xref: /linux/include/net/ipv6.h (revision 3f0a50f345f78183f6e9b39c2f45ca5dcaa511ca)
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 #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 static inline struct ipv6_txoptions *
447 ipv6_fixup_options(struct ipv6_txoptions *opt_space, struct ipv6_txoptions *opt)
448 {
449 	if (!opt)
450 		return NULL;
451 	return __ipv6_fixup_options(opt_space, opt);
452 }
453 
454 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
455 		       const struct inet6_skb_parm *opt);
456 struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
457 					   struct ipv6_txoptions *opt);
458 
459 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
460 {
461 	/* If forwarding is enabled, RA are not accepted unless the special
462 	 * hybrid mode (accept_ra=2) is enabled.
463 	 */
464 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
465 	    idev->cnf.accept_ra;
466 }
467 
468 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
469 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
470 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
471 
472 int __ipv6_addr_type(const struct in6_addr *addr);
473 static inline int ipv6_addr_type(const struct in6_addr *addr)
474 {
475 	return __ipv6_addr_type(addr) & 0xffff;
476 }
477 
478 static inline int ipv6_addr_scope(const struct in6_addr *addr)
479 {
480 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
481 }
482 
483 static inline int __ipv6_addr_src_scope(int type)
484 {
485 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
486 }
487 
488 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
489 {
490 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
491 }
492 
493 static inline bool __ipv6_addr_needs_scope_id(int type)
494 {
495 	return type & IPV6_ADDR_LINKLOCAL ||
496 	       (type & IPV6_ADDR_MULTICAST &&
497 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
498 }
499 
500 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
501 {
502 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
503 }
504 
505 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
506 {
507 	return memcmp(a1, a2, sizeof(struct in6_addr));
508 }
509 
510 static inline bool
511 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
512 		     const struct in6_addr *a2)
513 {
514 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
515 	const unsigned long *ul1 = (const unsigned long *)a1;
516 	const unsigned long *ulm = (const unsigned long *)m;
517 	const unsigned long *ul2 = (const unsigned long *)a2;
518 
519 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
520 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
521 #else
522 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
523 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
524 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
525 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
526 #endif
527 }
528 
529 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
530 				    const struct in6_addr *addr,
531 				    int plen)
532 {
533 	/* caller must guarantee 0 <= plen <= 128 */
534 	int o = plen >> 3,
535 	    b = plen & 0x7;
536 
537 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
538 	memcpy(pfx->s6_addr, addr, o);
539 	if (b != 0)
540 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
541 }
542 
543 static inline void ipv6_addr_prefix_copy(struct in6_addr *addr,
544 					 const struct in6_addr *pfx,
545 					 int plen)
546 {
547 	/* caller must guarantee 0 <= plen <= 128 */
548 	int o = plen >> 3,
549 	    b = plen & 0x7;
550 
551 	memcpy(addr->s6_addr, pfx, o);
552 	if (b != 0) {
553 		addr->s6_addr[o] &= ~(0xff00 >> b);
554 		addr->s6_addr[o] |= (pfx->s6_addr[o] & (0xff00 >> b));
555 	}
556 }
557 
558 static inline void __ipv6_addr_set_half(__be32 *addr,
559 					__be32 wh, __be32 wl)
560 {
561 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
562 #if defined(__BIG_ENDIAN)
563 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
564 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
565 		return;
566 	}
567 #elif defined(__LITTLE_ENDIAN)
568 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
569 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
570 		return;
571 	}
572 #endif
573 #endif
574 	addr[0] = wh;
575 	addr[1] = wl;
576 }
577 
578 static inline void ipv6_addr_set(struct in6_addr *addr,
579 				     __be32 w1, __be32 w2,
580 				     __be32 w3, __be32 w4)
581 {
582 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
583 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
584 }
585 
586 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
587 				   const struct in6_addr *a2)
588 {
589 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
590 	const unsigned long *ul1 = (const unsigned long *)a1;
591 	const unsigned long *ul2 = (const unsigned long *)a2;
592 
593 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
594 #else
595 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
596 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
597 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
598 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
599 #endif
600 }
601 
602 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
