xref: /openbmc/linux/include/net/ipv6.h (revision 930beb5a)
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 #define	IP6_OFFSET	0xFFF8
115 
116 #include <net/sock.h>
117 
118 /* sysctls */
119 extern int sysctl_mld_max_msf;
120 
121 #define _DEVINC(net, statname, modifier, idev, field)			\
122 ({									\
123 	struct inet6_dev *_idev = (idev);				\
124 	if (likely(_idev != NULL))					\
125 		SNMP_INC_STATS##modifier((_idev)->stats.statname, (field)); \
126 	SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
127 })
128 
129 /* per device counters are atomic_long_t */
130 #define _DEVINCATOMIC(net, statname, modifier, idev, field)		\
131 ({									\
132 	struct inet6_dev *_idev = (idev);				\
133 	if (likely(_idev != NULL))					\
134 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
135 	SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
136 })
137 
138 /* per device and per net counters are atomic_long_t */
139 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)		\
140 ({									\
141 	struct inet6_dev *_idev = (idev);				\
142 	if (likely(_idev != NULL))					\
143 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
144 	SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
145 })
146 
147 #define _DEVADD(net, statname, modifier, idev, field, val)		\
148 ({									\
149 	struct inet6_dev *_idev = (idev);				\
150 	if (likely(_idev != NULL))					\
151 		SNMP_ADD_STATS##modifier((_idev)->stats.statname, (field), (val)); \
152 	SNMP_ADD_STATS##modifier((net)->mib.statname##_statistics, (field), (val));\
153 })
154 
155 #define _DEVUPD(net, statname, modifier, idev, field, val)		\
156 ({									\
157 	struct inet6_dev *_idev = (idev);				\
158 	if (likely(_idev != NULL))					\
159 		SNMP_UPD_PO_STATS##modifier((_idev)->stats.statname, field, (val)); \
160 	SNMP_UPD_PO_STATS##modifier((net)->mib.statname##_statistics, field, (val));\
161 })
162 
163 /* MIBs */
164 
165 #define IP6_INC_STATS(net, idev,field)		\
166 		_DEVINC(net, ipv6, 64, idev, field)
167 #define IP6_INC_STATS_BH(net, idev,field)	\
168 		_DEVINC(net, ipv6, 64_BH, idev, field)
169 #define IP6_ADD_STATS(net, idev,field,val)	\
170 		_DEVADD(net, ipv6, 64, idev, field, val)
171 #define IP6_ADD_STATS_BH(net, idev,field,val)	\
172 		_DEVADD(net, ipv6, 64_BH, idev, field, val)
173 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
174 		_DEVUPD(net, ipv6, 64, idev, field, val)
175 #define IP6_UPD_PO_STATS_BH(net, idev,field,val)   \
176 		_DEVUPD(net, ipv6, 64_BH, idev, field, val)
177 #define ICMP6_INC_STATS(net, idev, field)	\
178 		_DEVINCATOMIC(net, icmpv6, , idev, field)
179 #define ICMP6_INC_STATS_BH(net, idev, field)	\
180 		_DEVINCATOMIC(net, icmpv6, _BH, idev, field)
181 
182 #define ICMP6MSGOUT_INC_STATS(net, idev, field)		\
183 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
184 #define ICMP6MSGOUT_INC_STATS_BH(net, idev, field)	\
185 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
186 #define ICMP6MSGIN_INC_STATS_BH(net, idev, field)	\
187 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
188 
189 struct ip6_ra_chain {
190 	struct ip6_ra_chain	*next;
191 	struct sock		*sk;
192 	int			sel;
193 	void			(*destructor)(struct sock *);
194 };
195 
196 extern struct ip6_ra_chain	*ip6_ra_chain;
197 extern rwlock_t ip6_ra_lock;
198 
199 /*
200    This structure is prepared by protocol, when parsing
201    ancillary data and passed to IPv6.
