xref: /linux/include/net/ipv6.h (revision 80d443e8876602be2c130f79c4de81e12e2a700d)
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, mod, idev, field)			\
125 ({									\
126 	struct inet6_dev *_idev = (idev);				\
127 	if (likely(_idev != NULL))					\
128 		mod##SNMP_INC_STATS64((_idev)->stats.statname, (field));\
129 	mod##SNMP_INC_STATS64((net)->mib.statname##_statistics, (field));\
130 })
131 
132 /* per device counters are atomic_long_t */
133 #define _DEVINCATOMIC(net, statname, mod, 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 	mod##SNMP_INC_STATS((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, mod, idev, field, val)			\
151 ({									\
152 	struct inet6_dev *_idev = (idev);				\
153 	if (likely(_idev != NULL))					\
154 		mod##SNMP_ADD_STATS((_idev)->stats.statname, (field), (val)); \
155 	mod##SNMP_ADD_STATS((net)->mib.statname##_statistics, (field), (val));\
156 })
157 
158 #define _DEVUPD(net, statname, mod, idev, field, val)			\
159 ({									\
160 	struct inet6_dev *_idev = (idev);				\
161 	if (likely(_idev != NULL))					\
162 		mod##SNMP_UPD_PO_STATS((_idev)->stats.statname, field, (val)); \
163 	mod##SNMP_UPD_PO_STATS((net)->mib.statname##_statistics, field, (val));\
164 })
165 
166 /* MIBs */
167 
168 #define IP6_INC_STATS(net, idev,field)		\
169 		_DEVINC(net, ipv6, , idev, field)
170 #define __IP6_INC_STATS(net, idev,field)	\
171 		_DEVINC(net, ipv6, __, idev, field)
172 #define IP6_ADD_STATS(net, idev,field,val)	\
173 		_DEVADD(net, ipv6, , idev, field, val)
174 #define __IP6_ADD_STATS(net, idev,field,val)	\
175 		_DEVADD(net, ipv6, __, idev, field, val)
176 #define IP6_UPD_PO_STATS(net, idev,field,val)   \
177 		_DEVUPD(net, ipv6, , idev, field, val)
178 #define __IP6_UPD_PO_STATS(net, idev,field,val)   \
179 		_DEVUPD(net, ipv6, __, idev, field, val)
180 #define ICMP6_INC_STATS(net, idev, field)	\
181 		_DEVINCATOMIC(net, icmpv6, , idev, field)
182 #define __ICMP6_INC_STATS(net, idev, field)	\
183 		_DEVINCATOMIC(net, icmpv6, __, idev, field)
184 
185 #define ICMP6MSGOUT_INC_STATS(net, idev, field)		\
186 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256)
187 #define ICMP6MSGIN_INC_STATS(net, idev, field)	\
188 	_DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field)
189 
190 struct ip6_ra_chain {
191 	struct ip6_ra_chain	*next;
192 	struct sock		*sk;
193 	int			sel;
194 	void			(*destructor)(struct sock *);
195 };
196 
197 extern struct ip6_ra_chain	*ip6_ra_chain;
198 extern rwlock_t ip6_ra_lock;
199 
200 /*
201    This structure is prepared by protocol, when parsing
202    ancillary data and passed to IPv6.
