getifaddrs.c revision 1.3 
1/*	$NetBSD: getifaddrs.c,v 1.3 2000/04/24 09:27:31 itojun 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#include "namespace.h"
28#include <sys/types.h>
29#include <sys/ioctl.h>
30#include <sys/socket.h>
31#include <net/if.h>
32#ifdef	NET_RT_IFLIST
33#include <sys/param.h>
34#include <net/route.h>
35#include <sys/sysctl.h>
36#include <net/if_dl.h>
37#endif
38
39#include <errno.h>
40#include <ifaddrs.h>
41#include <stdlib.h>
42#include <string.h>
43
44#ifdef __weak_alias
45__weak_alias(getifaddrs,_getifaddrs)
46__weak_alias(freeifaddrs,_freeifaddrs)
47#endif
48
49#if !defined(AF_LINK)
50#define	SA_LEN(sa)	sizeof(struct sockaddr)
51#endif
52
53#if !defined(SA_LEN)
54#define	SA_LEN(sa)	(sa)->sa_len
55#endif
56
57#define	SALIGN	(sizeof(long) - 1)
58#define	SA_RLEN(sa)	((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1))
59
60#ifndef	ALIGNBYTES
61/*
62 * On systems with a routing socket, ALIGNBYTES should match the value
63 * that the kernel uses when building the messages.
64 */
65#define	ALIGNBYTES	XXX
66#endif
67#ifndef	ALIGN
68#define	ALIGN(p)	(((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES)
69#endif
70
71#if	_BSDI_VERSION >= 199701
72#define	HAVE_IFM_DATA
73#endif
74
75#if	_BSDI_VERSION >= 199802
76#define	HAVE_IFAM_DATA
77#endif
78
79int
80getifaddrs(struct ifaddrs **pif)
81{
82	int icnt = 1;
83	int dcnt = 0;
84	int ncnt = 0;
85#ifdef	NET_RT_IFLIST
86	int mib[6];
87	size_t needed;
88	char *buf;
89	char *next;
90	struct ifaddrs *cif = 0;
91	char *p, *p0;
92	struct rt_msghdr *rtm;
93	struct if_msghdr *ifm;
94	struct ifa_msghdr *ifam;
95	struct sockaddr_dl *dl;
96	struct sockaddr *sa;
97	struct ifaddrs *ifa, *ift;
98	u_short index = 0;
99#else	/* NET_RT_IFLIST */
100	char buf[1024];
101	int m, sock;
102	struct ifconf ifc;
103	struct ifreq *ifr;
104	struct ifreq *lifr;
105#endif	/* NET_RT_IFLIST */
106	int i;
107	size_t len, alen;
108	char *data;
109	char *names;
110
111#ifdef	NET_RT_IFLIST
112	mib[0] = CTL_NET;
113	mib[1] = PF_ROUTE;
114	mib[2] = 0;             /* protocol */
115	mib[3] = 0;             /* wildcard address family */
116	mib[4] = NET_RT_IFLIST;
117	mib[5] = 0;             /* no flags */
118	if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
119		return (-1);
120	if ((buf = malloc(needed)) == NULL)
121		return (-1);
122	if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
123		free(buf);
124		return (-1);
125	}
126
127	for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
128		rtm = (struct rt_msghdr *)next;
129		if (rtm->rtm_version != RTM_VERSION)
130			continue;
131		switch (rtm->rtm_type) {
132		case RTM_IFINFO:
133			ifm = (struct if_msghdr *)rtm;
134			if (ifm->ifm_addrs & RTA_IFP) {
135				index = ifm->ifm_index;
136				++icnt;
137				dl = (struct sockaddr_dl *)(ifm + 1);
138				dcnt += SA_RLEN((struct sockaddr *)dl) +
139					ALIGNBYTES;
140#ifdef	HAVE_IFM_DATA
141				dcnt += sizeof(ifm->ifm_data);
142#endif	/* HAVE_IFM_DATA */
143				ncnt += dl->sdl_nlen + 1;
144			} else
145				index = 0;
146			break;
147
148		case RTM_NEWADDR:
149			ifam = (struct ifa_msghdr *)rtm;
150			if (index && ifam->ifam_index != index)
151				abort();	/* this cannot happen */
152
153#define	RTA_MASKS	(RTA_NETMASK | RTA_IFA | RTA_BRD)
154			if (index == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
155				break;
156			p = (char *)(ifam + 1);
157			++icnt;
158#ifdef	HAVE_IFAM_DATA
159			dcnt += sizeof(ifam->ifam_data) + ALIGNBYTES;
160#endif	/* HAVE_IFAM_DATA */
161			/* Scan to look for length of address */
162			alen = 0;
163			for (p0 = p, i = 0; i < RTAX_MAX; i++) {
164				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
165				    == 0)
166					continue;
167				sa = (struct sockaddr *)p;
168				len = SA_RLEN(sa);
169				if (i == RTAX_IFA) {
170					alen = len;
171					break;
172				}
173				p += len;
174			}
175			for (p = p0, i = 0; i < RTAX_MAX; i++) {
176				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
177				    == 0)
178					continue;
179				sa = (struct sockaddr *)p;
180				len = SA_RLEN(sa);
181				if (i == RTAX_NETMASK && SA_LEN(sa) == 0)
182					dcnt += alen;
183				else
184					dcnt += len;
185				p += len;
186			}
187			break;
188		}
189	}
190#else	/* NET_RT_IFLIST */
191	ifc.ifc_buf = buf;
192	ifc.ifc_len = sizeof(buf);
193
194	if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
195		return (-1);
196	i =  ioctl(sock, SIOCGIFCONF, (char *)&ifc);
197	close(sock);
198	if (i < 0)
199		return (-1);
200
201	ifr = ifc.ifc_req;
202	lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len];
203
