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 */ 37 38 #include <sys/param.h> 39 #include <sys/ioctl.h> 40 #include <sys/socket.h> 41 #include <sys/sysctl.h> 42 #include <sys/module.h> 43 #include <sys/linker.h> 44 45 #include <net/ethernet.h> 46 #include <net/if.h> 47 #include <net/if_var.h> 48 #include <net/if_dl.h> 49 #include <net/if_types.h> 50 #include <net/route.h> 51 #include <netinet/in.h> 52 53 #include <err.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <unistd.h> 58 59 #include <netdb.h> 60 #include <sys/types.h> 61 #include <arpa/inet.h> 62 63 #include <errno.h> 64 65 #define HST_IF (1 << 0) 66 #define HST_IF_V6 (1 << 1) 67 #define HST_IF_V4 (1 << 2) 68 69 70 71 /* 72 * Expand the compacted form of addresses as returned via the 73 * configuration read via sysctl(). 74 * Lifted from getifaddrs(3) 75 */ 76 77 static void rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *); 78 static void usage (void); 79 80 #define ROUNDUP(a) \ 81 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) 82 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len)) 83 84 static 85 void 86 rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo) 87 { 88 struct sockaddr *sa; 89 int i; 90 91 memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info)); 92 for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) { 93 if ((rtinfo->rti_addrs & (1 << i)) == 0) 94 continue; 95 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp; 96 ADVANCE(cp, sa); 97 } 98 } 99 100 int 101 main(int argc, char **argv) 102 { 103 int ch, sflag, rflag, ret, flag6, iflag; 104 int silen = 0; 105 char hostname[MAXHOSTNAMELEN]; 106 char *srflag, *siflag; 107 struct hostent *hst; 108 struct in_addr ia; 109 struct in6_addr ia6; 110 111 int mib[6]; 112 size_t needed; 113 char *buf, *next, *p; 114 int idx; 115 struct sockaddr_dl *sdl; 116 struct rt_msghdr *rtm; 117 struct if_msghdr *ifm; 118 struct ifa_msghdr *ifam; 119 struct rt_addrinfo info; 120 struct sockaddr_in *sai; 121 struct sockaddr_in6 *sai6; 122 123 srflag = NULL; 124 siflag = NULL; 125 iflag = sflag = rflag = 0; 126 flag6 = 0; 127 hst = NULL; 128 129 while ((ch = getopt(argc, argv, "46i:r:s")) != -1) { 130 switch (ch) { 131 case '4': 132 iflag |= HST_IF_V4; 133 break; 134 case '6': 135 iflag |= HST_IF_V6; 136 break; 137 case 'i': 138 siflag = optarg; 139 silen = strlen(siflag); 140 iflag |= HST_IF; 141 break; 142 case 'r': 143 srflag = optarg; 144 rflag = 1; 145 break; 146 case 's': 147 sflag = 1; 148 break; 149 default: 150 usage(); 151 } 152 } 153 argc -= optind; 154 argv += optind; 155 156 if (argc > 1) 157 usage(); 158 159 if (iflag && *argv) 160 usage(); 161 162 if (rflag && *argv) 163 usage(); 164 165 if (rflag && (iflag & HST_IF)) 166 usage(); 167 168 if ((iflag & HST_IF_V6) && (iflag & HST_IF_V4)) 169 usage(); 170 171 if (!