xref: /linux/include/net/ipv6.h (revision ff5599816711d2e67da2d7561fd36ac48debd433)
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_MOBILITY	135	/* Mobility header. */
45 
46 #define NEXTHDR_MAX		255
47 
48 
49 
50 #define IPV6_DEFAULT_HOPLIMIT   64
51 #define IPV6_DEFAULT_MCASTHOPS	1
52 
53 /*
54  *	Addr type
55  *
56  *	type	-	unicast | multicast
57  *	scope	-	local	| site	    | global
58  *	v4	-	compat
59  *	v4mapped
60  *	any
61  *	loopback
62  */
63 
64 #define IPV6_ADDR_ANY		0x0000U
65 
66 #define IPV6_ADDR_UNICAST      	0x0001U
67 #define IPV6_ADDR_MULTICAST    	0x0002U
68 
69 #define IPV6_ADDR_LOOPBACK	0x0010U
70 #define IPV6_ADDR_LINKLOCAL	0x0020U
71 #define IPV6_ADDR_SITELOCAL	0x0040U
72 
73 #define IPV6_ADDR_COMPATv4	0x0080U
74 
75 #define IPV6_ADDR_SCOPE_MASK	0x00f0U
76 
77 #define IPV6_ADDR_MAPPED	0x1000U
78 
79 /*
80  *	Addr scopes
81  */
82 #define IPV6_ADDR_MC_SCOPE(a)	\
83 	((a)->s6_addr[1] & 0x0f)	/* nonstandard */
84 #define __IPV6_ADDR_SCOPE_INVALID	-1
85 #define IPV6_ADDR_SCOPE_NODELOCAL	0x01
86 #define IPV6_ADDR_SCOPE_LINKLOCAL	0x02
87 #define IPV6_ADDR_SCOPE_SITELOCAL	0x05
88 #define IPV6_ADDR_SCOPE_ORGLOCAL	0x08
89 #define IPV6_ADDR_SCOPE_GLOBAL		0x0e
90 
91 /*
92  *	Addr flags
93  */
94 #define IPV6_ADDR_MC_FLAG_TRANSIENT(a)	\
95 	((a)->s6_addr[1] & 0x10)
96 #define IPV6_ADDR_MC_FLAG_PREFIX(a)	\
97 	((a)->s6_addr[1] & 0x20)
98 #define IPV6_ADDR_MC_FLAG_RENDEZVOUS(a)	\
99 	((a)->s6_addr[1] & 0x40)
100 
101 /*
102  *	fragmentation header
103  */
104 
105 struct frag_hdr {
106 	__u8	nexthdr;
107 	__u8	reserved;
108 	__be16	frag_off;
109 	__be32	identification;
110 };
111 
112 #define	IP6_MF	0x0001
113 
114 #include <net/sock.h>
115 
116 /* sysctls */
117 extern int sysctl_mld_max_msf;
118 
119 #define _DEVINC(net, statname, modifier, idev, field)			\
120 ({									\
121 	struct inet6_dev *_idev = (idev);				\
122 	if (likely(_idev != NULL))					\
123 		SNMP_INC_STATS##modifier((_idev)->stats.statname, (field)); \
124 	SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
125 })
126 
127 /* per device counters are atomic_long_t */
128 #define _DEVINCATOMIC(net, statname, modifier, idev, field)		\
129 ({									\
130 	struct inet6_dev *_idev = (idev);				\
131 	if (likely(_idev != NULL))					\
132 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
133 	SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
134 })
135 
136 /* per device and per net counters are atomic_long_t */
137 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)		\
138 ({									\
139 	struct inet6_dev *_idev = (idev);				\
140 	if (likely(_idev != NULL))					\
141 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
142 	SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
143 })
144 
145 #define _DEVADD(net, statname, modifier, idev, field, val)		\
146 ({									\
147 	struct inet6_dev *_idev = (idev);				\
148 	if (likely(_idev != NULL))					\
149 		SNMP_ADD_STATS##modifier((_idev)->stats.statname, (field), (val)); \
150 	SNMP_ADD_STATS##modifier((net)->mib.statname##_statistics, (field), (val));\
151 })
152 
153 #define _DEVUPD(net, statname, modifier, idev, field, val)		\
154 ({									\
155 	struct inet6_dev *_idev = (idev);				\
156 	if (likely(_idev != NULL))					\
157 		SNMP_UPD_PO_STATS##modifier((_idev)->stats.statname, field, (val)); \
158 	SNMP_UPD_PO_STATS##modifier((net)->mib.statname##_statistics, field, (val));\
159 })
160 
161 /* MIBs */
162 
163 #define IP6_INC_STATS(net, idev,field)		\
164 		_DEVINC(net, ipv6, 64, idev, field)
165 #define IP6_INC_STATS_BH(net, idev,field)	\
166 		_DEVINC(net, ipv6, 64_BH, idev, field)
167 #define IP6_ADD_STATS(net, idev,field,val)	\
168 		_DEVADD(net, ipv6, 64, idev, field, val)
169 #define IP6_ADD_STATS_BH(net, idev,field,val)	\
170 		_DEVADD(net, ipv6, 64_BH, idev, field, val)
171 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
