xref: /freebsd/sys/netinet6/ip6_var.h (revision f126890ac5386406dadf7c4cfa9566cbb56537c5)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	$KAME: ip6_var.h,v 1.62 2001/05/03 14:51:48 itojun Exp $
32  */
33 
34 /*-
35  * Copyright (c) 1982, 1986, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  */
62 
63 #ifndef _NETINET6_IP6_VAR_H_
64 #define _NETINET6_IP6_VAR_H_
65 
66 #include <sys/epoch.h>
67 
68 #ifdef _KERNEL
69 struct ip6asfrag;		/* frag6.c */
70 TAILQ_HEAD(ip6fraghead, ip6asfrag);
71 
72 /*
73  * IP6 reassembly queue structure.  Each fragment
74  * being reassembled is attached to one of these structures.
75  */
76 struct	ip6q {
77 	struct ip6fraghead ip6q_frags;
78 	u_int32_t	ip6q_ident;
79 	u_int8_t	ip6q_nxt;
80 	u_int8_t	ip6q_ecn;
81 	u_int16_t	ip6q_ttl;
82 	struct in6_addr ip6q_src, ip6q_dst;
83 	TAILQ_ENTRY(ip6q) ip6q_tq;
84 	int		ip6q_unfrglen;	/* len of unfragmentable part */
85 	int		ip6q_nfrag;	/* # of fragments */
86 	struct label	*ip6q_label;
87 };
88 #endif /* _KERNEL */
89 
90 /*
91  * IP6 reinjecting structure.
92  */
93 struct ip6_direct_ctx {
94 	uint32_t	ip6dc_nxt;	/* next header to process */
95 	uint32_t	ip6dc_off;	/* offset to next header */
96 };
97 
98 #if defined(_NETINET6_IN6_VAR_H_) && defined(_KERNEL)
99 /*
100  * Structure attached to inpcb.in6p_moptions and
101  * passed to ip6_output when IPv6 multicast options are in use.
102  * This structure is lazy-allocated.
103  */
104 struct ip6_moptions {
105 	struct	ifnet *im6o_multicast_ifp; /* ifp for outgoing multicasts */
106 	u_char	im6o_multicast_hlim;	/* hoplimit for outgoing multicasts */
107 	u_char	im6o_multicast_loop;	/* 1 >= hear sends if a member */
108 	struct ip6_mfilter_head im6o_head; /* group membership list */
109 };
110 #else
111 struct ip6_moptions;
112 #endif
113 /*
114  * Control options for outgoing packets
115  */
116 
117 /* Routing header related info */
118 struct	ip6po_rhinfo {
119 	struct	ip6_rthdr *ip6po_rhi_rthdr; /* Routing header */
120 	struct	route_in6 ip6po_rhi_route; /* Route to the 1st hop */
121 };
122 #define ip6po_rthdr	ip6po_rhinfo.ip6po_rhi_rthdr
123 #define ip6po_route	ip6po_rhinfo.ip6po_rhi_route
124 
125 /* Nexthop related info */
126 struct	ip6po_nhinfo {
127 	struct	sockaddr *ip6po_nhi_nexthop;
128 	struct	route_in6 ip6po_nhi_route; /* Route to the nexthop */
129 };
130 #define ip6po_nexthop	ip6po_nhinfo.ip6po_nhi_nexthop
131 #define ip6po_nextroute	ip6po_nhinfo.ip6po_nhi_route
132 
133 /*
134  * Note that fields with valid data must be flagged in ip6po_valid.
135  * This is done to reduce cache misses in ip6_output().  Before
136  * ip6po_valid, ip6_output needed to check all the individual fields
137  * of ip6_pktopts needed to be checked themselves, and they are spread
138  * across 4 cachelines. ip6_output() is currently the only consumer of
139  * these flags, as it is in the critical path of every packet sent.
