xref: /openbmc/linux/include/net/ipv6.h (revision 94c7b6fc)
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 #define IP6_REPLY_MARK(net, mark) \
117 	((net)->ipv6.sysctl.fwmark_reflect ? (mark) : 0)
118 
119 #include <net/sock.h>
120 
121 /* sysctls */
122 extern int sysctl_mld_max_msf;
123 
124 #define _DEVINC(net, statname, modifier, idev, field)			\
125 ({									\
126 	struct inet6_dev *_idev = (idev);				\
127 	if (likely(_idev != NULL))					\
128 		SNMP_INC_STATS##modifier((_idev)->stats.statname, (field)); \
129 	SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
130 })
131 
132 /* per device counters are atomic_long_t */
133 #define _DEVINCATOMIC(net, statname, modifier, idev, field)		\
134 ({									\
135 	struct inet6_dev *_idev = (idev);				\
136 	if (likely(_idev != NULL))					\
137 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
138 	SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
139 })
140 
141 /* per device and per net counters are atomic_long_t */
142 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)		\
143 ({									\
144 	struct inet6_dev *_idev = (idev);				\
145 	if (likely(_idev != NULL))					\
146 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
147 	SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
148 })
149 
150 #define _DEVADD(net, statname, modifier, idev, field, val)		\
151 ({									\
152 	struct inet6_dev *_idev = (idev);				\
153 	if (likely(_idev != NULL))					\
154 		SNMP_ADD_STATS##modifier((_idev)->stats.statname, (field), (val)); \
155 	SNMP_ADD_STATS##modifier((net)->mib.statname##_statistics, (field), (val));\
156 })
157 
158 #define _DEVUPD(net, statname, modifier, idev, field, val)		\
159 ({									\
160 	struct inet6_dev *_idev = (idev);				\
161 	if (likely(_idev != NULL))					\
162 		SNMP_UPD_PO_STATS##modifier((_idev)->stats.statname, field, (val)); \
163 	SNMP_UPD_PO_STATS##modifier((net)->mib.statname##_statistics, field, (val));\
164 })
165 
166 /* MIBs */
167 
168 #define IP6_INC_STATS(net, idev,field)		\
169 		_DEVINC(net, ipv6, 64, idev, field)
170 #define IP6_INC_STATS_BH(net, idev,field)	\
171 		_DEVINC(net, ipv6, 64_BH, idev, field)
172 #define IP6_ADD_STATS(net, idev,field,val)	\
173 		_DEVADD(net, ipv6, 64, idev, field, val)
174 #define IP6_ADD_STATS_BH(net, idev,field,val)	\
175 		_DEVADD(net, ipv6, 64_BH, idev, field, val)
176 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
177 		_DEVUPD(net, ipv6, 64, idev, field, val)
178 #define IP6_UPD_PO_STATS_BH(net, idev,field,val)   \
179 		_DEVUPD(net, ipv6, 64_BH, idev, field, val)
180 #define ICMP6_INC_STATS(net, idev, field)	\
181 		_DEVINCATOMIC(net, icmpv6, , idev, field)
182 #define ICMP6_INC_STATS_BH(net, idev, field)	\
183 		_DEVINCATOMIC(net, icmpv6, _BH, idev, field)
184 
185 #define ICMP6MSGOUT_INC_STATS(net, idev, field)		\
186 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
187 #define ICMP6MSGOUT_INC_STATS_BH(net, idev, field)	\
188 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
189 #define ICMP6MSGIN_INC_STATS_BH(net, idev, field)	\
190 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
191 
192 struct ip6_ra_chain {
193 	struct ip6_ra_chain	*next;
194 	struct sock		*sk;
195 	int			sel;
196 	void			(*destructor)(struct sock *);
197 };
198 
199 extern struct ip6_ra_chain	*ip6_ra_chain;
200 extern rwlock_t ip6_ra_lock;
201 
202 /*
203    This structure is prepared by protocol, when parsing
204    ancillary data and passed to IPv6.
