xref: /linux-6.15/include/linux/ipv6.h (revision eb2bce7f)
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	/* this hop must be a neighbor	*/
31 #define IPV6_SRCRT_TYPE_0	0	/* IPv6 type 0 Routing Header	*/
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 };
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 struct ipv6_auth_hdr {
100 	__u8  nexthdr;
101 	__u8  hdrlen;           /* This one is measured in 32 bit units! */
102 	__be16 reserved;
103 	__be32 spi;
104 	__be32 seq_no;           /* Sequence number */
105 	__u8  auth_data[0];     /* Length variable but >=4. Mind the 64 bit alignment! */
106 };
107 
108 struct ipv6_esp_hdr {
109 	__be32 spi;
110 	__be32 seq_no;           /* Sequence number */
111 	__u8  enc_data[0];      /* Length variable but >=8. Mind the 64 bit alignment! */
112 };
113 
114 struct ipv6_comp_hdr {
115 	__u8 nexthdr;
116 	__u8 flags;
117 	__be16 cpi;
118 };
119 
120 /*
121  *	IPv6 fixed header
122  *
123  *	BEWARE, it is incorrect. The first 4 bits of flow_lbl
124  *	are glued to priority now, forming "class".
125  */
126 
127 struct ipv6hdr {
128 #if defined(__LITTLE_ENDIAN_BITFIELD)
129 	__u8			priority:4,
130 				version:4;
131 #elif defined(__BIG_ENDIAN_BITFIELD)
132 	__u8			version:4,
133 				priority:4;
134 #else
135 #error	"Please fix <asm/byteorder.h>"
136 #endif
137 	__u8			flow_lbl[3];
138 
139 	__be16			payload_len;
140 	__u8			nexthdr;
141 	__u8			hop_limit;
142 
143 	struct	in6_addr	saddr;
144 	struct	in6_addr	daddr;
145 };
146 
147 /*
148  * This structure contains configuration options per IPv6 link.
149  */
150 struct ipv6_devconf {
151 	__s32		forwarding;
152 	__s32		hop_limit;
153 	__s32		mtu6;
154 	__s32		accept_ra;
155 	__s32		accept_redirects;
156 	__s32		autoconf;
157 	__s32		dad_transmits;
158 	__s32		rtr_solicits;
159 	__s32		rtr_solicit_interval;
160 	__s32		rtr_solicit_delay;
161 	__s32		force_mld_version;
162 #ifdef CONFIG_IPV6_PRIVACY
163 	__s32		use_tempaddr;
164 	__s32		temp_valid_lft;
165 	__s32		temp_prefered_lft;
166 	__s32		regen_max_retry;
167 	__s32		max_desync_factor;
168 #endif
169 	__s32		max_addresses;
170 	__s32		accept_ra_defrtr;
171 	__s32		accept_ra_pinfo;
172 #ifdef CONFIG_IPV6_ROUTER_PREF
173 	__s32		accept_ra_rtr_pref;
174 	__s32		rtr_probe_interval;
175 #ifdef CONFIG_IPV6_ROUTE_INFO
176 	__s32		accept_ra_rt_info_max_plen;
177 #endif
178 #endif
179 	__s32		proxy_ndp;
180 	__s32		accept_source_route;
181 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
182 	__s32		optimistic_dad;
183 #endif
184 	void		*sysctl;
185 };
186 
187 /* index values for the variables in ipv6_devconf */
188 enum {
189 	DEVCONF_FORWARDING = 0,
190 	DEVCONF_HOPLIMIT,
191 	DEVCONF_MTU6,
192 	DEVCONF_ACCEPT_RA,
193 	DEVCONF_ACCEPT_REDIRECTS,
194 	DEVCONF_AUTOCONF,
195 	DEVCONF_DAD_TRANSMITS,
196 	DEVCONF_RTR_SOLICITS,
197 	DEVCONF_RTR_SOLICIT_INTERVAL,
198 	DEVCONF_RTR_SOLICIT_DELAY,
199 	DEVCONF_USE_TEMPADDR,
200 	DEVCONF_TEMP_VALID_LFT,
201 	DEVCONF_TEMP_PREFERED_LFT,
202 	DEVCONF_REGEN_MAX_RETRY,
203 	DEVCONF_MAX_DESYNC_FACTOR,
204 	DEVCONF_MAX_ADDRESSES,
205 	DEVCONF_FORCE_MLD_VERSION,
206 	DEVCONF_ACCEPT_RA_DEFRTR,
207 	DEVCONF_ACCEPT_RA_PINFO,
208 	DEVCONF_ACCEPT_RA_RTR_PREF,
209 	DEVCONF_RTR_PROBE_INTERVAL,
210 	DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN,
211 	DEVCONF_PROXY_NDP,
212 	__DEVCONF_OPTIMISTIC_DAD,
213 	DEVCONF_ACCEPT_SOURCE_ROUTE,
214 	DEVCONF_OPTIMISTIC_DAD,
215 	DEVCONF_MAX
216 };
217 
218 #ifdef __KERNEL__
219 #include <linux/icmpv6.h>
220 #include <linux/tcp.h>
221 #include <linux/udp.h>
222 
223 #include <net/if_inet6.h>       /* struct ipv6_mc_socklist */
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 /*
237    This structure contains results of exthdrs parsing
238    as offsets from skb->nh.
