xref: /openbmc/linux/include/net/ipv6.h (revision 97da55fc)
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	*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	*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 extern int 			ip6_ra_control(struct sock *sk, int sel);
264 
265 extern int			ipv6_parse_hopopts(struct sk_buff *skb);
266 
267 extern struct ipv6_txoptions *  ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt);
268 extern struct ipv6_txoptions *	ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
269 						   int newtype,
270 						   struct ipv6_opt_hdr __user *newopt,
271 						   int newoptlen);
272 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
273 					  struct ipv6_txoptions *opt);
274 
275 extern bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb);
276 
277 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
278 {
279 	/* If forwarding is enabled, RA are not accepted unless the special
280 	 * hybrid mode (accept_ra=2) is enabled.
281 	 */
282 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
283 	    idev->cnf.accept_ra;
284 }
285 
286 #if IS_ENABLED(CONFIG_IPV6)
287 static inline int ip6_frag_nqueues(struct net *net)
288 {
289 	return net->ipv6.frags.nqueues;
290 }
291 
292 static inline int ip6_frag_mem(struct net *net)
293 {
294 	return sum_frag_mem_limit(&net->ipv6.frags);
295 }
296 #endif
297 
298 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
299 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
300 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
301 
302 extern int __ipv6_addr_type(const struct in6_addr *addr);
303 static inline int ipv6_addr_type(const struct in6_addr *addr)
304 {
305 	return __ipv6_addr_type(addr) & 0xffff;
306 }
307 
308 static inline int ipv6_addr_scope(const struct in6_addr *addr)
309 {
310 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
311 }
312 
313 static inline int __ipv6_addr_src_scope(int type)
314 {
315 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
316 }
317 
318 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
319 {
320 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
321 }
322 
323 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
324 {
325 	return memcmp(a1, a2, sizeof(struct in6_addr));
326 }
327 
328 static inline bool
329 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
330 		     const struct in6_addr *a2)
331 {
332 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
333 	const unsigned long *ul1 = (const unsigned long *)a1;
334 	const unsigned long *ulm = (const unsigned long *)m;
335 	const unsigned long *ul2 = (const unsigned long *)a2;
336 
337 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
338 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
339 #else
340 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
341 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
342 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
343 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
344 #endif
345 }
346 
347 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
348 				    const struct in6_addr *addr,
349 				    int plen)
350 {
351 	/* caller must guarantee 0 <= plen <= 128 */
352 	int o = plen >> 3,
353 	    b = plen & 0x7;
354 
355 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
356 	memcpy(pfx->s6_addr, addr, o);
357 	if (b != 0)
358 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
359 }
360 
361 static inline void __ipv6_addr_set_half(__be32 *addr,
362 					__be32 wh, __be32 wl)
363 {
364 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
365 #if defined(__BIG_ENDIAN)
366 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
367 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
368 		return;
369 	}
370 #elif defined(__LITTLE_ENDIAN)
371 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
372 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
373 		return;
374 	}
375 #endif
376 #endif
377 	addr[0] = wh;
378 	addr[1] = wl;
379 }
380 
381 static inline void ipv6_addr_set(struct in6_addr *addr,
382 				     __be32 w1, __be32 w2,
383 				     __be32 w3, __be32 w4)
384 {
385 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
386 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
387 }
388 
389 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
390 				   const struct in6_addr *a2)
391 {
392 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
393 	const unsigned long *ul1 = (const unsigned long *)a1;
394 	const unsigned long *ul2 = (const unsigned long *)a2;
395 
396 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
397 #else
398 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
399 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
400 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
401 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
402 #endif
403 }
404 
405 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
406 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
407 					      const __be64 *a2,
408 					      unsigned int len)
409 {
410 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
