xref: /openbmc/linux/include/net/ipv6.h (revision a8fe58ce)
1 /*
2  *	Linux INET6 implementation
3  *
4  *	Authors:
5  *	Pedro Roque		<roque@di.fc.ul.pt>
6  *
7  *	This program is free software; you can redistribute it and/or
8  *      modify it under the terms of the GNU General Public License
9  *      as published by the Free Software Foundation; either version
10  *      2 of the License, or (at your option) any later version.
11  */
12 
13 #ifndef _NET_IPV6_H
14 #define _NET_IPV6_H
15 
16 #include <linux/ipv6.h>
17 #include <linux/hardirq.h>
18 #include <linux/jhash.h>
19 #include <net/if_inet6.h>
20 #include <net/ndisc.h>
21 #include <net/flow.h>
22 #include <net/flow_dissector.h>
23 #include <net/snmp.h>
24 
25 #define SIN6_LEN_RFC2133	24
26 
27 #define IPV6_MAXPLEN		65535
28 
29 /*
30  *	NextHeader field of IPv6 header
31  */
32 
33 #define NEXTHDR_HOP		0	/* Hop-by-hop option header. */
34 #define NEXTHDR_TCP		6	/* TCP segment. */
35 #define NEXTHDR_UDP		17	/* UDP message. */
36 #define NEXTHDR_IPV6		41	/* IPv6 in IPv6 */
37 #define NEXTHDR_ROUTING		43	/* Routing header. */
38 #define NEXTHDR_FRAGMENT	44	/* Fragmentation/reassembly header. */
39 #define NEXTHDR_GRE		47	/* GRE header. */
40 #define NEXTHDR_ESP		50	/* Encapsulating security payload. */
41 #define NEXTHDR_AUTH		51	/* Authentication header. */
42 #define NEXTHDR_ICMP		58	/* ICMP for IPv6. */
43 #define NEXTHDR_NONE		59	/* No next header */
44 #define NEXTHDR_DEST		60	/* Destination options header. */
45 #define NEXTHDR_SCTP		132	/* SCTP message. */
46 #define NEXTHDR_MOBILITY	135	/* Mobility header. */
47 
48 #define NEXTHDR_MAX		255
49 
50 #define IPV6_DEFAULT_HOPLIMIT   64
51 #define IPV6_DEFAULT_MCASTHOPS	1
52 
53 /*
54  *	Addr type
55  *
56  *	type	-	unicast | multicast
57  *	scope	-	local	| site	    | global
58  *	v4	-	compat
59  *	v4mapped
60  *	any
61  *	loopback
62  */
63 
64 #define IPV6_ADDR_ANY		0x0000U
65 
66 #define IPV6_ADDR_UNICAST      	0x0001U
67 #define IPV6_ADDR_MULTICAST    	0x0002U
68 
69 #define IPV6_ADDR_LOOPBACK	0x0010U
70 #define IPV6_ADDR_LINKLOCAL	0x0020U
71 #define IPV6_ADDR_SITELOCAL	0x0040U
72 
73 #define IPV6_ADDR_COMPATv4	0x0080U
74 
75 #define IPV6_ADDR_SCOPE_MASK	0x00f0U
76 
77 #define IPV6_ADDR_MAPPED	0x1000U
78 
79 /*
80  *	Addr scopes
81  */
82 #define IPV6_ADDR_MC_SCOPE(a)	\
83 	((a)->s6_addr[1] & 0x0f)	/* nonstandard */
84 #define __IPV6_ADDR_SCOPE_INVALID	-1
85 #define IPV6_ADDR_SCOPE_NODELOCAL	0x01
86 #define IPV6_ADDR_SCOPE_LINKLOCAL	0x02
87 #define IPV6_ADDR_SCOPE_SITELOCAL	0x05
88 #define IPV6_ADDR_SCOPE_ORGLOCAL	0x08
89 #define IPV6_ADDR_SCOPE_GLOBAL		0x0e
90 
91 /*
92  *	Addr flags
93  */
94 #define IPV6_ADDR_MC_FLAG_TRANSIENT(a)	\
95 	((a)->s6_addr[1] & 0x10)
96 #define IPV6_ADDR_MC_FLAG_PREFIX(a)	\
97 	((a)->s6_addr[1] & 0x20)
98 #define IPV6_ADDR_MC_FLAG_RENDEZVOUS(a)	\
99 	((a)->s6_addr[1] & 0x40)
100 
101 /*
102  *	fragmentation header
103  */
104 
105 struct frag_hdr {
106 	__u8	nexthdr;
107 	__u8	reserved;
108 	__be16	frag_off;
109 	__be32	identification;
110 };
111 
112 #define	IP6_MF		0x0001
113 #define	IP6_OFFSET	0xFFF8
114 
115 #define IP6_REPLY_MARK(net, mark) \
116 	((net)->ipv6.sysctl.fwmark_reflect ? (mark) : 0)
117 
118 #include <net/sock.h>
119 
120 /* sysctls */
