1/*	$KAME: getifaddrs.c,v 1.9 2001/08/20 02:31:20 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/*
28 * NOTE: SIOCGIFCONF case is not LP64 friendly.  it also does not perform
29 * try-and-error for region size.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD$");
34
35#include "namespace.h"
36#include <sys/types.h>
37#include <sys/ioctl.h>
38#include <sys/socket.h>
39#include <net/if.h>
40#ifdef	NET_RT_IFLIST
41#include <sys/param.h>
42#include <net/route.h>
43#include <sys/sysctl.h>
44#include <net/if_dl.h>
45#endif
46
47#include <errno.h>
48#include <ifaddrs.h>
49#include <stdlib.h>
50#include <string.h>
51#include "un-namespace.h"
52
53#if !defined(AF_LINK)
54#define	SA_LEN(sa)	sizeof(struct sockaddr)
55#endif
56
57#if !defined(SA_LEN)
58#define	SA_LEN(sa)	(sa)->sa_len
59#endif
60
61#define	SALIGN	(sizeof(long) - 1)
62#define	SA_RLEN(sa)	((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1))
63
64#ifndef	ALIGNBYTES
65/*
66 * On systems with a routing socket, ALIGNBYTES should match the value
67 * that the kernel uses when building the messages.
68 */
69#define	ALIGNBYTES	XXX
70#endif
71#ifndef	ALIGN
72#define	ALIGN(p)	(((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES)
73#endif
74
75#if	_BSDI_VERSION >= 199701
76#define	HAVE_IFM_DATA
77#endif
78
79#if	_BSDI_VERSION >= 199802
80/* ifam_data is very specific to recent versions of bsdi */
81#define	HAVE_IFAM_DATA
82#endif
83
84#if defined(__NetBSD__) || defined(__OpenBSD__) || defined(__FreeBSD__)
85#define	HAVE_IFM_DATA
86#endif
87
88#define MAX_SYSCTL_TRY 5
89
90int
91getifaddrs(struct ifaddrs **pif)
92{
93	int icnt = 1;
94	int dcnt = 0;
95	int ncnt = 0;
96#ifdef	NET_RT_IFLIST
97	int ntry = 0;
98	int mib[6];
99	size_t needed;
100	char *buf;
101	char *next;
102	struct ifaddrs *cif = 0;
103	char *p, *p0;
104	struct rt_msghdr *rtm;
105	struct if_msghdr *ifm;
106	struct ifa_msghdr *ifam;
107	struct sockaddr_dl *dl;
108	struct sockaddr *sa;
109	struct ifaddrs *ifa, *ift;
110	u_short idx = 0;
111#else	/* NET_RT_IFLIST */
112	char buf[1024];
113	int m, sock;
114	struct ifconf ifc;
115	struct ifreq *ifr;
116	struct ifreq *lifr;
117#endif	/* NET_RT_IFLIST */
118	int i;
119	size_t len, alen;
120	char *data;
121	char *names;
122
123#ifdef	NET_RT_IFLIST
124	mib[0] = CTL_NET;
125	mib[1] = PF_ROUTE;
126	mib[2] = 0;             /* protocol */
127	mib[3] = 0;             /* wildcard address family */
128	mib[4] = NET_RT_IFLIST;
129	mib[5] = 0;             /* no flags */
130	do {
131		/*
132		 * We'll try to get addresses several times in case that
133		 * the number of addresses is unexpectedly increased during
134		 * the two sysctl calls.  This should rarely happen, but we'll
135		 * try to do our best for applications that assume success of
136		 * this library (which should usually be the case).
137		 * Portability note: since FreeBSD does not add margin of
138		 * memory at the first sysctl, the possibility of failure on
139		 * the second sysctl call is a bit higher.
