1 /*
2  * Copyright (c) 2002 Michael Shalayeff. All rights reserved.
3  * Copyright (c) 2003 Ryan McBride. All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
18  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
20  * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
23  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
24  * THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 /*
28  * The CARP header layout is as follows:
29  *
30  *     0                   1                   2                   3
31  *     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
32  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
33  *    |Version| Type  | VirtualHostID |    AdvSkew    |    Auth Len   |
34  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
35  *    |   Reserved    |     AdvBase   |          Checksum             |
36  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
37  *    |                         Counter (1)                           |
38  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
39  *    |                         Counter (2)                           |
40  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
41  *    |                        SHA-1 HMAC (1)                         |
42  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
43  *    |                        SHA-1 HMAC (2)                         |
44  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
45  *    |                        SHA-1 HMAC (3)                         |
46  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
47  *    |                        SHA-1 HMAC (4)                         |
48  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
49  *    |                        SHA-1 HMAC (5)                         |
50  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
51  *
52  */
53 
54 #ifndef __IP_CARP_H__
55 #define __IP_CARP_H__ 1
56 
57 struct carp_header {
58 #ifdef WORDS_BIGENDIAN
59         u_int8_t        carp_version:4,
60                         carp_type:4;
61 #else
62         u_int8_t        carp_type:4,
63                         carp_version:4;
64 #endif
65         u_int8_t        carp_vhid;      /* virtual host id */
66         u_int8_t        carp_advskew;   /* advertisement skew */
67         u_int8_t        carp_authlen;   /* size of counter+md, 32bit chunks */
68         u_int8_t        carp_pad1;      /* reserved */
69         u_int8_t        carp_advbase;   /* advertisement interval */
70         u_int16_t       carp_cksum;
71         u_int32_t       carp_counter[2];
72         unsigned char   carp_md[20];    /* SHA1 HMAC */
73 } __packed;
74 
75 #define CARP_DFLTTL             255
76 
77 /* carp_version */
78 #define CARP_VERSION            2
79 
80 /* carp_type */
81 #define CARP_ADVERTISEMENT      0x01
82 
83 #define CARP_KEY_LEN            20      /* a sha1 hash of a passphrase */
84 
85 /* carp_advbase */
86 #define CARP_DFLTINTV           1
87 
88 #define CARP_BULK_UPDATE_MIN_DELAY      240
89 
90 /*
91  * Statistics.
92  */
93 struct carpstats {
94         u_int64_t       carps_ipackets;         /* total input packets, IPv4 */
95         u_int64_t       carps_ipackets6;        /* total input packets, IPv6 */
96         u_int64_t       carps_badif;            /* wrong interface */
97         u_int64_t       carps_badttl;           /* TTL is not CARP_DFLTTL */
98         u_int64_t       carps_hdrops;           /* packets shorter than header */
99         u_int64_t       carps_badsum;           /* bad checksum */
100         u_int64_t       carps_badver;           /* bad (incl unsupp) version */
101         u_int64_t       carps_badlen;           /* data length does not match */
102         u_int64_t       carps_badauth;          /* bad authentication */
103         u_int64_t       carps_badvhid;          /* bad VHID */
104         u_int64_t       carps_badaddrs;         /* bad address list */
105 
106         u_int64_t       carps_opackets;         /* total output packets, IPv4 */
107         u_int64_t       carps_opackets6;        /* total output packets, IPv6 */
108         u_int64_t       carps_onomem;           /* no memory for an mbuf */
109         u_int64_t       carps_ostates;          /* total state updates sent */
110 
111         u_int64_t       carps_preempt;          /* if enabled, preemptions */
112 };
113 
114 /*
115  * Configuration structure for SIOCSVH SIOCGVH
116  */
117 struct carpreq {
118         int             carpr_state;
119 #define CARP_STATES     "INIT", "BACKUP", "MASTER"
120 #define CARP_MAXSTATE   2
121         int             carpr_vhid;
122         int             carpr_advskew;
123         int             carpr_advbase;
124         unsigned char   carpr_key[CARP_KEY_LEN];
125 };
126 #define SIOCSVH _IOWR('i', 245, struct ifreq)
127 #define SIOCGVH _IOWR('i', 246, struct ifreq)
128 
129 /*
130  * Names for CARP sysctl objects
131  */
132 #define CARPCTL_ALLOW           1       /* accept incoming CARP packets */
133 #define CARPCTL_PREEMPT         2       /* high-pri backup preemption mode */
134 #define CARPCTL_LOG             3       /* log bad packets */
135 #define CARPCTL_ARPBALANCE      4       /* balance arp responses */
136 #define CARPCTL_MAXID           5
137 
138 #define CARPCTL_NAMES { \
139         { 0, 0 }, \
140         { "allow", CTLTYPE_INT }, \
141         { "preempt", CTLTYPE_INT }, \
142         { "log", CTLTYPE_INT }, \
143         { "arpbalance", CTLTYPE_INT }, \
144 }
145 
146 #endif
147