121 extern int sysctl_mld_max_msf;
122 extern int sysctl_mld_qrv;
123 
124 #define _DEVINC(net, statname, modifier, idev, field)			\
125 ({									\
126 	struct inet6_dev *_idev = (idev);				\
127 	if (likely(_idev != NULL))					\
128 		SNMP_INC_STATS##modifier((_idev)->stats.statname, (field)); \
129 	SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
130 })
131 
132 /* per device counters are atomic_long_t */
133 #define _DEVINCATOMIC(net, statname, modifier, idev, field)		\
134 ({									\
135 	struct inet6_dev *_idev = (idev);				\
136 	if (likely(_idev != NULL))					\
137 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
138 	SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\
139 })
140 
141 /* per device and per net counters are atomic_long_t */
142 #define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field)		\
143 ({									\
144 	struct inet6_dev *_idev = (idev);				\
145 	if (likely(_idev != NULL))					\
146 		SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \
147 	SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\
148 })
149 
150 #define _DEVADD(net, statname, modifier, idev, field, val)		\
151 ({									\
152 	struct inet6_dev *_idev = (idev);				\
153 	if (likely(_idev != NULL))					\
154 		SNMP_ADD_STATS##modifier((_idev)->stats.statname, (field), (val)); \
155 	SNMP_ADD_STATS##modifier((net)->mib.statname##_statistics, (field), (val));\
156 })
157 
158 #define _DEVUPD(net, statname, modifier, idev, field, val)		\
159 ({									\
160 	struct inet6_dev *_idev = (idev);				\
161 	if (likely(_idev != NULL))					\
162 		SNMP_UPD_PO_STATS##modifier((_idev)->stats.statname, field, (val)); \
163 	SNMP_UPD_PO_STATS##modifier((net)->mib.statname##_statistics, field, (val));\
164 })
165 
166 /* MIBs */
167 
168 #define IP6_INC_STATS(net, idev,field)		\
169 		_DEVINC(net, ipv6, 64, idev, field)
170 #define IP6_INC_STATS_BH(net, idev,field)	\
171 		_DEVINC(net, ipv6, 64_BH, idev, field)
172 #define IP6_ADD_STATS(net, idev,field,val)	\
173 		_DEVADD(net, ipv6, 64, idev, field, val)
174 #define IP6_ADD_STATS_BH(net, idev,field,val)	\
175 		_DEVADD(net, ipv6, 64_BH, idev, field, val)
176 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
177 		_DEVUPD(net, ipv6, 64, idev, field, val)
178 #define IP6_UPD_PO_STATS_BH(net, idev,field,val)   \
179 		_DEVUPD(net, ipv6, 64_BH, idev, field, val)
180 #define ICMP6_INC_STATS(net, idev, field)	\
181 		_DEVINCATOMIC(net, icmpv6, , idev, field)
182 #define ICMP6_INC_STATS_BH(net, idev, field)	\
183 		_DEVINCATOMIC(net, icmpv6, _BH, idev, field)
184 
185 #define ICMP6MSGOUT_INC_STATS(net, idev, field)		\
186 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
187 #define ICMP6MSGOUT_INC_STATS_BH(net, idev, field)	\
188 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
189 #define ICMP6MSGIN_INC_STATS_BH(net, idev, field)	\
190 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
191 
192 struct ip6_ra_chain {
193 	struct ip6_ra_chain	*next;
194 	struct sock		*sk;
195 	int			sel;
196 	void			(*destructor)(struct sock *);
197 };
198 
199 extern struct ip6_ra_chain	*ip6_ra_chain;
200 extern rwlock_t ip6_ra_lock;
201 
202 /*
203    This structure is prepared by protocol, when parsing
204    ancillary data and passed to IPv6.
