xref: /linux/include/net/ipv6.h (revision 35f66ce900370ed0eab6553977adc0a2fb9cccfb)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  *	Linux INET6 implementation
4  *
5  *	Authors:
6  *	Pedro Roque		<roque@di.fc.ul.pt>
7  */
8 
9 #ifndef _NET_IPV6_H
10 #define _NET_IPV6_H
11 
12 #include <linux/ipv6.h>
13 #include <linux/hardirq.h>
14 #include <linux/jhash.h>
15 #include <linux/refcount.h>
16 #include <linux/jump_label_ratelimit.h>
17 #include <net/if_inet6.h>
18 #include <net/flow.h>
19 #include <net/flow_dissector.h>
20 #include <net/inet_dscp.h>
21 #include <net/snmp.h>
22 #include <net/netns/hash.h>
23 
24 struct ip_tunnel_info;
25 
26 #define SIN6_LEN_RFC2133	24
27 
28 /*
29  *	NextHeader field of IPv6 header
30  */
31 
32 #define NEXTHDR_HOP		0	/* Hop-by-hop option header. */
33 #define NEXTHDR_IPV4		4	/* IPv4 in IPv6 */
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 /* Limits on Hop-by-Hop and Destination options.
54  *
55  * Per RFC8200 there is no limit on the maximum number or lengths of options in
56  * Hop-by-Hop or Destination options other then the packet must fit in an MTU.
57  * We allow configurable limits in order to mitigate potential denial of
58  * service attacks.
59  *
60  * There are three limits that may be set:
61  *   - Limit the number of options in a Hop-by-Hop or Destination options
62  *     extension header
63  *   - Limit the byte length of a Hop-by-Hop or Destination options extension
64  *     header
65  *   - Disallow unknown options
66  *
67  * The limits are expressed in corresponding sysctls:
68  *
69  * ipv6.sysctl.max_dst_opts_cnt
70  * ipv6.sysctl.max_hbh_opts_cnt
71  * ipv6.sysctl.max_dst_opts_len
72  * ipv6.sysctl.max_hbh_opts_len
73  *
74  * max_*_opts_cnt is the number of TLVs that are allowed for Destination
75  * options or Hop-by-Hop options. If the number is less than zero then unknown
76  * TLVs are disallowed and the number of known options that are allowed is the
77  * absolute value. Setting the value to INT_MAX indicates no limit.
78  *
79  * max_*_opts_len is the length limit in bytes of a Destination or
80  * Hop-by-Hop options extension header. Setting the value to INT_MAX
81  * indicates no length limit.
82  *
83  * If a limit is exceeded when processing an extension header the packet is
84  * silently discarded.
85  */
86 
87 /* Default limits for Hop-by-Hop and Destination options */
88 #define IP6_DEFAULT_MAX_DST_OPTS_CNT	 8
89 #define IP6_DEFAULT_MAX_HBH_OPTS_CNT	 8
90 #define IP6_DEFAULT_MAX_DST_OPTS_LEN	 INT_MAX /* No limit */
91 #define IP6_DEFAULT_MAX_HBH_OPTS_LEN	 INT_MAX /* No limit */
92 
93 /*
94  *	Addr type
95  *
96  *	type	-	unicast | multicast
97  *	scope	-	local	| site	    | global
98  *	v4	-	compat
99  *	v4mapped
100  *	any
101  *	loopback
102  */
103 
104 #define IPV6_ADDR_ANY		0x0000U
105 
106 #define IPV6_ADDR_UNICAST	0x0001U
107 #define IPV6_ADDR_MULTICAST	0x0002U
108 
109 #define IPV6_ADDR_LOOPBACK	0x0010U
110 #define IPV6_ADDR_LINKLOCAL	0x0020U
111 #define IPV6_ADDR_SITELOCAL	0x0040U
112 
113 #define IPV6_ADDR_COMPATv4	0x0080U
114 
115 #define IPV6_ADDR_SCOPE_MASK	0x00f0U
116 
117 #define IPV6_ADDR_MAPPED	0x1000U
118 
119 /*
120  *	Addr scopes
121  */
122 #define IPV6_ADDR_MC_SCOPE(a)	\
123 	((a)->s6_addr[1] & 0x0f)	/* nonstandard */
124 #define __IPV6_ADDR_SCOPE_INVALID	-1
125 #define IPV6_ADDR_SCOPE_NODELOCAL	0x01
126 #define IPV6_ADDR_SCOPE_LINKLOCAL	0x02
127 #define IPV6_ADDR_SCOPE_SITELOCAL	0x05
128 #define IPV6_ADDR_SCOPE_ORGLOCAL	0x08
129 #define IPV6_ADDR_SCOPE_GLOBAL		0x0e
130 
131 /*
132  *	Addr flags
133  */
134 #define IPV6_ADDR_MC_FLAG_TRANSIENT(a)	\
135 	((a)->s6_addr[1] & 0x10)
136 #define IPV6_ADDR_MC_FLAG_PREFIX(a)	\
137 	((a)->s6_addr[1] & 0x20)
138 #define IPV6_ADDR_MC_FLAG_RENDEZVOUS(a)	\
139 	((a)->s6_addr[1] & 0x40)
140 
141 /*
142  *	fragmentation header
143  */
144 
145 struct frag_hdr {
146 	__u8	nexthdr;
147 	__u8	reserved;
148 	__be16	frag_off;
149 	__be32	identification;
150 };
151 
152 #define	IP6_MF		0x0001
153 #define	IP6_OFFSET	0xFFF8
154 
155 struct ip6_fraglist_iter {
156 	struct ipv6hdr	*tmp_hdr;
157 	struct sk_buff	*frag;
158 	int		offset;
159 	unsigned int	hlen;
160 	__be32		frag_id;
161 	u8		nexthdr;
162 };
163 
164 int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr,
