xref: /linux/include/net/ipv6.h (revision b8e85e6f3a09fc56b0ff574887798962ef8a8f80)
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 sock *sk)
377 {
378 	*ipc6 = (struct ipcm6_cookie) {
379 		.hlimit = -1,
380 		.tclass = inet6_sk(sk)->tclass,
381 		.dontfrag = inet6_test_bit(DONTFRAG, sk),
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 sock *sk);
432 
433 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
434 {
435 	if (fl)
436 		atomic_dec(&fl->users);
437 }
438 
439 enum skb_drop_reason icmpv6_notify(struct sk_buff *skb, u8 type,
440 				   u8 code, __be32 info);
441 
442 void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
443 				struct icmp6hdr *thdr, int len);
444 
445 int ip6_ra_control(struct sock *sk, int sel);
446 
447 int ipv6_parse_hopopts(struct sk_buff *skb);
448 
449 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
450 					struct ipv6_txoptions *opt);
451 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
452 					  struct ipv6_txoptions *opt,
453 					  int newtype,
454 					  struct ipv6_opt_hdr *newopt);
455 struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space,
456 					    struct ipv6_txoptions *opt);
457 
458 static inline struct ipv6_txoptions *
459 ipv6_fixup_options(struct ipv6_txoptions *opt_space, struct ipv6_txoptions *opt)
460 {
461 	if (!opt)
462 		return NULL;
463 	return __ipv6_fixup_options(opt_space, opt);
464 }
465 
466 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
467 		       const struct inet6_skb_parm *opt);
468 struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
469 					   struct ipv6_txoptions *opt);
470 
471 /* This helper is specialized for BIG TCP needs.
472  * It assumes the hop_jumbo_hdr will immediately follow the IPV6 header.
473  * It assumes headers are already in skb->head.
474  * Returns 0, or IPPROTO_TCP if a BIG TCP packet is there.
475  */
476 static inline int ipv6_has_hopopt_jumbo(const struct sk_buff *skb)
477 {
478 	const struct hop_jumbo_hdr *jhdr;
479 	const struct ipv6hdr *nhdr;
480 
481 	if (likely(skb->len <= GRO_LEGACY_MAX_SIZE))
482 		return 0;
483 
484 	if (skb->protocol != htons(ETH_P_IPV6))
485 		return 0;
486 
487 	if (skb_network_offset(skb) +
488 	    sizeof(struct ipv6hdr) +
489 	    sizeof(struct hop_jumbo_hdr) > skb_headlen(skb))
490 		return 0;
491 
492 	nhdr = ipv6_hdr(skb);
493 
494 	if (nhdr->nexthdr != NEXTHDR_HOP)
495 		return 0;
496 
497 	jhdr = (const struct hop_jumbo_hdr *) (nhdr + 1);
498 	if (jhdr->tlv_type != IPV6_TLV_JUMBO || jhdr->hdrlen != 0 ||
499 	    jhdr->nexthdr != IPPROTO_TCP)
500 		return 0;
501 	return jhdr->nexthdr;
502 }
503 
504 /* Return 0 if HBH header is successfully removed
505  * Or if HBH removal is unnecessary (packet is not big TCP)
506  * Return error to indicate dropping the packet
507  */
508 static inline int ipv6_hopopt_jumbo_remove(struct sk_buff *skb)
509 {
510 	const int hophdr_len = sizeof(struct hop_jumbo_hdr);
511 	int nexthdr = ipv6_has_hopopt_jumbo(skb);
512 	struct ipv6hdr *h6;
513 
514 	if (!nexthdr)
515 		return 0;
516 
517 	if (skb_cow_head(skb, 0))
518 		return -1;
519 
520 	/* Remove the HBH header.
521 	 * Layout: [Ethernet header][IPv6 header][HBH][L4 Header]
522 	 */
523 	memmove(skb_mac_header(skb) + hophdr_len, skb_mac_header(skb),
524 		skb_network_header(skb) - skb_mac_header(skb) +
525 		sizeof(struct ipv6hdr));
526 
527 	__skb_pull(skb, hophdr_len);
528 	skb->network_header += hophdr_len;
529 	skb->mac_header += hophdr_len;
530 
531 	h6 = ipv6_hdr(skb);
532 	h6->nexthdr = nexthdr;
533 
534 	return 0;
535 }
536 
537 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
538 {
539 	/* If forwarding is enabled, RA are not accepted unless the special
540 	 * hybrid mode (accept_ra=2) is enabled.
