xref: /freebsd/sys/netinet/ip6.h (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*	$FreeBSD$	*/
2 /*	$KAME: ip6.h,v 1.18 2001/03/29 05:34:30 itojun Exp $	*/
3 
4 /*-
5  * SPDX-License-Identifier: BSD-3-Clause
6  *
7  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the project nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 /*-
36  * Copyright (c) 1982, 1986, 1993
37  *	The Regents of the University of California.  All rights reserved.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  * 3. Neither the name of the University nor the names of its contributors
48  *    may be used to endorse or promote products derived from this software
49  *    without specific prior written permission.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61  * SUCH DAMAGE.
62  *
63  *	@(#)ip.h	8.1 (Berkeley) 6/10/93
64  */
65 
66 #ifndef _NETINET_IP6_H_
67 #define _NETINET_IP6_H_
68 
69 /*
70  * Definition for internet protocol version 6.
71  * RFC 2460
72  */
73 
74 struct ip6_hdr {
75 	union {
76 		struct ip6_hdrctl {
77 			u_int32_t ip6_un1_flow;	/* 20 bits of flow-ID */
78 			u_int16_t ip6_un1_plen;	/* payload length */
79 			u_int8_t  ip6_un1_nxt;	/* next header */
80 			u_int8_t  ip6_un1_hlim;	/* hop limit */
81 		} ip6_un1;
82 		u_int8_t ip6_un2_vfc;	/* 4 bits version, top 4 bits class */
83 	} ip6_ctlun;
84 	struct in6_addr ip6_src;	/* source address */
85 	struct in6_addr ip6_dst;	/* destination address */
86 } __packed;
87 
88 #define ip6_vfc		ip6_ctlun.ip6_un2_vfc
89 #define ip6_flow	ip6_ctlun.ip6_un1.ip6_un1_flow
90 #define ip6_plen	ip6_ctlun.ip6_un1.ip6_un1_plen
91 #define ip6_nxt		ip6_ctlun.ip6_un1.ip6_un1_nxt
92 #define ip6_hlim	ip6_ctlun.ip6_un1.ip6_un1_hlim
93 #define ip6_hops	ip6_ctlun.ip6_un1.ip6_un1_hlim
94 
95 #define IPV6_VERSION		0x60
96 #define IPV6_VERSION_MASK	0xf0
97 
98 #if BYTE_ORDER == BIG_ENDIAN
99 #define IPV6_FLOWINFO_MASK	0x0fffffff	/* flow info (28 bits) */
100 #define IPV6_FLOWLABEL_MASK	0x000fffff	/* flow label (20 bits) */
101 #else
102 #if BYTE_ORDER == LITTLE_ENDIAN
103 #define IPV6_FLOWINFO_MASK	0xffffff0f	/* flow info (28 bits) */
104 #define IPV6_FLOWLABEL_MASK	0xffff0f00	/* flow label (20 bits) */
105 #endif /* LITTLE_ENDIAN */
106 #endif
107 #define IPV6_FLOWLABEL_LEN	20
108 #if 1
109 /* ECN bits proposed by Sally Floyd */
110 #define IP6TOS_CE		0x01	/* congestion experienced */
111 #define IP6TOS_ECT		0x02	/* ECN-capable transport */
112 #endif
113 
114 /*
115  * Extension Headers
116  */
117 
118 struct	ip6_ext {
119 	u_int8_t ip6e_nxt;
120 	u_int8_t ip6e_len;
121 } __packed;
122 
123 /* Hop-by-Hop options header */
124 /* XXX should we pad it to force alignment on an 8-byte boundary? */
125 struct ip6_hbh {
126 	u_int8_t ip6h_nxt;	/* next header */
127 	u_int8_t ip6h_len;	/* length in units of 8 octets */
128 	/* followed by options */
129 } __packed;
130 
131 /* Destination options header */
132 /* XXX should we pad it to force alignment on an 8-byte boundary? */
133 struct ip6_dest {
134 	u_int8_t ip6d_nxt;	/* next header */
135 	u_int8_t ip6d_len;	/* length in units of 8 octets */
136 	/* followed by options */
137 } __packed;
138 
139 /* Option types and related macros */
140 #define IP6OPT_PAD1		0x00	/* 00 0 00000 */
141 #define IP6OPT_PADN		0x01	/* 00 0 00001 */
142 #define IP6OPT_JUMBO		0xC2	/* 11 0 00010 = 194 */
143 #define IP6OPT_NSAP_ADDR	0xC3	/* 11 0 00011 */
144 #define IP6OPT_TUNNEL_LIMIT	0x04	/* 00 0 00100 */
145 #ifndef _KERNEL
146 #define IP6OPT_RTALERT		0x05	/* 00 0 00101 (KAME definition) */