165 		      u8 nexthdr, __be32 frag_id,
166 		      struct ip6_fraglist_iter *iter);
167 void ip6_fraglist_prepare(struct sk_buff *skb, struct ip6_fraglist_iter *iter);
168 
169 static inline struct sk_buff *ip6_fraglist_next(struct ip6_fraglist_iter *iter)
170 {
171 	struct sk_buff *skb = iter->frag;
172 
173 	iter->frag = skb->next;
174 	skb_mark_not_on_list(skb);
175 
176 	return skb;
177 }
178 
179 struct ip6_frag_state {
180 	u8		*prevhdr;
181 	unsigned int	hlen;
182 	unsigned int	mtu;
183 	unsigned int	left;
184 	int		offset;
185 	int		ptr;
186 	int		hroom;
187 	int		troom;
188 	__be32		frag_id;
189 	u8		nexthdr;
190 };
191 
192 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu,
193 		   unsigned short needed_tailroom, int hdr_room, u8 *prevhdr,
194 		   u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state);
195 struct sk_buff *ip6_frag_next(struct sk_buff *skb,
196 			      struct ip6_frag_state *state);
197 
198 #define IP6_REPLY_MARK(net, mark) \
199 	((net)->ipv6.sysctl.fwmark_reflect ? (mark) : 0)
200 
201 #include <net/sock.h>
202 
203 /* sysctls */
204 extern int sysctl_mld_max_msf;
205 extern int sysctl_mld_qrv;
206 
207 #define _DEVINC(net, statname, mod, idev, field)			\
208 ({									\
209 	struct inet6_dev *_idev = (idev);				\
210 	if (likely(_idev != NULL))					\
211 		mod##SNMP_INC_STATS64((_idev)->stats.statname, (field));\
212 	mod##SNMP_INC_STATS64((net)->mib.statname##_statistics, (field));\
213 })
214 
215 /* per device counters are atomic_long_t */
216 #define _DEVINCATOMIC(net, statname, mod, idev, field)			\
217 ({									\
218 	struct inet6_dev *_idev = (idev);				\
219 	if (likely(_idev != NULL))					\
220 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
221 	mod##SNMP_INC_STATS((net)->mib.statname##_statistics, (field));\
222 })
223 
224 /* per device and per net counters are atomic_long_t */
225 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)		\
226 ({									\
227 	struct inet6_dev *_idev = (idev);				\
228 	if (likely(_idev != NULL))					\
229 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
230 	SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
231 })
232 
233 #define _DEVADD(net, statname, mod, idev, field, val)			\
234 ({									\
235 	struct inet6_dev *_idev = (idev);				\
236 	unsigned long _field = (field);					\
237 	unsigned long _val = (val);					\
238 	if (likely(_idev != NULL))					\
239 		mod##SNMP_ADD_STATS((_idev)->stats.statname, _field,  _val); \
240 	mod##SNMP_ADD_STATS((net)->mib.statname##_statistics, _field, _val);\
241 })
242 
243 #define _DEVUPD(net, statname, mod, idev, field, val)			\
244 ({									\
245 	struct inet6_dev *_idev = (idev);				\
246 	unsigned long _val = (val);					\
247 	if (likely(_idev != NULL))					\
248 		mod##SNMP_UPD_PO_STATS((_idev)->stats.statname, field, _val); \
249 	mod##SNMP_UPD_PO_STATS((net)->mib.statname##_statistics, field, _val);\
250 })
251 
252 /* MIBs */
253 
254 #define IP6_INC_STATS(net, idev,field)		\
255 		_DEVINC(net, ipv6, , idev, field)
256 #define __IP6_INC_STATS(net, idev,field)	\
257 		_DEVINC(net, ipv6, __, idev, field)
258 #define IP6_ADD_STATS(net, idev,field,val)	\
259 		_DEVADD(net, ipv6, , idev, field, val)
260 #define __IP6_ADD_STATS(net, idev,field,val)	\
261 		_DEVADD(net, ipv6, __, idev, field, val)
262 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
263 		_DEVUPD(net, ipv6, , idev, field, val)
264 #define __IP6_UPD_PO_STATS(net, idev,field,val)   \
265 		_DEVUPD(net, ipv6, __, idev, field, val)
266 #define ICMP6_INC_STATS(net, idev, field)	\
267 		_DEVINCATOMIC(net, icmpv6, , idev, field)
268 #define __ICMP6_INC_STATS(net, idev, field)	\
269 		_DEVINCATOMIC(net, icmpv6, __, idev, field)
270 
271 #define ICMP6MSGOUT_INC_STATS(net, idev, field)		\
272 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
273 #define ICMP6MSGIN_INC_STATS(net, idev, field)	\
274 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
275 
276 struct ip6_ra_chain {
277 	struct ip6_ra_chain	*next;
278 	struct sock		*sk;
279 	int			sel;
280 	void			(*destructor)(struct sock *);
281 };
282 
283 extern struct ip6_ra_chain	*ip6_ra_chain;
284 extern rwlock_t ip6_ra_lock;
285 
286 /*
287    This structure is prepared by protocol, when parsing
288    ancillary data and passed to IPv6.
