xref: /linux-6.15/include/linux/ipv6.h (revision de2fe5e0)
1 #ifndef _IPV6_H
2 #define _IPV6_H
3 
4 #include <linux/config.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	/* this hop must be a neighbor	*/
32 #define IPV6_SRCRT_TYPE_0	0	/* IPv6 type 0 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 struct ipv6_auth_hdr {
78 	__u8  nexthdr;
79 	__u8  hdrlen;           /* This one is measured in 32 bit units! */
80 	__u16 reserved;
81 	__u32 spi;
82 	__u32 seq_no;           /* Sequence number */
83 	__u8  auth_data[0];     /* Length variable but >=4. Mind the 64 bit alignment! */
84 };
85 
86 struct ipv6_esp_hdr {
87 	__u32 spi;
88 	__u32 seq_no;           /* Sequence number */
89 	__u8  enc_data[0];      /* Length variable but >=8. Mind the 64 bit alignment! */
90 };
91 
92 struct ipv6_comp_hdr {
93 	__u8 nexthdr;
94 	__u8 flags;
95 	__u16 cpi;
96 };
97 
98 /*
99  *	IPv6 fixed header
100  *
101  *	BEWARE, it is incorrect. The first 4 bits of flow_lbl
102  *	are glued to priority now, forming "class".
103  */
104 
105 struct ipv6hdr {
106 #if defined(__LITTLE_ENDIAN_BITFIELD)
107 	__u8			priority:4,
108 				version:4;
109 #elif defined(__BIG_ENDIAN_BITFIELD)
110 	__u8			version:4,
111 				priority:4;
112 #else
113 #error	"Please fix <asm/byteorder.h>"
114 #endif
115 	__u8			flow_lbl[3];
116 
117 	__u16			payload_len;
118 	__u8			nexthdr;
119 	__u8			hop_limit;
120 
121 	struct	in6_addr	saddr;
122 	struct	in6_addr	daddr;
123 };
124 
125 /*
126  * This structure contains configuration options per IPv6 link.
127  */
128 struct ipv6_devconf {
129 	__s32		forwarding;
130 	__s32		hop_limit;
131 	__s32		mtu6;
132 	__s32		accept_ra;
133 	__s32		accept_redirects;
134 	__s32		autoconf;
135 	__s32		dad_transmits;
136 	__s32		rtr_solicits;
137 	__s32		rtr_solicit_interval;
138 	__s32		rtr_solicit_delay;
139 	__s32		force_mld_version;
140 #ifdef CONFIG_IPV6_PRIVACY
141 	__s32		use_tempaddr;
142 	__s32		temp_valid_lft;
143 	__s32		temp_prefered_lft;
144 	__s32		regen_max_retry;
145 	__s32		max_desync_factor;
146 #endif
147 	__s32		max_addresses;
148 	__s32		accept_ra_defrtr;
149 	__s32		accept_ra_pinfo;
150 #ifdef CONFIG_IPV6_ROUTER_PREF
151 	__s32		accept_ra_rtr_pref;
152 	__s32		rtr_probe_interval;
153 #ifdef CONFIG_IPV6_ROUTE_INFO
154 	__s32		accept_ra_rt_info_max_plen;
155 #endif
156 #endif
157 	void		*sysctl;
158 };
159 
160 /* index values for the variables in ipv6_devconf */
161 enum {
162 	DEVCONF_FORWARDING = 0,
163 	DEVCONF_HOPLIMIT,
164 	DEVCONF_MTU6,
165 	DEVCONF_ACCEPT_RA,
166 	DEVCONF_ACCEPT_REDIRECTS,
167 	DEVCONF_AUTOCONF,
168 	DEVCONF_DAD_TRANSMITS,
169 	DEVCONF_RTR_SOLICITS,
170 	DEVCONF_RTR_SOLICIT_INTERVAL,
171 	DEVCONF_RTR_SOLICIT_DELAY,
172 	DEVCONF_USE_TEMPADDR,
173 	DEVCONF_TEMP_VALID_LFT,
174 	DEVCONF_TEMP_PREFERED_LFT,
175 	DEVCONF_REGEN_MAX_RETRY,
176 	DEVCONF_MAX_DESYNC_FACTOR,
177 	DEVCONF_MAX_ADDRESSES,
178 	DEVCONF_FORCE_MLD_VERSION,
179 	DEVCONF_ACCEPT_RA_DEFRTR,
180 	DEVCONF_ACCEPT_RA_PINFO,
181 	DEVCONF_ACCEPT_RA_RTR_PREF,
182 	DEVCONF_RTR_PROBE_INTERVAL,
183 	DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN,
184 	DEVCONF_MAX
185 };
186 
187 #ifdef __KERNEL__
188 #include <linux/icmpv6.h>
189 #include <linux/tcp.h>
190 #include <linux/udp.h>
191 
192 #include <net/if_inet6.h>       /* struct ipv6_mc_socklist */
193 #include <net/inet_sock.h>
194 
195 /*
196    This structure contains results of exthdrs parsing
197    as offsets from skb->nh.
