xref: /openbmc/linux/include/net/ipv6.h (revision a48acad7)
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 /*
155  * Jumbo payload option, as described in RFC 2675 2.
156  */
157 struct hop_jumbo_hdr {
158 	u8	nexthdr;
159 	u8	hdrlen;
160 	u8	tlv_type;	/* IPV6_TLV_JUMBO, 0xC2 */
161 	u8	tlv_len;	/* 4 */
162 	__be32	jumbo_payload_len;
163 };
164 
165 #define	IP6_MF		0x0001
166 #define	IP6_OFFSET	0xFFF8
167 
168 struct ip6_fraglist_iter {
169 	struct ipv6hdr	*tmp_hdr;
170 	struct sk_buff	*frag;
171 	int		offset;
172 	unsigned int	hlen;
173 	__be32		frag_id;
174 	u8		nexthdr;
175 };
176 
177 int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr,
178 		      u8 nexthdr, __be32 frag_id,
179 		      struct ip6_fraglist_iter *iter);
180 void ip6_fraglist_prepare(struct sk_buff *skb, struct ip6_fraglist_iter *iter);
181 
182 static inline struct sk_buff *ip6_fraglist_next(struct ip6_fraglist_iter *iter)
183 {
184 	struct sk_buff *skb = iter->frag;
185 
186 	iter->frag = skb->next;
187 	skb_mark_not_on_list(skb);
188 
189 	return skb;
190 }
191 
192 struct ip6_frag_state {
193 	u8		*prevhdr;
194 	unsigned int	hlen;
195 	unsigned int	mtu;
196 	unsigned int	left;
197 	int		offset;
198 	int		ptr;
199 	int		hroom;
200 	int		troom;
201 	__be32		frag_id;
202 	u8		nexthdr;
203 };
204 
205 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu,
206 		   unsigned short needed_tailroom, int hdr_room, u8 *prevhdr,
207 		   u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state);
208 struct sk_buff *ip6_frag_next(struct sk_buff *skb,
209 			      struct ip6_frag_state *state);
210 
211 #define IP6_REPLY_MARK(net, mark) \
212 	((net)->ipv6.sysctl.fwmark_reflect ? (mark) : 0)
213 
214 #include <net/sock.h>
215 
216 /* sysctls */
217 extern int sysctl_mld_max_msf;
218 extern int sysctl_mld_qrv;
219 
220 #define _DEVINC(net, statname, mod, idev, field)			\
221 ({									\
222 	struct inet6_dev *_idev = (idev);				\
223 	if (likely(_idev != NULL))					\
224 		mod##SNMP_INC_STATS64((_idev)->stats.statname, (field));\
225 	mod##SNMP_INC_STATS64((net)->mib.statname##_statistics, (field));\
226 })
227 
228 /* per device counters are atomic_long_t */
229 #define _DEVINCATOMIC(net, statname, mod, idev, field)			\
230 ({									\
231 	struct inet6_dev *_idev = (idev);				\
232 	if (likely(_idev != NULL))					\
233 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
234 	mod##SNMP_INC_STATS((net)->mib.statname##_statistics, (field));\
235 })
236 
237 /* per device and per net counters are atomic_long_t */
238 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)		\
239 ({									\
240 	struct inet6_dev *_idev = (idev);				\
241 	if (likely(_idev != NULL))					\
242 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
243 	SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
244 })
245 
246 #define _DEVADD(net, statname, mod, idev, field, val)			\
247 ({									\
248 	struct inet6_dev *_idev = (idev);				\
249 	if (likely(_idev != NULL))					\
250 		mod##SNMP_ADD_STATS((_idev)->stats.statname, (field), (val)); \
251 	mod##SNMP_ADD_STATS((net)->mib.statname##_statistics, (field), (val));\
252 })
253 
254 #define _DEVUPD(net, statname, mod, idev, field, val)			\
255 ({									\
256 	struct inet6_dev *_idev = (idev);				\
257 	if (likely(_idev != NULL))					\
258 		mod##SNMP_UPD_PO_STATS((_idev)->stats.statname, field, (val)); \
259 	mod##SNMP_UPD_PO_STATS((net)->mib.statname##_statistics, field, (val));\
260 })
261 
262 /* MIBs */
263 
264 #define IP6_INC_STATS(net, idev,field)		\
265 		_DEVINC(net, ipv6, , idev, field)
266 #define __IP6_INC_STATS(net, idev,field)	\
267 		_DEVINC(net, ipv6, __, idev, field)
268 #define IP6_ADD_STATS(net, idev,field,val)	\
269 		_DEVADD(net, ipv6, , idev, field, val)
270 #define __IP6_ADD_STATS(net, idev,field,val)	\
271 		_DEVADD(net, ipv6, __, idev, field, val)
272 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
273 		_DEVUPD(net, ipv6, , idev, field, val)
274 #define __IP6_UPD_PO_STATS(net, idev,field,val)   \
275 		_DEVUPD(net, ipv6, __, idev, field, val)
276 #define ICMP6_INC_STATS(net, idev, field)	\
277 		_DEVINCATOMIC(net, icmpv6, , idev, field)
278 #define __ICMP6_INC_STATS(net, idev, field)	\
279 		_DEVINCATOMIC(net, icmpv6, __, idev, field)
280 
281 #define ICMP6MSGOUT_INC_STATS(net, idev, field)		\
282 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
283 #define ICMP6MSGIN_INC_STATS(net, idev, field)	\
284 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
285 
286 struct ip6_ra_chain {
287 	struct ip6_ra_chain	*next;
288 	struct sock		*sk;
289 	int			sel;
290 	void			(*destructor)(struct sock *);
291 };
292 
293 extern struct ip6_ra_chain	*ip6_ra_chain;
294 extern rwlock_t ip6_ra_lock;
295 
296 /*
297    This structure is prepared by protocol, when parsing
298    ancillary data and passed to IPv6.