172 		_DEVUPD(net, ipv6, 64, idev, field, val)
173 #define IP6_UPD_PO_STATS_BH(net, idev,field,val)   \
174 		_DEVUPD(net, ipv6, 64_BH, idev, field, val)
175 #define ICMP6_INC_STATS(net, idev, field)	\
176 		_DEVINCATOMIC(net, icmpv6, , idev, field)
177 #define ICMP6_INC_STATS_BH(net, idev, field)	\
178 		_DEVINCATOMIC(net, icmpv6, _BH, idev, field)
179 
180 #define ICMP6MSGOUT_INC_STATS(net, idev, field)		\
181 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
182 #define ICMP6MSGOUT_INC_STATS_BH(net, idev, field)	\
183 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
184 #define ICMP6MSGIN_INC_STATS_BH(net, idev, field)	\
185 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
186 
187 struct ip6_ra_chain {
188 	struct ip6_ra_chain	*next;
189 	struct sock		*sk;
190 	int			sel;
191 	void			(*destructor)(struct sock *);
192 };
193 
194 extern struct ip6_ra_chain	*ip6_ra_chain;
195 extern rwlock_t ip6_ra_lock;
196 
197 /*
198    This structure is prepared by protocol, when parsing
199    ancillary data and passed to IPv6.
200  */
201 
202 struct ipv6_txoptions {
203 	/* Length of this structure */
204 	int			tot_len;
205 
206 	/* length of extension headers   */
207 
208 	__u16			opt_flen;	/* after fragment hdr */
209 	__u16			opt_nflen;	/* before fragment hdr */
210 
211 	struct ipv6_opt_hdr	*hopopt;
212 	struct ipv6_opt_hdr	*dst0opt;
213 	struct ipv6_rt_hdr	*srcrt;	/* Routing Header */
214 	struct ipv6_opt_hdr	*dst1opt;
215 
216 	/* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
217 };
218 
219 struct ip6_flowlabel {
220 	struct ip6_flowlabel __rcu *next;
221 	__be32			label;
222 	atomic_t		users;
223 	struct in6_addr		dst;
224 	struct ipv6_txoptions	*opt;
225 	unsigned long		linger;
226 	struct rcu_head		rcu;
227 	u8			share;
228 	union {
229 		struct pid *pid;
230 		kuid_t uid;
231 	} owner;
232 	unsigned long		lastuse;
233 	unsigned long		expires;
234 	struct net		*fl_net;
235 };
236 
237 #define IPV6_FLOWINFO_MASK	cpu_to_be32(0x0FFFFFFF)
238 #define IPV6_FLOWLABEL_MASK	cpu_to_be32(0x000FFFFF)
239 
240 struct ipv6_fl_socklist {
241 	struct ipv6_fl_socklist	__rcu	*next;
242 	struct ip6_flowlabel		*fl;
243 	struct rcu_head			rcu;
244 };
245 
246 extern struct ip6_flowlabel	*fl6_sock_lookup(struct sock *sk, __be32 label);
247 extern struct ipv6_txoptions	*fl6_merge_options(struct ipv6_txoptions * opt_space,
248 						   struct ip6_flowlabel * fl,
249 						   struct ipv6_txoptions * fopt);
250 extern void			fl6_free_socklist(struct sock *sk);
251 extern int			ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
252 extern int			ip6_flowlabel_init(void);
253 extern void			ip6_flowlabel_cleanup(void);
254 
255 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
256 {
257 	if (fl)
258 		atomic_dec(&fl->users);
259 }
260 
261 extern void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
262 
263 int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
264 			       struct icmp6hdr *thdr, int len);
265 
266 struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb,
267 				      struct sock *sk, struct flowi6 *fl6);
268 
269 extern int 			ip6_ra_control(struct sock *sk, int sel);
270 
271 extern int			ipv6_parse_hopopts(struct sk_buff *skb);
272 
273 extern struct ipv6_txoptions *  ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt);
274 extern struct ipv6_txoptions *	ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
275 						   int newtype,
276 						   struct ipv6_opt_hdr __user *newopt,
277 						   int newoptlen);
278 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
279 					  struct ipv6_txoptions *opt);
280 
281 extern bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb);
282 
283 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
284 {
285 	/* If forwarding is enabled, RA are not accepted unless the special
286 	 * hybrid mode (accept_ra=2) is enabled.