205  */
206 
207 struct ipv6_txoptions {
208 	/* Length of this structure */
209 	int			tot_len;
210 
211 	/* length of extension headers   */
212 
213 	__u16			opt_flen;	/* after fragment hdr */
214 	__u16			opt_nflen;	/* before fragment hdr */
215 
216 	struct ipv6_opt_hdr	*hopopt;
217 	struct ipv6_opt_hdr	*dst0opt;
218 	struct ipv6_rt_hdr	*srcrt;	/* Routing Header */
219 	struct ipv6_opt_hdr	*dst1opt;
220 
221 	/* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
222 };
223 
224 struct ip6_flowlabel {
225 	struct ip6_flowlabel __rcu *next;
226 	__be32			label;
227 	atomic_t		users;
228 	struct in6_addr		dst;
229 	struct ipv6_txoptions	*opt;
230 	unsigned long		linger;
231 	struct rcu_head		rcu;
232 	u8			share;
233 	union {
234 		struct pid *pid;
235 		kuid_t uid;
236 	} owner;
237 	unsigned long		lastuse;
238 	unsigned long		expires;
239 	struct net		*fl_net;
240 };
241 
242 #define IPV6_FLOWINFO_MASK	cpu_to_be32(0x0FFFFFFF)
243 #define IPV6_FLOWLABEL_MASK	cpu_to_be32(0x000FFFFF)
244 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
245 #define IPV6_TCLASS_SHIFT	20
246 
247 struct ipv6_fl_socklist {
248 	struct ipv6_fl_socklist	__rcu	*next;
249 	struct ip6_flowlabel		*fl;
250 	struct rcu_head			rcu;
251 };
252 
253 struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label);
254 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
255 					 struct ip6_flowlabel *fl,
256 					 struct ipv6_txoptions *fopt);
257 void fl6_free_socklist(struct sock *sk);
258 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
259 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
260 			   int flags);
261 int ip6_flowlabel_init(void);
262 void ip6_flowlabel_cleanup(void);
263 
264 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
265 {
266 	if (fl)
267 		atomic_dec(&fl->users);
268 }
269 
270 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
271 
272 int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
273 			       struct icmp6hdr *thdr, int len);
274 
275 int ip6_ra_control(struct sock *sk, int sel);
276 
277 int ipv6_parse_hopopts(struct sk_buff *skb);
278 
279 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
280 					struct ipv6_txoptions *opt);
281 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
282 					  struct ipv6_txoptions *opt,
283 					  int newtype,
284 					  struct ipv6_opt_hdr __user *newopt,
285 					  int newoptlen);
286 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
287 					  struct ipv6_txoptions *opt);
288 
289 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb);
290 
291 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
292 {
293 	/* If forwarding is enabled, RA are not accepted unless the special
294 	 * hybrid mode (accept_ra=2) is enabled.
295 	 */
296 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
297 	    idev->cnf.accept_ra;
298 }
299 
300 #if IS_ENABLED(CONFIG_IPV6)
301 static inline int ip6_frag_nqueues(struct net *net)
302 {
303 	return net->ipv6.frags.nqueues;
304 }
305 
306 static inline int ip6_frag_mem(struct net *net)
307 {
308 	return sum_frag_mem_limit(&net->ipv6.frags);
309 }
310 #endif
311 
312 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
313 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
314 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
315 
316 int __ipv6_addr_type(const struct in6_addr *addr);
317 static inline int ipv6_addr_type(const struct in6_addr *addr)
318 {
319 	return __ipv6_addr_type(addr) & 0xffff;
320 }
321 
322 static inline int ipv6_addr_scope(const struct in6_addr *addr)
323 {
324 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
325 }
326 
327 static inline int __ipv6_addr_src_scope(int type)
328 {
329 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
330 }
331 
332 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
333 {
334 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
335 }
336 
337 static inline bool __ipv6_addr_needs_scope_id(int type)
338 {
339 	return type & IPV6_ADDR_LINKLOCAL ||
340 	       (type & IPV6_ADDR_MULTICAST &&
341 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
342 }
343 
344 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
345 {
346 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
347 }
348 
349 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
350 {
351 	return memcmp(a1, a2, sizeof(struct in6_addr));
352 }
353 
354 static inline bool
355 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
356 		     const struct in6_addr *a2)
357 {
358 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
359 	const unsigned long *ul1 = (const unsigned long *)a1;
360 	const unsigned long *ulm = (const unsigned long *)m;
361 	const unsigned long *ul2 = (const unsigned long *)a2;
362 
363 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
364 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
365 #else
366 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
367 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
368 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
369 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
