xref: /linux/include/net/ipv6.h (revision 3b27d13940c3710a1128527c43719cb0bb05d73b)
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_dissector.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 #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 #define	IP6_OFFSET	0xFFF8
114 
115 #define IP6_REPLY_MARK(net, mark) \
116 	((net)->ipv6.sysctl.fwmark_reflect ? (mark) : 0)
117 
118 #include <net/sock.h>
119 
120 /* sysctls */
121 extern int sysctl_mld_max_msf;
122 extern int sysctl_mld_qrv;
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_FLOWLABEL_STATELESS_FLAG	cpu_to_be32(0x00080000)
245 
246 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
247 #define IPV6_TCLASS_SHIFT	20
248 
249 struct ipv6_fl_socklist {
250 	struct ipv6_fl_socklist	__rcu	*next;
251 	struct ip6_flowlabel		*fl;
252 	struct rcu_head			rcu;
253 };
254 
255 struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label);
256 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
257 					 struct ip6_flowlabel *fl,
258 					 struct ipv6_txoptions *fopt);
259 void fl6_free_socklist(struct sock *sk);
260 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
261 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
262 			   int flags);
263 int ip6_flowlabel_init(void);
264 void ip6_flowlabel_cleanup(void);
265 
266 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
267 {
268 	if (fl)
269 		atomic_dec(&fl->users);
270 }
271 
272 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
273 
274 int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
275 			       struct icmp6hdr *thdr, int len);
276 
277 int ip6_ra_control(struct sock *sk, int sel);
278 
279 int ipv6_parse_hopopts(struct sk_buff *skb);
280 
281 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
282 					struct ipv6_txoptions *opt);
283 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
284 					  struct ipv6_txoptions *opt,
285 					  int newtype,
286 					  struct ipv6_opt_hdr __user *newopt,
287 					  int newoptlen);
288 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
289 					  struct ipv6_txoptions *opt);
290 
291 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
292 		       const struct inet6_skb_parm *opt);
293 
294 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
295 {
296 	/* If forwarding is enabled, RA are not accepted unless the special
297 	 * hybrid mode (accept_ra=2) is enabled.
298 	 */
299 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
300 	    idev->cnf.accept_ra;
301 }
302 
303 #if IS_ENABLED(CONFIG_IPV6)
304 static inline int ip6_frag_mem(struct net *net)
305 {
306 	return sum_frag_mem_limit(&net->ipv6.frags);
307 }
308 #endif
309 
310 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
311 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
312 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
313 
314 int __ipv6_addr_type(const struct in6_addr *addr);
315 static inline int ipv6_addr_type(const struct in6_addr *addr)
316 {
317 	return __ipv6_addr_type(addr) & 0xffff;
318 }
319 
320 static inline int ipv6_addr_scope(const struct in6_addr *addr)
321 {
322 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
323 }
324 
325 static inline int __ipv6_addr_src_scope(int type)
326 {
327 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
328 }
329 
330 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
331 {
332 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
333 }
334 
335 static inline bool __ipv6_addr_needs_scope_id(int type)
336 {
337 	return type & IPV6_ADDR_LINKLOCAL ||
338 	       (type & IPV6_ADDR_MULTICAST &&
339 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
340 }
341 
342 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
343 {
344 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
345 }
346 
347 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
348 {
349 	return memcmp(a1, a2, sizeof(struct in6_addr));
350 }
351 
352 static inline bool
353 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
354 		     const struct in6_addr *a2)
355 {
356 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
357 	const unsigned long *ul1 = (const unsigned long *)a1;
358 	const unsigned long *ulm = (const unsigned long *)m;
359 	const unsigned long *ul2 = (const unsigned long *)a2;
360 
361 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
362 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
363 #else
364 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
365 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
366 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
367 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
368 #endif
369 }
370 
371 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
372 				    const struct in6_addr *addr,
373 				    int plen)
374 {
375 	/* caller must guarantee 0 <= plen <= 128 */
376 	int o = plen >> 3,
377 	    b = plen & 0x7;
378 
379 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
380 	memcpy(pfx->s6_addr, addr, o);
381 	if (b != 0)
382 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
383 }
384 
385 static inline void __ipv6_addr_set_half(__be32 *addr,
386 					__be32 wh, __be32 wl)
387 {
388 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
389 #if defined(__BIG_ENDIAN)
390 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
