xref: /linux/include/net/ipv6.h (revision 1c4b5ecb7ea190fa3e9f9d6891e6c90b60e04f24)
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/ndisc.h>
19 #include <net/flow.h>
20 #include <net/flow_dissector.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 #define IPV6_MAXPLEN		65535
29 
30 /*
31  *	NextHeader field of IPv6 header
32  */
33 
34 #define NEXTHDR_HOP		0	/* Hop-by-hop option header. */
35 #define NEXTHDR_IPV4		4	/* IPv4 in IPv6 */
36 #define NEXTHDR_TCP		6	/* TCP segment. */
37 #define NEXTHDR_UDP		17	/* UDP message. */
38 #define NEXTHDR_IPV6		41	/* IPv6 in IPv6 */
39 #define NEXTHDR_ROUTING		43	/* Routing header. */
40 #define NEXTHDR_FRAGMENT	44	/* Fragmentation/reassembly header. */
41 #define NEXTHDR_GRE		47	/* GRE header. */
42 #define NEXTHDR_ESP		50	/* Encapsulating security payload. */
43 #define NEXTHDR_AUTH		51	/* Authentication header. */
44 #define NEXTHDR_ICMP		58	/* ICMP for IPv6. */
45 #define NEXTHDR_NONE		59	/* No next header */
46 #define NEXTHDR_DEST		60	/* Destination options header. */
47 #define NEXTHDR_SCTP		132	/* SCTP message. */
48 #define NEXTHDR_MOBILITY	135	/* Mobility header. */
49 
50 #define NEXTHDR_MAX		255
51 
52 #define IPV6_DEFAULT_HOPLIMIT   64
53 #define IPV6_DEFAULT_MCASTHOPS	1
54 
55 /* Limits on Hop-by-Hop and Destination options.
56  *
57  * Per RFC8200 there is no limit on the maximum number or lengths of options in
58  * Hop-by-Hop or Destination options other then the packet must fit in an MTU.
59  * We allow configurable limits in order to mitigate potential denial of
60  * service attacks.
61  *
62  * There are three limits that may be set:
63  *   - Limit the number of options in a Hop-by-Hop or Destination options
64  *     extension header
65  *   - Limit the byte length of a Hop-by-Hop or Destination options extension
66  *     header
67  *   - Disallow unknown options
68  *
69  * The limits are expressed in corresponding sysctls:
70  *
71  * ipv6.sysctl.max_dst_opts_cnt
72  * ipv6.sysctl.max_hbh_opts_cnt
73  * ipv6.sysctl.max_dst_opts_len
74  * ipv6.sysctl.max_hbh_opts_len
75  *
76  * max_*_opts_cnt is the number of TLVs that are allowed for Destination
77  * options or Hop-by-Hop options. If the number is less than zero then unknown
78  * TLVs are disallowed and the number of known options that are allowed is the
79  * absolute value. Setting the value to INT_MAX indicates no limit.
80  *
81  * max_*_opts_len is the length limit in bytes of a Destination or
82  * Hop-by-Hop options extension header. Setting the value to INT_MAX
83  * indicates no length limit.
84  *
85  * If a limit is exceeded when processing an extension header the packet is
86  * silently discarded.
87  */
88 
89 /* Default limits for Hop-by-Hop and Destination options */
90 #define IP6_DEFAULT_MAX_DST_OPTS_CNT	 8
91 #define IP6_DEFAULT_MAX_HBH_OPTS_CNT	 8
92 #define IP6_DEFAULT_MAX_DST_OPTS_LEN	 INT_MAX /* No limit */
93 #define IP6_DEFAULT_MAX_HBH_OPTS_LEN	 INT_MAX /* No limit */
94 
95 /*
96  *	Addr type
97  *
98  *	type	-	unicast | multicast
99  *	scope	-	local	| site	    | global
100  *	v4	-	compat
101  *	v4mapped
102  *	any
103  *	loopback
104  */
105 
106 #define IPV6_ADDR_ANY		0x0000U
107 
108 #define IPV6_ADDR_UNICAST	0x0001U
109 #define IPV6_ADDR_MULTICAST	0x0002U
110 
111 #define IPV6_ADDR_LOOPBACK	0x0010U
112 #define IPV6_ADDR_LINKLOCAL	0x0020U
113 #define IPV6_ADDR_SITELOCAL	0x0040U
114 
115 #define IPV6_ADDR_COMPATv4	0x0080U
116 
117 #define IPV6_ADDR_SCOPE_MASK	0x00f0U
118 
119 #define IPV6_ADDR_MAPPED	0x1000U
120 
121 /*
122  *	Addr scopes
123  */
124 #define IPV6_ADDR_MC_SCOPE(a)	\
125 	((a)->s6_addr[1] & 0x0f)	/* nonstandard */
126 #define __IPV6_ADDR_SCOPE_INVALID	-1
127 #define IPV6_ADDR_SCOPE_NODELOCAL	0x01
128 #define IPV6_ADDR_SCOPE_LINKLOCAL	0x02
129 #define IPV6_ADDR_SCOPE_SITELOCAL	0x05
130 #define IPV6_ADDR_SCOPE_ORGLOCAL	0x08
131 #define IPV6_ADDR_SCOPE_GLOBAL		0x0e
132 
133 /*
134  *	Addr flags
135  */
136 #define IPV6_ADDR_MC_FLAG_TRANSIENT(a)	\
137 	((a)->s6_addr[1] & 0x10)
138 #define IPV6_ADDR_MC_FLAG_PREFIX(a)	\
139 	((a)->s6_addr[1] & 0x20)
140 #define IPV6_ADDR_MC_FLAG_RENDEZVOUS(a)	\
141 	((a)->s6_addr[1] & 0x40)
142 
143 /*
144  *	fragmentation header
145  */
146 
147 struct frag_hdr {
148 	__u8	nexthdr;
149 	__u8	reserved;
