xref: /linux-6.15/include/linux/ipv6.h (revision 266fe2f2)
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 
25 struct in6_ifreq {
26 	struct in6_addr	ifr6_addr;
27 	__u32		ifr6_prefixlen;
28 	int		ifr6_ifindex;
29 };
30 
31 #define IPV6_SRCRT_STRICT	0x01	/* Deprecated; will be removed */
32 #define IPV6_SRCRT_TYPE_0	0	/* Deprecated; will be removed */
33 #define IPV6_SRCRT_TYPE_2	2	/* IPv6 type 2 Routing Header	*/
34 
35 /*
36  *	routing header
37  */
38 struct ipv6_rt_hdr {
39 	__u8		nexthdr;
40 	__u8		hdrlen;
41 	__u8		type;
42 	__u8		segments_left;
43 
44 	/*
45 	 *	type specific data
46 	 *	variable length field
47 	 */
48 };
49 
50 
51 struct ipv6_opt_hdr {
52 	__u8 		nexthdr;
53 	__u8 		hdrlen;
54 	/*
55 	 * TLV encoded option data follows.
56 	 */
57 } __attribute__ ((packed));	/* required for some archs */
58 
59 #define ipv6_destopt_hdr ipv6_opt_hdr
60 #define ipv6_hopopt_hdr  ipv6_opt_hdr
61 
62 #ifdef __KERNEL__
63 #define ipv6_optlen(p)  (((p)->hdrlen+1) << 3)
64 #endif
65 
66 /*
67  *	routing header type 0 (used in cmsghdr struct)
68  */
69 
70 struct rt0_hdr {
71 	struct ipv6_rt_hdr	rt_hdr;
72 	__u32			reserved;
73 	struct in6_addr		addr[0];
74 
75 #define rt0_type		rt_hdr.type
76 };
77 
78 /*
79  *	routing header type 2
80  */
81 
82 struct rt2_hdr {
83 	struct ipv6_rt_hdr	rt_hdr;
84 	__u32			reserved;
85 	struct in6_addr		addr;
86 
87 #define rt2_type		rt_hdr.type
88 };
89 
90 /*
91  *	home address option in destination options header
92  */
93 
94 struct ipv6_destopt_hao {
95 	__u8			type;
96 	__u8			length;
97 	struct in6_addr		addr;
98 } __attribute__ ((__packed__));
99 
100 /*
101  *	IPv6 fixed header
102  *
103  *	BEWARE, it is incorrect. The first 4 bits of flow_lbl
104  *	are glued to priority now, forming "class".
105  */
106 
107 struct ipv6hdr {
108 #if defined(__LITTLE_ENDIAN_BITFIELD)
109 	__u8			priority:4,
110 				version:4;
111 #elif defined(__BIG_ENDIAN_BITFIELD)
112 	__u8			version:4,
113 				priority:4;
114 #else
115 #error	"Please fix <asm/byteorder.h>"
116 #endif
117 	__u8			flow_lbl[3];
118 
119 	__be16			payload_len;
120 	__u8			nexthdr;
121 	__u8			hop_limit;
122 
123 	struct	in6_addr	saddr;
124 	struct	in6_addr	daddr;
125 };
126 
127 #ifdef __KERNEL__
128 /*
129  * This structure contains configuration options per IPv6 link.
