1/* $OpenBSD: ip_carp.h,v 1.52 2025/03/02 21:28:32 bluhm Exp $ */
2
3/*
4 * Copyright (c) 2002 Michael Shalayeff. All rights reserved.
5 * Copyright (c) 2003 Ryan McBride. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
25 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
26 * THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef _NETINET_IP_CARP_H_
30#define _NETINET_IP_CARP_H_
31
32/*
33 * The CARP header layout is as follows:
34 *
35 * 0 1 2 3
36 * 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
37 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
38 * |Version| Type | VirtualHostID | AdvSkew | Auth Len |
39 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
40 * | Demotion | AdvBase | Checksum |
41 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
42 * | Counter (1) |
43 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44 * | Counter (2) |
45 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46 * | SHA-1 HMAC (1) |
47 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
48 * | SHA-1 HMAC (2) |
49 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
50 * | SHA-1 HMAC (3) |
51 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
52 * | SHA-1 HMAC (4) |
53 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
54 * | SHA-1 HMAC (5) |
55 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
56 *
57 */
58
59struct carp_header {
60#if _BYTE_ORDER == _LITTLE_ENDIAN
61 u_int carp_type:4,
62 carp_version:4;
63#endif
64#if _BYTE_ORDER == _BIG_ENDIAN
65 u_int carp_version:4,
66 carp_type:4;
67#endif
68 u_int8_t carp_vhid; /* virtual host id */
69 u_int8_t carp_advskew; /* advertisement skew */
70 u_int8_t carp_authlen; /* size of counter+md, 32bit chunks */
71 u_int8_t carp_demote; /* demotion indicator */
72 u_int8_t carp_advbase; /* advertisement interval */
73 u_int16_t carp_cksum;
74 u_int32_t carp_counter[2];
75 unsigned char carp_md[20]; /* SHA1 HMAC */
76} __packed;
77
78#define CARP_DFLTTL 255
79
80/* carp_version */
81#define CARP_VERSION 2
82
83/* carp_type */
84#define CARP_ADVERTISEMENT 0x01
85
86#define CARP_KEY_LEN 20 /* a sha1 hash of a passphrase */
87
88/* carp_advbase */
89#define CARP_DFLTINTV 1
90
91/*
92 * Statistics.
93 */
94struct carpstats {
95 u_int64_t carps_ipackets; /* total input packets, IPv4 */
96 u_int64_t carps_ipackets6; /* total input packets, IPv6 */
97 u_int64_t carps_badif; /* wrong interface */
98 u_int64_t carps_badttl; /* TTL is not CARP_DFLTTL */
99 u_int64_t carps_hdrops; /* packets shorter than hdr */
100 u_int64_t carps_badsum; /* bad checksum */
101 u_int64_t carps_badver; /* bad (incl unsupp) version */
102 u_int64_t carps_badlen; /* data length does not match */
103 u_int64_t carps_badauth; /* bad authentication */
104 u_int64_t carps_badvhid; /* bad VHID */
105 u_int64_t carps_badaddrs; /* bad address list */
106
107 u_int64_t carps_opackets; /* total output packets, IPv4 */
108 u_int64_t carps_opackets6; /* total output packets, IPv6 */
109 u_int64_t carps_onomem; /* no memory for an mbuf */
110 u_int64_t carps_ostates; /* total state updates sent */
111
112 u_int64_t carps_preempt; /* transitions to master */
113};
114
115#define CARPDEVNAMSIZ 16
