xref: /dragonfly/contrib/dhcpcd/src/arp.h (revision 80aa9461)
1 /* SPDX-License-Identifier: BSD-2-Clause */
2 /*
3  * dhcpcd - DHCP client daemon
4  * Copyright (c) 2006-2023 Roy Marples <roy@marples.name>
5  * 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 AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifndef ARP_H
30 #define ARP_H
31 
32 /* ARP timings from RFC5227 */
33 #define PROBE_WAIT		 1
34 #define PROBE_NUM		 3
35 #define PROBE_MIN		 1
36 #define PROBE_MAX		 2
37 #define ANNOUNCE_WAIT		 2
38 #define ANNOUNCE_NUM		 2
39 #define ANNOUNCE_INTERVAL	 2
40 #define MAX_CONFLICTS		10
41 #define RATE_LIMIT_INTERVAL	60
42 #define DEFEND_INTERVAL		10
43 
44 #include "bpf.h"
45 #include "dhcpcd.h"
46 #include "if.h"
47 
48 #ifdef IN_IFF_DUPLICATED
49 /* NetBSD gained RFC 5227 support in the kernel.
50  * This means dhcpcd doesn't need ARP except for ARPing support
51  * and ARP announcing an address. */
52 #if defined(__NetBSD_Version__) && __NetBSD_Version__ >= 799003900
53 #define KERNEL_RFC5227
54 #endif
55 #endif
56 
57 struct arp_msg {
58 	uint16_t op;
59 	uint8_t sha[HWADDR_LEN];
60 	struct in_addr sip;
61 	uint8_t tha[HWADDR_LEN];
62 	struct in_addr tip;
63 	/* Frame header and sender to diagnose failures */
64 	uint8_t fsha[HWADDR_LEN];
65 	uint8_t ftha[HWADDR_LEN];
66 };
67 
68 struct arp_state {
69 	TAILQ_ENTRY(arp_state) next;
70 	struct interface *iface;
71 	struct in_addr addr;
72 	struct bpf *bpf;
73 
74 	int probes;
75 	int claims;
76 	struct timespec defend;
77 
78 	void (*found_cb)(struct arp_state *, const struct arp_msg *);
79 	void (*not_found_cb)(struct arp_state *);
80 	void (*announced_cb)(struct arp_state *);
81 	void (*defend_failed_cb)(struct arp_state *);
82 	void (*free_cb)(struct arp_state *);
83 };
84 TAILQ_HEAD(arp_statehead, arp_state);
85 
86 struct iarp_state {
87 	struct arp_statehead arp_states;
88 };
89 
90 #define ARP_STATE(ifp)							       \
91 	((struct iarp_state *)(ifp)->if_data[IF_DATA_ARP])
92 #define ARP_CSTATE(ifp)							       \
93 	((const struct iarp_state *)(ifp)->if_data[IF_DATA_ARP])
94 
95 #ifdef ARP
96 void arp_packet(struct interface *, uint8_t *, size_t, unsigned int);
97 struct arp_state *arp_new(struct interface *, const struct in_addr *);
98 void arp_probe(struct arp_state *);
99 struct arp_state *arp_announceaddr(struct dhcpcd_ctx *, const struct in_addr *);
100 struct arp_state *arp_ifannounceaddr(struct interface *, const struct in_addr *);
101 struct arp_state * arp_find(struct interface *, const struct in_addr *);
102 void arp_free(struct arp_state *);
103 void arp_freeaddr(struct interface *, const struct in_addr *);
104 void arp_drop(struct interface *);
105 #endif /* ARP */
106 #endif /* ARP_H */
107