xref: /linux/include/net/ipv6.h (revision 1cc3462159babb69c84c39cb1b4e262aef3ea325)
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_sk(struct ipcm6_cookie *ipc6,
367 				 const struct sock *sk)
368 {
369 	*ipc6 = (struct ipcm6_cookie) {
370 		.hlimit = -1,
371 		.tclass = inet6_sk(sk)->tclass,
372 		.dontfrag = inet6_test_bit(DONTFRAG, sk),
373 	};
374 
375 	sockcm_init(&ipc6->sockc, sk);
376 }
377 
378 static inline struct ipv6_txoptions *txopt_get(const struct ipv6_pinfo *np)
379 {
380 	struct ipv6_txoptions *opt;
381 
382 	rcu_read_lock();
383 	opt = rcu_dereference(np->opt);
384 	if (opt) {
385 		if (!refcount_inc_not_zero(&opt->refcnt))
386 			opt = NULL;
387 		else
388 			opt = rcu_pointer_handoff(opt);
389 	}
390 	rcu_read_unlock();
391 	return opt;
392 }
393 
394 static inline void txopt_put(struct ipv6_txoptions *opt)
395 {
396 	if (opt && refcount_dec_and_test(&opt->refcnt))
397 		kfree_rcu(opt, rcu);
398 }
399 
400 #if IS_ENABLED(CONFIG_IPV6)
401 struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label);
402 
403 extern struct static_key_false_deferred ipv6_flowlabel_exclusive;
404 static inline struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk,
405 						    __be32 label)
406 {
407 	if (static_branch_unlikely(&ipv6_flowlabel_exclusive.key) &&
408 	    READ_ONCE(sock_net(sk)->ipv6.flowlabel_has_excl))
409 		return __fl6_sock_lookup(sk, label) ? : ERR_PTR(-ENOENT);
410 
411 	return NULL;
412 }
413 #endif
414 
415 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
416 					 struct ip6_flowlabel *fl,
417 					 struct ipv6_txoptions *fopt);
418 void fl6_free_socklist(struct sock *sk);
419 int ipv6_flowlabel_opt(struct sock *sk, sockptr_t optval, int optlen);
420 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
421 			   int flags);
422 int ip6_flowlabel_init(void);
423 void ip6_flowlabel_cleanup(void);
424 bool ip6_autoflowlabel(struct net *net, const struct sock *sk);
425 
426 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
427 {
428 	if (fl)
429 		atomic_dec(&fl->users);
430 }
431 
432 enum skb_drop_reason icmpv6_notify(struct sk_buff *skb, u8 type,
433 				   u8 code, __be32 info);
434 
435 void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
436 				struct icmp6hdr *thdr, int len);
437 
438 int ip6_ra_control(struct sock *sk, int sel);
439 
440 int ipv6_parse_hopopts(struct sk_buff *skb);
441 
442 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
443 					struct ipv6_txoptions *opt);
444 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
445 					  struct ipv6_txoptions *opt,
446 					  int newtype,
447 					  struct ipv6_opt_hdr *newopt);
448 struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space,
449 					    struct ipv6_txoptions *opt);
450 
451 static inline struct ipv6_txoptions *
452 ipv6_fixup_options(struct ipv6_txoptions *opt_space, struct ipv6_txoptions *opt)
453 {
454 	if (!opt)
455 		return NULL;
456 	return __ipv6_fixup_options(opt_space, opt);
457 }
458 
459 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
460 		       const struct inet6_skb_parm *opt);
461 struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
462 					   struct ipv6_txoptions *opt);
463 
464 /* This helper is specialized for BIG TCP needs.
465  * It assumes the hop_jumbo_hdr will immediately follow the IPV6 header.
466  * It assumes headers are already in skb->head.
467  * Returns: 0, or IPPROTO_TCP if a BIG TCP packet is there.