203  */
204 
205 struct ipv6_txoptions {
206 	atomic_t		refcnt;
207 	/* Length of this structure */
208 	int			tot_len;
209 
210 	/* length of extension headers   */
211 
212 	__u16			opt_flen;	/* after fragment hdr */
213 	__u16			opt_nflen;	/* before fragment hdr */
214 
215 	struct ipv6_opt_hdr	*hopopt;
216 	struct ipv6_opt_hdr	*dst0opt;
217 	struct ipv6_rt_hdr	*srcrt;	/* Routing Header */
218 	struct ipv6_opt_hdr	*dst1opt;
219 	struct rcu_head		rcu;
220 	/* Option buffer, as read by IPV6_PKTOPTIONS, starts here. */
221 };
222 
223 struct ip6_flowlabel {
224 	struct ip6_flowlabel __rcu *next;
225 	__be32			label;
226 	atomic_t		users;
227 	struct in6_addr		dst;
228 	struct ipv6_txoptions	*opt;
229 	unsigned long		linger;
230 	struct rcu_head		rcu;
231 	u8			share;
232 	union {
233 		struct pid *pid;
234 		kuid_t uid;
235 	} owner;
236 	unsigned long		lastuse;
237 	unsigned long		expires;
238 	struct net		*fl_net;
239 };
240 
241 #define IPV6_FLOWINFO_MASK		cpu_to_be32(0x0FFFFFFF)
242 #define IPV6_FLOWLABEL_MASK		cpu_to_be32(0x000FFFFF)
243 #define IPV6_FLOWLABEL_STATELESS_FLAG	cpu_to_be32(0x00080000)
244 
245 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
246 #define IPV6_TCLASS_SHIFT	20
247 
248 struct ipv6_fl_socklist {
249 	struct ipv6_fl_socklist	__rcu	*next;
250 	struct ip6_flowlabel		*fl;
251 	struct rcu_head			rcu;
252 };
253 
254 struct ipcm6_cookie {
255 	__s16 hlimit;
256 	__s16 tclass;
257 	__s8  dontfrag;
258 	struct ipv6_txoptions *opt;
259 };
260 
261 static inline struct ipv6_txoptions *txopt_get(const struct ipv6_pinfo *np)
262 {
263 	struct ipv6_txoptions *opt;
264 
265 	rcu_read_lock();
266 	opt = rcu_dereference(np->opt);
267 	if (opt) {
268 		if (!atomic_inc_not_zero(&opt->refcnt))
269 			opt = NULL;
270 		else
271 			opt = rcu_pointer_handoff(opt);
272 	}
273 	rcu_read_unlock();
274 	return opt;
275 }
276 
277 static inline void txopt_put(struct ipv6_txoptions *opt)
278 {
279 	if (opt && atomic_dec_and_test(&opt->refcnt))
280 		kfree_rcu(opt, rcu);
281 }
282 
283 struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label);
284 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
285 					 struct ip6_flowlabel *fl,
286 					 struct ipv6_txoptions *fopt);
287 void fl6_free_socklist(struct sock *sk);
288 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
289 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
290 			   int flags);
291 int ip6_flowlabel_init(void);
292 void ip6_flowlabel_cleanup(void);
293 
294 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
295 {
296 	if (fl)
297 		atomic_dec(&fl->users);
298 }
299 
300 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info);
301 
302 int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
303 			       struct icmp6hdr *thdr, int len);
304 
305 int ip6_ra_control(struct sock *sk, int sel);
306 
307 int ipv6_parse_hopopts(struct sk_buff *skb);
308 
309 struct ipv6_txoptions *ipv6_dup_options(struct sock *sk,
310 					struct ipv6_txoptions *opt);
311 struct ipv6_txoptions *ipv6_renew_options(struct sock *sk,
312 					  struct ipv6_txoptions *opt,
313 					  int newtype,
314 					  struct ipv6_opt_hdr __user *newopt,
315 					  int newoptlen);
316 struct ipv6_txoptions *
317 ipv6_renew_options_kern(struct sock *sk,
318 			struct ipv6_txoptions *opt,
319 			int newtype,
320 			struct ipv6_opt_hdr *newopt,
321 			int newoptlen);
322 struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
323 					  struct ipv6_txoptions *opt);
324 
325 bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
326 		       const struct inet6_skb_parm *opt);
327 struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
328 					   struct ipv6_txoptions *opt);
329 
330 static inline bool ipv6_accept_ra(struct inet6_dev *idev)
331 {
332 	/* If forwarding is enabled, RA are not accepted unless the special
333 	 * hybrid mode (accept_ra=2) is enabled.
