1/*	$NetBSD: getifaddrs.c,v 1.13 2010/11/05 16:23:56 pooka Exp $	*/
2
3/*
4 * Copyright (c) 1995, 1999
5 *	Berkeley Software Design, Inc.  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 *
13 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``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 Berkeley Software Design, Inc. 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 *	BSDI getifaddrs.c,v 2.12 2000/02/23 14:51:59 dab Exp
26 */
27
28#include <sys/cdefs.h>
29#if defined(LIBC_SCCS) && !defined(lint)
30__RCSID("$NetBSD: getifaddrs.c,v 1.13 2010/11/05 16:23:56 pooka Exp $");
31#endif /* LIBC_SCCS and not lint */
32
33#ifndef RUMP_ACTION
34#include "namespace.h"
35#endif
36#include <sys/types.h>
37#include <sys/ioctl.h>
38#include <sys/socket.h>
39#include <net/if.h>
40#include <sys/param.h>
41#include <net/route.h>
42#include <sys/sysctl.h>
43#include <net/if_dl.h>
44
45#include <assert.h>
46#include <errno.h>
47#include <ifaddrs.h>
48#include <stdlib.h>
49#include <string.h>
50
51#if defined(__weak_alias) && !defined(RUMP_ACTION)
52__weak_alias(getifaddrs,_getifaddrs)
53__weak_alias(freeifaddrs,_freeifaddrs)
54#endif
55
56#ifdef RUMP_ACTION
57#include <rump/rump_syscalls.h>
58#define sysctl(a,b,c,d,e,f) rump_sys___sysctl(a,b,c,d,e,f)
59#endif
60
61#define	SA_RLEN(sa)	RT_ROUNDUP((sa)->sa_len)
62
63int
64getifaddrs(struct ifaddrs **pif)
65{
66	int icnt = 1;
67	int dcnt = 0;
68	int ncnt = 0;
69	int mib[6];
70	size_t needed;
71	char *buf;
72	char *next;
73	struct ifaddrs cif;
74	char *p, *p0;
75	struct rt_msghdr *rtm;
76	struct if_msghdr *ifm;
77	struct ifa_msghdr *ifam;
78	struct sockaddr *sa;
79	struct ifaddrs *ifa, *ift;
80	u_short idx = 0;
81	int i;
82	size_t len, alen;
83	char *data;
84	char *names;
85
86	_DIAGASSERT(pif != NULL);
87
88	mib[0] = CTL_NET;
89	mib[1] = PF_ROUTE;
90	mib[2] = 0;             /* protocol */
91	mib[3] = 0;             /* wildcard address family */
92	mib[4] = NET_RT_IFLIST;
93	mib[5] = 0;             /* no flags */
94	if (sysctl(mib, __arraycount(mib), NULL, &needed, NULL, 0) < 0)
95		return (-1);
96	if ((buf = malloc(needed)) == NULL)
97		return (-1);
98	if (sysctl(mib, __arraycount(mib), buf, &needed, NULL, 0) < 0) {
99		free(buf);
100		return (-1);
101	}
102
103	for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
104		rtm = (struct rt_msghdr *)(void *)next;
105		if (rtm->rtm_version != RTM_VERSION)
106			continue;
107		switch (rtm->rtm_type) {
108		case RTM_IFINFO:
109			ifm = (struct if_msghdr *)(void *)rtm;
110			if (ifm->ifm_addrs & RTA_IFP) {
111				const struct sockaddr_dl *dl;
112
113				idx = ifm->ifm_index;
114				++icnt;
115				dl = (struct sockaddr_dl *)(void *)(ifm + 1);
116				dcnt += SA_RLEN((const struct sockaddr *)(const void *)dl) +
117				    ALIGNBYTES;
118				dcnt += sizeof(ifm->ifm_data);
119				ncnt += dl->sdl_nlen + 1;
120			} else
121				idx = 0;
122			break;
123
124		case RTM_NEWADDR:
125			ifam = (struct ifa_msghdr *)(void *)rtm;
126			if (idx && ifam->ifam_index != idx)
127				abort();	/* this cannot happen */
128
129#define	RTA_MASKS	(RTA_NETMASK | RTA_IFA | RTA_BRD)
130			if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
131				break;
132			p = (char *)(void *)(ifam + 1);
133			++icnt;
134			/* Scan to look for length of address */
135			alen = 0;
136			for (p0 = p, i = 0; i < RTAX_MAX; i++) {
137				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
138				    == 0)
139					continue;
140				sa = (struct sockaddr *)(void *)p;
141				len = SA_RLEN(sa);
142				if (i == RTAX_IFA) {
143					alen = len;
144					break;
145				}
146				p += len;
147			}
148			for (p = p0, i = 0; i < RTAX_MAX; i++) {
149				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
150				    == 0)
151					continue;
152				sa = (struct sockaddr *)(void *)p;