289  */
290 
291 struct ipv6_txoptions {
292 	refcount_t		refcnt;
293 	/* Length of this structure */
294 	int			tot_len;
295 
296 	/* length of extension headers   */
297 
298 	__u16			opt_flen;	/* after fragment hdr */
299 	__u16			opt_nflen;	/* before fragment hdr */
300 
301 	struct ipv6_opt_hdr	*hopopt;
302 	struct ipv6_opt_hdr	*dst0opt;
303 	struct ipv6_rt_hdr	*srcrt;	/* Routing Header */
304 	struct ipv6_opt_hdr	*dst1opt;
305 	struct rcu_head		rcu;
306 	/* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
307 };
308 
309 /* flowlabel_reflect sysctl values */
310 enum flowlabel_reflect {
311 	FLOWLABEL_REFLECT_ESTABLISHED		= 1,
312 	FLOWLABEL_REFLECT_TCP_RESET		= 2,
313 	FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES	= 4,
314 };
315 
316 struct ip6_flowlabel {
317 	struct ip6_flowlabel __rcu *next;
318 	__be32			label;
319 	atomic_t		users;
320 	struct in6_addr		dst;
321 	struct ipv6_txoptions	*opt;
322 	unsigned long		linger;
323 	struct rcu_head		rcu;
324 	u8			share;
325 	union {
326 		struct pid *pid;
327 		kuid_t uid;
328 	} owner;
329 	unsigned long		lastuse;
330 	unsigned long		expires;
331 	struct net		*fl_net;
332 };
333 
334 #define IPV6_FLOWINFO_MASK		cpu_to_be32(0x0FFFFFFF)
335 #define IPV6_FLOWLABEL_MASK		cpu_to_be32(0x000FFFFF)
336 #define IPV6_FLOWLABEL_STATELESS_FLAG	cpu_to_be32(0x00080000)
337 
338 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
339 #define IPV6_TCLASS_SHIFT	20
340 
341 struct ipv6_fl_socklist {
342 	struct ipv6_fl_socklist	__rcu	*next;
343 	struct ip6_flowlabel		*fl;
344 	struct rcu_head			rcu;
345 };
346 
347 struct ipcm6_cookie {
348 	struct sockcm_cookie sockc;
349 	__s16 hlimit;
350 	__s16 tclass;
351 	__u16 gso_size;
352 	__s8  dontfrag;
353 	struct ipv6_txoptions *opt;
354 };
355 
356 static inline void ipcm6_init_sk(struct ipcm6_cookie *ipc6,
357 				 const struct sock *sk)
358 {
359 	*ipc6 = (struct ipcm6_cookie) {
360 		.hlimit = -1,
361 		.tclass = inet6_sk(sk)->tclass,
362 		.dontfrag = inet6_test_bit(DONTFRAG, sk),
363 	};
364 
365 	sockcm_init(&ipc6->sockc, sk);
366 }
367 
368 static inline struct ipv6_txoptions *txopt_get(const struct ipv6_pinfo *np)
369 {
370 	struct ipv6_txoptions *opt;
371 
372 	rcu_read_lock();
373 	opt = rcu_dereference(np->opt);
374 	if (opt) {
375 		if (!refcount_inc_not_zero(&opt->refcnt))
376 			opt = NULL;
377 		else
378 			opt = rcu_pointer_handoff(opt);
379 	}
380 	rcu_read_unlock();
381 	return opt;
382 }
383 
384 static inline void txopt_put(struct ipv6_txoptions *opt)
385 {
386 	if (opt && refcount_dec_and_test(&opt->refcnt))
387 		kfree_rcu(opt, rcu);
388 }
389 
390 #if IS_ENABLED(CONFIG_IPV6)
391 struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label);
392 
393 extern struct static_key_false_deferred ipv6_flowlabel_exclusive;
394 static inline struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk,
395 						    __be32 label)
396 {
397 	if (static_branch_unlikely(&ipv6_flowlabel_exclusive.key) &&
398 	    READ_ONCE(sock_net(sk)->ipv6.flowlabel_has_excl))
399 		return __fl6_sock_lookup(sk, label) ? : ERR_PTR(-ENOENT);
400 
401 	return NULL;
402 }
403 #endif
404 
405 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
406 					 struct ip6_flowlabel *fl,
407 					 struct ipv6_txoptions *fopt);
408 void fl6_free_socklist(struct sock *sk);
409 int ipv6_flowlabel_opt(struct sock *sk, sockptr_t optval, int optlen);
410 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
411 			   int flags);
412 int ip6_flowlabel_init(void);
413 void ip6_flowlabel_cleanup(void);
414 bool ip6_autoflowlabel(struct net *net, const struct sock *sk);
415 
416 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
417 {
418 	if (fl)
419 		atomic_dec(&fl->users);
420 }
421 
422 enum skb_drop_reason icmpv6_notify(struct sk_buff *skb, u8 type,
423 				   u8 code, __be32 info);
424 
425 void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
426 				struct icmp6hdr *thdr, int len);
427 
428 int ip6_ra_control(struct sock *sk, int sel);
429 
430 int ipv6_parse_hopopts(struct sk_buff *skb);
431 
432 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
433 					struct ipv6_txoptions *opt);
434 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
435 					  struct ipv6_txoptions *opt,
436 					  int newtype,
437 					  struct ipv6_opt_hdr *newopt);
438 struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space,
439 					    struct ipv6_txoptions *opt);
440 
441 static inline struct ipv6_txoptions *
442 ipv6_fixup_options(struct ipv6_txoptions *opt_space, struct ipv6_txoptions *opt)
443 {
444 	if (!opt)
445 		return NULL;
446 	return __ipv6_fixup_options(opt_space, opt);
447 }
448 
449 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
450 		       const struct inet6_skb_parm *opt);
451 struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
452 					   struct ipv6_txoptions *opt);
453 
454 static inline bool ipv6_accept_ra(const struct inet6_dev *idev)
455 {
456 	s32 accept_ra = READ_ONCE(idev->cnf.accept_ra);
457 
458 	/* If forwarding is enabled, RA are not accepted unless the special
459 	 * hybrid mode (accept_ra=2) is enabled.