299  */
300 
301 struct ipv6_txoptions {
302 	refcount_t		refcnt;
303 	/* Length of this structure */
304 	int			tot_len;
305 
306 	/* length of extension headers   */
307 
308 	__u16			opt_flen;	/* after fragment hdr */
309 	__u16			opt_nflen;	/* before fragment hdr */
310 
311 	struct ipv6_opt_hdr	*hopopt;
312 	struct ipv6_opt_hdr	*dst0opt;
313 	struct ipv6_rt_hdr	*srcrt;	/* Routing Header */
314 	struct ipv6_opt_hdr	*dst1opt;
315 	struct rcu_head		rcu;
316 	/* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
317 };
318 
319 /* flowlabel_reflect sysctl values */
320 enum flowlabel_reflect {
321 	FLOWLABEL_REFLECT_ESTABLISHED		= 1,
322 	FLOWLABEL_REFLECT_TCP_RESET		= 2,
323 	FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES	= 4,
324 };
325 
326 struct ip6_flowlabel {
327 	struct ip6_flowlabel __rcu *next;
328 	__be32			label;
329 	atomic_t		users;
330 	struct in6_addr		dst;
331 	struct ipv6_txoptions	*opt;
332 	unsigned long		linger;
333 	struct rcu_head		rcu;
334 	u8			share;
335 	union {
336 		struct pid *pid;
337 		kuid_t uid;
338 	} owner;
339 	unsigned long		lastuse;
340 	unsigned long		expires;
341 	struct net		*fl_net;
342 };
343 
344 #define IPV6_FLOWINFO_MASK		cpu_to_be32(0x0FFFFFFF)
345 #define IPV6_FLOWLABEL_MASK		cpu_to_be32(0x000FFFFF)
346 #define IPV6_FLOWLABEL_STATELESS_FLAG	cpu_to_be32(0x00080000)
347 
348 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
349 #define IPV6_TCLASS_SHIFT	20
350 
351 struct ipv6_fl_socklist {
352 	struct ipv6_fl_socklist	__rcu	*next;
353 	struct ip6_flowlabel		*fl;
354 	struct rcu_head			rcu;
355 };
356 
357 struct ipcm6_cookie {
358 	struct sockcm_cookie sockc;
359 	__s16 hlimit;
360 	__s16 tclass;
361 	__u16 gso_size;
362 	__s8  dontfrag;
363 	struct ipv6_txoptions *opt;
364 };
365 
366 static inline void ipcm6_init(struct ipcm6_cookie *ipc6)
367 {
368 	*ipc6 = (struct ipcm6_cookie) {
369 		.hlimit = -1,
370 		.tclass = -1,
371 		.dontfrag = -1,
372 	};
373 }
374 
375 static inline void ipcm6_init_sk(struct ipcm6_cookie *ipc6,
376 				 const struct ipv6_pinfo *np)
377 {
378 	*ipc6 = (struct ipcm6_cookie) {
379 		.hlimit = -1,
380 		.tclass = np->tclass,
381 		.dontfrag = np->dontfrag,
382 	};
383 }
384 
385 static inline struct ipv6_txoptions *txopt_get(const struct ipv6_pinfo *np)
386 {
387 	struct ipv6_txoptions *opt;
388 
389 	rcu_read_lock();
390 	opt = rcu_dereference(np->opt);
391 	if (opt) {
392 		if (!refcount_inc_not_zero(&opt->refcnt))
393 			opt = NULL;
394 		else
395 			opt = rcu_pointer_handoff(opt);
396 	}
397 	rcu_read_unlock();
398 	return opt;
399 }
400 
401 static inline void txopt_put(struct ipv6_txoptions *opt)
402 {
403 	if (opt && refcount_dec_and_test(&opt->refcnt))
404 		kfree_rcu(opt, rcu);
405 }
406 
407 #if IS_ENABLED(CONFIG_IPV6)
408 struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label);
409 
410 extern struct static_key_false_deferred ipv6_flowlabel_exclusive;
411 static inline struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk,
412 						    __be32 label)
413 {
414 	if (static_branch_unlikely(&ipv6_flowlabel_exclusive.key) &&