140  */
141 struct	ip6_pktopts {
142 	uint32_t ip6po_valid;
143 #define IP6PO_VALID_HLIM	0x0001
144 #define IP6PO_VALID_PKTINFO	0x0002
145 #define IP6PO_VALID_NHINFO	0x0004
146 #define IP6PO_VALID_HBH		0x0008
147 #define IP6PO_VALID_DEST1	0x0010
148 #define IP6PO_VALID_RHINFO	0x0020
149 #define IP6PO_VALID_DEST2	0x0040
150 #define IP6PO_VALID_TC		0x0080
151 
152 	int	ip6po_hlim;	/* Hoplimit for outgoing packets */
153 	int	ip6po_tclass;	/* traffic class */
154 
155 	int	ip6po_minmtu;  /* fragment vs PMTU discovery policy */
156 #define IP6PO_MINMTU_MCASTONLY	-1 /* default; send at min MTU for multicast*/
157 #define IP6PO_MINMTU_DISABLE	 0 /* always perform pmtu disc */
158 #define IP6PO_MINMTU_ALL	 1 /* always send at min MTU */
159 
160 	int	ip6po_prefer_tempaddr;  /* whether temporary addresses are
161 					   preferred as source address */
162 #define IP6PO_TEMPADDR_SYSTEM	-1 /* follow the system default */
163 #define IP6PO_TEMPADDR_NOTPREFER 0 /* not prefer temporary address */
164 #define IP6PO_TEMPADDR_PREFER	 1 /* prefer temporary address */
165 
166 	int ip6po_flags;
167 #if 0	/* parameters in this block is obsolete. do not reuse the values. */
168 #define IP6PO_REACHCONF	0x01	/* upper-layer reachability confirmation. */
169 #define IP6PO_MINMTU	0x02	/* use minimum MTU (IPV6_USE_MIN_MTU) */
170 #endif
171 #define IP6PO_DONTFRAG	0x04	/* disable fragmentation (IPV6_DONTFRAG) */
172 #define IP6PO_USECOA	0x08	/* use care of address */
173 
174 	struct	mbuf *ip6po_m;	/* Pointer to mbuf storing the data */
175 
176 	/* Outgoing IF/address information */
177 	struct	in6_pktinfo *ip6po_pktinfo;
178 
179 	/* Next-hop address information */
180 	struct	ip6po_nhinfo ip6po_nhinfo;
181 
182 	struct	ip6_hbh *ip6po_hbh; /* Hop-by-Hop options header */
183 
184 	/* Destination options header (before a routing header) */
185 	struct	ip6_dest *ip6po_dest1;
186 
187 	/* Routing header related info. */
188 	struct	ip6po_rhinfo ip6po_rhinfo;
189 
190 	/* Destination options header (after a routing header) */
191 	struct	ip6_dest *ip6po_dest2;
192 };
193 
194 /*
195  * Control options for incoming packets
196  */
197 
198 struct	ip6stat {
199 	uint64_t ip6s_total;		/* total packets received */
200 	uint64_t ip6s_tooshort;		/* packet too short */
201 	uint64_t ip6s_toosmall;		/* not enough data */
202 	uint64_t ip6s_fragments;	/* fragments received */
203 	uint64_t ip6s_fragdropped;	/* frags dropped(dups, out of space) */
204 	uint64_t ip6s_fragtimeout;	/* fragments timed out */
205 	uint64_t ip6s_fragoverflow;	/* fragments that exceeded limit */
206 	uint64_t ip6s_forward;		/* packets forwarded */
207 	uint64_t ip6s_cantforward;	/* packets rcvd for unreachable dest */
208 	uint64_t ip6s_redirectsent;	/* packets forwarded on same net */
209 	uint64_t ip6s_delivered;	/* datagrams delivered to upper level*/
210 	uint64_t ip6s_localout;		/* total ip packets generated here */