541 	 */
542 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
543 	    idev->cnf.accept_ra;
544 }
545 
546 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
547 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
548 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
549 
550 int __ipv6_addr_type(const struct in6_addr *addr);
551 static inline int ipv6_addr_type(const struct in6_addr *addr)
552 {
553 	return __ipv6_addr_type(addr) & 0xffff;
554 }
555 
556 static inline int ipv6_addr_scope(const struct in6_addr *addr)
557 {
558 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
559 }
560 
561 static inline int __ipv6_addr_src_scope(int type)
562 {
563 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
564 }
565 
566 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
567 {
568 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
569 }
570 
571 static inline bool __ipv6_addr_needs_scope_id(int type)
572 {
573 	return type & IPV6_ADDR_LINKLOCAL ||
574 	       (type & IPV6_ADDR_MULTICAST &&
575 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
576 }
577 
578 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
579 {
580 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
581 }
582 
583 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
584 {
585 	return memcmp(a1, a2, sizeof(struct in6_addr));
586 }
587 
588 static inline bool
589 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
590 		     const struct in6_addr *a2)
591 {
592 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
593 	const unsigned long *ul1 = (const unsigned long *)a1;
594 	const unsigned long *ulm = (const unsigned long *)m;
595 	const unsigned long *ul2 = (const unsigned long *)a2;
596 
597 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
598 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
599 #else
600 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
601 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
602 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
603 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
604 #endif
605 }
606 
607 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
608 				    const struct in6_addr *addr,
609 				    int plen)
610 {
611 	/* caller must guarantee 0 <= plen <= 128 */
612 	int o = plen >> 3,
613 	    b = plen & 0x7;
614 
615 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
616 	memcpy(pfx->s6_addr, addr, o);
617 	if (b != 0)
618 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
619 }
620 
621 static inline void ipv6_addr_prefix_copy(struct in6_addr *addr,
622 					 const struct in6_addr *pfx,
623 					 int plen)
624 {
625 	/* caller must guarantee 0 <= plen <= 128 */
626 	int o = plen >> 3,
627 	    b = plen & 0x7;
628 
629 	memcpy(addr->s6_addr, pfx, o);
630 	if (b != 0) {
631 		addr->s6_addr[o] &= ~(0xff00 >> b);
632 		addr->s6_addr[o] |= (pfx->s6_addr[o] & (0xff00 >> b));
633 	}
634 }
635 
636 static inline void __ipv6_addr_set_half(__be32 *addr,
637 					__be32 wh, __be32 wl)
638 {
639 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
640 #if defined(__BIG_ENDIAN)
641 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
642 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
643 		return;
644 	}
645 #elif defined(__LITTLE_ENDIAN)
646 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
647 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
648 		return;
649 	}
650 #endif
651 #endif
652 	addr[0] = wh;
653 	addr[1] = wl;
654 }
655 
656 static inline void ipv6_addr_set(struct in6_addr *addr,
657 				     __be32 w1, __be32 w2,
658 				     __be32 w3, __be32 w4)
659 {
660 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
661 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
662 }
663 
664 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
665 				   const struct in6_addr *a2)
666 {
667 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
668 	const unsigned long *ul1 = (const unsigned long *)a1;
669 	const unsigned long *ul2 = (const unsigned long *)a2;
670 
671 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
672 #else
673 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
674 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
675 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
676 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
677 #endif
678 }
679 
680 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
681 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
682 					      const __be64 *a2,
683 					      unsigned int len)
684 {
685 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
686 		return false;
687 	return true;
688 }
689 
690 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
691 				     const struct in6_addr *addr2,
692 				     unsigned int prefixlen)
693 {
694 	const __be64 *a1 = (const __be64 *)addr1;
695 	const __be64 *a2 = (const __be64 *)addr2;