239  */
240 
241 struct inet6_skb_parm {
242 	int			iif;
243 	__u16			ra;
244 	__u16			hop;
245 	__u16			dst0;
246 	__u16			srcrt;
247 	__u16			dst1;
248 	__u16			lastopt;
249 	__u32			nhoff;
250 	__u16			flags;
251 #ifdef CONFIG_IPV6_MIP6
252 	__u16			dsthao;
253 #endif
254 
255 #define IP6SKB_XFRM_TRANSFORMED	1
256 };
257 
258 #define IP6CB(skb)	((struct inet6_skb_parm*)((skb)->cb))
259 
260 static inline int inet6_iif(const struct sk_buff *skb)
261 {
262 	return IP6CB(skb)->iif;
263 }
264 
265 struct inet6_request_sock {
266 	struct in6_addr		loc_addr;
267 	struct in6_addr		rmt_addr;
268 	struct sk_buff		*pktopts;
269 	int			iif;
270 };
271 
272 struct tcp6_request_sock {
273 	struct tcp_request_sock	  tcp6rsk_tcp;
274 	struct inet6_request_sock tcp6rsk_inet6;
275 };
276 
277 /**
278  * struct ipv6_pinfo - ipv6 private area
279  *
280  * In the struct sock hierarchy (tcp6_sock, upd6_sock, etc)
281  * this _must_ be the last member, so that inet6_sk_generic
282  * is able to calculate its offset from the base struct sock
283  * by using the struct proto->slab_obj_size member. -acme
284  */
285 struct ipv6_pinfo {
286 	struct in6_addr 	saddr;
287 	struct in6_addr 	rcv_saddr;
288 	struct in6_addr		daddr;
289 	struct in6_addr		*daddr_cache;
290 #ifdef CONFIG_IPV6_SUBTREES
291 	struct in6_addr		*saddr_cache;
292 #endif
293 
294 	__be32			flow_label;
295 	__u32			frag_size;
296 	__s16			hop_limit;
297 	__s16			mcast_hops;
298 	int			mcast_oif;
299 
300 	/* pktoption flags */
301 	union {
302 		struct {
303 			__u16	srcrt:2,
304 				osrcrt:2,
305 			        rxinfo:1,
306 			        rxoinfo:1,
307 				rxhlim:1,
308 				rxohlim:1,
309 				hopopts:1,
310 				ohopopts:1,
311 				dstopts:1,
312 				odstopts:1,
313                                 rxflow:1,
314 				rxtclass:1;
315 		} bits;
316 		__u16		all;
317 	} rxopt;
318 
319 	/* sockopt flags */
320 	__u8			mc_loop:1,
321 	                        recverr:1,
322 	                        sndflow:1,
323 				pmtudisc:2,
324 				ipv6only:1;
325 	__u8			tclass;
326 
327 	__u32			dst_cookie;
328 
329 	struct ipv6_mc_socklist	*ipv6_mc_list;
330 	struct ipv6_ac_socklist	*ipv6_ac_list;
331 	struct ipv6_fl_socklist *ipv6_fl_list;
332 
333 	struct ipv6_txoptions	*opt;
334 	struct sk_buff		*pktoptions;
335 	struct {
336 		struct ipv6_txoptions *opt;
337 		struct rt6_info	*rt;
338 		int hop_limit;
339 		int tclass;
340 	} cork;
341 };
342 
343 /* WARNING: don't change the layout of the members in {raw,udp,tcp}6_sock! */
344 struct raw6_sock {
345 	/* inet_sock has to be the first member of raw6_sock */
346 	struct inet_sock	inet;
347 	__u32			checksum;	/* perform checksum */
348 	__u32			offset;		/* checksum offset  */
349 	struct icmp6_filter	filter;
350 	/* ipv6_pinfo has to be the last member of raw6_sock, see inet6_sk_generic */
351 	struct ipv6_pinfo	inet6;
352 };
353 
354 struct udp6_sock {
355 	struct udp_sock	  udp;
356 	/* ipv6_pinfo has to be the last member of udp6_sock, see inet6_sk_generic */
357 	struct ipv6_pinfo inet6;
358 };
359 
360 struct tcp6_sock {
361 	struct tcp_sock	  tcp;
362 	/* ipv6_pinfo has to be the last member of tcp6_sock, see inet6_sk_generic */
363 	struct ipv6_pinfo inet6;
364 };
365 
366 extern int inet6_sk_rebuild_header(struct sock *sk);
367 
368 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
369 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
370 {
371 	return inet_sk(__sk)->pinet6;
372 }
373 
374 static inline struct inet6_request_sock *
