xref: /linux-6.15/include/linux/ipv6.h (revision 4f193362)
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 	void		*sysctl;
149 };
150 
151 /* index values for the variables in ipv6_devconf */
152 enum {
153 	DEVCONF_FORWARDING = 0,
154 	DEVCONF_HOPLIMIT,
155 	DEVCONF_MTU6,
156 	DEVCONF_ACCEPT_RA,
157 	DEVCONF_ACCEPT_REDIRECTS,
158 	DEVCONF_AUTOCONF,
159 	DEVCONF_DAD_TRANSMITS,
160 	DEVCONF_RTR_SOLICITS,
161 	DEVCONF_RTR_SOLICIT_INTERVAL,
162 	DEVCONF_RTR_SOLICIT_DELAY,
163 	DEVCONF_USE_TEMPADDR,
164 	DEVCONF_TEMP_VALID_LFT,
165 	DEVCONF_TEMP_PREFERED_LFT,
166 	DEVCONF_REGEN_MAX_RETRY,
167 	DEVCONF_MAX_DESYNC_FACTOR,
168 	DEVCONF_MAX_ADDRESSES,
169 	DEVCONF_FORCE_MLD_VERSION,
170 	DEVCONF_MAX
171 };
172 
173 #ifdef __KERNEL__
174 #include <linux/icmpv6.h>
175 #include <linux/tcp.h>
176 #include <linux/udp.h>
177 
178 #include <net/if_inet6.h>       /* struct ipv6_mc_socklist */
179 #include <net/inet_sock.h>
180 
181 /*
182    This structure contains results of exthdrs parsing
183    as offsets from skb->nh.
184  */
185 
186 struct inet6_skb_parm {
187 	int			iif;
188 	__u16			ra;
189 	__u16			hop;
190 	__u16			dst0;
191 	__u16			srcrt;
192 	__u16			dst1;
193 	__u16			lastopt;
194 	__u32			nhoff;
195 	__u16			flags;
196 
197 #define IP6SKB_XFRM_TRANSFORMED	1
198 };
199 
200 #define IP6CB(skb)	((struct inet6_skb_parm*)((skb)->cb))
201 
202 static inline int inet6_iif(const struct sk_buff *skb)
203 {
204 	return IP6CB(skb)->iif;
205 }
206 
207 struct inet6_request_sock {
208 	struct in6_addr		loc_addr;
209 	struct in6_addr		rmt_addr;
210 	struct sk_buff		*pktopts;
211 	int			iif;
212 };
213 
214 struct tcp6_request_sock {
215 	struct tcp_request_sock	  tcp6rsk_tcp;
216 	struct inet6_request_sock tcp6rsk_inet6;
217 };
218 
219 /**
220  * struct ipv6_pinfo - ipv6 private area
221  *
222  * In the struct sock hierarchy (tcp6_sock, upd6_sock, etc)
223  * this _must_ be the last member, so that inet6_sk_generic
224  * is able to calculate its offset from the base struct sock
225  * by using the struct proto->slab_obj_size member. -acme
226  */
227 struct ipv6_pinfo {
228 	struct in6_addr 	saddr;
229 	struct in6_addr 	rcv_saddr;
230 	struct in6_addr		daddr;
231 	struct in6_addr		*daddr_cache;
232 
233 	__u32			flow_label;
234 	__u32			frag_size;
235 	__s16			hop_limit;
236 	__s16			mcast_hops;
237 	int			mcast_oif;
238 
239 	/* pktoption flags */
240 	union {
241 		struct {
242 			__u16	srcrt:2,
243 				osrcrt:2,
244 			        rxinfo:1,
245 			        rxoinfo:1,
246 				rxhlim:1,
247 				rxohlim:1,
248 				hopopts:1,
249 				ohopopts:1,
250 				dstopts:1,
251 				odstopts:1,
252                                 rxflow:1,
253 				rxtclass:1;
254 		} bits;
255 		__u16		all;
256 	} rxopt;
257 
258 	/* sockopt flags */
259 	__u8			mc_loop:1,
260 	                        recverr:1,
261 	                        sndflow:1,
262 				pmtudisc:2,
263 				ipv6only:1;
264 	__u8			tclass;
265 
266 	__u32			dst_cookie;
267 
268 	struct ipv6_mc_socklist	*ipv6_mc_list;
269 	struct ipv6_ac_socklist	*ipv6_ac_list;
270 	struct ipv6_fl_socklist *ipv6_fl_list;
271 
272 	struct ipv6_txoptions	*opt;
273 	struct sk_buff		*pktoptions;
274 	struct {
275 		struct ipv6_txoptions *opt;
276 		struct rt6_info	*rt;
277 		int hop_limit;
278 		int tclass;
279 	} cork;
280 };
281 
282 /* WARNING: don't change the layout of the members in {raw,udp,tcp}6_sock! */
283 struct raw6_sock {
284 	/* inet_sock has to be the first member of raw6_sock */
285 	struct inet_sock	inet;
286 	__u32			checksum;	/* perform checksum */
287 	__u32			offset;		/* checksum offset  */
288 	struct icmp6_filter	filter;
289 	/* ipv6_pinfo has to be the last member of raw6_sock, see inet6_sk_generic */
290 	struct ipv6_pinfo	inet6;
291 };
292 
293 struct udp6_sock {
294 	struct udp_sock	  udp;
295 	/* ipv6_pinfo has to be the last member of udp6_sock, see inet6_sk_generic */
296 	struct ipv6_pinfo inet6;
297 };
298 