202  */
203 
204 struct ipv6_txoptions {
205 	/* Length of this structure */
206 	int			tot_len;
207 
208 	/* length of extension headers   */
209 
210 	__u16			opt_flen;	/* after fragment hdr */
211 	__u16			opt_nflen;	/* before fragment hdr */
212 
213 	struct ipv6_opt_hdr	*hopopt;
214 	struct ipv6_opt_hdr	*dst0opt;
215 	struct ipv6_rt_hdr	*srcrt;	/* Routing Header */
216 	struct ipv6_opt_hdr	*dst1opt;
217 
218 	/* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
219 };
220 
221 struct ip6_flowlabel {
222 	struct ip6_flowlabel __rcu *next;
223 	__be32			label;
224 	atomic_t		users;
225 	struct in6_addr		dst;
226 	struct ipv6_txoptions	*opt;
227 	unsigned long		linger;
228 	struct rcu_head		rcu;
229 	u8			share;
230 	union {
231 		struct pid *pid;
232 		kuid_t uid;
233 	} owner;
234 	unsigned long		lastuse;
235 	unsigned long		expires;
236 	struct net		*fl_net;
237 };
238 
239 #define IPV6_FLOWINFO_MASK	cpu_to_be32(0x0FFFFFFF)
240 #define IPV6_FLOWLABEL_MASK	cpu_to_be32(0x000FFFFF)
241 
242 struct ipv6_fl_socklist {
243 	struct ipv6_fl_socklist	__rcu	*next;
244 	struct ip6_flowlabel		*fl;
245 	struct rcu_head			rcu;
246 };
247 
248 struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label);
249 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
250 					 struct ip6_flowlabel *fl,
251 					 struct ipv6_txoptions *fopt);
252 void fl6_free_socklist(struct sock *sk);
253 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
254 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq);
255 int ip6_flowlabel_init(void);
256 void ip6_flowlabel_cleanup(void);
257 
258 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
259 {
260 	if (fl)
261 		atomic_dec(&fl->users);
262 }
263 
264 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
265 
266 int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
267 			       struct icmp6hdr *thdr, int len);
268 
269 struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb,
270 				      struct sock *sk, struct flowi6 *fl6);
271 
272 int ip6_ra_control(struct sock *sk, int sel);
273 
274 int ipv6_parse_hopopts(struct sk_buff *skb);
275 
276 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
277 					struct ipv6_txoptions *opt);
278 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
279 					  struct ipv6_txoptions *opt,
280 					  int newtype,
281 					  struct ipv6_opt_hdr __user *newopt,
282 					  int newoptlen);
283 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
284 					  struct ipv6_txoptions *opt);
285 
286 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb);
287 
288 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
289 {
290 	/* If forwarding is enabled, RA are not accepted unless the special
291 	 * hybrid mode (accept_ra=2) is enabled.
292 	 */
293 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
294 	    idev->cnf.accept_ra;
295 }
296 
297 #if IS_ENABLED(CONFIG_IPV6)
298 static inline int ip6_frag_nqueues(struct net *net)
299 {
300 	return net->ipv6.frags.nqueues;
301 }
302 
303 static inline int ip6_frag_mem(struct net *net)
304 {
305 	return sum_frag_mem_limit(&net->ipv6.frags);
306 }
307 #endif
308 
309 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
310 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
311 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
312 
313 int __ipv6_addr_type(const struct in6_addr *addr);
314 static inline int ipv6_addr_type(const struct in6_addr *addr)
315 {
316 	return __ipv6_addr_type(addr) & 0xffff;
317 }
318 
319 static inline int ipv6_addr_scope(const struct in6_addr *addr)
320 {
321 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
322 }
323 
324 static inline int __ipv6_addr_src_scope(int type)
325 {
326 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
327 }
328 
329 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
330 {
331 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
332 }
333 
334 static inline bool __ipv6_addr_needs_scope_id(int type)
335 {
336 	return type & IPV6_ADDR_LINKLOCAL ||
337 	       (type & IPV6_ADDR_MULTICAST &&
338 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
339 }
340 
341 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
342 {
343 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
344 }
345 
346 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
347 {
348 	return memcmp(a1, a2, sizeof(struct in6_addr));
349 }
350 
351 static inline bool
352 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
353 		     const struct in6_addr *a2)
354 {
355 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
356 	const unsigned long *ul1 = (const unsigned long *)a1;
357 	const unsigned long *ulm = (const unsigned long *)m;
358 	const unsigned long *ul2 = (const unsigned long *)a2;
359 
360 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
361 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
362 #else
363 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