334 	 */
335 	return idev->cnf.forwarding ? idev->cnf.accept_ra == 2 :
336 	    idev->cnf.accept_ra;
337 }
338 
339 #if IS_ENABLED(CONFIG_IPV6)
340 static inline int ip6_frag_mem(struct net *net)
341 {
342 	return sum_frag_mem_limit(&net->ipv6.frags);
343 }
344 #endif
345 
346 #define IPV6_FRAG_HIGH_THRESH	(4 * 1024*1024)	/* 4194304 */
347 #define IPV6_FRAG_LOW_THRESH	(3 * 1024*1024)	/* 3145728 */
348 #define IPV6_FRAG_TIMEOUT	(60 * HZ)	/* 60 seconds */
349 
350 int __ipv6_addr_type(const struct in6_addr *addr);
351 static inline int ipv6_addr_type(const struct in6_addr *addr)
352 {
353 	return __ipv6_addr_type(addr) & 0xffff;
354 }
355 
356 static inline int ipv6_addr_scope(const struct in6_addr *addr)
357 {
358 	return __ipv6_addr_type(addr) & IPV6_ADDR_SCOPE_MASK;
359 }
360 
361 static inline int __ipv6_addr_src_scope(int type)
362 {
363 	return (type == IPV6_ADDR_ANY) ? __IPV6_ADDR_SCOPE_INVALID : (type >> 16);
364 }
365 
366 static inline int ipv6_addr_src_scope(const struct in6_addr *addr)
367 {
368 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
369 }
370 
371 static inline bool __ipv6_addr_needs_scope_id(int type)
372 {
373 	return type & IPV6_ADDR_LINKLOCAL ||
374 	       (type & IPV6_ADDR_MULTICAST &&
375 		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
376 }
377 
378 static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
379 {
380 	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
381 }
382 
383 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
384 {
385 	return memcmp(a1, a2, sizeof(struct in6_addr));
386 }
387 
388 static inline bool
389 ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,
390 		     const struct in6_addr *a2)
391 {
392 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
393 	const unsigned long *ul1 = (const unsigned long *)a1;
394 	const unsigned long *ulm = (const unsigned long *)m;
395 	const unsigned long *ul2 = (const unsigned long *)a2;
396 
397 	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |
398 		  ((ul1[1] ^ ul2[1]) & ulm[1]));
399 #else
400 	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |
401 		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |
402 		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |
403 		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));
404 #endif
405 }
406 
407 static inline void ipv6_addr_prefix(struct in6_addr *pfx,
408 				    const struct in6_addr *addr,
409 				    int plen)
410 {
411 	/* caller must guarantee 0 <= plen <= 128 */
412 	int o = plen >> 3,
413 	    b = plen & 0x7;
414 
415 	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));
416 	memcpy(pfx->s6_addr, addr, o);
417 	if (b != 0)
418 		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);
419 }
420 
421 static inline void ipv6_addr_prefix_copy(struct in6_addr *addr,
422 					 const struct in6_addr *pfx,
423 					 int plen)
424 {
425 	/* caller must guarantee 0 <= plen <= 128 */
426 	int o = plen >> 3,
427 	    b = plen & 0x7;
428 
429 	memcpy(addr->s6_addr, pfx, o);
430 	if (b != 0) {
431 		addr->s6_addr[o] &= ~(0xff00 >> b);
432 		addr->s6_addr[o] |= (pfx->s6_addr[o] & (0xff00 >> b));
433 	}
434 }
435 
436 static inline void __ipv6_addr_set_half(__be32 *addr,
437 					__be32 wh, __be32 wl)
438 {
439 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
440 #if defined(__BIG_ENDIAN)
441 	if (__builtin_constant_p(wh) && __builtin_constant_p(wl)) {
442 		*(__force u64 *)addr = ((__force u64)(wh) << 32 | (__force u64)(wl));
443 		return;
444 	}
445 #elif defined(__LITTLE_ENDIAN)
