config.c revision 1.1 
1/*	$NetBSD: config.c,v 1.5 1995/10/09 03:51:37 thorpej 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
13#include "defs.h"
14
15
16/*
17 * Query the kernel to find network interfaces that are multicast-capable
18 * and install them in the uvifs array.
19 */
20void config_vifs_from_kernel()
21{
22    struct ifreq ifbuf[32];
23    struct ifreq *ifrp, *ifend;
24    struct ifconf ifc;
25    register struct uvif *v;
26    register vifi_t vifi;
27    int n;
28    u_int32_t addr, mask, subnet;
29    short flags;
30
31    ifc.ifc_buf = (char *)ifbuf;
32    ifc.ifc_len = sizeof(ifbuf);
33    if (ioctl(udp_socket, SIOCGIFCONF, (char *)&ifc) < 0)
34	log(LOG_ERR, errno, "ioctl SIOCGIFCONF");
35
36    ifrp = (struct ifreq *)ifbuf;
37    ifend = (struct ifreq *)((char *)ifbuf + ifc.ifc_len);
38    /*
39     * Loop through all of the interfaces.
40     */
41    for (; ifrp < ifend; ifrp = (struct ifreq *)((char *)ifrp + n)) {
42	struct ifreq ifr;
43#if BSD >= 199006
44	n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
45	if (n < sizeof(*ifrp))
46	    n = sizeof(*ifrp);
47#else
48	n = sizeof(*ifrp);
49#endif
50	/*
51	 * Ignore any interface for an address family other than IP.
52	 */
53	if (ifrp->ifr_addr.sa_family != AF_INET)
54	    continue;
55
56	addr = ((struct sockaddr_in *)&ifrp->ifr_addr)->sin_addr.s_addr;
57
58	/*
59	 * Need a template to preserve address info that is
60	 * used below to locate the next entry.  (Otherwise,
61	 * SIOCGIFFLAGS stomps over it because the requests
62	 * are returned in a union.)
63	 */
64	bcopy(ifrp->ifr_name, ifr.ifr_name, sizeof(ifr.ifr_name));
65
66	/*
67	 * Ignore loopback interfaces and interfaces that do not support
68	 * multicast.
69	 */
70	if (ioctl(udp_socket, SIOCGIFFLAGS, (char *)&ifr) < 0)
71	    log(LOG_ERR, errno, "ioctl SIOCGIFFLAGS for %s", ifr.ifr_name);
72	flags = ifr.ifr_flags;
73	if ((flags & (IFF_LOOPBACK|IFF_MULTICAST)) != IFF_MULTICAST) continue;
74
75	/*
76	 * Ignore any interface whose address and mask do not define a
77	 * valid subnet number, or whose address is of the form {subnet,0}
78	 * or {subnet,-1}.
79	 */
80	if (ioctl(udp_socket, SIOCGIFNETMASK, (char *)&ifr) < 0)
81	    log(LOG_ERR, errno, "ioctl SIOCGIFNETMASK for %s", ifr.ifr_name);
82	mask = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr;
83	subnet = addr & mask;
84	if (!inet_valid_subnet(subnet, mask) ||
85	    addr == subnet ||
86	    addr == (subnet | ~mask)) {
87	    log(LOG_WARNING, 0,
88		"ignoring %s, has invalid address (%s) and/or mask (%s)",
89		ifr.ifr_name, inet_fmt(addr, s1), inet_fmt(mask, s2));
90	    continue;
91	}
92
93	/*
94	 * Ignore any interface that is connected to the same subnet as
95	 * one already installed in the uvifs array.
96	 */
97	for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
98	    if ((addr & v->uv_subnetmask) == v->uv_subnet ||
99		(v->uv_subnet & mask) == subnet) {
100		log(LOG_WARNING, 0, "ignoring %s, same subnet as %s",
101					ifr.ifr_name, v->uv_name);
102		break;
103	    }
104	}
105	if (vifi != numvifs) continue;
106
107	/*
108	 * If there is room in the uvifs array, install this interface.
109	 */
110	if (numvifs == MAXVIFS) {
111	    log(LOG_WARNING, 0, "too many vifs, ignoring %s", ifr.ifr_name);
112	    continue;
113	}
114	v  = &uvifs[numvifs];
115	v->uv_flags       = 0;
116	v->uv_metric      = DEFAULT_METRIC;
117	v->uv_rate_limit  = DEFAULT_PHY_RATE_LIMIT;
118	v->uv_threshold   = DEFAULT_THRESHOLD;
119	v->uv_lcl_addr    = addr;
120	v->uv_rmt_addr    = 0;
121	v->uv_subnet      = subnet;
122	v->uv_subnetmask  = mask;
123	v->uv_subnetbcast = subnet | ~mask;
124	strncpy(v->uv_name, ifr.ifr_name, IFNAMSIZ);
125	v->uv_groups      = NULL;
126	v->uv_neighbors   = NULL;
127	v->uv_acl         = NULL;
128	v->uv_addrs	  = NULL;
129
130	log(LOG_INFO,0,"installing %s (%s on subnet %s) as vif #%u - rate=%d",
131	    v->uv_name, inet_fmt(addr, s1), inet_fmts(subnet, mask, s2),
132	    numvifs, v->uv_rate_limit);
133
134	++numvifs;
135
136	/*
137	 * If the interface is not yet up, set the vifs_down flag to
138	 * remind us to check again later.
139	 */
140	if (!(flags & IFF_UP)) {
141	    v->uv_flags |= VIFF_DOWN;
142	    vifs_down = TRUE;
143	}
144    }
145}
146