130  */
131 struct ipv6_devconf {
132 	__s32		forwarding;
133 	__s32		hop_limit;
134 	__s32		mtu6;
135 	__s32		accept_ra;
136 	__s32		accept_redirects;
137 	__s32		autoconf;
138 	__s32		dad_transmits;
139 	__s32		rtr_solicits;
140 	__s32		rtr_solicit_interval;
141 	__s32		rtr_solicit_delay;
142 	__s32		force_mld_version;
143 #ifdef CONFIG_IPV6_PRIVACY
144 	__s32		use_tempaddr;
145 	__s32		temp_valid_lft;
146 	__s32		temp_prefered_lft;
147 	__s32		regen_max_retry;
148 	__s32		max_desync_factor;
149 #endif
150 	__s32		max_addresses;
151 	__s32		accept_ra_defrtr;
152 	__s32		accept_ra_pinfo;
153 #ifdef CONFIG_IPV6_ROUTER_PREF
154 	__s32		accept_ra_rtr_pref;
155 	__s32		rtr_probe_interval;
156 #ifdef CONFIG_IPV6_ROUTE_INFO
157 	__s32		accept_ra_rt_info_max_plen;
158 #endif
159 #endif
160 	__s32		proxy_ndp;
161 	__s32		accept_source_route;
162 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
163 	__s32		optimistic_dad;
164 #endif
165 #ifdef CONFIG_IPV6_MROUTE
166 	__s32		mc_forwarding;
167 #endif
168 	__s32		disable_ipv6;
169 	__s32		accept_dad;
170 	__s32		force_tllao;
171 	void		*sysctl;
172 };
173 
174 struct ipv6_params {
175 	__s32 disable_ipv6;
176 	__s32 autoconf;
177 };
178 extern struct ipv6_params ipv6_defaults;
179 #endif
180 
181 /* index values for the variables in ipv6_devconf */
182 enum {
183 	DEVCONF_FORWARDING = 0,
184 	DEVCONF_HOPLIMIT,
185 	DEVCONF_MTU6,
186 	DEVCONF_ACCEPT_RA,
187 	DEVCONF_ACCEPT_REDIRECTS,
188 	DEVCONF_AUTOCONF,
189 	DEVCONF_DAD_TRANSMITS,
190 	DEVCONF_RTR_SOLICITS,
191 	DEVCONF_RTR_SOLICIT_INTERVAL,
192 	DEVCONF_RTR_SOLICIT_DELAY,
193 	DEVCONF_USE_TEMPADDR,
194 	DEVCONF_TEMP_VALID_LFT,
195 	DEVCONF_TEMP_PREFERED_LFT,
196 	DEVCONF_REGEN_MAX_RETRY,
197 	DEVCONF_MAX_DESYNC_FACTOR,
198 	DEVCONF_MAX_ADDRESSES,
199 	DEVCONF_FORCE_MLD_VERSION,
200 	DEVCONF_ACCEPT_RA_DEFRTR,
201 	DEVCONF_ACCEPT_RA_PINFO,
202 	DEVCONF_ACCEPT_RA_RTR_PREF,
203 	DEVCONF_RTR_PROBE_INTERVAL,
204 	DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN,
205 	DEVCONF_PROXY_NDP,
206 	DEVCONF_OPTIMISTIC_DAD,
207 	DEVCONF_ACCEPT_SOURCE_ROUTE,
208 	DEVCONF_MC_FORWARDING,
209 	DEVCONF_DISABLE_IPV6,
210 	DEVCONF_ACCEPT_DAD,
211 	DEVCONF_FORCE_TLLAO,
212 	DEVCONF_MAX
213 };
214 
215 #ifdef __KERNEL__
216 #include <linux/icmpv6.h>
217 #include <linux/tcp.h>
218 #include <linux/udp.h>
219 
220 #include <net/inet_sock.h>
221 
222 static inline struct ipv6hdr *ipv6_hdr(const struct sk_buff *skb)
223 {
224 	return (struct ipv6hdr *)skb_network_header(skb);
225 }
226 
227 static inline struct ipv6hdr *ipipv6_hdr(const struct sk_buff *skb)
228 {
229 	return (struct ipv6hdr *)skb_transport_header(skb);
230 }
231 
232 /*
233    This structure contains results of exthdrs parsing
234    as offsets from skb->nh.
235  */
236 
237 struct inet6_skb_parm {
238 	int			iif;
239 	__u16			ra;
240 	__u16			hop;
241 	__u16			dst0;
242 	__u16			srcrt;
243 	__u16			dst1;
244 	__u16			lastopt;
245 	__u32			nhoff;
246 	__u16			flags;
247 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
248 	__u16			dsthao;
249 #endif
250 
251 #define IP6SKB_XFRM_TRANSFORMED	1
252 #define IP6SKB_FORWARDED	2
253 };
254 
255 #define IP6CB(skb)	((struct inet6_skb_parm*)((skb)->cb))
256 
257 static inline int inet6_iif(const struct sk_buff *skb)
258 {
259 	return IP6CB(skb)->iif;
260 }
261 
262 struct inet6_request_sock {
263 	struct in6_addr		loc_addr;
264 	struct in6_addr		rmt_addr;
265 	struct sk_buff		*pktopts;
266 	int			iif;
267 };
268 
269 struct tcp6_request_sock {
270 	struct tcp_request_sock	  tcp6rsk_tcp;
271 	struct inet6_request_sock tcp6rsk_inet6;
272 };
273 
274 struct ipv6_mc_socklist;
275 struct ipv6_ac_socklist;
276 struct ipv6_fl_socklist;
277 
278 /**
279  * struct ipv6_pinfo - ipv6 private area
280  *
281  * In the struct sock hierarchy (tcp6_sock, upd6_sock, etc)
282  * this _must_ be the last member, so that inet6_sk_generic
283  * is able to calculate its offset from the base struct sock
284  * by using the struct proto->slab_obj_size member. -acme
285  */
286 struct ipv6_pinfo {
287 	struct in6_addr 	saddr;
288 	struct in6_addr 	rcv_saddr;
289 	struct in6_addr		daddr;
290 	struct in6_pktinfo	sticky_pktinfo;
291 	struct in6_addr		*daddr_cache;
292 #ifdef CONFIG_IPV6_SUBTREES
293 	struct in6_addr		*saddr_cache;
294 #endif
295 
296 	__be32			flow_label;
297 	__u32			frag_size;
298 
299 	/*
300 	 * Packed in 16bits.