411 		return false;
412 	return true;
413 }
414 
415 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
416 				     const struct in6_addr *addr2,
417 				     unsigned int prefixlen)
418 {
419 	const __be64 *a1 = (const __be64 *)addr1;
420 	const __be64 *a2 = (const __be64 *)addr2;
421 
422 	if (prefixlen >= 64) {
423 		if (a1[0] ^ a2[0])
424 			return false;
425 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
426 	}
427 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
428 }
429 #else
430 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
431 				     const struct in6_addr *addr2,
432 				     unsigned int prefixlen)
433 {
434 	const __be32 *a1 = addr1->s6_addr32;
435 	const __be32 *a2 = addr2->s6_addr32;
436 	unsigned int pdw, pbi;
437 
438 	/* check complete u32 in prefix */
439 	pdw = prefixlen >> 5;
440 	if (pdw && memcmp(a1, a2, pdw << 2))
441 		return false;
442 
443 	/* check incomplete u32 in prefix */
444 	pbi = prefixlen & 0x1f;
445 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
446 		return false;
447 
448 	return true;
449 }
450 #endif
451 
452 struct inet_frag_queue;
453 
454 enum ip6_defrag_users {
455 	IP6_DEFRAG_LOCAL_DELIVER,
456 	IP6_DEFRAG_CONNTRACK_IN,
457 	__IP6_DEFRAG_CONNTRACK_IN	= IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
458 	IP6_DEFRAG_CONNTRACK_OUT,
459 	__IP6_DEFRAG_CONNTRACK_OUT	= IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
460 	IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
461 	__IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
462 };
463 
464 struct ip6_create_arg {
465 	__be32 id;
466 	u32 user;
467 	const struct in6_addr *src;
468 	const struct in6_addr *dst;
469 };
470 
471 void ip6_frag_init(struct inet_frag_queue *q, void *a);
472 bool ip6_frag_match(struct inet_frag_queue *q, void *a);
473 
474 /*
475  *	Equivalent of ipv4 struct ip
476  */
477 struct frag_queue {
478 	struct inet_frag_queue	q;
479 
480 	__be32			id;		/* fragment id		*/
481 	u32			user;
482 	struct in6_addr		saddr;
483 	struct in6_addr		daddr;
484 
485 	int			iif;
486 	unsigned int		csum;
487 	__u16			nhoffset;
488 };
489 
490 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
491 			   struct inet_frags *frags);
492 
493 static inline bool ipv6_addr_any(const struct in6_addr *a)
494 {
495 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
496 	const unsigned long *ul = (const unsigned long *)a;
497 
498 	return (ul[0] | ul[1]) == 0UL;
499 #else
500 	return (a->s6_addr32[0] | a->s6_addr32[1] |
501 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
502 #endif
503 }
504 
505 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
506 {
507 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
508 	const unsigned long *ul = (const unsigned long *)a;
509 	unsigned long x = ul[0] ^ ul[1];
510 
511 	return (u32)(x ^ (x >> 32));
512 #else
513 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
514 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
515 #endif
516 }
517 
518 /* more secured version of ipv6_addr_hash() */
519 static inline u32 ipv6_addr_jhash(const struct in6_addr *a)
520 {
521 	u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
522 
523 	return jhash_3words(v,
524 			    (__force u32)a->s6_addr32[2],
525 			    (__force u32)a->s6_addr32[3],
526 			    ipv6_hash_secret);
527 }
528 
529 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
530 {
531 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
532 	const unsigned long *ul = (const unsigned long *)a;
533 
534 	return (ul[0] | (ul[1] ^ cpu_to_be64(1))) == 0UL;
535 #else
536 	return (a->s6_addr32[0] | a->s6_addr32[1] |
537 		a->s6_addr32[2] | (a->s6_addr32[3] ^ htonl(1))) == 0;
538 #endif
539 }
540 
541 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
542 {
543 	return (
544 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
545 		*(__be64 *)a |
546 #else
547 		(a->s6_addr32[0] | a->s6_addr32[1]) |
548 #endif
549 		(a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0UL;
550 }
551 
552 /*
553  * Check for a RFC 4843 ORCHID address
554  * (Overlay Routable Cryptographic Hash Identifiers)
555  */
556 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
557 {
558 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
559 }
560 
561 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
562 					  struct in6_addr *v4mapped)
563 {
564 	ipv6_addr_set(v4mapped,
565 			0, 0,
566 			htonl(0x0000FFFF),
567 			addr);
568 }
569 
570 /*
571  * find the first different bit between two addresses
572  * length of address must be a multiple of 32bits
573  */
574 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
575 {
576 	const __be32 *a1 = token1, *a2 = token2;
577 	int i;
578 
579 	addrlen >>= 2;
580 
581 	for (i = 0; i < addrlen; i++) {
582 		__be32 xb = a1[i] ^ a2[i];
583 		if (xb)
584 			return i * 32 + 31 - __fls(ntohl(xb));
585 	}
586 
587 	/*
588 	 *	we should *never* get to this point since that
589 	 *	would mean the addrs are equal
590 	 *
591 	 *	However, we do get to it 8) And exacly, when
592 	 *	addresses are equal 8)
593 	 *
594 	 *	ip route add 1111::/128 via ...
