xref: /linux-6.15/include/linux/ipv6.h (revision 2d6ffcca)
1 #ifndef _IPV6_H
2 #define _IPV6_H
3 
4 #include <linux/in6.h>
5 #include <asm/byteorder.h>
6 
7 /* The latest drafts declared increase in minimal mtu up to 1280. */
8 
9 #define IPV6_MIN_MTU	1280
10 
11 /*
12  *	Advanced API
13  *	source interface/address selection, source routing, etc...
14  *	*under construction*
15  */
16 
17 
18 struct in6_pktinfo {
19 	struct in6_addr	ipi6_addr;
20 	int		ipi6_ifindex;
21 };
22 
23 
24 struct in6_ifreq {
25 	struct in6_addr	ifr6_addr;
26 	__u32		ifr6_prefixlen;
27 	int		ifr6_ifindex;
28 };
29 
30 #define IPV6_SRCRT_STRICT	0x01	/* Deprecated; will be removed */
31 #define IPV6_SRCRT_TYPE_0	0	/* Deprecated; will be removed */
32 #define IPV6_SRCRT_TYPE_2	2	/* IPv6 type 2 Routing Header	*/
33 
34 /*
35  *	routing header
36  */
37 struct ipv6_rt_hdr {
38 	__u8		nexthdr;
39 	__u8		hdrlen;
40 	__u8		type;
41 	__u8		segments_left;
42 
43 	/*
44 	 *	type specific data
45 	 *	variable length field
46 	 */
47 };
48 
49 
50 struct ipv6_opt_hdr {
51 	__u8 		nexthdr;
52 	__u8 		hdrlen;
53 	/*
54 	 * TLV encoded option data follows.
55 	 */
56 } __attribute__ ((packed));	/* required for some archs */
57 
58 #define ipv6_destopt_hdr ipv6_opt_hdr
59 #define ipv6_hopopt_hdr  ipv6_opt_hdr
60 
61 #ifdef __KERNEL__
62 #define ipv6_optlen(p)  (((p)->hdrlen+1) << 3)
63 #endif
64 
65 /*
66  *	routing header type 0 (used in cmsghdr struct)
67  */
68 
69 struct rt0_hdr {
70 	struct ipv6_rt_hdr	rt_hdr;
71 	__u32			reserved;
72 	struct in6_addr		addr[0];
73 
74 #define rt0_type		rt_hdr.type
75 };
76 
77 /*
78  *	routing header type 2
79  */
80 
81 struct rt2_hdr {
82 	struct ipv6_rt_hdr	rt_hdr;
83 	__u32			reserved;
84 	struct in6_addr		addr;
85 
86 #define rt2_type		rt_hdr.type
87 };
88 
89 /*
90  *	home address option in destination options header
91  */
92 
93 struct ipv6_destopt_hao {
94 	__u8			type;
95 	__u8			length;
96 	struct in6_addr		addr;
97 } __attribute__ ((__packed__));
98 
99 /*
100  *	IPv6 fixed header
101  *
102  *	BEWARE, it is incorrect. The first 4 bits of flow_lbl
103  *	are glued to priority now, forming "class".
104  */
105 
106 struct ipv6hdr {
107 #if defined(__LITTLE_ENDIAN_BITFIELD)
108 	__u8			priority:4,
109 				version:4;
110 #elif defined(__BIG_ENDIAN_BITFIELD)
111 	__u8			version:4,
112 				priority:4;
113 #else
114 #error	"Please fix <asm/byteorder.h>"
115 #endif
116 	__u8			flow_lbl[3];
117 
118 	__be16			payload_len;
119 	__u8			nexthdr;
120 	__u8			hop_limit;
121 
122 	struct	in6_addr	saddr;
123 	struct	in6_addr	daddr;
124 };
125 
126 #ifdef __KERNEL__
127 /*
128  * This structure contains configuration options per IPv6 link.