391 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
392 		return;
393 	}
394 #elif defined(__LITTLE_ENDIAN)
395 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
396 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
397 		return;
398 	}
399 #endif
400 #endif
401 	addr[0] = wh;
402 	addr[1] = wl;
403 }
404 
405 static inline void ipv6_addr_set(struct in6_addr *addr,
406 				     __be32 w1, __be32 w2,
407 				     __be32 w3, __be32 w4)
408 {
409 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
410 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
411 }
412 
413 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
414 				   const struct in6_addr *a2)
415 {
416 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
417 	const unsigned long *ul1 = (const unsigned long *)a1;
418 	const unsigned long *ul2 = (const unsigned long *)a2;
419 
420 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
421 #else
422 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
423 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
424 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
425 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
426 #endif
427 }
428 
429 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
430 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
431 					      const __be64 *a2,
432 					      unsigned int len)
433 {
434 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
435 		return false;
436 	return true;
437 }
438 
439 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
440 				     const struct in6_addr *addr2,
441 				     unsigned int prefixlen)
442 {
443 	const __be64 *a1 = (const __be64 *)addr1;
444 	const __be64 *a2 = (const __be64 *)addr2;
445 
446 	if (prefixlen >= 64) {
447 		if (a1[0] ^ a2[0])
448 			return false;
449 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
450 	}
451 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
452 }
453 #else
454 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
455 				     const struct in6_addr *addr2,
456 				     unsigned int prefixlen)
457 {
458 	const __be32 *a1 = addr1->s6_addr32;
459 	const __be32 *a2 = addr2->s6_addr32;
460 	unsigned int pdw, pbi;
461 
462 	/* check complete u32 in prefix */
463 	pdw = prefixlen >> 5;
464 	if (pdw && memcmp(a1, a2, pdw << 2))
465 		return false;
466 
467 	/* check incomplete u32 in prefix */
468 	pbi = prefixlen & 0x1f;
469 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
470 		return false;
471 
472 	return true;
473 }
474 #endif
475 
476 struct inet_frag_queue;
477 
478 enum ip6_defrag_users {
479 	IP6_DEFRAG_LOCAL_DELIVER,
480 	IP6_DEFRAG_CONNTRACK_IN,
481 	__IP6_DEFRAG_CONNTRACK_IN	= IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
482 	IP6_DEFRAG_CONNTRACK_OUT,
483 	__IP6_DEFRAG_CONNTRACK_OUT	= IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
484 	IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
485 	__IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
486 };
487 
488 struct ip6_create_arg {
489 	__be32 id;
490 	u32 user;
491 	const struct in6_addr *src;
492 	const struct in6_addr *dst;
493 	u8 ecn;
494 };
495 
496 void ip6_frag_init(struct inet_frag_queue *q, const void *a);
497 bool ip6_frag_match(const struct inet_frag_queue *q, const void *a);
498 
499 /*
500  *	Equivalent of ipv4 struct ip
501  */
502 struct frag_queue {
503 	struct inet_frag_queue	q;
504 
505 	__be32			id;		/* fragment id		*/
506 	u32			user;
507 	struct in6_addr		saddr;
508 	struct in6_addr		daddr;
509 
510 	int			iif;
511 	unsigned int		csum;
512 	__u16			nhoffset;
513 	u8			ecn;
514 };
515 
516 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
517 			   struct inet_frags *frags);
518 
519 static inline bool ipv6_addr_any(const struct in6_addr *a)
520 {
521 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
522 	const unsigned long *ul = (const unsigned long *)a;
523 
524 	return (ul[0] | ul[1]) == 0UL;
525 #else
526 	return (a->s6_addr32[0] | a->s6_addr32[1] |
527 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
528 #endif
529 }
530 
531 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
532 {
533 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
534 	const unsigned long *ul = (const unsigned long *)a;
535 	unsigned long x = ul[0] ^ ul[1];
536 
537 	return (u32)(x ^ (x >> 32));
538 #else
539 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
540 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
541 #endif
542 }
543 
544 /* more secured version of ipv6_addr_hash() */
545 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
546 {
547 	u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
548 
549 	return jhash_3words(v,
550 			    (__force u32)a->s6_addr32[2],
551 			    (__force u32)a->s6_addr32[3],
552 			    initval);
553 }
554 
555 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
556 {
557 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
558 	const __be64 *be = (const __be64 *)a;
559 
560 	return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
561 #else
562 	return (a->s6_addr32[0] | a->s6_addr32[1] |
563 		a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
564 #endif
565 }
566 
567 /*
568  * Note that we must __force cast these to unsigned long to make sparse happy,
569  * since all of the endian-annotated types are fixed size regardless of arch.