415 	    READ_ONCE(sock_net(sk)->ipv6.flowlabel_has_excl))
416 		return __fl6_sock_lookup(sk, label) ? : ERR_PTR(-ENOENT);
417 
418 	return NULL;
419 }
420 #endif
421 
422 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
423 					 struct ip6_flowlabel *fl,
424 					 struct ipv6_txoptions *fopt);
425 void fl6_free_socklist(struct sock *sk);
426 int ipv6_flowlabel_opt(struct sock *sk, sockptr_t optval, int optlen);
427 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
428 			   int flags);
429 int ip6_flowlabel_init(void);
430 void ip6_flowlabel_cleanup(void);
431 bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np);
432 
433 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
434 {
435 	if (fl)
436 		atomic_dec(&fl->users);
437 }
438 
439 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
440 
441 void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
442 				struct icmp6hdr *thdr, int len);
443 
444 int ip6_ra_control(struct sock *sk, int sel);
445 
446 int ipv6_parse_hopopts(struct sk_buff *skb);
447 
448 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
449 					struct ipv6_txoptions *opt);
450 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
451 					  struct ipv6_txoptions *opt,
452 					  int newtype,
453 					  struct ipv6_opt_hdr *newopt);
454 struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space,
455 					    struct ipv6_txoptions *opt);
456 
457 static inline struct ipv6_txoptions *
458 ipv6_fixup_options(struct ipv6_txoptions *opt_space, struct ipv6_txoptions *opt)
459 {
460 	if (!opt)
461 		return NULL;
462 	return __ipv6_fixup_options(opt_space, opt);
463 }
464 
465 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
466 		       const struct inet6_skb_parm *opt);
467 struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
468 					   struct ipv6_txoptions *opt);
469 
470 /* This helper is specialized for BIG TCP needs.
471  * It assumes the hop_jumbo_hdr will immediately follow the IPV6 header.
472  * It assumes headers are already in skb->head.
473  * Returns 0, or IPPROTO_TCP if a BIG TCP packet is there.
474  */
475 static inline int ipv6_has_hopopt_jumbo(const struct sk_buff *skb)
476 {
477 	const struct hop_jumbo_hdr *jhdr;
478 	const struct ipv6hdr *nhdr;
479 
480 	if (likely(skb->len <= GRO_LEGACY_MAX_SIZE))
481 		return 0;
482 
483 	if (skb->protocol != htons(ETH_P_IPV6))
484 		return 0;
485 
486 	if (skb_network_offset(skb) +
487 	    sizeof(struct ipv6hdr) +
488 	    sizeof(struct hop_jumbo_hdr) > skb_headlen(skb))
489 		return 0;
490 
491 	nhdr = ipv6_hdr(skb);
492 
493 	if (nhdr->nexthdr != NEXTHDR_HOP)
494 		return 0;
495 
496 	jhdr = (const struct hop_jumbo_hdr *) (nhdr + 1);
497 	if (jhdr->tlv_type != IPV6_TLV_JUMBO || jhdr->hdrlen != 0 ||
498 	    jhdr->nexthdr != IPPROTO_TCP)
499 		return 0;
500 	return jhdr->nexthdr;
501 }
502 
503 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
504 {
505 	/* If forwarding is enabled, RA are not accepted unless the special
506 	 * hybrid mode (accept_ra=2) is enabled.