204	while (ifr < lifr) {
205		struct sockaddr *sa;
206
207		sa = &ifr->ifr_addr;
208		++icnt;
209		dcnt += SA_RLEN(sa);
210		ncnt += sizeof(ifr->ifr_name) + 1;
211
212		ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa));
213	}
214#endif	/* NET_RT_IFLIST */
215
216	if (icnt + dcnt + ncnt == 1) {
217		*pif = NULL;
218		free(buf);
219		return (0);
220	}
221	data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt);
222	if (data == NULL) {
223		free(buf);
224		return(-1);
225	}
226
227	ifa = (struct ifaddrs *)data;
228	data += sizeof(struct ifaddrs) * icnt;
229	names = data + dcnt;
230
231	memset(ifa, 0, sizeof(struct ifaddrs) * icnt);
232	ift = ifa;
233
234#ifdef	NET_RT_IFLIST
235	index = 0;
236	for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
237		rtm = (struct rt_msghdr *)next;
238		if (rtm->rtm_version != RTM_VERSION)
239			continue;
240		switch (rtm->rtm_type) {
241		case RTM_IFINFO:
242			ifm = (struct if_msghdr *)rtm;
243			if (ifm->ifm_addrs & RTA_IFP) {
244				index = ifm->ifm_index;
245				dl = (struct sockaddr_dl *)(ifm + 1);
246
247				cif = ift;
248				ift->ifa_name = names;
249				ift->ifa_flags = (int)ifm->ifm_flags;
250				memcpy(names, dl->sdl_data, dl->sdl_nlen);
251				names[dl->sdl_nlen] = 0;
252				names += dl->sdl_nlen + 1;
253
254				ift->ifa_addr = (struct sockaddr *)data;
255				memcpy(data, dl, SA_LEN((struct sockaddr *)dl));
256				data += SA_RLEN((struct sockaddr *)dl);
257
258#ifdef	HAVE_IFM_DATA
259				/* ifm_data needs to be aligned */
260				ift->ifa_data = data = (void *)ALIGN(data);
261				memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data));
262 				data += sizeof(ifm->ifm_data);
263#else	/* HAVE_IFM_DATA */
264				ift->ifa_data = NULL;
265#endif	/* HAVE_IFM_DATA */
266
267				ift = (ift->ifa_next = ift + 1);
268			} else
269				index = 0;
270			break;
271
272		case RTM_NEWADDR:
273			ifam = (struct ifa_msghdr *)rtm;
274			if (index && ifam->ifam_index != index)
275				abort();	/* this cannot happen */
276
277			if (index == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
278				break;
279			ift->ifa_name = cif->ifa_name;
280			ift->ifa_flags = cif->ifa_flags;
281			ift->ifa_data = NULL;
282			p = (char *)(ifam + 1);
283			/* Scan to look for length of address */
284			alen = 0;
285			for (p0 = p, i = 0; i < RTAX_MAX; i++) {
286				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
287				    == 0)
288					continue;
289				sa = (struct sockaddr *)p;
290				len = SA_RLEN(sa);
291				if (i == RTAX_IFA) {
292					alen = len;
293					break;
294				}
295				p += len;
296			}
297			for (p = p0, i = 0; i < RTAX_MAX; i++) {
298				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
299				    == 0)
300					continue;
301				sa = (struct sockaddr *)p;
302				len = SA_RLEN(sa);
303				switch (i) {
304				case RTAX_IFA:
305					ift->ifa_addr = (struct sockaddr *)data;
306					memcpy(data, p, len);
307					data += len;
308					break;
309
310				case RTAX_NETMASK:
311					ift->ifa_netmask =
312					    (struct sockaddr *)data;
313					if (SA_LEN(sa) == 0) {
314						memset(data, 0, alen);
315						data += alen;
316						break;
317					}
318					memcpy(data, p, len);
319					data += len;
320					break;
321
322				case RTAX_BRD:
323					ift->ifa_broadaddr =
324					    (struct sockaddr *)data;
325					memcpy(data, p, len);
326					data += len;
327					break;
328				}
329				p += len;
330			}
331
332#ifdef	HAVE_IFAM_DATA
333			/* ifam_data needs to be aligned */
334			ift->ifa_data = data = (void *)ALIGN(data);
335			memcpy(data, &ifam->ifam_data, sizeof(ifam->ifam_data));
336			data += sizeof(ifam->ifam_data);
337#endif	/* HAVE_IFAM_DATA */
338
339			ift = (ift->ifa_next = ift + 1);
340			break;
341		}
342	}
343
344	free(buf);
345#else	/* NET_RT_IFLIST */
346	ifr = ifc.ifc_req;
347	lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len];
348
349	while (ifr < lifr) {
350		struct sockaddr *sa;
351
352		ift->ifa_name = names;
353		names[sizeof(ifr->ifr_name)] = 0;
354		strncpy(names, ifr->ifr_name, sizeof(ifr->ifr_name));
355		while (*names++)
356			;
357
358		ift->ifa_addr = (struct sockaddr *)data;
359		sa = &ifr->ifr_addr;
360		memcpy(data, sa, SA_LEN(sa));
361		data += SA_RLEN(sa);
362
363		ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa));
364		ift = (ift->ifa_next = ift + 1);
365	}
366#endif	/* NET_RT_IFLIST */
367	if (--ift >= ifa) {
368		ift->ifa_next = NULL;
369		*pif = ifa;
370	} else {
371		*pif = NULL;
372		free(ifa);
373	}
374	return (0);
375}
376
377void
378freeifaddrs(struct ifaddrs *ifp)
379{
380	free(ifp);
381}
382