xref: /linux-6.15/include/linux/ipv6.h (revision 185000fc)
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 /*
127  * This structure contains configuration options per IPv6 link.
128  */
129 struct ipv6_devconf {
130 	__s32		forwarding;
131 	__s32		hop_limit;
132 	__s32		mtu6;
133 	__s32		accept_ra;
134 	__s32		accept_redirects;
135 	__s32		autoconf;
136 	__s32		dad_transmits;
137 	__s32		rtr_solicits;
138 	__s32		rtr_solicit_interval;
139 	__s32		rtr_solicit_delay;
140 	__s32		force_mld_version;
141 #ifdef CONFIG_IPV6_PRIVACY
142 	__s32		use_tempaddr;
143 	__s32		temp_valid_lft;
144 	__s32		temp_prefered_lft;
145 	__s32		regen_max_retry;
146 	__s32		max_desync_factor;
147 #endif
148 	__s32		max_addresses;
149 	__s32		accept_ra_defrtr;
150 	__s32		accept_ra_pinfo;
151 #ifdef CONFIG_IPV6_ROUTER_PREF
152 	__s32		accept_ra_rtr_pref;
153 	__s32		rtr_probe_interval;
154 #ifdef CONFIG_IPV6_ROUTE_INFO
155 	__s32		accept_ra_rt_info_max_plen;
156 #endif
157 #endif
158 	__s32		proxy_ndp;
159 	__s32		accept_source_route;
160 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
161 	__s32		optimistic_dad;
162 #endif
163 #ifdef CONFIG_IPV6_MROUTE
164 	__s32		mc_forwarding;
165 #endif
166 	__s32		disable_ipv6;
167 	__s32		accept_dad;
168 	void		*sysctl;
169 };
170 
171 /* index values for the variables in ipv6_devconf */
172 enum {
173 	DEVCONF_FORWARDING = 0,
174 	DEVCONF_HOPLIMIT,
175 	DEVCONF_MTU6,
176 	DEVCONF_ACCEPT_RA,
177 	DEVCONF_ACCEPT_REDIRECTS,
178 	DEVCONF_AUTOCONF,
179 	DEVCONF_DAD_TRANSMITS,
180 	DEVCONF_RTR_SOLICITS,
181 	DEVCONF_RTR_SOLICIT_INTERVAL,
182 	DEVCONF_RTR_SOLICIT_DELAY,
183 	DEVCONF_USE_TEMPADDR,
184 	DEVCONF_TEMP_VALID_LFT,
185 	DEVCONF_TEMP_PREFERED_LFT,
186 	DEVCONF_REGEN_MAX_RETRY,
187 	DEVCONF_MAX_DESYNC_FACTOR,
188 	DEVCONF_MAX_ADDRESSES,
189 	DEVCONF_FORCE_MLD_VERSION,
190 	DEVCONF_ACCEPT_RA_DEFRTR,
191 	DEVCONF_ACCEPT_RA_PINFO,
192 	DEVCONF_ACCEPT_RA_RTR_PREF,
193 	DEVCONF_RTR_PROBE_INTERVAL,
194 	DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN,
195 	DEVCONF_PROXY_NDP,
196 	DEVCONF_OPTIMISTIC_DAD,
197 	DEVCONF_ACCEPT_SOURCE_ROUTE,
198 	DEVCONF_MC_FORWARDING,
199 	DEVCONF_DISABLE_IPV6,
200 	DEVCONF_ACCEPT_DAD,
201 	DEVCONF_MAX
202 };
203 
204 #ifdef __KERNEL__
205 #include <linux/icmpv6.h>
206 #include <linux/tcp.h>
207 #include <linux/udp.h>
208 
209 #include <net/inet_sock.h>
210 
211 static inline struct ipv6hdr *ipv6_hdr(const struct sk_buff *skb)
212 {
213 	return (struct ipv6hdr *)skb_network_header(skb);
214 }
215 
216 static inline struct ipv6hdr *ipipv6_hdr(const struct sk_buff *skb)
217 {
218 	return (struct ipv6hdr *)skb_transport_header(skb);
219 }
220 
221 /*
222    This structure contains results of exthdrs parsing
223    as offsets from skb->nh.