603 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
604 					      const __be64 *a2,
605 					      unsigned int len)
606 {
607 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
608 		return false;
609 	return true;
610 }
611 
612 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
613 				     const struct in6_addr *addr2,
614 				     unsigned int prefixlen)
615 {
616 	const __be64 *a1 = (const __be64 *)addr1;
617 	const __be64 *a2 = (const __be64 *)addr2;
618 
619 	if (prefixlen >= 64) {
620 		if (a1[0] ^ a2[0])
621 			return false;
622 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
623 	}
624 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
625 }
626 #else
627 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
628 				     const struct in6_addr *addr2,
629 				     unsigned int prefixlen)
630 {
631 	const __be32 *a1 = addr1->s6_addr32;
632 	const __be32 *a2 = addr2->s6_addr32;
633 	unsigned int pdw, pbi;
634 
635 	/* check complete u32 in prefix */
636 	pdw = prefixlen >> 5;
637 	if (pdw && memcmp(a1, a2, pdw << 2))
638 		return false;
639 
640 	/* check incomplete u32 in prefix */
641 	pbi = prefixlen & 0x1f;
642 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
643 		return false;
644 
645 	return true;
646 }
647 #endif
648 
649 static inline bool ipv6_addr_any(const struct in6_addr *a)
650 {
651 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
652 	const unsigned long *ul = (const unsigned long *)a;
653 
654 	return (ul[0] | ul[1]) == 0UL;
655 #else
656 	return (a->s6_addr32[0] | a->s6_addr32[1] |
657 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
658 #endif
659 }
660 
661 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
662 {
663 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
664 	const unsigned long *ul = (const unsigned long *)a;
665 	unsigned long x = ul[0] ^ ul[1];
666 
667 	return (u32)(x ^ (x >> 32));
668 #else
669 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
670 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
671 #endif
672 }
673 
674 /* more secured version of ipv6_addr_hash() */
675 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
676 {
677 	u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
678 
679 	return jhash_3words(v,
680 			    (__force u32)a->s6_addr32[2],
681 			    (__force u32)a->s6_addr32[3],
682 			    initval);
683 }
684 
685 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
686 {
687 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
688 	const __be64 *be = (const __be64 *)a;
689 
690 	return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
691 #else
692 	return (a->s6_addr32[0] | a->s6_addr32[1] |
693 		a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
694 #endif
695 }
696 
697 /*
698  * Note that we must __force cast these to unsigned long to make sparse happy,
699  * since all of the endian-annotated types are fixed size regardless of arch.
700  */
701 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
702 {
703 	return (
704 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
705 		*(unsigned long *)a |
706 #else
707 		(__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
708 #endif
709 		(__force unsigned long)(a->s6_addr32[2] ^
710 					cpu_to_be32(0x0000ffff))) == 0UL;
711 }
712 
713 static inline bool ipv6_addr_v4mapped_loopback(const struct in6_addr *a)
714 {
715 	return ipv6_addr_v4mapped(a) && ipv4_is_loopback(a->s6_addr32[3]);
716 }
717 
718 static inline u32 ipv6_portaddr_hash(const struct net *net,
719 				     const struct in6_addr *addr6,
720 				     unsigned int port)
721 {
722 	unsigned int hash, mix = net_hash_mix(net);
723 
724 	if (ipv6_addr_any(addr6))
725 		hash = jhash_1word(0, mix);
726 	else if (ipv6_addr_v4mapped(addr6))
727 		hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
728 	else
729 		hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
730 
731 	return hash ^ port;
732 }
733 
734 /*
735  * Check for a RFC 4843 ORCHID address
736  * (Overlay Routable Cryptographic Hash Identifiers)
737  */
738 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
739 {
740 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
741 }
742 
743 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
744 {
745 	return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
746 }
747 
748 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
749 					  struct in6_addr *v4mapped)
750 {
751 	ipv6_addr_set(v4mapped,
752 			0, 0,
753 			htonl(0x0000FFFF),
754 			addr);
755 }
756 
757 /*
758  * find the first different bit between two addresses
759  * length of address must be a multiple of 32bits
760  */
761 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
762 {
763 	const __be32 *a1 = token1, *a2 = token2;
764 	int i;
765 
766 	addrlen >>= 2;
767 
768 	for (i = 0; i < addrlen; i++) {
769 		__be32 xb = a1[i] ^ a2[i];
770 		if (xb)
771 			return i * 32 + 31 - __fls(ntohl(xb));
772 	}
773 
774 	/*
775 	 *	we should *never* get to this point since that
776 	 *	would mean the addrs are equal
777 	 *
778 	 *	However, we do get to it 8) And exacly, when
779 	 *	addresses are equal 8)
780 	 *
781 	 *	ip route add 1111::/128 via ...
