xref: /netbsd/sys/netinet/ip_carp.h (revision 62448faa)
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 
60 struct 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  */
128 struct 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
151 void		 carp_init(void);
152 void		 carp_ifdetach(struct ifnet *);
153 void		 carp_proto_input(struct mbuf *, int, int);
154 void		 carp_carpdev_state(void *);
155 int		 carp6_proto_input(struct mbuf **, int *, int);
156 int		 carp_iamatch(struct in_ifaddr *, u_char *,
157 		     u_int32_t *, u_int32_t);
158 struct ifaddr	*carp_iamatch6(void *, struct in6_addr *);
159 struct ifnet	*carp_ourether(void *, struct ether_header *, u_char, int);
160 int		 carp_input(struct mbuf *, u_int8_t *, u_int8_t *, u_int16_t);
161 int		 carp_output(struct ifnet *, struct mbuf *,
162 		     const struct sockaddr *, const struct rtentry *);
163 #endif /* _KERNEL */
164 #endif /* _NETINET_IP_CARP_H_ */
165