301 	 * Omit one shift by by putting the signed field at MSB.
302 	 */
303 #if defined(__BIG_ENDIAN_BITFIELD)
304 	__s16			hop_limit:9;
305 	__u16			__unused_1:7;
306 #else
307 	__u16			__unused_1:7;
308 	__s16			hop_limit:9;
309 #endif
310 
311 #if defined(__BIG_ENDIAN_BITFIELD)
312 	/* Packed in 16bits. */
313 	__s16			mcast_hops:9;
314 	__u16			__unused_2:6,
315 				mc_loop:1;
316 #else
317 	__u16			mc_loop:1,
318 				__unused_2:6;
319 	__s16			mcast_hops:9;
320 #endif
321 	int			mcast_oif;
322 
323 	/* pktoption flags */
324 	union {
325 		struct {
326 			__u16	srcrt:1,
327 				osrcrt:1,
328 			        rxinfo:1,
329 			        rxoinfo:1,
330 				rxhlim:1,
331 				rxohlim:1,
332 				hopopts:1,
333 				ohopopts:1,
334 				dstopts:1,
335 				odstopts:1,
336                                 rxflow:1,
337 				rxtclass:1;
338 		} bits;
339 		__u16		all;
340 	} rxopt;
341 
342 	/* sockopt flags */
343 	__u8			recverr:1,
344 	                        sndflow:1,
345 				pmtudisc:2,
346 				ipv6only:1,
347 				srcprefs:3;	/* 001: prefer temporary address
348 						 * 010: prefer public address
349 						 * 100: prefer care-of address
350 						 */
351 	__u8			tclass;
352 
353 	__u32			dst_cookie;
354 
355 	struct ipv6_mc_socklist	*ipv6_mc_list;
356 	struct ipv6_ac_socklist	*ipv6_ac_list;
357 	struct ipv6_fl_socklist *ipv6_fl_list;
358 
359 	struct ipv6_txoptions	*opt;
360 	struct sk_buff		*pktoptions;
361 	struct {
362 		struct ipv6_txoptions *opt;
363 		u8 hop_limit;
364 		u8 tclass;
365 	} cork;
366 };
367 
368 /* WARNING: don't change the layout of the members in {raw,udp,tcp}6_sock! */
369 struct raw6_sock {
370 	/* inet_sock has to be the first member of raw6_sock */
371 	struct inet_sock	inet;
372 	__u32			checksum;	/* perform checksum */
373 	__u32			offset;		/* checksum offset  */
374 	struct icmp6_filter	filter;
375 	/* ipv6_pinfo has to be the last member of raw6_sock, see inet6_sk_generic */
376 	struct ipv6_pinfo	inet6;
377 };
378 
379 struct udp6_sock {
380 	struct udp_sock	  udp;
381 	/* ipv6_pinfo has to be the last member of udp6_sock, see inet6_sk_generic */
382 	struct ipv6_pinfo inet6;
383 };
384 
385 struct tcp6_sock {
386 	struct tcp_sock	  tcp;
387 	/* ipv6_pinfo has to be the last member of tcp6_sock, see inet6_sk_generic */
388 	struct ipv6_pinfo inet6;
389 };
390 
391 extern int inet6_sk_rebuild_header(struct sock *sk);
392 
393 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
394 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
395 {
396 	return inet_sk(__sk)->pinet6;
397 }
398 
399 static inline struct inet6_request_sock *
400 			inet6_rsk(const struct request_sock *rsk)
401 {
402 	return (struct inet6_request_sock *)(((u8 *)rsk) +
403 					     inet_rsk(rsk)->inet6_rsk_offset);
404 }
405 
406 static inline u32 inet6_rsk_offset(struct request_sock *rsk)
407 {
408 	return rsk->rsk_ops->obj_size - sizeof(struct inet6_request_sock);
409 }
410 
411 static inline struct request_sock *inet6_reqsk_alloc(struct request_sock_ops *ops)
412 {
413 	struct request_sock *req = reqsk_alloc(ops);
414 
415 	if (req != NULL) {
416 		inet_rsk(req)->inet6_rsk_offset = inet6_rsk_offset(req);
417 		inet6_rsk(req)->pktopts = NULL;
418 	}
419 
420 	return req;
421 }
422 
423 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
424 {
425 	return (struct raw6_sock *)sk;