205  */
206 
207 struct ipv6_txoptions {
208 	atomic_t		refcnt;
209 	/* Length of this structure */
210 	int			tot_len;
211 
212 	/* length of extension headers   */
213 
214 	__u16			opt_flen;	/* after fragment hdr */
215 	__u16			opt_nflen;	/* before fragment hdr */
216 
217 	struct ipv6_opt_hdr	*hopopt;
218 	struct ipv6_opt_hdr	*dst0opt;
219 	struct ipv6_rt_hdr	*srcrt;	/* Routing Header */
220 	struct ipv6_opt_hdr	*dst1opt;
221 	struct rcu_head		rcu;
222 	/* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
223 };
224 
225 struct ip6_flowlabel {
226 	struct ip6_flowlabel __rcu *next;
227 	__be32			label;
228 	atomic_t		users;
229 	struct in6_addr		dst;
230 	struct ipv6_txoptions	*opt;
231 	unsigned long		linger;
232 	struct rcu_head		rcu;
233 	u8			share;
234 	union {
235 		struct pid *pid;
236 		kuid_t uid;
237 	} owner;
238 	unsigned long		lastuse;
239 	unsigned long		expires;
240 	struct net		*fl_net;
241 };
242 
243 #define IPV6_FLOWINFO_MASK		cpu_to_be32(0x0FFFFFFF)
244 #define IPV6_FLOWLABEL_MASK		cpu_to_be32(0x000FFFFF)
245 #define IPV6_FLOWLABEL_STATELESS_FLAG	cpu_to_be32(0x00080000)
246 
247 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
248 #define IPV6_TCLASS_SHIFT	20
249 
250 struct ipv6_fl_socklist {
251 	struct ipv6_fl_socklist	__rcu	*next;
252 	struct ip6_flowlabel		*fl;
253 	struct rcu_head			rcu;
254 };
255 
256 static inline struct ipv6_txoptions *txopt_get(const struct ipv6_pinfo *np)
257 {
258 	struct ipv6_txoptions *opt;
259 
260 	rcu_read_lock();
261 	opt = rcu_dereference(np->opt);
262 	if (opt && !atomic_inc_not_zero(&opt->refcnt))
263 		opt = NULL;
264 	rcu_read_unlock();
265 	return opt;
266 }
267 
268 static inline void txopt_put(struct ipv6_txoptions *opt)
269 {
270 	if (opt && atomic_dec_and_test(&opt->refcnt))
271 		kfree_rcu(opt, rcu);
272 }
273 
274 struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label);
275 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
276 					 struct ip6_flowlabel *fl,
277 					 struct ipv6_txoptions *fopt);
278 void fl6_free_socklist(struct sock *sk);
279 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
280 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
281 			   int flags);
282 int ip6_flowlabel_init(void);
283 void ip6_flowlabel_cleanup(void);
284 
285 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
286 {
287 	if (fl)
288 		atomic_dec(&fl->users);
289 }
290 
291 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
292 
293 int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
294 			       struct icmp6hdr *thdr, int len);
295 
296 int ip6_ra_control(struct sock *sk, int sel);
297 
298 int ipv6_parse_hopopts(struct sk_buff *skb);
299 
300 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
301 					struct ipv6_txoptions *opt);
302 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
303 					  struct ipv6_txoptions *opt,
304 					  int newtype,
305 					  struct ipv6_opt_hdr __user *newopt,
306 					  int newoptlen);
307 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
308 					  struct ipv6_txoptions *opt);
309 
310 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
311 		       const struct inet6_skb_parm *opt);
312 
313 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
314 {
315 	/* If forwarding is enabled, RA are not accepted unless the special
316 	 * hybrid mode (accept_ra=2) is enabled.