468  */
469 static inline int ipv6_has_hopopt_jumbo(const struct sk_buff *skb)
470 {
471 	const struct hop_jumbo_hdr *jhdr;
472 	const struct ipv6hdr *nhdr;
473 
474 	if (likely(skb->len <= GRO_LEGACY_MAX_SIZE))
475 		return 0;
476 
477 	if (skb->protocol != htons(ETH_P_IPV6))
478 		return 0;
479 
480 	if (skb_network_offset(skb) +
481 	    sizeof(struct ipv6hdr) +
482 	    sizeof(struct hop_jumbo_hdr) > skb_headlen(skb))
483 		return 0;
484 
485 	nhdr = ipv6_hdr(skb);
486 
487 	if (nhdr->nexthdr != NEXTHDR_HOP)
488 		return 0;
489 
490 	jhdr = (const struct hop_jumbo_hdr *) (nhdr + 1);
491 	if (jhdr->tlv_type != IPV6_TLV_JUMBO || jhdr->hdrlen != 0 ||
492 	    jhdr->nexthdr != IPPROTO_TCP)
493 		return 0;
494 	return jhdr->nexthdr;
495 }
496 
497 /* Return 0 if HBH header is successfully removed
498  * Or if HBH removal is unnecessary (packet is not big TCP)
499  * Return error to indicate dropping the packet
500  */
501 static inline int ipv6_hopopt_jumbo_remove(struct sk_buff *skb)
502 {
503 	const int hophdr_len = sizeof(struct hop_jumbo_hdr);
504 	int nexthdr = ipv6_has_hopopt_jumbo(skb);
505 	struct ipv6hdr *h6;
506 
507 	if (!nexthdr)
508 		return 0;
509 
510 	if (skb_cow_head(skb, 0))
511 		return -1;
512 
513 	/* Remove the HBH header.
514 	 * Layout: [Ethernet header][IPv6 header][HBH][L4 Header]
515 	 */
516 	memmove(skb_mac_header(skb) + hophdr_len, skb_mac_header(skb),
517 		skb_network_header(skb) - skb_mac_header(skb) +
518 		sizeof(struct ipv6hdr));
519 
520 	__skb_pull(skb, hophdr_len);
521 	skb->network_header += hophdr_len;
522 	skb->mac_header += hophdr_len;
523 
524 	h6 = ipv6_hdr(skb);
525 	h6->nexthdr = nexthdr;
526 
527 	return 0;
528 }
529 
530 static inline bool ipv6_accept_ra(const struct inet6_dev *idev)
531 {
532 	s32 accept_ra = READ_ONCE(idev->cnf.accept_ra);
533 
534 	/* If forwarding is enabled, RA are not accepted unless the special
535 	 * hybrid mode (accept_ra=2) is enabled.
536 	 */
537 	return READ_ONCE(idev->cnf.forwarding) ? accept_ra == 2 :
538 		accept_ra;
539 }
540 
541 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
542 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
543 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
544 
545 int __ipv6_addr_type(const struct in6_addr *addr);
546 static inline int ipv6_addr_type(const struct in6_addr *addr)
547 {
548 	return __ipv6_addr_type(addr) & 0xffff;
549 }
550 
551 static inline int ipv6_addr_scope(const struct in6_addr *addr)
552 {
553 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
554 }
555 
556 static inline int __ipv6_addr_src_scope(int type)
557 {
558 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
559 }
560 
561 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
562 {
563 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
564 }
565 
566 static inline bool __ipv6_addr_needs_scope_id(int type)
567 {
568 	return type & IPV6_ADDR_LINKLOCAL ||
569 	       (type & IPV6_ADDR_MULTICAST &&
570 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
571 }
572 
573 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
574 {
575 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
576 }
577 
578 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
579 {
580 	return memcmp(a1, a2, sizeof(struct in6_addr));
581 }
582 
583 static inline bool
584 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
585 		     const struct in6_addr *a2)
586 {
587 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
588 	const unsigned long *ul1 = (const unsigned long *)a1;
589 	const unsigned long *ulm = (const unsigned long *)m;
590 	const unsigned long *ul2 = (const unsigned long *)a2;
591 
592 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
593 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
594 #else
595 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
596 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
597 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
598 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
599 #endif
600 }
601 
602 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
603 				    const struct in6_addr *addr,
604 				    int plen)
605 {
606 	/* caller must guarantee 0 <= plen <= 128 */
607 	int o = plen >> 3,
608 	    b = plen & 0x7;
609 
610 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
611 	memcpy(pfx->s6_addr, addr, o);
612 	if (b != 0)
613 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
614 }
615 
616 static inline void ipv6_addr_prefix_copy(struct in6_addr *addr,
617 					 const struct in6_addr *pfx,
618 					 int plen)
619 {
