xref: /freebsd/sys/netinet/ip6.h (revision d93a896ef95946b0bf1219866fcb324b78543444)
1 /*	$FreeBSD$	*/
2 /*	$KAME: ip6.h,v 1.18 2001/03/29 05:34:30 itojun Exp $	*/
3 
4 /*-
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*-
34  * Copyright (c) 1982, 1986, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)ip.h	8.1 (Berkeley) 6/10/93
62  */
63 
64 #ifndef _NETINET_IP6_H_
65 #define _NETINET_IP6_H_
66 
67 /*
68  * Definition for internet protocol version 6.
69  * RFC 2460
70  */
71 
72 struct ip6_hdr {
73 	union {
74 		struct ip6_hdrctl {
75 			u_int32_t ip6_un1_flow;	/* 20 bits of flow-ID */
76 			u_int16_t ip6_un1_plen;	/* payload length */
77 			u_int8_t  ip6_un1_nxt;	/* next header */
78 			u_int8_t  ip6_un1_hlim;	/* hop limit */
79 		} ip6_un1;
80 		u_int8_t ip6_un2_vfc;	/* 4 bits version, top 4 bits class */
81 	} ip6_ctlun;
82 	struct in6_addr ip6_src;	/* source address */
83 	struct in6_addr ip6_dst;	/* destination address */
84 } __packed;
85 
86 #define ip6_vfc		ip6_ctlun.ip6_un2_vfc
87 #define ip6_flow	ip6_ctlun.ip6_un1.ip6_un1_flow
88 #define ip6_plen	ip6_ctlun.ip6_un1.ip6_un1_plen
89 #define ip6_nxt		ip6_ctlun.ip6_un1.ip6_un1_nxt
90 #define ip6_hlim	ip6_ctlun.ip6_un1.ip6_un1_hlim
91 #define ip6_hops	ip6_ctlun.ip6_un1.ip6_un1_hlim
92 
93 #define IPV6_VERSION		0x60
94 #define IPV6_VERSION_MASK	0xf0
95 
96 #if BYTE_ORDER == BIG_ENDIAN
97 #define IPV6_FLOWINFO_MASK	0x0fffffff	/* flow info (28 bits) */
98 #define IPV6_FLOWLABEL_MASK	0x000fffff	/* flow label (20 bits) */
99 #else
100 #if BYTE_ORDER == LITTLE_ENDIAN
101 #define IPV6_FLOWINFO_MASK	0xffffff0f	/* flow info (28 bits) */
102 #define IPV6_FLOWLABEL_MASK	0xffff0f00	/* flow label (20 bits) */
103 #endif /* LITTLE_ENDIAN */
104 #endif
105 #if 1
106 /* ECN bits proposed by Sally Floyd */
107 #define IP6TOS_CE		0x01	/* congestion experienced */
108 #define IP6TOS_ECT		0x02	/* ECN-capable transport */
109 #endif
110 
111 /*
112  * Extension Headers
113  */
114 
115 struct	ip6_ext {
116 	u_int8_t ip6e_nxt;
117 	u_int8_t ip6e_len;
118 } __packed;
119 
120 /* Hop-by-Hop options header */
121 /* XXX should we pad it to force alignment on an 8-byte boundary? */
122 struct ip6_hbh {
123 	u_int8_t ip6h_nxt;	/* next header */
124 	u_int8_t ip6h_len;	/* length in units of 8 octets */
125 	/* followed by options */
126 } __packed;
127 
128 /* Destination options header */
129 /* XXX should we pad it to force alignment on an 8-byte boundary? */
130 struct ip6_dest {
131 	u_int8_t ip6d_nxt;	/* next header */
132 	u_int8_t ip6d_len;	/* length in units of 8 octets */
133 	/* followed by options */
134 } __packed;
135 
136 /* Option types and related macros */
137 #define IP6OPT_PAD1		0x00	/* 00 0 00000 */
138 #define IP6OPT_PADN		0x01	/* 00 0 00001 */
139 #define IP6OPT_JUMBO		0xC2	/* 11 0 00010 = 194 */
140 #define IP6OPT_NSAP_ADDR	0xC3	/* 11 0 00011 */
141 #define IP6OPT_TUNNEL_LIMIT	0x04	/* 00 0 00100 */
142 #ifndef _KERNEL
143 #define IP6OPT_RTALERT		0x05	/* 00 0 00101 (KAME definition) */
144 #endif
145 #define IP6OPT_ROUTER_ALERT	0x05	/* 00 0 00101 (RFC3542, recommended) */
146 
147 #define IP6OPT_RTALERT_LEN	4
148 #define IP6OPT_RTALERT_MLD	0	/* Datagram contains an MLD message */
149 #define IP6OPT_RTALERT_RSVP	1	/* Datagram contains an RSVP message */