198  */
199 
200 struct inet6_skb_parm {
201 	int			iif;
202 	__u16			ra;
203 	__u16			hop;
204 	__u16			dst0;
205 	__u16			srcrt;
206 	__u16			dst1;
207 	__u16			lastopt;
208 	__u32			nhoff;
209 	__u16			flags;
210 
211 #define IP6SKB_XFRM_TRANSFORMED	1
212 };
213 
214 #define IP6CB(skb)	((struct inet6_skb_parm*)((skb)->cb))
215 
216 static inline int inet6_iif(const struct sk_buff *skb)
217 {
218 	return IP6CB(skb)->iif;
219 }
220 
221 struct inet6_request_sock {
222 	struct in6_addr		loc_addr;
223 	struct in6_addr		rmt_addr;
224 	struct sk_buff		*pktopts;
225 	int			iif;
226 };
227 
228 struct tcp6_request_sock {
229 	struct tcp_request_sock	  tcp6rsk_tcp;
230 	struct inet6_request_sock tcp6rsk_inet6;
231 };
232 
233 /**
234  * struct ipv6_pinfo - ipv6 private area
235  *
236  * In the struct sock hierarchy (tcp6_sock, upd6_sock, etc)
237  * this _must_ be the last member, so that inet6_sk_generic
238  * is able to calculate its offset from the base struct sock
239  * by using the struct proto->slab_obj_size member. -acme
240  */
241 struct ipv6_pinfo {
242 	struct in6_addr 	saddr;
243 	struct in6_addr 	rcv_saddr;
244 	struct in6_addr		daddr;
245 	struct in6_addr		*daddr_cache;
246 
247 	__u32			flow_label;
248 	__u32			frag_size;
249 	__s16			hop_limit;
250 	__s16			mcast_hops;
251 	int			mcast_oif;
252 
253 	/* pktoption flags */
254 	union {
255 		struct {
256 			__u16	srcrt:2,
257 				osrcrt:2,
258 			        rxinfo:1,
259 			        rxoinfo:1,
260 				rxhlim:1,
261 				rxohlim:1,
262 				hopopts:1,
263 				ohopopts:1,
264 				dstopts:1,
265 				odstopts:1,
266                                 rxflow:1,
267 				rxtclass:1;
268 		} bits;
269 		__u16		all;
270 	} rxopt;
271 
272 	/* sockopt flags */
273 	__u8			mc_loop:1,
274 	                        recverr:1,
275 	                        sndflow:1,
276 				pmtudisc:2,
277 				ipv6only:1;
278 	__u8			tclass;
279 
280 	__u32			dst_cookie;
281 
282 	struct ipv6_mc_socklist	*ipv6_mc_list;
283 	struct ipv6_ac_socklist	*ipv6_ac_list;
284 	struct ipv6_fl_socklist *ipv6_fl_list;
285 
286 	struct ipv6_txoptions	*opt;
287 	struct sk_buff		*pktoptions;
288 	struct {
289 		struct ipv6_txoptions *opt;
290 		struct rt6_info	*rt;
291 		int hop_limit;
292 		int tclass;
293 	} cork;
294 };
295 
296 /* WARNING: don't change the layout of the members in {raw,udp,tcp}6_sock! */
297 struct raw6_sock {
298 	/* inet_sock has to be the first member of raw6_sock */
299 	struct inet_sock	inet;
300 	__u32			checksum;	/* perform checksum */
301 	__u32			offset;		/* checksum offset  */
302 	struct icmp6_filter	filter;
303 	/* ipv6_pinfo has to be the last member of raw6_sock, see inet6_sk_generic */
304 	struct ipv6_pinfo	inet6;
305 };
306 
307 struct udp6_sock {
308 	struct udp_sock	  udp;
309 	/* ipv6_pinfo has to be the last member of udp6_sock, see inet6_sk_generic */
310 	struct ipv6_pinfo inet6;
311 };
312 
313 struct tcp6_sock {
314 	struct tcp_sock	  tcp;
315 	/* ipv6_pinfo has to be the last member of tcp6_sock, see inet6_sk_generic */
316 	struct ipv6_pinfo inet6;
317 };
318 
319 extern int inet6_sk_rebuild_header(struct sock *sk);
320 
321 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
322 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
323 {
324 	return inet_sk(__sk)->pinet6;
325 }
326 
327 static inline struct inet6_request_sock *
328 			inet6_rsk(const struct request_sock *rsk)
329 {
