db8dd090096f2864e360eb3e5a1591b8a2f6d81e
[games.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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *      This product includes software developed by the University of
16  *      California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * @(#) Copyright (c) 1988, 1993 The Regents of the University of California.  All rights reserved.
34  * @(#)hostname.c       8.1 (Berkeley) 5/31/93
35  * $FreeBSD: src/bin/hostname/hostname.c,v 1.10.2.1 2001/08/01 02:40:23 obrien Exp $
36  * $DragonFly: src/bin/hostname/hostname.c,v 1.14 2008/09/02 22:20:55 swildner Exp $
37  */
38
39 #include <sys/param.h>
40 #include <sys/ioctl.h>
41 #include <sys/socket.h>
42 #include <sys/sysctl.h>
43 #include <sys/module.h>
44 #include <sys/linker.h>
45
46 #include <net/ethernet.h>
47 #include <net/if.h>
48 #include <net/if_var.h>
49 #include <net/if_dl.h>
50 #include <net/if_types.h>
51 #include <net/route.h>
52 #include <netinet/in.h>
53
54 #include <err.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <unistd.h>
59
60 #include <netdb.h>
61 #include <sys/types.h>
62 #include <netinet/in.h>
63 #include <arpa/inet.h>
64
65 #include <errno.h>
66
67 #define HST_IF    (1 << 0)
68 #define HST_IF_V6 (1 << 1)
69 #define HST_IF_V4 (1 << 2)
70
71
72
73 /*
74  * Expand the compacted form of addresses as returned via the
75  * configuration read via sysctl().
76  * Lifted from getifaddrs(3)
77  */
78
79 static void rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *);
80 static void usage (void);
81
82 #define ROUNDUP(a) \
83         ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
84 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
85
86 static
87 void
88 rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
89 {
90         struct sockaddr *sa;
91         int i;
92
93         memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
94         for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
95                 if ((rtinfo->rti_addrs & (1 << i)) == 0)
96                         continue;
97                 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
98                 ADVANCE(cp, sa);
99         }
100 }
101
102 int
103 main(int argc, char **argv)
104 {
105         int ch, sflag, rflag, ret, flag6, iflag;
106         int silen = 0;
107         char hostname[MAXHOSTNAMELEN];
108         char *srflag, *siflag;
109         struct hostent *hst;
110         struct in_addr ia;
111         struct in6_addr ia6;
112
113         int mib[6];
114         size_t needed;
115         char *buf, *next, *p;
116         int idx;
117         struct sockaddr_dl *sdl;
118         struct rt_msghdr *rtm;
119         struct if_msghdr *ifm;
120         struct ifa_msghdr *ifam;
121         struct rt_addrinfo info;
122         struct sockaddr_in *sai;
123         struct sockaddr_in6 *sai6;
124
125         srflag = NULL;
126         siflag = NULL;
127         iflag = sflag = rflag = 0;
128         flag6 = 0;
129         hst = NULL;
130
131         while ((ch = getopt(argc, argv, "46i:r:s")) != -1) {
132                 switch (ch) {
133                 case '4':
134                         iflag |= HST_IF_V4;
135                         break;
136                 case '6':
137                         iflag |= HST_IF_V6;
138                         break;
139                 case 'i':
140                         siflag = optarg;
141                         silen = strlen(siflag);
142                         iflag |= HST_IF;
143                         break;
144                 case 'r':
145                         srflag = optarg;
146                         rflag = 1;
147                         break;
148                 case 's':
149                         sflag = 1;
150                         break;
151                 default:
152                         usage();
153                 }
154         }
155         argc -= optind;
156         argv += optind;
157
158         if (argc > 1)
159                 usage();
160
161         if (iflag && *argv)
162                 usage();
163
164         if (rflag && *argv)
165                 usage();
166
167         if (rflag && (iflag & HST_IF))
168                 usage();
169
170         if ((iflag & HST_IF_V6) && (iflag & HST_IF_V4))
171                 usage();
172
173         if (!(iflag & HST_IF) && ((iflag & HST_IF_V6)||iflag & HST_IF_V4))
174                 usage();
175
176         if (iflag & HST_IF) {
177                 mib[0] = CTL_NET;
178                 mib[1] = PF_ROUTE;
179                 mib[2] = 0;
180                 mib[3] = 0;
181                 mib[4] = NET_RT_IFLIST;
182                 mib[5] = 0;
183
184                 idx = 0;
185                 needed = 1;
186
187                 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
188                         err(1, "sysctl: iflist-sysctl-estimate");
189                 if ((buf = malloc(needed)) == NULL)
190                         err(1, "malloc failed");
191                 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
192                         err(1, "sysctl: retrieval of interface table");
193         
194                 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
195                         rtm = (struct rt_msghdr *)(void *)next;
196                         if (rtm->rtm_version != RTM_VERSION)
197                                 continue;