460 	 */
461 	return READ_ONCE(idev->cnf.forwarding) ? accept_ra == 2 :
462 		accept_ra;
463 }
464 
465 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
466 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
467 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
468 
469 int __ipv6_addr_type(const struct in6_addr *addr);
470 static inline int ipv6_addr_type(const struct in6_addr *addr)
471 {
472 	return __ipv6_addr_type(addr) & 0xffff;
473 }
474 
475 static inline int ipv6_addr_scope(const struct in6_addr *addr)
476 {
477 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
478 }
479 
480 static inline int __ipv6_addr_src_scope(int type)
481 {
482 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
483 }
484 
485 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
486 {
487 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
488 }
489 
490 static inline bool __ipv6_addr_needs_scope_id(int type)
491 {
492 	return type & IPV6_ADDR_LINKLOCAL ||
493 	       (type & IPV6_ADDR_MULTICAST &&
494 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
495 }
496 
497 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
498 {
499 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
500 }
501 
502 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
503 {
504 	return memcmp(a1, a2, sizeof(struct in6_addr));
505 }
506 
507 static inline bool
508 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
509 		     const struct in6_addr *a2)
510 {
511 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
512 	const unsigned long *ul1 = (const unsigned long *)a1;
513 	const unsigned long *ulm = (const unsigned long *)m;
514 	const unsigned long *ul2 = (const unsigned long *)a2;
515 
516 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
517 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
518 #else
519 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
520 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
521 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
522 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
523 #endif
524 }
525 
526 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
527 				    const struct in6_addr *addr,
528 				    int plen)
529 {
530 	/* caller must guarantee 0 <= plen <= 128 */
531 	int o = plen >> 3,
532 	    b = plen & 0x7;
533 
534 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
535 	memcpy(pfx->s6_addr, addr, o);
536 	if (b != 0)
537 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
538 }
539 
540 static inline void ipv6_addr_prefix_copy(struct in6_addr *addr,
541 					 const struct in6_addr *pfx,
542 					 int plen)
543 {
544 	/* caller must guarantee 0 <= plen <= 128 */
545 	int o = plen >> 3,
546 	    b = plen & 0x7;
547 
548 	memcpy(addr->s6_addr, pfx, o);
549 	if (b != 0) {
550 		addr->s6_addr[o] &= ~(0xff00 >> b);
551 		addr->s6_addr[o] |= (pfx->s6_addr[o] & (0xff00 >> b));
552 	}
553 }
554 
555 static inline void __ipv6_addr_set_half(__be32 *addr,
556 					__be32 wh, __be32 wl)
557 {
558 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
559 #if defined(__BIG_ENDIAN)
560 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
561 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
562 		return;
563 	}
564 #elif defined(__LITTLE_ENDIAN)
565 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
566 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
567 		return;
568 	}
569 #endif
570 #endif
571 	addr[0] = wh;
572 	addr[1] = wl;
573 }
574 
575 static inline void ipv6_addr_set(struct in6_addr *addr,
576 				     __be32 w1, __be32 w2,
577 				     __be32 w3, __be32 w4)
578 {
579 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
580 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
581 }
582 
583 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
584 				   const struct in6_addr *a2)
585 {
586 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
587 	const unsigned long *ul1 = (const unsigned long *)a1;
588 	const unsigned long *ul2 = (const unsigned long *)a2;
589 
590 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
591 #else
592 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
593 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
594 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
595 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
596 #endif
597 }
598 
599 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
600 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
601 					      const __be64 *a2,
602 					      unsigned int len)
603 {
604 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
605 		return false;
606 	return true;
607 }
608 
609 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
610 				     const struct in6_addr *addr2,
611 				     unsigned int prefixlen)
612 {
613 	const __be64 *a1 = (const __be64 *)addr1;
614 	const __be64 *a2 = (const __be64 *)addr2;
615 
616 	if (prefixlen >= 64) {
617 		if (a1[0] ^ a2[0])
618 			return false;
619 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
620 	}
621 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
622 }
623 #else
624 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
625 				     const struct in6_addr *addr2,
626 				     unsigned int prefixlen)
627 {
628 	const __be32 *a1 = addr1->s6_addr32;
629 	const __be32 *a2 = addr2->s6_addr32;
630 	unsigned int pdw, pbi;
631 
632 	/* check complete u32 in prefix */
633 	pdw = prefixlen >> 5;
634 	if (pdw && memcmp(a1, a2, pdw << 2))
635 		return false;
636 
637 	/* check incomplete u32 in prefix */
638 	pbi = prefixlen & 0x1f;
639 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
640 		return false;
641 
642 	return true;
643 }
644 #endif
645 
646 static inline bool ipv6_addr_any(const struct in6_addr *a)
647 {
648 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
649 	const unsigned long *ul = (const unsigned long *)a;
650 
651 	return (ul[0] | ul[1]) == 0UL;
652 #else
653 	return (a->s6_addr32[0] | a->s6_addr32[1] |
654 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
655 #endif
656 }
657 
658 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
659 {
660 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
661 	const unsigned long *ul = (const unsigned long *)a;
662 	unsigned long x = ul[0] ^ ul[1];
663 
664 	return (u32)(x ^ (x >> 32));
665 #else
666 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
667 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
668 #endif
669 }
670 
671 /* more secured version of ipv6_addr_hash() */
672 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
673 {
674 	return jhash2((__force const u32 *)a->s6_addr32,
675 		      ARRAY_SIZE(a->s6_addr32), initval);
676 }
677 
678 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
679 {
680 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
681 	const __be64 *be = (const __be64 *)a;
682 
683 	return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
684 #else
685 	return (a->s6_addr32[0] | a->s6_addr32[1] |
686 		a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
687 #endif
688 }
689 
690 /*
691  * Note that we must __force cast these to unsigned long to make sparse happy,
692  * since all of the endian-annotated types are fixed size regardless of arch.
