af_nd6.c revision 222527 
1/*
2 * Copyright (c) 2009 Hiroki Sato.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26#ifndef lint
27static const char rcsid[] =
28  "$FreeBSD: head/sbin/ifconfig/af_nd6.c 222527 2011-05-31 14:40:21Z bz $";
29#endif /* not lint */
30
31#include <sys/param.h>
32#include <sys/ioctl.h>
33#include <sys/socket.h>
34#include <sys/sysctl.h>
35#include <net/if.h>
36#include <net/route.h>
37
38#include <err.h>
39#include <errno.h>
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43#include <unistd.h>
44#include <ifaddrs.h>
45
46#include <arpa/inet.h>
47
48#include <netinet/in.h>
49#include <net/if_var.h>
50#include <netinet/in_var.h>
51#include <arpa/inet.h>
52#include <netdb.h>
53
54#include <netinet6/nd6.h>
55
56#include "ifconfig.h"
57
58#define	MAX_SYSCTL_TRY	5
59#define	ND6BITS	"\020\001PERFORMNUD\002ACCEPT_RTADV\003PREFER_SOURCE" \
60		"\004IFDISABLED\005DONT_SET_IFROUTE\006AUTO_LINKLOCAL" \
61		"\020DEFAULTIF"
62
63static int isnd6defif(int);
64void setnd6flags(const char *, int, int, const struct afswtch *);
65void setnd6defif(const char *, int, int, const struct afswtch *);
66
67void
68setnd6flags(const char *dummyaddr __unused,
69	int d, int s,
70	const struct afswtch *afp)
71{
72	struct in6_ndireq nd;
73	int error;
74
75	memset(&nd, 0, sizeof(nd));
76	strncpy(nd.ifname, ifr.ifr_name, sizeof(nd.ifname));
77	error = ioctl(s, SIOCGIFINFO_IN6, &nd);
78	if (error) {
79		warn("ioctl(SIOCGIFINFO_IN6)");
80		return;
81	}
82	if (d < 0)
83		nd.ndi.flags &= ~(-d);
84	else
85		nd.ndi.flags |= d;
86	error = ioctl(s, SIOCSIFINFO_IN6, (caddr_t)&nd);
87	if (error)
88		warn("ioctl(SIOCSIFINFO_IN6)");
89}
90
91void
92setnd6defif(const char *dummyaddr __unused,
93	int d, int s,
94	const struct afswtch *afp)
95{
96	struct in6_ndifreq ndifreq;
97	int ifindex;
98	int error;
99
100	memset(&ndifreq, 0, sizeof(ndifreq));
101	strncpy(ndifreq.ifname, ifr.ifr_name, sizeof(ndifreq.ifname));
102
103	if (d < 0) {
104		if (isnd6defif(s)) {
105			/* ifindex = 0 means to remove default if */
106			ifindex = 0;
107		} else
108			return;
109	} else if ((ifindex = if_nametoindex(ndifreq.ifname)) == 0) {
110		warn("if_nametoindex(%s)", ndifreq.ifname);
111		return;
112	}
113
114	ndifreq.ifindex = ifindex;
115	error = ioctl(s, SIOCSDEFIFACE_IN6, (caddr_t)&ndifreq);
116	if (error)
117		warn("ioctl(SIOCSDEFIFACE_IN6)");
118}
119
120static int
121isnd6defif(int s)
122{
123	struct in6_ndifreq ndifreq;
124	unsigned int ifindex;
125	int error;
126
127	memset(&ndifreq, 0, sizeof(ndifreq));
128	strncpy(ndifreq.ifname, ifr.ifr_name, sizeof(ndifreq.ifname));
129
130	ifindex = if_nametoindex(ndifreq.ifname);
131	error = ioctl(s, SIOCGDEFIFACE_IN6, (caddr_t)&ndifreq);
132	if (error) {
133		warn("ioctl(SIOCGDEFIFACE_IN6)");
134		return (error);
135	}
136	return (ndifreq.ifindex == ifindex);
137}
138
139static void
140nd6_status(int s)
141{
142	struct in6_ndireq nd;
143	struct rt_msghdr *rtm;
144	size_t needed;
145	char *buf, *next;
146	int mib[6], ntry;
147	int s6;
148	int error;
149	int isinet6, isdefif;
150
151	/* Check if the interface has at least one IPv6 address. */
152	mib[0] = CTL_NET;
153	mib[1] = PF_ROUTE;
154	mib[2] = 0;
155	mib[3] = AF_INET6;
156	mib[4] = NET_RT_IFLIST;
157	mib[5] = if_nametoindex(ifr.ifr_name);
158
159	/* Try to prevent a race between two sysctls. */
160	ntry = 0;
161	do {
162		error = sysctl(mib, 6, NULL, &needed, NULL, 0);
163		if (error) {
164			warn("sysctl(NET_RT_IFLIST)/estimate");
165			return;
166		}
167		buf = malloc(needed);
168		if (buf == NULL) {
169			warn("malloc for sysctl(NET_RT_IFLIST) failed");
170			return;
171		}
172		if ((error = sysctl(mib, 6, buf, &needed, NULL, 0)) < 0) {
173			if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) {
174				warn("sysctl(NET_RT_IFLIST)/get");
175				free(buf);
176				return;
177			}
178			free(buf);
179			buf = NULL;
180		}
181	} while (buf == NULL);
182
183	isinet6 = 0;
184	for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
185		rtm = (struct rt_msghdr *)next;
186
187		if (rtm->rtm_version != RTM_VERSION)
188			continue;
189		if (rtm->rtm_type == RTM_NEWADDR) {
190			isinet6 = 1;
191			break;
192		}
193	}
194	free(buf);
195	if (!isinet6)
196		return;
197
198	memset(&nd, 0, sizeof(nd));
199	strncpy(nd.ifname, ifr.ifr_name, sizeof(nd.ifname));
200	if ((s6 = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
201		warn("socket(AF_INET6, SOCK_DGRAM)");
202		return;
203	}
204	error = ioctl(s6, SIOCGIFINFO_IN6, &nd);
205	if (error) {
206		warn("ioctl(SIOCGIFINFO_IN6)");
207		close(s6);
208		return;
209	}
210	isdefif = isnd6defif(s6);
211	close(s6);
212	if (nd.ndi.flags == 0 && !isdefif)
213		return;
214	printb("\tnd6 options",
215	    (unsigned int)(nd.ndi.flags | (isdefif << 15)), ND6BITS);
216	putchar('\n');
217}
218
219static struct afswtch af_nd6 = {
220	.af_name	= "nd6",
221	.af_af		= AF_LOCAL,
222	.af_other_status= nd6_status,
223};
224
225static __constructor void
226nd6_ctor(void)
227{
228
229	if (!feature_present("inet6"))
230		return;
231
232	af_register(&af_nd6);
233}
234