xref: /minix3/lib/libc/net/getifaddrs.c (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1 /*	$NetBSD: getifaddrs.c,v 1.15 2012/03/13 21:13:40 christos 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 1.15 2012/03/13 21:13:40 christos 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)
__weak_alias(getifaddrs,_getifaddrs)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 
63 int
64 getifaddrs(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 			p = (char *)(void *)(ifam + 1);
229 			/* Scan to look for length of address */
230 			alen = 0;
231 			for (p0 = p, i = 0; i < RTAX_MAX; i++) {
232 				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
233 				    == 0)
234 					continue;
235 				sa = (struct sockaddr *)(void *)p;
236 				len = SA_RLEN(sa);
237 				if (i == RTAX_IFA) {
238 					alen = len;
239 					break;
240 				}
241 				p += len;
242 			}
243 			for (p = p0, i = 0; i < RTAX_MAX; i++) {
244 				if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
245 				    == 0)
246 					continue;
247 				sa = (struct sockaddr *)(void *)p;
248 				len = SA_RLEN(sa);
249 				switch (i) {
250 				case RTAX_IFA:
251 					ift->ifa_addr =
252 					    (struct sockaddr *)(void *)data;
253 					memcpy(data, p, len);
254 					data += len;
255 					if (ift->ifa_addr->sa_family == AF_LINK)
256 						ift->ifa_data = cif.ifa_data;
257 					break;
258 
259 				case RTAX_NETMASK:
260 					ift->ifa_netmask =
261 					    (struct sockaddr *)(void *)data;
262 					if (sa->sa_len == 0) {
263 						memset(data, 0, alen);
264 						data += alen;
265 						break;
266 					}
267 					memcpy(data, p, len);
268 					data += len;
269 					break;
270 
271 				case RTAX_BRD:
272 					ift->ifa_broadaddr =
273 					    (struct sockaddr *)(void *)data;
274 					memcpy(data, p, len);
275 					data += len;
276 					break;
277 				}
278 				p += len;
279 			}
280 
281 
282 			ift = (ift->ifa_next = ift + 1);
283 			break;
284 		}
285 	}
286 
287 	free(buf);
288 	if (--ift >= ifa) {
289 		ift->ifa_next = NULL;
290 		*pif = ifa;
291 	} else {
292 		*pif = NULL;
293 		free(ifa);
294 	}
295 	return (0);
296 }
297 
298 void
freeifaddrs(struct ifaddrs * ifp)299 freeifaddrs(struct ifaddrs *ifp)
300 {
301 
302 	_DIAGASSERT(ifp != NULL);
303 
304 	free(ifp);
305 }
306