446 	if (__builtin_constant_p(wl) && __builtin_constant_p(wh)) {
447 		*(__force u64 *)addr = ((__force u64)(wl) << 32 | (__force u64)(wh));
448 		return;
449 	}
450 #endif
451 #endif
452 	addr[0] = wh;
453 	addr[1] = wl;
454 }
455 
456 static inline void ipv6_addr_set(struct in6_addr *addr,
457 				     __be32 w1, __be32 w2,
458 				     __be32 w3, __be32 w4)
459 {
460 	__ipv6_addr_set_half(&addr->s6_addr32[0], w1, w2);
461 	__ipv6_addr_set_half(&addr->s6_addr32[2], w3, w4);
462 }
463 
464 static inline bool ipv6_addr_equal(const struct in6_addr *a1,
465 				   const struct in6_addr *a2)
466 {
467 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
468 	const unsigned long *ul1 = (const unsigned long *)a1;
469 	const unsigned long *ul2 = (const unsigned long *)a2;
470 
471 	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
472 #else
473 	return ((a1->s6_addr32[0] ^ a2->s6_addr32[0]) |
474 		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |
475 		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |
476 		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;
477 #endif
478 }
479 
480 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
481 static inline bool __ipv6_prefix_equal64_half(const __be64 *a1,
482 					      const __be64 *a2,
483 					      unsigned int len)
484 {
485 	if (len && ((*a1 ^ *a2) & cpu_to_be64((~0UL) << (64 - len))))
486 		return false;
487 	return true;
488 }
489 
490 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
491 				     const struct in6_addr *addr2,
492 				     unsigned int prefixlen)
493 {
494 	const __be64 *a1 = (const __be64 *)addr1;
495 	const __be64 *a2 = (const __be64 *)addr2;
496 
497 	if (prefixlen >= 64) {
498 		if (a1[0] ^ a2[0])
499 			return false;
500 		return __ipv6_prefix_equal64_half(a1 + 1, a2 + 1, prefixlen - 64);
501 	}
502 	return __ipv6_prefix_equal64_half(a1, a2, prefixlen);
503 }
504 #else
505 static inline bool ipv6_prefix_equal(const struct in6_addr *addr1,
506 				     const struct in6_addr *addr2,
507 				     unsigned int prefixlen)
508 {
509 	const __be32 *a1 = addr1->s6_addr32;
510 	const __be32 *a2 = addr2->s6_addr32;
511 	unsigned int pdw, pbi;
512 
513 	/* check complete u32 in prefix */
514 	pdw = prefixlen >> 5;
515 	if (pdw && memcmp(a1, a2, pdw << 2))
516 		return false;
517 
518 	/* check incomplete u32 in prefix */
519 	pbi = prefixlen & 0x1f;
520 	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
521 		return false;
522 
523 	return true;
524 }
525 #endif
526 
527 struct inet_frag_queue;
528 
529 enum ip6_defrag_users {
530 	IP6_DEFRAG_LOCAL_DELIVER,
531 	IP6_DEFRAG_CONNTRACK_IN,
532 	__IP6_DEFRAG_CONNTRACK_IN	= IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
533 	IP6_DEFRAG_CONNTRACK_OUT,
534 	__IP6_DEFRAG_CONNTRACK_OUT	= IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
535 	IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
536 	__IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
537 };
538 
539 struct ip6_create_arg {
540 	__be32 id;
541 	u32 user;
542 	const struct in6_addr *src;
543 	const struct in6_addr *dst;
544 	int iif;
545 	u8 ecn;
546 };
547 
548 void ip6_frag_init(struct inet_frag_queue *q, const void *a);
549 bool ip6_frag_match(const struct inet_frag_queue *q, const void *a);
550 
551 /*
552  *	Equivalent of ipv4 struct ip
553  */
554 struct frag_queue {
555 	struct inet_frag_queue	q;
556 
557 	__be32			id;		/* fragment id		*/
558 	u32			user;
559 	struct in6_addr		saddr;
560 	struct in6_addr		daddr;
561 
562 	int			iif;
563 	unsigned int		csum;
