xref: /linux-6.15/include/linux/ipv6.h (revision d0807da7)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _IPV6_H
3 #define _IPV6_H
4 
5 #include <uapi/linux/ipv6.h>
6 
7 #define ipv6_optlen(p)  (((p)->hdrlen+1) << 3)
8 #define ipv6_authlen(p) (((p)->hdrlen+2) << 2)
9 /*
10  * This structure contains configuration options per IPv6 link.
11  */
12 struct ipv6_devconf {
13 	__s32		forwarding;
14 	__s32		hop_limit;
15 	__s32		mtu6;
16 	__s32		accept_ra;
17 	__s32		accept_redirects;
18 	__s32		autoconf;
19 	__s32		dad_transmits;
20 	__s32		rtr_solicits;
21 	__s32		rtr_solicit_interval;
22 	__s32		rtr_solicit_max_interval;
23 	__s32		rtr_solicit_delay;
24 	__s32		force_mld_version;
25 	__s32		mldv1_unsolicited_report_interval;
26 	__s32		mldv2_unsolicited_report_interval;
27 	__s32		use_tempaddr;
28 	__s32		temp_valid_lft;
29 	__s32		temp_prefered_lft;
30 	__s32		regen_max_retry;
31 	__s32		max_desync_factor;
32 	__s32		max_addresses;
33 	__s32		accept_ra_defrtr;
34 	__s32		accept_ra_min_hop_limit;
35 	__s32		accept_ra_pinfo;
36 	__s32		ignore_routes_with_linkdown;
37 #ifdef CONFIG_IPV6_ROUTER_PREF
38 	__s32		accept_ra_rtr_pref;
39 	__s32		rtr_probe_interval;
40 #ifdef CONFIG_IPV6_ROUTE_INFO
41 	__s32		accept_ra_rt_info_min_plen;
42 	__s32		accept_ra_rt_info_max_plen;
43 #endif
44 #endif
45 	__s32		proxy_ndp;
46 	__s32		accept_source_route;
47 	__s32		accept_ra_from_local;
48 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
49 	__s32		optimistic_dad;
50 	__s32		use_optimistic;
51 #endif
52 #ifdef CONFIG_IPV6_MROUTE
53 	__s32		mc_forwarding;
54 #endif
55 	__s32		disable_ipv6;
56 	__s32		drop_unicast_in_l2_multicast;
57 	__s32		accept_dad;
58 	__s32		force_tllao;
59 	__s32           ndisc_notify;
60 	__s32		suppress_frag_ndisc;
61 	__s32		accept_ra_mtu;
62 	__s32		drop_unsolicited_na;
63 	struct ipv6_stable_secret {
64 		bool initialized;
65 		struct in6_addr secret;
66 	} stable_secret;
67 	__s32		use_oif_addrs_only;
68 	__s32		keep_addr_on_down;
69 	__s32		seg6_enabled;
70 #ifdef CONFIG_IPV6_SEG6_HMAC
71 	__s32		seg6_require_hmac;
72 #endif
73 	__u32		enhanced_dad;
74 	__u32		addr_gen_mode;
75 	__s32		disable_policy;
76 
77 	struct ctl_table_header *sysctl_header;
78 };
79 
80 struct ipv6_params {
81 	__s32 disable_ipv6;
82 	__s32 autoconf;
83 };
84 extern struct ipv6_params ipv6_defaults;
85 #include <linux/icmpv6.h>
86 #include <linux/tcp.h>
87 #include <linux/udp.h>
88 
89 #include <net/inet_sock.h>
90 
91 static inline struct ipv6hdr *ipv6_hdr(const struct sk_buff *skb)
92 {
93 	return (struct ipv6hdr *)skb_network_header(skb);
94 }
95 
96 static inline struct ipv6hdr *inner_ipv6_hdr(const struct sk_buff *skb)
97 {
98 	return (struct ipv6hdr *)skb_inner_network_header(skb);
99 }
100 
101 static inline struct ipv6hdr *ipipv6_hdr(const struct sk_buff *skb)
102 {
103 	return (struct ipv6hdr *)skb_transport_header(skb);
104 }
105 
106 /*
107    This structure contains results of exthdrs parsing
108    as offsets from skb->nh.
