1/* $NetBSD: getifaddrs.c,v 1.16 2016/09/21 10:53:24 roy 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 1.16 2016/09/21 10:53:24 roy 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 size_t icnt = 1;
67 size_t dcnt = 0;
68 size_t ncnt = 0;
69 static const int mib[] = {
70 CTL_NET,
71 PF_ROUTE,
72 0, /* protocol */
73 0, /* wildcard address family */
74 NET_RT_IFLIST,
75 0 /* no flags */
76 };
77 size_t needed;
78 char *buf;
79 char *next;
80 struct ifaddrs cif;
81 char *p, *p0;
82 struct rt_msghdr *rtm;
83 struct if_msghdr *ifm;
84 struct ifa_msghdr *ifam;
85 struct sockaddr *sa;
86 struct ifaddrs *ifa, *ift;
87 u_short idx = 0;
88 int i;
89 size_t len, alen;
90 char *data;
91 char *names;
92
93 _DIAGASSERT(pif != NULL);
94
95 if (sysctl(mib, (u_int)__arraycount(mib), NULL, &needed, NULL, 0) < 0)
96 return (-1);
97 if ((buf = malloc(needed)) == NULL)
98 return (-1);
99 if (sysctl(mib, (u_int)__arraycount(mib), buf, &needed, NULL, 0) < 0) {
100 free(buf);
101 return (-1);
102 }
103
104 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
105 rtm = (struct rt_msghdr *)(void *)next;
106 if (rtm->rtm_version != RTM_VERSION)
107 continue;
108 switch (rtm->rtm_type) {
109 case RTM_IFINFO:
110 ifm = (struct if_msghdr *)(void *)rtm;
111 if (ifm->ifm_addrs & RTA_IFP) {
112 const struct sockaddr_dl *dl;
113
114 idx = ifm->ifm_index;
115 ++icnt;
116 dl = (struct sockaddr_dl *)(void *)(ifm + 1);
117 dcnt += SA_RLEN((const struct sockaddr *)(const void *)dl) +
118 ALIGNBYTES;
119 dcnt += sizeof(ifm->ifm_data);
120 ncnt += dl->sdl_nlen + 1;
121 } else
122 idx = 0;
123 break;
124
125 case RTM_NEWADDR:
126 ifam = (struct ifa_msghdr *)(void *)rtm;
127 if (idx && ifam->ifam_index != idx)
128 abort(); /* this cannot happen */
129
130#define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD)
131 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
132 break;
133 p = (char *)(void *)(ifam + 1);
134 ++icnt;
135 /* Scan to look for length of address */
136 alen = 0;
137 for (p0 = p, i = 0; i < RTAX_MAX; i++) {
138 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
139 == 0)
140 continue;
141 sa = (struct sockaddr *)(void *)p;
142 len = SA_RLEN(sa);
143 if (i == RTAX_IFA) {
144 alen = len;
145 break;
146 }
147 p += len;
148 }
149 for (p = p0, i = 0; i < RTAX_MAX; i++) {
150 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
151 == 0)
152 continue;
153 sa = (struct sockaddr *)(void *)p;
154 len = SA_RLEN(sa);
155 if (i == RTAX_NETMASK && sa->sa_len == 0)
156 dcnt += alen;
157 else
158 dcnt += len;
159 p += len;
160 }
161 break;
162 }
163 }
164
165 if (icnt + dcnt + ncnt == 1) {
166 *pif = NULL;
167 free(buf);
168 return (0);
169 }
170 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt);
171 if (data == NULL) {
172 free(buf);
173 return(-1);
174 }
175
176 ifa = (struct ifaddrs *)(void *)data;
177 data += sizeof(struct ifaddrs) * icnt;
178 names = data + dcnt;
179
180 memset(ifa, 0, sizeof(struct ifaddrs) * icnt);
181 ift = ifa;
182
183 idx = 0;
184 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
185 rtm = (struct rt_msghdr *)(void *)next;
186 if (rtm->rtm_version != RTM_VERSION)
187 continue;
188 switch (rtm->rtm_type) {
189 case RTM_IFINFO:
190 ifm = (struct if_msghdr *)(void *)rtm;
191 if (ifm->ifm_addrs & RTA_IFP) {
192 const struct sockaddr_dl *dl;
193
194 idx = ifm->ifm_index;
195 dl = (struct sockaddr_dl *)(void *)(ifm + 1);
196
197 memset(&cif, 0, sizeof(cif));
198
199 cif.ifa_name = names;
200 cif.ifa_flags = (int)ifm->ifm_flags;
201 memcpy(names, dl->sdl_data,
202 (size_t)dl->sdl_nlen);
203 names[dl->sdl_nlen] = 0;
204 names += dl->sdl_nlen + 1;
205
206 cif.ifa_addr = (struct sockaddr *)(void *)data;
207 memcpy(data, dl, (size_t)dl->sdl_len);
208 data += SA_RLEN((const struct sockaddr *)(const void *)dl);
209
210 /* ifm_data needs to be aligned */
211 cif.ifa_data = data = (void *)ALIGN(data);
212 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data));
213 data += sizeof(ifm->ifm_data);
214 } else
215 idx = 0;
216 break;
217
218 case RTM_NEWADDR:
219 ifam = (struct ifa_msghdr *)(void *)rtm;
220 if (idx && ifam->ifam_index != idx)
221 abort(); /* this cannot happen */
222
223 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
224 break;
225 ift->ifa_name = cif.ifa_name;
226 ift->ifa_flags = cif.ifa_flags;
227 ift->ifa_data = NULL;
228 ift->ifa_addrflags = ifam->ifam_addrflags;
229 p = (char *)(void *)(ifam + 1);
230 /* Scan to look for length of address */
231 alen = 0;
232 for (p0 = p, i = 0; i < RTAX_MAX; i++) {
233 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
234 == 0)
235 continue;
236 sa = (struct sockaddr *)(void *)p;
237 len = SA_RLEN(sa);
238 if (i == RTAX_IFA) {
239 alen = len;
240 break;
241 }
242 p += len;
243 }
244 for (p = p0, i = 0; i < RTAX_MAX; i++) {
245 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
246 == 0)
247 continue;
248 sa = (struct sockaddr *)(void *)p;
249 len = SA_RLEN(sa);
250 switch (i) {
251 case RTAX_IFA:
252 ift->ifa_addr =
253 (struct sockaddr *)(void *)data;
254 memcpy(data, p, len);
255 data += len;
256 if (ift->ifa_addr->sa_family == AF_LINK)
257 ift->ifa_data = cif.ifa_data;
258 break;
259
260 case RTAX_NETMASK:
261 ift->ifa_netmask =
262 (struct sockaddr *)(void *)data;
263 if (sa->sa_len == 0) {
264 memset(data, 0, alen);
265 data += alen;
266 break;
267 }
268 memcpy(data, p, len);
269 data += len;
270 break;
271
272 case RTAX_BRD:
273 ift->ifa_broadaddr =
274 (struct sockaddr *)(void *)data;
275 memcpy(data, p, len);
276 data += len;
277 break;
278 }
279 p += len;
280 }
281
282
283 ift = (ift->ifa_next = ift + 1);
284 break;
285 }
286 }
287
288 free(buf);
289 if (--ift >= ifa) {
290 ift->ifa_next = NULL;
291 *pif = ifa;
292 } else {
293 *pif = NULL;
294 free(ifa);
295 }
296 return (0);
297}
298
299void
300freeifaddrs(struct ifaddrs *ifp)
301{
302
303 _DIAGASSERT(ifp != NULL);
304
305 free(ifp);
306}
307