570  */
571 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
572 {
573 	return (
574 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
575 		*(unsigned long *)a |
576 #else
577 		(__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
578 #endif
579 		(__force unsigned long)(a->s6_addr32[2] ^
580 					cpu_to_be32(0x0000ffff))) == 0UL;
581 }
582 
583 /*
584  * Check for a RFC 4843 ORCHID address
585  * (Overlay Routable Cryptographic Hash Identifiers)
586  */
587 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
588 {
589 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
590 }
591 
592 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
593 {
594 	return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
595 }
596 
597 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
598 					  struct in6_addr *v4mapped)
599 {
600 	ipv6_addr_set(v4mapped,
601 			0, 0,
602 			htonl(0x0000FFFF),
603 			addr);
604 }
605 
606 /*
607  * find the first different bit between two addresses
608  * length of address must be a multiple of 32bits
609  */
610 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
611 {
612 	const __be32 *a1 = token1, *a2 = token2;
613 	int i;
614 
615 	addrlen >>= 2;
616 
617 	for (i = 0; i < addrlen; i++) {
618 		__be32 xb = a1[i] ^ a2[i];
619 		if (xb)
620 			return i * 32 + 31 - __fls(ntohl(xb));
621 	}
622 
623 	/*
624 	 *	we should *never* get to this point since that
625 	 *	would mean the addrs are equal
626 	 *
627 	 *	However, we do get to it 8) And exacly, when
628 	 *	addresses are equal 8)
629 	 *
630 	 *	ip route add 1111::/128 via ...
631 	 *	ip route add 1111::/64 via ...
632 	 *	and we are here.
633 	 *
634 	 *	Ideally, this function should stop comparison
635 	 *	at prefix length. It does not, but it is still OK,
636 	 *	if returned value is greater than prefix length.
637 	 *					--ANK (980803)
638 	 */
639 	return addrlen << 5;
640 }
641 
642 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
643 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
644 {
645 	const __be64 *a1 = token1, *a2 = token2;
646 	int i;
647 
648 	addrlen >>= 3;
649 
650 	for (i = 0; i < addrlen; i++) {
651 		__be64 xb = a1[i] ^ a2[i];
652 		if (xb)
653 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
654 	}
655 
656 	return addrlen << 6;
657 }
658 #endif
659 
660 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
661 {
662 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
663 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
664 		return __ipv6_addr_diff64(token1, token2, addrlen);
665 #endif
666 	return __ipv6_addr_diff32(token1, token2, addrlen);
667 }
668 
669 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
670 {
671 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
672 }
673 
674 __be32 ipv6_select_ident(struct net *net,
675 			 const struct in6_addr *daddr,
676 			 const struct in6_addr *saddr);
677 void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
678 
679 int ip6_dst_hoplimit(struct dst_entry *dst);
680 
681 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
682 				      struct dst_entry *dst)
683 {
684 	int hlimit;
685 
686 	if (ipv6_addr_is_multicast(&fl6->daddr))
687 		hlimit = np->mcast_hops;
688 	else
689 		hlimit = np->hop_limit;
690 	if (hlimit < 0)
691 		hlimit = ip6_dst_hoplimit(dst);
692 	return hlimit;
693 }
694 
695 /* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
696  * Equivalent to :	flow->v6addrs.src = iph->saddr;
697  *			flow->v6addrs.dst = iph->daddr;
698  */
699 static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
700 					    const struct ipv6hdr *iph)
701 {
702 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
703 		     offsetof(typeof(flow->addrs), v6addrs.src) +
704 		     sizeof(flow->addrs.v6addrs.src));
705 	memcpy(&flow->addrs.v6addrs, &iph->saddr, sizeof(flow->addrs.v6addrs));
706 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
707 }
708 
709 #if IS_ENABLED(CONFIG_IPV6)
710 static inline void ip6_set_txhash(struct sock *sk)
711 {
712 	struct inet_sock *inet = inet_sk(sk);
713 	struct ipv6_pinfo *np = inet6_sk(sk);
714 	struct flow_keys keys;
715 
716 	memset(&keys, 0, sizeof(keys));
717 
718 	memcpy(&keys.addrs.v6addrs.src, &np->saddr,
719 	       sizeof(keys.addrs.v6addrs.src));