287 	 */
288 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
289 	    idev->cnf.accept_ra;
290 }
291 
292 #if IS_ENABLED(CONFIG_IPV6)
293 static inline int ip6_frag_nqueues(struct net *net)
294 {
295 	return net->ipv6.frags.nqueues;
296 }
297 
298 static inline int ip6_frag_mem(struct net *net)
299 {
300 	return sum_frag_mem_limit(&net->ipv6.frags);
301 }
302 #endif
303 
304 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
305 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
306 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
307 
308 extern int __ipv6_addr_type(const struct in6_addr *addr);
309 static inline int ipv6_addr_type(const struct in6_addr *addr)
310 {
311 	return __ipv6_addr_type(addr) & 0xffff;
312 }
313 
314 static inline int ipv6_addr_scope(const struct in6_addr *addr)
315 {
316 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
317 }
318 
319 static inline int __ipv6_addr_src_scope(int type)
320 {
321 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
322 }
323 
324 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
325 {
326 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
327 }
328 
329 static inline bool __ipv6_addr_needs_scope_id(int type)
330 {
331 	return type & IPV6_ADDR_LINKLOCAL ||
332 	       (type & IPV6_ADDR_MULTICAST &&
333 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
334 }
335 
336 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
337 {
338 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
339 }
340 
341 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
342 {
343 	return memcmp(a1, a2, sizeof(struct in6_addr));
344 }
345 
346 static inline bool
347 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
348 		     const struct in6_addr *a2)
349 {
350 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
351 	const unsigned long *ul1 = (const unsigned long *)a1;
352 	const unsigned long *ulm = (const unsigned long *)m;
353 	const unsigned long *ul2 = (const unsigned long *)a2;
354 
355 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
356 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
357 #else
358 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
359 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
360 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
361 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
362 #endif
363 }
364 
365 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
366 				    const struct in6_addr *addr,
367 				    int plen)
368 {
369 	/* caller must guarantee 0 <= plen <= 128 */
370 	int o = plen >> 3,
371 	    b = plen & 0x7;
372 
373 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
374 	memcpy(pfx->s6_addr, addr, o);
375 	if (b != 0)
376 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
377 }
378 
379 static inline void __ipv6_addr_set_half(__be32 *addr,
380 					__be32 wh, __be32 wl)
381 {
382 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
383 #if defined(__BIG_ENDIAN)
384 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
385 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
386 		return;
387 	}
388 #elif defined(__LITTLE_ENDIAN)
389 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
390 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
391 		return;
392 	}
393 #endif
394 #endif
395 	addr[0] = wh;
396 	addr[1] = wl;
397 }
398 
399 static inline void ipv6_addr_set(struct in6_addr *addr,
400 				     __be32 w1, __be32 w2,
401 				     __be32 w3, __be32 w4)
402 {
403 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
404 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
405 }
406 
407 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
408 				   const struct in6_addr *a2)
409 {
410 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
411 	const unsigned long *ul1 = (const unsigned long *)a1;
412 	const unsigned long *ul2 = (const unsigned long *)a2;
413 
414 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
415 #else
416 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
417 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
418 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
419 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
420 #endif
421 }
422 
423 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
424 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
425 					      const __be64 *a2,
426 					      unsigned int len)
427 {
428 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
429 		return false;
430 	return true;
431 }
432 
433 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
434 				     const struct in6_addr *addr2,
435 				     unsigned int prefixlen)
436 {
437 	const __be64 *a1 = (const __be64 *)addr1;
438 	const __be64 *a2 = (const __be64 *)addr2;
439 
440 	if (prefixlen >= 64) {
441 		if (a1[0] ^ a2[0])