116#ifdef IFNAMSIZ
117#if CARPDEVNAMSIZ != IFNAMSIZ
118#error namsiz mismatch
119#endif
120#endif
121
122/*
123 * Configuration structure for SIOCSVH SIOCGVH
124 */
125struct carpreq {
126 int carpr_state;
127#define CARP_STATES "INIT", "BACKUP", "MASTER"
128#define CARP_MAXSTATE 2
129#define CARP_MAXNODES 32
130
131 char carpr_carpdev[CARPDEVNAMSIZ];
132 u_int8_t carpr_vhids[CARP_MAXNODES];
133 u_int8_t carpr_advskews[CARP_MAXNODES];
134 u_int8_t carpr_states[CARP_MAXNODES];
135#define CARP_BAL_MODES "none", "ip", "ip-stealth", "ip-unicast"
136#define CARP_BAL_NONE 0
137#define CARP_BAL_IP 1
138#define CARP_BAL_IPSTEALTH 2
139#define CARP_BAL_IPUNICAST 3
140#define CARP_BAL_MAXID 3
141 u_int8_t carpr_balancing;
142 int carpr_advbase;
143 unsigned char carpr_key[CARP_KEY_LEN];
144 struct in_addr carpr_peer;
145};
146
147/*
148 * Names for CARP sysctl objects
149 */
150#define CARPCTL_ALLOW 1 /* accept incoming CARP packets */
151#define CARPCTL_PREEMPT 2 /* high-pri backup preemption mode */
152#define CARPCTL_LOG 3 /* log bad packets */
153#define CARPCTL_STATS 4 /* CARP stats */
154#define CARPCTL_MAXID 5
155
156#define CARPCTL_NAMES { \
157 { 0, 0 }, \
158 { "allow", CTLTYPE_INT }, \
159 { "preempt", CTLTYPE_INT }, \
160 { "log", CTLTYPE_INT }, \
161 { "stats", CTLTYPE_STRUCT }, \
162}
163
164#ifdef _KERNEL
165
166#include <net/if_types.h>
167#include <sys/percpu.h>
168
169enum carpstat_counters {
170 carps_ipackets,
171 carps_ipackets6,
172 carps_badif,
173 carps_badttl,
174 carps_hdrops,
175 carps_badsum,
176 carps_badver,
177 carps_badlen,
178 carps_badauth,
179 carps_badvhid,
180 carps_badaddrs,
181 carps_opackets,
182 carps_opackets6,
183 carps_onomem,
184 carps_ostates,
185 carps_preempt,
186 carps_ncounters,
187};
188
189extern struct cpumem *carpcounters;
190
191static inline void
192carpstat_inc(enum carpstat_counters c)
193{
194 counters_inc(carpcounters, c);
195}
196
197/*
198 * If two carp interfaces share same physical interface, then we pretend all IP
199 * addresses belong to single interface.
200 */
201static inline int
202carp_strict_addr_chk(struct ifnet *ifp_a, struct ifnet *ifp_b)
203{
204 return ((ifp_a->if_type == IFT_CARP &&
205 ifp_b->if_index == ifp_a->if_carpdevidx) ||
206 (ifp_b->if_type == IFT_CARP &&
207 ifp_a->if_index == ifp_b->if_carpdevidx) ||
208 (ifp_a->if_type == IFT_CARP && ifp_b->if_type == IFT_CARP &&
209 ifp_a->if_carpdevidx == ifp_b->if_carpdevidx));
210}
211
212struct mbuf *carp_input(struct ifnet *, struct mbuf *, uint64_t,
213 struct netstack *);
214int carp_proto_input(struct mbuf **, int *, int, int,
215 struct netstack *);
216void carp_carpdev_state(void *);
217void carp_group_demote_adj(struct ifnet *, int, char *);
218int carp6_proto_input(struct mbuf **, int *, int, int,
219 struct netstack *);
220int carp_iamatch(struct ifnet *);
221int carp_ourether(struct ifnet *, u_int8_t *);
222int carp_output(struct ifnet *, struct mbuf *, struct sockaddr *,
223 struct rtentry *);
224int carp_sysctl(int *, u_int, void *, size_t *, void *, size_t);
225int carp_lsdrop(struct ifnet *, struct mbuf *, sa_family_t,
226 u_int32_t *, u_int32_t *, int);
227#endif /* _KERNEL */
228#endif /* _NETINET_IP_CARP_H_ */