129  */
130 struct ipv6_devconf {
131 	__s32		forwarding;
132 	__s32		hop_limit;
133 	__s32		mtu6;
134 	__s32		accept_ra;
135 	__s32		accept_redirects;
136 	__s32		autoconf;
137 	__s32		dad_transmits;
138 	__s32		rtr_solicits;
139 	__s32		rtr_solicit_interval;
140 	__s32		rtr_solicit_delay;
141 	__s32		force_mld_version;
142 #ifdef CONFIG_IPV6_PRIVACY
143 	__s32		use_tempaddr;
144 	__s32		temp_valid_lft;
145 	__s32		temp_prefered_lft;
146 	__s32		regen_max_retry;
147 	__s32		max_desync_factor;
148 #endif
149 	__s32		max_addresses;
150 	__s32		accept_ra_defrtr;
151 	__s32		accept_ra_pinfo;
152 #ifdef CONFIG_IPV6_ROUTER_PREF
153 	__s32		accept_ra_rtr_pref;
154 	__s32		rtr_probe_interval;
155 #ifdef CONFIG_IPV6_ROUTE_INFO
156 	__s32		accept_ra_rt_info_max_plen;
157 #endif
158 #endif
159 	__s32		proxy_ndp;
160 	__s32		accept_source_route;
161 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
162 	__s32		optimistic_dad;
163 #endif
164 #ifdef CONFIG_IPV6_MROUTE
165 	__s32		mc_forwarding;
166 #endif
167 	__s32		disable_ipv6;
168 	__s32		accept_dad;
169 	void		*sysctl;
170 };
171 #endif
172 
173 /* index values for the variables in ipv6_devconf */
174 enum {
175 	DEVCONF_FORWARDING = 0,
176 	DEVCONF_HOPLIMIT,
177 	DEVCONF_MTU6,
178 	DEVCONF_ACCEPT_RA,
179 	DEVCONF_ACCEPT_REDIRECTS,
180 	DEVCONF_AUTOCONF,
181 	DEVCONF_DAD_TRANSMITS,
182 	DEVCONF_RTR_SOLICITS,
183 	DEVCONF_RTR_SOLICIT_INTERVAL,
184 	DEVCONF_RTR_SOLICIT_DELAY,
185 	DEVCONF_USE_TEMPADDR,
186 	DEVCONF_TEMP_VALID_LFT,
187 	DEVCONF_TEMP_PREFERED_LFT,
188 	DEVCONF_REGEN_MAX_RETRY,
189 	DEVCONF_MAX_DESYNC_FACTOR,
190 	DEVCONF_MAX_ADDRESSES,
191 	DEVCONF_FORCE_MLD_VERSION,
192 	DEVCONF_ACCEPT_RA_DEFRTR,
193 	DEVCONF_ACCEPT_RA_PINFO,
194 	DEVCONF_ACCEPT_RA_RTR_PREF,
195 	DEVCONF_RTR_PROBE_INTERVAL,
196 	DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN,
197 	DEVCONF_PROXY_NDP,
198 	DEVCONF_OPTIMISTIC_DAD,
199 	DEVCONF_ACCEPT_SOURCE_ROUTE,
200 	DEVCONF_MC_FORWARDING,
201 	DEVCONF_DISABLE_IPV6,
202 	DEVCONF_ACCEPT_DAD,
203 	DEVCONF_MAX
204 };
205 
206 #ifdef __KERNEL__
207 #include <linux/icmpv6.h>
208 #include <linux/tcp.h>
209 #include <linux/udp.h>
210 
211 #include <net/inet_sock.h>
212 
213 static inline struct ipv6hdr *ipv6_hdr(const struct sk_buff *skb)
214 {
215 	return (struct ipv6hdr *)skb_network_header(skb);
216 }
217 
218 static inline struct ipv6hdr *ipipv6_hdr(const struct sk_buff *skb)
219 {
220 	return (struct ipv6hdr *)skb_transport_header(skb);
221 }
222 
223 /*
224    This structure contains results of exthdrs parsing
225    as offsets from skb->nh.
226  */
227 
228 struct inet6_skb_parm {
229 	int			iif;
230 	__u16			ra;
231 	__u16			hop;
232 	__u16			dst0;
233 	__u16			srcrt;
234 	__u16			dst1;
235 	__u16			lastopt;
236 	__u32			nhoff;
237 	__u16			flags;
238 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
239 	__u16			dsthao;
240 #endif
241 
242 #define IP6SKB_XFRM_TRANSFORMED	1
243 #define IP6SKB_FORWARDED	2
244 };
245 
246 #define IP6CB(skb)	((struct inet6_skb_parm*)((skb)->cb))
247 
248 static inline int inet6_iif(const struct sk_buff *skb)
249 {
250 	return IP6CB(skb)->iif;
251 }
252 
253 struct inet6_request_sock {
254 	struct in6_addr		loc_addr;
255 	struct in6_addr		rmt_addr;
256 	struct sk_buff		*pktopts;
257 	int			iif;
258 };
259 
260 struct tcp6_request_sock {
261 	struct tcp_request_sock	  tcp6rsk_tcp;
262 	struct inet6_request_sock tcp6rsk_inet6;
263 };
264 
265 struct ipv6_mc_socklist;
266 struct ipv6_ac_socklist;
267 struct ipv6_fl_socklist;
268 
269 /**
270  * struct ipv6_pinfo - ipv6 private area
271  *
272  * In the struct sock hierarchy (tcp6_sock, upd6_sock, etc)
273  * this _must_ be the last member, so that inet6_sk_generic
274  * is able to calculate its offset from the base struct sock
275  * by using the struct proto->slab_obj_size member. -acme
276  */
277 struct ipv6_pinfo {
278 	struct in6_addr 	saddr;
279 	struct in6_addr 	rcv_saddr;
280 	struct in6_addr		daddr;
281 	struct in6_addr		*daddr_cache;
282 #ifdef CONFIG_IPV6_SUBTREES
283 	struct in6_addr		*saddr_cache;
284 #endif
285 
286 	__be32			flow_label;
287 	__u32			frag_size;
288 
289 	/*
290 	 * Packed in 16bits.