696 
697 	if (prefixlen >= 64) {
698 		if (a1[0] ^ a2[0])
699 			return false;
700 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
701 	}
702 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
703 }
704 #else
705 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
706 				     const struct in6_addr *addr2,
707 				     unsigned int prefixlen)
708 {
709 	const __be32 *a1 = addr1->s6_addr32;
710 	const __be32 *a2 = addr2->s6_addr32;
711 	unsigned int pdw, pbi;
712 
713 	/* check complete u32 in prefix */
714 	pdw = prefixlen >> 5;
715 	if (pdw && memcmp(a1, a2, pdw << 2))
716 		return false;
717 
718 	/* check incomplete u32 in prefix */
719 	pbi = prefixlen & 0x1f;
720 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
721 		return false;
722 
723 	return true;
724 }
725 #endif
726 
727 static inline bool ipv6_addr_any(const struct in6_addr *a)
728 {
729 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
730 	const unsigned long *ul = (const unsigned long *)a;
731 
732 	return (ul[0] | ul[1]) == 0UL;
733 #else
734 	return (a->s6_addr32[0] | a->s6_addr32[1] |
735 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
736 #endif
737 }
738 
739 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
740 {
741 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
742 	const unsigned long *ul = (const unsigned long *)a;
743 	unsigned long x = ul[0] ^ ul[1];
744 
745 	return (u32)(x ^ (x >> 32));
746 #else
747 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
748 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
749 #endif
750 }
751 
752 /* more secured version of ipv6_addr_hash() */
753 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
754 {
755 	return jhash2((__force const u32 *)a->s6_addr32,
756 		      ARRAY_SIZE(a->s6_addr32), initval);
757 }
758 
759 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
760 {
761 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
762 	const __be64 *be = (const __be64 *)a;
763 
764 	return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
765 #else
766 	return (a->s6_addr32[0] | a->s6_addr32[1] |
767 		a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
768 #endif
769 }
770 
771 /*
772  * Note that we must __force cast these to unsigned long to make sparse happy,
773  * since all of the endian-annotated types are fixed size regardless of arch.
774  */
775 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
776 {
777 	return (
778 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
779 		*(unsigned long *)a |
780 #else
781 		(__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
782 #endif
783 		(__force unsigned long)(a->s6_addr32[2] ^
784 					cpu_to_be32(0x0000ffff))) == 0UL;
785 }
786 
787 static inline bool ipv6_addr_v4mapped_loopback(const struct in6_addr *a)
788 {
789 	return ipv6_addr_v4mapped(a) && ipv4_is_loopback(a->s6_addr32[3]);
790 }
791 
792 static inline u32 ipv6_portaddr_hash(const struct net *net,
793 				     const struct in6_addr *addr6,
794 				     unsigned int port)
795 {
796 	unsigned int hash, mix = net_hash_mix(net);
797 
798 	if (ipv6_addr_any(addr6))
799 		hash = jhash_1word(0, mix);
800 	else if (ipv6_addr_v4mapped(addr6))
801 		hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
802 	else
803 		hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
804 
805 	return hash ^ port;
806 }
807 
808 /*
809  * Check for a RFC 4843 ORCHID address
810  * (Overlay Routable Cryptographic Hash Identifiers)
811  */
812 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
813 {
814 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
815 }
816 
817 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
818 {
819 	return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
820 }
821 
822 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
823 					  struct in6_addr *v4mapped)
824 {
825 	ipv6_addr_set(v4mapped,
826 			0, 0,
827 			htonl(0x0000FFFF),
828 			addr);
829 }
830 
831 /*
832  * find the first different bit between two addresses
833  * length of address must be a multiple of 32bits
834  */
835 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
836 {
837 	const __be32 *a1 = token1, *a2 = token2;
838 	int i;
839 
840 	addrlen >>= 2;
841 
842 	for (i = 0; i < addrlen; i++) {
843 		__be32 xb = a1[i] ^ a2[i];
844 		if (xb)
845 			return i * 32 + 31 - __fls(ntohl(xb));
846 	}
847 
848 	/*
849 	 *	we should *never* get to this point since that
850 	 *	would mean the addrs are equal
851 	 *
852 	 *	However, we do get to it 8) And exacly, when
853 	 *	addresses are equal 8)
854 	 *
855 	 *	ip route add 1111::/128 via ...
856 	 *	ip route add 1111::/64 via ...
857 	 *	and we are here.
858 	 *
859 	 *	Ideally, this function should stop comparison
860 	 *	at prefix length. It does not, but it is still OK,
861 	 *	if returned value is greater than prefix length.
