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 1.12 2004/11/07 20:54:51 eirikn 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/time.h> 44 #include <sys/module.h> 45 #include <sys/linker.h> 46 47 48 #include <net/ethernet.h> 49 #include <net/if.h> 50 #include <net/if_var.h> 51 #include <net/if_dl.h> 52 #include <net/if_types.h> 53 #include <net/route.h> 54 #include <netinet/in.h> 55 56 57 #include <err.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 63 #include <netdb.h> 64 #include <sys/types.h> 65 #include <netinet/in.h> 66 #include <arpa/inet.h> 67 68 #include <errno.h> 69 70 #define HST_IF (1 << 0) 71 #define HST_IF_V6 (1 << 1) 72 #define HST_IF_V4 (1 << 2) 73 74 75 76 /* 77 * Expand the compacted form of addresses as returned via the 78 * configuration read via sysctl(). 79 * Lifted from getifaddrs(3) 80 */ 81 82 static void rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *); 83 static void usage (void); 84 85 #define ROUNDUP(a) \ 86 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) 87 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len)) 88 89 static 90 void 91 rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo) 92 { 93 struct sockaddr *sa; 94 int i; 95 96 memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info)); 97 for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) { 98 if ((rtinfo->rti_addrs & (1 << i)) == 0) 99 continue; 100 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp; 101 ADVANCE(cp, sa); 102 } 103 } 104 105 int 106 main(int argc, char **argv) 107 { 108 int ch, sflag, rflag, ret, flag6, iflag; 109 int silen = 0; 110 char hostname[MAXHOSTNAMELEN]; 111 char *srflag, *siflag; 112 struct hostent *hst; 113 struct in_addr ia; 114 struct in6_addr ia6; 115 116 int mib[6]; 117 size_t needed; 118 char *buf,*lim,*next,*p; 119 int idx; 120 struct sockaddr_dl *sdl; 121 struct rt_msghdr *rtm; 122 struct if_msghdr *ifm; 123 struct ifa_msghdr *ifam; 124 struct rt_addrinfo info; 125 struct sockaddr_in *sai; 126 struct sockaddr_in6 *sai6; 127 128 srflag = NULL; 129 siflag = NULL; 130 iflag = sflag = rflag = 0; 131 flag6 = 0; 132 hst = NULL; 133 134 while ((ch = getopt(argc, argv, "46i:r:s")) != -1) { 135 switch (ch) { 136 case '4': 137 iflag |= HST_IF_V4; 138 break; 139 case '6': 140 iflag |= HST_IF_V6; 141 break; 142 case 'i': 143 siflag = strdup(optarg); 144 silen = strlen(siflag); 145 iflag |= HST_IF; 146 break; 147 case 'r': 148 srflag = strdup(optarg); 149 rflag = 1; 150 break; 151 case 's': 152 sflag = 1; 153 break; 154 case '?': 155 default: 156 usage(); 157 } 158 } 159 argc -= optind; 160 argv += optind; 161 162 if (argc > 1) 163 usage(); 164 165 if (iflag && *argv) 166 usage(); 167 168 if (rflag && *argv) 169 usage(); 170 171 if (rflag && (iflag & HST_IF)) 172 usage(); 173 174 if ((iflag & HST_IF_V6) && (iflag & HST_IF_V4)) 175 usage(); 176 177 if (!