48874a974e1f808ef1b5b5cd4b6e03f7e0ca45b5
[dragonfly.git] / bin / hostname / hostname.c
1 /*
2  * Copyright (c) 1988, 1993
3  *      The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#) Copyright (c) 1988, 1993 The Regents of the University of California.  All rights reserved.
30  * @(#)hostname.c       8.1 (Berkeley) 5/31/93
31  * $FreeBSD: src/bin/hostname/hostname.c,v 1.10.2.1 2001/08/01 02:40:23 obrien Exp $
32  */
33
34 #include <sys/param.h>
35 #include <sys/ioctl.h>
36 #include <sys/socket.h>
37 #include <sys/sysctl.h>
38 #include <sys/module.h>
39 #include <sys/linker.h>
40
41 #include <net/ethernet.h>
42 #include <net/if.h>
43 #include <net/if_var.h>
44 #include <net/if_dl.h>
45 #include <net/if_types.h>
46 #include <net/route.h>
47 #include <netinet/in.h>
48
49 #include <err.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54
55 #include <netdb.h>
56 #include <sys/types.h>
57 #include <arpa/inet.h>
58
59 #include <errno.h>
60
61 #define HST_IF    (1 << 0)
62 #define HST_IF_V6 (1 << 1)
63 #define HST_IF_V4 (1 << 2)
64
65
66
67 /*
68  * Expand the compacted form of addresses as returned via the
69  * configuration read via sysctl().
70  * Lifted from getifaddrs(3)
71  */
72
73 static void rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *);
74 static void usage (void);
75
76 #define ROUNDUP(a) \
77         ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
78 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
79
80 static
81 void
82 rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
83 {
84         struct sockaddr *sa;
85         int i;
86
87         memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
88         for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
89                 if ((rtinfo->rti_addrs & (1 << i)) == 0)
90                         continue;
91                 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
92                 ADVANCE(cp, sa);
93         }
94 }
95
96 int
97 main(int argc, char **argv)
98 {
99         int ch, sflag, rflag, ret, flag6, iflag;
100         int silen = 0;
101         char hostname[MAXHOSTNAMELEN];
102         char *srflag, *siflag;
103         struct hostent *hst;
104         struct in_addr ia;
105         struct in6_addr ia6;
106
107         int mib[6];
108         size_t needed;
109         char *buf, *next, *p;
110         int idx;
111         struct sockaddr_dl *sdl;
112         struct rt_msghdr *rtm;
113         struct if_msghdr *ifm;
114         struct ifa_msghdr *ifam;
115         struct rt_addrinfo info;
116         struct sockaddr_in *sai;
117         struct sockaddr_in6 *sai6;
118
119         srflag = NULL;
120         siflag = NULL;
121         iflag = sflag = rflag = 0;
122         flag6 = 0;
123         hst = NULL;
124
125         while ((ch = getopt(argc, argv, "46i:r:s")) != -1) {
126                 switch (ch) {
127                 case '4':
128                         iflag |= HST_IF_V4;
129                         break;
130                 case '6':
131                         iflag |= HST_IF_V6;
132                         break;
133                 case 'i':
134                         siflag = optarg;
135                         silen = strlen(siflag);
136                         iflag |= HST_IF;
137                         break;
138                 case 'r':
139                         srflag = optarg;
140                         rflag = 1;
141                         break;
142                 case 's':
143                         sflag = 1;
144                         break;
145                 default:
146                         usage();
147                 }
148         }
149         argc -= optind;
150         argv += optind;
151
152         if (argc > 1)
153                 usage();
154
155         if (iflag && *argv)
156                 usage();
157
158         if (rflag && *argv)
159                 usage();
160
161         if (rflag && (iflag & HST_IF))
162                 usage();
163
164         if ((iflag & HST_IF_V6) && (iflag & HST_IF_V4))
165                 usage();
166
167         if (!(iflag & HST_IF) && ((iflag & HST_IF_V6)||iflag & HST_IF_V4))
168                 usage();
169
170         if (iflag & HST_IF) {
171                 mib[0] = CTL_NET;
172                 mib[1] = PF_ROUTE;
173                 mib[2] = 0;
174                 mib[3] = 0;
175                 mib[4] = NET_RT_IFLIST;
176                 mib[5] = 0;
177
178                 idx = 0;
179                 needed = 1;
180
181                 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
182                         err(1, "sysctl: iflist-sysctl-estimate");
183                 if ((buf = malloc(needed)) == NULL)
184                         err(1, "malloc failed");
185                 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
186                         err(1, "sysctl: retrieval of interface table");
187         
188                 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
189                         rtm = (struct rt_msghdr *)(void *)next;
190                         if (rtm->rtm_version != RTM_VERSION)
191                                 continue;
192                         switch (rtm->rtm_type) {
193                         case RTM_IFINFO:
194                                 ifm = (struct if_msghdr *)(void *)rtm;
195
196                                 if ((ifm->ifm_addrs & RTA_IFP) == 0)
197                                         break;
198                                 sdl = (struct sockaddr_dl *)(ifm + 1);
199                                 if (silen != sdl->sdl_nlen)
200                                         break;
201                                 if (!strncmp(siflag, sdl->sdl_data, silen)) {
202                                         idx = ifm->ifm_index;
203                                 }
204                                 break;
205                         case RTM_NEWADDR:
206                                 ifam = (struct ifa_msghdr *)(void *)rtm;
207
208                                 if (ifam->ifam_index == idx) {
209                                         info.rti_addrs = ifam->ifam_addrs;
210                                         rt_xaddrs((char *)(ifam + 1),
211                                                 ifam->ifam_msglen + (char *)ifam, &info);
212                                         sai = (struct sockaddr_in *)info.rti_info[RTAX_IFA];
213
214                                         if (iflag & HST_IF_V6) {
215                                                 if (sai->sin_family == AF_INET6) {
216                                                         sai6 = (struct sockaddr_in6 *)info.rti_info[RTAX_IFA];
217                                                         hst = gethostbyaddr(&sai6->sin6_addr,
218                                                                         sizeof(sai6->sin6_addr),AF_INET6);
219
220                                                         if (h_errno == NETDB_SUCCESS) {
221                                                                 next = buf + needed;
222                                                                 continue;
223                                                         }
224                                                 }
225                                         } else {
226                                                 if ((sai->sin_family == AF_INET)) {
227
228                                                         hst = gethostbyaddr(&sai->sin_addr,
229                                                                         sizeof(sai->sin_addr),AF_INET);
230
231                                                         if (h_errno == NETDB_SUCCESS) {
232                                                                 next = buf + needed;
233                                                                 continue;
234                                                         }
235                                                 }
236                                         }
237                                 }
238                                 break;
239                         } /* switch */
240                 } /* loop */
241
242                 free(buf);
243
244                 if (idx == 0)
245                         errx(1,"interface not found");
246                 if (hst == NULL)
247                         errx(1, "ip not found on interface");
248
249                 if (h_errno == NETDB_SUCCESS) {
250                         if (sethostname(hst->h_name, (int)strlen(hst->h_name)))
251                                 err(1, "sethostname");
252                 } else if (h_errno == HOST_NOT_FOUND) {
253                         errx(1,"hostname not found");
254                 } else {
255                         herror("gethostbyaddr");
256                         exit(1);
257                 }
258         } else if (rflag) {
259                 ret = inet_pton(AF_INET, srflag, &ia);
260                 if (ret != 1) {
261                         /* check IPV6 */
262                         ret = inet_pton(AF_INET6, srflag, &ia6);
263
264                         if (ret != 1) {
265                                 errx(1, "invalid ip address");
266                         }
267
268                         flag6 = 1;
269                 }
270                 
271                 if (flag6 == 1) 
272                         hst = gethostbyaddr(&ia6, sizeof(ia6), AF_INET6);
273                 else
274                         hst = gethostbyaddr(&ia, sizeof(ia), AF_INET);
275                 if (!hst) {
276                         if (h_errno == HOST_NOT_FOUND) 
277                                 errx(1,"host not found\n");
278                 }
279
280                 if (sethostname(hst->h_name, (int)strlen(hst->h_name)))
281                         err(1, "sethostname");
282         } else if (*argv) {
283                 if (sethostname(*argv, (int)strlen(*argv)))
284                         err(1, "sethostname");
285         } else {
286                 if (gethostname(hostname, (int)sizeof(hostname)))
287                         err(1, "gethostname");
288                 if (sflag && (p = strchr(hostname, '.')))
289                         *p = '\0';
290                 printf("%s\n", hostname);
291         }
292         exit(0);
293 }
294
295 static void
296 usage(void)
297 {
298         fprintf(stderr, "usage: hostname [-s] [name-of-host |"
299                         " -r ip-address | -i interface [-4 | -6]]\n");
300         exit(1);
301 }
302