109  */
110 
111 struct inet6_skb_parm {
112 	int			iif;
113 	__be16			ra;
114 	__u16			dst0;
115 	__u16			srcrt;
116 	__u16			dst1;
117 	__u16			lastopt;
118 	__u16			nhoff;
119 	__u16			flags;
120 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
121 	__u16			dsthao;
122 #endif
123 	__u16			frag_max_size;
124 
125 #define IP6SKB_XFRM_TRANSFORMED	1
126 #define IP6SKB_FORWARDED	2
127 #define IP6SKB_REROUTED		4
128 #define IP6SKB_ROUTERALERT	8
129 #define IP6SKB_FRAGMENTED      16
130 #define IP6SKB_HOPBYHOP        32
131 #define IP6SKB_L3SLAVE         64
132 #define IP6SKB_JUMBOGRAM      128
133 };
134 
135 #if defined(CONFIG_NET_L3_MASTER_DEV)
136 static inline bool ipv6_l3mdev_skb(__u16 flags)
137 {
138 	return flags & IP6SKB_L3SLAVE;
139 }
140 #else
141 static inline bool ipv6_l3mdev_skb(__u16 flags)
142 {
143 	return false;
144 }
145 #endif
146 
147 #define IP6CB(skb)	((struct inet6_skb_parm*)((skb)->cb))
148 #define IP6CBMTU(skb)	((struct ip6_mtuinfo *)((skb)->cb))
149 
150 static inline int inet6_iif(const struct sk_buff *skb)
151 {
152 	bool l3_slave = ipv6_l3mdev_skb(IP6CB(skb)->flags);
153 
154 	return l3_slave ? skb->skb_iif : IP6CB(skb)->iif;
155 }
156 
157 static inline bool inet6_is_jumbogram(const struct sk_buff *skb)
158 {
159 	return !!(IP6CB(skb)->flags & IP6SKB_JUMBOGRAM);
160 }
161 
162 /* can not be used in TCP layer after tcp_v6_fill_cb */
163 static inline int inet6_sdif(const struct sk_buff *skb)
164 {
165 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
166 	if (skb && ipv6_l3mdev_skb(IP6CB(skb)->flags))
167 		return IP6CB(skb)->iif;
168 #endif
169 	return 0;
170 }
171 
172 /* can not be used in TCP layer after tcp_v6_fill_cb */
173 static inline bool inet6_exact_dif_match(struct net *net, struct sk_buff *skb)
174 {
175 #if defined(CONFIG_NET_L3_MASTER_DEV)
176 	if (!net->ipv4.sysctl_tcp_l3mdev_accept &&
177 	    skb && ipv6_l3mdev_skb(IP6CB(skb)->flags))
178 		return true;
179 #endif
180 	return false;
181 }
182 
183 struct tcp6_request_sock {
184 	struct tcp_request_sock	  tcp6rsk_tcp;
185 };
186 
187 struct ipv6_mc_socklist;
188 struct ipv6_ac_socklist;
189 struct ipv6_fl_socklist;
190 
191 struct inet6_cork {
192 	struct ipv6_txoptions *opt;
193 	u8 hop_limit;
194 	u8 tclass;
195 };
196 
197 /**
198  * struct ipv6_pinfo - ipv6 private area
199  *
200  * In the struct sock hierarchy (tcp6_sock, upd6_sock, etc)
201  * this _must_ be the last member, so that inet6_sk_generic
202  * is able to calculate its offset from the base struct sock
203  * by using the struct proto->slab_obj_size member. -acme
204  */
205 struct ipv6_pinfo {
206 	struct in6_addr 	saddr;
207 	struct in6_pktinfo	sticky_pktinfo;
208 	const struct in6_addr		*daddr_cache;
209 #ifdef CONFIG_IPV6_SUBTREES
210 	const struct in6_addr		*saddr_cache;
211 #endif
212 
213 	__be32			flow_label;
214 	__u32			frag_size;
215 
216 	/*
217 	 * Packed in 16bits.
218 	 * Omit one shift by by putting the signed field at MSB.
219 	 */
220 #if defined(__BIG_ENDIAN_BITFIELD)
221 	__s16			hop_limit:9;
222 	__u16			__unused_1:7;
223 #else
224 	__u16			__unused_1:7;
225 	__s16			hop_limit:9;
226 #endif
227 
228 #if defined(__BIG_ENDIAN_BITFIELD)
229 	/* Packed in 16bits. */
230 	__s16			mcast_hops:9;
231 	__u16			__unused_2:6,
232 				mc_loop:1;
233 #else
234 	__u16			mc_loop:1,
235 				__unused_2:6;
236 	__s16			mcast_hops:9;
237 #endif
238 	int			ucast_oif;
239 	int			mcast_oif;
240 
241 	/* pktoption flags */
242 	union {
243 		struct {
244 			__u16	srcrt:1,
245 				osrcrt:1,
246 			        rxinfo:1,
247 			        rxoinfo:1,
248 				rxhlim:1,
249 				rxohlim:1,
250 				hopopts:1,
251 				ohopopts:1,
252 				dstopts:1,
253 				odstopts:1,
254                                 rxflow:1,
255 				rxtclass:1,
256 				rxpmtu:1,
257 				rxorigdstaddr:1,
258 				recvfragsize:1;
