xref: /freebsd/sys/netinet/ip6.h (revision 834063202a16592e1ef5c3a9fbd04ca5f1df3ed0)
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 #if 1
108 /* ECN bits proposed by Sally Floyd */
109 #define IP6TOS_CE		0x01	/* congestion experienced */
110 #define IP6TOS_ECT		0x02	/* ECN-capable transport */
111 #endif
112 
113 /*
114  * Extension Headers
115  */
116 
117 struct	ip6_ext {
118 	u_int8_t ip6e_nxt;
119 	u_int8_t ip6e_len;
120 } __packed;
121 
122 /* Hop-by-Hop options header */
123 /* XXX should we pad it to force alignment on an 8-byte boundary? */
124 struct ip6_hbh {
125 	u_int8_t ip6h_nxt;	/* next header */
126 	u_int8_t ip6h_len;	/* length in units of 8 octets */
127 	/* followed by options */
128 } __packed;
129 
130 /* Destination options header */
131 /* XXX should we pad it to force alignment on an 8-byte boundary? */
132 struct ip6_dest {
133 	u_int8_t ip6d_nxt;	/* next header */
134 	u_int8_t ip6d_len;	/* length in units of 8 octets */
135 	/* followed by options */
136 } __packed;
137 
138 /* Option types and related macros */
139 #define IP6OPT_PAD1		0x00	/* 00 0 00000 */
140 #define IP6OPT_PADN		0x01	/* 00 0 00001 */
141 #define IP6OPT_JUMBO		0xC2	/* 11 0 00010 = 194 */
142 #define IP6OPT_NSAP_ADDR	0xC3	/* 11 0 00011 */
143 #define IP6OPT_TUNNEL_LIMIT	0x04	/* 00 0 00100 */
144 #ifndef _KERNEL
145 #define IP6OPT_RTALERT		0x05	/* 00 0 00101 (KAME definition) */
146 #endif
147 #define IP6OPT_ROUTER_ALERT	0x05	/* 00 0 00101 (RFC3542, recommended) */
148 
149 #define IP6OPT_RTALERT_LEN	4
150 #define IP6OPT_RTALERT_MLD	0	/* Datagram contains an MLD message */
151 #define IP6OPT_RTALERT_RSVP	1	/* Datagram contains an RSVP message */
152 #define IP6OPT_RTALERT_ACTNET	2 	/* contains an Active Networks msg */
153 #define IP6OPT_MINLEN		2
154 
155 #define IP6OPT_EID		0x8a	/* 10 0 01010 */
156 
157 #define IP6OPT_TYPE(o)		((o) & 0xC0)
158 #define IP6OPT_TYPE_SKIP	0x00
159 #define IP6OPT_TYPE_DISCARD	0x40
160 #define IP6OPT_TYPE_FORCEICMP	0x80
161 #define IP6OPT_TYPE_ICMP	0xC0
162 
163 #define IP6OPT_MUTABLE		0x20
164 
165 /* IPv6 options: common part */
166 struct ip6_opt {
167 	u_int8_t ip6o_type;
168 	u_int8_t ip6o_len;
169 } __packed;
170 
171 /* Jumbo Payload Option */
172 struct ip6_opt_jumbo {
173 	u_int8_t ip6oj_type;
174 	u_int8_t ip6oj_len;
175 	u_int8_t ip6oj_jumbo_len[4];
176 } __packed;
177 #define IP6OPT_JUMBO_LEN	6
178 
179 /* NSAP Address Option */
180 struct ip6_opt_nsap {
181 	u_int8_t ip6on_type;
182 	u_int8_t ip6on_len;
183 	u_int8_t ip6on_src_nsap_len;
184 	u_int8_t ip6on_dst_nsap_len;
185 	/* followed by source NSAP */
186 	/* followed by destination NSAP */
187 } __packed;
188 
189 /* Tunnel Limit Option */
190 struct ip6_opt_tunnel {
191 	u_int8_t ip6ot_type;
192 	u_int8_t ip6ot_len;
193 	u_int8_t ip6ot_encap_limit;
194 } __packed;
195 
196 /* Router Alert Option */
197 struct ip6_opt_router {
198 	u_int8_t ip6or_type;
199 	u_int8_t ip6or_len;
200 	u_int8_t ip6or_value[2];
201 } __packed;
202 /* Router alert values (in network byte order) */
203 #if BYTE_ORDER == BIG_ENDIAN
204 #define IP6_ALERT_MLD	0x0000
205 #define IP6_ALERT_RSVP	0x0001
206 #define IP6_ALERT_AN	0x0002
207 #else
208 #if BYTE_ORDER == LITTLE_ENDIAN
209 #define IP6_ALERT_MLD	0x0000
210 #define IP6_ALERT_RSVP	0x0100
211 #define IP6_ALERT_AN	0x0200
212 #endif /* LITTLE_ENDIAN */
213 #endif
214 
215 /* Routing header */
216 struct ip6_rthdr {
217 	u_int8_t  ip6r_nxt;	/* next header */
218 	u_int8_t  ip6r_len;	/* length in units of 8 octets */
219 	u_int8_t  ip6r_type;	/* routing type */
220 	u_int8_t  ip6r_segleft;	/* segments left */
221 	/* followed by routing type specific data */
222 } __packed;
223 
224 /* Type 0 Routing header, deprecated by RFC 5095. */
225 struct ip6_rthdr0 {
226 	u_int8_t  ip6r0_nxt;		/* next header */
227 	u_int8_t  ip6r0_len;		/* length in units of 8 octets */
228 	u_int8_t  ip6r0_type;		/* always zero */
229 	u_int8_t  ip6r0_segleft;	/* segments left */
230 	u_int32_t  ip6r0_reserved;	/* reserved field */
231 	/* followed by up to 127 struct in6_addr */
232 } __packed;
233 
234 /* Fragment header */
235 struct ip6_frag {
236 	u_int8_t  ip6f_nxt;		/* next header */
237 	u_int8_t  ip6f_reserved;	/* reserved field */
238 	u_int16_t ip6f_offlg;		/* offset, reserved, and flag */
239 	u_int32_t ip6f_ident;		/* identification */
240 } __packed;
241 
242 #if BYTE_ORDER == BIG_ENDIAN
243 #define IP6F_OFF_MASK		0xfff8	/* mask out offset from _offlg */
244 #define IP6F_RESERVED_MASK	0x0006	/* reserved bits in ip6f_offlg */
245 #define IP6F_MORE_FRAG		0x0001	/* more-fragments flag */
246 #else /* BYTE_ORDER == LITTLE_ENDIAN */
247 #define IP6F_OFF_MASK		0xf8ff	/* mask out offset from _offlg */
248 #define IP6F_RESERVED_MASK	0x0600	/* reserved bits in ip6f_offlg */
249 #define IP6F_MORE_FRAG		0x0100	/* more-fragments flag */
250 #endif /* BYTE_ORDER == LITTLE_ENDIAN */
251 
252 /*
253  * Internet implementation parameters.