620 	/* caller must guarantee 0 <= plen <= 128 */
621 	int o = plen >> 3,
622 	    b = plen & 0x7;
623 
624 	memcpy(addr->s6_addr, pfx, o);
625 	if (b != 0) {
626 		addr->s6_addr[o] &= ~(0xff00 >> b);
627 		addr->s6_addr[o] |= (pfx->s6_addr[o] & (0xff00 >> b));
628 	}
629 }
630 
631 static inline void __ipv6_addr_set_half(__be32 *addr,
632 					__be32 wh, __be32 wl)
633 {
634 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
635 #if defined(__BIG_ENDIAN)
636 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
637 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
638 		return;
639 	}
640 #elif defined(__LITTLE_ENDIAN)
641 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
642 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
643 		return;
644 	}
645 #endif
646 #endif
647 	addr[0] = wh;
648 	addr[1] = wl;
649 }
650 
651 static inline void ipv6_addr_set(struct in6_addr *addr,
652 				     __be32 w1, __be32 w2,
653 				     __be32 w3, __be32 w4)
654 {
655 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
656 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
657 }
658 
659 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
660 				   const struct in6_addr *a2)
661 {
662 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
663 	const unsigned long *ul1 = (const unsigned long *)a1;
664 	const unsigned long *ul2 = (const unsigned long *)a2;
665 
666 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
667 #else
668 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
669 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
670 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
671 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
672 #endif
673 }
674 
675 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
676 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
677 					      const __be64 *a2,
678 					      unsigned int len)
679 {
680 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
681 		return false;
682 	return true;
683 }
684 
685 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
686 				     const struct in6_addr *addr2,
687 				     unsigned int prefixlen)
688 {
689 	const __be64 *a1 = (const __be64 *)addr1;
690 	const __be64 *a2 = (const __be64 *)addr2;
691 
692 	if (prefixlen >= 64) {
693 		if (a1[0] ^ a2[0])
694 			return false;
695 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
696 	}
697 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
698 }
699 #else
700 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
701 				     const struct in6_addr *addr2,
702 				     unsigned int prefixlen)
703 {
704 	const __be32 *a1 = addr1->s6_addr32;
705 	const __be32 *a2 = addr2->s6_addr32;
706 	unsigned int pdw, pbi;
707 
708 	/* check complete u32 in prefix */
709 	pdw = prefixlen >> 5;
710 	if (pdw && memcmp(a1, a2, pdw << 2))
711 		return false;
712 
713 	/* check incomplete u32 in prefix */
714 	pbi = prefixlen & 0x1f;
715 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
716 		return false;
717 
718 	return true;
719 }
720 #endif
721 
722 static inline bool ipv6_addr_any(const struct in6_addr *a)
723 {
724 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
725 	const unsigned long *ul = (const unsigned long *)a;
726 
727 	return (ul[0] | ul[1]) == 0UL;
728 #else
729 	return (a->s6_addr32[0] | a->s6_addr32[1] |
730 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
731 #endif
732 }
733 
734 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
735 {
736 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
737 	const unsigned long *ul = (const unsigned long *)a;
738 	unsigned long x = ul[0] ^ ul[1];
739 
740 	return (u32)(x ^ (x >> 32));
741 #else
742 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
743 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
744 #endif
745 }
746 
747 /* more secured version of ipv6_addr_hash() */
748 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
749 {
750 	return jhash2((__force const u32 *)a->s6_addr32,
751 		      ARRAY_SIZE(a->s6_addr32), initval);
752 }
753 
754 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
755 {
756 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
757 	const __be64 *be = (const __be64 *)a;
758 
759 	return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
760 #else
761 	return (a->s6_addr32[0] | a->s6_addr32[1] |
762 		a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
763 #endif
764 }
765 
766 /*
767  * Note that we must __force cast these to unsigned long to make sparse happy,
768  * since all of the endian-annotated types are fixed size regardless of arch.