224  */
225 
226 struct inet6_skb_parm {
227 	int			iif;
228 	__u16			ra;
229 	__u16			hop;
230 	__u16			dst0;
231 	__u16			srcrt;
232 	__u16			dst1;
233 	__u16			lastopt;
234 	__u32			nhoff;
235 	__u16			flags;
236 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
237 	__u16			dsthao;
238 #endif
239 
240 #define IP6SKB_XFRM_TRANSFORMED	1
241 #define IP6SKB_FORWARDED	2
242 };
243 
244 #define IP6CB(skb)	((struct inet6_skb_parm*)((skb)->cb))
245 
246 static inline int inet6_iif(const struct sk_buff *skb)
247 {
248 	return IP6CB(skb)->iif;
249 }
250 
251 struct inet6_request_sock {
252 	struct in6_addr		loc_addr;
253 	struct in6_addr		rmt_addr;
254 	struct sk_buff		*pktopts;
255 	int			iif;
256 };
257 
258 struct tcp6_request_sock {
259 	struct tcp_request_sock	  tcp6rsk_tcp;
260 	struct inet6_request_sock tcp6rsk_inet6;
261 };
262 
263 struct ipv6_mc_socklist;
264 struct ipv6_ac_socklist;
265 struct ipv6_fl_socklist;
266 
267 /**
268  * struct ipv6_pinfo - ipv6 private area
269  *
270  * In the struct sock hierarchy (tcp6_sock, upd6_sock, etc)
271  * this _must_ be the last member, so that inet6_sk_generic
272  * is able to calculate its offset from the base struct sock
273  * by using the struct proto->slab_obj_size member. -acme
274  */
275 struct ipv6_pinfo {
276 	struct in6_addr 	saddr;
277 	struct in6_addr 	rcv_saddr;
278 	struct in6_addr		daddr;
279 	struct in6_addr		*daddr_cache;
280 #ifdef CONFIG_IPV6_SUBTREES
281 	struct in6_addr		*saddr_cache;
282 #endif
283 
284 	__be32			flow_label;
285 	__u32			frag_size;
286 
287 	/*
288 	 * Packed in 16bits.
289 	 * Omit one shift by by putting the signed field at MSB.
290 	 */
291 #if defined(__BIG_ENDIAN_BITFIELD)
292 	__s16			hop_limit:9;
293 	__u16			__unused_1:7;
294 #else
295 	__u16			__unused_1:7;
296 	__s16			hop_limit:9;
297 #endif
298 
299 #if defined(__BIG_ENDIAN_BITFIELD)
300 	/* Packed in 16bits. */
301 	__s16			mcast_hops:9;
302 	__u16			__unused_2:6,
303 				mc_loop:1;
304 #else
305 	__u16			mc_loop:1,
306 				__unused_2:6;
307 	__s16			mcast_hops:9;
308 #endif
309 	int			mcast_oif;
310 
311 	/* pktoption flags */
312 	union {
313 		struct {
314 			__u16	srcrt:1,
315 				osrcrt:1,
316 			        rxinfo:1,
317 			        rxoinfo:1,
318 				rxhlim:1,
319 				rxohlim:1,
320 				hopopts:1,
321 				ohopopts:1,
322 				dstopts:1,
323 				odstopts:1,
324                                 rxflow:1,
325 				rxtclass:1;
326 		} bits;
327 		__u16		all;
328 	} rxopt;
329 
330 	/* sockopt flags */
331 	__u8			recverr:1,
332 	                        sndflow:1,
333 				pmtudisc:2,
334 				ipv6only:1,
335 				srcprefs:3;	/* 001: prefer temporary address
336 						 * 010: prefer public address
337 						 * 100: prefer care-of address
338 						 */
339 	__u8			tclass;
340 
341 	__u32			dst_cookie;
342 
343 	struct ipv6_mc_socklist	*ipv6_mc_list;
344 	struct ipv6_ac_socklist	*ipv6_ac_list;
345 	struct ipv6_fl_socklist *ipv6_fl_list;
346 
347 	struct ipv6_txoptions	*opt;
348 	struct sk_buff		*pktoptions;
349 	struct {
350 		struct ipv6_txoptions *opt;
351 		u8 hop_limit;
352 		u8 tclass;
353 	} cork;
354 };
355 
356 /* WARNING: don't change the layout of the members in {raw,udp,tcp}6_sock! */
357 struct raw6_sock {
358 	/* inet_sock has to be the first member of raw6_sock */
359 	struct inet_sock	inet;
360 	__u32			checksum;	/* perform checksum */
361 	__u32			offset;		/* checksum offset  */
362 	struct icmp6_filter	filter;
363 	/* ipv6_pinfo has to be the last member of raw6_sock, see inet6_sk_generic */
364 	struct ipv6_pinfo	inet6;
365 };
366 
367 struct udp6_sock {
368 	struct udp_sock	  udp;
369 	/* ipv6_pinfo has to be the last member of udp6_sock, see inet6_sk_generic */
370 	struct ipv6_pinfo inet6;
371 };
372 
373 struct tcp6_sock {
374 	struct tcp_sock	  tcp;
375 	/* ipv6_pinfo has to be the last member of tcp6_sock, see inet6_sk_generic */
376 	struct ipv6_pinfo inet6;
377 };
378 
379 extern int inet6_sk_rebuild_header(struct sock *sk);
380 
381 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
382 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
383 {
384 	return inet_sk(__sk)->pinet6;