140		 */
141
142		if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
143			return (-1);
144		if ((buf = malloc(needed)) == NULL)
145			return (-1);
146		if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
147			if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) {
148				free(buf);
149				return (-1);
150			}
151			free(buf);
152			buf = NULL;
153		}
154	} while (buf == NULL);
155
156	for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
157		rtm = (struct rt_msghdr *)(void *)next;
158		if (rtm->rtm_version != RTM_VERSION)
159			continue;
160		switch (rtm->rtm_type) {
161		case RTM_IFINFO:
162			ifm = (struct if_msghdr *)(void *)rtm;
163			if (ifm->ifm_addrs & RTA_IFP) {
164				idx = ifm->ifm_index;
165				++icnt;
166				dl = (struct sockaddr_dl *)(void *)(ifm + 1);
167				dcnt += SA_RLEN((struct sockaddr *)(void*)dl) +
168				    ALIGNBYTES;
169#ifdef	HAVE_IFM_DATA
170				dcnt += sizeof(ifm->ifm_data);
171#endif	/* HAVE_IFM_DATA */
172				ncnt += dl->sdl_nlen + 1;
173			} else
174				idx = 0;
175			break;
176
177		case RTM_NEWADDR:
178			ifam = (struct ifa_msghdr *)(void *)rtm;
179			if (idx && ifam->ifam_index != idx)
180				abort();	/* this cannot happen */
181
182#define	RTA_MASKS	(RTA_NETMASK | RTA_IFA | RTA_BRD)
183			if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
184				break;
185			p = (char *)(void *)(ifam + 1);
186			++icnt;
187#ifdef	HAVE_IFAM_DATA
188			dcnt += sizeof(ifam->ifam_data) + ALIGNBYTES;
189#endif	/* HAVE_IFAM_DATA */
190			/* Scan to look for length of address */
191			alen = 0;
192			for (p0 = p, i = 0; i < RTAX_MAX; i++) {
193				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
194				    == 0)
195					continue;
196				sa = (struct sockaddr *)(void *)p;
197				len = SA_RLEN(sa);
198				if (i == RTAX_IFA) {
199					alen = len;
200					break;
201				}
202				p += len;
203			}
204			for (p = p0, i = 0; i < RTAX_MAX; i++) {
205				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
206				    == 0)
207					continue;
208				sa = (struct sockaddr *)(void *)p;
209				len = SA_RLEN(sa);
210				if (i == RTAX_NETMASK && SA_LEN(sa) == 0)
211					dcnt += alen;
212				else
213					dcnt += len;
214				p += len;
215			}
216			break;
217		}
218	}
219#else	/* NET_RT_IFLIST */
220	ifc.ifc_buf = buf;
221	ifc.ifc_len = sizeof(buf);
222
223	if ((sock = _socket(AF_INET, SOCK_STREAM, 0)) < 0)
224		return (-1);
225	i =  _ioctl(sock, SIOCGIFCONF, (char *)&ifc);
226	_close(sock);
227	if (i < 0)
228		return (-1);
229
230	ifr = ifc.ifc_req;
231	lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len];
232
233	while (ifr < lifr) {
234		struct sockaddr *sa;
235
236		sa = &ifr->ifr_addr;
237		++icnt;
238		dcnt += SA_RLEN(sa);
239		ncnt += sizeof(ifr->ifr_name) + 1;
240
241		if (SA_LEN(sa) < sizeof(*sa))
242			ifr = (struct ifreq *)(((char *)sa) + sizeof(*sa));
243		else
244			ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa));
245	}
246#endif	/* NET_RT_IFLIST */
247
248	if (icnt + dcnt + ncnt == 1) {
249		*pif = NULL;
250		free(buf);
251		return (0);
252	}
253	data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt);
254	if (data == NULL) {
255		free(buf);
256		return(-1);
257	}
258
259	ifa = (struct ifaddrs *)(void *)data;
260	data += sizeof(struct ifaddrs) * icnt;
261	names = data + dcnt;
262
263	memset(ifa, 0, sizeof(struct ifaddrs) * icnt);
264	ift = ifa;
265
266#ifdef	NET_RT_IFLIST
267	idx = 0;
268	for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
269		rtm = (struct rt_msghdr *)(void *)next;
270		if (rtm->rtm_version != RTM_VERSION)
271			continue;
272		switch (rtm->rtm_type) {
273		case RTM_IFINFO:
274			ifm = (struct if_msghdr *)(void *)rtm;
275			if (ifm->ifm_addrs & RTA_IFP) {