291 	 * Omit one shift by by putting the signed field at MSB.
292 	 */
293 #if defined(__BIG_ENDIAN_BITFIELD)
294 	__s16			hop_limit:9;
295 	__u16			__unused_1:7;
296 #else
297 	__u16			__unused_1:7;
298 	__s16			hop_limit:9;
299 #endif
300 
301 #if defined(__BIG_ENDIAN_BITFIELD)
302 	/* Packed in 16bits. */
303 	__s16			mcast_hops:9;
304 	__u16			__unused_2:6,
305 				mc_loop:1;
306 #else
307 	__u16			mc_loop:1,
308 				__unused_2:6;
309 	__s16			mcast_hops:9;
310 #endif
311 	int			mcast_oif;
312 
313 	/* pktoption flags */
314 	union {
315 		struct {
316 			__u16	srcrt:1,
317 				osrcrt:1,
318 			        rxinfo:1,
319 			        rxoinfo:1,
320 				rxhlim:1,
321 				rxohlim:1,
322 				hopopts:1,
323 				ohopopts:1,
324 				dstopts:1,
325 				odstopts:1,
326                                 rxflow:1,
327 				rxtclass:1;
328 		} bits;
329 		__u16		all;
330 	} rxopt;
331 
332 	/* sockopt flags */
333 	__u8			recverr:1,
334 	                        sndflow:1,
335 				pmtudisc:2,
336 				ipv6only:1,
337 				srcprefs:3;	/* 001: prefer temporary address
338 						 * 010: prefer public address
339 						 * 100: prefer care-of address
340 						 */
341 	__u8			tclass;
342 
343 	__u32			dst_cookie;
344 
345 	struct ipv6_mc_socklist	*ipv6_mc_list;
346 	struct ipv6_ac_socklist	*ipv6_ac_list;
347 	struct ipv6_fl_socklist *ipv6_fl_list;
348 
349 	struct ipv6_txoptions	*opt;
350 	struct sk_buff		*pktoptions;
351 	struct {
352 		struct ipv6_txoptions *opt;
353 		u8 hop_limit;
354 		u8 tclass;
355 	} cork;
356 };
357 
358 /* WARNING: don't change the layout of the members in {raw,udp,tcp}6_sock! */
359 struct raw6_sock {
360 	/* inet_sock has to be the first member of raw6_sock */
361 	struct inet_sock	inet;
362 	__u32			checksum;	/* perform checksum */
363 	__u32			offset;		/* checksum offset  */
364 	struct icmp6_filter	filter;
365 	/* ipv6_pinfo has to be the last member of raw6_sock, see inet6_sk_generic */
366 	struct ipv6_pinfo	inet6;
367 };
368 
369 struct udp6_sock {
370 	struct udp_sock	  udp;
371 	/* ipv6_pinfo has to be the last member of udp6_sock, see inet6_sk_generic */
372 	struct ipv6_pinfo inet6;
373 };
374 
375 struct tcp6_sock {
376 	struct tcp_sock	  tcp;
377 	/* ipv6_pinfo has to be the last member of tcp6_sock, see inet6_sk_generic */
378 	struct ipv6_pinfo inet6;
379 };
380 
381 extern int inet6_sk_rebuild_header(struct sock *sk);
382 
383 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
384 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
385 {
386 	return inet_sk(__sk)->pinet6;
387 }
388 
389 static inline struct inet6_request_sock *
390 			inet6_rsk(const struct request_sock *rsk)
391 {
392 	return (struct inet6_request_sock *)(((u8 *)rsk) +
393 					     inet_rsk(rsk)->inet6_rsk_offset);
394 }
395 
396 static inline u32 inet6_rsk_offset(struct request_sock *rsk)
397 {
398 	return rsk->rsk_ops->obj_size - sizeof(struct inet6_request_sock);
399 }
400 
401 static inline struct request_sock *inet6_reqsk_alloc(struct request_sock_ops *ops)
402 {
403 	struct request_sock *req = reqsk_alloc(ops);
404 
405 	if (req != NULL) {
406 		inet_rsk(req)->inet6_rsk_offset = inet6_rsk_offset(req);
407 		inet6_rsk(req)->pktopts = NULL;
408 	}
409 
410 	return req;
411 }
412 
413 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
414 {
415 	return (struct raw6_sock *)sk;