330 	return (struct inet6_request_sock *)(((u8 *)rsk) +
331 					     inet_rsk(rsk)->inet6_rsk_offset);
332 }
333 
334 static inline u32 inet6_rsk_offset(struct request_sock *rsk)
335 {
336 	return rsk->rsk_ops->obj_size - sizeof(struct inet6_request_sock);
337 }
338 
339 static inline struct request_sock *inet6_reqsk_alloc(struct request_sock_ops *ops)
340 {
341 	struct request_sock *req = reqsk_alloc(ops);
342 
343 	if (req != NULL)
344 		inet_rsk(req)->inet6_rsk_offset = inet6_rsk_offset(req);
345 
346 	return req;
347 }
348 
349 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
350 {
351 	return (struct raw6_sock *)sk;
352 }
353 
354 static inline void inet_sk_copy_descendant(struct sock *sk_to,
355 					   const struct sock *sk_from)
356 {
357 	int ancestor_size = sizeof(struct inet_sock);
358 
359 	if (sk_from->sk_family == PF_INET6)
360 		ancestor_size += sizeof(struct ipv6_pinfo);
361 
362 	__inet_sk_copy_descendant(sk_to, sk_from, ancestor_size);
363 }
364 
365 #define __ipv6_only_sock(sk)	(inet6_sk(sk)->ipv6only)
366 #define ipv6_only_sock(sk)	((sk)->sk_family == PF_INET6 && __ipv6_only_sock(sk))
367 
368 struct inet6_timewait_sock {
369 	struct in6_addr tw_v6_daddr;
370 	struct in6_addr	tw_v6_rcv_saddr;
371 };
372 
373 struct tcp6_timewait_sock {
374 	struct tcp_timewait_sock   tcp6tw_tcp;
375 	struct inet6_timewait_sock tcp6tw_inet6;
376 };
377 
378 static inline u16 inet6_tw_offset(const struct proto *prot)
379 {
380 	return prot->twsk_prot->twsk_obj_size -
381 			sizeof(struct inet6_timewait_sock);
382 }
383 
384 static inline struct inet6_timewait_sock *inet6_twsk(const struct sock *sk)
385 {
386 	return (struct inet6_timewait_sock *)(((u8 *)sk) +
387 					      inet_twsk(sk)->tw_ipv6_offset);
388 }
389 
390 static inline struct in6_addr *__inet6_rcv_saddr(const struct sock *sk)
391 {
392 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
393 		&inet6_sk(sk)->rcv_saddr : &inet6_twsk(sk)->tw_v6_rcv_saddr;
394 }
395 
396 static inline struct in6_addr *inet6_rcv_saddr(const struct sock *sk)
397 {
398 	return sk->sk_family == AF_INET6 ? __inet6_rcv_saddr(sk) : NULL;
399 }
400 
401 static inline int inet_v6_ipv6only(const struct sock *sk)
402 {
403 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
404 		ipv6_only_sock(sk) : inet_twsk(sk)->tw_ipv6only;
405 }
406 #else
407 #define __ipv6_only_sock(sk)	0
408 #define ipv6_only_sock(sk)	0
409 
410 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
411 {
412 	return NULL;
413 }
414 
415 static inline struct inet6_request_sock *
416 			inet6_rsk(const struct request_sock *rsk)
417 {
418 	return NULL;
419 }
420 
421 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
422 {
423 	return NULL;
424 }
425 
426 #define __inet6_rcv_saddr(__sk)	NULL
427 #define inet6_rcv_saddr(__sk)	NULL
428 #define tcp_twsk_ipv6only(__sk)		0
429 #define inet_v6_ipv6only(__sk)		0
430 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
431 
432 #define INET6_MATCH(__sk, __hash, __saddr, __daddr, __ports, __dif)\
433 	(((__sk)->sk_hash == (__hash))				&& \
434 	 ((*((__u32 *)&(inet_sk(__sk)->dport))) == (__ports))  	&& \
435 	 ((__sk)->sk_family		== AF_INET6)		&& \
436 	 ipv6_addr_equal(&inet6_sk(__sk)->daddr, (__saddr))	&& \
437 	 ipv6_addr_equal(&inet6_sk(__sk)->rcv_saddr, (__daddr))	&& \
438 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
439 
440 #endif /* __KERNEL__ */
441 
442 #endif /* _IPV6_H */
443