xref: /linux/include/net/ipv6.h (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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/flow_keys.h>
23 #include <net/snmp.h>
24 
25 #define SIN6_LEN_RFC2133	24
26 
27 #define IPV6_MAXPLEN		65535
28 
29 /*
30  *	NextHeader field of IPv6 header
31  */
32 
33 #define NEXTHDR_HOP		0	/* Hop-by-hop option header. */
34 #define NEXTHDR_TCP		6	/* TCP segment. */
35 #define NEXTHDR_UDP		17	/* UDP message. */
36 #define NEXTHDR_IPV6		41	/* IPv6 in IPv6 */
37 #define NEXTHDR_ROUTING		43	/* Routing header. */
38 #define NEXTHDR_FRAGMENT	44	/* Fragmentation/reassembly header. */
39 #define NEXTHDR_GRE		47	/* GRE header. */
40 #define NEXTHDR_ESP		50	/* Encapsulating security payload. */
41 #define NEXTHDR_AUTH		51	/* Authentication header. */
42 #define NEXTHDR_ICMP		58	/* ICMP for IPv6. */
43 #define NEXTHDR_NONE		59	/* No next header */
44 #define NEXTHDR_DEST		60	/* Destination options header. */
45 #define NEXTHDR_SCTP		132	/* SCTP message. */
46 #define NEXTHDR_MOBILITY	135	/* Mobility header. */
47 
48 #define NEXTHDR_MAX		255
49 
50 
51 
52 #define IPV6_DEFAULT_HOPLIMIT   64
53 #define IPV6_DEFAULT_MCASTHOPS	1
54 
55 /*
56  *	Addr type
57  *
58  *	type	-	unicast | multicast
59  *	scope	-	local	| site	    | global
60  *	v4	-	compat
61  *	v4mapped
62  *	any
63  *	loopback
64  */
65 
66 #define IPV6_ADDR_ANY		0x0000U
67 
68 #define IPV6_ADDR_UNICAST      	0x0001U
69 #define IPV6_ADDR_MULTICAST    	0x0002U
70 
71 #define IPV6_ADDR_LOOPBACK	0x0010U
72 #define IPV6_ADDR_LINKLOCAL	0x0020U
73 #define IPV6_ADDR_SITELOCAL	0x0040U
74 
75 #define IPV6_ADDR_COMPATv4	0x0080U
76 
77 #define IPV6_ADDR_SCOPE_MASK	0x00f0U
78 
79 #define IPV6_ADDR_MAPPED	0x1000U
80 
81 /*
82  *	Addr scopes
83  */
84 #define IPV6_ADDR_MC_SCOPE(a)	\
85 	((a)->s6_addr[1] & 0x0f)	/* nonstandard */
86 #define __IPV6_ADDR_SCOPE_INVALID	-1
87 #define IPV6_ADDR_SCOPE_NODELOCAL	0x01
88 #define IPV6_ADDR_SCOPE_LINKLOCAL	0x02
89 #define IPV6_ADDR_SCOPE_SITELOCAL	0x05
90 #define IPV6_ADDR_SCOPE_ORGLOCAL	0x08
91 #define IPV6_ADDR_SCOPE_GLOBAL		0x0e
92 
93 /*
94  *	Addr flags
95  */
96 #define IPV6_ADDR_MC_FLAG_TRANSIENT(a)	\
97 	((a)->s6_addr[1] & 0x10)
98 #define IPV6_ADDR_MC_FLAG_PREFIX(a)	\
99 	((a)->s6_addr[1] & 0x20)
100 #define IPV6_ADDR_MC_FLAG_RENDEZVOUS(a)	\
101 	((a)->s6_addr[1] & 0x40)
102 
103 /*
104  *	fragmentation header
105  */
106 
107 struct frag_hdr {
108 	__u8	nexthdr;
109 	__u8	reserved;
110 	__be16	frag_off;
111 	__be32	identification;
112 };
113 
114 #define	IP6_MF		0x0001
115 #define	IP6_OFFSET	0xFFF8
116 
117 #define IP6_REPLY_MARK(net, mark) \
118 	((net)->ipv6.sysctl.fwmark_reflect ? (mark) : 0)
119 
120 #include <net/sock.h>
121 
122 /* sysctls */
123 extern int sysctl_mld_max_msf;
124 
125 #define _DEVINC(net, statname, modifier, idev, field)			\
126 ({									\
127 	struct inet6_dev *_idev = (idev);				\
128 	if (likely(_idev != NULL))					\
129 		SNMP_INC_STATS##modifier((_idev)->stats.statname, (field)); \