150 	__be16	frag_off;
151 	__be32	identification;
152 };
153 
154 #define	IP6_MF		0x0001
155 #define	IP6_OFFSET	0xFFF8
156 
157 struct ip6_fraglist_iter {
158 	struct ipv6hdr	*tmp_hdr;
159 	struct sk_buff	*frag;
160 	int		offset;
161 	unsigned int	hlen;
162 	__be32		frag_id;
163 	u8		nexthdr;
164 };
165 
166 int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr,
167 		      u8 nexthdr, __be32 frag_id,
168 		      struct ip6_fraglist_iter *iter);
169 void ip6_fraglist_prepare(struct sk_buff *skb, struct ip6_fraglist_iter *iter);
170 
171 static inline struct sk_buff *ip6_fraglist_next(struct ip6_fraglist_iter *iter)
172 {
173 	struct sk_buff *skb = iter->frag;
174 
175 	iter->frag = skb->next;
176 	skb_mark_not_on_list(skb);
177 
178 	return skb;
179 }
180 
181 struct ip6_frag_state {
182 	u8		*prevhdr;
183 	unsigned int	hlen;
184 	unsigned int	mtu;
185 	unsigned int	left;
186 	int		offset;
187 	int		ptr;
188 	int		hroom;
189 	int		troom;
190 	__be32		frag_id;
191 	u8		nexthdr;
192 };
193 
194 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu,
195 		   unsigned short needed_tailroom, int hdr_room, u8 *prevhdr,
196 		   u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state);
197 struct sk_buff *ip6_frag_next(struct sk_buff *skb,
198 			      struct ip6_frag_state *state);
199 
200 #define IP6_REPLY_MARK(net, mark) \
201 	((net)->ipv6.sysctl.fwmark_reflect ? (mark) : 0)
202 
203 #include <net/sock.h>
204 
205 /* sysctls */
206 extern int sysctl_mld_max_msf;
207 extern int sysctl_mld_qrv;
208 
209 #define _DEVINC(net, statname, mod, idev, field)			\
210 ({									\
211 	struct inet6_dev *_idev = (idev);				\
212 	if (likely(_idev != NULL))					\
213 		mod##SNMP_INC_STATS64((_idev)->stats.statname, (field));\
214 	mod##SNMP_INC_STATS64((net)->mib.statname##_statistics, (field));\
215 })
216 
217 /* per device counters are atomic_long_t */
218 #define _DEVINCATOMIC(net, statname, mod, idev, field)			\
219 ({									\
220 	struct inet6_dev *_idev = (idev);				\
221 	if (likely(_idev != NULL))					\
222 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
223 	mod##SNMP_INC_STATS((net)->mib.statname##_statistics, (field));\
224 })
225 
226 /* per device and per net counters are atomic_long_t */
227 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)		\
228 ({									\
229 	struct inet6_dev *_idev = (idev);				\
230 	if (likely(_idev != NULL))					\
231 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
232 	SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
233 })
234 
235 #define _DEVADD(net, statname, mod, idev, field, val)			\
236 ({									\
237 	struct inet6_dev *_idev = (idev);				\
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 	if (likely(_idev != NULL))					\
247 		mod##SNMP_UPD_PO_STATS((_idev)->stats.statname, field, (val)); \
248 	mod##SNMP_UPD_PO_STATS((net)->mib.statname##_statistics, field, (val));\
249 })
250 
251 /* MIBs */
252 
253 #define IP6_INC_STATS(net, idev,field)		\
254 		_DEVINC(net, ipv6, , idev, field)
255 #define __IP6_INC_STATS(net, idev,field)	\
256 		_DEVINC(net, ipv6, __, idev, field)
257 #define IP6_ADD_STATS(net, idev,field,val)	\
258 		_DEVADD(net, ipv6, , idev, field, val)
259 #define __IP6_ADD_STATS(net, idev,field,val)	\
260 		_DEVADD(net, ipv6, __, idev, field, val)
261 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
262 		_DEVUPD(net, ipv6, , idev, field, val)
263 #define __IP6_UPD_PO_STATS(net, idev,field,val)   \
264 		_DEVUPD(net, ipv6, __, idev, field, val)
265 #define ICMP6_INC_STATS(net, idev, field)	\
266 		_DEVINCATOMIC(net, icmpv6, , idev, field)
267 #define __ICMP6_INC_STATS(net, idev, field)	\
268 		_DEVINCATOMIC(net, icmpv6, __, idev, field)
269 
270 #define ICMP6MSGOUT_INC_STATS(net, idev, field)		\
271 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
272 #define ICMP6MSGIN_INC_STATS(net, idev, field)	\
273 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
274 
275 struct ip6_ra_chain {
276 	struct ip6_ra_chain	*next;
277 	struct sock		*sk;
278 	int			sel;
279 	void			(*destructor)(struct sock *);
280 };
281 
282 extern struct ip6_ra_chain	*ip6_ra_chain;
283 extern rwlock_t ip6_ra_lock;
284 
285 /*
286    This structure is prepared by protocol, when parsing
287    ancillary data and passed to IPv6.
