1 /* $KAME: getifaddrs.c,v 1.9 2001/08/20 02:31:20 itojun Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-1-Clause
5 *
6 * Copyright (c) 1995, 1999
7 * Berkeley Software Design, Inc. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * BSDI getifaddrs.c,v 2.12 2000/02/23 14:51:59 dab Exp
28 */
29 /*
30 * NOTE: SIOCGIFCONF case is not LP64 friendly. it also does not perform
31 * try-and-error for region size.
32 */
33
34 #include "namespace.h"
35 #include <sys/types.h>
36 #include <sys/ioctl.h>
37 #include <sys/socket.h>
38 #include <net/if.h>
39 #ifdef NET_RT_IFLIST
40 #include <sys/param.h>
41 #include <net/route.h>
42 #include <sys/sysctl.h>
43 #include <net/if_dl.h>
44 #endif
45
46 #include <errno.h>
47 #include <ifaddrs.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include "un-namespace.h"
51
52 #if !defined(AF_LINK)
53 #define SA_LEN(sa) sizeof(struct sockaddr)
54 #endif
55
56 #if !defined(SA_LEN)
57 #define SA_LEN(sa) (sa)->sa_len
58 #endif
59
60 #define SALIGN (sizeof(long) - 1)
61 #define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1))
62
63 #ifndef ALIGNBYTES
64 /*
65 * On systems with a routing socket, ALIGNBYTES should match the value
66 * that the kernel uses when building the messages.
67 */
68 #define ALIGNBYTES XXX
69 #endif
70 #ifndef ALIGN
71 #define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES)
72 #endif
73
74 #define MAX_SYSCTL_TRY 5
75
76 int
getifaddrs(struct ifaddrs ** pif)77 getifaddrs(struct ifaddrs **pif)
78 {
79 int icnt = 1;
80 int dcnt = 0;
81 int ncnt = 0;
82 int ntry = 0;
83 int mib[6];
84 size_t needed;
85 char *buf;
86 char *next;
87 struct ifaddrs *cif;
88 char *p, *p0;
89 struct rt_msghdr *rtm;
90 struct if_msghdrl *ifm;
91 struct ifa_msghdrl *ifam;
92 struct sockaddr_dl *dl;
93 struct sockaddr *sa;
94 struct ifaddrs *ifa, *ift;
95 struct if_data *if_data;
96 u_short idx = 0;
97 int i;
98 size_t len, alen;
99 char *data;
100 char *names;
101
102 mib[0] = CTL_NET;
103 mib[1] = PF_ROUTE;
104 mib[2] = 0; /* protocol */
105 mib[3] = 0; /* wildcard address family */
106 mib[4] = NET_RT_IFLISTL;/* extra fields for extensible msghdr structs */
107 mib[5] = 0; /* no flags */
108 do {
109 /*
110 * We'll try to get addresses several times in case that
111 * the number of addresses is unexpectedly increased during
112 * the two sysctl calls. This should rarely happen, but we'll
113 * try to do our best for applications that assume success of
114 * this library (which should usually be the case).
115 * Portability note: since FreeBSD does not add margin of
116 * memory at the first sysctl, the possibility of failure on
117 * the second sysctl call is a bit higher.
118 */
119
120 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
121 return (-1);
122 if ((buf = malloc(needed)) == NULL)
123 return (-1);
124 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
125 if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) {
126 free(buf);
127 return (-1);
128 }
129 free(buf);
130 buf = NULL;
131 }
132 } while (buf == NULL);
133
134 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
135 rtm = (struct rt_msghdr *)(void *)next;
136 if (rtm->rtm_version != RTM_VERSION)
137 continue;
138 switch (rtm->rtm_type) {
139 case RTM_IFINFO:
140 ifm = (struct if_msghdrl *)(void *)rtm;
141 if (ifm->ifm_addrs & RTA_IFP) {
142 idx = ifm->ifm_index;
143 ++icnt;
144 if_data = IF_MSGHDRL_IFM_DATA(ifm);
145 dcnt += if_data->ifi_datalen;
146 dl = (struct sockaddr_dl *)IF_MSGHDRL_RTA(ifm);
147 dcnt += SA_RLEN((struct sockaddr *)(void*)dl) +
148 ALIGNBYTES;
149 ncnt += dl->sdl_nlen + 1;
150 } else
151 idx = 0;
152 break;
153
154 case RTM_NEWADDR:
155 ifam = (struct ifa_msghdrl *)(void *)rtm;
156 if (idx && ifam->ifam_index != idx)
157 abort(); /* this cannot happen */
158
159 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD)
160 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
161 break;
162 p = (char *)IFA_MSGHDRL_RTA(ifam);
163 ++icnt;
164 if_data = IFA_MSGHDRL_IFAM_DATA(ifam);
165 dcnt += if_data->ifi_datalen + ALIGNBYTES;
166
167 /* Scan to look for length of address */
