
746 /*
747  *	Extension header (options) processing
748  */
749 
750 extern void 			ipv6_push_nfrag_opts(struct sk_buff *skb,
751 						     struct ipv6_txoptions *opt,
752 						     u8 *proto,
753 						     struct in6_addr **daddr_p);
754 extern void			ipv6_push_frag_opts(struct sk_buff *skb,
755 						    struct ipv6_txoptions *opt,
756 						    u8 *proto);
757 
758 extern int			ipv6_skip_exthdr(const struct sk_buff *, int start,
759 					         u8 *nexthdrp, __be16 *frag_offp);
760 
761 extern bool			ipv6_ext_hdr(u8 nexthdr);
762 
763 enum {
764 	IP6_FH_F_FRAG		= (1 << 0),
765 	IP6_FH_F_AUTH		= (1 << 1),
766 	IP6_FH_F_SKIP_RH	= (1 << 2),
767 };
768 
769 /* find specified header and get offset to it */
770 extern int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
771 			 int target, unsigned short *fragoff, int *fragflg);
772 
773 extern int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
774 
775 extern struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
776 				       const struct ipv6_txoptions *opt,
777 				       struct in6_addr *orig);
778 
779 /*
780  *	socket options (ipv6_sockglue.c)
781  */
782 
783 extern int			ipv6_setsockopt(struct sock *sk, int level,
784 						int optname,
785 						char __user *optval,
786 						unsigned int optlen);
787 extern int			ipv6_getsockopt(struct sock *sk, int level,
788 						int optname,
789 						char __user *optval,
790 						int __user *optlen);
791 extern int			compat_ipv6_setsockopt(struct sock *sk,
792 						int level,
793 						int optname,
794 						char __user *optval,
795 						unsigned int optlen);
796 extern int			compat_ipv6_getsockopt(struct sock *sk,
797 						int level,
798 						int optname,
799 						char __user *optval,
800 						int __user *optlen);
801 
802 extern int			ip6_datagram_connect(struct sock *sk,
803 						     struct sockaddr *addr, int addr_len);
804 
805 extern int 			ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len);
806 extern int 			ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len);
807 extern void			ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
808 						u32 info, u8 *payload);
809 extern void			ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
810 extern void			ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
811 
812 extern int inet6_release(struct socket *sock);
813 extern int inet6_bind(struct socket *sock, struct sockaddr *uaddr,
814 		      int addr_len);
815 extern int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
816 			 int *uaddr_len, int peer);
817 extern int inet6_ioctl(struct socket *sock, unsigned int cmd,
818 		       unsigned long arg);
819 
820 extern int inet6_hash_connect(struct inet_timewait_death_row *death_row,
821 			      struct sock *sk);
822 
823 /*
824  * reassembly.c
825  */
826 extern const struct proto_ops inet6_stream_ops;
827 extern const struct proto_ops inet6_dgram_ops;
828 
829 struct group_source_req;
830 struct group_filter;
831 
832 extern int ip6_mc_source(int add, int omode, struct sock *sk,
833 			 struct group_source_req *pgsr);
834 extern int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
835 extern int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
836 			 struct group_filter __user *optval,
837 			 int __user *optlen);
838 extern unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
839 				    const struct in6_addr *daddr, u32 rnd);
840 
841 #ifdef CONFIG_PROC_FS
842 extern int  ac6_proc_init(struct net *net);
843 extern void ac6_proc_exit(struct net *net);
844 extern int  raw6_proc_init(void);
845 extern void raw6_proc_exit(void);
846 extern int  tcp6_proc_init(struct net *net);
847 extern void tcp6_proc_exit(struct net *net);
848 extern int  udp6_proc_init(struct net *net);
849 extern void udp6_proc_exit(struct net *net);
850 extern int  udplite6_proc_init(void);
851 extern void udplite6_proc_exit(void);
852 extern int  ipv6_misc_proc_init(void);
853 extern void ipv6_misc_proc_exit(void);
854 extern int snmp6_register_dev(struct inet6_dev *idev);
855 extern int snmp6_unregister_dev(struct inet6_dev *idev);
856 
857 #else
858 static inline int ac6_proc_init(struct net *net) { return 0; }
859 static inline void ac6_proc_exit(struct net *net) { }
860 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
861 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
862 #endif
863 
864 #ifdef CONFIG_SYSCTL
865 extern struct ctl_table ipv6_route_table_template[];
866 extern struct ctl_table ipv6_icmp_table_template[];
867 
868 extern struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
869 extern struct ctl_table *ipv6_route_sysctl_init(struct net *net);
870 extern int ipv6_sysctl_register(void);
871 extern void ipv6_sysctl_unregister(void);
872 #endif
873 
874 #endif /* _NET_IPV6_H */
875