693  */
694 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
695 {
696 	return (
697 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
698 		*(unsigned long *)a |
699 #else
700 		(__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
701 #endif
702 		(__force unsigned long)(a->s6_addr32[2] ^
703 					cpu_to_be32(0x0000ffff))) == 0UL;
704 }
705 
706 static inline bool ipv6_addr_v4mapped_loopback(const struct in6_addr *a)
707 {
708 	return ipv6_addr_v4mapped(a) && ipv4_is_loopback(a->s6_addr32[3]);
709 }
710 
711 static inline u32 ipv6_portaddr_hash(const struct net *net,
712 				     const struct in6_addr *addr6,
713 				     unsigned int port)
714 {
715 	unsigned int hash, mix = net_hash_mix(net);
716 
717 	if (ipv6_addr_any(addr6))
718 		hash = jhash_1word(0, mix);
719 	else if (ipv6_addr_v4mapped(addr6))
720 		hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
721 	else
722 		hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
723 
724 	return hash ^ port;
725 }
726 
727 /*
728  * Check for a RFC 4843 ORCHID address
729  * (Overlay Routable Cryptographic Hash Identifiers)
730  */
731 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
732 {
733 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
734 }
735 
736 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
737 {
738 	return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
739 }
740 
741 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
742 					  struct in6_addr *v4mapped)
743 {
744 	ipv6_addr_set(v4mapped,
745 			0, 0,
746 			htonl(0x0000FFFF),
747 			addr);
748 }
749 
750 /*
751  * find the first different bit between two addresses
752  * length of address must be a multiple of 32bits
753  */
754 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
755 {
756 	const __be32 *a1 = token1, *a2 = token2;
757 	int i;
758 
759 	addrlen >>= 2;
760 
761 	for (i = 0; i < addrlen; i++) {
762 		__be32 xb = a1[i] ^ a2[i];
763 		if (xb)
764 			return i * 32 + 31 - __fls(ntohl(xb));
765 	}
766 
767 	/*
768 	 *	we should *never* get to this point since that
769 	 *	would mean the addrs are equal
770 	 *
771 	 *	However, we do get to it 8) And exactly, when
772 	 *	addresses are equal 8)
773 	 *
774 	 *	ip route add 1111::/128 via ...
775 	 *	ip route add 1111::/64 via ...
776 	 *	and we are here.
777 	 *
778 	 *	Ideally, this function should stop comparison
779 	 *	at prefix length. It does not, but it is still OK,
780 	 *	if returned value is greater than prefix length.
781 	 *					--ANK (980803)
782 	 */
783 	return addrlen << 5;
784 }
785 
786 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
787 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
788 {
789 	const __be64 *a1 = token1, *a2 = token2;
790 	int i;
791 
792 	addrlen >>= 3;
793 
794 	for (i = 0; i < addrlen; i++) {
795 		__be64 xb = a1[i] ^ a2[i];
796 		if (xb)
797 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
798 	}
799 
800 	return addrlen << 6;
801 }
802 #endif
803 
804 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
805 {
806 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
807 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
808 		return __ipv6_addr_diff64(token1, token2, addrlen);
809 #endif
810 	return __ipv6_addr_diff32(token1, token2, addrlen);
811 }
812 
813 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
814 {
815 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
816 }
817 
818 __be32 ipv6_select_ident(struct net *net,
819 			 const struct in6_addr *daddr,
820 			 const struct in6_addr *saddr);
821 __be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
822 
823 int ip6_dst_hoplimit(struct dst_entry *dst);
824 
825 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
826 				      struct dst_entry *dst)
827 {
828 	int hlimit;
829 
830 	if (ipv6_addr_is_multicast(&fl6->daddr))
831 		hlimit = READ_ONCE(np->mcast_hops);
832 	else
833 		hlimit = READ_ONCE(np->hop_limit);
834 	if (hlimit < 0)
835 		hlimit = ip6_dst_hoplimit(dst);
836 	return hlimit;
837 }
838 
839 /* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
840  * Equivalent to :	flow->v6addrs.src = iph->saddr;
841  *			flow->v6addrs.dst = iph->daddr;
842  */
843 static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
844 					    const struct ipv6hdr *iph)
845 {
846 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
847 		     offsetof(typeof(flow->addrs), v6addrs.src) +
848 		     sizeof(flow->addrs.v6addrs.src));
849 	memcpy(&flow->addrs.v6addrs, &iph->addrs, sizeof(flow->addrs.v6addrs));
850 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
851 }
852 
853 #if IS_ENABLED(CONFIG_IPV6)
854 
855 static inline bool ipv6_can_nonlocal_bind(const struct net *net,
856 					  const struct inet_sock *inet)
857 {
858 	return READ_ONCE(net->ipv6.sysctl.ip_nonlocal_bind) ||
859 		test_bit(INET_FLAGS_FREEBIND, &inet->inet_flags) ||
860 		test_bit(INET_FLAGS_TRANSPARENT, &inet->inet_flags);
861 }
862 
863 /* Sysctl settings for net ipv6.auto_flowlabels */
864 #define IP6_AUTO_FLOW_LABEL_OFF		0
865 #define IP6_AUTO_FLOW_LABEL_OPTOUT	1
866 #define IP6_AUTO_FLOW_LABEL_OPTIN	2
867 #define IP6_AUTO_FLOW_LABEL_FORCED	3
868 
869 #define IP6_AUTO_FLOW_LABEL_MAX		IP6_AUTO_FLOW_LABEL_FORCED
870 
871 #define IP6_DEFAULT_AUTO_FLOW_LABELS	IP6_AUTO_FLOW_LABEL_OPTOUT
872 
873 static inline __be32 ip6_make_flowlabel(const struct net *net,
874 					struct sk_buff *skb,
875 					__be32 flowlabel, bool autolabel,
876 					struct flowi6 *fl6)
877 {
878 	u8 auto_flowlabels;
879 	u32 hash;
880 
881 	/* @flowlabel may include more than a flow label, eg, the traffic class.