130 	SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
131 })
132 
133 /* per device counters are atomic_long_t */
134 #define _DEVINCATOMIC(net, statname, modifier, idev, field)		\
135 ({									\
136 	struct inet6_dev *_idev = (idev);				\
137 	if (likely(_idev != NULL))					\
138 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
139 	SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
140 })
141 
142 /* per device and per net counters are atomic_long_t */
143 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)		\
144 ({									\
145 	struct inet6_dev *_idev = (idev);				\
146 	if (likely(_idev != NULL))					\
147 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
148 	SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
149 })
150 
151 #define _DEVADD(net, statname, modifier, idev, field, val)		\
152 ({									\
153 	struct inet6_dev *_idev = (idev);				\
154 	if (likely(_idev != NULL))					\
155 		SNMP_ADD_STATS##modifier((_idev)->stats.statname, (field), (val)); \
156 	SNMP_ADD_STATS##modifier((net)->mib.statname##_statistics, (field), (val));\
157 })
158 
159 #define _DEVUPD(net, statname, modifier, idev, field, val)		\
160 ({									\
161 	struct inet6_dev *_idev = (idev);				\
162 	if (likely(_idev != NULL))					\
163 		SNMP_UPD_PO_STATS##modifier((_idev)->stats.statname, field, (val)); \
164 	SNMP_UPD_PO_STATS##modifier((net)->mib.statname##_statistics, field, (val));\
165 })
166 
167 /* MIBs */
168 
169 #define IP6_INC_STATS(net, idev,field)		\
170 		_DEVINC(net, ipv6, 64, idev, field)
171 #define IP6_INC_STATS_BH(net, idev,field)	\
172 		_DEVINC(net, ipv6, 64_BH, idev, field)
173 #define IP6_ADD_STATS(net, idev,field,val)	\
174 		_DEVADD(net, ipv6, 64, idev, field, val)
175 #define IP6_ADD_STATS_BH(net, idev,field,val)	\
176 		_DEVADD(net, ipv6, 64_BH, idev, field, val)
177 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
178 		_DEVUPD(net, ipv6, 64, idev, field, val)
179 #define IP6_UPD_PO_STATS_BH(net, idev,field,val)   \
180 		_DEVUPD(net, ipv6, 64_BH, idev, field, val)
181 #define ICMP6_INC_STATS(net, idev, field)	\
182 		_DEVINCATOMIC(net, icmpv6, , idev, field)
183 #define ICMP6_INC_STATS_BH(net, idev, field)	\
184 		_DEVINCATOMIC(net, icmpv6, _BH, idev, field)
185 
186 #define ICMP6MSGOUT_INC_STATS(net, idev, field)		\
187 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
188 #define ICMP6MSGOUT_INC_STATS_BH(net, idev, field)	\
189 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
190 #define ICMP6MSGIN_INC_STATS_BH(net, idev, field)	\
191 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
192 
193 struct ip6_ra_chain {
194 	struct ip6_ra_chain	*next;
195 	struct sock		*sk;
196 	int			sel;
197 	void			(*destructor)(struct sock *);
198 };
199 
200 extern struct ip6_ra_chain	*ip6_ra_chain;
201 extern rwlock_t ip6_ra_lock;
202 
203 /*
204    This structure is prepared by protocol, when parsing
205    ancillary data and passed to IPv6.