442 			return false;
443 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
444 	}
445 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
446 }
447 #else
448 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
449 				     const struct in6_addr *addr2,
450 				     unsigned int prefixlen)
451 {
452 	const __be32 *a1 = addr1->s6_addr32;
453 	const __be32 *a2 = addr2->s6_addr32;
454 	unsigned int pdw, pbi;
455 
456 	/* check complete u32 in prefix */
457 	pdw = prefixlen >> 5;
458 	if (pdw && memcmp(a1, a2, pdw << 2))
459 		return false;
460 
461 	/* check incomplete u32 in prefix */
462 	pbi = prefixlen & 0x1f;
463 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
464 		return false;
465 
466 	return true;
467 }
468 #endif
469 
470 struct inet_frag_queue;
471 
472 enum ip6_defrag_users {
473 	IP6_DEFRAG_LOCAL_DELIVER,
474 	IP6_DEFRAG_CONNTRACK_IN,
475 	__IP6_DEFRAG_CONNTRACK_IN	= IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
476 	IP6_DEFRAG_CONNTRACK_OUT,
477 	__IP6_DEFRAG_CONNTRACK_OUT	= IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
478 	IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
479 	__IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
480 };
481 
482 struct ip6_create_arg {
483 	__be32 id;
484 	u32 user;
485 	const struct in6_addr *src;
486 	const struct in6_addr *dst;
487 	u8 ecn;
488 };
489 
490 void ip6_frag_init(struct inet_frag_queue *q, void *a);
491 bool ip6_frag_match(struct inet_frag_queue *q, void *a);
492 
493 /*
494  *	Equivalent of ipv4 struct ip
495  */
496 struct frag_queue {
497 	struct inet_frag_queue	q;
498 
499 	__be32			id;		/* fragment id		*/
500 	u32			user;
501 	struct in6_addr		saddr;
502 	struct in6_addr		daddr;
503 
504 	int			iif;
505 	unsigned int		csum;
506 	__u16			nhoffset;
507 	u8			ecn;
508 };
509 
510 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
511 			   struct inet_frags *frags);
512 
513 static inline bool ipv6_addr_any(const struct in6_addr *a)
514 {
515 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
516 	const unsigned long *ul = (const unsigned long *)a;
517 
518 	return (ul[0] | ul[1]) == 0UL;
519 #else
520 	return (a->s6_addr32[0] | a->s6_addr32[1] |
521 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
522 #endif
523 }
524 
525 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
526 {
527 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
528 	const unsigned long *ul = (const unsigned long *)a;
529 	unsigned long x = ul[0] ^ ul[1];
530 
531 	return (u32)(x ^ (x >> 32));
532 #else
533 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
534 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
535 #endif
536 }
537 
538 /* more secured version of ipv6_addr_hash() */
539 static inline u32 ipv6_addr_jhash(const struct in6_addr *a)
540 {
541 	u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
542 
543 	return jhash_3words(v,
544 			    (__force u32)a->s6_addr32[2],
545 			    (__force u32)a->s6_addr32[3],
546 			    ipv6_hash_secret);
547 }
548 
549 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
550 {
551 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
552 	const unsigned long *ul = (const unsigned long *)a;
553 
554 	return (ul[0] | (ul[1] ^ cpu_to_be64(1))) == 0UL;
555 #else
556 	return (a->s6_addr32[0] | a->s6_addr32[1] |
557 		a->s6_addr32[2] | (a->s6_addr32[3] ^ htonl(1))) == 0;
558 #endif
559 }
560 
561 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
562 {
563 	return (
564 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
565 		*(__be64 *)a |
566 #else
567 		(a->s6_addr32[0] | a->s6_addr32[1]) |
568 #endif
569 		(a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0UL;
570 }
571 
572 /*
573  * Check for a RFC 4843 ORCHID address
574  * (Overlay Routable Cryptographic Hash Identifiers)
575  */
576 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
577 {
578 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
579 }
580 
581 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
582 					  struct in6_addr *v4mapped)
583 {
584 	ipv6_addr_set(v4mapped,
585 			0, 0,
586 			htonl(0x0000FFFF),
587 			addr);
588 }
589 
590 /*
591  * find the first different bit between two addresses
592  * length of address must be a multiple of 32bits
593  */
594 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
595 {
596 	const __be32 *a1 = token1, *a2 = token2;
597 	int i;
598 
599 	addrlen >>= 2;
600 
601 	for (i = 0; i < addrlen; i++) {
602 		__be32 xb = a1[i] ^ a2[i];
603 		if (xb)
604 			return i * 32 + 31 - __fls(ntohl(xb));
605 	}
606 
607 	/*
608 	 *	we should *never* get to this point since that
609 	 *	would mean the addrs are equal
610 	 *
611 	 *	However, we do get to it 8) And exacly, when
612 	 *	addresses are equal 8)
613 	 *
614 	 *	ip route add 1111::/128 via ...