317 	 */
318 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
319 	    idev->cnf.accept_ra;
320 }
321 
322 #if IS_ENABLED(CONFIG_IPV6)
323 static inline int ip6_frag_mem(struct net *net)
324 {
325 	return sum_frag_mem_limit(&net->ipv6.frags);
326 }
327 #endif
328 
329 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
330 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
331 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
332 
333 int __ipv6_addr_type(const struct in6_addr *addr);
334 static inline int ipv6_addr_type(const struct in6_addr *addr)
335 {
336 	return __ipv6_addr_type(addr) & 0xffff;
337 }
338 
339 static inline int ipv6_addr_scope(const struct in6_addr *addr)
340 {
341 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
342 }
343 
344 static inline int __ipv6_addr_src_scope(int type)
345 {
346 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
347 }
348 
349 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
350 {
351 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
352 }
353 
354 static inline bool __ipv6_addr_needs_scope_id(int type)
355 {
356 	return type & IPV6_ADDR_LINKLOCAL ||
357 	       (type & IPV6_ADDR_MULTICAST &&
358 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
359 }
360 
361 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
362 {
363 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
364 }
365 
366 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
367 {
368 	return memcmp(a1, a2, sizeof(struct in6_addr));
369 }
370 
371 static inline bool
372 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
373 		     const struct in6_addr *a2)
374 {
375 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
376 	const unsigned long *ul1 = (const unsigned long *)a1;
377 	const unsigned long *ulm = (const unsigned long *)m;
378 	const unsigned long *ul2 = (const unsigned long *)a2;
379 
380 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
381 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
382 #else
383 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
384 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
385 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
386 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
387 #endif
388 }
389 
390 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
391 				    const struct in6_addr *addr,
392 				    int plen)
393 {
394 	/* caller must guarantee 0 <= plen <= 128 */
395 	int o = plen >> 3,
396 	    b = plen & 0x7;
397 
398 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
399 	memcpy(pfx->s6_addr, addr, o);
400 	if (b != 0)
401 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
402 }
403 
404 static inline void ipv6_addr_prefix_copy(struct in6_addr *addr,
405 					 const struct in6_addr *pfx,
406 					 int plen)
407 {
408 	/* caller must guarantee 0 <= plen <= 128 */
409 	int o = plen >> 3,
410 	    b = plen & 0x7;
411 
412 	memcpy(addr->s6_addr, pfx, o);
413 	if (b != 0) {
414 		addr->s6_addr[o] &= ~(0xff00 >> b);
415 		addr->s6_addr[o] |= (pfx->s6_addr[o] & (0xff00 >> b));
416 	}
417 }
418 
419 static inline void __ipv6_addr_set_half(__be32 *addr,
420 					__be32 wh, __be32 wl)
421 {
422 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
423 #if defined(__BIG_ENDIAN)
424 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
425 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
426 		return;
427 	}
428 #elif defined(__LITTLE_ENDIAN)
429 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
430 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
431 		return;
432 	}
433 #endif
434 #endif
435 	addr[0] = wh;
436 	addr[1] = wl;
437 }
438 
439 static inline void ipv6_addr_set(struct in6_addr *addr,
440 				     __be32 w1, __be32 w2,
441 				     __be32 w3, __be32 w4)
442 {
443 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
444 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
445 }
446 
447 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
448 				   const struct in6_addr *a2)
449 {
450 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
451 	const unsigned long *ul1 = (const unsigned long *)a1;
452 	const unsigned long *ul2 = (const unsigned long *)a2;
453 
454 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
455 #else
456 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