564 	__u16			nhoffset;
565 	u8			ecn;
566 };
567 
568 void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
569 			   struct inet_frags *frags);
570 
571 static inline bool ipv6_addr_any(const struct in6_addr *a)
572 {
573 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
574 	const unsigned long *ul = (const unsigned long *)a;
575 
576 	return (ul[0] | ul[1]) == 0UL;
577 #else
578 	return (a->s6_addr32[0] | a->s6_addr32[1] |
579 		a->s6_addr32[2] | a->s6_addr32[3]) == 0;
580 #endif
581 }
582 
583 static inline u32 ipv6_addr_hash(const struct in6_addr *a)
584 {
585 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
586 	const unsigned long *ul = (const unsigned long *)a;
587 	unsigned long x = ul[0] ^ ul[1];
588 
589 	return (u32)(x ^ (x >> 32));
590 #else
591 	return (__force u32)(a->s6_addr32[0] ^ a->s6_addr32[1] ^
592 			     a->s6_addr32[2] ^ a->s6_addr32[3]);
593 #endif
594 }
595 
596 /* more secured version of ipv6_addr_hash() */
597 static inline u32 __ipv6_addr_jhash(const struct in6_addr *a, const u32 initval)
598 {
599 	u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1];
600 
601 	return jhash_3words(v,
602 			    (__force u32)a->s6_addr32[2],
603 			    (__force u32)a->s6_addr32[3],
604 			    initval);
605 }
606 
607 static inline bool ipv6_addr_loopback(const struct in6_addr *a)
608 {
609 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
610 	const __be64 *be = (const __be64 *)a;
611 
612 	return (be[0] | (be[1] ^ cpu_to_be64(1))) == 0UL;
613 #else
614 	return (a->s6_addr32[0] | a->s6_addr32[1] |
615 		a->s6_addr32[2] | (a->s6_addr32[3] ^ cpu_to_be32(1))) == 0;
616 #endif
617 }
618 
619 /*
620  * Note that we must __force cast these to unsigned long to make sparse happy,
621  * since all of the endian-annotated types are fixed size regardless of arch.
622  */
623 static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
624 {
625 	return (
626 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
627 		*(unsigned long *)a |
628 #else
629 		(__force unsigned long)(a->s6_addr32[0] | a->s6_addr32[1]) |
630 #endif
631 		(__force unsigned long)(a->s6_addr32[2] ^
632 					cpu_to_be32(0x0000ffff))) == 0UL;
633 }
634 
635 /*
636  * Check for a RFC 4843 ORCHID address
637  * (Overlay Routable Cryptographic Hash Identifiers)
638  */
639 static inline bool ipv6_addr_orchid(const struct in6_addr *a)
640 {
641 	return (a->s6_addr32[0] & htonl(0xfffffff0)) == htonl(0x20010010);
642 }
643 
644 static inline bool ipv6_addr_is_multicast(const struct in6_addr *addr)
645 {
646 	return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);
647 }
648 
649 static inline void ipv6_addr_set_v4mapped(const __be32 addr,
650 					  struct in6_addr *v4mapped)
651 {
652 	ipv6_addr_set(v4mapped,
653 			0, 0,
654 			htonl(0x0000FFFF),
655 			addr);
656 }
657 
658 /*
659  * find the first different bit between two addresses
660  * length of address must be a multiple of 32bits
661  */
662 static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)
663 {
664 	const __be32 *a1 = token1, *a2 = token2;
665 	int i;
666 
667 	addrlen >>= 2;
668 
669 	for (i = 0; i < addrlen; i++) {
670 		__be32 xb = a1[i] ^ a2[i];
671 		if (xb)
672 			return i * 32 + 31 - __fls(ntohl(xb));
673 	}
674 
675 	/*
676 	 *	we should *never* get to this point since that
677 	 *	would mean the addrs are equal
678 	 *
679 	 *	However, we do get to it 8) And exacly, when
680 	 *	addresses are equal 8)
681 	 *
682 	 *	ip route add 1111::/128 via ...
683 	 *	ip route add 1111::/64 via ...
684 	 *	and we are here.