595 	 *	ip route add 1111::/64 via ...
596 	 *	and we are here.
597 	 *
598 	 *	Ideally, this function should stop comparison
599 	 *	at prefix length. It does not, but it is still OK,
600 	 *	if returned value is greater than prefix length.
601 	 *					--ANK (980803)
602 	 */
603 	return addrlen << 5;
604 }
605 
606 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
607 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
608 {
609 	const __be64 *a1 = token1, *a2 = token2;
610 	int i;
611 
612 	addrlen >>= 3;
613 
614 	for (i = 0; i < addrlen; i++) {
615 		__be64 xb = a1[i] ^ a2[i];
616 		if (xb)
617 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
618 	}
619 
620 	return addrlen << 6;
621 }
622 #endif
623 
624 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
625 {
626 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
627 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
628 		return __ipv6_addr_diff64(token1, token2, addrlen);
629 #endif
630 	return __ipv6_addr_diff32(token1, token2, addrlen);
631 }
632 
633 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
634 {
635 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
636 }
637 
638 extern void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt);
639 
640 /*
641  *	Header manipulation
642  */
643 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
644 				__be32 flowlabel)
645 {
646 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
647 }
648 
649 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
650 {
651 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
652 }
653 
654 /*
655  *	Prototypes exported by ipv6
656  */
657 
658 /*
659  *	rcv function (called from netdevice level)
660  */
661 
662 extern int			ipv6_rcv(struct sk_buff *skb,
663 					 struct net_device *dev,
664 					 struct packet_type *pt,
665 					 struct net_device *orig_dev);
666 
667 extern int			ip6_rcv_finish(struct sk_buff *skb);
668 
669 /*
670  *	upper-layer output functions
671  */
672 extern int			ip6_xmit(struct sock *sk,
673 					 struct sk_buff *skb,
674 					 struct flowi6 *fl6,
675 					 struct ipv6_txoptions *opt,
676 					 int tclass);
677 
678 extern int			ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
679 
680 extern int			ip6_append_data(struct sock *sk,
681 						int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb),
682 		    				void *from,
683 						int length,
684 						int transhdrlen,
685 		      				int hlimit,
686 		      				int tclass,
687 						struct ipv6_txoptions *opt,
688 						struct flowi6 *fl6,
689 						struct rt6_info *rt,
690 						unsigned int flags,
691 						int dontfrag);
692 
693 extern int			ip6_push_pending_frames(struct sock *sk);
694 
695 extern void			ip6_flush_pending_frames(struct sock *sk);
696 
697 extern int			ip6_dst_lookup(struct sock *sk,
698 					       struct dst_entry **dst,
699 					       struct flowi6 *fl6);
700 extern struct dst_entry *	ip6_dst_lookup_flow(struct sock *sk,
701 						    struct flowi6 *fl6,
702 						    const struct in6_addr *final_dst,
703 						    bool can_sleep);
704 extern struct dst_entry *	ip6_sk_dst_lookup_flow(struct sock *sk,
705 						       struct flowi6 *fl6,
706 						       const struct in6_addr *final_dst,
707 						       bool can_sleep);
708 extern struct dst_entry *	ip6_blackhole_route(struct net *net,
709 						    struct dst_entry *orig_dst);
710 
711 /*
712  *	skb processing functions
713  */
714 
715 extern int			ip6_output(struct sk_buff *skb);
716 extern int			ip6_forward(struct sk_buff *skb);
717 extern int			ip6_input(struct sk_buff *skb);
718 extern int			ip6_mc_input(struct sk_buff *skb);
719 
720 extern int			__ip6_local_out(struct sk_buff *skb);
721 extern int			ip6_local_out(struct sk_buff *skb);
722 
723 /*
724  *	Extension header (options) processing
725  */
726 
727 extern void 			ipv6_push_nfrag_opts(struct sk_buff *skb,
728 						     struct ipv6_txoptions *opt,
729 						     u8 *proto,
730 						     struct in6_addr **daddr_p);
731 extern void			ipv6_push_frag_opts(struct sk_buff *skb,
732 						    struct ipv6_txoptions *opt,
733 						    u8 *proto);
734 
735 extern int			ipv6_skip_exthdr(const struct sk_buff *, int start,
736 					         u8 *nexthdrp, __be16 *frag_offp);
737 