288  */
289 
290 struct ipv6_txoptions {
291 	refcount_t		refcnt;
292 	/* Length of this structure */
293 	int			tot_len;
294 
295 	/* length of extension headers   */
296 
297 	__u16			opt_flen;	/* after fragment hdr */
298 	__u16			opt_nflen;	/* before fragment hdr */
299 
300 	struct ipv6_opt_hdr	*hopopt;
301 	struct ipv6_opt_hdr	*dst0opt;
302 	struct ipv6_rt_hdr	*srcrt;	/* Routing Header */
303 	struct ipv6_opt_hdr	*dst1opt;
304 	struct rcu_head		rcu;
305 	/* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
306 };
307 
308 /* flowlabel_reflect sysctl values */
309 enum flowlabel_reflect {
310 	FLOWLABEL_REFLECT_ESTABLISHED		= 1,
311 	FLOWLABEL_REFLECT_TCP_RESET		= 2,
312 	FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES	= 4,
313 };
314 
315 struct ip6_flowlabel {
316 	struct ip6_flowlabel __rcu *next;
317 	__be32			label;
318 	atomic_t		users;
319 	struct in6_addr		dst;
320 	struct ipv6_txoptions	*opt;
321 	unsigned long		linger;
322 	struct rcu_head		rcu;
323 	u8			share;
324 	union {
325 		struct pid *pid;
326 		kuid_t uid;
327 	} owner;
328 	unsigned long		lastuse;
329 	unsigned long		expires;
330 	struct net		*fl_net;
331 };
332 
333 #define IPV6_FLOWINFO_MASK		cpu_to_be32(0x0FFFFFFF)
334 #define IPV6_FLOWLABEL_MASK		cpu_to_be32(0x000FFFFF)
335 #define IPV6_FLOWLABEL_STATELESS_FLAG	cpu_to_be32(0x00080000)
336 
337 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
338 #define IPV6_TCLASS_SHIFT	20
339 
340 struct ipv6_fl_socklist {
341 	struct ipv6_fl_socklist	__rcu	*next;
342 	struct ip6_flowlabel		*fl;
343 	struct rcu_head			rcu;
344 };
345 
346 struct ipcm6_cookie {
347 	struct sockcm_cookie sockc;
348 	__s16 hlimit;
349 	__s16 tclass;
350 	__u16 gso_size;
351 	__s8  dontfrag;
352 	struct ipv6_txoptions *opt;
353 };
354 
355 static inline void ipcm6_init(struct ipcm6_cookie *ipc6)
356 {
357 	*ipc6 = (struct ipcm6_cookie) {
358 		.hlimit = -1,
359 		.tclass = -1,
360 		.dontfrag = -1,
361 	};
362 }
363 
364 static inline void ipcm6_init_sk(struct ipcm6_cookie *ipc6,
365 				 const struct ipv6_pinfo *np)
366 {
367 	*ipc6 = (struct ipcm6_cookie) {
368 		.hlimit = -1,
369 		.tclass = np->tclass,
370 		.dontfrag = np->dontfrag,
371 	};
372 }
373 
374 static inline struct ipv6_txoptions *txopt_get(const struct ipv6_pinfo *np)
375 {
376 	struct ipv6_txoptions *opt;
377 
378 	rcu_read_lock();
379 	opt = rcu_dereference(np->opt);
380 	if (opt) {
381 		if (!refcount_inc_not_zero(&opt->refcnt))
382 			opt = NULL;
383 		else
384 			opt = rcu_pointer_handoff(opt);
385 	}
386 	rcu_read_unlock();
387 	return opt;
388 }
389 
390 static inline void txopt_put(struct ipv6_txoptions *opt)
391 {
392 	if (opt && refcount_dec_and_test(&opt->refcnt))
393 		kfree_rcu(opt, rcu);
394 }
395 
396 #if IS_ENABLED(CONFIG_IPV6)
397 struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label);
398 
399 extern struct static_key_false_deferred ipv6_flowlabel_exclusive;
400 static inline struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk,
401 						    __be32 label)
402 {
403 	if (static_branch_unlikely(&ipv6_flowlabel_exclusive.key) &&
404 	    READ_ONCE(sock_net(sk)->ipv6.flowlabel_has_excl))
405 		return __fl6_sock_lookup(sk, label) ? : ERR_PTR(-ENOENT);
406 
407 	return NULL;
408 }
409 #endif
410 
411 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
412 					 struct ip6_flowlabel *fl,
413 					 struct ipv6_txoptions *fopt);
414 void fl6_free_socklist(struct sock *sk);
415 int ipv6_flowlabel_opt(struct sock *sk, sockptr_t optval, int optlen);
416 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
417 			   int flags);
418 int ip6_flowlabel_init(void);
419 void ip6_flowlabel_cleanup(void);
420 bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np);
421 
422 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
423 {
424 	if (fl)
425 		atomic_dec(&fl->users);
426 }
427 
428 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
429 
430 void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
431 				struct icmp6hdr *thdr, int len);
432 
433 int ip6_ra_control(struct sock *sk, int sel);
434 
435 int ipv6_parse_hopopts(struct sk_buff *skb);
436 
437 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
438 					struct ipv6_txoptions *opt);
439 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
440 					  struct ipv6_txoptions *opt,
441 					  int newtype,
442 					  struct ipv6_opt_hdr *newopt);
443 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
444 					  struct ipv6_txoptions *opt);
445 
446 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
447 		       const struct inet6_skb_parm *opt);
448 struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
449 					   struct ipv6_txoptions *opt);
450 
451 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
452 {
453 	/* If forwarding is enabled, RA are not accepted unless the special
454 	 * hybrid mode (accept_ra=2) is enabled.