615 	 *	ip route add 1111::/64 via ...
616 	 *	and we are here.
617 	 *
618 	 *	Ideally, this function should stop comparison
619 	 *	at prefix length. It does not, but it is still OK,
620 	 *	if returned value is greater than prefix length.
621 	 *					--ANK (980803)
622 	 */
623 	return addrlen << 5;
624 }
625 
626 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
627 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
628 {
629 	const __be64 *a1 = token1, *a2 = token2;
630 	int i;
631 
632 	addrlen >>= 3;
633 
634 	for (i = 0; i < addrlen; i++) {
635 		__be64 xb = a1[i] ^ a2[i];
636 		if (xb)
637 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
638 	}
639 
640 	return addrlen << 6;
641 }
642 #endif
643 
644 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
645 {
646 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
647 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
648 		return __ipv6_addr_diff64(token1, token2, addrlen);
649 #endif
650 	return __ipv6_addr_diff32(token1, token2, addrlen);
651 }
652 
653 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
654 {
655 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
656 }
657 
658 extern void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt);
659 
660 /*
661  *	Header manipulation
662  */
663 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
664 				__be32 flowlabel)
665 {
666 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
667 }
668 
669 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
670 {
671 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
672 }
673 
674 /*
675  *	Prototypes exported by ipv6
676  */
677 
678 /*
679  *	rcv function (called from netdevice level)
680  */
681 
682 extern int			ipv6_rcv(struct sk_buff *skb,
683 					 struct net_device *dev,
684 					 struct packet_type *pt,
685 					 struct net_device *orig_dev);
686 
687 extern int			ip6_rcv_finish(struct sk_buff *skb);
688 
689 /*
690  *	upper-layer output functions
691  */
692 extern int			ip6_xmit(struct sock *sk,
693 					 struct sk_buff *skb,
694 					 struct flowi6 *fl6,
695 					 struct ipv6_txoptions *opt,
696 					 int tclass);
697 
698 extern int			ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
699 
700 extern int			ip6_append_data(struct sock *sk,
701 						int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb),
702 		    				void *from,
703 						int length,
704 						int transhdrlen,
705 		      				int hlimit,
706 		      				int tclass,
707 						struct ipv6_txoptions *opt,
708 						struct flowi6 *fl6,
709 						struct rt6_info *rt,
710 						unsigned int flags,
711 						int dontfrag);
712 
713 extern int			ip6_push_pending_frames(struct sock *sk);
714 
715 extern void			ip6_flush_pending_frames(struct sock *sk);
716 
717 extern int			ip6_dst_lookup(struct sock *sk,
718 					       struct dst_entry **dst,
719 					       struct flowi6 *fl6);
720 extern struct dst_entry *	ip6_dst_lookup_flow(struct sock *sk,
721 						    struct flowi6 *fl6,
722 						    const struct in6_addr *final_dst,
723 						    bool can_sleep);
724 extern struct dst_entry *	ip6_sk_dst_lookup_flow(struct sock *sk,
725 						       struct flowi6 *fl6,
726 						       const struct in6_addr *final_dst,
727 						       bool can_sleep);
728 extern struct dst_entry *	ip6_blackhole_route(struct net *net,
729 						    struct dst_entry *orig_dst);
730 
731 /*
732  *	skb processing functions
733  */
734 
735 extern int			ip6_output(struct sk_buff *skb);
736 extern int			ip6_forward(struct sk_buff *skb);
737 extern int			ip6_input(struct sk_buff *skb);
738 extern int			ip6_mc_input(struct sk_buff *skb);
739 
740 extern int			__ip6_local_out(struct sk_buff *skb);
741 extern int			ip6_local_out(struct sk_buff *skb);
742 
743 /*
744  *	Extension header (options) processing
745  */
746 
747 extern void 			ipv6_push_nfrag_opts(struct sk_buff *skb,
748 						     struct ipv6_txoptions *opt,
749 						     u8 *proto,
750 						     struct in6_addr **daddr_p);
751 extern void			ipv6_push_frag_opts(struct sk_buff *skb,
752 						    struct ipv6_txoptions *opt,
753 						    u8 *proto);
754 
755 extern int			ipv6_skip_exthdr(const struct sk_buff *, int start,
756 					         u8 *nexthdrp, __be16 *frag_offp);
757 