769  */
770 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
771 {
772 	return (
773 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
774 		*(unsigned long *)a |
775 #else
776 		(__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
777 #endif
778 		(__force unsigned long)(a->s6_addr32[2] ^
779 					cpu_to_be32(0x0000ffff))) == 0UL;
780 }
781 
782 static inline bool ipv6_addr_v4mapped_loopback(const struct in6_addr *a)
783 {
784 	return ipv6_addr_v4mapped(a) && ipv4_is_loopback(a->s6_addr32[3]);
785 }
786 
787 static inline u32 ipv6_portaddr_hash(const struct net *net,
788 				     const struct in6_addr *addr6,
789 				     unsigned int port)
790 {
791 	unsigned int hash, mix = net_hash_mix(net);
792 
793 	if (ipv6_addr_any(addr6))
794 		hash = jhash_1word(0, mix);
795 	else if (ipv6_addr_v4mapped(addr6))
796 		hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
797 	else
798 		hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
799 
800 	return hash ^ port;
801 }
802 
803 /*
804  * Check for a RFC 4843 ORCHID address
805  * (Overlay Routable Cryptographic Hash Identifiers)
806  */
807 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
808 {
809 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
810 }
811 
812 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
813 {
814 	return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
815 }
816 
817 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
818 					  struct in6_addr *v4mapped)
819 {
820 	ipv6_addr_set(v4mapped,
821 			0, 0,
822 			htonl(0x0000FFFF),
823 			addr);
824 }
825 
826 /*
827  * find the first different bit between two addresses
828  * length of address must be a multiple of 32bits
829  */
830 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
831 {
832 	const __be32 *a1 = token1, *a2 = token2;
833 	int i;
834 
835 	addrlen >>= 2;
836 
837 	for (i = 0; i < addrlen; i++) {
838 		__be32 xb = a1[i] ^ a2[i];
839 		if (xb)
840 			return i * 32 + 31 - __fls(ntohl(xb));
841 	}
842 
843 	/*
844 	 *	we should *never* get to this point since that
845 	 *	would mean the addrs are equal
846 	 *
847 	 *	However, we do get to it 8) And exactly, when
848 	 *	addresses are equal 8)
849 	 *
850 	 *	ip route add 1111::/128 via ...
851 	 *	ip route add 1111::/64 via ...
852 	 *	and we are here.
853 	 *
854 	 *	Ideally, this function should stop comparison
855 	 *	at prefix length. It does not, but it is still OK,
856 	 *	if returned value is greater than prefix length.
857 	 *					--ANK (980803)
858 	 */
859 	return addrlen << 5;
860 }
861 
862 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
863 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
864 {
865 	const __be64 *a1 = token1, *a2 = token2;
866 	int i;
867 
868 	addrlen >>= 3;
869 
870 	for (i = 0; i < addrlen; i++) {
871 		__be64 xb = a1[i] ^ a2[i];
872 		if (xb)
873 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
874 	}
875 
876 	return addrlen << 6;
877 }
878 #endif
879 
880 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
881 {
882 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
883 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
884 		return __ipv6_addr_diff64(token1, token2, addrlen);
885 #endif
886 	return __ipv6_addr_diff32(token1, token2, addrlen);
887 }
888 
889 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
890 {
891 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
892 }
893 
894 __be32 ipv6_select_ident(struct net *net,
895 			 const struct in6_addr *daddr,
896 			 const struct in6_addr *saddr);
897 __be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
898 
899 int ip6_dst_hoplimit(struct dst_entry *dst);
900 
901 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
902 				      struct dst_entry *dst)
903 {
904 	int hlimit;
905 
906 	if (ipv6_addr_is_multicast(&fl6->daddr))