385 }
386 
387 static inline struct inet6_request_sock *
388 			inet6_rsk(const struct request_sock *rsk)
389 {
390 	return (struct inet6_request_sock *)(((u8 *)rsk) +
391 					     inet_rsk(rsk)->inet6_rsk_offset);
392 }
393 
394 static inline u32 inet6_rsk_offset(struct request_sock *rsk)
395 {
396 	return rsk->rsk_ops->obj_size - sizeof(struct inet6_request_sock);
397 }
398 
399 static inline struct request_sock *inet6_reqsk_alloc(struct request_sock_ops *ops)
400 {
401 	struct request_sock *req = reqsk_alloc(ops);
402 
403 	if (req != NULL) {
404 		inet_rsk(req)->inet6_rsk_offset = inet6_rsk_offset(req);
405 		inet6_rsk(req)->pktopts = NULL;
406 	}
407 
408 	return req;
409 }
410 
411 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
412 {
413 	return (struct raw6_sock *)sk;
414 }
415 
416 static inline void inet_sk_copy_descendant(struct sock *sk_to,
417 					   const struct sock *sk_from)
418 {
419 	int ancestor_size = sizeof(struct inet_sock);
420 
421 	if (sk_from->sk_family == PF_INET6)
422 		ancestor_size += sizeof(struct ipv6_pinfo);
423 
424 	__inet_sk_copy_descendant(sk_to, sk_from, ancestor_size);
425 }
426 
427 #define __ipv6_only_sock(sk)	(inet6_sk(sk)->ipv6only)
428 #define ipv6_only_sock(sk)	((sk)->sk_family == PF_INET6 && __ipv6_only_sock(sk))
429 
430 struct inet6_timewait_sock {
431 	struct in6_addr tw_v6_daddr;
432 	struct in6_addr	tw_v6_rcv_saddr;
433 };
434 
435 struct tcp6_timewait_sock {
436 	struct tcp_timewait_sock   tcp6tw_tcp;
437 	struct inet6_timewait_sock tcp6tw_inet6;
438 };
439 
440 static inline u16 inet6_tw_offset(const struct proto *prot)
441 {
442 	return prot->twsk_prot->twsk_obj_size -
443 			sizeof(struct inet6_timewait_sock);
444 }
445 
446 static inline struct inet6_timewait_sock *inet6_twsk(const struct sock *sk)
447 {
448 	return (struct inet6_timewait_sock *)(((u8 *)sk) +
449 					      inet_twsk(sk)->tw_ipv6_offset);
450 }
451 
452 static inline struct in6_addr *__inet6_rcv_saddr(const struct sock *sk)
453 {
454 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
455 		&inet6_sk(sk)->rcv_saddr : &inet6_twsk(sk)->tw_v6_rcv_saddr;
456 }
457 
458 static inline struct in6_addr *inet6_rcv_saddr(const struct sock *sk)
459 {
460 	return sk->sk_family == AF_INET6 ? __inet6_rcv_saddr(sk) : NULL;
461 }
462 
463 static inline int inet_v6_ipv6only(const struct sock *sk)
464 {
465 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
466 		ipv6_only_sock(sk) : inet_twsk(sk)->tw_ipv6only;
467 }
468 #else
469 #define __ipv6_only_sock(sk)	0
470 #define ipv6_only_sock(sk)	0
471 
472 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
473 {
474 	return NULL;
475 }
476 
477 static inline struct inet6_request_sock *
478 			inet6_rsk(const struct request_sock *rsk)
479 {
480 	return NULL;
481 }
482 
483 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
484 {
485 	return NULL;
486 }
487 
488 #define __inet6_rcv_saddr(__sk)	NULL
489 #define inet6_rcv_saddr(__sk)	NULL
490 #define tcp_twsk_ipv6only(__sk)		0
491 #define inet_v6_ipv6only(__sk)		0
492 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
493 
494 #define INET6_MATCH(__sk, __net, __hash, __saddr, __daddr, __ports, __dif)\
495 	(((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net)	&& \
496 	 ((*((__portpair *)&(inet_sk(__sk)->dport))) == (__ports))  	&& \
497 	 ((__sk)->sk_family		== AF_INET6)		&& \
498 	 ipv6_addr_equal(&inet6_sk(__sk)->daddr, (__saddr))	&& \
499 	 ipv6_addr_equal(&inet6_sk(__sk)->rcv_saddr, (__daddr))	&& \
500 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
501 
502 #define INET6_TW_MATCH(__sk, __net, __hash, __saddr, __daddr, __ports, __dif) \
503 	(((__sk)->sk_hash == (__hash)) && sock_net((__sk)) == (__net)	&& \
504 	 (*((__portpair *)&(inet_twsk(__sk)->tw_dport)) == (__ports))	&& \
505 	 ((__sk)->sk_family	       == PF_INET6)			&& \
506 	 (ipv6_addr_equal(&inet6_twsk(__sk)->tw_v6_daddr, (__saddr)))	&& \
507 	 (ipv6_addr_equal(&inet6_twsk(__sk)->tw_v6_rcv_saddr, (__daddr))) && \
508 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
509 
510 #endif /* __KERNEL__ */
511 
512 #endif /* _IPV6_H */
513