153				len = SA_RLEN(sa);
154				if (i == RTAX_NETMASK && sa->sa_len == 0)
155					dcnt += alen;
156				else
157					dcnt += len;
158				p += len;
159			}
160			break;
161		}
162	}
163
164	if (icnt + dcnt + ncnt == 1) {
165		*pif = NULL;
166		free(buf);
167		return (0);
168	}
169	data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt);
170	if (data == NULL) {
171		free(buf);
172		return(-1);
173	}
174
175	ifa = (struct ifaddrs *)(void *)data;
176	data += sizeof(struct ifaddrs) * icnt;
177	names = data + dcnt;
178
179	memset(ifa, 0, sizeof(struct ifaddrs) * icnt);
180	ift = ifa;
181
182	idx = 0;
183	for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
184		rtm = (struct rt_msghdr *)(void *)next;
185		if (rtm->rtm_version != RTM_VERSION)
186			continue;
187		switch (rtm->rtm_type) {
188		case RTM_IFINFO:
189			ifm = (struct if_msghdr *)(void *)rtm;
190			if (ifm->ifm_addrs & RTA_IFP) {
191				const struct sockaddr_dl *dl;
192
193				idx = ifm->ifm_index;
194				dl = (struct sockaddr_dl *)(void *)(ifm + 1);
195
196				memset(&cif, 0, sizeof(cif));
197
198				cif.ifa_name = names;
199				cif.ifa_flags = (int)ifm->ifm_flags;
200				memcpy(names, dl->sdl_data,
201				    (size_t)dl->sdl_nlen);
202				names[dl->sdl_nlen] = 0;
203				names += dl->sdl_nlen + 1;
204
205				cif.ifa_addr = (struct sockaddr *)(void *)data;
206				memcpy(data, dl, (size_t)dl->sdl_len);
207				data += SA_RLEN((const struct sockaddr *)(const void *)dl);
208
209				/* ifm_data needs to be aligned */
210				cif.ifa_data = data = (void *)ALIGN(data);
211				memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data));
212 				data += sizeof(ifm->ifm_data);
213			} else
214				idx = 0;
215			break;
216
217		case RTM_NEWADDR:
218			ifam = (struct ifa_msghdr *)(void *)rtm;
219			if (idx && ifam->ifam_index != idx)
220				abort();	/* this cannot happen */
221
222			if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
223				break;
224			ift->ifa_name = cif.ifa_name;
225			ift->ifa_flags = cif.ifa_flags;
226			ift->ifa_data = NULL;
227			p = (char *)(void *)(ifam + 1);
228			/* Scan to look for length of address */
229			alen = 0;
230			for (p0 = p, i = 0; i < RTAX_MAX; i++) {
231				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
232				    == 0)
233					continue;
234				sa = (struct sockaddr *)(void *)p;
235				len = SA_RLEN(sa);
236				if (i == RTAX_IFA) {
237					alen = len;
238					break;
239				}
240				p += len;
241			}
242			for (p = p0, i = 0; i < RTAX_MAX; i++) {
243				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
244				    == 0)
245					continue;
246				sa = (struct sockaddr *)(void *)p;
247				len = SA_RLEN(sa);
248				switch (i) {
249				case RTAX_IFA:
250					ift->ifa_addr =
251					    (struct sockaddr *)(void *)data;
252					memcpy(data, p, len);
253					data += len;
254					if (ift->ifa_addr->sa_family == AF_LINK)
255						ift->ifa_data = cif.ifa_data;
256					break;
257
258				case RTAX_NETMASK:
259					ift->ifa_netmask =
260					    (struct sockaddr *)(void *)data;
261					if (sa->sa_len == 0) {
262						memset(data, 0, alen);
263						data += alen;
264						break;
265					}
266					memcpy(data, p, len);
267					data += len;
268					break;
269
270				case RTAX_BRD:
271					ift->ifa_broadaddr =
272					    (struct sockaddr *)(void *)data;
273					memcpy(data, p, len);
274					data += len;
275					break;
276				}
277				p += len;
278			}
279
280
281			ift = (ift->ifa_next = ift + 1);
282			break;
283		}
284	}
285
286	free(buf);
287	if (--ift >= ifa) {
288		ift->ifa_next = NULL;
289		*pif = ifa;
290	} else {
291		*pif = NULL;
292		free(ifa);
293	}
294	return (0);
295}
296
297void
298freeifaddrs(struct ifaddrs *ifp)
299{
300
301	_DIAGASSERT(ifp != NULL);
302
303	free(ifp);
304}
305