457 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
458 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
459 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
460 #endif
461 }
462 
463 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
464 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
465 					      const __be64 *a2,
466 					      unsigned int len)
467 {
468 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
469 		return false;
470 	return true;
471 }
472 
473 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
474 				     const struct in6_addr *addr2,
475 				     unsigned int prefixlen)
476 {
477 	const __be64 *a1 = (const __be64 *)addr1;
478 	const __be64 *a2 = (const __be64 *)addr2;
479 
480 	if (prefixlen >= 64) {
481 		if (a1[0] ^ a2[0])
482 			return false;
483 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
484 	}
485 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
486 }
487 #else
488 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
489 				     const struct in6_addr *addr2,
490 				     unsigned int prefixlen)
491 {
492 	const __be32 *a1 = addr1->s6_addr32;
493 	const __be32 *a2 = addr2->s6_addr32;
494 	unsigned int pdw, pbi;
495 
496 	/* check complete u32 in prefix */
497 	pdw = prefixlen >> 5;
498 	if (pdw && memcmp(a1, a2, pdw << 2))
499 		return false;
500 
501 	/* check incomplete u32 in prefix */
502 	pbi = prefixlen & 0x1f;
503 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
504 		return false;
505 
506 	return true;
507 }
508 #endif
509 
510 struct inet_frag_queue;
511 
512 enum ip6_defrag_users {
513 	IP6_DEFRAG_LOCAL_DELIVER,
514 	IP6_DEFRAG_CONNTRACK_IN,
515 	__IP6_DEFRAG_CONNTRACK_IN	= IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
516 	IP6_DEFRAG_CONNTRACK_OUT,
517 	__IP6_DEFRAG_CONNTRACK_OUT	= IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
518 	IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
519 	__IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
520 };
521 
522 struct ip6_create_arg {
523 	__be32 id;
524 	u32 user;
525 	const struct in6_addr *src;
526 	const struct in6_addr *dst;
527 	int iif;
528 	u8 ecn;
529 };
530 
531 void ip6_frag_init(struct inet_frag_queue *q, const void *a);
532 bool ip6_frag_match(const struct inet_frag_queue *q, const void *a);
533 
534 /*
535  *	Equivalent of ipv4 struct ip
536  */
537 struct frag_queue {
538 	struct inet_frag_queue	q;
539 
540 	__be32			id;		/* fragment id		*/
541 	u32			user;
542 	struct in6_addr		saddr;
543 	struct in6_addr		daddr;
544 
545 	int			iif;
546 	unsigned int		csum;
547 	__u16			nhoffset;
548 	u8			ecn;
549 };
550 
551 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
552 			   struct inet_frags *frags);
553 
554 static inline bool ipv6_addr_any(const struct in6_addr *a)
555 {
556 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
557 	const unsigned long *ul = (const unsigned long *)a;
558 
559 	return (ul[0] | ul[1]) == 0UL;
560 #else
561 	return (a->s6_addr32[0] | a->s6_addr32[1] |
562 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
563 #endif
564 }
565 
566 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
567 {
568 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
569 	const unsigned long *ul = (const unsigned long *)a;
570 	unsigned long x = ul[0] ^ ul[1];
571 
572 	return (u32)(x ^ (x >> 32));
573 #else
574 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
575 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
576 #endif
577 }
578 
579 /* more secured version of ipv6_addr_hash() */
580 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
581 {
582 	u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
583 
584 	return jhash_3words(v,
585 			    (__force u32)a->s6_addr32[2],
586 			    (__force u32)a->s6_addr32[3],
587 			    initval);
588 }
589 
590 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
591 {
592 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
593 	const __be64 *be = (const __be64 *)a;
594 
595 	return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
596 #else
597 	return (a->s6_addr32[0] | a->s6_addr32[1] |
598 		a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
599 #endif
600 }
601 
602 /*
603  * Note that we must __force cast these to unsigned long to make sparse happy,
604  * since all of the endian-annotated types are fixed size regardless of arch.