147 #endif
148 #define IP6OPT_ROUTER_ALERT	0x05	/* 00 0 00101 (RFC3542, recommended) */
149 
150 #define IP6OPT_RTALERT_LEN	4
151 #define IP6OPT_RTALERT_MLD	0	/* Datagram contains an MLD message */
152 #define IP6OPT_RTALERT_RSVP	1	/* Datagram contains an RSVP message */
153 #define IP6OPT_RTALERT_ACTNET	2 	/* contains an Active Networks msg */
154 #define IP6OPT_MINLEN		2
155 
156 #define IP6OPT_EID		0x8a	/* 10 0 01010 */
157 
158 #define IP6OPT_TYPE(o)		((o) & 0xC0)
159 #define IP6OPT_TYPE_SKIP	0x00
160 #define IP6OPT_TYPE_DISCARD	0x40
161 #define IP6OPT_TYPE_FORCEICMP	0x80
162 #define IP6OPT_TYPE_ICMP	0xC0
163 
164 #define IP6OPT_MUTABLE		0x20
165 
166 /* IPv6 options: common part */
167 struct ip6_opt {
168 	u_int8_t ip6o_type;
169 	u_int8_t ip6o_len;
170 } __packed;
171 
172 /* Jumbo Payload Option */
173 struct ip6_opt_jumbo {
174 	u_int8_t ip6oj_type;
175 	u_int8_t ip6oj_len;
176 	u_int8_t ip6oj_jumbo_len[4];
177 } __packed;
178 #define IP6OPT_JUMBO_LEN	6
179 
180 /* NSAP Address Option */
181 struct ip6_opt_nsap {
182 	u_int8_t ip6on_type;
183 	u_int8_t ip6on_len;
184 	u_int8_t ip6on_src_nsap_len;
185 	u_int8_t ip6on_dst_nsap_len;
186 	/* followed by source NSAP */
187 	/* followed by destination NSAP */
188 } __packed;
189 
190 /* Tunnel Limit Option */
191 struct ip6_opt_tunnel {
192 	u_int8_t ip6ot_type;
193 	u_int8_t ip6ot_len;
194 	u_int8_t ip6ot_encap_limit;
195 } __packed;
196 
197 /* Router Alert Option */
198 struct ip6_opt_router {
199 	u_int8_t ip6or_type;
200 	u_int8_t ip6or_len;
201 	u_int8_t ip6or_value[2];
202 } __packed;
203 /* Router alert values (in network byte order) */
204 #if BYTE_ORDER == BIG_ENDIAN
205 #define IP6_ALERT_MLD	0x0000
206 #define IP6_ALERT_RSVP	0x0001
207 #define IP6_ALERT_AN	0x0002
208 #else
209 #if BYTE_ORDER == LITTLE_ENDIAN
210 #define IP6_ALERT_MLD	0x0000
211 #define IP6_ALERT_RSVP	0x0100
212 #define IP6_ALERT_AN	0x0200
213 #endif /* LITTLE_ENDIAN */
214 #endif
215 
216 /* Routing header */
217 struct ip6_rthdr {
218 	u_int8_t  ip6r_nxt;	/* next header */
219 	u_int8_t  ip6r_len;	/* length in units of 8 octets */
220 	u_int8_t  ip6r_type;	/* routing type */
221 	u_int8_t  ip6r_segleft;	/* segments left */
222 	/* followed by routing type specific data */
223 } __packed;
224 
225 /* Type 0 Routing header, deprecated by RFC 5095. */
226 struct ip6_rthdr0 {
227 	u_int8_t  ip6r0_nxt;		/* next header */
228 	u_int8_t  ip6r0_len;		/* length in units of 8 octets */
229 	u_int8_t  ip6r0_type;		/* always zero */
230 	u_int8_t  ip6r0_segleft;	/* segments left */
231 	u_int32_t  ip6r0_reserved;	/* reserved field */
232 	/* followed by up to 127 struct in6_addr */
233 } __packed;
234 
235 /* Fragment header */
236 struct ip6_frag {
237 	u_int8_t  ip6f_nxt;		/* next header */
238 	u_int8_t  ip6f_reserved;	/* reserved field */
239 	u_int16_t ip6f_offlg;		/* offset, reserved, and flag */
240 	u_int32_t ip6f_ident;		/* identification */
241 } __packed;
242 
243 #if BYTE_ORDER == BIG_ENDIAN
244 #define IP6F_OFF_MASK		0xfff8	/* mask out offset from _offlg */
245 #define IP6F_RESERVED_MASK	0x0006	/* reserved bits in ip6f_offlg */
246 #define IP6F_MORE_FRAG		0x0001	/* more-fragments flag */
247 #else /* BYTE_ORDER == LITTLE_ENDIAN */
248 #define IP6F_OFF_MASK		0xf8ff	/* mask out offset from _offlg */
249 #define IP6F_RESERVED_MASK	0x0600	/* reserved bits in ip6f_offlg */
250 #define IP6F_MORE_FRAG		0x0100	/* more-fragments flag */
251 #endif /* BYTE_ORDER == LITTLE_ENDIAN */
252 
253 /*
254  * Internet implementation parameters.