685 	 *
686 	 *	Ideally, this function should stop comparison
687 	 *	at prefix length. It does not, but it is still OK,
688 	 *	if returned value is greater than prefix length.
689 	 *					--ANK (980803)
690 	 */
691 	return addrlen << 5;
692 }
693 
694 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
695 static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)
696 {
697 	const __be64 *a1 = token1, *a2 = token2;
698 	int i;
699 
700 	addrlen >>= 3;
701 
702 	for (i = 0; i < addrlen; i++) {
703 		__be64 xb = a1[i] ^ a2[i];
704 		if (xb)
705 			return i * 64 + 63 - __fls(be64_to_cpu(xb));
706 	}
707 
708 	return addrlen << 6;
709 }
710 #endif
711 
712 static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
713 {
714 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
715 	if (__builtin_constant_p(addrlen) && !(addrlen & 7))
716 		return __ipv6_addr_diff64(token1, token2, addrlen);
717 #endif
718 	return __ipv6_addr_diff32(token1, token2, addrlen);
719 }
720 
721 static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
722 {
723 	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
724 }
725 
726 __be32 ipv6_select_ident(struct net *net,
727 			 const struct in6_addr *daddr,
728 			 const struct in6_addr *saddr);
729 void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb);
730 
731 int ip6_dst_hoplimit(struct dst_entry *dst);
732 
733 static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
734 				      struct dst_entry *dst)
735 {
736 	int hlimit;
737 
738 	if (ipv6_addr_is_multicast(&fl6->daddr))
739 		hlimit = np->mcast_hops;
740 	else
741 		hlimit = np->hop_limit;
742 	if (hlimit < 0)
743 		hlimit = ip6_dst_hoplimit(dst);
744 	return hlimit;
745 }
746 
747 /* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
748  * Equivalent to :	flow->v6addrs.src = iph->saddr;
749  *			flow->v6addrs.dst = iph->daddr;
750  */
751 static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
752 					    const struct ipv6hdr *iph)
753 {
754 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
755 		     offsetof(typeof(flow->addrs), v6addrs.src) +
756 		     sizeof(flow->addrs.v6addrs.src));
757 	memcpy(&flow->addrs.v6addrs, &iph->saddr, sizeof(flow->addrs.v6addrs));
758 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
759 }
760 
761 #if IS_ENABLED(CONFIG_IPV6)
762 
763 /* Sysctl settings for net ipv6.auto_flowlabels */
764 #define IP6_AUTO_FLOW_LABEL_OFF		0
765 #define IP6_AUTO_FLOW_LABEL_OPTOUT	1
766 #define IP6_AUTO_FLOW_LABEL_OPTIN	2
767 #define IP6_AUTO_FLOW_LABEL_FORCED	3
768 
769 #define IP6_AUTO_FLOW_LABEL_MAX		IP6_AUTO_FLOW_LABEL_FORCED
770 
771 #define IP6_DEFAULT_AUTO_FLOW_LABELS	IP6_AUTO_FLOW_LABEL_OPTOUT
772 
773 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
774 					__be32 flowlabel, bool autolabel,
775 					struct flowi6 *fl6)
776 {
777 	u32 hash;
778 
779 	if (flowlabel ||
780 	    net->ipv6.sysctl.auto_flowlabels == IP6_AUTO_FLOW_LABEL_OFF ||
781 	    (!autolabel &&
782 	     net->ipv6.sysctl.auto_flowlabels != IP6_AUTO_FLOW_LABEL_FORCED))
783 		return flowlabel;
784 
785 	hash = skb_get_hash_flowi6(skb, fl6);
786 
787 	/* Since this is being sent on the wire obfuscate hash a bit
788 	 * to minimize possbility that any useful information to an
789 	 * attacker is leaked. Only lower 20 bits are relevant.