206  */
207 
208 struct ipv6_txoptions {
209 	/* Length of this structure */
210 	int			tot_len;
211 
212 	/* length of extension headers   */
213 
214 	__u16			opt_flen;	/* after fragment hdr */
215 	__u16			opt_nflen;	/* before fragment hdr */
216 
217 	struct ipv6_opt_hdr	*hopopt;
218 	struct ipv6_opt_hdr	*dst0opt;
219 	struct ipv6_rt_hdr	*srcrt;	/* Routing Header */
220 	struct ipv6_opt_hdr	*dst1opt;
221 
222 	/* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
223 };
224 
225 struct ip6_flowlabel {
226 	struct ip6_flowlabel __rcu *next;
227 	__be32			label;
228 	atomic_t		users;
229 	struct in6_addr		dst;
230 	struct ipv6_txoptions	*opt;
231 	unsigned long		linger;
232 	struct rcu_head		rcu;
233 	u8			share;
234 	union {
235 		struct pid *pid;
236 		kuid_t uid;
237 	} owner;
238 	unsigned long		lastuse;
239 	unsigned long		expires;
240 	struct net		*fl_net;
241 };
242 
243 #define IPV6_FLOWINFO_MASK	cpu_to_be32(0x0FFFFFFF)
244 #define IPV6_FLOWLABEL_MASK	cpu_to_be32(0x000FFFFF)
245 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
246 #define IPV6_TCLASS_SHIFT	20
247 
248 struct ipv6_fl_socklist {
249 	struct ipv6_fl_socklist	__rcu	*next;
250 	struct ip6_flowlabel		*fl;
251 	struct rcu_head			rcu;
252 };
253 
254 struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label);
255 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
256 					 struct ip6_flowlabel *fl,
257 					 struct ipv6_txoptions *fopt);
258 void fl6_free_socklist(struct sock *sk);
259 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
260 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
261 			   int flags);
262 int ip6_flowlabel_init(void);
263 void ip6_flowlabel_cleanup(void);
264 
265 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
266 {
267 	if (fl)
268 		atomic_dec(&fl->users);
269 }
270 
271 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
272 
273 int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
274 			       struct icmp6hdr *thdr, int len);
275 
276 int ip6_ra_control(struct sock *sk, int sel);
277 
278 int ipv6_parse_hopopts(struct sk_buff *skb);
279 
280 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
281 					struct ipv6_txoptions *opt);
282 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
283 					  struct ipv6_txoptions *opt,
284 					  int newtype,
285 					  struct ipv6_opt_hdr __user *newopt,
286 					  int newoptlen);
287 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
288 					  struct ipv6_txoptions *opt);
289 
290 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb);
291 
292 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
293 {
294 	/* If forwarding is enabled, RA are not accepted unless the special
295 	 * hybrid mode (accept_ra=2) is enabled.