782 	 *	ip route add 1111::/64 via ...
783 	 *	and we are here.
784 	 *
785 	 *	Ideally, this function should stop comparison
786 	 *	at prefix length. It does not, but it is still OK,
787 	 *	if returned value is greater than prefix length.
788 	 *					--ANK (980803)
789 	 */
790 	return addrlen << 5;
791 }
792 
793 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
794 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
795 {
796 	const __be64 *a1 = token1, *a2 = token2;
797 	int i;
798 
799 	addrlen >>= 3;
800 
801 	for (i = 0; i < addrlen; i++) {
802 		__be64 xb = a1[i] ^ a2[i];
803 		if (xb)
804 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
805 	}
806 
807 	return addrlen << 6;
808 }
809 #endif
810 
811 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
812 {
813 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
814 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
815 		return __ipv6_addr_diff64(token1, token2, addrlen);
816 #endif
817 	return __ipv6_addr_diff32(token1, token2, addrlen);
818 }
819 
820 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
821 {
822 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
823 }
824 
825 __be32 ipv6_select_ident(struct net *net,
826 			 const struct in6_addr *daddr,
827 			 const struct in6_addr *saddr);
828 __be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
829 
830 int ip6_dst_hoplimit(struct dst_entry *dst);
831 
832 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
833 				      struct dst_entry *dst)
834 {
835 	int hlimit;
836 
837 	if (ipv6_addr_is_multicast(&fl6->daddr))
838 		hlimit = np->mcast_hops;
839 	else
840 		hlimit = np->hop_limit;
841 	if (hlimit < 0)
842 		hlimit = ip6_dst_hoplimit(dst);
843 	return hlimit;
844 }
845 
846 /* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
847  * Equivalent to :	flow->v6addrs.src = iph->saddr;
848  *			flow->v6addrs.dst = iph->daddr;
849  */
850 static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
851 					    const struct ipv6hdr *iph)
852 {
853 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
854 		     offsetof(typeof(flow->addrs), v6addrs.src) +
855 		     sizeof(flow->addrs.v6addrs.src));
856 	memcpy(&flow->addrs.v6addrs, &iph->saddr, sizeof(flow->addrs.v6addrs));
857 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
858 }
859 
860 #if IS_ENABLED(CONFIG_IPV6)
861 
862 static inline bool ipv6_can_nonlocal_bind(struct net *net,
863 					  struct inet_sock *inet)
864 {
865 	return net->ipv6.sysctl.ip_nonlocal_bind ||
866 		inet->freebind || inet->transparent;
867 }
868 
869 /* Sysctl settings for net ipv6.auto_flowlabels */
870 #define IP6_AUTO_FLOW_LABEL_OFF		0
871 #define IP6_AUTO_FLOW_LABEL_OPTOUT	1
872 #define IP6_AUTO_FLOW_LABEL_OPTIN	2
873 #define IP6_AUTO_FLOW_LABEL_FORCED	3
874 
875 #define IP6_AUTO_FLOW_LABEL_MAX		IP6_AUTO_FLOW_LABEL_FORCED
876 
877 #define IP6_DEFAULT_AUTO_FLOW_LABELS	IP6_AUTO_FLOW_LABEL_OPTOUT
878 
879 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
880 					__be32 flowlabel, bool autolabel,
881 					struct flowi6 *fl6)
882 {
883 	u32 hash;
884 
885 	/* @flowlabel may include more than a flow label, eg, the traffic class.
886 	 * Here we want only the flow label value.
887 	 */
888 	flowlabel &= IPV6_FLOWLABEL_MASK;
889 
890 	if (flowlabel ||
891 	    net->ipv6.sysctl.auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF ||
892 	    (!autolabel &&
893 	     net->ipv6.sysctl.auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED))
894 		return flowlabel;
895 
896 	hash = skb_get_hash_flowi6(skb, fl6);
897 
898 	/* Since this is being sent on the wire obfuscate hash a bit
899 	 * to minimize possbility that any useful information to an
900 	 * attacker is leaked. Only lower 20 bits are relevant.