907 		hlimit = READ_ONCE(np->mcast_hops);
908 	else
909 		hlimit = READ_ONCE(np->hop_limit);
910 	if (hlimit < 0)
911 		hlimit = ip6_dst_hoplimit(dst);
912 	return hlimit;
913 }
914 
915 /* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
916  * Equivalent to :	flow->v6addrs.src = iph->saddr;
917  *			flow->v6addrs.dst = iph->daddr;
918  */
919 static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
920 					    const struct ipv6hdr *iph)
921 {
922 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
923 		     offsetof(typeof(flow->addrs), v6addrs.src) +
924 		     sizeof(flow->addrs.v6addrs.src));
925 	memcpy(&flow->addrs.v6addrs, &iph->addrs, sizeof(flow->addrs.v6addrs));
926 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
927 }
928 
929 #if IS_ENABLED(CONFIG_IPV6)
930 
931 static inline bool ipv6_can_nonlocal_bind(struct net *net,
932 					  struct inet_sock *inet)
933 {
934 	return net->ipv6.sysctl.ip_nonlocal_bind ||
935 		test_bit(INET_FLAGS_FREEBIND, &inet->inet_flags) ||
936 		test_bit(INET_FLAGS_TRANSPARENT, &inet->inet_flags);
937 }
938 
939 /* Sysctl settings for net ipv6.auto_flowlabels */
940 #define IP6_AUTO_FLOW_LABEL_OFF		0
941 #define IP6_AUTO_FLOW_LABEL_OPTOUT	1
942 #define IP6_AUTO_FLOW_LABEL_OPTIN	2
943 #define IP6_AUTO_FLOW_LABEL_FORCED	3
944 
945 #define IP6_AUTO_FLOW_LABEL_MAX		IP6_AUTO_FLOW_LABEL_FORCED
946 
947 #define IP6_DEFAULT_AUTO_FLOW_LABELS	IP6_AUTO_FLOW_LABEL_OPTOUT
948 
949 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
950 					__be32 flowlabel, bool autolabel,
951 					struct flowi6 *fl6)
952 {
953 	u32 hash;
954 
955 	/* @flowlabel may include more than a flow label, eg, the traffic class.
956 	 * Here we want only the flow label value.
957 	 */
958 	flowlabel &= IPV6_FLOWLABEL_MASK;
959 
960 	if (flowlabel ||
961 	    net->ipv6.sysctl.auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF ||
962 	    (!autolabel &&
963 	     net->ipv6.sysctl.auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED))
964 		return flowlabel;
965 
966 	hash = skb_get_hash_flowi6(skb, fl6);
967 
968 	/* Since this is being sent on the wire obfuscate hash a bit
969 	 * to minimize possibility that any useful information to an
970 	 * attacker is leaked. Only lower 20 bits are relevant.
971 	 */
972 	hash = rol32(hash, 16);
973 
974 	flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
975 
976 	if (net->ipv6.sysctl.flowlabel_state_ranges)
977 		flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
978 
979 	return flowlabel;
980 }
981 
982 static inline int ip6_default_np_autolabel(struct net *net)
983 {
984 	switch (net->ipv6.sysctl.auto_flowlabels) {
985 	case IP6_AUTO_FLOW_LABEL_OFF:
986 	case IP6_AUTO_FLOW_LABEL_OPTIN:
987 	default:
988 		return 0;
989 	case IP6_AUTO_FLOW_LABEL_OPTOUT:
990 	case IP6_AUTO_FLOW_LABEL_FORCED:
991 		return 1;
992 	}
993 }
994 #else
995 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
996 					__be32 flowlabel, bool autolabel,
997 					struct flowi6 *fl6)
998 {
999 	return flowlabel;
1000 }
1001 static inline int ip6_default_np_autolabel(struct net *net)
1002 {
1003 	return 0;
1004 }
1005 #endif
1006 
1007 #if IS_ENABLED(CONFIG_IPV6)
1008 static inline int ip6_multipath_hash_policy(const struct net *net)
1009 {
1010 	return net->ipv6.sysctl.multipath_hash_policy;
1011 }
1012 static inline u32 ip6_multipath_hash_fields(const struct net *net)
1013 {
1014 	return net->ipv6.sysctl.multipath_hash_fields;
1015 }
1016 #else
1017 static inline int ip6_multipath_hash_policy(const struct net *net)
1018 {
1019 	return 0;
1020 }
1021 static inline u32 ip6_multipath_hash_fields(const struct net *net)
1022 {
1023 	return 0;
1024 }
1025 #endif
1026 
1027 /*
1028  *	Header manipulation
1029  */
1030 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
1031 				__be32 flowlabel)
1032 {
1033 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