416 }
417 
418 static inline void inet_sk_copy_descendant(struct sock *sk_to,
419 					   const struct sock *sk_from)
420 {
421 	int ancestor_size = sizeof(struct inet_sock);
422 
423 	if (sk_from->sk_family == PF_INET6)
424 		ancestor_size += sizeof(struct ipv6_pinfo);
425 
426 	__inet_sk_copy_descendant(sk_to, sk_from, ancestor_size);
427 }
428 
429 #define __ipv6_only_sock(sk)	(inet6_sk(sk)->ipv6only)
430 #define ipv6_only_sock(sk)	((sk)->sk_family == PF_INET6 && __ipv6_only_sock(sk))
431 
432 struct inet6_timewait_sock {
433 	struct in6_addr tw_v6_daddr;
434 	struct in6_addr	tw_v6_rcv_saddr;
435 };
436 
437 struct tcp6_timewait_sock {
438 	struct tcp_timewait_sock   tcp6tw_tcp;
439 	struct inet6_timewait_sock tcp6tw_inet6;
440 };
441 
442 static inline u16 inet6_tw_offset(const struct proto *prot)
443 {
444 	return prot->twsk_prot->twsk_obj_size -
445 			sizeof(struct inet6_timewait_sock);
446 }
447 
448 static inline struct inet6_timewait_sock *inet6_twsk(const struct sock *sk)
449 {
450 	return (struct inet6_timewait_sock *)(((u8 *)sk) +
451 					      inet_twsk(sk)->tw_ipv6_offset);
452 }
453 
454 static inline struct in6_addr *__inet6_rcv_saddr(const struct sock *sk)
455 {
456 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
457 		&inet6_sk(sk)->rcv_saddr : &inet6_twsk(sk)->tw_v6_rcv_saddr;
458 }
459 
460 static inline struct in6_addr *inet6_rcv_saddr(const struct sock *sk)
461 {
462 	return sk->sk_family == AF_INET6 ? __inet6_rcv_saddr(sk) : NULL;
463 }
464 
465 static inline int inet_v6_ipv6only(const struct sock *sk)
466 {
467 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
468 		ipv6_only_sock(sk) : inet_twsk(sk)->tw_ipv6only;
469 }
470 #else
471 #define __ipv6_only_sock(sk)	0
472 #define ipv6_only_sock(sk)	0
473 
474 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
475 {
476 	return NULL;
477 }
478 
479 static inline struct inet6_request_sock *
480 			inet6_rsk(const struct request_sock *rsk)
481 {
482 	return NULL;
483 }
484 
485 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
486 {
487 	return NULL;
488 }
489 
490 #define __inet6_rcv_saddr(__sk)	NULL
491 #define inet6_rcv_saddr(__sk)	NULL
492 #define tcp_twsk_ipv6only(__sk)		0
493 #define inet_v6_ipv6only(__sk)		0
494 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
495 
496 #define INET6_MATCH(__sk, __net, __hash, __saddr, __daddr, __ports, __dif)\
497 	(((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net)	&& \
498 	 ((*((__portpair *)&(inet_sk(__sk)->dport))) == (__ports))  	&& \
499 	 ((__sk)->sk_family		== AF_INET6)		&& \
500 	 ipv6_addr_equal(&inet6_sk(__sk)->daddr, (__saddr))	&& \
501 	 ipv6_addr_equal(&inet6_sk(__sk)->rcv_saddr, (__daddr))	&& \
502 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
503 
504 #define INET6_TW_MATCH(__sk, __net, __hash, __saddr, __daddr, __ports, __dif) \
505 	(((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net)	&& \
506 	 (*((__portpair *)&(inet_twsk(__sk)->tw_dport)) == (__ports))	&& \
507 	 ((__sk)->sk_family	       == PF_INET6)			&& \
508 	 (ipv6_addr_equal(&inet6_twsk(__sk)->tw_v6_daddr, (__saddr)))	&& \
509 	 (ipv6_addr_equal(&inet6_twsk(__sk)->tw_v6_rcv_saddr, (__daddr))) && \
510 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
511 
512 #endif /* __KERNEL__ */
513 
514 #endif /* _IPV6_H */
515