211 	uint64_t ip6s_odropped;		/* lost packets due to nobufs, etc. */
212 	uint64_t ip6s_reassembled;	/* total packets reassembled ok */
213 	uint64_t ip6s_atomicfrags;	/* atomic fragments */
214 	uint64_t ip6s_fragmented;	/* datagrams successfully fragmented */
215 	uint64_t ip6s_ofragments;	/* output fragments created */
216 	uint64_t ip6s_cantfrag;		/* don't fragment flag was set, etc. */
217 	uint64_t ip6s_badoptions;	/* error in option processing */
218 	uint64_t ip6s_noroute;		/* packets discarded due to no route */
219 	uint64_t ip6s_badvers;		/* ip6 version != 6 */
220 	uint64_t ip6s_rawout;		/* total raw ip packets generated */
221 	uint64_t ip6s_badscope;		/* scope error */
222 	uint64_t ip6s_notmember;	/* don't join this multicast group */
223 #define	IP6S_HDRCNT		256	/* headers count */
224 	uint64_t ip6s_nxthist[IP6S_HDRCNT]; /* next header history */
225 	uint64_t ip6s_m1;		/* one mbuf */
226 #define	IP6S_M2MMAX		32
227 	uint64_t ip6s_m2m[IP6S_M2MMAX];	/* two or more mbuf */
228 	uint64_t ip6s_mext1;		/* one ext mbuf */
229 	uint64_t ip6s_mext2m;		/* two or more ext mbuf */
230 	uint64_t ip6s_exthdrtoolong;	/* ext hdr are not contiguous */
231 	uint64_t ip6s_nogif;		/* no match gif found */
232 	uint64_t ip6s_toomanyhdr;	/* discarded due to too many headers */
233 
234 	/*
235 	 * statistics for improvement of the source address selection
236 	 * algorithm:
237 	 * XXX: hardcoded 16 = # of ip6 multicast scope types + 1
238 	 */
239 #define	IP6S_RULESMAX		16
240 #define	IP6S_SCOPECNT		16
241 	/* number of times that address selection fails */
242 	uint64_t ip6s_sources_none;
243 	/* number of times that an address on the outgoing I/F is chosen */
244 	uint64_t ip6s_sources_sameif[IP6S_SCOPECNT];
245 	/* number of times that an address on a non-outgoing I/F is chosen */
246 	uint64_t ip6s_sources_otherif[IP6S_SCOPECNT];
247 	/*
248 	 * number of times that an address that has the same scope
249 	 * from the destination is chosen.
250 	 */
251 	uint64_t ip6s_sources_samescope[IP6S_SCOPECNT];
252 	/*
253 	 * number of times that an address that has a different scope
254 	 * from the destination is chosen.
255 	 */
256 	uint64_t ip6s_sources_otherscope[IP6S_SCOPECNT];
257 	/* number of times that a deprecated address is chosen */
258 	uint64_t ip6s_sources_deprecated[IP6S_SCOPECNT];
259 
260 	/* number of times that each rule of source selection is applied. */
261 	uint64_t ip6s_sources_rule[IP6S_RULESMAX];
262 };
263 
264 #ifdef _KERNEL
265 #include <sys/counter.h>
266 
267 VNET_PCPUSTAT_DECLARE(struct ip6stat, ip6stat);
268 #define	IP6STAT_ADD(name, val)	\
269     VNET_PCPUSTAT_ADD(struct ip6stat, ip6stat, name, (val))
270 #define	IP6STAT_SUB(name, val)	IP6STAT_ADD(name, -(val))
271 #define	IP6STAT_INC(name)	IP6STAT_ADD(name, 1)
272 #define	IP6STAT_DEC(name)	IP6STAT_SUB(name, 1)
273 #endif
274 
275 #ifdef _KERNEL