1034 }
1035 
1036 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
1037 {
1038 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
1039 }
1040 
1041 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
1042 {
1043 	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
1044 }
1045 
1046 static inline u8 ip6_tclass(__be32 flowinfo)
1047 {
1048 	return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
1049 }
1050 
1051 static inline dscp_t ip6_dscp(__be32 flowinfo)
1052 {
1053 	return inet_dsfield_to_dscp(ip6_tclass(flowinfo));
1054 }
1055 
1056 static inline __be32 ip6_make_flowinfo(unsigned int tclass, __be32 flowlabel)
1057 {
1058 	return htonl(tclass << IPV6_TCLASS_SHIFT) | flowlabel;
1059 }
1060 
1061 static inline __be32 flowi6_get_flowlabel(const struct flowi6 *fl6)
1062 {
1063 	return fl6->flowlabel & IPV6_FLOWLABEL_MASK;
1064 }
1065 
1066 /*
1067  *	Prototypes exported by ipv6
1068  */
1069 
1070 /*
1071  *	rcv function (called from netdevice level)
1072  */
1073 
1074 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
1075 	     struct packet_type *pt, struct net_device *orig_dev);
1076 void ipv6_list_rcv(struct list_head *head, struct packet_type *pt,
1077 		   struct net_device *orig_dev);
1078 
1079 int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
1080 
1081 /*
1082  *	upper-layer output functions
1083  */
1084 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
1085 	     __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority);
1086 
1087 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
1088 
1089 int ip6_append_data(struct sock *sk,
1090 		    int getfrag(void *from, char *to, int offset, int len,
1091 				int odd, struct sk_buff *skb),
1092 		    void *from, size_t length, int transhdrlen,
1093 		    struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
1094 		    struct rt6_info *rt, unsigned int flags);
1095 
1096 int ip6_push_pending_frames(struct sock *sk);
1097 
1098 void ip6_flush_pending_frames(struct sock *sk);
1099 
1100 int ip6_send_skb(struct sk_buff *skb);
1101 
1102 struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
1103 			       struct inet_cork_full *cork,
1104 			       struct inet6_cork *v6_cork);
1105 struct sk_buff *ip6_make_skb(struct sock *sk,
1106 			     int getfrag(void *from, char *to, int offset,
1107 					 int len, int odd, struct sk_buff *skb),
1108 			     void *from, size_t length, int transhdrlen,
1109 			     struct ipcm6_cookie *ipc6,
1110 			     struct rt6_info *rt, unsigned int flags,
1111 			     struct inet_cork_full *cork);
1112 
1113 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
1114 {
1115 	return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
1116 			      &inet6_sk(sk)->cork);
1117 }
1118 
1119 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
1120 		   struct flowi6 *fl6);
1121 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6,
1122 				      const struct in6_addr *final_dst);
1123 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
1124 					 const struct in6_addr *final_dst,
1125 					 bool connected);
1126 struct dst_entry *ip6_blackhole_route(struct net *net,
1127 				      struct dst_entry *orig_dst);
1128 
1129 /*
1130  *	skb processing functions
1131  */
1132 
1133 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb);
1134 int ip6_forward(struct sk_buff *skb);
1135 int ip6_input(struct sk_buff *skb);
1136 int ip6_mc_input(struct sk_buff *skb);
1137 void ip6_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int nexthdr,
1138 			      bool have_final);
1139 
1140 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
1141 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
1142 
1143 /*
1144  *	Extension header (options) processing
1145  */
1146 
1147 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1148 			  u8 *proto, struct in6_addr **daddr_p,