(iflag & HST_IF) && ((iflag & HST_IF_V6)||iflag & HST_IF_V4)) 172 usage(); 173 174 if (iflag & HST_IF) { 175 mib[0] = CTL_NET; 176 mib[1] = PF_ROUTE; 177 mib[2] = 0; 178 mib[3] = 0; 179 mib[4] = NET_RT_IFLIST; 180 mib[5] = 0; 181 182 idx = 0; 183 needed = 1; 184 185 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 186 err(1, "sysctl: iflist-sysctl-estimate"); 187 if ((buf = malloc(needed)) == NULL) 188 err(1, "malloc failed"); 189 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) 190 err(1, "sysctl: retrieval of interface table"); 191 192 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 193 rtm = (struct rt_msghdr *)(void *)next; 194 if (rtm->rtm_version != RTM_VERSION) 195 continue; 196 switch (rtm->rtm_type) { 197 case RTM_IFINFO: 198 ifm = (struct if_msghdr *)(void *)rtm; 199 200 if ((ifm->ifm_addrs & RTA_IFP) == 0) 201 break; 202 sdl = (struct sockaddr_dl *)(ifm + 1); 203 if (silen != sdl->sdl_nlen) 204 break; 205 if (!strncmp(siflag, sdl->sdl_data, silen)) { 206 idx = ifm->ifm_index; 207 } 208 break; 209 case RTM_NEWADDR: 210 ifam = (struct ifa_msghdr *)(void *)rtm; 211 212 if (ifam->ifam_index == idx) { 213 info.rti_addrs = ifam->ifam_addrs; 214 rt_xaddrs((char *)(ifam + 1), 215 ifam->ifam_msglen + (char *)ifam, &info); 216 sai = (struct sockaddr_in *)info.rti_info[RTAX_IFA]; 217 218 if (iflag & HST_IF_V6) { 219 if (sai->sin_family == AF_INET6) { 220 sai6 = (struct sockaddr_in6 *)info.rti_info[RTAX_IFA]; 221 hst = gethostbyaddr(&sai6->sin6_addr, 222 sizeof(sai6->sin6_addr),AF_INET6); 223 224 if (h_errno == NETDB_SUCCESS) { 225 next = buf + needed; 226 continue; 227 } 228 } 229 } else { 230 if ((sai->sin_family == AF_INET)) { 231 232 hst = gethostbyaddr(&sai->sin_addr, 233 sizeof(sai->sin_addr),AF_INET); 234 235 if (h_errno == NETDB_SUCCESS) { 236 next = buf + needed; 237 continue; 238 } 239 } 240 } 241 } 242 break; 243 } /* switch */ 244 } /* loop */ 245 246 free(buf); 247 248 if (idx == 0) 249 errx(1,"interface not found"); 250 if (hst == NULL) 251 errx(1, "ip not found on interface"); 252 253 if (h_errno == NETDB_SUCCESS) { 254 if (sethostname(hst->h_name, (int)strlen(hst->h_name))) 255 err(1, "sethostname"); 256 } else if (h_errno == HOST_NOT_FOUND) { 257 errx(1,"hostname not found"); 258 } else { 259 herror("gethostbyaddr"); 260 exit(1); 261 } 262 } else if (rflag) { 263 ret = inet_pton(AF_INET, srflag, &ia); 264 if (ret != 1) { 265 /* check IPV6 */ 266 ret = inet_pton(AF_INET6, srflag, &ia6); 267 268 if (ret != 1) { 269 errx(1, "invalid ip address"); 270 } 271 272 flag6 = 1; 273 } 274 275 if (flag6 == 1) 276 hst = gethostbyaddr(&ia6, sizeof(ia6), AF_INET6); 277 else 278 hst = gethostbyaddr(&ia, sizeof(ia), AF_INET); 279 if (!hst) { 280 if (h_errno == HOST_NOT_FOUND) 281 errx(1,"host not found\n"); 282 } 283 284 if (sethostname(hst->h_name, (int)strlen(hst->h_name))) 285 err(1, "sethostname"); 286 } else if (*argv) { 287 if (sethostname(*argv, (int)strlen(*argv))) 288 err(1, "sethostname"); 289 } else { 290 if (gethostname(hostname, (int)sizeof(hostname))) 291 err(1, "gethostname"); 292 if (sflag && (p = strchr(hostname, '.'))) 293 *p = '\0'; 294 printf("%s\n", hostname); 295 } 296 exit(0); 297 } 298 299 static void 300 usage(void) 301 { 302 fprintf(stderr, "usage: hostname [-s] [name-of-host |" 303 " -r ip-address | -i interface [-4 | -6]]\n"); 304 exit(1); 305 } 306 307