605  */
606 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
607 {
608 	return (
609 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
610 		*(unsigned long *)a |
611 #else
612 		(__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
613 #endif
614 		(__force unsigned long)(a->s6_addr32[2] ^
615 					cpu_to_be32(0x0000ffff))) == 0UL;
616 }
617 
618 /*
619  * Check for a RFC 4843 ORCHID address
620  * (Overlay Routable Cryptographic Hash Identifiers)
621  */
622 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
623 {
624 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
625 }
626 
627 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
628 {
629 	return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
630 }
631 
632 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
633 					  struct in6_addr *v4mapped)
634 {
635 	ipv6_addr_set(v4mapped,
636 			0, 0,
637 			htonl(0x0000FFFF),
638 			addr);
639 }
640 
641 /*
642  * find the first different bit between two addresses
643  * length of address must be a multiple of 32bits
644  */
645 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
646 {
647 	const __be32 *a1 = token1, *a2 = token2;
648 	int i;
649 
650 	addrlen >>= 2;
651 
652 	for (i = 0; i < addrlen; i++) {
653 		__be32 xb = a1[i] ^ a2[i];
654 		if (xb)
655 			return i * 32 + 31 - __fls(ntohl(xb));
656 	}
657 
658 	/*
659 	 *	we should *never* get to this point since that
660 	 *	would mean the addrs are equal
661 	 *
662 	 *	However, we do get to it 8) And exacly, when
663 	 *	addresses are equal 8)
664 	 *
665 	 *	ip route add 1111::/128 via ...
666 	 *	ip route add 1111::/64 via ...
667 	 *	and we are here.
668 	 *
669 	 *	Ideally, this function should stop comparison
670 	 *	at prefix length. It does not, but it is still OK,
671 	 *	if returned value is greater than prefix length.
672 	 *					--ANK (980803)
673 	 */
674 	return addrlen << 5;
675 }
676 
677 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
678 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
679 {
680 	const __be64 *a1 = token1, *a2 = token2;
681 	int i;
682 
683 	addrlen >>= 3;
684 
685 	for (i = 0; i < addrlen; i++) {
686 		__be64 xb = a1[i] ^ a2[i];
687 		if (xb)
688 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
689 	}
690 
691 	return addrlen << 6;
692 }
693 #endif
694 
695 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
696 {
697 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
698 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
699 		return __ipv6_addr_diff64(token1, token2, addrlen);
700 #endif
701 	return __ipv6_addr_diff32(token1, token2, addrlen);
702 }
703 
704 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
705 {
706 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
707 }
708 
709 __be32 ipv6_select_ident(struct net *net,
710 			 const struct in6_addr *daddr,
711 			 const struct in6_addr *saddr);
712 void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
713 
714 int ip6_dst_hoplimit(struct dst_entry *dst);
715 
716 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
717 				      struct dst_entry *dst)
718 {
719 	int hlimit;
720 
721 	if (ipv6_addr_is_multicast(&fl6->daddr))
722 		hlimit = np->mcast_hops;
723 	else
724 		hlimit = np->hop_limit;
725 	if (hlimit < 0)
726 		hlimit = ip6_dst_hoplimit(dst);
727 	return hlimit;
728 }
729 
730 /* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
731  * Equivalent to :	flow->v6addrs.src = iph->saddr;
732  *			flow->v6addrs.dst = iph->daddr;
733  */
734 static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
735 					    const struct ipv6hdr *iph)
736 {
737 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
738 		     offsetof(typeof(flow->addrs), v6addrs.src) +
739 		     sizeof(flow->addrs.v6addrs.src));
740 	memcpy(&flow->addrs.v6addrs, &iph->saddr, sizeof(flow->addrs.v6addrs));
741 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
742 }
743 
744 #if IS_ENABLED(CONFIG_IPV6)
745 
746 /* Sysctl settings for net ipv6.auto_flowlabels */
747 #define IP6_AUTO_FLOW_LABEL_OFF		0
748 #define IP6_AUTO_FLOW_LABEL_OPTOUT	1
749 #define IP6_AUTO_FLOW_LABEL_OPTIN	2
750 #define IP6_AUTO_FLOW_LABEL_FORCED	3
751 
752 #define IP6_AUTO_FLOW_LABEL_MAX		IP6_AUTO_FLOW_LABEL_FORCED
753 
754 #define IP6_DEFAULT_AUTO_FLOW_LABELS	IP6_AUTO_FLOW_LABEL_OPTOUT
755 
756 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
757 					__be32 flowlabel, bool autolabel,
758 					struct flowi6 *fl6)
759 {
760 	u32 hash;
761 
762 	if (flowlabel ||
763 	    net->ipv6.sysctl.auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF ||
764 	    (!autolabel &&
765 	     net->ipv6.sysctl.auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED))
766 		return flowlabel;
767 
768 	hash = skb_get_hash_flowi6(skb, fl6);
769 
770 	/* Since this is being sent on the wire obfuscate hash a bit
771 	 * to minimize possbility that any useful information to an
772 	 * attacker is leaked. Only lower 20 bits are relevant.