150 #define IP6OPT_RTALERT_ACTNET	2 	/* contains an Active Networks msg */
151 #define IP6OPT_MINLEN		2
152 
153 #define IP6OPT_EID		0x8a	/* 10 0 01010 */
154 
155 #define IP6OPT_TYPE(o)		((o) & 0xC0)
156 #define IP6OPT_TYPE_SKIP	0x00
157 #define IP6OPT_TYPE_DISCARD	0x40
158 #define IP6OPT_TYPE_FORCEICMP	0x80
159 #define IP6OPT_TYPE_ICMP	0xC0
160 
161 #define IP6OPT_MUTABLE		0x20
162 
163 /* IPv6 options: common part */
164 struct ip6_opt {
165 	u_int8_t ip6o_type;
166 	u_int8_t ip6o_len;
167 } __packed;
168 
169 /* Jumbo Payload Option */
170 struct ip6_opt_jumbo {
171 	u_int8_t ip6oj_type;
172 	u_int8_t ip6oj_len;
173 	u_int8_t ip6oj_jumbo_len[4];
174 } __packed;
175 #define IP6OPT_JUMBO_LEN	6
176 
177 /* NSAP Address Option */
178 struct ip6_opt_nsap {
179 	u_int8_t ip6on_type;
180 	u_int8_t ip6on_len;
181 	u_int8_t ip6on_src_nsap_len;
182 	u_int8_t ip6on_dst_nsap_len;
183 	/* followed by source NSAP */
184 	/* followed by destination NSAP */
185 } __packed;
186 
187 /* Tunnel Limit Option */
188 struct ip6_opt_tunnel {
189 	u_int8_t ip6ot_type;
190 	u_int8_t ip6ot_len;
191 	u_int8_t ip6ot_encap_limit;
192 } __packed;
193 
194 /* Router Alert Option */
195 struct ip6_opt_router {
196 	u_int8_t ip6or_type;
197 	u_int8_t ip6or_len;
198 	u_int8_t ip6or_value[2];
199 } __packed;
200 /* Router alert values (in network byte order) */
201 #if BYTE_ORDER == BIG_ENDIAN
202 #define IP6_ALERT_MLD	0x0000
203 #define IP6_ALERT_RSVP	0x0001
204 #define IP6_ALERT_AN	0x0002
205 #else
206 #if BYTE_ORDER == LITTLE_ENDIAN
207 #define IP6_ALERT_MLD	0x0000
208 #define IP6_ALERT_RSVP	0x0100
209 #define IP6_ALERT_AN	0x0200
210 #endif /* LITTLE_ENDIAN */
211 #endif
212 
213 /* Routing header */
214 struct ip6_rthdr {
215 	u_int8_t  ip6r_nxt;	/* next header */
216 	u_int8_t  ip6r_len;	/* length in units of 8 octets */
217 	u_int8_t  ip6r_type;	/* routing type */
218 	u_int8_t  ip6r_segleft;	/* segments left */
219 	/* followed by routing type specific data */
220 } __packed;
221 
222 /* Type 0 Routing header, deprecated by RFC 5095. */
223 struct ip6_rthdr0 {
224 	u_int8_t  ip6r0_nxt;		/* next header */
225 	u_int8_t  ip6r0_len;		/* length in units of 8 octets */
226 	u_int8_t  ip6r0_type;		/* always zero */
227 	u_int8_t  ip6r0_segleft;	/* segments left */
228 	u_int32_t  ip6r0_reserved;	/* reserved field */
229 	/* followed by up to 127 struct in6_addr */
230 } __packed;
231 
232 /* Fragment header */
233 struct ip6_frag {
234 	u_int8_t  ip6f_nxt;		/* next header */
235 	u_int8_t  ip6f_reserved;	/* reserved field */
236 	u_int16_t ip6f_offlg;		/* offset, reserved, and flag */
237 	u_int32_t ip6f_ident;		/* identification */
238 } __packed;
239 
240 #if BYTE_ORDER == BIG_ENDIAN
241 #define IP6F_OFF_MASK		0xfff8	/* mask out offset from _offlg */
242 #define IP6F_RESERVED_MASK	0x0006	/* reserved bits in ip6f_offlg */
243 #define IP6F_MORE_FRAG		0x0001	/* more-fragments flag */
244 #else /* BYTE_ORDER == LITTLE_ENDIAN */
245 #define IP6F_OFF_MASK		0xf8ff	/* mask out offset from _offlg */
246 #define IP6F_RESERVED_MASK	0x0600	/* reserved bits in ip6f_offlg */
247 #define IP6F_MORE_FRAG		0x0100	/* more-fragments flag */
248 #endif /* BYTE_ORDER == LITTLE_ENDIAN */
249 
250 /*
251  * Internet implementation parameters.