276 /* flags passed to ip6_output as last parameter */
277 #define	IPV6_UNSPECSRC		0x01	/* allow :: as the source address */
278 #define	IPV6_FORWARDING		0x02	/* most of IPv6 header exists */
279 #define	IPV6_MINMTU		0x04	/* use minimum MTU (IPV6_USE_MIN_MTU) */
280 
281 #ifdef __NO_STRICT_ALIGNMENT
282 #define IP6_HDR_ALIGNED_P(ip)	1
283 #else
284 #define IP6_HDR_ALIGNED_P(ip)	((((intptr_t) (ip)) & 3) == 0)
285 #endif
286 
287 VNET_DECLARE(int, ip6_defhlim);		/* default hop limit */
288 VNET_DECLARE(int, ip6_defmcasthlim);	/* default multicast hop limit */
289 VNET_DECLARE(int, ip6_forwarding);	/* act as router? */
290 VNET_DECLARE(int, ip6_use_deprecated);	/* allow deprecated addr as source */
291 VNET_DECLARE(int, ip6_rr_prune);	/* router renumbering prefix
292 					 * walk list every 5 sec.    */
293 VNET_DECLARE(int, ip6_mcast_pmtu);	/* enable pMTU discovery for multicast? */
294 VNET_DECLARE(int, ip6_v6only);
295 #define	V_ip6_defhlim			VNET(ip6_defhlim)
296 #define	V_ip6_defmcasthlim		VNET(ip6_defmcasthlim)
297 #define	V_ip6_forwarding		VNET(ip6_forwarding)
298 #define	V_ip6_use_deprecated		VNET(ip6_use_deprecated)
299 #define	V_ip6_rr_prune			VNET(ip6_rr_prune)
300 #define	V_ip6_mcast_pmtu		VNET(ip6_mcast_pmtu)
301 #define	V_ip6_v6only			VNET(ip6_v6only)
302 
303 VNET_DECLARE(struct socket *, ip6_mrouter);	/* multicast routing daemon */
304 VNET_DECLARE(int, ip6_sendredirects);	/* send IP redirects when forwarding? */
305 VNET_DECLARE(int, ip6_accept_rtadv);	/* Acts as a host not a router */
306 VNET_DECLARE(int, ip6_no_radr);		/* No defroute from RA */
307 VNET_DECLARE(int, ip6_norbit_raif);	/* Disable R-bit in NA on RA
308 					 * receiving IF. */
309 VNET_DECLARE(int, ip6_rfc6204w3);	/* Accept defroute from RA even when
310 					   forwarding enabled */
311 VNET_DECLARE(int, ip6_hdrnestlimit);	/* upper limit of # of extension
312 					 * headers */
313 VNET_DECLARE(int, ip6_dad_count);	/* DupAddrDetectionTransmits */
314 #define	V_ip6_mrouter			VNET(ip6_mrouter)
315 #define	V_ip6_sendredirects		VNET(ip6_sendredirects)
316 #define	V_ip6_accept_rtadv		VNET(ip6_accept_rtadv)
317 #define	V_ip6_no_radr			VNET(ip6_no_radr)
318 #define	V_ip6_norbit_raif		VNET(ip6_norbit_raif)
319 #define	V_ip6_rfc6204w3			VNET(ip6_rfc6204w3)
320 #define	V_ip6_hdrnestlimit		VNET(ip6_hdrnestlimit)
321 #define	V_ip6_dad_count			VNET(ip6_dad_count)
322 
323 VNET_DECLARE(int, ip6_auto_flowlabel);
324 VNET_DECLARE(int, ip6_auto_linklocal);
325 #define	V_ip6_auto_flowlabel		VNET(ip6_auto_flowlabel)
326 #define	V_ip6_auto_linklocal		VNET(ip6_auto_linklocal)
327 
328 VNET_DECLARE(int, ip6_use_tempaddr);	/* Whether to use temporary addresses */
329 VNET_DECLARE(int, ip6_prefer_tempaddr);	/* Whether to prefer temporary
330 					 * addresses in the source address
331 					 * selection */
332 #define	V_ip6_use_tempaddr		VNET(ip6_use_tempaddr)
333 #define	V_ip6_prefer_tempaddr		VNET(ip6_prefer_tempaddr)
