1 /*
2  * dhcpcd - DHCP client daemon
3  * Copyright (c) 2006-2015 Roy Marples <roy@marples.name>
4  * All rights reserved
5 
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #ifndef ARP_H
29 #define ARP_H
30 
31 /* ARP timings from RFC5227 */
32 #define PROBE_WAIT		 1
33 #define PROBE_NUM		 3
34 #define PROBE_MIN		 1
35 #define PROBE_MAX		 2
36 #define ANNOUNCE_WAIT		 2
37 #define ANNOUNCE_NUM		 2
38 #define ANNOUNCE_INTERVAL	 2
39 #define MAX_CONFLICTS		10
40 #define RATE_LIMIT_INTERVAL	60
41 #define DEFEND_INTERVAL		10
42 
43 #include "dhcpcd.h"
44 
45 struct arp_msg {
46 	uint16_t op;
47 	unsigned char sha[HWADDR_LEN];
48 	struct in_addr sip;
49 	unsigned char tha[HWADDR_LEN];
50 	struct in_addr tip;
51 };
52 
53 struct arp_state {
54 	TAILQ_ENTRY(arp_state) next;
55 	struct interface *iface;
56 
57 	void (*probed_cb)(struct arp_state *);
58 	void (*announced_cb)(struct arp_state *);
59 	void (*conflicted_cb)(struct arp_state *, const struct arp_msg *);
60 
61 	struct in_addr src_addr;
62 	struct in_addr addr;
63 	int probes;
64 	int claims;
65 	struct in_addr failed;
66 	uint8_t dest_hwlen;
67 	unsigned char dest_hwaddr[HWADDR_LEN];
68 };
69 TAILQ_HEAD(arp_statehead, arp_state);
70 
71 #ifdef INET
72 void arp_report_conflicted(const struct arp_state *, const struct arp_msg *);
73 void arp_announce(struct arp_state *);
74 void arp_probe(struct arp_state *);
75 struct arp_state *arp_new(struct interface *, const struct in_addr *);
76 void arp_cancel(struct arp_state *);
77 void arp_free(struct arp_state *);
78 void arp_free_but(struct arp_state *);
79 void arp_close(struct interface *);
80 
81 void arp_handleifa(int, struct interface *, const struct in_addr *, int);
82 #else
83 #define arp_close(a) {}
84 #endif
85 #endif
86