255  */
256 #define IPV6_MAXHLIM	255	/* maximum hoplimit */
257 #define IPV6_DEFHLIM	64	/* default hlim */
258 #define IPV6_FRAGTTL	120	/* ttl for fragment packets, in slowtimo tick */
259 #define IPV6_HLIMDEC	1	/* subtracted when forwarding */
260 
261 #define IPV6_MMTU	1280	/* minimal MTU and reassembly. 1024 + 256 */
262 #define IPV6_MAXPACKET	65535	/* ip6 max packet size without Jumbo payload*/
263 #define IPV6_MAXOPTHDR	2048	/* max option header size, 256 64-bit words */
264 
265 #ifdef _KERNEL
266 /*
267  * IP6_EXTHDR_CHECK ensures that region between the IP6 header and the
268  * target header (including IPv6 itself, extension headers and
269  * TCP/UDP/ICMP6 headers) are contiguous. KAME requires drivers
270  * to store incoming data into one internal mbuf or one or more external
271  * mbufs(never into two or more internal mbufs). Thus, the third case is
272  * supposed to never be matched but is prepared just in case.
273  */
274 
275 #define IP6_EXTHDR_CHECK(m, off, hlen, ret)				\
276 do {									\
277     if ((m)->m_next != NULL) {						\
278 	if (((m)->m_flags & M_LOOP) &&					\
279 	    ((m)->m_len < (off) + (hlen)) &&				\
280 	    (((m) = m_pullup((m), (off) + (hlen))) == NULL)) {		\
281 		IP6STAT_INC(ip6s_exthdrtoolong);				\
282 		return ret;						\
283 	} else {							\
284 		if ((m)->m_len < (off) + (hlen)) {			\
285 			IP6STAT_INC(ip6s_exthdrtoolong);			\
286 			m_freem(m);					\
287 			return ret;					\
288 		}							\
289 	}								\
290     } else {								\
291 	if ((m)->m_len < (off) + (hlen)) {				\
292 		IP6STAT_INC(ip6s_tooshort);				\
293 		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);	\
294 		m_freem(m);						\
295 		return ret;						\
296 	}								\
297     }									\
298 } while (/*CONSTCOND*/ 0)
299 
300 /*
301  * IP6_EXTHDR_GET ensures that intermediate protocol header (from "off" to
302  * "len") is located in single mbuf, on contiguous memory region.
303  * The pointer to the region will be returned to pointer variable "val",
304  * with type "typ".
305  * IP6_EXTHDR_GET0 does the same, except that it aligns the structure at the
306  * very top of mbuf.  GET0 is likely to make memory copy than GET.
307  *
308  * XXX we're now testing this, needs m_pulldown()
309  */
310 #define IP6_EXTHDR_GET(val, typ, m, off, len) \
311 do {									\
312 	struct mbuf *t;							\
313 	int tmp;							\
314 	if ((m)->m_len >= (off) + (len))				\
315 		(val) = (typ)(mtod((m), caddr_t) + (off));		\
316 	else {								\
317 		t = m_pulldown((m), (off), (len), &tmp);		\
318 		if (t) {						\
319 			if (t->m_len < tmp + (len))			\
320 				panic("m_pulldown malfunction");	\
321 			(val) = (typ)(mtod(t, caddr_t) + tmp);		\
322 		} else {						\
323 			(val) = (typ)NULL;				\
324 			(m) = NULL;					\
325 		}							\
326 	}								\
327 } while (/*CONSTCOND*/ 0)
328 
329 #define IP6_EXTHDR_GET0(val, typ, m, off, len) \
330 do {									\
331 	struct mbuf *t;							\
332 	if ((off) == 0)							\
333 		(val) = (typ)mtod(m, caddr_t);				\
334 	else {								\
335 		t = m_pulldown((m), (off), (len), NULL);		\
336 		if (t) {						\
337 			if (t->m_len < (len))				\
338 				panic("m_pulldown malfunction");	\
339 			(val) = (typ)mtod(t, caddr_t);			\
340 		} else {						\
341 			(val) = (typ)NULL;				\
342 			(m) = NULL;					\
343 		}							\
344 	}								\
345 } while (/*CONSTCOND*/ 0)
346 
347 #endif /*_KERNEL*/
348 
349 #endif /* not _NETINET_IP6_H_ */
350