252  */
253 #define IPV6_MAXHLIM	255	/* maximum hoplimit */
254 #define IPV6_DEFHLIM	64	/* default hlim */
255 #define IPV6_FRAGTTL	120	/* ttl for fragment packets, in slowtimo tick */
256 #define IPV6_HLIMDEC	1	/* subtracted when forwarding */
257 
258 #define IPV6_MMTU	1280	/* minimal MTU and reassembly. 1024 + 256 */
259 #define IPV6_MAXPACKET	65535	/* ip6 max packet size without Jumbo payload*/
260 #define IPV6_MAXOPTHDR	2048	/* max option header size, 256 64-bit words */
261 
262 #ifdef _KERNEL
263 /*
264  * IP6_EXTHDR_CHECK ensures that region between the IP6 header and the
265  * target header (including IPv6 itself, extension headers and
266  * TCP/UDP/ICMP6 headers) are contiguous. KAME requires drivers
267  * to store incoming data into one internal mbuf or one or more external
268  * mbufs(never into two or more internal mbufs). Thus, the third case is
269  * supposed to never be matched but is prepared just in case.
270  */
271 
272 #define IP6_EXTHDR_CHECK(m, off, hlen, ret)				\
273 do {									\
274     if ((m)->m_next != NULL) {						\
275 	if (((m)->m_flags & M_LOOP) &&					\
276 	    ((m)->m_len < (off) + (hlen)) &&				\
277 	    (((m) = m_pullup((m), (off) + (hlen))) == NULL)) {		\
278 		IP6STAT_INC(ip6s_exthdrtoolong);				\
279 		return ret;						\
280 	} else {							\
281 		if ((m)->m_len < (off) + (hlen)) {			\
282 			IP6STAT_INC(ip6s_exthdrtoolong);			\
283 			m_freem(m);					\
284 			return ret;					\
285 		}							\
286 	}								\
287     } else {								\
288 	if ((m)->m_len < (off) + (hlen)) {				\
289 		IP6STAT_INC(ip6s_tooshort);				\
290 		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);	\
291 		m_freem(m);						\
292 		return ret;						\
293 	}								\
294     }									\
295 } while (/*CONSTCOND*/ 0)
296 
297 /*
298  * IP6_EXTHDR_GET ensures that intermediate protocol header (from "off" to
299  * "len") is located in single mbuf, on contiguous memory region.
300  * The pointer to the region will be returned to pointer variable "val",
301  * with type "typ".
302  * IP6_EXTHDR_GET0 does the same, except that it aligns the structure at the
303  * very top of mbuf.  GET0 is likely to make memory copy than GET.
304  *
305  * XXX we're now testing this, needs m_pulldown()
306  */
307 #define IP6_EXTHDR_GET(val, typ, m, off, len) \
308 do {									\
309 	struct mbuf *t;							\
310 	int tmp;							\
311 	if ((m)->m_len >= (off) + (len))				\
312 		(val) = (typ)(mtod((m), caddr_t) + (off));		\
313 	else {								\
314 		t = m_pulldown((m), (off), (len), &tmp);		\
315 		if (t) {						\
316 			if (t->m_len < tmp + (len))			\
317 				panic("m_pulldown malfunction");	\
318 			(val) = (typ)(mtod(t, caddr_t) + tmp);		\
319 		} else {						\
320 			(val) = (typ)NULL;				\
321 			(m) = NULL;					\
322 		}							\
323 	}								\
324 } while (/*CONSTCOND*/ 0)
325 
326 #define IP6_EXTHDR_GET0(val, typ, m, off, len) \
327 do {									\
328 	struct mbuf *t;							\
329 	if ((off) == 0)							\
330 		(val) = (typ)mtod(m, caddr_t);				\
331 	else {								\
332 		t = m_pulldown((m), (off), (len), NULL);		\
333 		if (t) {						\
334 			if (t->m_len < (len))				\
335 				panic("m_pulldown malfunction");	\
336 			(val) = (typ)mtod(t, caddr_t);			\
337 		} else {						\
338 			(val) = (typ)NULL;				\
339 			(m) = NULL;					\
340 		}							\
341 	}								\
342 } while (/*CONSTCOND*/ 0)
343 
344 #endif /*_KERNEL*/
345 
346 #endif /* not _NETINET_IP6_H_ */
347