296 	 */
297 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
298 	    idev->cnf.accept_ra;
299 }
300 
301 #if IS_ENABLED(CONFIG_IPV6)
302 static inline int ip6_frag_mem(struct net *net)
303 {
304 	return sum_frag_mem_limit(&net->ipv6.frags);
305 }
306 #endif
307 
308 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
309 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
310 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
311 
312 int __ipv6_addr_type(const struct in6_addr *addr);
313 static inline int ipv6_addr_type(const struct in6_addr *addr)
314 {
315 	return __ipv6_addr_type(addr) & 0xffff;
316 }
317 
318 static inline int ipv6_addr_scope(const struct in6_addr *addr)
319 {
320 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
321 }
322 
323 static inline int __ipv6_addr_src_scope(int type)
324 {
325 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
326 }
327 
328 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
329 {
330 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
331 }
332 
333 static inline bool __ipv6_addr_needs_scope_id(int type)
334 {
335 	return type & IPV6_ADDR_LINKLOCAL ||
336 	       (type & IPV6_ADDR_MULTICAST &&
337 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
338 }
339 
340 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
341 {
342 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
343 }
344 
345 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
346 {
347 	return memcmp(a1, a2, sizeof(struct in6_addr));
348 }
349 
350 static inline bool
351 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
352 		     const struct in6_addr *a2)
353 {
354 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
355 	const unsigned long *ul1 = (const unsigned long *)a1;
356 	const unsigned long *ulm = (const unsigned long *)m;
357 	const unsigned long *ul2 = (const unsigned long *)a2;
358 
359 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
360 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
361 #else
362 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
363 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
364 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
365 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
366 #endif
367 }
368 
369 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
370 				    const struct in6_addr *addr,
371 				    int plen)
372 {
373 	/* caller must guarantee 0 <= plen <= 128 */
374 	int o = plen >> 3,
375 	    b = plen & 0x7;
376 
377 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
378 	memcpy(pfx->s6_addr, addr, o);
379 	if (b != 0)
380 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
381 }
382 
383 static inline void __ipv6_addr_set_half(__be32 *addr,
384 					__be32 wh, __be32 wl)
385 {
386 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
387 #if defined(__BIG_ENDIAN)
388 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
389 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
390 		return;
391 	}
392 #elif defined(__LITTLE_ENDIAN)
393 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
394 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
395 		return;
396 	}
397 #endif
398 #endif
399 	addr[0] = wh;
400 	addr[1] = wl;
401 }
402 
403 static inline void ipv6_addr_set(struct in6_addr *addr,
404 				     __be32 w1, __be32 w2,
405 				     __be32 w3, __be32 w4)
406 {
407 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
408 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
409 }
410 
411 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
412 				   const struct in6_addr *a2)
413 {
414 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
415 	const unsigned long *ul1 = (const unsigned long *)a1;
416 	const unsigned long *ul2 = (const unsigned long *)a2;
417 
418 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
419 #else
420 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
421 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
422 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
423 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
424 #endif
425 }
426 
427 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
428 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
429 					      const __be64 *a2,
430 					      unsigned int len)
431 {
432 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
433 		return false;
434 	return true;
435 }
436 
437 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
438 				     const struct in6_addr *addr2,
439 				     unsigned int prefixlen)
440 {
441 	const __be64 *a1 = (const __be64 *)addr1;
442 	const __be64 *a2 = (const __be64 *)addr2;
443 
444 	if (prefixlen >= 64) {
445 		if (a1[0] ^ a2[0])
446 			return false;
447 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
448 	}
449 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
450 }
451 #else
452 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
453 				     const struct in6_addr *addr2,