773 	 */
774 	rol32(hash, 16);
775 
776 	flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
777 
778 	if (net->ipv6.sysctl.flowlabel_state_ranges)
779 		flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
780 
781 	return flowlabel;
782 }
783 
784 static inline int ip6_default_np_autolabel(struct net *net)
785 {
786 	switch (net->ipv6.sysctl.auto_flowlabels) {
787 	case IP6_AUTO_FLOW_LABEL_OFF:
788 	case IP6_AUTO_FLOW_LABEL_OPTIN:
789 	default:
790 		return 0;
791 	case IP6_AUTO_FLOW_LABEL_OPTOUT:
792 	case IP6_AUTO_FLOW_LABEL_FORCED:
793 		return 1;
794 	}
795 }
796 #else
797 static inline void ip6_set_txhash(struct sock *sk) { }
798 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
799 					__be32 flowlabel, bool autolabel,
800 					struct flowi6 *fl6)
801 {
802 	return flowlabel;
803 }
804 static inline int ip6_default_np_autolabel(struct net *net)
805 {
806 	return 0;
807 }
808 #endif
809 
810 
811 /*
812  *	Header manipulation
813  */
814 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
815 				__be32 flowlabel)
816 {
817 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
818 }
819 
820 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
821 {
822 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
823 }
824 
825 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
826 {
827 	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
828 }
829 
830 static inline u8 ip6_tclass(__be32 flowinfo)
831 {
832 	return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
833 }
834 /*
835  *	Prototypes exported by ipv6
836  */
837 
838 /*
839  *	rcv function (called from netdevice level)
840  */
841 
842 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
843 	     struct packet_type *pt, struct net_device *orig_dev);
844 
845 int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
846 
847 /*
848  *	upper-layer output functions
849  */
850 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
851 	     struct ipv6_txoptions *opt, int tclass);
852 
853 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
854 
855 int ip6_append_data(struct sock *sk,
856 		    int getfrag(void *from, char *to, int offset, int len,
857 				int odd, struct sk_buff *skb),
858 		    void *from, int length, int transhdrlen, int hlimit,
859 		    int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
860 		    struct rt6_info *rt, unsigned int flags, int dontfrag);
861 
862 int ip6_push_pending_frames(struct sock *sk);
863 
864 void ip6_flush_pending_frames(struct sock *sk);
865 
866 int ip6_send_skb(struct sk_buff *skb);
867 
868 struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
869 			       struct inet_cork_full *cork,
870 			       struct inet6_cork *v6_cork);
871 struct sk_buff *ip6_make_skb(struct sock *sk,
872 			     int getfrag(void *from, char *to, int offset,
873 					 int len, int odd, struct sk_buff *skb),
874 			     void *from, int length, int transhdrlen,
875 			     int hlimit, int tclass, struct ipv6_txoptions *opt,
876 			     struct flowi6 *fl6, struct rt6_info *rt,
877 			     unsigned int flags, int dontfrag);
878 
879 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
880 {
881 	return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
882 			      &inet6_sk(sk)->cork);
883 }
884 
885 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
886 		   struct flowi6 *fl6);
887 struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
888 				      const struct in6_addr *final_dst);
889 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
890 					 const struct in6_addr *final_dst);
891 struct dst_entry *ip6_blackhole_route(struct net *net,
892 				      struct dst_entry *orig_dst);
893 
894 /*
895  *	skb processing functions
896  */
897 
898 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb);
899 int ip6_forward(struct sk_buff *skb);
900 int ip6_input(struct sk_buff *skb);
901 int ip6_mc_input(struct sk_buff *skb);
902 
903 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
904 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
905 
906 /*
907  *	Extension header (options) processing
908  */
909 