720 	memcpy(&keys.addrs.v6addrs.dst, &sk->sk_v6_daddr,
721 	       sizeof(keys.addrs.v6addrs.dst));
722 	keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
723 	keys.ports.src = inet->inet_sport;
724 	keys.ports.dst = inet->inet_dport;
725 
726 	sk->sk_txhash = flow_hash_from_keys(&keys);
727 }
728 
729 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
730 					__be32 flowlabel, bool autolabel)
731 {
732 	if (!flowlabel && (autolabel || net->ipv6.sysctl.auto_flowlabels)) {
733 		u32 hash;
734 
735 		hash = skb_get_hash(skb);
736 
737 		/* Since this is being sent on the wire obfuscate hash a bit
738 		 * to minimize possbility that any useful information to an
739 		 * attacker is leaked. Only lower 20 bits are relevant.
740 		 */
741 		hash ^= hash >> 12;
742 
743 		flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
744 
745 		if (net->ipv6.sysctl.flowlabel_state_ranges)
746 			flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
747 	}
748 
749 	return flowlabel;
750 }
751 #else
752 static inline void ip6_set_txhash(struct sock *sk) { }
753 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
754 					__be32 flowlabel, bool autolabel)
755 {
756 	return flowlabel;
757 }
758 #endif
759 
760 
761 /*
762  *	Header manipulation
763  */
764 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
765 				__be32 flowlabel)
766 {
767 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
768 }
769 
770 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
771 {
772 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
773 }
774 
775 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
776 {
777 	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
778 }
779 
780 static inline u8 ip6_tclass(__be32 flowinfo)
781 {
782 	return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
783 }
784 /*
785  *	Prototypes exported by ipv6
786  */
787 
788 /*
789  *	rcv function (called from netdevice level)
790  */
791 
792 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
793 	     struct packet_type *pt, struct net_device *orig_dev);
794 
795 int ip6_rcv_finish(struct sock *sk, struct sk_buff *skb);
796 
797 /*
798  *	upper-layer output functions
799  */
800 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
801 	     struct ipv6_txoptions *opt, int tclass);
802 
803 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
804 
805 int ip6_append_data(struct sock *sk,
806 		    int getfrag(void *from, char *to, int offset, int len,
807 				int odd, struct sk_buff *skb),
808 		    void *from, int length, int transhdrlen, int hlimit,
809 		    int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
810 		    struct rt6_info *rt, unsigned int flags, int dontfrag);
811 
812 int ip6_push_pending_frames(struct sock *sk);
813 
814 void ip6_flush_pending_frames(struct sock *sk);
815 
816 int ip6_send_skb(struct sk_buff *skb);
817 
818 struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
819 			       struct inet_cork_full *cork,
820 			       struct inet6_cork *v6_cork);
821 struct sk_buff *ip6_make_skb(struct sock *sk,
822 			     int getfrag(void *from, char *to, int offset,
823 					 int len, int odd, struct sk_buff *skb),
824 			     void *from, int length, int transhdrlen,
825 			     int hlimit, int tclass, struct ipv6_txoptions *opt,
826 			     struct flowi6 *fl6, struct rt6_info *rt,
827 			     unsigned int flags, int dontfrag);
828 
829 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
830 {
831 	return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
832 			      &inet6_sk(sk)->cork);
833 }
834 
835 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6);
836 struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
837 				      const struct in6_addr *final_dst);
838 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
839 					 const struct in6_addr *final_dst);
840 struct dst_entry *ip6_blackhole_route(struct net *net,
841 				      struct dst_entry *orig_dst);
842 
843 /*
844  *	skb processing functions
845  */
846 
847 int ip6_output(struct sock *sk, struct sk_buff *skb);
848 int ip6_forward(struct sk_buff *skb);
849 int ip6_input(struct sk_buff *skb);
850 int ip6_mc_input(struct sk_buff *skb);
851 
852 int __ip6_local_out(struct sk_buff *skb);