455 	 */
456 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
457 	    idev->cnf.accept_ra;
458 }
459 
460 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
461 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
462 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
463 
464 int __ipv6_addr_type(const struct in6_addr *addr);
465 static inline int ipv6_addr_type(const struct in6_addr *addr)
466 {
467 	return __ipv6_addr_type(addr) & 0xffff;
468 }
469 
470 static inline int ipv6_addr_scope(const struct in6_addr *addr)
471 {
472 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
473 }
474 
475 static inline int __ipv6_addr_src_scope(int type)
476 {
477 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
478 }
479 
480 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
481 {
482 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
483 }
484 
485 static inline bool __ipv6_addr_needs_scope_id(int type)
486 {
487 	return type & IPV6_ADDR_LINKLOCAL ||
488 	       (type & IPV6_ADDR_MULTICAST &&
489 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
490 }
491 
492 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
493 {
494 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
495 }
496 
497 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
498 {
499 	return memcmp(a1, a2, sizeof(struct in6_addr));
500 }
501 
502 static inline bool
503 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
504 		     const struct in6_addr *a2)
505 {
506 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
507 	const unsigned long *ul1 = (const unsigned long *)a1;
508 	const unsigned long *ulm = (const unsigned long *)m;
509 	const unsigned long *ul2 = (const unsigned long *)a2;
510 
511 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
512 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
513 #else
514 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
515 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
516 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
517 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
518 #endif
519 }
520 
521 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
522 				    const struct in6_addr *addr,
523 				    int plen)
524 {
525 	/* caller must guarantee 0 <= plen <= 128 */
526 	int o = plen >> 3,
527 	    b = plen & 0x7;
528 
529 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
530 	memcpy(pfx->s6_addr, addr, o);
531 	if (b != 0)
532 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
533 }
534 
535 static inline void ipv6_addr_prefix_copy(struct in6_addr *addr,
536 					 const struct in6_addr *pfx,
537 					 int plen)
538 {
539 	/* caller must guarantee 0 <= plen <= 128 */
540 	int o = plen >> 3,
541 	    b = plen & 0x7;
542 
543 	memcpy(addr->s6_addr, pfx, o);
544 	if (b != 0) {
545 		addr->s6_addr[o] &= ~(0xff00 >> b);
546 		addr->s6_addr[o] |= (pfx->s6_addr[o] & (0xff00 >> b));
547 	}
548 }
549 
550 static inline void __ipv6_addr_set_half(__be32 *addr,
551 					__be32 wh, __be32 wl)
552 {
553 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
554 #if defined(__BIG_ENDIAN)
555 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
556 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
557 		return;
558 	}
559 #elif defined(__LITTLE_ENDIAN)
560 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
561 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
562 		return;
563 	}
564 #endif
565 #endif
566 	addr[0] = wh;
567 	addr[1] = wl;
568 }
569 
570 static inline void ipv6_addr_set(struct in6_addr *addr,
571 				     __be32 w1, __be32 w2,
572 				     __be32 w3, __be32 w4)
573 {
574 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
575 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
576 }
577 
578 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
579 				   const struct in6_addr *a2)
580 {
581 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
582 	const unsigned long *ul1 = (const unsigned long *)a1;
583 	const unsigned long *ul2 = (const unsigned long *)a2;
584 
585 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
586 #else
587 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
588 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
589 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
590 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
591 #endif
592 }
593 
594 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
595 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
596 					      const __be64 *a2,
597 					      unsigned int len)
598 {
599 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
600 		return false;
601 	return true;
602 }
603 
604 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
605 				     const struct in6_addr *addr2,
606 				     unsigned int prefixlen)
607 {
608 	const __be64 *a1 = (const __be64 *)addr1;
609 	const __be64 *a2 = (const __be64 *)addr2;
610 
611 	if (prefixlen >= 64) {