882 	 * Here we want only the flow label value.
883 	 */
884 	flowlabel &= IPV6_FLOWLABEL_MASK;
885 
886 	if (flowlabel)
887 		return flowlabel;
888 
889 	auto_flowlabels = READ_ONCE(net->ipv6.sysctl.auto_flowlabels);
890 	if (auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF ||
891 	    (!autolabel && auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED))
892 		return flowlabel;
893 
894 	hash = skb_get_hash_flowi6(skb, fl6);
895 
896 	/* Since this is being sent on the wire obfuscate hash a bit
897 	 * to minimize possibility that any useful information to an
898 	 * attacker is leaked. Only lower 20 bits are relevant.
899 	 */
900 	hash = rol32(hash, 16);
901 
902 	flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
903 
904 	if (READ_ONCE(net->ipv6.sysctl.flowlabel_state_ranges))
905 		flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
906 
907 	return flowlabel;
908 }
909 
910 static inline int ip6_default_np_autolabel(const struct net *net)
911 {
912 	switch (READ_ONCE(net->ipv6.sysctl.auto_flowlabels)) {
913 	case IP6_AUTO_FLOW_LABEL_OFF:
914 	case IP6_AUTO_FLOW_LABEL_OPTIN:
915 	default:
916 		return 0;
917 	case IP6_AUTO_FLOW_LABEL_OPTOUT:
918 	case IP6_AUTO_FLOW_LABEL_FORCED:
919 		return 1;
920 	}
921 }
922 #else
923 static inline __be32 ip6_make_flowlabel(const struct net *net, struct sk_buff *skb,
924 					__be32 flowlabel, bool autolabel,
925 					struct flowi6 *fl6)
926 {
927 	return flowlabel;
928 }
929 static inline int ip6_default_np_autolabel(const struct net *net)
930 {
931 	return 0;
932 }
933 #endif
934 
935 #if IS_ENABLED(CONFIG_IPV6)
936 static inline int ip6_multipath_hash_policy(const struct net *net)
937 {
938 	return READ_ONCE(net->ipv6.sysctl.multipath_hash_policy);
939 }
940 static inline u32 ip6_multipath_hash_fields(const struct net *net)
941 {
942 	return READ_ONCE(net->ipv6.sysctl.multipath_hash_fields);
943 }
944 #else
945 static inline int ip6_multipath_hash_policy(const struct net *net)
946 {
947 	return 0;
948 }
949 static inline u32 ip6_multipath_hash_fields(const struct net *net)
950 {
951 	return 0;
952 }
953 #endif
954 
955 /*
956  *	Header manipulation
957  */
958 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
959 				__be32 flowlabel)
960 {
961 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
962 }
963 
964 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
965 {
966 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
967 }
968 
969 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
970 {
971 	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
972 }
973 
974 static inline u8 ip6_tclass(__be32 flowinfo)
975 {
976 	return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
977 }
978 
979 static inline dscp_t ip6_dscp(__be32 flowinfo)
980 {
981 	return inet_dsfield_to_dscp(ip6_tclass(flowinfo));
982 }
983 
984 static inline __be32 ip6_make_flowinfo(unsigned int tclass, __be32 flowlabel)
985 {
986 	return htonl(tclass << IPV6_TCLASS_SHIFT) | flowlabel;
987 }
988 
989 static inline __be32 flowi6_get_flowlabel(const struct flowi6 *fl6)
990 {
991 	return fl6->flowlabel & IPV6_FLOWLABEL_MASK;
992 }
993 
994 /*
995  *	Prototypes exported by ipv6
996  */
997 
998 /*
999  *	rcv function (called from netdevice level)
1000  */
1001 
1002 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
1003 	     struct packet_type *pt, struct net_device *orig_dev);
1004 void ipv6_list_rcv(struct list_head *head, struct packet_type *pt,
1005 		   struct net_device *orig_dev);
1006 
1007 int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
1008 
1009 /*
1010  *	upper-layer output functions
1011  */
1012 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
1013 	     __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority);
1014 
1015 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
1016 
1017 int ip6_append_data(struct sock *sk,
1018 		    int getfrag(void *from, char *to, int offset, int len,
1019 				int odd, struct sk_buff *skb),
1020 		    void *from, size_t length, int transhdrlen,
1021 		    struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1022 		    struct rt6_info *rt, unsigned int flags);
1023 
1024 int ip6_push_pending_frames(struct sock *sk);
1025 
1026 void ip6_flush_pending_frames(struct sock *sk);
1027 
1028 int ip6_send_skb(struct sk_buff *skb);
1029 
1030 struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
1031 			       struct inet_cork_full *cork);
1032 struct sk_buff *ip6_make_skb(struct sock *sk,
1033 			     int getfrag(void *from, char *to, int offset,
1034 					 int len, int odd, struct sk_buff *skb),
1035 			     void *from, size_t length, int transhdrlen,
1036 			     struct ipcm6_cookie *ipc6,