364 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
365 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
366 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
367 #endif
368 }
369 
370 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
371 				    const struct in6_addr *addr,
372 				    int plen)
373 {
374 	/* caller must guarantee 0 <= plen <= 128 */
375 	int o = plen >> 3,
376 	    b = plen & 0x7;
377 
378 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
379 	memcpy(pfx->s6_addr, addr, o);
380 	if (b != 0)
381 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
382 }
383 
384 static inline void __ipv6_addr_set_half(__be32 *addr,
385 					__be32 wh, __be32 wl)
386 {
387 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
388 #if defined(__BIG_ENDIAN)
389 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
390 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
391 		return;
392 	}
393 #elif defined(__LITTLE_ENDIAN)
394 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
395 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
396 		return;
397 	}
398 #endif
399 #endif
400 	addr[0] = wh;
401 	addr[1] = wl;
402 }
403 
404 static inline void ipv6_addr_set(struct in6_addr *addr,
405 				     __be32 w1, __be32 w2,
406 				     __be32 w3, __be32 w4)
407 {
408 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
409 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
410 }
411 
412 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
413 				   const struct in6_addr *a2)
414 {
415 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
416 	const unsigned long *ul1 = (const unsigned long *)a1;
417 	const unsigned long *ul2 = (const unsigned long *)a2;
418 
419 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
420 #else
421 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
422 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
423 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
424 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
425 #endif
426 }
427 
428 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
429 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
430 					      const __be64 *a2,
431 					      unsigned int len)
432 {
433 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
434 		return false;
435 	return true;
436 }
437 
438 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
439 				     const struct in6_addr *addr2,
440 				     unsigned int prefixlen)
441 {
442 	const __be64 *a1 = (const __be64 *)addr1;
443 	const __be64 *a2 = (const __be64 *)addr2;
444 
445 	if (prefixlen >= 64) {
446 		if (a1[0] ^ a2[0])
447 			return false;
448 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
449 	}
450 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
451 }
452 #else
453 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
454 				     const struct in6_addr *addr2,
455 				     unsigned int prefixlen)
456 {
457 	const __be32 *a1 = addr1->s6_addr32;
458 	const __be32 *a2 = addr2->s6_addr32;
459 	unsigned int pdw, pbi;
460 
461 	/* check complete u32 in prefix */
462 	pdw = prefixlen >> 5;
463 	if (pdw && memcmp(a1, a2, pdw << 2))
464 		return false;
465 
466 	/* check incomplete u32 in prefix */
467 	pbi = prefixlen & 0x1f;
468 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
469 		return false;
470 
471 	return true;
472 }
473 #endif
474 
475 struct inet_frag_queue;
476 
477 enum ip6_defrag_users {
478 	IP6_DEFRAG_LOCAL_DELIVER,
479 	IP6_DEFRAG_CONNTRACK_IN,
480 	__IP6_DEFRAG_CONNTRACK_IN	= IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
481 	IP6_DEFRAG_CONNTRACK_OUT,
482 	__IP6_DEFRAG_CONNTRACK_OUT	= IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
483 	IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
484 	__IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
485 };
486 
487 struct ip6_create_arg {
488 	__be32 id;
489 	u32 user;
490 	const struct in6_addr *src;
491 	const struct in6_addr *dst;
492 	u8 ecn;
493 };
494 
495 void ip6_frag_init(struct inet_frag_queue *q, void *a);
496 bool ip6_frag_match(struct inet_frag_queue *q, void *a);
497 
498 /*
499  *	Equivalent of ipv4 struct ip
500  */
501 struct frag_queue {
502 	struct inet_frag_queue	q;
503 
504 	__be32			id;		/* fragment id		*/
505 	u32			user;
506 	struct in6_addr		saddr;
507 	struct in6_addr		daddr;
508 
509 	int			iif;
510 	unsigned int		csum;
511 	__u16			nhoffset;
512 	u8			ecn;
513 };
514 
515 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
516 			   struct inet_frags *frags);
517 
518 static inline bool ipv6_addr_any(const struct in6_addr *a)
519 {
520 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
521 	const unsigned long *ul = (const unsigned long *)a;
522 
523 	return (ul[0] | ul[1]) == 0UL;
524 #else
525 	return (a->s6_addr32[0] | a->s6_addr32[1] |
526 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
527 #endif