758 extern bool			ipv6_ext_hdr(u8 nexthdr);
759 
760 enum {
761 	IP6_FH_F_FRAG		= (1 << 0),
762 	IP6_FH_F_AUTH		= (1 << 1),
763 	IP6_FH_F_SKIP_RH	= (1 << 2),
764 };
765 
766 /* find specified header and get offset to it */
767 extern int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
768 			 int target, unsigned short *fragoff, int *fragflg);
769 
770 extern int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
771 
772 extern struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
773 				       const struct ipv6_txoptions *opt,
774 				       struct in6_addr *orig);
775 
776 /*
777  *	socket options (ipv6_sockglue.c)
778  */
779 
780 extern int			ipv6_setsockopt(struct sock *sk, int level,
781 						int optname,
782 						char __user *optval,
783 						unsigned int optlen);
784 extern int			ipv6_getsockopt(struct sock *sk, int level,
785 						int optname,
786 						char __user *optval,
787 						int __user *optlen);
788 extern int			compat_ipv6_setsockopt(struct sock *sk,
789 						int level,
790 						int optname,
791 						char __user *optval,
792 						unsigned int optlen);
793 extern int			compat_ipv6_getsockopt(struct sock *sk,
794 						int level,
795 						int optname,
796 						char __user *optval,
797 						int __user *optlen);
798 
799 extern int			ip6_datagram_connect(struct sock *sk,
800 						     struct sockaddr *addr, int addr_len);
801 
802 extern int 			ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len);
803 extern int 			ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len);
804 extern void			ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
805 						u32 info, u8 *payload);
806 extern void			ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
807 extern void			ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
808 
809 extern int inet6_release(struct socket *sock);
810 extern int inet6_bind(struct socket *sock, struct sockaddr *uaddr,
811 		      int addr_len);
812 extern int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
813 			 int *uaddr_len, int peer);
814 extern int inet6_ioctl(struct socket *sock, unsigned int cmd,
815 		       unsigned long arg);
816 
817 extern int inet6_hash_connect(struct inet_timewait_death_row *death_row,
818 			      struct sock *sk);
819 
820 /*
821  * reassembly.c
822  */
823 extern const struct proto_ops inet6_stream_ops;
824 extern const struct proto_ops inet6_dgram_ops;
825 
826 struct group_source_req;
827 struct group_filter;
828 
829 extern int ip6_mc_source(int add, int omode, struct sock *sk,
830 			 struct group_source_req *pgsr);
831 extern int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
832 extern int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
833 			 struct group_filter __user *optval,
834 			 int __user *optlen);
835 extern unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
836 				    const struct in6_addr *daddr, u32 rnd);
837 
838 #ifdef CONFIG_PROC_FS
839 extern int  ac6_proc_init(struct net *net);
840 extern void ac6_proc_exit(struct net *net);
841 extern int  raw6_proc_init(void);
842 extern void raw6_proc_exit(void);
843 extern int  tcp6_proc_init(struct net *net);
844 extern void tcp6_proc_exit(struct net *net);
845 extern int  udp6_proc_init(struct net *net);
846 extern void udp6_proc_exit(struct net *net);
847 extern int  udplite6_proc_init(void);
848 extern void udplite6_proc_exit(void);
849 extern int  ipv6_misc_proc_init(void);
850 extern void ipv6_misc_proc_exit(void);
851 extern int snmp6_register_dev(struct inet6_dev *idev);
852 extern int snmp6_unregister_dev(struct inet6_dev *idev);
853 
854 #else
855 static inline int ac6_proc_init(struct net *net) { return 0; }
856 static inline void ac6_proc_exit(struct net *net) { }
857 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
858 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
859 #endif
860 
861 #ifdef CONFIG_SYSCTL
862 extern struct ctl_table ipv6_route_table_template[];
863 extern struct ctl_table ipv6_icmp_table_template[];
864 
865 extern struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
866 extern struct ctl_table *ipv6_route_sysctl_init(struct net *net);
867 extern int ipv6_sysctl_register(void);
868 extern void ipv6_sysctl_unregister(void);
869 #endif
870 
871 #endif /* _NET_IPV6_H */
872