738 extern bool			ipv6_ext_hdr(u8 nexthdr);
739 
740 enum {
741 	IP6_FH_F_FRAG		= (1 << 0),
742 	IP6_FH_F_AUTH		= (1 << 1),
743 	IP6_FH_F_SKIP_RH	= (1 << 2),
744 };
745 
746 /* find specified header and get offset to it */
747 extern int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
748 			 int target, unsigned short *fragoff, int *fragflg);
749 
750 extern int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
751 
752 extern struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
753 				       const struct ipv6_txoptions *opt,
754 				       struct in6_addr *orig);
755 
756 /*
757  *	socket options (ipv6_sockglue.c)
758  */
759 
760 extern int			ipv6_setsockopt(struct sock *sk, int level,
761 						int optname,
762 						char __user *optval,
763 						unsigned int optlen);
764 extern int			ipv6_getsockopt(struct sock *sk, int level,
765 						int optname,
766 						char __user *optval,
767 						int __user *optlen);
768 extern int			compat_ipv6_setsockopt(struct sock *sk,
769 						int level,
770 						int optname,
771 						char __user *optval,
772 						unsigned int optlen);
773 extern int			compat_ipv6_getsockopt(struct sock *sk,
774 						int level,
775 						int optname,
776 						char __user *optval,
777 						int __user *optlen);
778 
779 extern int			ip6_datagram_connect(struct sock *sk,
780 						     struct sockaddr *addr, int addr_len);
781 
782 extern int 			ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len);
783 extern int 			ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len);
784 extern void			ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
785 						u32 info, u8 *payload);
786 extern void			ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
787 extern void			ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
788 
789 extern int inet6_release(struct socket *sock);
790 extern int inet6_bind(struct socket *sock, struct sockaddr *uaddr,
791 		      int addr_len);
792 extern int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
793 			 int *uaddr_len, int peer);
794 extern int inet6_ioctl(struct socket *sock, unsigned int cmd,
795 		       unsigned long arg);
796 
797 extern int inet6_hash_connect(struct inet_timewait_death_row *death_row,
798 			      struct sock *sk);
799 
800 /*
801  * reassembly.c
802  */
803 extern const struct proto_ops inet6_stream_ops;
804 extern const struct proto_ops inet6_dgram_ops;
805 
806 struct group_source_req;
807 struct group_filter;
808 
809 extern int ip6_mc_source(int add, int omode, struct sock *sk,
810 			 struct group_source_req *pgsr);
811 extern int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
812 extern int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
813 			 struct group_filter __user *optval,
814 			 int __user *optlen);
815 extern unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
816 				    const struct in6_addr *daddr, u32 rnd);
817 
818 #ifdef CONFIG_PROC_FS
819 extern int  ac6_proc_init(struct net *net);
820 extern void ac6_proc_exit(struct net *net);
821 extern int  raw6_proc_init(void);
822 extern void raw6_proc_exit(void);
823 extern int  tcp6_proc_init(struct net *net);
824 extern void tcp6_proc_exit(struct net *net);
825 extern int  udp6_proc_init(struct net *net);
826 extern void udp6_proc_exit(struct net *net);
827 extern int  udplite6_proc_init(void);
828 extern void udplite6_proc_exit(void);
829 extern int  ipv6_misc_proc_init(void);
830 extern void ipv6_misc_proc_exit(void);
831 extern int snmp6_register_dev(struct inet6_dev *idev);
832 extern int snmp6_unregister_dev(struct inet6_dev *idev);
833 
834 #else
835 static inline int ac6_proc_init(struct net *net) { return 0; }
836 static inline void ac6_proc_exit(struct net *net) { }
837 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
838 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
839 #endif
840 
841 #ifdef CONFIG_SYSCTL
842 extern ctl_table ipv6_route_table_template[];
843 extern ctl_table ipv6_icmp_table_template[];
844 
845 extern struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
846 extern struct ctl_table *ipv6_route_sysctl_init(struct net *net);
847 extern int ipv6_sysctl_register(void);
848 extern void ipv6_sysctl_unregister(void);
849 #endif
850 
851 #endif /* _NET_IPV6_H */
852