370 #endif
371 }
372 
373 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
374 				    const struct in6_addr *addr,
375 				    int plen)
376 {
377 	/* caller must guarantee 0 <= plen <= 128 */
378 	int o = plen >> 3,
379 	    b = plen & 0x7;
380 
381 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
382 	memcpy(pfx->s6_addr, addr, o);
383 	if (b != 0)
384 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
385 }
386 
387 static inline void __ipv6_addr_set_half(__be32 *addr,
388 					__be32 wh, __be32 wl)
389 {
390 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
391 #if defined(__BIG_ENDIAN)
392 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
393 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
394 		return;
395 	}
396 #elif defined(__LITTLE_ENDIAN)
397 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
398 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
399 		return;
400 	}
401 #endif
402 #endif
403 	addr[0] = wh;
404 	addr[1] = wl;
405 }
406 
407 static inline void ipv6_addr_set(struct in6_addr *addr,
408 				     __be32 w1, __be32 w2,
409 				     __be32 w3, __be32 w4)
410 {
411 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
412 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
413 }
414 
415 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
416 				   const struct in6_addr *a2)
417 {
418 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
419 	const unsigned long *ul1 = (const unsigned long *)a1;
420 	const unsigned long *ul2 = (const unsigned long *)a2;
421 
422 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
423 #else
424 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
425 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
426 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
427 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
428 #endif
429 }
430 
431 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
432 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
433 					      const __be64 *a2,
434 					      unsigned int len)
435 {
436 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
437 		return false;
438 	return true;
439 }
440 
441 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
442 				     const struct in6_addr *addr2,
443 				     unsigned int prefixlen)
444 {
445 	const __be64 *a1 = (const __be64 *)addr1;
446 	const __be64 *a2 = (const __be64 *)addr2;
447 
448 	if (prefixlen >= 64) {
449 		if (a1[0] ^ a2[0])
450 			return false;
451 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
452 	}
453 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
454 }
455 #else
456 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
457 				     const struct in6_addr *addr2,
458 				     unsigned int prefixlen)
459 {
460 	const __be32 *a1 = addr1->s6_addr32;
461 	const __be32 *a2 = addr2->s6_addr32;
462 	unsigned int pdw, pbi;
463 
464 	/* check complete u32 in prefix */
465 	pdw = prefixlen >> 5;
466 	if (pdw && memcmp(a1, a2, pdw << 2))
467 		return false;
468 
469 	/* check incomplete u32 in prefix */
470 	pbi = prefixlen & 0x1f;
471 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
472 		return false;
473 
474 	return true;
475 }
476 #endif
477 
478 struct inet_frag_queue;
479 
480 enum ip6_defrag_users {
481 	IP6_DEFRAG_LOCAL_DELIVER,
482 	IP6_DEFRAG_CONNTRACK_IN,
483 	__IP6_DEFRAG_CONNTRACK_IN	= IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
484 	IP6_DEFRAG_CONNTRACK_OUT,
485 	__IP6_DEFRAG_CONNTRACK_OUT	= IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
486 	IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
487 	__IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
488 };
489 
490 struct ip6_create_arg {
491 	__be32 id;
492 	u32 user;
493 	const struct in6_addr *src;
494 	const struct in6_addr *dst;
495 	u8 ecn;
496 };
497 
498 void ip6_frag_init(struct inet_frag_queue *q, void *a);
499 bool ip6_frag_match(struct inet_frag_queue *q, void *a);
500 
501 /*
502  *	Equivalent of ipv4 struct ip
503  */
504 struct frag_queue {
505 	struct inet_frag_queue	q;
506 
507 	__be32			id;		/* fragment id		*/
508 	u32			user;
509 	struct in6_addr		saddr;
510 	struct in6_addr		daddr;
511 
512 	int			iif;
513 	unsigned int		csum;
514 	__u16			nhoffset;
515 	u8			ecn;
516 };
517 
518 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
519 			   struct inet_frags *frags);
520 
521 static inline bool ipv6_addr_any(const struct in6_addr *a)
522 {
523 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
524 	const unsigned long *ul = (const unsigned long *)a;
525 
526 	return (ul[0] | ul[1]) == 0UL;
527 #else
528 	return (a->s6_addr32[0] | a->s6_addr32[1] |
529 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
530 #endif
531 }
532 
533 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
534 {
535 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
536 	const unsigned long *ul = (const unsigned long *)a;
537 	unsigned long x = ul[0] ^ ul[1];
538 
539 	return (u32)(x ^ (x >> 32));
540 #else
541 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