612 		if (a1[0] ^ a2[0])
613 			return false;
614 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
615 	}
616 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
617 }
618 #else
619 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
620 				     const struct in6_addr *addr2,
621 				     unsigned int prefixlen)
622 {
623 	const __be32 *a1 = addr1->s6_addr32;
624 	const __be32 *a2 = addr2->s6_addr32;
625 	unsigned int pdw, pbi;
626 
627 	/* check complete u32 in prefix */
628 	pdw = prefixlen >> 5;
629 	if (pdw && memcmp(a1, a2, pdw << 2))
630 		return false;
631 
632 	/* check incomplete u32 in prefix */
633 	pbi = prefixlen & 0x1f;
634 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
635 		return false;
636 
637 	return true;
638 }
639 #endif
640 
641 static inline bool ipv6_addr_any(const struct in6_addr *a)
642 {
643 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
644 	const unsigned long *ul = (const unsigned long *)a;
645 
646 	return (ul[0] | ul[1]) == 0UL;
647 #else
648 	return (a->s6_addr32[0] | a->s6_addr32[1] |
649 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
650 #endif
651 }
652 
653 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
654 {
655 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
656 	const unsigned long *ul = (const unsigned long *)a;
657 	unsigned long x = ul[0] ^ ul[1];
658 
659 	return (u32)(x ^ (x >> 32));
660 #else
661 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
662 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
663 #endif
664 }
665 
666 /* more secured version of ipv6_addr_hash() */
667 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
668 {
669 	u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
670 
671 	return jhash_3words(v,
672 			    (__force u32)a->s6_addr32[2],
673 			    (__force u32)a->s6_addr32[3],
674 			    initval);
675 }
676 
677 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
678 {
679 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
680 	const __be64 *be = (const __be64 *)a;
681 
682 	return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
683 #else
684 	return (a->s6_addr32[0] | a->s6_addr32[1] |
685 		a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
686 #endif
687 }
688 
689 /*
690  * Note that we must __force cast these to unsigned long to make sparse happy,
691  * since all of the endian-annotated types are fixed size regardless of arch.
692  */
693 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
694 {
695 	return (
696 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
697 		*(unsigned long *)a |
698 #else
699 		(__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
700 #endif
701 		(__force unsigned long)(a->s6_addr32[2] ^
702 					cpu_to_be32(0x0000ffff))) == 0UL;
703 }
704 
705 static inline bool ipv6_addr_v4mapped_loopback(const struct in6_addr *a)
706 {
707 	return ipv6_addr_v4mapped(a) && ipv4_is_loopback(a->s6_addr32[3]);
708 }
709 
710 static inline u32 ipv6_portaddr_hash(const struct net *net,
711 				     const struct in6_addr *addr6,
712 				     unsigned int port)
713 {
714 	unsigned int hash, mix = net_hash_mix(net);
715 
716 	if (ipv6_addr_any(addr6))
717 		hash = jhash_1word(0, mix);
718 	else if (ipv6_addr_v4mapped(addr6))
719 		hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
720 	else
721 		hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
722 
723 	return hash ^ port;
724 }
725 
726 /*
727  * Check for a RFC 4843 ORCHID address
728  * (Overlay Routable Cryptographic Hash Identifiers)
729  */
730 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
731 {
732 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
733 }
734 
735 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
736 {
737 	return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
738 }
739 
740 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
741 					  struct in6_addr *v4mapped)
742 {
743 	ipv6_addr_set(v4mapped,
744 			0, 0,
745 			htonl(0x0000FFFF),
746 			addr);
747 }
748 
749 /*
750  * find the first different bit between two addresses
751  * length of address must be a multiple of 32bits
752  */
753 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
754 {
755 	const __be32 *a1 = token1, *a2 = token2;
756 	int i;
757 
758 	addrlen >>= 2;
759 
760 	for (i = 0; i < addrlen; i++) {
761 		__be32 xb = a1[i] ^ a2[i];
762 		if (xb)
763 			return i * 32 + 31 - __fls(ntohl(xb));
764 	}
765 
766 	/*
767 	 *	we should *never* get to this point since that
768 	 *	would mean the addrs are equal
769 	 *
770 	 *	However, we do get to it 8) And exacly, when
771 	 *	addresses are equal 8)
772 	 *
773 	 *	ip route add 1111::/128 via ...
774 	 *	ip route add 1111::/64 via ...
775 	 *	and we are here.
776 	 *
777 	 *	Ideally, this function should stop comparison
778 	 *	at prefix length. It does not, but it is still OK,
779 	 *	if returned value is greater than prefix length.
