xref: /linux-6.15/include/linux/ipv6.h (revision 4e57b681)
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/in6.h>          /* struct sockaddr_in6 */
175 #include <linux/icmpv6.h>
176 #include <net/if_inet6.h>       /* struct ipv6_mc_socklist */
177 #include <linux/tcp.h>
178 #include <linux/udp.h>
179 
180 /*
181    This structure contains results of exthdrs parsing
182    as offsets from skb->nh.
183  */
184 
185 struct inet6_skb_parm {
186 	int			iif;
187 	__u16			ra;
188 	__u16			hop;
189 	__u16			dst0;
190 	__u16			srcrt;
191 	__u16			dst1;
192 	__u16			lastopt;
193 };
194 
195 #define IP6CB(skb)	((struct inet6_skb_parm*)((skb)->cb))
196 
197 static inline int inet6_iif(const struct sk_buff *skb)
198 {
199 	return IP6CB(skb)->iif;
200 }
201 
202 struct tcp6_request_sock {
203 	struct tcp_request_sock	req;
204 	struct in6_addr		loc_addr;
205 	struct in6_addr		rmt_addr;
206 	struct sk_buff		*pktopts;
207 	int			iif;
208 };
209 
210 static inline struct tcp6_request_sock *tcp6_rsk(const struct request_sock *sk)
211 {
212 	return (struct tcp6_request_sock *)sk;
213 }
214 
215 /**
216  * struct ipv6_pinfo - ipv6 private area
217  *
218  * In the struct sock hierarchy (tcp6_sock, upd6_sock, etc)
219  * this _must_ be the last member, so that inet6_sk_generic
220  * is able to calculate its offset from the base struct sock
221  * by using the struct proto->slab_obj_size member. -acme
222  */
223 struct ipv6_pinfo {
224 	struct in6_addr 	saddr;
225 	struct in6_addr 	rcv_saddr;
226 	struct in6_addr		daddr;
227 	struct in6_addr		*daddr_cache;
228 
229 	__u32			flow_label;
230 	__u32			frag_size;
231 	__s16			hop_limit;
232 	__s16			mcast_hops;
233 	int			mcast_oif;
234 
235 	/* pktoption flags */
236 	union {
237 		struct {
238 			__u16	srcrt:2,
239 				osrcrt:2,
240 			        rxinfo:1,
241 			        rxoinfo:1,
242 				rxhlim:1,
243 				rxohlim:1,
244 				hopopts:1,
245 				ohopopts:1,
246 				dstopts:1,
247 				odstopts:1,
248                                 rxflow:1,
249 				rxtclass:1;
250 		} bits;
251 		__u16		all;
252 	} rxopt;
253 
254 	/* sockopt flags */
255 	__u8			mc_loop:1,
256 	                        recverr:1,
257 	                        sndflow:1,
258 				pmtudisc:2,
259 				ipv6only:1;
260 	__u8			tclass;
261 
262 	__u32			dst_cookie;
263 
264 	struct ipv6_mc_socklist	*ipv6_mc_list;
265 	struct ipv6_ac_socklist	*ipv6_ac_list;
266 	struct ipv6_fl_socklist *ipv6_fl_list;
267 
268 	struct ipv6_txoptions	*opt;
269 	struct sk_buff		*pktoptions;
270 	struct {
271 		struct ipv6_txoptions *opt;
272 		struct rt6_info	*rt;
273 		int hop_limit;
274 		int tclass;
275 	} cork;
276 };
277 
278 /* WARNING: don't change the layout of the members in {raw,udp,tcp}6_sock! */
279 struct raw6_sock {
280 	/* inet_sock has to be the first member of raw6_sock */
281 	struct inet_sock	inet;
282 	__u32			checksum;	/* perform checksum */
283 	__u32			offset;		/* checksum offset  */
284 	struct icmp6_filter	filter;
285 	/* ipv6_pinfo has to be the last member of raw6_sock, see inet6_sk_generic */