276				idx = ifm->ifm_index;
277				dl = (struct sockaddr_dl *)(void *)(ifm + 1);
278
279				cif = ift;
280				ift->ifa_name = names;
281				ift->ifa_flags = (int)ifm->ifm_flags;
282				memcpy(names, dl->sdl_data,
283				    (size_t)dl->sdl_nlen);
284				names[dl->sdl_nlen] = 0;
285				names += dl->sdl_nlen + 1;
286
287				ift->ifa_addr = (struct sockaddr *)(void *)data;
288				memcpy(data, dl,
289				    (size_t)SA_LEN((struct sockaddr *)
290				    (void *)dl));
291				data += SA_RLEN((struct sockaddr *)(void *)dl);
292
293#ifdef	HAVE_IFM_DATA
294				/* ifm_data needs to be aligned */
295				ift->ifa_data = data = (void *)ALIGN(data);
296				memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data));
297 				data += sizeof(ifm->ifm_data);
298#else	/* HAVE_IFM_DATA */
299				ift->ifa_data = NULL;
300#endif	/* HAVE_IFM_DATA */
301
302				ift = (ift->ifa_next = ift + 1);
303			} else
304				idx = 0;
305			break;
306
307		case RTM_NEWADDR:
308			ifam = (struct ifa_msghdr *)(void *)rtm;
309			if (idx && ifam->ifam_index != idx)
310				abort();	/* this cannot happen */
311
312			if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
313				break;
314			ift->ifa_name = cif->ifa_name;
315			ift->ifa_flags = cif->ifa_flags;
316			ift->ifa_data = NULL;
317			p = (char *)(void *)(ifam + 1);
318			/* Scan to look for length of address */
319			alen = 0;
320			for (p0 = p, i = 0; i < RTAX_MAX; i++) {
321				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
322				    == 0)
323					continue;
324				sa = (struct sockaddr *)(void *)p;
325				len = SA_RLEN(sa);
326				if (i == RTAX_IFA) {
327					alen = len;
328					break;
329				}
330				p += len;
331			}
332			for (p = p0, i = 0; i < RTAX_MAX; i++) {
333				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
334				    == 0)
335					continue;
336				sa = (struct sockaddr *)(void *)p;
337				len = SA_RLEN(sa);
338				switch (i) {
339				case RTAX_IFA:
340					ift->ifa_addr =
341					    (struct sockaddr *)(void *)data;
342					memcpy(data, p, len);
343					data += len;
344					break;
345
346				case RTAX_NETMASK:
347					ift->ifa_netmask =
348					    (struct sockaddr *)(void *)data;
349					if (SA_LEN(sa) == 0) {
350						memset(data, 0, alen);
351						data += alen;
352						break;
353					}
354					memcpy(data, p, len);
355					data += len;
356					break;
357
358				case RTAX_BRD:
359					ift->ifa_broadaddr =
360					    (struct sockaddr *)(void *)data;
361					memcpy(data, p, len);
362					data += len;
363					break;
364				}
365				p += len;
366			}
367
368#ifdef	HAVE_IFAM_DATA
369			/* ifam_data needs to be aligned */
370			ift->ifa_data = data = (void *)ALIGN(data);
371			memcpy(data, &ifam->ifam_data, sizeof(ifam->ifam_data));
372			data += sizeof(ifam->ifam_data);
373#endif	/* HAVE_IFAM_DATA */
374
375			ift = (ift->ifa_next = ift + 1);
376			break;
377		}
378	}
379
380	free(buf);
381#else	/* NET_RT_IFLIST */
382	ifr = ifc.ifc_req;
383	lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len];
384
385	while (ifr < lifr) {
386		struct sockaddr *sa;
387
388		ift->ifa_name = names;
389		names[sizeof(ifr->ifr_name)] = 0;
390		strncpy(names, ifr->ifr_name, sizeof(ifr->ifr_name));
391		while (*names++)
392			;
393
394		ift->ifa_addr = (struct sockaddr *)data;
395		sa = &ifr->ifr_addr;
396		memcpy(data, sa, SA_LEN(sa));
397		data += SA_RLEN(sa);
398
399		ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa));
400		ift = (ift->ifa_next = ift + 1);
401	}
402#endif	/* NET_RT_IFLIST */
403	if (--ift >= ifa) {
404		ift->ifa_next = NULL;
405		*pif = ifa;
406	} else {
407		*pif = NULL;
408		free(ifa);
409	}
410	return (0);
411}
412
413void
414freeifaddrs(struct ifaddrs *ifp)
415{
416
417	free(ifp);
418}
419