375 			inet6_rsk(const struct request_sock *rsk)
376 {
377 	return (struct inet6_request_sock *)(((u8 *)rsk) +
378 					     inet_rsk(rsk)->inet6_rsk_offset);
379 }
380 
381 static inline u32 inet6_rsk_offset(struct request_sock *rsk)
382 {
383 	return rsk->rsk_ops->obj_size - sizeof(struct inet6_request_sock);
384 }
385 
386 static inline struct request_sock *inet6_reqsk_alloc(struct request_sock_ops *ops)
387 {
388 	struct request_sock *req = reqsk_alloc(ops);
389 
390 	if (req != NULL)
391 		inet_rsk(req)->inet6_rsk_offset = inet6_rsk_offset(req);
392 
393 	return req;
394 }
395 
396 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
397 {
398 	return (struct raw6_sock *)sk;
399 }
400 
401 static inline void inet_sk_copy_descendant(struct sock *sk_to,
402 					   const struct sock *sk_from)
403 {
404 	int ancestor_size = sizeof(struct inet_sock);
405 
406 	if (sk_from->sk_family == PF_INET6)
407 		ancestor_size += sizeof(struct ipv6_pinfo);
408 
409 	__inet_sk_copy_descendant(sk_to, sk_from, ancestor_size);
410 }
411 
412 #define __ipv6_only_sock(sk)	(inet6_sk(sk)->ipv6only)
413 #define ipv6_only_sock(sk)	((sk)->sk_family == PF_INET6 && __ipv6_only_sock(sk))
414 
415 struct inet6_timewait_sock {
416 	struct in6_addr tw_v6_daddr;
417 	struct in6_addr	tw_v6_rcv_saddr;
418 };
419 
420 struct tcp6_timewait_sock {
421 	struct tcp_timewait_sock   tcp6tw_tcp;
422 	struct inet6_timewait_sock tcp6tw_inet6;
423 };
424 
425 static inline u16 inet6_tw_offset(const struct proto *prot)
426 {
427 	return prot->twsk_prot->twsk_obj_size -
428 			sizeof(struct inet6_timewait_sock);
429 }
430 
431 static inline struct inet6_timewait_sock *inet6_twsk(const struct sock *sk)
432 {
433 	return (struct inet6_timewait_sock *)(((u8 *)sk) +
434 					      inet_twsk(sk)->tw_ipv6_offset);
435 }
436 
437 static inline struct in6_addr *__inet6_rcv_saddr(const struct sock *sk)
438 {
439 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
440 		&inet6_sk(sk)->rcv_saddr : &inet6_twsk(sk)->tw_v6_rcv_saddr;
441 }
442 
443 static inline struct in6_addr *inet6_rcv_saddr(const struct sock *sk)
444 {
445 	return sk->sk_family == AF_INET6 ? __inet6_rcv_saddr(sk) : NULL;
446 }
447 
448 static inline int inet_v6_ipv6only(const struct sock *sk)
449 {
450 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
451 		ipv6_only_sock(sk) : inet_twsk(sk)->tw_ipv6only;
452 }
453 #else
454 #define __ipv6_only_sock(sk)	0
455 #define ipv6_only_sock(sk)	0
456 
457 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
458 {
459 	return NULL;
460 }
461 
462 static inline struct inet6_request_sock *
463 			inet6_rsk(const struct request_sock *rsk)
464 {
465 	return NULL;
466 }
467 
468 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
469 {
470 	return NULL;
471 }
472 
473 #define __inet6_rcv_saddr(__sk)	NULL
474 #define inet6_rcv_saddr(__sk)	NULL
475 #define tcp_twsk_ipv6only(__sk)		0
476 #define inet_v6_ipv6only(__sk)		0
477 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
478 
479 #define INET6_MATCH(__sk, __hash, __saddr, __daddr, __ports, __dif)\
480 	(((__sk)->sk_hash == (__hash))				&& \
481 	 ((*((__portpair *)&(inet_sk(__sk)->dport))) == (__ports))  	&& \
482 	 ((__sk)->sk_family		== AF_INET6)		&& \
483 	 ipv6_addr_equal(&inet6_sk(__sk)->daddr, (__saddr))	&& \
484 	 ipv6_addr_equal(&inet6_sk(__sk)->rcv_saddr, (__daddr))	&& \
485 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
486 
487 #endif /* __KERNEL__ */
488 
489 #endif /* _IPV6_H */
490