334 
335 VNET_DECLARE(int, ip6_use_defzone);	/* Whether to use the default scope
336 					 * zone when unspecified */
337 #define	V_ip6_use_defzone		VNET(ip6_use_defzone)
338 
339 VNET_DECLARE(struct pfil_head *, inet6_pfil_head);
340 #define	V_inet6_pfil_head	VNET(inet6_pfil_head)
341 #define	PFIL_INET6_NAME		"inet6"
342 
343 VNET_DECLARE(struct pfil_head *, inet6_local_pfil_head);
344 #define	V_inet6_local_pfil_head	VNET(inet6_local_pfil_head)
345 #define	PFIL_INET6_LOCAL_NAME	"inet6-local"
346 
347 #ifdef IPSTEALTH
348 VNET_DECLARE(int, ip6stealth);
349 #define	V_ip6stealth			VNET(ip6stealth)
350 #endif
351 
352 #ifdef EXPERIMENTAL
353 VNET_DECLARE(int, nd6_ignore_ipv6_only_ra);
354 #define	V_nd6_ignore_ipv6_only_ra	VNET(nd6_ignore_ipv6_only_ra)
355 #endif
356 
357 VNET_DECLARE(bool, ip6_log_cannot_forward);
358 #define	V_ip6_log_cannot_forward	VNET(ip6_log_cannot_forward)
359 
360 extern struct	pr_usrreqs rip6_usrreqs;
361 struct sockopt;
362 
363 struct inpcb;
364 struct ucred;
365 
366 int	icmp6_ctloutput(struct socket *, struct sockopt *sopt);
367 
368 void	ip6_input(struct mbuf *);
369 void	ip6_direct_input(struct mbuf *);
370 void	ip6_freepcbopts(struct ip6_pktopts *);
371 
372 int	ip6_unknown_opt(u_int8_t *, struct mbuf *, int);
373 int	ip6_get_prevhdr(const struct mbuf *, int);
374 int	ip6_nexthdr(const struct mbuf *, int, int, int *);
375 int	ip6_lasthdr(const struct mbuf *, int, int, int *);
376 
377 extern int	(*ip6_mforward)(struct ip6_hdr *, struct ifnet *,
378     struct mbuf *);
379 
380 int	ip6_process_hopopts(struct mbuf *, u_int8_t *, int, u_int32_t *,
381 				 u_int32_t *);
382 struct mbuf	**ip6_savecontrol_v4(struct inpcb *, struct mbuf *,
383 	    struct mbuf **, int *);
384 void	ip6_savecontrol(struct inpcb *, struct mbuf *, struct mbuf **);
385 void	ip6_notify_pmtu(struct inpcb *, struct sockaddr_in6 *, u_int32_t);
386 int	ip6_sysctl(int *, u_int, void *, size_t *, void *, size_t);
387 
388 void	ip6_forward(struct mbuf *, int);
389 
390 void	ip6_mloopback(struct ifnet *, struct mbuf *);
391 int	ip6_output(struct mbuf *, struct ip6_pktopts *,
392 			struct route_in6 *,
393 			int,
394 			struct ip6_moptions *, struct ifnet **,
395 			struct inpcb *);
396 int	ip6_ctloutput(struct socket *, struct sockopt *);
397 int	ip6_raw_ctloutput(struct socket *, struct sockopt *);
398 void	ip6_initpktopts(struct ip6_pktopts *);
399 int	ip6_setpktopts(struct mbuf *, struct ip6_pktopts *,
400 	struct ip6_pktopts *, struct ucred *, int);
401 void	ip6_clearpktopts(struct ip6_pktopts *, int);
402 struct ip6_pktopts *ip6_copypktopts(struct ip6_pktopts *, int);
403 int	ip6_optlen(struct inpcb *);
404 int	ip6_deletefraghdr(struct mbuf *, int, int);
405 int	ip6_fragment(struct ifnet *, struct mbuf *, int, u_char, int,
406 			uint32_t);
407 
408 int	route6_input(struct mbuf **, int *, int);
409 
410 void	frag6_init(void);
411 void	frag6_destroy(void);