1037 			     struct rt6_info *rt, unsigned int flags,
1038 			     struct inet_cork_full *cork);
1039 
1040 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
1041 {
1042 	return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork);
1043 }
1044 
1045 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1046 		   struct flowi6 *fl6);
1047 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6,
1048 				      const struct in6_addr *final_dst);
1049 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1050 					 const struct in6_addr *final_dst,
1051 					 bool connected);
1052 struct dst_entry *ip6_blackhole_route(struct net *net,
1053 				      struct dst_entry *orig_dst);
1054 
1055 /*
1056  *	skb processing functions
1057  */
1058 
1059 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb);
1060 int ip6_forward(struct sk_buff *skb);
1061 int ip6_input(struct sk_buff *skb);
1062 int ip6_mc_input(struct sk_buff *skb);
1063 void ip6_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int nexthdr,
1064 			      bool have_final);
1065 
1066 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
1067 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
1068 
1069 /*
1070  *	Extension header (options) processing
1071  */
1072 
1073 u8 ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1074 			u8 proto, struct in6_addr **daddr_p,
1075 			struct in6_addr *saddr);
1076 u8 ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1077 		       u8 proto);
1078 
1079 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
1080 		     __be16 *frag_offp);
1081 
1082 bool ipv6_ext_hdr(u8 nexthdr);
1083 
1084 enum {
1085 	IP6_FH_F_FRAG		= (1 << 0),
1086 	IP6_FH_F_AUTH		= (1 << 1),
1087 	IP6_FH_F_SKIP_RH	= (1 << 2),
1088 };
1089 
1090 /* find specified header and get offset to it */
1091 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
1092 		  unsigned short *fragoff, int *fragflg);
1093 
1094 int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type);
1095 
1096 struct in6_addr *__fl6_update_dst(struct flowi6 *fl6,
1097 				  const struct ipv6_txoptions *opt,
1098 				  struct in6_addr *orig);
1099 
1100 static inline struct in6_addr *
1101 fl6_update_dst(struct flowi6 *fl6, const struct ipv6_txoptions *opt,
1102 	       struct in6_addr *orig)
1103 {
1104 	if (likely(!opt))
1105 		return NULL;
1106 
1107 	return __fl6_update_dst(fl6, opt, orig);
1108 }
1109 
1110 /*
1111  *	socket options (ipv6_sockglue.c)
1112  */
1113 DECLARE_STATIC_KEY_FALSE(ip6_min_hopcount);
1114 
1115 int do_ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1116 		       unsigned int optlen);
1117 int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1118 		    unsigned int optlen);
1119 int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
1120 		       sockptr_t optval, sockptr_t optlen);
1121 int ipv6_getsockopt(struct sock *sk, int level, int optname,
1122 		    char __user *optval, int __user *optlen);
1123 
1124 int __ip6_datagram_connect(struct sock *sk, struct sockaddr_unsized *addr,
1125 			   int addr_len);
1126 int ip6_datagram_connect(struct sock *sk, struct sockaddr_unsized *addr, int addr_len);
1127 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr_unsized *addr,
1128 				 int addr_len);
1129 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr);
1130 void ip6_datagram_release_cb(struct sock *sk);
1131 
1132 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
1133 		    int *addr_len);
1134 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
1135 		     int *addr_len);
1136 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
1137 		     u32 info, u8 *payload);
1138 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
1139 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
1140 
1141 void inet6_cleanup_sock(struct sock *sk);
1142 void inet6_sock_destruct(struct sock *sk);
1143 int inet6_release(struct socket *sock);
1144 int inet6_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int addr_len);
1145 int inet6_bind_sk(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len);
1146 int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
1147 		  int peer);
1148 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
1149 int inet6_compat_ioctl(struct socket *sock, unsigned int cmd,
1150 		unsigned long arg);
1151 
1152 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
1153 			      struct sock *sk);
1154 int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size);
1155 int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1156 		  int flags);
1157 
1158 /*
1159  * reassembly.c
1160  */
1161 extern const struct proto_ops inet6_stream_ops;
1162 extern const struct proto_ops inet6_dgram_ops;