780 	 *					--ANK (980803)
781 	 */
782 	return addrlen << 5;
783 }
784 
785 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
786 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
787 {
788 	const __be64 *a1 = token1, *a2 = token2;
789 	int i;
790 
791 	addrlen >>= 3;
792 
793 	for (i = 0; i < addrlen; i++) {
794 		__be64 xb = a1[i] ^ a2[i];
795 		if (xb)
796 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
797 	}
798 
799 	return addrlen << 6;
800 }
801 #endif
802 
803 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
804 {
805 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
806 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
807 		return __ipv6_addr_diff64(token1, token2, addrlen);
808 #endif
809 	return __ipv6_addr_diff32(token1, token2, addrlen);
810 }
811 
812 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
813 {
814 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
815 }
816 
817 __be32 ipv6_select_ident(struct net *net,
818 			 const struct in6_addr *daddr,
819 			 const struct in6_addr *saddr);
820 __be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
821 
822 int ip6_dst_hoplimit(struct dst_entry *dst);
823 
824 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
825 				      struct dst_entry *dst)
826 {
827 	int hlimit;
828 
829 	if (ipv6_addr_is_multicast(&fl6->daddr))
830 		hlimit = np->mcast_hops;
831 	else
832 		hlimit = np->hop_limit;
833 	if (hlimit < 0)
834 		hlimit = ip6_dst_hoplimit(dst);
835 	return hlimit;
836 }
837 
838 /* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
839  * Equivalent to :	flow->v6addrs.src = iph->saddr;
840  *			flow->v6addrs.dst = iph->daddr;
841  */
842 static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
843 					    const struct ipv6hdr *iph)
844 {
845 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
846 		     offsetof(typeof(flow->addrs), v6addrs.src) +
847 		     sizeof(flow->addrs.v6addrs.src));
848 	memcpy(&flow->addrs.v6addrs, &iph->saddr, sizeof(flow->addrs.v6addrs));
849 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
850 }
851 
852 #if IS_ENABLED(CONFIG_IPV6)
853 
854 static inline bool ipv6_can_nonlocal_bind(struct net *net,
855 					  struct inet_sock *inet)
856 {
857 	return net->ipv6.sysctl.ip_nonlocal_bind ||
858 		inet->freebind || inet->transparent;
859 }
860 
861 /* Sysctl settings for net ipv6.auto_flowlabels */
862 #define IP6_AUTO_FLOW_LABEL_OFF		0
863 #define IP6_AUTO_FLOW_LABEL_OPTOUT	1
864 #define IP6_AUTO_FLOW_LABEL_OPTIN	2
865 #define IP6_AUTO_FLOW_LABEL_FORCED	3
866 
867 #define IP6_AUTO_FLOW_LABEL_MAX		IP6_AUTO_FLOW_LABEL_FORCED
868 
869 #define IP6_DEFAULT_AUTO_FLOW_LABELS	IP6_AUTO_FLOW_LABEL_OPTOUT
870 
871 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
872 					__be32 flowlabel, bool autolabel,
873 					struct flowi6 *fl6)
874 {
875 	u32 hash;
876 
877 	/* @flowlabel may include more than a flow label, eg, the traffic class.
878 	 * Here we want only the flow label value.
879 	 */
880 	flowlabel &= IPV6_FLOWLABEL_MASK;
881 
882 	if (flowlabel ||
883 	    net->ipv6.sysctl.auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF ||
884 	    (!autolabel &&
885 	     net->ipv6.sysctl.auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED))
886 		return flowlabel;
887 
888 	hash = skb_get_hash_flowi6(skb, fl6);
889 
890 	/* Since this is being sent on the wire obfuscate hash a bit
891 	 * to minimize possbility that any useful information to an
892 	 * attacker is leaked. Only lower 20 bits are relevant.
893 	 */
894 	hash = rol32(hash, 16);
895 
896 	flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
897 
898 	if (net->ipv6.sysctl.flowlabel_state_ranges)
899 		flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
900 
901 	return flowlabel;
902 }
903 
904 static inline int ip6_default_np_autolabel(struct net *net)
905 {
906 	switch (net->ipv6.sysctl.auto_flowlabels) {
907 	case IP6_AUTO_FLOW_LABEL_OFF:
908 	case IP6_AUTO_FLOW_LABEL_OPTIN:
909 	default:
910 		return 0;
911 	case IP6_AUTO_FLOW_LABEL_OPTOUT:
912 	case IP6_AUTO_FLOW_LABEL_FORCED:
913 		return 1;
914 	}
915 }
916 #else
917 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
918 					__be32 flowlabel, bool autolabel,
919 					struct flowi6 *fl6)
920 {
921 	return flowlabel;
922 }
923 static inline int ip6_default_np_autolabel(struct net *net)
924 {
925 	return 0;
926 }
927 #endif
928 
929 #if IS_ENABLED(CONFIG_IPV6)
930 static inline int ip6_multipath_hash_policy(const struct net *net)
931 {
932 	return net->ipv6.sysctl.multipath_hash_policy;
933 }
934 static inline u32 ip6_multipath_hash_fields(const struct net *net)
935 {
936 	return net->ipv6.sysctl.multipath_hash_fields;
937 }
938 #else
939 static inline int ip6_multipath_hash_policy(const struct net *net)
940 {
941 	return 0;
942 }
943 static inline u32 ip6_multipath_hash_fields(const struct net *net)
944 {
945 	return 0;
946 }
947 #endif
948 
949 /*
950  *	Header manipulation
951  */
952 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
953 				__be32 flowlabel)
954 {
955 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
956 }
957 
958 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
959 {
960 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
961 }
962 
963 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
964 {
965 	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
