xref: /linux-6.15/include/linux/ipv6.h (revision e8fa600e)
1 #ifndef _IPV6_H
2 #define _IPV6_H
3 
4 #include <linux/types.h>
5 #include <linux/in6.h>
6 #include <asm/byteorder.h>
7 
8 /* The latest drafts declared increase in minimal mtu up to 1280. */
9 
10 #define IPV6_MIN_MTU	1280
11 
12 /*
13  *	Advanced API
14  *	source interface/address selection, source routing, etc...
15  *	*under construction*
16  */
17 
18 
19 struct in6_pktinfo {
20 	struct in6_addr	ipi6_addr;
21 	int		ipi6_ifindex;
22 };
23 
24 struct ip6_mtuinfo {
25 	struct sockaddr_in6	ip6m_addr;
26 	__u32			ip6m_mtu;
27 };
28 
29 struct in6_ifreq {
30 	struct in6_addr	ifr6_addr;
31 	__u32		ifr6_prefixlen;
32 	int		ifr6_ifindex;
33 };
34 
35 #define IPV6_SRCRT_STRICT	0x01	/* Deprecated; will be removed */
36 #define IPV6_SRCRT_TYPE_0	0	/* Deprecated; will be removed */
37 #define IPV6_SRCRT_TYPE_2	2	/* IPv6 type 2 Routing Header	*/
38 
39 /*
40  *	routing header
41  */
42 struct ipv6_rt_hdr {
43 	__u8		nexthdr;
44 	__u8		hdrlen;
45 	__u8		type;
46 	__u8		segments_left;
47 
48 	/*
49 	 *	type specific data
50 	 *	variable length field
51 	 */
52 };
53 
54 
55 struct ipv6_opt_hdr {
56 	__u8 		nexthdr;
57 	__u8 		hdrlen;
58 	/*
59 	 * TLV encoded option data follows.
60 	 */
61 } __attribute__((packed));	/* required for some archs */
62 
63 #define ipv6_destopt_hdr ipv6_opt_hdr
64 #define ipv6_hopopt_hdr  ipv6_opt_hdr
65 
66 #ifdef __KERNEL__
67 #define ipv6_optlen(p)  (((p)->hdrlen+1) << 3)
68 #endif
69 
70 /*
71  *	routing header type 0 (used in cmsghdr struct)
72  */
73 
74 struct rt0_hdr {
75 	struct ipv6_rt_hdr	rt_hdr;
76 	__u32			reserved;
77 	struct in6_addr		addr[0];
78 
79 #define rt0_type		rt_hdr.type
80 };
81 
82 /*
83  *	routing header type 2
84  */
85 
86 struct rt2_hdr {
87 	struct ipv6_rt_hdr	rt_hdr;
88 	__u32			reserved;
89 	struct in6_addr		addr;
90 
91 #define rt2_type		rt_hdr.type
92 };
93 
94 /*
95  *	home address option in destination options header
96  */
97 
98 struct ipv6_destopt_hao {
99 	__u8			type;
100 	__u8			length;
101 	struct in6_addr		addr;
102 } __attribute__((packed));
103 
104 /*
105  *	IPv6 fixed header
106  *
107  *	BEWARE, it is incorrect. The first 4 bits of flow_lbl
108  *	are glued to priority now, forming "class".
109  */
110 
111 struct ipv6hdr {
112 #if defined(__LITTLE_ENDIAN_BITFIELD)
113 	__u8			priority:4,
114 				version:4;
115 #elif defined(__BIG_ENDIAN_BITFIELD)
116 	__u8			version:4,
117 				priority:4;
118 #else
119 #error	"Please fix <asm/byteorder.h>"
120 #endif
121 	__u8			flow_lbl[3];
122 
123 	__be16			payload_len;
124 	__u8			nexthdr;
125 	__u8			hop_limit;
126 
127 	struct	in6_addr	saddr;
128 	struct	in6_addr	daddr;
129 };
130 
131 #ifdef __KERNEL__
132 /*
133  * This structure contains configuration options per IPv6 link.