790 	 */
791 	rol32(hash, 16);
792 
793 	flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;
794 
795 	if (net->ipv6.sysctl.flowlabel_state_ranges)
796 		flowlabel |= IPV6_FLOWLABEL_STATELESS_FLAG;
797 
798 	return flowlabel;
799 }
800 
801 static inline int ip6_default_np_autolabel(struct net *net)
802 {
803 	switch (net->ipv6.sysctl.auto_flowlabels) {
804 	case IP6_AUTO_FLOW_LABEL_OFF:
805 	case IP6_AUTO_FLOW_LABEL_OPTIN:
806 	default:
807 		return 0;
808 	case IP6_AUTO_FLOW_LABEL_OPTOUT:
809 	case IP6_AUTO_FLOW_LABEL_FORCED:
810 		return 1;
811 	}
812 }
813 #else
814 static inline void ip6_set_txhash(struct sock *sk) { }
815 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
816 					__be32 flowlabel, bool autolabel,
817 					struct flowi6 *fl6)
818 {
819 	return flowlabel;
820 }
821 static inline int ip6_default_np_autolabel(struct net *net)
822 {
823 	return 0;
824 }
825 #endif
826 
827 
828 /*
829  *	Header manipulation
830  */
831 static inline void ip6_flow_hdr(struct ipv6hdr *hdr, unsigned int tclass,
832 				__be32 flowlabel)
833 {
834 	*(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | flowlabel;
835 }
836 
837 static inline __be32 ip6_flowinfo(const struct ipv6hdr *hdr)
838 {
839 	return *(__be32 *)hdr & IPV6_FLOWINFO_MASK;
840 }
841 
842 static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
843 {
844 	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
845 }
846 
847 static inline u8 ip6_tclass(__be32 flowinfo)
848 {
849 	return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT;
850 }
851 
852 static inline __be32 ip6_make_flowinfo(unsigned int tclass, __be32 flowlabel)
853 {
854 	return htonl(tclass << IPV6_TCLASS_SHIFT) | flowlabel;
855 }
856 
857 /*
858  *	Prototypes exported by ipv6
859  */
860 
861 /*
862  *	rcv function (called from netdevice level)
863  */
864 
865 int ipv6_rcv(struct sk_buff *skb, struct net_device *dev,
866 	     struct packet_type *pt, struct net_device *orig_dev);
867 
868 int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
869 
870 /*
871  *	upper-layer output functions
872  */
873 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
874 	     struct ipv6_txoptions *opt, int tclass);
875 
876 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
877 
878 int ip6_append_data(struct sock *sk,
879 		    int getfrag(void *from, char *to, int offset, int len,
880 				int odd, struct sk_buff *skb),
881 		    void *from, int length, int transhdrlen,
882 		    struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
883 		    struct rt6_info *rt, unsigned int flags,
884 		    const struct sockcm_cookie *sockc);
885 
886 int ip6_push_pending_frames(struct sock *sk);
887 
888 void ip6_flush_pending_frames(struct sock *sk);
889 
890 int ip6_send_skb(struct sk_buff *skb);
891 
892 struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
893 			       struct inet_cork_full *cork,
894 			       struct inet6_cork *v6_cork);
895 struct sk_buff *ip6_make_skb(struct sock *sk,
896 			     int getfrag(void *from, char *to, int offset,
897 					 int len, int odd, struct sk_buff *skb),
898 			     void *from, int length, int transhdrlen,
899 			     struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
900 			     struct rt6_info *rt, unsigned int flags,
901 			     const struct sockcm_cookie *sockc);
902 
903 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
904 {
905 	return __ip6_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork,
906 			      &inet6_sk(sk)->cork);
907 }
908 
909 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
910 		   struct flowi6 *fl6);
911 struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
912 				      const struct in6_addr *final_dst);
913 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
914 					 const struct in6_addr *final_dst);
915 struct dst_entry *ip6_blackhole_route(struct net *net,
916 				      struct dst_entry *orig_dst);
917 
918 /*
919  *	skb processing functions
920  */
921 
922 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb);
923 int ip6_forward(struct sk_buff *skb);
924 int ip6_input(struct sk_buff *skb);
925 int ip6_mc_input(struct sk_buff *skb);
926 
927 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
928 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
929 
930 /*
931  *	Extension header (options) processing
932  */
933 
934 void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