(iflag & HST_IF) && ((iflag & HST_IF_V6)||iflag & HST_IF_V4)) 178 usage(); 179 180 if (iflag & HST_IF) { 181 mib[0] = CTL_NET; 182 mib[1] = PF_ROUTE; 183 mib[2] = 0; 184 mib[3] = 0; 185 mib[4] = NET_RT_IFLIST; 186 mib[5] = 0; 187 188 idx = 0; 189 needed = 1; 190 191 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 192 errx(1, "iflist-sysctl-estimate:%i",errno); 193 if ((buf = malloc(needed)) == NULL) 194 errx(1, "malloc"); 195 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) 196 errx(1, "actual retrieval of interface table"); 197 198 lim = buf + needed; 199 200 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 201 rtm = (struct rt_msghdr *)(void *)next; 202 if (rtm->rtm_version != RTM_VERSION) 203 continue; 204 switch (rtm->rtm_type) { 205 case RTM_IFINFO: 206 ifm = (struct if_msghdr *)(void *)rtm; 207 208 if ((ifm->ifm_addrs & RTA_IFP) == 0) 209 break; 210 sdl = (struct sockaddr_dl *)(ifm + 1); 211 if (silen != sdl->sdl_nlen) 212 break; 213 if (!strncmp(siflag, sdl->sdl_data, silen)) { 214 idx = ifm->ifm_index; 215 } 216 break; 217 case RTM_NEWADDR: 218 ifam = (struct ifa_msghdr *)(void *)rtm; 219 220 if (ifam->ifam_index == idx) { 221 info.rti_addrs = ifam->ifam_addrs; 222 rt_xaddrs((char *)(ifam + 1), 223 ifam->ifam_msglen + (char *)ifam, &info); 224 sai = (struct sockaddr_in *)info.rti_info[RTAX_IFA]; 225 226 if (iflag & HST_IF_V6) { 227 if (sai->sin_family == AF_INET6) { 228 sai6 = (struct sockaddr_in6 *)info.rti_info[RTAX_IFA]; 229 hst = gethostbyaddr((const char*)&sai6->sin6_addr, 230 sizeof(sai6->sin6_addr),AF_INET6); 231 232 if (h_errno == NETDB_SUCCESS) { 233 next = buf + needed; 234 continue; 235 } 236 } 237 } else { 238 if ((sai->sin_family == AF_INET)) { 239 240 hst = gethostbyaddr((const char*)&sai->sin_addr, 241 sizeof(sai->sin_addr),AF_INET); 242 243 if (h_errno == NETDB_SUCCESS) { 244 next = buf + needed; 245 continue; 246 } 247 } 248 } 249 } 250 break; 251 } /* switch */ 252 } /* loop */ 253 254 free(buf); 255 256 if (idx == 0) 257 errx(1,"interface not found"); 258 if (hst == NULL) 259 errx(1, "ip not found on interface"); 260 261 if (h_errno == NETDB_SUCCESS) { 262 if (sethostname(hst->h_name, (int)strlen(hst->h_name))) 263 errx(1, "sethostname"); 264 } else if (h_errno == HOST_NOT_FOUND) { 265 errx(1,"hostname not found"); 266 } else { 267 errx(1,"gethostbyaddr"); 268 } 269 } else if (rflag) { 270 ret = inet_pton(AF_INET, srflag, &ia); 271 if (ret != 1) { 272 /* check IPV6 */ 273 ret = inet_pton(AF_INET6, srflag, &ia6); 274 275 if (ret != 1) { 276 errx(1, "invalid ip address"); 277 } 278 279 flag6 = 1; 280 } 281 282 if (flag6 == 1) 283 hst = gethostbyaddr((const char*)&ia6, sizeof(ia6), AF_INET6); 284 else 285 hst = gethostbyaddr((const char*)&ia, sizeof(ia), AF_INET); 286 if (!hst) { 287 if (h_errno == HOST_NOT_FOUND) 288 errx(1,"host not found\n"); 289 } 290 291 if (sethostname(hst->h_name, (int)strlen(hst->h_name))) 292 err(1, "sethostname"); 293 } else if (*argv) { 294 if (sethostname(*argv, (int)strlen(*argv))) 295 err(1, "sethostname"); 296 } else { 297 if (gethostname(hostname, (int)sizeof(hostname))) 298 err(1, "gethostname"); 299 if (sflag && (p = strchr(hostname, '.'))) 300 *p = '\0'; 301 printf("%s\n", hostname); 302 } 303 exit(0); 304 } 305 306 static void 307 usage(void) 308 { 309 fprintf(stderr, "usage: hostname [-s] [name-of-host |" 310 " -r ip-address | -i interface [-4 | -6]]\n"); 311 exit(1); 312 } 313 314