901 	 */
902 	hash = rol32(hash, 16);
903 
904 	flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
905 
906 	if (net->ipv6.sysctl.flowlabel_state_ranges)
907 		flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
908 
909 	return flowlabel;
910 }
911 
912 static inline int ip6_default_np_autolabel(struct net *net)
913 {
914 	switch (net->ipv6.sysctl.auto_flowlabels) {
915 	case IP6_AUTO_FLOW_LABEL_OFF:
916 	case IP6_AUTO_FLOW_LABEL_OPTIN:
917 	default:
918 		return 0;
919 	case IP6_AUTO_FLOW_LABEL_OPTOUT:
920 	case IP6_AUTO_FLOW_LABEL_FORCED:
921 		return 1;
922 	}
923 }
924 #else
925 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
926 					__be32 flowlabel, bool autolabel,
927 					struct flowi6 *fl6)
928 {
929 	return flowlabel;
930 }
931 static inline int ip6_default_np_autolabel(struct net *net)
932 {
933 	return 0;
934 }
935 #endif
936 
937 #if IS_ENABLED(CONFIG_IPV6)
938 static inline int ip6_multipath_hash_policy(const struct net *net)
939 {
940 	return net->ipv6.sysctl.multipath_hash_policy;
941 }
942 static inline u32 ip6_multipath_hash_fields(const struct net *net)
943 {
944 	return net->ipv6.sysctl.multipath_hash_fields;
945 }
946 #else
947 static inline int ip6_multipath_hash_policy(const struct net *net)
948 {
949 	return 0;
950 }
951 static inline u32 ip6_multipath_hash_fields(const struct net *net)
952 {
953 	return 0;
954 }
955 #endif
956 
957 /*
958  *	Header manipulation
959  */
960 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
961 				__be32 flowlabel)
962 {
963 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
964 }
965 
966 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
967 {
968 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
969 }
970 
971 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
972 {
973 	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
974 }
975 
976 static inline u8 ip6_tclass(__be32 flowinfo)
977 {
978 	return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
979 }
980 
981 static inline dscp_t ip6_dscp(__be32 flowinfo)
982 {
983 	return inet_dsfield_to_dscp(ip6_tclass(flowinfo));
984 }
985 
986 static inline __be32 ip6_make_flowinfo(unsigned int tclass, __be32 flowlabel)
987 {
988 	return htonl(tclass << IPV6_TCLASS_SHIFT) | flowlabel;
989 }
990 
991 static inline __be32 flowi6_get_flowlabel(const struct flowi6 *fl6)
992 {
993 	return fl6->flowlabel & IPV6_FLOWLABEL_MASK;
994 }
995 
996 /*
997  *	Prototypes exported by ipv6
998  */
999 
1000 /*
1001  *	rcv function (called from netdevice level)
1002  */
1003 
1004 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
1005 	     struct packet_type *pt, struct net_device *orig_dev);
1006 void ipv6_list_rcv(struct list_head *head, struct packet_type *pt,
1007 		   struct net_device *orig_dev);
1008 
1009 int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
1010 
1011 /*
1012  *	upper-layer output functions
1013  */
1014 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
1015 	     __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority);
1016 
1017 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
1018 
1019 int ip6_append_data(struct sock *sk,
1020 		    int getfrag(void *from, char *to, int offset, int len,
1021 				int odd, struct sk_buff *skb),
1022 		    void *from, int length, int transhdrlen,
1023 		    struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1024 		    struct rt6_info *rt, unsigned int flags);
1025 
1026 int ip6_push_pending_frames(struct sock *sk);
1027 
1028 void ip6_flush_pending_frames(struct sock *sk);
1029 
1030 int ip6_send_skb(struct sk_buff *skb);
1031 
1032 struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
1033 			       struct inet_cork_full *cork,
1034 			       struct inet6_cork *v6_cork);
1035 struct sk_buff *ip6_make_skb(struct sock *sk,
1036 			     int getfrag(void *from, char *to, int offset,
1037 					 int len, int odd, struct sk_buff *skb),
1038 			     void *from, int length, int transhdrlen,
1039 			     struct ipcm6_cookie *ipc6,
1040 			     struct rt6_info *rt, unsigned int flags,
1041 			     struct inet_cork_full *cork);
1042 
1043 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
1044 {