1149 			  struct in6_addr *saddr);
1150 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
1151 			 u8 *proto);
1152 
1153 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
1154 		     __be16 *frag_offp);
1155 
1156 bool ipv6_ext_hdr(u8 nexthdr);
1157 
1158 enum {
1159 	IP6_FH_F_FRAG		= (1 << 0),
1160 	IP6_FH_F_AUTH		= (1 << 1),
1161 	IP6_FH_F_SKIP_RH	= (1 << 2),
1162 };
1163 
1164 /* find specified header and get offset to it */
1165 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
1166 		  unsigned short *fragoff, int *fragflg);
1167 
1168 int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type);
1169 
1170 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
1171 				const struct ipv6_txoptions *opt,
1172 				struct in6_addr *orig);
1173 
1174 /*
1175  *	socket options (ipv6_sockglue.c)
1176  */
1177 DECLARE_STATIC_KEY_FALSE(ip6_min_hopcount);
1178 
1179 int do_ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1180 		       unsigned int optlen);
1181 int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1182 		    unsigned int optlen);
1183 int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
1184 		       sockptr_t optval, sockptr_t optlen);
1185 int ipv6_getsockopt(struct sock *sk, int level, int optname,
1186 		    char __user *optval, int __user *optlen);
1187 
1188 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *addr,
1189 			   int addr_len);
1190 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
1191 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
1192 				 int addr_len);
1193 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr);
1194 void ip6_datagram_release_cb(struct sock *sk);
1195 
1196 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
1197 		    int *addr_len);
1198 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
1199 		     int *addr_len);
1200 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
1201 		     u32 info, u8 *payload);
1202 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
1203 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
1204 
1205 void inet6_cleanup_sock(struct sock *sk);
1206 void inet6_sock_destruct(struct sock *sk);
1207 int inet6_release(struct socket *sock);
1208 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
1209 int inet6_bind_sk(struct sock *sk, struct sockaddr *uaddr, int addr_len);
1210 int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
1211 		  int peer);
1212 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
1213 int inet6_compat_ioctl(struct socket *sock, unsigned int cmd,
1214 		unsigned long arg);
1215 
1216 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
1217 			      struct sock *sk);
1218 int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size);
1219 int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1220 		  int flags);
1221 
1222 /*
1223  * reassembly.c
1224  */
1225 extern const struct proto_ops inet6_stream_ops;
1226 extern const struct proto_ops inet6_dgram_ops;
1227 extern const struct proto_ops inet6_sockraw_ops;
1228 
1229 struct group_source_req;
1230 struct group_filter;
1231 
1232 int ip6_mc_source(int add, int omode, struct sock *sk,
1233 		  struct group_source_req *pgsr);
1234 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf,
1235 		  struct sockaddr_storage *list);
1236 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
1237 		  sockptr_t optval, size_t ss_offset);
1238 
1239 #ifdef CONFIG_PROC_FS
1240 int ac6_proc_init(struct net *net);
1241 void ac6_proc_exit(struct net *net);
1242 int raw6_proc_init(void);
1243 void raw6_proc_exit(void);
1244 int tcp6_proc_init(struct net *net);
1245 void tcp6_proc_exit(struct net *net);
1246 int udp6_proc_init(struct net *net);
1247 void udp6_proc_exit(struct net *net);
1248 int udplite6_proc_init(void);
1249 void udplite6_proc_exit(void);