862 	 *					--ANK (980803)
863 	 */
864 	return addrlen << 5;
865 }
866 
867 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
868 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
869 {
870 	const __be64 *a1 = token1, *a2 = token2;
871 	int i;
872 
873 	addrlen >>= 3;
874 
875 	for (i = 0; i < addrlen; i++) {
876 		__be64 xb = a1[i] ^ a2[i];
877 		if (xb)
878 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
879 	}
880 
881 	return addrlen << 6;
882 }
883 #endif
884 
885 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
886 {
887 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
888 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
889 		return __ipv6_addr_diff64(token1, token2, addrlen);
890 #endif
891 	return __ipv6_addr_diff32(token1, token2, addrlen);
892 }
893 
894 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
895 {
896 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
897 }
898 
899 __be32 ipv6_select_ident(struct net *net,
900 			 const struct in6_addr *daddr,
901 			 const struct in6_addr *saddr);
902 __be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
903 
904 int ip6_dst_hoplimit(struct dst_entry *dst);
905 
906 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
907 				      struct dst_entry *dst)
908 {
909 	int hlimit;
910 
911 	if (ipv6_addr_is_multicast(&fl6->daddr))
912 		hlimit = READ_ONCE(np->mcast_hops);
913 	else
914 		hlimit = READ_ONCE(np->hop_limit);
915 	if (hlimit < 0)
916 		hlimit = ip6_dst_hoplimit(dst);
917 	return hlimit;
918 }
919 
920 /* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
921  * Equivalent to :	flow->v6addrs.src = iph->saddr;
922  *			flow->v6addrs.dst = iph->daddr;
923  */
924 static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
925 					    const struct ipv6hdr *iph)
926 {
927 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
928 		     offsetof(typeof(flow->addrs), v6addrs.src) +
929 		     sizeof(flow->addrs.v6addrs.src));
930 	memcpy(&flow->addrs.v6addrs, &iph->addrs, sizeof(flow->addrs.v6addrs));
931 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
932 }
933 
934 #if IS_ENABLED(CONFIG_IPV6)
935 
936 static inline bool ipv6_can_nonlocal_bind(struct net *net,
937 					  struct inet_sock *inet)
938 {
939 	return net->ipv6.sysctl.ip_nonlocal_bind ||
940 		test_bit(INET_FLAGS_FREEBIND, &inet->inet_flags) ||
941 		test_bit(INET_FLAGS_TRANSPARENT, &inet->inet_flags);
942 }
943 
944 /* Sysctl settings for net ipv6.auto_flowlabels */
945 #define IP6_AUTO_FLOW_LABEL_OFF		0
946 #define IP6_AUTO_FLOW_LABEL_OPTOUT	1
947 #define IP6_AUTO_FLOW_LABEL_OPTIN	2
948 #define IP6_AUTO_FLOW_LABEL_FORCED	3
949 
950 #define IP6_AUTO_FLOW_LABEL_MAX		IP6_AUTO_FLOW_LABEL_FORCED
951 
952 #define IP6_DEFAULT_AUTO_FLOW_LABELS	IP6_AUTO_FLOW_LABEL_OPTOUT
953 
954 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
955 					__be32 flowlabel, bool autolabel,
956 					struct flowi6 *fl6)
957 {
958 	u32 hash;
959 
960 	/* @flowlabel may include more than a flow label, eg, the traffic class.
961 	 * Here we want only the flow label value.
962 	 */
963 	flowlabel &= IPV6_FLOWLABEL_MASK;
964 
965 	if (flowlabel ||
966 	    net->ipv6.sysctl.auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF ||
967 	    (!autolabel &&
968 	     net->ipv6.sysctl.auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED))
969 		return flowlabel;
970 
971 	hash = skb_get_hash_flowi6(skb, fl6);
972 
973 	/* Since this is being sent on the wire obfuscate hash a bit
974 	 * to minimize possbility that any useful information to an
975 	 * attacker is leaked. Only lower 20 bits are relevant.
