1/*
2 * Copyright (c) 1983, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Copyright (c) 1995 John Hay.  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 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by the University of
18 *	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * static char sccsid[] = "@(#)if.c	5.1 (Berkeley) 6/4/85"; (routed/if.c)
36 *
37 * $FreeBSD$
38 */
39
40#ifndef lint
41static const char sccsid[] = "@(#)if.c	8.1 (Berkeley) 6/5/93";
42#endif /* not lint */
43
44/*
45 * Routing Table Management Daemon
46 */
47#include "defs.h"
48
49extern	struct interface *ifnet;
50
51/*
52 * Find the interface with address addr.
53 */
54struct interface *
55if_ifwithaddr(addr)
56	struct sockaddr *addr;
57{
58	register struct interface *ifp;
59
60#define	same(a1, a2) \
61	(bcmp((caddr_t)((a1)->sa_data), (caddr_t)((a2)->sa_data), 10) == 0)
62	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
63		if (ifp->int_flags & IFF_REMOTE)
64			continue;
65		if (ifp->int_addr.sa_family != addr->sa_family)
66			continue;
67		if (same(&ifp->int_addr, addr))
68			break;
69		if ((ifp->int_flags & IFF_BROADCAST) &&
70		    same(&ifp->int_broadaddr, addr))
71			break;
72	}
73	return (ifp);
74}
75
76/*
77 * Find the point-to-point interface with destination address addr.
78 */
79struct interface *
80if_ifwithdstaddr(addr)
81	struct sockaddr *addr;
82{
83	register struct interface *ifp;
84
85	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
86		if ((ifp->int_flags & IFF_POINTOPOINT) == 0)
87			continue;
88		if (same(&ifp->int_dstaddr, addr))
89			break;
90	}
91	return (ifp);
92}
93
94/*
95 * Find the interface on the network
96 * of the specified address.
97 */
98struct interface *
99if_ifwithnet(addr)
100	register struct sockaddr *addr;
101{
102	register struct interface *ifp;
103	register int af = addr->sa_family;
104	register int (*netmatch)();
105
106	if (af >= AF_MAX)
107		return (0);
108	netmatch = afswitch[af].af_netmatch;
109	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
110		if (ifp->int_flags & IFF_REMOTE)
111			continue;
112		if (af != ifp->int_addr.sa_family)
113			continue;
114		if ((*netmatch)(addr, &ifp->int_addr))
115			break;
116	}
117	return (ifp);
118}
119
120/*
121 * Find an interface from which the specified address
122 * should have come from.  Used for figuring out which
123 * interface a packet came in on -- for tracing.
124 */
125struct interface *
126if_iflookup(addr)
127	struct sockaddr *addr;
128{
129	register struct interface *ifp, *maybe;
130	register int af = addr->sa_family;
131	register int (*netmatch)();
132
133	if (af >= AF_MAX)
134		return (0);
135	maybe = 0;
136	netmatch = afswitch[af].af_netmatch;
137	for (ifp = ifnet; ifp; ifp = ifp->int_next) {
138		if (ifp->int_addr.sa_family != af)
139			continue;
140		if (same(&ifp->int_addr, addr))
141			break;
142		if ((ifp->int_flags & IFF_BROADCAST) &&
143		    same(&ifp->int_broadaddr, addr))
144			break;
145		if (maybe == 0 && (*netmatch)(addr, &ifp->int_addr))
146			maybe = ifp;
147	}
148	if (ifp == 0)
149		ifp = maybe;
150	return (ifp);
151}
152