542 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
543 #endif
544 }
545 
546 /* more secured version of ipv6_addr_hash() */
547 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
548 {
549 	u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
550 
551 	return jhash_3words(v,
552 			    (__force u32)a->s6_addr32[2],
553 			    (__force u32)a->s6_addr32[3],
554 			    initval);
555 }
556 
557 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
558 {
559 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
560 	const unsigned long *ul = (const unsigned long *)a;
561 
562 	return (ul[0] | (ul[1] ^ cpu_to_be64(1))) == 0UL;
563 #else
564 	return (a->s6_addr32[0] | a->s6_addr32[1] |
565 		a->s6_addr32[2] | (a->s6_addr32[3] ^ htonl(1))) == 0;
566 #endif
567 }
568 
569 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
570 {
571 	return (
572 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
573 		*(__be64 *)a |
574 #else
575 		(a->s6_addr32[0] | a->s6_addr32[1]) |
576 #endif
577 		(a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0UL;
578 }
579 
580 /*
581  * Check for a RFC 4843 ORCHID address
582  * (Overlay Routable Cryptographic Hash Identifiers)
583  */
584 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
585 {
586 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
587 }
588 
589 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
590 {
591 	return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
592 }
593 
594 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
595 					  struct in6_addr *v4mapped)
596 {
597 	ipv6_addr_set(v4mapped,
598 			0, 0,
599 			htonl(0x0000FFFF),
600 			addr);
601 }
602 
603 /*
604  * find the first different bit between two addresses
605  * length of address must be a multiple of 32bits
606  */
607 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
608 {
609 	const __be32 *a1 = token1, *a2 = token2;
610 	int i;
611 
612 	addrlen >>= 2;
613 
614 	for (i = 0; i < addrlen; i++) {
615 		__be32 xb = a1[i] ^ a2[i];
616 		if (xb)
617 			return i * 32 + 31 - __fls(ntohl(xb));
618 	}
619 
620 	/*
621 	 *	we should *never* get to this point since that
622 	 *	would mean the addrs are equal
623 	 *
624 	 *	However, we do get to it 8) And exacly, when
625 	 *	addresses are equal 8)
626 	 *
627 	 *	ip route add 1111::/128 via ...
628 	 *	ip route add 1111::/64 via ...
629 	 *	and we are here.
630 	 *
631 	 *	Ideally, this function should stop comparison
632 	 *	at prefix length. It does not, but it is still OK,
633 	 *	if returned value is greater than prefix length.
634 	 *					--ANK (980803)
635 	 */
636 	return addrlen << 5;
637 }
638 
639 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
640 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
641 {
642 	const __be64 *a1 = token1, *a2 = token2;
643 	int i;
644 
645 	addrlen >>= 3;
646 
647 	for (i = 0; i < addrlen; i++) {
648 		__be64 xb = a1[i] ^ a2[i];
649 		if (xb)
650 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
651 	}
652 
653 	return addrlen << 6;
654 }
655 #endif
656 
657 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
658 {
659 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
660 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
661 		return __ipv6_addr_diff64(token1, token2, addrlen);
662 #endif
663 	return __ipv6_addr_diff32(token1, token2, addrlen);
664 }
665 
666 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
667 {
668 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
669 }
670 
671 int ip6_dst_hoplimit(struct dst_entry *dst);
672 
673 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
674 				      struct dst_entry *dst)
675 {
676 	int hlimit;
677 
678 	if (ipv6_addr_is_multicast(&fl6->daddr))
679 		hlimit = np->mcast_hops;
680 	else
681 		hlimit = np->hop_limit;
682 	if (hlimit < 0)
683 		hlimit = ip6_dst_hoplimit(dst);
684 	return hlimit;
685 }
686 
687 /*
688  *	Header manipulation
689  */
690 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
691 				__be32 flowlabel)
692 {
693 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
694 }
695 
696 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
697 {
698 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
699 }
700 
701 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
702 {
703 	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
704 }
705 
706 static inline u8 ip6_tclass(__be32 flowinfo)
707 {
708 	return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
709 }
710 /*
711  *	Prototypes exported by ipv6
712  */
713 
714 /*
715  *	rcv function (called from netdevice level)
716  */
717 
718 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
719 	     struct packet_type *pt, struct net_device *orig_dev);
720 
721 int ip6_rcv_finish(struct sk_buff *skb);
722 
723 /*
724  *	upper-layer output functions
725  */
726 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
727 	     struct ipv6_txoptions *opt, int tclass);
728 
729 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
730 
731 int ip6_append_data(struct sock *sk,