507 	 */
508 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
509 	    idev->cnf.accept_ra;
510 }
511 
512 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
513 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
514 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
515 
516 int __ipv6_addr_type(const struct in6_addr *addr);
517 static inline int ipv6_addr_type(const struct in6_addr *addr)
518 {
519 	return __ipv6_addr_type(addr) & 0xffff;
520 }
521 
522 static inline int ipv6_addr_scope(const struct in6_addr *addr)
523 {
524 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
525 }
526 
527 static inline int __ipv6_addr_src_scope(int type)
528 {
529 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
530 }
531 
532 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
533 {
534 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
535 }
536 
537 static inline bool __ipv6_addr_needs_scope_id(int type)
538 {
539 	return type & IPV6_ADDR_LINKLOCAL ||
540 	       (type & IPV6_ADDR_MULTICAST &&
541 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
542 }
543 
544 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
545 {
546 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
547 }
548 
549 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
550 {
551 	return memcmp(a1, a2, sizeof(struct in6_addr));
552 }
553 
554 static inline bool
555 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
556 		     const struct in6_addr *a2)
557 {
558 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
559 	const unsigned long *ul1 = (const unsigned long *)a1;
560 	const unsigned long *ulm = (const unsigned long *)m;
561 	const unsigned long *ul2 = (const unsigned long *)a2;
562 
563 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
564 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
565 #else
566 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
567 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
568 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
569 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
570 #endif
571 }
572 
573 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
574 				    const struct in6_addr *addr,
575 				    int plen)
576 {
577 	/* caller must guarantee 0 <= plen <= 128 */
578 	int o = plen >> 3,
579 	    b = plen & 0x7;
580 
581 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
582 	memcpy(pfx->s6_addr, addr, o);
583 	if (b != 0)
584 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
585 }
586 
587 static inline void ipv6_addr_prefix_copy(struct in6_addr *addr,
588 					 const struct in6_addr *pfx,
589 					 int plen)
590 {
591 	/* caller must guarantee 0 <= plen <= 128 */
592 	int o = plen >> 3,
593 	    b = plen & 0x7;
594 
595 	memcpy(addr->s6_addr, pfx, o);
596 	if (b != 0) {
597 		addr->s6_addr[o] &= ~(0xff00 >> b);
598 		addr->s6_addr[o] |= (pfx->s6_addr[o] & (0xff00 >> b));
599 	}
600 }
601 
602 static inline void __ipv6_addr_set_half(__be32 *addr,
603 					__be32 wh, __be32 wl)
604 {
605 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
606 #if defined(__BIG_ENDIAN)
607 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
608 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
609 		return;
610 	}
611 #elif defined(__LITTLE_ENDIAN)
612 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
613 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
614 		return;
615 	}
616 #endif
617 #endif
618 	addr[0] = wh;
619 	addr[1] = wl;
620 }
621 
622 static inline void ipv6_addr_set(struct in6_addr *addr,
623 				     __be32 w1, __be32 w2,
624 				     __be32 w3, __be32 w4)
625 {
626 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
627 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
628 }
629 
630 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
631 				   const struct in6_addr *a2)
632 {
633 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
634 	const unsigned long *ul1 = (const unsigned long *)a1;
635 	const unsigned long *ul2 = (const unsigned long *)a2;
636 
637 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
638 #else
639 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
640 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
641 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
642 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
643 #endif
644 }
645 
646 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
647 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
648 					      const __be64 *a2,
649 					      unsigned int len)
650 {
651 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
652 		return false;
653 	return true;
654 }
655 
656 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
657 				     const struct in6_addr *addr2,
658 				     unsigned int prefixlen)
659 {
660 	const __be64 *a1 = (const __be64 *)addr1;
661 	const __be64 *a2 = (const __be64 *)addr2;
662 
663 	if (prefixlen >= 64) {
664 		if (a1[0] ^ a2[0])
665 			return false;
666 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
667 	}
668 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
669 }
670 #else
671 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
672 				     const struct in6_addr *addr2,
673 				     unsigned int prefixlen)
674 {
675 	const __be32 *a1 = addr1->s6_addr32;
676 	const __be32 *a2 = addr2->s6_addr32;
677 	unsigned int pdw, pbi;
678 
679 	/* check complete u32 in prefix */
680 	pdw = prefixlen >> 5;
681 	if (pdw && memcmp(a1, a2, pdw << 2))
682 		return false;
683 
684 	/* check incomplete u32 in prefix */
685 	pbi = prefixlen & 0x1f;
686 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
687 		return false;
688 
689 	return true;
690 }
691 #endif
692 
693 static inline bool ipv6_addr_any(const struct in6_addr *a)
694 {
695 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
696 	const unsigned long *ul = (const unsigned long *)a;
697 
698 	return (ul[0] | ul[1]) == 0UL;
699 #else
700 	return (a->s6_addr32[0] | a->s6_addr32[1] |
701 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
702 #endif
703 }
704 
705 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
706 {
707 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
708 	const unsigned long *ul = (const unsigned long *)a;
709 	unsigned long x = ul[0] ^ ul[1];
710 
711 	return (u32)(x ^ (x >> 32));
712 #else
713 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
714 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
715 #endif
716 }
717 
718 /* more secured version of ipv6_addr_hash() */
719 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
720 {
721 	u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
722 
723 	return jhash_3words(v,
724 			    (__force u32)a->s6_addr32[2],
725 			    (__force u32)a->s6_addr32[3],
726 			    initval);
727 }
728 
729 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
730 {
731 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
732 	const __be64 *be = (const __be64 *)a;
733 
734 	return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
735 #else
736 	return (a->s6_addr32[0] | a->s6_addr32[1] |
737 		a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
738 #endif
739 }
740 
741 /*
742  * Note that we must __force cast these to unsigned long to make sparse happy,
743  * since all of the endian-annotated types are fixed size regardless of arch.