910 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
911 			  u8 *proto, struct in6_addr **daddr_p);
912 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
913 			 u8 *proto);
914 
915 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
916 		     __be16 *frag_offp);
917 
918 bool ipv6_ext_hdr(u8 nexthdr);
919 
920 enum {
921 	IP6_FH_F_FRAG		= (1 << 0),
922 	IP6_FH_F_AUTH		= (1 << 1),
923 	IP6_FH_F_SKIP_RH	= (1 << 2),
924 };
925 
926 /* find specified header and get offset to it */
927 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
928 		  unsigned short *fragoff, int *fragflg);
929 
930 int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);
931 
932 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
933 				const struct ipv6_txoptions *opt,
934 				struct in6_addr *orig);
935 
936 /*
937  *	socket options (ipv6_sockglue.c)
938  */
939 
940 int ipv6_setsockopt(struct sock *sk, int level, int optname,
941 		    char __user *optval, unsigned int optlen);
942 int ipv6_getsockopt(struct sock *sk, int level, int optname,
943 		    char __user *optval, int __user *optlen);
944 int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
945 			   char __user *optval, unsigned int optlen);
946 int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
947 			   char __user *optval, int __user *optlen);
948 
949 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
950 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
951 				 int addr_len);
952 
953 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
954 		    int *addr_len);
955 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
956 		     int *addr_len);
957 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
958 		     u32 info, u8 *payload);
959 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
960 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
961 
962 int inet6_release(struct socket *sock);
963 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
964 int inet6_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len,
965 		  int peer);
966 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
967 
968 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
969 			      struct sock *sk);
970 
971 /*
972  * reassembly.c
973  */
974 extern const struct proto_ops inet6_stream_ops;
975 extern const struct proto_ops inet6_dgram_ops;
976 
977 struct group_source_req;
978 struct group_filter;
979 
980 int ip6_mc_source(int add, int omode, struct sock *sk,
981 		  struct group_source_req *pgsr);
982 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
983 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
984 		  struct group_filter __user *optval, int __user *optlen);
985 
986 #ifdef CONFIG_PROC_FS
987 int ac6_proc_init(struct net *net);
988 void ac6_proc_exit(struct net *net);
989 int raw6_proc_init(void);
990 void raw6_proc_exit(void);
991 int tcp6_proc_init(struct net *net);
992 void tcp6_proc_exit(struct net *net);
993 int udp6_proc_init(struct net *net);
994 void udp6_proc_exit(struct net *net);
995 int udplite6_proc_init(void);
996 void udplite6_proc_exit(void);
997 int ipv6_misc_proc_init(void);
998 void ipv6_misc_proc_exit(void);
999 int snmp6_register_dev(struct inet6_dev *idev);
1000 int snmp6_unregister_dev(struct inet6_dev *idev);
1001 
1002 #else
1003 static inline int ac6_proc_init(struct net *net) { return 0; }
1004 static inline void ac6_proc_exit(struct net *net) { }
1005 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
1006 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
1007 #endif
1008 
1009 #ifdef CONFIG_SYSCTL
1010 extern struct ctl_table ipv6_route_table_template[];
1011 
1012 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
1013 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
1014 int ipv6_sysctl_register(void);
1015 void ipv6_sysctl_unregister(void);
1016 #endif
1017 
1018 int ipv6_sock_mc_join(struct sock *sk, int ifindex,
1019 		      const struct in6_addr *addr);
1020 int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
1021 		      const struct in6_addr *addr);
1022 #endif /* _NET_IPV6_H */
1023