976 	 */
977 	hash = rol32(hash, 16);
978 
979 	flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
980 
981 	if (net->ipv6.sysctl.flowlabel_state_ranges)
982 		flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
983 
984 	return flowlabel;
985 }
986 
987 static inline int ip6_default_np_autolabel(struct net *net)
988 {
989 	switch (net->ipv6.sysctl.auto_flowlabels) {
990 	case IP6_AUTO_FLOW_LABEL_OFF:
991 	case IP6_AUTO_FLOW_LABEL_OPTIN:
992 	default:
993 		return 0;
994 	case IP6_AUTO_FLOW_LABEL_OPTOUT:
995 	case IP6_AUTO_FLOW_LABEL_FORCED:
996 		return 1;
997 	}
998 }
999 #else
1000 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
1001 					__be32 flowlabel, bool autolabel,
1002 					struct flowi6 *fl6)
1003 {
1004 	return flowlabel;
1005 }
1006 static inline int ip6_default_np_autolabel(struct net *net)
1007 {
1008 	return 0;
1009 }
1010 #endif
1011 
1012 #if IS_ENABLED(CONFIG_IPV6)
1013 static inline int ip6_multipath_hash_policy(const struct net *net)
1014 {
1015 	return net->ipv6.sysctl.multipath_hash_policy;
1016 }
1017 static inline u32 ip6_multipath_hash_fields(const struct net *net)
1018 {
1019 	return net->ipv6.sysctl.multipath_hash_fields;
1020 }
1021 #else
1022 static inline int ip6_multipath_hash_policy(const struct net *net)
1023 {
1024 	return 0;
1025 }
1026 static inline u32 ip6_multipath_hash_fields(const struct net *net)
1027 {
1028 	return 0;
1029 }
1030 #endif
1031 
1032 /*
1033  *	Header manipulation
1034  */
1035 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
1036 				__be32 flowlabel)
1037 {
1038 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
1039 }
1040 
1041 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
1042 {
1043 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
1044 }
1045 
1046 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
1047 {
1048 	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
1049 }
1050 
1051 static inline u8 ip6_tclass(__be32 flowinfo)
1052 {
1053 	return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
1054 }
1055 
1056 static inline dscp_t ip6_dscp(__be32 flowinfo)
1057 {
1058 	return inet_dsfield_to_dscp(ip6_tclass(flowinfo));
1059 }
1060 
1061 static inline __be32 ip6_make_flowinfo(unsigned int tclass, __be32 flowlabel)
1062 {
1063 	return htonl(tclass << IPV6_TCLASS_SHIFT) | flowlabel;
1064 }
1065 
1066 static inline __be32 flowi6_get_flowlabel(const struct flowi6 *fl6)
1067 {
1068 	return fl6->flowlabel & IPV6_FLOWLABEL_MASK;
1069 }
1070 
1071 /*
1072  *	Prototypes exported by ipv6
1073  */
1074 
1075 /*
1076  *	rcv function (called from netdevice level)
1077  */
1078 
1079 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
1080 	     struct packet_type *pt, struct net_device *orig_dev);
1081 void ipv6_list_rcv(struct list_head *head, struct packet_type *pt,
1082 		   struct net_device *orig_dev);
1083 
1084 int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
1085 
1086 /*
1087  *	upper-layer output functions
1088  */
1089 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
1090 	     __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority);
1091 
1092 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
1093 
1094 int ip6_append_data(struct sock *sk,
1095 		    int getfrag(void *from, char *to, int offset, int len,
1096 				int odd, struct sk_buff *skb),
1097 		    void *from, size_t length, int transhdrlen,
1098 		    struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1099 		    struct rt6_info *rt, unsigned int flags);
1100 
1101 int ip6_push_pending_frames(struct sock *sk);
1102 
1103 void ip6_flush_pending_frames(struct sock *sk);
1104 
1105 int ip6_send_skb(struct sk_buff *skb);
1106 
1107 struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
1108 			       struct inet_cork_full *cork,
1109 			       struct inet6_cork *v6_cork);
1110 struct sk_buff *ip6_make_skb(struct sock *sk,
1111 			     int getfrag(void *from, char *to, int offset,
1112 					 int len, int odd, struct sk_buff *skb),
1113 			     void *from, size_t length, int transhdrlen,
1114 			     struct ipcm6_cookie *ipc6,
1115 			     struct rt6_info *rt, unsigned int flags,
1116 			     struct inet_cork_full *cork);
1117 
1118 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
1119 {