744  */
745 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
746 {
747 	return (
748 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
749 		*(unsigned long *)a |
750 #else
751 		(__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
752 #endif
753 		(__force unsigned long)(a->s6_addr32[2] ^
754 					cpu_to_be32(0x0000ffff))) == 0UL;
755 }
756 
757 static inline bool ipv6_addr_v4mapped_loopback(const struct in6_addr *a)
758 {
759 	return ipv6_addr_v4mapped(a) && ipv4_is_loopback(a->s6_addr32[3]);
760 }
761 
762 static inline u32 ipv6_portaddr_hash(const struct net *net,
763 				     const struct in6_addr *addr6,
764 				     unsigned int port)
765 {
766 	unsigned int hash, mix = net_hash_mix(net);
767 
768 	if (ipv6_addr_any(addr6))
769 		hash = jhash_1word(0, mix);
770 	else if (ipv6_addr_v4mapped(addr6))
771 		hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
772 	else
773 		hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
774 
775 	return hash ^ port;
776 }
777 
778 /*
779  * Check for a RFC 4843 ORCHID address
780  * (Overlay Routable Cryptographic Hash Identifiers)
781  */
782 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
783 {
784 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
785 }
786 
787 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
788 {
789 	return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
790 }
791 
792 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
793 					  struct in6_addr *v4mapped)
794 {
795 	ipv6_addr_set(v4mapped,
796 			0, 0,
797 			htonl(0x0000FFFF),
798 			addr);
799 }
800 
801 /*
802  * find the first different bit between two addresses
803  * length of address must be a multiple of 32bits
804  */
805 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
806 {
807 	const __be32 *a1 = token1, *a2 = token2;
808 	int i;
809 
810 	addrlen >>= 2;
811 
812 	for (i = 0; i < addrlen; i++) {
813 		__be32 xb = a1[i] ^ a2[i];
814 		if (xb)
815 			return i * 32 + 31 - __fls(ntohl(xb));
816 	}
817 
818 	/*
819 	 *	we should *never* get to this point since that
820 	 *	would mean the addrs are equal
821 	 *
822 	 *	However, we do get to it 8) And exacly, when
823 	 *	addresses are equal 8)
824 	 *
825 	 *	ip route add 1111::/128 via ...
826 	 *	ip route add 1111::/64 via ...
827 	 *	and we are here.
828 	 *
829 	 *	Ideally, this function should stop comparison
830 	 *	at prefix length. It does not, but it is still OK,
831 	 *	if returned value is greater than prefix length.
832 	 *					--ANK (980803)
833 	 */
834 	return addrlen << 5;
835 }
836 
837 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
838 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
839 {
840 	const __be64 *a1 = token1, *a2 = token2;
841 	int i;
842 
843 	addrlen >>= 3;
844 
845 	for (i = 0; i < addrlen; i++) {
846 		__be64 xb = a1[i] ^ a2[i];
847 		if (xb)
848 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
849 	}
850 
851 	return addrlen << 6;
852 }
853 #endif
854 
855 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
856 {
857 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
858 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
859 		return __ipv6_addr_diff64(token1, token2, addrlen);
860 #endif
861 	return __ipv6_addr_diff32(token1, token2, addrlen);
862 }
863 
864 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
865 {
866 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
867 }
868 
869 __be32 ipv6_select_ident(struct net *net,
870 			 const struct in6_addr *daddr,
871 			 const struct in6_addr *saddr);
872 __be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
873 
874 int ip6_dst_hoplimit(struct dst_entry *dst);
875 
876 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
877 				      struct dst_entry *dst)
878 {
879 	int hlimit;
880 
881 	if (ipv6_addr_is_multicast(&fl6->daddr))
882 		hlimit = np->mcast_hops;
883 	else
884 		hlimit = np->hop_limit;
885 	if (hlimit < 0)
886 		hlimit = ip6_dst_hoplimit(dst);
887 	return hlimit;
888 }
889 
890 /* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
891  * Equivalent to :	flow->v6addrs.src = iph->saddr;
892  *			flow->v6addrs.dst = iph->daddr;
893  */
894 static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
895 					    const struct ipv6hdr *iph)
896 {
897 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
898 		     offsetof(typeof(flow->addrs), v6addrs.src) +
899 		     sizeof(flow->addrs.v6addrs.src));
900 	memcpy(&flow->addrs.v6addrs, &iph->addrs, sizeof(flow->addrs.v6addrs));
901 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
902 }
903 
904 #if IS_ENABLED(CONFIG_IPV6)
905 
906 static inline bool ipv6_can_nonlocal_bind(struct net *net,
907 					  struct inet_sock *inet)
908 {
909 	return net->ipv6.sysctl.ip_nonlocal_bind ||
910 		inet->freebind || inet->transparent;
911 }
912 
913 /* Sysctl settings for net ipv6.auto_flowlabels */
914 #define IP6_AUTO_FLOW_LABEL_OFF		0
915 #define IP6_AUTO_FLOW_LABEL_OPTOUT	1
916 #define IP6_AUTO_FLOW_LABEL_OPTIN	2
917 #define IP6_AUTO_FLOW_LABEL_FORCED	3
918 
919 #define IP6_AUTO_FLOW_LABEL_MAX		IP6_AUTO_FLOW_LABEL_FORCED
920 
921 #define IP6_DEFAULT_AUTO_FLOW_LABELS	IP6_AUTO_FLOW_LABEL_OPTOUT
922 
923 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
924 					__be32 flowlabel, bool autolabel,
925 					struct flowi6 *fl6)
926 {
927 	u32 hash;
928 
929 	/* @flowlabel may include more than a flow label, eg, the traffic class.