134  */
135 struct ipv6_devconf {
136 	__s32		forwarding;
137 	__s32		hop_limit;
138 	__s32		mtu6;
139 	__s32		accept_ra;
140 	__s32		accept_redirects;
141 	__s32		autoconf;
142 	__s32		dad_transmits;
143 	__s32		rtr_solicits;
144 	__s32		rtr_solicit_interval;
145 	__s32		rtr_solicit_delay;
146 	__s32		force_mld_version;
147 #ifdef CONFIG_IPV6_PRIVACY
148 	__s32		use_tempaddr;
149 	__s32		temp_valid_lft;
150 	__s32		temp_prefered_lft;
151 	__s32		regen_max_retry;
152 	__s32		max_desync_factor;
153 #endif
154 	__s32		max_addresses;
155 	__s32		accept_ra_defrtr;
156 	__s32		accept_ra_pinfo;
157 #ifdef CONFIG_IPV6_ROUTER_PREF
158 	__s32		accept_ra_rtr_pref;
159 	__s32		rtr_probe_interval;
160 #ifdef CONFIG_IPV6_ROUTE_INFO
161 	__s32		accept_ra_rt_info_max_plen;
162 #endif
163 #endif
164 	__s32		proxy_ndp;
165 	__s32		accept_source_route;
166 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
167 	__s32		optimistic_dad;
168 #endif
169 #ifdef CONFIG_IPV6_MROUTE
170 	__s32		mc_forwarding;
171 #endif
172 	__s32		disable_ipv6;
173 	__s32		accept_dad;
174 	__s32		force_tllao;
175 	void		*sysctl;
176 };
177 
178 struct ipv6_params {
179 	__s32 disable_ipv6;
180 	__s32 autoconf;
181 };
182 extern struct ipv6_params ipv6_defaults;
183 #endif
184 
185 /* index values for the variables in ipv6_devconf */
186 enum {
187 	DEVCONF_FORWARDING = 0,
188 	DEVCONF_HOPLIMIT,
189 	DEVCONF_MTU6,
190 	DEVCONF_ACCEPT_RA,
191 	DEVCONF_ACCEPT_REDIRECTS,
192 	DEVCONF_AUTOCONF,
193 	DEVCONF_DAD_TRANSMITS,
194 	DEVCONF_RTR_SOLICITS,
195 	DEVCONF_RTR_SOLICIT_INTERVAL,
196 	DEVCONF_RTR_SOLICIT_DELAY,
197 	DEVCONF_USE_TEMPADDR,
198 	DEVCONF_TEMP_VALID_LFT,
199 	DEVCONF_TEMP_PREFERED_LFT,
200 	DEVCONF_REGEN_MAX_RETRY,
201 	DEVCONF_MAX_DESYNC_FACTOR,
202 	DEVCONF_MAX_ADDRESSES,
203 	DEVCONF_FORCE_MLD_VERSION,
204 	DEVCONF_ACCEPT_RA_DEFRTR,
205 	DEVCONF_ACCEPT_RA_PINFO,
206 	DEVCONF_ACCEPT_RA_RTR_PREF,
207 	DEVCONF_RTR_PROBE_INTERVAL,
208 	DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN,
209 	DEVCONF_PROXY_NDP,
210 	DEVCONF_OPTIMISTIC_DAD,
211 	DEVCONF_ACCEPT_SOURCE_ROUTE,
212 	DEVCONF_MC_FORWARDING,
213 	DEVCONF_DISABLE_IPV6,
214 	DEVCONF_ACCEPT_DAD,
215 	DEVCONF_FORCE_TLLAO,
216 	DEVCONF_MAX
217 };
218 
219 #ifdef __KERNEL__
220 #include <linux/icmpv6.h>
221 #include <linux/tcp.h>
222 #include <linux/udp.h>
223 
224 #include <net/inet_sock.h>
225 
226 static inline struct ipv6hdr *ipv6_hdr(const struct sk_buff *skb)
227 {
228 	return (struct ipv6hdr *)skb_network_header(skb);
229 }
230 
231 static inline struct ipv6hdr *ipipv6_hdr(const struct sk_buff *skb)
232 {
233 	return (struct ipv6hdr *)skb_transport_header(skb);
234 }
235 
236 static inline __u8 ipv6_tclass(const struct ipv6hdr *iph)
237 {
238 	return (ntohl(*(__be32 *)iph) >> 20) & 0xff;
239 }
240 
241 /*
242    This structure contains results of exthdrs parsing
243    as offsets from skb->nh.