935 			  u8 *proto, struct in6_addr **daddr_p,
936 			  struct in6_addr *saddr);
937 void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
938 			 u8 *proto);
939 
940 int ipv6_skip_exthdr(const struct sk_buff *, int start, u8 *nexthdrp,
941 		     __be16 *frag_offp);
942 
943 bool ipv6_ext_hdr(u8 nexthdr);
944 
945 enum {
946 	IP6_FH_F_FRAG		= (1 << 0),
947 	IP6_FH_F_AUTH		= (1 << 1),
948 	IP6_FH_F_SKIP_RH	= (1 << 2),
949 };
950 
951 /* find specified header and get offset to it */
952 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target,
953 		  unsigned short *fragoff, int *fragflg);
954 
955 int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type);
956 
957 struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
958 				const struct ipv6_txoptions *opt,
959 				struct in6_addr *orig);
960 
961 /*
962  *	socket options (ipv6_sockglue.c)
963  */
964 
965 int ipv6_setsockopt(struct sock *sk, int level, int optname,
966 		    char __user *optval, unsigned int optlen);
967 int ipv6_getsockopt(struct sock *sk, int level, int optname,
968 		    char __user *optval, int __user *optlen);
969 int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
970 			   char __user *optval, unsigned int optlen);
971 int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
972 			   char __user *optval, int __user *optlen);
973 
974 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *addr,
975 			   int addr_len);
976 int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len);
977 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr,
978 				 int addr_len);
979 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr);
980 void ip6_datagram_release_cb(struct sock *sk);
981 
982 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
983 		    int *addr_len);
984 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
985 		     int *addr_len);
986 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
987 		     u32 info, u8 *payload);
988 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
989 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
990 
991 int inet6_release(struct socket *sock);
992 int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
993 int inet6_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len,
994 		  int peer);
995 int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
996 
997 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
998 			      struct sock *sk);
999 
1000 /*
1001  * reassembly.c
1002  */
1003 extern const struct proto_ops inet6_stream_ops;
1004 extern const struct proto_ops inet6_dgram_ops;
1005 
1006 struct group_source_req;
1007 struct group_filter;
1008 
1009 int ip6_mc_source(int add, int omode, struct sock *sk,
1010 		  struct group_source_req *pgsr);
1011 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
1012 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
1013 		  struct group_filter __user *optval, int __user *optlen);
1014 
1015 #ifdef CONFIG_PROC_FS
1016 int ac6_proc_init(struct net *net);
1017 void ac6_proc_exit(struct net *net);
1018 int raw6_proc_init(void);
1019 void raw6_proc_exit(void);
1020 int tcp6_proc_init(struct net *net);
1021 void tcp6_proc_exit(struct net *net);
1022 int udp6_proc_init(struct net *net);
1023 void udp6_proc_exit(struct net *net);
1024 int udplite6_proc_init(void);
1025 void udplite6_proc_exit(void);
1026 int ipv6_misc_proc_init(void);
1027 void ipv6_misc_proc_exit(void);
1028 int snmp6_register_dev(struct inet6_dev *idev);
1029 int snmp6_unregister_dev(struct inet6_dev *idev);
1030 
1031 #else
1032 static inline int ac6_proc_init(struct net *net) { return 0; }
1033 static inline void ac6_proc_exit(struct net *net) { }
1034 static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
1035 static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
1036 #endif
1037 
1038 #ifdef CONFIG_SYSCTL
1039 extern struct ctl_table ipv6_route_table_template[];
1040 
1041 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
1042 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
1043 int ipv6_sysctl_register(void);
1044 void ipv6_sysctl_unregister(void);
1045 #endif
1046 
1047 int ipv6_sock_mc_join(struct sock *sk, int ifindex,
1048 		      const struct in6_addr *addr);
1049 int ipv6_sock_mc_drop(struct sock *sk, int ifindex,
1050 		      const struct in6_addr *addr);
1051 #endif /* _NET_IPV6_H */
1052