930 	 * Here we want only the flow label value.
931 	 */
932 	flowlabel &= IPV6_FLOWLABEL_MASK;
933 
934 	if (flowlabel ||
935 	    net->ipv6.sysctl.auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF ||
936 	    (!autolabel &&
937 	     net->ipv6.sysctl.auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED))
938 		return flowlabel;
939 
940 	hash = skb_get_hash_flowi6(skb, fl6);
941 
942 	/* Since this is being sent on the wire obfuscate hash a bit
943 	 * to minimize possbility that any useful information to an
944 	 * attacker is leaked. Only lower 20 bits are relevant.
945 	 */
946 	hash = rol32(hash, 16);
947 
948 	flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
949 
950 	if (net->ipv6.sysctl.flowlabel_state_ranges)
951 		flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
952 
953 	return flowlabel;
954 }
955 
956 static inline int ip6_default_np_autolabel(struct net *net)
957 {
958 	switch (net->ipv6.sysctl.auto_flowlabels) {
959 	case IP6_AUTO_FLOW_LABEL_OFF:
960 	case IP6_AUTO_FLOW_LABEL_OPTIN:
961 	default:
962 		return 0;
963 	case IP6_AUTO_FLOW_LABEL_OPTOUT:
964 	case IP6_AUTO_FLOW_LABEL_FORCED:
965 		return 1;
966 	}
967 }
968 #else
969 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
970 					__be32 flowlabel, bool autolabel,
971 					struct flowi6 *fl6)
972 {
973 	return flowlabel;
974 }
975 static inline int ip6_default_np_autolabel(struct net *net)
976 {
977 	return 0;
978 }
979 #endif
980 
981 #if IS_ENABLED(CONFIG_IPV6)
982 static inline int ip6_multipath_hash_policy(const struct net *net)
983 {
984 	return net->ipv6.sysctl.multipath_hash_policy;
985 }
986 static inline u32 ip6_multipath_hash_fields(const struct net *net)
987 {
988 	return net->ipv6.sysctl.multipath_hash_fields;
989 }
990 #else
991 static inline int ip6_multipath_hash_policy(const struct net *net)
992 {
993 	return 0;
994 }
995 static inline u32 ip6_multipath_hash_fields(const struct net *net)
996 {
997 	return 0;
998 }
999 #endif
1000 
1001 /*
1002  *	Header manipulation
1003  */
1004 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
1005 				__be32 flowlabel)
1006 {
1007 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
1008 }
1009 
1010 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
1011 {
1012 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
1013 }
1014 
1015 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
1016 {
1017 	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
1018 }
1019 
1020 static inline u8 ip6_tclass(__be32 flowinfo)
1021 {
1022 	return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
1023 }
1024 
1025 static inline dscp_t ip6_dscp(__be32 flowinfo)
1026 {
1027 	return inet_dsfield_to_dscp(ip6_tclass(flowinfo));
1028 }
1029 
1030 static inline __be32 ip6_make_flowinfo(unsigned int tclass, __be32 flowlabel)
1031 {
1032 	return htonl(tclass << IPV6_TCLASS_SHIFT) | flowlabel;
1033 }
1034 
1035 static inline __be32 flowi6_get_flowlabel(const struct flowi6 *fl6)
1036 {
1037 	return fl6->flowlabel & IPV6_FLOWLABEL_MASK;
1038 }
1039 
1040 /*
1041  *	Prototypes exported by ipv6
1042  */
1043 
1044 /*
1045  *	rcv function (called from netdevice level)
1046  */
1047 
1048 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
1049 	     struct packet_type *pt, struct net_device *orig_dev);
1050 void ipv6_list_rcv(struct list_head *head, struct packet_type *pt,
1051 		   struct net_device *orig_dev);
1052 
1053 int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
1054 
1055 /*
1056  *	upper-layer output functions
1057  */
1058 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
1059 	     __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority);
1060 
1061 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
1062 
1063 int ip6_append_data(struct sock *sk,
1064 		    int getfrag(void *from, char *to, int offset, int len,
1065 				int odd, struct sk_buff *skb),
1066 		    void *from, size_t length, int transhdrlen,
1067 		    struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1068 		    struct rt6_info *rt, unsigned int flags);
1069 
1070 int ip6_push_pending_frames(struct sock *sk);
1071 
1072 void ip6_flush_pending_frames(struct sock *sk);
1073 
1074 int ip6_send_skb(struct sk_buff *skb);
1075 
1076 struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
1077 			       struct inet_cork_full *cork,
1078 			       struct inet6_cork *v6_cork);
1079 struct sk_buff *ip6_make_skb(struct sock *sk,
1080 			     int getfrag(void *from, char *to, int offset,