1120 	return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
1121 			      &inet6_sk(sk)->cork);
1122 }
1123 
1124 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1125 		   struct flowi6 *fl6);
1126 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6,
1127 				      const struct in6_addr *final_dst);
1128 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1129 					 const struct in6_addr *final_dst,
1130 					 bool connected);
1131 struct dst_entry *ip6_blackhole_route(struct net *net,
1132 				      struct dst_entry *orig_dst);
1133 
1134 /*
1135  *	skb processing functions
1136  */
1137 
1138 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb);
1139 int ip6_forward(struct sk_buff *skb);
1140 int ip6_input(struct sk_buff *skb);
1141 int ip6_mc_input(struct sk_buff *skb);
1142 void ip6_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int nexthdr,
1143 			      bool have_final);
1144 
1145 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
1146 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
1147 
1148 /*
1149  *	Extension header (options) processing
1150  */
1151 
1152 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1153 			  u8 *proto, struct in6_addr **daddr_p,
1154 			  struct in6_addr *saddr);
1155 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1156 			 u8 *proto);
1157 
1158 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
1159 		     __be16 *frag_offp);
1160 
1161 bool ipv6_ext_hdr(u8 nexthdr);
1162 
1163 enum {
1164 	IP6_FH_F_FRAG		= (1 << 0),
1165 	IP6_FH_F_AUTH		= (1 << 1),
1166 	IP6_FH_F_SKIP_RH	= (1 << 2),
1167 };
1168 
1169 /* find specified header and get offset to it */
1170 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
1171 		  unsigned short *fragoff, int *fragflg);
1172 
1173 int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type);
1174 
1175 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1176 				const struct ipv6_txoptions *opt,
1177 				struct in6_addr *orig);
1178 
1179 /*
1180  *	socket options (ipv6_sockglue.c)
1181  */
1182 DECLARE_STATIC_KEY_FALSE(ip6_min_hopcount);
1183 
1184 int do_ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1185 		       unsigned int optlen);
1186 int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1187 		    unsigned int optlen);
1188 int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
1189 		       sockptr_t optval, sockptr_t optlen);
1190 int ipv6_getsockopt(struct sock *sk, int level, int optname,
1191 		    char __user *optval, int __user *optlen);
1192 
1193 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *addr,
1194 			   int addr_len);
1195 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
1196 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
1197 				 int addr_len);
1198 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr);
1199 void ip6_datagram_release_cb(struct sock *sk);
1200 
1201 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
1202 		    int *addr_len);
1203 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
1204 		     int *addr_len);
1205 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
1206 		     u32 info, u8 *payload);
1207 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
1208 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
1209 
1210 void inet6_cleanup_sock(struct sock *sk);
1211 void inet6_sock_destruct(struct sock *sk);
1212 int inet6_release(struct socket *sock);
1213 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
1214 int inet6_bind_sk(struct sock *sk, struct sockaddr *uaddr, int addr_len);
1215 int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
1216 		  int peer);
1217 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
1218 int inet6_compat_ioctl(struct socket *sock, unsigned int cmd,
1219 		unsigned long arg);
1220 
1221 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
1222 			      struct sock *sk);
1223 int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size);
1224 int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1225 		  int flags);
1226 
1227 /*
1228  * reassembly.c
1229  */
1230 extern const struct proto_ops inet6_stream_ops;
1231 extern const struct proto_ops inet6_dgram_ops;
1232 extern const struct proto_ops inet6_sockraw_ops;
1233 
1234 struct group_source_req;