426 }
427 
428 static inline void inet_sk_copy_descendant(struct sock *sk_to,
429 					   const struct sock *sk_from)
430 {
431 	int ancestor_size = sizeof(struct inet_sock);
432 
433 	if (sk_from->sk_family == PF_INET6)
434 		ancestor_size += sizeof(struct ipv6_pinfo);
435 
436 	__inet_sk_copy_descendant(sk_to, sk_from, ancestor_size);
437 }
438 
439 #define __ipv6_only_sock(sk)	(inet6_sk(sk)->ipv6only)
440 #define ipv6_only_sock(sk)	((sk)->sk_family == PF_INET6 && __ipv6_only_sock(sk))
441 
442 struct inet6_timewait_sock {
443 	struct in6_addr tw_v6_daddr;
444 	struct in6_addr	tw_v6_rcv_saddr;
445 };
446 
447 struct tcp6_timewait_sock {
448 	struct tcp_timewait_sock   tcp6tw_tcp;
449 	struct inet6_timewait_sock tcp6tw_inet6;
450 };
451 
452 static inline u16 inet6_tw_offset(const struct proto *prot)
453 {
454 	return prot->twsk_prot->twsk_obj_size -
455 			sizeof(struct inet6_timewait_sock);
456 }
457 
458 static inline struct inet6_timewait_sock *inet6_twsk(const struct sock *sk)
459 {
460 	return (struct inet6_timewait_sock *)(((u8 *)sk) +
461 					      inet_twsk(sk)->tw_ipv6_offset);
462 }
463 
464 static inline struct in6_addr *__inet6_rcv_saddr(const struct sock *sk)
465 {
466 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
467 		&inet6_sk(sk)->rcv_saddr : &inet6_twsk(sk)->tw_v6_rcv_saddr;
468 }
469 
470 static inline struct in6_addr *inet6_rcv_saddr(const struct sock *sk)
471 {
472 	return sk->sk_family == AF_INET6 ? __inet6_rcv_saddr(sk) : NULL;
473 }
474 
475 static inline int inet_v6_ipv6only(const struct sock *sk)
476 {
477 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
478 		ipv6_only_sock(sk) : inet_twsk(sk)->tw_ipv6only;
479 }
480 #else
481 #define __ipv6_only_sock(sk)	0
482 #define ipv6_only_sock(sk)	0
483 
484 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
485 {
486 	return NULL;
487 }
488 
489 static inline struct inet6_request_sock *
490 			inet6_rsk(const struct request_sock *rsk)
491 {
492 	return NULL;
493 }
494 
495 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
496 {
497 	return NULL;
498 }
499 
500 #define __inet6_rcv_saddr(__sk)	NULL
501 #define inet6_rcv_saddr(__sk)	NULL
502 #define tcp_twsk_ipv6only(__sk)		0
503 #define inet_v6_ipv6only(__sk)		0
504 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
505 
506 #define INET6_MATCH(__sk, __net, __hash, __saddr, __daddr, __ports, __dif)\
507 	(((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net)	&& \
508 	 ((*((__portpair *)&(inet_sk(__sk)->inet_dport))) == (__ports)) && \
509 	 ((__sk)->sk_family		== AF_INET6)		&& \
510 	 ipv6_addr_equal(&inet6_sk(__sk)->daddr, (__saddr))	&& \
511 	 ipv6_addr_equal(&inet6_sk(__sk)->rcv_saddr, (__daddr))	&& \
512 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
513 
514 #define INET6_TW_MATCH(__sk, __net, __hash, __saddr, __daddr, __ports, __dif) \
515 	(((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net)	&& \
516 	 (*((__portpair *)&(inet_twsk(__sk)->tw_dport)) == (__ports))	&& \
517 	 ((__sk)->sk_family	       == PF_INET6)			&& \
518 	 (ipv6_addr_equal(&inet6_twsk(__sk)->tw_v6_daddr, (__saddr)))	&& \
519 	 (ipv6_addr_equal(&inet6_twsk(__sk)->tw_v6_rcv_saddr, (__daddr))) && \
520 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
521 
522 #endif /* __KERNEL__ */
523 
524 #endif /* _IPV6_H */
525