1045 	return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
1046 			      &inet6_sk(sk)->cork);
1047 }
1048 
1049 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1050 		   struct flowi6 *fl6);
1051 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6,
1052 				      const struct in6_addr *final_dst);
1053 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1054 					 const struct in6_addr *final_dst,
1055 					 bool connected);
1056 struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb,
1057 					struct net_device *dev,
1058 					struct net *net, struct socket *sock,
1059 					struct in6_addr *saddr,
1060 					const struct ip_tunnel_info *info,
1061 					u8 protocol, bool use_cache);
1062 struct dst_entry *ip6_blackhole_route(struct net *net,
1063 				      struct dst_entry *orig_dst);
1064 
1065 /*
1066  *	skb processing functions
1067  */
1068 
1069 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb);
1070 int ip6_forward(struct sk_buff *skb);
1071 int ip6_input(struct sk_buff *skb);
1072 int ip6_mc_input(struct sk_buff *skb);
1073 void ip6_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int nexthdr,
1074 			      bool have_final);
1075 
1076 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
1077 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
1078 
1079 /*
1080  *	Extension header (options) processing
1081  */
1082 
1083 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1084 			  u8 *proto, struct in6_addr **daddr_p,
1085 			  struct in6_addr *saddr);
1086 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1087 			 u8 *proto);
1088 
1089 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
1090 		     __be16 *frag_offp);
1091 
1092 bool ipv6_ext_hdr(u8 nexthdr);
1093 
1094 enum {
1095 	IP6_FH_F_FRAG		= (1 << 0),
1096 	IP6_FH_F_AUTH		= (1 << 1),
1097 	IP6_FH_F_SKIP_RH	= (1 << 2),
1098 };
1099 
1100 /* find specified header and get offset to it */
1101 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
1102 		  unsigned short *fragoff, int *fragflg);
1103 
1104 int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type);
1105 
1106 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1107 				const struct ipv6_txoptions *opt,
1108 				struct in6_addr *orig);
1109 
1110 /*
1111  *	socket options (ipv6_sockglue.c)
1112  */
1113 DECLARE_STATIC_KEY_FALSE(ip6_min_hopcount);
1114 
1115 int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1116 		    unsigned int optlen);
1117 int ipv6_getsockopt(struct sock *sk, int level, int optname,
1118 		    char __user *optval, int __user *optlen);
1119 
1120 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *addr,
1121 			   int addr_len);
1122 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
1123 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
1124 				 int addr_len);
1125 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr);
1126 void ip6_datagram_release_cb(struct sock *sk);
1127 
1128 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
1129 		    int *addr_len);
1130 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
1131 		     int *addr_len);
1132 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
1133 		     u32 info, u8 *payload);
1134 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
1135 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
1136 
1137 int inet6_release(struct socket *sock);
1138 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
1139 int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
1140 		  int peer);
1141 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
1142 int inet6_compat_ioctl(struct socket *sock, unsigned int cmd,
1143 		unsigned long arg);
1144 
1145 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
1146 			      struct sock *sk);
1147 int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size);
1148 int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1149 		  int flags);
1150 
1151 /*
1152  * reassembly.c
1153  */
1154 extern const struct proto_ops inet6_stream_ops;
1155 extern const struct proto_ops inet6_dgram_ops;
1156 extern const struct proto_ops inet6_sockraw_ops;
1157 
1158 struct group_source_req;
1159 struct group_filter;
1160 
1161 int ip6_mc_source(int add, int omode, struct sock *sk,