528 }
529 
530 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
531 {
532 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
533 	const unsigned long *ul = (const unsigned long *)a;
534 	unsigned long x = ul[0] ^ ul[1];
535 
536 	return (u32)(x ^ (x >> 32));
537 #else
538 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
539 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
540 #endif
541 }
542 
543 /* more secured version of ipv6_addr_hash() */
544 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
545 {
546 	u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
547 
548 	return jhash_3words(v,
549 			    (__force u32)a->s6_addr32[2],
550 			    (__force u32)a->s6_addr32[3],
551 			    initval);
552 }
553 
554 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
555 {
556 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
557 	const unsigned long *ul = (const unsigned long *)a;
558 
559 	return (ul[0] | (ul[1] ^ cpu_to_be64(1))) == 0UL;
560 #else
561 	return (a->s6_addr32[0] | a->s6_addr32[1] |
562 		a->s6_addr32[2] | (a->s6_addr32[3] ^ htonl(1))) == 0;
563 #endif
564 }
565 
566 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
567 {
568 	return (
569 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
570 		*(__be64 *)a |
571 #else
572 		(a->s6_addr32[0] | a->s6_addr32[1]) |
573 #endif
574 		(a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0UL;
575 }
576 
577 /*
578  * Check for a RFC 4843 ORCHID address
579  * (Overlay Routable Cryptographic Hash Identifiers)
580  */
581 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
582 {
583 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
584 }
585 
586 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
587 					  struct in6_addr *v4mapped)
588 {
589 	ipv6_addr_set(v4mapped,
590 			0, 0,
591 			htonl(0x0000FFFF),
592 			addr);
593 }
594 
595 /*
596  * find the first different bit between two addresses
597  * length of address must be a multiple of 32bits
598  */
599 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
600 {
601 	const __be32 *a1 = token1, *a2 = token2;
602 	int i;
603 
604 	addrlen >>= 2;
605 
606 	for (i = 0; i < addrlen; i++) {
607 		__be32 xb = a1[i] ^ a2[i];
608 		if (xb)
609 			return i * 32 + 31 - __fls(ntohl(xb));
610 	}
611 
612 	/*
613 	 *	we should *never* get to this point since that
614 	 *	would mean the addrs are equal
615 	 *
616 	 *	However, we do get to it 8) And exacly, when
617 	 *	addresses are equal 8)
618 	 *
619 	 *	ip route add 1111::/128 via ...
620 	 *	ip route add 1111::/64 via ...
621 	 *	and we are here.
622 	 *
623 	 *	Ideally, this function should stop comparison
624 	 *	at prefix length. It does not, but it is still OK,
625 	 *	if returned value is greater than prefix length.
626 	 *					--ANK (980803)
627 	 */
628 	return addrlen << 5;
629 }
630 
631 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
632 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
633 {
634 	const __be64 *a1 = token1, *a2 = token2;
635 	int i;
636 
637 	addrlen >>= 3;
638 
639 	for (i = 0; i < addrlen; i++) {
640 		__be64 xb = a1[i] ^ a2[i];
641 		if (xb)
642 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
643 	}
644 
645 	return addrlen << 6;
646 }
647 #endif
648 
649 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
650 {
651 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
652 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
653 		return __ipv6_addr_diff64(token1, token2, addrlen);
654 #endif
655 	return __ipv6_addr_diff32(token1, token2, addrlen);
656 }
657 
658 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
659 {
660 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
661 }
662 
663 void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt);
664 
665 int ip6_dst_hoplimit(struct dst_entry *dst);
666 
667 /*
668  *	Header manipulation
669  */
670 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
671 				__be32 flowlabel)
672 {
673 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
674 }
675 
676 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
677 {
678 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
679 }
680 
681 /*
682  *	Prototypes exported by ipv6
683  */
684 
685 /*
686  *	rcv function (called from netdevice level)
687  */
688 
689 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
690 	     struct packet_type *pt, struct net_device *orig_dev);
691 
692 int ip6_rcv_finish(struct sk_buff *skb);
693 
694 /*
695  *	upper-layer output functions
696  */
697 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
698 	     struct ipv6_txoptions *opt, int tclass);
699 
700 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
701 
702 int ip6_append_data(struct sock *sk,
703 		    int getfrag(void *from, char *to, int offset, int len,
704 				int odd, struct sk_buff *skb),
705 		    void *from, int length, int transhdrlen, int hlimit,