732 		    int getfrag(void *from, char *to, int offset, int len,
733 				int odd, struct sk_buff *skb),
734 		    void *from, int length, int transhdrlen, int hlimit,
735 		    int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
736 		    struct rt6_info *rt, unsigned int flags, int dontfrag);
737 
738 int ip6_push_pending_frames(struct sock *sk);
739 
740 void ip6_flush_pending_frames(struct sock *sk);
741 
742 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6);
743 struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
744 				      const struct in6_addr *final_dst);
745 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
746 					 const struct in6_addr *final_dst);
747 struct dst_entry *ip6_blackhole_route(struct net *net,
748 				      struct dst_entry *orig_dst);
749 
750 /*
751  *	skb processing functions
752  */
753 
754 int ip6_output(struct sock *sk, struct sk_buff *skb);
755 int ip6_forward(struct sk_buff *skb);
756 int ip6_input(struct sk_buff *skb);
757 int ip6_mc_input(struct sk_buff *skb);
758 
759 int __ip6_local_out(struct sk_buff *skb);
760 int ip6_local_out(struct sk_buff *skb);
761 
762 /*
763  *	Extension header (options) processing
764  */
765 
766 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
767 			  u8 *proto, struct in6_addr **daddr_p);
768 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
769 			 u8 *proto);
770 
771 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
772 		     __be16 *frag_offp);
773 
774 bool ipv6_ext_hdr(u8 nexthdr);
775 
776 enum {
777 	IP6_FH_F_FRAG		= (1 << 0),
778 	IP6_FH_F_AUTH		= (1 << 1),
779 	IP6_FH_F_SKIP_RH	= (1 << 2),
780 };
781 
782 /* find specified header and get offset to it */
783 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
784 		  unsigned short *fragoff, int *fragflg);
785 
786 int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
787 
788 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
789 				const struct ipv6_txoptions *opt,
790 				struct in6_addr *orig);
791 
792 /*
793  *	socket options (ipv6_sockglue.c)
794  */
795 
796 int ipv6_setsockopt(struct sock *sk, int level, int optname,
797 		    char __user *optval, unsigned int optlen);
798 int ipv6_getsockopt(struct sock *sk, int level, int optname,
799 		    char __user *optval, int __user *optlen);
800 int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
801 			   char __user *optval, unsigned int optlen);
802 int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
803 			   char __user *optval, int __user *optlen);
804 
805 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
806 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
807 				 int addr_len);
808 
809 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
810 		    int *addr_len);
811 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
812 		     int *addr_len);
813 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
814 		     u32 info, u8 *payload);
815 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
816 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
817 
818 int inet6_release(struct socket *sock);
819 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
820 int inet6_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len,
821 		  int peer);
822 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
823 
824 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
825 			      struct sock *sk);
826 
827 /*
828  * reassembly.c
829  */
830 extern const struct proto_ops inet6_stream_ops;
831 extern const struct proto_ops inet6_dgram_ops;
832 
833 struct group_source_req;
834 struct group_filter;
835 
836 int ip6_mc_source(int add, int omode, struct sock *sk,
837 		  struct group_source_req *pgsr);
838 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
839 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
840 		  struct group_filter __user *optval, int __user *optlen);
841 
842 #ifdef CONFIG_PROC_FS
843 int ac6_proc_init(struct net *net);
844 void ac6_proc_exit(struct net *net);
845 int raw6_proc_init(void);
846 void raw6_proc_exit(void);
847 int tcp6_proc_init(struct net *net);
848 void tcp6_proc_exit(struct net *net);
849 int udp6_proc_init(struct net *net);
850 void udp6_proc_exit(struct net *net);
851 int udplite6_proc_init(void);
852 void udplite6_proc_exit(void);
853 int ipv6_misc_proc_init(void);
854 void ipv6_misc_proc_exit(void);
855 int snmp6_register_dev(struct inet6_dev *idev);
856 int snmp6_unregister_dev(struct inet6_dev *idev);
857 
858 #else
859 static inline int ac6_proc_init(struct net *net) { return 0; }
860 static inline void ac6_proc_exit(struct net *net) { }
861 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
862 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
863 #endif
864 
865 #ifdef CONFIG_SYSCTL
866 extern struct ctl_table ipv6_route_table_template[];
867 
868 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
869 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
870 int ipv6_sysctl_register(void);
871 void ipv6_sysctl_unregister(void);
872 #endif
873 
874 #endif /* _NET_IPV6_H */
875