244  */
245 
246 struct inet6_skb_parm {
247 	int			iif;
248 	__u16			ra;
249 	__u16			hop;
250 	__u16			dst0;
251 	__u16			srcrt;
252 	__u16			dst1;
253 	__u16			lastopt;
254 	__u16			nhoff;
255 	__u16			flags;
256 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
257 	__u16			dsthao;
258 #endif
259 
260 #define IP6SKB_XFRM_TRANSFORMED	1
261 #define IP6SKB_FORWARDED	2
262 #define IP6SKB_REROUTED		4
263 };
264 
265 #define IP6CB(skb)	((struct inet6_skb_parm*)((skb)->cb))
266 #define IP6CBMTU(skb)	((struct ip6_mtuinfo *)((skb)->cb))
267 
268 static inline int inet6_iif(const struct sk_buff *skb)
269 {
270 	return IP6CB(skb)->iif;
271 }
272 
273 struct inet6_request_sock {
274 	struct in6_addr		loc_addr;
275 	struct in6_addr		rmt_addr;
276 	struct sk_buff		*pktopts;
277 	int			iif;
278 };
279 
280 struct tcp6_request_sock {
281 	struct tcp_request_sock	  tcp6rsk_tcp;
282 	struct inet6_request_sock tcp6rsk_inet6;
283 };
284 
285 struct ipv6_mc_socklist;
286 struct ipv6_ac_socklist;
287 struct ipv6_fl_socklist;
288 
289 /**
290  * struct ipv6_pinfo - ipv6 private area
291  *
292  * In the struct sock hierarchy (tcp6_sock, upd6_sock, etc)
293  * this _must_ be the last member, so that inet6_sk_generic
294  * is able to calculate its offset from the base struct sock
295  * by using the struct proto->slab_obj_size member. -acme
296  */
297 struct ipv6_pinfo {
298 	struct in6_addr 	saddr;
299 	struct in6_addr 	rcv_saddr;
300 	struct in6_addr		daddr;
301 	struct in6_pktinfo	sticky_pktinfo;
302 	const struct in6_addr		*daddr_cache;
303 #ifdef CONFIG_IPV6_SUBTREES
304 	const struct in6_addr		*saddr_cache;
305 #endif
306 
307 	__be32			flow_label;
308 	__u32			frag_size;
309 
310 	/*
311 	 * Packed in 16bits.
312 	 * Omit one shift by by putting the signed field at MSB.
