1 /* $FreeBSD: src/lib/libc/net/getifaddrs.c,v 1.6 2002/07/25 08:08:30 ume Exp $ */
2 /* $KAME: getifaddrs.c,v 1.9 2001/08/20 02:31:20 itojun Exp $ */
5 * Copyright (c) 1995, 1999
6 * Berkeley Software Design, Inc. All rights reserved.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
14 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * BSDI getifaddrs.c,v 2.12 2000/02/23 14:51:59 dab Exp
29 * NOTE: SIOCGIFCONF case is not LP64 friendly. it also does not perform
30 * try-and-error for region size.
32 #include "namespace.h"
33 #include <sys/types.h>
34 #include <sys/ioctl.h>
35 #include <sys/socket.h>
37 #include <sys/param.h>
38 #include <net/route.h>
39 #include <sys/sysctl.h>
40 #include <net/if_dl.h>
46 #include "un-namespace.h"
49 #define SA_LEN(sa) sizeof(struct sockaddr)
53 #define SA_LEN(sa) (sa)->sa_len
56 #define SA_RLEN(sa) RT_ROUNDUP((sa)->sa_len)
60 * On systems with a routing socket, ALIGNBYTES should match the value
61 * that the kernel uses when building the messages.
63 #define ALIGNBYTES XXX
66 #define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES)
69 #define MAX_SYSCTL_TRY 5
72 getifaddrs(struct ifaddrs **pif)
82 struct ifaddrs *cif = NULL;
84 struct rt_msghdr *rtm;
85 struct if_msghdr *ifm;
86 struct ifa_msghdr *ifam;
87 struct sockaddr_dl *dl;
89 struct ifaddrs *ifa, *ift;
98 mib[2] = 0; /* protocol */
99 mib[3] = 0; /* wildcard address family */
100 mib[4] = NET_RT_IFLIST;
101 mib[5] = 0; /* no flags */
104 * We'll try to get addresses several times in case that
105 * the number of addresses is unexpectedly increased during
106 * the two sysctl calls. This should rarely happen, but we'll
107 * try to do our best for applications that assume success of
108 * this library (which should usually be the case).
109 * Portability note: since FreeBSD does not add margin of
110 * memory at the first sysctl, the possibility of failure on
111 * the second sysctl call is a bit higher.
114 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
116 if ((buf = malloc(needed)) == NULL)
118 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
119 if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) {
126 } while (buf == NULL);
128 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
129 rtm = (struct rt_msghdr *)(void *)next;
130 if (rtm->rtm_version != RTM_VERSION)
132 switch (rtm->rtm_type) {
134 ifm = (struct if_msghdr *)(void *)rtm;
135 if (ifm->ifm_addrs & RTA_IFP) {
136 idx = ifm->ifm_index;
138 dl = (struct sockaddr_dl *)(void *)(ifm + 1);
139 dcnt += SA_RLEN((struct sockaddr *)(void*)dl) +
141 dcnt += sizeof(ifm->ifm_data);
142 ncnt += dl->sdl_nlen + 1;
148 ifam = (struct ifa_msghdr *)(void *)rtm;
149 if (idx && ifam->ifam_index != idx)
150 abort(); /* this cannot happen */
152 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD)
153 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
155 p = (char *)(void *)(ifam + 1);
157 /* Scan to look for length of address */
159 for (p0 = p, i = 0; i < RTAX_MAX; i++) {
160 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
163 sa = (struct sockaddr *)(void *)p;
171 for (p = p0, i = 0; i < RTAX_MAX; i++) {
172 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
175 sa = (struct sockaddr *)(void *)p;
177 if (i == RTAX_NETMASK && SA_LEN(sa) == 0)
187 if (icnt + dcnt + ncnt == 1) {
192 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt);
198 ifa = (struct ifaddrs *)(void *)data;
199 data += sizeof(struct ifaddrs) * icnt;
202 memset(ifa, 0, sizeof(struct ifaddrs) * icnt);
206 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
207 rtm = (struct rt_msghdr *)(void *)next;
208 if (rtm->rtm_version != RTM_VERSION)
210 switch (rtm->rtm_type) {
212 ifm = (struct if_msghdr *)(void *)rtm;
213 if (ifm->ifm_addrs & RTA_IFP) {
214 idx = ifm->ifm_index;
215 dl = (struct sockaddr_dl *)(void *)(ifm + 1);
218 ift->ifa_name = names;
219 ift->ifa_flags = (int)ifm->ifm_flags;
220 memcpy(names, dl->sdl_data,
221 (size_t)dl->sdl_nlen);
222 names[dl->sdl_nlen] = 0;
223 names += dl->sdl_nlen + 1;
225 ift->ifa_addr = (struct sockaddr *)(void *)data;
227 (size_t)SA_LEN((struct sockaddr *)
229 data += SA_RLEN((struct sockaddr *)(void *)dl);
231 /* ifm_data needs to be aligned */
232 ift->ifa_data = data = (void *)ALIGN(data);
233 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data));
234 data += sizeof(ifm->ifm_data);
235 ift = (ift->ifa_next = ift + 1);
241 ifam = (struct ifa_msghdr *)(void *)rtm;
242 if (idx && ifam->ifam_index != idx)
243 abort(); /* this cannot happen */
245 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
247 ift->ifa_name = cif->ifa_name;
248 ift->ifa_flags = cif->ifa_flags;
249 ift->ifa_data = NULL;
250 p = (char *)(void *)(ifam + 1);
251 /* Scan to look for length of address */
253 for (p0 = p, i = 0; i < RTAX_MAX; i++) {
254 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
257 sa = (struct sockaddr *)(void *)p;
265 for (p = p0, i = 0; i < RTAX_MAX; i++) {
266 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
269 sa = (struct sockaddr *)(void *)p;
274 (struct sockaddr *)(void *)data;
275 memcpy(data, p, len);
281 (struct sockaddr *)(void *)data;
282 if (SA_LEN(sa) == 0) {
283 memset(data, 0, alen);
287 memcpy(data, p, len);
293 (struct sockaddr *)(void *)data;
294 memcpy(data, p, len);
301 ift = (ift->ifa_next = ift + 1);
308 ift->ifa_next = NULL;
318 freeifaddrs(struct ifaddrs *ifp)