454 				     unsigned int prefixlen)
455 {
456 	const __be32 *a1 = addr1->s6_addr32;
457 	const __be32 *a2 = addr2->s6_addr32;
458 	unsigned int pdw, pbi;
459 
460 	/* check complete u32 in prefix */
461 	pdw = prefixlen >> 5;
462 	if (pdw && memcmp(a1, a2, pdw << 2))
463 		return false;
464 
465 	/* check incomplete u32 in prefix */
466 	pbi = prefixlen & 0x1f;
467 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
468 		return false;
469 
470 	return true;
471 }
472 #endif
473 
474 struct inet_frag_queue;
475 
476 enum ip6_defrag_users {
477 	IP6_DEFRAG_LOCAL_DELIVER,
478 	IP6_DEFRAG_CONNTRACK_IN,
479 	__IP6_DEFRAG_CONNTRACK_IN	= IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
480 	IP6_DEFRAG_CONNTRACK_OUT,
481 	__IP6_DEFRAG_CONNTRACK_OUT	= IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
482 	IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
483 	__IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
484 };
485 
486 struct ip6_create_arg {
487 	__be32 id;
488 	u32 user;
489 	const struct in6_addr *src;
490 	const struct in6_addr *dst;
491 	u8 ecn;
492 };
493 
494 void ip6_frag_init(struct inet_frag_queue *q, const void *a);
495 bool ip6_frag_match(const struct inet_frag_queue *q, const void *a);
496 
497 /*
498  *	Equivalent of ipv4 struct ip
499  */
500 struct frag_queue {
501 	struct inet_frag_queue	q;
502 
503 	__be32			id;		/* fragment id		*/
504 	u32			user;
505 	struct in6_addr		saddr;
506 	struct in6_addr		daddr;
507 
508 	int			iif;
509 	unsigned int		csum;
510 	__u16			nhoffset;
511 	u8			ecn;
512 };
513 
514 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
515 			   struct inet_frags *frags);
516 
517 static inline bool ipv6_addr_any(const struct in6_addr *a)
518 {
519 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
520 	const unsigned long *ul = (const unsigned long *)a;
521 
522 	return (ul[0] | ul[1]) == 0UL;
523 #else
524 	return (a->s6_addr32[0] | a->s6_addr32[1] |
525 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
526 #endif
527 }
528 
529 static inline u32 ipv6_addr_hash(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 	unsigned long x = ul[0] ^ ul[1];
534 
535 	return (u32)(x ^ (x >> 32));
536 #else
537 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
538 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
539 #endif
540 }
541 
542 /* more secured version of ipv6_addr_hash() */
543 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
544 {
545 	u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
546 
547 	return jhash_3words(v,
548 			    (__force u32)a->s6_addr32[2],
549 			    (__force u32)a->s6_addr32[3],
550 			    initval);
551 }
552 
553 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
554 {
555 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
556 	const __be64 *be = (const __be64 *)a;
557 
558 	return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
559 #else
560 	return (a->s6_addr32[0] | a->s6_addr32[1] |
561 		a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
562 #endif
563 }
564 
565 /*
566  * Note that we must __force cast these to unsigned long to make sparse happy,
567  * since all of the endian-annotated types are fixed size regardless of arch.
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 		*(unsigned long *)a |
574 #else
575 		(__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
576 #endif
577 		(__force unsigned long)(a->s6_addr32[2] ^
578 					cpu_to_be32(0x0000ffff))) == 0UL;
579 }
580 
581 /*
582  * Check for a RFC 4843 ORCHID address
583  * (Overlay Routable Cryptographic Hash Identifiers)
584  */
585 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
586 {
587 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
588 }
589 
590 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
591 {
592 	return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
593 }
594 
595 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
596 					  struct in6_addr *v4mapped)
597 {
598 	ipv6_addr_set(v4mapped,
599 			0, 0,
600 			htonl(0x0000FFFF),
601 			addr);
602 }
603 
604 /*
605  * find the first different bit between two addresses
606  * length of address must be a multiple of 32bits
607  */
608 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
609 {
610 	const __be32 *a1 = token1, *a2 = token2;
611 	int i;
612 
613 	addrlen >>= 2;
614 
615 	for (i = 0; i < addrlen; i++) {
616 		__be32 xb = a1[i] ^ a2[i];
617 		if (xb)
618 			return i * 32 + 31 - __fls(ntohl(xb));
619 	}
620 
621 	/*
622 	 *	we should *never* get to this point since that
623 	 *	would mean the addrs are equal
624 	 *
625 	 *	However, we do get to it 8) And exacly, when
626 	 *	addresses are equal 8)
627 	 *
628 	 *	ip route add 1111::/128 via ...
629 	 *	ip route add 1111::/64 via ...
630 	 *	and we are here.
631 	 *
632 	 *	Ideally, this function should stop comparison
633 	 *	at prefix length. It does not, but it is still OK,
634 	 *	if returned value is greater than prefix length.