966 }
967 
968 static inline u8 ip6_tclass(__be32 flowinfo)
969 {
970 	return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
971 }
972 
973 static inline __be32 ip6_make_flowinfo(unsigned int tclass, __be32 flowlabel)
974 {
975 	return htonl(tclass << IPV6_TCLASS_SHIFT) | flowlabel;
976 }
977 
978 static inline __be32 flowi6_get_flowlabel(const struct flowi6 *fl6)
979 {
980 	return fl6->flowlabel & IPV6_FLOWLABEL_MASK;
981 }
982 
983 /*
984  *	Prototypes exported by ipv6
985  */
986 
987 /*
988  *	rcv function (called from netdevice level)
989  */
990 
991 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
992 	     struct packet_type *pt, struct net_device *orig_dev);
993 void ipv6_list_rcv(struct list_head *head, struct packet_type *pt,
994 		   struct net_device *orig_dev);
995 
996 int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
997 
998 /*
999  *	upper-layer output functions
1000  */
1001 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
1002 	     __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority);
1003 
1004 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
1005 
1006 int ip6_append_data(struct sock *sk,
1007 		    int getfrag(void *from, char *to, int offset, int len,
1008 				int odd, struct sk_buff *skb),
1009 		    void *from, int length, int transhdrlen,
1010 		    struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1011 		    struct rt6_info *rt, unsigned int flags);
1012 
1013 int ip6_push_pending_frames(struct sock *sk);
1014 
1015 void ip6_flush_pending_frames(struct sock *sk);
1016 
1017 int ip6_send_skb(struct sk_buff *skb);
1018 
1019 struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
1020 			       struct inet_cork_full *cork,
1021 			       struct inet6_cork *v6_cork);
1022 struct sk_buff *ip6_make_skb(struct sock *sk,
1023 			     int getfrag(void *from, char *to, int offset,
1024 					 int len, int odd, struct sk_buff *skb),
1025 			     void *from, int length, int transhdrlen,
1026 			     struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1027 			     struct rt6_info *rt, unsigned int flags,
1028 			     struct inet_cork_full *cork);
1029 
1030 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
1031 {
1032 	return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
1033 			      &inet6_sk(sk)->cork);
1034 }
1035 
1036 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1037 		   struct flowi6 *fl6);
1038 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6,
1039 				      const struct in6_addr *final_dst);
1040 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1041 					 const struct in6_addr *final_dst,
1042 					 bool connected);
1043 struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb,
1044 					struct net_device *dev,
1045 					struct net *net, struct socket *sock,
1046 					struct in6_addr *saddr,
1047 					const struct ip_tunnel_info *info,
1048 					u8 protocol, bool use_cache);
1049 struct dst_entry *ip6_blackhole_route(struct net *net,
1050 				      struct dst_entry *orig_dst);
1051 
1052 /*
1053  *	skb processing functions
1054  */
1055 
1056 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb);
1057 int ip6_forward(struct sk_buff *skb);
1058 int ip6_input(struct sk_buff *skb);
1059 int ip6_mc_input(struct sk_buff *skb);
1060 void ip6_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int nexthdr,
1061 			      bool have_final);
1062 
1063 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
1064 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
1065 
1066 /*
1067  *	Extension header (options) processing
1068  */
1069 
1070 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1071 			  u8 *proto, struct in6_addr **daddr_p,
1072 			  struct in6_addr *saddr);
1073 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1074 			 u8 *proto);
1075 
1076 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
1077 		     __be16 *frag_offp);
1078 
1079 bool ipv6_ext_hdr(u8 nexthdr);
1080 
1081 enum {
1082 	IP6_FH_F_FRAG		= (1 << 0),
1083 	IP6_FH_F_AUTH		= (1 << 1),
1084 	IP6_FH_F_SKIP_RH	= (1 << 2),
1085 };
1086 
1087 /* find specified header and get offset to it */
1088 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
1089 		  unsigned short *fragoff, int *fragflg);
1090 
1091 int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type);
1092 
1093 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1094 				const struct ipv6_txoptions *opt,
1095 				struct in6_addr *orig);
1096 
1097 /*
1098  *	socket options (ipv6_sockglue.c)
1099  */
1100 DECLARE_STATIC_KEY_FALSE(ip6_min_hopcount);
1101 
1102 int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1103 		    unsigned int optlen);
1104 int ipv6_getsockopt(struct sock *sk, int level, int optname,
1105 		    char __user *optval, int __user *optlen);
1106 
1107 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *addr,
1108 			   int addr_len);
1109 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
1110 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
1111 				 int addr_len);
1112 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr);
1113 void ip6_datagram_release_cb(struct sock *sk);
1114 
1115 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
1116 		    int *addr_len);
1117 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
