1/* $NetBSD: ip_carp.h,v 1.14 2021/02/03 18:13:13 roy Exp $ */
2/* $OpenBSD: ip_carp.h,v 1.18 2005/04/20 23:00:41 mpf Exp $ */
3
4/*
5 * Copyright (c) 2002 Michael Shalayeff. All rights reserved.
6 * Copyright (c) 2003 Ryan McBride. 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 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
21 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23 * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
26 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27 * THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#ifndef _NETINET_IP_CARP_H_
31#define _NETINET_IP_CARP_H_
32
33/*
34 * The CARP header layout is as follows:
35 *
36 * 0 1 2 3
37 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
38 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
39 * |Version| Type | VirtualHostID | AdvSkew | Auth Len |
40 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
41 * | Reserved | AdvBase | Checksum |
42 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
43 * | Counter (1) |
44 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
45 * | Counter (2) |
46 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
47 * | SHA-1 HMAC (1) |
48 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
49 * | SHA-1 HMAC (2) |
50 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
51 * | SHA-1 HMAC (3) |
52 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
53 * | SHA-1 HMAC (4) |
54 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
55 * | SHA-1 HMAC (5) |
56 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
57 *
58 */
59
60struct carp_header {
61#if BYTE_ORDER == LITTLE_ENDIAN
62 unsigned int carp_type:4,
63 carp_version:4;
64#endif
65#if BYTE_ORDER == BIG_ENDIAN
66 unsigned int carp_version:4,
67 carp_type:4;
68#endif
69 u_int8_t carp_vhid; /* virtual host id */
70 u_int8_t carp_advskew; /* advertisement skew */
71 u_int8_t carp_authlen; /* size of counter+md, 32bit chunks */
72 u_int8_t carp_pad1; /* reserved */
73 u_int8_t carp_advbase; /* advertisement interval */
74 u_int16_t carp_cksum;
75 u_int32_t carp_counter[2];
76 unsigned char carp_md[20]; /* SHA1 HMAC */
77};
78
79#ifdef __CTASSERT
80__CTASSERT(sizeof(struct carp_header) == 36);
81#endif
82
83#define CARP_DFLTTL 255
84
85/* carp_version */
86#define CARP_VERSION 2
87
88/* carp_type */
89#define CARP_ADVERTISEMENT 0x01
90
91#define CARP_KEY_LEN 20 /* a sha1 hash of a passphrase */
92
93/* carp_advbase */
94#define CARP_DFLTINTV 1
95
96/*
97 * Statistics.
98 */
99#define CARP_STAT_IPACKETS 0 /* total input packets, IPv4 */
100#define CARP_STAT_IPACKETS6 1 /* total input packets, IPv6 */
101#define CARP_STAT_BADIF 2 /* wrong interface */
102#define CARP_STAT_BADTTL 3 /* TTL is not CARP_DFLTTL */
103#define CARP_STAT_HDROPS 4 /* packets shorter than hdr */
104#define CARP_STAT_BADSUM 5 /* bad checksum */
105#define CARP_STAT_BADVER 6 /* bad (incl unsupported) version */
106#define CARP_STAT_BADLEN 7 /* data length does not match */
107#define CARP_STAT_BADAUTH 8 /* bad authentication */
108#define CARP_STAT_BADVHID 9 /* bad VHID */
109#define CARP_STAT_BADADDRS 10 /* bad address list */
110#define CARP_STAT_OPACKETS 11 /* total output packets, IPv4 */
111#define CARP_STAT_OPACKETS6 12 /* total output packets, IPv6 */
112#define CARP_STAT_ONOMEM 13 /* no memory for an mbuf */
113#define CARP_STAT_OSTATES 14 /* total state updates sent */
114#define CARP_STAT_PREEMPT 15 /* in enabled, preemptions */
115
116#define CARP_NSTATS 16
117
118#define CARPDEVNAMSIZ 16
119#ifdef IFNAMSIZ
120#if CARPDEVNAMSIZ != IFNAMSIZ
121#error
122#endif
123#endif
124
125/*
126 * Configuration structure for SIOCSVH SIOCGVH
127 */
128struct carpreq {
129 int carpr_state;
130#define CARP_STATES "INIT", "BACKUP", "MASTER"
131#define CARP_MAXSTATE 2
132
133 char carpr_carpdev[CARPDEVNAMSIZ];
134 int carpr_vhid;
135 int carpr_advskew;
136 int carpr_advbase;
137 unsigned char carpr_key[CARP_KEY_LEN];
138};
139
140/*
141 * Names for CARP sysctl objects
142 */
143#define CARPCTL_ALLOW 1 /* accept incoming CARP packets */
144#define CARPCTL_PREEMPT 2 /* high-pri backup preemption mode */
145#define CARPCTL_LOG 3 /* log bad packets */
146#define CARPCTL_ARPBALANCE 4 /* balance arp responses */
147#define CARPCTL_STATS 5 /* carp statistics */
148#define CARPCTL_MAXID 6
149
150#ifdef _KERNEL
151void carp_init(void);
152void carp_ifdetach(struct ifnet *);
153void carp_proto_input(struct mbuf *, int, int);
154void carp_carpdev_state(void *);
155int carp6_proto_input(struct mbuf **, int *, int);
156int carp_iamatch(struct in_ifaddr *, u_char *,
157 u_int32_t *, u_int32_t);
158struct ifaddr *carp_iamatch6(void *, struct in6_addr *);
159struct ifnet *carp_ourether(void *, struct ether_header *, u_char, int);
160int carp_input(struct mbuf *, u_int8_t *, u_int8_t *, u_int16_t);
161int carp_output(struct ifnet *, struct mbuf *,
162 const struct sockaddr *, const struct rtentry *);
163#endif /* _KERNEL */
164#endif /* _NETINET_IP_CARP_H_ */