1081 					 int len, int odd, struct sk_buff *skb),
1082 			     void *from, size_t length, int transhdrlen,
1083 			     struct ipcm6_cookie *ipc6,
1084 			     struct rt6_info *rt, unsigned int flags,
1085 			     struct inet_cork_full *cork);
1086 
1087 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
1088 {
1089 	return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
1090 			      &inet6_sk(sk)->cork);
1091 }
1092 
1093 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1094 		   struct flowi6 *fl6);
1095 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6,
1096 				      const struct in6_addr *final_dst);
1097 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1098 					 const struct in6_addr *final_dst,
1099 					 bool connected);
1100 struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb,
1101 					struct net_device *dev,
1102 					struct net *net, struct socket *sock,
1103 					struct in6_addr *saddr,
1104 					const struct ip_tunnel_info *info,
1105 					u8 protocol, bool use_cache);
1106 struct dst_entry *ip6_blackhole_route(struct net *net,
1107 				      struct dst_entry *orig_dst);
1108 
1109 /*
1110  *	skb processing functions
1111  */
1112 
1113 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb);
1114 int ip6_forward(struct sk_buff *skb);
1115 int ip6_input(struct sk_buff *skb);
1116 int ip6_mc_input(struct sk_buff *skb);
1117 void ip6_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int nexthdr,
1118 			      bool have_final);
1119 
1120 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
1121 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
1122 
1123 /*
1124  *	Extension header (options) processing
1125  */
1126 
1127 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1128 			  u8 *proto, struct in6_addr **daddr_p,
1129 			  struct in6_addr *saddr);
1130 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1131 			 u8 *proto);
1132 
1133 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
1134 		     __be16 *frag_offp);
1135 
1136 bool ipv6_ext_hdr(u8 nexthdr);
1137 
1138 enum {
1139 	IP6_FH_F_FRAG		= (1 << 0),
1140 	IP6_FH_F_AUTH		= (1 << 1),
1141 	IP6_FH_F_SKIP_RH	= (1 << 2),
1142 };
1143 
1144 /* find specified header and get offset to it */
1145 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
1146 		  unsigned short *fragoff, int *fragflg);
1147 
1148 int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type);
1149 
1150 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1151 				const struct ipv6_txoptions *opt,
1152 				struct in6_addr *orig);
1153 
1154 /*
1155  *	socket options (ipv6_sockglue.c)
1156  */
1157 DECLARE_STATIC_KEY_FALSE(ip6_min_hopcount);
1158 
1159 int do_ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1160 		       unsigned int optlen);
1161 int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1162 		    unsigned int optlen);
1163 int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
1164 		       sockptr_t optval, sockptr_t optlen);
1165 int ipv6_getsockopt(struct sock *sk, int level, int optname,
1166 		    char __user *optval, int __user *optlen);
1167 
1168 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *addr,
1169 			   int addr_len);
1170 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
1171 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
1172 				 int addr_len);
1173 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr);
1174 void ip6_datagram_release_cb(struct sock *sk);
1175 
1176 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
1177 		    int *addr_len);
1178 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
1179 		     int *addr_len);
1180 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
1181 		     u32 info, u8 *payload);
1182 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
1183 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
1184 
1185 void inet6_cleanup_sock(struct sock *sk);
1186 void inet6_sock_destruct(struct sock *sk);
1187 int inet6_release(struct socket *sock);
1188 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
1189 int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
1190 		  int peer);
1191 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
1192 int inet6_compat_ioctl(struct socket *sock, unsigned int cmd,
1193 		unsigned long arg);
1194 
1195 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
1196 			      struct sock *sk);
1197 int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size);
1198 int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1199 		  int flags);
