1 /* $NetBSD: config.c,v 1.13 2003/05/16 22:59:50 dsl 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 */
21 void
config_vifs_from_kernel(void)22 config_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