1118 		     int *addr_len);
1119 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
1120 		     u32 info, u8 *payload);
1121 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
1122 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
1123 
1124 int inet6_release(struct socket *sock);
1125 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
1126 int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
1127 		  int peer);
1128 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
1129 int inet6_compat_ioctl(struct socket *sock, unsigned int cmd,
1130 		unsigned long arg);
1131 
1132 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
1133 			      struct sock *sk);
1134 int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size);
1135 int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1136 		  int flags);
1137 
1138 /*
1139  * reassembly.c
1140  */
1141 extern const struct proto_ops inet6_stream_ops;
1142 extern const struct proto_ops inet6_dgram_ops;
1143 extern const struct proto_ops inet6_sockraw_ops;
1144 
1145 struct group_source_req;
1146 struct group_filter;
1147 
1148 int ip6_mc_source(int add, int omode, struct sock *sk,
1149 		  struct group_source_req *pgsr);
1150 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf,
1151 		  struct sockaddr_storage *list);
1152 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
1153 		  struct sockaddr_storage __user *p);
1154 
1155 #ifdef CONFIG_PROC_FS
1156 int ac6_proc_init(struct net *net);
1157 void ac6_proc_exit(struct net *net);
1158 int raw6_proc_init(void);
1159 void raw6_proc_exit(void);
1160 int tcp6_proc_init(struct net *net);
1161 void tcp6_proc_exit(struct net *net);
1162 int udp6_proc_init(struct net *net);
1163 void udp6_proc_exit(struct net *net);
1164 int udplite6_proc_init(void);
1165 void udplite6_proc_exit(void);
1166 int ipv6_misc_proc_init(void);
1167 void ipv6_misc_proc_exit(void);
1168 int snmp6_register_dev(struct inet6_dev *idev);
1169 int snmp6_unregister_dev(struct inet6_dev *idev);
1170 
1171 #else
1172 static inline int ac6_proc_init(struct net *net) { return 0; }
1173 static inline void ac6_proc_exit(struct net *net) { }
1174 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
1175 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
1176 #endif
1177 
1178 #ifdef CONFIG_SYSCTL
1179 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
1180 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
1181 int ipv6_sysctl_register(void);
1182 void ipv6_sysctl_unregister(void);
1183 #endif
1184 
1185 int ipv6_sock_mc_join(struct sock *sk, int ifindex,
1186 		      const struct in6_addr *addr);
1187 int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,
1188 			  const struct in6_addr *addr, unsigned int mode);
1189 int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
1190 		      const struct in6_addr *addr);
1191 
1192 static inline int ip6_sock_set_v6only(struct sock *sk)
1193 {
1194 	if (inet_sk(sk)->inet_num)
1195 		return -EINVAL;
1196 	lock_sock(sk);
1197 	sk->sk_ipv6only = true;
1198 	release_sock(sk);
1199 	return 0;
1200 }
1201 
1202 static inline void ip6_sock_set_recverr(struct sock *sk)
1203 {
1204 	lock_sock(sk);
1205 	inet6_sk(sk)->recverr = true;
1206 	release_sock(sk);
1207 }
1208 
1209 static inline int __ip6_sock_set_addr_preferences(struct sock *sk, int val)
1210 {
1211 	unsigned int pref = 0;
1212 	unsigned int prefmask = ~0;
1213 
1214 	/* check PUBLIC/TMP/PUBTMP_DEFAULT conflicts */
1215 	switch (val & (IPV6_PREFER_SRC_PUBLIC |
1216 		       IPV6_PREFER_SRC_TMP |
1217 		       IPV6_PREFER_SRC_PUBTMP_DEFAULT)) {
1218 	case IPV6_PREFER_SRC_PUBLIC:
1219 		pref |= IPV6_PREFER_SRC_PUBLIC;
1220 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1221 			      IPV6_PREFER_SRC_TMP);
1222 		break;
1223 	case IPV6_PREFER_SRC_TMP:
1224 		pref |= IPV6_PREFER_SRC_TMP;
1225 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1226 			      IPV6_PREFER_SRC_TMP);
1227 		break;
1228 	case IPV6_PREFER_SRC_PUBTMP_DEFAULT:
1229 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1230 			      IPV6_PREFER_SRC_TMP);
1231 		break;
1232 	case 0:
1233 		break;
1234 	default:
1235 		return -EINVAL;
1236 	}
1237 
1238 	/* check HOME/COA conflicts */
1239 	switch (val & (IPV6_PREFER_SRC_HOME | IPV6_PREFER_SRC_COA)) {
1240 	case IPV6_PREFER_SRC_HOME:
1241 		prefmask &= ~IPV6_PREFER_SRC_COA;
1242 		break;
1243 	case IPV6_PREFER_SRC_COA:
1244 		pref |= IPV6_PREFER_SRC_COA;
1245 		break;
1246 	case 0:
1247 		break;
1248 	default:
1249 		return -EINVAL;
1250 	}
1251 
1252 	/* check CGA/NONCGA conflicts */
1253 	switch (val & (IPV6_PREFER_SRC_CGA|IPV6_PREFER_SRC_NONCGA)) {
1254 	case IPV6_PREFER_SRC_CGA:
1255 	case IPV6_PREFER_SRC_NONCGA:
1256 	case 0:
1257 		break;
1258 	default:
1259 		return -EINVAL;
1260 	}
1261 
1262 	inet6_sk(sk)->srcprefs = (inet6_sk(sk)->srcprefs & prefmask) | pref;
1263 	return 0;
1264 }
1265 
1266 static inline int ip6_sock_set_addr_preferences(struct sock *sk, bool val)
1267 {
1268 	int ret;
1269 
1270 	lock_sock(sk);
1271 	ret = __ip6_sock_set_addr_preferences(sk, val);
1272 	release_sock(sk);
1273 	return ret;
1274 }
1275 
1276 static inline void ip6_sock_set_recvpktinfo(struct sock *sk)
1277 {
1278 	lock_sock(sk);
1279 	inet6_sk(sk)->rxopt.bits.rxinfo = true;
1280 	release_sock(sk);
1281 }
1282 
1283 #endif /* _NET_IPV6_H */
1284