1200 
1201 /*
1202  * reassembly.c
1203  */
1204 extern const struct proto_ops inet6_stream_ops;
1205 extern const struct proto_ops inet6_dgram_ops;
1206 extern const struct proto_ops inet6_sockraw_ops;
1207 
1208 struct group_source_req;
1209 struct group_filter;
1210 
1211 int ip6_mc_source(int add, int omode, struct sock *sk,
1212 		  struct group_source_req *pgsr);
1213 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf,
1214 		  struct sockaddr_storage *list);
1215 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
1216 		  sockptr_t optval, size_t ss_offset);
1217 
1218 #ifdef CONFIG_PROC_FS
1219 int ac6_proc_init(struct net *net);
1220 void ac6_proc_exit(struct net *net);
1221 int raw6_proc_init(void);
1222 void raw6_proc_exit(void);
1223 int tcp6_proc_init(struct net *net);
1224 void tcp6_proc_exit(struct net *net);
1225 int udp6_proc_init(struct net *net);
1226 void udp6_proc_exit(struct net *net);
1227 int udplite6_proc_init(void);
1228 void udplite6_proc_exit(void);
1229 int ipv6_misc_proc_init(void);
1230 void ipv6_misc_proc_exit(void);
1231 int snmp6_register_dev(struct inet6_dev *idev);
1232 int snmp6_unregister_dev(struct inet6_dev *idev);
1233 
1234 #else
1235 static inline int ac6_proc_init(struct net *net) { return 0; }
1236 static inline void ac6_proc_exit(struct net *net) { }
1237 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
1238 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
1239 #endif
1240 
1241 #ifdef CONFIG_SYSCTL
1242 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
1243 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
1244 int ipv6_sysctl_register(void);
1245 void ipv6_sysctl_unregister(void);
1246 #endif
1247 
1248 int ipv6_sock_mc_join(struct sock *sk, int ifindex,
1249 		      const struct in6_addr *addr);
1250 int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,
1251 			  const struct in6_addr *addr, unsigned int mode);
1252 int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
1253 		      const struct in6_addr *addr);
1254 
1255 static inline int ip6_sock_set_v6only(struct sock *sk)
1256 {
1257 	if (inet_sk(sk)->inet_num)
1258 		return -EINVAL;
1259 	lock_sock(sk);
1260 	sk->sk_ipv6only = true;
1261 	release_sock(sk);
1262 	return 0;
1263 }
1264 
1265 static inline void ip6_sock_set_recverr(struct sock *sk)
1266 {
1267 	lock_sock(sk);
1268 	inet6_sk(sk)->recverr = true;
1269 	release_sock(sk);
1270 }
1271 
1272 static inline int __ip6_sock_set_addr_preferences(struct sock *sk, int val)
1273 {
1274 	unsigned int pref = 0;
1275 	unsigned int prefmask = ~0;
1276 
1277 	/* check PUBLIC/TMP/PUBTMP_DEFAULT conflicts */
1278 	switch (val & (IPV6_PREFER_SRC_PUBLIC |
1279 		       IPV6_PREFER_SRC_TMP |
1280 		       IPV6_PREFER_SRC_PUBTMP_DEFAULT)) {
1281 	case IPV6_PREFER_SRC_PUBLIC:
1282 		pref |= IPV6_PREFER_SRC_PUBLIC;
1283 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1284 			      IPV6_PREFER_SRC_TMP);
1285 		break;
1286 	case IPV6_PREFER_SRC_TMP:
1287 		pref |= IPV6_PREFER_SRC_TMP;
1288 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1289 			      IPV6_PREFER_SRC_TMP);
1290 		break;
1291 	case IPV6_PREFER_SRC_PUBTMP_DEFAULT:
1292 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1293 			      IPV6_PREFER_SRC_TMP);
1294 		break;
1295 	case 0:
1296 		break;
1297 	default:
1298 		return -EINVAL;
1299 	}
1300 
1301 	/* check HOME/COA conflicts */
1302 	switch (val & (IPV6_PREFER_SRC_HOME | IPV6_PREFER_SRC_COA)) {
1303 	case IPV6_PREFER_SRC_HOME:
1304 		prefmask &= ~IPV6_PREFER_SRC_COA;
1305 		break;
1306 	case IPV6_PREFER_SRC_COA:
1307 		pref |= IPV6_PREFER_SRC_COA;
1308 		break;
1309 	case 0:
1310 		break;
1311 	default:
1312 		return -EINVAL;
1313 	}
1314 
1315 	/* check CGA/NONCGA conflicts */
1316 	switch (val & (IPV6_PREFER_SRC_CGA|IPV6_PREFER_SRC_NONCGA)) {
1317 	case IPV6_PREFER_SRC_CGA:
1318 	case IPV6_PREFER_SRC_NONCGA:
1319 	case 0:
1320 		break;
1321 	default:
1322 		return -EINVAL;
1323 	}
1324 
1325 	inet6_sk(sk)->srcprefs = (inet6_sk(sk)->srcprefs & prefmask) | pref;
1326 	return 0;
1327 }
1328 
1329 static inline int ip6_sock_set_addr_preferences(struct sock *sk, bool val)
1330 {
1331 	int ret;
1332 
1333 	lock_sock(sk);
1334 	ret = __ip6_sock_set_addr_preferences(sk, val);
1335 	release_sock(sk);
1336 	return ret;
1337 }
1338 
1339 static inline void ip6_sock_set_recvpktinfo(struct sock *sk)
1340 {
1341 	lock_sock(sk);
1342 	inet6_sk(sk)->rxopt.bits.rxinfo = true;
1343 	release_sock(sk);
1344 }
1345 
1346 #endif /* _NET_IPV6_H */
1347