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_ */