706 		    int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
707 		    struct rt6_info *rt, unsigned int flags, int dontfrag);
708 
709 int ip6_push_pending_frames(struct sock *sk);
710 
711 void ip6_flush_pending_frames(struct sock *sk);
712 
713 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6);
714 struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
715 				      const struct in6_addr *final_dst,
716 				      bool can_sleep);
717 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
718 					 const struct in6_addr *final_dst,
719 					 bool can_sleep);
720 struct dst_entry *ip6_blackhole_route(struct net *net,
721 				      struct dst_entry *orig_dst);
722 
723 /*
724  *	skb processing functions
725  */
726 
727 int ip6_output(struct sk_buff *skb);
728 int ip6_forward(struct sk_buff *skb);
729 int ip6_input(struct sk_buff *skb);
730 int ip6_mc_input(struct sk_buff *skb);
731 
732 int __ip6_local_out(struct sk_buff *skb);
733 int ip6_local_out(struct sk_buff *skb);
734 
735 /*
736  *	Extension header (options) processing
737  */
738 
739 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
740 			  u8 *proto, struct in6_addr **daddr_p);
741 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
742 			 u8 *proto);
743 
744 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
745 		     __be16 *frag_offp);
746 
747 bool ipv6_ext_hdr(u8 nexthdr);
748 
749 enum {
750 	IP6_FH_F_FRAG		= (1 << 0),
751 	IP6_FH_F_AUTH		= (1 << 1),
752 	IP6_FH_F_SKIP_RH	= (1 << 2),
753 };
754 
755 /* find specified header and get offset to it */
756 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
757 		  unsigned short *fragoff, int *fragflg);
758 
759 int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
760 
761 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
762 				const struct ipv6_txoptions *opt,
763 				struct in6_addr *orig);
764 
765 /*
766  *	socket options (ipv6_sockglue.c)
767  */
768 
769 int ipv6_setsockopt(struct sock *sk, int level, int optname,
770 		    char __user *optval, unsigned int optlen);
771 int ipv6_getsockopt(struct sock *sk, int level, int optname,
772 		    char __user *optval, int __user *optlen);
773 int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
774 			   char __user *optval, unsigned int optlen);
775 int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
776 			   char __user *optval, int __user *optlen);
777 
778 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
779 
780 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
781 		    int *addr_len);
782 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
783 		     int *addr_len);
784 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
785 		     u32 info, u8 *payload);
786 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
787 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
788 
789 int inet6_release(struct socket *sock);
790 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
791 int inet6_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len,
792 		  int peer);
793 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
794 
795 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
796 			      struct sock *sk);
797 
798 /*
799  * reassembly.c
800  */
801 extern const struct proto_ops inet6_stream_ops;
802 extern const struct proto_ops inet6_dgram_ops;
803 
804 struct group_source_req;
805 struct group_filter;
806 
807 int ip6_mc_source(int add, int omode, struct sock *sk,
808 		  struct group_source_req *pgsr);
809 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
810 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
811 		  struct group_filter __user *optval, int __user *optlen);
812 
813 #ifdef CONFIG_PROC_FS
814 int ac6_proc_init(struct net *net);
815 void ac6_proc_exit(struct net *net);
816 int raw6_proc_init(void);
817 void raw6_proc_exit(void);
818 int tcp6_proc_init(struct net *net);
819 void tcp6_proc_exit(struct net *net);
820 int udp6_proc_init(struct net *net);
821 void udp6_proc_exit(struct net *net);
822 int udplite6_proc_init(void);
823 void udplite6_proc_exit(void);
824 int ipv6_misc_proc_init(void);
825 void ipv6_misc_proc_exit(void);
826 int snmp6_register_dev(struct inet6_dev *idev);
827 int snmp6_unregister_dev(struct inet6_dev *idev);
828 
829 #else
830 static inline int ac6_proc_init(struct net *net) { return 0; }
831 static inline void ac6_proc_exit(struct net *net) { }
832 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
833 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
834 #endif
835 
836 #ifdef CONFIG_SYSCTL
837 extern struct ctl_table ipv6_route_table_template[];
838 extern struct ctl_table ipv6_icmp_table_template[];
839 
840 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
841 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
842 int ipv6_sysctl_register(void);
843 void ipv6_sysctl_unregister(void);
844 #endif
845 
846 #endif /* _NET_IPV6_H */
847