635 	 *					--ANK (980803)
636 	 */
637 	return addrlen << 5;
638 }
639 
640 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
641 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
642 {
643 	const __be64 *a1 = token1, *a2 = token2;
644 	int i;
645 
646 	addrlen >>= 3;
647 
648 	for (i = 0; i < addrlen; i++) {
649 		__be64 xb = a1[i] ^ a2[i];
650 		if (xb)
651 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
652 	}
653 
654 	return addrlen << 6;
655 }
656 #endif
657 
658 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
659 {
660 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
661 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
662 		return __ipv6_addr_diff64(token1, token2, addrlen);
663 #endif
664 	return __ipv6_addr_diff32(token1, token2, addrlen);
665 }
666 
667 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
668 {
669 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
670 }
671 
672 int ip6_dst_hoplimit(struct dst_entry *dst);
673 
674 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
675 				      struct dst_entry *dst)
676 {
677 	int hlimit;
678 
679 	if (ipv6_addr_is_multicast(&fl6->daddr))
680 		hlimit = np->mcast_hops;
681 	else
682 		hlimit = np->hop_limit;
683 	if (hlimit < 0)
684 		hlimit = ip6_dst_hoplimit(dst);
685 	return hlimit;
686 }
687 
688 #if IS_ENABLED(CONFIG_IPV6)
689 static inline void ip6_set_txhash(struct sock *sk)
690 {
691 	struct inet_sock *inet = inet_sk(sk);
692 	struct ipv6_pinfo *np = inet6_sk(sk);
693 	struct flow_keys keys;
694 
695 	keys.src = (__force __be32)ipv6_addr_hash(&np->saddr);
696 	keys.dst = (__force __be32)ipv6_addr_hash(&sk->sk_v6_daddr);
697 	keys.port16[0] = inet->inet_sport;
698 	keys.port16[1] = inet->inet_dport;
699 
700 	sk->sk_txhash = flow_hash_from_keys(&keys);
701 }
702 
703 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
704 					__be32 flowlabel, bool autolabel)
705 {
706 	if (!flowlabel && (autolabel || net->ipv6.sysctl.auto_flowlabels)) {
707 		__be32 hash;
708 
709 		hash = skb_get_hash(skb);
710 
711 		/* Since this is being sent on the wire obfuscate hash a bit
712 		 * to minimize possbility that any useful information to an
713 		 * attacker is leaked. Only lower 20 bits are relevant.
714 		 */
715 		hash ^= hash >> 12;
716 
717 		flowlabel = hash & IPV6_FLOWLABEL_MASK;
718 	}
719 
720 	return flowlabel;
721 }
722 #else
723 static inline void ip6_set_txhash(struct sock *sk) { }
724 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
725 					__be32 flowlabel, bool autolabel)
726 {
727 	return flowlabel;
728 }
729 #endif
730 
731 
732 /*
733  *	Header manipulation
734  */
735 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
736 				__be32 flowlabel)
737 {
738 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
739 }
740 
741 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
742 {
743 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
744 }
745 
746 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
747 {
748 	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
749 }
750 
751 static inline u8 ip6_tclass(__be32 flowinfo)
752 {
753 	return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
754 }
755 /*
756  *	Prototypes exported by ipv6
757  */
758 
759 /*
760  *	rcv function (called from netdevice level)
761  */
762 
763 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
764 	     struct packet_type *pt, struct net_device *orig_dev);
765 
766 int ip6_rcv_finish(struct sk_buff *skb);
767 
768 /*
769  *	upper-layer output functions
770  */
771 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
772 	     struct ipv6_txoptions *opt, int tclass);
773 
774 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
775 
776 int ip6_append_data(struct sock *sk,
777 		    int getfrag(void *from, char *to, int offset, int len,
778 				int odd, struct sk_buff *skb),
779 		    void *from, int length, int transhdrlen, int hlimit,
780 		    int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
781 		    struct rt6_info *rt, unsigned int flags, int dontfrag);
782 
783 int ip6_push_pending_frames(struct sock *sk);
784 
785 void ip6_flush_pending_frames(struct sock *sk);
786 
787 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6);
788 struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
789 				      const struct in6_addr *final_dst);
790 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