313 	 */
314 #if defined(__BIG_ENDIAN_BITFIELD)
315 	__s16			hop_limit:9;
316 	__u16			__unused_1:7;
317 #else
318 	__u16			__unused_1:7;
319 	__s16			hop_limit:9;
320 #endif
321 
322 #if defined(__BIG_ENDIAN_BITFIELD)
323 	/* Packed in 16bits. */
324 	__s16			mcast_hops:9;
325 	__u16			__unused_2:6,
326 				mc_loop:1;
327 #else
328 	__u16			mc_loop:1,
329 				__unused_2:6;
330 	__s16			mcast_hops:9;
331 #endif
332 	int			ucast_oif;
333 	int			mcast_oif;
334 
335 	/* pktoption flags */
336 	union {
337 		struct {
338 			__u16	srcrt:1,
339 				osrcrt:1,
340 			        rxinfo:1,
341 			        rxoinfo:1,
342 				rxhlim:1,
343 				rxohlim:1,
344 				hopopts:1,
345 				ohopopts:1,
346 				dstopts:1,
347 				odstopts:1,
348                                 rxflow:1,
349 				rxtclass:1,
350 				rxpmtu:1,
351 				rxorigdstaddr:1;
352 				/* 2 bits hole */
353 		} bits;
354 		__u16		all;
355 	} rxopt;
356 
357 	/* sockopt flags */
358 	__u16			recverr:1,
359 	                        sndflow:1,
360 				pmtudisc:2,
361 				ipv6only:1,
362 				srcprefs:3,	/* 001: prefer temporary address
363 						 * 010: prefer public address
364 						 * 100: prefer care-of address
365 						 */
366 				dontfrag:1;
367 	__u8			min_hopcount;
368 	__u8			tclass;
369 	__u8			rcv_tclass;
370 
371 	__u32			dst_cookie;
372 
373 	struct ipv6_mc_socklist	__rcu *ipv6_mc_list;
374 	struct ipv6_ac_socklist	*ipv6_ac_list;
375 	struct ipv6_fl_socklist *ipv6_fl_list;
376 
377 	struct ipv6_txoptions	*opt;
378 	struct sk_buff		*pktoptions;
379 	struct sk_buff		*rxpmtu;
380 	struct {
381 		struct ipv6_txoptions *opt;
382 		u8 hop_limit;
383 		u8 tclass;
384 	} cork;
385 };
386 
387 /* WARNING: don't change the layout of the members in {raw,udp,tcp}6_sock! */
388 struct raw6_sock {
389 	/* inet_sock has to be the first member of raw6_sock */
390 	struct inet_sock	inet;
391 	__u32			checksum;	/* perform checksum */
392 	__u32			offset;		/* checksum offset  */
393 	struct icmp6_filter	filter;
394 	__u32			ip6mr_table;
395 	/* ipv6_pinfo has to be the last member of raw6_sock, see inet6_sk_generic */
396 	struct ipv6_pinfo	inet6;
397 };
398 
399 struct udp6_sock {
400 	struct udp_sock	  udp;
401 	/* ipv6_pinfo has to be the last member of udp6_sock, see inet6_sk_generic */
402 	struct ipv6_pinfo inet6;
403 };
404 
405 struct tcp6_sock {
406 	struct tcp_sock	  tcp;
407 	/* ipv6_pinfo has to be the last member of tcp6_sock, see inet6_sk_generic */
408 	struct ipv6_pinfo inet6;
409 };
410 
411 extern int inet6_sk_rebuild_header(struct sock *sk);
412 
413 struct inet6_timewait_sock {
414 	struct in6_addr tw_v6_daddr;
415 	struct in6_addr	tw_v6_rcv_saddr;
416 };
417 
418 struct tcp6_timewait_sock {
419 	struct tcp_timewait_sock   tcp6tw_tcp;
420 	struct inet6_timewait_sock tcp6tw_inet6;
421 };
422 
423 static inline struct inet6_timewait_sock *inet6_twsk(const struct sock *sk)
424 {
425 	return (struct inet6_timewait_sock *)(((u8 *)sk) +
426 					      inet_twsk(sk)->tw_ipv6_offset);
427 }
428 
429 #if IS_ENABLED(CONFIG_IPV6)
430 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
431 {
432 	return inet_sk(__sk)->pinet6;
433 }
434 
435 static inline struct inet6_request_sock *
436 			inet6_rsk(const struct request_sock *rsk)
437 {
438 	return (struct inet6_request_sock *)(((u8 *)rsk) +
439 					     inet_rsk(rsk)->inet6_rsk_offset);
440 }
441 