1162 		  struct group_source_req *pgsr);
1163 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf,
1164 		  struct sockaddr_storage *list);
1165 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
1166 		  struct sockaddr_storage __user *p);
1167 
1168 #ifdef CONFIG_PROC_FS
1169 int ac6_proc_init(struct net *net);
1170 void ac6_proc_exit(struct net *net);
1171 int raw6_proc_init(void);
1172 void raw6_proc_exit(void);
1173 int tcp6_proc_init(struct net *net);
1174 void tcp6_proc_exit(struct net *net);
1175 int udp6_proc_init(struct net *net);
1176 void udp6_proc_exit(struct net *net);
1177 int udplite6_proc_init(void);
1178 void udplite6_proc_exit(void);
1179 int ipv6_misc_proc_init(void);
1180 void ipv6_misc_proc_exit(void);
1181 int snmp6_register_dev(struct inet6_dev *idev);
1182 int snmp6_unregister_dev(struct inet6_dev *idev);
1183 
1184 #else
1185 static inline int ac6_proc_init(struct net *net) { return 0; }
1186 static inline void ac6_proc_exit(struct net *net) { }
1187 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
1188 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
1189 #endif
1190 
1191 #ifdef CONFIG_SYSCTL
1192 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
1193 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
1194 int ipv6_sysctl_register(void);
1195 void ipv6_sysctl_unregister(void);
1196 #endif
1197 
1198 int ipv6_sock_mc_join(struct sock *sk, int ifindex,
1199 		      const struct in6_addr *addr);
1200 int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,
1201 			  const struct in6_addr *addr, unsigned int mode);
1202 int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
1203 		      const struct in6_addr *addr);
1204 
1205 static inline int ip6_sock_set_v6only(struct sock *sk)
1206 {
1207 	if (inet_sk(sk)->inet_num)
1208 		return -EINVAL;
1209 	lock_sock(sk);
1210 	sk->sk_ipv6only = true;
1211 	release_sock(sk);
1212 	return 0;
1213 }
1214 
1215 static inline void ip6_sock_set_recverr(struct sock *sk)
1216 {
1217 	lock_sock(sk);
1218 	inet6_sk(sk)->recverr = true;
1219 	release_sock(sk);
1220 }
1221 
1222 static inline int __ip6_sock_set_addr_preferences(struct sock *sk, int val)
1223 {
1224 	unsigned int pref = 0;
1225 	unsigned int prefmask = ~0;
1226 
1227 	/* check PUBLIC/TMP/PUBTMP_DEFAULT conflicts */
1228 	switch (val & (IPV6_PREFER_SRC_PUBLIC |
1229 		       IPV6_PREFER_SRC_TMP |
1230 		       IPV6_PREFER_SRC_PUBTMP_DEFAULT)) {
1231 	case IPV6_PREFER_SRC_PUBLIC:
1232 		pref |= IPV6_PREFER_SRC_PUBLIC;
1233 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1234 			      IPV6_PREFER_SRC_TMP);
1235 		break;
1236 	case IPV6_PREFER_SRC_TMP:
1237 		pref |= IPV6_PREFER_SRC_TMP;
1238 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1239 			      IPV6_PREFER_SRC_TMP);
1240 		break;
1241 	case IPV6_PREFER_SRC_PUBTMP_DEFAULT:
1242 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1243 			      IPV6_PREFER_SRC_TMP);
1244 		break;
1245 	case 0:
1246 		break;
1247 	default:
1248 		return -EINVAL;
1249 	}
1250 
1251 	/* check HOME/COA conflicts */
1252 	switch (val & (IPV6_PREFER_SRC_HOME | IPV6_PREFER_SRC_COA)) {
1253 	case IPV6_PREFER_SRC_HOME:
1254 		prefmask &= ~IPV6_PREFER_SRC_COA;
1255 		break;
1256 	case IPV6_PREFER_SRC_COA:
1257 		pref |= IPV6_PREFER_SRC_COA;
1258 		break;
1259 	case 0:
1260 		break;
1261 	default:
1262 		return -EINVAL;
1263 	}
1264 
1265 	/* check CGA/NONCGA conflicts */
1266 	switch (val & (IPV6_PREFER_SRC_CGA|IPV6_PREFER_SRC_NONCGA)) {
1267 	case IPV6_PREFER_SRC_CGA:
1268 	case IPV6_PREFER_SRC_NONCGA:
1269 	case 0:
1270 		break;
1271 	default:
1272 		return -EINVAL;
1273 	}
1274 
1275 	inet6_sk(sk)->srcprefs = (inet6_sk(sk)->srcprefs & prefmask) | pref;
1276 	return 0;
1277 }
1278 
1279 static inline int ip6_sock_set_addr_preferences(struct sock *sk, bool val)
1280 {
1281 	int ret;
1282 
1283 	lock_sock(sk);
1284 	ret = __ip6_sock_set_addr_preferences(sk, val);
1285 	release_sock(sk);
1286 	return ret;
1287 }
1288 
1289 static inline void ip6_sock_set_recvpktinfo(struct sock *sk)
1290 {
1291 	lock_sock(sk);
1292 	inet6_sk(sk)->rxopt.bits.rxinfo = true;
1293 	release_sock(sk);
1294 }
1295 
1296 #endif /* _NET_IPV6_H */
1297