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 * 4. 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 } 302 303