853 int ip6_local_out_sk(struct sock *sk, struct sk_buff *skb);
854 int ip6_local_out(struct sk_buff *skb);
855 
856 /*
857  *	Extension header (options) processing
858  */
859 
860 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
861 			  u8 *proto, struct in6_addr **daddr_p);
862 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
863 			 u8 *proto);
864 
865 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
866 		     __be16 *frag_offp);
867 
868 bool ipv6_ext_hdr(u8 nexthdr);
869 
870 enum {
871 	IP6_FH_F_FRAG		= (1 << 0),
872 	IP6_FH_F_AUTH		= (1 << 1),
873 	IP6_FH_F_SKIP_RH	= (1 << 2),
874 };
875 
876 /* find specified header and get offset to it */
877 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
878 		  unsigned short *fragoff, int *fragflg);
879 
880 int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
881 
882 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
883 				const struct ipv6_txoptions *opt,
884 				struct in6_addr *orig);
885 
886 /*
887  *	socket options (ipv6_sockglue.c)
888  */
889 
890 int ipv6_setsockopt(struct sock *sk, int level, int optname,
891 		    char __user *optval, unsigned int optlen);
892 int ipv6_getsockopt(struct sock *sk, int level, int optname,
893 		    char __user *optval, int __user *optlen);
894 int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
895 			   char __user *optval, unsigned int optlen);
896 int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
897 			   char __user *optval, int __user *optlen);
898 
899 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
900 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
901 				 int addr_len);
902 
903 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
904 		    int *addr_len);
905 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
906 		     int *addr_len);
907 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
908 		     u32 info, u8 *payload);
909 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
910 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
911 
912 int inet6_release(struct socket *sock);
913 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
914 int inet6_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len,
915 		  int peer);
916 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
917 
918 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
919 			      struct sock *sk);
920 
921 /*
922  * reassembly.c
923  */
924 extern const struct proto_ops inet6_stream_ops;
925 extern const struct proto_ops inet6_dgram_ops;
926 
927 struct group_source_req;
928 struct group_filter;
929 
930 int ip6_mc_source(int add, int omode, struct sock *sk,
931 		  struct group_source_req *pgsr);
932 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
933 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
934 		  struct group_filter __user *optval, int __user *optlen);
935 
936 #ifdef CONFIG_PROC_FS
937 int ac6_proc_init(struct net *net);
938 void ac6_proc_exit(struct net *net);
939 int raw6_proc_init(void);
940 void raw6_proc_exit(void);
941 int tcp6_proc_init(struct net *net);
942 void tcp6_proc_exit(struct net *net);
943 int udp6_proc_init(struct net *net);
944 void udp6_proc_exit(struct net *net);
945 int udplite6_proc_init(void);
946 void udplite6_proc_exit(void);
947 int ipv6_misc_proc_init(void);
948 void ipv6_misc_proc_exit(void);
949 int snmp6_register_dev(struct inet6_dev *idev);
950 int snmp6_unregister_dev(struct inet6_dev *idev);
951 
952 #else
953 static inline int ac6_proc_init(struct net *net) { return 0; }
954 static inline void ac6_proc_exit(struct net *net) { }
955 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
956 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
957 #endif
958 
959 #ifdef CONFIG_SYSCTL
960 extern struct ctl_table ipv6_route_table_template[];
961 
962 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
963 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
964 int ipv6_sysctl_register(void);
965 void ipv6_sysctl_unregister(void);
966 #endif
967 
968 int ipv6_sock_mc_join(struct sock *sk, int ifindex,
969 		      const struct in6_addr *addr);
970 int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
971 		      const struct in6_addr *addr);
972 #endif /* _NET_IPV6_H */
973