286 	struct ipv6_pinfo	inet6;
287 };
288 
289 struct udp6_sock {
290 	struct udp_sock	  udp;
291 	/* ipv6_pinfo has to be the last member of udp6_sock, see inet6_sk_generic */
292 	struct ipv6_pinfo inet6;
293 };
294 
295 struct tcp6_sock {
296 	struct tcp_sock	  tcp;
297 	/* ipv6_pinfo has to be the last member of tcp6_sock, see inet6_sk_generic */
298 	struct ipv6_pinfo inet6;
299 };
300 
301 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
302 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
303 {
304 	return inet_sk(__sk)->pinet6;
305 }
306 
307 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
308 {
309 	return (struct raw6_sock *)sk;
310 }
311 
312 static inline void inet_sk_copy_descendant(struct sock *sk_to,
313 					   const struct sock *sk_from)
314 {
315 	int ancestor_size = sizeof(struct inet_sock);
316 
317 	if (sk_from->sk_family == PF_INET6)
318 		ancestor_size += sizeof(struct ipv6_pinfo);
319 
320 	__inet_sk_copy_descendant(sk_to, sk_from, ancestor_size);
321 }
322 
323 #define __ipv6_only_sock(sk)	(inet6_sk(sk)->ipv6only)
324 #define ipv6_only_sock(sk)	((sk)->sk_family == PF_INET6 && __ipv6_only_sock(sk))
325 
326 #include <linux/tcp.h>
327 
328 struct tcp6_timewait_sock {
329 	struct tcp_timewait_sock tw_v6_sk;
330 	struct in6_addr		 tw_v6_daddr;
331 	struct in6_addr		 tw_v6_rcv_saddr;
332 };
333 
334 static inline struct tcp6_timewait_sock *tcp6_twsk(const struct sock *sk)
335 {
336 	return (struct tcp6_timewait_sock *)sk;
337 }
338 
339 static inline struct in6_addr *__tcp_v6_rcv_saddr(const struct sock *sk)
340 {
341 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
342 		&inet6_sk(sk)->rcv_saddr : &tcp6_twsk(sk)->tw_v6_rcv_saddr;
343 }
344 
345 static inline struct in6_addr *tcp_v6_rcv_saddr(const struct sock *sk)
346 {
347 	return sk->sk_family == AF_INET6 ? __tcp_v6_rcv_saddr(sk) : NULL;
348 }
349 
350 static inline int inet_v6_ipv6only(const struct sock *sk)
351 {
352 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
353 		ipv6_only_sock(sk) : inet_twsk(sk)->tw_ipv6only;
354 }
355 #else
356 #define __ipv6_only_sock(sk)	0
357 #define ipv6_only_sock(sk)	0
358 
359 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
360 {
361 	return NULL;
362 }
363 
364 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
365 {
366 	return NULL;
367 }
368 
369 #define __tcp_v6_rcv_saddr(__sk)	NULL
370 #define tcp_v6_rcv_saddr(__sk)		NULL
371 #define tcp_twsk_ipv6only(__sk)		0
372 #define inet_v6_ipv6only(__sk)		0
373 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
374 
375 #define INET6_MATCH(__sk, __hash, __saddr, __daddr, __ports, __dif)\
376 	(((__sk)->sk_hash == (__hash))				&& \
377 	 ((*((__u32 *)&(inet_sk(__sk)->dport))) == (__ports))  	&& \
378 	 ((__sk)->sk_family		== AF_INET6)		&& \
379 	 ipv6_addr_equal(&inet6_sk(__sk)->daddr, (__saddr))	&& \
380 	 ipv6_addr_equal(&inet6_sk(__sk)->rcv_saddr, (__daddr))	&& \
381 	 (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
382 
383 #endif /* __KERNEL__ */
384 
385 #endif /* _IPV6_H */
386