412 int	frag6_input(struct mbuf **, int *, int);
413 void	frag6_drain(void);
414 
415 void	rip6_init(void);
416 int	rip6_ctloutput(struct socket *, struct sockopt *);
417 int	rip6_usrreq(struct socket *,
418 	    int, struct mbuf *, struct mbuf *, struct mbuf *, struct thread *);
419 
420 int	dest6_input(struct mbuf **, int *, int);
421 int	none_input(struct mbuf **, int *, int);
422 
423 int	in6_selectsrc_socket(struct sockaddr_in6 *, struct ip6_pktopts *,
424     struct inpcb *, struct ucred *, int, struct in6_addr *, int *);
425 int	in6_selectsrc_addr(uint32_t, const struct in6_addr *,
426     uint32_t, struct ifnet *, struct in6_addr *, int *);
427 int in6_selectroute(struct sockaddr_in6 *, struct ip6_pktopts *,
428 	struct ip6_moptions *, struct route_in6 *, struct ifnet **,
429 	struct nhop_object **, u_int, uint32_t);
430 u_int32_t ip6_randomid(void);
431 u_int32_t ip6_randomflowlabel(void);
432 void in6_delayed_cksum(struct mbuf *m, uint32_t plen, u_short offset);
433 
434 int	ip6_log_ratelimit(void);
435 
436 /*
437  * Argument type for the last arg of ip6proto_ctlinput_t().
438  *
439  * IPv6 ICMP IPv6 [exthdrs] finalhdr payload
440  * ^    ^    ^              ^
441  * |    |    ip6c_ip6       ip6c_off
442  * |    ip6c_icmp6
443  * ip6c_m
444  *
445  * ip6c_finaldst's sin6_addr usually points to ip6c_ip6->ip6_dst.  If the
446  * original * (internal) packet carries a routing header, it may point the
447  * final * destination address in the routing header.
448  *
449  * ip6c_src: ip6c_ip6->ip6_src + scope info + flowlabel in ip6c_ip6
450  *	(beware of flowlabel, if you try to compare it against others)
451  * ip6c_dst: ip6c_finaldst + scope info
452  */
453 struct ip6ctlparam {
454 	struct mbuf *ip6c_m;		/* start of mbuf chain */
455 	struct icmp6_hdr *ip6c_icmp6;	/* icmp6 header of target packet */
456 	struct ip6_hdr *ip6c_ip6;	/* ip6 header of target packet */
457 	int ip6c_off;			/* offset of the target proto header */
458 	struct sockaddr_in6 *ip6c_src;	/* srcaddr w/ additional info */
459 	struct sockaddr_in6 *ip6c_dst;	/* (final) dstaddr w/ additional info */
460 	struct sockaddr_in6 *ip6c_finaldst;	/* final destination address */
461 	void *ip6c_cmdarg;		/* control command dependent data */
462 	u_int8_t ip6c_nxt;		/* final next header field */
463 };
464 
465 typedef int	ip6proto_input_t(struct mbuf **, int *, int);
466 typedef void	ip6proto_ctlinput_t(struct ip6ctlparam *);
467 int	ip6proto_register(uint8_t, ip6proto_input_t, ip6proto_ctlinput_t);
468 int	ip6proto_unregister(uint8_t);
469 #define	IP6PROTO_REGISTER(prot, input, ctl)	do {			\
470 	int error __diagused;						\
471 	error = ip6proto_register(prot, input, ctl);			\
472 	MPASS(error == 0);						\
473 } while (0)
474 
475 ip6proto_input_t	rip6_input;
476 ip6proto_ctlinput_t	rip6_ctlinput;
477 
478 #endif /* _KERNEL */
479 
480 #endif /* !_NETINET6_IP6_VAR_H_ */
481