1235 struct group_filter;
1236 
1237 int ip6_mc_source(int add, int omode, struct sock *sk,
1238 		  struct group_source_req *pgsr);
1239 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf,
1240 		  struct sockaddr_storage *list);
1241 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
1242 		  sockptr_t optval, size_t ss_offset);
1243 
1244 #ifdef CONFIG_PROC_FS
1245 int ac6_proc_init(struct net *net);
1246 void ac6_proc_exit(struct net *net);
1247 int raw6_proc_init(void);
1248 void raw6_proc_exit(void);
1249 int tcp6_proc_init(struct net *net);
1250 void tcp6_proc_exit(struct net *net);
1251 int udp6_proc_init(struct net *net);
1252 void udp6_proc_exit(struct net *net);
1253 int udplite6_proc_init(void);
1254 void udplite6_proc_exit(void);
1255 int ipv6_misc_proc_init(void);
1256 void ipv6_misc_proc_exit(void);
1257 int snmp6_register_dev(struct inet6_dev *idev);
1258 int snmp6_unregister_dev(struct inet6_dev *idev);
1259 
1260 #else
1261 static inline int ac6_proc_init(struct net *net) { return 0; }
1262 static inline void ac6_proc_exit(struct net *net) { }
1263 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
1264 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
1265 #endif
1266 
1267 #ifdef CONFIG_SYSCTL
1268 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
1269 size_t ipv6_icmp_sysctl_table_size(void);
1270 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
1271 size_t ipv6_route_sysctl_table_size(struct net *net);
1272 int ipv6_sysctl_register(void);
1273 void ipv6_sysctl_unregister(void);
1274 #endif
1275 
1276 int ipv6_sock_mc_join(struct sock *sk, int ifindex,
1277 		      const struct in6_addr *addr);
1278 int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,
1279 			  const struct in6_addr *addr, unsigned int mode);
1280 int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
1281 		      const struct in6_addr *addr);
1282 
1283 static inline int ip6_sock_set_v6only(struct sock *sk)
1284 {
1285 	if (inet_sk(sk)->inet_num)
1286 		return -EINVAL;
1287 	lock_sock(sk);
1288 	sk->sk_ipv6only = true;
1289 	release_sock(sk);
1290 	return 0;
1291 }
1292 
1293 static inline void ip6_sock_set_recverr(struct sock *sk)
1294 {
1295 	inet6_set_bit(RECVERR6, sk);
1296 }
1297 
1298 #define IPV6_PREFER_SRC_MASK (IPV6_PREFER_SRC_TMP | IPV6_PREFER_SRC_PUBLIC | \
1299 			      IPV6_PREFER_SRC_COA)
1300 
1301 static inline int ip6_sock_set_addr_preferences(struct sock *sk, int val)
1302 {
1303 	unsigned int prefmask = ~IPV6_PREFER_SRC_MASK;
1304 	unsigned int pref = 0;
1305 
1306 	/* check PUBLIC/TMP/PUBTMP_DEFAULT conflicts */
1307 	switch (val & (IPV6_PREFER_SRC_PUBLIC |
1308 		       IPV6_PREFER_SRC_TMP |
1309 		       IPV6_PREFER_SRC_PUBTMP_DEFAULT)) {
1310 	case IPV6_PREFER_SRC_PUBLIC:
1311 		pref |= IPV6_PREFER_SRC_PUBLIC;
1312 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1313 			      IPV6_PREFER_SRC_TMP);
1314 		break;
1315 	case IPV6_PREFER_SRC_TMP:
1316 		pref |= IPV6_PREFER_SRC_TMP;
1317 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1318 			      IPV6_PREFER_SRC_TMP);
1319 		break;
1320 	case IPV6_PREFER_SRC_PUBTMP_DEFAULT:
1321 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1322 			      IPV6_PREFER_SRC_TMP);
1323 		break;
1324 	case 0:
1325 		break;
1326 	default:
1327 		return -EINVAL;
1328 	}
1329 
1330 	/* check HOME/COA conflicts */
1331 	switch (val & (IPV6_PREFER_SRC_HOME | IPV6_PREFER_SRC_COA)) {
1332 	case IPV6_PREFER_SRC_HOME:
1333 		prefmask &= ~IPV6_PREFER_SRC_COA;
1334 		break;
1335 	case IPV6_PREFER_SRC_COA:
1336 		pref |= IPV6_PREFER_SRC_COA;
1337 		break;
1338 	case 0:
1339 		break;
1340 	default:
1341 		return -EINVAL;
1342 	}
1343 
1344 	/* check CGA/NONCGA conflicts */
1345 	switch (val & (IPV6_PREFER_SRC_CGA|IPV6_PREFER_SRC_NONCGA)) {
1346 	case IPV6_PREFER_SRC_CGA:
1347 	case IPV6_PREFER_SRC_NONCGA:
1348 	case 0:
1349 		break;
1350 	default:
1351 		return -EINVAL;
1352 	}
1353 
1354 	WRITE_ONCE(inet6_sk(sk)->srcprefs,
1355 		   (READ_ONCE(inet6_sk(sk)->srcprefs) & prefmask) | pref);
1356 	return 0;
1357 }
1358 
1359 static inline void ip6_sock_set_recvpktinfo(struct sock *sk)
1360 {
1361 	lock_sock(sk);
1362 	inet6_sk(sk)->rxopt.bits.rxinfo = true;
1363 	release_sock(sk);
1364 }
1365 
1366 #endif /* _NET_IPV6_H */
1367