198                         switch (rtm->rtm_type) {
199                         case RTM_IFINFO:
200                                 ifm = (struct if_msghdr *)(void *)rtm;
201
202                                 if ((ifm->ifm_addrs & RTA_IFP) == 0)
203                                         break;
204                                 sdl = (struct sockaddr_dl *)(ifm + 1);
205                                 if (silen != sdl->sdl_nlen)
206                                         break;
207                                 if (!strncmp(siflag, sdl->sdl_data, silen)) {
208                                         idx = ifm->ifm_index;
209                                 }
210                                 break;
211                         case RTM_NEWADDR:
212                                 ifam = (struct ifa_msghdr *)(void *)rtm;
213
214                                 if (ifam->ifam_index == idx) {
215                                         info.rti_addrs = ifam->ifam_addrs;
216                                         rt_xaddrs((char *)(ifam + 1),
217                                                 ifam->ifam_msglen + (char *)ifam, &info);
218                                         sai = (struct sockaddr_in *)info.rti_info[RTAX_IFA];
219
220                                         if (iflag & HST_IF_V6) {
221                                                 if (sai->sin_family == AF_INET6) {
222                                                         sai6 = (struct sockaddr_in6 *)info.rti_info[RTAX_IFA];
223                                                         hst = gethostbyaddr(&sai6->sin6_addr,
224                                                                         sizeof(sai6->sin6_addr),AF_INET6);
225
226                                                         if (h_errno == NETDB_SUCCESS) {
227                                                                 next = buf + needed;
228                                                                 continue;
229                                                         }
230                                                 }
231                                         } else {
232                                                 if ((sai->sin_family == AF_INET)) {
233
234                                                         hst = gethostbyaddr(&sai->sin_addr,
235                                                                         sizeof(sai->sin_addr),AF_INET);
236
237                                                         if (h_errno == NETDB_SUCCESS) {
238                                                                 next = buf + needed;
239                                                                 continue;
240                                                         }
241                                                 }
242                                         }
243                                 }
244                                 break;
245                         } /* switch */
246                 } /* loop */
247
248                 free(buf);
249
250                 if (idx == 0)
251                         errx(1,"interface not found");
252                 if (hst == NULL)
253                         errx(1, "ip not found on interface");
254
255                 if (h_errno == NETDB_SUCCESS) {
256                         if (sethostname(hst->h_name, (int)strlen(hst->h_name)))
257                                 err(1, "sethostname");
258                 } else if (h_errno == HOST_NOT_FOUND) {
259                         errx(1,"hostname not found");
260                 } else {
261                         herror("gethostbyaddr");
262                         exit(1);
263                 }
264         } else if (rflag) {
265                 ret = inet_pton(AF_INET, srflag, &ia);
266                 if (ret != 1) {
267                         /* check IPV6 */
268                         ret = inet_pton(AF_INET6, srflag, &ia6);
269
270                         if (ret != 1) {
271                                 errx(1, "invalid ip address");
272                         }
273
274                         flag6 = 1;
275                 }
276                 
277                 if (flag6 == 1) 
278                         hst = gethostbyaddr(&ia6, sizeof(ia6), AF_INET6);
279                 else
280                         hst = gethostbyaddr(&ia, sizeof(ia), AF_INET);
281                 if (!hst) {
282                         if (h_errno == HOST_NOT_FOUND) 
283                                 errx(1,"host not found\n");
284                 }
285
286                 if (sethostname(hst->h_name, (int)strlen(hst->h_name)))
287                         err(1, "sethostname");
288         } else if (*argv) {
289                 if (sethostname(*argv, (int)strlen(*argv)))
290                         err(1, "sethostname");
291         } else {
292                 if (gethostname(hostname, (int)sizeof(hostname)))
293                         err(1, "gethostname");
294                 if (sflag && (p = strchr(hostname, '.')))
295                         *p = '\0';
296                 printf("%s\n", hostname);
297         }
298         exit(0);
299 }
300
301 static void
302 usage(void)
303 {
304         fprintf(stderr, "usage: hostname [-s] [name-of-host |"
305                         " -r ip-address | -i interface [-4 | -6]]\n");
306         exit(1);
307 }
308