259 				/* 1 bits hole */
260 		} bits;
261 		__u16		all;
262 	} rxopt;
263 
264 	/* sockopt flags */
265 	__u16			recverr:1,
266 	                        sndflow:1,
267 				repflow:1,
268 				pmtudisc:3,
269 				padding:1,	/* 1 bit hole */
270 				srcprefs:3,	/* 001: prefer temporary address
271 						 * 010: prefer public address
272 						 * 100: prefer care-of address
273 						 */
274 				dontfrag:1,
275 				autoflowlabel:1;
276 	__u8			min_hopcount;
277 	__u8			tclass;
278 	__be32			rcv_flowinfo;
279 
280 	__u32			dst_cookie;
281 	__u32			rx_dst_cookie;
282 
283 	struct ipv6_mc_socklist	__rcu *ipv6_mc_list;
284 	struct ipv6_ac_socklist	*ipv6_ac_list;
285 	struct ipv6_fl_socklist __rcu *ipv6_fl_list;
286 
287 	struct ipv6_txoptions __rcu	*opt;
288 	struct sk_buff		*pktoptions;
289 	struct sk_buff		*rxpmtu;
290 	struct inet6_cork	cork;
291 };
292 
293 /* WARNING: don't change the layout of the members in {raw,udp,tcp}6_sock! */
294 struct raw6_sock {
295 	/* inet_sock has to be the first member of raw6_sock */
296 	struct inet_sock	inet;
297 	__u32			checksum;	/* perform checksum */
298 	__u32			offset;		/* checksum offset  */
299 	struct icmp6_filter	filter;
300 	__u32			ip6mr_table;
301 	/* ipv6_pinfo has to be the last member of raw6_sock, see inet6_sk_generic */
302 	struct ipv6_pinfo	inet6;
303 };
304 
305 struct udp6_sock {
306 	struct udp_sock	  udp;
307 	/* ipv6_pinfo has to be the last member of udp6_sock, see inet6_sk_generic */
308 	struct ipv6_pinfo inet6;
309 };
310 
311 struct tcp6_sock {
312 	struct tcp_sock	  tcp;
313 	/* ipv6_pinfo has to be the last member of tcp6_sock, see inet6_sk_generic */
314 	struct ipv6_pinfo inet6;
315 };
316 
317 extern int inet6_sk_rebuild_header(struct sock *sk);
318 
319 struct tcp6_timewait_sock {
320 	struct tcp_timewait_sock   tcp6tw_tcp;
321 };
322 
323 #if IS_ENABLED(CONFIG_IPV6)
324 bool ipv6_mod_enabled(void);
325 
326 static inline struct ipv6_pinfo *inet6_sk(const struct sock *__sk)
327 {
328 	return sk_fullsock(__sk) ? inet_sk(__sk)->pinet6 : NULL;
329 }
330 
331 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
332 {
333 	return (struct raw6_sock *)sk;
334 }
335 
336 static inline void inet_sk_copy_descendant(struct sock *sk_to,
337 					   const struct sock *sk_from)
338 {
339 	int ancestor_size = sizeof(struct inet_sock);
340 
341 	if (sk_from->sk_family == PF_INET6)
342 		ancestor_size += sizeof(struct ipv6_pinfo);
343 
344 	__inet_sk_copy_descendant(sk_to, sk_from, ancestor_size);
345 }
346 
347 #define __ipv6_only_sock(sk)	(sk->sk_ipv6only)
348 #define ipv6_only_sock(sk)	(__ipv6_only_sock(sk))
349 #define ipv6_sk_rxinfo(sk)	((sk)->sk_family == PF_INET6 && \
350 				 inet6_sk(sk)->rxopt.bits.rxinfo)
351 
352 static inline const struct in6_addr *inet6_rcv_saddr(const struct sock *sk)
353 {
354 	if (sk->sk_family == AF_INET6)
355 		return &sk->sk_v6_rcv_saddr;
356 	return NULL;
357 }
358 
359 static inline int inet_v6_ipv6only(const struct sock *sk)
360 {
361 	/* ipv6only field is at same position for timewait and other sockets */
362 	return ipv6_only_sock(sk);
363 }
364 #else
365 #define __ipv6_only_sock(sk)	0
366 #define ipv6_only_sock(sk)	0
367 #define ipv6_sk_rxinfo(sk)	0
368 
369 static inline bool ipv6_mod_enabled(void)
370 {
371 	return false;
372 }
373 
374 static inline struct ipv6_pinfo * inet6_sk(const struct sock *__sk)
375 {
376 	return NULL;
377 }
378 
379 static inline struct inet6_request_sock *
380 			inet6_rsk(const struct request_sock *rsk)
381 {
382 	return NULL;
383 }
384 
385 static inline struct raw6_sock *raw6_sk(const struct sock *sk)
386 {
387 	return NULL;
388 }
389 
390 #define inet6_rcv_saddr(__sk)	NULL
391 #define tcp_twsk_ipv6only(__sk)		0
392 #define inet_v6_ipv6only(__sk)		0
393 #endif /* IS_ENABLED(CONFIG_IPV6) */
394 #endif /* _IPV6_H */
395