1163 extern const struct proto_ops inet6_sockraw_ops;
1164 
1165 struct group_source_req;
1166 struct group_filter;
1167 
1168 int ip6_mc_source(int add, int omode, struct sock *sk,
1169 		  struct group_source_req *pgsr);
1170 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf,
1171 		  struct sockaddr_storage *list);
1172 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
1173 		  sockptr_t optval, size_t ss_offset);
1174 
1175 #ifdef CONFIG_PROC_FS
1176 int ac6_proc_init(struct net *net);
1177 void ac6_proc_exit(struct net *net);
1178 int raw6_proc_init(void);
1179 void raw6_proc_exit(void);
1180 int tcp6_proc_init(struct net *net);
1181 void tcp6_proc_exit(struct net *net);
1182 int udp6_proc_init(struct net *net);
1183 void udp6_proc_exit(struct net *net);
1184 int udplite6_proc_init(void);
1185 void udplite6_proc_exit(void);
1186 int ipv6_misc_proc_init(void);
1187 void ipv6_misc_proc_exit(void);
1188 int snmp6_register_dev(struct inet6_dev *idev);
1189 int snmp6_unregister_dev(struct inet6_dev *idev);
1190 
1191 #else
1192 static inline int ac6_proc_init(struct net *net) { return 0; }
1193 static inline void ac6_proc_exit(struct net *net) { }
1194 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
1195 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
1196 #endif
1197 
1198 #ifdef CONFIG_SYSCTL
1199 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
1200 size_t ipv6_icmp_sysctl_table_size(void);
1201 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
1202 size_t ipv6_route_sysctl_table_size(struct net *net);
1203 int ipv6_sysctl_register(void);
1204 void ipv6_sysctl_unregister(void);
1205 #endif
1206 
1207 int ipv6_sock_mc_join(struct sock *sk, int ifindex,
1208 		      const struct in6_addr *addr);
1209 int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,
1210 			  const struct in6_addr *addr, unsigned int mode);
1211 int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
1212 		      const struct in6_addr *addr);
1213 
1214 static inline int ip6_sock_set_v6only(struct sock *sk)
1215 {
1216 	if (inet_sk(sk)->inet_num)
1217 		return -EINVAL;
1218 	lock_sock(sk);
1219 	sk->sk_ipv6only = true;
1220 	release_sock(sk);
1221 	return 0;
1222 }
1223 
1224 static inline void ip6_sock_set_recverr(struct sock *sk)
1225 {
1226 	inet6_set_bit(RECVERR6, sk);
1227 }
1228 
1229 #define IPV6_PREFER_SRC_MASK (IPV6_PREFER_SRC_TMP | IPV6_PREFER_SRC_PUBLIC | \
1230 			      IPV6_PREFER_SRC_COA)
1231 
1232 static inline int ip6_sock_set_addr_preferences(struct sock *sk, int val)
1233 {
1234 	unsigned int prefmask = ~IPV6_PREFER_SRC_MASK;
1235 	unsigned int pref = 0;
1236 
1237 	/* check PUBLIC/TMP/PUBTMP_DEFAULT conflicts */
1238 	switch (val & (IPV6_PREFER_SRC_PUBLIC |
1239 		       IPV6_PREFER_SRC_TMP |
1240 		       IPV6_PREFER_SRC_PUBTMP_DEFAULT)) {
1241 	case IPV6_PREFER_SRC_PUBLIC:
1242 		pref |= IPV6_PREFER_SRC_PUBLIC;
1243 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1244 			      IPV6_PREFER_SRC_TMP);
1245 		break;
1246 	case IPV6_PREFER_SRC_TMP:
1247 		pref |= IPV6_PREFER_SRC_TMP;
1248 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1249 			      IPV6_PREFER_SRC_TMP);
1250 		break;
1251 	case IPV6_PREFER_SRC_PUBTMP_DEFAULT:
1252 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1253 			      IPV6_PREFER_SRC_TMP);
1254 		break;
1255 	case 0:
1256 		break;
1257 	default:
1258 		return -EINVAL;
1259 	}
1260 
1261 	/* check HOME/COA conflicts */
1262 	switch (val & (IPV6_PREFER_SRC_HOME | IPV6_PREFER_SRC_COA)) {
1263 	case IPV6_PREFER_SRC_HOME:
1264 		prefmask &= ~IPV6_PREFER_SRC_COA;
1265 		break;
1266 	case IPV6_PREFER_SRC_COA:
1267 		pref |= IPV6_PREFER_SRC_COA;
1268 		break;
1269 	case 0:
1270 		break;
1271 	default:
1272 		return -EINVAL;
1273 	}
1274 
1275 	/* check CGA/NONCGA conflicts */
1276 	switch (val & (IPV6_PREFER_SRC_CGA|IPV6_PREFER_SRC_NONCGA)) {
1277 	case IPV6_PREFER_SRC_CGA:
1278 	case IPV6_PREFER_SRC_NONCGA:
1279 	case 0:
1280 		break;
1281 	default:
1282 		return -EINVAL;
1283 	}
1284 
1285 	WRITE_ONCE(inet6_sk(sk)->srcprefs,
1286 		   (READ_ONCE(inet6_sk(sk)->srcprefs) & prefmask) | pref);
1287 	return 0;
1288 }
1289 
1290 static inline void ip6_sock_set_recvpktinfo(struct sock *sk)
1291 {
1292 	lock_sock(sk);
1293 	inet6_sk(sk)->rxopt.bits.rxinfo = true;
1294 	release_sock(sk);
1295 }
1296 
1297 #define IPV6_ADDR_WORDS 4
1298 
1299 static inline void ipv6_addr_cpu_to_be32(__be32 *dst, const u32 *src)
1300 {
1301 	cpu_to_be32_array(dst, src, IPV6_ADDR_WORDS);
1302 }
1303 
1304 static inline void ipv6_addr_be32_to_cpu(u32 *dst, const __be32 *src)
1305 {
1306 	be32_to_cpu_array(dst, src, IPV6_ADDR_WORDS);
1307 }
1308 
1309 #endif /* _NET_IPV6_H */
1310