168 alen = 0;
169 for (p0 = p, i = 0; i < RTAX_MAX; i++) {
170 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
171 == 0)
172 continue;
173 sa = (struct sockaddr *)(void *)p;
174 len = SA_RLEN(sa);
175 if (i == RTAX_IFA) {
176 alen = len;
177 break;
178 }
179 p += len;
180 }
181 for (p = p0, i = 0; i < RTAX_MAX; i++) {
182 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
183 == 0)
184 continue;
185 sa = (struct sockaddr *)(void *)p;
186 len = SA_RLEN(sa);
187 if (i == RTAX_NETMASK && SA_LEN(sa) == 0)
188 dcnt += alen;
189 else
190 dcnt += len;
191 p += len;
192 }
193 break;
194 }
195 }
196
197 if (icnt + dcnt + ncnt == 1) {
198 *pif = NULL;
199 free(buf);
200 return (0);
201 }
202 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt);
203 if (data == NULL) {
204 free(buf);
205 return(-1);
206 }
207
208 ifa = (struct ifaddrs *)(void *)data;
209 data += sizeof(struct ifaddrs) * icnt;
210 names = data + dcnt;
211
212 memset(ifa, 0, sizeof(struct ifaddrs) * icnt);
213 ift = ifa;
214
215 idx = 0;
216 cif = NULL;
217 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
218 rtm = (struct rt_msghdr *)(void *)next;
219 if (rtm->rtm_version != RTM_VERSION)
220 continue;
221 switch (rtm->rtm_type) {
222 case RTM_IFINFO:
223 ifm = (struct if_msghdrl *)(void *)rtm;
224 if ((ifm->ifm_addrs & RTA_IFP) == 0) {
225 idx = 0;
226 break;
227 }
228
229 idx = ifm->ifm_index;
230 dl = (struct sockaddr_dl *)IF_MSGHDRL_RTA(ifm);
231
232 cif = ift;
233 ift->ifa_name = names;
234 ift->ifa_flags = (int)ifm->ifm_flags;
235 memcpy(names, dl->sdl_data, (size_t)dl->sdl_nlen);
236 names[dl->sdl_nlen] = 0;
237 names += dl->sdl_nlen + 1;
238
239 ift->ifa_addr = (struct sockaddr *)(void *)data;
240 memcpy(data, dl, (size_t)SA_LEN((struct sockaddr *)
241 (void *)dl));
242 data += SA_RLEN((struct sockaddr *)(void *)dl);
243
244 if_data = IF_MSGHDRL_IFM_DATA(ifm);
245 /* ifm_data needs to be aligned */
246 ift->ifa_data = data = (void *)ALIGN(data);
247 memcpy(data, if_data, if_data->ifi_datalen);
248 data += if_data->ifi_datalen;
249
250 ift = (ift->ifa_next = ift + 1);
251 break;
252
253 case RTM_NEWADDR:
254 ifam = (struct ifa_msghdrl *)(void *)rtm;
255 if (idx && ifam->ifam_index != idx)
256 abort(); /* this cannot happen */
257
258 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
259 break;
260 ift->ifa_name = cif->ifa_name;
261 ift->ifa_flags = cif->ifa_flags;
262 ift->ifa_data = NULL;
263
264 p = (char *)IFA_MSGHDRL_RTA(ifam);
265 /* Scan to look for length of address */
266 alen = 0;
267 for (p0 = p, i = 0; i < RTAX_MAX; i++) {
268 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
269 == 0)
270 continue;
271 sa = (struct sockaddr *)(void *)p;
272 len = SA_RLEN(sa);
273 if (i == RTAX_IFA) {
274 alen = len;
275 break;
276 }
277 p += len;
278 }
279 for (p = p0, i = 0; i < RTAX_MAX; i++) {
280 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
281 == 0)
282 continue;
283 sa = (struct sockaddr *)(void *)p;
284 len = SA_RLEN(sa);
285 switch (i) {
286 case RTAX_IFA:
287 ift->ifa_addr =
288 (struct sockaddr *)(void *)data;
289 memcpy(data, p, len);
290 data += len;
291 break;
292
293 case RTAX_NETMASK:
294 ift->ifa_netmask =
295 (struct sockaddr *)(void *)data;
296 if (SA_LEN(sa) == 0) {
297 memset(data, 0, alen);
298 data += alen;
299 break;
300 }
301 memcpy(data, p, len);
302 data += len;
303 break;
304
305 case RTAX_BRD:
306 ift->ifa_broadaddr =
307 (struct sockaddr *)(void *)data;
308 memcpy(data, p, len);
309 data += len;
310 break;
311 }
312 p += len;
313 }
314
315 if_data = IFA_MSGHDRL_IFAM_DATA(ifam);
316 /* ifam_data needs to be aligned */
317 ift->ifa_data = data = (void *)ALIGN(data);
318 memcpy(data, if_data, if_data->ifi_datalen);
319 data += if_data->ifi_datalen;
320
321 ift = (ift->ifa_next = ift + 1);
322 break;
323 }
324 }
325
326 free(buf);
327
328 if (--ift >= ifa) {
329 ift->ifa_next = NULL;
330 *pif = ifa;
331 } else {
332 *pif = NULL;
333 free(ifa);
334 }
335 return (0);
336 }
337
338 void
freeifaddrs(struct ifaddrs * ifp)339 freeifaddrs(struct ifaddrs *ifp)
340 {
341
342 free(ifp);
343 }
344