1250 int ipv6_misc_proc_init(void);
1251 void ipv6_misc_proc_exit(void);
1252 int snmp6_register_dev(struct inet6_dev *idev);
1253 int snmp6_unregister_dev(struct inet6_dev *idev);
1254 
1255 #else
1256 static inline int ac6_proc_init(struct net *net) { return 0; }
1257 static inline void ac6_proc_exit(struct net *net) { }
1258 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
1259 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
1260 #endif
1261 
1262 #ifdef CONFIG_SYSCTL
1263 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
1264 size_t ipv6_icmp_sysctl_table_size(void);
1265 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
1266 size_t ipv6_route_sysctl_table_size(struct net *net);
1267 int ipv6_sysctl_register(void);
1268 void ipv6_sysctl_unregister(void);
1269 #endif
1270 
1271 int ipv6_sock_mc_join(struct sock *sk, int ifindex,
1272 		      const struct in6_addr *addr);
1273 int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,
1274 			  const struct in6_addr *addr, unsigned int mode);
1275 int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
1276 		      const struct in6_addr *addr);
1277 
1278 static inline int ip6_sock_set_v6only(struct sock *sk)
1279 {
1280 	if (inet_sk(sk)->inet_num)
1281 		return -EINVAL;
1282 	lock_sock(sk);
1283 	sk->sk_ipv6only = true;
1284 	release_sock(sk);
1285 	return 0;
1286 }
1287 
1288 static inline void ip6_sock_set_recverr(struct sock *sk)
1289 {
1290 	inet6_set_bit(RECVERR6, sk);
1291 }
1292 
1293 #define IPV6_PREFER_SRC_MASK (IPV6_PREFER_SRC_TMP | IPV6_PREFER_SRC_PUBLIC | \
1294 			      IPV6_PREFER_SRC_COA)
1295 
1296 static inline int ip6_sock_set_addr_preferences(struct sock *sk, int val)
1297 {
1298 	unsigned int prefmask = ~IPV6_PREFER_SRC_MASK;
1299 	unsigned int pref = 0;
1300 
1301 	/* check PUBLIC/TMP/PUBTMP_DEFAULT conflicts */
1302 	switch (val & (IPV6_PREFER_SRC_PUBLIC |
1303 		       IPV6_PREFER_SRC_TMP |
1304 		       IPV6_PREFER_SRC_PUBTMP_DEFAULT)) {
1305 	case IPV6_PREFER_SRC_PUBLIC:
1306 		pref |= IPV6_PREFER_SRC_PUBLIC;
1307 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1308 			      IPV6_PREFER_SRC_TMP);
1309 		break;
1310 	case IPV6_PREFER_SRC_TMP:
1311 		pref |= IPV6_PREFER_SRC_TMP;
1312 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1313 			      IPV6_PREFER_SRC_TMP);
1314 		break;
1315 	case IPV6_PREFER_SRC_PUBTMP_DEFAULT:
1316 		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
1317 			      IPV6_PREFER_SRC_TMP);
1318 		break;
1319 	case 0:
1320 		break;
1321 	default:
1322 		return -EINVAL;
1323 	}
1324 
1325 	/* check HOME/COA conflicts */
1326 	switch (val & (IPV6_PREFER_SRC_HOME | IPV6_PREFER_SRC_COA)) {
1327 	case IPV6_PREFER_SRC_HOME:
1328 		prefmask &= ~IPV6_PREFER_SRC_COA;
1329 		break;
1330 	case IPV6_PREFER_SRC_COA:
1331 		pref |= IPV6_PREFER_SRC_COA;
1332 		break;
1333 	case 0:
1334 		break;
1335 	default:
1336 		return -EINVAL;
1337 	}
1338 
1339 	/* check CGA/NONCGA conflicts */
1340 	switch (val & (IPV6_PREFER_SRC_CGA|IPV6_PREFER_SRC_NONCGA)) {
1341 	case IPV6_PREFER_SRC_CGA:
1342 	case IPV6_PREFER_SRC_NONCGA:
1343 	case 0:
1344 		break;
1345 	default:
1346 		return -EINVAL;
1347 	}
1348 
1349 	WRITE_ONCE(inet6_sk(sk)->srcprefs,
1350 		   (READ_ONCE(inet6_sk(sk)->srcprefs) & prefmask) | pref);
1351 	return 0;
1352 }
1353 
1354 static inline void ip6_sock_set_recvpktinfo(struct sock *sk)
1355 {
1356 	lock_sock(sk);
1357 	inet6_sk(sk)->rxopt.bits.rxinfo = true;
1358 	release_sock(sk);
1359 }
1360 
1361 #define IPV6_ADDR_WORDS 4
1362 
1363 static inline void ipv6_addr_cpu_to_be32(__be32 *dst, const u32 *src)
1364 {
1365 	cpu_to_be32_array(dst, src, IPV6_ADDR_WORDS);
1366 }
1367 
1368 static inline void ipv6_addr_be32_to_cpu(u32 *dst, const __be32 *src)
1369 {
1370 	be32_to_cpu_array(dst, src, IPV6_ADDR_WORDS);
1371 }
1372 
1373 #endif /* _NET_IPV6_H */
1374