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 1.13 2005/03/21 16:59:31 liamfoy 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,*lim,*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 lim = buf + needed; 195 196 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 197 rtm = (struct rt_msghdr *)(void *)next; 198 if (rtm->rtm_version != RTM_VERSION) 199 continue; 200 switch (rtm->rtm_type) { 201 case RTM_IFINFO: 202 ifm = (struct if_msghdr *)(void *)rtm; 203 204 if ((ifm->ifm_addrs & RTA_IFP) == 0) 205 break; 206 sdl = (struct sockaddr_dl *)(ifm + 1); 207 if (silen != sdl->sdl_nlen) 208 break; 209 if (!strncmp(siflag, sdl->sdl_data, silen)) { 210 idx = ifm->ifm_index; 211 } 212 break; 213 case RTM_NEWADDR: 214 ifam = (struct ifa_msghdr *)(void *)rtm; 215 216 if (ifam->ifam_index == idx) { 217 info.rti_addrs = ifam->ifam_addrs; 218 rt_xaddrs((char *)(ifam + 1), 219 ifam->ifam_msglen + (char *)ifam, &info); 220 sai = (struct sockaddr_in *)info.rti_info[RTAX_IFA]; 221 222 if (iflag & HST_IF_V6) { 223 if (sai->sin_family == AF_INET6) { 224 sai6 = (struct sockaddr_in6 *)info.rti_info[RTAX_IFA]; 225 hst = gethostbyaddr((const char*)&sai6->sin6_addr, 226 sizeof(sai6->sin6_addr),AF_INET6); 227 228 if (h_errno == NETDB_SUCCESS) { 229 next = buf + needed; 230 continue; 231 } 232 } 233 } else { 234 if ((sai->sin_family == AF_INET)) { 235 236 hst = gethostbyaddr((const char*)&sai->sin_addr, 237 sizeof(sai->sin_addr),AF_INET); 238 239 if (h_errno == NETDB_SUCCESS) { 240 next = buf + needed; 241 continue; 242 } 243 } 244 } 245 } 246 break; 247 } /* switch */ 248 } /* loop */ 249 250 free(buf); 251 252 if (idx == 0) 253 errx(1,"interface not found"); 254 if (hst == NULL) 255 errx(1, "ip not found on interface"); 256 257 if (h_errno == NETDB_SUCCESS) { 258 if (sethostname(hst->h_name, (int)strlen(hst->h_name))) 259 err(1, "sethostname"); 260 } else if (h_errno == HOST_NOT_FOUND) { 261 errx(1,"hostname not found"); 262 } else { 263 herror("gethostbyaddr"); 264 exit(1); 265 } 266 } else if (rflag) { 267 ret = inet_pton(AF_INET, srflag, &ia); 268 if (ret != 1) { 269 /* check IPV6 */ 270 ret = inet_pton(AF_INET6, srflag, &ia6); 271 272 if (ret != 1) { 273 errx(1, "invalid ip address"); 274 } 275 276 flag6 = 1; 277 } 278 279 if (flag6 == 1) 280 hst = gethostbyaddr((const char*)&ia6, sizeof(ia6), AF_INET6); 281 else 282 hst = gethostbyaddr((const char*)&ia, sizeof(ia), AF_INET); 283 if (!hst) { 284 if (h_errno == HOST_NOT_FOUND) 285 errx(1,"host not found\n"); 286 } 287 288 if (sethostname(hst->h_name, (int)strlen(hst->h_name))) 289 err(1, "sethostname"); 290 } else if (*argv) { 291 if (sethostname(*argv, (int)strlen(*argv))) 292 err(1, "sethostname"); 293 } else { 294 if (gethostname(hostname, (int)sizeof(hostname))) 295 err(1, "gethostname"); 296 if (sflag && (p = strchr(hostname, '.'))) 297 *p = '\0'; 298 printf("%s\n", hostname); 299 } 300 exit(0); 301 } 302 303 static void 304 usage(void) 305 { 306 fprintf(stderr, "usage: hostname [-s] [name-of-host |" 307 " -r ip-address | -i interface [-4 | -6]]\n"); 308 exit(1); 309 } 310 311