442 static inline u32 inet6_rsk_offset(struct request_sock *rsk)
443 {
444 	return rsk->rsk_ops->obj_size - sizeof(struct inet6_request_sock);
445 }
446 
447 static inline struct request_sock *inet6_reqsk_alloc(struct request_sock_ops *ops)
448 {
449 	struct request_sock *req = reqsk_alloc(ops);
450 
451 	if (req != NULL) {
452 		inet_rsk(req)->inet6_rsk_offset = inet6_rsk_offset(req);
453 		inet6_rsk(req)->pktopts = NULL;
454 	}
455 
456 	return req;
457 }
458 
459 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
460 {
461 	return (struct raw6_sock *)sk;
462 }
463 
464 static inline void inet_sk_copy_descendant(struct sock *sk_to,
465 					   const struct sock *sk_from)
466 {
467 	int ancestor_size = sizeof(struct inet_sock);
468 
469 	if (sk_from->sk_family == PF_INET6)
470 		ancestor_size += sizeof(struct ipv6_pinfo);
471 
472 	__inet_sk_copy_descendant(sk_to, sk_from, ancestor_size);
473 }
474 
475 #define __ipv6_only_sock(sk)	(inet6_sk(sk)->ipv6only)
476 #define ipv6_only_sock(sk)	((sk)->sk_family == PF_INET6 && __ipv6_only_sock(sk))
477 
478 static inline u16 inet6_tw_offset(const struct proto *prot)
479 {
480 	return prot->twsk_prot->twsk_obj_size -
481 			sizeof(struct inet6_timewait_sock);
482 }
483 
484 static inline struct in6_addr *__inet6_rcv_saddr(const struct sock *sk)
485 {
486 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
487 		&inet6_sk(sk)->rcv_saddr : &inet6_twsk(sk)->tw_v6_rcv_saddr;
488 }
489 
490 static inline struct in6_addr *inet6_rcv_saddr(const struct sock *sk)
491 {
492 	return sk->sk_family == AF_INET6 ? __inet6_rcv_saddr(sk) : NULL;
493 }
494 
495 static inline int inet_v6_ipv6only(const struct sock *sk)
496 {
497 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
498 		ipv6_only_sock(sk) : inet_twsk(sk)->tw_ipv6only;
499 }
500 #else
501 #define __ipv6_only_sock(sk)	0
502 #define ipv6_only_sock(sk)	0
503 
504 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
505 {
506 	return NULL;
507 }
508 
509 static inline struct inet6_request_sock *
510 			inet6_rsk(const struct request_sock *rsk)
511 {
512 	return NULL;
513 }
514 
515 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
516 {
517 	return NULL;
518 }
519 
520 #define __inet6_rcv_saddr(__sk)	NULL
521 #define inet6_rcv_saddr(__sk)	NULL
522 #define tcp_twsk_ipv6only(__sk)		0
523 #define inet_v6_ipv6only(__sk)		0
524 #endif /* IS_ENABLED(CONFIG_IPV6) */
525 
526 #define INET6_MATCH(__sk, __net, __hash, __saddr, __daddr, __ports, __dif)\
527 	(((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net)	&& \
528 	 ((*((__portpair *)&(inet_sk(__sk)->inet_dport))) == (__ports)) && \
529 	 ((__sk)->sk_family		== AF_INET6)		&& \
530 	 ipv6_addr_equal(&inet6_sk(__sk)->daddr, (__saddr))	&& \
531 	 ipv6_addr_equal(&inet6_sk(__sk)->rcv_saddr, (__daddr))	&& \
532 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
533 
534 #define INET6_TW_MATCH(__sk, __net, __hash, __saddr, __daddr, __ports, __dif) \
535 	(((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net)	&& \
536 	 (*((__portpair *)&(inet_twsk(__sk)->tw_dport)) == (__ports))	&& \
537 	 ((__sk)->sk_family	       == PF_INET6)			&& \
538 	 (ipv6_addr_equal(&inet6_twsk(__sk)->tw_v6_daddr, (__saddr)))	&& \
539 	 (ipv6_addr_equal(&inet6_twsk(__sk)->tw_v6_rcv_saddr, (__daddr))) && \
540 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
541 
542 #endif /* __KERNEL__ */
543 
544 #endif /* _IPV6_H */
545