791 					 const struct in6_addr *final_dst);
792 struct dst_entry *ip6_blackhole_route(struct net *net,
793 				      struct dst_entry *orig_dst);
794 
795 /*
796  *	skb processing functions
797  */
798 
799 int ip6_output(struct sock *sk, struct sk_buff *skb);
800 int ip6_forward(struct sk_buff *skb);
801 int ip6_input(struct sk_buff *skb);
802 int ip6_mc_input(struct sk_buff *skb);
803 
804 int __ip6_local_out(struct sk_buff *skb);
805 int ip6_local_out(struct sk_buff *skb);
806 
807 /*
808  *	Extension header (options) processing
809  */
810 
811 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
812 			  u8 *proto, struct in6_addr **daddr_p);
813 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
814 			 u8 *proto);
815 
816 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
817 		     __be16 *frag_offp);
818 
819 bool ipv6_ext_hdr(u8 nexthdr);
820 
821 enum {
822 	IP6_FH_F_FRAG		= (1 << 0),
823 	IP6_FH_F_AUTH		= (1 << 1),
824 	IP6_FH_F_SKIP_RH	= (1 << 2),
825 };
826 
827 /* find specified header and get offset to it */
828 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
829 		  unsigned short *fragoff, int *fragflg);
830 
831 int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
832 
833 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
834 				const struct ipv6_txoptions *opt,
835 				struct in6_addr *orig);
836 
837 /*
838  *	socket options (ipv6_sockglue.c)
839  */
840 
841 int ipv6_setsockopt(struct sock *sk, int level, int optname,
842 		    char __user *optval, unsigned int optlen);
843 int ipv6_getsockopt(struct sock *sk, int level, int optname,
844 		    char __user *optval, int __user *optlen);
845 int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
846 			   char __user *optval, unsigned int optlen);
847 int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
848 			   char __user *optval, int __user *optlen);
849 
850 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
851 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
852 				 int addr_len);
853 
854 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
855 		    int *addr_len);
856 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
857 		     int *addr_len);
858 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
859 		     u32 info, u8 *payload);
860 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
861 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
862 
863 int inet6_release(struct socket *sock);
864 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
865 int inet6_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len,
866 		  int peer);
867 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
868 
869 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
870 			      struct sock *sk);
871 
872 /*
873  * reassembly.c
874  */
875 extern const struct proto_ops inet6_stream_ops;
876 extern const struct proto_ops inet6_dgram_ops;
877 
878 struct group_source_req;
879 struct group_filter;
880 
881 int ip6_mc_source(int add, int omode, struct sock *sk,
882 		  struct group_source_req *pgsr);
883 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
884 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
885 		  struct group_filter __user *optval, int __user *optlen);
886 
887 #ifdef CONFIG_PROC_FS
888 int ac6_proc_init(struct net *net);
889 void ac6_proc_exit(struct net *net);
890 int raw6_proc_init(void);
891 void raw6_proc_exit(void);
892 int tcp6_proc_init(struct net *net);
893 void tcp6_proc_exit(struct net *net);
894 int udp6_proc_init(struct net *net);
895 void udp6_proc_exit(struct net *net);
896 int udplite6_proc_init(void);
897 void udplite6_proc_exit(void);
898 int ipv6_misc_proc_init(void);
899 void ipv6_misc_proc_exit(void);
900 int snmp6_register_dev(struct inet6_dev *idev);
901 int snmp6_unregister_dev(struct inet6_dev *idev);
902 
903 #else
904 static inline int ac6_proc_init(struct net *net) { return 0; }
905 static inline void ac6_proc_exit(struct net *net) { }
906 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
907 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
908 #endif
909 
910 #ifdef CONFIG_SYSCTL
911 extern struct ctl_table ipv6_route_table_template[];
912 
913 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
914 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
915 int ipv6_sysctl_register(void);
916 void ipv6_sysctl_unregister(void);
917 #endif
918 
919 #endif /* _NET_IPV6_H */
920