1/*	$NetBSD: config.c,v 1.12 2003/05/16 18:10:38 itojun Exp $	*/
2
3/*
4 * The mrouted program is covered by the license in the accompanying file
5 * named "LICENSE".  Use of the mrouted program represents acceptance of
6 * the terms and conditions listed in that file.
7 *
8 * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
9 * Leland Stanford Junior University.
10 */
11
12#include "defs.h"
13#include <net/if.h>
14#include <ifaddrs.h>
15
16
17/*
18 * Query the kernel to find network interfaces that are multicast-capable
19 * and install them in the uvifs array.
20 */
21void
22config_vifs_from_kernel(void)
23{
24    struct ifaddrs *ifa, *ifap;
25    struct uvif *v;
26    vifi_t vifi;
27    u_int32_t addr, mask, subnet;
28    short flags;
29
30    if (getifaddrs(&ifap) < 0)
31	logit(LOG_ERR, errno, "getifaddrs");
32
33    for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
34	/*
35	 * Ignore any interface for an address family other than IP.
36	 */
37	if (ifa->ifa_addr->sa_family != AF_INET)
38	    continue;
39
40	addr = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
41
42	/*
43	 * Ignore loopback interfaces and interfaces that do not support
44	 * multicast.
45	 */
46	flags = ifa->ifa_flags;
47	if ((flags & (IFF_LOOPBACK|IFF_MULTICAST)) != IFF_MULTICAST)
48	    continue;
49
50	/*
51	 * Ignore any interface whose address and mask do not define a
52	 * valid subnet number, or whose address is of the form {subnet,0}
53	 * or {subnet,-1}.
54	 */
55	mask = ((struct sockaddr_in *)ifa->ifa_netmask)->sin_addr.s_addr;
56	subnet = addr & mask;
57	if (!inet_valid_subnet(subnet, mask) ||
58	    addr == subnet ||
59	    addr == (subnet | ~mask)) {
60	    logit(LOG_WARNING, 0,
61		"ignoring %s, has invalid address (%s) and/or mask (%s)",
62		ifa->ifa_name, inet_fmt(addr),
63		inet_fmt(mask));
64	    continue;
65	}
66
67	/*
68	 * Ignore any interface that is connected to the same subnet as
69	 * one already installed in the uvifs array.
70	 */
71	for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
72	    if ((addr & v->uv_subnetmask) == v->uv_subnet ||
73		(v->uv_subnet & mask) == subnet) {
74		logit(LOG_WARNING, 0, "ignoring %s, same subnet as %s",
75		    ifa->ifa_name, v->uv_name);
76		break;
77	    }
78	}
79	if (vifi != numvifs)
80	    continue;
81
82	/*
83	 * If there is room in the uvifs array, install this interface.
84	 */
85	if (numvifs == MAXVIFS) {
86	    logit(LOG_WARNING, 0, "too many vifs, ignoring %s", ifa->ifa_name);
87	    continue;
88	}
89	v  = &uvifs[numvifs];
90	v->uv_flags       = 0;
91	v->uv_metric      = DEFAULT_METRIC;
92	v->uv_rate_limit  = DEFAULT_PHY_RATE_LIMIT;
93	v->uv_threshold   = DEFAULT_THRESHOLD;
94	v->uv_lcl_addr    = addr;
95	v->uv_rmt_addr    = 0;
96	v->uv_subnet      = subnet;
97	v->uv_subnetmask  = mask;
98	v->uv_subnetbcast = subnet | ~mask;
99	strlcpy(v->uv_name, ifa->ifa_name, sizeof(v->uv_name));
100	v->uv_groups      = NULL;
101	v->uv_neighbors   = NULL;
102	v->uv_acl         = NULL;
103	v->uv_addrs	  = NULL;
104
105	logit(LOG_INFO,0,"installing %s (%s on subnet %s) as vif #%u - rate=%d",
106	    v->uv_name, inet_fmt(addr),
107	    inet_fmts(subnet, mask),
108	    numvifs, v->uv_rate_limit);
109
110	++numvifs;
111
112	/*
113	 * If the interface is not yet up, set the vifs_down flag to
114	 * remind us to check again later.
115	 */
116	if (!(flags & IFF_UP)) {
117	    v->uv_flags |= VIFF_DOWN;
118	    vifs_down = TRUE;
119	}
120    }
121
122    freeifaddrs(ifap);
123}
124