254  */
255 #define IPV6_MAXHLIM	255	/* maximum hoplimit */
256 #define IPV6_DEFHLIM	64	/* default hlim */
257 #define IPV6_FRAGTTL	120	/* ttl for fragment packets, in slowtimo tick */
258 #define IPV6_HLIMDEC	1	/* subtracted when forwarding */
259 
260 #define IPV6_MMTU	1280	/* minimal MTU and reassembly. 1024 + 256 */
261 #define IPV6_MAXPACKET	65535	/* ip6 max packet size without Jumbo payload*/
262 #define IPV6_MAXOPTHDR	2048	/* max option header size, 256 64-bit words */
263 
264 #ifdef _KERNEL
265 /*
266  * IP6_EXTHDR_CHECK ensures that region between the IP6 header and the
267  * target header (including IPv6 itself, extension headers and
268  * TCP/UDP/ICMP6 headers) are contiguous. KAME requires drivers
269  * to store incoming data into one internal mbuf or one or more external
270  * mbufs(never into two or more internal mbufs). Thus, the third case is
271  * supposed to never be matched but is prepared just in case.
272  */
273 
274 #define IP6_EXTHDR_CHECK(m, off, hlen, ret)				\
275 do {									\
276     if ((m)->m_next != NULL) {						\
277 	if (((m)->m_flags & M_LOOP) &&					\
278 	    ((m)->m_len < (off) + (hlen)) &&				\
279 	    (((m) = m_pullup((m), (off) + (hlen))) == NULL)) {		\
280 		IP6STAT_INC(ip6s_exthdrtoolong);				\
281 		return ret;						\
282 	} else {							\
283 		if ((m)->m_len < (off) + (hlen)) {			\
284 			IP6STAT_INC(ip6s_exthdrtoolong);			\
285 			m_freem(m);					\
286 			return ret;					\
287 		}							\
288 	}								\
289     } else {								\
290 	if ((m)->m_len < (off) + (hlen)) {				\
291 		IP6STAT_INC(ip6s_tooshort);				\
292 		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);	\
293 		m_freem(m);						\
294 		return ret;						\
295 	}								\
296     }									\
297 } while (/*CONSTCOND*/ 0)
298 
299 /*
300  * IP6_EXTHDR_GET ensures that intermediate protocol header (from "off" to
301  * "len") is located in single mbuf, on contiguous memory region.
302  * The pointer to the region will be returned to pointer variable "val",
303  * with type "typ".
304  * IP6_EXTHDR_GET0 does the same, except that it aligns the structure at the
305  * very top of mbuf.  GET0 is likely to make memory copy than GET.
306  *
307  * XXX we're now testing this, needs m_pulldown()
308  */
309 #define IP6_EXTHDR_GET(val, typ, m, off, len) \
310 do {									\
311 	struct mbuf *t;							\
312 	int tmp;							\
313 	if ((m)->m_len >= (off) + (len))				\
314 		(val) = (typ)(mtod((m), caddr_t) + (off));		\
315 	else {								\
316 		t = m_pulldown((m), (off), (len), &tmp);		\
317 		if (t) {						\
318 			if (t->m_len < tmp + (len))			\
319 				panic("m_pulldown malfunction");	\
320 			(val) = (typ)(mtod(t, caddr_t) + tmp);		\
321 		} else {						\
322 			(val) = (typ)NULL;				\
323 			(m) = NULL;					\
324 		}							\
325 	}								\
326 } while (/*CONSTCOND*/ 0)
327 
328 #define IP6_EXTHDR_GET0(val, typ, m, off, len) \
329 do {									\
330 	struct mbuf *t;							\
331 	if ((off) == 0)							\
332 		(val) = (typ)mtod(m, caddr_t);				\
333 	else {								\
334 		t = m_pulldown((m), (off), (len), NULL);		\
335 		if (t) {						\
336 			if (t->m_len < (len))				\
337 				panic("m_pulldown malfunction");	\
338 			(val) = (typ)mtod(t, caddr_t);			\
339 		} else {						\
340 			(val) = (typ)NULL;				\
341 			(m) = NULL;					\
342 		}							\
343 	}								\
344 } while (/*CONSTCOND*/ 0)
345 
346 #endif /*_KERNEL*/
347 
348 #endif /* not _NETINET_IP6_H_ */
349