299 struct tcp6_sock {
300 	struct tcp_sock	  tcp;
301 	/* ipv6_pinfo has to be the last member of tcp6_sock, see inet6_sk_generic */
302 	struct ipv6_pinfo inet6;
303 };
304 
305 extern int inet6_sk_rebuild_header(struct sock *sk);
306 
307 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
308 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
309 {
310 	return inet_sk(__sk)->pinet6;
311 }
312 
313 static inline struct inet6_request_sock *
314 			inet6_rsk(const struct request_sock *rsk)
315 {
316 	return (struct inet6_request_sock *)(((u8 *)rsk) +
317 					     inet_rsk(rsk)->inet6_rsk_offset);
318 }
319 
320 static inline u32 inet6_rsk_offset(struct request_sock *rsk)
321 {
322 	return rsk->rsk_ops->obj_size - sizeof(struct inet6_request_sock);
323 }
324 
325 static inline struct request_sock *inet6_reqsk_alloc(struct request_sock_ops *ops)
326 {
327 	struct request_sock *req = reqsk_alloc(ops);
328 
329 	if (req != NULL)
330 		inet_rsk(req)->inet6_rsk_offset = inet6_rsk_offset(req);
331 
332 	return req;
333 }
334 
335 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
336 {
337 	return (struct raw6_sock *)sk;
338 }
339 
340 static inline void inet_sk_copy_descendant(struct sock *sk_to,
341 					   const struct sock *sk_from)
342 {
343 	int ancestor_size = sizeof(struct inet_sock);
344 
345 	if (sk_from->sk_family == PF_INET6)
346 		ancestor_size += sizeof(struct ipv6_pinfo);
347 
348 	__inet_sk_copy_descendant(sk_to, sk_from, ancestor_size);
349 }
350 
351 #define __ipv6_only_sock(sk)	(inet6_sk(sk)->ipv6only)
352 #define ipv6_only_sock(sk)	((sk)->sk_family == PF_INET6 && __ipv6_only_sock(sk))
353 
354 struct inet6_timewait_sock {
355 	struct in6_addr tw_v6_daddr;
356 	struct in6_addr	tw_v6_rcv_saddr;
357 };
358 
359 struct tcp6_timewait_sock {
360 	struct tcp_timewait_sock   tcp6tw_tcp;
361 	struct inet6_timewait_sock tcp6tw_inet6;
362 };
363 
364 static inline u16 inet6_tw_offset(const struct proto *prot)
365 {
366 	return prot->twsk_prot->twsk_obj_size -
367 			sizeof(struct inet6_timewait_sock);
368 }
369 
370 static inline struct inet6_timewait_sock *inet6_twsk(const struct sock *sk)
371 {
372 	return (struct inet6_timewait_sock *)(((u8 *)sk) +
373 					      inet_twsk(sk)->tw_ipv6_offset);
374 }
375 
376 static inline struct in6_addr *__inet6_rcv_saddr(const struct sock *sk)
377 {
378 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
379 		&inet6_sk(sk)->rcv_saddr : &inet6_twsk(sk)->tw_v6_rcv_saddr;
380 }
381 
382 static inline struct in6_addr *inet6_rcv_saddr(const struct sock *sk)
383 {
384 	return sk->sk_family == AF_INET6 ? __inet6_rcv_saddr(sk) : NULL;
385 }
386 
387 static inline int inet_v6_ipv6only(const struct sock *sk)
388 {
389 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
390 		ipv6_only_sock(sk) : inet_twsk(sk)->tw_ipv6only;
391 }
392 #else
393 #define __ipv6_only_sock(sk)	0
394 #define ipv6_only_sock(sk)	0
395 
396 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
397 {
398 	return NULL;
399 }
400 
401 static inline struct inet6_request_sock *
402 			inet6_rsk(const struct request_sock *rsk)
403 {
404 	return NULL;
405 }
406 
407 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
408 {
409 	return NULL;
410 }
411 
412 #define __inet6_rcv_saddr(__sk)	NULL
413 #define inet6_rcv_saddr(__sk)	NULL
414 #define tcp_twsk_ipv6only(__sk)		0
415 #define inet_v6_ipv6only(__sk)		0
416 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
417 
418 #define INET6_MATCH(__sk, __hash, __saddr, __daddr, __ports, __dif)\
419 	(((__sk)->sk_hash == (__hash))				&& \
420 	 ((*((__u32 *)&(inet_sk(__sk)->dport))) == (__ports))  	&& \
421 	 ((__sk)->sk_family		== AF_INET6)		&& \
422 	 ipv6_addr_equal(&inet6_sk(__sk)->daddr, (__saddr))	&& \
423 	 ipv6_addr_equal(&inet6_sk(__sk)->rcv_saddr, (__daddr))	&& \
424 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
425 
426 #endif /* __KERNEL__ */
427 
428 #endif /* _IPV6_H */
429